Bug Summary

File:build/source/clang/lib/Sema/SemaInit.cpp
Warning:line 9532, column 27
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 1679782259 -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-2023-03-26-004757-16329-1 -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//===----------------------------------------------------------------------===//
12
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"
31
32using namespace clang;
33
34//===----------------------------------------------------------------------===//
35// Sema Initialization Checking
36//===----------------------------------------------------------------------===//
37
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) {
41 if (Context.typesAreCompatible(Context.getWideCharType(), T))
42 return true;
43 if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
44 return Context.typesAreCompatible(Context.Char16Ty, T) ||
45 Context.typesAreCompatible(Context.Char32Ty, T);
46 }
47 return false;
48}
49
50enum StringInitFailureKind {
51 SIF_None,
52 SIF_NarrowStringIntoWideChar,
53 SIF_WideStringIntoChar,
54 SIF_IncompatWideStringIntoWideChar,
55 SIF_UTF8StringIntoPlainChar,
56 SIF_PlainStringIntoUTF8Char,
57 SIF_Other
58};
59
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,
65 ASTContext &Context) {
66 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
67 return SIF_Other;
68
69 // See if this is a string literal or @encode.
70 Init = Init->IgnoreParens();
71
72 // Handle @encode, which is a narrow string.
73 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
74 return SIF_None;
75
76 // Otherwise we can only handle string literals.
77 StringLiteral *SL = dyn_cast<StringLiteral>(Init);
78 if (!SL)
79 return SIF_Other;
80
81 const QualType ElemTy =
82 Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();
83
84 auto IsCharOrUnsignedChar = [](const QualType &T) {
85 const BuiltinType *BT = dyn_cast<BuiltinType>(T.getTypePtr());
86 return BT && BT->isCharType() && BT->getKind() != BuiltinType::SChar;
87 };
88
89 switch (SL->getKind()) {
90 case StringLiteral::UTF8:
91 // char8_t array can be initialized with a UTF-8 string.
92 // - C++20 [dcl.init.string] (DR)
93 // Additionally, an array of char or unsigned char may be initialized
94 // by a UTF-8 string literal.
95 if (ElemTy->isChar8Type() ||
96 (Context.getLangOpts().Char8 &&
97 IsCharOrUnsignedChar(ElemTy.getCanonicalType())))
98 return SIF_None;
99 [[fallthrough]];
100 case StringLiteral::Ordinary:
101 // char array can be initialized with a narrow string.
102 // Only allow char x[] = "foo"; not char x[] = L"foo";
103 if (ElemTy->isCharType())
104 return (SL->getKind() == StringLiteral::UTF8 &&
105 Context.getLangOpts().Char8)
106 ? SIF_UTF8StringIntoPlainChar
107 : SIF_None;
108 if (ElemTy->isChar8Type())
109 return SIF_PlainStringIntoUTF8Char;
110 if (IsWideCharCompatible(ElemTy, Context))
111 return SIF_NarrowStringIntoWideChar;
112 return SIF_Other;
113 // C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
114 // "An array with element type compatible with a qualified or unqualified
115 // version of wchar_t, char16_t, or char32_t may be initialized by a wide
116 // string literal with the corresponding encoding prefix (L, u, or U,
117 // respectively), optionally enclosed in braces.
118 case StringLiteral::UTF16:
119 if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
120 return SIF_None;
121 if (ElemTy->isCharType() || ElemTy->isChar8Type())
122 return SIF_WideStringIntoChar;
123 if (IsWideCharCompatible(ElemTy, Context))
124 return SIF_IncompatWideStringIntoWideChar;
125 return SIF_Other;
126 case StringLiteral::UTF32:
127 if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
128 return SIF_None;
129 if (ElemTy->isCharType() || ElemTy->isChar8Type())
130 return SIF_WideStringIntoChar;
131 if (IsWideCharCompatible(ElemTy, Context))
132 return SIF_IncompatWideStringIntoWideChar;
133 return SIF_Other;
134 case StringLiteral::Wide:
135 if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
136 return SIF_None;
137 if (ElemTy->isCharType() || ElemTy->isChar8Type())
138 return SIF_WideStringIntoChar;
139 if (IsWideCharCompatible(ElemTy, Context))
140 return SIF_IncompatWideStringIntoWideChar;
141 return SIF_Other;
142 }
143
144 llvm_unreachable("missed a StringLiteral kind?")::llvm::llvm_unreachable_internal("missed a StringLiteral kind?"
, "clang/lib/Sema/SemaInit.cpp", 144)
;
145}
146
147static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
148 ASTContext &Context) {
149 const ArrayType *arrayType = Context.getAsArrayType(declType);
150 if (!arrayType)
151 return SIF_Other;
152 return IsStringInit(init, arrayType, Context);
153}
154
155bool Sema::IsStringInit(Expr *Init, const ArrayType *AT) {
156 return ::IsStringInit(Init, AT, Context) == SIF_None;
157}
158
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) {
162 while (true) {
163 E->setType(Ty);
164 E->setValueKind(VK_PRValue);
165 if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) {
166 break;
167 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
168 E = PE->getSubExpr();
169 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
170 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__
))
;
171 E = UO->getSubExpr();
172 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
173 E = GSE->getResultExpr();
174 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
175 E = CE->getChosenSubExpr();
176 } else {
177 llvm_unreachable("unexpected expr in string literal init")::llvm::llvm_unreachable_internal("unexpected expr in string literal init"
, "clang/lib/Sema/SemaInit.cpp", 177)
;
178 }
179 }
180}
181
182/// Fix a compound literal initializing an array so it's correctly marked
183/// as an rvalue.
184static void updateGNUCompoundLiteralRValue(Expr *E) {
185 while (true) {
186 E->setValueKind(VK_PRValue);
187 if (isa<CompoundLiteralExpr>(E)) {
188 break;
189 } else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
190 E = PE->getSubExpr();
191 } else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
192 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__
))
;
193 E = UO->getSubExpr();
194 } else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) {
195 E = GSE->getResultExpr();
196 } else if (ChooseExpr *CE = dyn_cast<ChooseExpr>(E)) {
197 E = CE->getChosenSubExpr();
198 } else {
199 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)
;
200 }
201 }
202}
203
204static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
205 Sema &S) {
206 // Get the length of the string as parsed.
207 auto *ConstantArrayTy =
208 cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
209 uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();
210
211 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
212 // C99 6.7.8p14. We have an array of character type with unknown size
213 // being initialized to a string literal.
214 llvm::APInt ConstVal(32, StrLength);
215 // Return a new array type (C99 6.7.8p22).
216 DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
217 ConstVal, nullptr,
218 ArrayType::Normal, 0);
219 updateStringLiteralType(Str, DeclT);
220 return;
221 }
222
223 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
224
225 // We have an array of character type with known size. However,
226 // the size may be smaller or larger than the string we are initializing.
227 // FIXME: Avoid truncation for 64-bit length strings.
228 if (S.getLangOpts().CPlusPlus) {
229 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
230 // For Pascal strings it's OK to strip off the terminating null character,
231 // so the example below is valid:
232 //
233 // unsigned char a[2] = "\pa";
234 if (SL->isPascal())
235 StrLength--;
236 }
237
238 // [dcl.init.string]p2
239 if (StrLength > CAT->getSize().getZExtValue())
240 S.Diag(Str->getBeginLoc(),
241 diag::err_initializer_string_for_char_array_too_long)
242 << CAT->getSize().getZExtValue() << StrLength
243 << Str->getSourceRange();
244 } else {
245 // C99 6.7.8p14.
246 if (StrLength-1 > CAT->getSize().getZExtValue())
247 S.Diag(Str->getBeginLoc(),
248 diag::ext_initializer_string_for_char_array_too_long)
249 << Str->getSourceRange();
250 }
251
252 // Set the type to the actual size that we are initializing. If we have
253 // something like:
254 // char x[1] = "foo";
255 // then this will set the string literal's type to char[1].
256 updateStringLiteralType(Str, DeclT);
257}
258
259//===----------------------------------------------------------------------===//
260// Semantic checking for initializer lists.
261//===----------------------------------------------------------------------===//
262
263namespace {
264
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 {
297 Sema &SemaRef;
298 bool hadError = false;
299 bool VerifyOnly; // No diagnostics.
300 bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
301 bool InOverloadResolution;
302 InitListExpr *FullyStructuredList = nullptr;
303 NoInitExpr *DummyExpr = nullptr;
304
305 NoInitExpr *getDummyInit() {
306 if (!DummyExpr)
307 DummyExpr = new (SemaRef.Context) NoInitExpr(SemaRef.Context.VoidTy);
308 return DummyExpr;
309 }
310
311 void CheckImplicitInitList(const InitializedEntity &Entity,
312 InitListExpr *ParentIList, QualType T,
313 unsigned &Index, InitListExpr *StructuredList,
314 unsigned &StructuredIndex);
315 void CheckExplicitInitList(const InitializedEntity &Entity,
316 InitListExpr *IList, QualType &T,
317 InitListExpr *StructuredList,
318 bool TopLevelObject = false);
319 void CheckListElementTypes(const InitializedEntity &Entity,
320 InitListExpr *IList, QualType &DeclType,
321 bool SubobjectIsDesignatorContext,
322 unsigned &Index,
323 InitListExpr *StructuredList,
324 unsigned &StructuredIndex,
325 bool TopLevelObject = false);
326 void CheckSubElementType(const InitializedEntity &Entity,
327 InitListExpr *IList, QualType ElemType,
328 unsigned &Index,
329 InitListExpr *StructuredList,
330 unsigned &StructuredIndex,
331 bool DirectlyDesignated = false);
332 void CheckComplexType(const InitializedEntity &Entity,
333 InitListExpr *IList, QualType DeclType,
334 unsigned &Index,
335 InitListExpr *StructuredList,
336 unsigned &StructuredIndex);
337 void CheckScalarType(const InitializedEntity &Entity,
338 InitListExpr *IList, QualType DeclType,
339 unsigned &Index,
340 InitListExpr *StructuredList,
341 unsigned &StructuredIndex);
342 void CheckReferenceType(const InitializedEntity &Entity,
343 InitListExpr *IList, QualType DeclType,
344 unsigned &Index,
345 InitListExpr *StructuredList,
346 unsigned &StructuredIndex);
347 void CheckVectorType(const InitializedEntity &Entity,
348 InitListExpr *IList, QualType DeclType, unsigned &Index,
349 InitListExpr *StructuredList,
350 unsigned &StructuredIndex);
351 void CheckStructUnionTypes(const InitializedEntity &Entity,
352 InitListExpr *IList, QualType DeclType,
353 CXXRecordDecl::base_class_range Bases,
354 RecordDecl::field_iterator Field,
355 bool SubobjectIsDesignatorContext, unsigned &Index,
356 InitListExpr *StructuredList,
357 unsigned &StructuredIndex,
358 bool TopLevelObject = false);
359 void CheckArrayType(const InitializedEntity &Entity,
360 InitListExpr *IList, QualType &DeclType,
361 llvm::APSInt elementIndex,
362 bool SubobjectIsDesignatorContext, unsigned &Index,
363 InitListExpr *StructuredList,
364 unsigned &StructuredIndex);
365 bool CheckDesignatedInitializer(const InitializedEntity &Entity,
366 InitListExpr *IList, DesignatedInitExpr *DIE,
367 unsigned DesigIdx,
368 QualType &CurrentObjectType,
369 RecordDecl::field_iterator *NextField,
370 llvm::APSInt *NextElementIndex,
371 unsigned &Index,
372 InitListExpr *StructuredList,
373 unsigned &StructuredIndex,
374 bool FinishSubobjectInit,
375 bool TopLevelObject);
376 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
377 QualType CurrentObjectType,
378 InitListExpr *StructuredList,
379 unsigned StructuredIndex,
380 SourceRange InitRange,
381 bool IsFullyOverwritten = false);
382 void UpdateStructuredListElement(InitListExpr *StructuredList,
383 unsigned &StructuredIndex,
384 Expr *expr);
385 InitListExpr *createInitListExpr(QualType CurrentObjectType,
386 SourceRange InitRange,
387 unsigned ExpectedNumInits);
388 int numArrayElements(QualType DeclType);
389 int numStructUnionElements(QualType DeclType);
390
391 ExprResult PerformEmptyInit(SourceLocation Loc,
392 const InitializedEntity &Entity);
393
394 /// Diagnose that OldInit (or part thereof) has been overridden by NewInit.
395 void diagnoseInitOverride(Expr *OldInit, SourceRange NewInitRange,
396 bool FullyOverwritten = true) {
397 // Overriding an initializer via a designator is valid with C99 designated
398 // initializers, but ill-formed with C++20 designated initializers.
399 unsigned DiagID = SemaRef.getLangOpts().CPlusPlus
400 ? diag::ext_initializer_overrides
401 : diag::warn_initializer_overrides;
402
403 if (InOverloadResolution && SemaRef.getLangOpts().CPlusPlus) {
404 // In overload resolution, we have to strictly enforce the rules, and so
405 // don't allow any overriding of prior initializers. This matters for a
406 // case such as:
407 //
408 // union U { int a, b; };
409 // struct S { int a, b; };
410 // void f(U), f(S);
411 //
412 // Here, f({.a = 1, .b = 2}) is required to call the struct overload. For
413 // consistency, we disallow all overriding of prior initializers in
414 // overload resolution, not only overriding of union members.
415 hadError = true;
416 } else if (OldInit->getType().isDestructedType() && !FullyOverwritten) {
417 // If we'll be keeping around the old initializer but overwriting part of
418 // the object it initialized, and that object is not trivially
419 // destructible, this can leak. Don't allow that, not even as an
420 // extension.
421 //
422 // FIXME: It might be reasonable to allow this in cases where the part of
423 // the initializer that we're overriding has trivial destruction.
424 DiagID = diag::err_initializer_overrides_destructed;
425 } else if (!OldInit->getSourceRange().isValid()) {
426 // We need to check on source range validity because the previous
427 // initializer does not have to be an explicit initializer. e.g.,
428 //
429 // struct P { int a, b; };
430 // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
431 //
432 // There is an overwrite taking place because the first braced initializer
433 // list "{ .a = 2 }" already provides value for .p.b (which is zero).
434 //
435 // Such overwrites are harmless, so we don't diagnose them. (Note that in
436 // C++, this cannot be reached unless we've already seen and diagnosed a
437 // different conformance issue, such as a mixture of designated and
438 // non-designated initializers or a multi-level designator.)
439 return;
440 }
441
442 if (!VerifyOnly) {
443 SemaRef.Diag(NewInitRange.getBegin(), DiagID)
444 << NewInitRange << FullyOverwritten << OldInit->getType();
445 SemaRef.Diag(OldInit->getBeginLoc(), diag::note_previous_initializer)
446 << (OldInit->HasSideEffects(SemaRef.Context) && FullyOverwritten)
447 << OldInit->getSourceRange();
448 }
449 }
450
451 // Explanation on the "FillWithNoInit" mode:
452 //
453 // Assume we have the following definitions (Case#1):
454 // struct P { char x[6][6]; } xp = { .x[1] = "bar" };
455 // struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
456 //
457 // l.lp.x[1][0..1] should not be filled with implicit initializers because the
458 // "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
459 //
460 // But if we have (Case#2):
461 // struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
462 //
463 // l.lp.x[1][0..1] are implicitly initialized and do not use values from the
464 // "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
465 //
466 // To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
467 // in the InitListExpr, the "holes" in Case#1 are filled not with empty
468 // initializers but with special "NoInitExpr" place holders, which tells the
469 // CodeGen not to generate any initializers for these parts.
470 void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
471 const InitializedEntity &ParentEntity,
472 InitListExpr *ILE, bool &RequiresSecondPass,
473 bool FillWithNoInit);
474 void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
475 const InitializedEntity &ParentEntity,
476 InitListExpr *ILE, bool &RequiresSecondPass,
477 bool FillWithNoInit = false);
478 void FillInEmptyInitializations(const InitializedEntity &Entity,
479 InitListExpr *ILE, bool &RequiresSecondPass,
480 InitListExpr *OuterILE, unsigned OuterIndex,
481 bool FillWithNoInit = false);
482 bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
483 Expr *InitExpr, FieldDecl *Field,
484 bool TopLevelObject);
485 void CheckEmptyInitializable(const InitializedEntity &Entity,
486 SourceLocation Loc);
487
488public:
489 InitListChecker(Sema &S, const InitializedEntity &Entity, InitListExpr *IL,
490 QualType &T, bool VerifyOnly, bool TreatUnavailableAsInvalid,
491 bool InOverloadResolution = false);
492 bool HadError() { return hadError; }
493
494 // Retrieves the fully-structured initializer list used for
495 // semantic analysis and code generation.
496 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
497};
498
499} // end anonymous namespace
500
501ExprResult InitListChecker::PerformEmptyInit(SourceLocation Loc,
502 const InitializedEntity &Entity) {
503 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
504 true);
505 MultiExprArg SubInit;
506 Expr *InitExpr;
507 InitListExpr DummyInitList(SemaRef.Context, Loc, std::nullopt, Loc);
508
509 // C++ [dcl.init.aggr]p7:
510 // If there are fewer initializer-clauses in the list than there are
511 // members in the aggregate, then each member not explicitly initialized
512 // ...
513 bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
514 Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
515 if (EmptyInitList) {
516 // C++1y / DR1070:
517 // shall be initialized [...] from an empty initializer list.
518 //
519 // We apply the resolution of this DR to C++11 but not C++98, since C++98
520 // does not have useful semantics for initialization from an init list.
521 // We treat this as copy-initialization, because aggregate initialization
522 // always performs copy-initialization on its elements.
523 //
524 // Only do this if we're initializing a class type, to avoid filling in
525 // the initializer list where possible.
526 InitExpr = VerifyOnly
527 ? &DummyInitList
528 : new (SemaRef.Context)
529 InitListExpr(SemaRef.Context, Loc, std::nullopt, Loc);
530 InitExpr->setType(SemaRef.Context.VoidTy);
531 SubInit = InitExpr;
532 Kind = InitializationKind::CreateCopy(Loc, Loc);
533 } else {
534 // C++03:
535 // shall be value-initialized.
536 }
537
538 InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
539 // libstdc++4.6 marks the vector default constructor as explicit in
540 // _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
541 // stlport does so too. Look for std::__debug for libstdc++, and for
542 // std:: for stlport. This is effectively a compiler-side implementation of
543 // LWG2193.
544 if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
545 InitializationSequence::FK_ExplicitConstructor) {
546 OverloadCandidateSet::iterator Best;
547 OverloadingResult O =
548 InitSeq.getFailedCandidateSet()
549 .BestViableFunction(SemaRef, Kind.getLocation(), Best);
550 (void)O;
551 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__
))
;
552 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
553 CXXRecordDecl *R = CtorDecl->getParent();
554
555 if (CtorDecl->getMinRequiredArguments() == 0 &&
556 CtorDecl->isExplicit() && R->getDeclName() &&
557 SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
558 bool IsInStd = false;
559 for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
560 ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
561 if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
562 IsInStd = true;
563 }
564
565 if (IsInStd && llvm::StringSwitch<bool>(R->getName())
566 .Cases("basic_string", "deque", "forward_list", true)
567 .Cases("list", "map", "multimap", "multiset", true)
568 .Cases("priority_queue", "queue", "set", "stack", true)
569 .Cases("unordered_map", "unordered_set", "vector", true)
570 .Default(false)) {
571 InitSeq.InitializeFrom(
572 SemaRef, Entity,
573 InitializationKind::CreateValue(Loc, Loc, Loc, true),
574 MultiExprArg(), /*TopLevelOfInitList=*/false,
575 TreatUnavailableAsInvalid);
576 // Emit a warning for this. System header warnings aren't shown
577 // by default, but people working on system headers should see it.
578 if (!VerifyOnly) {
579 SemaRef.Diag(CtorDecl->getLocation(),
580 diag::warn_invalid_initializer_from_system_header);
581 if (Entity.getKind() == InitializedEntity::EK_Member)
582 SemaRef.Diag(Entity.getDecl()->getLocation(),
583 diag::note_used_in_initialization_here);
584 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
585 SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
586 }
587 }
588 }
589 }
590 if (!InitSeq) {
591 if (!VerifyOnly) {
592 InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
593 if (Entity.getKind() == InitializedEntity::EK_Member)
594 SemaRef.Diag(Entity.getDecl()->getLocation(),
595 diag::note_in_omitted_aggregate_initializer)
596 << /*field*/1 << Entity.getDecl();
597 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) {
598 bool IsTrailingArrayNewMember =
599 Entity.getParent() &&
600 Entity.getParent()->isVariableLengthArrayNew();
601 SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
602 << (IsTrailingArrayNewMember ? 2 : /*array element*/0)
603 << Entity.getElementIndex();
604 }
605 }
606 hadError = true;
607 return ExprError();
608 }
609
610 return VerifyOnly ? ExprResult()
611 : InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
612}
613
614void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
615 SourceLocation Loc) {
616 // If we're building a fully-structured list, we'll check this at the end
617 // once we know which elements are actually initialized. Otherwise, we know
618 // that there are no designators so we can just check now.
619 if (FullyStructuredList)
620 return;
621 PerformEmptyInit(Loc, Entity);
622}
623
624void InitListChecker::FillInEmptyInitForBase(
625 unsigned Init, const CXXBaseSpecifier &Base,
626 const InitializedEntity &ParentEntity, InitListExpr *ILE,
627 bool &RequiresSecondPass, bool FillWithNoInit) {
628 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
629 SemaRef.Context, &Base, false, &ParentEntity);
630
631 if (Init >= ILE->getNumInits() || !ILE->getInit(Init)) {
632 ExprResult BaseInit = FillWithNoInit
633 ? new (SemaRef.Context) NoInitExpr(Base.getType())
634 : PerformEmptyInit(ILE->getEndLoc(), BaseEntity);
635 if (BaseInit.isInvalid()) {
636 hadError = true;
637 return;
638 }
639
640 if (!VerifyOnly) {
641 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__
))
;
642 ILE->setInit(Init, BaseInit.getAs<Expr>());
643 }
644 } else if (InitListExpr *InnerILE =
645 dyn_cast<InitListExpr>(ILE->getInit(Init))) {
646 FillInEmptyInitializations(BaseEntity, InnerILE, RequiresSecondPass,
647 ILE, Init, FillWithNoInit);
648 } else if (DesignatedInitUpdateExpr *InnerDIUE =
649 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
650 FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
651 RequiresSecondPass, ILE, Init,
652 /*FillWithNoInit =*/true);
653 }
654}
655
656void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
657 const InitializedEntity &ParentEntity,
658 InitListExpr *ILE,
659 bool &RequiresSecondPass,
660 bool FillWithNoInit) {
661 SourceLocation Loc = ILE->getEndLoc();
662 unsigned NumInits = ILE->getNumInits();
663 InitializedEntity MemberEntity
664 = InitializedEntity::InitializeMember(Field, &ParentEntity);
665
666 if (Init >= NumInits || !ILE->getInit(Init)) {
667 if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
668 if (!RType->getDecl()->isUnion())
669 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__
))
670 "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__
))
;
671
672 if (FillWithNoInit) {
673 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__
))
;
674 Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
675 if (Init < NumInits)
676 ILE->setInit(Init, Filler);
677 else
678 ILE->updateInit(SemaRef.Context, Init, Filler);
679 return;
680 }
681 // C++1y [dcl.init.aggr]p7:
682 // If there are fewer initializer-clauses in the list than there are
683 // members in the aggregate, then each member not explicitly initialized
684 // shall be initialized from its brace-or-equal-initializer [...]
685 if (Field->hasInClassInitializer()) {
686 if (VerifyOnly)
687 return;
688
689 ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
690 if (DIE.isInvalid()) {
691 hadError = true;
692 return;
693 }
694 SemaRef.checkInitializerLifetime(MemberEntity, DIE.get());
695 if (Init < NumInits)
696 ILE->setInit(Init, DIE.get());
697 else {
698 ILE->updateInit(SemaRef.Context, Init, DIE.get());
699 RequiresSecondPass = true;
700 }
701 return;
702 }
703
704 if (Field->getType()->isReferenceType()) {
705 if (!VerifyOnly) {
706 // C++ [dcl.init.aggr]p9:
707 // If an incomplete or empty initializer-list leaves a
708 // member of reference type uninitialized, the program is
709 // ill-formed.
710 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
711 << Field->getType()
712 << (ILE->isSyntacticForm() ? ILE : ILE->getSyntacticForm())
713 ->getSourceRange();
714 SemaRef.Diag(Field->getLocation(), diag::note_uninit_reference_member);
715 }
716 hadError = true;
717 return;
718 }
719
720 ExprResult MemberInit = PerformEmptyInit(Loc, MemberEntity);
721 if (MemberInit.isInvalid()) {
722 hadError = true;
723 return;
724 }
725
726 if (hadError || VerifyOnly) {
727 // Do nothing
728 } else if (Init < NumInits) {
729 ILE->setInit(Init, MemberInit.getAs<Expr>());
730 } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
731 // Empty initialization requires a constructor call, so
732 // extend the initializer list to include the constructor
733 // call and make a note that we'll need to take another pass
734 // through the initializer list.
735 ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
736 RequiresSecondPass = true;
737 }
738 } else if (InitListExpr *InnerILE
739 = dyn_cast<InitListExpr>(ILE->getInit(Init))) {
740 FillInEmptyInitializations(MemberEntity, InnerILE,
741 RequiresSecondPass, ILE, Init, FillWithNoInit);
742 } else if (DesignatedInitUpdateExpr *InnerDIUE =
743 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
744 FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
745 RequiresSecondPass, ILE, Init,
746 /*FillWithNoInit =*/true);
747 }
748}
749
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,
755 InitListExpr *ILE,
756 bool &RequiresSecondPass,
757 InitListExpr *OuterILE,
758 unsigned OuterIndex,
759 bool FillWithNoInit) {
760 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__
))
761 "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__
))
;
762
763 // We don't need to do any checks when just filling NoInitExprs; that can't
764 // fail.
765 if (FillWithNoInit && VerifyOnly)
766 return;
767
768 // If this is a nested initializer list, we might have changed its contents
769 // (and therefore some of its properties, such as instantiation-dependence)
770 // while filling it in. Inform the outer initializer list so that its state
771 // can be updated to match.
772 // FIXME: We should fully build the inner initializers before constructing
773 // the outer InitListExpr instead of mutating AST nodes after they have
774 // been used as subexpressions of other nodes.
775 struct UpdateOuterILEWithUpdatedInit {
776 InitListExpr *Outer;
777 unsigned OuterIndex;
778 ~UpdateOuterILEWithUpdatedInit() {
779 if (Outer)
780 Outer->setInit(OuterIndex, Outer->getInit(OuterIndex));
781 }
782 } UpdateOuterRAII = {OuterILE, OuterIndex};
783
784 // A transparent ILE is not performing aggregate initialization and should
785 // not be filled in.
786 if (ILE->isTransparent())
787 return;
788
789 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
790 const RecordDecl *RDecl = RType->getDecl();
791 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
792 FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
793 Entity, ILE, RequiresSecondPass, FillWithNoInit);
794 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
795 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
796 for (auto *Field : RDecl->fields()) {
797 if (Field->hasInClassInitializer()) {
798 FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
799 FillWithNoInit);
800 break;
801 }
802 }
803 } else {
804 // The fields beyond ILE->getNumInits() are default initialized, so in
805 // order to leave them uninitialized, the ILE is expanded and the extra
806 // fields are then filled with NoInitExpr.
807 unsigned NumElems = numStructUnionElements(ILE->getType());
808 if (RDecl->hasFlexibleArrayMember())
809 ++NumElems;
810 if (!VerifyOnly && ILE->getNumInits() < NumElems)
811 ILE->resizeInits(SemaRef.Context, NumElems);
812
813 unsigned Init = 0;
814
815 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
816 for (auto &Base : CXXRD->bases()) {
817 if (hadError)
818 return;
819
820 FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
821 FillWithNoInit);
822 ++Init;
823 }
824 }
825
826 for (auto *Field : RDecl->fields()) {
827 if (Field->isUnnamedBitfield())
828 continue;
829
830 if (hadError)
831 return;
832
833 FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
834 FillWithNoInit);
835 if (hadError)
836 return;
837
838 ++Init;
839
840 // Only look at the first initialization of a union.
841 if (RDecl->isUnion())
842 break;
843 }
844 }
845
846 return;
847 }
848
849 QualType ElementType;
850
851 InitializedEntity ElementEntity = Entity;
852 unsigned NumInits = ILE->getNumInits();
853 unsigned NumElements = NumInits;
854 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
855 ElementType = AType->getElementType();
856 if (const auto *CAType = dyn_cast<ConstantArrayType>(AType))
857 NumElements = CAType->getSize().getZExtValue();
858 // For an array new with an unknown bound, ask for one additional element
859 // in order to populate the array filler.
860 if (Entity.isVariableLengthArrayNew())
861 ++NumElements;
862 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
863 0, Entity);
864 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
865 ElementType = VType->getElementType();
866 NumElements = VType->getNumElements();
867 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
868 0, Entity);
869 } else
870 ElementType = ILE->getType();
871
872 bool SkipEmptyInitChecks = false;
873 for (unsigned Init = 0; Init != NumElements; ++Init) {
874 if (hadError)
875 return;
876
877 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
878 ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
879 ElementEntity.setElementIndex(Init);
880
881 if (Init >= NumInits && (ILE->hasArrayFiller() || SkipEmptyInitChecks))
882 return;
883
884 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
885 if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
886 ILE->setInit(Init, ILE->getArrayFiller());
887 else if (!InitExpr && !ILE->hasArrayFiller()) {
888 // In VerifyOnly mode, there's no point performing empty initialization
889 // more than once.
890 if (SkipEmptyInitChecks)
891 continue;
892
893 Expr *Filler = nullptr;
894
895 if (FillWithNoInit)
896 Filler = new (SemaRef.Context) NoInitExpr(ElementType);
897 else {
898 ExprResult ElementInit =
899 PerformEmptyInit(ILE->getEndLoc(), ElementEntity);
900 if (ElementInit.isInvalid()) {
901 hadError = true;
902 return;
903 }
904
905 Filler = ElementInit.getAs<Expr>();
906 }
907
908 if (hadError) {
909 // Do nothing
910 } else if (VerifyOnly) {
911 SkipEmptyInitChecks = true;
912 } else if (Init < NumInits) {
913 // For arrays, just set the expression used for value-initialization
914 // of the "holes" in the array.
915 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
916 ILE->setArrayFiller(Filler);
917 else
918 ILE->setInit(Init, Filler);
919 } else {
920 // For arrays, just set the expression used for value-initialization
921 // of the rest of elements and exit.
922 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
923 ILE->setArrayFiller(Filler);
924 return;
925 }
926
927 if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
928 // Empty initialization requires a constructor call, so
929 // extend the initializer list to include the constructor
930 // call and make a note that we'll need to take another pass
931 // through the initializer list.
932 ILE->updateInit(SemaRef.Context, Init, Filler);
933 RequiresSecondPass = true;
934 }
935 }
936 } else if (InitListExpr *InnerILE
937 = dyn_cast_or_null<InitListExpr>(InitExpr)) {
938 FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
939 ILE, Init, FillWithNoInit);
940 } else if (DesignatedInitUpdateExpr *InnerDIUE =
941 dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr)) {
942 FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
943 RequiresSecondPass, ILE, Init,
944 /*FillWithNoInit =*/true);
945 }
946 }
947}
948
949static bool hasAnyDesignatedInits(const InitListExpr *IL) {
950 for (const Stmt *Init : *IL)
951 if (Init && isa<DesignatedInitExpr>(Init))
952 return true;
953 return false;
954}
955
956InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
957 InitListExpr *IL, QualType &T, bool VerifyOnly,
958 bool TreatUnavailableAsInvalid,
959 bool InOverloadResolution)
960 : SemaRef(S), VerifyOnly(VerifyOnly),
961 TreatUnavailableAsInvalid(TreatUnavailableAsInvalid),
962 InOverloadResolution(InOverloadResolution) {
963 if (!VerifyOnly || hasAnyDesignatedInits(IL)) {
964 FullyStructuredList =
965 createInitListExpr(T, IL->getSourceRange(), IL->getNumInits());
966
967 // FIXME: Check that IL isn't already the semantic form of some other
968 // InitListExpr. If it is, we'd create a broken AST.
969 if (!VerifyOnly)
970 FullyStructuredList->setSyntacticForm(IL);
971 }
972
973 CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
974 /*TopLevelObject=*/true);
975
976 if (!hadError && FullyStructuredList) {
977 bool RequiresSecondPass = false;
978 FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass,
979 /*OuterILE=*/nullptr, /*OuterIndex=*/0);
980 if (RequiresSecondPass && !hadError)
981 FillInEmptyInitializations(Entity, FullyStructuredList,
982 RequiresSecondPass, nullptr, 0);
983 }
984 if (hadError && FullyStructuredList)
985 FullyStructuredList->markError();
986}
987
988int InitListChecker::numArrayElements(QualType DeclType) {
989 // FIXME: use a proper constant
990 int maxElements = 0x7FFFFFFF;
991 if (const ConstantArrayType *CAT =
992 SemaRef.Context.getAsConstantArrayType(DeclType)) {
993 maxElements = static_cast<int>(CAT->getSize().getZExtValue());
994 }
995 return maxElements;
996}
997
998int InitListChecker::numStructUnionElements(QualType DeclType) {
999 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
1000 int InitializableMembers = 0;
1001 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
1002 InitializableMembers += CXXRD->getNumBases();
1003 for (const auto *Field : structDecl->fields())
1004 if (!Field->isUnnamedBitfield())
1005 ++InitializableMembers;
1006
1007 if (structDecl->isUnion())
1008 return std::min(InitializableMembers, 1);
1009 return InitializableMembers - structDecl->hasFlexibleArrayMember();
1010}
1011
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) {
1015 // Recursive initialization of the one and only field within an aggregate
1016 // class is considered idiomatic. This case arises in particular for
1017 // initialization of std::array, where the C++ standard suggests the idiom of
1018 //
1019 // std::array<T, N> arr = {1, 2, 3};
1020 //
1021 // (where std::array is an aggregate struct containing a single array field.
1022
1023 if (!Entity.getParent())
1024 return false;
1025
1026 // Allows elide brace initialization for aggregates with empty base.
1027 if (Entity.getKind() == InitializedEntity::EK_Base) {
1028 auto *ParentRD =
1029 Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
1030 CXXRecordDecl *CXXRD = cast<CXXRecordDecl>(ParentRD);
1031 return CXXRD->getNumBases() == 1 && CXXRD->field_empty();
1032 }
1033
1034 // Allow brace elision if the only subobject is a field.
1035 if (Entity.getKind() == InitializedEntity::EK_Member) {
1036 auto *ParentRD =
1037 Entity.getParent()->getType()->castAs<RecordType>()->getDecl();
1038 if (CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(ParentRD)) {
1039 if (CXXRD->getNumBases()) {
1040 return false;
1041 }
1042 }
1043 auto FieldIt = ParentRD->field_begin();
1044 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__
))
1045 "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__
))
;
1046 return ++FieldIt == ParentRD->field_end();
1047 }
1048
1049 return false;
1050}
1051
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,
1059 InitListExpr *ParentIList,
1060 QualType T, unsigned &Index,
1061 InitListExpr *StructuredList,
1062 unsigned &StructuredIndex) {
1063 int maxElements = 0;
1064
1065 if (T->isArrayType())
1066 maxElements = numArrayElements(T);
1067 else if (T->isRecordType())
1068 maxElements = numStructUnionElements(T);
1069 else if (T->isVectorType())
1070 maxElements = T->castAs<VectorType>()->getNumElements();
1071 else
1072 llvm_unreachable("CheckImplicitInitList(): Illegal type")::llvm::llvm_unreachable_internal("CheckImplicitInitList(): Illegal type"
, "clang/lib/Sema/SemaInit.cpp", 1072)
;
1073
1074 if (maxElements == 0) {
1075 if (!VerifyOnly)
1076 SemaRef.Diag(ParentIList->getInit(Index)->getBeginLoc(),
1077 diag::err_implicit_empty_initializer);
1078 ++Index;
1079 hadError = true;
1080 return;
1081 }
1082
1083 // Build a structured initializer list corresponding to this subobject.
1084 InitListExpr *StructuredSubobjectInitList = getStructuredSubobjectInit(
1085 ParentIList, Index, T, StructuredList, StructuredIndex,
1086 SourceRange(ParentIList->getInit(Index)->getBeginLoc(),
1087 ParentIList->getSourceRange().getEnd()));
1088 unsigned StructuredSubobjectInitIndex = 0;
1089
1090 // Check the element types and build the structural subobject.
1091 unsigned StartIndex = Index;
1092 CheckListElementTypes(Entity, ParentIList, T,
1093 /*SubobjectIsDesignatorContext=*/false, Index,
1094 StructuredSubobjectInitList,
1095 StructuredSubobjectInitIndex);
1096
1097 if (StructuredSubobjectInitList) {
1098 StructuredSubobjectInitList->setType(T);
1099
1100 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
1101 // Update the structured sub-object initializer so that it's ending
1102 // range corresponds with the end of the last initializer it used.
1103 if (EndIndex < ParentIList->getNumInits() &&
1104 ParentIList->getInit(EndIndex)) {
1105 SourceLocation EndLoc
1106 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
1107 StructuredSubobjectInitList->setRBraceLoc(EndLoc);
1108 }
1109
1110 // Complain about missing braces.
1111 if (!VerifyOnly && (T->isArrayType() || T->isRecordType()) &&
1112 !ParentIList->isIdiomaticZeroInitializer(SemaRef.getLangOpts()) &&
1113 !isIdiomaticBraceElisionEntity(Entity)) {
1114 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1115 diag::warn_missing_braces)
1116 << StructuredSubobjectInitList->getSourceRange()
1117 << FixItHint::CreateInsertion(
1118 StructuredSubobjectInitList->getBeginLoc(), "{")
1119 << FixItHint::CreateInsertion(
1120 SemaRef.getLocForEndOfToken(
1121 StructuredSubobjectInitList->getEndLoc()),
1122 "}");
1123 }
1124
1125 // Warn if this type won't be an aggregate in future versions of C++.
1126 auto *CXXRD = T->getAsCXXRecordDecl();
1127 if (!VerifyOnly && CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1128 SemaRef.Diag(StructuredSubobjectInitList->getBeginLoc(),
1129 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1130 << StructuredSubobjectInitList->getSourceRange() << T;
1131 }
1132 }
1133}
1134
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,
1138 SourceRange Braces) {
1139 // Don't warn during template instantiation. If the initialization was
1140 // non-dependent, we warned during the initial parse; otherwise, the
1141 // type might not be scalar in some uses of the template.
1142 if (S.inTemplateInstantiation())
1143 return;
1144
1145 unsigned DiagID = 0;
1146
1147 switch (Entity.getKind()) {
1148 case InitializedEntity::EK_VectorElement:
1149 case InitializedEntity::EK_ComplexElement:
1150 case InitializedEntity::EK_ArrayElement:
1151 case InitializedEntity::EK_Parameter:
1152 case InitializedEntity::EK_Parameter_CF_Audited:
1153 case InitializedEntity::EK_TemplateParameter:
1154 case InitializedEntity::EK_Result:
1155 // Extra braces here are suspicious.
1156 DiagID = diag::warn_braces_around_init;
1157 break;
1158
1159 case InitializedEntity::EK_Member:
1160 // Warn on aggregate initialization but not on ctor init list or
1161 // default member initializer.
1162 if (Entity.getParent())
1163 DiagID = diag::warn_braces_around_init;
1164 break;
1165
1166 case InitializedEntity::EK_Variable:
1167 case InitializedEntity::EK_LambdaCapture:
1168 // No warning, might be direct-list-initialization.
1169 // FIXME: Should we warn for copy-list-initialization in these cases?
1170 break;
1171
1172 case InitializedEntity::EK_New:
1173 case InitializedEntity::EK_Temporary:
1174 case InitializedEntity::EK_CompoundLiteralInit:
1175 // No warning, braces are part of the syntax of the underlying construct.
1176 break;
1177
1178 case InitializedEntity::EK_RelatedResult:
1179 // No warning, we already warned when initializing the result.
1180 break;
1181
1182 case InitializedEntity::EK_Exception:
1183 case InitializedEntity::EK_Base:
1184 case InitializedEntity::EK_Delegating:
1185 case InitializedEntity::EK_BlockElement:
1186 case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
1187 case InitializedEntity::EK_Binding:
1188 case InitializedEntity::EK_StmtExprResult:
1189 llvm_unreachable("unexpected braced scalar init")::llvm::llvm_unreachable_internal("unexpected braced scalar init"
, "clang/lib/Sema/SemaInit.cpp", 1189)
;
1190 }
1191
1192 if (DiagID) {
1193 S.Diag(Braces.getBegin(), DiagID)
1194 << Entity.getType()->isSizelessBuiltinType() << Braces
1195 << FixItHint::CreateRemoval(Braces.getBegin())
1196 << FixItHint::CreateRemoval(Braces.getEnd());
1197 }
1198}
1199
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,
1206 InitListExpr *IList, QualType &T,
1207 InitListExpr *StructuredList,
1208 bool TopLevelObject) {
1209 unsigned Index = 0, StructuredIndex = 0;
1210 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
1211 Index, StructuredList, StructuredIndex, TopLevelObject);
1212 if (StructuredList) {
1213 QualType ExprTy = T;
1214 if (!ExprTy->isArrayType())
1215 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
1216 if (!VerifyOnly)
1217 IList->setType(ExprTy);
1218 StructuredList->setType(ExprTy);
1219 }
1220 if (hadError)
1221 return;
1222
1223 // Don't complain for incomplete types, since we'll get an error elsewhere.
1224 if (Index < IList->getNumInits() && !T->isIncompleteType()) {
1225 // We have leftover initializers
1226 bool ExtraInitsIsError = SemaRef.getLangOpts().CPlusPlus ||
1227 (SemaRef.getLangOpts().OpenCL && T->isVectorType());
1228 hadError = ExtraInitsIsError;
1229 if (VerifyOnly) {
1230 return;
1231 } else if (StructuredIndex == 1 &&
1232 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
1233 SIF_None) {
1234 unsigned DK =
1235 ExtraInitsIsError
1236 ? diag::err_excess_initializers_in_char_array_initializer
1237 : diag::ext_excess_initializers_in_char_array_initializer;
1238 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1239 << IList->getInit(Index)->getSourceRange();
1240 } else if (T->isSizelessBuiltinType()) {
1241 unsigned DK = ExtraInitsIsError
1242 ? diag::err_excess_initializers_for_sizeless_type
1243 : diag::ext_excess_initializers_for_sizeless_type;
1244 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1245 << T << IList->getInit(Index)->getSourceRange();
1246 } else {
1247 int initKind = T->isArrayType() ? 0 :
1248 T->isVectorType() ? 1 :
1249 T->isScalarType() ? 2 :
1250 T->isUnionType() ? 3 :
1251 4;
1252
1253 unsigned DK = ExtraInitsIsError ? diag::err_excess_initializers
1254 : diag::ext_excess_initializers;
1255 SemaRef.Diag(IList->getInit(Index)->getBeginLoc(), DK)
1256 << initKind << IList->getInit(Index)->getSourceRange();
1257 }
1258 }
1259
1260 if (!VerifyOnly) {
1261 if (T->isScalarType() && IList->getNumInits() == 1 &&
1262 !isa<InitListExpr>(IList->getInit(0)))
1263 warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());
1264
1265 // Warn if this is a class type that won't be an aggregate in future
1266 // versions of C++.
1267 auto *CXXRD = T->getAsCXXRecordDecl();
1268 if (CXXRD && CXXRD->hasUserDeclaredConstructor()) {
1269 // Don't warn if there's an equivalent default constructor that would be
1270 // used instead.
1271 bool HasEquivCtor = false;
1272 if (IList->getNumInits() == 0) {
1273 auto *CD = SemaRef.LookupDefaultConstructor(CXXRD);
1274 HasEquivCtor = CD && !CD->isDeleted();
1275 }
1276
1277 if (!HasEquivCtor) {
1278 SemaRef.Diag(IList->getBeginLoc(),
1279 diag::warn_cxx20_compat_aggregate_init_with_ctors)
1280 << IList->getSourceRange() << T;
1281 }
1282 }
1283 }
1284}
1285
1286void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
1287 InitListExpr *IList,
1288 QualType &DeclType,
1289 bool SubobjectIsDesignatorContext,
1290 unsigned &Index,
1291 InitListExpr *StructuredList,
1292 unsigned &StructuredIndex,
1293 bool TopLevelObject) {
1294 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
1295 // Explicitly braced initializer for complex type can be real+imaginary
1296 // parts.
1297 CheckComplexType(Entity, IList, DeclType, Index,
1298 StructuredList, StructuredIndex);
1299 } else if (DeclType->isScalarType()) {
1300 CheckScalarType(Entity, IList, DeclType, Index,
1301 StructuredList, StructuredIndex);
1302 } else if (DeclType->isVectorType()) {
1303 CheckVectorType(Entity, IList, DeclType, Index,
1304 StructuredList, StructuredIndex);
1305 } else if (DeclType->isRecordType()) {
1306 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__
))
1307 "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__
))
;
1308 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
1309 auto Bases =
1310 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
1311 CXXRecordDecl::base_class_iterator());
1312 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1313 Bases = CXXRD->bases();
1314 CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
1315 SubobjectIsDesignatorContext, Index, StructuredList,
1316 StructuredIndex, TopLevelObject);
1317 } else if (DeclType->isArrayType()) {
1318 llvm::APSInt Zero(
1319 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
1320 false);
1321 CheckArrayType(Entity, IList, DeclType, Zero,
1322 SubobjectIsDesignatorContext, Index,
1323 StructuredList, StructuredIndex);
1324 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
1325 // This type is invalid, issue a diagnostic.
1326 ++Index;
1327 if (!VerifyOnly)
1328 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1329 << DeclType;
1330 hadError = true;
1331 } else if (DeclType->isReferenceType()) {
1332 CheckReferenceType(Entity, IList, DeclType, Index,
1333 StructuredList, StructuredIndex);
1334 } else if (DeclType->isObjCObjectType()) {
1335 if (!VerifyOnly)
1336 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_objc_class) << DeclType;
1337 hadError = true;
1338 } else if (DeclType->isOCLIntelSubgroupAVCType() ||
1339 DeclType->isSizelessBuiltinType()) {
1340 // Checks for scalar type are sufficient for these types too.
1341 CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1342 StructuredIndex);
1343 } else {
1344 if (!VerifyOnly)
1345 SemaRef.Diag(IList->getBeginLoc(), diag::err_illegal_initializer_type)
1346 << DeclType;
1347 hadError = true;
1348 }
1349}
1350
1351void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
1352 InitListExpr *IList,
1353 QualType ElemType,
1354 unsigned &Index,
1355 InitListExpr *StructuredList,
1356 unsigned &StructuredIndex,
1357 bool DirectlyDesignated) {
1358 Expr *expr = IList->getInit(Index);
1359
1360 if (ElemType->isReferenceType())
1361 return CheckReferenceType(Entity, IList, ElemType, Index,
1362 StructuredList, StructuredIndex);
1363
1364 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
1365 if (SubInitList->getNumInits() == 1 &&
1366 IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
1367 SIF_None) {
1368 // FIXME: It would be more faithful and no less correct to include an
1369 // InitListExpr in the semantic form of the initializer list in this case.
1370 expr = SubInitList->getInit(0);
1371 }
1372 // Nested aggregate initialization and C++ initialization are handled later.
1373 } else if (isa<ImplicitValueInitExpr>(expr)) {
1374 // This happens during template instantiation when we see an InitListExpr
1375 // that we've already checked once.
1376 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__
))
1377 "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__
))
;
1378 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1379 ++Index;
1380 return;
1381 }
1382
1383 if (SemaRef.getLangOpts().CPlusPlus || isa<InitListExpr>(expr)) {
1384 // C++ [dcl.init.aggr]p2:
1385 // Each member is copy-initialized from the corresponding
1386 // initializer-clause.
1387
1388 // FIXME: Better EqualLoc?
1389 InitializationKind Kind =
1390 InitializationKind::CreateCopy(expr->getBeginLoc(), SourceLocation());
1391
1392 // Vector elements can be initialized from other vectors in which case
1393 // we need initialization entity with a type of a vector (and not a vector
1394 // element!) initializing multiple vector elements.
1395 auto TmpEntity =
1396 (ElemType->isExtVectorType() && !Entity.getType()->isExtVectorType())
1397 ? InitializedEntity::InitializeTemporary(ElemType)
1398 : Entity;
1399
1400 InitializationSequence Seq(SemaRef, TmpEntity, Kind, expr,
1401 /*TopLevelOfInitList*/ true);
1402
1403 // C++14 [dcl.init.aggr]p13:
1404 // If the assignment-expression can initialize a member, the member is
1405 // initialized. Otherwise [...] brace elision is assumed
1406 //
1407 // Brace elision is never performed if the element is not an
1408 // assignment-expression.
1409 if (Seq || isa<InitListExpr>(expr)) {
1410 if (!VerifyOnly) {
1411 ExprResult Result = Seq.Perform(SemaRef, TmpEntity, Kind, expr);
1412 if (Result.isInvalid())
1413 hadError = true;
1414
1415 UpdateStructuredListElement(StructuredList, StructuredIndex,
1416 Result.getAs<Expr>());
1417 } else if (!Seq) {
1418 hadError = true;
1419 } else if (StructuredList) {
1420 UpdateStructuredListElement(StructuredList, StructuredIndex,
1421 getDummyInit());
1422 }
1423 ++Index;
1424 return;
1425 }
1426
1427 // Fall through for subaggregate initialization
1428 } else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
1429 // FIXME: Need to handle atomic aggregate types with implicit init lists.
1430 return CheckScalarType(Entity, IList, ElemType, Index,
1431 StructuredList, StructuredIndex);
1432 } else if (const ArrayType *arrayType =
1433 SemaRef.Context.getAsArrayType(ElemType)) {
1434 // arrayType can be incomplete if we're initializing a flexible
1435 // array member. There's nothing we can do with the completed
1436 // type here, though.
1437
1438 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
1439 // FIXME: Should we do this checking in verify-only mode?
1440 if (!VerifyOnly)
1441 CheckStringInit(expr, ElemType, arrayType, SemaRef);
1442 if (StructuredList)
1443 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1444 ++Index;
1445 return;
1446 }
1447
1448 // Fall through for subaggregate initialization.
1449
1450 } else {
1451 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__
))
1452 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__
))
;
1453
1454 // C99 6.7.8p13:
1455 //
1456 // The initializer for a structure or union object that has
1457 // automatic storage duration shall be either an initializer
1458 // list as described below, or a single expression that has
1459 // compatible structure or union type. In the latter case, the
1460 // initial value of the object, including unnamed members, is
1461 // that of the expression.
1462 ExprResult ExprRes = expr;
1463 if (SemaRef.CheckSingleAssignmentConstraints(
1464 ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
1465 if (ExprRes.isInvalid())
1466 hadError = true;
1467 else {
1468 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
1469 if (ExprRes.isInvalid())
1470 hadError = true;
1471 }
1472 UpdateStructuredListElement(StructuredList, StructuredIndex,
1473 ExprRes.getAs<Expr>());
1474 ++Index;
1475 return;
1476 }
1477 ExprRes.get();
1478 // Fall through for subaggregate initialization
1479 }
1480
1481 // C++ [dcl.init.aggr]p12:
1482 //
1483 // [...] Otherwise, if the member is itself a non-empty
1484 // subaggregate, brace elision is assumed and the initializer is
1485 // considered for the initialization of the first member of
1486 // the subaggregate.
1487 // OpenCL vector initializer is handled elsewhere.
1488 if ((!SemaRef.getLangOpts().OpenCL && ElemType->isVectorType()) ||
1489 ElemType->isAggregateType()) {
1490 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
1491 StructuredIndex);
1492 ++StructuredIndex;
1493
1494 // In C++20, brace elision is not permitted for a designated initializer.
1495 if (DirectlyDesignated && SemaRef.getLangOpts().CPlusPlus && !hadError) {
1496 if (InOverloadResolution)
1497 hadError = true;
1498 if (!VerifyOnly) {
1499 SemaRef.Diag(expr->getBeginLoc(),
1500 diag::ext_designated_init_brace_elision)
1501 << expr->getSourceRange()
1502 << FixItHint::CreateInsertion(expr->getBeginLoc(), "{")
1503 << FixItHint::CreateInsertion(
1504 SemaRef.getLocForEndOfToken(expr->getEndLoc()), "}");
1505 }
1506 }
1507 } else {
1508 if (!VerifyOnly) {
1509 // We cannot initialize this element, so let PerformCopyInitialization
1510 // produce the appropriate diagnostic. We already checked that this
1511 // initialization will fail.
1512 ExprResult Copy =
1513 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
1514 /*TopLevelOfInitList=*/true);
1515 (void)Copy;
1516 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__
))
1517 "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__
))
;
1518 }
1519 hadError = true;
1520 ++Index;
1521 ++StructuredIndex;
1522 }
1523}
1524
1525void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
1526 InitListExpr *IList, QualType DeclType,
1527 unsigned &Index,
1528 InitListExpr *StructuredList,
1529 unsigned &StructuredIndex) {
1530 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__
))
;
1531
1532 // As an extension, clang supports complex initializers, which initialize
1533 // a complex number component-wise. When an explicit initializer list for
1534 // a complex number contains two initializers, this extension kicks in:
1535 // it expects the initializer list to contain two elements convertible to
1536 // the element type of the complex type. The first element initializes
1537 // the real part, and the second element intitializes the imaginary part.
1538
1539 if (IList->getNumInits() < 2)
1540 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1541 StructuredIndex);
1542
1543 // This is an extension in C. (The builtin _Complex type does not exist
1544 // in the C++ standard.)
1545 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
1546 SemaRef.Diag(IList->getBeginLoc(), diag::ext_complex_component_init)
1547 << IList->getSourceRange();
1548
1549 // Initialize the complex number.
1550 QualType elementType = DeclType->castAs<ComplexType>()->getElementType();
1551 InitializedEntity ElementEntity =
1552 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1553
1554 for (unsigned i = 0; i < 2; ++i) {
1555 ElementEntity.setElementIndex(Index);
1556 CheckSubElementType(ElementEntity, IList, elementType, Index,
1557 StructuredList, StructuredIndex);
1558 }
1559}
1560
1561void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
1562 InitListExpr *IList, QualType DeclType,
1563 unsigned &Index,
1564 InitListExpr *StructuredList,
1565 unsigned &StructuredIndex) {
1566 if (Index >= IList->getNumInits()) {
1567 if (!VerifyOnly) {
1568 if (DeclType->isSizelessBuiltinType())
1569 SemaRef.Diag(IList->getBeginLoc(),
1570 SemaRef.getLangOpts().CPlusPlus11
1571 ? diag::warn_cxx98_compat_empty_sizeless_initializer
1572 : diag::err_empty_sizeless_initializer)
1573 << DeclType << IList->getSourceRange();
1574 else
1575 SemaRef.Diag(IList->getBeginLoc(),
1576 SemaRef.getLangOpts().CPlusPlus11
1577 ? diag::warn_cxx98_compat_empty_scalar_initializer
1578 : diag::err_empty_scalar_initializer)
1579 << IList->getSourceRange();
1580 }
1581 hadError = !SemaRef.getLangOpts().CPlusPlus11;
1582 ++Index;
1583 ++StructuredIndex;
1584 return;
1585 }
1586
1587 Expr *expr = IList->getInit(Index);
1588 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
1589 // FIXME: This is invalid, and accepting it causes overload resolution
1590 // to pick the wrong overload in some corner cases.
1591 if (!VerifyOnly)
1592 SemaRef.Diag(SubIList->getBeginLoc(), diag::ext_many_braces_around_init)
1593 << DeclType->isSizelessBuiltinType() << SubIList->getSourceRange();
1594
1595 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
1596 StructuredIndex);
1597 return;
1598 } else if (isa<DesignatedInitExpr>(expr)) {
1599 if (!VerifyOnly)
1600 SemaRef.Diag(expr->getBeginLoc(),
1601 diag::err_designator_for_scalar_or_sizeless_init)
1602 << DeclType->isSizelessBuiltinType() << DeclType
1603 << expr->getSourceRange();
1604 hadError = true;
1605 ++Index;
1606 ++StructuredIndex;
1607 return;
1608 }
1609
1610 ExprResult Result;
1611 if (VerifyOnly) {
1612 if (SemaRef.CanPerformCopyInitialization(Entity, expr))
1613 Result = getDummyInit();
1614 else
1615 Result = ExprError();
1616 } else {
1617 Result =
1618 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1619 /*TopLevelOfInitList=*/true);
1620 }
1621
1622 Expr *ResultExpr = nullptr;
1623
1624 if (Result.isInvalid())
1625 hadError = true; // types weren't compatible.
1626 else {
1627 ResultExpr = Result.getAs<Expr>();
1628
1629 if (ResultExpr != expr && !VerifyOnly) {
1630 // The type was promoted, update initializer list.
1631 // FIXME: Why are we updating the syntactic init list?
1632 IList->setInit(Index, ResultExpr);
1633 }
1634 }
1635 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1636 ++Index;
1637}
1638
1639void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
1640 InitListExpr *IList, QualType DeclType,
1641 unsigned &Index,
1642 InitListExpr *StructuredList,
1643 unsigned &StructuredIndex) {
1644 if (Index >= IList->getNumInits()) {
1645 // FIXME: It would be wonderful if we could point at the actual member. In
1646 // general, it would be useful to pass location information down the stack,
1647 // so that we know the location (or decl) of the "current object" being
1648 // initialized.
1649 if (!VerifyOnly)
1650 SemaRef.Diag(IList->getBeginLoc(),
1651 diag::err_init_reference_member_uninitialized)
1652 << DeclType << IList->getSourceRange();
1653 hadError = true;
1654 ++Index;
1655 ++StructuredIndex;
1656 return;
1657 }
1658
1659 Expr *expr = IList->getInit(Index);
1660 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
1661 if (!VerifyOnly)
1662 SemaRef.Diag(IList->getBeginLoc(), diag::err_init_non_aggr_init_list)
1663 << DeclType << IList->getSourceRange();
1664 hadError = true;
1665 ++Index;
1666 ++StructuredIndex;
1667 return;
1668 }
1669
1670 ExprResult Result;
1671 if (VerifyOnly) {
1672 if (SemaRef.CanPerformCopyInitialization(Entity,expr))
1673 Result = getDummyInit();
1674 else
1675 Result = ExprError();
1676 } else {
1677 Result =
1678 SemaRef.PerformCopyInitialization(Entity, expr->getBeginLoc(), expr,
1679 /*TopLevelOfInitList=*/true);
1680 }
1681
1682 if (Result.isInvalid())
1683 hadError = true;
1684
1685 expr = Result.getAs<Expr>();
1686 // FIXME: Why are we updating the syntactic init list?
1687 if (!VerifyOnly && expr)
1688 IList->setInit(Index, expr);
1689
1690 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1691 ++Index;
1692}
1693
1694void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
1695 InitListExpr *IList, QualType DeclType,
1696 unsigned &Index,
1697 InitListExpr *StructuredList,
1698 unsigned &StructuredIndex) {
1699 const VectorType *VT = DeclType->castAs<VectorType>();
1700 unsigned maxElements = VT->getNumElements();
1701 unsigned numEltsInit = 0;
1702 QualType elementType = VT->getElementType();
1703
1704 if (Index >= IList->getNumInits()) {
1705 // Make sure the element type can be value-initialized.
1706 CheckEmptyInitializable(
1707 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1708 IList->getEndLoc());
1709 return;
1710 }
1711
1712 if (!SemaRef.getLangOpts().OpenCL && !SemaRef.getLangOpts().HLSL ) {
1713 // If the initializing element is a vector, try to copy-initialize
1714 // instead of breaking it apart (which is doomed to failure anyway).
1715 Expr *Init = IList->getInit(Index);
1716 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
1717 ExprResult Result;
1718 if (VerifyOnly) {
1719 if (SemaRef.CanPerformCopyInitialization(Entity, Init))
1720 Result = getDummyInit();
1721 else
1722 Result = ExprError();
1723 } else {
1724 Result =
1725 SemaRef.PerformCopyInitialization(Entity, Init->getBeginLoc(), Init,
1726 /*TopLevelOfInitList=*/true);
1727 }
1728
1729 Expr *ResultExpr = nullptr;
1730 if (Result.isInvalid())
1731 hadError = true; // types weren't compatible.
1732 else {
1733 ResultExpr = Result.getAs<Expr>();
1734
1735 if (ResultExpr != Init && !VerifyOnly) {
1736 // The type was promoted, update initializer list.
1737 // FIXME: Why are we updating the syntactic init list?
1738 IList->setInit(Index, ResultExpr);
1739 }
1740 }
1741 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1742 ++Index;
1743 return;
1744 }
1745
1746 InitializedEntity ElementEntity =
1747 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1748
1749 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
1750 // Don't attempt to go past the end of the init list
1751 if (Index >= IList->getNumInits()) {
1752 CheckEmptyInitializable(ElementEntity, IList->getEndLoc());
1753 break;
1754 }
1755
1756 ElementEntity.setElementIndex(Index);
1757 CheckSubElementType(ElementEntity, IList, elementType, Index,
1758 StructuredList, StructuredIndex);
1759 }
1760
1761 if (VerifyOnly)
1762 return;
1763
1764 bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
1765 const VectorType *T = Entity.getType()->castAs<VectorType>();
1766 if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
1767 T->getVectorKind() == VectorType::NeonPolyVector)) {
1768 // The ability to use vector initializer lists is a GNU vector extension
1769 // and is unrelated to the NEON intrinsics in arm_neon.h. On little
1770 // endian machines it works fine, however on big endian machines it
1771 // exhibits surprising behaviour:
1772 //
1773 // uint32x2_t x = {42, 64};
1774 // return vget_lane_u32(x, 0); // Will return 64.
1775 //
1776 // Because of this, explicitly call out that it is non-portable.
1777 //
1778 SemaRef.Diag(IList->getBeginLoc(),
1779 diag::warn_neon_vector_initializer_non_portable);
1780
1781 const char *typeCode;
1782 unsigned typeSize = SemaRef.Context.getTypeSize(elementType);
1783
1784 if (elementType->isFloatingType())
1785 typeCode = "f";
1786 else if (elementType->isSignedIntegerType())
1787 typeCode = "s";
1788 else if (elementType->isUnsignedIntegerType())
1789 typeCode = "u";
1790 else
1791 llvm_unreachable("Invalid element type!")::llvm::llvm_unreachable_internal("Invalid element type!", "clang/lib/Sema/SemaInit.cpp"
, 1791)
;
1792
1793 SemaRef.Diag(IList->getBeginLoc(),
1794 SemaRef.Context.getTypeSize(VT) > 64
1795 ? diag::note_neon_vector_initializer_non_portable_q
1796 : diag::note_neon_vector_initializer_non_portable)
1797 << typeCode << typeSize;
1798 }
1799
1800 return;
1801 }
1802
1803 InitializedEntity ElementEntity =
1804 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1805
1806 // OpenCL and HLSL initializers allow vectors to be constructed from vectors.
1807 for (unsigned i = 0; i < maxElements; ++i) {
1808 // Don't attempt to go past the end of the init list
1809 if (Index >= IList->getNumInits())
1810 break;
1811
1812 ElementEntity.setElementIndex(Index);
1813
1814 QualType IType = IList->getInit(Index)->getType();
1815 if (!IType->isVectorType()) {
1816 CheckSubElementType(ElementEntity, IList, elementType, Index,
1817 StructuredList, StructuredIndex);
1818 ++numEltsInit;
1819 } else {
1820 QualType VecType;
1821 const VectorType *IVT = IType->castAs<VectorType>();
1822 unsigned numIElts = IVT->getNumElements();
1823
1824 if (IType->isExtVectorType())
1825 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
1826 else
1827 VecType = SemaRef.Context.getVectorType(elementType, numIElts,
1828 IVT->getVectorKind());
1829 CheckSubElementType(ElementEntity, IList, VecType, Index,
1830 StructuredList, StructuredIndex);
1831 numEltsInit += numIElts;
1832 }
1833 }
1834
1835 // OpenCL and HLSL require all elements to be initialized.
1836 if (numEltsInit != maxElements) {
1837 if (!VerifyOnly)
1838 SemaRef.Diag(IList->getBeginLoc(),
1839 diag::err_vector_incorrect_num_initializers)
1840 << (numEltsInit < maxElements) << maxElements << numEltsInit;
1841 hadError = true;
1842 }
1843}
1844
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,
1856 Sema &SemaRef) {
1857 auto *CXXRD = ElementType->getAsCXXRecordDecl();
1858 if (!CXXRD)
1859 return false;
1860
1861 CXXDestructorDecl *Destructor = SemaRef.LookupDestructor(CXXRD);
1862 SemaRef.CheckDestructorAccess(Loc, Destructor,
1863 SemaRef.PDiag(diag::err_access_dtor_temp)
1864 << ElementType);
1865 SemaRef.MarkFunctionReferenced(Loc, Destructor);
1866 return SemaRef.DiagnoseUseOfDecl(Destructor, Loc);
1867}
1868
1869void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
1870 InitListExpr *IList, QualType &DeclType,
1871 llvm::APSInt elementIndex,
1872 bool SubobjectIsDesignatorContext,
1873 unsigned &Index,
1874 InitListExpr *StructuredList,
1875 unsigned &StructuredIndex) {
1876 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);
1877
1878 if (!VerifyOnly) {
1879 if (checkDestructorReference(arrayType->getElementType(),
1880 IList->getEndLoc(), SemaRef)) {
1881 hadError = true;
1882 return;
1883 }
1884 }
1885
1886 // Check for the special-case of initializing an array with a string.
1887 if (Index < IList->getNumInits()) {
1888 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
1889 SIF_None) {
1890 // We place the string literal directly into the resulting
1891 // initializer list. This is the only place where the structure
1892 // of the structured initializer list doesn't match exactly,
1893 // because doing so would involve allocating one character
1894 // constant for each string.
1895 // FIXME: Should we do these checks in verify-only mode too?
1896 if (!VerifyOnly)
1897 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
1898 if (StructuredList) {
1899 UpdateStructuredListElement(StructuredList, StructuredIndex,
1900 IList->getInit(Index));
1901 StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
1902 }
1903 ++Index;
1904 return;
1905 }
1906 }
1907 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
1908 // Check for VLAs; in standard C it would be possible to check this
1909 // earlier, but I don't know where clang accepts VLAs (gcc accepts
1910 // them in all sorts of strange places).
1911 if (!VerifyOnly)
1912 SemaRef.Diag(VAT->getSizeExpr()->getBeginLoc(),
1913 diag::err_variable_object_no_init)
1914 << VAT->getSizeExpr()->getSourceRange();
1915 hadError = true;
1916 ++Index;
1917 ++StructuredIndex;
1918 return;
1919 }
1920
1921 // We might know the maximum number of elements in advance.
1922 llvm::APSInt maxElements(elementIndex.getBitWidth(),
1923 elementIndex.isUnsigned());
1924 bool maxElementsKnown = false;
1925 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
1926 maxElements = CAT->getSize();
1927 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
1928 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1929 maxElementsKnown = true;
1930 }
1931
1932 QualType elementType = arrayType->getElementType();
1933 while (Index < IList->getNumInits()) {
1934 Expr *Init = IList->getInit(Index);
1935 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
1936 // If we're not the subobject that matches up with the '{' for
1937 // the designator, we shouldn't be handling the
1938 // designator. Return immediately.
1939 if (!SubobjectIsDesignatorContext)
1940 return;
1941
1942 // Handle this designated initializer. elementIndex will be
1943 // updated to be the next array element we'll initialize.
1944 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
1945 DeclType, nullptr, &elementIndex, Index,
1946 StructuredList, StructuredIndex, true,
1947 false)) {
1948 hadError = true;
1949 continue;
1950 }
1951
1952 if (elementIndex.getBitWidth() > maxElements.getBitWidth())
1953 maxElements = maxElements.extend(elementIndex.getBitWidth());
1954 else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
1955 elementIndex = elementIndex.extend(maxElements.getBitWidth());
1956 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1957
1958 // If the array is of incomplete type, keep track of the number of
1959 // elements in the initializer.
1960 if (!maxElementsKnown && elementIndex > maxElements)
1961 maxElements = elementIndex;
1962
1963 continue;
1964 }
1965
1966 // If we know the maximum number of elements, and we've already
1967 // hit it, stop consuming elements in the initializer list.
1968 if (maxElementsKnown && elementIndex == maxElements)
1969 break;
1970
1971 InitializedEntity ElementEntity =
1972 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
1973 Entity);
1974 // Check this element.
1975 CheckSubElementType(ElementEntity, IList, elementType, Index,
1976 StructuredList, StructuredIndex);
1977 ++elementIndex;
1978
1979 // If the array is of incomplete type, keep track of the number of
1980 // elements in the initializer.
1981 if (!maxElementsKnown && elementIndex > maxElements)
1982 maxElements = elementIndex;
1983 }
1984 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
1985 // If this is an incomplete array type, the actual type needs to
1986 // be calculated here.
1987 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
1988 if (maxElements == Zero && !Entity.isVariableLengthArrayNew()) {
1989 // Sizing an array implicitly to zero is not allowed by ISO C,
1990 // but is supported by GNU.
1991 SemaRef.Diag(IList->getBeginLoc(), diag::ext_typecheck_zero_array_size);
1992 }
1993
1994 DeclType = SemaRef.Context.getConstantArrayType(
1995 elementType, maxElements, nullptr, ArrayType::Normal, 0);
1996 }
1997 if (!hadError) {
1998 // If there are any members of the array that get value-initialized, check
1999 // that is possible. That happens if we know the bound and don't have
2000 // enough elements, or if we're performing an array new with an unknown
2001 // bound.
2002 if ((maxElementsKnown && elementIndex < maxElements) ||
2003 Entity.isVariableLengthArrayNew())
2004 CheckEmptyInitializable(
2005 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
2006 IList->getEndLoc());
2007 }
2008}
2009
2010bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
2011 Expr *InitExpr,
2012 FieldDecl *Field,
2013 bool TopLevelObject) {
2014 // Handle GNU flexible array initializers.
2015 unsigned FlexArrayDiag;
2016 if (isa<InitListExpr>(InitExpr) &&
2017 cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
2018 // Empty flexible array init always allowed as an extension
2019 FlexArrayDiag = diag::ext_flexible_array_init;
2020 } else if (!TopLevelObject) {
2021 // Disallow flexible array init on non-top-level object
2022 FlexArrayDiag = diag::err_flexible_array_init;
2023 } else if (Entity.getKind() != InitializedEntity::EK_Variable) {
2024 // Disallow flexible array init on anything which is not a variable.
2025 FlexArrayDiag = diag::err_flexible_array_init;
2026 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
2027 // Disallow flexible array init on local variables.
2028 FlexArrayDiag = diag::err_flexible_array_init;
2029 } else {
2030 // Allow other cases.
2031 FlexArrayDiag = diag::ext_flexible_array_init;
2032 }
2033
2034 if (!VerifyOnly) {
2035 SemaRef.Diag(InitExpr->getBeginLoc(), FlexArrayDiag)
2036 << InitExpr->getBeginLoc();
2037 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2038 << Field;
2039 }
2040
2041 return FlexArrayDiag != diag::ext_flexible_array_init;
2042}
2043
2044void InitListChecker::CheckStructUnionTypes(
2045 const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
2046 CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
2047 bool SubobjectIsDesignatorContext, unsigned &Index,
2048 InitListExpr *StructuredList, unsigned &StructuredIndex,
2049 bool TopLevelObject) {
2050 RecordDecl *structDecl = DeclType->castAs<RecordType>()->getDecl();
2051
2052 // If the record is invalid, some of it's members are invalid. To avoid
2053 // confusion, we forgo checking the initializer for the entire record.
2054 if (structDecl->isInvalidDecl()) {
2055 // Assume it was supposed to consume a single initializer.
2056 ++Index;
2057 hadError = true;
2058 return;
2059 }
2060
2061 if (DeclType->isUnionType() && IList->getNumInits() == 0) {
2062 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2063
2064 if (!VerifyOnly)
2065 for (FieldDecl *FD : RD->fields()) {
2066 QualType ET = SemaRef.Context.getBaseElementType(FD->getType());
2067 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2068 hadError = true;
2069 return;
2070 }
2071 }
2072
2073 // If there's a default initializer, use it.
2074 if (isa<CXXRecordDecl>(RD) &&
2075 cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
2076 if (!StructuredList)
2077 return;
2078 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2079 Field != FieldEnd; ++Field) {
2080 if (Field->hasInClassInitializer()) {
2081 StructuredList->setInitializedFieldInUnion(*Field);
2082 // FIXME: Actually build a CXXDefaultInitExpr?
2083 return;
2084 }
2085 }
2086 }
2087
2088 // Value-initialize the first member of the union that isn't an unnamed
2089 // bitfield.
2090 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
2091 Field != FieldEnd; ++Field) {
2092 if (!Field->isUnnamedBitfield()) {
2093 CheckEmptyInitializable(
2094 InitializedEntity::InitializeMember(*Field, &Entity),
2095 IList->getEndLoc());
2096 if (StructuredList)
2097 StructuredList->setInitializedFieldInUnion(*Field);
2098 break;
2099 }
2100 }
2101 return;
2102 }
2103
2104 bool InitializedSomething = false;
2105
2106 // If we have any base classes, they are initialized prior to the fields.
2107 for (auto &Base : Bases) {
2108 Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;
2109
2110 // Designated inits always initialize fields, so if we see one, all
2111 // remaining base classes have no explicit initializer.
2112 if (Init && isa<DesignatedInitExpr>(Init))
2113 Init = nullptr;
2114
2115 SourceLocation InitLoc = Init ? Init->getBeginLoc() : IList->getEndLoc();
2116 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
2117 SemaRef.Context, &Base, false, &Entity);
2118 if (Init) {
2119 CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
2120 StructuredList, StructuredIndex);
2121 InitializedSomething = true;
2122 } else {
2123 CheckEmptyInitializable(BaseEntity, InitLoc);
2124 }
2125
2126 if (!VerifyOnly)
2127 if (checkDestructorReference(Base.getType(), InitLoc, SemaRef)) {
2128 hadError = true;
2129 return;
2130 }
2131 }
2132
2133 // If structDecl is a forward declaration, this loop won't do
2134 // anything except look at designated initializers; That's okay,
2135 // because an error should get printed out elsewhere. It might be
2136 // worthwhile to skip over the rest of the initializer, though.
2137 RecordDecl *RD = DeclType->castAs<RecordType>()->getDecl();
2138 RecordDecl::field_iterator FieldEnd = RD->field_end();
2139 size_t NumRecordDecls = llvm::count_if(RD->decls(), [&](const Decl *D) {
2140 return isa<FieldDecl>(D) || isa<RecordDecl>(D);
2141 });
2142 bool CheckForMissingFields =
2143 !IList->isIdiomaticZeroInitializer(SemaRef.getLangOpts());
2144 bool HasDesignatedInit = false;
2145
2146 while (Index < IList->getNumInits()) {
2147 Expr *Init = IList->getInit(Index);
2148 SourceLocation InitLoc = Init->getBeginLoc();
2149
2150 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
2151 // If we're not the subobject that matches up with the '{' for
2152 // the designator, we shouldn't be handling the
2153 // designator. Return immediately.
2154 if (!SubobjectIsDesignatorContext)
2155 return;
2156
2157 HasDesignatedInit = true;
2158
2159 // Handle this designated initializer. Field will be updated to
2160 // the next field that we'll be initializing.
2161 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
2162 DeclType, &Field, nullptr, Index,
2163 StructuredList, StructuredIndex,
2164 true, TopLevelObject))
2165 hadError = true;
2166 else if (!VerifyOnly) {
2167 // Find the field named by the designated initializer.
2168 RecordDecl::field_iterator F = RD->field_begin();
2169 while (std::next(F) != Field)
2170 ++F;
2171 QualType ET = SemaRef.Context.getBaseElementType(F->getType());
2172 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2173 hadError = true;
2174 return;
2175 }
2176 }
2177
2178 InitializedSomething = true;
2179
2180 // Disable check for missing fields when designators are used.
2181 // This matches gcc behaviour.
2182 CheckForMissingFields = false;
2183 continue;
2184 }
2185
2186 // Check if this is an initializer of forms:
2187 //
2188 // struct foo f = {};
2189 // struct foo g = {0};
2190 //
2191 // These are okay for randomized structures. [C99 6.7.8p19]
2192 //
2193 // Also, if there is only one element in the structure, we allow something
2194 // like this, because it's really not randomized in the tranditional sense.
2195 //
2196 // struct foo h = {bar};
2197 auto IsZeroInitializer = [&](const Expr *I) {
2198 if (IList->getNumInits() == 1) {
2199 if (NumRecordDecls == 1)
2200 return true;
2201 if (const auto *IL = dyn_cast<IntegerLiteral>(I))
2202 return IL->getValue().isZero();
2203 }
2204 return false;
2205 };
2206
2207 // Don't allow non-designated initializers on randomized structures.
2208 if (RD->isRandomized() && !IsZeroInitializer(Init)) {
2209 if (!VerifyOnly)
2210 SemaRef.Diag(InitLoc, diag::err_non_designated_init_used);
2211 hadError = true;
2212 break;
2213 }
2214
2215 if (Field == FieldEnd) {
2216 // We've run out of fields. We're done.
2217 break;
2218 }
2219
2220 // We've already initialized a member of a union. We're done.
2221 if (InitializedSomething && DeclType->isUnionType())
2222 break;
2223
2224 // If we've hit the flexible array member at the end, we're done.
2225 if (Field->getType()->isIncompleteArrayType())
2226 break;
2227
2228 if (Field->isUnnamedBitfield()) {
2229 // Don't initialize unnamed bitfields, e.g. "int : 20;"
2230 ++Field;
2231 continue;
2232 }
2233
2234 // Make sure we can use this declaration.
2235 bool InvalidUse;
2236 if (VerifyOnly)
2237 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2238 else
2239 InvalidUse = SemaRef.DiagnoseUseOfDecl(
2240 *Field, IList->getInit(Index)->getBeginLoc());
2241 if (InvalidUse) {
2242 ++Index;
2243 ++Field;
2244 hadError = true;
2245 continue;
2246 }
2247
2248 if (!VerifyOnly) {
2249 QualType ET = SemaRef.Context.getBaseElementType(Field->getType());
2250 if (checkDestructorReference(ET, InitLoc, SemaRef)) {
2251 hadError = true;
2252 return;
2253 }
2254 }
2255
2256 InitializedEntity MemberEntity =
2257 InitializedEntity::InitializeMember(*Field, &Entity);
2258 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2259 StructuredList, StructuredIndex);
2260 InitializedSomething = true;
2261
2262 if (DeclType->isUnionType() && StructuredList) {
2263 // Initialize the first field within the union.
2264 StructuredList->setInitializedFieldInUnion(*Field);
2265 }
2266
2267 ++Field;
2268 }
2269
2270 // Emit warnings for missing struct field initializers.
2271 if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
2272 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
2273 !DeclType->isUnionType()) {
2274 // It is possible we have one or more unnamed bitfields remaining.
2275 // Find first (if any) named field and emit warning.
2276 for (RecordDecl::field_iterator it = Field, end = RD->field_end();
2277 it != end; ++it) {
2278 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
2279 SemaRef.Diag(IList->getSourceRange().getEnd(),
2280 diag::warn_missing_field_initializers) << *it;
2281 break;
2282 }
2283 }
2284 }
2285
2286 // Check that any remaining fields can be value-initialized if we're not
2287 // building a structured list. (If we are, we'll check this later.)
2288 if (!StructuredList && Field != FieldEnd && !DeclType->isUnionType() &&
2289 !Field->getType()->isIncompleteArrayType()) {
2290 for (; Field != FieldEnd && !hadError; ++Field) {
2291 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
2292 CheckEmptyInitializable(
2293 InitializedEntity::InitializeMember(*Field, &Entity),
2294 IList->getEndLoc());
2295 }
2296 }
2297
2298 // Check that the types of the remaining fields have accessible destructors.
2299 if (!VerifyOnly) {
2300 // If the initializer expression has a designated initializer, check the
2301 // elements for which a designated initializer is not provided too.
2302 RecordDecl::field_iterator I = HasDesignatedInit ? RD->field_begin()
2303 : Field;
2304 for (RecordDecl::field_iterator E = RD->field_end(); I != E; ++I) {
2305 QualType ET = SemaRef.Context.getBaseElementType(I->getType());
2306 if (checkDestructorReference(ET, IList->getEndLoc(), SemaRef)) {
2307 hadError = true;
2308 return;
2309 }
2310 }
2311 }
2312
2313 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
2314 Index >= IList->getNumInits())
2315 return;
2316
2317 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
2318 TopLevelObject)) {
2319 hadError = true;
2320 ++Index;
2321 return;
2322 }
2323
2324 InitializedEntity MemberEntity =
2325 InitializedEntity::InitializeMember(*Field, &Entity);
2326
2327 if (isa<InitListExpr>(IList->getInit(Index)))
2328 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2329 StructuredList, StructuredIndex);
2330 else
2331 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
2332 StructuredList, StructuredIndex);
2333}
2334
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,
2340 DesignatedInitExpr *DIE,
2341 unsigned DesigIdx,
2342 IndirectFieldDecl *IndirectField) {
2343 typedef DesignatedInitExpr::Designator Designator;
2344
2345 // Build the replacement designators.
2346 SmallVector<Designator, 4> Replacements;
2347 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
2348 PE = IndirectField->chain_end(); PI != PE; ++PI) {
2349 if (PI + 1 == PE)
2350 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2351 DIE->getDesignator(DesigIdx)->getDotLoc(),
2352 DIE->getDesignator(DesigIdx)->getFieldLoc()));
2353 else
2354 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
2355 SourceLocation(), SourceLocation()));
2356 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__))
;
2357 Replacements.back().setField(cast<FieldDecl>(*PI));
2358 }
2359
2360 // Expand the current designator into the set of replacement
2361 // designators, so we have a full subobject path down to where the
2362 // member of the anonymous struct/union is actually stored.
2363 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
2364 &Replacements[0] + Replacements.size());
2365}
2366
2367static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
2368 DesignatedInitExpr *DIE) {
2369 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
2370 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
2371 for (unsigned I = 0; I < NumIndexExprs; ++I)
2372 IndexExprs[I] = DIE->getSubExpr(I + 1);
2373 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
2374 IndexExprs,
2375 DIE->getEqualOrColonLoc(),
2376 DIE->usesGNUSyntax(), DIE->getInit());
2377}
2378
2379namespace {
2380
2381// Callback to only accept typo corrections that are for field members of
2382// the given struct or union.
2383class FieldInitializerValidatorCCC final : public CorrectionCandidateCallback {
2384 public:
2385 explicit FieldInitializerValidatorCCC(RecordDecl *RD)
2386 : Record(RD) {}
2387
2388 bool ValidateCandidate(const TypoCorrection &candidate) override {
2389 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
2390 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
2391 }
2392
2393 std::unique_ptr<CorrectionCandidateCallback> clone() override {
2394 return std::make_unique<FieldInitializerValidatorCCC>(*this);
2395 }
2396
2397 private:
2398 RecordDecl *Record;
2399};
2400
2401} // end anonymous namespace
2402
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,
2442 InitListExpr *IList,
2443 DesignatedInitExpr *DIE,
2444 unsigned DesigIdx,
2445 QualType &CurrentObjectType,
2446 RecordDecl::field_iterator *NextField,
2447 llvm::APSInt *NextElementIndex,
2448 unsigned &Index,
2449 InitListExpr *StructuredList,
2450 unsigned &StructuredIndex,
2451 bool FinishSubobjectInit,
2452 bool TopLevelObject) {
2453 if (DesigIdx == DIE->size()) {
2454 // C++20 designated initialization can result in direct-list-initialization
2455 // of the designated subobject. This is the only way that we can end up
2456 // performing direct initialization as part of aggregate initialization, so
2457 // it needs special handling.
2458 if (DIE->isDirectInit()) {
2459 Expr *Init = DIE->getInit();
2460 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__
))
2461 "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__
))
;
2462 InitializationKind Kind = InitializationKind::CreateDirectList(
2463 DIE->getBeginLoc(), Init->getBeginLoc(), Init->getEndLoc());
2464 InitializationSequence Seq(SemaRef, Entity, Kind, Init,
2465 /*TopLevelOfInitList*/ true);
2466 if (StructuredList) {
2467 ExprResult Result = VerifyOnly
2468 ? getDummyInit()
2469 : Seq.Perform(SemaRef, Entity, Kind, Init);
2470 UpdateStructuredListElement(StructuredList, StructuredIndex,
2471 Result.get());
2472 }
2473 ++Index;
2474 return !Seq;
2475 }
2476
2477 // Check the actual initialization for the designated object type.
2478 bool prevHadError = hadError;
2479
2480 // Temporarily remove the designator expression from the
2481 // initializer list that the child calls see, so that we don't try
2482 // to re-process the designator.
2483 unsigned OldIndex = Index;
2484 IList->setInit(OldIndex, DIE->getInit());
2485
2486 CheckSubElementType(Entity, IList, CurrentObjectType, Index, StructuredList,
2487 StructuredIndex, /*DirectlyDesignated=*/true);
2488
2489 // Restore the designated initializer expression in the syntactic
2490 // form of the initializer list.
2491 if (IList->getInit(OldIndex) != DIE->getInit())
2492 DIE->setInit(IList->getInit(OldIndex));
2493 IList->setInit(OldIndex, DIE);
2494
2495 return hadError && !prevHadError;
2496 }
2497
2498 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
2499 bool IsFirstDesignator = (DesigIdx == 0);
2500 if (IsFirstDesignator ? FullyStructuredList : StructuredList) {
2501 // Determine the structural initializer list that corresponds to the
2502 // current subobject.
2503 if (IsFirstDesignator)
2504 StructuredList = FullyStructuredList;
2505 else {
2506 Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
2507 StructuredList->getInit(StructuredIndex) : nullptr;
2508 if (!ExistingInit && StructuredList->hasArrayFiller())
2509 ExistingInit = StructuredList->getArrayFiller();
2510
2511 if (!ExistingInit)
2512 StructuredList = getStructuredSubobjectInit(
2513 IList, Index, CurrentObjectType, StructuredList, StructuredIndex,
2514 SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2515 else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
2516 StructuredList = Result;
2517 else {
2518 // We are creating an initializer list that initializes the
2519 // subobjects of the current object, but there was already an
2520 // initialization that completely initialized the current
2521 // subobject, e.g., by a compound literal:
2522 //
2523 // struct X { int a, b; };
2524 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
2525 //
2526 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
2527 // designated initializer re-initializes only its current object
2528 // subobject [0].b.
2529 diagnoseInitOverride(ExistingInit,
2530 SourceRange(D->getBeginLoc(), DIE->getEndLoc()),
2531 /*FullyOverwritten=*/false);
2532
2533 if (!VerifyOnly) {
2534 if (DesignatedInitUpdateExpr *E =
2535 dyn_cast<DesignatedInitUpdateExpr>(ExistingInit))
2536 StructuredList = E->getUpdater();
2537 else {
2538 DesignatedInitUpdateExpr *DIUE = new (SemaRef.Context)
2539 DesignatedInitUpdateExpr(SemaRef.Context, D->getBeginLoc(),
2540 ExistingInit, DIE->getEndLoc());
2541 StructuredList->updateInit(SemaRef.Context, StructuredIndex, DIUE);
2542 StructuredList = DIUE->getUpdater();
2543 }
2544 } else {
2545 // We don't need to track the structured representation of a
2546 // designated init update of an already-fully-initialized object in
2547 // verify-only mode. The only reason we would need the structure is
2548 // to determine where the uninitialized "holes" are, and in this
2549 // case, we know there aren't any and we can't introduce any.
2550 StructuredList = nullptr;
2551 }
2552 }
2553 }
2554 }
2555
2556 if (D->isFieldDesignator()) {
2557 // C99 6.7.8p7:
2558 //
2559 // If a designator has the form
2560 //
2561 // . identifier
2562 //
2563 // then the current object (defined below) shall have
2564 // structure or union type and the identifier shall be the
2565 // name of a member of that type.
2566 const RecordType *RT = CurrentObjectType->getAs<RecordType>();
2567 if (!RT) {
2568 SourceLocation Loc = D->getDotLoc();
2569 if (Loc.isInvalid())
2570 Loc = D->getFieldLoc();
2571 if (!VerifyOnly)
2572 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
2573 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
2574 ++Index;
2575 return true;
2576 }
2577
2578 FieldDecl *KnownField = D->getField();
2579 if (!KnownField) {
2580 IdentifierInfo *FieldName = D->getFieldName();
2581 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
2582 for (NamedDecl *ND : Lookup) {
2583 if (auto *FD = dyn_cast<FieldDecl>(ND)) {
2584 KnownField = FD;
2585 break;
2586 }
2587 if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
2588 // In verify mode, don't modify the original.
2589 if (VerifyOnly)
2590 DIE = CloneDesignatedInitExpr(SemaRef, DIE);
2591 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
2592 D = DIE->getDesignator(DesigIdx);
2593 KnownField = cast<FieldDecl>(*IFD->chain_begin());
2594 break;
2595 }
2596 }
2597 if (!KnownField) {
2598 if (VerifyOnly) {
2599 ++Index;
2600 return true; // No typo correction when just trying this out.
2601 }
2602
2603 // Name lookup found something, but it wasn't a field.
2604 if (!Lookup.empty()) {
2605 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
2606 << FieldName;
2607 SemaRef.Diag(Lookup.front()->getLocation(),
2608 diag::note_field_designator_found);
2609 ++Index;
2610 return true;
2611 }
2612
2613 // Name lookup didn't find anything.
2614 // Determine whether this was a typo for another field name.
2615 FieldInitializerValidatorCCC CCC(RT->getDecl());
2616 if (TypoCorrection Corrected = SemaRef.CorrectTypo(
2617 DeclarationNameInfo(FieldName, D->getFieldLoc()),
2618 Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr, CCC,
2619 Sema::CTK_ErrorRecovery, RT->getDecl())) {
2620 SemaRef.diagnoseTypo(
2621 Corrected,
2622 SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
2623 << FieldName << CurrentObjectType);
2624 KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
2625 hadError = true;
2626 } else {
2627 // Typo correction didn't find anything.
2628 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
2629 << FieldName << CurrentObjectType;
2630 ++Index;
2631 return true;
2632 }
2633 }
2634 }
2635
2636 unsigned NumBases = 0;
2637 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2638 NumBases = CXXRD->getNumBases();
2639
2640 unsigned FieldIndex = NumBases;
2641
2642 for (auto *FI : RT->getDecl()->fields()) {
2643 if (FI->isUnnamedBitfield())
2644 continue;
2645 if (declaresSameEntity(KnownField, FI)) {
2646 KnownField = FI;
2647 break;
2648 }
2649 ++FieldIndex;
2650 }
2651
2652 RecordDecl::field_iterator Field =
2653 RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));
2654
2655 // All of the fields of a union are located at the same place in
2656 // the initializer list.
2657 if (RT->getDecl()->isUnion()) {
2658 FieldIndex = 0;
2659 if (StructuredList) {
2660 FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
2661 if (CurrentField && !declaresSameEntity(CurrentField, *Field)) {
2662 assert(StructuredList->getNumInits() == 1(static_cast <bool> (StructuredList->getNumInits() ==
1 && "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__
))
2663 && "A union should never have more than one initializer!")(static_cast <bool> (StructuredList->getNumInits() ==
1 && "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__
))
;
2664
2665 Expr *ExistingInit = StructuredList->getInit(0);
2666 if (ExistingInit) {
2667 // We're about to throw away an initializer, emit warning.
2668 diagnoseInitOverride(
2669 ExistingInit, SourceRange(D->getBeginLoc(), DIE->getEndLoc()));
2670 }
2671
2672 // remove existing initializer
2673 StructuredList->resizeInits(SemaRef.Context, 0);
2674 StructuredList->setInitializedFieldInUnion(nullptr);
2675 }
2676
2677 StructuredList->setInitializedFieldInUnion(*Field);
2678 }
2679 }
2680
2681 // Make sure we can use this declaration.
2682 bool InvalidUse;
2683 if (VerifyOnly)
2684 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2685 else
2686 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
2687 if (InvalidUse) {
2688 ++Index;
2689 return true;
2690 }
2691
2692 // C++20 [dcl.init.list]p3:
2693 // The ordered identifiers in the designators of the designated-
2694 // initializer-list shall form a subsequence of the ordered identifiers
2695 // in the direct non-static data members of T.
2696 //
2697 // Note that this is not a condition on forming the aggregate
2698 // initialization, only on actually performing initialization,
2699 // so it is not checked in VerifyOnly mode.
2700 //
2701 // FIXME: This is the only reordering diagnostic we produce, and it only
2702 // catches cases where we have a top-level field designator that jumps
2703 // backwards. This is the only such case that is reachable in an
2704 // otherwise-valid C++20 program, so is the only case that's required for
2705 // conformance, but for consistency, we should diagnose all the other
2706 // cases where a designator takes us backwards too.
2707 if (IsFirstDesignator && !VerifyOnly && SemaRef.getLangOpts().CPlusPlus &&
2708 NextField &&
2709 (*NextField == RT->getDecl()->field_end() ||
2710 (*NextField)->getFieldIndex() > Field->getFieldIndex() + 1)) {
2711 // Find the field that we just initialized.
2712 FieldDecl *PrevField = nullptr;
2713 for (auto FI = RT->getDecl()->field_begin();
2714 FI != RT->getDecl()->field_end(); ++FI) {
2715 if (FI->isUnnamedBitfield())
2716 continue;
2717 if (*NextField != RT->getDecl()->field_end() &&
2718 declaresSameEntity(*FI, **NextField))
2719 break;
2720 PrevField = *FI;
2721 }
2722
2723 if (PrevField &&
2724 PrevField->getFieldIndex() > KnownField->getFieldIndex()) {
2725 SemaRef.Diag(DIE->getBeginLoc(), diag::ext_designated_init_reordered)
2726 << KnownField << PrevField << DIE->getSourceRange();
2727
2728 unsigned OldIndex = NumBases + PrevField->getFieldIndex();
2729 if (StructuredList && OldIndex <= StructuredList->getNumInits()) {
2730 if (Expr *PrevInit = StructuredList->getInit(OldIndex)) {
2731 SemaRef.Diag(PrevInit->getBeginLoc(),
2732 diag::note_previous_field_init)
2733 << PrevField << PrevInit->getSourceRange();
2734 }
2735 }
2736 }
2737 }
2738
2739
2740 // Update the designator with the field declaration.
2741 if (!VerifyOnly)
2742 D->setField(*Field);
2743
2744 // Make sure that our non-designated initializer list has space
2745 // for a subobject corresponding to this field.
2746 if (StructuredList && FieldIndex >= StructuredList->getNumInits())
2747 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
2748
2749 // This designator names a flexible array member.
2750 if (Field->getType()->isIncompleteArrayType()) {
2751 bool Invalid = false;
2752 if ((DesigIdx + 1) != DIE->size()) {
2753 // We can't designate an object within the flexible array
2754 // member (because GCC doesn't allow it).
2755 if (!VerifyOnly) {
2756 DesignatedInitExpr::Designator *NextD
2757 = DIE->getDesignator(DesigIdx + 1);
2758 SemaRef.Diag(NextD->getBeginLoc(),
2759 diag::err_designator_into_flexible_array_member)
2760 << SourceRange(NextD->getBeginLoc(), DIE->getEndLoc());
2761 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2762 << *Field;
2763 }
2764 Invalid = true;
2765 }
2766
2767 if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
2768 !isa<StringLiteral>(DIE->getInit())) {
2769 // The initializer is not an initializer list.
2770 if (!VerifyOnly) {
2771 SemaRef.Diag(DIE->getInit()->getBeginLoc(),
2772 diag::err_flexible_array_init_needs_braces)
2773 << DIE->getInit()->getSourceRange();
2774 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2775 << *Field;
2776 }
2777 Invalid = true;
2778 }
2779
2780 // Check GNU flexible array initializer.
2781 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
2782 TopLevelObject))
2783 Invalid = true;
2784
2785 if (Invalid) {
2786 ++Index;
2787 return true;
2788 }
2789
2790 // Initialize the array.
2791 bool prevHadError = hadError;
2792 unsigned newStructuredIndex = FieldIndex;
2793 unsigned OldIndex = Index;
2794 IList->setInit(Index, DIE->getInit());
2795
2796 InitializedEntity MemberEntity =
2797 InitializedEntity::InitializeMember(*Field, &Entity);
2798 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2799 StructuredList, newStructuredIndex);
2800
2801 IList->setInit(OldIndex, DIE);
2802 if (hadError && !prevHadError) {
2803 ++Field;
2804 ++FieldIndex;
2805 if (NextField)
2806 *NextField = Field;
2807 StructuredIndex = FieldIndex;
2808 return true;
2809 }
2810 } else {
2811 // Recurse to check later designated subobjects.
2812 QualType FieldType = Field->getType();
2813 unsigned newStructuredIndex = FieldIndex;
2814
2815 InitializedEntity MemberEntity =
2816 InitializedEntity::InitializeMember(*Field, &Entity);
2817 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
2818 FieldType, nullptr, nullptr, Index,
2819 StructuredList, newStructuredIndex,
2820 FinishSubobjectInit, false))
2821 return true;
2822 }
2823
2824 // Find the position of the next field to be initialized in this
2825 // subobject.
2826 ++Field;
2827 ++FieldIndex;
2828
2829 // If this the first designator, our caller will continue checking
2830 // the rest of this struct/class/union subobject.
2831 if (IsFirstDesignator) {
2832 if (NextField)
2833 *NextField = Field;
2834 StructuredIndex = FieldIndex;
2835 return false;
2836 }
2837
2838 if (!FinishSubobjectInit)
2839 return false;
2840
2841 // We've already initialized something in the union; we're done.
2842 if (RT->getDecl()->isUnion())
2843 return hadError;
2844
2845 // Check the remaining fields within this class/struct/union subobject.
2846 bool prevHadError = hadError;
2847
2848 auto NoBases =
2849 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
2850 CXXRecordDecl::base_class_iterator());
2851 CheckStructUnionTypes(Entity, IList, CurrentObjectType, NoBases, Field,
2852 false, Index, StructuredList, FieldIndex);
2853 return hadError && !prevHadError;
2854 }
2855
2856 // C99 6.7.8p6:
2857 //
2858 // If a designator has the form
2859 //
2860 // [ constant-expression ]
2861 //
2862 // then the current object (defined below) shall have array
2863 // type and the expression shall be an integer constant
2864 // expression. If the array is of unknown size, any
2865 // nonnegative value is valid.
2866 //
2867 // Additionally, cope with the GNU extension that permits
2868 // designators of the form
2869 //
2870 // [ constant-expression ... constant-expression ]
2871 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
2872 if (!AT) {
2873 if (!VerifyOnly)
2874 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
2875 << CurrentObjectType;
2876 ++Index;
2877 return true;
2878 }
2879
2880 Expr *IndexExpr = nullptr;
2881 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
2882 if (D->isArrayDesignator()) {
2883 IndexExpr = DIE->getArrayIndex(*D);
2884 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
2885 DesignatedEndIndex = DesignatedStartIndex;
2886 } else {
2887 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__
))
;
2888
2889 DesignatedStartIndex =
2890 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
2891 DesignatedEndIndex =
2892 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
2893 IndexExpr = DIE->getArrayRangeEnd(*D);
2894
2895 // Codegen can't handle evaluating array range designators that have side
2896 // effects, because we replicate the AST value for each initialized element.
2897 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
2898 // elements with something that has a side effect, so codegen can emit an
2899 // "error unsupported" error instead of miscompiling the app.
2900 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
2901 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
2902 FullyStructuredList->sawArrayRangeDesignator();
2903 }
2904
2905 if (isa<ConstantArrayType>(AT)) {
2906 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
2907 DesignatedStartIndex
2908 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
2909 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
2910 DesignatedEndIndex
2911 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
2912 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
2913 if (DesignatedEndIndex >= MaxElements) {
2914 if (!VerifyOnly)
2915 SemaRef.Diag(IndexExpr->getBeginLoc(),
2916 diag::err_array_designator_too_large)
2917 << toString(DesignatedEndIndex, 10) << toString(MaxElements, 10)
2918 << IndexExpr->getSourceRange();
2919 ++Index;
2920 return true;
2921 }
2922 } else {
2923 unsigned DesignatedIndexBitWidth =
2924 ConstantArrayType::getMaxSizeBits(SemaRef.Context);
2925 DesignatedStartIndex =
2926 DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
2927 DesignatedEndIndex =
2928 DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
2929 DesignatedStartIndex.setIsUnsigned(true);
2930 DesignatedEndIndex.setIsUnsigned(true);
2931 }
2932
2933 bool IsStringLiteralInitUpdate =
2934 StructuredList && StructuredList->isStringLiteralInit();
2935 if (IsStringLiteralInitUpdate && VerifyOnly) {
2936 // We're just verifying an update to a string literal init. We don't need
2937 // to split the string up into individual characters to do that.
2938 StructuredList = nullptr;
2939 } else if (IsStringLiteralInitUpdate) {
2940 // We're modifying a string literal init; we have to decompose the string
2941 // so we can modify the individual characters.
2942 ASTContext &Context = SemaRef.Context;
2943 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParenImpCasts();
2944
2945 // Compute the character type
2946 QualType CharTy = AT->getElementType();
2947
2948 // Compute the type of the integer literals.
2949 QualType PromotedCharTy = CharTy;
2950 if (Context.isPromotableIntegerType(CharTy))
2951 PromotedCharTy = Context.getPromotedIntegerType(CharTy);
2952 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);
2953
2954 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
2955 // Get the length of the string.
2956 uint64_t StrLen = SL->getLength();
2957 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2958 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2959 StructuredList->resizeInits(Context, StrLen);
2960
2961 // Build a literal for each character in the string, and put them into
2962 // the init list.
2963 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2964 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
2965 Expr *Init = new (Context) IntegerLiteral(
2966 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2967 if (CharTy != PromotedCharTy)
2968 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2969 Init, nullptr, VK_PRValue,
2970 FPOptionsOverride());
2971 StructuredList->updateInit(Context, i, Init);
2972 }
2973 } else {
2974 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
2975 std::string Str;
2976 Context.getObjCEncodingForType(E->getEncodedType(), Str);
2977
2978 // Get the length of the string.
2979 uint64_t StrLen = Str.size();
2980 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2981 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2982 StructuredList->resizeInits(Context, StrLen);
2983
2984 // Build a literal for each character in the string, and put them into
2985 // the init list.
2986 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2987 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
2988 Expr *Init = new (Context) IntegerLiteral(
2989 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2990 if (CharTy != PromotedCharTy)
2991 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2992 Init, nullptr, VK_PRValue,
2993 FPOptionsOverride());
2994 StructuredList->updateInit(Context, i, Init);
2995 }
2996 }
2997 }
2998
2999 // Make sure that our non-designated initializer list has space
3000 // for a subobject corresponding to this array element.
3001 if (StructuredList &&
3002 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
3003 StructuredList->resizeInits(SemaRef.Context,
3004 DesignatedEndIndex.getZExtValue() + 1);
3005
3006 // Repeatedly perform subobject initializations in the range
3007 // [DesignatedStartIndex, DesignatedEndIndex].
3008
3009 // Move to the next designator
3010 unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
3011 unsigned OldIndex = Index;
3012
3013 InitializedEntity ElementEntity =
3014 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
3015
3016 while (DesignatedStartIndex <= DesignatedEndIndex) {
3017 // Recurse to check later designated subobjects.
3018 QualType ElementType = AT->getElementType();
3019 Index = OldIndex;
3020
3021 ElementEntity.setElementIndex(ElementIndex);
3022 if (CheckDesignatedInitializer(
3023 ElementEntity, IList, DIE, DesigIdx + 1, ElementType, nullptr,
3024 nullptr, Index, StructuredList, ElementIndex,
3025 FinishSubobjectInit && (DesignatedStartIndex == DesignatedEndIndex),
3026 false))
3027 return true;
3028
3029 // Move to the next index in the array that we'll be initializing.
3030 ++DesignatedStartIndex;
3031 ElementIndex = DesignatedStartIndex.getZExtValue();
3032 }
3033
3034 // If this the first designator, our caller will continue checking
3035 // the rest of this array subobject.
3036 if (IsFirstDesignator) {
3037 if (NextElementIndex)
3038 *NextElementIndex = DesignatedStartIndex;
3039 StructuredIndex = ElementIndex;
3040 return false;
3041 }
3042
3043 if (!FinishSubobjectInit)
3044 return false;
3045
3046 // Check the remaining elements within this array subobject.
3047 bool prevHadError = hadError;
3048 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
3049 /*SubobjectIsDesignatorContext=*/false, Index,
3050 StructuredList, ElementIndex);
3051 return hadError && !prevHadError;
3052}
3053
3054// Get the structured initializer list for a subobject of type
3055// @p CurrentObjectType.
3056InitListExpr *
3057InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
3058 QualType CurrentObjectType,
3059 InitListExpr *StructuredList,
3060 unsigned StructuredIndex,
3061 SourceRange InitRange,
3062 bool IsFullyOverwritten) {
3063 if (!StructuredList)
3064 return nullptr;
3065
3066 Expr *ExistingInit = nullptr;
3067 if (StructuredIndex < StructuredList->getNumInits())
3068 ExistingInit = StructuredList->getInit(StructuredIndex);
3069
3070 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
3071 // There might have already been initializers for subobjects of the current
3072 // object, but a subsequent initializer list will overwrite the entirety
3073 // of the current object. (See DR 253 and C99 6.7.8p21). e.g.,
3074 //
3075 // struct P { char x[6]; };
3076 // struct P l = { .x[2] = 'x', .x = { [0] = 'f' } };
3077 //
3078 // The first designated initializer is ignored, and l.x is just "f".
3079 if (!IsFullyOverwritten)
3080 return Result;
3081
3082 if (ExistingInit) {
3083 // We are creating an initializer list that initializes the
3084 // subobjects of the current object, but there was already an
3085 // initialization that completely initialized the current
3086 // subobject:
3087 //
3088 // struct X { int a, b; };
3089 // struct X xs[] = { [0] = { 1, 2 }, [0].b = 3 };
3090 //
3091 // Here, xs[0].a == 1 and xs[0].b == 3, since the second,
3092 // designated initializer overwrites the [0].b initializer
3093 // from the prior initialization.
3094 //
3095 // When the existing initializer is an expression rather than an
3096 // initializer list, we cannot decompose and update it in this way.
3097 // For example:
3098 //
3099 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
3100 //
3101 // This case is handled by CheckDesignatedInitializer.
3102 diagnoseInitOverride(ExistingInit, InitRange);
3103 }
3104
3105 unsigned ExpectedNumInits = 0;
3106 if (Index < IList->getNumInits()) {
3107 if (auto *Init = dyn_cast_or_null<InitListExpr>(IList->getInit(Index)))
3108 ExpectedNumInits = Init->getNumInits();
3109 else
3110 ExpectedNumInits = IList->getNumInits() - Index;
3111 }
3112
3113 InitListExpr *Result =
3114 createInitListExpr(CurrentObjectType, InitRange, ExpectedNumInits);
3115
3116 // Link this new initializer list into the structured initializer
3117 // lists.
3118 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
3119 return Result;
3120}
3121
3122InitListExpr *
3123InitListChecker::createInitListExpr(QualType CurrentObjectType,
3124 SourceRange InitRange,
3125 unsigned ExpectedNumInits) {
3126 InitListExpr *Result = new (SemaRef.Context) InitListExpr(
3127 SemaRef.Context, InitRange.getBegin(), std::nullopt, InitRange.getEnd());
3128
3129 QualType ResultType = CurrentObjectType;
3130 if (!ResultType->isArrayType())
3131 ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
3132 Result->setType(ResultType);
3133
3134 // Pre-allocate storage for the structured initializer list.
3135 unsigned NumElements = 0;
3136
3137 if (const ArrayType *AType
3138 = SemaRef.Context.getAsArrayType(CurrentObjectType)) {
3139 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
3140 NumElements = CAType->getSize().getZExtValue();
3141 // Simple heuristic so that we don't allocate a very large
3142 // initializer with many empty entries at the end.
3143 if (NumElements > ExpectedNumInits)
3144 NumElements = 0;
3145 }
3146 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) {
3147 NumElements = VType->getNumElements();
3148 } else if (CurrentObjectType->isRecordType()) {
3149 NumElements = numStructUnionElements(CurrentObjectType);
3150 }
3151
3152 Result->reserveInits(SemaRef.Context, NumElements);
3153
3154 return Result;
3155}
3156
3157/// Update the initializer at index @p StructuredIndex within the
3158/// structured initializer list to the value @p expr.
3159void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
3160 unsigned &StructuredIndex,
3161 Expr *expr) {
3162 // No structured initializer list to update
3163 if (!StructuredList)
3164 return;
3165
3166 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
3167 StructuredIndex, expr)) {
3168 // This initializer overwrites a previous initializer.
3169 // No need to diagnose when `expr` is nullptr because a more relevant
3170 // diagnostic has already been issued and this diagnostic is potentially
3171 // noise.
3172 if (expr)
3173 diagnoseInitOverride(PrevInit, expr->getSourceRange());
3174 }
3175
3176 ++StructuredIndex;
3177}
3178
3179/// Determine whether we can perform aggregate initialization for the purposes
3180/// of overload resolution.
3181bool Sema::CanPerformAggregateInitializationForOverloadResolution(
3182 const InitializedEntity &Entity, InitListExpr *From) {
3183 QualType Type = Entity.getType();
3184 InitListChecker Check(*this, Entity, From, Type, /*VerifyOnly=*/true,
3185 /*TreatUnavailableAsInvalid=*/false,
3186 /*InOverloadResolution=*/true);
3187 return !Check.HadError();
3188}
3189
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) {
3199 SourceLocation Loc = Index->getBeginLoc();
3200
3201 // Make sure this is an integer constant expression.
3202 ExprResult Result =
3203 S.VerifyIntegerConstantExpression(Index, &Value, Sema::AllowFold);
3204 if (Result.isInvalid())
3205 return Result;
3206
3207 if (Value.isSigned() && Value.isNegative())
3208 return S.Diag(Loc, diag::err_array_designator_negative)
3209 << toString(Value, 10) << Index->getSourceRange();
3210
3211 Value.setIsUnsigned(true);
3212 return Result;
3213}
3214
3215ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
3216 SourceLocation EqualOrColonLoc,
3217 bool GNUSyntax,
3218 ExprResult Init) {
3219 typedef DesignatedInitExpr::Designator ASTDesignator;
3220
3221 bool Invalid = false;
3222 SmallVector<ASTDesignator, 32> Designators;
3223 SmallVector<Expr *, 32> InitExpressions;
3224
3225 // Build designators and check array designator expressions.
3226 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
3227 const Designator &D = Desig.getDesignator(Idx);
3228 switch (D.getKind()) {
3229 case Designator::FieldDesignator:
3230 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
3231 D.getFieldLoc()));
3232 break;
3233
3234 case Designator::ArrayDesignator: {
3235 Expr *Index = static_cast<Expr *>(D.getArrayIndex());
3236 llvm::APSInt IndexValue;
3237 if (!Index->isTypeDependent() && !Index->isValueDependent())
3238 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
3239 if (!Index)
3240 Invalid = true;
3241 else {
3242 Designators.push_back(ASTDesignator(InitExpressions.size(),
3243 D.getLBracketLoc(),
3244 D.getRBracketLoc()));
3245 InitExpressions.push_back(Index);
3246 }
3247 break;
3248 }
3249
3250 case Designator::ArrayRangeDesignator: {
3251 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
3252 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
3253 llvm::APSInt StartValue;
3254 llvm::APSInt EndValue;
3255 bool StartDependent = StartIndex->isTypeDependent() ||
3256 StartIndex->isValueDependent();
3257 bool EndDependent = EndIndex->isTypeDependent() ||
3258 EndIndex->isValueDependent();
3259 if (!StartDependent)
3260 StartIndex =
3261 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
3262 if (!EndDependent)
3263 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();
3264
3265 if (!StartIndex || !EndIndex)
3266 Invalid = true;
3267 else {
3268 // Make sure we're comparing values with the same bit width.
3269 if (StartDependent || EndDependent) {
3270 // Nothing to compute.
3271 } else if (StartValue.getBitWidth() > EndValue.getBitWidth())
3272 EndValue = EndValue.extend(StartValue.getBitWidth());
3273 else if (StartValue.getBitWidth() < EndValue.getBitWidth())
3274 StartValue = StartValue.extend(EndValue.getBitWidth());
3275
3276 if (!StartDependent && !EndDependent && EndValue < StartValue) {
3277 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
3278 << toString(StartValue, 10) << toString(EndValue, 10)
3279 << StartIndex->getSourceRange() << EndIndex->getSourceRange();
3280 Invalid = true;
3281 } else {
3282 Designators.push_back(ASTDesignator(InitExpressions.size(),
3283 D.getLBracketLoc(),
3284 D.getEllipsisLoc(),
3285 D.getRBracketLoc()));
3286 InitExpressions.push_back(StartIndex);
3287 InitExpressions.push_back(EndIndex);
3288 }
3289 }
3290 break;
3291 }
3292 }
3293 }
3294
3295 if (Invalid || Init.isInvalid())
3296 return ExprError();
3297
3298 // Clear out the expressions within the designation.
3299 Desig.ClearExprs(*this);
3300
3301 return DesignatedInitExpr::Create(Context, Designators, InitExpressions,
3302 EqualOrColonLoc, GNUSyntax,
3303 Init.getAs<Expr>());
3304}
3305
3306//===----------------------------------------------------------------------===//
3307// Initialization entity
3308//===----------------------------------------------------------------------===//
3309
3310InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
3311 const InitializedEntity &Parent)
3312 : Parent(&Parent), Index(Index)
3313{
3314 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
3315 Kind = EK_ArrayElement;
3316 Type = AT->getElementType();
3317 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
3318 Kind = EK_VectorElement;
3319 Type = VT->getElementType();
3320 } else {
3321 const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
3322 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__
))
;
3323 Kind = EK_ComplexElement;
3324 Type = CT->getElementType();
3325 }
3326}
3327
3328InitializedEntity
3329InitializedEntity::InitializeBase(ASTContext &Context,
3330 const CXXBaseSpecifier *Base,
3331 bool IsInheritedVirtualBase,
3332 const InitializedEntity *Parent) {
3333 InitializedEntity Result;
3334 Result.Kind = EK_Base;
3335 Result.Parent = Parent;
3336 Result.Base = {Base, IsInheritedVirtualBase};
3337 Result.Type = Base->getType();
3338 return Result;
3339}
3340
3341DeclarationName InitializedEntity::getName() const {
3342 switch (getKind()) {
3343 case EK_Parameter:
3344 case EK_Parameter_CF_Audited: {
3345 ParmVarDecl *D = Parameter.getPointer();
3346 return (D ? D->getDeclName() : DeclarationName());
3347 }
3348
3349 case EK_Variable:
3350 case EK_Member:
3351 case EK_Binding:
3352 case EK_TemplateParameter:
3353 return Variable.VariableOrMember->getDeclName();
3354
3355 case EK_LambdaCapture:
3356 return DeclarationName(Capture.VarID);
3357
3358 case EK_Result:
3359 case EK_StmtExprResult:
3360 case EK_Exception:
3361 case EK_New:
3362 case EK_Temporary:
3363 case EK_Base:
3364 case EK_Delegating:
3365 case EK_ArrayElement:
3366 case EK_VectorElement:
3367 case EK_ComplexElement:
3368 case EK_BlockElement:
3369 case EK_LambdaToBlockConversionBlockElement:
3370 case EK_CompoundLiteralInit:
3371 case EK_RelatedResult:
3372 return DeclarationName();
3373 }
3374
3375 llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3375)
;
3376}
3377
3378ValueDecl *InitializedEntity::getDecl() const {
3379 switch (getKind()) {
3380 case EK_Variable:
3381 case EK_Member:
3382 case EK_Binding:
3383 case EK_TemplateParameter:
3384 return Variable.VariableOrMember;
3385
3386 case EK_Parameter:
3387 case EK_Parameter_CF_Audited:
3388 return Parameter.getPointer();
3389
3390 case EK_Result:
3391 case EK_StmtExprResult:
3392 case EK_Exception:
3393 case EK_New:
3394 case EK_Temporary:
3395 case EK_Base:
3396 case EK_Delegating:
3397 case EK_ArrayElement:
3398 case EK_VectorElement:
3399 case EK_ComplexElement:
3400 case EK_BlockElement:
3401 case EK_LambdaToBlockConversionBlockElement:
3402 case EK_LambdaCapture:
3403 case EK_CompoundLiteralInit:
3404 case EK_RelatedResult:
3405 return nullptr;
3406 }
3407
3408 llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3408)
;
3409}
3410
3411bool InitializedEntity::allowsNRVO() const {
3412 switch (getKind()) {
3413 case EK_Result:
3414 case EK_Exception:
3415 return LocAndNRVO.NRVO;
3416
3417 case EK_StmtExprResult:
3418 case EK_Variable:
3419 case EK_Parameter:
3420 case EK_Parameter_CF_Audited:
3421 case EK_TemplateParameter:
3422 case EK_Member:
3423 case EK_Binding:
3424 case EK_New:
3425 case EK_Temporary:
3426 case EK_CompoundLiteralInit:
3427 case EK_Base:
3428 case EK_Delegating:
3429 case EK_ArrayElement:
3430 case EK_VectorElement:
3431 case EK_ComplexElement:
3432 case EK_BlockElement:
3433 case EK_LambdaToBlockConversionBlockElement:
3434 case EK_LambdaCapture:
3435 case EK_RelatedResult:
3436 break;
3437 }
3438
3439 return false;
3440}
3441
3442unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
3443 assert(getParent() != this)(static_cast <bool> (getParent() != this) ? void (0) : __assert_fail
("getParent() != this", "clang/lib/Sema/SemaInit.cpp", 3443,
__extension__ __PRETTY_FUNCTION__))
;
3444 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
3445 for (unsigned I = 0; I != Depth; ++I)
3446 OS << "`-";
3447
3448 switch (getKind()) {
3449 case EK_Variable: OS << "Variable"; break;
3450 case EK_Parameter: OS << "Parameter"; break;
3451 case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
3452 break;
3453 case EK_TemplateParameter: OS << "TemplateParameter"; break;
3454 case EK_Result: OS << "Result"; break;
3455 case EK_StmtExprResult: OS << "StmtExprResult"; break;
3456 case EK_Exception: OS << "Exception"; break;
3457 case EK_Member: OS << "Member"; break;
3458 case EK_Binding: OS << "Binding"; break;
3459 case EK_New: OS << "New"; break;
3460 case EK_Temporary: OS << "Temporary"; break;
3461 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
3462 case EK_RelatedResult: OS << "RelatedResult"; break;
3463 case EK_Base: OS << "Base"; break;
3464 case EK_Delegating: OS << "Delegating"; break;
3465 case EK_ArrayElement: OS << "ArrayElement " << Index; break;
3466 case EK_VectorElement: OS << "VectorElement " << Index; break;
3467 case EK_ComplexElement: OS << "ComplexElement " << Index; break;
3468 case EK_BlockElement: OS << "Block"; break;
3469 case EK_LambdaToBlockConversionBlockElement:
3470 OS << "Block (lambda)";
3471 break;
3472 case EK_LambdaCapture:
3473 OS << "LambdaCapture ";
3474 OS << DeclarationName(Capture.VarID);
3475 break;
3476 }
3477
3478 if (auto *D = getDecl()) {
3479 OS << " ";
3480 D->printQualifiedName(OS);
3481 }
3482
3483 OS << " '" << getType() << "'\n";
3484
3485 return Depth + 1;
3486}
3487
3488LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void InitializedEntity::dump() const {
3489 dumpImpl(llvm::errs());
3490}
3491
3492//===----------------------------------------------------------------------===//
3493// Initialization sequence
3494//===----------------------------------------------------------------------===//
3495
3496void InitializationSequence::Step::Destroy() {
3497 switch (Kind) {
3498 case SK_ResolveAddressOfOverloadedFunction:
3499 case SK_CastDerivedToBasePRValue:
3500 case SK_CastDerivedToBaseXValue:
3501 case SK_CastDerivedToBaseLValue:
3502 case SK_BindReference:
3503 case SK_BindReferenceToTemporary:
3504 case SK_FinalCopy:
3505 case SK_ExtraneousCopyToTemporary:
3506 case SK_UserConversion:
3507 case SK_QualificationConversionPRValue:
3508 case SK_QualificationConversionXValue:
3509 case SK_QualificationConversionLValue:
3510 case SK_FunctionReferenceConversion:
3511 case SK_AtomicConversion:
3512 case SK_ListInitialization:
3513 case SK_UnwrapInitList:
3514 case SK_RewrapInitList:
3515 case SK_ConstructorInitialization:
3516 case SK_ConstructorInitializationFromList:
3517 case SK_ZeroInitialization:
3518 case SK_CAssignment:
3519 case SK_StringInit:
3520 case SK_ObjCObjectConversion:
3521 case SK_ArrayLoopIndex:
3522 case SK_ArrayLoopInit:
3523 case SK_ArrayInit:
3524 case SK_GNUArrayInit:
3525 case SK_ParenthesizedArrayInit:
3526 case SK_PassByIndirectCopyRestore:
3527 case SK_PassByIndirectRestore:
3528 case SK_ProduceObjCObject:
3529 case SK_StdInitializerList:
3530 case SK_StdInitializerListConstructorCall:
3531 case SK_OCLSamplerInit:
3532 case SK_OCLZeroOpaqueType:
3533 case SK_ParenthesizedListInit:
3534 break;
3535
3536 case SK_ConversionSequence:
3537 case SK_ConversionSequenceNoNarrowing:
3538 delete ICS;
3539 }
3540}
3541
3542bool InitializationSequence::isDirectReferenceBinding() const {
3543 // There can be some lvalue adjustments after the SK_BindReference step.
3544 for (const Step &S : llvm::reverse(Steps)) {
3545 if (S.Kind == SK_BindReference)
3546 return true;
3547 if (S.Kind == SK_BindReferenceToTemporary)
3548 return false;
3549 }
3550 return false;
3551}
3552
3553bool InitializationSequence::isAmbiguous() const {
3554 if (!Failed())
3555 return false;
3556
3557 switch (getFailureKind()) {
3558 case FK_TooManyInitsForReference:
3559 case FK_ParenthesizedListInitForReference:
3560 case FK_ArrayNeedsInitList:
3561 case FK_ArrayNeedsInitListOrStringLiteral:
3562 case FK_ArrayNeedsInitListOrWideStringLiteral:
3563 case FK_NarrowStringIntoWideCharArray:
3564 case FK_WideStringIntoCharArray:
3565 case FK_IncompatWideStringIntoWideChar:
3566 case FK_PlainStringIntoUTF8Char:
3567 case FK_UTF8StringIntoPlainChar:
3568 case FK_AddressOfOverloadFailed: // FIXME: Could do better
3569 case FK_NonConstLValueReferenceBindingToTemporary:
3570 case FK_NonConstLValueReferenceBindingToBitfield:
3571 case FK_NonConstLValueReferenceBindingToVectorElement:
3572 case FK_NonConstLValueReferenceBindingToMatrixElement:
3573 case FK_NonConstLValueReferenceBindingToUnrelated:
3574 case FK_RValueReferenceBindingToLValue:
3575 case FK_ReferenceAddrspaceMismatchTemporary:
3576 case FK_ReferenceInitDropsQualifiers:
3577 case FK_ReferenceInitFailed:
3578 case FK_ConversionFailed:
3579 case FK_ConversionFromPropertyFailed:
3580 case FK_TooManyInitsForScalar:
3581 case FK_ParenthesizedListInitForScalar:
3582 case FK_ReferenceBindingToInitList:
3583 case FK_InitListBadDestinationType:
3584 case FK_DefaultInitOfConst:
3585 case FK_Incomplete:
3586 case FK_ArrayTypeMismatch:
3587 case FK_NonConstantArrayInit:
3588 case FK_ListInitializationFailed:
3589 case FK_VariableLengthArrayHasInitializer:
3590 case FK_PlaceholderType:
3591 case FK_ExplicitConstructor:
3592 case FK_AddressOfUnaddressableFunction:
3593 case FK_ParenthesizedListInitFailed:
3594 return false;
3595
3596 case FK_ReferenceInitOverloadFailed:
3597 case FK_UserConversionOverloadFailed:
3598 case FK_ConstructorOverloadFailed:
3599 case FK_ListConstructorOverloadFailed:
3600 return FailedOverloadResult == OR_Ambiguous;
3601 }
3602
3603 llvm_unreachable("Invalid EntityKind!")::llvm::llvm_unreachable_internal("Invalid EntityKind!", "clang/lib/Sema/SemaInit.cpp"
, 3603)
;
3604}
3605
3606bool InitializationSequence::isConstructorInitialization() const {
3607 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3608}
3609
3610void
3611InitializationSequence
3612::AddAddressOverloadResolutionStep(FunctionDecl *Function,
3613 DeclAccessPair Found,
3614 bool HadMultipleCandidates) {
3615 Step S;
3616 S.Kind = SK_ResolveAddressOfOverloadedFunction;
3617 S.Type = Function->getType();
3618 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3619 S.Function.Function = Function;
3620 S.Function.FoundDecl = Found;
3621 Steps.push_back(S);
3622}
3623
3624void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
3625 ExprValueKind VK) {
3626 Step S;
3627 switch (VK) {
3628 case VK_PRValue:
3629 S.Kind = SK_CastDerivedToBasePRValue;
3630 break;
3631 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
3632 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
3633 }
3634 S.Type = BaseType;
3635 Steps.push_back(S);
3636}
3637
3638void InitializationSequence::AddReferenceBindingStep(QualType T,
3639 bool BindingTemporary) {
3640 Step S;
3641 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
3642 S.Type = T;
3643 Steps.push_back(S);
3644}
3645
3646void InitializationSequence::AddFinalCopy(QualType T) {
3647 Step S;
3648 S.Kind = SK_FinalCopy;
3649 S.Type = T;
3650 Steps.push_back(S);
3651}
3652
3653void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
3654 Step S;
3655 S.Kind = SK_ExtraneousCopyToTemporary;
3656 S.Type = T;
3657 Steps.push_back(S);
3658}
3659
3660void
3661InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
3662 DeclAccessPair FoundDecl,
3663 QualType T,
3664 bool HadMultipleCandidates) {
3665 Step S;
3666 S.Kind = SK_UserConversion;
3667 S.Type = T;
3668 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3669 S.Function.Function = Function;
3670 S.Function.FoundDecl = FoundDecl;
3671 Steps.push_back(S);
3672}
3673
3674void InitializationSequence::AddQualificationConversionStep(QualType Ty,
3675 ExprValueKind VK) {
3676 Step S;
3677 S.Kind = SK_QualificationConversionPRValue; // work around a gcc warning
3678 switch (VK) {
3679 case VK_PRValue:
3680 S.Kind = SK_QualificationConversionPRValue;
3681 break;
3682 case VK_XValue:
3683 S.Kind = SK_QualificationConversionXValue;
3684 break;
3685 case VK_LValue:
3686 S.Kind = SK_QualificationConversionLValue;
3687 break;
3688 }
3689 S.Type = Ty;
3690 Steps.push_back(S);
3691}
3692
3693void InitializationSequence::AddFunctionReferenceConversionStep(QualType Ty) {
3694 Step S;
3695 S.Kind = SK_FunctionReferenceConversion;
3696 S.Type = Ty;
3697 Steps.push_back(S);
3698}
3699
3700void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
3701 Step S;
3702 S.Kind = SK_AtomicConversion;
3703 S.Type = Ty;
3704 Steps.push_back(S);
3705}
3706
3707void InitializationSequence::AddConversionSequenceStep(
3708 const ImplicitConversionSequence &ICS, QualType T,
3709 bool TopLevelOfInitList) {
3710 Step S;
3711 S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
3712 : SK_ConversionSequence;
3713 S.Type = T;
3714 S.ICS = new ImplicitConversionSequence(ICS);
3715 Steps.push_back(S);
3716}
3717
3718void InitializationSequence::AddListInitializationStep(QualType T) {
3719 Step S;
3720 S.Kind = SK_ListInitialization;
3721 S.Type = T;
3722 Steps.push_back(S);
3723}
3724
3725void InitializationSequence::AddConstructorInitializationStep(
3726 DeclAccessPair FoundDecl, CXXConstructorDecl *Constructor, QualType T,
3727 bool HadMultipleCandidates, bool FromInitList, bool AsInitList) {
3728 Step S;
3729 S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
3730 : SK_ConstructorInitializationFromList
3731 : SK_ConstructorInitialization;
3732 S.Type = T;
3733 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3734 S.Function.Function = Constructor;
3735 S.Function.FoundDecl = FoundDecl;
3736 Steps.push_back(S);
3737}
3738
3739void InitializationSequence::AddZeroInitializationStep(QualType T) {
3740 Step S;
3741 S.Kind = SK_ZeroInitialization;
3742 S.Type = T;
3743 Steps.push_back(S);
3744}
3745
3746void InitializationSequence::AddCAssignmentStep(QualType T) {
3747 Step S;
3748 S.Kind = SK_CAssignment;
3749 S.Type = T;
3750 Steps.push_back(S);
3751}
3752
3753void InitializationSequence::AddStringInitStep(QualType T) {
3754 Step S;
3755 S.Kind = SK_StringInit;
3756 S.Type = T;
3757 Steps.push_back(S);
3758}
3759
3760void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
3761 Step S;
3762 S.Kind = SK_ObjCObjectConversion;
3763 S.Type = T;
3764 Steps.push_back(S);
3765}
3766
3767void InitializationSequence::AddArrayInitStep(QualType T, bool IsGNUExtension) {
3768 Step S;
3769 S.Kind = IsGNUExtension ? SK_GNUArrayInit : SK_ArrayInit;
3770 S.Type = T;
3771 Steps.push_back(S);
3772}
3773
3774void InitializationSequence::AddArrayInitLoopStep(QualType T, QualType EltT) {
3775 Step S;
3776 S.Kind = SK_ArrayLoopIndex;
3777 S.Type = EltT;
3778 Steps.insert(Steps.begin(), S);
3779
3780 S.Kind = SK_ArrayLoopInit;
3781 S.Type = T;
3782 Steps.push_back(S);
3783}
3784
3785void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
3786 Step S;
3787 S.Kind = SK_ParenthesizedArrayInit;
3788 S.Type = T;
3789 Steps.push_back(S);
3790}
3791
3792void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
3793 bool shouldCopy) {
3794 Step s;
3795 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
3796 : SK_PassByIndirectRestore);
3797 s.Type = type;
3798 Steps.push_back(s);
3799}
3800
3801void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
3802 Step S;
3803 S.Kind = SK_ProduceObjCObject;
3804 S.Type = T;
3805 Steps.push_back(S);
3806}
3807
3808void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
3809 Step S;
3810 S.Kind = SK_StdInitializerList;
3811 S.Type = T;
3812 Steps.push_back(S);
3813}
3814
3815void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
3816 Step S;
3817 S.Kind = SK_OCLSamplerInit;
3818 S.Type = T;
3819 Steps.push_back(S);
3820}
3821
3822void InitializationSequence::AddOCLZeroOpaqueTypeStep(QualType T) {
3823 Step S;
3824 S.Kind = SK_OCLZeroOpaqueType;
3825 S.Type = T;
3826 Steps.push_back(S);
3827}
3828
3829void InitializationSequence::AddParenthesizedListInitStep(QualType T) {
3830 Step S;
3831 S.Kind = SK_ParenthesizedListInit;
3832 S.Type = T;
3833 Steps.push_back(S);
3834}
3835
3836void InitializationSequence::RewrapReferenceInitList(QualType T,
3837 InitListExpr *Syntactic) {
3838 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__
))
3839 "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__
))
;
3840 Step S;
3841 S.Kind = SK_UnwrapInitList;
3842 S.Type = Syntactic->getInit(0)->getType();
3843 Steps.insert(Steps.begin(), S);
3844
3845 S.Kind = SK_RewrapInitList;
3846 S.Type = T;
3847 S.WrappingSyntacticList = Syntactic;
3848 Steps.push_back(S);
3849}
3850
3851void InitializationSequence::SetOverloadFailure(FailureKind Failure,
3852 OverloadingResult Result) {
3853 setSequenceKind(FailedSequence);
3854 this->Failure = Failure;
3855 this->FailedOverloadResult = Result;
3856}
3857
3858//===----------------------------------------------------------------------===//
3859// Attempt initialization
3860//===----------------------------------------------------------------------===//
3861
3862/// Tries to add a zero initializer. Returns true if that worked.
3863static bool
3864maybeRecoverWithZeroInitialization(Sema &S, InitializationSequence &Sequence,
3865 const InitializedEntity &Entity) {
3866 if (Entity.getKind() != InitializedEntity::EK_Variable)
3867 return false;
3868
3869 VarDecl *VD = cast<VarDecl>(Entity.getDecl());
3870 if (VD->getInit() || VD->getEndLoc().isMacroID())
3871 return false;
3872
3873 QualType VariableTy = VD->getType().getCanonicalType();
3874 SourceLocation Loc = S.getLocForEndOfToken(VD->getEndLoc());
3875 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
3876 if (!Init.empty()) {
3877 Sequence.AddZeroInitializationStep(Entity.getType());
3878 Sequence.SetZeroInitializationFixit(Init, Loc);
3879 return true;
3880 }
3881 return false;
3882}
3883
3884static void MaybeProduceObjCObject(Sema &S,
3885 InitializationSequence &Sequence,
3886 const InitializedEntity &Entity) {
3887 if (!S.getLangOpts().ObjCAutoRefCount) return;
3888
3889 /// When initializing a parameter, produce the value if it's marked
3890 /// __attribute__((ns_consumed)).
3891 if (Entity.isParameterKind()) {
3892 if (!Entity.isParameterConsumed())
3893 return;
3894
3895 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__
))
3896 "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__
))
;
3897 Sequence.AddProduceObjCObjectStep(Entity.getType());
3898
3899 /// When initializing a return value, if the return type is a
3900 /// retainable type, then returns need to immediately retain the
3901 /// object. If an autorelease is required, it will be done at the
3902 /// last instant.
3903 } else if (Entity.getKind() == InitializedEntity::EK_Result ||
3904 Entity.getKind() == InitializedEntity::EK_StmtExprResult) {
3905 if (!Entity.getType()->isObjCRetainableType())
3906 return;
3907
3908 Sequence.AddProduceObjCObjectStep(Entity.getType());
3909 }
3910}
3911
3912static void TryListInitialization(Sema &S,
3913 const InitializedEntity &Entity,
3914 const InitializationKind &Kind,
3915 InitListExpr *InitList,
3916 InitializationSequence &Sequence,
3917 bool TreatUnavailableAsInvalid);
3918
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,
3925 InitListExpr *List,
3926 QualType DestType,
3927 InitializationSequence &Sequence,
3928 bool TreatUnavailableAsInvalid) {
3929 QualType E;
3930 if (!S.isStdInitializerList(DestType, &E))
3931 return false;
3932
3933 if (!S.isCompleteType(List->getExprLoc(), E)) {
3934 Sequence.setIncompleteTypeFailure(E);
3935 return true;
3936 }
3937
3938 // Try initializing a temporary array from the init list.
3939 QualType ArrayType = S.Context.getConstantArrayType(
3940 E.withConst(),
3941 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
3942 List->getNumInits()),
3943 nullptr, clang::ArrayType::Normal, 0);
3944 InitializedEntity HiddenArray =
3945 InitializedEntity::InitializeTemporary(ArrayType);
3946 InitializationKind Kind = InitializationKind::CreateDirectList(
3947 List->getExprLoc(), List->getBeginLoc(), List->getEndLoc());
3948 TryListInitialization(S, HiddenArray, Kind, List, Sequence,
3949 TreatUnavailableAsInvalid);
3950 if (Sequence)
3951 Sequence.AddStdInitializerListConstructionStep(DestType);
3952 return true;
3953}
3954
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,
3960 const ConstructorInfo &Info) {
3961 if (Info.Constructor->getNumParams() == 0)
3962 return false;
3963
3964 QualType ParmT =
3965 Info.Constructor->getParamDecl(0)->getType().getNonReferenceType();
3966 QualType ClassT =
3967 Ctx.getRecordType(cast<CXXRecordDecl>(Info.FoundDecl->getDeclContext()));
3968
3969 return Ctx.hasSameUnqualifiedType(ParmT, ClassT);
3970}
3971
3972static OverloadingResult
3973ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
3974 MultiExprArg Args,
3975 OverloadCandidateSet &CandidateSet,
3976 QualType DestType,
3977 DeclContext::lookup_result Ctors,
3978 OverloadCandidateSet::iterator &Best,
3979 bool CopyInitializing, bool AllowExplicit,
3980 bool OnlyListConstructors, bool IsListInit,
3981 bool SecondStepOfCopyInit = false) {
3982 CandidateSet.clear(OverloadCandidateSet::CSK_InitByConstructor);
3983 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
3984
3985 for (NamedDecl *D : Ctors) {
3986 auto Info = getConstructorInfo(D);
3987 if (!Info.Constructor || Info.Constructor->isInvalidDecl())
3988 continue;
3989
3990 if (OnlyListConstructors && !S.isInitListConstructor(Info.Constructor))
3991 continue;
3992
3993 // C++11 [over.best.ics]p4:
3994 // ... and the constructor or user-defined conversion function is a
3995 // candidate by
3996 // - 13.3.1.3, when the argument is the temporary in the second step
3997 // of a class copy-initialization, or
3998 // - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases), [not handled here]
3999 // - the second phase of 13.3.1.7 when the initializer list has exactly
4000 // one element that is itself an initializer list, and the target is
4001 // the first parameter of a constructor of class X, and the conversion
4002 // is to X or reference to (possibly cv-qualified X),
4003 // user-defined conversion sequences are not considered.
4004 bool SuppressUserConversions =
4005 SecondStepOfCopyInit ||
4006 (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
4007 hasCopyOrMoveCtorParam(S.Context, Info));
4008
4009 if (Info.ConstructorTmpl)
4010 S.AddTemplateOverloadCandidate(
4011 Info.ConstructorTmpl, Info.FoundDecl,
4012 /*ExplicitArgs*/ nullptr, Args, CandidateSet, SuppressUserConversions,
4013 /*PartialOverloading=*/false, AllowExplicit);
4014 else {
4015 // C++ [over.match.copy]p1:
4016 // - When initializing a temporary to be bound to the first parameter
4017 // of a constructor [for type T] that takes a reference to possibly
4018 // cv-qualified T as its first argument, called with a single
4019 // argument in the context of direct-initialization, explicit
4020 // conversion functions are also considered.
4021 // FIXME: What if a constructor template instantiates to such a signature?
4022 bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
4023 Args.size() == 1 &&
4024 hasCopyOrMoveCtorParam(S.Context, Info);
4025 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, Args,
4026 CandidateSet, SuppressUserConversions,
4027 /*PartialOverloading=*/false, AllowExplicit,
4028 AllowExplicitConv);
4029 }
4030 }
4031
4032 // FIXME: Work around a bug in C++17 guaranteed copy elision.
4033 //
4034 // When initializing an object of class type T by constructor
4035 // ([over.match.ctor]) or by list-initialization ([over.match.list])
4036 // from a single expression of class type U, conversion functions of
4037 // U that convert to the non-reference type cv T are candidates.
4038 // Explicit conversion functions are only candidates during
4039 // direct-initialization.
4040 //
4041 // Note: SecondStepOfCopyInit is only ever true in this case when
4042 // evaluating whether to produce a C++98 compatibility warning.
4043 if (S.getLangOpts().CPlusPlus17 && Args.size() == 1 &&
4044 !SecondStepOfCopyInit) {
4045 Expr *Initializer = Args[0];
4046 auto *SourceRD = Initializer->getType()->getAsCXXRecordDecl();
4047 if (SourceRD && S.isCompleteType(DeclLoc, Initializer->getType())) {
4048 const auto &Conversions = SourceRD->getVisibleConversionFunctions();
4049 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4050 NamedDecl *D = *I;
4051 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4052 D = D->getUnderlyingDecl();
4053
4054 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4055 CXXConversionDecl *Conv;
4056 if (ConvTemplate)
4057 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4058 else
4059 Conv = cast<CXXConversionDecl>(D);
4060
4061 if (ConvTemplate)
4062 S.AddTemplateConversionCandidate(
4063 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
4064 CandidateSet, AllowExplicit, AllowExplicit,
4065 /*AllowResultConversion*/ false);
4066 else
4067 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
4068 DestType, CandidateSet, AllowExplicit,
4069 AllowExplicit,
4070 /*AllowResultConversion*/ false);
4071 }
4072 }
4073 }
4074
4075 // Perform overload resolution and return the result.
4076 return CandidateSet.BestViableFunction(S, DeclLoc, Best);
4077}
4078
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,
4090 const InitializedEntity &Entity,
4091 const InitializationKind &Kind,
4092 MultiExprArg Args, QualType DestType,
4093 QualType DestArrayType,
4094 InitializationSequence &Sequence,
4095 bool IsListInit = false,
4096 bool IsInitListCopy = false) {
4097 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__
))
4098 (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__
))
4099 "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__
))
4100 "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__
))
;
4101 InitListExpr *ILE =
4102 (IsListInit || IsInitListCopy) ? cast<InitListExpr>(Args[0]) : nullptr;
4103 MultiExprArg UnwrappedArgs =
4104 ILE ? MultiExprArg(ILE->getInits(), ILE->getNumInits()) : Args;
4105
4106 // The type we're constructing needs to be complete.
4107 if (!S.isCompleteType(Kind.getLocation(), DestType)) {
4108 Sequence.setIncompleteTypeFailure(DestType);
4109 return;
4110 }
4111
4112 // C++17 [dcl.init]p17:
4113 // - If the initializer expression is a prvalue and the cv-unqualified
4114 // version of the source type is the same class as the class of the
4115 // destination, the initializer expression is used to initialize the
4116 // destination object.
4117 // Per DR (no number yet), this does not apply when initializing a base
4118 // class or delegating to another constructor from a mem-initializer.
4119 // ObjC++: Lambda captured by the block in the lambda to block conversion
4120 // should avoid copy elision.
4121 if (S.getLangOpts().CPlusPlus17 &&
4122 Entity.getKind() != InitializedEntity::EK_Base &&
4123 Entity.getKind() != InitializedEntity::EK_Delegating &&
4124 Entity.getKind() !=
4125 InitializedEntity::EK_LambdaToBlockConversionBlockElement &&
4126 UnwrappedArgs.size() == 1 && UnwrappedArgs[0]->isPRValue() &&
4127 S.Context.hasSameUnqualifiedType(UnwrappedArgs[0]->getType(), DestType)) {
4128 // Convert qualifications if necessary.
4129 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
4130 if (ILE)
4131 Sequence.RewrapReferenceInitList(DestType, ILE);
4132 return;
4133 }
4134
4135 const RecordType *DestRecordType = DestType->getAs<RecordType>();
4136 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__
))
;
4137 CXXRecordDecl *DestRecordDecl
4138 = cast<CXXRecordDecl>(DestRecordType->getDecl());
4139
4140 // Build the candidate set directly in the initialization sequence
4141 // structure, so that it will persist if we fail.
4142 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4143
4144 // Determine whether we are allowed to call explicit constructors or
4145 // explicit conversion operators.
4146 bool AllowExplicit = Kind.AllowExplicit() || IsListInit;
4147 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;
4148
4149 // - Otherwise, if T is a class type, constructors are considered. The
4150 // applicable constructors are enumerated, and the best one is chosen
4151 // through overload resolution.
4152 DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl);
4153
4154 OverloadingResult Result = OR_No_Viable_Function;
4155 OverloadCandidateSet::iterator Best;
4156 bool AsInitializerList = false;
4157
4158 // C++11 [over.match.list]p1, per DR1467:
4159 // When objects of non-aggregate type T are list-initialized, such that
4160 // 8.5.4 [dcl.init.list] specifies that overload resolution is performed
4161 // according to the rules in this section, overload resolution selects
4162 // the constructor in two phases:
4163 //
4164 // - Initially, the candidate functions are the initializer-list
4165 // constructors of the class T and the argument list consists of the
4166 // initializer list as a single argument.
4167 if (IsListInit) {
4168 AsInitializerList = true;
4169
4170 // If the initializer list has no elements and T has a default constructor,
4171 // the first phase is omitted.
4172 if (!(UnwrappedArgs.empty() && S.LookupDefaultConstructor(DestRecordDecl)))
4173 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
4174 CandidateSet, DestType, Ctors, Best,
4175 CopyInitialization, AllowExplicit,
4176 /*OnlyListConstructors=*/true,
4177 IsListInit);
4178 }
4179
4180 // C++11 [over.match.list]p1:
4181 // - If no viable initializer-list constructor is found, overload resolution
4182 // is performed again, where the candidate functions are all the
4183 // constructors of the class T and the argument list consists of the
4184 // elements of the initializer list.
4185 if (Result == OR_No_Viable_Function) {
4186 AsInitializerList = false;
4187 Result = ResolveConstructorOverload(S, Kind.getLocation(), UnwrappedArgs,
4188 CandidateSet, DestType, Ctors, Best,
4189 CopyInitialization, AllowExplicit,
4190 /*OnlyListConstructors=*/false,
4191 IsListInit);
4192 }
4193 if (Result) {
4194 Sequence.SetOverloadFailure(
4195 IsListInit ? InitializationSequence::FK_ListConstructorOverloadFailed
4196 : InitializationSequence::FK_ConstructorOverloadFailed,
4197 Result);
4198
4199 if (Result != OR_Deleted)
4200 return;
4201 }
4202
4203 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4204
4205 // In C++17, ResolveConstructorOverload can select a conversion function
4206 // instead of a constructor.
4207 if (auto *CD = dyn_cast<CXXConversionDecl>(Best->Function)) {
4208 // Add the user-defined conversion step that calls the conversion function.
4209 QualType ConvType = CD->getConversionType();
4210 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__
))
4211 "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__
))
;
4212 Sequence.AddUserConversionStep(CD, Best->FoundDecl, ConvType,
4213 HadMultipleCandidates);
4214 if (!S.Context.hasSameType(ConvType, DestType))
4215 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
4216 if (IsListInit)
4217 Sequence.RewrapReferenceInitList(Entity.getType(), ILE);
4218 return;
4219 }
4220
4221 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
4222 if (Result != OR_Deleted) {
4223 // C++11 [dcl.init]p6:
4224 // If a program calls for the default initialization of an object
4225 // of a const-qualified type T, T shall be a class type with a
4226 // user-provided default constructor.
4227 // C++ core issue 253 proposal:
4228 // If the implicit default constructor initializes all subobjects, no
4229 // initializer should be required.
4230 // The 253 proposal is for example needed to process libstdc++ headers
4231 // in 5.x.
4232 if (Kind.getKind() == InitializationKind::IK_Default &&
4233 Entity.getType().isConstQualified()) {
4234 if (!CtorDecl->getParent()->allowConstDefaultInit()) {
4235 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
4236 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
4237 return;
4238 }
4239 }
4240
4241 // C++11 [over.match.list]p1:
4242 // In copy-list-initialization, if an explicit constructor is chosen, the
4243 // initializer is ill-formed.
4244 if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
4245 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
4246 return;
4247 }
4248 }
4249
4250 // [class.copy.elision]p3:
4251 // In some copy-initialization contexts, a two-stage overload resolution
4252 // is performed.
4253 // If the first overload resolution selects a deleted function, we also
4254 // need the initialization sequence to decide whether to perform the second
4255 // overload resolution.
4256 // For deleted functions in other contexts, there is no need to get the
4257 // initialization sequence.
4258 if (Result == OR_Deleted && Kind.getKind() != InitializationKind::IK_Copy)
4259 return;
4260
4261 // Add the constructor initialization step. Any cv-qualification conversion is
4262 // subsumed by the initialization.
4263 Sequence.AddConstructorInitializationStep(
4264 Best->FoundDecl, CtorDecl, DestArrayType, HadMultipleCandidates,
4265 IsListInit | IsInitListCopy, AsInitializerList);
4266}
4267
4268static bool
4269ResolveOverloadedFunctionForReferenceBinding(Sema &S,
4270 Expr *Initializer,
4271 QualType &SourceType,
4272 QualType &UnqualifiedSourceType,
4273 QualType UnqualifiedTargetType,
4274 InitializationSequence &Sequence) {
4275 if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
4276 S.Context.OverloadTy) {
4277 DeclAccessPair Found;
4278 bool HadMultipleCandidates = false;
4279 if (FunctionDecl *Fn
4280 = S.ResolveAddressOfOverloadedFunction(Initializer,
4281 UnqualifiedTargetType,
4282 false, Found,
4283 &HadMultipleCandidates)) {
4284 Sequence.AddAddressOverloadResolutionStep(Fn, Found,
4285 HadMultipleCandidates);
4286 SourceType = Fn->getType();
4287 UnqualifiedSourceType = SourceType.getUnqualifiedType();
4288 } else if (!UnqualifiedTargetType->isRecordType()) {
4289 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4290 return true;
4291 }
4292 }
4293 return false;
4294}
4295
4296static void TryReferenceInitializationCore(Sema &S,
4297 const InitializedEntity &Entity,
4298 const InitializationKind &Kind,
4299 Expr *Initializer,
4300 QualType cv1T1, QualType T1,
4301 Qualifiers T1Quals,
4302 QualType cv2T2, QualType T2,
4303 Qualifiers T2Quals,
4304 InitializationSequence &Sequence);
4305
4306static void TryValueInitialization(Sema &S,
4307 const InitializedEntity &Entity,
4308 const InitializationKind &Kind,
4309 InitializationSequence &Sequence,
4310 InitListExpr *InitList = nullptr);
4311
4312/// Attempt list initialization of a reference.
4313static void TryReferenceListInitialization(Sema &S,
4314 const InitializedEntity &Entity,
4315 const InitializationKind &Kind,
4316 InitListExpr *InitList,
4317 InitializationSequence &Sequence,
4318 bool TreatUnavailableAsInvalid) {
4319 // First, catch C++03 where this isn't possible.
4320 if (!S.getLangOpts().CPlusPlus11) {
4321 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4322 return;
4323 }
4324 // Can't reference initialize a compound literal.
4325 if (Entity.getKind() == InitializedEntity::EK_CompoundLiteralInit) {
4326 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
4327 return;
4328 }
4329
4330 QualType DestType = Entity.getType();
4331 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4332 Qualifiers T1Quals;
4333 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4334
4335 // Reference initialization via an initializer list works thus:
4336 // If the initializer list consists of a single element that is
4337 // reference-related to the referenced type, bind directly to that element
4338 // (possibly creating temporaries).
4339 // Otherwise, initialize a temporary with the initializer list and
4340 // bind to that.
4341 if (InitList->getNumInits() == 1) {
4342 Expr *Initializer = InitList->getInit(0);
4343 QualType cv2T2 = S.getCompletedType(Initializer);
4344 Qualifiers T2Quals;
4345 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4346
4347 // If this fails, creating a temporary wouldn't work either.
4348 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4349 T1, Sequence))
4350 return;
4351
4352 SourceLocation DeclLoc = Initializer->getBeginLoc();
4353 Sema::ReferenceCompareResult RefRelationship
4354 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2);
4355 if (RefRelationship >= Sema::Ref_Related) {
4356 // Try to bind the reference here.
4357 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4358 T1Quals, cv2T2, T2, T2Quals, Sequence);
4359 if (Sequence)
4360 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4361 return;
4362 }
4363
4364 // Update the initializer if we've resolved an overloaded function.
4365 if (Sequence.step_begin() != Sequence.step_end())
4366 Sequence.RewrapReferenceInitList(cv1T1, InitList);
4367 }
4368 // Perform address space compatibility check.
4369 QualType cv1T1IgnoreAS = cv1T1;
4370 if (T1Quals.hasAddressSpace()) {
4371 Qualifiers T2Quals;
4372 (void)S.Context.getUnqualifiedArrayType(InitList->getType(), T2Quals);
4373 if (!T1Quals.isAddressSpaceSupersetOf(T2Quals)) {
4374 Sequence.SetFailed(
4375 InitializationSequence::FK_ReferenceInitDropsQualifiers);
4376 return;
4377 }
4378 // Ignore address space of reference type at this point and perform address
4379 // space conversion after the reference binding step.
4380 cv1T1IgnoreAS =
4381 S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace());
4382 }
4383 // Not reference-related. Create a temporary and bind to that.
4384 InitializedEntity TempEntity =
4385 InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);
4386
4387 TryListInitialization(S, TempEntity, Kind, InitList, Sequence,
4388 TreatUnavailableAsInvalid);
4389 if (Sequence) {
4390 if (DestType->isRValueReferenceType() ||
4391 (T1Quals.hasConst() && !T1Quals.hasVolatile())) {
4392 Sequence.AddReferenceBindingStep(cv1T1IgnoreAS,
4393 /*BindingTemporary=*/true);
4394 if (T1Quals.hasAddressSpace())
4395 Sequence.AddQualificationConversionStep(
4396 cv1T1, DestType->isRValueReferenceType() ? VK_XValue : VK_LValue);
4397 } else
4398 Sequence.SetFailed(
4399 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
4400 }
4401}
4402
4403/// Attempt list initialization (C++0x [dcl.init.list])
4404static void TryListInitialization(Sema &S,
4405 const InitializedEntity &Entity,
4406 const InitializationKind &Kind,
4407 InitListExpr *InitList,
4408 InitializationSequence &Sequence,
4409 bool TreatUnavailableAsInvalid) {
4410 QualType DestType = Entity.getType();
4411
4412 // C++ doesn't allow scalar initialization with more than one argument.
4413 // But C99 complex numbers are scalars and it makes sense there.
4414 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
4415 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
4416 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
4417 return;
4418 }
4419 if (DestType->isReferenceType()) {
4420 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence,
4421 TreatUnavailableAsInvalid);
4422 return;
4423 }
4424
4425 if (DestType->isRecordType() &&
4426 !S.isCompleteType(InitList->getBeginLoc(), DestType)) {
4427 Sequence.setIncompleteTypeFailure(DestType);
4428 return;
4429 }
4430
4431 // C++11 [dcl.init.list]p3, per DR1467:
4432 // - If T is a class type and the initializer list has a single element of
4433 // type cv U, where U is T or a class derived from T, the object is
4434 // initialized from that element (by copy-initialization for
4435 // copy-list-initialization, or by direct-initialization for
4436 // direct-list-initialization).
4437 // - Otherwise, if T is a character array and the initializer list has a
4438 // single element that is an appropriately-typed string literal
4439 // (8.5.2 [dcl.init.string]), initialization is performed as described
4440 // in that section.
4441 // - Otherwise, if T is an aggregate, [...] (continue below).
4442 if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) {
4443 if (DestType->isRecordType()) {
4444 QualType InitType = InitList->getInit(0)->getType();
4445 if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
4446 S.IsDerivedFrom(InitList->getBeginLoc(), InitType, DestType)) {
4447 Expr *InitListAsExpr = InitList;
4448 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4449 DestType, Sequence,
4450 /*InitListSyntax*/false,
4451 /*IsInitListCopy*/true);
4452 return;
4453 }
4454 }
4455 if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) {
4456 Expr *SubInit[1] = {InitList->getInit(0)};
4457 if (!isa<VariableArrayType>(DestAT) &&
4458 IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) {
4459 InitializationKind SubKind =
4460 Kind.getKind() == InitializationKind::IK_DirectList
4461 ? InitializationKind::CreateDirect(Kind.getLocation(),
4462 InitList->getLBraceLoc(),
4463 InitList->getRBraceLoc())
4464 : Kind;
4465 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4466 /*TopLevelOfInitList*/ true,
4467 TreatUnavailableAsInvalid);
4468
4469 // TryStringLiteralInitialization() (in InitializeFrom()) will fail if
4470 // the element is not an appropriately-typed string literal, in which
4471 // case we should proceed as in C++11 (below).
4472 if (Sequence) {
4473 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4474 return;
4475 }
4476 }
4477 }
4478 }
4479
4480 // C++11 [dcl.init.list]p3:
4481 // - If T is an aggregate, aggregate initialization is performed.
4482 if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
4483 (S.getLangOpts().CPlusPlus11 &&
4484 S.isStdInitializerList(DestType, nullptr))) {
4485 if (S.getLangOpts().CPlusPlus11) {
4486 // - Otherwise, if the initializer list has no elements and T is a
4487 // class type with a default constructor, the object is
4488 // value-initialized.
4489 if (InitList->getNumInits() == 0) {
4490 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
4491 if (S.LookupDefaultConstructor(RD)) {
4492 TryValueInitialization(S, Entity, Kind, Sequence, InitList);
4493 return;
4494 }
4495 }
4496
4497 // - Otherwise, if T is a specialization of std::initializer_list<E>,
4498 // an initializer_list object constructed [...]
4499 if (TryInitializerListConstruction(S, InitList, DestType, Sequence,
4500 TreatUnavailableAsInvalid))
4501 return;
4502
4503 // - Otherwise, if T is a class type, constructors are considered.
4504 Expr *InitListAsExpr = InitList;
4505 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
4506 DestType, Sequence, /*InitListSyntax*/true);
4507 } else
4508 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
4509 return;
4510 }
4511
4512 if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
4513 InitList->getNumInits() == 1) {
4514 Expr *E = InitList->getInit(0);
4515
4516 // - Otherwise, if T is an enumeration with a fixed underlying type,
4517 // the initializer-list has a single element v, and the initialization
4518 // is direct-list-initialization, the object is initialized with the
4519 // value T(v); if a narrowing conversion is required to convert v to
4520 // the underlying type of T, the program is ill-formed.
4521 auto *ET = DestType->getAs<EnumType>();
4522 if (S.getLangOpts().CPlusPlus17 &&
4523 Kind.getKind() == InitializationKind::IK_DirectList &&
4524 ET && ET->getDecl()->isFixed() &&
4525 !S.Context.hasSameUnqualifiedType(E->getType(), DestType) &&
4526 (E->getType()->isIntegralOrUnscopedEnumerationType() ||
4527 E->getType()->isFloatingType())) {
4528 // There are two ways that T(v) can work when T is an enumeration type.
4529 // If there is either an implicit conversion sequence from v to T or
4530 // a conversion function that can convert from v to T, then we use that.
4531 // Otherwise, if v is of integral, unscoped enumeration, or floating-point
4532 // type, it is converted to the enumeration type via its underlying type.
4533 // There is no overlap possible between these two cases (except when the
4534 // source value is already of the destination type), and the first
4535 // case is handled by the general case for single-element lists below.
4536 ImplicitConversionSequence ICS;
4537 ICS.setStandard();
4538 ICS.Standard.setAsIdentityConversion();
4539 if (!E->isPRValue())
4540 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
4541 // If E is of a floating-point type, then the conversion is ill-formed
4542 // due to narrowing, but go through the motions in order to produce the
4543 // right diagnostic.
4544 ICS.Standard.Second = E->getType()->isFloatingType()
4545 ? ICK_Floating_Integral
4546 : ICK_Integral_Conversion;
4547 ICS.Standard.setFromType(E->getType());
4548 ICS.Standard.setToType(0, E->getType());
4549 ICS.Standard.setToType(1, DestType);
4550 ICS.Standard.setToType(2, DestType);
4551 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2),
4552 /*TopLevelOfInitList*/true);
4553 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4554 return;
4555 }
4556
4557 // - Otherwise, if the initializer list has a single element of type E
4558 // [...references are handled above...], the object or reference is
4559 // initialized from that element (by copy-initialization for
4560 // copy-list-initialization, or by direct-initialization for
4561 // direct-list-initialization); if a narrowing conversion is required
4562 // to convert the element to T, the program is ill-formed.
4563 //
4564 // Per core-24034, this is direct-initialization if we were performing
4565 // direct-list-initialization and copy-initialization otherwise.
4566 // We can't use InitListChecker for this, because it always performs
4567 // copy-initialization. This only matters if we might use an 'explicit'
4568 // conversion operator, or for the special case conversion of nullptr_t to
4569 // bool, so we only need to handle those cases.
4570 //
4571 // FIXME: Why not do this in all cases?
4572 Expr *Init = InitList->getInit(0);
4573 if (Init->getType()->isRecordType() ||
4574 (Init->getType()->isNullPtrType() && DestType->isBooleanType())) {
4575 InitializationKind SubKind =
4576 Kind.getKind() == InitializationKind::IK_DirectList
4577 ? InitializationKind::CreateDirect(Kind.getLocation(),
4578 InitList->getLBraceLoc(),
4579 InitList->getRBraceLoc())
4580 : Kind;
4581 Expr *SubInit[1] = { Init };
4582 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
4583 /*TopLevelOfInitList*/true,
4584 TreatUnavailableAsInvalid);
4585 if (Sequence)
4586 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
4587 return;
4588 }
4589 }
4590
4591 InitListChecker CheckInitList(S, Entity, InitList,
4592 DestType, /*VerifyOnly=*/true, TreatUnavailableAsInvalid);
4593 if (CheckInitList.HadError()) {
4594 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
4595 return;
4596 }
4597
4598 // Add the list initialization step with the built init list.
4599 Sequence.AddListInitializationStep(DestType);
4600}
4601
4602/// Try a reference initialization that involves calling a conversion
4603/// function.
4604static OverloadingResult TryRefInitWithConversionFunction(
4605 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
4606 Expr *Initializer, bool AllowRValues, bool IsLValueRef,
4607 InitializationSequence &Sequence) {
4608 QualType DestType = Entity.getType();
4609 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4610 QualType T1 = cv1T1.getUnqualifiedType();
4611 QualType cv2T2 = Initializer->getType();
4612 QualType T2 = cv2T2.getUnqualifiedType();
4613
4614 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__
))
4615 "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__
))
;
4616
4617 // Build the candidate set directly in the initialization sequence
4618 // structure, so that it will persist if we fail.
4619 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4620 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4621
4622 // Determine whether we are allowed to call explicit conversion operators.
4623 // Note that none of [over.match.copy], [over.match.conv], nor
4624 // [over.match.ref] permit an explicit constructor to be chosen when
4625 // initializing a reference, not even for direct-initialization.
4626 bool AllowExplicitCtors = false;
4627 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();
4628
4629 const RecordType *T1RecordType = nullptr;
4630 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
4631 S.isCompleteType(Kind.getLocation(), T1)) {
4632 // The type we're converting to is a class type. Enumerate its constructors
4633 // to see if there is a suitable conversion.
4634 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
4635
4636 for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) {
4637 auto Info = getConstructorInfo(D);
4638 if (!Info.Constructor)
4639 continue;
4640
4641 if (!Info.Constructor->isInvalidDecl() &&
4642 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
4643 if (Info.ConstructorTmpl)
4644 S.AddTemplateOverloadCandidate(
4645 Info.ConstructorTmpl, Info.FoundDecl,
4646 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
4647 /*SuppressUserConversions=*/true,
4648 /*PartialOverloading*/ false, AllowExplicitCtors);
4649 else
4650 S.AddOverloadCandidate(
4651 Info.Constructor, Info.FoundDecl, Initializer, CandidateSet,
4652 /*SuppressUserConversions=*/true,
4653 /*PartialOverloading*/ false, AllowExplicitCtors);
4654 }
4655 }
4656 }
4657 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
4658 return OR_No_Viable_Function;
4659
4660 const RecordType *T2RecordType = nullptr;
4661 if ((T2RecordType = T2->getAs<RecordType>()) &&
4662 S.isCompleteType(Kind.getLocation(), T2)) {
4663 // The type we're converting from is a class type, enumerate its conversion
4664 // functions.
4665 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
4666
4667 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4668 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4669 NamedDecl *D = *I;
4670 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4671 if (isa<UsingShadowDecl>(D))
4672 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4673
4674 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4675 CXXConversionDecl *Conv;
4676 if (ConvTemplate)
4677 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4678 else
4679 Conv = cast<CXXConversionDecl>(D);
4680
4681 // If the conversion function doesn't return a reference type,
4682 // it can't be considered for this conversion unless we're allowed to
4683 // consider rvalues.
4684 // FIXME: Do we need to make sure that we only consider conversion
4685 // candidates with reference-compatible results? That might be needed to
4686 // break recursion.
4687 if ((AllowRValues ||
4688 Conv->getConversionType()->isLValueReferenceType())) {
4689 if (ConvTemplate)
4690 S.AddTemplateConversionCandidate(
4691 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
4692 CandidateSet,
4693 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4694 else
4695 S.AddConversionCandidate(
4696 Conv, I.getPair(), ActingDC, Initializer, DestType, CandidateSet,
4697 /*AllowObjCConversionOnExplicit=*/false, AllowExplicitConvs);
4698 }
4699 }
4700 }
4701 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
4702 return OR_No_Viable_Function;
4703
4704 SourceLocation DeclLoc = Initializer->getBeginLoc();
4705
4706 // Perform overload resolution. If it fails, return the failed result.
4707 OverloadCandidateSet::iterator Best;
4708 if (OverloadingResult Result
4709 = CandidateSet.BestViableFunction(S, DeclLoc, Best))
4710 return Result;
4711
4712 FunctionDecl *Function = Best->Function;
4713 // This is the overload that will be used for this initialization step if we
4714 // use this initialization. Mark it as referenced.
4715 Function->setReferenced();
4716
4717 // Compute the returned type and value kind of the conversion.
4718 QualType cv3T3;
4719 if (isa<CXXConversionDecl>(Function))
4720 cv3T3 = Function->getReturnType();
4721 else
4722 cv3T3 = T1;
4723
4724 ExprValueKind VK = VK_PRValue;
4725 if (cv3T3->isLValueReferenceType())
4726 VK = VK_LValue;
4727 else if (const auto *RRef = cv3T3->getAs<RValueReferenceType>())
4728 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
4729 cv3T3 = cv3T3.getNonLValueExprType(S.Context);
4730
4731 // Add the user-defined conversion step.
4732 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4733 Sequence.AddUserConversionStep(Function, Best->FoundDecl, cv3T3,
4734 HadMultipleCandidates);
4735
4736 // Determine whether we'll need to perform derived-to-base adjustments or
4737 // other conversions.
4738 Sema::ReferenceConversions RefConv;
4739 Sema::ReferenceCompareResult NewRefRelationship =
4740 S.CompareReferenceRelationship(DeclLoc, T1, cv3T3, &RefConv);
4741
4742 // Add the final conversion sequence, if necessary.
4743 if (NewRefRelationship == Sema::Ref_Incompatible) {
4744 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__
))
4745 "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__
))
;
4746
4747 ImplicitConversionSequence ICS;
4748 ICS.setStandard();
4749 ICS.Standard = Best->FinalConversion;
4750 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2));
4751
4752 // Every implicit conversion results in a prvalue, except for a glvalue
4753 // derived-to-base conversion, which we handle below.
4754 cv3T3 = ICS.Standard.getToType(2);
4755 VK = VK_PRValue;
4756 }
4757
4758 // If the converted initializer is a prvalue, its type T4 is adjusted to
4759 // type "cv1 T4" and the temporary materialization conversion is applied.
4760 //
4761 // We adjust the cv-qualifications to match the reference regardless of
4762 // whether we have a prvalue so that the AST records the change. In this
4763 // case, T4 is "cv3 T3".
4764 QualType cv1T4 = S.Context.getQualifiedType(cv3T3, cv1T1.getQualifiers());
4765 if (cv1T4.getQualifiers() != cv3T3.getQualifiers())
4766 Sequence.AddQualificationConversionStep(cv1T4, VK);
4767 Sequence.AddReferenceBindingStep(cv1T4, VK == VK_PRValue);
4768 VK = IsLValueRef ? VK_LValue : VK_XValue;
4769
4770 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4771 Sequence.AddDerivedToBaseCastStep(cv1T1, VK);
4772 else if (RefConv & Sema::ReferenceConversions::ObjC)
4773 Sequence.AddObjCObjectConversionStep(cv1T1);
4774 else if (RefConv & Sema::ReferenceConversions::Function)
4775 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4776 else if (RefConv & Sema::ReferenceConversions::Qualification) {
4777 if (!S.Context.hasSameType(cv1T4, cv1T1))
4778 Sequence.AddQualificationConversionStep(cv1T1, VK);
4779 }
4780
4781 return OR_Success;
4782}
4783
4784static void CheckCXX98CompatAccessibleCopy(Sema &S,
4785 const InitializedEntity &Entity,
4786 Expr *CurInitExpr);
4787
4788/// Attempt reference initialization (C++0x [dcl.init.ref])
4789static void TryReferenceInitialization(Sema &S,
4790 const InitializedEntity &Entity,
4791 const InitializationKind &Kind,
4792 Expr *Initializer,
4793 InitializationSequence &Sequence) {
4794 QualType DestType = Entity.getType();
4795 QualType cv1T1 = DestType->castAs<ReferenceType>()->getPointeeType();
4796 Qualifiers T1Quals;
4797 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4798 QualType cv2T2 = S.getCompletedType(Initializer);
4799 Qualifiers T2Quals;
4800 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4801
4802 // If the initializer is the address of an overloaded function, try
4803 // to resolve the overloaded function. If all goes well, T2 is the
4804 // type of the resulting function.
4805 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4806 T1, Sequence))
4807 return;
4808
4809 // Delegate everything else to a subfunction.
4810 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4811 T1Quals, cv2T2, T2, T2Quals, Sequence);
4812}
4813
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) {
4818 return E->refersToBitField() || E->refersToVectorElement() ||
4819 E->refersToMatrixElement();
4820}
4821
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,
4827 const InitializedEntity &Entity,
4828 const InitializationKind &Kind,
4829 Expr *Initializer,
4830 QualType cv1T1, QualType T1,
4831 Qualifiers T1Quals,
4832 QualType cv2T2, QualType T2,
4833 Qualifiers T2Quals,
4834 InitializationSequence &Sequence) {
4835 QualType DestType = Entity.getType();
4836 SourceLocation DeclLoc = Initializer->getBeginLoc();
4837
4838 // Compute some basic properties of the types and the initializer.
4839 bool isLValueRef = DestType->isLValueReferenceType();
4840 bool isRValueRef = !isLValueRef;
4841 Expr::Classification InitCategory = Initializer->Classify(S.Context);
4842
4843 Sema::ReferenceConversions RefConv;
4844 Sema::ReferenceCompareResult RefRelationship =
4845 S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, &RefConv);
4846
4847 // C++0x [dcl.init.ref]p5:
4848 // A reference to type "cv1 T1" is initialized by an expression of type
4849 // "cv2 T2" as follows:
4850 //
4851 // - If the reference is an lvalue reference and the initializer
4852 // expression
4853 // Note the analogous bullet points for rvalue refs to functions. Because
4854 // there are no function rvalues in C++, rvalue refs to functions are treated
4855 // like lvalue refs.
4856 OverloadingResult ConvOvlResult = OR_Success;
4857 bool T1Function = T1->isFunctionType();
4858 if (isLValueRef || T1Function) {
4859 if (InitCategory.isLValue() && !isNonReferenceableGLValue(Initializer) &&
4860 (RefRelationship == Sema::Ref_Compatible ||
4861 (Kind.isCStyleOrFunctionalCast() &&
4862 RefRelationship == Sema::Ref_Related))) {
4863 // - is an lvalue (but is not a bit-field), and "cv1 T1" is
4864 // reference-compatible with "cv2 T2," or
4865 if (RefConv & (Sema::ReferenceConversions::DerivedToBase |
4866 Sema::ReferenceConversions::ObjC)) {
4867 // If we're converting the pointee, add any qualifiers first;
4868 // these qualifiers must all be top-level, so just convert to "cv1 T2".
4869 if (RefConv & (Sema::ReferenceConversions::Qualification))
4870 Sequence.AddQualificationConversionStep(
4871 S.Context.getQualifiedType(T2, T1Quals),
4872 Initializer->getValueKind());
4873 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
4874 Sequence.AddDerivedToBaseCastStep(cv1T1, VK_LValue);
4875 else
4876 Sequence.AddObjCObjectConversionStep(cv1T1);
4877 } else if (RefConv & Sema::ReferenceConversions::Qualification) {
4878 // Perform a (possibly multi-level) qualification conversion.
4879 Sequence.AddQualificationConversionStep(cv1T1,
4880 Initializer->getValueKind());
4881 } else if (RefConv & Sema::ReferenceConversions::Function) {
4882 Sequence.AddFunctionReferenceConversionStep(cv1T1);
4883 }
4884
4885 // We only create a temporary here when binding a reference to a
4886 // bit-field or vector element. Those cases are't supposed to be
4887 // handled by this bullet, but the outcome is the same either way.
4888 Sequence.AddReferenceBindingStep(cv1T1, false);
4889 return;
4890 }
4891
4892 // - has a class type (i.e., T2 is a class type), where T1 is not
4893 // reference-related to T2, and can be implicitly converted to an
4894 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
4895 // with "cv3 T3" (this conversion is selected by enumerating the
4896 // applicable conversion functions (13.3.1.6) and choosing the best
4897 // one through overload resolution (13.3)),
4898 // If we have an rvalue ref to function type here, the rhs must be
4899 // an rvalue. DR1287 removed the "implicitly" here.
4900 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
4901 (isLValueRef || InitCategory.isRValue())) {
4902 if (S.getLangOpts().CPlusPlus) {
4903 // Try conversion functions only for C++.
4904 ConvOvlResult = TryRefInitWithConversionFunction(
4905 S, Entity, Kind, Initializer, /*AllowRValues*/ isRValueRef,
4906 /*IsLValueRef*/ isLValueRef, Sequence);
4907 if (ConvOvlResult == OR_Success)
4908 return;
4909 if (ConvOvlResult != OR_No_Viable_Function)
4910 Sequence.SetOverloadFailure(
4911 InitializationSequence::FK_ReferenceInitOverloadFailed,
4912 ConvOvlResult);
4913 } else {
4914 ConvOvlResult = OR_No_Viable_Function;
4915 }
4916 }
4917 }
4918
4919 // - Otherwise, the reference shall be an lvalue reference to a
4920 // non-volatile const type (i.e., cv1 shall be const), or the reference
4921 // shall be an rvalue reference.
4922 // For address spaces, we interpret this to mean that an addr space
4923 // of a reference "cv1 T1" is a superset of addr space of "cv2 T2".
4924 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile() &&
4925 T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
4926 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
4927 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4928 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
4929 Sequence.SetOverloadFailure(
4930 InitializationSequence::FK_ReferenceInitOverloadFailed,
4931 ConvOvlResult);
4932 else if (!InitCategory.isLValue())
4933 Sequence.SetFailed(
4934 T1Quals.isAddressSpaceSupersetOf(T2Quals)
4935 ? InitializationSequence::
4936 FK_NonConstLValueReferenceBindingToTemporary
4937 : InitializationSequence::FK_ReferenceInitDropsQualifiers);
4938 else {
4939 InitializationSequence::FailureKind FK;
4940 switch (RefRelationship) {
4941 case Sema::Ref_Compatible:
4942 if (Initializer->refersToBitField())
4943 FK = InitializationSequence::
4944 FK_NonConstLValueReferenceBindingToBitfield;
4945 else if (Initializer->refersToVectorElement())
4946 FK = InitializationSequence::
4947 FK_NonConstLValueReferenceBindingToVectorElement;
4948 else if (Initializer->refersToMatrixElement())
4949 FK = InitializationSequence::
4950 FK_NonConstLValueReferenceBindingToMatrixElement;
4951 else
4952 llvm_unreachable("unexpected kind of compatible initializer")::llvm::llvm_unreachable_internal("unexpected kind of compatible initializer"
, "clang/lib/Sema/SemaInit.cpp", 4952)
;
4953 break;
4954 case Sema::Ref_Related:
4955 FK = InitializationSequence::FK_ReferenceInitDropsQualifiers;
4956 break;
4957 case Sema::Ref_Incompatible:
4958 FK = InitializationSequence::
4959 FK_NonConstLValueReferenceBindingToUnrelated;
4960 break;
4961 }
4962 Sequence.SetFailed(FK);
4963 }
4964 return;
4965 }
4966
4967 // - If the initializer expression
4968 // - is an
4969 // [<=14] xvalue (but not a bit-field), class prvalue, array prvalue, or
4970 // [1z] rvalue (but not a bit-field) or
4971 // function lvalue and "cv1 T1" is reference-compatible with "cv2 T2"
4972 //
4973 // Note: functions are handled above and below rather than here...
4974 if (!T1Function &&
4975 (RefRelationship == Sema::Ref_Compatible ||
4976 (Kind.isCStyleOrFunctionalCast() &&
4977 RefRelationship == Sema::Ref_Related)) &&
4978 ((InitCategory.isXValue() && !isNonReferenceableGLValue(Initializer)) ||
4979 (InitCategory.isPRValue() &&
4980 (S.getLangOpts().CPlusPlus17 || T2->isRecordType() ||
4981 T2->isArrayType())))) {
4982 ExprValueKind ValueKind = InitCategory.isXValue() ? VK_XValue : VK_PRValue;
4983 if (InitCategory.isPRValue() && T2->isRecordType()) {
4984 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
4985 // compiler the freedom to perform a copy here or bind to the
4986 // object, while C++0x requires that we bind directly to the
4987 // object. Hence, we always bind to the object without making an
4988 // extra copy. However, in C++03 requires that we check for the
4989 // presence of a suitable copy constructor:
4990 //
4991 // The constructor that would be used to make the copy shall
4992 // be callable whether or not the copy is actually done.
4993 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
4994 Sequence.AddExtraneousCopyToTemporary(cv2T2);
4995 else if (S.getLangOpts().CPlusPlus11)
4996 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
4997 }
4998
4999 // C++1z [dcl.init.ref]/5.2.1.2:
5000 // If the converted initializer is a prvalue, its type T4 is adjusted
5001 // to type "cv1 T4" and the temporary materialization conversion is
5002 // applied.
5003 // Postpone address space conversions to after the temporary materialization
5004 // conversion to allow creating temporaries in the alloca address space.
5005 auto T1QualsIgnoreAS = T1Quals;
5006 auto T2QualsIgnoreAS = T2Quals;
5007 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
5008 T1QualsIgnoreAS.removeAddressSpace();
5009 T2QualsIgnoreAS.removeAddressSpace();
5010 }
5011 QualType cv1T4 = S.Context.getQualifiedType(cv2T2, T1QualsIgnoreAS);
5012 if (T1QualsIgnoreAS != T2QualsIgnoreAS)
5013 Sequence.AddQualificationConversionStep(cv1T4, ValueKind);
5014 Sequence.AddReferenceBindingStep(cv1T4, ValueKind == VK_PRValue);
5015 ValueKind = isLValueRef ? VK_LValue : VK_XValue;
5016 // Add addr space conversion if required.
5017 if (T1Quals.getAddressSpace() != T2Quals.getAddressSpace()) {
5018 auto T4Quals = cv1T4.getQualifiers();
5019 T4Quals.addAddressSpace(T1Quals.getAddressSpace());
5020 QualType cv1T4WithAS = S.Context.getQualifiedType(T2, T4Quals);
5021 Sequence.AddQualificationConversionStep(cv1T4WithAS, ValueKind);
5022 cv1T4 = cv1T4WithAS;
5023 }
5024
5025 // In any case, the reference is bound to the resulting glvalue (or to
5026 // an appropriate base class subobject).
5027 if (RefConv & Sema::ReferenceConversions::DerivedToBase)
5028 Sequence.AddDerivedToBaseCastStep(cv1T1, ValueKind);
5029 else if (RefConv & Sema::ReferenceConversions::ObjC)
5030 Sequence.AddObjCObjectConversionStep(cv1T1);
5031 else if (RefConv & Sema::ReferenceConversions::Qualification) {
5032 if (!S.Context.hasSameType(cv1T4, cv1T1))
5033 Sequence.AddQualificationConversionStep(cv1T1, ValueKind);
5034 }
5035 return;
5036 }
5037
5038 // - has a class type (i.e., T2 is a class type), where T1 is not
5039 // reference-related to T2, and can be implicitly converted to an
5040 // xvalue, class prvalue, or function lvalue of type "cv3 T3",
5041 // where "cv1 T1" is reference-compatible with "cv3 T3",
5042 //
5043 // DR1287 removes the "implicitly" here.
5044 if (T2->isRecordType()) {
5045 if (RefRelationship == Sema::Ref_Incompatible) {
5046 ConvOvlResult = TryRefInitWithConversionFunction(
5047 S, Entity, Kind, Initializer, /*AllowRValues*/ true,
5048 /*IsLValueRef*/ isLValueRef, Sequence);
5049 if (ConvOvlResult)
5050 Sequence.SetOverloadFailure(
5051 InitializationSequence::FK_ReferenceInitOverloadFailed,
5052 ConvOvlResult);
5053
5054 return;
5055 }
5056
5057 if (RefRelationship == Sema::Ref_Compatible &&
5058 isRValueRef && InitCategory.isLValue()) {
5059 Sequence.SetFailed(
5060 InitializationSequence::FK_RValueReferenceBindingToLValue);
5061 return;
5062 }
5063
5064 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
5065 return;
5066 }
5067
5068 // - Otherwise, a temporary of type "cv1 T1" is created and initialized
5069 // from the initializer expression using the rules for a non-reference
5070 // copy-initialization (8.5). The reference is then bound to the
5071 // temporary. [...]
5072
5073 // Ignore address space of reference type at this point and perform address
5074 // space conversion after the reference binding step.
5075 QualType cv1T1IgnoreAS =
5076 T1Quals.hasAddressSpace()
5077 ? S.Context.getQualifiedType(T1, T1Quals.withoutAddressSpace())
5078 : cv1T1;
5079
5080 InitializedEntity TempEntity =
5081 InitializedEntity::InitializeTemporary(cv1T1IgnoreAS);
5082
5083 // FIXME: Why do we use an implicit conversion here rather than trying
5084 // copy-initialization?
5085 ImplicitConversionSequence ICS
5086 = S.TryImplicitConversion(Initializer, TempEntity.getType(),
5087 /*SuppressUserConversions=*/false,
5088 Sema::AllowedExplicit::None,
5089 /*FIXME:InOverloadResolution=*/false,
5090 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
5091 /*AllowObjCWritebackConversion=*/false);
5092
5093 if (ICS.isBad()) {
5094 // FIXME: Use the conversion function set stored in ICS to turn
5095 // this into an overloading ambiguity diagnostic. However, we need
5096 // to keep that set as an OverloadCandidateSet rather than as some
5097 // other kind of set.
5098 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
5099 Sequence.SetOverloadFailure(
5100 InitializationSequence::FK_ReferenceInitOverloadFailed,
5101 ConvOvlResult);
5102 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
5103 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
5104 else
5105 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
5106 return;
5107 } else {
5108 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
5109 }
5110
5111 // [...] If T1 is reference-related to T2, cv1 must be the
5112 // same cv-qualification as, or greater cv-qualification
5113 // than, cv2; otherwise, the program is ill-formed.
5114 unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
5115 unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
5116 if (RefRelationship == Sema::Ref_Related &&
5117 ((T1CVRQuals | T2CVRQuals) != T1CVRQuals ||
5118 !T1Quals.isAddressSpaceSupersetOf(T2Quals))) {
5119 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
5120 return;
5121 }
5122
5123 // [...] If T1 is reference-related to T2 and the reference is an rvalue
5124 // reference, the initializer expression shall not be an lvalue.
5125 if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
5126 InitCategory.isLValue()) {
5127 Sequence.SetFailed(
5128 InitializationSequence::FK_RValueReferenceBindingToLValue);
5129 return;
5130 }
5131
5132 Sequence.AddReferenceBindingStep(cv1T1IgnoreAS, /*BindingTemporary=*/true);
5133
5134 if (T1Quals.hasAddressSpace()) {
5135 if (!Qualifiers::isAddressSpaceSupersetOf(T1Quals.getAddressSpace(),
5136 LangAS::Default)) {
5137 Sequence.SetFailed(
5138 InitializationSequence::FK_ReferenceAddrspaceMismatchTemporary);
5139 return;
5140 }
5141 Sequence.AddQualificationConversionStep(cv1T1, isLValueRef ? VK_LValue
5142 : VK_XValue);
5143 }
5144}
5145
5146/// Attempt character array initialization from a string literal
5147/// (C++ [dcl.init.string], C99 6.7.8).
5148static void TryStringLiteralInitialization(Sema &S,
5149 const InitializedEntity &Entity,
5150 const InitializationKind &Kind,
5151 Expr *Initializer,
5152 InitializationSequence &Sequence) {
5153 Sequence.AddStringInitStep(Entity.getType());
5154}
5155
5156/// Attempt value initialization (C++ [dcl.init]p7).
5157static void TryValueInitialization(Sema &S,
5158 const InitializedEntity &Entity,
5159 const InitializationKind &Kind,
5160 InitializationSequence &Sequence,
5161 InitListExpr *InitList) {
5162 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__
))
5163 "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__
))
;
5164
5165 // C++98 [dcl.init]p5, C++11 [dcl.init]p7:
5166 //
5167 // To value-initialize an object of type T means:
5168 QualType T = Entity.getType();
5169
5170 // -- if T is an array type, then each element is value-initialized;
5171 T = S.Context.getBaseElementType(T);
5172
5173 if (const RecordType *RT = T->getAs<RecordType>()) {
5174 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
5175 bool NeedZeroInitialization = true;
5176 // C++98:
5177 // -- if T is a class type (clause 9) with a user-declared constructor
5178 // (12.1), then the default constructor for T is called (and the
5179 // initialization is ill-formed if T has no accessible default
5180 // constructor);
5181 // C++11:
5182 // -- if T is a class type (clause 9) with either no default constructor
5183 // (12.1 [class.ctor]) or a default constructor that is user-provided
5184 // or deleted, then the object is default-initialized;
5185 //
5186 // Note that the C++11 rule is the same as the C++98 rule if there are no
5187 // defaulted or deleted constructors, so we just use it unconditionally.
5188 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
5189 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
5190 NeedZeroInitialization = false;
5191
5192 // -- if T is a (possibly cv-qualified) non-union class type without a
5193 // user-provided or deleted default constructor, then the object is
5194 // zero-initialized and, if T has a non-trivial default constructor,
5195 // default-initialized;
5196 // The 'non-union' here was removed by DR1502. The 'non-trivial default
5197 // constructor' part was removed by DR1507.
5198 if (NeedZeroInitialization)
5199 Sequence.AddZeroInitializationStep(Entity.getType());
5200
5201 // C++03:
5202 // -- if T is a non-union class type without a user-declared constructor,
5203 // then every non-static data member and base class component of T is
5204 // value-initialized;
5205 // [...] A program that calls for [...] value-initialization of an
5206 // entity of reference type is ill-formed.
5207 //
5208 // C++11 doesn't need this handling, because value-initialization does not
5209 // occur recursively there, and the implicit default constructor is
5210 // defined as deleted in the problematic cases.
5211 if (!S.getLangOpts().CPlusPlus11 &&
5212 ClassDecl->hasUninitializedReferenceMember()) {
5213 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
5214 return;
5215 }
5216
5217 // If this is list-value-initialization, pass the empty init list on when
5218 // building the constructor call. This affects the semantics of a few
5219 // things (such as whether an explicit default constructor can be called).
5220 Expr *InitListAsExpr = InitList;
5221 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
5222 bool InitListSyntax = InitList;
5223
5224 // FIXME: Instead of creating a CXXConstructExpr of array type here,
5225 // wrap a class-typed CXXConstructExpr in an ArrayInitLoopExpr.
5226 return TryConstructorInitialization(
5227 S, Entity, Kind, Args, T, Entity.getType(), Sequence, InitListSyntax);
5228 }
5229 }
5230
5231 Sequence.AddZeroInitializationStep(Entity.getType());
5232}
5233
5234/// Attempt default initialization (C++ [dcl.init]p6).
5235static void TryDefaultInitialization(Sema &S,
5236 const InitializedEntity &Entity,
5237 const InitializationKind &Kind,
5238 InitializationSequence &Sequence) {
5239 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__
))
;
5240
5241 // C++ [dcl.init]p6:
5242 // To default-initialize an object of type T means:
5243 // - if T is an array type, each element is default-initialized;
5244 QualType DestType = S.Context.getBaseElementType(Entity.getType());
5245
5246 // - if T is a (possibly cv-qualified) class type (Clause 9), the default
5247 // constructor for T is called (and the initialization is ill-formed if
5248 // T has no accessible default constructor);
5249 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
5250 TryConstructorInitialization(S, Entity, Kind, std::nullopt, DestType,
5251 Entity.getType(), Sequence);
5252 return;
5253 }
5254
5255 // - otherwise, no initialization is performed.
5256
5257 // If a program calls for the default initialization of an object of
5258 // a const-qualified type T, T shall be a class type with a user-provided
5259 // default constructor.
5260 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
5261 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
5262 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
5263 return;
5264 }
5265
5266 // If the destination type has a lifetime property, zero-initialize it.
5267 if (DestType.getQualifiers().hasObjCLifetime()) {
5268 Sequence.AddZeroInitializationStep(Entity.getType());
5269 return;
5270 }
5271}
5272
5273static void TryOrBuildParenListInitialization(
5274 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
5275 ArrayRef<Expr *> Args, InitializationSequence &Sequence, bool VerifyOnly,
5276 ExprResult *Result = nullptr) {
5277 unsigned ArgIndexToProcess = 0;
5278 SmallVector<Expr *, 4> InitExprs;
5279 QualType ResultType;
5280 Expr *ArrayFiller = nullptr;
5281 FieldDecl *InitializedFieldInUnion = nullptr;
5282
5283 // Process entities (i.e. array members, base classes, or class fields) by
5284 // adding an initialization expression to InitExprs for each entity to
5285 // initialize.
5286 auto ProcessEntities = [&](auto Range) -> bool {
5287 bool IsUnionType = Entity.getType()->isUnionType();
5288 for (InitializedEntity SubEntity : Range) {
5289 // Unions should only have one initializer expression.
5290 // If there are more initializers than it will be caught when we check
5291 // whether Index equals Args.size().
5292 if (ArgIndexToProcess == 1 && IsUnionType)
5293 return true;
5294
5295 bool IsMember = SubEntity.getKind() == InitializedEntity::EK_Member;
5296
5297 // Unnamed bitfields should not be initialized at all, either with an arg
5298 // or by default.
5299 if (IsMember && cast<FieldDecl>(SubEntity.getDecl())->isUnnamedBitfield())
5300 continue;
5301
5302 if (ArgIndexToProcess < Args.size()) {
5303 // There are still expressions in Args that haven't been processed.
5304 // Let's match them to the current entity to initialize.
5305 Expr *E = Args[ArgIndexToProcess++];
5306
5307 // Incomplete array types indicate flexible array members. Do not allow
5308 // paren list initializations of structs with these members, as GCC
5309 // doesn't either.
5310 if (IsMember) {
5311 auto *FD = cast<FieldDecl>(SubEntity.getDecl());
5312 if (FD->getType()->isIncompleteArrayType()) {
5313 if (!VerifyOnly) {
5314 S.Diag(E->getBeginLoc(), diag::err_flexible_array_init)
5315 << SourceRange(E->getBeginLoc(), E->getEndLoc());
5316 S.Diag(FD->getLocation(), diag::note_flexible_array_member) << FD;
5317 }
5318 Sequence.SetFailed(
5319 InitializationSequence::FK_ParenthesizedListInitFailed);
5320 return false;
5321 }
5322 }
5323
5324 InitializationKind SubKind = InitializationKind::CreateForInit(
5325 E->getExprLoc(), /*isDirectInit=*/false, E);
5326 InitializationSequence SubSeq(S, SubEntity, SubKind, E);
5327
5328 if (SubSeq.Failed()) {
5329 if (!VerifyOnly)
5330 SubSeq.Diagnose(S, SubEntity, SubKind, E);
5331 else
5332 Sequence.SetFailed(
5333 InitializationSequence::FK_ParenthesizedListInitFailed);
5334
5335 return false;
5336 }
5337 if (!VerifyOnly) {
5338 ExprResult ER = SubSeq.Perform(S, SubEntity, SubKind, E);
5339 InitExprs.push_back(ER.get());
5340 if (IsMember && IsUnionType)
5341 InitializedFieldInUnion = cast<FieldDecl>(SubEntity.getDecl());
5342 }
5343 } else {
5344 // We've processed all of the args, but there are still entities that
5345 // have to be initialized.
5346 if (IsMember) {
5347 // C++ [dcl.init]p17.6.2.2
5348 // The remaining elements are initialized with their default member
5349 // initializers, if any
5350 auto *FD = cast<FieldDecl>(SubEntity.getDecl());
5351 if (Expr *ICE = FD->getInClassInitializer(); ICE && !VerifyOnly) {
5352 ExprResult DIE = S.BuildCXXDefaultInitExpr(FD->getLocation(), FD);
5353 if (DIE.isInvalid())
5354 return false;
5355 S.checkInitializerLifetime(SubEntity, DIE.get());
5356 InitExprs.push_back(DIE.get());
5357 continue;
5358 };
5359 }
5360 // Remaining class elements without default member initializers and
5361 // array elements are value initialized:
5362 //
5363 // C++ [dcl.init]p17.6.2.2
5364 // The remaining elements...otherwise are value initialzed
5365 //
5366 // C++ [dcl.init]p17.5
5367 // if the destination type is an array, the object is initialized as
5368 // . follows. Let x1, . . . , xk be the elements of the expression-list
5369 // ...Let n denote the array size...the ith array element is...value-
5370 // initialized for each k < i <= n.
5371 InitializationKind SubKind = InitializationKind::CreateValue(
5372 Kind.getLocation(), Kind.getLocation(), Kind.getLocation(), true);
5373 InitializationSequence SubSeq(S, SubEntity, SubKind, std::nullopt);
5374 if (SubSeq.Failed()) {
5375 if (!VerifyOnly)
5376 SubSeq.Diagnose(S, SubEntity, SubKind, std::nullopt);
5377 return false;
5378 }
5379 if (!VerifyOnly) {
5380 ExprResult ER = SubSeq.Perform(S, SubEntity, SubKind, std::nullopt);
5381 if (SubEntity.getKind() == InitializedEntity::EK_ArrayElement) {
5382 ArrayFiller = ER.get();
5383 return true;
5384 }
5385 InitExprs.push_back(ER.get());
5386 }
5387 }
5388 }
5389 return true;
5390 };
5391
5392 if (const ArrayType *AT =
5393 S.getASTContext().getAsArrayType(Entity.getType())) {
5394
5395 SmallVector<InitializedEntity, 4> ElementEntities;
5396 uint64_t ArrayLength;
5397 // C++ [dcl.init]p17.5
5398 // if the destination type is an array, the object is initialized as
5399 // follows. Let x1, . . . , xk be the elements of the expression-list. If
5400 // the destination type is an array of unknown bound, it is define as
5401 // having k elements.
5402 if (const ConstantArrayType *CAT =
5403 S.getASTContext().getAsConstantArrayType(Entity.getType()))
5404 ArrayLength = CAT->getSize().getZExtValue();
5405 else
5406 ArrayLength = Args.size();
5407
5408 if (ArrayLength >= Args.size()) {
5409 for (uint64_t I = 0; I < ArrayLength; ++I)
5410 ElementEntities.push_back(
5411 InitializedEntity::InitializeElement(S.getASTContext(), I, Entity));
5412
5413 if (!ProcessEntities(ElementEntities))
5414 return;
5415
5416 ResultType = S.Context.getConstantArrayType(
5417 AT->getElementType(), llvm::APInt(/*numBits=*/32, ArrayLength),
5418 nullptr, ArrayType::Normal, 0);
5419 }
5420 } else if (auto *RT = Entity.getType()->getAs<RecordType>()) {
5421 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
5422
5423 auto BaseRange = map_range(RD->bases(), [&S](auto &base) {
5424 return InitializedEntity::InitializeBase(S.getASTContext(), &base, false);
5425 });
5426 auto FieldRange = map_range(RD->fields(), [](auto *field) {
5427 return InitializedEntity::InitializeMember(field);
5428 });
5429
5430 if (!ProcessEntities(BaseRange))
5431 return;
5432
5433 if (!ProcessEntities(FieldRange))
5434 return;
5435
5436 ResultType = Entity.getType();
5437 }
5438
5439 // Not all of the args have been processed, so there must've been more args
5440 // than were required to initialize the element.
5441 if (ArgIndexToProcess < Args.size()) {
5442 Sequence.SetFailed(InitializationSequence::FK_ParenthesizedListInitFailed);
5443 if (!VerifyOnly) {
5444 QualType T = Entity.getType();
5445 int InitKind = T->isArrayType() ? 0 : T->isUnionType() ? 3 : 4;
5446 SourceRange ExcessInitSR(Args[ArgIndexToProcess]->getBeginLoc(),
5447 Args.back()->getEndLoc());
5448 S.Diag(Kind.getLocation(), diag::err_excess_initializers)
5449 << InitKind << ExcessInitSR;
5450 }
5451 return;
5452 }
5453
5454 if (VerifyOnly) {
5455 Sequence.setSequenceKind(InitializationSequence::NormalSequence);
5456 Sequence.AddParenthesizedListInitStep(Entity.getType());
5457 } else if (Result) {
5458 SourceRange SR = Kind.getParenOrBraceRange();
5459 auto *CPLIE = CXXParenListInitExpr::Create(
5460 S.getASTContext(), InitExprs, ResultType, Args.size(),
5461 Kind.getLocation(), SR.getBegin(), SR.getEnd());
5462 if (ArrayFiller)
5463 CPLIE->setArrayFiller(ArrayFiller);
5464 if (InitializedFieldInUnion)
5465 CPLIE->setInitializedFieldInUnion(InitializedFieldInUnion);
5466 *Result = CPLIE;
5467 S.Diag(Kind.getLocation(),
5468 diag::warn_cxx17_compat_aggregate_init_paren_list)
5469 << Kind.getLocation() << SR << ResultType;
5470 }
5471
5472 return;
5473}
5474
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,
5479 QualType DestType,
5480 const InitializationKind &Kind,
5481 Expr *Initializer,
5482 InitializationSequence &Sequence,
5483 bool TopLevelOfInitList) {
5484 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__
))
;
5485 QualType SourceType = Initializer->getType();
5486 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__
))
5487 "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__
))
;
5488
5489 // Build the candidate set directly in the initialization sequence
5490 // structure, so that it will persist if we fail.
5491 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
5492 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
5493 CandidateSet.setDestAS(DestType.getQualifiers().getAddressSpace());
5494
5495 // Determine whether we are allowed to call explicit constructors or
5496 // explicit conversion operators.
5497 bool AllowExplicit = Kind.AllowExplicit();
5498
5499 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
5500 // The type we're converting to is a class type. Enumerate its constructors
5501 // to see if there is a suitable conversion.
5502 CXXRecordDecl *DestRecordDecl
5503 = cast<CXXRecordDecl>(DestRecordType->getDecl());
5504
5505 // Try to complete the type we're converting to.
5506 if (S.isCompleteType(Kind.getLocation(), DestType)) {
5507 for (NamedDecl *D : S.LookupConstructors(DestRecordDecl)) {
5508 auto Info = getConstructorInfo(D);
5509 if (!Info.Constructor)
5510 continue;
5511
5512 if (!Info.Constructor->isInvalidDecl() &&
5513 Info.Constructor->isConvertingConstructor(/*AllowExplicit*/true)) {
5514 if (Info.ConstructorTmpl)
5515 S.AddTemplateOverloadCandidate(
5516 Info.ConstructorTmpl, Info.FoundDecl,
5517 /*ExplicitArgs*/ nullptr, Initializer, CandidateSet,
5518 /*SuppressUserConversions=*/true,
5519 /*PartialOverloading*/ false, AllowExplicit);
5520 else
5521 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
5522 Initializer, CandidateSet,
5523 /*SuppressUserConversions=*/true,
5524 /*PartialOverloading*/ false, AllowExplicit);
5525 }
5526 }
5527 }
5528 }
5529
5530 SourceLocation DeclLoc = Initializer->getBeginLoc();
5531
5532 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
5533 // The type we're converting from is a class type, enumerate its conversion
5534 // functions.
5535
5536 // We can only enumerate the conversion functions for a complete type; if
5537 // the type isn't complete, simply skip this step.
5538 if (S.isCompleteType(DeclLoc, SourceType)) {
5539 CXXRecordDecl *SourceRecordDecl
5540 = cast<CXXRecordDecl>(SourceRecordType->getDecl());
5541
5542 const auto &Conversions =
5543 SourceRecordDecl->getVisibleConversionFunctions();
5544 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5545 NamedDecl *D = *I;
5546 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
5547 if (isa<UsingShadowDecl>(D))
5548 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5549
5550 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5551 CXXConversionDecl *Conv;
5552 if (ConvTemplate)
5553 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5554 else
5555 Conv = cast<CXXConversionDecl>(D);
5556
5557 if (ConvTemplate)
5558 S.AddTemplateConversionCandidate(
5559 ConvTemplate, I.getPair(), ActingDC, Initializer, DestType,
5560 CandidateSet, AllowExplicit, AllowExplicit);
5561 else
5562 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Initializer,
5563 DestType, CandidateSet, AllowExplicit,
5564 AllowExplicit);
5565 }
5566 }
5567 }
5568
5569 // Perform overload resolution. If it fails, return the failed result.
5570 OverloadCandidateSet::iterator Best;
5571 if (OverloadingResult Result
5572 = CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
5573 Sequence.SetOverloadFailure(
5574 InitializationSequence::FK_UserConversionOverloadFailed, Result);
5575
5576 // [class.copy.elision]p3:
5577 // In some copy-initialization contexts, a two-stage overload resolution
5578 // is performed.
5579 // If the first overload resolution selects a deleted function, we also
5580 // need the initialization sequence to decide whether to perform the second
5581 // overload resolution.
5582 if (!(Result == OR_Deleted &&
5583 Kind.getKind() == InitializationKind::IK_Copy))
5584 return;
5585 }
5586
5587 FunctionDecl *Function = Best->Function;
5588 Function->setReferenced();
5589 bool HadMultipleCandidates = (CandidateSet.size() > 1);
5590
5591 if (isa<CXXConstructorDecl>(Function)) {
5592 // Add the user-defined conversion step. Any cv-qualification conversion is
5593 // subsumed by the initialization. Per DR5, the created temporary is of the
5594 // cv-unqualified type of the destination.
5595 Sequence.AddUserConversionStep(Function, Best->FoundDecl,
5596 DestType.getUnqualifiedType(),
5597 HadMultipleCandidates);
5598
5599 // C++14 and before:
5600 // - if the function is a constructor, the call initializes a temporary
5601 // of the cv-unqualified version of the destination type. The [...]
5602 // temporary [...] is then used to direct-initialize, according to the
5603 // rules above, the object that is the destination of the
5604 // copy-initialization.
5605 // Note that this just performs a simple object copy from the temporary.
5606 //
5607 // C++17:
5608 // - if the function is a constructor, the call is a prvalue of the
5609 // cv-unqualified version of the destination type whose return object
5610 // is initialized by the constructor. The call is used to
5611 // direct-initialize, according to the rules above, the object that
5612 // is the destination of the copy-initialization.
5613 // Therefore we need to do nothing further.
5614 //
5615 // FIXME: Mark this copy as extraneous.
5616 if (!S.getLangOpts().CPlusPlus17)
5617 Sequence.AddFinalCopy(DestType);
5618 else if (DestType.hasQualifiers())
5619 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
5620 return;
5621 }
5622
5623 // Add the user-defined conversion step that calls the conversion function.
5624 QualType ConvType = Function->getCallResultType();
5625 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
5626 HadMultipleCandidates);
5627
5628 if (ConvType->getAs<RecordType>()) {
5629 // The call is used to direct-initialize [...] the object that is the
5630 // destination of the copy-initialization.
5631 //
5632 // In C++17, this does not call a constructor if we enter /17.6.1:
5633 // - If the initializer expression is a prvalue and the cv-unqualified
5634 // version of the source type is the same as the class of the
5635 // destination [... do not make an extra copy]
5636 //
5637 // FIXME: Mark this copy as extraneous.
5638 if (!S.getLangOpts().CPlusPlus17 ||
5639 Function->getReturnType()->isReferenceType() ||
5640 !S.Context.hasSameUnqualifiedType(ConvType, DestType))
5641 Sequence.AddFinalCopy(DestType);
5642 else if (!S.Context.hasSameType(ConvType, DestType))
5643 Sequence.AddQualificationConversionStep(DestType, VK_PRValue);
5644 return;
5645 }
5646
5647 // If the conversion following the call to the conversion function
5648 // is interesting, add it as a separate step.
5649 if (Best->FinalConversion.First || Best->FinalConversion.Second ||
5650 Best->FinalConversion.Third) {
5651 ImplicitConversionSequence ICS;
5652 ICS.setStandard();
5653 ICS.Standard = Best->FinalConversion;
5654 Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
5655 }
5656}
5657
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,
5666 const InitializedEntity &Entity,
5667 const Expr *Init) {
5668 return S.getLangOpts().CPlusPlus11 &&
5669 Entity.getKind() == InitializedEntity::EK_Result &&
5670 Entity.getType()->isPointerType() &&
5671 isa<CXXBoolLiteralExpr>(Init) &&
5672 !cast<CXXBoolLiteralExpr>(Init)->getValue() &&
5673 S.getSourceManager().isInSystemHeader(Init->getExprLoc());
5674}
5675
5676/// The non-zero enum values here are indexes into diagnostic alternatives.
5677enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };
5678
5679/// Determines whether this expression is an acceptable ICR source.
5680static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
5681 bool isAddressOf, bool &isWeakAccess) {
5682 // Skip parens.
5683 e = e->IgnoreParens();
5684
5685 // Skip address-of nodes.
5686 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
5687 if (op->getOpcode() == UO_AddrOf)
5688 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
5689 isWeakAccess);
5690
5691 // Skip certain casts.
5692 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
5693 switch (ce->getCastKind()) {
5694 case CK_Dependent:
5695 case CK_BitCast:
5696 case CK_LValueBitCast:
5697 case CK_NoOp:
5698 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);
5699
5700 case CK_ArrayToPointerDecay:
5701 return IIK_nonscalar;
5702
5703 case CK_NullToPointer:
5704 return IIK_okay;
5705
5706 default:
5707 break;
5708 }
5709
5710 // If we have a declaration reference, it had better be a local variable.
5711 } else if (isa<DeclRefExpr>(e)) {
5712 // set isWeakAccess to true, to mean that there will be an implicit
5713 // load which requires a cleanup.
5714 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
5715 isWeakAccess = true;
5716
5717 if (!isAddressOf) return IIK_nonlocal;
5718
5719 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
5720 if (!var) return IIK_nonlocal;
5721
5722 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);
5723
5724 // If we have a conditional operator, check both sides.
5725 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
5726 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
5727 isWeakAccess))
5728 return iik;
5729
5730 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);
5731
5732 // These are never scalar.
5733 } else if (isa<ArraySubscriptExpr>(e)) {
5734 return IIK_nonscalar;
5735
5736 // Otherwise, it needs to be a null pointer constant.
5737 } else {
5738 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
5739 ? IIK_okay : IIK_nonlocal);
5740 }
5741
5742 return IIK_nonlocal;
5743}
5744
5745/// Check whether the given expression is a valid operand for an
5746/// indirect copy/restore.
5747static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
5748 assert(src->isPRValue())(static_cast <bool> (src->isPRValue()) ? void (0) : __assert_fail
("src->isPRValue()", "clang/lib/Sema/SemaInit.cpp", 5748,
__extension__ __PRETTY_FUNCTION__))
;
5749 bool isWeakAccess = false;
5750 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
5751 // If isWeakAccess to true, there will be an implicit
5752 // load which requires a cleanup.
5753 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
5754 S.Cleanup.setExprNeedsCleanups(true);
5755
5756 if (iik == IIK_okay) return;
5757
5758 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
5759 << ((unsigned) iik - 1) // shift index into diagnostic explanations
5760 << src->getSourceRange();
5761}
5762
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,
5766 const ArrayType *Source) {
5767 // If the source and destination array types are equivalent, we're
5768 // done.
5769 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
5770 return true;
5771
5772 // Make sure that the element types are the same.
5773 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
5774 return false;
5775
5776 // The only mismatch we allow is when the destination is an
5777 // incomplete array type and the source is a constant array type.
5778 return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
5779}
5780
5781static bool tryObjCWritebackConversion(Sema &S,
5782 InitializationSequence &Sequence,
5783 const InitializedEntity &Entity,
5784 Expr *Initializer) {
5785 bool ArrayDecay = false;
5786 QualType ArgType = Initializer->getType();
5787 QualType ArgPointee;
5788 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
5789 ArrayDecay = true;
5790 ArgPointee = ArgArrayType->getElementType();
5791 ArgType = S.Context.getPointerType(ArgPointee);
5792 }
5793
5794 // Handle write-back conversion.
5795 QualType ConvertedArgType;
5796 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
5797 ConvertedArgType))
5798 return false;
5799
5800 // We should copy unless we're passing to an argument explicitly
5801 // marked 'out'.
5802 bool ShouldCopy = true;
5803 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
5804 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
5805
5806 // Do we need an lvalue conversion?
5807 if (ArrayDecay || Initializer->isGLValue()) {
5808 ImplicitConversionSequence ICS;
5809 ICS.setStandard();
5810 ICS.Standard.setAsIdentityConversion();
5811
5812 QualType ResultType;
5813 if (ArrayDecay) {
5814 ICS.Standard.First = ICK_Array_To_Pointer;
5815 ResultType = S.Context.getPointerType(ArgPointee);
5816 } else {
5817 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
5818 ResultType = Initializer->getType().getNonLValueExprType(S.Context);
5819 }
5820
5821 Sequence.AddConversionSequenceStep(ICS, ResultType);
5822 }
5823
5824 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
5825 return true;
5826}
5827
5828static bool TryOCLSamplerInitialization(Sema &S,
5829 InitializationSequence &Sequence,
5830 QualType DestType,
5831 Expr *Initializer) {
5832 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
5833 (!Initializer->isIntegerConstantExpr(S.Context) &&
5834 !Initializer->getType()->isSamplerT()))
5835 return false;
5836
5837 Sequence.AddOCLSamplerInitStep(DestType);
5838 return true;
5839}
5840
5841static bool IsZeroInitializer(Expr *Initializer, Sema &S) {
5842 return Initializer->isIntegerConstantExpr(S.getASTContext()) &&
5843 (Initializer->EvaluateKnownConstInt(S.getASTContext()) == 0);
5844}
5845
5846static bool TryOCLZeroOpaqueTypeInitialization(Sema &S,
5847 InitializationSequence &Sequence,
5848 QualType DestType,
5849 Expr *Initializer) {
5850 if (!S.getLangOpts().OpenCL)
5851 return false;
5852
5853 //
5854 // OpenCL 1.2 spec, s6.12.10
5855 //
5856 // The event argument can also be used to associate the
5857 // async_work_group_copy with a previous async copy allowing
5858 // an event to be shared by multiple async copies; otherwise
5859 // event should be zero.
5860 //
5861 if (DestType->isEventT() || DestType->isQueueT()) {
5862 if (!IsZeroInitializer(Initializer, S))
5863 return false;
5864
5865 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5866 return true;
5867 }
5868
5869 // We should allow zero initialization for all types defined in the
5870 // cl_intel_device_side_avc_motion_estimation extension, except
5871 // intel_sub_group_avc_mce_payload_t and intel_sub_group_avc_mce_result_t.
5872 if (S.getOpenCLOptions().isAvailableOption(
5873 "cl_intel_device_side_avc_motion_estimation", S.getLangOpts()) &&
5874 DestType->isOCLIntelSubgroupAVCType()) {
5875 if (DestType->isOCLIntelSubgroupAVCMcePayloadType() ||
5876 DestType->isOCLIntelSubgroupAVCMceResultType())
5877 return false;
5878 if (!IsZeroInitializer(Initializer, S))
5879 return false;
5880
5881 Sequence.AddOCLZeroOpaqueTypeStep(DestType);
5882 return true;
5883 }
5884
5885 return false;
5886}
5887
5888InitializationSequence::InitializationSequence(
5889 Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind,
5890 MultiExprArg Args, bool TopLevelOfInitList, bool TreatUnavailableAsInvalid)
5891 : FailedOverloadResult(OR_Success),
5892 FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
5893 InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList,
5894 TreatUnavailableAsInvalid);
5895}
5896
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) {
5900 auto *DRE = dyn_cast<DeclRefExpr>(E);
5901 if (!DRE || !isa<FunctionDecl>(DRE->getDecl()))
5902 return false;
5903
5904 return !S.checkAddressOfFunctionIsAvailable(
5905 cast<FunctionDecl>(DRE->getDecl()));
5906}
5907
5908/// Determine whether we can perform an elementwise array copy for this kind
5909/// of entity.
5910static bool canPerformArrayCopy(const InitializedEntity &Entity) {
5911 switch (Entity.getKind()) {
5912 case InitializedEntity::EK_LambdaCapture:
5913 // C++ [expr.prim.lambda]p24:
5914 // For array members, the array elements are direct-initialized in
5915 // increasing subscript order.
5916 return true;
5917
5918 case InitializedEntity::EK_Variable:
5919 // C++ [dcl.decomp]p1:
5920 // [...] each element is copy-initialized or direct-initialized from the
5921 // corresponding element of the assignment-expression [...]
5922 return isa<DecompositionDecl>(Entity.getDecl());
5923
5924 case InitializedEntity::EK_Member:
5925 // C++ [class.copy.ctor]p14:
5926 // - if the member is an array, each element is direct-initialized with
5927 // the corresponding subobject of x
5928 return Entity.isImplicitMemberInitializer();
5929
5930 case InitializedEntity::EK_ArrayElement:
5931 // All the above cases are intended to apply recursively, even though none
5932 // of them actually say that.
5933 if (auto *E = Entity.getParent())
5934 return canPerformArrayCopy(*E);
5935 break;
5936
5937 default:
5938 break;
5939 }
5940
5941 return false;
5942}
5943
5944void InitializationSequence::InitializeFrom(Sema &S,
5945 const InitializedEntity &Entity,
5946 const InitializationKind &Kind,
5947 MultiExprArg Args,
5948 bool TopLevelOfInitList,
5949 bool TreatUnavailableAsInvalid) {
5950 ASTContext &Context = S.Context;
5951
5952 // Eliminate non-overload placeholder types in the arguments. We
5953 // need to do this before checking whether types are dependent
5954 // because lowering a pseudo-object expression might well give us
5955 // something of dependent type.
5956 for (unsigned I = 0, E = Args.size(); I != E; ++I)
5957 if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
5958 // FIXME: should we be doing this here?
5959 ExprResult result = S.CheckPlaceholderExpr(Args[I]);
5960 if (result.isInvalid()) {
5961 SetFailed(FK_PlaceholderType);
5962 return;
5963 }
5964 Args[I] = result.get();
5965 }
5966
5967 // C++0x [dcl.init]p16:
5968 // The semantics of initializers are as follows. The destination type is
5969 // the type of the object or reference being initialized and the source
5970 // type is the type of the initializer expression. The source type is not
5971 // defined when the initializer is a braced-init-list or when it is a
5972 // parenthesized list of expressions.
5973 QualType DestType = Entity.getType();
5974
5975 if (DestType->isDependentType() ||
5976 Expr::hasAnyTypeDependentArguments(Args)) {
5977 SequenceKind = DependentSequence;
5978 return;
5979 }
5980
5981 // Almost everything is a normal sequence.
5982 setSequenceKind(NormalSequence);
5983
5984 QualType SourceType;
5985 Expr *Initializer = nullptr;
5986 if (Args.size() == 1) {
5987 Initializer = Args[0];</