/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/clang/lib/Sema/SemaInit.cpp

Bug Summary

File:	build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/clang/lib/Sema/SemaInit.cpp
Warning:	line 9291, column 10 Called C++ object pointer is null
Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name SemaInit.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/build-llvm -resource-dir /usr/lib/llvm-16/lib/clang/16.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/clang/lib/Sema -I /build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/clang/include -I tools/clang/include -I include -I /build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-16/lib/clang/16.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-10-03-140002-15933-1 -x c++ /build/llvm-toolchain-snapshot-16~++20221003111214+1fa2019828ca/clang/lib/Sema/SemaInit.cpp
1//===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements semantic analysis for initializers.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/AST/ASTContext.h"
14#include "clang/AST/DeclObjC.h"
15#include "clang/AST/ExprCXX.h"
16#include "clang/AST/ExprObjC.h"
17#include "clang/AST/ExprOpenMP.h"
18#include "clang/AST/TypeLoc.h"
19#include "clang/Basic/CharInfo.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Basic/TargetInfo.h"
22#include "clang/Sema/Designator.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Lookup.h"
25#include "clang/Sema/SemaInternal.h"
26#include "llvm/ADT/APInt.h"
27#include "llvm/ADT/PointerIntPair.h"
28#include "llvm/ADT/SmallString.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/raw_ostream.h"

32using namespace clang;

34//===----------------------------------------------------------------------===//
35// Sema Initialization Checking
36//===----------------------------------------------------------------------===//

38/// Check whether T is compatible with a wide character type (wchar_t,
39/// char16_t or char32_t).
40static bool IsWideCharCompatible(QualType T, ASTContext &Context) {
if (Context.typesAreCompatible(Context.getWideCharType(), T))
  return true;
if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
  return Context.typesAreCompatible(Context.Char16Ty, T) ||
         Context.typesAreCompatible(Context.Char32Ty, T);
}
return false;
48}

50enum StringInitFailureKind {
SIF_None,
SIF_NarrowStringIntoWideChar,
SIF_WideStringIntoChar,
SIF_IncompatWideStringIntoWideChar,
SIF_UTF8StringIntoPlainChar,
SIF_PlainStringIntoUTF8Char,
SIF_Other
58};

60/// Check whether the array of type AT can be initialized by the Init
61/// expression by means of string initialization. Returns SIF_None if so,
62/// otherwise returns a StringInitFailureKind that describes why the
63/// initialization would not work.
64static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT,
                                        ASTContext &Context) {
if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
  return SIF_Other;

// See if this is a string literal or @encode.
Init = Init->IgnoreParens();

// Handle @encode, which is a narrow string.
if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
  return SIF_None;

// Otherwise we can only handle string literals.
StringLiteral *SL = dyn_cast<StringLiteral>(Init);
if (!SL)
  return SIF_Other;

const QualType ElemTy =
    Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();

switch (SL->getKind()) {
case StringLiteral::UTF8:
  // char8_t array can be initialized with a UTF-8 string.
  if (ElemTy->isChar8Type())
    return SIF_None;
  [[fallthrough]];
case StringLiteral::Ordinary:
  // char array can be initialized with a narrow string.
  // Only allow char x[] = "foo";  not char x[] = L"foo";
  if (ElemTy->isCharType())
    return (SL->getKind() == StringLiteral::UTF8 &&
            Context.getLangOpts().Char8)
               ? SIF_UTF8StringIntoPlainChar
               : SIF_None;
  if (ElemTy->isChar8Type())
    return SIF_PlainStringIntoUTF8Char;
  if (IsWideCharCompatible(ElemTy, Context))
    return SIF_NarrowStringIntoWideChar;
  return SIF_Other;
// C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
// "An array with element type compatible with a qualified or unqualified
// version of wchar_t, char16_t, or char32_t may be initialized by a wide
// string literal with the corresponding encoding prefix (L, u, or U,
// respectively), optionally enclosed in braces.
case StringLiteral::UTF16:
  if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
    return SIF_None;
  if (ElemTy->isCharType() || ElemTy->isChar8Type())
    return SIF_WideStringIntoChar;
  if (IsWideCharCompatible(ElemTy, Context))
    return SIF_IncompatWideStringIntoWideChar;
  return SIF_Other;
case StringLiteral::UTF32:
  if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
    return SIF_None;
  if (ElemTy->isCharType() || ElemTy->isChar8Type())
    return SIF_WideStringIntoChar;
  if (IsWideCharCompatible(ElemTy, Context))
    return SIF_IncompatWideStringIntoWideChar;
  return SIF_Other;
case StringLiteral::Wide:
  if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
    return SIF_None;
  if (ElemTy->isCharType() || ElemTy->isChar8Type())
    return SIF_WideStringIntoChar;
  if (IsWideCharCompatible(ElemTy, Context))
    return SIF_IncompatWideStringIntoWideChar;
  return SIF_Other;
}

llvm_unreachable("missed a StringLiteral kind?")::llvm::llvm_unreachable_internal("missed a StringLiteral kind?"
, "clang/lib/Sema/SemaInit.cpp", 134);
135}

137static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
                                        ASTContext &Context) {
const ArrayType *arrayType = Context.getAsArrayType(declType);
if (!arrayType)
  return SIF_Other;
return IsStringInit(init, arrayType, Context);
143}

145bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
return ::IsStringInit(Init, AT, Context) == SIF_None;
147}

149/// Update the type of a string literal, including any surrounding parentheses,
150/// to match the type of the object which it is initializing.
151static void updateStringLiteralType(Expr *E, QualType Ty) {
while (true) {
  E->setType(Ty);
  E->setValueKind(VK_PRValue);
  if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) {
    break;
  } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
    E = PE->getSubExpr();
  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
    assert(UO->getOpcode() == UO_Extension)(static_cast <bool> (UO->getOpcode() == UO_Extension
) ? void (0) : __assert_fail ("UO->getOpcode() == UO_Extension"
, "clang/lib/Sema/SemaInit.cpp", 160, __extension__ __PRETTY_FUNCTION__
));
    E = UO->getSubExpr();
  } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
    E = GSE->getResultExpr();
  } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
    E = CE->getChosenSubExpr();
  } else {
    llvm_unreachable("unexpected expr in string literal init")::llvm::llvm_unreachable_internal("unexpected expr in string literal init"
, "clang/lib/Sema/SemaInit.cpp", 167);
  }
}
170}

172/// Fix a compound literal initializing an array so it's correctly marked
173/// as an rvalue.
174static void updateGNUCompoundLiteralRValue(Expr *E) {
while (true) {
  E->setValueKind(VK_PRValue);
  if (isa<CompoundLiteralExpr>(E)) {
    break;
  } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
    E = PE->getSubExpr();
  } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
    assert(UO->getOpcode() == UO_Extension)(static_cast <bool> (UO->getOpcode() == UO_Extension
) ? void (0) : __assert_fail ("UO->getOpcode() == UO_Extension"
, "clang/lib/Sema/SemaInit.cpp", 182, __extension__ __PRETTY_FUNCTION__
));
    E = UO->getSubExpr();
  } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
    E = GSE->getResultExpr();
  } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
    E = CE->getChosenSubExpr();
  } else {
    llvm_unreachable("unexpected expr in array compound literal init")::llvm::llvm_unreachable_internal("unexpected expr in array compound literal init"
, "clang/lib/Sema/SemaInit.cpp", 189);
  }
}
192}

194static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
                          Sema &S) {
// Get the length of the string as parsed.
auto *ConstantArrayTy =
    cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();

if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
  // C99 6.7.8p14. We have an array of character type with unknown size
  // being initialized to a string literal.
  llvm::APInt ConstVal(32, StrLength);
  // Return a new array type (C99 6.7.8p22).
  DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
                                         ConstVal, nullptr,
                                         ArrayType::Normal, 0);
  updateStringLiteralType(Str, DeclT);
  return;
}

const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);

// We have an array of character type with known size.  However,
// the size may be smaller or larger than the string we are initializing.
// FIXME: Avoid truncation for 64-bit length strings.
if (S.getLangOpts().CPlusPlus) {
  if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
    // For Pascal strings it's OK to strip off the terminating null character,
    // so the example below is valid:
    //
    // unsigned char a[2] = "\pa";
    if (SL->isPascal())
      StrLength--;
  }

  // [dcl.init.string]p2
  if (StrLength > CAT->getSize().getZExtValue())
    S.Diag(Str->getBeginLoc(),
           diag::err_initializer_string_for_char_array_too_long)
        << Str->getSourceRange();
} else {
  // C99 6.7.8p14.
  if (StrLength-1 > CAT->getSize().getZExtValue())
    S.Diag(Str->getBeginLoc(),
           diag::ext_initializer_string_for_char_array_too_long)
        << Str->getSourceRange();
}

// Set the type to the actual size that we are initializing.  If we have
// something like:
//   char x[1] = "foo";
// then this will set the string literal's type to char[1].
updateStringLiteralType(Str, DeclT);
246}

248//===----------------------------------------------------------------------===//
249// Semantic checking for initializer lists.
250//===----------------------------------------------------------------------===//

252namespace {

254/// Semantic checking for initializer lists.
255///
256/// The InitListChecker class contains a set of routines that each
257/// handle the initialization of a certain kind of entity, e.g.,
258/// arrays, vectors, struct/union types, scalars, etc. The
259/// InitListChecker itself performs a recursive walk of the subobject
260/// structure of the type to be initialized, while stepping through
261/// the initializer list one element at a time. The IList and Index
262/// parameters to each of the Check* routines contain the active
263/// (syntactic) initializer list and the index into that initializer
264/// list that represents the current initializer. Each routine is
265/// responsible for moving that Index forward as it consumes elements.
266///
267/// Each Check* routine also has a StructuredList/StructuredIndex
268/// arguments, which contains the current "structured" (semantic)
269/// initializer list and the index into that initializer list where we
270/// are copying initializers as we map them over to the semantic
271/// list. Once we have completed our recursive walk of the subobject
272/// structure, we will have constructed a full semantic initializer
273/// list.
274///
275/// C99 designators cause changes in the initializer list traversal,
276/// because they make the initialization "jump" into a specific
277/// subobject and then continue the initialization from that
278/// point. CheckDesignatedInitializer() recursively steps into the
279/// designated subobject and manages backing out the recursion to
280/// initialize the subobjects after the one designated.
281///
282/// If an initializer list contains any designators, we build a placeholder
283/// structured list even in 'verify only' mode, so that we can track which
284/// elements need 'empty' initializtion.
285class InitListChecker {
Sema &SemaRef;
bool hadError = false;
bool VerifyOnly; // No diagnostics.
bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
bool InOverloadResolution;
InitListExpr *FullyStructuredList = nullptr;
NoInitExpr *DummyExpr = nullptr;

NoInitExpr *getDummyInit() {
  if (!DummyExpr)
    DummyExpr = new (SemaRef.Context) NoInitExpr(SemaRef.Context.VoidTy);
  return DummyExpr;
}

void CheckImplicitInitList(const InitializedEntity &Entity,
                           InitListExpr *ParentIList, QualType T,
                           unsigned &Index, InitListExpr *StructuredList,
                           unsigned &StructuredIndex);
void CheckExplicitInitList(const InitializedEntity &Entity,
                           InitListExpr *IList, QualType &T,
                           InitListExpr *StructuredList,
                           bool TopLevelObject = false);
void CheckListElementTypes(const InitializedEntity &Entity,
                           InitListExpr *IList, QualType &DeclType,
                           bool SubobjectIsDesignatorContext,
                           unsigned &Index,
                           InitListExpr *StructuredList,
                           unsigned &StructuredIndex,
                           bool TopLevelObject = false);
void CheckSubElementType(const InitializedEntity &Entity,
                         InitListExpr *IList, QualType ElemType,
                         unsigned &Index,
                         InitListExpr *StructuredList,
                         unsigned &StructuredIndex,
                         bool DirectlyDesignated = false);
void CheckComplexType(const InitializedEntity &Entity,
                      InitListExpr *IList, QualType DeclType,
                      unsigned &Index,
                      InitListExpr *StructuredList,
                      unsigned &StructuredIndex);
void CheckScalarType(const InitializedEntity &Entity,
                     InitListExpr *IList, QualType DeclType,
                     unsigned &Index,
                     InitListExpr *StructuredList,
                     unsigned &StructuredIndex);
void CheckReferenceType(const InitializedEntity &Entity,
                        InitListExpr *IList, QualType DeclType,
                        unsigned &Index,
                        InitListExpr *StructuredList,
                        unsigned &StructuredIndex);
void CheckVectorType(const InitializedEntity &Entity,
                     InitListExpr *IList, QualType DeclType, unsigned &Index,
                     InitListExpr *StructuredList,
                     unsigned &StructuredIndex);
void CheckStructUnionTypes(const InitializedEntity &Entity,
                           InitListExpr *IList, QualType DeclType,
                           CXXRecordDecl::base_class_range Bases,
                           RecordDecl::field_iterator Field,
                           bool SubobjectIsDesignatorContext, unsigned &Index,
                           InitListExpr *StructuredList,
                           unsigned &StructuredIndex,
                           bool TopLevelObject = false);
void CheckArrayType(const InitializedEntity &Entity,
                    InitListExpr *IList, QualType &DeclType,
                    llvm::APSInt elementIndex,
                    bool SubobjectIsDesignatorContext, unsigned &Index,
                    InitListExpr *StructuredList,
                    unsigned &StructuredIndex);
bool CheckDesignatedInitializer(const InitializedEntity &Entity,
                                InitListExpr *IList, DesignatedInitExpr *DIE,
                                unsigned DesigIdx,
                                QualType &CurrentObjectType,
                                RecordDecl::field_iterator *NextField,
                                llvm::APSInt *NextElementIndex,
                                unsigned &Index,
                                InitListExpr *StructuredList,
                                unsigned &StructuredIndex,
                                bool FinishSubobjectInit,
                                bool TopLevelObject);
InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
                                         QualType CurrentObjectType,
                                         InitListExpr *StructuredList,
                                         unsigned StructuredIndex,
                                         SourceRange InitRange,
                                         bool IsFullyOverwritten = false);
void UpdateStructuredListElement(InitListExpr *StructuredList,
                                 unsigned &StructuredIndex,
                                 Expr *expr);
InitListExpr *createInitListExpr(QualType CurrentObjectType,
                                 SourceRange InitRange,
                                 unsigned ExpectedNumInits);
int numArrayElements(QualType DeclType);
int numStructUnionElements(QualType DeclType);

ExprResult PerformEmptyInit(SourceLocation Loc,
                            const InitializedEntity &Entity);

/// Diagnose that OldInit (or part thereof) has been overridden by NewInit.
void diagnoseInitOverride(Expr *OldInit, SourceRange NewInitRange,
                          bool FullyOverwritten = true) {
  // Overriding an initializer via a designator is valid with C99 designated
  // initializers, but ill-formed with C++20 designated initializers.
  unsigned DiagID = SemaRef.getLangOpts().CPlusPlus
                        ? diag::ext_initializer_overrides
                        : diag::warn_initializer_overrides;

  if (InOverloadResolution && SemaRef.getLangOpts().CPlusPlus) {
    // In overload resolution, we have to strictly enforce the rules, and so
    // don't allow any overriding of prior initializers. This matters for a
    // case such as:
    //
    //   union U { int a, b; };
    //   struct S { int a, b; };
    //   void f(U), f(S);
    //
    // Here, f({.a = 1, .b = 2}) is required to call the struct overload. For
    // consistency, we disallow all overriding of prior initializers in
    // overload resolution, not only overriding of union members.
    hadError = true;
  } else if (OldInit->getType().isDestructedType() && !FullyOverwritten) {
    // If we'll be keeping around the old initializer but overwriting part of
    // the object it initialized, and that object is not trivially
    // destructible, this can leak. Don't allow that, not even as an
    // extension.
    //
    // FIXME: It might be reasonable to allow this in cases where the part of
    // the initializer that we're overriding has trivial destruction.
    DiagID = diag::err_initializer_overrides_destructed;
  } else if (!OldInit->getSourceRange().isValid()) {
    // We need to check on source range validity because the previous
    // initializer does not have to be an explicit initializer. e.g.,
    //
    // struct P { int a, b; };
    // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
    //
    // There is an overwrite taking place because the first braced initializer
    // list "{ .a = 2 }" already provides value for .p.b (which is zero).
    //
    // Such overwrites are harmless, so we don't diagnose them. (Note that in
    // C++, this cannot be reached unless we've already seen and diagnosed a
    // different conformance issue, such as a mixture of designated and
    // non-designated initializers or a multi-level designator.)
    return;
  }

  if (!VerifyOnly) {
    SemaRef.Diag(NewInitRange.getBegin(), DiagID)
        << NewInitRange << FullyOverwritten << OldInit->getType();
    SemaRef.Diag(OldInit->getBeginLoc(), diag::note_previous_initializer)
        << (OldInit->HasSideEffects(SemaRef.Context) && FullyOverwritten)
        << OldInit->getSourceRange();
  }
}

// Explanation on the "FillWithNoInit" mode:
//
// Assume we have the following definitions (Case#1):
// struct P { char x[6][6]; } xp = { .x[1] = "bar" };
// struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
//
// l.lp.x[1][0..1] should not be filled with implicit initializers because the
// "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
//
// But if we have (Case#2):
// struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
//
// l.lp.x[1][0..1] are implicitly initialized and do not use values from the
// "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
//
// To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
// in the InitListExpr, the "holes" in Case#1 are filled not with empty
// initializers but with special "NoInitExpr" place holders, which tells the
// CodeGen not to generate any initializers for these parts.
void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
                            const InitializedEntity &ParentEntity,
                            InitListExpr *ILE, bool &RequiresSecondPass,
                            bool FillWithNoInit);
void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
                             const InitializedEntity &ParentEntity,
                             InitListExpr *ILE, bool &RequiresSecondPass,
                             bool FillWithNoInit = false);
void FillInEmptyInitializations(const InitializedEntity &Entity,
                                InitListExpr *ILE, bool &RequiresSecondPass,
                                InitListExpr *OuterILE, unsigned OuterIndex,
                                bool FillWithNoInit = false);
bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
                            Expr *InitExpr, FieldDecl *Field,
                            bool TopLevelObject);
void CheckEmptyInitializable(const InitializedEntity &Entity,
                             SourceLocation Loc);

477public:
InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
                QualType &T, bool VerifyOnly, bool TreatUnavailableAsInvalid,
                bool InOverloadResolution = false);
bool HadError() { return hadError; }

// Retrieves the fully-structured initializer list used for
// semantic analysis and code generation.
InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
486};

488} // end anonymous namespace

490ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
                                           const InitializedEntity &Entity) {
InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
                                                          true);
MultiExprArg SubInit;
Expr *InitExpr;
InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc);

// C++ [dcl.init.aggr]p7:
//   If there are fewer initializer-clauses in the list than there are
//   members in the aggregate, then each member not explicitly initialized
//   ...
bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
    Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
if (EmptyInitList) {
  // C++1y / DR1070:
  //   shall be initialized [...] from an empty initializer list.
  //
  // We apply the resolution of this DR to C++11 but not C++98, since C++98
  // does not have useful semantics for initialization from an init list.
  // We treat this as copy-initialization, because aggregate initialization
  // always performs copy-initialization on its elements.
  //
  // Only do this if we're initializing a class type, to avoid filling in
  // the initializer list where possible.
  InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context)
                 InitListExpr(SemaRef.Context, Loc, None, Loc);
  InitExpr->setType(SemaRef.Context.VoidTy);
  SubInit = InitExpr;
  Kind = InitializationKind::CreateCopy(Loc, Loc);
} else {
  // C++03:
  //   shall be value-initialized.
}

InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
// libstdc++4.6 marks the vector default constructor as explicit in
// _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
// stlport does so too. Look for std::__debug for libstdc++, and for
// std:: for stlport.  This is effectively a compiler-side implementation of
// LWG2193.
if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
        InitializationSequence::FK_ExplicitConstructor) {
  OverloadCandidateSet::iterator Best;
  OverloadingResult O =
      InitSeq.getFailedCandidateSet()
          .BestViableFunction(SemaRef, Kind.getLocation(), Best);
  (void)O;
  assert(O == OR_Success && "Inconsistent overload resolution")(static_cast <bool> (O == OR_Success && "Inconsistent overload resolution"
) ? void (0) : __assert_fail ("O == OR_Success && \"Inconsistent overload resolution\""
, "clang/lib/Sema/SemaInit.cpp", 538, __extension__ __PRETTY_FUNCTION__
));
  CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
  CXXRecordDecl *R = CtorDecl->getParent();

  if (CtorDecl->getMinRequiredArguments() == 0 &&
      CtorDecl->isExplicit() && R->getDeclName() &&
      SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
    bool IsInStd = false;
    for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
         ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
      if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
        IsInStd = true;
    }

    if (IsInStd && llvm::StringSwitch<bool>(R->getName())
            .Cases("basic_string", "deque", "forward_list", true)
            .Cases("list", "map", "multimap", "multiset", true)
            .Cases("priority_queue", "queue", "set", "stack", true)
            .Cases("unordered_map", "unordered_set", "vector", true)
            .Default(false)) {
      InitSeq.InitializeFrom(
          SemaRef, Entity,
          InitializationKind::CreateValue(Loc, Loc, Loc, true),
          MultiExprArg(), /*TopLevelOfInitList=*/false,
          TreatUnavailableAsInvalid);
      // Emit a warning for this.  System header warnings aren't shown
      // by default, but people working on system headers should see it.
      if (!VerifyOnly) {
        SemaRef.Diag(CtorDecl->getLocation(),
                     diag::warn_invalid_initializer_from_system_header);
        if (Entity.getKind() == InitializedEntity::EK_Member)
          SemaRef.Diag(Entity.getDecl()->getLocation(),
                       diag::note_used_in_initialization_here);
        else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
          SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
      }
    }
  }
}
if (!InitSeq) {
  if (!VerifyOnly) {
    InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
    if (Entity.getKind() == InitializedEntity::EK_Member)
      SemaRef.Diag(Entity.getDecl()->getLocation(),
                   diag::note_in_omitted_aggregate_initializer)
        << /*field*/1 << Entity.getDecl();
    else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) {
      bool IsTrailingArrayNewMember =
          Entity.getParent() &&
          Entity.getParent()->isVariableLengthArrayNew();
      SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
        << (IsTrailingArrayNewMember ? 2 : /*array element*/0)
        << Entity.getElementIndex();
    }
  }
  hadError = true;
  return ExprError();
}

return VerifyOnly ? ExprResult()
                  : InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
599}

601void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
                                            SourceLocation Loc) {
// If we're building a fully-structured list, we'll check this at the end
// once we know which elements are actually initialized. Otherwise, we know
// that there are no designators so we can just check now.
if (FullyStructuredList)
  return;
PerformEmptyInit(Loc, Entity);
609}

611void InitListChecker::FillInEmptyInitForBase(
  unsigned Init, const CXXBaseSpecifier &Base,
  const InitializedEntity &ParentEntity, InitListExpr *ILE,
  bool &RequiresSecondPass, bool FillWithNoInit) {
InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
    SemaRef.Context, &Base, false, &ParentEntity);

if (Init >= ILE->getNumInits() || !ILE->getInit(Init)) {
  ExprResult BaseInit = FillWithNoInit
                            ? new (SemaRef.Context) NoInitExpr(Base.getType())
                            : PerformEmptyInit(ILE->getEndLoc(), BaseEntity);
  if (BaseInit.isInvalid()) {
    hadError = true;
    return;
  }

  if (!VerifyOnly) {
    assert(Init < ILE->getNumInits() && "should have been expanded")(static_cast <bool> (Init < ILE->getNumInits() &&
 "should have been expanded") ? void (0) : __assert_fail ("Init < ILE->getNumInits() && \"should have been expanded\""
, "clang/lib/Sema/SemaInit.cpp", 628, __extension__ __PRETTY_FUNCTION__
));
    ILE->setInit(Init, BaseInit.getAs<Expr>());
  }
} else if (InitListExpr *InnerILE =
               dyn_cast<InitListExpr>(ILE->getInit(Init))) {
  FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
                             ILE, Init, FillWithNoInit);
} else if (DesignatedInitUpdateExpr *InnerDIUE =
             dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
  FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
                             RequiresSecondPass, ILE, Init,
                             /*FillWithNoInit =*/true);
}
641}

643void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
                                      const InitializedEntity &ParentEntity,
                                            InitListExpr *ILE,
                                            bool &RequiresSecondPass,
                                            bool FillWithNoInit) {
SourceLocation Loc = ILE->getEndLoc();
unsigned NumInits = ILE->getNumInits();
InitializedEntity MemberEntity
  = InitializedEntity::InitializeMember(Field, &ParentEntity);

if (Init >= NumInits || !ILE->getInit(Init)) {
  if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
    if (!RType->getDecl()->isUnion())
      assert((Init < NumInits || VerifyOnly) &&(static_cast <bool> ((Init < NumInits || VerifyOnly)
 && "This ILE should have been expanded") ? void (0) :
 __assert_fail ("(Init < NumInits || VerifyOnly) && \"This ILE should have been expanded\""
, "clang/lib/Sema/SemaInit.cpp", 657, __extension__ __PRETTY_FUNCTION__
))
             "This ILE should have been expanded")(static_cast <bool> ((Init < NumInits || VerifyOnly)
 && "This ILE should have been expanded") ? void (0) :
 __assert_fail ("(Init < NumInits || VerifyOnly) && \"This ILE should have been expanded\""
, "clang/lib/Sema/SemaInit.cpp", 657, __extension__ __PRETTY_FUNCTION__
));

  if (FillWithNoInit) {
    assert(!VerifyOnly && "should not fill with no-init in verify-only mode")(static_cast <bool> (!VerifyOnly && "should not fill with no-init in verify-only mode"
) ? void (0) : __assert_fail ("!VerifyOnly && \"should not fill with no-init in verify-only mode\""
, "clang/lib/Sema/SemaInit.cpp", 660, __extension__ __PRETTY_FUNCTION__
));
    Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
    if (Init < NumInits)
      ILE->setInit(Init, Filler);
    else
      ILE->updateInit(SemaRef.Context, Init, Filler);
    return;
  }
  // C++1y [dcl.init.aggr]p7:
  //   If there are fewer initializer-clauses in the list than there are
  //   members in the aggregate, then each member not explicitly initialized
  //   shall be initialized from its brace-or-equal-initializer [...]
  if (Field->hasInClassInitializer()) {
    if (VerifyOnly)
      return;

    ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
    if (DIE.isInvalid()) {
      hadError = true;
      return;
    }
    SemaRef.checkInitializerLifetime(MemberEntity, DIE.get());
    if (Init < NumInits)
      ILE->setInit(Init, DIE.get());
    else {
      ILE->updateInit(SemaRef.Context, Init, DIE.get());
      RequiresSecondPass = true;
    }
    return;
  }

  if (Field->getType()->isReferenceType()) {
    if (!VerifyOnly) {
      // C++ [dcl.init.aggr]p9:
      //   If an incomplete or empty initializer-list leaves a
      //   member of reference type uninitialized, the program is
      //   ill-formed.
      SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
          << Field->getType()
          << (ILE->isSyntacticForm() ? ILE : ILE->getSyntacticForm())
                 ->getSourceRange();
      SemaRef.Diag(Field->getLocation(), diag::note_uninit_reference_member);
    }
    hadError = true;
    return;
  }

  ExprResult MemberInit = PerformEmptyInit(Loc, MemberEntity);
  if (MemberInit.isInvalid()) {
    hadError = true;
    return;
  }

  if (hadError || VerifyOnly) {
    // Do nothing
  } else if (Init < NumInits) {
    ILE->setInit(Init, MemberInit.getAs<Expr>());
  } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
    // Empty initialization requires a constructor call, so
    // extend the initializer list to include the constructor
    // call and make a note that we'll need to take another pass
    // through the initializer list.
    ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
    RequiresSecondPass = true;
  }
} else if (InitListExpr *InnerILE
             = dyn_cast<InitListExpr>(ILE->getInit(Init))) {
  FillInEmptyInitializations(MemberEntity, InnerILE,
                             RequiresSecondPass, ILE, Init, FillWithNoInit);
} else if (DesignatedInitUpdateExpr *InnerDIUE =
               dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
  FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
                             RequiresSecondPass, ILE, Init,
                             /*FillWithNoInit =*/true);
}
735}

737/// Recursively replaces NULL values within the given initializer list
738/// with expressions that perform value-initialization of the
739/// appropriate type, and finish off the InitListExpr formation.
740void
741InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
                                          InitListExpr *ILE,
                                          bool &RequiresSecondPass,
                                          InitListExpr *OuterILE,
                                          unsigned OuterIndex,
                                          bool FillWithNoInit) {
assert((ILE->getType() != SemaRef.Context.VoidTy) &&(static_cast <bool> ((ILE->getType() != SemaRef.Context
.VoidTy) && "Should not have void type") ? void (0) :
 __assert_fail ("(ILE->getType() != SemaRef.Context.VoidTy) && \"Should not have void type\""
, "clang/lib/Sema/SemaInit.cpp", 748, __extension__ __PRETTY_FUNCTION__
))
       "Should not have void type")(static_cast <bool> ((ILE->getType() != SemaRef.Context
.VoidTy) && "Should not have void type") ? void (0) :
 __assert_fail ("(ILE->getType() != SemaRef.Context.VoidTy) && \"Should not have void type\""
, "clang/lib/Sema/SemaInit.cpp", 748, __extension__ __PRETTY_FUNCTION__
));

// We don't need to do any checks when just filling NoInitExprs; that can't
// fail.
if (FillWithNoInit && VerifyOnly)
  return;

// If this is a nested initializer list, we might have changed its contents
// (and therefore some of its properties, such as instantiation-dependence)
// while filling it in. Inform the outer initializer list so that its state
// can be updated to match.
// FIXME: We should fully build the inner initializers before constructing
// the outer InitListExpr instead of mutating AST nodes after they have
// been used as subexpressions of other nodes.
struct UpdateOuterILEWithUpdatedInit {
  InitListExpr *Outer;
  unsigned OuterIndex;
  ~UpdateOuterILEWithUpdatedInit() {
    if (Outer)
      Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
  }
} UpdateOuterRAII = {OuterILE, OuterIndex};

// A transparent ILE is not performing aggregate initialization and should
// not be filled in.
if (ILE->isTransparent())
  return;

if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
  const RecordDecl *RDecl = RType->getDecl();
  if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
    FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
                            Entity, ILE, RequiresSecondPass, FillWithNoInit);
  else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
           cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
    for (auto *Field : RDecl->fields()) {
      if (Field->hasInClassInitializer()) {
        FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
                                FillWithNoInit);
        break;
      }
    }
  } else {
    // The fields beyond ILE->getNumInits() are default initialized, so in
    // order to leave them uninitialized, the ILE is expanded and the extra
    // fields are then filled with NoInitExpr.
    unsigned NumElems = numStructUnionElements(ILE->getType());
    if (RDecl->hasFlexibleArrayMember())
      ++NumElems;
    if (!VerifyOnly && ILE->getNumInits() < NumElems)
      ILE->resizeInits(SemaRef.Context, NumElems);

    unsigned Init = 0;

    if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
      for (auto &Base : CXXRD->bases()) {
        if (hadError)
          return;

        FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
                               FillWithNoInit);
        ++Init;
      }
    }

    for (auto *Field : RDecl->fields()) {
      if (Field->isUnnamedBitfield())
        continue;

      if (hadError)
        return;

      FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
                              FillWithNoInit);
      if (hadError)
        return;

      ++Init;

      // Only look at the first initialization of a union.
      if (RDecl->isUnion())
        break;
    }
  }

  return;
}

QualType ElementType;

InitializedEntity ElementEntity = Entity;
unsigned NumInits = ILE->getNumInits();
unsigned NumElements = NumInits;
if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
  ElementType = AType->getElementType();
  if (const auto *CAType = dyn_cast<ConstantArrayType>(AType))
    NumElements = CAType->getSize().getZExtValue();
  // For an array new with an unknown bound, ask for one additional element
  // in order to populate the array filler.
  if (Entity.isVariableLengthArrayNew())
    ++NumElements;
  ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
                                                       0, Entity);
} else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
  ElementType = VType->getElementType();
  NumElements = VType->getNumElements();
  ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
                                                       0, Entity);
} else
  ElementType = ILE->getType();

bool SkipEmptyInitChecks = false;
for (unsigned Init = 0; Init != NumElements; ++Init) {
  if (hadError)
    return;

  if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
      ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
    ElementEntity.setElementIndex(Init);

  if (Init >= NumInits && (ILE->hasArrayFiller() || SkipEmptyInitChecks))
    return;

  Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
  if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
    ILE->setInit(Init, ILE->getArrayFiller());
  else if (!InitExpr && !ILE->hasArrayFiller()) {
    // In VerifyOnly mode, there's no point performing empty initialization
    // more than once.
    if (SkipEmptyInitChecks)
      continue;

    Expr *Filler = nullptr;

    if (FillWithNoInit)
      Filler = new (SemaRef.Context) NoInitExpr(ElementType);
    else {
      ExprResult ElementInit =
          PerformEmptyInit(ILE->getEndLoc(), ElementEntity);
      if (ElementInit.isInvalid()) {
        hadError = true;
        return;
      }

      Filler = ElementInit.getAs<Expr>();
    }

    if (hadError) {
      // Do nothing
    } else if (VerifyOnly) {
      SkipEmptyInitChecks = true;
    } else if (Init < NumInits) {
      // For arrays, just set the expression used for value-initialization
      // of the "holes" in the array.
      if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
        ILE->setArrayFiller(Filler);
      else
        ILE->setInit(Init, Filler);
    } else {
      // For arrays, just set the expression used for value-initialization
      // of the rest of elements and exit.
      if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
        ILE->setArrayFiller(Filler);
        return;
      }

      if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
        // Empty initialization requires a constructor call, so
        // extend the initializer list to include the constructor
        // call and make a note that we'll need to take another pass
        // through the initializer list.
        ILE->updateInit(SemaRef.Context, Init, Filler);
        RequiresSecondPass = true;
      }
    }
  } else if (InitListExpr *InnerILE
               = dyn_cast_or_null<InitListExpr>(InitExpr)) {
    FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
                               ILE, Init, FillWithNoInit);
  } else if (DesignatedInitUpdateExpr *InnerDIUE =
                 dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr)) {
    FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
                               RequiresSecondPass, ILE, Init,
                               /*FillWithNoInit =*/true);
  }
}
934}

936static bool hasAnyDesignatedInits(const InitListExpr *IL) {
for (const Stmt *Init : *IL)
  if (Init && isa<DesignatedInitExpr>(Init))
    return true;
return false;
941}

943InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
                               InitListExpr *IL, QualType &T, bool VerifyOnly,
                               bool TreatUnavailableAsInvalid,
                               bool InOverloadResolution)
  : SemaRef(S), VerifyOnly(VerifyOnly),
    TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
    InOverloadResolution(InOverloadResolution) {
if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
  FullyStructuredList =
      createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());

  // FIXME: Check that IL isn't already the semantic form of some other
  // InitListExpr. If it is, we'd create a broken AST.
  if (!VerifyOnly)
    FullyStructuredList->setSyntacticForm(IL);
}

CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
                      /*TopLevelObject=*/true);

if (!hadError && FullyStructuredList) {
  bool RequiresSecondPass = false;
  FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
                             /*OuterILE=*/nullptr, /*OuterIndex=*/0);
  if (RequiresSecondPass && !hadError)
    FillInEmptyInitializations(Entity, FullyStructuredList,
                               RequiresSecondPass, nullptr, 0);
}
if (hadError && FullyStructuredList)
  FullyStructuredList->markError();
973}

975int InitListChecker::numArrayElements(QualType DeclType) {
// FIXME: use a proper constant
int maxElements = 0x7FFFFFFF;
if (const ConstantArrayType *CAT =
      SemaRef.Context.getAsConstantArrayType(DeclType)) {
  maxElements = static_cast<int>(CAT->getSize().getZExtValue());
}
return maxElements;
983}

985int InitListChecker::numStructUnionElements(QualType DeclType) {
RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
int InitializableMembers = 0;
if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
  InitializableMembers += CXXRD->getNumBases();
for (const auto *Field : structDecl->fields())
  if (!Field->isUnnamedBitfield())
    ++InitializableMembers;

if (structDecl->isUnion())
  return std::min(InitializableMembers, 1);
return InitializableMembers - structDecl->hasFlexibleArrayMember();
997}

999/// Determine whether Entity is an entity for which it is idiomatic to elide
1000/// the braces in aggregate initialization.
1001static bool isIdiomaticBraceElisionEntity(const InitializedEntity &Entity) {
// Recursive initialization of the one and only field within an aggregate
// class is considered idiomatic. This case arises in particular for
// initialization of std::array, where the C++ standard suggests the idiom of
//
//   std::array<T, N> arr = {1, 2, 3};
//
// (where std::array is an aggregate struct containing a single array field.

if (!Entity.getParent())
  return false;

// Allows elide brace initialization for aggregates with empty base.
if (Entity.getKind() == InitializedEntity::EK_Base) {
  auto *ParentRD =
      Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
  CXXRecordDecl *CXXRD = cast<CXXRecordDecl>(ParentRD);
  return CXXRD->getNumBases() == 1 && CXXRD->field_empty();
}

// Allow brace elision if the only subobject is a field.
if (Entity.getKind() == InitializedEntity::EK_Member) {
  auto *ParentRD =
      Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
  if (CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(ParentRD)) {
    if (CXXRD->getNumBases()) {
      return false;
    }
  }
  auto FieldIt = ParentRD->field_begin();
  assert(FieldIt != ParentRD->field_end() &&(static_cast <bool> (FieldIt != ParentRD->field_end(
) && "no fields but have initializer for member?") ? void
 (0) : __assert_fail ("FieldIt != ParentRD->field_end() && \"no fields but have initializer for member?\""
, "clang/lib/Sema/SemaInit.cpp", 1032, __extension__ __PRETTY_FUNCTION__
))
         "no fields but have initializer for member?")(static_cast <bool> (FieldIt != ParentRD->field_end(
) && "no fields but have initializer for member?") ? void
 (0) : __assert_fail ("FieldIt != ParentRD->field_end() && \"no fields but have initializer for member?\""
, "clang/lib/Sema/SemaInit.cpp", 1032, __extension__ __PRETTY_FUNCTION__
));
  return ++FieldIt == ParentRD->field_end();
}

return false;
1037}

1039/// Check whether the range of the initializer \p ParentIList from element
1040/// \p Index onwards can be used to initialize an object of type \p T. Update
1041/// \p Index to indicate how many elements of the list were consumed.
1042///
1043/// This also fills in \p StructuredList, from element \p StructuredIndex
1044/// onwards, with the fully-braced, desugared form of the initialization.
1045void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
                                          InitListExpr *ParentIList,
                                          QualType T, unsigned &Index,
                                          InitListExpr *StructuredList,
                                          unsigned &StructuredIndex) {
int maxElements = 0;

if (T->isArrayType())
  maxElements = numArrayElements(T);
else if (T->isRecordType())
  maxElements = numStructUnionElements(T);
else if (T->isVectorType())
  maxElements = T->castAs<VectorType>()->getNumElements();
else
  llvm_unreachable("CheckImplicitInitList(): Illegal type")::llvm::llvm_unreachable_internal("CheckImplicitInitList(): Illegal type"
, "clang/lib/Sema/SemaInit.cpp", 1059);

if (maxElements == 0) {
  if (!VerifyOnly)
    SemaRef.Diag(ParentIList->getInit(Index)->getBeginLoc(),
                 diag::err_implicit_empty_initializer);
  ++Index;
  hadError = true;
  return;
}

// Build a structured initializer list corresponding to this subobject.
InitListExpr *StructuredSubobjectInitList = getStructuredSubobjectInit(
    ParentIList, Index, T, StructuredList, StructuredIndex,
    SourceRange(ParentIList->getInit(Index)->getBeginLoc(),
                ParentIList->getSourceRange().getEnd()));
unsigned StructuredSubobjectInitIndex = 0;

// Check the element types and build the structural subobject.
unsigned StartIndex = Index;
CheckListElementTypes(Entity, ParentIList, T,
                      /*SubobjectIsDesignatorContext=*/false, Index,
                      StructuredSubobjectInitList,
                      StructuredSubobjectInitIndex);

if (StructuredSubobjectInitList) {
  StructuredSubobjectInitList->setType(T);

  unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
  // Update the structured sub-object initializer so that it's ending
  // range corresponds with the end of the last initializer it used.
  if (EndIndex < ParentIList->getNumInits() &&
      ParentIList->getInit(EndIndex)) {
    SourceLocation EndLoc
      = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
    StructuredSubobjectInitList->setRBraceLoc(EndLoc);
  }

  // Complain about missing braces.
  if (!VerifyOnly && (T->isArrayType() || T->isRecordType()) &&
      !ParentIList->isIdiomaticZeroInitializer(SemaRef.getLangOpts()) &&
      !isIdiomaticBraceElisionEntity(Entity)) {
    SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
                 diag::warn_missing_braces)
        << StructuredSubobjectInitList->getSourceRange()
        << FixItHint::CreateInsertion(
               StructuredSubobjectInitList->getBeginLoc(), "{")
        << FixItHint::CreateInsertion(
               SemaRef.getLocForEndOfToken(
                   StructuredSubobjectInitList->getEndLoc()),
               "}");
  }

  // Warn if this type won't be an aggregate in future versions of C++.
  auto *CXXRD = T->getAsCXXRecordDecl();
  if (!VerifyOnly && CXXRD && CXXRD->hasUserDeclaredConstructor()) {
    SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
                 diag::warn_cxx20_compat_aggregate_init_with_ctors)
        << StructuredSubobjectInitList->getSourceRange() << T;
  }
}
1120}

1122/// Warn that \p Entity was of scalar type and was initialized by a
1123/// single-element braced initializer list.
1124static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
                               SourceRange Braces) {
// Don't warn during template instantiation. If the initialization was
// non-dependent, we warned during the initial parse; otherwise, the
// type might not be scalar in some uses of the template.
if (S.inTemplateInstantiation())
  return;

unsigned DiagID = 0;

switch (Entity.getKind()) {
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_TemplateParameter:
case InitializedEntity::EK_Result:
  // Extra braces here are suspicious.
  DiagID = diag::warn_braces_around_init;
  break;

case InitializedEntity::EK_Member:
  // Warn on aggregate initialization but not on ctor init list or
  // default member initializer.
  if (Entity.getParent())
    DiagID = diag::warn_braces_around_init;
  break;

case InitializedEntity::EK_Variable:
case InitializedEntity::EK_LambdaCapture:
  // No warning, might be direct-list-initialization.
  // FIXME: Should we warn for copy-list-initialization in these cases?
  break;

case InitializedEntity::EK_New:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
  // No warning, braces are part of the syntax of the underlying construct.
  break;

case InitializedEntity::EK_RelatedResult:
  // No warning, we already warned when initializing the result.
  break;

case InitializedEntity::EK_Exception:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_Binding:
case InitializedEntity::EK_StmtExprResult:
  llvm_unreachable("unexpected braced scalar init")::llvm::llvm_unreachable_internal("unexpected braced scalar init"
, "clang/lib/Sema/SemaInit.cpp", 1176);
}

if (DiagID) {
  S.Diag(Braces.getBegin(), DiagID)
      << Entity.getType()->isSizelessBuiltinType() << Braces
      << FixItHint::CreateRemoval(Braces.getBegin())
      << FixItHint::CreateRemoval(Braces.getEnd());
}
1185}

1187/// Check whether the initializer \p IList (that was written with explicit
1188/// braces) can be used to initialize an object of type \p T.
1189///
1190/// This also fills in \p StructuredList with the fully-braced, desugared
1191/// form of the initialization.
1192void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
                                          InitListExpr *IList, QualType &T,
                                          InitListExpr *StructuredList,
                                          bool TopLevelObject) {
unsigned Index = 0, StructuredIndex = 0;
CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
                      Index, StructuredList, StructuredIndex, TopLevelObject);
if (StructuredList) {
  QualType ExprTy = T;
  if (!ExprTy->isArrayType())
    ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
  if (!VerifyOnly)
    IList->setType(ExprTy);
  StructuredList->setType(ExprTy);
}
if (hadError)
  return;

// Don't complain for incomplete types, since we'll get an error elsewhere.
if (Index < IList->getNumInits() && !T->isIncompleteType()) {
  // We have leftover initializers
  bool ExtraInitsIsError = SemaRef.getLangOpts().CPlusPlus ||
        (SemaRef.getLangOpts().OpenCL && T->isVectorType());
  hadError = ExtraInitsIsError;
  if (VerifyOnly) {
    return;
  } else if (StructuredIndex == 1 &&
             IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
                 SIF_None) {
    unsigned DK =
        ExtraInitsIsError
            ? diag::err_excess_initializers_in_char_array_initializer
            : diag::ext_excess_initializers_in_char_array_initializer;
    SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
        << IList->getInit(Index)->getSourceRange();
  } else if (T->isSizelessBuiltinType()) {
    unsigned DK = ExtraInitsIsError
                      ? diag::err_excess_initializers_for_sizeless_type
                      : diag::ext_excess_initializers_for_sizeless_type;
    SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
        << T << IList->getInit(Index)->getSourceRange();
  } else {
    int initKind = T->isArrayType() ? 0 :
                   T->isVectorType() ? 1 :
                   T->isScalarType() ? 2 :
                   T->isUnionType() ? 3 :
                   4;

    unsigned DK = ExtraInitsIsError ? diag::err_excess_initializers
                                    : diag::ext_excess_initializers;
    SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
        << initKind << IList->getInit(Index)->getSourceRange();
  }
}

if (!VerifyOnly) {
  if (T->isScalarType() && IList->getNumInits() == 1 &&
      !isa<InitListExpr>(IList->getInit(0)))
    warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());

  // Warn if this is a class type that won't be an aggregate in future
  // versions of C++.
  auto *CXXRD = T->getAsCXXRecordDecl();
  if (CXXRD && CXXRD->hasUserDeclaredConstructor()) {
    // Don't warn if there's an equivalent default constructor that would be
    // used instead.
    bool HasEquivCtor = false;
    if (IList->getNumInits() == 0) {
      auto *CD = SemaRef.LookupDefaultConstructor(CXXRD);
      HasEquivCtor = CD && !CD->isDeleted();
    }

    if (!HasEquivCtor) {
      SemaRef.Diag(IList->getBeginLoc(),
                   diag::warn_cxx20_compat_aggregate_init_with_ctors)
          << IList->getSourceRange() << T;
    }
  }
}
1271}

1273void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
                                          InitListExpr *IList,
                                          QualType &DeclType,
                                          bool SubobjectIsDesignatorContext,
                                          unsigned &Index,
                                          InitListExpr *StructuredList,
                                          unsigned &StructuredIndex,
                                          bool TopLevelObject) {
if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
  // Explicitly braced initializer for complex type can be real+imaginary
  // parts.
  CheckComplexType(Entity, IList, DeclType, Index,
                   StructuredList, StructuredIndex);
} else if (DeclType->isScalarType()) {
  CheckScalarType(Entity, IList, DeclType, Index,
                  StructuredList, StructuredIndex);
} else if (DeclType->isVectorType()) {
  CheckVectorType(Entity, IList, DeclType, Index,
                  StructuredList, StructuredIndex);
} else if (DeclType->isRecordType()) {
  assert(DeclType->isAggregateType() &&(static_cast <bool> (DeclType->isAggregateType() &&
 "non-aggregate records should be handed in CheckSubElementType"
) ? void (0) : __assert_fail ("DeclType->isAggregateType() && \"non-aggregate records should be handed in CheckSubElementType\""
, "clang/lib/Sema/SemaInit.cpp", 1294, __extension__ __PRETTY_FUNCTION__
))
         "non-aggregate records should be handed in CheckSubElementType")(static_cast <bool> (DeclType->isAggregateType() &&
 "non-aggregate records should be handed in CheckSubElementType"
) ? void (0) : __assert_fail ("DeclType->isAggregateType() && \"non-aggregate records should be handed in CheckSubElementType\""
, "clang/lib/Sema/SemaInit.cpp", 1294, __extension__ __PRETTY_FUNCTION__
));
  RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
  auto Bases =
      CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
                                      CXXRecordDecl::base_class_iterator());
  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
    Bases = CXXRD->bases();
  CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
                        SubobjectIsDesignatorContext, Index, StructuredList,
                        StructuredIndex, TopLevelObject);
} else if (DeclType->isArrayType()) {
  llvm::APSInt Zero(
                  SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
                  false);
  CheckArrayType(Entity, IList, DeclType, Zero,
                 SubobjectIsDesignatorContext, Index,
                 StructuredList, StructuredIndex);
} else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
  // This type is invalid, issue a diagnostic.
  ++Index;
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
        << DeclType;
  hadError = true;
} else if (DeclType->isReferenceType()) {
  CheckReferenceType(Entity, IList, DeclType, Index,
                     StructuredList, StructuredIndex);
} else if (DeclType->isObjCObjectType()) {
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(), diag::err_init_objc_class) << DeclType;
  hadError = true;
} else if (DeclType->isOCLIntelSubgroupAVCType() ||
           DeclType->isSizelessBuiltinType()) {
  // Checks for scalar type are sufficient for these types too.
  CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
                  StructuredIndex);
} else {
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
        << DeclType;
  hadError = true;
}
1336}

1338void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
                                        InitListExpr *IList,
                                        QualType ElemType,
                                        unsigned &Index,
                                        InitListExpr *StructuredList,
                                        unsigned &StructuredIndex,
                                        bool DirectlyDesignated) {
Expr *expr = IList->getInit(Index);

if (ElemType->isReferenceType())
  return CheckReferenceType(Entity, IList, ElemType, Index,
                            StructuredList, StructuredIndex);

if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
  if (SubInitList->getNumInits() == 1 &&
      IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
      SIF_None) {
    // FIXME: It would be more faithful and no less correct to include an
    // InitListExpr in the semantic form of the initializer list in this case.
    expr = SubInitList->getInit(0);
  }
  // Nested aggregate initialization and C++ initialization are handled later.
} else if (isa<ImplicitValueInitExpr>(expr)) {
  // This happens during template instantiation when we see an InitListExpr
  // that we've already checked once.
  assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) &&(static_cast <bool> (SemaRef.Context.hasSameType(expr->
getType(), ElemType) && "found implicit initialization for the wrong type"
) ? void (0) : __assert_fail ("SemaRef.Context.hasSameType(expr->getType(), ElemType) && \"found implicit initialization for the wrong type\""
, "clang/lib/Sema/SemaInit.cpp", 1364, __extension__ __PRETTY_FUNCTION__
))
         "found implicit initialization for the wrong type")(static_cast <bool> (SemaRef.Context.hasSameType(expr->
getType(), ElemType) && "found implicit initialization for the wrong type"
) ? void (0) : __assert_fail ("SemaRef.Context.hasSameType(expr->getType(), ElemType) && \"found implicit initialization for the wrong type\""
, "clang/lib/Sema/SemaInit.cpp", 1364, __extension__ __PRETTY_FUNCTION__
));
  UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
  ++Index;
  return;
}

if (SemaRef.getLangOpts().CPlusPlus || isa<InitListExpr>(expr)) {
  // C++ [dcl.init.aggr]p2:
  //   Each member is copy-initialized from the corresponding
  //   initializer-clause.

  // FIXME: Better EqualLoc?
  InitializationKind Kind =
      InitializationKind::CreateCopy(expr->getBeginLoc(), SourceLocation());

  // Vector elements can be initialized from other vectors in which case
  // we need initialization entity with a type of a vector (and not a vector
  // element!) initializing multiple vector elements.
  auto TmpEntity =
      (ElemType->isExtVectorType() && !Entity.getType()->isExtVectorType())
          ? InitializedEntity::InitializeTemporary(ElemType)
          : Entity;

  InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
                             /*TopLevelOfInitList*/ true);

  // C++14 [dcl.init.aggr]p13:
  //   If the assignment-expression can initialize a member, the member is
  //   initialized. Otherwise [...] brace elision is assumed
  //
  // Brace elision is never performed if the element is not an
  // assignment-expression.
  if (Seq || isa<InitListExpr>(expr)) {
    if (!VerifyOnly) {
      ExprResult Result = Seq.Perform(SemaRef, TmpEntity, Kind, expr);
      if (Result.isInvalid())
        hadError = true;

      UpdateStructuredListElement(StructuredList, StructuredIndex,
                                  Result.getAs<Expr>());
    } else if (!Seq) {
      hadError = true;
    } else if (StructuredList) {
      UpdateStructuredListElement(StructuredList, StructuredIndex,
                                  getDummyInit());
    }
    ++Index;
    return;
  }

  // Fall through for subaggregate initialization
} else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
  // FIXME: Need to handle atomic aggregate types with implicit init lists.
  return CheckScalarType(Entity, IList, ElemType, Index,
                         StructuredList, StructuredIndex);
} else if (const ArrayType *arrayType =
               SemaRef.Context.getAsArrayType(ElemType)) {
  // arrayType can be incomplete if we're initializing a flexible
  // array member.  There's nothing we can do with the completed
  // type here, though.

  if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
    // FIXME: Should we do this checking in verify-only mode?
    if (!VerifyOnly)
      CheckStringInit(expr, ElemType, arrayType, SemaRef);
    if (StructuredList)
      UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
    ++Index;
    return;
  }

  // Fall through for subaggregate initialization.

} else {
  assert((ElemType->isRecordType() || ElemType->isVectorType() ||(static_cast <bool> ((ElemType->isRecordType() || ElemType
->isVectorType() || ElemType->isOpenCLSpecificType()) &&
 "Unexpected type") ? void (0) : __assert_fail ("(ElemType->isRecordType() || ElemType->isVectorType() || ElemType->isOpenCLSpecificType()) && \"Unexpected type\""
, "clang/lib/Sema/SemaInit.cpp", 1439, __extension__ __PRETTY_FUNCTION__
))
          ElemType->isOpenCLSpecificType()) && "Unexpected type")(static_cast <bool> ((ElemType->isRecordType() || ElemType
->isVectorType() || ElemType->isOpenCLSpecificType()) &&
 "Unexpected type") ? void (0) : __assert_fail ("(ElemType->isRecordType() || ElemType->isVectorType() || ElemType->isOpenCLSpecificType()) && \"Unexpected type\""
, "clang/lib/Sema/SemaInit.cpp", 1439, __extension__ __PRETTY_FUNCTION__
));

  // C99 6.7.8p13:
  //
  //   The initializer for a structure or union object that has
  //   automatic storage duration shall be either an initializer
  //   list as described below, or a single expression that has
  //   compatible structure or union type. In the latter case, the
  //   initial value of the object, including unnamed members, is
  //   that of the expression.
  ExprResult ExprRes = expr;
  if (SemaRef.CheckSingleAssignmentConstraints(
          ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
    if (ExprRes.isInvalid())
      hadError = true;
    else {
      ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
      if (ExprRes.isInvalid())
        hadError = true;
    }
    UpdateStructuredListElement(StructuredList, StructuredIndex,
                                ExprRes.getAs<Expr>());
    ++Index;
    return;
  }
  ExprRes.get();
  // Fall through for subaggregate initialization
}

// C++ [dcl.init.aggr]p12:
//
//   [...] Otherwise, if the member is itself a non-empty
//   subaggregate, brace elision is assumed and the initializer is
//   considered for the initialization of the first member of
//   the subaggregate.
// OpenCL vector initializer is handled elsewhere.
if ((!SemaRef.getLangOpts().OpenCL && ElemType->isVectorType()) ||
    ElemType->isAggregateType()) {
  CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
                        StructuredIndex);
  ++StructuredIndex;

  // In C++20, brace elision is not permitted for a designated initializer.
  if (DirectlyDesignated && SemaRef.getLangOpts().CPlusPlus && !hadError) {
    if (InOverloadResolution)
      hadError = true;
    if (!VerifyOnly) {
      SemaRef.Diag(expr->getBeginLoc(),
                   diag::ext_designated_init_brace_elision)
          << expr->getSourceRange()
          << FixItHint::CreateInsertion(expr->getBeginLoc(), "{")
          << FixItHint::CreateInsertion(
                 SemaRef.getLocForEndOfToken(expr->getEndLoc()), "}");
    }
  }
} else {
  if (!VerifyOnly) {
    // We cannot initialize this element, so let PerformCopyInitialization
    // produce the appropriate diagnostic. We already checked that this
    // initialization will fail.
    ExprResult Copy =
        SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
                                          /*TopLevelOfInitList=*/true);
    (void)Copy;
    assert(Copy.isInvalid() &&(static_cast <bool> (Copy.isInvalid() && "expected non-aggregate initialization to fail"
) ? void (0) : __assert_fail ("Copy.isInvalid() && \"expected non-aggregate initialization to fail\""
, "clang/lib/Sema/SemaInit.cpp", 1504, __extension__ __PRETTY_FUNCTION__
))
           "expected non-aggregate initialization to fail")(static_cast <bool> (Copy.isInvalid() && "expected non-aggregate initialization to fail"
) ? void (0) : __assert_fail ("Copy.isInvalid() && \"expected non-aggregate initialization to fail\""
, "clang/lib/Sema/SemaInit.cpp", 1504, __extension__ __PRETTY_FUNCTION__
));
  }
  hadError = true;
  ++Index;
  ++StructuredIndex;
}
1510}

1512void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
                                     InitListExpr *IList, QualType DeclType,
                                     unsigned &Index,
                                     InitListExpr *StructuredList,
                                     unsigned &StructuredIndex) {
assert(Index == 0 && "Index in explicit init list must be zero")(static_cast <bool> (Index == 0 && "Index in explicit init list must be zero"
) ? void (0) : __assert_fail ("Index == 0 && \"Index in explicit init list must be zero\""
, "clang/lib/Sema/SemaInit.cpp", 1517, __extension__ __PRETTY_FUNCTION__
));

// As an extension, clang supports complex initializers, which initialize
// a complex number component-wise.  When an explicit initializer list for
// a complex number contains two two initializers, this extension kicks in:
// it exepcts the initializer list to contain two elements convertible to
// the element type of the complex type. The first element initializes
// the real part, and the second element intitializes the imaginary part.

if (IList->getNumInits() != 2)
  return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
                         StructuredIndex);

// This is an extension in C.  (The builtin _Complex type does not exist
// in the C++ standard.)
if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
  SemaRef.Diag(IList->getBeginLoc(), diag::ext_complex_component_init)
      << IList->getSourceRange();

// Initialize the complex number.
QualType elementType = DeclType->castAs<ComplexType>()->getElementType();
InitializedEntity ElementEntity =
  InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);

for (unsigned i = 0; i < 2; ++i) {
  ElementEntity.setElementIndex(Index);
  CheckSubElementType(ElementEntity, IList, elementType, Index,
                      StructuredList, StructuredIndex);
}
1546}

1548void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
                                    InitListExpr *IList, QualType DeclType,
                                    unsigned &Index,
                                    InitListExpr *StructuredList,
                                    unsigned &StructuredIndex) {
if (Index >= IList->getNumInits()) {
  if (!VerifyOnly) {
    if (DeclType->isSizelessBuiltinType())
      SemaRef.Diag(IList->getBeginLoc(),
                   SemaRef.getLangOpts().CPlusPlus11
                       ? diag::warn_cxx98_compat_empty_sizeless_initializer
                       : diag::err_empty_sizeless_initializer)
          << DeclType << IList->getSourceRange();
    else
      SemaRef.Diag(IList->getBeginLoc(),
                   SemaRef.getLangOpts().CPlusPlus11
                       ? diag::warn_cxx98_compat_empty_scalar_initializer
                       : diag::err_empty_scalar_initializer)
          << IList->getSourceRange();
  }
  hadError = !SemaRef.getLangOpts().CPlusPlus11;
  ++Index;
  ++StructuredIndex;
  return;
}

Expr *expr = IList->getInit(Index);
if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
  // FIXME: This is invalid, and accepting it causes overload resolution
  // to pick the wrong overload in some corner cases.
  if (!VerifyOnly)
    SemaRef.Diag(SubIList->getBeginLoc(), diag::ext_many_braces_around_init)
        << DeclType->isSizelessBuiltinType() << SubIList->getSourceRange();

  CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
                  StructuredIndex);
  return;
} else if (isa<DesignatedInitExpr>(expr)) {
  if (!VerifyOnly)
    SemaRef.Diag(expr->getBeginLoc(),
                 diag::err_designator_for_scalar_or_sizeless_init)
        << DeclType->isSizelessBuiltinType() << DeclType
        << expr->getSourceRange();
  hadError = true;
  ++Index;
  ++StructuredIndex;
  return;
}

ExprResult Result;
if (VerifyOnly) {
  if (SemaRef.CanPerformCopyInitialization(Entity, expr))
    Result = getDummyInit();
  else
    Result = ExprError();
} else {
  Result =
      SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
                                        /*TopLevelOfInitList=*/true);
}

Expr *ResultExpr = nullptr;

if (Result.isInvalid())
  hadError = true; // types weren't compatible.
else {
  ResultExpr = Result.getAs<Expr>();

  if (ResultExpr != expr && !VerifyOnly) {
    // The type was promoted, update initializer list.
    // FIXME: Why are we updating the syntactic init list?
    IList->setInit(Index, ResultExpr);
  }
}
UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
++Index;
1624}

1626void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
                                       InitListExpr *IList, QualType DeclType,
                                       unsigned &Index,
                                       InitListExpr *StructuredList,
                                       unsigned &StructuredIndex) {
if (Index >= IList->getNumInits()) {
  // FIXME: It would be wonderful if we could point at the actual member. In
  // general, it would be useful to pass location information down the stack,
  // so that we know the location (or decl) of the "current object" being
  // initialized.
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(),
                 diag::err_init_reference_member_uninitialized)
        << DeclType << IList->getSourceRange();
  hadError = true;
  ++Index;
  ++StructuredIndex;
  return;
}

Expr *expr = IList->getInit(Index);
if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(), diag::err_init_non_aggr_init_list)
        << DeclType << IList->getSourceRange();
  hadError = true;
  ++Index;
  ++StructuredIndex;
  return;
}

ExprResult Result;
if (VerifyOnly) {
  if (SemaRef.CanPerformCopyInitialization(Entity,expr))
    Result = getDummyInit();
  else
    Result = ExprError();
} else {
  Result =
      SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
                                        /*TopLevelOfInitList=*/true);
}

if (Result.isInvalid())
  hadError = true;

expr = Result.getAs<Expr>();
// FIXME: Why are we updating the syntactic init list?
if (!VerifyOnly && expr)
  IList->setInit(Index, expr);

UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
++Index;
1679}

1681void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
                                    InitListExpr *IList, QualType DeclType,
                                    unsigned &Index,
                                    InitListExpr *StructuredList,
                                    unsigned &StructuredIndex) {
const VectorType *VT = DeclType->castAs<VectorType>();
unsigned maxElements = VT->getNumElements();
unsigned numEltsInit = 0;
QualType elementType = VT->getElementType();

if (Index >= IList->getNumInits()) {
  // Make sure the element type can be value-initialized.
  CheckEmptyInitializable(
      InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
      IList->getEndLoc());
  return;
}

if (!SemaRef.getLangOpts().OpenCL && !SemaRef.getLangOpts().HLSL ) {
  // If the initializing element is a vector, try to copy-initialize
  // instead of breaking it apart (which is doomed to failure anyway).
  Expr *Init = IList->getInit(Index);
  if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
    ExprResult Result;
    if (VerifyOnly) {
      if (SemaRef.CanPerformCopyInitialization(Entity, Init))
        Result = getDummyInit();
      else
        Result = ExprError();
    } else {
      Result =
          SemaRef.PerformCopyInitialization(Entity, Init->getBeginLoc(), Init,
                                            /*TopLevelOfInitList=*/true);
    }

    Expr *ResultExpr = nullptr;
    if (Result.isInvalid())
      hadError = true; // types weren't compatible.
    else {
      ResultExpr = Result.getAs<Expr>();

      if (ResultExpr != Init && !VerifyOnly) {
        // The type was promoted, update initializer list.
        // FIXME: Why are we updating the syntactic init list?
        IList->setInit(Index, ResultExpr);
      }
    }
    UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
    ++Index;
    return;
  }

  InitializedEntity ElementEntity =
    InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);

  for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
    // Don't attempt to go past the end of the init list
    if (Index >= IList->getNumInits()) {
      CheckEmptyInitializable(ElementEntity, IList->getEndLoc());
      break;
    }

    ElementEntity.setElementIndex(Index);
    CheckSubElementType(ElementEntity, IList, elementType, Index,
                        StructuredList, StructuredIndex);
  }

  if (VerifyOnly)
    return;

  bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
  const VectorType *T = Entity.getType()->castAs<VectorType>();
  if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
                      T->getVectorKind() == VectorType::NeonPolyVector)) {
    // The ability to use vector initializer lists is a GNU vector extension
    // and is unrelated to the NEON intrinsics in arm_neon.h. On little
    // endian machines it works fine, however on big endian machines it
    // exhibits surprising behaviour:
    //
    //   uint32x2_t x = {42, 64};
    //   return vget_lane_u32(x, 0); // Will return 64.
    //
    // Because of this, explicitly call out that it is non-portable.
    //
    SemaRef.Diag(IList->getBeginLoc(),
                 diag::warn_neon_vector_initializer_non_portable);

    const char *typeCode;
    unsigned typeSize = SemaRef.Context.getTypeSize(elementType);

    if (elementType->isFloatingType())
      typeCode = "f";
    else if (elementType->isSignedIntegerType())
      typeCode = "s";
    else if (elementType->isUnsignedIntegerType())
      typeCode = "u";
    else
      llvm_unreachable("Invalid element type!")::llvm::llvm_unreachable_internal("Invalid element type!", "clang/lib/Sema/SemaInit.cpp"
, 1778);

    SemaRef.Diag(IList->getBeginLoc(),
                 SemaRef.Context.getTypeSize(VT) > 64
                     ? diag::note_neon_vector_initializer_non_portable_q
                     : diag::note_neon_vector_initializer_non_portable)
        << typeCode << typeSize;
  }

  return;
}

InitializedEntity ElementEntity =
  InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);

// OpenCL and HLSL initializers allow vectors to be constructed from vectors.
for (unsigned i = 0; i < maxElements; ++i) {
  // Don't attempt to go past the end of the init list
  if (Index >= IList->getNumInits())
    break;

  ElementEntity.setElementIndex(Index);

  QualType IType = IList->getInit(Index)->getType();
  if (!IType->isVectorType()) {
    CheckSubElementType(ElementEntity, IList, elementType, Index,
                        StructuredList, StructuredIndex);
    ++numEltsInit;
  } else {
    QualType VecType;
    const VectorType *IVT = IType->castAs<VectorType>();
    unsigned numIElts = IVT->getNumElements();

    if (IType->isExtVectorType())
      VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
    else
      VecType = SemaRef.Context.getVectorType(elementType, numIElts,
                                              IVT->getVectorKind());
    CheckSubElementType(ElementEntity, IList, VecType, Index,
                        StructuredList, StructuredIndex);
    numEltsInit += numIElts;
  }
}

// OpenCL and HLSL require all elements to be initialized.
if (numEltsInit != maxElements) {
  if (!VerifyOnly)
    SemaRef.Diag(IList->getBeginLoc(),
                 diag::err_vector_incorrect_num_initializers)
        << (numEltsInit < maxElements) << maxElements << numEltsInit;
  hadError = true;
}
1830}

1832/// Check if the type of a class element has an accessible destructor, and marks
1833/// it referenced. Returns true if we shouldn't form a reference to the
1834/// destructor.
1835///
1836/// Aggregate initialization requires a class element's destructor be
1837/// accessible per 11.6.1 [dcl.init.aggr]:
1838///
1839/// The destructor for each element of class type is potentially invoked
1840/// (15.4 [class.dtor]) from the context where the aggregate initialization
1841/// occurs.
1842static bool checkDestructorReference(QualType ElementType, SourceLocation Loc,
                                   Sema &SemaRef) {
auto *CXXRD = ElementType->getAsCXXRecordDecl();
if (!CXXRD)
  return false;

CXXDestructorDecl *Destructor = SemaRef.LookupDestructor(CXXRD);
SemaRef.CheckDestructorAccess(Loc, Destructor,
                              SemaRef.PDiag(diag::err_access_dtor_temp)
                              << ElementType);
SemaRef.MarkFunctionReferenced(Loc, Destructor);
return SemaRef.DiagnoseUseOfDecl(Destructor, Loc);
1854}

1856void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
                                   InitListExpr *IList, QualType &DeclType,
                                   llvm::APSInt elementIndex,
                                   bool SubobjectIsDesignatorContext,
                                   unsigned &Index,
                                   InitListExpr *StructuredList,
                                   unsigned &StructuredIndex) {
const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);

if (!VerifyOnly) {
  if (checkDestructorReference(arrayType->getElementType(),
                               IList->getEndLoc(), SemaRef)) {
    hadError = true;
    return;
  }
}

// Check for the special-case of initializing an array with a string.
if (Index < IList->getNumInits()) {
  if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
      SIF_None) {
    // We place the string literal directly into the resulting
    // initializer list. This is the only place where the structure
    // of the structured initializer list doesn't match exactly,
    // because doing so would involve allocating one character
    // constant for each string.
    // FIXME: Should we do these checks in verify-only mode too?
    if (!VerifyOnly)
      CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
    if (StructuredList) {
      UpdateStructuredListElement(StructuredList, StructuredIndex,
                                  IList->getInit(Index));
      StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
    }
    ++Index;
    return;
  }
}
if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
  // Check for VLAs; in standard C it would be possible to check this
  // earlier, but I don't know where clang accepts VLAs (gcc accepts
  // them in all sorts of strange places).
  if (!VerifyOnly)
    SemaRef.Diag(VAT->getSizeExpr()->getBeginLoc(),
                 diag::err_variable_object_no_init)
        << VAT->getSizeExpr()->getSourceRange();
  hadError = true;
  ++Index;
  ++StructuredIndex;
  return;
}

// We might know the maximum number of elements in advance.
llvm::APSInt maxElements(elementIndex.getBitWidth(),
                         elementIndex.isUnsigned());
bool maxElementsKnown = false;
if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
  maxElements = CAT->getSize();
  elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
  elementIndex.setIsUnsigned(maxElements.isUnsigned());
  maxElementsKnown = true;
}

QualType elementType = arrayType->getElementType();
while (Index < IList->getNumInits()) {
  Expr *Init = IList->getInit(Index);
  if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
    // If we're not the subobject that matches up with the '{' for
    // the designator, we shouldn't be handling the
    // designator. Return immediately.
    if (!SubobjectIsDesignatorContext)
      return;

    // Handle this designated initializer. elementIndex will be
    // updated to be the next array element we'll initialize.
    if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
                                   DeclType, nullptr, &elementIndex, Index,
                                   StructuredList, StructuredIndex, true,
                                   false)) {
      hadError = true;
      continue;
    }

    if (elementIndex.getBitWidth() > maxElements.getBitWidth())
      maxElements = maxElements.extend(elementIndex.getBitWidth());
    else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
      elementIndex = elementIndex.extend(maxElements.getBitWidth());
    elementIndex.setIsUnsigned(maxElements.isUnsigned());

    // If the array is of incomplete type, keep track of the number of
    // elements in the initializer.
    if (!maxElementsKnown && elementIndex > maxElements)
      maxElements = elementIndex;

    continue;
  }

  // If we know the maximum number of elements, and we've already
  // hit it, stop consuming elements in the initializer list.
  if (maxElementsKnown && elementIndex == maxElements)
    break;

  InitializedEntity ElementEntity =
    InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
                                         Entity);
  // Check this element.
  CheckSubElementType(ElementEntity, IList, elementType, Index,
                      StructuredList, StructuredIndex);
  ++elementIndex;

  // If the array is of incomplete type, keep track of the number of
  // elements in the initializer.
  if (!maxElementsKnown && elementIndex > maxElements)
    maxElements = elementIndex;
}
if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
  // If this is an incomplete array type, the actual type needs to
  // be calculated here.
  llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
  if (maxElements == Zero && !Entity.isVariableLengthArrayNew()) {
    // Sizing an array implicitly to zero is not allowed by ISO C,
    // but is supported by GNU.
    SemaRef.Diag(IList->getBeginLoc(), diag::ext_typecheck_zero_array_size);
  }

  DeclType = SemaRef.Context.getConstantArrayType(
      elementType, maxElements, nullptr, ArrayType::Normal, 0);
}
if (!hadError) {
  // If there are any members of the array that get value-initialized, check
  // that is possible. That happens if we know the bound and don't have
  // enough elements, or if we're performing an array new with an unknown
  // bound.
  if ((maxElementsKnown && elementIndex < maxElements) ||
      Entity.isVariableLengthArrayNew())
    CheckEmptyInitializable(
        InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
        IList->getEndLoc());
}
1995}

1997bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
                                           Expr *InitExpr,
                                           FieldDecl *Field,
                                           bool TopLevelObject) {
// Handle GNU flexible array initializers.
unsigned FlexArrayDiag;
if (isa<InitListExpr>(InitExpr) &&
    cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
  // Empty flexible array init always allowed as an extension
  FlexArrayDiag = diag::ext_flexible_array_init;
} else if (!TopLevelObject) {
  // Disallow flexible array init on non-top-level object
  FlexArrayDiag = diag::err_flexible_array_init;
} else if (Entity.getKind() != InitializedEntity::EK_Variable) {
  // Disallow flexible array init on anything which is not a variable.
  FlexArrayDiag = diag::err_flexible_array_init;
} else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
  // Disallow flexible array init on local variables.
  FlexArrayDiag = diag::err_flexible_array_init;
} else {
  // Allow other cases.
  FlexArrayDiag = diag::ext_flexible_array_init;
}

if (!VerifyOnly) {
  SemaRef.Diag(InitExpr->getBeginLoc(), FlexArrayDiag)
      << InitExpr->getBeginLoc();
  SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
    << Field;
}

return FlexArrayDiag != diag::ext_flexible_array_init;
2029}

2031void InitListChecker::CheckStructUnionTypes(
  const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
  CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
  bool SubobjectIsDesignatorContext, unsigned &Index,
  InitListExpr *StructuredList, unsigned &StructuredIndex,
  bool TopLevelObject) {
RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();

// If the record is invalid, some of it's members are invalid. To avoid
// confusion, we forgo checking the initializer for the entire record.
if (structDecl->isInvalidDecl()) {
  // Assume it was supposed to consume a single initializer.
  ++Index;
  hadError = true;
  return;
}

if (DeclType->isUnionType() && IList->getNumInits() == 0) {
  RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();

  if (!VerifyOnly)
    for (FieldDecl *FD : RD->fields()) {
      QualType ET = SemaRef.Context.getBaseElementType(FD->getType());
      if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
        hadError = true;
        return;
      }
    }

  // If there's a default initializer, use it.
  if (isa<CXXRecordDecl>(RD) &&
      cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
    if (!StructuredList)
      return;
    for (RecordDecl::field_iterator FieldEnd = RD->field_end();
         Field != FieldEnd; ++Field) {
      if (Field->hasInClassInitializer()) {
        StructuredList->setInitializedFieldInUnion(*Field);
        // FIXME: Actually build a CXXDefaultInitExpr?
        return;
      }
    }
  }

  // Value-initialize the first member of the union that isn't an unnamed
  // bitfield.
  for (RecordDecl::field_iterator FieldEnd = RD->field_end();
       Field != FieldEnd; ++Field) {
    if (!Field->isUnnamedBitfield()) {
      CheckEmptyInitializable(
          InitializedEntity::InitializeMember(*Field, &Entity),
          IList->getEndLoc());
      if (StructuredList)
        StructuredList->setInitializedFieldInUnion(*Field);
      break;
    }
  }
  return;
}

bool InitializedSomething = false;

// If we have any base classes, they are initialized prior to the fields.
for (auto &Base : Bases) {
  Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;

  // Designated inits always initialize fields, so if we see one, all
  // remaining base classes have no explicit initializer.
  if (Init && isa<DesignatedInitExpr>(Init))
    Init = nullptr;

  SourceLocation InitLoc = Init ? Init->getBeginLoc() : IList->getEndLoc();
  InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
      SemaRef.Context, &Base, false, &Entity);
  if (Init) {
    CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
                        StructuredList, StructuredIndex);
    InitializedSomething = true;
  } else {
    CheckEmptyInitializable(BaseEntity, InitLoc);
  }

  if (!VerifyOnly)
    if (checkDestructorReference(Base.getType(), InitLoc, SemaRef)) {
      hadError = true;
      return;
    }
}

// If structDecl is a forward declaration, this loop won't do
// anything except look at designated initializers; That's okay,
// because an error should get printed out elsewhere. It might be
// worthwhile to skip over the rest of the initializer, though.
RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
RecordDecl::field_iterator FieldEnd = RD->field_end();
size_t NumRecordDecls = llvm::count_if(RD->decls(), [&](const Decl *D) {
  return isa<FieldDecl>(D) || isa<RecordDecl>(D);
});
bool CheckForMissingFields =
  !IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
bool HasDesignatedInit = false;

while (Index < IList->getNumInits()) {
  Expr *Init = IList->getInit(Index);
  SourceLocation InitLoc = Init->getBeginLoc();

  if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
    // If we're not the subobject that matches up with the '{' for
    // the designator, we shouldn't be handling the
    // designator. Return immediately.
    if (!SubobjectIsDesignatorContext)
      return;

    HasDesignatedInit = true;

    // Handle this designated initializer. Field will be updated to
    // the next field that we'll be initializing.
    if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
                                   DeclType, &Field, nullptr, Index,
                                   StructuredList, StructuredIndex,
                                   true, TopLevelObject))
      hadError = true;
    else if (!VerifyOnly) {
      // Find the field named by the designated initializer.
      RecordDecl::field_iterator F = RD->field_begin();
      while (std::next(F) != Field)
        ++F;
      QualType ET = SemaRef.Context.getBaseElementType(F->getType());
      if (checkDestructorReference(ET, InitLoc, SemaRef)) {
        hadError = true;
        return;
      }
    }

    InitializedSomething = true;

    // Disable check for missing fields when designators are used.
    // This matches gcc behaviour.
    CheckForMissingFields = false;
    continue;
  }

  // Check if this is an initializer of forms:
  //
  //   struct foo f = {};
  //   struct foo g = {0};
  //
  // These are okay for randomized structures. [C99 6.7.8p19]
  //
  // Also, if there is only one element in the structure, we allow something
  // like this, because it's really not randomized in the tranditional sense.
  //
  //   struct foo h = {bar};
  auto IsZeroInitializer = [&](const Expr *I) {
    if (IList->getNumInits() == 1) {
      if (NumRecordDecls == 1)
        return true;
      if (const auto *IL = dyn_cast<IntegerLiteral>(I))
        return IL->getValue().isZero();
    }
    return false;
  };

  // Don't allow non-designated initializers on randomized structures.
  if (RD->isRandomized() && !IsZeroInitializer(Init)) {
    if (!VerifyOnly)
      SemaRef.Diag(InitLoc, diag::err_non_designated_init_used);
    hadError = true;
    break;
  }

  if (Field == FieldEnd) {
    // We've run out of fields. We're done.
    break;
  }

  // We've already initialized a member of a union. We're done.
  if (InitializedSomething && DeclType->isUnionType())
    break;

  // If we've hit the flexible array member at the end, we're done.
  if (Field->getType()->isIncompleteArrayType())
    break;

  if (Field->isUnnamedBitfield()) {
    // Don't initialize unnamed bitfields, e.g. "int : 20;"
    ++Field;
    continue;
  }

  // Make sure we can use this declaration.
  bool InvalidUse;
  if (VerifyOnly)
    InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
  else
    InvalidUse = SemaRef.DiagnoseUseOfDecl(
        *Field, IList->getInit(Index)->getBeginLoc());
  if (InvalidUse) {
    ++Index;
    ++Field;
    hadError = true;
    continue;
  }

  if (!VerifyOnly) {
    QualType ET = SemaRef.Context.getBaseElementType(Field->getType());
    if (checkDestructorReference(ET, InitLoc, SemaRef)) {
      hadError = true;
      return;
    }
  }

  InitializedEntity MemberEntity =
    InitializedEntity::InitializeMember(*Field, &Entity);
  CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
                      StructuredList, StructuredIndex);
  InitializedSomething = true;

  if (DeclType->isUnionType() && StructuredList) {
    // Initialize the first field within the union.
    StructuredList->setInitializedFieldInUnion(*Field);
  }

  ++Field;
}

// Emit warnings for missing struct field initializers.
if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
    Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
    !DeclType->isUnionType()) {
  // It is possible we have one or more unnamed bitfields remaining.
  // Find first (if any) named field and emit warning.
  for (RecordDecl::field_iterator it = Field, end = RD->field_end();
       it != end; ++it) {
    if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
      SemaRef.Diag(IList->getSourceRange().getEnd(),
                   diag::warn_missing_field_initializers) << *it;
      break;
    }
  }
}

// Check that any remaining fields can be value-initialized if we're not
// building a structured list. (If we are, we'll check this later.)
if (!StructuredList && Field != FieldEnd && !DeclType->isUnionType() &&
    !Field->getType()->isIncompleteArrayType()) {
  for (; Field != FieldEnd && !hadError; ++Field) {
    if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
      CheckEmptyInitializable(
          InitializedEntity::InitializeMember(*Field, &Entity),
          IList->getEndLoc());
  }
}

// Check that the types of the remaining fields have accessible destructors.
if (!VerifyOnly) {
  // If the initializer expression has a designated initializer, check the
  // elements for which a designated initializer is not provided too.
  RecordDecl::field_iterator I = HasDesignatedInit ? RD->field_begin()
                                                   : Field;
  for (RecordDecl::field_iterator E = RD->field_end(); I != E; ++I) {
    QualType ET = SemaRef.Context.getBaseElementType(I->getType());
    if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
      hadError = true;
      return;
    }
  }
}

if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
    Index >= IList->getNumInits())
  return;

if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
                           TopLevelObject)) {
  hadError = true;
  ++Index;
  return;
}

InitializedEntity MemberEntity =
  InitializedEntity::InitializeMember(*Field, &Entity);

if (isa<InitListExpr>(IList->getInit(Index)))
  CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
                      StructuredList, StructuredIndex);
else
  CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
                        StructuredList, StructuredIndex);
2320}

2322/// Expand a field designator that refers to a member of an
2323/// anonymous struct or union into a series of field designators that
2324/// refers to the field within the appropriate subobject.
2325///
2326static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
                                         DesignatedInitExpr *DIE,
                                         unsigned DesigIdx,
                                         IndirectFieldDecl *IndirectField) {
typedef DesignatedInitExpr::Designator Designator;

// Build the replacement designators.
SmallVector<Designator, 4> Replacements;
for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
     PE = IndirectField->chain_end(); PI != PE; ++PI) {
  if (PI + 1 == PE)
    Replacements.push_back(Designator((IdentifierInfo *)nullptr,
                                  DIE->getDesignator(DesigIdx)->getDotLoc(),
                              DIE->getDesignator(DesigIdx)->getFieldLoc()));
  else
    Replacements.push_back(Designator((IdentifierInfo *)nullptr,
                                      SourceLocation(), SourceLocation()));
  assert(isa<FieldDecl>(*PI))(static_cast <bool> (isa<FieldDecl>(*PI)) ? void (
0) : __assert_fail ("isa<FieldDecl>(*PI)", "clang/lib/Sema/SemaInit.cpp"
, 2343, __extension__ __PRETTY_FUNCTION__));
  Replacements.back().setField(cast<FieldDecl>(*PI));
}

// Expand the current designator into the set of replacement
// designators, so we have a full subobject path down to where the
// member of the anonymous struct/union is actually stored.
DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
                      &Replacements[0] + Replacements.size());
2352}

2354static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
                                                 DesignatedInitExpr *DIE) {
unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
for (unsigned I = 0; I < NumIndexExprs; ++I)
  IndexExprs[I] = DIE->getSubExpr(I + 1);
return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
                                  IndexExprs,
                                  DIE->getEqualOrColonLoc(),
                                  DIE->usesGNUSyntax(), DIE->getInit());
2364}

2366namespace {

2368// Callback to only accept typo corrections that are for field members of
2369// the given struct or union.
2370class FieldInitializerValidatorCCC final : public CorrectionCandidateCallback {
public:
explicit FieldInitializerValidatorCCC(RecordDecl *RD)
    : Record(RD) {}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
  return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<FieldInitializerValidatorCCC>(*this);
}

private:
RecordDecl *Record;
2386};

2388} // end anonymous namespace

2390/// Check the well-formedness of a C99 designated initializer.
2391///
2392/// Determines whether the designated initializer @p DIE, which
2393/// resides at the given @p Index within the initializer list @p
2394/// IList, is well-formed for a current object of type @p DeclType
2395/// (C99 6.7.8). The actual subobject that this designator refers to
2396/// within the current subobject is returned in either
2397/// @p NextField or @p NextElementIndex (whichever is appropriate).
2398///
2399/// @param IList  The initializer list in which this designated
2400/// initializer occurs.
2401///
2402/// @param DIE The designated initializer expression.
2403///
2404/// @param DesigIdx  The index of the current designator.
2405///
2406/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
2407/// into which the designation in @p DIE should refer.
2408///
2409/// @param NextField  If non-NULL and the first designator in @p DIE is
2410/// a field, this will be set to the field declaration corresponding
2411/// to the field named by the designator. On input, this is expected to be
2412/// the next field that would be initialized in the absence of designation,
2413/// if the complete object being initialized is a struct.
2414///
2415/// @param NextElementIndex  If non-NULL and the first designator in @p
2416/// DIE is an array designator or GNU array-range designator, this
2417/// will be set to the last index initialized by this designator.
2418///
2419/// @param Index  Index into @p IList where the designated initializer
2420/// @p DIE occurs.
2421///
2422/// @param StructuredList  The initializer list expression that
2423/// describes all of the subobject initializers in the order they'll
2424/// actually be initialized.
2425///
2426/// @returns true if there was an error, false otherwise.
2427bool
2428InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
                                          InitListExpr *IList,
                                          DesignatedInitExpr *DIE,
                                          unsigned DesigIdx,
                                          QualType &CurrentObjectType,
                                        RecordDecl::field_iterator *NextField,
                                          llvm::APSInt *NextElementIndex,
                                          unsigned &Index,
                                          InitListExpr *StructuredList,
                                          unsigned &StructuredIndex,
                                          bool FinishSubobjectInit,
                                          bool TopLevelObject) {
if (DesigIdx == DIE->size()) {
  // C++20 designated initialization can result in direct-list-initialization
  // of the designated subobject. This is the only way that we can end up
  // performing direct initialization as part of aggregate initialization, so
  // it needs special handling.
  if (DIE->isDirectInit()) {
    Expr *Init = DIE->getInit();
    assert(isa<InitListExpr>(Init) &&(static_cast <bool> (isa<InitListExpr>(Init) &&
 "designator result in direct non-list initialization?") ? void
 (0) : __assert_fail ("isa<InitListExpr>(Init) && \"designator result in direct non-list initialization?\""
, "clang/lib/Sema/SemaInit.cpp", 2448, __extension__ __PRETTY_FUNCTION__
))
           "designator result in direct non-list initialization?")(static_cast <bool> (isa<InitListExpr>(Init) &&
 "designator result in direct non-list initialization?") ? void
 (0) : __assert_fail ("isa<InitListExpr>(Init) && \"designator result in direct non-list initialization?\""
, "clang/lib/Sema/SemaInit.cpp", 2448, __extension__ __PRETTY_FUNCTION__
));
    InitializationKind Kind = InitializationKind::CreateDirectList(
        DIE->getBeginLoc(), Init->getBeginLoc(), Init->getEndLoc());
    InitializationSequence Seq(SemaRef, Entity, Kind, Init,
                               /*TopLevelOfInitList*/ true);
    if (StructuredList) {
      ExprResult Result = VerifyOnly
                              ? getDummyInit()
                              : Seq.Perform(SemaRef, Entity, Kind, Init);
      UpdateStructuredListElement(StructuredList, StructuredIndex,
                                  Result.get());
    }
    ++Index;
    return !Seq;
  }

  // Check the actual initialization for the designated object type.
  bool prevHadError = hadError;

  // Temporarily remove the designator expression from the
  // initializer list that the child calls see, so that we don't try
  // to re-process the designator.
  unsigned OldIndex = Index;
  IList->setInit(OldIndex, DIE->getInit());

  CheckSubElementType(Entity, IList, CurrentObjectType, Index, StructuredList,
                      StructuredIndex, /*DirectlyDesignated=*/true);

  // Restore the designated initializer expression in the syntactic
  // form of the initializer list.
  if (IList->getInit(OldIndex) != DIE->getInit())
    DIE->setInit(IList->getInit(OldIndex));
  IList->setInit(OldIndex, DIE);

  return hadError && !prevHadError;
}

DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
bool IsFirstDesignator = (DesigIdx == 0);
if (IsFirstDesignator ? FullyStructuredList : StructuredList) {
  // Determine the structural initializer list that corresponds to the
  // current subobject.
  if (IsFirstDesignator)
    StructuredList = FullyStructuredList;
  else {
    Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
        StructuredList->getInit(StructuredIndex) : nullptr;
    if (!ExistingInit && StructuredList->hasArrayFiller())
      ExistingInit = StructuredList->getArrayFiller();

    if (!ExistingInit)
      StructuredList = getStructuredSubobjectInit(
          IList, Index, CurrentObjectType, StructuredList, StructuredIndex,
          SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
    else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
      StructuredList = Result;
    else {
      // We are creating an initializer list that initializes the
      // subobjects of the current object, but there was already an
      // initialization that completely initialized the current
      // subobject, e.g., by a compound literal:
      //
      // struct X { int a, b; };
      // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
      //
      // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
      // designated initializer re-initializes only its current object
      // subobject [0].b.
      diagnoseInitOverride(ExistingInit,
                           SourceRange(D->getBeginLoc(), DIE->getEndLoc()),
                           /*FullyOverwritten=*/false);

      if (!VerifyOnly) {
        if (DesignatedInitUpdateExpr *E =
                dyn_cast<DesignatedInitUpdateExpr>(ExistingInit))
          StructuredList = E->getUpdater();
        else {
          DesignatedInitUpdateExpr *DIUE = new (SemaRef.Context)
              DesignatedInitUpdateExpr(SemaRef.Context, D->getBeginLoc(),
                                       ExistingInit, DIE->getEndLoc());
          StructuredList->updateInit(SemaRef.Context, StructuredIndex, DIUE);
          StructuredList = DIUE->getUpdater();
        }
      } else {
        // We don't need to track the structured representation of a
        // designated init update of an already-fully-initialized object in
        // verify-only mode. The only reason we would need the structure is
        // to determine where the uninitialized "holes" are, and in this
        // case, we know there aren't any and we can't introduce any.
        StructuredList = nullptr;
      }
    }
  }
}

if (D->isFieldDesignator()) {
  // C99 6.7.8p7:
  //
  //   If a designator has the form
  //
  //      . identifier
  //
  //   then the current object (defined below) shall have
  //   structure or union type and the identifier shall be the
  //   name of a member of that type.
  const RecordType *RT = CurrentObjectType->getAs<RecordType>();
  if (!RT) {
    SourceLocation Loc = D->getDotLoc();
    if (Loc.isInvalid())
      Loc = D->getFieldLoc();
    if (!VerifyOnly)
      SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
        << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
    ++Index;
    return true;
  }

  FieldDecl *KnownField = D->getField();
  if (!KnownField) {
    IdentifierInfo *FieldName = D->getFieldName();
    DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
    for (NamedDecl *ND : Lookup) {
      if (auto *FD = dyn_cast<FieldDecl>(ND)) {
        KnownField = FD;
        break;
      }
      if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
        // In verify mode, don't modify the original.
        if (VerifyOnly)
          DIE = CloneDesignatedInitExpr(SemaRef, DIE);
        ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
        D = DIE->getDesignator(DesigIdx);
        KnownField = cast<FieldDecl>(*IFD->chain_begin());
        break;
      }
    }
    if (!KnownField) {
      if (VerifyOnly) {
        ++Index;
        return true;  // No typo correction when just trying this out.
      }

      // Name lookup found something, but it wasn't a field.
      if (!Lookup.empty()) {
        SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
          << FieldName;
        SemaRef.Diag(Lookup.front()->getLocation(),
                     diag::note_field_designator_found);
        ++Index;
        return true;
      }

      // Name lookup didn't find anything.
      // Determine whether this was a typo for another field name.
      FieldInitializerValidatorCCC CCC(RT->getDecl());
      if (TypoCorrection Corrected = SemaRef.CorrectTypo(
              DeclarationNameInfo(FieldName, D->getFieldLoc()),
              Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr, CCC,
              Sema::CTK_ErrorRecovery, RT->getDecl())) {
        SemaRef.diagnoseTypo(
            Corrected,
            SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
              << FieldName << CurrentObjectType);
        KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
        hadError = true;
      } else {
        // Typo correction didn't find anything.
        SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
          << FieldName << CurrentObjectType;
        ++Index;
        return true;
      }
    }
  }

  unsigned NumBases = 0;
  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
    NumBases = CXXRD->getNumBases();

  unsigned FieldIndex = NumBases;

  for (auto *FI : RT->getDecl()->fields()) {
    if (FI->isUnnamedBitfield())
      continue;
    if (declaresSameEntity(KnownField, FI)) {
      KnownField = FI;
      break;
    }
    ++FieldIndex;
  }

  RecordDecl::field_iterator Field =
      RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));

  // All of the fields of a union are located at the same place in
  // the initializer list.
  if (RT->getDecl()->isUnion()) {
    FieldIndex = 0;
    if (StructuredList) {
      FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
      if (CurrentField && !declaresSameEntity(CurrentField, *Field)) {
        assert(StructuredList->getNumInits() == 1(static_cast <bool> (StructuredList->getNumInits() ==
&& "A union should never have more than one initializer!"
) ? void (0) : __assert_fail ("StructuredList->getNumInits() == 1 && \"A union should never have more than one initializer!\""
, "clang/lib/Sema/SemaInit.cpp", 2650, __extension__ __PRETTY_FUNCTION__
))
               && "A union should never have more than one initializer!")(static_cast <bool> (StructuredList->getNumInits() ==
&& "A union should never have more than one initializer!"
) ? void (0) : __assert_fail ("StructuredList->getNumInits() == 1 && \"A union should never have more than one initializer!\""
, "clang/lib/Sema/SemaInit.cpp", 2650, __extension__ __PRETTY_FUNCTION__
));

        Expr *ExistingInit = StructuredList->getInit(0);
        if (ExistingInit) {
          // We're about to throw away an initializer, emit warning.
          diagnoseInitOverride(
              ExistingInit, SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
        }

        // remove existing initializer
        StructuredList->resizeInits(SemaRef.Context, 0);
        StructuredList->setInitializedFieldInUnion(nullptr);
      }

      StructuredList->setInitializedFieldInUnion(*Field);
    }
  }

  // Make sure we can use this declaration.
  bool InvalidUse;
  if (VerifyOnly)
    InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
  else
    InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
  if (InvalidUse) {
    ++Index;
    return true;
  }

  // C++20 [dcl.init.list]p3:
  //   The ordered identifiers in the designators of the designated-
  //   initializer-list shall form a subsequence of the ordered identifiers
  //   in the direct non-static data members of T.
  //
  // Note that this is not a condition on forming the aggregate
  // initialization, only on actually performing initialization,
  // so it is not checked in VerifyOnly mode.
  //
  // FIXME: This is the only reordering diagnostic we produce, and it only
  // catches cases where we have a top-level field designator that jumps
  // backwards. This is the only such case that is reachable in an
  // otherwise-valid C++20 program, so is the only case that's required for
  // conformance, but for consistency, we should diagnose all the other
  // cases where a designator takes us backwards too.
  if (IsFirstDesignator && !VerifyOnly && SemaRef.getLangOpts().CPlusPlus &&
      NextField &&
      (*NextField == RT->getDecl()->field_end() ||
       (*NextField)->getFieldIndex() > Field->getFieldIndex() + 1)) {
    // Find the field that we just initialized.
    FieldDecl *PrevField = nullptr;
    for (auto FI = RT->getDecl()->field_begin();
         FI != RT->getDecl()->field_end(); ++FI) {
      if (FI->isUnnamedBitfield())
        continue;
      if (*NextField != RT->getDecl()->field_end() &&
          declaresSameEntity(*FI, **NextField))
        break;
      PrevField = *FI;
    }

    if (PrevField &&
        PrevField->getFieldIndex() > KnownField->getFieldIndex()) {
      SemaRef.Diag(DIE->getBeginLoc(), diag::ext_designated_init_reordered)
          << KnownField << PrevField << DIE->getSourceRange();

      unsigned OldIndex = NumBases + PrevField->getFieldIndex();
      if (StructuredList && OldIndex <= StructuredList->getNumInits()) {
        if (Expr *PrevInit = StructuredList->getInit(OldIndex)) {
          SemaRef.Diag(PrevInit->getBeginLoc(),
                       diag::note_previous_field_init)
              << PrevField << PrevInit->getSourceRange();
        }
      }
    }
  }


  // Update the designator with the field declaration.
  if (!VerifyOnly)
    D->setField(*Field);

  // Make sure that our non-designated initializer list has space
  // for a subobject corresponding to this field.
  if (StructuredList && FieldIndex >= StructuredList->getNumInits())
    StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);

  // This designator names a flexible array member.
  if (Field->getType()->isIncompleteArrayType()) {
    bool Invalid = false;
    if ((DesigIdx + 1) != DIE->size()) {
      // We can't designate an object within the flexible array
      // member (because GCC doesn't allow it).
      if (!VerifyOnly) {
        DesignatedInitExpr::Designator *NextD
          = DIE->getDesignator(DesigIdx + 1);
        SemaRef.Diag(NextD->getBeginLoc(),
                     diag::err_designator_into_flexible_array_member)
            << SourceRange(NextD->getBeginLoc(), DIE->getEndLoc());
        SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
          << *Field;
      }
      Invalid = true;
    }

    if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
        !isa<StringLiteral>(DIE->getInit())) {
      // The initializer is not an initializer list.
      if (!VerifyOnly) {
        SemaRef.Diag(DIE->getInit()->getBeginLoc(),
                     diag::err_flexible_array_init_needs_braces)
            << DIE->getInit()->getSourceRange();
        SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
          << *Field;
      }
      Invalid = true;
    }

    // Check GNU flexible array initializer.
    if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
                                           TopLevelObject))
      Invalid = true;

    if (Invalid) {
      ++Index;
      return true;
    }

    // Initialize the array.
    bool prevHadError = hadError;
    unsigned newStructuredIndex = FieldIndex;
    unsigned OldIndex = Index;
    IList->setInit(Index, DIE->getInit());

    InitializedEntity MemberEntity =
      InitializedEntity::InitializeMember(*Field, &Entity);
    CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
                        StructuredList, newStructuredIndex);

    IList->setInit(OldIndex, DIE);
    if (hadError && !prevHadError) {
      ++Field;
      ++FieldIndex;
      if (NextField)
        *NextField = Field;
      StructuredIndex = FieldIndex;
      return true;
    }
  } else {
    // Recurse to check later designated subobjects.
    QualType FieldType = Field->getType();
    unsigned newStructuredIndex = FieldIndex;

    InitializedEntity MemberEntity =
      InitializedEntity::InitializeMember(*Field, &Entity);
    if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
                                   FieldType, nullptr, nullptr, Index,
                                   StructuredList, newStructuredIndex,
                                   FinishSubobjectInit, false))
      return true;
  }

  // Find the position of the next field to be initialized in this
  // subobject.
  ++Field;
  ++FieldIndex;

  // If this the first designator, our caller will continue checking
  // the rest of this struct/class/union subobject.
  if (IsFirstDesignator) {
    if (NextField)
      *NextField = Field;
    StructuredIndex = FieldIndex;
    return false;
  }

  if (!FinishSubobjectInit)
    return false;

  // We've already initialized something in the union; we're done.
  if (RT->getDecl()->isUnion())
    return hadError;

  // Check the remaining fields within this class/struct/union subobject.
  bool prevHadError = hadError;

  auto NoBases =
      CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
                                      CXXRecordDecl::base_class_iterator());
  CheckStructUnionTypes(Entity, IList, CurrentObjectType, NoBases, Field,
                        false, Index, StructuredList, FieldIndex);
  return hadError && !prevHadError;
}

// C99 6.7.8p6:
//
//   If a designator has the form
//
//      [ constant-expression ]
//
//   then the current object (defined below) shall have array
//   type and the expression shall be an integer constant
//   expression. If the array is of unknown size, any
//   nonnegative value is valid.
//
// Additionally, cope with the GNU extension that permits
// designators of the form
//
//      [ constant-expression ... constant-expression ]
const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
if (!AT) {
  if (!VerifyOnly)
    SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
      << CurrentObjectType;
  ++Index;
  return true;
}

Expr *IndexExpr = nullptr;
llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
if (D->isArrayDesignator()) {
  IndexExpr = DIE->getArrayIndex(*D);
  DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
  DesignatedEndIndex = DesignatedStartIndex;
} else {
  assert(D->isArrayRangeDesignator() && "Need array-range designator")(static_cast <bool> (D->isArrayRangeDesignator() &&
 "Need array-range designator") ? void (0) : __assert_fail ("D->isArrayRangeDesignator() && \"Need array-range designator\""
, "clang/lib/Sema/SemaInit.cpp", 2874, __extension__ __PRETTY_FUNCTION__
));

  DesignatedStartIndex =
    DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
  DesignatedEndIndex =
    DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
  IndexExpr = DIE->getArrayRangeEnd(*D);

  // Codegen can't handle evaluating array range designators that have side
  // effects, because we replicate the AST value for each initialized element.
  // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
  // elements with something that has a side effect, so codegen can emit an
  // "error unsupported" error instead of miscompiling the app.
  if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
      DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
    FullyStructuredList->sawArrayRangeDesignator();
}

if (isa<ConstantArrayType>(AT)) {
  llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
  DesignatedStartIndex
    = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
  DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
  DesignatedEndIndex
    = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
  DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
  if (DesignatedEndIndex >= MaxElements) {
    if (!VerifyOnly)
      SemaRef.Diag(IndexExpr->getBeginLoc(),
                   diag::err_array_designator_too_large)
          << toString(DesignatedEndIndex, 10) << toString(MaxElements, 10)
          << IndexExpr->getSourceRange();
    ++Index;
    return true;
  }
} else {
  unsigned DesignatedIndexBitWidth =
    ConstantArrayType::getMaxSizeBits(SemaRef.Context);
  DesignatedStartIndex =
    DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
  DesignatedEndIndex =
    DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
  DesignatedStartIndex.setIsUnsigned(true);
  DesignatedEndIndex.setIsUnsigned(true);
}

bool IsStringLiteralInitUpdate =
    StructuredList && StructuredList->isStringLiteralInit();
if (IsStringLiteralInitUpdate && VerifyOnly) {
  // We're just verifying an update to a string literal init. We don't need
  // to split the string up into individual characters to do that.
  StructuredList = nullptr;
} else if (IsStringLiteralInitUpdate) {
  // We're modifying a string literal init; we have to decompose the string
  // so we can modify the individual characters.
  ASTContext &Context = SemaRef.Context;
  Expr *SubExpr = StructuredList->getInit(0)->IgnoreParenImpCasts();

  // Compute the character type
  QualType CharTy = AT->getElementType();

  // Compute the type of the integer literals.
  QualType PromotedCharTy = CharTy;
  if (CharTy->isPromotableIntegerType())
    PromotedCharTy = Context.getPromotedIntegerType(CharTy);
  unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);

  if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
    // Get the length of the string.
    uint64_t StrLen = SL->getLength();
    if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
      StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
    StructuredList->resizeInits(Context, StrLen);

    // Build a literal for each character in the string, and put them into
    // the init list.
    for (unsigned i = 0, e = StrLen; i != e; ++i) {
      llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
      Expr *Init = new (Context) IntegerLiteral(
          Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
      if (CharTy != PromotedCharTy)
        Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
                                        Init, nullptr, VK_PRValue,
                                        FPOptionsOverride());
      StructuredList->updateInit(Context, i, Init);
    }
  } else {
    ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
    std::string Str;
    Context.getObjCEncodingForType(E->getEncodedType(), Str);

    // Get the length of the string.
    uint64_t StrLen = Str.size();
    if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
      StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
    StructuredList->resizeInits(Context, StrLen);

    // Build a literal for each character in the string, and put them into
    // the init list.
    for (unsigned i = 0, e = StrLen; i != e; ++i) {
      llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
      Expr *Init = new (Context) IntegerLiteral(
          Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
      if (CharTy != PromotedCharTy)
        Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
                                        Init, nullptr, VK_PRValue,
                                        FPOptionsOverride());
      StructuredList->updateInit(Context, i, Init);
    }
  }
}

// Make sure that our non-designated initializer list has space
// for a subobject corresponding to this array element.
if (StructuredList &&
    DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
  StructuredList->resizeInits(SemaRef.Context,
                              DesignatedEndIndex.getZExtValue() + 1);

// Repeatedly perform subobject initializations in the range
// [DesignatedStartIndex, DesignatedEndIndex].

// Move to the next designator
unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
unsigned OldIndex = Index;

InitializedEntity ElementEntity =
  InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);

while (DesignatedStartIndex <= DesignatedEndIndex) {
  // Recurse to check later designated subobjects.
  QualType ElementType = AT->getElementType();
  Index = OldIndex;

  ElementEntity.setElementIndex(ElementIndex);
  if (CheckDesignatedInitializer(
          ElementEntity, IList, DIE, DesigIdx + 1, ElementType, nullptr,
          nullptr, Index, StructuredList, ElementIndex,
          FinishSubobjectInit && (DesignatedStartIndex == DesignatedEndIndex),
          false))
    return true;

  // Move to the next index in the array that we'll be initializing.
  ++DesignatedStartIndex;
  ElementIndex = DesignatedStartIndex.getZExtValue();
}

// If this the first designator, our caller will continue checking
// the rest of this array subobject.
if (IsFirstDesignator) {
  if (NextElementIndex)
    *NextElementIndex = DesignatedStartIndex;
  StructuredIndex = ElementIndex;
  return false;
}

if (!FinishSubobjectInit)
  return false;

// Check the remaining elements within this array subobject.
bool prevHadError = hadError;
CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
               /*SubobjectIsDesignatorContext=*/false, Index,
               StructuredList, ElementIndex);
return hadError && !prevHadError;
3039}

3041// Get the structured initializer list for a subobject of type
3042// @p CurrentObjectType.
3043InitListExpr *
3044InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
                                          QualType CurrentObjectType,
                                          InitListExpr *StructuredList,
                                          unsigned StructuredIndex,
                                          SourceRange InitRange,
                                          bool IsFullyOverwritten) {
if (!StructuredList)
  return nullptr;

Expr *ExistingInit = nullptr;
if (StructuredIndex < StructuredList->getNumInits())
  ExistingInit = StructuredList->getInit(StructuredIndex);

if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
  // There might have already been initializers for subobjects of the current
  // object, but a subsequent initializer list will overwrite the entirety
  // of the current object. (See DR 253 and C99 6.7.8p21). e.g.,
  //
  // struct P { char x[6]; };
  // struct P l = { .x[2] = 'x', .x = { [0] = 'f' } };
  //
  // The first designated initializer is ignored, and l.x is just "f".
  if (!IsFullyOverwritten)
    return Result;

if (ExistingInit) {
  // We are creating an initializer list that initializes the
  // subobjects of the current object, but there was already an
  // initialization that completely initialized the current
  // subobject:
  //
  // struct X { int a, b; };
  // struct X xs[] = { [0] = { 1, 2 }, [0].b = 3 };
  //
  // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
  // designated initializer overwrites the [0].b initializer
  // from the prior initialization.
  //
  // When the existing initializer is an expression rather than an
  // initializer list, we cannot decompose and update it in this way.
  // For example:
  //
  // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
  //
  // This case is handled by CheckDesignatedInitializer.
  diagnoseInitOverride(ExistingInit, InitRange);
}

unsigned ExpectedNumInits = 0;
if (Index < IList->getNumInits()) {
  if (auto *Init = dyn_cast_or_null<InitListExpr>(IList->getInit(Index)))
    ExpectedNumInits = Init->getNumInits();
  else
    ExpectedNumInits = IList->getNumInits() - Index;
}

InitListExpr *Result =
    createInitListExpr(CurrentObjectType, InitRange, ExpectedNumInits);

// Link this new initializer list into the structured initializer
// lists.
StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
return Result;
3107}

3109InitListExpr *
3110InitListChecker::createInitListExpr(QualType CurrentObjectType,
                                  SourceRange InitRange,
                                  unsigned ExpectedNumInits) {
InitListExpr *Result
  = new (SemaRef.Context) InitListExpr(SemaRef.Context,
                                       InitRange.getBegin(), None,
                                       InitRange.getEnd());

QualType ResultType = CurrentObjectType;
if (!ResultType->isArrayType())
  ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
Result->setType(ResultType);

// Pre-allocate storage for the structured initializer list.
unsigned NumElements = 0;

if (const ArrayType *AType
    = SemaRef.Context.getAsArrayType(CurrentObjectType)) {
  if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
    NumElements = CAType->getSize().getZExtValue();
    // Simple heuristic so that we don't allocate a very large
    // initializer with many empty entries at the end.
    if (NumElements > ExpectedNumInits)
      NumElements = 0;
  }
} else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) {
  NumElements = VType->getNumElements();
} else if (CurrentObjectType->isRecordType()) {
  NumElements = numStructUnionElements(CurrentObjectType);
}

Result->reserveInits(SemaRef.Context, NumElements);

return Result;
3144}

3146/// Update the initializer at index @p StructuredIndex within the
3147/// structured initializer list to the value @p expr.
3148void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
                                                unsigned &StructuredIndex,
                                                Expr *expr) {
// No structured initializer list to update
if (!StructuredList)
  return;

if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
                                                StructuredIndex, expr)) {
  // This initializer overwrites a previous initializer.
  // No need to diagnose when `expr` is nullptr because a more relevant
  // diagnostic has already been issued and this diagnostic is potentially
  // noise.
  if (expr)
    diagnoseInitOverride(PrevInit, expr->getSourceRange());
}

++StructuredIndex;
3166}

3168/// Determine whether we can perform aggregate initialization for the purposes
3169/// of overload resolution.
3170bool Sema::CanPerformAggregateInitializationForOverloadResolution(
  const InitializedEntity &Entity, InitListExpr *From) {
QualType Type = Entity.getType();
InitListChecker Check(*this, Entity, From, Type, /*VerifyOnly=*/true,
                      /*TreatUnavailableAsInvalid=*/false,
                      /*InOverloadResolution=*/true);
return !Check.HadError();
3177}

3179/// Check that the given Index expression is a valid array designator
3180/// value. This is essentially just a wrapper around
3181/// VerifyIntegerConstantExpression that also checks for negative values
3182/// and produces a reasonable diagnostic if there is a
3183/// failure. Returns the index expression, possibly with an implicit cast
3184/// added, on success.  If everything went okay, Value will receive the
3185/// value of the constant expression.
3186static ExprResult
3187CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
SourceLocation Loc = Index->getBeginLoc();

// Make sure this is an integer constant expression.
ExprResult Result =
    S.VerifyIntegerConstantExpression(Index, &Value, Sema::AllowFold);
if (Result.isInvalid())
  return Result;

if (Value.isSigned() && Value.isNegative())
  return S.Diag(Loc, diag::err_array_designator_negative)
         << toString(Value, 10) << Index->getSourceRange();

Value.setIsUnsigned(true);
return Result;
3202}

3204ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
                                          SourceLocation EqualOrColonLoc,
                                          bool GNUSyntax,
                                          ExprResult Init) {
typedef DesignatedInitExpr::Designator ASTDesignator;

bool Invalid = false;
SmallVector<ASTDesignator, 32> Designators;
SmallVector<Expr *, 32> InitExpressions;

// Build designators and check array designator expressions.
for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
  const Designator &D = Desig.getDesignator(Idx);
  switch (D.getKind()) {
  case Designator::FieldDesignator:
    Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
                                        D.getFieldLoc()));
    break;

  case Designator::ArrayDesignator: {
    Expr *Index = static_cast<Expr *>(D.getArrayIndex());
    llvm::APSInt IndexValue;
    if (!Index->isTypeDependent() && !Index->isValueDependent())
      Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
    if (!Index)
      Invalid = true;
    else {
      Designators.push_back(ASTDesignator(InitExpressions.size(),
                                          D.getLBracketLoc(),
                                          D.getRBracketLoc()));
      InitExpressions.push_back(Index);
    }
    break;
  }

  case Designator::ArrayRangeDesignator: {
    Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
    Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
    llvm::APSInt StartValue;
    llvm::APSInt EndValue;
    bool StartDependent = StartIndex->isTypeDependent() ||
                          StartIndex->isValueDependent();
    bool EndDependent = EndIndex->isTypeDependent() ||
                        EndIndex->isValueDependent();
    if (!StartDependent)
      StartIndex =
          CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
    if (!EndDependent)
      EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();

    if (!StartIndex || !EndIndex)
      Invalid = true;
    else {
      // Make sure we're comparing values with the same bit width.
      if (StartDependent || EndDependent) {
        // Nothing to compute.
      } else if (StartValue.getBitWidth() > EndValue.getBitWidth())
        EndValue = EndValue.extend(StartValue.getBitWidth());
      else if (StartValue.getBitWidth() < EndValue.getBitWidth())
        StartValue = StartValue.extend(EndValue.getBitWidth());

      if (!StartDependent && !EndDependent && EndValue < StartValue) {
        Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
          << toString(StartValue, 10) << toString(EndValue, 10)
          << StartIndex->getSourceRange() << EndIndex->getSourceRange();
        Invalid = true;
      } else {
        Designators.push_back(ASTDesignator(InitExpressions.size(),
                                            D.getLBracketLoc(),
                                            D.getEllipsisLoc(),
                                            D.getRBracketLoc()));
        InitExpressions.push_back(StartIndex);
        InitExpressions.push_back(EndIndex);
      }
    }
    break;
  }
  }
}

if (Invalid || Init.isInvalid())
  return ExprError();

// Clear out the expressions within the designation.
Desig.ClearExprs(*this);

return DesignatedInitExpr::Create(Context, Designators, InitExpressions,
                                  EqualOrColonLoc, GNUSyntax,
                                  Init.getAs<Expr>());
3293}

3295//===----------------------------------------------------------------------===//
3296// Initialization entity
3297//===----------------------------------------------------------------------===//

3299InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
                                   const InitializedEntity &Parent)
: Parent(&Parent), Index(Index)
3302{
if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
  Kind = EK_ArrayElement;
  Type = AT->getElementType();
} else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
  Kind = EK_VectorElement;
  Type = VT->getElementType();
} else {
  const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
  assert(CT && "Unexpected type")(static_cast <bool> (CT && "Unexpected type") ?
 void (0) : __assert_fail ("CT && \"Unexpected type\""
, "clang/lib/Sema/SemaInit.cpp", 3311, __extension__ __PRETTY_FUNCTION__
));
  Kind = EK_ComplexElement;
  Type = CT->getElementType();
}
3315}

3317InitializedEntity
3318InitializedEntity::InitializeBase(ASTContext &Context,
                                const CXXBaseSpecifier *Base,
                                bool IsInheritedVirtualBase,
                                const InitializedEntity *Parent) {
InitializedEntity Result;
Result.Kind = EK_Base;
Result.Parent = Parent;
Result.Base = {Base, IsInheritedVirtualBase};
Result.Type = Base->getType();
return Result;
3328}

3330DeclarationName InitializedEntity::getName() const {
switch (getKind()) {
case EK_Parameter:
case EK_Parameter_CF_Audited: {
  ParmVarDecl *D = Parameter.getPointer();
  return (D ? D->getDeclName() : DeclarationName());
}

case EK_Variable:
case EK_Member:
case EK_Binding:
case EK_TemplateParameter:
  return Variable.VariableOrMember->getDeclName();

case EK_LambdaCapture:
  return DeclarationName(Capture.VarID);

case EK_Result:
case EK_StmtExprResult:
case EK_Exception:
case EK_New:
case EK_Temporary:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_LambdaToBlockConversionBlockElement:
case EK_CompoundLiteralInit:
case EK_RelatedResult:
  return DeclarationName();
}

llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3364);
3365}

3367ValueDecl *InitializedEntity::getDecl() const {
switch (getKind()) {
case EK_Variable:
case EK_Member:
case EK_Binding:
case EK_TemplateParameter:
  return Variable.VariableOrMember;

case EK_Parameter:
case EK_Parameter_CF_Audited:
  return Parameter.getPointer();

case EK_Result:
case EK_StmtExprResult:
case EK_Exception:
case EK_New:
case EK_Temporary:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_LambdaToBlockConversionBlockElement:
case EK_LambdaCapture:
case EK_CompoundLiteralInit:
case EK_RelatedResult:
  return nullptr;
}

llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3397);
3398}

3400bool InitializedEntity::allowsNRVO() const {
switch (getKind()) {
case EK_Result:
case EK_Exception:
  return LocAndNRVO.NRVO;

case EK_StmtExprResult:
case EK_Variable:
case EK_Parameter:
case EK_Parameter_CF_Audited:
case EK_TemplateParameter:
case EK_Member:
case EK_Binding:
case EK_New:
case EK_Temporary:
case EK_CompoundLiteralInit:
case EK_Base:
case EK_Delegating:
case EK_ArrayElement:
case EK_VectorElement:
case EK_ComplexElement:
case EK_BlockElement:
case EK_LambdaToBlockConversionBlockElement:
case EK_LambdaCapture:
case EK_RelatedResult:
  break;
}

return false;
3429}

3431unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
assert(getParent() != this)(static_cast <bool> (getParent() != this) ? void (0) : __assert_fail
 ("getParent() != this", "clang/lib/Sema/SemaInit.cpp", 3432,
 __extension__ __PRETTY_FUNCTION__));
unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
for (unsigned I = 0; I != Depth; ++I)
  OS << "`-";

switch (getKind()) {
case EK_Variable: OS << "Variable"; break;
case EK_Parameter: OS << "Parameter"; break;
case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
  break;
case EK_TemplateParameter: OS << "TemplateParameter"; break;
case EK_Result: OS << "Result"; break;
case EK_StmtExprResult: OS << "StmtExprResult"; break;
case EK_Exception: OS << "Exception"; break;
case EK_Member: OS << "Member"; break;
case EK_Binding: OS << "Binding"; break;
case EK_New: OS << "New"; break;
case EK_Temporary: OS << "Temporary"; break;
case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
case EK_RelatedResult: OS << "RelatedResult"; break;
case EK_Base: OS << "Base"; break;
case EK_Delegating: OS << "Delegating"; break;
case EK_ArrayElement: OS << "ArrayElement " << Index; break;
case EK_VectorElement: OS << "VectorElement " << Index; break;
case EK_ComplexElement: OS << "ComplexElement " << Index; break;
case EK_BlockElement: OS << "Block"; break;
case EK_LambdaToBlockConversionBlockElement:
  OS << "Block (lambda)";
  break;
case EK_LambdaCapture:
  OS << "LambdaCapture ";
  OS << DeclarationName(Capture.VarID);
  break;
}

if (auto *D = getDecl()) {
  OS << " ";
  D->printQualifiedName(OS);
}

OS << " '" << getType() << "'\n";

return Depth + 1;
3475}

3477LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void InitializedEntity::dump() const {
dumpImpl(llvm::errs());
3479}

3481//===----------------------------------------------------------------------===//
3482// Initialization sequence
3483//===----------------------------------------------------------------------===//

3485void InitializationSequence::Step::Destroy() {
switch (Kind) {
case SK_ResolveAddressOfOverloadedFunction:
case SK_CastDerivedToBasePRValue:
case SK_CastDerivedToBaseXValue:
case SK_CastDerivedToBaseLValue:
case SK_BindReference:
case SK_BindReferenceToTemporary:
case SK_FinalCopy:
case SK_ExtraneousCopyToTemporary:
case SK_UserConversion:
case SK_QualificationConversionPRValue:
case SK_QualificationConversionXValue:
case SK_QualificationConversionLValue:
case SK_FunctionReferenceConversion:
case SK_AtomicConversion:
case SK_ListInitialization:
case SK_UnwrapInitList:
case SK_RewrapInitList:
case SK_ConstructorInitialization:
case SK_ConstructorInitializationFromList:
case SK_ZeroInitialization:
case SK_CAssignment:
case SK_StringInit:
case SK_ObjCObjectConversion:
case SK_ArrayLoopIndex:
case SK_ArrayLoopInit:
case SK_ArrayInit:
case SK_GNUArrayInit:
case SK_ParenthesizedArrayInit:
case SK_PassByIndirectCopyRestore:
case SK_PassByIndirectRestore:
case SK_ProduceObjCObject:
case SK_StdInitializerList:
case SK_StdInitializerListConstructorCall:
case SK_OCLSamplerInit:
case SK_OCLZeroOpaqueType:
  break;

case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing:
  delete ICS;
}
3528}

3530bool InitializationSequence::isDirectReferenceBinding() const {
// There can be some lvalue adjustments after the SK_BindReference step.
for (const Step &S : llvm::reverse(Steps)) {
  if (S.Kind == SK_BindReference)
    return true;
  if (S.Kind == SK_BindReferenceToTemporary)
    return false;
}
return false;
3539}

3541bool InitializationSequence::isAmbiguous() const {
if (!Failed())
  return false;

switch (getFailureKind()) {
case FK_TooManyInitsForReference:
case FK_ParenthesizedListInitForReference:
case FK_ArrayNeedsInitList:
case FK_ArrayNeedsInitListOrStringLiteral:
case FK_ArrayNeedsInitListOrWideStringLiteral:
case FK_NarrowStringIntoWideCharArray:
case FK_WideStringIntoCharArray:
case FK_IncompatWideStringIntoWideChar:
case FK_PlainStringIntoUTF8Char:
case FK_UTF8StringIntoPlainChar:
case FK_AddressOfOverloadFailed: // FIXME: Could do better
case FK_NonConstLValueReferenceBindingToTemporary:
case FK_NonConstLValueReferenceBindingToBitfield:
case FK_NonConstLValueReferenceBindingToVectorElement:
case FK_NonConstLValueReferenceBindingToMatrixElement:
case FK_NonConstLValueReferenceBindingToUnrelated:
case FK_RValueReferenceBindingToLValue:
case FK_ReferenceAddrspaceMismatchTemporary:
case FK_ReferenceInitDropsQualifiers:
case FK_ReferenceInitFailed:
case FK_ConversionFailed:
case FK_ConversionFromPropertyFailed:
case FK_TooManyInitsForScalar:
case FK_ParenthesizedListInitForScalar:
case FK_ReferenceBindingToInitList:
case FK_InitListBadDestinationType:
case FK_DefaultInitOfConst:
case FK_Incomplete:
case FK_ArrayTypeMismatch:
case FK_NonConstantArrayInit:
case FK_ListInitializationFailed:
case FK_VariableLengthArrayHasInitializer:
case FK_PlaceholderType:
case FK_ExplicitConstructor:
case FK_AddressOfUnaddressableFunction:
  return false;

case FK_ReferenceInitOverloadFailed:
case FK_UserConversionOverloadFailed:
case FK_ConstructorOverloadFailed:
case FK_ListConstructorOverloadFailed:
  return FailedOverloadResult == OR_Ambiguous;
}

llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3590);
3591}

3593bool InitializationSequence::isConstructorInitialization() const {
return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3595}

3597void
3598InitializationSequence
:AddAddressOverloadResolutionStep(FunctionDecl *Function,
                                 DeclAccessPair Found,
                                 bool HadMultipleCandidates) {
Step S;
S.Kind = SK_ResolveAddressOfOverloadedFunction;
S.Type = Function->getType();
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Function;
S.Function.FoundDecl = Found;
Steps.push_back(S);
3609}

3611void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
                                                    ExprValueKind VK) {
Step S;
switch (VK) {
case VK_PRValue:
  S.Kind = SK_CastDerivedToBasePRValue;
  break;
case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
}
S.Type = BaseType;
Steps.push_back(S);
3623}

3625void InitializationSequence::AddReferenceBindingStep(QualType T,
                                                   bool BindingTemporary) {
Step S;
S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
S.Type = T;
Steps.push_back(S);
3631}

3633void InitializationSequence::AddFinalCopy(QualType T) {
Step S;
S.Kind = SK_FinalCopy;
S.Type = T;
Steps.push_back(S);
3638}

3640void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
Step S;
S.Kind = SK_ExtraneousCopyToTemporary;
S.Type = T;
Steps.push_back(S);
3645}

3647void
3648InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
                                            DeclAccessPair FoundDecl,
                                            QualType T,
                                            bool HadMultipleCandidates) {
Step S;
S.Kind = SK_UserConversion;
S.Type = T;
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Function;
S.Function.FoundDecl = FoundDecl;
Steps.push_back(S);
3659}

3661void InitializationSequence::AddQualificationConversionStep(QualType Ty,
                                                          ExprValueKind VK) {
Step S;
S.Kind = SK_QualificationConversionPRValue; // work around a gcc warning
switch (VK) {
case VK_PRValue:
  S.Kind = SK_QualificationConversionPRValue;
  break;
case VK_XValue:
  S.Kind = SK_QualificationConversionXValue;
  break;
case VK_LValue:
  S.Kind = SK_QualificationConversionLValue;
  break;
}
S.Type = Ty;
Steps.push_back(S);
3678}

3680void InitializationSequence::AddFunctionReferenceConversionStep(QualType Ty) {
Step S;
S.Kind = SK_FunctionReferenceConversion;
S.Type = Ty;
Steps.push_back(S);
3685}

3687void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
Step S;
S.Kind = SK_AtomicConversion;
S.Type = Ty;
Steps.push_back(S);
3692}

3694void InitializationSequence::AddConversionSequenceStep(
  const ImplicitConversionSequence &ICS, QualType T,
  bool TopLevelOfInitList) {
Step S;
S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
                            : SK_ConversionSequence;
S.Type = T;
S.ICS = new ImplicitConversionSequence(ICS);
Steps.push_back(S);
3703}

3705void InitializationSequence::AddListInitializationStep(QualType T) {
Step S;
S.Kind = SK_ListInitialization;
S.Type = T;
Steps.push_back(S);
3710}

3712void InitializationSequence::AddConstructorInitializationStep(
  DeclAccessPair FoundDecl, CXXConstructorDecl *Constructor, QualType T,
  bool HadMultipleCandidates, bool FromInitList, bool AsInitList) {
Step S;
S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
                                   : SK_ConstructorInitializationFromList
                      : SK_ConstructorInitialization;
S.Type = T;
S.Function.HadMultipleCandidates = HadMultipleCandidates;
S.Function.Function = Constructor;
S.Function.FoundDecl = FoundDecl;
Steps.push_back(S);
3724}

3726void InitializationSequence::AddZeroInitializationStep(QualType T) {
Step S;
S.Kind = SK_ZeroInitialization;
S.Type = T;
Steps.push_back(S);
3731}

3733void InitializationSequence::AddCAssignmentStep(QualType T) {
Step S;
S.Kind = SK_CAssignment;
S.Type = T;
Steps.push_back(S);
3738}

3740void InitializationSequence::AddStringInitStep(QualType T) {
Step S;
S.Kind = SK_StringInit;
S.Type = T;
Steps.push_back(S);
3745}

3747void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
Step S;
S.Kind = SK_ObjCObjectConversion;
S.Type = T;
Steps.push_back(S);
3752}

3754void InitializationSequence::AddArrayInitStep(QualType T, bool IsGNUExtension) {
Step S;
S.Kind = IsGNUExtension ? SK_GNUArrayInit : SK_ArrayInit;
S.Type = T;
Steps.push_back(S);
3759}

3761void InitializationSequence::AddArrayInitLoopStep(QualType T, QualType EltT) {
Step S;
S.Kind = SK_ArrayLoopIndex;
S.Type = EltT;
Steps.insert(Steps.begin(), S);

S.Kind = SK_ArrayLoopInit;
S.Type = T;
Steps.push_back(S);
3770}

3772void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
Step S;
S.Kind = SK_ParenthesizedArrayInit;
S.Type = T;
Steps.push_back(S);
3777}

3779void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
                                                            bool shouldCopy) {
Step s;
s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
                     : SK_PassByIndirectRestore);
s.Type = type;
Steps.push_back(s);
3786}

3788void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
Step S;
S.Kind = SK_ProduceObjCObject;
S.Type = T;
Steps.push_back(S);
3793}

3795void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
Step S;
S.Kind = SK_StdInitializerList;
S.Type = T;
Steps.push_back(S);
3800}

3802void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
Step S;
S.Kind = SK_OCLSamplerInit;
S.Type = T;
Steps.push_back(S);
3807}

3809void InitializationSequence::AddOCLZeroOpaqueTypeStep(QualType T) {
Step S;
S.Kind = SK_OCLZeroOpaqueType;
S.Type = T;
Steps.push_back(S);
3814}

3816void InitializationSequence::RewrapReferenceInitList(QualType T,
                                                   InitListExpr *Syntactic) {
assert(Syntactic->getNumInits() == 1 &&(static_cast <bool> (Syntactic->getNumInits() == 1 &&
 "Can only rewrap trivial init lists.") ? void (0) : __assert_fail
 ("Syntactic->getNumInits() == 1 && \"Can only rewrap trivial init lists.\""
, "clang/lib/Sema/SemaInit.cpp", 3819, __extension__ __PRETTY_FUNCTION__
))
       "Can only rewrap trivial init lists.")(static_cast <bool> (Syntactic->getNumInits() == 1 &&
 "Can only rewrap trivial init lists.") ? void (0) : __assert_fail
 ("Syntactic->getNumInits() == 1 && \"Can only rewrap trivial init lists.\""
, "clang/lib/Sema/SemaInit.cpp", 3819, __extension__ __PRETTY_FUNCTION__
));
Step S;
S.Kind = SK_UnwrapInitList;
S.Type = Syntactic->getInit(0)->getType();
Steps.insert(Steps.begin(), S);

S.Kind = SK_RewrapInitList;
S.Type = T;
S.WrappingSyntacticList = Syntactic;
Steps.push_back(S);
3829}

3831void InitializationSequence::SetOverloadFailure(FailureKind Failure,
                                              OverloadingResult Result) {
setSequenceKind(FailedSequence);
this->Failure = Failure;
this->FailedOverloadResult = Result;
3836}

3838//===----------------------------------------------------------------------===//
3839// Attempt initialization
3840//===----------------------------------------------------------------------===//

3842/// Tries to add a zero initializer. Returns true if that worked.
3843static bool
3844maybeRecoverWithZeroInitialization(Sema &S, InitializationSequence &Sequence,
                                 const InitializedEntity &Entity) {
if (Entity.getKind() != InitializedEntity::EK_Variable)
  return false;

VarDecl *VD = cast<VarDecl>(Entity.getDecl());
if (VD->getInit() || VD->getEndLoc().isMacroID())
  return false;

QualType VariableTy = VD->getType().getCanonicalType();
SourceLocation Loc = S.getLocForEndOfToken(VD->getEndLoc());
std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
if (!Init.empty()) {
  Sequence.AddZeroInitializationStep(Entity.getType());
  Sequence.SetZeroInitializationFixit(Init, Loc);
  return true;
}
return false;
3862}

3864static void MaybeProduceObjCObject(Sema &S,
                                 InitializationSequence &Sequence,
                                 const InitializedEntity &Entity) {
if (!S.getLangOpts().ObjCAutoRefCount) return;

/// When initializing a parameter, produce the value if it's marked
/// __attribute__((ns_consumed)).
if (Entity.isParameterKind()) {
  if (!Entity.isParameterConsumed())
    return;

  assert(Entity.getType()->isObjCRetainableType() &&(static_cast <bool> (Entity.getType()->isObjCRetainableType
() && "consuming an object of unretainable type?") ? void
 (0) : __assert_fail ("Entity.getType()->isObjCRetainableType() && \"consuming an object of unretainable type?\""
, "clang/lib/Sema/SemaInit.cpp", 3876, __extension__ __PRETTY_FUNCTION__
))
         "consuming an object of unretainable type?")(static_cast <bool> (Entity.getType()->isObjCRetainableType
() && "consuming an object of unretainable type?") ? void
 (0) : __assert_fail ("Entity.getType()->isObjCRetainableType() && \"consuming an object of unretainable type?\""
, "clang/lib/Sema/SemaInit.cpp", 3876, __extension__ __PRETTY_FUNCTION__
));
  Sequence.AddProduceObjCObjectStep(Entity.getType());

/// When initializing a return value, if the return type is a
/// retainable type, then returns need to immediately retain the
/// object.  If an autorelease is required, it will be done at the
/// last instant.
} else if (Entity.getKind() == InitializedEntity::EK_Result ||
           Entity.getKind() == InitializedEntity::EK_StmtExprResult) {
  if (!Entity.getType()->isObjCRetainableType())
    return;

  Sequence.AddProduceObjCObjectStep(Entity.getType());
}
3890}

3892static void TryListInitialization(Sema &S,
                                const InitializedEntity &Entity,
                                const InitializationKind &Kind,
                                InitListExpr *InitList,
                                InitializationSequence &Sequence,
                                bool TreatUnavailableAsInvalid);

3899/// When initializing from init list via constructor, handle
3900/// initialization of an object of type std::initializer_list<T>.
3901///
3902/// \return true if we have handled initialization of an object of type
3903/// std::initializer_list<T>, false otherwise.
3904static bool TryInitializerListConstruction(Sema &S,
                                         InitListExpr *List,
                                         QualType DestType,
                                         InitializationSequence &Sequence,
                                         bool TreatUnavailableAsInvalid) {
QualType E;
if (!S.isStdInitializerList(DestType, &E))
  return false;

if (!S.isCompleteType(List->getExprLoc(), E)) {
  Sequence.setIncompleteTypeFailure(E);
  return true;
}

// Try initializing a temporary array from the init list.
QualType ArrayType = S.Context.getConstantArrayType(
    E.withConst(),
    llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
                List->getNumInits()),
    nullptr, clang::ArrayType::Normal, 0);
InitializedEntity HiddenArray =
    InitializedEntity::InitializeTemporary(ArrayType);
InitializationKind Kind = InitializationKind::CreateDirectList(
    List->getExprLoc(), List->getBeginLoc(), List->getEndLoc());
TryListInitialization(S, HiddenArray, Kind, List, Sequence,
                      TreatUnavailableAsInvalid);
if (Sequence)
  Sequence.AddStdInitializerListConstructionStep(DestType);
return true;
3933}

3935/// Determine if the constructor has the signature of a copy or move
3936/// constructor for the type T of the class in which it was found. That is,
3937/// determine if its first parameter is of type T or reference to (possibly
3938/// cv-qualified) T.
3939static bool hasCopyOrMoveCtorParam(ASTContext &Ctx,
                                 const ConstructorInfo &Info) {
if (Info.Constructor->getNumParams() == 0)
  return false;

QualType ParmT =
    Info.Constructor->getParamDecl(0)->getType().getNonReferenceType();
QualType ClassT =
    Ctx.getRecordType(cast<CXXRecordDecl>(Info.FoundDecl->getDeclContext()));

return Ctx.hasSameUnqualifiedType(ParmT, ClassT);
3950}

3952static OverloadingResult
3953ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
                         MultiExprArg Args,
                         OverloadCandidateSet &CandidateSet,
                         QualType DestType,
                         DeclContext::lookup_result Ctors,
                         OverloadCandidateSet::iterator &Best,
                         bool CopyInitializing, bool AllowExplicit,
                         bool OnlyListConstructors, bool IsListInit,
                         bool SecondStepOfCopyInit = false) {
CandidateSet.clear(OverloadCandidateSet::CSK_InitByConstructor);
CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());

for (NamedDecl *D : Ctors) {
  auto Info = getConstructorInfo(D);
  if (!Info.Constructor || Info.Constructor->isInvalidDecl())
    continue;

  if (OnlyListConstructors && !S.isInitListConstructor(Info.Constructor))
    continue;

  // C++11 [over.best.ics]p4:
  //   ... and the constructor or user-defined conversion function is a
  //   candidate by
  //   - 13.3.1.3, when the argument is the temporary in the second step
  //     of a class copy-initialization, or
  //   - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases), [not handled here]
  //   - the second phase of 13.3.1.7 when the initializer list has exactly
  //     one element that is itself an initializer list, and the target is
  //     the first parameter of a constructor of class X, and the conversion
  //     is to X or reference to (possibly cv-qualified X),
  //   user-defined conversion sequences are not considered.
  bool SuppressUserConversions =
      SecondStepOfCopyInit ||
      (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
       hasCopyOrMoveCtorParam(S.Context, Info));

  if (Info.ConstructorTmpl)
    S.AddTemplateOverloadCandidate(
        Info.ConstructorTmpl, Info.FoundDecl,
        /*ExplicitArgs*/ nullptr, Args, CandidateSet, SuppressUserConversions,
        /*PartialOverloading=*/false, AllowExplicit);
  else {
    // C++ [over.match.copy]p1:
    //   - When initializing a temporary to be bound to the first parameter
    //     of a constructor [for type T] that takes a reference to possibly
    //     cv-qualified T as its first argument, called with a single
    //     argument in the context of direct-initialization, explicit
    //     conversion functions are also considered.
    // FIXME: What if a constructor template instantiates to such a signature?
    bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
                             Args.size() == 1 &&
                             hasCopyOrMoveCtorParam(S.Context, Info);
    S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, Args,
                           CandidateSet, SuppressUserConversions,
                           /*PartialOverloading=*/false, AllowExplicit,
                           AllowExplicitConv);
  }
}

// FIXME: Work around a bug in C++17 guaranteed copy elision.
//
// When initializing an object of class type T by constructor
// ([over.match.ctor]) or by list-initialization ([over.match.list])
// from a single expression of class type U, conversion functions of
// U that convert to the non-reference type cv T are candidates.
// Explicit conversion functions are only candidates during
// direct-initialization.
//
// Note: SecondStepOfCopyInit is only ever true in this case when
// evaluating whether to produce a C++98 compatibility warning.
if (S.getLangOpts().CPlusPlus17 && Args.size() == 1 &&
    !SecondStepOfCopyInit) {
  Expr *Initializer = Args[0];
  auto *SourceRD = Initializer->getType()->getAsCXXRecordDecl();
  if (SourceRD && S.isCompleteType(DeclLoc, Initializer->getType())) {
    const auto &Conversions = SourceRD->getVisibleConversionFunctions();
    for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
      NamedDecl *D = *I;
      CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
      D = D->getUnderlyingDecl();

      FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
      CXXConversionDecl *Conv;
      if (ConvTemplate)
        Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
      else
        Conv = cast<CXXConversionDecl>(D);

      if (ConvTemplate)
        S.AddTemplateConversionCandidate(
            ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
            CandidateSet, AllowExplicit, AllowExplicit,
            /*AllowResultConversion*/ false);
      else
        S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
                                 DestType, CandidateSet, AllowExplicit,
                                 AllowExplicit,
                                 /*AllowResultConversion*/ false);
    }
  }
}

// Perform overload resolution and return the result.
return CandidateSet.BestViableFunction(S, DeclLoc, Best);
4057}

4059/// Attempt initialization by constructor (C++ [dcl.init]), which
4060/// enumerates the constructors of the initialized entity and performs overload
4061/// resolution to select the best.
4062/// \param DestType       The destination class type.
4063/// \param DestArrayType  The destination type, which is either DestType or
4064///                       a (possibly multidimensional) array of DestType.
4065/// \param IsListInit     Is this list-initialization?
4066/// \param IsInitListCopy Is this non-list-initialization resulting from a
4067///                       list-initialization from {x} where x is the same
4068///                       type as the entity?
4069static void TryConstructorInitialization(Sema &S,
                                       const InitializedEntity &Entity,
                                       const InitializationKind &Kind,
                                       MultiExprArg Args, QualType DestType,
                                       QualType DestArrayType,
                                       InitializationSequence &Sequence,
                                       bool IsListInit = false,
                                       bool IsInitListCopy = false) {
assert(((!IsListInit && !IsInitListCopy) ||(static_cast <bool> (((!IsListInit && !IsInitListCopy
) || (Args.size() == 1 && isa<InitListExpr>(Args
[0]))) && "IsListInit/IsInitListCopy must come with a single initializer list "
 "argument.") ? void (0) : __assert_fail ("((!IsListInit && !IsInitListCopy) || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && \"IsListInit/IsInitListCopy must come with a single initializer list \" \"argument.\""
, "clang/lib/Sema/SemaInit.cpp", 4080, __extension__ __PRETTY_FUNCTION__
))
        (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&(static_cast <bool> (((!IsListInit && !IsInitListCopy
) || (Args.size() == 1 && isa<InitListExpr>(Args
[0]))) && "IsListInit/IsInitListCopy must come with a single initializer list "
 "argument.") ? void (0) : __assert_fail ("((!IsListInit && !IsInitListCopy) || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && \"IsListInit/IsInitListCopy must come with a single initializer list \" \"argument.\""
, "clang/lib/Sema/SemaInit.cpp", 4080, __extension__ __PRETTY_FUNCTION__
))
       "IsListInit/IsInitListCopy must come with a single initializer list "(static_cast <bool> (((!IsListInit && !IsInitListCopy
) || (Args.size() == 1 && isa<InitListExpr>(Args
[0]))) && "IsListInit/IsInitListCopy must come with a single initializer list "
 "argument.") ? void (0) : __assert_fail ("((!IsListInit && !IsInitListCopy) || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && \"IsListInit/IsInitListCopy must come with a single initializer list \" \"argument.\""
, "clang/lib/Sema/SemaInit.cpp", 4080, __extension__ __PRETTY_FUNCTION__
))
       "argument.")(static_cast <bool> (((!IsListInit && !IsInitListCopy
) || (Args.size() == 1 && isa<InitListExpr>(Args
[0]))) && "IsListInit/IsInitListCopy must come with a single initializer list "
 "argument.") ? void (0) : __assert_fail ("((!IsListInit && !IsInitListCopy) || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && \"IsListInit/IsInitListCopy must come with a single initializer list \" \"argument.\""
, "clang/lib/Sema/SemaInit.cpp", 4080, __extension__ __PRETTY_FUNCTION__
));
InitListExpr *ILE =
    (IsListInit || IsInitListCopy) ? cast<InitListExpr>(Args[0]) : nullptr;
MultiExprArg UnwrappedArgs =
    ILE ? MultiExprArg(ILE->getInits(), ILE->getNumInits()) : Args;

// The type we're constructing needs to be complete.
if (!S.isCompleteType(Kind.getLocation(), DestType)) {
  Sequence.setIncompleteTypeFailure(DestType);
  return;
}

// C++17 [dcl.init]p17:
//     - If the initializer expression is a prvalue and the cv-unqualified
//       version of the source type is the same class as the class of the
//       destination, the initializer expression is used to initialize the
//       destination object.
// Per DR (no number yet), this does not apply when initializing a base
// class or delegating to another constructor from a mem-initializer.
// ObjC++: Lambda captured by the block in the lambda to block conversion
// should avoid copy elision.
if (S.getLangOpts().CPlusPlus17 &&
    Entity.getKind() != InitializedEntity::EK_Base &&
    Entity.getKind() != InitializedEntity::EK_Delegating &&
    Entity.getKind() !=
        InitializedEntity::EK_LambdaToBlockConversionBlockElement &&
    UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isPRValue() &&
    S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
  // Convert qualifications if necessary.
  Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
  if (ILE)
    Sequence.RewrapReferenceInitList(DestType, ILE);
  return;
}

const RecordType *DestRecordType = DestType->getAs<RecordType>();
assert(DestRecordType && "Constructor initialization requires record type")(static_cast <bool> (DestRecordType && "Constructor initialization requires record type"
) ? void (0) : __assert_fail ("DestRecordType && \"Constructor initialization requires record type\""
, "clang/lib/Sema/SemaInit.cpp", 4116, __extension__ __PRETTY_FUNCTION__
));
CXXRecordDecl *DestRecordDecl
  = cast<CXXRecordDecl>(DestRecordType->getDecl());

// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();

// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.AllowExplicit() || IsListInit;
bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;

//   - Otherwise, if T is a class type, constructors are considered. The
//     applicable constructors are enumerated, and the best one is chosen
//     through overload resolution.
DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl);

OverloadingResult Result = OR_No_Viable_Function;
OverloadCandidateSet::iterator Best;
bool AsInitializerList = false;

// C++11 [over.match.list]p1, per DR1467:
//   When objects of non-aggregate type T are list-initialized, such that
//   8.5.4 [dcl.init.list] specifies that overload resolution is performed
//   according to the rules in this section, overload resolution selects
//   the constructor in two phases:
//
//   - Initially, the candidate functions are the initializer-list
//     constructors of the class T and the argument list consists of the
//     initializer list as a single argument.
if (IsListInit) {
  AsInitializerList = true;

  // If the initializer list has no elements and T has a default constructor,
  // the first phase is omitted.
  if (!(UnwrappedArgs.empty() && S.LookupDefaultConstructor(DestRecordDecl)))
    Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
                                        CandidateSet, DestType, Ctors, Best,
                                        CopyInitialization, AllowExplicit,
                                        /*OnlyListConstructors=*/true,
                                        IsListInit);
}

// C++11 [over.match.list]p1:
//   - If no viable initializer-list constructor is found, overload resolution
//     is performed again, where the candidate functions are all the
//     constructors of the class T and the argument list consists of the
//     elements of the initializer list.
if (Result == OR_No_Viable_Function) {
  AsInitializerList = false;
  Result = ResolveConstructorOverload(S, Kind.getLocation(), UnwrappedArgs,
                                      CandidateSet, DestType, Ctors, Best,
                                      CopyInitialization, AllowExplicit,
                                      /*OnlyListConstructors=*/false,
                                      IsListInit);
}
if (Result) {
  Sequence.SetOverloadFailure(
      IsListInit ? InitializationSequence::FK_ListConstructorOverloadFailed
                 : InitializationSequence::FK_ConstructorOverloadFailed,
      Result);

  if (Result != OR_Deleted)
    return;
}

bool HadMultipleCandidates = (CandidateSet.size() > 1);

// In C++17, ResolveConstructorOverload can select a conversion function
// instead of a constructor.
if (auto *CD = dyn_cast<CXXConversionDecl>(Best->Function)) {
  // Add the user-defined conversion step that calls the conversion function.
  QualType ConvType = CD->getConversionType();
  assert(S.Context.hasSameUnqualifiedType(ConvType, DestType) &&(static_cast <bool> (S.Context.hasSameUnqualifiedType(ConvType
, DestType) && "should not have selected this conversion function"
) ? void (0) : __assert_fail ("S.Context.hasSameUnqualifiedType(ConvType, DestType) && \"should not have selected this conversion function\""
, "clang/lib/Sema/SemaInit.cpp", 4191, __extension__ __PRETTY_FUNCTION__
))
         "should not have selected this conversion function")(static_cast <bool> (S.Context.hasSameUnqualifiedType(ConvType
, DestType) && "should not have selected this conversion function"
) ? void (0) : __assert_fail ("S.Context.hasSameUnqualifiedType(ConvType, DestType) && \"should not have selected this conversion function\""
, "clang/lib/Sema/SemaInit.cpp", 4191, __extension__ __PRETTY_FUNCTION__
));
  Sequence.AddUserConversionStep(CD, Best->FoundDecl, ConvType,
                                 HadMultipleCandidates);
  if (!S.Context.hasSameType(ConvType, DestType))
    Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
  if (IsListInit)
    Sequence.RewrapReferenceInitList(Entity.getType(), ILE);
  return;
}

CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
if (Result != OR_Deleted) {
  // C++11 [dcl.init]p6:
  //   If a program calls for the default initialization of an object
  //   of a const-qualified type T, T shall be a class type with a
  //   user-provided default constructor.
  // C++ core issue 253 proposal:
  //   If the implicit default constructor initializes all subobjects, no
  //   initializer should be required.
  // The 253 proposal is for example needed to process libstdc++ headers
  // in 5.x.
  if (Kind.getKind() == InitializationKind::IK_Default &&
      Entity.getType().isConstQualified()) {
    if (!CtorDecl->getParent()->allowConstDefaultInit()) {
      if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
        Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
      return;
    }
  }

  // C++11 [over.match.list]p1:
  //   In copy-list-initialization, if an explicit constructor is chosen, the
  //   initializer is ill-formed.
  if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
    Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
    return;
  }
}

// [class.copy.elision]p3:
// In some copy-initialization contexts, a two-stage overload resolution
// is performed.
// If the first overload resolution selects a deleted function, we also
// need the initialization sequence to decide whether to perform the second
// overload resolution.
// For deleted functions in other contexts, there is no need to get the
// initialization sequence.
if (Result == OR_Deleted && Kind.getKind() != InitializationKind::IK_Copy)
  return;

// Add the constructor initialization step. Any cv-qualification conversion is
// subsumed by the initialization.
Sequence.AddConstructorInitializationStep(
    Best->FoundDecl, CtorDecl, DestArrayType, HadMultipleCandidates,
    IsListInit | IsInitListCopy, AsInitializerList);
4246}

4248static bool
4249ResolveOverloadedFunctionForReferenceBinding(Sema &S,
                                           Expr *Initializer,
                                           QualType &SourceType,
                                           QualType &UnqualifiedSourceType,
                                           QualType UnqualifiedTargetType,
                                           InitializationSequence &Sequence) {
if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
      S.Context.OverloadTy) {
  DeclAccessPair Found;
  bool HadMultipleCandidates = false;
  if (FunctionDecl *Fn
      = S.ResolveAddressOfOverloadedFunction(Initializer,
                                             UnqualifiedTargetType,
                                             false, Found,
                                             &HadMultipleCandidates)) {
    Sequence.AddAddressOverloadResolutionStep(Fn, Found,
                                              HadMultipleCandidates);
    SourceType = Fn->getType();
    UnqualifiedSourceType = SourceType.getUnqualifiedType();
  } else if (!UnqualifiedTargetType->isRecordType()) {
    Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
    return true;
  }
}
return false;
4274}

4276static void TryReferenceInitializationCore(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         Expr *Initializer,
                                         QualType cv1T1, QualType T1,
                                         Qualifiers T1Quals,
                                         QualType cv2T2, QualType T2,
                                         Qualifiers T2Quals,
                                         InitializationSequence &Sequence);

4286static void TryValueInitialization(Sema &S,
                                 const InitializedEntity &Entity,
                                 const InitializationKind &Kind,
                                 InitializationSequence &Sequence,
                                 InitListExpr *InitList = nullptr);

4292/// Attempt list initialization of a reference.
4293static void TryReferenceListInitialization(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         InitListExpr *InitList,
                                         InitializationSequence &Sequence,
                                         bool TreatUnavailableAsInvalid) {
// First, catch C++03 where this isn't possible.
if (!S.getLangOpts().CPlusPlus11) {
  Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
  return;
}
// Can't reference initialize a compound literal.
if (Entity.getKind() == InitializedEntity::EK_CompoundLiteralInit) {
  Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
  return;
}

QualType DestType = Entity.getType();
QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
Qualifiers T1Quals;
QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);

// Reference initialization via an initializer list works thus:
// If the initializer list consists of a single element that is
// reference-related to the referenced type, bind directly to that element
// (possibly creating temporaries).
// Otherwise, initialize a temporary with the initializer list and
// bind to that.
if (InitList->getNumInits() == 1) {
  Expr *Initializer = InitList->getInit(0);
  QualType cv2T2 = S.getCompletedType(Initializer);
  Qualifiers T2Quals;
  QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);

  // If this fails, creating a temporary wouldn't work either.
  if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
                                                   T1, Sequence))
    return;

  SourceLocation DeclLoc = Initializer->getBeginLoc();
  Sema::ReferenceCompareResult RefRelationship
    = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2);
  if (RefRelationship >= Sema::Ref_Related) {
    // Try to bind the reference here.
    TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
                                   T1Quals, cv2T2, T2, T2Quals, Sequence);
    if (Sequence)
      Sequence.RewrapReferenceInitList(cv1T1, InitList);
    return;
  }

  // Update the initializer if we've resolved an overloaded function.
  if (Sequence.step_begin() != Sequence.step_end())
    Sequence.RewrapReferenceInitList(cv1T1, InitList);
}
// Perform address space compatibility check.
QualType cv1T1IgnoreAS = cv1T1;
if (T1Quals.hasAddressSpace()) {
  Qualifiers T2Quals;
  (void)S.Context.getUnqualifiedArrayType(InitList->getType(), T2Quals);
  if (!T1Quals.isAddressSpaceSupersetOf(T2Quals)) {
    Sequence.SetFailed(
        InitializationSequence::FK_ReferenceInitDropsQualifiers);
    return;
  }
  // Ignore address space of reference type at this point and perform address
  // space conversion after the reference binding step.
  cv1T1IgnoreAS =
      S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace());
}
// Not reference-related. Create a temporary and bind to that.
InitializedEntity TempEntity =
    InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);

TryListInitialization(S, TempEntity, Kind, InitList, Sequence,
                      TreatUnavailableAsInvalid);
if (Sequence) {
  if (DestType->isRValueReferenceType() ||
      (T1Quals.hasConst() && !T1Quals.hasVolatile())) {
    Sequence.AddReferenceBindingStep(cv1T1IgnoreAS,
                                     /*BindingTemporary=*/true);
    if (T1Quals.hasAddressSpace())
      Sequence.AddQualificationConversionStep(
          cv1T1, DestType->isRValueReferenceType() ? VK_XValue : VK_LValue);
  } else
    Sequence.SetFailed(
        InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
}
4381}

4383/// Attempt list initialization (C++0x [dcl.init.list])
4384static void TryListInitialization(Sema &S,
                                const InitializedEntity &Entity,
                                const InitializationKind &Kind,
                                InitListExpr *InitList,
                                InitializationSequence &Sequence,
                                bool TreatUnavailableAsInvalid) {
QualType DestType = Entity.getType();

// C++ doesn't allow scalar initialization with more than one argument.
// But C99 complex numbers are scalars and it makes sense there.
if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
    !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
  Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
  return;
}
if (DestType->isReferenceType()) {
  TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence,
                                 TreatUnavailableAsInvalid);
  return;
}

if (DestType->isRecordType() &&
    !S.isCompleteType(InitList->getBeginLoc(), DestType)) {
  Sequence.setIncompleteTypeFailure(DestType);
  return;
}

// C++11 [dcl.init.list]p3, per DR1467:
// - If T is a class type and the initializer list has a single element of
//   type cv U, where U is T or a class derived from T, the object is
//   initialized from that element (by copy-initialization for
//   copy-list-initialization, or by direct-initialization for
//   direct-list-initialization).
// - Otherwise, if T is a character array and the initializer list has a
//   single element that is an appropriately-typed string literal
//   (8.5.2 [dcl.init.string]), initialization is performed as described
//   in that section.
// - Otherwise, if T is an aggregate, [...] (continue below).
if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) {
  if (DestType->isRecordType()) {
    QualType InitType = InitList->getInit(0)->getType();
    if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
        S.IsDerivedFrom(InitList->getBeginLoc(), InitType, DestType)) {
      Expr *InitListAsExpr = InitList;
      TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
                                   DestType, Sequence,
                                   /*InitListSyntax*/false,
                                   /*IsInitListCopy*/true);
      return;
    }
  }
  if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) {
    Expr *SubInit[1] = {InitList->getInit(0)};
    if (!isa<VariableArrayType>(DestAT) &&
        IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) {
      InitializationKind SubKind =
          Kind.getKind() == InitializationKind::IK_DirectList
              ? InitializationKind::CreateDirect(Kind.getLocation(),
                                                 InitList->getLBraceLoc(),
                                                 InitList->getRBraceLoc())
              : Kind;
      Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
                              /*TopLevelOfInitList*/ true,
                              TreatUnavailableAsInvalid);

      // TryStringLiteralInitialization() (in InitializeFrom()) will fail if
      // the element is not an appropriately-typed string literal, in which
      // case we should proceed as in C++11 (below).
      if (Sequence) {
        Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
        return;
      }
    }
  }
}

// C++11 [dcl.init.list]p3:
//   - If T is an aggregate, aggregate initialization is performed.
if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
    (S.getLangOpts().CPlusPlus11 &&
     S.isStdInitializerList(DestType, nullptr))) {
  if (S.getLangOpts().CPlusPlus11) {
    //   - Otherwise, if the initializer list has no elements and T is a
    //     class type with a default constructor, the object is
    //     value-initialized.
    if (InitList->getNumInits() == 0) {
      CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
      if (S.LookupDefaultConstructor(RD)) {
        TryValueInitialization(S, Entity, Kind, Sequence, InitList);
        return;
      }
    }

    //   - Otherwise, if T is a specialization of std::initializer_list<E>,
    //     an initializer_list object constructed [...]
    if (TryInitializerListConstruction(S, InitList, DestType, Sequence,
                                       TreatUnavailableAsInvalid))
      return;

    //   - Otherwise, if T is a class type, constructors are considered.
    Expr *InitListAsExpr = InitList;
    TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
                                 DestType, Sequence, /*InitListSyntax*/true);
  } else
    Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
  return;
}

if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
    InitList->getNumInits() == 1) {
  Expr *E = InitList->getInit(0);

  //   - Otherwise, if T is an enumeration with a fixed underlying type,
  //     the initializer-list has a single element v, and the initialization
  //     is direct-list-initialization, the object is initialized with the
  //     value T(v); if a narrowing conversion is required to convert v to
  //     the underlying type of T, the program is ill-formed.
  auto *ET = DestType->getAs<EnumType>();
  if (S.getLangOpts().CPlusPlus17 &&
      Kind.getKind() == InitializationKind::IK_DirectList &&
      ET && ET->getDecl()->isFixed() &&
      !S.Context.hasSameUnqualifiedType(E->getType(), DestType) &&
      (E->getType()->isIntegralOrUnscopedEnumerationType() ||
       E->getType()->isFloatingType())) {
    // There are two ways that T(v) can work when T is an enumeration type.
    // If there is either an implicit conversion sequence from v to T or
    // a conversion function that can convert from v to T, then we use that.
    // Otherwise, if v is of integral, unscoped enumeration, or floating-point
    // type, it is converted to the enumeration type via its underlying type.
    // There is no overlap possible between these two cases (except when the
    // source value is already of the destination type), and the first
    // case is handled by the general case for single-element lists below.
    ImplicitConversionSequence ICS;
    ICS.setStandard();
    ICS.Standard.setAsIdentityConversion();
    if (!E->isPRValue())
      ICS.Standard.First = ICK_Lvalue_To_Rvalue;
    // If E is of a floating-point type, then the conversion is ill-formed
    // due to narrowing, but go through the motions in order to produce the
    // right diagnostic.
    ICS.Standard.Second = E->getType()->isFloatingType()
                              ? ICK_Floating_Integral
                              : ICK_Integral_Conversion;
    ICS.Standard.setFromType(E->getType());
    ICS.Standard.setToType(0, E->getType());
    ICS.Standard.setToType(1, DestType);
    ICS.Standard.setToType(2, DestType);
    Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2),
                                       /*TopLevelOfInitList*/true);
    Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
    return;
  }

  //   - Otherwise, if the initializer list has a single element of type E
  //     [...references are handled above...], the object or reference is
  //     initialized from that element (by copy-initialization for
  //     copy-list-initialization, or by direct-initialization for
  //     direct-list-initialization); if a narrowing conversion is required
  //     to convert the element to T, the program is ill-formed.
  //
  // Per core-24034, this is direct-initialization if we were performing
  // direct-list-initialization and copy-initialization otherwise.
  // We can't use InitListChecker for this, because it always performs
  // copy-initialization. This only matters if we might use an 'explicit'
  // conversion operator, or for the special case conversion of nullptr_t to
  // bool, so we only need to handle those cases.
  //
  // FIXME: Why not do this in all cases?
  Expr *Init = InitList->getInit(0);
  if (Init->getType()->isRecordType() ||
      (Init->getType()->isNullPtrType() && DestType->isBooleanType())) {
    InitializationKind SubKind =
        Kind.getKind() == InitializationKind::IK_DirectList
            ? InitializationKind::CreateDirect(Kind.getLocation(),
                                               InitList->getLBraceLoc(),
                                               InitList->getRBraceLoc())
            : Kind;
    Expr *SubInit[1] = { Init };
    Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
                            /*TopLevelOfInitList*/true,
                            TreatUnavailableAsInvalid);
    if (Sequence)
      Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
    return;
  }
}

InitListChecker CheckInitList(S, Entity, InitList,
        DestType, /*VerifyOnly=*/true, TreatUnavailableAsInvalid);
if (CheckInitList.HadError()) {
  Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
  return;
}

// Add the list initialization step with the built init list.
Sequence.AddListInitializationStep(DestType);
4580}

4582/// Try a reference initialization that involves calling a conversion
4583/// function.
4584static OverloadingResult TryRefInitWithConversionFunction(
  Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
  Expr *Initializer, bool AllowRValues, bool IsLValueRef,
  InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
QualType T1 = cv1T1.getUnqualifiedType();
QualType cv2T2 = Initializer->getType();
QualType T2 = cv2T2.getUnqualifiedType();

assert(!S.CompareReferenceRelationship(Initializer->getBeginLoc(), T1, T2) &&(static_cast <bool> (!S.CompareReferenceRelationship(Initializer
->getBeginLoc(), T1, T2) && "Must have incompatible references when binding via conversion"
) ? void (0) : __assert_fail ("!S.CompareReferenceRelationship(Initializer->getBeginLoc(), T1, T2) && \"Must have incompatible references when binding via conversion\""
, "clang/lib/Sema/SemaInit.cpp", 4595, __extension__ __PRETTY_FUNCTION__
))
       "Must have incompatible references when binding via conversion")(static_cast <bool> (!S.CompareReferenceRelationship(Initializer
->getBeginLoc(), T1, T2) && "Must have incompatible references when binding via conversion"
) ? void (0) : __assert_fail ("!S.CompareReferenceRelationship(Initializer->getBeginLoc(), T1, T2) && \"Must have incompatible references when binding via conversion\""
, "clang/lib/Sema/SemaInit.cpp", 4595, __extension__ __PRETTY_FUNCTION__
));

// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);

// Determine whether we are allowed to call explicit conversion operators.
// Note that none of [over.match.copy], [over.match.conv], nor
// [over.match.ref] permit an explicit constructor to be chosen when
// initializing a reference, not even for direct-initialization.
bool AllowExplicitCtors = false;
bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();

const RecordType *T1RecordType = nullptr;
if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
    S.isCompleteType(Kind.getLocation(), T1)) {
  // The type we're converting to is a class type. Enumerate its constructors
  // to see if there is a suitable conversion.
  CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());

  for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) {
    auto Info = getConstructorInfo(D);
    if (!Info.Constructor)
      continue;

    if (!Info.Constructor->isInvalidDecl() &&
        Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
      if (Info.ConstructorTmpl)
        S.AddTemplateOverloadCandidate(
            Info.ConstructorTmpl, Info.FoundDecl,
            /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
            /*SuppressUserConversions=*/true,
            /*PartialOverloading*/ false, AllowExplicitCtors);
      else
        S.AddOverloadCandidate(
            Info.Constructor, Info.FoundDecl, Initializer, CandidateSet,
            /*SuppressUserConversions=*/true,
            /*PartialOverloading*/ false, AllowExplicitCtors);
    }
  }
}
if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
  return OR_No_Viable_Function;

const RecordType *T2RecordType = nullptr;
if ((T2RecordType = T2->getAs<RecordType>()) &&
    S.isCompleteType(Kind.getLocation(), T2)) {
  // The type we're converting from is a class type, enumerate its conversion
  // functions.
  CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());

  const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
  for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
    NamedDecl *D = *I;
    CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
    if (isa<UsingShadowDecl>(D))
      D = cast<UsingShadowDecl>(D)->getTargetDecl();

    FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
    CXXConversionDecl *Conv;
    if (ConvTemplate)
      Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
    else
      Conv = cast<CXXConversionDecl>(D);

    // If the conversion function doesn't return a reference type,
    // it can't be considered for this conversion unless we're allowed to
    // consider rvalues.
    // FIXME: Do we need to make sure that we only consider conversion
    // candidates with reference-compatible results? That might be needed to
    // break recursion.
    if ((AllowRValues ||
         Conv->getConversionType()->isLValueReferenceType())) {
      if (ConvTemplate)
        S.AddTemplateConversionCandidate(
            ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
            CandidateSet,
            /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
      else
        S.AddConversionCandidate(
            Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet,
            /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
    }
  }
}
if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
  return OR_No_Viable_Function;

SourceLocation DeclLoc = Initializer->getBeginLoc();

// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
      = CandidateSet.BestViableFunction(S, DeclLoc, Best))
  return Result;

FunctionDecl *Function = Best->Function;
// This is the overload that will be used for this initialization step if we
// use this initialization. Mark it as referenced.
Function->setReferenced();

// Compute the returned type and value kind of the conversion.
QualType cv3T3;
if (isa<CXXConversionDecl>(Function))
  cv3T3 = Function->getReturnType();
else
  cv3T3 = T1;

ExprValueKind VK = VK_PRValue;
if (cv3T3->isLValueReferenceType())
  VK = VK_LValue;
else if (const auto *RRef = cv3T3->getAs<RValueReferenceType>())
  VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
cv3T3 = cv3T3.getNonLValueExprType(S.Context);

// Add the user-defined conversion step.
bool HadMultipleCandidates = (CandidateSet.size() > 1);
Sequence.AddUserConversionStep(Function, Best->FoundDecl, cv3T3,
                               HadMultipleCandidates);

// Determine whether we'll need to perform derived-to-base adjustments or
// other conversions.
Sema::ReferenceConversions RefConv;
Sema::ReferenceCompareResult NewRefRelationship =
    S.CompareReferenceRelationship(DeclLoc, T1, cv3T3, &RefConv);

// Add the final conversion sequence, if necessary.
if (NewRefRelationship == Sema::Ref_Incompatible) {
  assert(!isa<CXXConstructorDecl>(Function) &&(static_cast <bool> (!isa<CXXConstructorDecl>(Function
) && "should not have conversion after constructor") ?
 void (0) : __assert_fail ("!isa<CXXConstructorDecl>(Function) && \"should not have conversion after constructor\""
, "clang/lib/Sema/SemaInit.cpp", 4725, __extension__ __PRETTY_FUNCTION__
))
         "should not have conversion after constructor")(static_cast <bool> (!isa<CXXConstructorDecl>(Function
) && "should not have conversion after constructor") ?
 void (0) : __assert_fail ("!isa<CXXConstructorDecl>(Function) && \"should not have conversion after constructor\""
, "clang/lib/Sema/SemaInit.cpp", 4725, __extension__ __PRETTY_FUNCTION__
));

  ImplicitConversionSequence ICS;
  ICS.setStandard();
  ICS.Standard = Best->FinalConversion;
  Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2));

  // Every implicit conversion results in a prvalue, except for a glvalue
  // derived-to-base conversion, which we handle below.
  cv3T3 = ICS.Standard.getToType(2);
  VK = VK_PRValue;
}

//   If the converted initializer is a prvalue, its type T4 is adjusted to
//   type "cv1 T4" and the temporary materialization conversion is applied.
//
// We adjust the cv-qualifications to match the reference regardless of
// whether we have a prvalue so that the AST records the change. In this
// case, T4 is "cv3 T3".
QualType cv1T4 = S.Context.getQualifiedType(cv3T3, cv1T1.getQualifiers());
if (cv1T4.getQualifiers() != cv3T3.getQualifiers())
  Sequence.AddQualificationConversionStep(cv1T4, VK);
Sequence.AddReferenceBindingStep(cv1T4, VK == VK_PRValue);
VK = IsLValueRef ? VK_LValue : VK_XValue;

if (RefConv & Sema::ReferenceConversions::DerivedToBase)
  Sequence.AddDerivedToBaseCastStep(cv1T1, VK);
else if (RefConv & Sema::ReferenceConversions::ObjC)
  Sequence.AddObjCObjectConversionStep(cv1T1);
else if (RefConv & Sema::ReferenceConversions::Function)
  Sequence.AddFunctionReferenceConversionStep(cv1T1);
else if (RefConv & Sema::ReferenceConversions::Qualification) {
  if (!S.Context.hasSameType(cv1T4, cv1T1))
    Sequence.AddQualificationConversionStep(cv1T1, VK);
}

return OR_Success;
4762}

4764static void CheckCXX98CompatAccessibleCopy(Sema &S,
                                         const InitializedEntity &Entity,
                                         Expr *CurInitExpr);

4768/// Attempt reference initialization (C++0x [dcl.init.ref])
4769static void TryReferenceInitialization(Sema &S,
                                     const InitializedEntity &Entity,
                                     const InitializationKind &Kind,
                                     Expr *Initializer,
                                     InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
Qualifiers T1Quals;
QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
QualType cv2T2 = S.getCompletedType(Initializer);
Qualifiers T2Quals;
QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);

// If the initializer is the address of an overloaded function, try
// to resolve the overloaded function. If all goes well, T2 is the
// type of the resulting function.
if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
                                                 T1, Sequence))
  return;

// Delegate everything else to a subfunction.
TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
                               T1Quals, cv2T2, T2, T2Quals, Sequence);
4792}

4794/// Determine whether an expression is a non-referenceable glvalue (one to
4795/// which a reference can never bind). Attempting to bind a reference to
4796/// such a glvalue will always create a temporary.
4797static bool isNonReferenceableGLValue(Expr *E) {
return E->refersToBitField() || E->refersToVectorElement() ||
       E->refersToMatrixElement();
4800}

4802/// Reference initialization without resolving overloaded functions.
4803///
4804/// We also can get here in C if we call a builtin which is declared as
4805/// a function with a parameter of reference type (such as __builtin_va_end()).
4806static void TryReferenceInitializationCore(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         Expr *Initializer,
                                         QualType cv1T1, QualType T1,
                                         Qualifiers T1Quals,
                                         QualType cv2T2, QualType T2,
                                         Qualifiers T2Quals,
                                         InitializationSequence &Sequence) {
QualType DestType = Entity.getType();
SourceLocation DeclLoc = Initializer->getBeginLoc();

// Compute some basic properties of the types and the initializer.
bool isLValueRef = DestType->isLValueReferenceType();
bool isRValueRef = !isLValueRef;
Expr::Classification InitCategory = Initializer->Classify(S.Context);

Sema::ReferenceConversions RefConv;
Sema::ReferenceCompareResult RefRelationship =
    S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, &RefConv);

// C++0x [dcl.init.ref]p5:
//   A reference to type "cv1 T1" is initialized by an expression of type
//   "cv2 T2" as follows:
//
//     - If the reference is an lvalue reference and the initializer
//       expression
// Note the analogous bullet points for rvalue refs to functions. Because
// there are no function rvalues in C++, rvalue refs to functions are treated
// like lvalue refs.
OverloadingResult ConvOvlResult = OR_Success;
bool T1Function = T1->isFunctionType();
if (isLValueRef || T1Function) {
  if (InitCategory.isLValue() && !isNonReferenceableGLValue(Initializer) &&
      (RefRelationship == Sema::Ref_Compatible ||
       (Kind.isCStyleOrFunctionalCast() &&
        RefRelationship == Sema::Ref_Related))) {
    //   - is an lvalue (but is not a bit-field), and "cv1 T1" is
    //     reference-compatible with "cv2 T2," or
    if (RefConv & (Sema::ReferenceConversions::DerivedToBase |
                   Sema::ReferenceConversions::ObjC)) {
      // If we're converting the pointee, add any qualifiers first;
      // these qualifiers must all be top-level, so just convert to "cv1 T2".
      if (RefConv & (Sema::ReferenceConversions::Qualification))
        Sequence.AddQualificationConversionStep(
            S.Context.getQualifiedType(T2, T1Quals),
            Initializer->getValueKind());
      if (RefConv & Sema::ReferenceConversions::DerivedToBase)
        Sequence.AddDerivedToBaseCastStep(cv1T1, VK_LValue);
      else
        Sequence.AddObjCObjectConversionStep(cv1T1);
    } else if (RefConv & Sema::ReferenceConversions::Qualification) {
      // Perform a (possibly multi-level) qualification conversion.
      Sequence.AddQualificationConversionStep(cv1T1,
                                              Initializer->getValueKind());
    } else if (RefConv & Sema::ReferenceConversions::Function) {
      Sequence.AddFunctionReferenceConversionStep(cv1T1);
    }

    // We only create a temporary here when binding a reference to a
    // bit-field or vector element. Those cases are't supposed to be
    // handled by this bullet, but the outcome is the same either way.
    Sequence.AddReferenceBindingStep(cv1T1, false);
    return;
  }

  //     - has a class type (i.e., T2 is a class type), where T1 is not
  //       reference-related to T2, and can be implicitly converted to an
  //       lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
  //       with "cv3 T3" (this conversion is selected by enumerating the
  //       applicable conversion functions (13.3.1.6) and choosing the best
  //       one through overload resolution (13.3)),
  // If we have an rvalue ref to function type here, the rhs must be
  // an rvalue. DR1287 removed the "implicitly" here.
  if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
      (isLValueRef || InitCategory.isRValue())) {
    if (S.getLangOpts().CPlusPlus) {
      // Try conversion functions only for C++.
      ConvOvlResult = TryRefInitWithConversionFunction(
          S, Entity, Kind, Initializer, /*AllowRValues*/ isRValueRef,
          /*IsLValueRef*/ isLValueRef, Sequence);
      if (ConvOvlResult == OR_Success)
        return;
      if (ConvOvlResult != OR_No_Viable_Function)
        Sequence.SetOverloadFailure(
            InitializationSequence::FK_ReferenceInitOverloadFailed,
            ConvOvlResult);
    } else {
      ConvOvlResult = OR_No_Viable_Function;
    }
  }
}

//     - Otherwise, the reference shall be an lvalue reference to a
//       non-volatile const type (i.e., cv1 shall be const), or the reference
//       shall be an rvalue reference.
//       For address spaces, we interpret this to mean that an addr space
//       of a reference "cv1 T1" is a superset of addr space of "cv2 T2".
if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile() &&
                     T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
  if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
    Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
  else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
    Sequence.SetOverloadFailure(
                      InitializationSequence::FK_ReferenceInitOverloadFailed,
                                ConvOvlResult);
  else if (!InitCategory.isLValue())
    Sequence.SetFailed(
        T1Quals.isAddressSpaceSupersetOf(T2Quals)
            ? InitializationSequence::
                  FK_NonConstLValueReferenceBindingToTemporary
            : InitializationSequence::FK_ReferenceInitDropsQualifiers);
  else {
    InitializationSequence::FailureKind FK;
    switch (RefRelationship) {
    case Sema::Ref_Compatible:
      if (Initializer->refersToBitField())
        FK = InitializationSequence::
            FK_NonConstLValueReferenceBindingToBitfield;
      else if (Initializer->refersToVectorElement())
        FK = InitializationSequence::
            FK_NonConstLValueReferenceBindingToVectorElement;
      else if (Initializer->refersToMatrixElement())
        FK = InitializationSequence::
            FK_NonConstLValueReferenceBindingToMatrixElement;
      else
        llvm_unreachable("unexpected kind of compatible initializer")::llvm::llvm_unreachable_internal("unexpected kind of compatible initializer"
, "clang/lib/Sema/SemaInit.cpp", 4932);
      break;
    case Sema::Ref_Related:
      FK = InitializationSequence::FK_ReferenceInitDropsQualifiers;
      break;
    case Sema::Ref_Incompatible:
      FK = InitializationSequence::
          FK_NonConstLValueReferenceBindingToUnrelated;
      break;
    }
    Sequence.SetFailed(FK);
  }
  return;
}

//    - If the initializer expression
//      - is an
// [<=14] xvalue (but not a bit-field), class prvalue, array prvalue, or
// [1z]   rvalue (but not a bit-field) or
//        function lvalue and "cv1 T1" is reference-compatible with "cv2 T2"
//
// Note: functions are handled above and below rather than here...
if (!T1Function &&
    (RefRelationship == Sema::Ref_Compatible ||
     (Kind.isCStyleOrFunctionalCast() &&
      RefRelationship == Sema::Ref_Related)) &&
    ((InitCategory.isXValue() && !isNonReferenceableGLValue(Initializer)) ||
     (InitCategory.isPRValue() &&
      (S.getLangOpts().CPlusPlus17 || T2->isRecordType() ||
       T2->isArrayType())))) {
  ExprValueKind ValueKind = InitCategory.isXValue() ? VK_XValue : VK_PRValue;
  if (InitCategory.isPRValue() && T2->isRecordType()) {
    // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
    // compiler the freedom to perform a copy here or bind to the
    // object, while C++0x requires that we bind directly to the
    // object. Hence, we always bind to the object without making an
    // extra copy. However, in C++03 requires that we check for the
    // presence of a suitable copy constructor:
    //
    //   The constructor that would be used to make the copy shall
    //   be callable whether or not the copy is actually done.
    if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
      Sequence.AddExtraneousCopyToTemporary(cv2T2);
    else if (S.getLangOpts().CPlusPlus11)
      CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
  }

  // C++1z [dcl.init.ref]/5.2.1.2:
  //   If the converted initializer is a prvalue, its type T4 is adjusted
  //   to type "cv1 T4" and the temporary materialization conversion is
  //   applied.
  // Postpone address space conversions to after the temporary materialization
  // conversion to allow creating temporaries in the alloca address space.
  auto T1QualsIgnoreAS = T1Quals;
  auto T2QualsIgnoreAS = T2Quals;
  if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
    T1QualsIgnoreAS.removeAddressSpace();
    T2QualsIgnoreAS.removeAddressSpace();
  }
  QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS);
  if (T1QualsIgnoreAS != T2QualsIgnoreAS)
    Sequence.AddQualificationConversionStep(cv1T4, ValueKind);
  Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_PRValue);
  ValueKind = isLValueRef ? VK_LValue : VK_XValue;
  // Add addr space conversion if required.
  if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
    auto T4Quals = cv1T4.getQualifiers();
    T4Quals.addAddressSpace(T1Quals.getAddressSpace());
    QualType cv1T4WithAS = S.Context.getQualifiedType(T2, T4Quals);
    Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind);
    cv1T4 = cv1T4WithAS;
  }

  //   In any case, the reference is bound to the resulting glvalue (or to
  //   an appropriate base class subobject).
  if (RefConv & Sema::ReferenceConversions::DerivedToBase)
    Sequence.AddDerivedToBaseCastStep(cv1T1, ValueKind);
  else if (RefConv & Sema::ReferenceConversions::ObjC)
    Sequence.AddObjCObjectConversionStep(cv1T1);
  else if (RefConv & Sema::ReferenceConversions::Qualification) {
    if (!S.Context.hasSameType(cv1T4, cv1T1))
      Sequence.AddQualificationConversionStep(cv1T1, ValueKind);
  }
  return;
}

//       - has a class type (i.e., T2 is a class type), where T1 is not
//         reference-related to T2, and can be implicitly converted to an
//         xvalue, class prvalue, or function lvalue of type "cv3 T3",
//         where "cv1 T1" is reference-compatible with "cv3 T3",
//
// DR1287 removes the "implicitly" here.
if (T2->isRecordType()) {
  if (RefRelationship == Sema::Ref_Incompatible) {
    ConvOvlResult = TryRefInitWithConversionFunction(
        S, Entity, Kind, Initializer, /*AllowRValues*/ true,
        /*IsLValueRef*/ isLValueRef, Sequence);
    if (ConvOvlResult)
      Sequence.SetOverloadFailure(
          InitializationSequence::FK_ReferenceInitOverloadFailed,
          ConvOvlResult);

    return;
  }

  if (RefRelationship == Sema::Ref_Compatible &&
      isRValueRef && InitCategory.isLValue()) {
    Sequence.SetFailed(
      InitializationSequence::FK_RValueReferenceBindingToLValue);
    return;
  }

  Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
  return;
}

//      - Otherwise, a temporary of type "cv1 T1" is created and initialized
//        from the initializer expression using the rules for a non-reference
//        copy-initialization (8.5). The reference is then bound to the
//        temporary. [...]

// Ignore address space of reference type at this point and perform address
// space conversion after the reference binding step.
QualType cv1T1IgnoreAS =
    T1Quals.hasAddressSpace()
        ? S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace())
        : cv1T1;

InitializedEntity TempEntity =
    InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);

// FIXME: Why do we use an implicit conversion here rather than trying
// copy-initialization?
ImplicitConversionSequence ICS
  = S.TryImplicitConversion(Initializer, TempEntity.getType(),
                            /*SuppressUserConversions=*/false,
                            Sema::AllowedExplicit::None,
                            /*FIXME:InOverloadResolution=*/false,
                            /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
                            /*AllowObjCWritebackConversion=*/false);

if (ICS.isBad()) {
  // FIXME: Use the conversion function set stored in ICS to turn
  // this into an overloading ambiguity diagnostic. However, we need
  // to keep that set as an OverloadCandidateSet rather than as some
  // other kind of set.
  if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
    Sequence.SetOverloadFailure(
                      InitializationSequence::FK_ReferenceInitOverloadFailed,
                                ConvOvlResult);
  else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
    Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
  else
    Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
  return;
} else {
  Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
}

//        [...] If T1 is reference-related to T2, cv1 must be the
//        same cv-qualification as, or greater cv-qualification
//        than, cv2; otherwise, the program is ill-formed.
unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
if (RefRelationship == Sema::Ref_Related &&
    ((T1CVRQuals | T2CVRQuals) != T1CVRQuals ||
     !T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
  Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
  return;
}

//   [...] If T1 is reference-related to T2 and the reference is an rvalue
//   reference, the initializer expression shall not be an lvalue.
if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
    InitCategory.isLValue()) {
  Sequence.SetFailed(
                  InitializationSequence::FK_RValueReferenceBindingToLValue);
  return;
}

Sequence.AddReferenceBindingStep(cv1T1IgnoreAS, /*BindingTemporary=*/true);

if (T1Quals.hasAddressSpace()) {
  if (!Qualifiers::isAddressSpaceSupersetOf(T1Quals.getAddressSpace(),
                                            LangAS::Default)) {
    Sequence.SetFailed(
        InitializationSequence::FK_ReferenceAddrspaceMismatchTemporary);
    return;
  }
  Sequence.AddQualificationConversionStep(cv1T1, isLValueRef ? VK_LValue
                                                             : VK_XValue);
}
5124}

5126/// Attempt character array initialization from a string literal
5127/// (C++ [dcl.init.string], C99 6.7.8).
5128static void TryStringLiteralInitialization(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         Expr *Initializer,
                                     InitializationSequence &Sequence) {
Sequence.AddStringInitStep(Entity.getType());
5134}

5136/// Attempt value initialization (C++ [dcl.init]p7).
5137static void TryValueInitialization(Sema &S,
                                 const InitializedEntity &Entity,
                                 const InitializationKind &Kind,
                                 InitializationSequence &Sequence,
                                 InitListExpr *InitList) {
assert((!InitList || InitList->getNumInits() == 0) &&(static_cast <bool> ((!InitList || InitList->getNumInits
() == 0) && "Shouldn't use value-init for non-empty init lists"
) ? void (0) : __assert_fail ("(!InitList || InitList->getNumInits() == 0) && \"Shouldn't use value-init for non-empty init lists\""
, "clang/lib/Sema/SemaInit.cpp", 5143, __extension__ __PRETTY_FUNCTION__
))
       "Shouldn't use value-init for non-empty init lists")(static_cast <bool> ((!InitList || InitList->getNumInits
() == 0) && "Shouldn't use value-init for non-empty init lists"
) ? void (0) : __assert_fail ("(!InitList || InitList->getNumInits() == 0) && \"Shouldn't use value-init for non-empty init lists\""
, "clang/lib/Sema/SemaInit.cpp", 5143, __extension__ __PRETTY_FUNCTION__
));

// C++98 [dcl.init]p5, C++11 [dcl.init]p7:
//
//   To value-initialize an object of type T means:
QualType T = Entity.getType();

//     -- if T is an array type, then each element is value-initialized;
T = S.Context.getBaseElementType(T);

if (const RecordType *RT = T->getAs<RecordType>()) {
  if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
    bool NeedZeroInitialization = true;
    // C++98:
    // -- if T is a class type (clause 9) with a user-declared constructor
    //    (12.1), then the default constructor for T is called (and the
    //    initialization is ill-formed if T has no accessible default
    //    constructor);
    // C++11:
    // -- if T is a class type (clause 9) with either no default constructor
    //    (12.1 [class.ctor]) or a default constructor that is user-provided
    //    or deleted, then the object is default-initialized;
    //
    // Note that the C++11 rule is the same as the C++98 rule if there are no
    // defaulted or deleted constructors, so we just use it unconditionally.
    CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
    if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
      NeedZeroInitialization = false;

    // -- if T is a (possibly cv-qualified) non-union class type without a
    //    user-provided or deleted default constructor, then the object is
    //    zero-initialized and, if T has a non-trivial default constructor,
    //    default-initialized;
    // The 'non-union' here was removed by DR1502. The 'non-trivial default
    // constructor' part was removed by DR1507.
    if (NeedZeroInitialization)
      Sequence.AddZeroInitializationStep(Entity.getType());

    // C++03:
    // -- if T is a non-union class type without a user-declared constructor,
    //    then every non-static data member and base class component of T is
    //    value-initialized;
    // [...] A program that calls for [...] value-initialization of an
    // entity of reference type is ill-formed.
    //
    // C++11 doesn't need this handling, because value-initialization does not
    // occur recursively there, and the implicit default constructor is
    // defined as deleted in the problematic cases.
    if (!S.getLangOpts().CPlusPlus11 &&
        ClassDecl->hasUninitializedReferenceMember()) {
      Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
      return;
    }

    // If this is list-value-initialization, pass the empty init list on when
    // building the constructor call. This affects the semantics of a few
    // things (such as whether an explicit default constructor can be called).
    Expr *InitListAsExpr = InitList;
    MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
    bool InitListSyntax = InitList;

    // FIXME: Instead of creating a CXXConstructExpr of array type here,
    // wrap a class-typed CXXConstructExpr in an ArrayInitLoopExpr.
    return TryConstructorInitialization(
        S, Entity, Kind, Args, T, Entity.getType(), Sequence, InitListSyntax);
  }
}

Sequence.AddZeroInitializationStep(Entity.getType());
5212}

5214/// Attempt default initialization (C++ [dcl.init]p6).
5215static void TryDefaultInitialization(Sema &S,
                                   const InitializedEntity &Entity,
                                   const InitializationKind &Kind,
                                   InitializationSequence &Sequence) {
assert(Kind.getKind() == InitializationKind::IK_Default)(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Default) ? void (0) : __assert_fail ("Kind.getKind() == InitializationKind::IK_Default"
, "clang/lib/Sema/SemaInit.cpp", 5219, __extension__ __PRETTY_FUNCTION__
));

// C++ [dcl.init]p6:
//   To default-initialize an object of type T means:
//     - if T is an array type, each element is default-initialized;
QualType DestType = S.Context.getBaseElementType(Entity.getType());

//     - if T is a (possibly cv-qualified) class type (Clause 9), the default
//       constructor for T is called (and the initialization is ill-formed if
//       T has no accessible default constructor);
if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
  TryConstructorInitialization(S, Entity, Kind, None, DestType,
                               Entity.getType(), Sequence);
  return;
}

//     - otherwise, no initialization is performed.

//   If a program calls for the default initialization of an object of
//   a const-qualified type T, T shall be a class type with a user-provided
//   default constructor.
if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
  if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
    Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
  return;
}

// If the destination type has a lifetime property, zero-initialize it.
if (DestType.getQualifiers().hasObjCLifetime()) {
  Sequence.AddZeroInitializationStep(Entity.getType());
  return;
}
5251}

5253/// Attempt a user-defined conversion between two types (C++ [dcl.init]),
5254/// which enumerates all conversion functions and performs overload resolution
5255/// to select the best.
5256static void TryUserDefinedConversion(Sema &S,
                                   QualType DestType,
                                   const InitializationKind &Kind,
                                   Expr *Initializer,
                                   InitializationSequence &Sequence,
                                   bool TopLevelOfInitList) {
assert(!DestType->isReferenceType() && "References are handled elsewhere")(static_cast <bool> (!DestType->isReferenceType() &&
 "References are handled elsewhere") ? void (0) : __assert_fail
 ("!DestType->isReferenceType() && \"References are handled elsewhere\""
, "clang/lib/Sema/SemaInit.cpp", 5262, __extension__ __PRETTY_FUNCTION__
));
QualType SourceType = Initializer->getType();
assert((DestType->isRecordType() || SourceType->isRecordType()) &&(static_cast <bool> ((DestType->isRecordType() || SourceType
->isRecordType()) && "Must have a class type to perform a user-defined conversion"
) ? void (0) : __assert_fail ("(DestType->isRecordType() || SourceType->isRecordType()) && \"Must have a class type to perform a user-defined conversion\""
, "clang/lib/Sema/SemaInit.cpp", 5265, __extension__ __PRETTY_FUNCTION__
))
       "Must have a class type to perform a user-defined conversion")(static_cast <bool> ((DestType->isRecordType() || SourceType
->isRecordType()) && "Must have a class type to perform a user-defined conversion"
) ? void (0) : __assert_fail ("(DestType->isRecordType() || SourceType->isRecordType()) && \"Must have a class type to perform a user-defined conversion\""
, "clang/lib/Sema/SemaInit.cpp", 5265, __extension__ __PRETTY_FUNCTION__
));

// Build the candidate set directly in the initialization sequence
// structure, so that it will persist if we fail.
OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());

// Determine whether we are allowed to call explicit constructors or
// explicit conversion operators.
bool AllowExplicit = Kind.AllowExplicit();

if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
  // The type we're converting to is a class type. Enumerate its constructors
  // to see if there is a suitable conversion.
  CXXRecordDecl *DestRecordDecl
    = cast<CXXRecordDecl>(DestRecordType->getDecl());

  // Try to complete the type we're converting to.
  if (S.isCompleteType(Kind.getLocation(), DestType)) {
    for (NamedDecl *D : S.LookupConstructors(DestRecordDecl)) {
      auto Info = getConstructorInfo(D);
      if (!Info.Constructor)
        continue;

      if (!Info.Constructor->isInvalidDecl() &&
          Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
        if (Info.ConstructorTmpl)
          S.AddTemplateOverloadCandidate(
              Info.ConstructorTmpl, Info.FoundDecl,
              /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
              /*SuppressUserConversions=*/true,
              /*PartialOverloading*/ false, AllowExplicit);
        else
          S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
                                 Initializer, CandidateSet,
                                 /*SuppressUserConversions=*/true,
                                 /*PartialOverloading*/ false, AllowExplicit);
      }
    }
  }
}

SourceLocation DeclLoc = Initializer->getBeginLoc();

if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
  // The type we're converting from is a class type, enumerate its conversion
  // functions.

  // We can only enumerate the conversion functions for a complete type; if
  // the type isn't complete, simply skip this step.
  if (S.isCompleteType(DeclLoc, SourceType)) {
    CXXRecordDecl *SourceRecordDecl
      = cast<CXXRecordDecl>(SourceRecordType->getDecl());

    const auto &Conversions =
        SourceRecordDecl->getVisibleConversionFunctions();
    for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
      NamedDecl *D = *I;
      CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
      if (isa<UsingShadowDecl>(D))
        D = cast<UsingShadowDecl>(D)->getTargetDecl();

      FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
      CXXConversionDecl *Conv;
      if (ConvTemplate)
        Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
      else
        Conv = cast<CXXConversionDecl>(D);

      if (ConvTemplate)
        S.AddTemplateConversionCandidate(
            ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
            CandidateSet, AllowExplicit, AllowExplicit);
      else
        S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
                                 DestType, CandidateSet, AllowExplicit,
                                 AllowExplicit);
    }
  }
}

// Perform overload resolution. If it fails, return the failed result.
OverloadCandidateSet::iterator Best;
if (OverloadingResult Result
      = CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
  Sequence.SetOverloadFailure(
      InitializationSequence::FK_UserConversionOverloadFailed, Result);

  // [class.copy.elision]p3:
  // In some copy-initialization contexts, a two-stage overload resolution
  // is performed.
  // If the first overload resolution selects a deleted function, we also
  // need the initialization sequence to decide whether to perform the second
  // overload resolution.
  if (!(Result == OR_Deleted &&
        Kind.getKind() == InitializationKind::IK_Copy))
    return;
}

FunctionDecl *Function = Best->Function;
Function->setReferenced();
bool HadMultipleCandidates = (CandidateSet.size() > 1);

if (isa<CXXConstructorDecl>(Function)) {
  // Add the user-defined conversion step. Any cv-qualification conversion is
  // subsumed by the initialization. Per DR5, the created temporary is of the
  // cv-unqualified type of the destination.
  Sequence.AddUserConversionStep(Function, Best->FoundDecl,
                                 DestType.getUnqualifiedType(),
                                 HadMultipleCandidates);

  // C++14 and before:
  //   - if the function is a constructor, the call initializes a temporary
  //     of the cv-unqualified version of the destination type. The [...]
  //     temporary [...] is then used to direct-initialize, according to the
  //     rules above, the object that is the destination of the
  //     copy-initialization.
  // Note that this just performs a simple object copy from the temporary.
  //
  // C++17:
  //   - if the function is a constructor, the call is a prvalue of the
  //     cv-unqualified version of the destination type whose return object
  //     is initialized by the constructor. The call is used to
  //     direct-initialize, according to the rules above, the object that
  //     is the destination of the copy-initialization.
  // Therefore we need to do nothing further.
  //
  // FIXME: Mark this copy as extraneous.
  if (!S.getLangOpts().CPlusPlus17)
    Sequence.AddFinalCopy(DestType);
  else if (DestType.hasQualifiers())
    Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
  return;
}

// Add the user-defined conversion step that calls the conversion function.
QualType ConvType = Function->getCallResultType();
Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
                               HadMultipleCandidates);

if (ConvType->getAs<RecordType>()) {
  //   The call is used to direct-initialize [...] the object that is the
  //   destination of the copy-initialization.
  //
  // In C++17, this does not call a constructor if we enter /17.6.1:
  //   - If the initializer expression is a prvalue and the cv-unqualified
  //     version of the source type is the same as the class of the
  //     destination [... do not make an extra copy]
  //
  // FIXME: Mark this copy as extraneous.
  if (!S.getLangOpts().CPlusPlus17 ||
      Function->getReturnType()->isReferenceType() ||
      !S.Context.hasSameUnqualifiedType(ConvType, DestType))
    Sequence.AddFinalCopy(DestType);
  else if (!S.Context.hasSameType(ConvType, DestType))
    Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
  return;
}

// If the conversion following the call to the conversion function
// is interesting, add it as a separate step.
if (Best->FinalConversion.First || Best->FinalConversion.Second ||
    Best->FinalConversion.Third) {
  ImplicitConversionSequence ICS;
  ICS.setStandard();
  ICS.Standard = Best->FinalConversion;
  Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
}
5434}

5436/// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
5437/// a function with a pointer return type contains a 'return false;' statement.
5438/// In C++11, 'false' is not a null pointer, so this breaks the build of any
5439/// code using that header.
5440///
5441/// Work around this by treating 'return false;' as zero-initializing the result
5442/// if it's used in a pointer-returning function in a system header.
5443static bool isLibstdcxxPointerReturnFalseHack(Sema &S,
                                            const InitializedEntity &Entity,
                                            const Expr *Init) {
return S.getLangOpts().CPlusPlus11 &&
       Entity.getKind() == InitializedEntity::EK_Result &&
       Entity.getType()->isPointerType() &&
       isa<CXXBoolLiteralExpr>(Init) &&
       !cast<CXXBoolLiteralExpr>(Init)->getValue() &&
       S.getSourceManager().isInSystemHeader(Init->getExprLoc());
5452}

5454/// The non-zero enum values here are indexes into diagnostic alternatives.
5455enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };

5457/// Determines whether this expression is an acceptable ICR source.
5458static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
                                       bool isAddressOf, bool &isWeakAccess) {
// Skip parens.
e = e->IgnoreParens();

// Skip address-of nodes.
if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
  if (op->getOpcode() == UO_AddrOf)
    return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
                              isWeakAccess);

// Skip certain casts.
} else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
  switch (ce->getCastKind()) {
  case CK_Dependent:
  case CK_BitCast:
  case CK_LValueBitCast:
  case CK_NoOp:
    return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);

  case CK_ArrayToPointerDecay:
    return IIK_nonscalar;

  case CK_NullToPointer:
    return IIK_okay;

  default:
    break;
  }

// If we have a declaration reference, it had better be a local variable.
} else if (isa<DeclRefExpr>(e)) {
  // set isWeakAccess to true, to mean that there will be an implicit
  // load which requires a cleanup.
  if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
    isWeakAccess = true;

  if (!isAddressOf) return IIK_nonlocal;

  VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
  if (!var) return IIK_nonlocal;

  return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);

// If we have a conditional operator, check both sides.
} else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
  if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
                                              isWeakAccess))
    return iik;

  return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);

// These are never scalar.
} else if (isa<ArraySubscriptExpr>(e)) {
  return IIK_nonscalar;

// Otherwise, it needs to be a null pointer constant.
} else {
  return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
          ? IIK_okay : IIK_nonlocal);
}

return IIK_nonlocal;
5521}

5523/// Check whether the given expression is a valid operand for an
5524/// indirect copy/restore.
5525static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
assert(src->isPRValue())(static_cast <bool> (src->isPRValue()) ? void (0) : __assert_fail
 ("src->isPRValue()", "clang/lib/Sema/SemaInit.cpp", 5526,
 __extension__ __PRETTY_FUNCTION__));
bool isWeakAccess = false;
InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
// If isWeakAccess to true, there will be an implicit
// load which requires a cleanup.
if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
  S.Cleanup.setExprNeedsCleanups(true);

if (iik == IIK_okay) return;

S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
  << ((unsigned) iik - 1)  // shift index into diagnostic explanations
  << src->getSourceRange();
5539}

5541/// Determine whether we have compatible array types for the
5542/// purposes of GNU by-copy array initialization.
5543static bool hasCompatibleArrayTypes(ASTContext &Context, const ArrayType *Dest,
                                  const ArrayType *Source) {
// If the source and destination array types are equivalent, we're
// done.
if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
  return true;

// Make sure that the element types are the same.
if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
  return false;

// The only mismatch we allow is when the destination is an
// incomplete array type and the source is a constant array type.
return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
5557}

5559static bool tryObjCWritebackConversion(Sema &S,
                                     InitializationSequence &Sequence,
                                     const InitializedEntity &Entity,
                                     Expr *Initializer) {
bool ArrayDecay = false;
QualType ArgType = Initializer->getType();
QualType ArgPointee;
if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
  ArrayDecay = true;
  ArgPointee = ArgArrayType->getElementType();
  ArgType = S.Context.getPointerType(ArgPointee);
}

// Handle write-back conversion.
QualType ConvertedArgType;
if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
                                 ConvertedArgType))
  return false;

// We should copy unless we're passing to an argument explicitly
// marked 'out'.
bool ShouldCopy = true;
if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
  ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);

// Do we need an lvalue conversion?
if (ArrayDecay || Initializer->isGLValue()) {
  ImplicitConversionSequence ICS;
  ICS.setStandard();
  ICS.Standard.setAsIdentityConversion();

  QualType ResultType;
  if (ArrayDecay) {
    ICS.Standard.First = ICK_Array_To_Pointer;
    ResultType = S.Context.getPointerType(ArgPointee);
  } else {
    ICS.Standard.First = ICK_Lvalue_To_Rvalue;
    ResultType = Initializer->getType().getNonLValueExprType(S.Context);
  }

  Sequence.AddConversionSequenceStep(ICS, ResultType);
}

Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
return true;
5604}

5606static bool TryOCLSamplerInitialization(Sema &S,
                                      InitializationSequence &Sequence,
                                      QualType DestType,
                                      Expr *Initializer) {
if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
    (!Initializer->isIntegerConstantExpr(S.Context) &&
    !Initializer->getType()->isSamplerT()))
  return false;

Sequence.AddOCLSamplerInitStep(DestType);
return true;
5617}

5619static bool IsZeroInitializer(Expr *Initializer, Sema &S) {
return Initializer->isIntegerConstantExpr(S.getASTContext()) &&
  (Initializer->EvaluateKnownConstInt(S.getASTContext()) == 0);
5622}

5624static bool TryOCLZeroOpaqueTypeInitialization(Sema &S,
                                             InitializationSequence &Sequence,
                                             QualType DestType,
                                             Expr *Initializer) {
if (!S.getLangOpts().OpenCL)
  return false;

//
// OpenCL 1.2 spec, s6.12.10
//
// The event argument can also be used to associate the
// async_work_group_copy with a previous async copy allowing
// an event to be shared by multiple async copies; otherwise
// event should be zero.
//
if (DestType->isEventT() || DestType->isQueueT()) {
  if (!IsZeroInitializer(Initializer, S))
    return false;

  Sequence.AddOCLZeroOpaqueTypeStep(DestType);
  return true;
}

// We should allow zero initialization for all types defined in the
// cl_intel_device_side_avc_motion_estimation extension, except
// intel_sub_group_avc_mce_payload_t and intel_sub_group_avc_mce_result_t.
if (S.getOpenCLOptions().isAvailableOption(
        "cl_intel_device_side_avc_motion_estimation", S.getLangOpts()) &&
    DestType->isOCLIntelSubgroupAVCType()) {
  if (DestType->isOCLIntelSubgroupAVCMcePayloadType() ||
      DestType->isOCLIntelSubgroupAVCMceResultType())
    return false;
  if (!IsZeroInitializer(Initializer, S))
    return false;

  Sequence.AddOCLZeroOpaqueTypeStep(DestType);
  return true;
}

return false;
5664}

5666InitializationSequence::InitializationSequence(
  Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
  MultiExprArg Args, bool TopLevelOfInitList, bool TreatUnavailableAsInvalid)
  : FailedOverloadResult(OR_Success),
    FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList,
               TreatUnavailableAsInvalid);
5673}

5675/// Tries to get a FunctionDecl out of `E`. If it succeeds and we can take the
5676/// address of that function, this returns true. Otherwise, it returns false.
5677static bool isExprAnUnaddressableFunction(Sema &S, const Expr *E) {
auto *DRE = dyn_cast<DeclRefExpr>(E);
if (!DRE || !isa<FunctionDecl>(DRE->getDecl()))
  return false;

return !S.checkAddressOfFunctionIsAvailable(
    cast<FunctionDecl>(DRE->getDecl()));
5684}

5686/// Determine whether we can perform an elementwise array copy for this kind
5687/// of entity.
5688static bool canPerformArrayCopy(const InitializedEntity &Entity) {
switch (Entity.getKind()) {
case InitializedEntity::EK_LambdaCapture:
  // C++ [expr.prim.lambda]p24:
  //   For array members, the array elements are direct-initialized in
  //   increasing subscript order.
  return true;

case InitializedEntity::EK_Variable:
  // C++ [dcl.decomp]p1:
  //   [...] each element is copy-initialized or direct-initialized from the
  //   corresponding element of the assignment-expression [...]
  return isa<DecompositionDecl>(Entity.getDecl());

case InitializedEntity::EK_Member:
  // C++ [class.copy.ctor]p14:
  //   - if the member is an array, each element is direct-initialized with
  //     the corresponding subobject of x
  return Entity.isImplicitMemberInitializer();

case InitializedEntity::EK_ArrayElement:
  // All the above cases are intended to apply recursively, even though none
  // of them actually say that.
  if (auto *E = Entity.getParent())
    return canPerformArrayCopy(*E);
  break;

default:
  break;
}

return false;
5720}

5722void InitializationSequence::InitializeFrom(Sema &S,
                                          const InitializedEntity &Entity,
                                          const InitializationKind &Kind,
                                          MultiExprArg Args,
                                          bool TopLevelOfInitList,
                                          bool TreatUnavailableAsInvalid) {
ASTContext &Context = S.Context;

// Eliminate non-overload placeholder types in the arguments.  We
// need to do this before checking whether types are dependent
// because lowering a pseudo-object expression might well give us
// something of dependent type.
for (unsigned I = 0, E = Args.size(); I != E; ++I)
  if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
    // FIXME: should we be doing this here?
    ExprResult result = S.CheckPlaceholderExpr(Args[I]);
    if (result.isInvalid()) {
      SetFailed(FK_PlaceholderType);
      return;
    }
    Args[I] = result.get();
  }

// C++0x [dcl.init]p16:
//   The semantics of initializers are as follows. The destination type is
//   the type of the object or reference being initialized and the source
//   type is the type of the initializer expression. The source type is not
//   defined when the initializer is a braced-init-list or when it is a
//   parenthesized list of expressions.
QualType DestType = Entity.getType();

if (DestType->isDependentType() ||
    Expr::hasAnyTypeDependentArguments(Args)) {
  SequenceKind = DependentSequence;
  return;
}

// Almost everything is a normal sequence.
setSequenceKind(NormalSequence);

QualType SourceType;
Expr *Initializer = nullptr;
if (Args.size() == 1) {
  Initializer = Args[0];
  if (S.getLangOpts().ObjC) {
    if (S.CheckObjCBridgeRelatedConversions(Initializer->getBeginLoc(),
                                            DestType, Initializer->getType(),
                                            Initializer) ||
        S.CheckConversionToObjCLiteral(DestType, Initializer))
      Args[0] = Initializer;
  }
  if (!isa<InitListExpr>(Initializer))
    SourceType = Initializer->getType();
}

//     - If the initializer is a (non-parenthesized) braced-init-list, the
//       object is list-initialized (8.5.4).
if (Kind.getKind() != InitializationKind::IK_Direct) {
  if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
    TryListInitialization(S, Entity, Kind, InitList, *this,
                          TreatUnavailableAsInvalid);
    return;
  }
}

//     - If the destination type is a reference type, see 8.5.3.
if (DestType->isReferenceType()) {
  // C++0x [dcl.init.ref]p1:
  //   A variable declared to be a T& or T&&, that is, "reference to type T"
  //   (8.3.2), shall be initialized by an object, or function, of type T or
  //   by an object that can be converted into a T.
  // (Therefore, multiple arguments are not permitted.)
  if (Args.size() != 1)
    SetFailed(FK_TooManyInitsForReference);
  // C++17 [dcl.init.ref]p5:
  //   A reference [...] is initialized by an expression [...] as follows:
  // If the initializer is not an expression, presumably we should reject,
  // but the standard fails to actually say so.
  else if (isa<InitListExpr>(Args[0]))
    SetFailed(FK_ParenthesizedListInitForReference);
  else
    TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
  return;
}

//     - If the initializer is (), the object is value-initialized.
if (Kind.getKind() == InitializationKind::IK_Value ||
    (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) {
  TryValueInitialization(S, Entity, Kind, *this);
  return;
}

// Handle default initialization.
if (Kind.getKind() == InitializationKind::IK_Default) {
  TryDefaultInitialization(S, Entity, Kind, *this);
  return;
}

//     - If the destination type is an array of characters, an array of
//       char16_t, an array of char32_t, or an array of wchar_t, and the
//       initializer is a string literal, see 8.5.2.
//     - Otherwise, if the destination type is an array, the program is
//       ill-formed.
if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
  if (Initializer && isa<VariableArrayType>(DestAT)) {
    SetFailed(FK_VariableLengthArrayHasInitializer);
    return;
  }

  if (Initializer) {
    switch (IsStringInit(Initializer, DestAT, Context)) {
    case SIF_None:
      TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
      return;
    case SIF_NarrowStringIntoWideChar:
      SetFailed(FK_NarrowStringIntoWideCharArray);
      return;
    case SIF_WideStringIntoChar:
      SetFailed(FK_WideStringIntoCharArray);
      return;
    case SIF_IncompatWideStringIntoWideChar:
      SetFailed(FK_IncompatWideStringIntoWideChar);
      return;
    case SIF_PlainStringIntoUTF8Char:
      SetFailed(FK_PlainStringIntoUTF8Char);
      return;
    case SIF_UTF8StringIntoPlainChar:
      SetFailed(FK_UTF8StringIntoPlainChar);
      return;
    case SIF_Other:
      break;
    }
  }

  // Some kinds of initialization permit an array to be initialized from
  // another array of the same type, and perform elementwise initialization.
  if (Initializer && isa<ConstantArrayType>(DestAT) &&
      S.Context.hasSameUnqualifiedType(Initializer->getType(),
                                       Entity.getType()) &&
      canPerformArrayCopy(Entity)) {
    // If source is a prvalue, use it directly.
    if (Initializer->isPRValue()) {
      AddArrayInitStep(DestType, /*IsGNUExtension*/false);
      return;
    }

    // Emit element-at-a-time copy loop.
    InitializedEntity Element =
        InitializedEntity::InitializeElement(S.Context, 0, Entity);
    QualType InitEltT =
        Context.getAsArrayType(Initializer->getType())->getElementType();
    OpaqueValueExpr OVE(Initializer->getExprLoc(), InitEltT,
                        Initializer->getValueKind(),
                        Initializer->getObjectKind());
    Expr *OVEAsExpr = &OVE;
    InitializeFrom(S, Element, Kind, OVEAsExpr, TopLevelOfInitList,
                   TreatUnavailableAsInvalid);
    if (!Failed())
      AddArrayInitLoopStep(Entity.getType(), InitEltT);
    return;
  }

  // Note: as an GNU C extension, we allow initialization of an
  // array from a compound literal that creates an array of the same
  // type, so long as the initializer has no side effects.
  if (!S.getLangOpts().CPlusPlus && Initializer &&
      isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) &&
      Initializer->getType()->isArrayType()) {
    const ArrayType *SourceAT
      = Context.getAsArrayType(Initializer->getType());
    if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT))
      SetFailed(FK_ArrayTypeMismatch);
    else if (Initializer->HasSideEffects(S.Context))
      SetFailed(FK_NonConstantArrayInit);
    else {
      AddArrayInitStep(DestType, /*IsGNUExtension*/true);
    }
  }
  // Note: as a GNU C++ extension, we allow list-initialization of a
  // class member of array type from a parenthesized initializer list.
  else if (S.getLangOpts().CPlusPlus &&
           Entity.getKind() == InitializedEntity::EK_Member &&
           Initializer && isa<InitListExpr>(Initializer)) {
    TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer),
                          *this, TreatUnavailableAsInvalid);
    AddParenthesizedArrayInitStep(DestType);
  } else if (DestAT->getElementType()->isCharType())
    SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
  else if (IsWideCharCompatible(DestAT->getElementType(), Context))
    SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral);
  else
    SetFailed(FK_ArrayNeedsInitList);

  return;
}

// Determine whether we should consider writeback conversions for
// Objective-C ARC.
bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
       Entity.isParameterKind();

if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
  return;

// We're at the end of the line for C: it's either a write-back conversion
// or it's a C assignment. There's no need to check anything else.
if (!S.getLangOpts().CPlusPlus) {
  // If allowed, check whether this is an Objective-C writeback conversion.
  if (allowObjCWritebackConversion &&
      tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
    return;
  }

  if (TryOCLZeroOpaqueTypeInitialization(S, *this, DestType, Initializer))
    return;

  // Handle initialization in C
  AddCAssignmentStep(DestType);
  MaybeProduceObjCObject(S, *this, Entity);
  return;
}

assert(S.getLangOpts().CPlusPlus)(static_cast <bool> (S.getLangOpts().CPlusPlus) ? void (
0) : __assert_fail ("S.getLangOpts().CPlusPlus", "clang/lib/Sema/SemaInit.cpp"
, 5944, __extension__ __PRETTY_FUNCTION__));

//     - If the destination type is a (possibly cv-qualified) class type:
if (DestType->isRecordType()) {
  //     - If the initialization is direct-initialization, or if it is
  //       copy-initialization where the cv-unqualified version of the
  //       source type is the same class as, or a derived class of, the
  //       class of the destination, constructors are considered. [...]
  if (Kind.getKind() == InitializationKind::IK_Direct ||
      (Kind.getKind() == InitializationKind::IK_Copy &&
       (Context.hasSameUnqualifiedType(SourceType, DestType) ||
        S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType, DestType))))
    TryConstructorInitialization(S, Entity, Kind, Args,
                                 DestType, DestType, *this);
  //     - Otherwise (i.e., for the remaining copy-initialization cases),
  //       user-defined conversion sequences that can convert from the source
  //       type to the destination type or (when a conversion function is
  //       used) to a derived class thereof are enumerated as described in
  //       13.3.1.4, and the best one is chosen through overload resolution
  //       (13.3).
  else
    TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
                             TopLevelOfInitList);
  return;
}

assert(Args.size() >= 1 && "Zero-argument case handled above")(static_cast <bool> (Args.size() >= 1 && "Zero-argument case handled above"
) ? void (0) : __assert_fail ("Args.size() >= 1 && \"Zero-argument case handled above\""
, "clang/lib/Sema/SemaInit.cpp", 5970, __extension__ __PRETTY_FUNCTION__
));

// For HLSL ext vector types we allow list initialization behavior for C++
// constructor syntax. This is accomplished by converting initialization
// arguments an InitListExpr late.
if (S.getLangOpts().HLSL && DestType->isExtVectorType() &&
    (SourceType.isNull() ||
     !Context.hasSameUnqualifiedType(SourceType, DestType))) {

  llvm::SmallVector<Expr *> InitArgs;
  for (auto *Arg : Args) {
    if (Arg->getType()->isExtVectorType()) {
      const auto *VTy = Arg->getType()->castAs<ExtVectorType>();
      unsigned Elm = VTy->getNumElements();
      for (unsigned Idx = 0; Idx < Elm; ++Idx) {
        InitArgs.emplace_back(new (Context) ArraySubscriptExpr(
            Arg,
            IntegerLiteral::Create(
                Context, llvm::APInt(Context.getIntWidth(Context.IntTy), Idx),
                Context.IntTy, SourceLocation()),
            VTy->getElementType(), Arg->getValueKind(), Arg->getObjectKind(),
            SourceLocation()));
      }
    } else
      InitArgs.emplace_back(Arg);
  }
  InitListExpr *ILE = new (Context) InitListExpr(
      S.getASTContext(), SourceLocation(), InitArgs, SourceLocation());
  Args[0] = ILE;
  AddListInitializationStep(DestType);
  return;
}

// The remaining cases all need a source type.
if (Args.size() > 1) {
  SetFailed(FK_TooManyInitsForScalar);
  return;
} else if (isa<InitListExpr>(Args[0])) {
  SetFailed(FK_ParenthesizedListInitForScalar);
  return;
}

//    - Otherwise, if the source type is a (possibly cv-qualified) class
//      type, conversion functions are considered.
if (!SourceType.isNull() && SourceType->isRecordType()) {
  // For a conversion to _Atomic(T) from either T or a class type derived
  // from T, initialize the T object then convert to _Atomic type.
  bool NeedAtomicConversion = false;
  if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) {
    if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) ||
        S.IsDerivedFrom(Initializer->getBeginLoc(), SourceType,
                        Atomic->getValueType())) {
      DestType = Atomic->getValueType();
      NeedAtomicConversion = true;
    }
  }

  TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
                           TopLevelOfInitList);
  MaybeProduceObjCObject(S, *this, Entity);
  if (!Failed() && NeedAtomicConversion)
    AddAtomicConversionStep(Entity.getType());
  return;
}

//    - Otherwise, if the initialization is direct-initialization, the source
//    type is std::nullptr_t, and the destination type is bool, the initial
//    value of the object being initialized is false.
if (!SourceType.isNull() && SourceType->isNullPtrType() &&
    DestType->isBooleanType() &&
    Kind.getKind() == InitializationKind::IK_Direct) {
  AddConversionSequenceStep(
      ImplicitConversionSequence::getNullptrToBool(SourceType, DestType,
                                                   Initializer->isGLValue()),
      DestType);
  return;
}

//    - Otherwise, the initial value of the object being initialized is the
//      (possibly converted) value of the initializer expression. Standard
//      conversions (Clause 4) will be used, if necessary, to convert the
//      initializer expression to the cv-unqualified version of the
//      destination type; no user-defined conversions are considered.

ImplicitConversionSequence ICS
  = S.TryImplicitConversion(Initializer, DestType,
                            /*SuppressUserConversions*/true,
                            Sema::AllowedExplicit::None,
                            /*InOverloadResolution*/ false,
                            /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
                            allowObjCWritebackConversion);

if (ICS.isStandard() &&
    ICS.Standard.Second == ICK_Writeback_Conversion) {
  // Objective-C ARC writeback conversion.

  // We should copy unless we're passing to an argument explicitly
  // marked 'out'.
  bool ShouldCopy = true;
  if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
    ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);

  // If there was an lvalue adjustment, add it as a separate conversion.
  if (ICS.Standard.First == ICK_Array_To_Pointer ||
      ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
    ImplicitConversionSequence LvalueICS;
    LvalueICS.setStandard();
    LvalueICS.Standard.setAsIdentityConversion();
    LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0));
    LvalueICS.Standard.First = ICS.Standard.First;
    AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0));
  }

  AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy);
} else if (ICS.isBad()) {
  DeclAccessPair dap;
  if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
    AddZeroInitializationStep(Entity.getType());
  } else if (Initializer->getType() == Context.OverloadTy &&
             !S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
                                                   false, dap))
    SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
  else if (Initializer->getType()->isFunctionType() &&
           isExprAnUnaddressableFunction(S, Initializer))
    SetFailed(InitializationSequence::FK_AddressOfUnaddressableFunction);
  else
    SetFailed(InitializationSequence::FK_ConversionFailed);
} else {
  AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);

  MaybeProduceObjCObject(S, *this, Entity);
}
6102}

6104InitializationSequence::~InitializationSequence() {
for (auto &S : Steps)
  S.Destroy();
6107}

6109//===----------------------------------------------------------------------===//
6110// Perform initialization
6111//===----------------------------------------------------------------------===//
6112static Sema::AssignmentAction
6113getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
switch(Entity.getKind()) {
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
  return Sema::AA_Initializing;

case InitializedEntity::EK_Parameter:
  if (Entity.getDecl() &&
      isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
    return Sema::AA_Sending;

  return Sema::AA_Passing;

case InitializedEntity::EK_Parameter_CF_Audited:
  if (Entity.getDecl() &&
    isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
    return Sema::AA_Sending;

  return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;

case InitializedEntity::EK_Result:
case InitializedEntity::EK_StmtExprResult: // FIXME: Not quite right.
  return Sema::AA_Returning;

case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_RelatedResult:
  // FIXME: Can we tell apart casting vs. converting?
  return Sema::AA_Casting;

case InitializedEntity::EK_TemplateParameter:
  // This is really initialization, but refer to it as conversion for
  // consistency with CheckConvertedConstantExpression.
  return Sema::AA_Converting;

case InitializedEntity::EK_Member:
case InitializedEntity::EK_Binding:
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_CompoundLiteralInit:
  return Sema::AA_Initializing;
}

llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 6162);
6163}

6165/// Whether we should bind a created object as a temporary when
6166/// initializing the given entity.
6167static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
switch (Entity.getKind()) {
case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Member:
case InitializedEntity::EK_Result:
case InitializedEntity::EK_StmtExprResult:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Variable:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_Exception:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_TemplateParameter:
  return false;

case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_RelatedResult:
case InitializedEntity::EK_Binding:
  return true;
}

llvm_unreachable("missed an InitializedEntity kind?")::llvm::llvm_unreachable_internal("missed an InitializedEntity kind?"
, "clang/lib/Sema/SemaInit.cpp", 6195);
6196}

6198/// Whether the given entity, when initialized with an object
6199/// created for that initialization, requires destruction.
6200static bool shouldDestroyEntity(const InitializedEntity &Entity) {
switch (Entity.getKind()) {
  case InitializedEntity::EK_Result:
  case InitializedEntity::EK_StmtExprResult:
  case InitializedEntity::EK_New:
  case InitializedEntity::EK_Base:
  case InitializedEntity::EK_Delegating:
  case InitializedEntity::EK_VectorElement:
  case InitializedEntity::EK_ComplexElement:
  case InitializedEntity::EK_BlockElement:
  case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
  case InitializedEntity::EK_LambdaCapture:
    return false;

  case InitializedEntity::EK_Member:
  case InitializedEntity::EK_Binding:
  case InitializedEntity::EK_Variable:
  case InitializedEntity::EK_Parameter:
  case InitializedEntity::EK_Parameter_CF_Audited:
  case InitializedEntity::EK_TemplateParameter:
  case InitializedEntity::EK_Temporary:
  case InitializedEntity::EK_ArrayElement:
  case InitializedEntity::EK_Exception:
  case InitializedEntity::EK_CompoundLiteralInit:
  case InitializedEntity::EK_RelatedResult:
    return true;
}

llvm_unreachable("missed an InitializedEntity kind?")::llvm::llvm_unreachable_internal("missed an InitializedEntity kind?"
, "clang/lib/Sema/SemaInit.cpp", 6228);
6229}

6231/// Get the location at which initialization diagnostics should appear.
6232static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
                                         Expr *Initializer) {
switch (Entity.getKind()) {
case InitializedEntity::EK_Result:
case InitializedEntity::EK_StmtExprResult:
  return Entity.getReturnLoc();

case InitializedEntity::EK_Exception:
  return Entity.getThrowLoc();

case InitializedEntity::EK_Variable:
case InitializedEntity::EK_Binding:
  return Entity.getDecl()->getLocation();

case InitializedEntity::EK_LambdaCapture:
  return Entity.getCaptureLoc();

case InitializedEntity::EK_ArrayElement:
case InitializedEntity::EK_Member:
case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
case InitializedEntity::EK_TemplateParameter:
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_New:
case InitializedEntity::EK_Base:
case InitializedEntity::EK_Delegating:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
  return Initializer->getBeginLoc();
}
llvm_unreachable("missed an InitializedEntity kind?")::llvm::llvm_unreachable_internal("missed an InitializedEntity kind?"
, "clang/lib/Sema/SemaInit.cpp", 6266);
6267}

6269/// Make a (potentially elidable) temporary copy of the object
6270/// provided by the given initializer by calling the appropriate copy
6271/// constructor.
6272///
6273/// \param S The Sema object used for type-checking.
6274///
6275/// \param T The type of the temporary object, which must either be
6276/// the type of the initializer expression or a superclass thereof.
6277///
6278/// \param Entity The entity being initialized.
6279///
6280/// \param CurInit The initializer expression.
6281///
6282/// \param IsExtraneousCopy Whether this is an "extraneous" copy that
6283/// is permitted in C++03 (but not C++0x) when binding a reference to
6284/// an rvalue.
6285///
6286/// \returns An expression that copies the initializer expression into
6287/// a temporary object, or an error expression if a copy could not be
6288/// created.
6289static ExprResult CopyObject(Sema &S,
                           QualType T,
                           const InitializedEntity &Entity,
                           ExprResult CurInit,
                           bool IsExtraneousCopy) {
if (CurInit.isInvalid())
  return CurInit;
// Determine which class type we're copying to.
Expr *CurInitExpr = (Expr *)CurInit.get();
CXXRecordDecl *Class = nullptr;
if (const RecordType *Record = T->getAs<RecordType>())
  Class = cast<CXXRecordDecl>(Record->getDecl());
if (!Class)
  return CurInit;

SourceLocation Loc = getInitializationLoc(Entity, CurInit.get());

// Make sure that the type we are copying is complete.
if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete))
  return CurInit;

// Perform overload resolution using the class's constructors. Per
// C++11 [dcl.init]p16, second bullet for class types, this initialization
// is direct-initialization.
OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
DeclContext::lookup_result Ctors = S.LookupConstructors(Class);

OverloadCandidateSet::iterator Best;
switch (ResolveConstructorOverload(
    S, Loc, CurInitExpr, CandidateSet, T, Ctors, Best,
    /*CopyInitializing=*/false, /*AllowExplicit=*/true,
    /*OnlyListConstructors=*/false, /*IsListInit=*/false,
    /*SecondStepOfCopyInit=*/true)) {
case OR_Success:
  break;

case OR_No_Viable_Function:
  CandidateSet.NoteCandidates(
      PartialDiagnosticAt(
          Loc, S.PDiag(IsExtraneousCopy && !S.isSFINAEContext()
                           ? diag::ext_rvalue_to_reference_temp_copy_no_viable
                           : diag::err_temp_copy_no_viable)
                   << (int)Entity.getKind() << CurInitExpr->getType()
                   << CurInitExpr->getSourceRange()),
      S, OCD_AllCandidates, CurInitExpr);
  if (!IsExtraneousCopy || S.isSFINAEContext())
    return ExprError();
  return CurInit;

case OR_Ambiguous:
  CandidateSet.NoteCandidates(
      PartialDiagnosticAt(Loc, S.PDiag(diag::err_temp_copy_ambiguous)
                                   << (int)Entity.getKind()
                                   << CurInitExpr->getType()
                                   << CurInitExpr->getSourceRange()),
      S, OCD_AmbiguousCandidates, CurInitExpr);
  return ExprError();

case OR_Deleted:
  S.Diag(Loc, diag::err_temp_copy_deleted)
    << (int)Entity.getKind() << CurInitExpr->getType()
    << CurInitExpr->getSourceRange();
  S.NoteDeletedFunction(Best->Function);
  return ExprError();
}

bool HadMultipleCandidates = CandidateSet.size() > 1;

CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
SmallVector<Expr*, 8> ConstructorArgs;
CurInit.get(); // Ownership transferred into MultiExprArg, below.

S.CheckConstructorAccess(Loc, Constructor, Best->FoundDecl, Entity,
                         IsExtraneousCopy);

if (IsExtraneousCopy) {
  // If this is a totally extraneous copy for C++03 reference
  // binding purposes, just return the original initialization
  // expression. We don't generate an (elided) copy operation here
  // because doing so would require us to pass down a flag to avoid
  // infinite recursion, where each step adds another extraneous,
  // elidable copy.

  // Instantiate the default arguments of any extra parameters in
  // the selected copy constructor, as if we were going to create a
  // proper call to the copy constructor.
  for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) {
    ParmVarDecl *Parm = Constructor->getParamDecl(I);
    if (S.RequireCompleteType(Loc, Parm->getType(),
                              diag::err_call_incomplete_argument))
      break;

    // Build the default argument expression; we don't actually care
    // if this succeeds or not, because this routine will complain
    // if there was a problem.
    S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm);
  }

  return CurInitExpr;
}

// Determine the arguments required to actually perform the
// constructor call (we might have derived-to-base conversions, or
// the copy constructor may have default arguments).
if (S.CompleteConstructorCall(Constructor, T, CurInitExpr, Loc,
                              ConstructorArgs))
  return ExprError();

// C++0x [class.copy]p32:
//   When certain criteria are met, an implementation is allowed to
//   omit the copy/move construction of a class object, even if the
//   copy/move constructor and/or destructor for the object have
//   side effects. [...]
//     - when a temporary class object that has not been bound to a
//       reference (12.2) would be copied/moved to a class object
//       with the same cv-unqualified type, the copy/move operation
//       can be omitted by constructing the temporary object
//       directly into the target of the omitted copy/move
//
// Note that the other three bullets are handled elsewhere. Copy
// elision for return statements and throw expressions are handled as part
// of constructor initialization, while copy elision for exception handlers
// is handled by the run-time.
//
// FIXME: If the function parameter is not the same type as the temporary, we
// should still be able to elide the copy, but we don't have a way to
// represent in the AST how much should be elided in this case.
bool Elidable =
    CurInitExpr->isTemporaryObject(S.Context, Class) &&
    S.Context.hasSameUnqualifiedType(
        Best->Function->getParamDecl(0)->getType().getNonReferenceType(),
        CurInitExpr->getType());

// Actually perform the constructor call.
CurInit = S.BuildCXXConstructExpr(Loc, T, Best->FoundDecl, Constructor,
                                  Elidable,
                                  ConstructorArgs,
                                  HadMultipleCandidates,
                                  /*ListInit*/ false,
                                  /*StdInitListInit*/ false,
                                  /*ZeroInit*/ false,
                                  CXXConstructExpr::CK_Complete,
                                  SourceRange());

// If we're supposed to bind temporaries, do so.
if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity))
  CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
return CurInit;
6437}

6439/// Check whether elidable copy construction for binding a reference to
6440/// a temporary would have succeeded if we were building in C++98 mode, for
6441/// -Wc++98-compat.
6442static void CheckCXX98CompatAccessibleCopy(Sema &S,
                                         const InitializedEntity &Entity,
                                         Expr *CurInitExpr) {
assert(S.getLangOpts().CPlusPlus11)(static_cast <bool> (S.getLangOpts().CPlusPlus11) ? void
 (0) : __assert_fail ("S.getLangOpts().CPlusPlus11", "clang/lib/Sema/SemaInit.cpp"
, 6445, __extension__ __PRETTY_FUNCTION__));

const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>();
if (!Record)
  return;

SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr);
if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc))
  return;

// Find constructors which would have been considered.
OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
DeclContext::lookup_result Ctors =
    S.LookupConstructors(cast<CXXRecordDecl>(Record->getDecl()));

// Perform overload resolution.
OverloadCandidateSet::iterator Best;
OverloadingResult OR = ResolveConstructorOverload(
    S, Loc, CurInitExpr, CandidateSet, CurInitExpr->getType(), Ctors, Best,
    /*CopyInitializing=*/false, /*AllowExplicit=*/true,
    /*OnlyListConstructors=*/false, /*IsListInit=*/false,
    /*SecondStepOfCopyInit=*/true);

PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy)
  << OR << (int)Entity.getKind() << CurInitExpr->getType()
  << CurInitExpr->getSourceRange();

switch (OR) {
case OR_Success:
  S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function),
                           Best->FoundDecl, Entity, Diag);
  // FIXME: Check default arguments as far as that's possible.
  break;

case OR_No_Viable_Function:
  CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
                              OCD_AllCandidates, CurInitExpr);
  break;

case OR_Ambiguous:
  CandidateSet.NoteCandidates(PartialDiagnosticAt(Loc, Diag), S,
                              OCD_AmbiguousCandidates, CurInitExpr);
  break;

case OR_Deleted:
  S.Diag(Loc, Diag);
  S.NoteDeletedFunction(Best->Function);
  break;
}
6494}

6496void InitializationSequence::PrintInitLocationNote(Sema &S,
                                            const InitializedEntity &Entity) {
if (Entity.isParamOrTemplateParamKind() && Entity.getDecl()) {
  if (Entity.getDecl()->getLocation().isInvalid())
    return;

  if (Entity.getDecl()->getDeclName())
    S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here)
      << Entity.getDecl()->getDeclName();
  else
    S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here);
}
else if (Entity.getKind() == InitializedEntity::EK_RelatedResult &&
         Entity.getMethodDecl())
  S.Diag(Entity.getMethodDecl()->getLocation(),
         diag::note_method_return_type_change)
    << Entity.getMethodDecl()->getDeclName();
6513}

6515/// Returns true if the parameters describe a constructor initialization of
6516/// an explicit temporary object, e.g. "Point(x, y)".
6517static bool isExplicitTemporary(const InitializedEntity &Entity,
                              const InitializationKind &Kind,
                              unsigned NumArgs) {
switch (Entity.getKind()) {
case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
  break;
default:
  return false;
}

switch (Kind.getKind()) {
case InitializationKind::IK_DirectList:
  return true;
// FIXME: Hack to work around cast weirdness.
case InitializationKind::IK_Direct:
case InitializationKind::IK_Value:
  return NumArgs != 1;
default:
  return false;
}
6539}

6541static ExprResult
6542PerformConstructorInitialization(Sema &S,
                               const InitializedEntity &Entity,
                               const InitializationKind &Kind,
                               MultiExprArg Args,
                               const InitializationSequence::Step& Step,
                               bool &ConstructorInitRequiresZeroInit,
                               bool IsListInitialization,
                               bool IsStdInitListInitialization,
                               SourceLocation LBraceLoc,
                               SourceLocation RBraceLoc) {
unsigned NumArgs = Args.size();
CXXConstructorDecl *Constructor
  = cast<CXXConstructorDecl>(Step.Function.Function);
bool HadMultipleCandidates = Step.Function.HadMultipleCandidates;

// Build a call to the selected constructor.
SmallVector<Expr*, 8> ConstructorArgs;
SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid())
                       ? Kind.getEqualLoc()
                       : Kind.getLocation();

if (Kind.getKind() == InitializationKind::IK_Default) {
  // Force even a trivial, implicit default constructor to be
  // semantically checked. We do this explicitly because we don't build
  // the definition for completely trivial constructors.
  assert(Constructor->getParent() && "No parent class for constructor.")(static_cast <bool> (Constructor->getParent() &&
 "No parent class for constructor.") ? void (0) : __assert_fail
 ("Constructor->getParent() && \"No parent class for constructor.\""
, "clang/lib/Sema/SemaInit.cpp", 6567, __extension__ __PRETTY_FUNCTION__
));
  if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
      Constructor->isTrivial() && !Constructor->isUsed(false)) {
    S.runWithSufficientStackSpace(Loc, [&] {
      S.DefineImplicitDefaultConstructor(Loc, Constructor);
    });
  }
}

ExprResult CurInit((Expr *)nullptr);

// C++ [over.match.copy]p1:
//   - When initializing a temporary to be bound to the first parameter
//     of a constructor that takes a reference to possibly cv-qualified
//     T as its first argument, called with a single argument in the
//     context of direct-initialization, explicit conversion functions
//     are also considered.
bool AllowExplicitConv =
    Kind.AllowExplicit() && !Kind.isCopyInit() && Args.size() == 1 &&
    hasCopyOrMoveCtorParam(S.Context,
                           getConstructorInfo(Step.Function.FoundDecl));

// Determine the arguments required to actually perform the constructor
// call.
if (S.CompleteConstructorCall(Constructor, Step.Type, Args, Loc,
                              ConstructorArgs, AllowExplicitConv,
                              IsListInitialization))
  return ExprError();

if (isExplicitTemporary(Entity, Kind, NumArgs)) {
  // An explicitly-constructed temporary, e.g., X(1, 2).
  if (S.DiagnoseUseOfDecl(Constructor, Loc))
    return ExprError();

  TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
  if (!TSInfo)
    TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc);
  SourceRange ParenOrBraceRange =
      (Kind.getKind() == InitializationKind::IK_DirectList)
      ? SourceRange(LBraceLoc, RBraceLoc)
      : Kind.getParenOrBraceRange();

  CXXConstructorDecl *CalleeDecl = Constructor;
  if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(
          Step.Function.FoundDecl.getDecl())) {
    CalleeDecl = S.findInheritingConstructor(Loc, Constructor, Shadow);
    if (S.DiagnoseUseOfDecl(CalleeDecl, Loc))
      return ExprError();
  }
  S.MarkFunctionReferenced(Loc, CalleeDecl);

  CurInit = S.CheckForImmediateInvocation(
      CXXTemporaryObjectExpr::Create(
          S.Context, CalleeDecl,
          Entity.getType().getNonLValueExprType(S.Context), TSInfo,
          ConstructorArgs, ParenOrBraceRange, HadMultipleCandidates,
          IsListInitialization, IsStdInitListInitialization,
          ConstructorInitRequiresZeroInit),
      CalleeDecl);
} else {
  CXXConstructExpr::ConstructionKind ConstructKind =
    CXXConstructExpr::CK_Complete;

  if (Entity.getKind() == InitializedEntity::EK_Base) {
    ConstructKind = Entity.getBaseSpecifier()->isVirtual() ?
      CXXConstructExpr::CK_VirtualBase :
      CXXConstructExpr::CK_NonVirtualBase;
  } else if (Entity.getKind() == InitializedEntity::EK_Delegating) {
    ConstructKind = CXXConstructExpr::CK_Delegating;
  }

  // Only get the parenthesis or brace range if it is a list initialization or
  // direct construction.
  SourceRange ParenOrBraceRange;
  if (IsListInitialization)
    ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc);
  else if (Kind.getKind() == InitializationKind::IK_Direct)
    ParenOrBraceRange = Kind.getParenOrBraceRange();

  // If the entity allows NRVO, mark the construction as elidable
  // unconditionally.
  if (Entity.allowsNRVO())
    CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
                                      Step.Function.FoundDecl,
                                      Constructor, /*Elidable=*/true,
                                      ConstructorArgs,
                                      HadMultipleCandidates,
                                      IsListInitialization,
                                      IsStdInitListInitialization,
                                      ConstructorInitRequiresZeroInit,
                                      ConstructKind,
                                      ParenOrBraceRange);
  else
    CurInit = S.BuildCXXConstructExpr(Loc, Step.Type,
                                      Step.Function.FoundDecl,
                                      Constructor,
                                      ConstructorArgs,
                                      HadMultipleCandidates,
                                      IsListInitialization,
                                      IsStdInitListInitialization,
                                      ConstructorInitRequiresZeroInit,
                                      ConstructKind,
                                      ParenOrBraceRange);
}
if (CurInit.isInvalid())
  return ExprError();

// Only check access if all of that succeeded.
S.CheckConstructorAccess(Loc, Constructor, Step.Function.FoundDecl, Entity);
if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc))
  return ExprError();

if (const ArrayType *AT = S.Context.getAsArrayType(Entity.getType()))
  if (checkDestructorReference(S.Context.getBaseElementType(AT), Loc, S))
    return ExprError();

if (shouldBindAsTemporary(Entity))
  CurInit = S.MaybeBindToTemporary(CurInit.get());

return CurInit;
6687}

6689namespace {
6690enum LifetimeKind {
/// The lifetime of a temporary bound to this entity ends at the end of the
/// full-expression, and that's (probably) fine.
LK_FullExpression,

/// The lifetime of a temporary bound to this entity is extended to the
/// lifeitme of the entity itself.
LK_Extended,

/// The lifetime of a temporary bound to this entity probably ends too soon,
/// because the entity is allocated in a new-expression.
LK_New,

/// The lifetime of a temporary bound to this entity ends too soon, because
/// the entity is a return object.
LK_Return,

/// The lifetime of a temporary bound to this entity ends too soon, because
/// the entity is the result of a statement expression.
LK_StmtExprResult,

/// This is a mem-initializer: if it would extend a temporary (other than via
/// a default member initializer), the program is ill-formed.
LK_MemInitializer,
6714};
6715using LifetimeResult =
  llvm::PointerIntPair<const InitializedEntity *, 3, LifetimeKind>;
6717}

6719/// Determine the declaration which an initialized entity ultimately refers to,
6720/// for the purpose of lifetime-extending a temporary bound to a reference in
6721/// the initialization of \p Entity.
6722static LifetimeResult getEntityLifetime(
  const InitializedEntity *Entity,
  const InitializedEntity *InitField = nullptr) {
// C++11 [class.temporary]p5:
switch (Entity->getKind()) {
case InitializedEntity::EK_Variable:
  //   The temporary [...] persists for the lifetime of the reference
  return {Entity, LK_Extended};

case InitializedEntity::EK_Member:
  // For subobjects, we look at the complete object.
  if (Entity->getParent())
    return getEntityLifetime(Entity->getParent(), Entity);

  //   except:
  // C++17 [class.base.init]p8:
  //   A temporary expression bound to a reference member in a
  //   mem-initializer is ill-formed.
  // C++17 [class.base.init]p11:
  //   A temporary expression bound to a reference member from a
  //   default member initializer is ill-formed.
  //
  // The context of p11 and its example suggest that it's only the use of a
  // default member initializer from a constructor that makes the program
  // ill-formed, not its mere existence, and that it can even be used by
  // aggregate initialization.
  return {Entity, Entity->isDefaultMemberInitializer() ? LK_Extended
                                                       : LK_MemInitializer};

case InitializedEntity::EK_Binding:
  // Per [dcl.decomp]p3, the binding is treated as a variable of reference
  // type.
  return {Entity, LK_Extended};

case InitializedEntity::EK_Parameter:
case InitializedEntity::EK_Parameter_CF_Audited:
  //   -- A temporary bound to a reference parameter in a function call
  //      persists until the completion of the full-expression containing
  //      the call.
  return {nullptr, LK_FullExpression};

case InitializedEntity::EK_TemplateParameter:
  // FIXME: This will always be ill-formed; should we eagerly diagnose it here?
  return {nullptr, LK_FullExpression};

case InitializedEntity::EK_Result:
  //   -- The lifetime of a temporary bound to the returned value in a
  //      function return statement is not extended; the temporary is
  //      destroyed at the end of the full-expression in the return statement.
  return {nullptr, LK_Return};

case InitializedEntity::EK_StmtExprResult:
  // FIXME: Should we lifetime-extend through the result of a statement
  // expression?
  return {nullptr, LK_StmtExprResult};

case InitializedEntity::EK_New:
  //   -- A temporary bound to a reference in a new-initializer persists
  //      until the completion of the full-expression containing the
  //      new-initializer.
  return {nullptr, LK_New};

case InitializedEntity::EK_Temporary:
case InitializedEntity::EK_CompoundLiteralInit:
case InitializedEntity::EK_RelatedResult:
  // We don't yet know the storage duration of the surrounding temporary.
  // Assume it's got full-expression duration for now, it will patch up our
  // storage duration if that's not correct.
  return {nullptr, LK_FullExpression};

case InitializedEntity::EK_ArrayElement:
  // For subobjects, we look at the complete object.
  return getEntityLifetime(Entity->getParent(), InitField);

case InitializedEntity::EK_Base:
  // For subobjects, we look at the complete object.
  if (Entity->getParent())
    return getEntityLifetime(Entity->getParent(), InitField);
  return {InitField, LK_MemInitializer};

case InitializedEntity::EK_Delegating:
  // We can reach this case for aggregate initialization in a constructor:
  //   struct A { int &&r; };
  //   struct B : A { B() : A{0} {} };
  // In this case, use the outermost field decl as the context.
  return {InitField, LK_MemInitializer};

case InitializedEntity::EK_BlockElement:
case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
case InitializedEntity::EK_LambdaCapture:
case InitializedEntity::EK_VectorElement:
case InitializedEntity::EK_ComplexElement:
  return {nullptr, LK_FullExpression};

case InitializedEntity::EK_Exception:
  // FIXME: Can we diagnose lifetime problems with exceptions?
  return {nullptr, LK_FullExpression};
}
llvm_unreachable("unknown entity kind")::llvm::llvm_unreachable_internal("unknown entity kind", "clang/lib/Sema/SemaInit.cpp"
, 6820);
6821}

6823namespace {
6824enum ReferenceKind {
/// Lifetime would be extended by a reference binding to a temporary.
RK_ReferenceBinding,
/// Lifetime would be extended by a std::initializer_list object binding to
/// its backing array.
RK_StdInitializerList,
6830};

6832/// A temporary or local variable. This will be one of:
6833///  * A MaterializeTemporaryExpr.
6834///  * A DeclRefExpr whose declaration is a local.
6835///  * An AddrLabelExpr.
6836///  * A BlockExpr for a block with captures.
6837using Local = Expr*;

6839/// Expressions we stepped over when looking for the local state. Any steps
6840/// that would inhibit lifetime extension or take us out of subexpressions of
6841/// the initializer are included.
6842struct IndirectLocalPathEntry {
enum EntryKind {
  DefaultInit,
  AddressOf,
  VarInit,
  LValToRVal,
  LifetimeBoundCall,
  TemporaryCopy,
  LambdaCaptureInit,
  GslReferenceInit,
  GslPointerInit
} Kind;
Expr *E;
union {
  const Decl *D = nullptr;
  const LambdaCapture *Capture;
};
IndirectLocalPathEntry() {}
IndirectLocalPathEntry(EntryKind K, Expr *E) : Kind(K), E(E) {}
IndirectLocalPathEntry(EntryKind K, Expr *E, const Decl *D)
    : Kind(K), E(E), D(D) {}
IndirectLocalPathEntry(EntryKind K, Expr *E, const LambdaCapture *Capture)
    : Kind(K), E(E), Capture(Capture) {}
6865};

6867using IndirectLocalPath = llvm::SmallVectorImpl<IndirectLocalPathEntry>;

6869struct RevertToOldSizeRAII {
IndirectLocalPath &Path;
unsigned OldSize = Path.size();
RevertToOldSizeRAII(IndirectLocalPath &Path) : Path(Path) {}
~RevertToOldSizeRAII() { Path.resize(OldSize); }
6874};

6876using LocalVisitor = llvm::function_ref<bool(IndirectLocalPath &Path, Local L,
                                           ReferenceKind RK)>;
6878}

6880static bool isVarOnPath(IndirectLocalPath &Path, VarDecl *VD) {
for (auto E : Path)
  if (E.Kind == IndirectLocalPathEntry::VarInit && E.D == VD)
    return true;
return false;
6885}

6887static bool pathContainsInit(IndirectLocalPath &Path) {
return llvm::any_of(Path, [=](IndirectLocalPathEntry E) {
  return E.Kind == IndirectLocalPathEntry::DefaultInit ||
         E.Kind == IndirectLocalPathEntry::VarInit;
});
6892}

6894static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
                                           Expr *Init, LocalVisitor Visit,
                                           bool RevisitSubinits,
                                           bool EnableLifetimeWarnings);

6899static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
                                                Expr *Init, ReferenceKind RK,
                                                LocalVisitor Visit,
                                                bool EnableLifetimeWarnings);

6904template <typename T> static bool isRecordWithAttr(QualType Type) {
if (auto *RD = Type->getAsCXXRecordDecl())
  return RD->hasAttr<T>();
return false;
6908}

6910// Decl::isInStdNamespace will return false for iterators in some STL
6911// implementations due to them being defined in a namespace outside of the std
6912// namespace.
6913static bool isInStlNamespace(const Decl *D) {
const DeclContext *DC = D->getDeclContext();
if (!DC)
  return false;
if (const auto *ND = dyn_cast<NamespaceDecl>(DC))
  if (const IdentifierInfo *II = ND->getIdentifier()) {
    StringRef Name = II->getName();
    if (Name.size() >= 2 && Name.front() == '_' &&
        (Name[1] == '_' || isUppercase(Name[1])))
      return true;
  }

return DC->isStdNamespace();
6926}

6928static bool shouldTrackImplicitObjectArg(const CXXMethodDecl *Callee) {
if (auto *Conv = dyn_cast_or_null<CXXConversionDecl>(Callee))
  if (isRecordWithAttr<PointerAttr>(Conv->getConversionType()))
    return true;
if (!isInStlNamespace(Callee->getParent()))
  return false;
if (!isRecordWithAttr<PointerAttr>(Callee->getThisObjectType()) &&
    !isRecordWithAttr<OwnerAttr>(Callee->getThisObjectType()))
  return false;
if (Callee->getReturnType()->isPointerType() ||
    isRecordWithAttr<PointerAttr>(Callee->getReturnType())) {
  if (!Callee->getIdentifier())
    return false;
  return llvm::StringSwitch<bool>(Callee->getName())
      .Cases("begin", "rbegin", "cbegin", "crbegin", true)
      .Cases("end", "rend", "cend", "crend", true)
      .Cases("c_str", "data", "get", true)
      // Map and set types.
      .Cases("find", "equal_range", "lower_bound", "upper_bound", true)
      .Default(false);
} else if (Callee->getReturnType()->isReferenceType()) {
  if (!Callee->getIdentifier()) {
    auto OO = Callee->getOverloadedOperator();
    return OO == OverloadedOperatorKind::OO_Subscript ||
           OO == OverloadedOperatorKind::OO_Star;
  }
  return llvm::StringSwitch<bool>(Callee->getName())
      .Cases("front", "back", "at", "top", "value", true)
      .Default(false);
}
return false;
6959}

6961static bool shouldTrackFirstArgument(const FunctionDecl *FD) {
if (!FD->getIdentifier() || FD->getNumParams() != 1)
  return false;
const auto *RD = FD->getParamDecl(0)->getType()->getPointeeCXXRecordDecl();
if (!FD->isInStdNamespace() || !RD || !RD->isInStdNamespace())
  return false;
if (!isRecordWithAttr<PointerAttr>(QualType(RD->getTypeForDecl(), 0)) &&
    !isRecordWithAttr<OwnerAttr>(QualType(RD->getTypeForDecl(), 0)))
  return false;
if (FD->getReturnType()->isPointerType() ||
    isRecordWithAttr<PointerAttr>(FD->getReturnType())) {
  return llvm::StringSwitch<bool>(FD->getName())
      .Cases("begin", "rbegin", "cbegin", "crbegin", true)
      .Cases("end", "rend", "cend", "crend", true)
      .Case("data", true)
      .Default(false);
} else if (FD->getReturnType()->isReferenceType()) {
  return llvm::StringSwitch<bool>(FD->getName())
      .Cases("get", "any_cast", true)
      .Default(false);
}
return false;
6983}

6985static void handleGslAnnotatedTypes(IndirectLocalPath &Path, Expr *Call,
                                  LocalVisitor Visit) {
auto VisitPointerArg = [&](const Decl *D, Expr *Arg, bool Value) {
  // We are not interested in the temporary base objects of gsl Pointers:
  //   Temp().ptr; // Here ptr might not dangle.
  if (isa<MemberExpr>(Arg->IgnoreImpCasts()))
    return;
  // Once we initialized a value with a reference, it can no longer dangle.
  if (!Value) {
    for (const IndirectLocalPathEntry &PE : llvm::reverse(Path)) {
      if (PE.Kind == IndirectLocalPathEntry::GslReferenceInit)
        continue;
      if (PE.Kind == IndirectLocalPathEntry::GslPointerInit)
        return;
      break;
    }
  }
  Path.push_back({Value ? IndirectLocalPathEntry::GslPointerInit
                        : IndirectLocalPathEntry::GslReferenceInit,
                  Arg, D});
  if (Arg->isGLValue())
    visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
                                          Visit,
                                          /*EnableLifetimeWarnings=*/true);
  else
    visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
                                     /*EnableLifetimeWarnings=*/true);
  Path.pop_back();
};

if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
  const auto *MD = cast_or_null<CXXMethodDecl>(MCE->getDirectCallee());
  if (MD && shouldTrackImplicitObjectArg(MD))
    VisitPointerArg(MD, MCE->getImplicitObjectArgument(),
                    !MD->getReturnType()->isReferenceType());
  return;
} else if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(Call)) {
  FunctionDecl *Callee = OCE->getDirectCallee();
  if (Callee && Callee->isCXXInstanceMember() &&
      shouldTrackImplicitObjectArg(cast<CXXMethodDecl>(Callee)))
    VisitPointerArg(Callee, OCE->getArg(0),
                    !Callee->getReturnType()->isReferenceType());
  return;
} else if (auto *CE = dyn_cast<CallExpr>(Call)) {
  FunctionDecl *Callee = CE->getDirectCallee();
  if (Callee && shouldTrackFirstArgument(Callee))
    VisitPointerArg(Callee, CE->getArg(0),
                    !Callee->getReturnType()->isReferenceType());
  return;
}

if (auto *CCE = dyn_cast<CXXConstructExpr>(Call)) {
  const auto *Ctor = CCE->getConstructor();
  const CXXRecordDecl *RD = Ctor->getParent();
  if (CCE->getNumArgs() > 0 && RD->hasAttr<PointerAttr>())
    VisitPointerArg(Ctor->getParamDecl(0), CCE->getArgs()[0], true);
}
7042}

7044static bool implicitObjectParamIsLifetimeBound(const FunctionDecl *FD) {
const TypeSourceInfo *TSI = FD->getTypeSourceInfo();
if (!TSI)
  return false;
// Don't declare this variable in the second operand of the for-statement;
// GCC miscompiles that by ending its lifetime before evaluating the
// third operand. See gcc.gnu.org/PR86769.
AttributedTypeLoc ATL;
for (TypeLoc TL = TSI->getTypeLoc();
     (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
     TL = ATL.getModifiedLoc()) {
  if (ATL.getAttrAs<LifetimeBoundAttr>())
    return true;
}

// Assume that all assignment operators with a "normal" return type return
// *this, that is, an lvalue reference that is the same type as the implicit
// object parameter (or the LHS for a non-member operator$=).
OverloadedOperatorKind OO = FD->getDeclName().getCXXOverloadedOperator();
if (OO == OO_Equal || isCompoundAssignmentOperator(OO)) {
  QualType RetT = FD->getReturnType();
  if (RetT->isLValueReferenceType()) {
    ASTContext &Ctx = FD->getASTContext();
    QualType LHST;
    auto *MD = dyn_cast<CXXMethodDecl>(FD);
    if (MD && MD->isCXXInstanceMember())
      LHST = Ctx.getLValueReferenceType(MD->getThisObjectType());
    else
      LHST = MD->getParamDecl(0)->getType();
    if (Ctx.hasSameType(RetT, LHST))
      return true;
  }
}

return false;
7079}

7081static void visitLifetimeBoundArguments(IndirectLocalPath &Path, Expr *Call,
                                      LocalVisitor Visit) {
const FunctionDecl *Callee;
ArrayRef<Expr*> Args;

if (auto *CE = dyn_cast<CallExpr>(Call)) {
  Callee = CE->getDirectCallee();
  Args = llvm::makeArrayRef(CE->getArgs(), CE->getNumArgs());
} else {
  auto *CCE = cast<CXXConstructExpr>(Call);
  Callee = CCE->getConstructor();
  Args = llvm::makeArrayRef(CCE->getArgs(), CCE->getNumArgs());
}
if (!Callee)
  return;

Expr *ObjectArg = nullptr;
if (isa<CXXOperatorCallExpr>(Call) && Callee->isCXXInstanceMember()) {
  ObjectArg = Args[0];
  Args = Args.slice(1);
} else if (auto *MCE = dyn_cast<CXXMemberCallExpr>(Call)) {
  ObjectArg = MCE->getImplicitObjectArgument();
}

auto VisitLifetimeBoundArg = [&](const Decl *D, Expr *Arg) {
  Path.push_back({IndirectLocalPathEntry::LifetimeBoundCall, Arg, D});
  if (Arg->isGLValue())
    visitLocalsRetainedByReferenceBinding(Path, Arg, RK_ReferenceBinding,
                                          Visit,
                                          /*EnableLifetimeWarnings=*/false);
  else
    visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
                                     /*EnableLifetimeWarnings=*/false);
  Path.pop_back();
};

if (ObjectArg && implicitObjectParamIsLifetimeBound(Callee))
  VisitLifetimeBoundArg(Callee, ObjectArg);

for (unsigned I = 0,
              N = std::min<unsigned>(Callee->getNumParams(), Args.size());
     I != N; ++I) {
  if (Callee->getParamDecl(I)->hasAttr<LifetimeBoundAttr>())
    VisitLifetimeBoundArg(Callee->getParamDecl(I), Args[I]);
}
7126}

7128/// Visit the locals that would be reachable through a reference bound to the
7129/// glvalue expression \c Init.
7130static void visitLocalsRetainedByReferenceBinding(IndirectLocalPath &Path,
                                                Expr *Init, ReferenceKind RK,
                                                LocalVisitor Visit,
                                                bool EnableLifetimeWarnings) {
RevertToOldSizeRAII RAII(Path);

// Walk past any constructs which we can lifetime-extend across.
Expr *Old;
do {
  Old = Init;

  if (auto *FE = dyn_cast<FullExpr>(Init))
    Init = FE->getSubExpr();

  if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
    // If this is just redundant braces around an initializer, step over it.
    if (ILE->isTransparent())
      Init = ILE->getInit(0);
  }

  // Step over any subobject adjustments; we may have a materialized
  // temporary inside them.
  Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());

  // Per current approach for DR1376, look through casts to reference type
  // when performing lifetime extension.
  if (CastExpr *CE = dyn_cast<CastExpr>(Init))
    if (CE->getSubExpr()->isGLValue())
      Init = CE->getSubExpr();

  // Per the current approach for DR1299, look through array element access
  // on array glvalues when performing lifetime extension.
  if (auto *ASE = dyn_cast<ArraySubscriptExpr>(Init)) {
    Init = ASE->getBase();
    auto *ICE = dyn_cast<ImplicitCastExpr>(Init);
    if (ICE && ICE->getCastKind() == CK_ArrayToPointerDecay)
      Init = ICE->getSubExpr();
    else
      // We can't lifetime extend through this but we might still find some
      // retained temporaries.
      return visitLocalsRetainedByInitializer(Path, Init, Visit, true,
                                              EnableLifetimeWarnings);
  }

  // Step into CXXDefaultInitExprs so we can diagnose cases where a
  // constructor inherits one as an implicit mem-initializer.
  if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
    Path.push_back(
        {IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
    Init = DIE->getExpr();
  }
} while (Init != Old);

if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(Init)) {
  if (Visit(Path, Local(MTE), RK))
    visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit, true,
                                     EnableLifetimeWarnings);
}

if (isa<CallExpr>(Init)) {
  if (EnableLifetimeWarnings)
    handleGslAnnotatedTypes(Path, Init, Visit);
  return visitLifetimeBoundArguments(Path, Init, Visit);
}

switch (Init->getStmtClass()) {
case Stmt::DeclRefExprClass: {
  // If we find the name of a local non-reference parameter, we could have a
  // lifetime problem.
  auto *DRE = cast<DeclRefExpr>(Init);
  auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
  if (VD && VD->hasLocalStorage() &&
      !DRE->refersToEnclosingVariableOrCapture()) {
    if (!VD->getType()->isReferenceType()) {
      Visit(Path, Local(DRE), RK);
    } else if (isa<ParmVarDecl>(DRE->getDecl())) {
      // The lifetime of a reference parameter is unknown; assume it's OK
      // for now.
      break;
    } else if (VD->getInit() && !isVarOnPath(Path, VD)) {
      Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
      visitLocalsRetainedByReferenceBinding(Path, VD->getInit(),
                                            RK_ReferenceBinding, Visit,
                                            EnableLifetimeWarnings);
    }
  }
  break;
}

case Stmt::UnaryOperatorClass: {
  // The only unary operator that make sense to handle here
  // is Deref.  All others don't resolve to a "name."  This includes
  // handling all sorts of rvalues passed to a unary operator.
  const UnaryOperator *U = cast<UnaryOperator>(Init);
  if (U->getOpcode() == UO_Deref)
    visitLocalsRetainedByInitializer(Path, U->getSubExpr(), Visit, true,
                                     EnableLifetimeWarnings);
  break;
}

case Stmt::OMPArraySectionExprClass: {
  visitLocalsRetainedByInitializer(Path,
                                   cast<OMPArraySectionExpr>(Init)->getBase(),
                                   Visit, true, EnableLifetimeWarnings);
  break;
}

case Stmt::ConditionalOperatorClass:
case Stmt::BinaryConditionalOperatorClass: {
  auto *C = cast<AbstractConditionalOperator>(Init);
  if (!C->getTrueExpr()->getType()->isVoidType())
    visitLocalsRetainedByReferenceBinding(Path, C->getTrueExpr(), RK, Visit,
                                          EnableLifetimeWarnings);
  if (!C->getFalseExpr()->getType()->isVoidType())
    visitLocalsRetainedByReferenceBinding(Path, C->getFalseExpr(), RK, Visit,
                                          EnableLifetimeWarnings);
  break;
}

// FIXME: Visit the left-hand side of an -> or ->*.

default:
  break;
}
7254}

7256/// Visit the locals that would be reachable through an object initialized by
7257/// the prvalue expression \c Init.
7258static void visitLocalsRetainedByInitializer(IndirectLocalPath &Path,
                                           Expr *Init, LocalVisitor Visit,
                                           bool RevisitSubinits,
                                           bool EnableLifetimeWarnings) {
RevertToOldSizeRAII RAII(Path);

Expr *Old;
do {
  Old = Init;

  // Step into CXXDefaultInitExprs so we can diagnose cases where a
  // constructor inherits one as an implicit mem-initializer.
  if (auto *DIE = dyn_cast<CXXDefaultInitExpr>(Init)) {
    Path.push_back({IndirectLocalPathEntry::DefaultInit, DIE, DIE->getField()});
    Init = DIE->getExpr();
  }

  if (auto *FE = dyn_cast<FullExpr>(Init))
    Init = FE->getSubExpr();

  // Dig out the expression which constructs the extended temporary.
  Init = const_cast<Expr *>(Init->skipRValueSubobjectAdjustments());

  if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
    Init = BTE->getSubExpr();

  Init = Init->IgnoreParens();

  // Step over value-preserving rvalue casts.
  if (auto *CE = dyn_cast<CastExpr>(Init)) {
    switch (CE->getCastKind()) {
    case CK_LValueToRValue:
      // If we can match the lvalue to a const object, we can look at its
      // initializer.
      Path.push_back({IndirectLocalPathEntry::LValToRVal, CE});
      return visitLocalsRetainedByReferenceBinding(
          Path, Init, RK_ReferenceBinding,
          [&](IndirectLocalPath &Path, Local L, ReferenceKind RK) -> bool {
        if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
          auto *VD = dyn_cast<VarDecl>(DRE->getDecl());
          if (VD && VD->getType().isConstQualified() && VD->getInit() &&
              !isVarOnPath(Path, VD)) {
            Path.push_back({IndirectLocalPathEntry::VarInit, DRE, VD});
            visitLocalsRetainedByInitializer(Path, VD->getInit(), Visit, true,
                                             EnableLifetimeWarnings);
          }
        } else if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L)) {
          if (MTE->getType().isConstQualified())
            visitLocalsRetainedByInitializer(Path, MTE->getSubExpr(), Visit,
                                             true, EnableLifetimeWarnings);
        }
        return false;
      }, EnableLifetimeWarnings);

      // We assume that objects can be retained by pointers cast to integers,
      // but not if the integer is cast to floating-point type or to _Complex.
      // We assume that casts to 'bool' do not preserve enough information to
      // retain a local object.
    case CK_NoOp:
    case CK_BitCast:
    case CK_BaseToDerived:
    case CK_DerivedToBase:
    case CK_UncheckedDerivedToBase:
    case CK_Dynamic:
    case CK_ToUnion:
    case CK_UserDefinedConversion:
    case CK_ConstructorConversion:
    case CK_IntegralToPointer:
    case CK_PointerToIntegral:
    case CK_VectorSplat:
    case CK_IntegralCast:
    case CK_CPointerToObjCPointerCast:
    case CK_BlockPointerToObjCPointerCast:
    case CK_AnyPointerToBlockPointerCast:
    case CK_AddressSpaceConversion:
      break;

    case CK_ArrayToPointerDecay:
      // Model array-to-pointer decay as taking the address of the array
      // lvalue.
      Path.push_back({IndirectLocalPathEntry::AddressOf, CE});
      return visitLocalsRetainedByReferenceBinding(Path, CE->getSubExpr(),
                                                   RK_ReferenceBinding, Visit,
                                                   EnableLifetimeWarnings);

    default:
      return;
    }

    Init = CE->getSubExpr();
  }
} while (Old != Init);

// C++17 [dcl.init.list]p6:
//   initializing an initializer_list object from the array extends the
//   lifetime of the array exactly like binding a reference to a temporary.
if (auto *ILE = dyn_cast<CXXStdInitializerListExpr>(Init))
  return visitLocalsRetainedByReferenceBinding(Path, ILE->getSubExpr(),
                                               RK_StdInitializerList, Visit,
                                               EnableLifetimeWarnings);

if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
  // We already visited the elements of this initializer list while
  // performing the initialization. Don't visit them again unless we've
  // changed the lifetime of the initialized entity.
  if (!RevisitSubinits)
    return;

  if (ILE->isTransparent())
    return visitLocalsRetainedByInitializer(Path, ILE->getInit(0), Visit,
                                            RevisitSubinits,
                                            EnableLifetimeWarnings);

  if (ILE->getType()->isArrayType()) {
    for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
      visitLocalsRetainedByInitializer(Path, ILE->getInit(I), Visit,
                                       RevisitSubinits,
                                       EnableLifetimeWarnings);
    return;
  }

  if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
    assert(RD->isAggregate() && "aggregate init on non-aggregate")(static_cast <bool> (RD->isAggregate() && "aggregate init on non-aggregate"
) ? void (0) : __assert_fail ("RD->isAggregate() && \"aggregate init on non-aggregate\""
, "clang/lib/Sema/SemaInit.cpp", 7380, __extension__ __PRETTY_FUNCTION__
));

    // If we lifetime-extend a braced initializer which is initializing an
    // aggregate, and that aggregate contains reference members which are
    // bound to temporaries, those temporaries are also lifetime-extended.
    if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
        ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
      visitLocalsRetainedByReferenceBinding(Path, ILE->getInit(0),
                                            RK_ReferenceBinding, Visit,
                                            EnableLifetimeWarnings);
    else {
      unsigned Index = 0;
      for (; Index < RD->getNumBases() && Index < ILE->getNumInits(); ++Index)
        visitLocalsRetainedByInitializer(Path, ILE->getInit(Index), Visit,
                                         RevisitSubinits,
                                         EnableLifetimeWarnings);
      for (const auto *I : RD->fields()) {
        if (Index >= ILE->getNumInits())
          break;
        if (I->isUnnamedBitfield())
          continue;
        Expr *SubInit = ILE->getInit(Index);
        if (I->getType()->isReferenceType())
          visitLocalsRetainedByReferenceBinding(Path, SubInit,
                                                RK_ReferenceBinding, Visit,
                                                EnableLifetimeWarnings);
        else
          // This might be either aggregate-initialization of a member or
          // initialization of a std::initializer_list object. Regardless,
          // we should recursively lifetime-extend that initializer.
          visitLocalsRetainedByInitializer(Path, SubInit, Visit,
                                           RevisitSubinits,
                                           EnableLifetimeWarnings);
        ++Index;
      }
    }
  }
  return;
}

// The lifetime of an init-capture is that of the closure object constructed
// by a lambda-expression.
if (auto *LE = dyn_cast<LambdaExpr>(Init)) {
  LambdaExpr::capture_iterator CapI = LE->capture_begin();
  for (Expr *E : LE->capture_inits()) {
    assert(CapI != LE->capture_end())(static_cast <bool> (CapI != LE->capture_end()) ? void
 (0) : __assert_fail ("CapI != LE->capture_end()", "clang/lib/Sema/SemaInit.cpp"
, 7425, __extension__ __PRETTY_FUNCTION__));
    const LambdaCapture &Cap = *CapI++;
    if (!E)
      continue;
    if (Cap.capturesVariable())
      Path.push_back({IndirectLocalPathEntry::LambdaCaptureInit, E, &Cap});
    if (E->isGLValue())
      visitLocalsRetainedByReferenceBinding(Path, E, RK_ReferenceBinding,
                                            Visit, EnableLifetimeWarnings);
    else
      visitLocalsRetainedByInitializer(Path, E, Visit, true,
                                       EnableLifetimeWarnings);
    if (Cap.capturesVariable())
      Path.pop_back();
  }
}

// Assume that a copy or move from a temporary references the same objects
// that the temporary does.
if (auto *CCE = dyn_cast<CXXConstructExpr>(Init)) {
  if (CCE->getConstructor()->isCopyOrMoveConstructor()) {
    if (auto *MTE = dyn_cast<MaterializeTemporaryExpr>(CCE->getArg(0))) {
      Expr *Arg = MTE->getSubExpr();
      Path.push_back({IndirectLocalPathEntry::TemporaryCopy, Arg,
                      CCE->getConstructor()});
      visitLocalsRetainedByInitializer(Path, Arg, Visit, true,
                                       /*EnableLifetimeWarnings*/false);
      Path.pop_back();
    }
  }
}

if (isa<CallExpr>(Init) || isa<CXXConstructExpr>(Init)) {
  if (EnableLifetimeWarnings)
    handleGslAnnotatedTypes(Path, Init, Visit);
  return visitLifetimeBoundArguments(Path, Init, Visit);
}

switch (Init->getStmtClass()) {
case Stmt::UnaryOperatorClass: {
  auto *UO = cast<UnaryOperator>(Init);
  // If the initializer is the address of a local, we could have a lifetime
  // problem.
  if (UO->getOpcode() == UO_AddrOf) {
    // If this is &rvalue, then it's ill-formed and we have already diagnosed
    // it. Don't produce a redundant warning about the lifetime of the
    // temporary.
    if (isa<MaterializeTemporaryExpr>(UO->getSubExpr()))
      return;

    Path.push_back({IndirectLocalPathEntry::AddressOf, UO});
    visitLocalsRetainedByReferenceBinding(Path, UO->getSubExpr(),
                                          RK_ReferenceBinding, Visit,
                                          EnableLifetimeWarnings);
  }
  break;
}

case Stmt::BinaryOperatorClass: {
  // Handle pointer arithmetic.
  auto *BO = cast<BinaryOperator>(Init);
  BinaryOperatorKind BOK = BO->getOpcode();
  if (!BO->getType()->isPointerType() || (BOK != BO_Add && BOK != BO_Sub))
    break;

  if (BO->getLHS()->getType()->isPointerType())
    visitLocalsRetainedByInitializer(Path, BO->getLHS(), Visit, true,
                                     EnableLifetimeWarnings);
  else if (BO->getRHS()->getType()->isPointerType())
    visitLocalsRetainedByInitializer(Path, BO->getRHS(), Visit, true,
                                     EnableLifetimeWarnings);
  break;
}

case Stmt::ConditionalOperatorClass:
case Stmt::BinaryConditionalOperatorClass: {
  auto *C = cast<AbstractConditionalOperator>(Init);
  // In C++, we can have a throw-expression operand, which has 'void' type
  // and isn't interesting from a lifetime perspective.
  if (!C->getTrueExpr()->getType()->isVoidType())
    visitLocalsRetainedByInitializer(Path, C->getTrueExpr(), Visit, true,
                                     EnableLifetimeWarnings);
  if (!C->getFalseExpr()->getType()->isVoidType())
    visitLocalsRetainedByInitializer(Path, C->getFalseExpr(), Visit, true,
                                     EnableLifetimeWarnings);
  break;
}

case Stmt::BlockExprClass:
  if (cast<BlockExpr>(Init)->getBlockDecl()->hasCaptures()) {
    // This is a local block, whose lifetime is that of the function.
    Visit(Path, Local(cast<BlockExpr>(Init)), RK_ReferenceBinding);
  }
  break;

case Stmt::AddrLabelExprClass:
  // We want to warn if the address of a label would escape the function.
  Visit(Path, Local(cast<AddrLabelExpr>(Init)), RK_ReferenceBinding);
  break;

default:
  break;
}
7528}

7530/// Whether a path to an object supports lifetime extension.
7531enum PathLifetimeKind {
/// Lifetime-extend along this path.
Extend,
/// We should lifetime-extend, but we don't because (due to technical
/// limitations) we can't. This happens for default member initializers,
/// which we don't clone for every use, so we don't have a unique
/// MaterializeTemporaryExpr to update.
ShouldExtend,
/// Do not lifetime extend along this path.
NoExtend
7541};

7543/// Determine whether this is an indirect path to a temporary that we are
7544/// supposed to lifetime-extend along.
7545static PathLifetimeKind
7546shouldLifetimeExtendThroughPath(const IndirectLocalPath &Path) {
PathLifetimeKind Kind = PathLifetimeKind::Extend;
for (auto Elem : Path) {
  if (Elem.Kind == IndirectLocalPathEntry::DefaultInit)
    Kind = PathLifetimeKind::ShouldExtend;
  else if (Elem.Kind != IndirectLocalPathEntry::LambdaCaptureInit)
    return PathLifetimeKind::NoExtend;
}
return Kind;
7555}

7557/// Find the range for the first interesting entry in the path at or after I.
7558static SourceRange nextPathEntryRange(const IndirectLocalPath &Path, unsigned I,
                                    Expr *E) {
for (unsigned N = Path.size(); I != N; ++I) {
  switch (Path[I].Kind) {
  case IndirectLocalPathEntry::AddressOf:
  case IndirectLocalPathEntry::LValToRVal:
  case IndirectLocalPathEntry::LifetimeBoundCall:
  case IndirectLocalPathEntry::TemporaryCopy:
  case IndirectLocalPathEntry::GslReferenceInit:
  case IndirectLocalPathEntry::GslPointerInit:
    // These exist primarily to mark the path as not permitting or
    // supporting lifetime extension.
    break;

  case IndirectLocalPathEntry::VarInit:
    if (cast<VarDecl>(Path[I].D)->isImplicit())
      return SourceRange();
    [[fallthrough]];
  case IndirectLocalPathEntry::DefaultInit:
    return Path[I].E->getSourceRange();

  case IndirectLocalPathEntry::LambdaCaptureInit:
    if (!Path[I].Capture->capturesVariable())
      continue;
    return Path[I].E->getSourceRange();
  }
}
return E->getSourceRange();
7586}

7588static bool pathOnlyInitializesGslPointer(IndirectLocalPath &Path) {
for (auto It = Path.rbegin(), End = Path.rend(); It != End; ++It) {
  if (It->Kind == IndirectLocalPathEntry::VarInit)
    continue;
  if (It->Kind == IndirectLocalPathEntry::AddressOf)
    continue;
  if (It->Kind == IndirectLocalPathEntry::LifetimeBoundCall)
    continue;
  return It->Kind == IndirectLocalPathEntry::GslPointerInit ||
         It->Kind == IndirectLocalPathEntry::GslReferenceInit;
}
return false;
7600}

7602void Sema::checkInitializerLifetime(const InitializedEntity &Entity,
                                  Expr *Init) {
LifetimeResult LR = getEntityLifetime(&Entity);
LifetimeKind LK = LR.getInt();
const InitializedEntity *ExtendingEntity = LR.getPointer();

// If this entity doesn't have an interesting lifetime, don't bother looking
// for temporaries within its initializer.
if (LK == LK_FullExpression)
  return;

auto TemporaryVisitor = [&](IndirectLocalPath &Path, Local L,
                            ReferenceKind RK) -> bool {
  SourceRange DiagRange = nextPathEntryRange(Path, 0, L);
  SourceLocation DiagLoc = DiagRange.getBegin();

  auto *MTE = dyn_cast<MaterializeTemporaryExpr>(L);

  bool IsGslPtrInitWithGslTempOwner = false;
  bool IsLocalGslOwner = false;
  if (pathOnlyInitializesGslPointer(Path)) {
    if (isa<DeclRefExpr>(L)) {
      // We do not want to follow the references when returning a pointer originating
      // from a local owner to avoid the following false positive:
      //   int &p = *localUniquePtr;
      //   someContainer.add(std::move(localUniquePtr));
      //   return p;
      IsLocalGslOwner = isRecordWithAttr<OwnerAttr>(L->getType());
      if (pathContainsInit(Path) || !IsLocalGslOwner)
        return false;
    } else {
      IsGslPtrInitWithGslTempOwner = MTE && !MTE->getExtendingDecl() &&
                          isRecordWithAttr<OwnerAttr>(MTE->getType());
      // Skipping a chain of initializing gsl::Pointer annotated objects.
      // We are looking only for the final source to find out if it was
      // a local or temporary owner or the address of a local variable/param.
      if (!IsGslPtrInitWithGslTempOwner)
        return true;
    }
  }

  switch (LK) {
  case LK_FullExpression:
    llvm_unreachable("already handled this")::llvm::llvm_unreachable_internal("already handled this", "clang/lib/Sema/SemaInit.cpp"
, 7645);

  case LK_Extended: {
    if (!MTE) {
      // The initialized entity has lifetime beyond the full-expression,
      // and the local entity does too, so don't warn.
      //
      // FIXME: We should consider warning if a static / thread storage
      // duration variable retains an automatic storage duration local.
      return false;
    }

    if (IsGslPtrInitWithGslTempOwner && DiagLoc.isValid()) {
      Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
      return false;
    }

    switch (shouldLifetimeExtendThroughPath(Path)) {
    case PathLifetimeKind::Extend:
      // Update the storage duration of the materialized temporary.
      // FIXME: Rebuild the expression instead of mutating it.
      MTE->setExtendingDecl(ExtendingEntity->getDecl(),
                            ExtendingEntity->allocateManglingNumber());
      // Also visit the temporaries lifetime-extended by this initializer.
      return true;

    case PathLifetimeKind::ShouldExtend:
      // We're supposed to lifetime-extend the temporary along this path (per
      // the resolution of DR1815), but we don't support that yet.
      //
      // FIXME: Properly handle this situation. Perhaps the easiest approach
      // would be to clone the initializer expression on each use that would
      // lifetime extend its temporaries.
      Diag(DiagLoc, diag::warn_unsupported_lifetime_extension)
          << RK << DiagRange;
      break;

    case PathLifetimeKind::NoExtend:
      // If the path goes through the initialization of a variable or field,
      // it can't possibly reach a temporary created in this full-expression.
      // We will have already diagnosed any problems with the initializer.
      if (pathContainsInit(Path))
        return false;

      Diag(DiagLoc, diag::warn_dangling_variable)
          << RK << !Entity.getParent()
          << ExtendingEntity->getDecl()->isImplicit()
          << ExtendingEntity->getDecl() << Init->isGLValue() << DiagRange;
      break;
    }
    break;
  }

  case LK_MemInitializer: {
    if (isa<MaterializeTemporaryExpr>(L)) {
      // Under C++ DR1696, if a mem-initializer (or a default member
      // initializer used by the absence of one) would lifetime-extend a
      // temporary, the program is ill-formed.
      if (auto *ExtendingDecl =
              ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
        if (IsGslPtrInitWithGslTempOwner) {
          Diag(DiagLoc, diag::warn_dangling_lifetime_pointer_member)
              << ExtendingDecl << DiagRange;
          Diag(ExtendingDecl->getLocation(),
               diag::note_ref_or_ptr_member_declared_here)
              << true;
          return false;
        }
        bool IsSubobjectMember = ExtendingEntity != &Entity;
        Diag(DiagLoc, shouldLifetimeExtendThroughPath(Path) !=
                              PathLifetimeKind::NoExtend
                          ? diag::err_dangling_member
                          : diag::warn_dangling_member)
            << ExtendingDecl << IsSubobjectMember << RK << DiagRange;
        // Don't bother adding a note pointing to the field if we're inside
        // its default member initializer; our primary diagnostic points to
        // the same place in that case.
        if (Path.empty() ||
            Path.back().Kind != IndirectLocalPathEntry::DefaultInit) {
          Diag(ExtendingDecl->getLocation(),
               diag::note_lifetime_extending_member_declared_here)
              << RK << IsSubobjectMember;
        }
      } else {
        // We have a mem-initializer but no particular field within it; this
        // is either a base class or a delegating initializer directly
        // initializing the base-class from something that doesn't live long
        // enough.
        //
        // FIXME: Warn on this.
        return false;
      }
    } else {
      // Paths via a default initializer can only occur during error recovery
      // (there's no other way that a default initializer can refer to a
      // local). Don't produce a bogus warning on those cases.
      if (pathContainsInit(Path))
        return false;

      // Suppress false positives for code like the one below:
      //   Ctor(unique_ptr<T> up) : member(*up), member2(move(up)) {}
      if (IsLocalGslOwner && pathOnlyInitializesGslPointer(Path))
        return false;

      auto *DRE = dyn_cast<DeclRefExpr>(L);
      auto *VD = DRE ? dyn_cast<VarDecl>(DRE->getDecl()) : nullptr;
      if (!VD) {
        // A member was initialized to a local block.
        // FIXME: Warn on this.
        return false;
      }

      if (auto *Member =
              ExtendingEntity ? ExtendingEntity->getDecl() : nullptr) {
        bool IsPointer = !Member->getType()->isReferenceType();
        Diag(DiagLoc, IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
                                : diag::warn_bind_ref_member_to_parameter)
            << Member << VD << isa<ParmVarDecl>(VD) << DiagRange;
        Diag(Member->getLocation(),
             diag::note_ref_or_ptr_member_declared_here)
            << (unsigned)IsPointer;
      }
    }
    break;
  }

  case LK_New:
    if (isa<MaterializeTemporaryExpr>(L)) {
      if (IsGslPtrInitWithGslTempOwner)
        Diag(DiagLoc, diag::warn_dangling_lifetime_pointer) << DiagRange;
      else
        Diag(DiagLoc, RK == RK_ReferenceBinding
                          ? diag::warn_new_dangling_reference
                          : diag::warn_new_dangling_initializer_list)
            << !Entity.getParent() << DiagRange;
    } else {
      // We can't determine if the allocation outlives the local declaration.
      return false;
    }
    break;

  case LK_Return:
  case LK_StmtExprResult:
    if (auto *DRE = dyn_cast<DeclRefExpr>(L)) {
      // We can't determine if the local variable outlives the statement
      // expression.
      if (LK == LK_StmtExprResult)
        return false;
      Diag(DiagLoc, diag::warn_ret_stack_addr_ref)
          << Entity.getType()->isReferenceType() << DRE->getDecl()
          << isa<ParmVarDecl>(DRE->getDecl()) << DiagRange;
    } else if (isa<BlockExpr>(L)) {
      Diag(DiagLoc, diag::err_ret_local_block) << DiagRange;
    } else if (isa<AddrLabelExpr>(L)) {
      // Don't warn when returning a label from a statement expression.
      // Leaving the scope doesn't end its lifetime.
      if (LK == LK_StmtExprResult)
        return false;
      Diag(DiagLoc, diag::warn_ret_addr_label) << DiagRange;
    } else {
      Diag(DiagLoc, diag::warn_ret_local_temp_addr_ref)
       << Entity.getType()->isReferenceType() << DiagRange;
    }
    break;
  }

  for (unsigned I = 0; I != Path.size(); ++I) {
    auto Elem = Path[I];

    switch (Elem.Kind) {
    case IndirectLocalPathEntry::AddressOf:
    case IndirectLocalPathEntry::LValToRVal:
      // These exist primarily to mark the path as not permitting or
      // supporting lifetime extension.
      break;

    case IndirectLocalPathEntry::LifetimeBoundCall:
    case IndirectLocalPathEntry::TemporaryCopy:
    case IndirectLocalPathEntry::GslPointerInit:
    case IndirectLocalPathEntry::GslReferenceInit:
      // FIXME: Consider adding a note for these.
      break;

    case IndirectLocalPathEntry::DefaultInit: {
      auto *FD = cast<FieldDecl>(Elem.D);
      Diag(FD->getLocation(), diag::note_init_with_default_member_initalizer)
          << FD << nextPathEntryRange(Path, I + 1, L);
      break;
    }

    case IndirectLocalPathEntry::VarInit: {
      const VarDecl *VD = cast<VarDecl>(Elem.D);
      Diag(VD->getLocation(), diag::note_local_var_initializer)
          << VD->getType()->isReferenceType()
          << VD->isImplicit() << VD->getDeclName()
          << nextPathEntryRange(Path, I + 1, L);
      break;
    }

    case IndirectLocalPathEntry::LambdaCaptureInit:
      if (!Elem.Capture->capturesVariable())
        break;
      // FIXME: We can't easily tell apart an init-capture from a nested
      // capture of an init-capture.
      const ValueDecl *VD = Elem.Capture->getCapturedVar();
      Diag(Elem.Capture->getLocation(), diag::note_lambda_capture_initializer)
          << VD << VD->isInitCapture() << Elem.Capture->isExplicit()
          << (Elem.Capture->getCaptureKind() == LCK_ByRef) << VD
          << nextPathEntryRange(Path, I + 1, L);
      break;
    }
  }

  // We didn't lifetime-extend, so don't go any further; we don't need more
  // warnings or errors on inner temporaries within this one's initializer.
  return false;
};

bool EnableLifetimeWarnings = !getDiagnostics().isIgnored(
    diag::warn_dangling_lifetime_pointer, SourceLocation());
llvm::SmallVector<IndirectLocalPathEntry, 8> Path;
if (Init->isGLValue())
  visitLocalsRetainedByReferenceBinding(Path, Init, RK_ReferenceBinding,
                                        TemporaryVisitor,
                                        EnableLifetimeWarnings);
else
  visitLocalsRetainedByInitializer(Path, Init, TemporaryVisitor, false,
                                   EnableLifetimeWarnings);
7873}

7875static void DiagnoseNarrowingInInitList(Sema &S,
                                      const ImplicitConversionSequence &ICS,
                                      QualType PreNarrowingType,
                                      QualType EntityType,
                                      const Expr *PostInit);

7881/// Provide warnings when std::move is used on construction.
7882static void CheckMoveOnConstruction(Sema &S, const Expr *InitExpr,
                                  bool IsReturnStmt) {
if (!InitExpr)
  return;

if (S.inTemplateInstantiation())
  return;

QualType DestType = InitExpr->getType();
if (!DestType->isRecordType())
  return;

unsigned DiagID = 0;
if (IsReturnStmt) {
  const CXXConstructExpr *CCE =
      dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
  if (!CCE || CCE->getNumArgs() != 1)
    return;

  if (!CCE->getConstructor()->isCopyOrMoveConstructor())
    return;

  InitExpr = CCE->getArg(0)->IgnoreImpCasts();
}

// Find the std::move call and get the argument.
const CallExpr *CE = dyn_cast<CallExpr>(InitExpr->IgnoreParens());
if (!CE || !CE->isCallToStdMove())
  return;

const Expr *Arg = CE->getArg(0)->IgnoreImplicit();

if (IsReturnStmt) {
  const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts());
  if (!DRE || DRE->refersToEnclosingVariableOrCapture())
    return;

  const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl());
  if (!VD || !VD->hasLocalStorage())
    return;

  // __block variables are not moved implicitly.
  if (VD->hasAttr<BlocksAttr>())
    return;

  QualType SourceType = VD->getType();
  if (!SourceType->isRecordType())
    return;

  if (!S.Context.hasSameUnqualifiedType(DestType, SourceType)) {
    return;
  }

  // If we're returning a function parameter, copy elision
  // is not possible.
  if (isa<ParmVarDecl>(VD))
    DiagID = diag::warn_redundant_move_on_return;
  else
    DiagID = diag::warn_pessimizing_move_on_return;
} else {
  DiagID = diag::warn_pessimizing_move_on_initialization;
  const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
  if (!ArgStripped->isPRValue() || !ArgStripped->getType()->isRecordType())
    return;
}

S.Diag(CE->getBeginLoc(), DiagID);

// Get all the locations for a fix-it.  Don't emit the fix-it if any location
// is within a macro.
SourceLocation CallBegin = CE->getCallee()->getBeginLoc();
if (CallBegin.isMacroID())
  return;
SourceLocation RParen = CE->getRParenLoc();
if (RParen.isMacroID())
  return;
SourceLocation LParen;
SourceLocation ArgLoc = Arg->getBeginLoc();

// Special testing for the argument location.  Since the fix-it needs the
// location right before the argument, the argument location can be in a
// macro only if it is at the beginning of the macro.
while (ArgLoc.isMacroID() &&
       S.getSourceManager().isAtStartOfImmediateMacroExpansion(ArgLoc)) {
  ArgLoc = S.getSourceManager().getImmediateExpansionRange(ArgLoc).getBegin();
}

if (LParen.isMacroID())
  return;

LParen = ArgLoc.getLocWithOffset(-1);

S.Diag(CE->getBeginLoc(), diag::note_remove_move)
    << FixItHint::CreateRemoval(SourceRange(CallBegin, LParen))
    << FixItHint::CreateRemoval(SourceRange(RParen, RParen));
7977}

7979static void CheckForNullPointerDereference(Sema &S, const Expr *E) {
// Check to see if we are dereferencing a null pointer.  If so, this is
// undefined behavior, so warn about it.  This only handles the pattern
// "*null", which is a very syntactic check.
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts()))
  if (UO->getOpcode() == UO_Deref &&
      UO->getSubExpr()->IgnoreParenCasts()->
      isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)) {
  S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
                        S.PDiag(diag::warn_binding_null_to_reference)
                          << UO->getSubExpr()->getSourceRange());
}
7991}

7993MaterializeTemporaryExpr *
7994Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
                                   bool BoundToLvalueReference) {
auto MTE = new (Context)
    MaterializeTemporaryExpr(T, Temporary, BoundToLvalueReference);

// Order an ExprWithCleanups for lifetime marks.
//
// TODO: It'll be good to have a single place to check the access of the
// destructor and generate ExprWithCleanups for various uses. Currently these
// are done in both CreateMaterializeTemporaryExpr and MaybeBindToTemporary,
// but there may be a chance to merge them.
Cleanup.setExprNeedsCleanups(false);
return MTE;
8007}

8009ExprResult Sema::TemporaryMaterializationConversion(Expr *E) {
// In C++98, we don't want to implicitly create an xvalue.
// FIXME: This means that AST consumers need to deal with "prvalues" that
// denote materialized temporaries. Maybe we should add another ValueKind
// for "xvalue pretending to be a prvalue" for C++98 support.
if (!E->isPRValue() || !getLangOpts().CPlusPlus11)
  return E;

// C++1z [conv.rval]/1: T shall be a complete type.
// FIXME: Does this ever matter (can we form a prvalue of incomplete type)?
// If so, we should check for a non-abstract class type here too.
QualType T = E->getType();
if (RequireCompleteType(E->getExprLoc(), T, diag::err_incomplete_type))
  return ExprError();

return CreateMaterializeTemporaryExpr(E->getType(), E, false);
8025}

8027ExprResult Sema::PerformQualificationConversion(Expr *E, QualType Ty,
                                              ExprValueKind VK,
                                              CheckedConversionKind CCK) {

CastKind CK = CK_NoOp;

if (VK == VK_PRValue) {
  auto PointeeTy = Ty->getPointeeType();
  auto ExprPointeeTy = E->getType()->getPointeeType();
  if (!PointeeTy.isNull() &&
      PointeeTy.getAddressSpace() != ExprPointeeTy.getAddressSpace())
    CK = CK_AddressSpaceConversion;
} else if (Ty.getAddressSpace() != E->getType().getAddressSpace()) {
  CK = CK_AddressSpaceConversion;
}

return ImpCastExprToType(E, Ty, CK, VK, /*BasePath=*/nullptr, CCK);
8044}

8046ExprResult InitializationSequence::Perform(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         MultiExprArg Args,
                                         QualType *ResultType) {
if (Failed()) {
  Diagnose(S, Entity, Kind, Args);
  return ExprError();
}
if (!ZeroInitializationFixit.empty()) {
  const Decl *D = Entity.getDecl();
  const auto *VD = dyn_cast_or_null<VarDecl>(D);
  QualType DestType = Entity.getType();

  // The initialization would have succeeded with this fixit. Since the fixit
  // is on the error, we need to build a valid AST in this case, so this isn't
  // handled in the Failed() branch above.
  if (!DestType->isRecordType() && VD && VD->isConstexpr()) {
    // Use a more useful diagnostic for constexpr variables.
    S.Diag(Kind.getLocation(), diag::err_constexpr_var_requires_const_init)
        << VD
        << FixItHint::CreateInsertion(ZeroInitializationFixitLoc,
                                      ZeroInitializationFixit);
  } else {
    unsigned DiagID = diag::err_default_init_const;
    if (S.getLangOpts().MSVCCompat && D && D->hasAttr<SelectAnyAttr>())
      DiagID = diag::ext_default_init_const;

    S.Diag(Kind.getLocation(), DiagID)
        << DestType << (bool)DestType->getAs<RecordType>()
        << FixItHint::CreateInsertion(ZeroInitializationFixitLoc,
                                      ZeroInitializationFixit);
  }
}

if (getKind() == DependentSequence) {
  // If the declaration is a non-dependent, incomplete array type
  // that has an initializer, then its type will be completed once
  // the initializer is instantiated.
  if (ResultType && !Entity.getType()->isDependentType() &&
      Args.size() == 1) {
    QualType DeclType = Entity.getType();
    if (const IncompleteArrayType *ArrayT
                         = S.Context.getAsIncompleteArrayType(DeclType)) {
      // FIXME: We don't currently have the ability to accurately
      // compute the length of an initializer list without
      // performing full type-checking of the initializer list
      // (since we have to determine where braces are implicitly
      // introduced and such).  So, we fall back to making the array
      // type a dependently-sized array type with no specified
      // bound.
      if (isa<InitListExpr>((Expr *)Args[0])) {
        SourceRange Brackets;

        // Scavange the location of the brackets from the entity, if we can.
        if (auto *DD = dyn_cast_or_null<DeclaratorDecl>(Entity.getDecl())) {
          if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) {
            TypeLoc TL = TInfo->getTypeLoc();
            if (IncompleteArrayTypeLoc ArrayLoc =
                    TL.getAs<IncompleteArrayTypeLoc>())
              Brackets = ArrayLoc.getBracketsRange();
          }
        }

        *ResultType
          = S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
                                                 /*NumElts=*/nullptr,
                                                 ArrayT->getSizeModifier(),
                                     ArrayT->getIndexTypeCVRQualifiers(),
                                                 Brackets);
      }

    }
  }
  if (Kind.getKind() == InitializationKind::IK_Direct &&
      !Kind.isExplicitCast()) {
    // Rebuild the ParenListExpr.
    SourceRange ParenRange = Kind.getParenOrBraceRange();
    return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(),
                                Args);
  }
  assert(Kind.getKind() == InitializationKind::IK_Copy ||(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind
::IK_DirectList) ? void (0) : __assert_fail ("Kind.getKind() == InitializationKind::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind::IK_DirectList"
, "clang/lib/Sema/SemaInit.cpp", 8129, __extension__ __PRETTY_FUNCTION__
))
         Kind.isExplicitCast() ||(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind
::IK_DirectList) ? void (0) : __assert_fail ("Kind.getKind() == InitializationKind::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind::IK_DirectList"
, "clang/lib/Sema/SemaInit.cpp", 8129, __extension__ __PRETTY_FUNCTION__
))
         Kind.getKind() == InitializationKind::IK_DirectList)(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind
::IK_DirectList) ? void (0) : __assert_fail ("Kind.getKind() == InitializationKind::IK_Copy || Kind.isExplicitCast() || Kind.getKind() == InitializationKind::IK_DirectList"
, "clang/lib/Sema/SemaInit.cpp", 8129, __extension__ __PRETTY_FUNCTION__
));
  return ExprResult(Args[0]);
}

// No steps means no initialization.
if (Steps.empty())
  return ExprResult((Expr *)nullptr);

if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() &&
    Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
    !Entity.isParamOrTemplateParamKind()) {
  // Produce a C++98 compatibility warning if we are initializing a reference
  // from an initializer list. For parameters, we produce a better warning
  // elsewhere.
  Expr *Init = Args[0];
  S.Diag(Init->getBeginLoc(), diag::warn_cxx98_compat_reference_list_init)
      << Init->getSourceRange();
}

// OpenCL v2.0 s6.13.11.1. atomic variables can be initialized in global scope
QualType ETy = Entity.getType();
bool HasGlobalAS = ETy.hasAddressSpace() &&
                   ETy.getAddressSpace() == LangAS::opencl_global;

if (S.getLangOpts().OpenCLVersion >= 200 &&
    ETy->isAtomicType() && !HasGlobalAS &&
    Entity.getKind() == InitializedEntity::EK_Variable && Args.size() > 0) {
  S.Diag(Args[0]->getBeginLoc(), diag::err_opencl_atomic_init)
      << 1
      << SourceRange(Entity.getDecl()->getBeginLoc(), Args[0]->getEndLoc());
  return ExprError();
}

QualType DestType = Entity.getType().getNonReferenceType();
// FIXME: Ugly hack around the fact that Entity.getType() is not
// the same as Entity.getDecl()->getType() in cases involving type merging,
//  and we want latter when it makes sense.
if (ResultType)
  *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() :
                                   Entity.getType();

ExprResult CurInit((Expr *)nullptr);
SmallVector<Expr*, 4> ArrayLoopCommonExprs;

// HLSL allows vector initialization to function like list initialization, but
// use the syntax of a C++-like constructor.
bool IsHLSLVectorInit = S.getLangOpts().HLSL && DestType->isExtVectorType() &&
                        isa<InitListExpr>(Args[0]);
(void)IsHLSLVectorInit;

// For initialization steps that start with a single initializer,
// grab the only argument out the Args and place it into the "current"
// initializer.
switch (Steps.front().Kind) {
case SK_ResolveAddressOfOverloadedFunction:
case SK_CastDerivedToBasePRValue:
case SK_CastDerivedToBaseXValue:
case SK_CastDerivedToBaseLValue:
case SK_BindReference:
case SK_BindReferenceToTemporary:
case SK_FinalCopy:
case SK_ExtraneousCopyToTemporary:
case SK_UserConversion:
case SK_QualificationConversionLValue:
case SK_QualificationConversionXValue:
case SK_QualificationConversionPRValue:
case SK_FunctionReferenceConversion:
case SK_AtomicConversion:
case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing:
case SK_ListInitialization:
case SK_UnwrapInitList:
case SK_RewrapInitList:
case SK_CAssignment:
case SK_StringInit:
case SK_ObjCObjectConversion:
case SK_ArrayLoopIndex:
case SK_ArrayLoopInit:
case SK_ArrayInit:
case SK_GNUArrayInit:
case SK_ParenthesizedArrayInit:
case SK_PassByIndirectCopyRestore:
case SK_PassByIndirectRestore:
case SK_ProduceObjCObject:
case SK_StdInitializerList:
case SK_OCLSamplerInit:
case SK_OCLZeroOpaqueType: {
  assert(Args.size() == 1 || IsHLSLVectorInit)(static_cast <bool> (Args.size() == 1 || IsHLSLVectorInit
) ? void (0) : __assert_fail ("Args.size() == 1 || IsHLSLVectorInit"
, "clang/lib/Sema/SemaInit.cpp", 8216, __extension__ __PRETTY_FUNCTION__
));
  CurInit = Args[0];
  if (!CurInit.get()) return ExprError();
  break;
}

case SK_ConstructorInitialization:
case SK_ConstructorInitializationFromList:
case SK_StdInitializerListConstructorCall:
case SK_ZeroInitialization:
  break;
}

// Promote from an unevaluated context to an unevaluated list context in
// C++11 list-initialization; we need to instantiate entities usable in
// constant expressions here in order to perform narrowing checks =(
EnterExpressionEvaluationContext Evaluated(
    S, EnterExpressionEvaluationContext::InitList,
    CurInit.get() && isa<InitListExpr>(CurInit.get()));

// C++ [class.abstract]p2:
//   no objects of an abstract class can be created except as subobjects
//   of a class derived from it
auto checkAbstractType = [&](QualType T) -> bool {
  if (Entity.getKind() == InitializedEntity::EK_Base ||
      Entity.getKind() == InitializedEntity::EK_Delegating)
    return false;
  return S.RequireNonAbstractType(Kind.getLocation(), T,
                                  diag::err_allocation_of_abstract_type);
};

// Walk through the computed steps for the initialization sequence,
// performing the specified conversions along the way.
bool ConstructorInitRequiresZeroInit = false;
for (step_iterator Step = step_begin(), StepEnd = step_end();
     Step != StepEnd; ++Step) {
  if (CurInit.isInvalid())
    return ExprError();

  QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType();

  switch (Step->Kind) {
  case SK_ResolveAddressOfOverloadedFunction:
    // Overload resolution determined which function invoke; update the
    // initializer to reflect that choice.
    S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl);
    if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()))
      return ExprError();
    CurInit = S.FixOverloadedFunctionReference(CurInit,
                                               Step->Function.FoundDecl,
                                               Step->Function.Function);
    // We might get back another placeholder expression if we resolved to a
    // builtin.
    if (!CurInit.isInvalid())
      CurInit = S.CheckPlaceholderExpr(CurInit.get());
    break;

  case SK_CastDerivedToBasePRValue:
  case SK_CastDerivedToBaseXValue:
  case SK_CastDerivedToBaseLValue: {
    // We have a derived-to-base cast that produces either an rvalue or an
    // lvalue. Perform that cast.

    CXXCastPath BasePath;

    // Casts to inaccessible base classes are allowed with C-style casts.
    bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
    if (S.CheckDerivedToBaseConversion(
            SourceType, Step->Type, CurInit.get()->getBeginLoc(),
            CurInit.get()->getSourceRange(), &BasePath, IgnoreBaseAccess))
      return ExprError();

    ExprValueKind VK =
        Step->Kind == SK_CastDerivedToBaseLValue
            ? VK_LValue
            : (Step->Kind == SK_CastDerivedToBaseXValue ? VK_XValue
                                                        : VK_PRValue);
    CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
                                       CK_DerivedToBase, CurInit.get(),
                                       &BasePath, VK, FPOptionsOverride());
    break;
  }

  case SK_BindReference:
    // Reference binding does not have any corresponding ASTs.

    // Check exception specifications
    if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
      return ExprError();

    // We don't check for e.g. function pointers here, since address
    // availability checks should only occur when the function first decays
    // into a pointer or reference.
    if (CurInit.get()->getType()->isFunctionProtoType()) {
      if (auto *DRE = dyn_cast<DeclRefExpr>(CurInit.get()->IgnoreParens())) {
        if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
          if (!S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
                                                   DRE->getBeginLoc()))
            return ExprError();
        }
      }
    }

    CheckForNullPointerDereference(S, CurInit.get());
    break;

  case SK_BindReferenceToTemporary: {
    // Make sure the "temporary" is actually an rvalue.
    assert(CurInit.get()->isPRValue() && "not a temporary")(static_cast <bool> (CurInit.get()->isPRValue() &&
 "not a temporary") ? void (0) : __assert_fail ("CurInit.get()->isPRValue() && \"not a temporary\""
, "clang/lib/Sema/SemaInit.cpp", 8324, __extension__ __PRETTY_FUNCTION__
));

    // Check exception specifications
    if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
      return ExprError();

    QualType MTETy = Step->Type;

    // When this is an incomplete array type (such as when this is
    // initializing an array of unknown bounds from an init list), use THAT
    // type instead so that we propagate the array bounds.
    if (MTETy->isIncompleteArrayType() &&
        !CurInit.get()->getType()->isIncompleteArrayType() &&
        S.Context.hasSameType(
            MTETy->getPointeeOrArrayElementType(),
            CurInit.get()->getType()->getPointeeOrArrayElementType()))
      MTETy = CurInit.get()->getType();

    // Materialize the temporary into memory.
    MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
        MTETy, CurInit.get(), Entity.getType()->isLValueReferenceType());
    CurInit = MTE;

    // If we're extending this temporary to automatic storage duration -- we
    // need to register its cleanup during the full-expression's cleanups.
    if (MTE->getStorageDuration() == SD_Automatic &&
        MTE->getType().isDestructedType())
      S.Cleanup.setExprNeedsCleanups(true);
    break;
  }

  case SK_FinalCopy:
    if (checkAbstractType(Step->Type))
      return ExprError();

    // If the overall initialization is initializing a temporary, we already
    // bound our argument if it was necessary to do so. If not (if we're
    // ultimately initializing a non-temporary), our argument needs to be
    // bound since it's initializing a function parameter.
    // FIXME: This is a mess. Rationalize temporary destruction.
    if (!shouldBindAsTemporary(Entity))
      CurInit = S.MaybeBindToTemporary(CurInit.get());
    CurInit = CopyObject(S, Step->Type, Entity, CurInit,
                         /*IsExtraneousCopy=*/false);
    break;

  case SK_ExtraneousCopyToTemporary:
    CurInit = CopyObject(S, Step->Type, Entity, CurInit,
                         /*IsExtraneousCopy=*/true);
    break;

  case SK_UserConversion: {
    // We have a user-defined conversion that invokes either a constructor
    // or a conversion function.
    CastKind CastKind;
    FunctionDecl *Fn = Step->Function.Function;
    DeclAccessPair FoundFn = Step->Function.FoundDecl;
    bool HadMultipleCandidates = Step->Function.HadMultipleCandidates;
    bool CreatedObject = false;
    if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) {
      // Build a call to the selected constructor.
      SmallVector<Expr*, 8> ConstructorArgs;
      SourceLocation Loc = CurInit.get()->getBeginLoc();

      // Determine the arguments required to actually perform the constructor
      // call.
      Expr *Arg = CurInit.get();
      if (S.CompleteConstructorCall(Constructor, Step->Type,
                                    MultiExprArg(&Arg, 1), Loc,
                                    ConstructorArgs))
        return ExprError();

      // Build an expression that constructs a temporary.
      CurInit = S.BuildCXXConstructExpr(Loc, Step->Type,
                                        FoundFn, Constructor,
                                        ConstructorArgs,
                                        HadMultipleCandidates,
                                        /*ListInit*/ false,
                                        /*StdInitListInit*/ false,
                                        /*ZeroInit*/ false,
                                        CXXConstructExpr::CK_Complete,
                                        SourceRange());
      if (CurInit.isInvalid())
        return ExprError();

      S.CheckConstructorAccess(Kind.getLocation(), Constructor, FoundFn,
                               Entity);
      if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
        return ExprError();

      CastKind = CK_ConstructorConversion;
      CreatedObject = true;
    } else {
      // Build a call to the conversion function.
      CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn);
      S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr,
                                  FoundFn);
      if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
        return ExprError();

      CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion,
                                         HadMultipleCandidates);
      if (CurInit.isInvalid())
        return ExprError();

      CastKind = CK_UserDefinedConversion;
      CreatedObject = Conversion->getReturnType()->isRecordType();
    }

    if (CreatedObject && checkAbstractType(CurInit.get()->getType()))
      return ExprError();

    CurInit = ImplicitCastExpr::Create(
        S.Context, CurInit.get()->getType(), CastKind, CurInit.get(), nullptr,
        CurInit.get()->getValueKind(), S.CurFPFeatureOverrides());

    if (shouldBindAsTemporary(Entity))
      // The overall entity is temporary, so this expression should be
      // destroyed at the end of its full-expression.
      CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
    else if (CreatedObject && shouldDestroyEntity(Entity)) {
      // The object outlasts the full-expression, but we need to prepare for
      // a destructor being run on it.
      // FIXME: It makes no sense to do this here. This should happen
      // regardless of how we initialized the entity.
      QualType T = CurInit.get()->getType();
      if (const RecordType *Record = T->getAs<RecordType>()) {
        CXXDestructorDecl *Destructor
          = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl()));
        S.CheckDestructorAccess(CurInit.get()->getBeginLoc(), Destructor,
                                S.PDiag(diag::err_access_dtor_temp) << T);
        S.MarkFunctionReferenced(CurInit.get()->getBeginLoc(), Destructor);
        if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getBeginLoc()))
          return ExprError();
      }
    }
    break;
  }

  case SK_QualificationConversionLValue:
  case SK_QualificationConversionXValue:
  case SK_QualificationConversionPRValue: {
    // Perform a qualification conversion; these can never go wrong.
    ExprValueKind VK =
        Step->Kind == SK_QualificationConversionLValue
            ? VK_LValue
            : (Step->Kind == SK_QualificationConversionXValue ? VK_XValue
                                                              : VK_PRValue);
    CurInit = S.PerformQualificationConversion(CurInit.get(), Step->Type, VK);
    break;
  }

  case SK_FunctionReferenceConversion:
    assert(CurInit.get()->isLValue() &&(static_cast <bool> (CurInit.get()->isLValue() &&
 "function reference should be lvalue") ? void (0) : __assert_fail
 ("CurInit.get()->isLValue() && \"function reference should be lvalue\""
, "clang/lib/Sema/SemaInit.cpp", 8478, __extension__ __PRETTY_FUNCTION__
))
           "function reference should be lvalue")(static_cast <bool> (CurInit.get()->isLValue() &&
 "function reference should be lvalue") ? void (0) : __assert_fail
 ("CurInit.get()->isLValue() && \"function reference should be lvalue\""
, "clang/lib/Sema/SemaInit.cpp", 8478, __extension__ __PRETTY_FUNCTION__
));
    CurInit =
        S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK_LValue);
    break;

  case SK_AtomicConversion: {
    assert(CurInit.get()->isPRValue() && "cannot convert glvalue to atomic")(static_cast <bool> (CurInit.get()->isPRValue() &&
 "cannot convert glvalue to atomic") ? void (0) : __assert_fail
 ("CurInit.get()->isPRValue() && \"cannot convert glvalue to atomic\""
, "clang/lib/Sema/SemaInit.cpp", 8484, __extension__ __PRETTY_FUNCTION__
));
    CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
                                  CK_NonAtomicToAtomic, VK_PRValue);
    break;
  }

  case SK_ConversionSequence:
  case SK_ConversionSequenceNoNarrowing: {
    if (const auto *FromPtrType =
            CurInit.get()->getType()->getAs<PointerType>()) {
      if (const auto *ToPtrType = Step->Type->getAs<PointerType>()) {
        if (FromPtrType->getPointeeType()->hasAttr(attr::NoDeref) &&
            !ToPtrType->getPointeeType()->hasAttr(attr::NoDeref)) {
          // Do not check static casts here because they are checked earlier
          // in Sema::ActOnCXXNamedCast()
          if (!Kind.isStaticCast()) {
            S.Diag(CurInit.get()->getExprLoc(),
                   diag::warn_noderef_to_dereferenceable_pointer)
                << CurInit.get()->getSourceRange();
          }
        }
      }
    }

    Sema::CheckedConversionKind CCK
      = Kind.isCStyleCast()? Sema::CCK_CStyleCast
      : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast
      : Kind.isExplicitCast()? Sema::CCK_OtherCast
      : Sema::CCK_ImplicitConversion;
    ExprResult CurInitExprRes =
      S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS,
                                  getAssignmentAction(Entity), CCK);
    if (CurInitExprRes.isInvalid())
      return ExprError();

    S.DiscardMisalignedMemberAddress(Step->Type.getTypePtr(), CurInit.get());

    CurInit = CurInitExprRes;

    if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
        S.getLangOpts().CPlusPlus)
      DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(),
                                  CurInit.get());

    break;
  }

  case SK_ListInitialization: {
    if (checkAbstractType(Step->Type))
      return ExprError();

    InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
    // If we're not initializing the top-level entity, we need to create an
    // InitializeTemporary entity for our target type.
    QualType Ty = Step->Type;
    bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
    InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
    InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
    InitListChecker PerformInitList(S, InitEntity,
        InitList, Ty, /*VerifyOnly=*/false,
        /*TreatUnavailableAsInvalid=*/false);
    if (PerformInitList.HadError())
      return ExprError();

    // Hack: We must update *ResultType if available in order to set the
    // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
    // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
    if (ResultType &&
        ResultType->getNonReferenceType()->isIncompleteArrayType()) {
      if ((*ResultType)->isRValueReferenceType())
        Ty = S.Context.getRValueReferenceType(Ty);
      else if ((*ResultType)->isLValueReferenceType())
        Ty = S.Context.getLValueReferenceType(Ty,
          (*ResultType)->castAs<LValueReferenceType>()->isSpelledAsLValue());
      *ResultType = Ty;
    }

    InitListExpr *StructuredInitList =
        PerformInitList.getFullyStructuredList();
    CurInit.get();
    CurInit = shouldBindAsTemporary(InitEntity)
        ? S.MaybeBindToTemporary(StructuredInitList)
        : StructuredInitList;
    break;
  }

  case SK_ConstructorInitializationFromList: {
    if (checkAbstractType(Step->Type))
      return ExprError();

    // When an initializer list is passed for a parameter of type "reference
    // to object", we don't get an EK_Temporary entity, but instead an
    // EK_Parameter entity with reference type.
    // FIXME: This is a hack. What we really should do is create a user
    // conversion step for this case, but this makes it considerably more
    // complicated. For now, this will do.
    InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
                                      Entity.getType().getNonReferenceType());
    bool UseTemporary = Entity.getType()->isReferenceType();
    assert(Args.size() == 1 && "expected a single argument for list init")(static_cast <bool> (Args.size() == 1 && "expected a single argument for list init"
) ? void (0) : __assert_fail ("Args.size() == 1 && \"expected a single argument for list init\""
, "clang/lib/Sema/SemaInit.cpp", 8583, __extension__ __PRETTY_FUNCTION__
));
    InitListExpr *InitList = cast<InitListExpr>(Args[0]);
    S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init)
      << InitList->getSourceRange();
    MultiExprArg Arg(InitList->getInits(), InitList->getNumInits());
    CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity :
                                                                 Entity,
                                               Kind, Arg, *Step,
                                             ConstructorInitRequiresZeroInit,
                                             /*IsListInitialization*/true,
                                             /*IsStdInitListInit*/false,
                                             InitList->getLBraceLoc(),
                                             InitList->getRBraceLoc());
    break;
  }

  case SK_UnwrapInitList:
    CurInit = cast<InitListExpr>(CurInit.get())->getInit(0);
    break;

  case SK_RewrapInitList: {
    Expr *E = CurInit.get();
    InitListExpr *Syntactic = Step->WrappingSyntacticList;
    InitListExpr *ILE = new (S.Context) InitListExpr(S.Context,
        Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc());
    ILE->setSyntacticForm(Syntactic);
    ILE->setType(E->getType());
    ILE->setValueKind(E->getValueKind());
    CurInit = ILE;
    break;
  }

  case SK_ConstructorInitialization:
  case SK_StdInitializerListConstructorCall: {
    if (checkAbstractType(Step->Type))
      return ExprError();

    // When an initializer list is passed for a parameter of type "reference
    // to object", we don't get an EK_Temporary entity, but instead an
    // EK_Parameter entity with reference type.
    // FIXME: This is a hack. What we really should do is create a user
    // conversion step for this case, but this makes it considerably more
    // complicated. For now, this will do.
    InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
                                      Entity.getType().getNonReferenceType());
    bool UseTemporary = Entity.getType()->isReferenceType();
    bool IsStdInitListInit =
        Step->Kind == SK_StdInitializerListConstructorCall;
    Expr *Source = CurInit.get();
    SourceRange Range = Kind.hasParenOrBraceRange()
                            ? Kind.getParenOrBraceRange()
                            : SourceRange();
    CurInit = PerformConstructorInitialization(
        S, UseTemporary ? TempEntity : Entity, Kind,
        Source ? MultiExprArg(Source) : Args, *Step,
        ConstructorInitRequiresZeroInit,
        /*IsListInitialization*/ IsStdInitListInit,
        /*IsStdInitListInitialization*/ IsStdInitListInit,
        /*LBraceLoc*/ Range.getBegin(),
        /*RBraceLoc*/ Range.getEnd());
    break;
  }

  case SK_ZeroInitialization: {
    step_iterator NextStep = Step;
    ++NextStep;
    if (NextStep != StepEnd &&
        (NextStep->Kind == SK_ConstructorInitialization ||
         NextStep->Kind == SK_ConstructorInitializationFromList)) {
      // The need for zero-initialization is recorded directly into
      // the call to the object's constructor within the next step.
      ConstructorInitRequiresZeroInit = true;
    } else if (Kind.getKind() == InitializationKind::IK_Value &&
               S.getLangOpts().CPlusPlus &&
               !Kind.isImplicitValueInit()) {
      TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
      if (!TSInfo)
        TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type,
                                                  Kind.getRange().getBegin());

      CurInit = new (S.Context) CXXScalarValueInitExpr(
          Entity.getType().getNonLValueExprType(S.Context), TSInfo,
          Kind.getRange().getEnd());
    } else {
      CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type);
    }
    break;
  }

  case SK_CAssignment: {
    QualType SourceType = CurInit.get()->getType();

    // Save off the initial CurInit in case we need to emit a diagnostic
    ExprResult InitialCurInit = CurInit;
    ExprResult Result = CurInit;
    Sema::AssignConvertType ConvTy =
      S.CheckSingleAssignmentConstraints(Step->Type, Result, true,
          Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited);
    if (Result.isInvalid())
      return ExprError();
    CurInit = Result;

    // If this is a call, allow conversion to a transparent union.
    ExprResult CurInitExprRes = CurInit;
    if (ConvTy != Sema::Compatible &&
        Entity.isParameterKind() &&
        S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes)
          == Sema::Compatible)
      ConvTy = Sema::Compatible;
    if (CurInitExprRes.isInvalid())
      return ExprError();
    CurInit = CurInitExprRes;

    bool Complained;
    if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(),
                                   Step->Type, SourceType,
                                   InitialCurInit.get(),
                                   getAssignmentAction(Entity, true),
                                   &Complained)) {
      PrintInitLocationNote(S, Entity);
      return ExprError();
    } else if (Complained)
      PrintInitLocationNote(S, Entity);
    break;
  }

  case SK_StringInit: {
    QualType Ty = Step->Type;
    bool UpdateType = ResultType && Entity.getType()->isIncompleteArrayType();
    CheckStringInit(CurInit.get(), UpdateType ? *ResultType : Ty,
                    S.Context.getAsArrayType(Ty), S);
    break;
  }

  case SK_ObjCObjectConversion:
    CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
                        CK_ObjCObjectLValueCast,
                        CurInit.get()->getValueKind());
    break;

  case SK_ArrayLoopIndex: {
    Expr *Cur = CurInit.get();
    Expr *BaseExpr = new (S.Context)
        OpaqueValueExpr(Cur->getExprLoc(), Cur->getType(),
                        Cur->getValueKind(), Cur->getObjectKind(), Cur);
    Expr *IndexExpr =
        new (S.Context) ArrayInitIndexExpr(S.Context.getSizeType());
    CurInit = S.CreateBuiltinArraySubscriptExpr(
        BaseExpr, Kind.getLocation(), IndexExpr, Kind.getLocation());
    ArrayLoopCommonExprs.push_back(BaseExpr);
    break;
  }

  case SK_ArrayLoopInit: {
    assert(!ArrayLoopCommonExprs.empty() &&(static_cast <bool> (!ArrayLoopCommonExprs.empty() &&
 "mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit") ? void (
0) : __assert_fail ("!ArrayLoopCommonExprs.empty() && \"mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit\""
, "clang/lib/Sema/SemaInit.cpp", 8738, __extension__ __PRETTY_FUNCTION__
))
           "mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit")(static_cast <bool> (!ArrayLoopCommonExprs.empty() &&
 "mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit") ? void (
0) : __assert_fail ("!ArrayLoopCommonExprs.empty() && \"mismatched SK_ArrayLoopIndex and SK_ArrayLoopInit\""
, "clang/lib/Sema/SemaInit.cpp", 8738, __extension__ __PRETTY_FUNCTION__
));
    Expr *Common = ArrayLoopCommonExprs.pop_back_val();
    CurInit = new (S.Context) ArrayInitLoopExpr(Step->Type, Common,
                                                CurInit.get());
    break;
  }

  case SK_GNUArrayInit:
    // Okay: we checked everything before creating this step. Note that
    // this is a GNU extension.
    S.Diag(Kind.getLocation(), diag::ext_array_init_copy)
      << Step->Type << CurInit.get()->getType()
      << CurInit.get()->getSourceRange();
    updateGNUCompoundLiteralRValue(CurInit.get());
    [[fallthrough]];
  case SK_ArrayInit:
    // If the destination type is an incomplete array type, update the
    // type accordingly.
    if (ResultType) {
      if (const IncompleteArrayType *IncompleteDest
                         = S.Context.getAsIncompleteArrayType(Step->Type)) {
        if (const ConstantArrayType *ConstantSource
               = S.Context.getAsConstantArrayType(CurInit.get()->getType())) {
          *ResultType = S.Context.getConstantArrayType(
                                           IncompleteDest->getElementType(),
                                           ConstantSource->getSize(),
                                           ConstantSource->getSizeExpr(),
                                           ArrayType::Normal, 0);
        }
      }
    }
    break;

  case SK_ParenthesizedArrayInit:
    // Okay: we checked everything before creating this step. Note that
    // this is a GNU extension.
    S.Diag(Kind.getLocation(), diag::ext_array_init_parens)
      << CurInit.get()->getSourceRange();
    break;

  case SK_PassByIndirectCopyRestore:
  case SK_PassByIndirectRestore:
    checkIndirectCopyRestoreSource(S, CurInit.get());
    CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr(
        CurInit.get(), Step->Type,
        Step->Kind == SK_PassByIndirectCopyRestore);
    break;

  case SK_ProduceObjCObject:
    CurInit = ImplicitCastExpr::Create(
        S.Context, Step->Type, CK_ARCProduceObject, CurInit.get(), nullptr,
        VK_PRValue, FPOptionsOverride());
    break;

  case SK_StdInitializerList: {
    S.Diag(CurInit.get()->getExprLoc(),
           diag::warn_cxx98_compat_initializer_list_init)
      << CurInit.get()->getSourceRange();

    // Materialize the temporary into memory.
    MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
        CurInit.get()->getType(), CurInit.get(),
        /*BoundToLvalueReference=*/false);

    // Wrap it in a construction of a std::initializer_list<T>.
    CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE);

    // Bind the result, in case the library has given initializer_list a
    // non-trivial destructor.
    if (shouldBindAsTemporary(Entity))
      CurInit = S.MaybeBindToTemporary(CurInit.get());
    break;
  }

  case SK_OCLSamplerInit: {
    // Sampler initialization have 5 cases:
    //   1. function argument passing
    //      1a. argument is a file-scope variable
    //      1b. argument is a function-scope variable
    //      1c. argument is one of caller function's parameters
    //   2. variable initialization
    //      2a. initializing a file-scope variable
    //      2b. initializing a function-scope variable
    //
    // For file-scope variables, since they cannot be initialized by function
    // call of __translate_sampler_initializer in LLVM IR, their references
    // need to be replaced by a cast from their literal initializers to
    // sampler type. Since sampler variables can only be used in function
    // calls as arguments, we only need to replace them when handling the
    // argument passing.
    assert(Step->Type->isSamplerT() &&(static_cast <bool> (Step->Type->isSamplerT() &&
 "Sampler initialization on non-sampler type.") ? void (0) : __assert_fail
 ("Step->Type->isSamplerT() && \"Sampler initialization on non-sampler type.\""
, "clang/lib/Sema/SemaInit.cpp", 8829, __extension__ __PRETTY_FUNCTION__
))
           "Sampler initialization on non-sampler type.")(static_cast <bool> (Step->Type->isSamplerT() &&
 "Sampler initialization on non-sampler type.") ? void (0) : __assert_fail
 ("Step->Type->isSamplerT() && \"Sampler initialization on non-sampler type.\""
, "clang/lib/Sema/SemaInit.cpp", 8829, __extension__ __PRETTY_FUNCTION__
));
    Expr *Init = CurInit.get()->IgnoreParens();
    QualType SourceType = Init->getType();
    // Case 1
    if (Entity.isParameterKind()) {
      if (!SourceType->isSamplerT() && !SourceType->isIntegerType()) {
        S.Diag(Kind.getLocation(), diag::err_sampler_argument_required)
          << SourceType;
        break;
      } else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init)) {
        auto Var = cast<VarDecl>(DRE->getDecl());
        // Case 1b and 1c
        // No cast from integer to sampler is needed.
        if (!Var->hasGlobalStorage()) {
          CurInit = ImplicitCastExpr::Create(
              S.Context, Step->Type, CK_LValueToRValue, Init,
              /*BasePath=*/nullptr, VK_PRValue, FPOptionsOverride());
          break;
        }
        // Case 1a
        // For function call with a file-scope sampler variable as argument,
        // get the integer literal.
        // Do not diagnose if the file-scope variable does not have initializer
        // since this has already been diagnosed when parsing the variable
        // declaration.
        if (!Var->getInit() || !isa<ImplicitCastExpr>(Var->getInit()))
          break;
        Init = cast<ImplicitCastExpr>(const_cast<Expr*>(
          Var->getInit()))->getSubExpr();
        SourceType = Init->getType();
      }
    } else {
      // Case 2
      // Check initializer is 32 bit integer constant.
      // If the initializer is taken from global variable, do not diagnose since
      // this has already been done when parsing the variable declaration.
      if (!Init->isConstantInitializer(S.Context, false))
        break;

      if (!SourceType->isIntegerType() ||
          32 != S.Context.getIntWidth(SourceType)) {
        S.Diag(Kind.getLocation(), diag::err_sampler_initializer_not_integer)
          << SourceType;
        break;
      }

      Expr::EvalResult EVResult;
      Init->EvaluateAsInt(EVResult, S.Context);
      llvm::APSInt Result = EVResult.Val.getInt();
      const uint64_t SamplerValue = Result.getLimitedValue();
      // 32-bit value of sampler's initializer is interpreted as
      // bit-field with the following structure:
      // |unspecified|Filter|Addressing Mode| Normalized Coords|
      // |31        6|5    4|3             1|                 0|
      // This structure corresponds to enum values of sampler properties
      // defined in SPIR spec v1.2 and also opencl-c.h
      unsigned AddressingMode  = (0x0E & SamplerValue) >> 1;
      unsigned FilterMode      = (0x30 & SamplerValue) >> 4;
      if (FilterMode != 1 && FilterMode != 2 &&
          !S.getOpenCLOptions().isAvailableOption(
              "cl_intel_device_side_avc_motion_estimation", S.getLangOpts()))
        S.Diag(Kind.getLocation(),
               diag::warn_sampler_initializer_invalid_bits)
               << "Filter Mode";
      if (AddressingMode > 4)
        S.Diag(Kind.getLocation(),
               diag::warn_sampler_initializer_invalid_bits)
               << "Addressing Mode";
    }

    // Cases 1a, 2a and 2b
    // Insert cast from integer to sampler.
    CurInit = S.ImpCastExprToType(Init, S.Context.OCLSamplerTy,
                                    CK_IntToOCLSampler);
    break;
  }
  case SK_OCLZeroOpaqueType: {
    assert((Step->Type->isEventT() || Step->Type->isQueueT() ||(static_cast <bool> ((Step->Type->isEventT() || Step
->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType
()) && "Wrong type for initialization of OpenCL opaque type."
) ? void (0) : __assert_fail ("(Step->Type->isEventT() || Step->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType()) && \"Wrong type for initialization of OpenCL opaque type.\""
, "clang/lib/Sema/SemaInit.cpp", 8908, __extension__ __PRETTY_FUNCTION__
))
            Step->Type->isOCLIntelSubgroupAVCType()) &&(static_cast <bool> ((Step->Type->isEventT() || Step
->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType
()) && "Wrong type for initialization of OpenCL opaque type."
) ? void (0) : __assert_fail ("(Step->Type->isEventT() || Step->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType()) && \"Wrong type for initialization of OpenCL opaque type.\""
, "clang/lib/Sema/SemaInit.cpp", 8908, __extension__ __PRETTY_FUNCTION__
))
           "Wrong type for initialization of OpenCL opaque type.")(static_cast <bool> ((Step->Type->isEventT() || Step
->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType
()) && "Wrong type for initialization of OpenCL opaque type."
) ? void (0) : __assert_fail ("(Step->Type->isEventT() || Step->Type->isQueueT() || Step->Type->isOCLIntelSubgroupAVCType()) && \"Wrong type for initialization of OpenCL opaque type.\""
, "clang/lib/Sema/SemaInit.cpp", 8908, __extension__ __PRETTY_FUNCTION__
));

    CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
                                  CK_ZeroToOCLOpaqueType,
                                  CurInit.get()->getValueKind());
    break;
  }
  }
}

// Check whether the initializer has a shorter lifetime than the initialized
// entity, and if not, either lifetime-extend or warn as appropriate.
if (auto *Init = CurInit.get())
  S.checkInitializerLifetime(Entity, Init);

// Diagnose non-fatal problems with the completed initialization.
if (Entity.getKind() == InitializedEntity::EK_Member &&
    cast<FieldDecl>(Entity.getDecl())->isBitField())
  S.CheckBitFieldInitialization(Kind.getLocation(),
                                cast<FieldDecl>(Entity.getDecl()),
                                CurInit.get());

// Check for std::move on construction.
if (const Expr *E = CurInit.get()) {
  CheckMoveOnConstruction(S, E,
                          Entity.getKind() == InitializedEntity::EK_Result);
}

return CurInit;
8937}

8939/// Somewhere within T there is an uninitialized reference subobject.
8940/// Dig it out and diagnose it.
8941static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc,
                                         QualType T) {
if (T->isReferenceType()) {
  S.Diag(Loc, diag::err_reference_without_init)
    << T.getNonReferenceType();
  return true;
}

CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
if (!RD || !RD->hasUninitializedReferenceMember())
  return false;

for (const auto *FI : RD->fields()) {
  if (FI->isUnnamedBitfield())
    continue;

  if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) {
    S.Diag(Loc, diag::note_value_initialization_here) << RD;
    return true;
  }
}

for (const auto &BI : RD->bases()) {
  if (DiagnoseUninitializedReference(S, BI.getBeginLoc(), BI.getType())) {
    S.Diag(Loc, diag::note_value_initialization_here) << RD;
    return true;
  }
}

return false;
8971}


8974//===----------------------------------------------------------------------===//
8975// Diagnose initialization failures
8976//===----------------------------------------------------------------------===//

8978/// Emit notes associated with an initialization that failed due to a
8979/// "simple" conversion failure.
8980static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity,
                                 Expr *op) {
QualType destType = entity.getType();
if (destType.getNonReferenceType()->isObjCObjectPointerType() &&
    op->getType()->isObjCObjectPointerType()) {

  // Emit a possible note about the conversion failing because the
  // operand is a message send with a related result type.
  S.EmitRelatedResultTypeNote(op);

  // Emit a possible note about a return failing because we're
  // expecting a related result type.
  if (entity.getKind() == InitializedEntity::EK_Result)
    S.EmitRelatedResultTypeNoteForReturn(destType);
}
QualType fromType = op->getType();
QualType fromPointeeType = fromType.getCanonicalType()->getPointeeType();
QualType destPointeeType = destType.getCanonicalType()->getPointeeType();
auto *fromDecl = fromType->getPointeeCXXRecordDecl();
auto *destDecl = destType->getPointeeCXXRecordDecl();
if (fromDecl && destDecl && fromDecl->getDeclKind() == Decl::CXXRecord &&
    destDecl->getDeclKind() == Decl::CXXRecord &&
    !fromDecl->isInvalidDecl() && !destDecl->isInvalidDecl() &&
    !fromDecl->hasDefinition() &&
    destPointeeType.getQualifiers().compatiblyIncludes(
        fromPointeeType.getQualifiers()))
  S.Diag(fromDecl->getLocation(), diag::note_forward_class_conversion)
      << S.getASTContext().getTagDeclType(fromDecl)
      << S.getASTContext().getTagDeclType(destDecl);
9009}

9011static void diagnoseListInit(Sema &S, const InitializedEntity &Entity,
                           InitListExpr *InitList) {
QualType DestType = Entity.getType();

QualType E;
if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) {
  QualType ArrayType = S.Context.getConstantArrayType(
      E.withConst(),
      llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
                  InitList->getNumInits()),
      nullptr, clang::ArrayType::Normal, 0);
  InitializedEntity HiddenArray =
      InitializedEntity::InitializeTemporary(ArrayType);
  return diagnoseListInit(S, HiddenArray, InitList);
}

if (DestType->isReferenceType()) {
  // A list-initialization failure for a reference means that we tried to
  // create a temporary of the inner type (per [dcl.init.list]p3.6) and the
  // inner initialization failed.
  QualType T = DestType->castAs<ReferenceType>()->getPointeeType();
  diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList);
  SourceLocation Loc = InitList->getBeginLoc();
  if (auto *D = Entity.getDecl())
    Loc = D->getLocation();
  S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T;
  return;
}

InitListChecker DiagnoseInitList(S, Entity, InitList, DestType,
                                 /*VerifyOnly=*/false,
                                 /*TreatUnavailableAsInvalid=*/false);
assert(DiagnoseInitList.HadError() &&(static_cast <bool> (DiagnoseInitList.HadError() &&
 "Inconsistent init list check result.") ? void (0) : __assert_fail
 ("DiagnoseInitList.HadError() && \"Inconsistent init list check result.\""
, "clang/lib/Sema/SemaInit.cpp", 9044, __extension__ __PRETTY_FUNCTION__
))
       "Inconsistent init list check result.")(static_cast <bool> (DiagnoseInitList.HadError() &&
 "Inconsistent init list check result.") ? void (0) : __assert_fail
 ("DiagnoseInitList.HadError() && \"Inconsistent init list check result.\""
, "clang/lib/Sema/SemaInit.cpp", 9044, __extension__ __PRETTY_FUNCTION__
));
9045}

9047bool InitializationSequence::Diagnose(Sema &S,
                                    const InitializedEntity &Entity,
                                    const InitializationKind &Kind,
                                    ArrayRef<Expr *> Args) {
if (!Failed())
1
Taking false branch→
  return false;

// When we want to diagnose only one element of a braced-init-list,
// we need to factor it out.
Expr *OnlyArg;
if (Args.size() == 1) {
2
←
Assuming the condition is false→
3
←
Taking false branch→
  auto *List = dyn_cast<InitListExpr>(Args[0]);
  if (List && List->getNumInits() == 1)
    OnlyArg = List->getInit(0);
  else
    OnlyArg = Args[0];
}
else
  OnlyArg = nullptr;
4
←
Null pointer value stored to 'OnlyArg'→

QualType DestType = Entity.getType();
switch (Failure) {
5
←
Control jumps to 'case FK_ReferenceInitFailed:'  at line 9287→
case FK_TooManyInitsForReference:
  // FIXME: Customize for the initialized entity?
  if (Args.empty()) {
    // Dig out the reference subobject which is uninitialized and diagnose it.
    // If this is value-initialization, this could be nested some way within
    // the target type.
    assert(Kind.getKind() == InitializationKind::IK_Value ||(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Value || DestType->isReferenceType()) ? void (0) : __assert_fail
 ("Kind.getKind() == InitializationKind::IK_Value || DestType->isReferenceType()"
, "clang/lib/Sema/SemaInit.cpp", 9076, __extension__ __PRETTY_FUNCTION__
))
           DestType->isReferenceType())(static_cast <bool> (Kind.getKind() == InitializationKind
::IK_Value || DestType->isReferenceType()) ? void (0) : __assert_fail
 ("Kind.getKind() == InitializationKind::IK_Value || DestType->isReferenceType()"
, "clang/lib/Sema/SemaInit.cpp", 9076, __extension__ __PRETTY_FUNCTION__
));
    bool Diagnosed =
      DiagnoseUninitializedReference(S, Kind.getLocation(), DestType);
    assert(Diagnosed && "couldn't find uninitialized reference to diagnose")(static_cast <bool> (Diagnosed && "couldn't find uninitialized reference to diagnose"
) ? void (0) : __assert_fail ("Diagnosed && \"couldn't find uninitialized reference to diagnose\""
, "clang/lib/Sema/SemaInit.cpp", 9079, __extension__ __PRETTY_FUNCTION__
));
    (void)Diagnosed;
  } else  // FIXME: diagnostic below could be better!
    S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
        << SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());
  break;
case FK_ParenthesizedListInitForReference:
  S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
    << 1 << Entity.getType() << Args[0]->getSourceRange();
  break;

case FK_ArrayNeedsInitList:
  S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0;
  break;
case FK_ArrayNeedsInitListOrStringLiteral:
  S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1;
  break;
case FK_ArrayNeedsInitListOrWideStringLiteral:
  S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2;
  break;
case FK_NarrowStringIntoWideCharArray:
  S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar);
  break;
case FK_WideStringIntoCharArray:
  S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char);
  break;
case FK_IncompatWideStringIntoWideChar:
  S.Diag(Kind.getLocation(),
         diag::err_array_init_incompat_wide_string_into_wchar);
  break;
case FK_PlainStringIntoUTF8Char:
  S.Diag(Kind.getLocation(),
         diag::err_array_init_plain_string_into_char8_t);
  S.Diag(Args.front()->getBeginLoc(),
         diag::note_array_init_plain_string_into_char8_t)
      << FixItHint::CreateInsertion(Args.front()->getBeginLoc(), "u8");
  break;
case FK_UTF8StringIntoPlainChar:
  S.Diag(Kind.getLocation(),
         diag::err_array_init_utf8_string_into_char)
    << S.getLangOpts().CPlusPlus20;
  break;
case FK_ArrayTypeMismatch:
case FK_NonConstantArrayInit:
  S.Diag(Kind.getLocation(),
         (Failure == FK_ArrayTypeMismatch
            ? diag::err_array_init_different_type
            : diag::err_array_init_non_constant_array))
    << DestType.getNonReferenceType()
    << OnlyArg->getType()
    << Args[0]->getSourceRange();
  break;

case FK_VariableLengthArrayHasInitializer:
  S.Diag(Kind.getLocation(), diag::err_variable_object_no_init)
    << Args[0]->getSourceRange();
  break;

case FK_AddressOfOverloadFailed: {
  DeclAccessPair Found;
  S.ResolveAddressOfOverloadedFunction(OnlyArg,
                                       DestType.getNonReferenceType(),
                                       true,
                                       Found);
  break;
}

case FK_AddressOfUnaddressableFunction: {
  auto *FD = cast<FunctionDecl>(cast<DeclRefExpr>(OnlyArg)->getDecl());
  S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
                                      OnlyArg->getBeginLoc());
  break;
}

case FK_ReferenceInitOverloadFailed:
case FK_UserConversionOverloadFailed:
  switch (FailedOverloadResult) {
  case OR_Ambiguous:

    FailedCandidateSet.NoteCandidates(
        PartialDiagnosticAt(
            Kind.getLocation(),
            Failure == FK_UserConversionOverloadFailed
                ? (S.PDiag(diag::err_typecheck_ambiguous_condition)
                   << OnlyArg->getType() << DestType
                   << Args[0]->getSourceRange())
                : (S.PDiag(diag::err_ref_init_ambiguous)
                   << DestType << OnlyArg->getType()
                   << Args[0]->getSourceRange())),
        S, OCD_AmbiguousCandidates, Args);
    break;

  case OR_No_Viable_Function: {
    auto Cands = FailedCandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args);
    if (!S.RequireCompleteType(Kind.getLocation(),
                               DestType.getNonReferenceType(),
                        diag::err_typecheck_nonviable_condition_incomplete,
                             OnlyArg->getType(), Args[0]->getSourceRange()))
      S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
        << (Entity.getKind() == InitializedEntity::EK_Result)
        << OnlyArg->getType() << Args[0]->getSourceRange()
        << DestType.getNonReferenceType();

    FailedCandidateSet.NoteCandidates(S, Args, Cands);
    break;
  }
  case OR_Deleted: {
    S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
      << OnlyArg->getType() << DestType.getNonReferenceType()
      << Args[0]->getSourceRange();
    OverloadCandidateSet::iterator Best;
    OverloadingResult Ovl
      = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
    if (Ovl == OR_Deleted) {
      S.NoteDeletedFunction(Best->Function);
    } else {
      llvm_unreachable("Inconsistent overload resolution?")::llvm::llvm_unreachable_internal("Inconsistent overload resolution?"
, "clang/lib/Sema/SemaInit.cpp", 9195);
    }
    break;
  }

  case OR_Success:
    llvm_unreachable("Conversion did not fail!")::llvm::llvm_unreachable_internal("Conversion did not fail!",
 "clang/lib/Sema/SemaInit.cpp", 9201);
  }
  break;

case FK_NonConstLValueReferenceBindingToTemporary:
  if (isa<InitListExpr>(Args[0])) {
    S.Diag(Kind.getLocation(),
           diag::err_lvalue_reference_bind_to_initlist)
    << DestType.getNonReferenceType().isVolatileQualified()
    << DestType.getNonReferenceType()
    << Args[0]->getSourceRange();
    break;
  }
  [[fallthrough]];

case FK_NonConstLValueReferenceBindingToUnrelated:
  S.Diag(Kind.getLocation(),
         Failure == FK_NonConstLValueReferenceBindingToTemporary
           ? diag::err_lvalue_reference_bind_to_temporary
           : diag::err_lvalue_reference_bind_to_unrelated)
    << DestType.getNonReferenceType().isVolatileQualified()
    << DestType.getNonReferenceType()
    << OnlyArg->getType()
    << Args[0]->getSourceRange();
  break;

case FK_NonConstLValueReferenceBindingToBitfield: {
  // We don't necessarily have an unambiguous source bit-field.
  FieldDecl *BitField = Args[0]->getSourceBitField();
  S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
    << DestType.isVolatileQualified()
    << (BitField ? BitField->getDeclName() : DeclarationName())
    << (BitField != nullptr)
    << Args[0]->getSourceRange();
  if (BitField)
    S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
  break;
}

case FK_NonConstLValueReferenceBindingToVectorElement:
  S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element)
    << DestType.isVolatileQualified()
    << Args[0]->getSourceRange();
  break;

case FK_NonConstLValueReferenceBindingToMatrixElement:
  S.Diag(Kind.getLocation(), diag::err_reference_bind_to_matrix_element)
      << DestType.isVolatileQualified() << Args[0]->getSourceRange();
  break;

case FK_RValueReferenceBindingToLValue:
  S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
    << DestType.getNonReferenceType() << OnlyArg->getType()
    << Args[0]->getSourceRange();
  break;

case FK_ReferenceAddrspaceMismatchTemporary:
  S.Diag(Kind.getLocation(), diag::err_reference_bind_temporary_addrspace)
      << DestType << Args[0]->getSourceRange();
  break;

case FK_ReferenceInitDropsQualifiers: {
  QualType SourceType = OnlyArg->getType();
  QualType NonRefType = DestType.getNonReferenceType();
  Qualifiers DroppedQualifiers =
      SourceType.getQualifiers() - NonRefType.getQualifiers();

  if (!NonRefType.getQualifiers().isAddressSpaceSupersetOf(
          SourceType.getQualifiers()))
    S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
        << NonRefType << SourceType << 1 /*addr space*/
        << Args[0]->getSourceRange();
  else if (DroppedQualifiers.hasQualifiers())
    S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
        << NonRefType << SourceType << 0 /*cv quals*/
        << Qualifiers::fromCVRMask(DroppedQualifiers.getCVRQualifiers())
        << DroppedQualifiers.getCVRQualifiers() << Args[0]->getSourceRange();
  else
    // FIXME: Consider decomposing the type and explaining which qualifiers
    // were dropped where, or on which level a 'const' is missing, etc.
    S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
        << NonRefType << SourceType << 2 /*incompatible quals*/
        << Args[0]->getSourceRange();
  break;
}

case FK_ReferenceInitFailed:
  S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
    << DestType.getNonReferenceType()
    << DestType.getNonReferenceType()->isIncompleteType()
    << OnlyArg->isLValue()
6
←
Called C++ object pointer is null
    << OnlyArg->getType()
    << Args[0]->getSourceRange();
  emitBadConversionNotes(S, Entity, Args[0]);
  break;

case FK_ConversionFailed: {
  QualType FromType = OnlyArg->getType();
  PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed)
    << (int)Entity.getKind()
    << DestType
    << OnlyArg->isLValue()
    << FromType
    << Args[0]->getSourceRange();
  S.HandleFunctionTypeMismatch(PDiag, FromType, DestType);
  S.Diag(Kind.getLocation(), PDiag);
  emitBadConversionNotes(S, Entity, Args[0]);
  break;
}

case FK_ConversionFromPropertyFailed:
  // No-op. This error has already been reported.
  break;

case FK_TooManyInitsForScalar: {
  SourceRange R;

  auto *InitList = dyn_cast<InitListExpr>(Args[0]);
  if (InitList && InitList->getNumInits() >= 1) {
    R = SourceRange(InitList->getInit(0)->getEndLoc(), InitList->getEndLoc());
  } else {
    assert(Args.size() > 1 && "Expected multiple initializers!")(static_cast <bool> (Args.size() > 1 && "Expected multiple initializers!"
) ? void (0) : __assert_fail ("Args.size() > 1 && \"Expected multiple initializers!\""
, "clang/lib/Sema/SemaInit.cpp", 9322, __extension__ __PRETTY_FUNCTION__
));
    R = SourceRange(Args.front()->getEndLoc(), Args.back()->getEndLoc());
  }

  R.setBegin(S.getLocForEndOfToken(R.getBegin()));
  if (Kind.isCStyleOrFunctionalCast())
    S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg)
      << R;
  else
    S.Diag(Kind.getLocation(), diag::err_excess_initializers)
      << /*scalar=*/2 << R;
  break;
}

case FK_ParenthesizedListInitForScalar:
  S.Diag(Kind.getLocation(), diag::err_list_init_in_parens)
    << 0 << Entity.getType() << Args[0]->getSourceRange();
  break;

case FK_ReferenceBindingToInitList:
  S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
    << DestType.getNonReferenceType() << Args[0]->getSourceRange();
  break;

case FK_InitListBadDestinationType:
  S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
    << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
  break;

case FK_ListConstructorOverloadFailed:
case FK_ConstructorOverloadFailed: {
  SourceRange ArgsRange;
  if (Args.size())
    ArgsRange =
        SourceRange(Args.front()->getBeginLoc(), Args.back()->getEndLoc());

  if (Failure == FK_ListConstructorOverloadFailed) {
    assert(Args.size() == 1 &&(static_cast <bool> (Args.size() == 1 && "List construction from other than 1 argument."
) ? void (0) : __assert_fail ("Args.size() == 1 && \"List construction from other than 1 argument.\""
, "clang/lib/Sema/SemaInit.cpp", 9360, __extension__ __PRETTY_FUNCTION__
))
           "List construction from other than 1 argument.")(static_cast <bool> (Args.size() == 1 && "List construction from other than 1 argument."
) ? void (0) : __assert_fail ("Args.size() == 1 && \"List construction from other than 1 argument.\""
, "clang/lib/Sema/SemaInit.cpp", 9360, __extension__ __PRETTY_FUNCTION__
));
    InitListExpr *InitList = cast<InitListExpr>(Args[0]);
    Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
  }

  // FIXME: Using "DestType" for the entity we're printing is probably
  // bad.
  switch (FailedOverloadResult) {
    case OR_Ambiguous:
      FailedCandidateSet.NoteCandidates(
          PartialDiagnosticAt(Kind.getLocation(),
                              S.PDiag(diag::err_ovl_ambiguous_init)
                                  << DestType << ArgsRange),
          S, OCD_AmbiguousCandidates, Args);
      break;

    case OR_No_Viable_Function:
      if (Kind.getKind() == InitializationKind::IK_Default &&
          (Entity.getKind() == InitializedEntity::EK_Base ||
           Entity.getKind() == InitializedEntity::EK_Member) &&
          isa<CXXConstructorDecl>(S.CurContext)) {
        // This is implicit default initialization of a member or
        // base within a constructor. If no viable function was
        // found, notify the user that they need to explicitly
        // initialize this base/member.
        CXXConstructorDecl *Constructor
          = cast<CXXConstructorDecl>(S.CurContext);
        const CXXRecordDecl *InheritedFrom = nullptr;
        if (auto Inherited = Constructor->getInheritedConstructor())
          InheritedFrom = Inherited.getShadowDecl()->getNominatedBaseClass();
        if (Entity.getKind() == InitializedEntity::EK_Base) {
          S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
            << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
            << S.Context.getTypeDeclType(Constructor->getParent())
            << /*base=*/0
            << Entity.getType()
            << InheritedFrom;

          RecordDecl *BaseDecl
            = Entity.getBaseSpecifier()->getType()->castAs<RecordType>()
                                                                ->getDecl();
          S.Diag(BaseDecl->getLocation(), diag::note_previous_decl)
            << S.Context.getTagDeclType(BaseDecl);
        } else {
          S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
            << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
            << S.Context.getTypeDeclType(Constructor->getParent())
            << /*member=*/1
            << Entity.getName()
            << InheritedFrom;
          S.Diag(Entity.getDecl()->getLocation(),
                 diag::note_member_declared_at);

          if (const RecordType *Record
                               = Entity.getType()->getAs<RecordType>())
            S.Diag(Record->getDecl()->getLocation(),
                   diag::note_previous_decl)
              << S.Context.getTagDeclType(Record->getDecl());
        }
        break;
      }

      FailedCandidateSet.NoteCandidates(
          PartialDiagnosticAt(
              Kind.getLocation(),
              S.PDiag(diag::err_ovl_no_viable_function_in_init)
                  << DestType << ArgsRange),
          S, OCD_AllCandidates, Args);
      break;

    case OR_Deleted: {
      OverloadCandidateSet::iterator Best;
      OverloadingResult Ovl
        = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
      if (Ovl != OR_Deleted) {
        S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
            << DestType << ArgsRange;
        llvm_unreachable("Inconsistent overload resolution?")::llvm::llvm_unreachable_internal("Inconsistent overload resolution?"
, "clang/lib/Sema/SemaInit.cpp", 9437);
        break;
      }

      // If this is a defaulted or implicitly-declared function, then
      // it was implicitly deleted. Make it clear that the deletion was
      // implicit.
      if (S.isImplicitlyDeleted(Best->Function))
        S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init)
          << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function))
          << DestType << ArgsRange;
      else
        S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
            << DestType << ArgsRange;

      S.NoteDeletedFunction(Best->Function);
      break;
    }

    case OR_Success:
      llvm_unreachable("Conversion did not fail!")::llvm::llvm_unreachable_internal("Conversion did not fail!",
 "clang/lib/Sema/SemaInit.cpp", 9457);
  }
}
break;

case FK_DefaultInitOfConst:
  if (Entity.getKind() == InitializedEntity::EK_Member &&
      isa<CXXConstructorDecl>(S.CurContext)) {
    // This is implicit default-initialization of a const member in
    // a constructor. Complain that it needs to be explicitly
    // initialized.
    CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext);
    S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor)
      << (Constructor->getInheritedConstructor() ? 2 :
          Constructor->isImplicit() ? 1 : 0)
      << S.Context.getTypeDeclType(Constructor->getParent())
      << /*const=*/1
      << Entity.getName();
    S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl)
      << Entity.getName();
  } else if (const auto *VD = dyn_cast_if_present<VarDecl>(Entity.getDecl());
             VD && VD->isConstexpr()) {
    S.Diag(Kind.getLocation(), diag::err_constexpr_var_requires_const_init)
        << VD;
  } else {
    S.Diag(Kind.getLocation(), diag::err_default_init_const)
        << DestType << (bool)DestType->getAs<RecordType>();
  }
  break;

case FK_Incomplete:
  S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType,
                        diag::err_init_incomplete_type);
  break;

case FK_ListInitializationFailed: {
  // Run the init list checker again to emit diagnostics.
  InitListExpr *InitList = cast<InitListExpr>(Args[0]);
  diagnoseListInit(S, Entity, InitList);
  break;
}

case FK_PlaceholderType: {
  // FIXME: Already diagnosed!
  break;
}

case FK_ExplicitConstructor: {
  S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor)
    << Args[0]->getSourceRange();
  OverloadCandidateSet::iterator Best;
  OverloadingResult Ovl
    = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
  (void)Ovl;
  assert(Ovl == OR_Success && "Inconsistent overload resolution")(static_cast <bool> (Ovl == OR_Success && "Inconsistent overload resolution"
) ? void (0) : __assert_fail ("Ovl == OR_Success && \"Inconsistent overload resolution\""
, "clang/lib/Sema/SemaInit.cpp", 9511, __extension__ __PRETTY_FUNCTION__
));
  CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
  S.Diag(CtorDecl->getLocation(),
         diag::note_explicit_ctor_deduction_guide_here) << false;
  break;
}
}

PrintInitLocationNote(S, Entity);
return true;
9521}

9523void InitializationSequence::dump(raw_ostream &OS) const {
switch (SequenceKind) {
case FailedSequence: {
  OS << "Failed sequence: ";
  switch (Failure) {
  case FK_TooManyInitsForReference:
    OS << "too many initializers for reference";
    break;

  case FK_ParenthesizedListInitForReference:
    OS << "parenthesized list init for reference";
    break;

  case FK_ArrayNeedsInitList:
    OS << "array requires initializer list";
    break;

  case FK_AddressOfUnaddressableFunction:
    OS << "address of unaddressable function was taken";
    break;

  case FK_ArrayNeedsInitListOrStringLiteral:
    OS << "array requires initializer list or string literal";
    break;

  case FK_ArrayNeedsInitListOrWideStringLiteral:
    OS << "array requires initializer list or wide string literal";
    break;

  case FK_NarrowStringIntoWideCharArray:
    OS << "narrow string into wide char array";
    break;

  case FK_WideStringIntoCharArray:
    OS << "wide string into char array";
    break;

  case FK_IncompatWideStringIntoWideChar:
    OS << "incompatible wide string into wide char array";
    break;

  case FK_PlainStringIntoUTF8Char:
    OS << "plain string literal into char8_t array";
    break;

  case FK_UTF8StringIntoPlainChar:
    OS << "u8 string literal into char array";
    break;

  case FK_ArrayTypeMismatch:
    OS << "array type mismatch";
    break;

  case FK_NonConstantArrayInit:
    OS << "non-constant array initializer";
    break;

  case FK_AddressOfOverloadFailed:
    OS << "address of overloaded function failed";
    break;

  case FK_ReferenceInitOverloadFailed:
    OS << "overload resolution for reference initialization failed";
    break;

  case FK_NonConstLValueReferenceBindingToTemporary:
    OS << "non-const lvalue reference bound to temporary";
    break;

  case FK_NonConstLValueReferenceBindingToBitfield:
    OS << "non-const lvalue reference bound to bit-field";
    break;

  case FK_NonConstLValueReferenceBindingToVectorElement:
    OS << "non-const lvalue reference bound to vector element";
    break;

  case FK_NonConstLValueReferenceBindingToMatrixElement:
    OS << "non-const lvalue reference bound to matrix element";
    break;

  case FK_NonConstLValueReferenceBindingToUnrelated:
    OS << "non-const lvalue reference bound to unrelated type";
    break;

  case FK_RValueReferenceBindingToLValue:
    OS << "rvalue reference bound to an lvalue";
    break;

  case FK_ReferenceInitDropsQualifiers:
    OS << "reference initialization drops qualifiers";
    break;

  case FK_ReferenceAddrspaceMismatchTemporary:
    OS << "reference with mismatching address space bound to temporary";
    break;

  case FK_ReferenceInitFailed:
    OS << "reference initialization failed";
    break;

  case FK_ConversionFailed:
    OS << "conversion failed";
    break;

  case FK_ConversionFromPropertyFailed:
    OS << "conversion from property failed";
    break;

  case FK_TooManyInitsForScalar:
    OS << "too many initializers for scalar";
    break;

  case FK_ParenthesizedListInitForScalar:
    OS << "parenthesized list init for reference";
    break;

  case FK_ReferenceBindingToInitList:
    OS << "referencing binding to initializer list";
    break;

  case FK_InitListBadDestinationType:
    OS << "initializer list for non-aggregate, non-scalar type";
    break;

  case FK_UserConversionOverloadFailed:
    OS << "overloading failed for user-defined conversion";
    break;

  case FK_ConstructorOverloadFailed:
    OS << "constructor overloading failed";
    break;

  case FK_DefaultInitOfConst:
    OS << "default initialization of a const variable";
    break;

  case FK_Incomplete:
    OS << "initialization of incomplete type";
    break;

  case FK_ListInitializationFailed:
    OS << "list initialization checker failure";
    break;

  case FK_VariableLengthArrayHasInitializer:
    OS << "variable length array has an initializer";
    break;

  case FK_PlaceholderType:
    OS << "initializer expression isn't contextually valid";
    break;

  case FK_ListConstructorOverloadFailed:
    OS << "list constructor overloading failed";
    break;

  case FK_ExplicitConstructor:
    OS << "list copy initialization chose explicit constructor";
    break;
  }
  OS << '\n';
  return;
}

case DependentSequence:
  OS << "Dependent sequence\n";
  return;

case NormalSequence:
  OS << "Normal sequence: ";
  break;
}

for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) {
  if (S != step_begin()) {
    OS << " -> ";
  }

  switch (S->Kind) {
  case SK_ResolveAddressOfOverloadedFunction:
    OS << "resolve address of overloaded function";
    break;

  case SK_CastDerivedToBasePRValue:
    OS << "derived-to-base (prvalue)";
    break;

  case SK_CastDerivedToBaseXValue:
    OS << "derived-to-base (xvalue)";
    break;

  case SK_CastDerivedToBaseLValue:
    OS << "derived-to-base (lvalue)";
    break;

  case SK_BindReference:
    OS << "bind reference to lvalue";
    break;

  case SK_BindReferenceToTemporary:
    OS << "bind reference to a temporary";
    break;

  case SK_FinalCopy:
    OS << "final copy in class direct-initialization";
    break;

  case SK_ExtraneousCopyToTemporary:
    OS << "extraneous C++03 copy to temporary";
    break;

  case SK_UserConversion:
    OS << "user-defined conversion via " << *S->Function.Function;
    break;

  case SK_QualificationConversionPRValue:
    OS << "qualification conversion (prvalue)";
    break;

  case SK_QualificationConversionXValue:
    OS << "qualification conversion (xvalue)";
    break;

  case SK_QualificationConversionLValue:
    OS << "qualification conversion (lvalue)";
    break;

  case SK_FunctionReferenceConversion:
    OS << "function reference conversion";
    break;

  case SK_AtomicConversion:
    OS << "non-atomic-to-atomic conversion";
    break;

  case SK_ConversionSequence:
    OS << "implicit conversion sequence (";
    S->ICS->dump(); // FIXME: use OS
    OS << ")";
    break;

  case SK_ConversionSequenceNoNarrowing:
    OS << "implicit conversion sequence with narrowing prohibited (";
    S->ICS->dump(); // FIXME: use OS
    OS << ")";
    break;

  case SK_ListInitialization:
    OS << "list aggregate initialization";
    break;

  case SK_UnwrapInitList:
    OS << "unwrap reference initializer list";
    break;

  case SK_RewrapInitList:
    OS << "rewrap reference initializer list";
    break;

  case SK_ConstructorInitialization:
    OS << "constructor initialization";
    break;

  case SK_ConstructorInitializationFromList:
    OS << "list initialization via constructor";
    break;

  case SK_ZeroInitialization:
    OS << "zero initialization";
    break;

  case SK_CAssignment:
    OS << "C assignment";
    break;

  case SK_StringInit:
    OS << "string initialization";
    break;

  case SK_ObjCObjectConversion:
    OS << "Objective-C object conversion";
    break;

  case SK_ArrayLoopIndex:
    OS << "indexing for array initialization loop";
    break;

  case SK_ArrayLoopInit:
    OS << "array initialization loop";
    break;

  case SK_ArrayInit:
    OS << "array initialization";
    break;

  case SK_GNUArrayInit:
    OS << "array initialization (GNU extension)";
    break;

  case SK_ParenthesizedArrayInit:
    OS << "parenthesized array initialization";
    break;

  case SK_PassByIndirectCopyRestore:
    OS << "pass by indirect copy and restore";
    break;

  case SK_PassByIndirectRestore:
    OS << "pass by indirect restore";
    break;

  case SK_ProduceObjCObject:
    OS << "Objective-C object retension";
    break;

  case SK_StdInitializerList:
    OS << "std::initializer_list from initializer list";
    break;

  case SK_StdInitializerListConstructorCall:
    OS << "list initialization from std::initializer_list";
    break;

  case SK_OCLSamplerInit:
    OS << "OpenCL sampler_t from integer constant";
    break;

  case SK_OCLZeroOpaqueType:
    OS << "OpenCL opaque type from zero";
    break;
  }

  OS << " [" << S->Type << ']';
}

OS << '\n';
9860}

9862void InitializationSequence::dump() const {
dump(llvm::errs());
9864}

9866static bool NarrowingErrs(const LangOptions &L) {
return L.CPlusPlus11 &&
       (!L.MicrosoftExt || L.isCompatibleWithMSVC(LangOptions::MSVC2015));
9869}

9871static void DiagnoseNarrowingInInitList(Sema &S,
                                      const ImplicitConversionSequence &ICS,
                                      QualType PreNarrowingType,
                                      QualType EntityType,
                                      const Expr *PostInit) {
const StandardConversionSequence *SCS = nullptr;
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion:
  SCS = &ICS.Standard;
  break;
case ImplicitConversionSequence::UserDefinedConversion:
  SCS = &ICS.UserDefined.After;
  break;
case ImplicitConversionSequence::AmbiguousConversion:
case ImplicitConversionSequence::StaticObjectArgumentConversion:
case ImplicitConversionSequence::EllipsisConversion:
case ImplicitConversionSequence::BadConversion:
  return;
}

// C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion.
APValue ConstantValue;
QualType ConstantType;
switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue,
                              ConstantType)) {
case NK_Not_Narrowing:
case NK_Dependent_Narrowing:
  // No narrowing occurred.
  return;

case NK_Type_Narrowing:
  // This was a floating-to-integer conversion, which is always considered a
  // narrowing conversion even if the value is a constant and can be
  // represented exactly as an integer.
  S.Diag(PostInit->getBeginLoc(), NarrowingErrs(S.getLangOpts())
                                      ? diag::ext_init_list_type_narrowing
                                      : diag::warn_init_list_type_narrowing)
      << PostInit->getSourceRange()
      << PreNarrowingType.getLocalUnqualifiedType()
      << EntityType.getLocalUnqualifiedType();
  break;

case NK_Constant_Narrowing:
  // A constant value was narrowed.
  S.Diag(PostInit->getBeginLoc(),
         NarrowingErrs(S.getLangOpts())
             ? diag::ext_init_list_constant_narrowing
             : diag::warn_init_list_constant_narrowing)
      << PostInit->getSourceRange()
      << ConstantValue.getAsString(S.getASTContext(), ConstantType)
      << EntityType.getLocalUnqualifiedType();
  break;

case NK_Variable_Narrowing:
  // A variable's value may have been narrowed.
  S.Diag(PostInit->getBeginLoc(),
         NarrowingErrs(S.getLangOpts())
             ? diag::ext_init_list_variable_narrowing
             : diag::warn_init_list_variable_narrowing)
      << PostInit->getSourceRange()
      << PreNarrowingType.getLocalUnqualifiedType()
      << EntityType.getLocalUnqualifiedType();
  break;
}

SmallString<128> StaticCast;
llvm::raw_svector_ostream OS(StaticCast);
OS << "static_cast<";
if (const TypedefType *TT = EntityType->getAs<TypedefType>()) {
  // It's important to use the typedef's name if there is one so that the
  // fixit doesn't break code using types like int64_t.
  //
  // FIXME: This will break if the typedef requires qualification.  But
  // getQualifiedNameAsString() includes non-machine-parsable components.
  OS << *TT->getDecl();
} else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>())
  OS << BT->getName(S.getLangOpts());
else {
  // Oops, we didn't find the actual type of the variable.  Don't emit a fixit
  // with a broken cast.
  return;
}
OS << ">(";
S.Diag(PostInit->getBeginLoc(), diag::note_init_list_narrowing_silence)
    << PostInit->getSourceRange()
    << FixItHint::CreateInsertion(PostInit->getBeginLoc(), OS.str())
    << FixItHint::CreateInsertion(
           S.getLocForEndOfToken(PostInit->getEndLoc()), ")");
9959}

9961//===----------------------------------------------------------------------===//
9962// Initialization helper functions
9963//===----------------------------------------------------------------------===//
9964bool
9965Sema::CanPerformCopyInitialization(const InitializedEntity &Entity,
                                 ExprResult Init) {
if (Init.isInvalid())
  return false;

Expr *InitE = Init.get();
assert(InitE && "No initialization expression")(static_cast <bool> (InitE && "No initialization expression"
) ? void (0) : __assert_fail ("InitE && \"No initialization expression\""
, "clang/lib/Sema/SemaInit.cpp", 9971, __extension__ __PRETTY_FUNCTION__
));

InitializationKind Kind =
    InitializationKind::CreateCopy(InitE->getBeginLoc(), SourceLocation());
InitializationSequence Seq(*this, Entity, Kind, InitE);
return !Seq.Failed();
9977}

9979ExprResult
9980Sema::PerformCopyInitialization(const InitializedEntity &Entity,
                              SourceLocation EqualLoc,
                              ExprResult Init,
                              bool TopLevelOfInitList,
                              bool AllowExplicit) {
if (Init.isInvalid())
  return ExprError();

Expr *InitE = Init.get();
assert(InitE && "No initialization expression?")(static_cast <bool> (InitE && "No initialization expression?"
) ? void (0) : __assert_fail ("InitE && \"No initialization expression?\""
, "clang/lib/Sema/SemaInit.cpp", 9989, __extension__ __PRETTY_FUNCTION__
));

if (EqualLoc.isInvalid())
  EqualLoc = InitE->getBeginLoc();

InitializationKind Kind = InitializationKind::CreateCopy(
    InitE->getBeginLoc(), EqualLoc, AllowExplicit);
InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList);

// Prevent infinite recursion when performing parameter copy-initialization.
const bool ShouldTrackCopy =
    Entity.isParameterKind() && Seq.isConstructorInitialization();
if (ShouldTrackCopy) {
  if (llvm::is_contained(CurrentParameterCopyTypes, Entity.getType())) {
    Seq.SetOverloadFailure(
        InitializationSequence::FK_ConstructorOverloadFailed,
        OR_No_Viable_Function);

    // Try to give a meaningful diagnostic note for the problematic
    // constructor.
    const auto LastStep = Seq.step_end() - 1;
    assert(LastStep->Kind ==(static_cast <bool> (LastStep->Kind == InitializationSequence
::SK_ConstructorInitialization) ? void (0) : __assert_fail ("LastStep->Kind == InitializationSequence::SK_ConstructorInitialization"
, "clang/lib/Sema/SemaInit.cpp", 10011, __extension__ __PRETTY_FUNCTION__
))
           InitializationSequence::SK_ConstructorInitialization)(static_cast <bool> (LastStep->Kind == InitializationSequence
::SK_ConstructorInitialization) ? void (0) : __assert_fail ("LastStep->Kind == InitializationSequence::SK_ConstructorInitialization"
, "clang/lib/Sema/SemaInit.cpp", 10011, __extension__ __PRETTY_FUNCTION__
));
    const FunctionDecl *Function = LastStep->Function.Function;
    auto Candidate =
        llvm::find_if(Seq.getFailedCandidateSet(),
                      [Function](const OverloadCandidate &Candidate) -> bool {
                        return Candidate.Viable &&
                               Candidate.Function == Function &&
                               Candidate.Conversions.size() > 0;
                      });
    if (Candidate != Seq.getFailedCandidateSet().end() &&
        Function->getNumParams() > 0) {
      Candidate->Viable = false;
      Candidate->FailureKind = ovl_fail_bad_conversion;
      Candidate->Conversions[0].setBad(BadConversionSequence::no_conversion,
                                       InitE,
                                       Function->getParamDecl(0)->getType());
    }
  }
  CurrentParameterCopyTypes.push_back(Entity.getType());
}

ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE);

if (ShouldTrackCopy)
  CurrentParameterCopyTypes.pop_back();

return Result;
10038}

10040/// Determine whether RD is, or is derived from, a specialization of CTD.
10041static bool isOrIsDerivedFromSpecializationOf(CXXRecordDecl *RD,
                                            ClassTemplateDecl *CTD) {
auto NotSpecialization = [&] (const CXXRecordDecl *Candidate) {
  auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(Candidate);
  return !CTSD || !declaresSameEntity(CTSD->getSpecializedTemplate(), CTD);
};
return !(NotSpecialization(RD) && RD->forallBases(NotSpecialization));
10048}

10050QualType Sema::DeduceTemplateSpecializationFromInitializer(
  TypeSourceInfo *TSInfo, const InitializedEntity &Entity,
  const InitializationKind &Kind, MultiExprArg Inits) {
auto *DeducedTST = dyn_cast<DeducedTemplateSpecializationType>(
    TSInfo->getType()->getContainedDeducedType());
assert(DeducedTST && "not a deduced template specialization type")(static_cast <bool> (DeducedTST && "not a deduced template specialization type"
) ? void (0) : __assert_fail ("DeducedTST && \"not a deduced template specialization type\""
, "clang/lib/Sema/SemaInit.cpp", 10055, __extension__ __PRETTY_FUNCTION__
));

auto TemplateName = DeducedTST->getTemplateName();
if (TemplateName.isDependent())
  return SubstAutoTypeDependent(TSInfo->getType());

// We can only perform deduction for class templates.
auto *Template =
    dyn_cast_or_null<ClassTemplateDecl>(TemplateName.getAsTemplateDecl());
if (!Template) {
  Diag(Kind.getLocation(),
       diag::err_deduced_non_class_template_specialization_type)
    << (int)getTemplateNameKindForDiagnostics(TemplateName) << TemplateName;
  if (auto *TD = TemplateName.getAsTemplateDecl())
    Diag(TD->getLocation(), diag::note_template_decl_here);
  return QualType();
}

// Can't deduce from dependent arguments.
if (Expr::hasAnyTypeDependentArguments(Inits)) {
  Diag(TSInfo->getTypeLoc().getBeginLoc(),
       diag::warn_cxx14_compat_class_template_argument_deduction)
      << TSInfo->getTypeLoc().getSourceRange() << 0;
  return SubstAutoTypeDependent(TSInfo->getType());
}

// FIXME: Perform "exact type" matching first, per CWG discussion?
//        Or implement this via an implied 'T(T) -> T' deduction guide?

// FIXME: Do we need/want a std::initializer_list<T> special case?

// Look up deduction guides, including those synthesized from constructors.
//
// C++1z [over.match.class.deduct]p1:
//   A set of functions and function templates is formed comprising:
//   - For each constructor of the class template designated by the
//     template-name, a function template [...]
//  - For each deduction-guide, a function or function template [...]
DeclarationNameInfo NameInfo(
    Context.DeclarationNames.getCXXDeductionGuideName(Template),
    TSInfo->getTypeLoc().getEndLoc());
LookupResult Guides(*this, NameInfo, LookupOrdinaryName);
LookupQualifiedName(Guides, Template->getDeclContext());

// FIXME: Do not diagnose inaccessible deduction guides. The standard isn't
// clear on this, but they're not found by name so access does not apply.
Guides.suppressDiagnostics();

// Figure out if this is list-initialization.
InitListExpr *ListInit =
    (Inits.size() == 1 && Kind.getKind() != InitializationKind::IK_Direct)
        ? dyn_cast<InitListExpr>(Inits[0])
        : nullptr;

// C++1z [over.match.class.deduct]p1:
//   Initialization and overload resolution are performed as described in
//   [dcl.init] and [over.match.ctor], [over.match.copy], or [over.match.list]
//   (as appropriate for the type of initialization performed) for an object
//   of a hypothetical class type, where the selected functions and function
//   templates are considered to be the constructors of that class type
//
// Since we know we're initializing a class type of a type unrelated to that
// of the initializer, this reduces to something fairly reasonable.
OverloadCandidateSet Candidates(Kind.getLocation(),
                                OverloadCandidateSet::CSK_Normal);
OverloadCandidateSet::iterator Best;

bool HasAnyDeductionGuide = false;
bool AllowExplicit = !Kind.isCopyInit() || ListInit;

auto tryToResolveOverload =
    [&](bool OnlyListConstructors) -> OverloadingResult {
  Candidates.clear(OverloadCandidateSet::CSK_Normal);
  HasAnyDeductionGuide = false;

  for (auto I = Guides.begin(), E = Guides.end(); I != E; ++I) {
    NamedDecl *D = (*I)->getUnderlyingDecl();
    if (D->isInvalidDecl())
      continue;

    auto *TD = dyn_cast<FunctionTemplateDecl>(D);
    auto *GD = dyn_cast_or_null<CXXDeductionGuideDecl>(
        TD ? TD->getTemplatedDecl() : dyn_cast<FunctionDecl>(D));
    if (!GD)
      continue;

    if (!GD->isImplicit())
      HasAnyDeductionGuide = true;

    // C++ [over.match.ctor]p1: (non-list copy-initialization from non-class)
    //   For copy-initialization, the candidate functions are all the
    //   converting constructors (12.3.1) of that class.
    // C++ [over.match.copy]p1: (non-list copy-initialization from class)
    //   The converting constructors of T are candidate functions.
    if (!AllowExplicit) {
      // Overload resolution checks whether the deduction guide is declared
      // explicit for us.

      // When looking for a converting constructor, deduction guides that
      // could never be called with one argument are not interesting to
      // check or note.
      if (GD->getMinRequiredArguments() > 1 ||
          (GD->getNumParams() == 0 && !GD->isVariadic()))
        continue;
    }

    // C++ [over.match.list]p1.1: (first phase list initialization)
    //   Initially, the candidate functions are the initializer-list
    //   constructors of the class T
    if (OnlyListConstructors && !isInitListConstructor(GD))
      continue;

    // C++ [over.match.list]p1.2: (second phase list initialization)
    //   the candidate functions are all the constructors of the class T
    // C++ [over.match.ctor]p1: (all other cases)
    //   the candidate functions are all the constructors of the class of
    //   the object being initialized

    // C++ [over.best.ics]p4:
    //   When [...] the constructor [...] is a candidate by
    //    - [over.match.copy] (in all cases)
    // FIXME: The "second phase of [over.match.list] case can also
    // theoretically happen here, but it's not clear whether we can
    // ever have a parameter of the right type.
    bool SuppressUserConversions = Kind.isCopyInit();

    if (TD)
      AddTemplateOverloadCandidate(TD, I.getPair(), /*ExplicitArgs*/ nullptr,
                                   Inits, Candidates, SuppressUserConversions,
                                   /*PartialOverloading*/ false,
                                   AllowExplicit);
    else
      AddOverloadCandidate(GD, I.getPair(), Inits, Candidates,
                           SuppressUserConversions,
                           /*PartialOverloading*/ false, AllowExplicit);
  }
  return Candidates.BestViableFunction(*this, Kind.getLocation(), Best);
};

OverloadingResult Result = OR_No_Viable_Function;

// C++11 [over.match.list]p1, per DR1467: for list-initialization, first
// try initializer-list constructors.
if (ListInit) {
  bool TryListConstructors = true;

  // Try list constructors unless the list is empty and the class has one or
  // more default constructors, in which case those constructors win.
  if (!ListInit->getNumInits()) {
    for (NamedDecl *D : Guides) {
      auto *FD = dyn_cast<FunctionDecl>(D->getUnderlyingDecl());
      if (FD && FD->getMinRequiredArguments() == 0) {
        TryListConstructors = false;
        break;
      }
    }
  } else if (ListInit->getNumInits() == 1) {
    // C++ [over.match.class.deduct]:
    //   As an exception, the first phase in [over.match.list] (considering
    //   initializer-list constructors) is omitted if the initializer list
    //   consists of a single expression of type cv U, where U is a
    //   specialization of C or a class derived from a specialization of C.
    Expr *E = ListInit->getInit(0);
    auto *RD = E->getType()->getAsCXXRecordDecl();
    if (!isa<InitListExpr>(E) && RD &&
        isCompleteType(Kind.getLocation(), E->getType()) &&
        isOrIsDerivedFromSpecializationOf(RD, Template))
      TryListConstructors = false;
  }

  if (TryListConstructors)
    Result = tryToResolveOverload(/*OnlyListConstructor*/true);
  // Then unwrap the initializer list and try again considering all
  // constructors.
  Inits = MultiExprArg(ListInit->getInits(), ListInit->getNumInits());
}

// If list-initialization fails, or if we're doing any other kind of
// initialization, we (eventually) consider constructors.
if (Result == OR_No_Viable_Function)
  Result = tryToResolveOverload(/*OnlyListConstructor*/false);

switch (Result) {
case OR_Ambiguous:
  // FIXME: For list-initialization candidates, it'd usually be better to
  // list why they were not viable when given the initializer list itself as
  // an argument.
  Candidates.NoteCandidates(
      PartialDiagnosticAt(
          Kind.getLocation(),
          PDiag(diag::err_deduced_class_template_ctor_ambiguous)
              << TemplateName),
      *this, OCD_AmbiguousCandidates, Inits);
  return QualType();

case OR_No_Viable_Function: {
  CXXRecordDecl *Primary =
      cast<ClassTemplateDecl>(Template)->getTemplatedDecl();
  bool Complete =
      isCompleteType(Kind.getLocation(), Context.getTypeDeclType(Primary));
  Candidates.NoteCandidates(
      PartialDiagnosticAt(
          Kind.getLocation(),
          PDiag(Complete ? diag::err_deduced_class_template_ctor_no_viable
                         : diag::err_deduced_class_template_incomplete)
              << TemplateName << !Guides.empty()),
      *this, OCD_AllCandidates, Inits);
  return QualType();
}

case OR_Deleted: {
  Diag(Kind.getLocation(), diag::err_deduced_class_template_deleted)
    << TemplateName;
  NoteDeletedFunction(Best->Function);
  return QualType();
}

case OR_Success:
  // C++ [over.match.list]p1:
  //   In copy-list-initialization, if an explicit constructor is chosen, the
  //   initialization is ill-formed.
  if (Kind.isCopyInit() && ListInit &&
      cast<CXXDeductionGuideDecl>(Best->Function)->isExplicit()) {
    bool IsDeductionGuide = !Best->Function->isImplicit();
    Diag(Kind.getLocation(), diag::err_deduced_class_template_explicit)
        << TemplateName << IsDeductionGuide;
    Diag(Best->Function->getLocation(),
         diag::note_explicit_ctor_deduction_guide_here)
        << IsDeductionGuide;
    return QualType();
  }

  // Make sure we didn't select an unusable deduction guide, and mark it
  // as referenced.
  DiagnoseUseOfDecl(Best->Function, Kind.getLocation());
  MarkFunctionReferenced(Kind.getLocation(), Best->Function);
  break;
}

// C++ [dcl.type.class.deduct]p1:
//  The placeholder is replaced by the return type of the function selected
//  by overload resolution for class template deduction.
QualType DeducedType =
    SubstAutoType(TSInfo->getType(), Best->Function->getReturnType());
Diag(TSInfo->getTypeLoc().getBeginLoc(),
     diag::warn_cxx14_compat_class_template_argument_deduction)
    << TSInfo->getTypeLoc().getSourceRange() << 1 << DeducedType;

// Warn if CTAD was used on a type that does not have any user-defined
// deduction guides.
if (!HasAnyDeductionGuide) {
  Diag(TSInfo->getTypeLoc().getBeginLoc(),
       diag::warn_ctad_maybe_unsupported)
      << TemplateName;
  Diag(Template->getLocation(), diag::note_suppress_ctad_maybe_unsupported);
}

return DeducedType;
10313}