/build/source/clang/lib/Sema/SemaInit.cpp

Bug Summary

File:	build/source/clang/lib/Sema/SemaInit.cpp
Warning:	line 6304, column 54 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/source/build-llvm -resource-dir /usr/lib/llvm-17/lib/clang/17 -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/lib/Sema -I /build/source/clang/lib/Sema -I /build/source/clang/include -I tools/clang/include -I include -I /build/source/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-17/lib/clang/17/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/source/build-llvm=build-llvm -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm=build-llvm -fcoverage-prefix-map=/build/source/= -source-date-epoch 1680088406 -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/source/build-llvm -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -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-2023-03-29-134735-16347-1 -x c++ /build/source/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();

auto IsCharOrUnsignedChar = [](const QualType &T) {
  const BuiltinType *BT = dyn_cast<BuiltinType>(T.getTypePtr());
  return BT && BT->isCharType() && BT->getKind() != BuiltinType::SChar;
};

switch (SL->getKind()) {
case StringLiteral::UTF8:
  // char8_t array can be initialized with a UTF-8 string.
  // - C++20 [dcl.init.string] (DR)
  //   Additionally, an array of char or unsigned char may be initialized
  //   by a UTF-8 string literal.
  if (ElemTy->isChar8Type() ||
      (Context.getLangOpts().Char8 &&
       IsCharOrUnsignedChar(ElemTy.getCanonicalType())))
    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", 144);
145}

147static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
                                        ASTContext &Context) {
const ArrayType *arrayType = Context.getAsArrayType(declType);
if (!arrayType)
  return SIF_Other;
return IsStringInit(init, arrayType, Context);
153}

155bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
return ::IsStringInit(Init, AT, Context) == SIF_None;
157}

159/// Update the type of a string literal, including any surrounding parentheses,
160/// to match the type of the object which it is initializing.
161static 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", 170, __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", 177);
  }
}
180}

182/// Fix a compound literal initializing an array so it's correctly marked
183/// as an rvalue.
184static 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", 192, __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", 199);
  }
}
202}

204static 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)
        << CAT->getSize().getZExtValue() << StrLength
        << 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);
257}

259//===----------------------------------------------------------------------===//
260// Semantic checking for initializer lists.
261//===----------------------------------------------------------------------===//

263namespace {

265/// Semantic checking for initializer lists.
266///
267/// The InitListChecker class contains a set of routines that each
268/// handle the initialization of a certain kind of entity, e.g.,
269/// arrays, vectors, struct/union types, scalars, etc. The
270/// InitListChecker itself performs a recursive walk of the subobject
271/// structure of the type to be initialized, while stepping through
272/// the initializer list one element at a time. The IList and Index
273/// parameters to each of the Check* routines contain the active
274/// (syntactic) initializer list and the index into that initializer
275/// list that represents the current initializer. Each routine is
276/// responsible for moving that Index forward as it consumes elements.
277///
278/// Each Check* routine also has a StructuredList/StructuredIndex
279/// arguments, which contains the current "structured" (semantic)
280/// initializer list and the index into that initializer list where we
281/// are copying initializers as we map them over to the semantic
282/// list. Once we have completed our recursive walk of the subobject
283/// structure, we will have constructed a full semantic initializer
284/// list.
285///
286/// C99 designators cause changes in the initializer list traversal,
287/// because they make the initialization "jump" into a specific
288/// subobject and then continue the initialization from that
289/// point. CheckDesignatedInitializer() recursively steps into the
290/// designated subobject and manages backing out the recursion to
291/// initialize the subobjects after the one designated.
292///
293/// If an initializer list contains any designators, we build a placeholder
294/// structured list even in 'verify only' mode, so that we can track which
295/// elements need 'empty' initializtion.
296class 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);

488public:
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; }
497};

499} // end anonymous namespace

501ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
                                           const InitializedEntity &Entity) {
InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
                                                          true);
MultiExprArg SubInit;
Expr *InitExpr;
InitListExpr DummyInitList(SemaRef.Context, Loc, std::nullopt, 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, std::nullopt, 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", 551, __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);
612}

614void 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);
622}

624void 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", 641, __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);
}
654}

656void 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", 670, __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", 670, __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", 673, __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);
}
748}

750/// Recursively replaces NULL values within the given initializer list
751/// with expressions that perform value-initialization of the
752/// appropriate type, and finish off the InitListExpr formation.
753void
754InitListChecker::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", 761, __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", 761, __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);
  }
}
947}

949static bool hasAnyDesignatedInits(const InitListExpr *IL) {
for (const Stmt *Init : *IL)
  if (Init && isa<DesignatedInitExpr>(Init))
    return true;
return false;
954}

956InitListChecker::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();
986}

988int 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;
996}

998int 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();
1010}

1012/// Determine whether Entity is an entity for which it is idiomatic to elide
1013/// the braces in aggregate initialization.
1014static 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", 1045, __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", 1045, __extension__ __PRETTY_FUNCTION__
));
  return ++FieldIt == ParentRD->field_end();
}

return false;
1050}

1052/// Check whether the range of the initializer \p ParentIList from element
1053/// \p Index onwards can be used to initialize an object of type \p T. Update
1054/// \p Index to indicate how many elements of the list were consumed.
1055///
1056/// This also fills in \p StructuredList, from element \p StructuredIndex
1057/// onwards, with the fully-braced, desugared form of the initialization.
1058void 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", 1072);

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;
  }
}
1133}

1135/// Warn that \p Entity was of scalar type and was initialized by a
1136/// single-element braced initializer list.
1137static 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", 1189);
}

if (DiagID) {
  S.Diag(Braces.getBegin(), DiagID)
      << Entity.getType()->isSizelessBuiltinType() << Braces
      << FixItHint::CreateRemoval(Braces.getBegin())
      << FixItHint::CreateRemoval(Braces.getEnd());
}
1198}

1200/// Check whether the initializer \p IList (that was written with explicit
1201/// braces) can be used to initialize an object of type \p T.
1202///
1203/// This also fills in \p StructuredList with the fully-braced, desugared
1204/// form of the initialization.
1205void 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;
    }
  }
}
1284}

1286void 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", 1307, __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", 1307, __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;
}
1349}

1351void 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", 1377, __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", 1377, __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", 1452, __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", 1452, __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", 1517, __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", 1517, __extension__ __PRETTY_FUNCTION__
));
  }
  hadError = true;
  ++Index;
  ++StructuredIndex;
}
1523}

1525void 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", 1530, __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 initializers, this extension kicks in:
// it expects 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);
}
1559}

1561void 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;
1637}

1639void 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;
1692}

1694void 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"
, 1791);

    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;
}
1843}

1845/// Check if the type of a class element has an accessible destructor, and marks
1846/// it referenced. Returns true if we shouldn't form a reference to the
1847/// destructor.
1848///
1849/// Aggregate initialization requires a class element's destructor be
1850/// accessible per 11.6.1 [dcl.init.aggr]:
1851///
1852/// The destructor for each element of class type is potentially invoked
1853/// (15.4 [class.dtor]) from the context where the aggregate initialization
1854/// occurs.
1855static 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);
1867}

1869void 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());
}
2008}

2010bool 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;
2042}

2044void 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);
2333}

2335/// Expand a field designator that refers to a member of an
2336/// anonymous struct or union into a series of field designators that
2337/// refers to the field within the appropriate subobject.
2338///
2339static 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"
, 2356, __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());
2365}

2367static 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());
2377}

2379namespace {

2381// Callback to only accept typo corrections that are for field members of
2382// the given struct or union.
2383class 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;
2399};

2401} // end anonymous namespace

2403/// Check the well-formedness of a C99 designated initializer.
2404///
2405/// Determines whether the designated initializer @p DIE, which
2406/// resides at the given @p Index within the initializer list @p
2407/// IList, is well-formed for a current object of type @p DeclType
2408/// (C99 6.7.8). The actual subobject that this designator refers to
2409/// within the current subobject is returned in either
2410/// @p NextField or @p NextElementIndex (whichever is appropriate).
2411///
2412/// @param IList  The initializer list in which this designated
2413/// initializer occurs.
2414///
2415/// @param DIE The designated initializer expression.
2416///
2417/// @param DesigIdx  The index of the current designator.
2418///
2419/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
2420/// into which the designation in @p DIE should refer.
2421///
2422/// @param NextField  If non-NULL and the first designator in @p DIE is
2423/// a field, this will be set to the field declaration corresponding
2424/// to the field named by the designator. On input, this is expected to be
2425/// the next field that would be initialized in the absence of designation,
2426/// if the complete object being initialized is a struct.
2427///
2428/// @param NextElementIndex  If non-NULL and the first designator in @p
2429/// DIE is an array designator or GNU array-range designator, this
2430/// will be set to the last index initialized by this designator.
2431///
2432/// @param Index  Index into @p IList where the designated initializer
2433/// @p DIE occurs.
2434///
2435/// @param StructuredList  The initializer list expression that
2436/// describes all of the subobject initializers in the order they'll
2437/// actually be initialized.
2438///
2439/// @returns true if there was an error, false otherwise.
2440bool
2441InitListChecker::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", 2461, __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", 2461, __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", 2663, __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", 2663, __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", 2887, __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 (Context.isPromotableIntegerType(CharTy))
    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;
3052}

3054// Get the structured initializer list for a subobject of type
3055// @p CurrentObjectType.
3056InitListExpr *
3057InitListChecker::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;
3120}

3122InitListExpr *
3123InitListChecker::createInitListExpr(QualType CurrentObjectType,
                                  SourceRange InitRange,
                                  unsigned ExpectedNumInits) {
InitListExpr *Result = new (SemaRef.Context) InitListExpr(
    SemaRef.Context, InitRange.getBegin(), std::nullopt, 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;
3155}

3157/// Update the initializer at index @p StructuredIndex within the
3158/// structured initializer list to the value @p expr.
3159void 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;
3177}

3179/// Determine whether we can perform aggregate initialization for the purposes
3180/// of overload resolution.
3181bool 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();
3188}

3190/// Check that the given Index expression is a valid array designator
3191/// value. This is essentially just a wrapper around
3192/// VerifyIntegerConstantExpression that also checks for negative values
3193/// and produces a reasonable diagnostic if there is a
3194/// failure. Returns the index expression, possibly with an implicit cast
3195/// added, on success.  If everything went okay, Value will receive the
3196/// value of the constant expression.
3197static ExprResult
3198CheckArrayDesignatorExpr(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;
3213}

3215ExprResult 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>());
3304}

3306//===----------------------------------------------------------------------===//
3307// Initialization entity
3308//===----------------------------------------------------------------------===//

3310InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
                                   const InitializedEntity &Parent)
: Parent(&Parent), Index(Index)
3313{
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", 3322, __extension__ __PRETTY_FUNCTION__
));
  Kind = EK_ComplexElement;
  Type = CT->getElementType();
}
3326}

3328InitializedEntity
3329InitializedEntity::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;
3339}

3341DeclarationName 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"
, 3375);
3376}

3378ValueDecl *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"
, 3408);
3409}

3411bool 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;
3440}

3442unsigned 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", 3443,
 __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;
3486}

3488LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void InitializedEntity::dump() const {
dumpImpl(llvm::errs());
3490}

3492//===----------------------------------------------------------------------===//
3493// Initialization sequence
3494//===----------------------------------------------------------------------===//

3496void 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:
case SK_ParenthesizedListInit:
  break;

case SK_ConversionSequence:
case SK_ConversionSequenceNoNarrowing:
  delete ICS;
}
3540}

3542bool 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;
3551}

3553bool 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:
case FK_ParenthesizedListInitFailed:
  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"
, 3603);
3604}

3606bool InitializationSequence::isConstructorInitialization() const {
return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3608}

3610void
3611InitializationSequence
: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);
3622}

3624void 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);
3636}

3638void InitializationSequence::AddReferenceBindingStep(QualType T,
                                                   bool BindingTemporary) {
Step S;
S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
S.Type = T;
Steps.push_back(S);
3644}

3646void InitializationSequence::AddFinalCopy(QualType T) {
Step S;
S.Kind = SK_FinalCopy;
S.Type = T;
Steps.push_back(S);
3651}

3653void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
Step S;
S.Kind = SK_ExtraneousCopyToTemporary;
S.Type = T;
Steps.push_back(S);
3658}

3660void
3661InitializationSequence::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);
3672}

3674void 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);
3691}

3693void InitializationSequence::AddFunctionReferenceConversionStep(QualType Ty) {
Step S;
S.Kind = SK_FunctionReferenceConversion;
S.Type = Ty;
Steps.push_back(S);
3698}

3700void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
Step S;
S.Kind = SK_AtomicConversion;
S.Type = Ty;
Steps.push_back(S);
3705}

3707void 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);
3716}

3718void InitializationSequence::AddListInitializationStep(QualType T) {
Step S;
S.Kind = SK_ListInitialization;
S.Type = T;
Steps.push_back(S);
3723}

3725void 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);
3737}

3739void InitializationSequence::AddZeroInitializationStep(QualType T) {
Step S;
S.Kind = SK_ZeroInitialization;
S.Type = T;
Steps.push_back(S);
3744}

3746void InitializationSequence::AddCAssignmentStep(QualType T) {
Step S;
S.Kind = SK_CAssignment;
S.Type = T;
Steps.push_back(S);
3751}

3753void InitializationSequence::AddStringInitStep(QualType T) {
Step S;
S.Kind = SK_StringInit;
S.Type = T;
Steps.push_back(S);
3758}

3760void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
Step S;
S.Kind = SK_ObjCObjectConversion;
S.Type = T;
Steps.push_back(S);
3765}

3767void InitializationSequence::AddArrayInitStep(QualType T, bool IsGNUExtension) {
Step S;
S.Kind = IsGNUExtension ? SK_GNUArrayInit : SK_ArrayInit;
S.Type = T;
Steps.push_back(S);
3772}

3774void 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);
3783}

3785void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
Step S;
S.Kind = SK_ParenthesizedArrayInit;
S.Type = T;
Steps.push_back(S);
3790}

3792void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
                                                            bool shouldCopy) {
Step s;
s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
                     : SK_PassByIndirectRestore);
s.Type = type;
Steps.push_back(s);
3799}

3801void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
Step S;
S.Kind = SK_ProduceObjCObject;
S.Type = T;
Steps.push_back(S);
3806}

3808void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
Step S;
S.Kind = SK_StdInitializerList;
S.Type = T;
Steps.push_back(S);
3813}

3815void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
Step S;
S.Kind = SK_OCLSamplerInit;
S.Type = T;
Steps.push_back(S);
3820}

3822void InitializationSequence::AddOCLZeroOpaqueTypeStep(QualType T) {
Step S;
S.Kind = SK_OCLZeroOpaqueType;
S.Type = T;
Steps.push_back(S);
3827}

3829void InitializationSequence::AddParenthesizedListInitStep(QualType T) {
Step S;
S.Kind = SK_ParenthesizedListInit;
S.Type = T;
Steps.push_back(S);
3834}

3836void 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", 3839, __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", 3839, __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);
3849}

3851void InitializationSequence::SetOverloadFailure(FailureKind Failure,
                                              OverloadingResult Result) {
setSequenceKind(FailedSequence);
this->Failure = Failure;
this->FailedOverloadResult = Result;
3856}

3858//===----------------------------------------------------------------------===//
3859// Attempt initialization
3860//===----------------------------------------------------------------------===//

3862/// Tries to add a zero initializer. Returns true if that worked.
3863static bool
3864maybeRecoverWithZeroInitialization(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;
3882}

3884static 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", 3896, __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", 3896, __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());
}
3910}

3912static void TryListInitialization(Sema &S,
                                const InitializedEntity &Entity,
                                const InitializationKind &Kind,
                                InitListExpr *InitList,
                                InitializationSequence &Sequence,
                                bool TreatUnavailableAsInvalid);

3919/// When initializing from init list via constructor, handle
3920/// initialization of an object of type std::initializer_list<T>.
3921///
3922/// \return true if we have handled initialization of an object of type
3923/// std::initializer_list<T>, false otherwise.
3924static 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;
3953}

3955/// Determine if the constructor has the signature of a copy or move
3956/// constructor for the type T of the class in which it was found. That is,
3957/// determine if its first parameter is of type T or reference to (possibly
3958/// cv-qualified) T.
3959static 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);
3970}

3972static OverloadingResult
3973ResolveConstructorOverload(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);
4077}

4079/// Attempt initialization by constructor (C++ [dcl.init]), which
4080/// enumerates the constructors of the initialized entity and performs overload
4081/// resolution to select the best.
4082/// \param DestType       The destination class type.
4083/// \param DestArrayType  The destination type, which is either DestType or
4084///                       a (possibly multidimensional) array of DestType.
4085/// \param IsListInit     Is this list-initialization?
4086/// \param IsInitListCopy Is this non-list-initialization resulting from a
4087///                       list-initialization from {x} where x is the same
4088///                       type as the entity?
4089static 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", 4100, __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", 4100, __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", 4100, __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", 4100, __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", 4136, __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", 4211, __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", 4211, __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);
4266}

4268static bool
4269ResolveOverloadedFunctionForReferenceBinding(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;
4294}

4296static 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);

4306static void TryValueInitialization(Sema &S,
                                 const InitializedEntity &Entity,
                                 const InitializationKind &Kind,
                                 InitializationSequence &Sequence,
                                 InitListExpr *InitList = nullptr);

4312/// Attempt list initialization of a reference.
4313static 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);
}
4401}

4403/// Attempt list initialization (C++0x [dcl.init.list])
4404static 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);
4600}

4602/// Try a reference initialization that involves calling a conversion
4603/// function.
4604static 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", 4615, __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", 4615, __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", 4745, __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", 4745, __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;
4782}

4784static void CheckCXX98CompatAccessibleCopy(Sema &S,
                                         const InitializedEntity &Entity,
                                         Expr *CurInitExpr);

4788/// Attempt reference initialization (C++0x [dcl.init.ref])
4789static 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);
4812}

4814/// Determine whether an expression is a non-referenceable glvalue (one to
4815/// which a reference can never bind). Attempting to bind a reference to
4816/// such a glvalue will always create a temporary.
4817static bool isNonReferenceableGLValue(Expr *E) {
return E->refersToBitField() || E->refersToVectorElement() ||
       E->refersToMatrixElement();
4820}

4822/// Reference initialization without resolving overloaded functions.
4823///
4824/// We also can get here in C if we call a builtin which is declared as
4825/// a function with a parameter of reference type (such as __builtin_va_end()).
4826static 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", 4952);
      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);
}
5144}

5146/// Attempt character array initialization from a string literal
5147/// (C++ [dcl.init.string], C99 6.7.8).
5148static void TryStringLiteralInitialization(Sema &S,
                                         const InitializedEntity &Entity,
                                         const InitializationKind &Kind,
                                         Expr *Initializer,
                                     InitializationSequence &Sequence) {
Sequence.AddStringInitStep(Entity.getType());
5154}

5156/// Attempt value initialization (C++ [dcl.init]p7).
5157static 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", 5163, __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", 5163, __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());
5232}

5234/// Attempt default initialization (C++ [dcl.init]p6).
5235static 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", 5239, __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, std::nullopt, 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;
}
5271}

5273static void TryOrBuildParenListInitialization(
  Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
  ArrayRef<Expr *> Args, InitializationSequence &Sequence, bool VerifyOnly,
  ExprResult *Result = nullptr) {
unsigned ArgIndexToProcess = 0;
SmallVector<Expr *, 4> InitExprs;
QualType ResultType;
Expr *ArrayFiller = nullptr;
FieldDecl *InitializedFieldInUnion = nullptr;

// Process entities (i.e. array members, base classes, or class fields) by
// adding an initialization expression to InitExprs for each entity to
// initialize.
auto ProcessEntities = [&](auto Range) -> bool {
  bool IsUnionType = Entity.getType()->isUnionType();
  for (InitializedEntity SubEntity : Range) {
    // Unions should only have one initializer expression.
    // If there are more initializers than it will be caught when we check
    // whether Index equals Args.size().
    if (ArgIndexToProcess == 1 && IsUnionType)
      return true;

    bool IsMember = SubEntity.getKind() == InitializedEntity::EK_Member;

    // Unnamed bitfields should not be initialized at all, either with an arg
    // or by default.
    if (IsMember && cast<FieldDecl>(SubEntity.getDecl())->isUnnamedBitfield())
      continue;

    if (ArgIndexToProcess < Args.size()) {
      // There are still expressions in Args that haven't been processed.
      // Let's match them to the current entity to initialize.
      Expr *E = Args[ArgIndexToProcess++];

      // Incomplete array types indicate flexible array members. Do not allow
      // paren list initializations of structs with these members, as GCC
      // doesn't either.
      if (IsMember) {
        auto *FD = cast<FieldDecl>(SubEntity.getDecl());
        if (FD->getType()->isIncompleteArrayType()) {
          if (!VerifyOnly) {
            S.Diag(E->getBeginLoc(), diag::err_flexible_array_init)
                << SourceRange(E->getBeginLoc(), E->getEndLoc());
            S.Diag(FD->getLocation(), diag::note_flexible_array_member) << FD;
          }
          Sequence.SetFailed(
              InitializationSequence::FK_ParenthesizedListInitFailed);
          return false;
        }
      }

      InitializationKind SubKind = InitializationKind::CreateForInit(
          E->getExprLoc(), /*isDirectInit=*/false, E);
      InitializationSequence SubSeq(S, SubEntity, SubKind, E);

      if (SubSeq.Failed()) {
        if (!VerifyOnly)
          SubSeq.Diagnose(S, SubEntity, SubKind, E);
        else
          Sequence.SetFailed(
              InitializationSequence::FK_ParenthesizedListInitFailed);

        return false;
      }
      if (!VerifyOnly) {
        ExprResult ER = SubSeq.Perform(S, SubEntity, SubKind, E);
        InitExprs.push_back(ER.get());
        if (IsMember && IsUnionType)
          InitializedFieldInUnion = cast<FieldDecl>(SubEntity.getDecl());
      }
    } else {
      // We've processed all of the args, but there are still entities that
      // have to be initialized.
      if (IsMember) {
        // C++ [dcl.init]p17.6.2.2
        //   The remaining elements are initialized with their default member
        //   initializers, if any
        auto *FD = cast<FieldDecl>(SubEntity.getDecl());
        if (Expr *ICE = FD->getInClassInitializer(); ICE && !VerifyOnly) {
          ExprResult DIE = S.BuildCXXDefaultInitExpr(FD->getLocation(), FD);
          if (DIE.isInvalid())
            return false;
          S.checkInitializerLifetime(SubEntity, DIE.get());
          InitExprs.push_back(DIE.get());
          continue;
        };
      }
      // Remaining class elements without default member initializers and
      // array elements are value initialized:
      //
      // C++ [dcl.init]p17.6.2.2
      //   The remaining elements...otherwise are value initialzed
      //
      // C++ [dcl.init]p17.5
      //   if the destination type is an array, the object is initialized as
      // . follows. Let x1, . . . , xk be the elements of the expression-list
      //   ...Let n denote the array size...the ith array element is...value-
      //   initialized for each k < i <= n.
      InitializationKind SubKind = InitializationKind::CreateValue(
          Kind.getLocation(), Kind.getLocation(), Kind.getLocation(), true);
      InitializationSequence SubSeq(S, SubEntity, SubKind, std::nullopt);
      if (SubSeq.Failed()) {
        if (!VerifyOnly)
          SubSeq.Diagnose(S, SubEntity, SubKind, std::nullopt);
        return false;
      }
      if (!VerifyOnly) {
        ExprResult ER = SubSeq.Perform(S, SubEntity, SubKind, std::nullopt);
        if (SubEntity.getKind() == InitializedEntity::EK_ArrayElement) {
          ArrayFiller = ER.get();
          return true;
        }
        InitExprs.push_back(ER.get());
      }
    }
  }
  return true;
};

if (const ArrayType *AT =
        S.getASTContext().getAsArrayType(Entity.getType())) {

  SmallVector<InitializedEntity, 4> ElementEntities;
  uint64_t ArrayLength;
  // C++ [dcl.init]p17.5
  //   if the destination type is an array, the object is initialized as
  //   follows. Let x1, . . . , xk be the elements of the expression-list. If
  //   the destination type is an array of unknown bound, it is define as
  //   having k elements.
  if (const ConstantArrayType *CAT =
          S.getASTContext().getAsConstantArrayType(Entity.getType()))
    ArrayLength = CAT->getSize().getZExtValue();
  else
    ArrayLength = Args.size();

  if (ArrayLength >= Args.size()) {
    for (uint64_t I = 0; I < ArrayLength; ++I)
      ElementEntities.push_back(
          InitializedEntity::InitializeElement(S.getASTContext(), I, Entity));

    if (!ProcessEntities(ElementEntities))
      return;

    ResultType = S.Context.getConstantArrayType(
        AT->getElementType(), llvm::APInt(/*numBits=*/32, ArrayLength),
        nullptr, ArrayType::Normal, 0);
  }
} else if (auto *RT = Entity.getType()->getAs<RecordType>()) {
  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());

  auto BaseRange = map_range(RD->bases(), [&S](auto &base) {
    return InitializedEntity::InitializeBase(S.getASTContext(), &base, false);
  });
  auto FieldRange = map_range(RD->fields(), [](auto *field) {
    return InitializedEntity::InitializeMember(field);
  });

  if (!ProcessEntities(BaseRange))
    return;

  if (!ProcessEntities(FieldRange))
    return;

  ResultType = Entity.getType();
}

// Not all of the args have been processed, so there must've been more args
// than were required to initialize the element.
if (ArgIndexToProcess < Args.size()) {
  Sequence.SetFailed(InitializationSequence::FK_ParenthesizedListInitFailed);
  if (!VerifyOnly) {
    QualType T = Entity.getType();
    int InitKind = T->isArrayType() ? 0 : T->isUnionType() ? 3 : 4;
    SourceRange ExcessInitSR(Args[ArgIndexToProcess]->getBeginLoc(),
                             Args.back()->getEndLoc());
    S.Diag(Kind.getLocation(), diag::err_excess_initializers)
        << InitKind << ExcessInitSR;
  }
  return;
}

if (VerifyOnly) {
  Sequence.setSequenceKind(InitializationSequence::NormalSequence);
  Sequence.AddParenthesizedListInitStep(Entity.getType());
} else if (Result) {
  SourceRange SR = Kind.getParenOrBraceRange();
  auto *CPLIE = CXXParenListInitExpr::Create(
      S.getASTContext(), InitExprs, ResultType, Args.size(),
      Kind.getLocation(), SR.getBegin(), SR.getEnd());
  if (ArrayFiller)
    CPLIE->setArrayFiller(ArrayFiller);
  if (InitializedFieldInUnion)
    CPLIE->setInitializedFieldInUnion(InitializedFieldInUnion);
  *Result = CPLIE;
  S.Diag(Kind.getLocation(),
         diag::warn_cxx17_compat_aggregate_init_paren_list)
      << Kind.getLocation() << SR << ResultType;
}

return;
5473}

5475/// Attempt a user-defined conversion between two types (C++ [dcl.init]),
5476/// which enumerates all conversion functions and performs overload resolution
5477/// to select the best.
5478static 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", 5484, __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", 5487, __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", 5487, __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);
}
5656}

5658/// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
5659/// a function with a pointer return type contains a 'return false;' statement.
5660/// In C++11, 'false' is not a null pointer, so this breaks the build of any
5661/// code using that header.
5662///
5663/// Work around this by treating 'return false;' as zero-initializing the result
5664/// if it's used in a pointer-returning function in a system header.
5665static 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());
5674}

5676/// The non-zero enum values here are indexes into diagnostic alternatives.
5677enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };

5679/// Determines whether this expression is an acceptable ICR source.
5680static 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;
5743}

5745/// Check whether the given expression is a valid operand for an
5746/// indirect copy/restore.
5747static 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", 5748,
 __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();
5761}

5763/// Determine whether we have compatible array types for the
5764/// purposes of GNU by-copy array initialization.
5765static 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();
5779}

5781static 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;
5826}

5828static 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;
5839}

5841static bool IsZeroInitializer(Expr *Initializer, Sema &S) {
return Initializer->isIntegerConstantExpr(S.getASTContext()) &&
  (Initializer->EvaluateKnownConstInt(S.getASTContext()) == 0);
5844}

5846static 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;
5886}

5888InitializationSequence::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);
5895}

5897/// Tries to get a FunctionDecl out of `E`. If it succeeds and we can take the
5898/// address of that function, this returns true. Otherwise, it returns false.
5899static 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()));
5906}

5908/// Determine whether we can perform an elementwise array copy for this kind
5909/// of entity.
5910static 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;
5942}

5944void 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)
1
Assuming 'I' is equal to 'E'→
2
←
Loop condition is false. Execution continues on line 5973