Bug Summary

File:build/source/clang/lib/Sema/SemaDeclCXX.cpp
Warning:line 16941, column 7
Value stored to 'IsMemberSpecialization' is never read

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 SemaDeclCXX.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-16/lib/clang/16 -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 _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-16/lib/clang/16/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 1673561342 -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-2023-01-13-042150-16221-1 -x c++ /build/source/clang/lib/Sema/SemaDeclCXX.cpp
1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
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 C++ declarations.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/AST/ASTConsumer.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/ASTLambda.h"
16#include "clang/AST/ASTMutationListener.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/ComparisonCategories.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclTemplate.h"
22#include "clang/AST/EvaluatedExprVisitor.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/RecordLayout.h"
25#include "clang/AST/RecursiveASTVisitor.h"
26#include "clang/AST/StmtVisitor.h"
27#include "clang/AST/TypeLoc.h"
28#include "clang/AST/TypeOrdering.h"
29#include "clang/Basic/AttributeCommonInfo.h"
30#include "clang/Basic/PartialDiagnostic.h"
31#include "clang/Basic/Specifiers.h"
32#include "clang/Basic/TargetInfo.h"
33#include "clang/Lex/LiteralSupport.h"
34#include "clang/Lex/Preprocessor.h"
35#include "clang/Sema/CXXFieldCollector.h"
36#include "clang/Sema/DeclSpec.h"
37#include "clang/Sema/Initialization.h"
38#include "clang/Sema/Lookup.h"
39#include "clang/Sema/ParsedTemplate.h"
40#include "clang/Sema/Scope.h"
41#include "clang/Sema/ScopeInfo.h"
42#include "clang/Sema/SemaInternal.h"
43#include "clang/Sema/Template.h"
44#include "llvm/ADT/ScopeExit.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/ADT/STLExtras.h"
47#include "llvm/ADT/StringExtras.h"
48#include <map>
49#include <set>
50
51using namespace clang;
52
53//===----------------------------------------------------------------------===//
54// CheckDefaultArgumentVisitor
55//===----------------------------------------------------------------------===//
56
57namespace {
58/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
59/// the default argument of a parameter to determine whether it
60/// contains any ill-formed subexpressions. For example, this will
61/// diagnose the use of local variables or parameters within the
62/// default argument expression.
63class CheckDefaultArgumentVisitor
64 : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
65 Sema &S;
66 const Expr *DefaultArg;
67
68public:
69 CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
70 : S(S), DefaultArg(DefaultArg) {}
71
72 bool VisitExpr(const Expr *Node);
73 bool VisitDeclRefExpr(const DeclRefExpr *DRE);
74 bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
75 bool VisitLambdaExpr(const LambdaExpr *Lambda);
76 bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
77};
78
79/// VisitExpr - Visit all of the children of this expression.
80bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
81 bool IsInvalid = false;
82 for (const Stmt *SubStmt : Node->children())
83 IsInvalid |= Visit(SubStmt);
84 return IsInvalid;
85}
86
87/// VisitDeclRefExpr - Visit a reference to a declaration, to
88/// determine whether this declaration can be used in the default
89/// argument expression.
90bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
91 const ValueDecl *Decl = dyn_cast<ValueDecl>(DRE->getDecl());
92
93 if (!isa<VarDecl, BindingDecl>(Decl))
94 return false;
95
96 if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
97 // C++ [dcl.fct.default]p9:
98 // [...] parameters of a function shall not be used in default
99 // argument expressions, even if they are not evaluated. [...]
100 //
101 // C++17 [dcl.fct.default]p9 (by CWG 2082):
102 // [...] A parameter shall not appear as a potentially-evaluated
103 // expression in a default argument. [...]
104 //
105 if (DRE->isNonOdrUse() != NOUR_Unevaluated)
106 return S.Diag(DRE->getBeginLoc(),
107 diag::err_param_default_argument_references_param)
108 << Param->getDeclName() << DefaultArg->getSourceRange();
109 } else if (auto *VD = Decl->getPotentiallyDecomposedVarDecl()) {
110 // C++ [dcl.fct.default]p7:
111 // Local variables shall not be used in default argument
112 // expressions.
113 //
114 // C++17 [dcl.fct.default]p7 (by CWG 2082):
115 // A local variable shall not appear as a potentially-evaluated
116 // expression in a default argument.
117 //
118 // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
119 // Note: A local variable cannot be odr-used (6.3) in a default
120 // argument.
121 //
122 if (VD->isLocalVarDecl() && !DRE->isNonOdrUse())
123 return S.Diag(DRE->getBeginLoc(),
124 diag::err_param_default_argument_references_local)
125 << Decl << DefaultArg->getSourceRange();
126 }
127 return false;
128}
129
130/// VisitCXXThisExpr - Visit a C++ "this" expression.
131bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
132 // C++ [dcl.fct.default]p8:
133 // The keyword this shall not be used in a default argument of a
134 // member function.
135 return S.Diag(ThisE->getBeginLoc(),
136 diag::err_param_default_argument_references_this)
137 << ThisE->getSourceRange();
138}
139
140bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
141 const PseudoObjectExpr *POE) {
142 bool Invalid = false;
143 for (const Expr *E : POE->semantics()) {
144 // Look through bindings.
145 if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
146 E = OVE->getSourceExpr();
147 assert(E && "pseudo-object binding without source expression?")(static_cast <bool> (E && "pseudo-object binding without source expression?"
) ? void (0) : __assert_fail ("E && \"pseudo-object binding without source expression?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 147, __extension__ __PRETTY_FUNCTION__
))
;
148 }
149
150 Invalid |= Visit(E);
151 }
152 return Invalid;
153}
154
155bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
156 // [expr.prim.lambda.capture]p9
157 // a lambda-expression appearing in a default argument cannot implicitly or
158 // explicitly capture any local entity. Such a lambda-expression can still
159 // have an init-capture if any full-expression in its initializer satisfies
160 // the constraints of an expression appearing in a default argument.
161 bool Invalid = false;
162 for (const LambdaCapture &LC : Lambda->captures()) {
163 if (!Lambda->isInitCapture(&LC))
164 return S.Diag(LC.getLocation(), diag::err_lambda_capture_default_arg);
165 // Init captures are always VarDecl.
166 auto *D = cast<VarDecl>(LC.getCapturedVar());
167 Invalid |= Visit(D->getInit());
168 }
169 return Invalid;
170}
171} // namespace
172
173void
174Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
175 const CXXMethodDecl *Method) {
176 // If we have an MSAny spec already, don't bother.
177 if (!Method || ComputedEST == EST_MSAny)
178 return;
179
180 const FunctionProtoType *Proto
181 = Method->getType()->getAs<FunctionProtoType>();
182 Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
183 if (!Proto)
184 return;
185
186 ExceptionSpecificationType EST = Proto->getExceptionSpecType();
187
188 // If we have a throw-all spec at this point, ignore the function.
189 if (ComputedEST == EST_None)
190 return;
191
192 if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
193 EST = EST_BasicNoexcept;
194
195 switch (EST) {
196 case EST_Unparsed:
197 case EST_Uninstantiated:
198 case EST_Unevaluated:
199 llvm_unreachable("should not see unresolved exception specs here")::llvm::llvm_unreachable_internal("should not see unresolved exception specs here"
, "clang/lib/Sema/SemaDeclCXX.cpp", 199)
;
200
201 // If this function can throw any exceptions, make a note of that.
202 case EST_MSAny:
203 case EST_None:
204 // FIXME: Whichever we see last of MSAny and None determines our result.
205 // We should make a consistent, order-independent choice here.
206 ClearExceptions();
207 ComputedEST = EST;
208 return;
209 case EST_NoexceptFalse:
210 ClearExceptions();
211 ComputedEST = EST_None;
212 return;
213 // FIXME: If the call to this decl is using any of its default arguments, we
214 // need to search them for potentially-throwing calls.
215 // If this function has a basic noexcept, it doesn't affect the outcome.
216 case EST_BasicNoexcept:
217 case EST_NoexceptTrue:
218 case EST_NoThrow:
219 return;
220 // If we're still at noexcept(true) and there's a throw() callee,
221 // change to that specification.
222 case EST_DynamicNone:
223 if (ComputedEST == EST_BasicNoexcept)
224 ComputedEST = EST_DynamicNone;
225 return;
226 case EST_DependentNoexcept:
227 llvm_unreachable(::llvm::llvm_unreachable_internal("should not generate implicit declarations for dependent cases"
, "clang/lib/Sema/SemaDeclCXX.cpp", 228)
228 "should not generate implicit declarations for dependent cases")::llvm::llvm_unreachable_internal("should not generate implicit declarations for dependent cases"
, "clang/lib/Sema/SemaDeclCXX.cpp", 228)
;
229 case EST_Dynamic:
230 break;
231 }
232 assert(EST == EST_Dynamic && "EST case not considered earlier.")(static_cast <bool> (EST == EST_Dynamic && "EST case not considered earlier."
) ? void (0) : __assert_fail ("EST == EST_Dynamic && \"EST case not considered earlier.\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 232, __extension__ __PRETTY_FUNCTION__
))
;
233 assert(ComputedEST != EST_None &&(static_cast <bool> (ComputedEST != EST_None &&
"Shouldn't collect exceptions when throw-all is guaranteed."
) ? void (0) : __assert_fail ("ComputedEST != EST_None && \"Shouldn't collect exceptions when throw-all is guaranteed.\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 234, __extension__ __PRETTY_FUNCTION__
))
234 "Shouldn't collect exceptions when throw-all is guaranteed.")(static_cast <bool> (ComputedEST != EST_None &&
"Shouldn't collect exceptions when throw-all is guaranteed."
) ? void (0) : __assert_fail ("ComputedEST != EST_None && \"Shouldn't collect exceptions when throw-all is guaranteed.\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 234, __extension__ __PRETTY_FUNCTION__
))
;
235 ComputedEST = EST_Dynamic;
236 // Record the exceptions in this function's exception specification.
237 for (const auto &E : Proto->exceptions())
238 if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
239 Exceptions.push_back(E);
240}
241
242void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
243 if (!S || ComputedEST == EST_MSAny)
244 return;
245
246 // FIXME:
247 //
248 // C++0x [except.spec]p14:
249 // [An] implicit exception-specification specifies the type-id T if and
250 // only if T is allowed by the exception-specification of a function directly
251 // invoked by f's implicit definition; f shall allow all exceptions if any
252 // function it directly invokes allows all exceptions, and f shall allow no
253 // exceptions if every function it directly invokes allows no exceptions.
254 //
255 // Note in particular that if an implicit exception-specification is generated
256 // for a function containing a throw-expression, that specification can still
257 // be noexcept(true).
258 //
259 // Note also that 'directly invoked' is not defined in the standard, and there
260 // is no indication that we should only consider potentially-evaluated calls.
261 //
262 // Ultimately we should implement the intent of the standard: the exception
263 // specification should be the set of exceptions which can be thrown by the
264 // implicit definition. For now, we assume that any non-nothrow expression can
265 // throw any exception.
266
267 if (Self->canThrow(S))
268 ComputedEST = EST_None;
269}
270
271ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
272 SourceLocation EqualLoc) {
273 if (RequireCompleteType(Param->getLocation(), Param->getType(),
274 diag::err_typecheck_decl_incomplete_type))
275 return true;
276
277 // C++ [dcl.fct.default]p5
278 // A default argument expression is implicitly converted (clause
279 // 4) to the parameter type. The default argument expression has
280 // the same semantic constraints as the initializer expression in
281 // a declaration of a variable of the parameter type, using the
282 // copy-initialization semantics (8.5).
283 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
284 Param);
285 InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
286 EqualLoc);
287 InitializationSequence InitSeq(*this, Entity, Kind, Arg);
288 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
289 if (Result.isInvalid())
290 return true;
291 Arg = Result.getAs<Expr>();
292
293 CheckCompletedExpr(Arg, EqualLoc);
294 Arg = MaybeCreateExprWithCleanups(Arg);
295
296 return Arg;
297}
298
299void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
300 SourceLocation EqualLoc) {
301 // Add the default argument to the parameter
302 Param->setDefaultArg(Arg);
303
304 // We have already instantiated this parameter; provide each of the
305 // instantiations with the uninstantiated default argument.
306 UnparsedDefaultArgInstantiationsMap::iterator InstPos
307 = UnparsedDefaultArgInstantiations.find(Param);
308 if (InstPos != UnparsedDefaultArgInstantiations.end()) {
309 for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
310 InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
311
312 // We're done tracking this parameter's instantiations.
313 UnparsedDefaultArgInstantiations.erase(InstPos);
314 }
315}
316
317/// ActOnParamDefaultArgument - Check whether the default argument
318/// provided for a function parameter is well-formed. If so, attach it
319/// to the parameter declaration.
320void
321Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
322 Expr *DefaultArg) {
323 if (!param || !DefaultArg)
324 return;
325
326 ParmVarDecl *Param = cast<ParmVarDecl>(param);
327 UnparsedDefaultArgLocs.erase(Param);
328
329 auto Fail = [&] {
330 Param->setInvalidDecl();
331 Param->setDefaultArg(new (Context) OpaqueValueExpr(
332 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
333 };
334
335 // Default arguments are only permitted in C++
336 if (!getLangOpts().CPlusPlus) {
337 Diag(EqualLoc, diag::err_param_default_argument)
338 << DefaultArg->getSourceRange();
339 return Fail();
340 }
341
342 // Check for unexpanded parameter packs.
343 if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
344 return Fail();
345 }
346
347 // C++11 [dcl.fct.default]p3
348 // A default argument expression [...] shall not be specified for a
349 // parameter pack.
350 if (Param->isParameterPack()) {
351 Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
352 << DefaultArg->getSourceRange();
353 // Recover by discarding the default argument.
354 Param->setDefaultArg(nullptr);
355 return;
356 }
357
358 ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
359 if (Result.isInvalid())
360 return Fail();
361
362 DefaultArg = Result.getAs<Expr>();
363
364 // Check that the default argument is well-formed
365 CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
366 if (DefaultArgChecker.Visit(DefaultArg))
367 return Fail();
368
369 SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
370}
371
372/// ActOnParamUnparsedDefaultArgument - We've seen a default
373/// argument for a function parameter, but we can't parse it yet
374/// because we're inside a class definition. Note that this default
375/// argument will be parsed later.
376void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
377 SourceLocation EqualLoc,
378 SourceLocation ArgLoc) {
379 if (!param)
380 return;
381
382 ParmVarDecl *Param = cast<ParmVarDecl>(param);
383 Param->setUnparsedDefaultArg();
384 UnparsedDefaultArgLocs[Param] = ArgLoc;
385}
386
387/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
388/// the default argument for the parameter param failed.
389void Sema::ActOnParamDefaultArgumentError(Decl *param,
390 SourceLocation EqualLoc) {
391 if (!param)
392 return;
393
394 ParmVarDecl *Param = cast<ParmVarDecl>(param);
395 Param->setInvalidDecl();
396 UnparsedDefaultArgLocs.erase(Param);
397 Param->setDefaultArg(new (Context) OpaqueValueExpr(
398 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
399}
400
401/// CheckExtraCXXDefaultArguments - Check for any extra default
402/// arguments in the declarator, which is not a function declaration
403/// or definition and therefore is not permitted to have default
404/// arguments. This routine should be invoked for every declarator
405/// that is not a function declaration or definition.
406void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
407 // C++ [dcl.fct.default]p3
408 // A default argument expression shall be specified only in the
409 // parameter-declaration-clause of a function declaration or in a
410 // template-parameter (14.1). It shall not be specified for a
411 // parameter pack. If it is specified in a
412 // parameter-declaration-clause, it shall not occur within a
413 // declarator or abstract-declarator of a parameter-declaration.
414 bool MightBeFunction = D.isFunctionDeclarationContext();
415 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
416 DeclaratorChunk &chunk = D.getTypeObject(i);
417 if (chunk.Kind == DeclaratorChunk::Function) {
418 if (MightBeFunction) {
419 // This is a function declaration. It can have default arguments, but
420 // keep looking in case its return type is a function type with default
421 // arguments.
422 MightBeFunction = false;
423 continue;
424 }
425 for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
426 ++argIdx) {
427 ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
428 if (Param->hasUnparsedDefaultArg()) {
429 std::unique_ptr<CachedTokens> Toks =
430 std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
431 SourceRange SR;
432 if (Toks->size() > 1)
433 SR = SourceRange((*Toks)[1].getLocation(),
434 Toks->back().getLocation());
435 else
436 SR = UnparsedDefaultArgLocs[Param];
437 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
438 << SR;
439 } else if (Param->getDefaultArg()) {
440 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
441 << Param->getDefaultArg()->getSourceRange();
442 Param->setDefaultArg(nullptr);
443 }
444 }
445 } else if (chunk.Kind != DeclaratorChunk::Paren) {
446 MightBeFunction = false;
447 }
448 }
449}
450
451static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
452 return llvm::any_of(FD->parameters(), [](ParmVarDecl *P) {
453 return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
454 });
455}
456
457/// MergeCXXFunctionDecl - Merge two declarations of the same C++
458/// function, once we already know that they have the same
459/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
460/// error, false otherwise.
461bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
462 Scope *S) {
463 bool Invalid = false;
464
465 // The declaration context corresponding to the scope is the semantic
466 // parent, unless this is a local function declaration, in which case
467 // it is that surrounding function.
468 DeclContext *ScopeDC = New->isLocalExternDecl()
469 ? New->getLexicalDeclContext()
470 : New->getDeclContext();
471
472 // Find the previous declaration for the purpose of default arguments.
473 FunctionDecl *PrevForDefaultArgs = Old;
474 for (/**/; PrevForDefaultArgs;
475 // Don't bother looking back past the latest decl if this is a local
476 // extern declaration; nothing else could work.
477 PrevForDefaultArgs = New->isLocalExternDecl()
478 ? nullptr
479 : PrevForDefaultArgs->getPreviousDecl()) {
480 // Ignore hidden declarations.
481 if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
482 continue;
483
484 if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
485 !New->isCXXClassMember()) {
486 // Ignore default arguments of old decl if they are not in
487 // the same scope and this is not an out-of-line definition of
488 // a member function.
489 continue;
490 }
491
492 if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
493 // If only one of these is a local function declaration, then they are
494 // declared in different scopes, even though isDeclInScope may think
495 // they're in the same scope. (If both are local, the scope check is
496 // sufficient, and if neither is local, then they are in the same scope.)
497 continue;
498 }
499
500 // We found the right previous declaration.
501 break;
502 }
503
504 // C++ [dcl.fct.default]p4:
505 // For non-template functions, default arguments can be added in
506 // later declarations of a function in the same
507 // scope. Declarations in different scopes have completely
508 // distinct sets of default arguments. That is, declarations in
509 // inner scopes do not acquire default arguments from
510 // declarations in outer scopes, and vice versa. In a given
511 // function declaration, all parameters subsequent to a
512 // parameter with a default argument shall have default
513 // arguments supplied in this or previous declarations. A
514 // default argument shall not be redefined by a later
515 // declaration (not even to the same value).
516 //
517 // C++ [dcl.fct.default]p6:
518 // Except for member functions of class templates, the default arguments
519 // in a member function definition that appears outside of the class
520 // definition are added to the set of default arguments provided by the
521 // member function declaration in the class definition.
522 for (unsigned p = 0, NumParams = PrevForDefaultArgs
523 ? PrevForDefaultArgs->getNumParams()
524 : 0;
525 p < NumParams; ++p) {
526 ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
527 ParmVarDecl *NewParam = New->getParamDecl(p);
528
529 bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
530 bool NewParamHasDfl = NewParam->hasDefaultArg();
531
532 if (OldParamHasDfl && NewParamHasDfl) {
533 unsigned DiagDefaultParamID =
534 diag::err_param_default_argument_redefinition;
535
536 // MSVC accepts that default parameters be redefined for member functions
537 // of template class. The new default parameter's value is ignored.
538 Invalid = true;
539 if (getLangOpts().MicrosoftExt) {
540 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
541 if (MD && MD->getParent()->getDescribedClassTemplate()) {
542 // Merge the old default argument into the new parameter.
543 NewParam->setHasInheritedDefaultArg();
544 if (OldParam->hasUninstantiatedDefaultArg())
545 NewParam->setUninstantiatedDefaultArg(
546 OldParam->getUninstantiatedDefaultArg());
547 else
548 NewParam->setDefaultArg(OldParam->getInit());
549 DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
550 Invalid = false;
551 }
552 }
553
554 // FIXME: If we knew where the '=' was, we could easily provide a fix-it
555 // hint here. Alternatively, we could walk the type-source information
556 // for NewParam to find the last source location in the type... but it
557 // isn't worth the effort right now. This is the kind of test case that
558 // is hard to get right:
559 // int f(int);
560 // void g(int (*fp)(int) = f);
561 // void g(int (*fp)(int) = &f);
562 Diag(NewParam->getLocation(), DiagDefaultParamID)
563 << NewParam->getDefaultArgRange();
564
565 // Look for the function declaration where the default argument was
566 // actually written, which may be a declaration prior to Old.
567 for (auto Older = PrevForDefaultArgs;
568 OldParam->hasInheritedDefaultArg(); /**/) {
569 Older = Older->getPreviousDecl();
570 OldParam = Older->getParamDecl(p);
571 }
572
573 Diag(OldParam->getLocation(), diag::note_previous_definition)
574 << OldParam->getDefaultArgRange();
575 } else if (OldParamHasDfl) {
576 // Merge the old default argument into the new parameter unless the new
577 // function is a friend declaration in a template class. In the latter
578 // case the default arguments will be inherited when the friend
579 // declaration will be instantiated.
580 if (New->getFriendObjectKind() == Decl::FOK_None ||
581 !New->getLexicalDeclContext()->isDependentContext()) {
582 // It's important to use getInit() here; getDefaultArg()
583 // strips off any top-level ExprWithCleanups.
584 NewParam->setHasInheritedDefaultArg();
585 if (OldParam->hasUnparsedDefaultArg())
586 NewParam->setUnparsedDefaultArg();
587 else if (OldParam->hasUninstantiatedDefaultArg())
588 NewParam->setUninstantiatedDefaultArg(
589 OldParam->getUninstantiatedDefaultArg());
590 else
591 NewParam->setDefaultArg(OldParam->getInit());
592 }
593 } else if (NewParamHasDfl) {
594 if (New->getDescribedFunctionTemplate()) {
595 // Paragraph 4, quoted above, only applies to non-template functions.
596 Diag(NewParam->getLocation(),
597 diag::err_param_default_argument_template_redecl)
598 << NewParam->getDefaultArgRange();
599 Diag(PrevForDefaultArgs->getLocation(),
600 diag::note_template_prev_declaration)
601 << false;
602 } else if (New->getTemplateSpecializationKind()
603 != TSK_ImplicitInstantiation &&
604 New->getTemplateSpecializationKind() != TSK_Undeclared) {
605 // C++ [temp.expr.spec]p21:
606 // Default function arguments shall not be specified in a declaration
607 // or a definition for one of the following explicit specializations:
608 // - the explicit specialization of a function template;
609 // - the explicit specialization of a member function template;
610 // - the explicit specialization of a member function of a class
611 // template where the class template specialization to which the
612 // member function specialization belongs is implicitly
613 // instantiated.
614 Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
615 << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
616 << New->getDeclName()
617 << NewParam->getDefaultArgRange();
618 } else if (New->getDeclContext()->isDependentContext()) {
619 // C++ [dcl.fct.default]p6 (DR217):
620 // Default arguments for a member function of a class template shall
621 // be specified on the initial declaration of the member function
622 // within the class template.
623 //
624 // Reading the tea leaves a bit in DR217 and its reference to DR205
625 // leads me to the conclusion that one cannot add default function
626 // arguments for an out-of-line definition of a member function of a
627 // dependent type.
628 int WhichKind = 2;
629 if (CXXRecordDecl *Record
630 = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
631 if (Record->getDescribedClassTemplate())
632 WhichKind = 0;
633 else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
634 WhichKind = 1;
635 else
636 WhichKind = 2;
637 }
638
639 Diag(NewParam->getLocation(),
640 diag::err_param_default_argument_member_template_redecl)
641 << WhichKind
642 << NewParam->getDefaultArgRange();
643 }
644 }
645 }
646
647 // DR1344: If a default argument is added outside a class definition and that
648 // default argument makes the function a special member function, the program
649 // is ill-formed. This can only happen for constructors.
650 if (isa<CXXConstructorDecl>(New) &&
651 New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
652 CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
653 OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
654 if (NewSM != OldSM) {
655 ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
656 assert(NewParam->hasDefaultArg())(static_cast <bool> (NewParam->hasDefaultArg()) ? void
(0) : __assert_fail ("NewParam->hasDefaultArg()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 656, __extension__ __PRETTY_FUNCTION__))
;
657 Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
658 << NewParam->getDefaultArgRange() << NewSM;
659 Diag(Old->getLocation(), diag::note_previous_declaration);
660 }
661 }
662
663 const FunctionDecl *Def;
664 // C++11 [dcl.constexpr]p1: If any declaration of a function or function
665 // template has a constexpr specifier then all its declarations shall
666 // contain the constexpr specifier.
667 if (New->getConstexprKind() != Old->getConstexprKind()) {
668 Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
669 << New << static_cast<int>(New->getConstexprKind())
670 << static_cast<int>(Old->getConstexprKind());
671 Diag(Old->getLocation(), diag::note_previous_declaration);
672 Invalid = true;
673 } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
674 Old->isDefined(Def) &&
675 // If a friend function is inlined but does not have 'inline'
676 // specifier, it is a definition. Do not report attribute conflict
677 // in this case, redefinition will be diagnosed later.
678 (New->isInlineSpecified() ||
679 New->getFriendObjectKind() == Decl::FOK_None)) {
680 // C++11 [dcl.fcn.spec]p4:
681 // If the definition of a function appears in a translation unit before its
682 // first declaration as inline, the program is ill-formed.
683 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
684 Diag(Def->getLocation(), diag::note_previous_definition);
685 Invalid = true;
686 }
687
688 // C++17 [temp.deduct.guide]p3:
689 // Two deduction guide declarations in the same translation unit
690 // for the same class template shall not have equivalent
691 // parameter-declaration-clauses.
692 if (isa<CXXDeductionGuideDecl>(New) &&
693 !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
694 Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
695 Diag(Old->getLocation(), diag::note_previous_declaration);
696 }
697
698 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
699 // argument expression, that declaration shall be a definition and shall be
700 // the only declaration of the function or function template in the
701 // translation unit.
702 if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
703 functionDeclHasDefaultArgument(Old)) {
704 Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
705 Diag(Old->getLocation(), diag::note_previous_declaration);
706 Invalid = true;
707 }
708
709 // C++11 [temp.friend]p4 (DR329):
710 // When a function is defined in a friend function declaration in a class
711 // template, the function is instantiated when the function is odr-used.
712 // The same restrictions on multiple declarations and definitions that
713 // apply to non-template function declarations and definitions also apply
714 // to these implicit definitions.
715 const FunctionDecl *OldDefinition = nullptr;
716 if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
717 Old->isDefined(OldDefinition, true))
718 CheckForFunctionRedefinition(New, OldDefinition);
719
720 return Invalid;
721}
722
723NamedDecl *
724Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
725 MultiTemplateParamsArg TemplateParamLists) {
726 assert(D.isDecompositionDeclarator())(static_cast <bool> (D.isDecompositionDeclarator()) ? void
(0) : __assert_fail ("D.isDecompositionDeclarator()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 726, __extension__ __PRETTY_FUNCTION__))
;
727 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
728
729 // The syntax only allows a decomposition declarator as a simple-declaration,
730 // a for-range-declaration, or a condition in Clang, but we parse it in more
731 // cases than that.
732 if (!D.mayHaveDecompositionDeclarator()) {
733 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
734 << Decomp.getSourceRange();
735 return nullptr;
736 }
737
738 if (!TemplateParamLists.empty()) {
739 // FIXME: There's no rule against this, but there are also no rules that
740 // would actually make it usable, so we reject it for now.
741 Diag(TemplateParamLists.front()->getTemplateLoc(),
742 diag::err_decomp_decl_template);
743 return nullptr;
744 }
745
746 Diag(Decomp.getLSquareLoc(),
747 !getLangOpts().CPlusPlus17
748 ? diag::ext_decomp_decl
749 : D.getContext() == DeclaratorContext::Condition
750 ? diag::ext_decomp_decl_cond
751 : diag::warn_cxx14_compat_decomp_decl)
752 << Decomp.getSourceRange();
753
754 // The semantic context is always just the current context.
755 DeclContext *const DC = CurContext;
756
757 // C++17 [dcl.dcl]/8:
758 // The decl-specifier-seq shall contain only the type-specifier auto
759 // and cv-qualifiers.
760 // C++20 [dcl.dcl]/8:
761 // If decl-specifier-seq contains any decl-specifier other than static,
762 // thread_local, auto, or cv-qualifiers, the program is ill-formed.
763 // C++2b [dcl.pre]/6:
764 // Each decl-specifier in the decl-specifier-seq shall be static,
765 // thread_local, auto (9.2.9.6 [dcl.spec.auto]), or a cv-qualifier.
766 auto &DS = D.getDeclSpec();
767 {
768 // Note: While constrained-auto needs to be checked, we do so separately so
769 // we can emit a better diagnostic.
770 SmallVector<StringRef, 8> BadSpecifiers;
771 SmallVector<SourceLocation, 8> BadSpecifierLocs;
772 SmallVector<StringRef, 8> CPlusPlus20Specifiers;
773 SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
774 if (auto SCS = DS.getStorageClassSpec()) {
775 if (SCS == DeclSpec::SCS_static) {
776 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
777 CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
778 } else {
779 BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
780 BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
781 }
782 }
783 if (auto TSCS = DS.getThreadStorageClassSpec()) {
784 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
785 CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
786 }
787 if (DS.hasConstexprSpecifier()) {
788 BadSpecifiers.push_back(
789 DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
790 BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
791 }
792 if (DS.isInlineSpecified()) {
793 BadSpecifiers.push_back("inline");
794 BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
795 }
796
797 if (!BadSpecifiers.empty()) {
798 auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
799 Err << (int)BadSpecifiers.size()
800 << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
801 // Don't add FixItHints to remove the specifiers; we do still respect
802 // them when building the underlying variable.
803 for (auto Loc : BadSpecifierLocs)
804 Err << SourceRange(Loc, Loc);
805 } else if (!CPlusPlus20Specifiers.empty()) {
806 auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
807 getLangOpts().CPlusPlus20
808 ? diag::warn_cxx17_compat_decomp_decl_spec
809 : diag::ext_decomp_decl_spec);
810 Warn << (int)CPlusPlus20Specifiers.size()
811 << llvm::join(CPlusPlus20Specifiers.begin(),
812 CPlusPlus20Specifiers.end(), " ");
813 for (auto Loc : CPlusPlus20SpecifierLocs)
814 Warn << SourceRange(Loc, Loc);
815 }
816 // We can't recover from it being declared as a typedef.
817 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
818 return nullptr;
819 }
820
821 // C++2a [dcl.struct.bind]p1:
822 // A cv that includes volatile is deprecated
823 if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
824 getLangOpts().CPlusPlus20)
825 Diag(DS.getVolatileSpecLoc(),
826 diag::warn_deprecated_volatile_structured_binding);
827
828 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
829 QualType R = TInfo->getType();
830
831 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
832 UPPC_DeclarationType))
833 D.setInvalidType();
834
835 // The syntax only allows a single ref-qualifier prior to the decomposition
836 // declarator. No other declarator chunks are permitted. Also check the type
837 // specifier here.
838 if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
839 D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
840 (D.getNumTypeObjects() == 1 &&
841 D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
842 Diag(Decomp.getLSquareLoc(),
843 (D.hasGroupingParens() ||
844 (D.getNumTypeObjects() &&
845 D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
846 ? diag::err_decomp_decl_parens
847 : diag::err_decomp_decl_type)
848 << R;
849
850 // In most cases, there's no actual problem with an explicitly-specified
851 // type, but a function type won't work here, and ActOnVariableDeclarator
852 // shouldn't be called for such a type.
853 if (R->isFunctionType())
854 D.setInvalidType();
855 }
856
857 // Constrained auto is prohibited by [decl.pre]p6, so check that here.
858 if (DS.isConstrainedAuto()) {
859 TemplateIdAnnotation *TemplRep = DS.getRepAsTemplateId();
860 assert(TemplRep->Kind == TNK_Concept_template &&(static_cast <bool> (TemplRep->Kind == TNK_Concept_template
&& "No other template kind should be possible for a constrained auto"
) ? void (0) : __assert_fail ("TemplRep->Kind == TNK_Concept_template && \"No other template kind should be possible for a constrained auto\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 861, __extension__ __PRETTY_FUNCTION__
))
861 "No other template kind should be possible for a constrained auto")(static_cast <bool> (TemplRep->Kind == TNK_Concept_template
&& "No other template kind should be possible for a constrained auto"
) ? void (0) : __assert_fail ("TemplRep->Kind == TNK_Concept_template && \"No other template kind should be possible for a constrained auto\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 861, __extension__ __PRETTY_FUNCTION__
))
;
862
863 SourceRange TemplRange{TemplRep->TemplateNameLoc,
864 TemplRep->RAngleLoc.isValid()
865 ? TemplRep->RAngleLoc
866 : TemplRep->TemplateNameLoc};
867 Diag(TemplRep->TemplateNameLoc, diag::err_decomp_decl_constraint)
868 << TemplRange << FixItHint::CreateRemoval(TemplRange);
869 }
870
871 // Build the BindingDecls.
872 SmallVector<BindingDecl*, 8> Bindings;
873
874 // Build the BindingDecls.
875 for (auto &B : D.getDecompositionDeclarator().bindings()) {
876 // Check for name conflicts.
877 DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
878 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
879 ForVisibleRedeclaration);
880 LookupName(Previous, S,
881 /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
882
883 // It's not permitted to shadow a template parameter name.
884 if (Previous.isSingleResult() &&
885 Previous.getFoundDecl()->isTemplateParameter()) {
886 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
887 Previous.getFoundDecl());
888 Previous.clear();
889 }
890
891 auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
892
893 // Find the shadowed declaration before filtering for scope.
894 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
895 ? getShadowedDeclaration(BD, Previous)
896 : nullptr;
897
898 bool ConsiderLinkage = DC->isFunctionOrMethod() &&
899 DS.getStorageClassSpec() == DeclSpec::SCS_extern;
900 FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
901 /*AllowInlineNamespace*/false);
902
903 if (!Previous.empty()) {
904 auto *Old = Previous.getRepresentativeDecl();
905 Diag(B.NameLoc, diag::err_redefinition) << B.Name;
906 Diag(Old->getLocation(), diag::note_previous_definition);
907 } else if (ShadowedDecl && !D.isRedeclaration()) {
908 CheckShadow(BD, ShadowedDecl, Previous);
909 }
910 PushOnScopeChains(BD, S, true);
911 Bindings.push_back(BD);
912 ParsingInitForAutoVars.insert(BD);
913 }
914
915 // There are no prior lookup results for the variable itself, because it
916 // is unnamed.
917 DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
918 Decomp.getLSquareLoc());
919 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
920 ForVisibleRedeclaration);
921
922 // Build the variable that holds the non-decomposed object.
923 bool AddToScope = true;
924 NamedDecl *New =
925 ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
926 MultiTemplateParamsArg(), AddToScope, Bindings);
927 if (AddToScope) {
928 S->AddDecl(New);
929 CurContext->addHiddenDecl(New);
930 }
931
932 if (isInOpenMPDeclareTargetContext())
933 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
934
935 return New;
936}
937
938static bool checkSimpleDecomposition(
939 Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
940 QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
941 llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
942 if ((int64_t)Bindings.size() != NumElems) {
943 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
944 << DecompType << (unsigned)Bindings.size()
945 << (unsigned)NumElems.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
946 << toString(NumElems, 10) << (NumElems < Bindings.size());
947 return true;
948 }
949
950 unsigned I = 0;
951 for (auto *B : Bindings) {
952 SourceLocation Loc = B->getLocation();
953 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
954 if (E.isInvalid())
955 return true;
956 E = GetInit(Loc, E.get(), I++);
957 if (E.isInvalid())
958 return true;
959 B->setBinding(ElemType, E.get());
960 }
961
962 return false;
963}
964
965static bool checkArrayLikeDecomposition(Sema &S,
966 ArrayRef<BindingDecl *> Bindings,
967 ValueDecl *Src, QualType DecompType,
968 const llvm::APSInt &NumElems,
969 QualType ElemType) {
970 return checkSimpleDecomposition(
971 S, Bindings, Src, DecompType, NumElems, ElemType,
972 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
973 ExprResult E = S.ActOnIntegerConstant(Loc, I);
974 if (E.isInvalid())
975 return ExprError();
976 return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
977 });
978}
979
980static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
981 ValueDecl *Src, QualType DecompType,
982 const ConstantArrayType *CAT) {
983 return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
984 llvm::APSInt(CAT->getSize()),
985 CAT->getElementType());
986}
987
988static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
989 ValueDecl *Src, QualType DecompType,
990 const VectorType *VT) {
991 return checkArrayLikeDecomposition(
992 S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
993 S.Context.getQualifiedType(VT->getElementType(),
994 DecompType.getQualifiers()));
995}
996
997static bool checkComplexDecomposition(Sema &S,
998 ArrayRef<BindingDecl *> Bindings,
999 ValueDecl *Src, QualType DecompType,
1000 const ComplexType *CT) {
1001 return checkSimpleDecomposition(
1002 S, Bindings, Src, DecompType, llvm::APSInt::get(2),
1003 S.Context.getQualifiedType(CT->getElementType(),
1004 DecompType.getQualifiers()),
1005 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
1006 return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
1007 });
1008}
1009
1010static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
1011 TemplateArgumentListInfo &Args,
1012 const TemplateParameterList *Params) {
1013 SmallString<128> SS;
1014 llvm::raw_svector_ostream OS(SS);
1015 bool First = true;
1016 unsigned I = 0;
1017 for (auto &Arg : Args.arguments()) {
1018 if (!First)
1019 OS << ", ";
1020 Arg.getArgument().print(PrintingPolicy, OS,
1021 TemplateParameterList::shouldIncludeTypeForArgument(
1022 PrintingPolicy, Params, I));
1023 First = false;
1024 I++;
1025 }
1026 return std::string(OS.str());
1027}
1028
1029static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
1030 SourceLocation Loc, StringRef Trait,
1031 TemplateArgumentListInfo &Args,
1032 unsigned DiagID) {
1033 auto DiagnoseMissing = [&] {
1034 if (DiagID)
1035 S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
1036 Args, /*Params*/ nullptr);
1037 return true;
1038 };
1039
1040 // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
1041 NamespaceDecl *Std = S.getStdNamespace();
1042 if (!Std)
1043 return DiagnoseMissing();
1044
1045 // Look up the trait itself, within namespace std. We can diagnose various
1046 // problems with this lookup even if we've been asked to not diagnose a
1047 // missing specialization, because this can only fail if the user has been
1048 // declaring their own names in namespace std or we don't support the
1049 // standard library implementation in use.
1050 LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
1051 Loc, Sema::LookupOrdinaryName);
1052 if (!S.LookupQualifiedName(Result, Std))
1053 return DiagnoseMissing();
1054 if (Result.isAmbiguous())
1055 return true;
1056
1057 ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
1058 if (!TraitTD) {
1059 Result.suppressDiagnostics();
1060 NamedDecl *Found = *Result.begin();
1061 S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
1062 S.Diag(Found->getLocation(), diag::note_declared_at);
1063 return true;
1064 }
1065
1066 // Build the template-id.
1067 QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
1068 if (TraitTy.isNull())
1069 return true;
1070 if (!S.isCompleteType(Loc, TraitTy)) {
1071 if (DiagID)
1072 S.RequireCompleteType(
1073 Loc, TraitTy, DiagID,
1074 printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1075 TraitTD->getTemplateParameters()));
1076 return true;
1077 }
1078
1079 CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
1080 assert(RD && "specialization of class template is not a class?")(static_cast <bool> (RD && "specialization of class template is not a class?"
) ? void (0) : __assert_fail ("RD && \"specialization of class template is not a class?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 1080, __extension__ __PRETTY_FUNCTION__
))
;
1081
1082 // Look up the member of the trait type.
1083 S.LookupQualifiedName(TraitMemberLookup, RD);
1084 return TraitMemberLookup.isAmbiguous();
1085}
1086
1087static TemplateArgumentLoc
1088getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
1089 uint64_t I) {
1090 TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
1091 return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1092}
1093
1094static TemplateArgumentLoc
1095getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
1096 return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1097}
1098
1099namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1100
1101static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
1102 llvm::APSInt &Size) {
1103 EnterExpressionEvaluationContext ContextRAII(
1104 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1105
1106 DeclarationName Value = S.PP.getIdentifierInfo("value");
1107 LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1108
1109 // Form template argument list for tuple_size<T>.
1110 TemplateArgumentListInfo Args(Loc, Loc);
1111 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1112
1113 // If there's no tuple_size specialization or the lookup of 'value' is empty,
1114 // it's not tuple-like.
1115 if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
1116 R.empty())
1117 return IsTupleLike::NotTupleLike;
1118
1119 // If we get this far, we've committed to the tuple interpretation, but
1120 // we can still fail if there actually isn't a usable ::value.
1121
1122 struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1123 LookupResult &R;
1124 TemplateArgumentListInfo &Args;
1125 ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1126 : R(R), Args(Args) {}
1127 Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
1128 SourceLocation Loc) override {
1129 return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1130 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1131 /*Params*/ nullptr);
1132 }
1133 } Diagnoser(R, Args);
1134
1135 ExprResult E =
1136 S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1137 if (E.isInvalid())
1138 return IsTupleLike::Error;
1139
1140 E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
1141 if (E.isInvalid())
1142 return IsTupleLike::Error;
1143
1144 return IsTupleLike::TupleLike;
1145}
1146
1147/// \return std::tuple_element<I, T>::type.
1148static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
1149 unsigned I, QualType T) {
1150 // Form template argument list for tuple_element<I, T>.
1151 TemplateArgumentListInfo Args(Loc, Loc);
1152 Args.addArgument(
1153 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1154 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1155
1156 DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1157 LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1158 if (lookupStdTypeTraitMember(
1159 S, R, Loc, "tuple_element", Args,
1160 diag::err_decomp_decl_std_tuple_element_not_specialized))
1161 return QualType();
1162
1163 auto *TD = R.getAsSingle<TypeDecl>();
1164 if (!TD) {
1165 R.suppressDiagnostics();
1166 S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1167 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1168 /*Params*/ nullptr);
1169 if (!R.empty())
1170 S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1171 return QualType();
1172 }
1173
1174 return S.Context.getTypeDeclType(TD);
1175}
1176
1177namespace {
1178struct InitializingBinding {
1179 Sema &S;
1180 InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
1181 Sema::CodeSynthesisContext Ctx;
1182 Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
1183 Ctx.PointOfInstantiation = BD->getLocation();
1184 Ctx.Entity = BD;
1185 S.pushCodeSynthesisContext(Ctx);
1186 }
1187 ~InitializingBinding() {
1188 S.popCodeSynthesisContext();
1189 }
1190};
1191}
1192
1193static bool checkTupleLikeDecomposition(Sema &S,
1194 ArrayRef<BindingDecl *> Bindings,
1195 VarDecl *Src, QualType DecompType,
1196 const llvm::APSInt &TupleSize) {
1197 if ((int64_t)Bindings.size() != TupleSize) {
1198 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1199 << DecompType << (unsigned)Bindings.size()
1200 << (unsigned)TupleSize.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
1201 << toString(TupleSize, 10) << (TupleSize < Bindings.size());
1202 return true;
1203 }
1204
1205 if (Bindings.empty())
1206 return false;
1207
1208 DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1209
1210 // [dcl.decomp]p3:
1211 // The unqualified-id get is looked up in the scope of E by class member
1212 // access lookup ...
1213 LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1214 bool UseMemberGet = false;
1215 if (S.isCompleteType(Src->getLocation(), DecompType)) {
1216 if (auto *RD = DecompType->getAsCXXRecordDecl())
1217 S.LookupQualifiedName(MemberGet, RD);
1218 if (MemberGet.isAmbiguous())
1219 return true;
1220 // ... and if that finds at least one declaration that is a function
1221 // template whose first template parameter is a non-type parameter ...
1222 for (NamedDecl *D : MemberGet) {
1223 if (FunctionTemplateDecl *FTD =
1224 dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1225 TemplateParameterList *TPL = FTD->getTemplateParameters();
1226 if (TPL->size() != 0 &&
1227 isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1228 // ... the initializer is e.get<i>().
1229 UseMemberGet = true;
1230 break;
1231 }
1232 }
1233 }
1234 }
1235
1236 unsigned I = 0;
1237 for (auto *B : Bindings) {
1238 InitializingBinding InitContext(S, B);
1239 SourceLocation Loc = B->getLocation();
1240
1241 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1242 if (E.isInvalid())
1243 return true;
1244
1245 // e is an lvalue if the type of the entity is an lvalue reference and
1246 // an xvalue otherwise
1247 if (!Src->getType()->isLValueReferenceType())
1248 E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1249 E.get(), nullptr, VK_XValue,
1250 FPOptionsOverride());
1251
1252 TemplateArgumentListInfo Args(Loc, Loc);
1253 Args.addArgument(
1254 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1255
1256 if (UseMemberGet) {
1257 // if [lookup of member get] finds at least one declaration, the
1258 // initializer is e.get<i-1>().
1259 E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1260 CXXScopeSpec(), SourceLocation(), nullptr,
1261 MemberGet, &Args, nullptr);
1262 if (E.isInvalid())
1263 return true;
1264
1265 E = S.BuildCallExpr(nullptr, E.get(), Loc, std::nullopt, Loc);
1266 } else {
1267 // Otherwise, the initializer is get<i-1>(e), where get is looked up
1268 // in the associated namespaces.
1269 Expr *Get = UnresolvedLookupExpr::Create(
1270 S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
1271 DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1272 UnresolvedSetIterator(), UnresolvedSetIterator());
1273
1274 Expr *Arg = E.get();
1275 E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
1276 }
1277 if (E.isInvalid())
1278 return true;
1279 Expr *Init = E.get();
1280
1281 // Given the type T designated by std::tuple_element<i - 1, E>::type,
1282 QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1283 if (T.isNull())
1284 return true;
1285
1286 // each vi is a variable of type "reference to T" initialized with the
1287 // initializer, where the reference is an lvalue reference if the
1288 // initializer is an lvalue and an rvalue reference otherwise
1289 QualType RefType =
1290 S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1291 if (RefType.isNull())
1292 return true;
1293 auto *RefVD = VarDecl::Create(
1294 S.Context, Src->getDeclContext(), Loc, Loc,
1295 B->getDeclName().getAsIdentifierInfo(), RefType,
1296 S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
1297 RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
1298 RefVD->setTSCSpec(Src->getTSCSpec());
1299 RefVD->setImplicit();
1300 if (Src->isInlineSpecified())
1301 RefVD->setInlineSpecified();
1302 RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1303
1304 InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
1305 InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
1306 InitializationSequence Seq(S, Entity, Kind, Init);
1307 E = Seq.Perform(S, Entity, Kind, Init);
1308 if (E.isInvalid())
1309 return true;
1310 E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1311 if (E.isInvalid())
1312 return true;
1313 RefVD->setInit(E.get());
1314 S.CheckCompleteVariableDeclaration(RefVD);
1315
1316 E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
1317 DeclarationNameInfo(B->getDeclName(), Loc),
1318 RefVD);
1319 if (E.isInvalid())
1320 return true;
1321
1322 B->setBinding(T, E.get());
1323 I++;
1324 }
1325
1326 return false;
1327}
1328
1329/// Find the base class to decompose in a built-in decomposition of a class type.
1330/// This base class search is, unfortunately, not quite like any other that we
1331/// perform anywhere else in C++.
1332static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
1333 const CXXRecordDecl *RD,
1334 CXXCastPath &BasePath) {
1335 auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1336 CXXBasePath &Path) {
1337 return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1338 };
1339
1340 const CXXRecordDecl *ClassWithFields = nullptr;
1341 AccessSpecifier AS = AS_public;
1342 if (RD->hasDirectFields())
1343 // [dcl.decomp]p4:
1344 // Otherwise, all of E's non-static data members shall be public direct
1345 // members of E ...
1346 ClassWithFields = RD;
1347 else {
1348 // ... or of ...
1349 CXXBasePaths Paths;
1350 Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1351 if (!RD->lookupInBases(BaseHasFields, Paths)) {
1352 // If no classes have fields, just decompose RD itself. (This will work
1353 // if and only if zero bindings were provided.)
1354 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1355 }
1356
1357 CXXBasePath *BestPath = nullptr;
1358 for (auto &P : Paths) {
1359 if (!BestPath)
1360 BestPath = &P;
1361 else if (!S.Context.hasSameType(P.back().Base->getType(),
1362 BestPath->back().Base->getType())) {
1363 // ... the same ...
1364 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1365 << false << RD << BestPath->back().Base->getType()
1366 << P.back().Base->getType();
1367 return DeclAccessPair();
1368 } else if (P.Access < BestPath->Access) {
1369 BestPath = &P;
1370 }
1371 }
1372
1373 // ... unambiguous ...
1374 QualType BaseType = BestPath->back().Base->getType();
1375 if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1376 S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1377 << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1378 return DeclAccessPair();
1379 }
1380
1381 // ... [accessible, implied by other rules] base class of E.
1382 S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1383 *BestPath, diag::err_decomp_decl_inaccessible_base);
1384 AS = BestPath->Access;
1385
1386 ClassWithFields = BaseType->getAsCXXRecordDecl();
1387 S.BuildBasePathArray(Paths, BasePath);
1388 }
1389
1390 // The above search did not check whether the selected class itself has base
1391 // classes with fields, so check that now.
1392 CXXBasePaths Paths;
1393 if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1394 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1395 << (ClassWithFields == RD) << RD << ClassWithFields
1396 << Paths.front().back().Base->getType();
1397 return DeclAccessPair();
1398 }
1399
1400 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1401}
1402
1403static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
1404 ValueDecl *Src, QualType DecompType,
1405 const CXXRecordDecl *OrigRD) {
1406 if (S.RequireCompleteType(Src->getLocation(), DecompType,
1407 diag::err_incomplete_type))
1408 return true;
1409
1410 CXXCastPath BasePath;
1411 DeclAccessPair BasePair =
1412 findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1413 const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1414 if (!RD)
1415 return true;
1416 QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
1417 DecompType.getQualifiers());
1418
1419 auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1420 unsigned NumFields = llvm::count_if(
1421 RD->fields(), [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1422 assert(Bindings.size() != NumFields)(static_cast <bool> (Bindings.size() != NumFields) ? void
(0) : __assert_fail ("Bindings.size() != NumFields", "clang/lib/Sema/SemaDeclCXX.cpp"
, 1422, __extension__ __PRETTY_FUNCTION__))
;
1423 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1424 << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
1425 << (NumFields < Bindings.size());
1426 return true;
1427 };
1428
1429 // all of E's non-static data members shall be [...] well-formed
1430 // when named as e.name in the context of the structured binding,
1431 // E shall not have an anonymous union member, ...
1432 unsigned I = 0;
1433 for (auto *FD : RD->fields()) {
1434 if (FD->isUnnamedBitfield())
1435 continue;
1436
1437 // All the non-static data members are required to be nameable, so they
1438 // must all have names.
1439 if (!FD->getDeclName()) {
1440 if (RD->isLambda()) {
1441 S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
1442 S.Diag(RD->getLocation(), diag::note_lambda_decl);
1443 return true;
1444 }
1445
1446 if (FD->isAnonymousStructOrUnion()) {
1447 S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1448 << DecompType << FD->getType()->isUnionType();
1449 S.Diag(FD->getLocation(), diag::note_declared_at);
1450 return true;
1451 }
1452
1453 // FIXME: Are there any other ways we could have an anonymous member?
1454 }
1455
1456 // We have a real field to bind.
1457 if (I >= Bindings.size())
1458 return DiagnoseBadNumberOfBindings();
1459 auto *B = Bindings[I++];
1460 SourceLocation Loc = B->getLocation();
1461
1462 // The field must be accessible in the context of the structured binding.
1463 // We already checked that the base class is accessible.
1464 // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1465 // const_cast here.
1466 S.CheckStructuredBindingMemberAccess(
1467 Loc, const_cast<CXXRecordDecl *>(OrigRD),
1468 DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
1469 BasePair.getAccess(), FD->getAccess())));
1470
1471 // Initialize the binding to Src.FD.
1472 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1473 if (E.isInvalid())
1474 return true;
1475 E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1476 VK_LValue, &BasePath);
1477 if (E.isInvalid())
1478 return true;
1479 E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1480 CXXScopeSpec(), FD,
1481 DeclAccessPair::make(FD, FD->getAccess()),
1482 DeclarationNameInfo(FD->getDeclName(), Loc));
1483 if (E.isInvalid())
1484 return true;
1485
1486 // If the type of the member is T, the referenced type is cv T, where cv is
1487 // the cv-qualification of the decomposition expression.
1488 //
1489 // FIXME: We resolve a defect here: if the field is mutable, we do not add
1490 // 'const' to the type of the field.
1491 Qualifiers Q = DecompType.getQualifiers();
1492 if (FD->isMutable())
1493 Q.removeConst();
1494 B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1495 }
1496
1497 if (I != Bindings.size())
1498 return DiagnoseBadNumberOfBindings();
1499
1500 return false;
1501}
1502
1503void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
1504 QualType DecompType = DD->getType();
1505
1506 // If the type of the decomposition is dependent, then so is the type of
1507 // each binding.
1508 if (DecompType->isDependentType()) {
1509 for (auto *B : DD->bindings())
1510 B->setType(Context.DependentTy);
1511 return;
1512 }
1513
1514 DecompType = DecompType.getNonReferenceType();
1515 ArrayRef<BindingDecl*> Bindings = DD->bindings();
1516
1517 // C++1z [dcl.decomp]/2:
1518 // If E is an array type [...]
1519 // As an extension, we also support decomposition of built-in complex and
1520 // vector types.
1521 if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1522 if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1523 DD->setInvalidDecl();
1524 return;
1525 }
1526 if (auto *VT = DecompType->getAs<VectorType>()) {
1527 if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1528 DD->setInvalidDecl();
1529 return;
1530 }
1531 if (auto *CT = DecompType->getAs<ComplexType>()) {
1532 if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1533 DD->setInvalidDecl();
1534 return;
1535 }
1536
1537 // C++1z [dcl.decomp]/3:
1538 // if the expression std::tuple_size<E>::value is a well-formed integral
1539 // constant expression, [...]
1540 llvm::APSInt TupleSize(32);
1541 switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1542 case IsTupleLike::Error:
1543 DD->setInvalidDecl();
1544 return;
1545
1546 case IsTupleLike::TupleLike:
1547 if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1548 DD->setInvalidDecl();
1549 return;
1550
1551 case IsTupleLike::NotTupleLike:
1552 break;
1553 }
1554
1555 // C++1z [dcl.dcl]/8:
1556 // [E shall be of array or non-union class type]
1557 CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1558 if (!RD || RD->isUnion()) {
1559 Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1560 << DD << !RD << DecompType;
1561 DD->setInvalidDecl();
1562 return;
1563 }
1564
1565 // C++1z [dcl.decomp]/4:
1566 // all of E's non-static data members shall be [...] direct members of
1567 // E or of the same unambiguous public base class of E, ...
1568 if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1569 DD->setInvalidDecl();
1570}
1571
1572/// Merge the exception specifications of two variable declarations.
1573///
1574/// This is called when there's a redeclaration of a VarDecl. The function
1575/// checks if the redeclaration might have an exception specification and
1576/// validates compatibility and merges the specs if necessary.
1577void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
1578 // Shortcut if exceptions are disabled.
1579 if (!getLangOpts().CXXExceptions)
1580 return;
1581
1582 assert(Context.hasSameType(New->getType(), Old->getType()) &&(static_cast <bool> (Context.hasSameType(New->getType
(), Old->getType()) && "Should only be called if types are otherwise the same."
) ? void (0) : __assert_fail ("Context.hasSameType(New->getType(), Old->getType()) && \"Should only be called if types are otherwise the same.\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 1583, __extension__ __PRETTY_FUNCTION__
))
1583 "Should only be called if types are otherwise the same.")(static_cast <bool> (Context.hasSameType(New->getType
(), Old->getType()) && "Should only be called if types are otherwise the same."
) ? void (0) : __assert_fail ("Context.hasSameType(New->getType(), Old->getType()) && \"Should only be called if types are otherwise the same.\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 1583, __extension__ __PRETTY_FUNCTION__
))
;
1584
1585 QualType NewType = New->getType();
1586 QualType OldType = Old->getType();
1587
1588 // We're only interested in pointers and references to functions, as well
1589 // as pointers to member functions.
1590 if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1591 NewType = R->getPointeeType();
1592 OldType = OldType->castAs<ReferenceType>()->getPointeeType();
1593 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1594 NewType = P->getPointeeType();
1595 OldType = OldType->castAs<PointerType>()->getPointeeType();
1596 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1597 NewType = M->getPointeeType();
1598 OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
1599 }
1600
1601 if (!NewType->isFunctionProtoType())
1602 return;
1603
1604 // There's lots of special cases for functions. For function pointers, system
1605 // libraries are hopefully not as broken so that we don't need these
1606 // workarounds.
1607 if (CheckEquivalentExceptionSpec(
1608 OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1609 NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1610 New->setInvalidDecl();
1611 }
1612}
1613
1614/// CheckCXXDefaultArguments - Verify that the default arguments for a
1615/// function declaration are well-formed according to C++
1616/// [dcl.fct.default].
1617void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
1618 unsigned NumParams = FD->getNumParams();
1619 unsigned ParamIdx = 0;
1620
1621 // This checking doesn't make sense for explicit specializations; their
1622 // default arguments are determined by the declaration we're specializing,
1623 // not by FD.
1624 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1625 return;
1626 if (auto *FTD = FD->getDescribedFunctionTemplate())
1627 if (FTD->isMemberSpecialization())
1628 return;
1629
1630 // Find first parameter with a default argument
1631 for (; ParamIdx < NumParams; ++ParamIdx) {
1632 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1633 if (Param->hasDefaultArg())
1634 break;
1635 }
1636
1637 // C++20 [dcl.fct.default]p4:
1638 // In a given function declaration, each parameter subsequent to a parameter
1639 // with a default argument shall have a default argument supplied in this or
1640 // a previous declaration, unless the parameter was expanded from a
1641 // parameter pack, or shall be a function parameter pack.
1642 for (; ParamIdx < NumParams; ++ParamIdx) {
1643 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1644 if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
1645 !(CurrentInstantiationScope &&
1646 CurrentInstantiationScope->isLocalPackExpansion(Param))) {
1647 if (Param->isInvalidDecl())
1648 /* We already complained about this parameter. */;
1649 else if (Param->getIdentifier())
1650 Diag(Param->getLocation(),
1651 diag::err_param_default_argument_missing_name)
1652 << Param->getIdentifier();
1653 else
1654 Diag(Param->getLocation(),
1655 diag::err_param_default_argument_missing);
1656 }
1657 }
1658}
1659
1660/// Check that the given type is a literal type. Issue a diagnostic if not,
1661/// if Kind is Diagnose.
1662/// \return \c true if a problem has been found (and optionally diagnosed).
1663template <typename... Ts>
1664static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
1665 SourceLocation Loc, QualType T, unsigned DiagID,
1666 Ts &&...DiagArgs) {
1667 if (T->isDependentType())
1668 return false;
1669
1670 switch (Kind) {
1671 case Sema::CheckConstexprKind::Diagnose:
1672 return SemaRef.RequireLiteralType(Loc, T, DiagID,
1673 std::forward<Ts>(DiagArgs)...);
1674
1675 case Sema::CheckConstexprKind::CheckValid:
1676 return !T->isLiteralType(SemaRef.Context);
1677 }
1678
1679 llvm_unreachable("unknown CheckConstexprKind")::llvm::llvm_unreachable_internal("unknown CheckConstexprKind"
, "clang/lib/Sema/SemaDeclCXX.cpp", 1679)
;
1680}
1681
1682/// Determine whether a destructor cannot be constexpr due to
1683static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
1684 const CXXDestructorDecl *DD,
1685 Sema::CheckConstexprKind Kind) {
1686 auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
1687 const CXXRecordDecl *RD =
1688 T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1689 if (!RD || RD->hasConstexprDestructor())
1690 return true;
1691
1692 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1693 SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
1694 << static_cast<int>(DD->getConstexprKind()) << !FD
1695 << (FD ? FD->getDeclName() : DeclarationName()) << T;
1696 SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
1697 << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
1698 }
1699 return false;
1700 };
1701
1702 const CXXRecordDecl *RD = DD->getParent();
1703 for (const CXXBaseSpecifier &B : RD->bases())
1704 if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
1705 return false;
1706 for (const FieldDecl *FD : RD->fields())
1707 if (!Check(FD->getLocation(), FD->getType(), FD))
1708 return false;
1709 return true;
1710}
1711
1712/// Check whether a function's parameter types are all literal types. If so,
1713/// return true. If not, produce a suitable diagnostic and return false.
1714static bool CheckConstexprParameterTypes(Sema &SemaRef,
1715 const FunctionDecl *FD,
1716 Sema::CheckConstexprKind Kind) {
1717 unsigned ArgIndex = 0;
1718 const auto *FT = FD->getType()->castAs<FunctionProtoType>();
1719 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1720 e = FT->param_type_end();
1721 i != e; ++i, ++ArgIndex) {
1722 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1723 SourceLocation ParamLoc = PD->getLocation();
1724 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1725 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1726 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1727 FD->isConsteval()))
1728 return false;
1729 }
1730 return true;
1731}
1732
1733/// Check whether a function's return type is a literal type. If so, return
1734/// true. If not, produce a suitable diagnostic and return false.
1735static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
1736 Sema::CheckConstexprKind Kind) {
1737 if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
1738 diag::err_constexpr_non_literal_return,
1739 FD->isConsteval()))
1740 return false;
1741 return true;
1742}
1743
1744/// Get diagnostic %select index for tag kind for
1745/// record diagnostic message.
1746/// WARNING: Indexes apply to particular diagnostics only!
1747///
1748/// \returns diagnostic %select index.
1749static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1750 switch (Tag) {
1751 case TTK_Struct: return 0;
1752 case TTK_Interface: return 1;
1753 case TTK_Class: return 2;
1754 default: llvm_unreachable("Invalid tag kind for record diagnostic!")::llvm::llvm_unreachable_internal("Invalid tag kind for record diagnostic!"
, "clang/lib/Sema/SemaDeclCXX.cpp", 1754)
;
1755 }
1756}
1757
1758static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1759 Stmt *Body,
1760 Sema::CheckConstexprKind Kind);
1761
1762// Check whether a function declaration satisfies the requirements of a
1763// constexpr function definition or a constexpr constructor definition. If so,
1764// return true. If not, produce appropriate diagnostics (unless asked not to by
1765// Kind) and return false.
1766//
1767// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1768bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1769 CheckConstexprKind Kind) {
1770 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1771 if (MD && MD->isInstance()) {
1772 // C++11 [dcl.constexpr]p4:
1773 // The definition of a constexpr constructor shall satisfy the following
1774 // constraints:
1775 // - the class shall not have any virtual base classes;
1776 //
1777 // FIXME: This only applies to constructors and destructors, not arbitrary
1778 // member functions.
1779 const CXXRecordDecl *RD = MD->getParent();
1780 if (RD->getNumVBases()) {
1781 if (Kind == CheckConstexprKind::CheckValid)
1782 return false;
1783
1784 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1785 << isa<CXXConstructorDecl>(NewFD)
1786 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1787 for (const auto &I : RD->vbases())
1788 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1789 << I.getSourceRange();
1790 return false;
1791 }
1792 }
1793
1794 if (!isa<CXXConstructorDecl>(NewFD)) {
1795 // C++11 [dcl.constexpr]p3:
1796 // The definition of a constexpr function shall satisfy the following
1797 // constraints:
1798 // - it shall not be virtual; (removed in C++20)
1799 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1800 if (Method && Method->isVirtual()) {
1801 if (getLangOpts().CPlusPlus20) {
1802 if (Kind == CheckConstexprKind::Diagnose)
1803 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1804 } else {
1805 if (Kind == CheckConstexprKind::CheckValid)
1806 return false;
1807
1808 Method = Method->getCanonicalDecl();
1809 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1810
1811 // If it's not obvious why this function is virtual, find an overridden
1812 // function which uses the 'virtual' keyword.
1813 const CXXMethodDecl *WrittenVirtual = Method;
1814 while (!WrittenVirtual->isVirtualAsWritten())
1815 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1816 if (WrittenVirtual != Method)
1817 Diag(WrittenVirtual->getLocation(),
1818 diag::note_overridden_virtual_function);
1819 return false;
1820 }
1821 }
1822
1823 // - its return type shall be a literal type;
1824 if (!CheckConstexprReturnType(*this, NewFD, Kind))
1825 return false;
1826 }
1827
1828 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1829 // A destructor can be constexpr only if the defaulted destructor could be;
1830 // we don't need to check the members and bases if we already know they all
1831 // have constexpr destructors.
1832 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1833 if (Kind == CheckConstexprKind::CheckValid)
1834 return false;
1835 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1836 return false;
1837 }
1838 }
1839
1840 // - each of its parameter types shall be a literal type;
1841 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1842 return false;
1843
1844 Stmt *Body = NewFD->getBody();
1845 assert(Body &&(static_cast <bool> (Body && "CheckConstexprFunctionDefinition called on function with no body"
) ? void (0) : __assert_fail ("Body && \"CheckConstexprFunctionDefinition called on function with no body\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 1846, __extension__ __PRETTY_FUNCTION__
))
1846 "CheckConstexprFunctionDefinition called on function with no body")(static_cast <bool> (Body && "CheckConstexprFunctionDefinition called on function with no body"
) ? void (0) : __assert_fail ("Body && \"CheckConstexprFunctionDefinition called on function with no body\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 1846, __extension__ __PRETTY_FUNCTION__
))
;
1847 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1848}
1849
1850/// Check the given declaration statement is legal within a constexpr function
1851/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1852///
1853/// \return true if the body is OK (maybe only as an extension), false if we
1854/// have diagnosed a problem.
1855static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1856 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1857 Sema::CheckConstexprKind Kind) {
1858 // C++11 [dcl.constexpr]p3 and p4:
1859 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1860 // contain only
1861 for (const auto *DclIt : DS->decls()) {
1862 switch (DclIt->getKind()) {
1863 case Decl::StaticAssert:
1864 case Decl::Using:
1865 case Decl::UsingShadow:
1866 case Decl::UsingDirective:
1867 case Decl::UnresolvedUsingTypename:
1868 case Decl::UnresolvedUsingValue:
1869 case Decl::UsingEnum:
1870 // - static_assert-declarations
1871 // - using-declarations,
1872 // - using-directives,
1873 // - using-enum-declaration
1874 continue;
1875
1876 case Decl::Typedef:
1877 case Decl::TypeAlias: {
1878 // - typedef declarations and alias-declarations that do not define
1879 // classes or enumerations,
1880 const auto *TN = cast<TypedefNameDecl>(DclIt);
1881 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1882 // Don't allow variably-modified types in constexpr functions.
1883 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1884 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1885 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1886 << TL.getSourceRange() << TL.getType()
1887 << isa<CXXConstructorDecl>(Dcl);
1888 }
1889 return false;
1890 }
1891 continue;
1892 }
1893
1894 case Decl::Enum:
1895 case Decl::CXXRecord:
1896 // C++1y allows types to be defined, not just declared.
1897 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1898 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1899 SemaRef.Diag(DS->getBeginLoc(),
1900 SemaRef.getLangOpts().CPlusPlus14
1901 ? diag::warn_cxx11_compat_constexpr_type_definition
1902 : diag::ext_constexpr_type_definition)
1903 << isa<CXXConstructorDecl>(Dcl);
1904 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1905 return false;
1906 }
1907 }
1908 continue;
1909
1910 case Decl::EnumConstant:
1911 case Decl::IndirectField:
1912 case Decl::ParmVar:
1913 // These can only appear with other declarations which are banned in
1914 // C++11 and permitted in C++1y, so ignore them.
1915 continue;
1916
1917 case Decl::Var:
1918 case Decl::Decomposition: {
1919 // C++1y [dcl.constexpr]p3 allows anything except:
1920 // a definition of a variable of non-literal type or of static or
1921 // thread storage duration or [before C++2a] for which no
1922 // initialization is performed.
1923 const auto *VD = cast<VarDecl>(DclIt);
1924 if (VD->isThisDeclarationADefinition()) {
1925 if (VD->isStaticLocal()) {
1926 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1927 SemaRef.Diag(VD->getLocation(),
1928 SemaRef.getLangOpts().CPlusPlus2b
1929 ? diag::warn_cxx20_compat_constexpr_var
1930 : diag::ext_constexpr_static_var)
1931 << isa<CXXConstructorDecl>(Dcl)
1932 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1933 } else if (!SemaRef.getLangOpts().CPlusPlus2b) {
1934 return false;
1935 }
1936 }
1937 if (SemaRef.LangOpts.CPlusPlus2b) {
1938 CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1939 diag::warn_cxx20_compat_constexpr_var,
1940 isa<CXXConstructorDecl>(Dcl),
1941 /*variable of non-literal type*/ 2);
1942 } else if (CheckLiteralType(
1943 SemaRef, Kind, VD->getLocation(), VD->getType(),
1944 diag::err_constexpr_local_var_non_literal_type,
1945 isa<CXXConstructorDecl>(Dcl))) {
1946 return false;
1947 }
1948 if (!VD->getType()->isDependentType() &&
1949 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1950 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1951 SemaRef.Diag(
1952 VD->getLocation(),
1953 SemaRef.getLangOpts().CPlusPlus20
1954 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1955 : diag::ext_constexpr_local_var_no_init)
1956 << isa<CXXConstructorDecl>(Dcl);
1957 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
1958 return false;
1959 }
1960 continue;
1961 }
1962 }
1963 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1964 SemaRef.Diag(VD->getLocation(),
1965 SemaRef.getLangOpts().CPlusPlus14
1966 ? diag::warn_cxx11_compat_constexpr_local_var
1967 : diag::ext_constexpr_local_var)
1968 << isa<CXXConstructorDecl>(Dcl);
1969 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1970 return false;
1971 }
1972 continue;
1973 }
1974
1975 case Decl::NamespaceAlias:
1976 case Decl::Function:
1977 // These are disallowed in C++11 and permitted in C++1y. Allow them
1978 // everywhere as an extension.
1979 if (!Cxx1yLoc.isValid())
1980 Cxx1yLoc = DS->getBeginLoc();
1981 continue;
1982
1983 default:
1984 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1985 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1986 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1987 }
1988 return false;
1989 }
1990 }
1991
1992 return true;
1993}
1994
1995/// Check that the given field is initialized within a constexpr constructor.
1996///
1997/// \param Dcl The constexpr constructor being checked.
1998/// \param Field The field being checked. This may be a member of an anonymous
1999/// struct or union nested within the class being checked.
2000/// \param Inits All declarations, including anonymous struct/union members and
2001/// indirect members, for which any initialization was provided.
2002/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
2003/// multiple notes for different members to the same error.
2004/// \param Kind Whether we're diagnosing a constructor as written or determining
2005/// whether the formal requirements are satisfied.
2006/// \return \c false if we're checking for validity and the constructor does
2007/// not satisfy the requirements on a constexpr constructor.
2008static bool CheckConstexprCtorInitializer(Sema &SemaRef,
2009 const FunctionDecl *Dcl,
2010 FieldDecl *Field,
2011 llvm::SmallSet<Decl*, 16> &Inits,
2012 bool &Diagnosed,
2013 Sema::CheckConstexprKind Kind) {
2014 // In C++20 onwards, there's nothing to check for validity.
2015 if (Kind == Sema::CheckConstexprKind::CheckValid &&
2016 SemaRef.getLangOpts().CPlusPlus20)
2017 return true;
2018
2019 if (Field->isInvalidDecl())
2020 return true;
2021
2022 if (Field->isUnnamedBitfield())
2023 return true;
2024
2025 // Anonymous unions with no variant members and empty anonymous structs do not
2026 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
2027 // indirect fields don't need initializing.
2028 if (Field->isAnonymousStructOrUnion() &&
2029 (Field->getType()->isUnionType()
2030 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
2031 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
2032 return true;
2033
2034 if (!Inits.count(Field)) {
2035 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2036 if (!Diagnosed) {
2037 SemaRef.Diag(Dcl->getLocation(),
2038 SemaRef.getLangOpts().CPlusPlus20
2039 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
2040 : diag::ext_constexpr_ctor_missing_init);
2041 Diagnosed = true;
2042 }
2043 SemaRef.Diag(Field->getLocation(),
2044 diag::note_constexpr_ctor_missing_init);
2045 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2046 return false;
2047 }
2048 } else if (Field->isAnonymousStructOrUnion()) {
2049 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
2050 for (auto *I : RD->fields())
2051 // If an anonymous union contains an anonymous struct of which any member
2052 // is initialized, all members must be initialized.
2053 if (!RD->isUnion() || Inits.count(I))
2054 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2055 Kind))
2056 return false;
2057 }
2058 return true;
2059}
2060
2061/// Check the provided statement is allowed in a constexpr function
2062/// definition.
2063static bool
2064CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
2065 SmallVectorImpl<SourceLocation> &ReturnStmts,
2066 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
2067 SourceLocation &Cxx2bLoc,
2068 Sema::CheckConstexprKind Kind) {
2069 // - its function-body shall be [...] a compound-statement that contains only
2070 switch (S->getStmtClass()) {
2071 case Stmt::NullStmtClass:
2072 // - null statements,
2073 return true;
2074
2075 case Stmt::DeclStmtClass:
2076 // - static_assert-declarations
2077 // - using-declarations,
2078 // - using-directives,
2079 // - typedef declarations and alias-declarations that do not define
2080 // classes or enumerations,
2081 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
2082 return false;
2083 return true;
2084
2085 case Stmt::ReturnStmtClass:
2086 // - and exactly one return statement;
2087 if (isa<CXXConstructorDecl>(Dcl)) {
2088 // C++1y allows return statements in constexpr constructors.
2089 if (!Cxx1yLoc.isValid())
2090 Cxx1yLoc = S->getBeginLoc();
2091 return true;
2092 }
2093
2094 ReturnStmts.push_back(S->getBeginLoc());
2095 return true;
2096
2097 case Stmt::AttributedStmtClass:
2098 // Attributes on a statement don't affect its formal kind and hence don't
2099 // affect its validity in a constexpr function.
2100 return CheckConstexprFunctionStmt(
2101 SemaRef, Dcl, cast<AttributedStmt>(S)->getSubStmt(), ReturnStmts,
2102 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind);
2103
2104 case Stmt::CompoundStmtClass: {
2105 // C++1y allows compound-statements.
2106 if (!Cxx1yLoc.isValid())
2107 Cxx1yLoc = S->getBeginLoc();
2108
2109 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2110 for (auto *BodyIt : CompStmt->body()) {
2111 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2112 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2113 return false;
2114 }
2115 return true;
2116 }
2117
2118 case Stmt::IfStmtClass: {
2119 // C++1y allows if-statements.
2120 if (!Cxx1yLoc.isValid())
2121 Cxx1yLoc = S->getBeginLoc();
2122
2123 IfStmt *If = cast<IfStmt>(S);
2124 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2125 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2126 return false;
2127 if (If->getElse() &&
2128 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2129 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2130 return false;
2131 return true;
2132 }
2133
2134 case Stmt::WhileStmtClass:
2135 case Stmt::DoStmtClass:
2136 case Stmt::ForStmtClass:
2137 case Stmt::CXXForRangeStmtClass:
2138 case Stmt::ContinueStmtClass:
2139 // C++1y allows all of these. We don't allow them as extensions in C++11,
2140 // because they don't make sense without variable mutation.
2141 if (!SemaRef.getLangOpts().CPlusPlus14)
2142 break;
2143 if (!Cxx1yLoc.isValid())
2144 Cxx1yLoc = S->getBeginLoc();
2145 for (Stmt *SubStmt : S->children()) {
2146 if (SubStmt &&
2147 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2148 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2149 return false;
2150 }
2151 return true;
2152
2153 case Stmt::SwitchStmtClass:
2154 case Stmt::CaseStmtClass:
2155 case Stmt::DefaultStmtClass:
2156 case Stmt::BreakStmtClass:
2157 // C++1y allows switch-statements, and since they don't need variable
2158 // mutation, we can reasonably allow them in C++11 as an extension.
2159 if (!Cxx1yLoc.isValid())
2160 Cxx1yLoc = S->getBeginLoc();
2161 for (Stmt *SubStmt : S->children()) {
2162 if (SubStmt &&
2163 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2164 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2165 return false;
2166 }
2167 return true;
2168
2169 case Stmt::LabelStmtClass:
2170 case Stmt::GotoStmtClass:
2171 if (Cxx2bLoc.isInvalid())
2172 Cxx2bLoc = S->getBeginLoc();
2173 for (Stmt *SubStmt : S->children()) {
2174 if (SubStmt &&
2175 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2176 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2177 return false;
2178 }
2179 return true;
2180
2181 case Stmt::GCCAsmStmtClass:
2182 case Stmt::MSAsmStmtClass:
2183 // C++2a allows inline assembly statements.
2184 case Stmt::CXXTryStmtClass:
2185 if (Cxx2aLoc.isInvalid())
2186 Cxx2aLoc = S->getBeginLoc();
2187 for (Stmt *SubStmt : S->children()) {
2188 if (SubStmt &&
2189 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2190 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2191 return false;
2192 }
2193 return true;
2194
2195 case Stmt::CXXCatchStmtClass:
2196 // Do not bother checking the language mode (already covered by the
2197 // try block check).
2198 if (!CheckConstexprFunctionStmt(
2199 SemaRef, Dcl, cast<CXXCatchStmt>(S)->getHandlerBlock(), ReturnStmts,
2200 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2201 return false;
2202 return true;
2203
2204 default:
2205 if (!isa<Expr>(S))
2206 break;
2207
2208 // C++1y allows expression-statements.
2209 if (!Cxx1yLoc.isValid())
2210 Cxx1yLoc = S->getBeginLoc();
2211 return true;
2212 }
2213
2214 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2215 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2216 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2217 }
2218 return false;
2219}
2220
2221/// Check the body for the given constexpr function declaration only contains
2222/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2223///
2224/// \return true if the body is OK, false if we have found or diagnosed a
2225/// problem.
2226static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2227 Stmt *Body,
2228 Sema::CheckConstexprKind Kind) {
2229 SmallVector<SourceLocation, 4> ReturnStmts;
2230
2231 if (isa<CXXTryStmt>(Body)) {
2232 // C++11 [dcl.constexpr]p3:
2233 // The definition of a constexpr function shall satisfy the following
2234 // constraints: [...]
2235 // - its function-body shall be = delete, = default, or a
2236 // compound-statement
2237 //
2238 // C++11 [dcl.constexpr]p4:
2239 // In the definition of a constexpr constructor, [...]
2240 // - its function-body shall not be a function-try-block;
2241 //
2242 // This restriction is lifted in C++2a, as long as inner statements also
2243 // apply the general constexpr rules.
2244 switch (Kind) {
2245 case Sema::CheckConstexprKind::CheckValid:
2246 if (!SemaRef.getLangOpts().CPlusPlus20)
2247 return false;
2248 break;
2249
2250 case Sema::CheckConstexprKind::Diagnose:
2251 SemaRef.Diag(Body->getBeginLoc(),
2252 !SemaRef.getLangOpts().CPlusPlus20
2253 ? diag::ext_constexpr_function_try_block_cxx20
2254 : diag::warn_cxx17_compat_constexpr_function_try_block)
2255 << isa<CXXConstructorDecl>(Dcl);
2256 break;
2257 }
2258 }
2259
2260 // - its function-body shall be [...] a compound-statement that contains only
2261 // [... list of cases ...]
2262 //
2263 // Note that walking the children here is enough to properly check for
2264 // CompoundStmt and CXXTryStmt body.
2265 SourceLocation Cxx1yLoc, Cxx2aLoc, Cxx2bLoc;
2266 for (Stmt *SubStmt : Body->children()) {
2267 if (SubStmt &&
2268 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2269 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2270 return false;
2271 }
2272
2273 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2274 // If this is only valid as an extension, report that we don't satisfy the
2275 // constraints of the current language.
2276 if ((Cxx2bLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus2b) ||
2277 (Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
2278 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2279 return false;
2280 } else if (Cxx2bLoc.isValid()) {
2281 SemaRef.Diag(Cxx2bLoc,
2282 SemaRef.getLangOpts().CPlusPlus2b
2283 ? diag::warn_cxx20_compat_constexpr_body_invalid_stmt
2284 : diag::ext_constexpr_body_invalid_stmt_cxx2b)
2285 << isa<CXXConstructorDecl>(Dcl);
2286 } else if (Cxx2aLoc.isValid()) {
2287 SemaRef.Diag(Cxx2aLoc,
2288 SemaRef.getLangOpts().CPlusPlus20
2289 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2290 : diag::ext_constexpr_body_invalid_stmt_cxx20)
2291 << isa<CXXConstructorDecl>(Dcl);
2292 } else if (Cxx1yLoc.isValid()) {
2293 SemaRef.Diag(Cxx1yLoc,
2294 SemaRef.getLangOpts().CPlusPlus14
2295 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2296 : diag::ext_constexpr_body_invalid_stmt)
2297 << isa<CXXConstructorDecl>(Dcl);
2298 }
2299
2300 if (const CXXConstructorDecl *Constructor
2301 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2302 const CXXRecordDecl *RD = Constructor->getParent();
2303 // DR1359:
2304 // - every non-variant non-static data member and base class sub-object
2305 // shall be initialized;
2306 // DR1460:
2307 // - if the class is a union having variant members, exactly one of them
2308 // shall be initialized;
2309 if (RD->isUnion()) {
2310 if (Constructor->getNumCtorInitializers() == 0 &&
2311 RD->hasVariantMembers()) {
2312 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2313 SemaRef.Diag(
2314 Dcl->getLocation(),
2315 SemaRef.getLangOpts().CPlusPlus20
2316 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2317 : diag::ext_constexpr_union_ctor_no_init);
2318 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2319 return false;
2320 }
2321 }
2322 } else if (!Constructor->isDependentContext() &&
2323 !Constructor->isDelegatingConstructor()) {
2324 assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases")(static_cast <bool> (RD->getNumVBases() == 0 &&
"constexpr ctor with virtual bases") ? void (0) : __assert_fail
("RD->getNumVBases() == 0 && \"constexpr ctor with virtual bases\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2324, __extension__ __PRETTY_FUNCTION__
))
;
2325
2326 // Skip detailed checking if we have enough initializers, and we would
2327 // allow at most one initializer per member.
2328 bool AnyAnonStructUnionMembers = false;
2329 unsigned Fields = 0;
2330 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2331 E = RD->field_end(); I != E; ++I, ++Fields) {
2332 if (I->isAnonymousStructOrUnion()) {
2333 AnyAnonStructUnionMembers = true;
2334 break;
2335 }
2336 }
2337 // DR1460:
2338 // - if the class is a union-like class, but is not a union, for each of
2339 // its anonymous union members having variant members, exactly one of
2340 // them shall be initialized;
2341 if (AnyAnonStructUnionMembers ||
2342 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2343 // Check initialization of non-static data members. Base classes are
2344 // always initialized so do not need to be checked. Dependent bases
2345 // might not have initializers in the member initializer list.
2346 llvm::SmallSet<Decl*, 16> Inits;
2347 for (const auto *I: Constructor->inits()) {
2348 if (FieldDecl *FD = I->getMember())
2349 Inits.insert(FD);
2350 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2351 Inits.insert(ID->chain_begin(), ID->chain_end());
2352 }
2353
2354 bool Diagnosed = false;
2355 for (auto *I : RD->fields())
2356 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2357 Kind))
2358 return false;
2359 }
2360 }
2361 } else {
2362 if (ReturnStmts.empty()) {
2363 // C++1y doesn't require constexpr functions to contain a 'return'
2364 // statement. We still do, unless the return type might be void, because
2365 // otherwise if there's no return statement, the function cannot
2366 // be used in a core constant expression.
2367 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2368 (Dcl->getReturnType()->isVoidType() ||
2369 Dcl->getReturnType()->isDependentType());
2370 switch (Kind) {
2371 case Sema::CheckConstexprKind::Diagnose:
2372 SemaRef.Diag(Dcl->getLocation(),
2373 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2374 : diag::err_constexpr_body_no_return)
2375 << Dcl->isConsteval();
2376 if (!OK)
2377 return false;
2378 break;
2379
2380 case Sema::CheckConstexprKind::CheckValid:
2381 // The formal requirements don't include this rule in C++14, even
2382 // though the "must be able to produce a constant expression" rules
2383 // still imply it in some cases.
2384 if (!SemaRef.getLangOpts().CPlusPlus14)
2385 return false;
2386 break;
2387 }
2388 } else if (ReturnStmts.size() > 1) {
2389 switch (Kind) {
2390 case Sema::CheckConstexprKind::Diagnose:
2391 SemaRef.Diag(
2392 ReturnStmts.back(),
2393 SemaRef.getLangOpts().CPlusPlus14
2394 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2395 : diag::ext_constexpr_body_multiple_return);
2396 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2397 SemaRef.Diag(ReturnStmts[I],
2398 diag::note_constexpr_body_previous_return);
2399 break;
2400
2401 case Sema::CheckConstexprKind::CheckValid:
2402 if (!SemaRef.getLangOpts().CPlusPlus14)
2403 return false;
2404 break;
2405 }
2406 }
2407 }
2408
2409 // C++11 [dcl.constexpr]p5:
2410 // if no function argument values exist such that the function invocation
2411 // substitution would produce a constant expression, the program is
2412 // ill-formed; no diagnostic required.
2413 // C++11 [dcl.constexpr]p3:
2414 // - every constructor call and implicit conversion used in initializing the
2415 // return value shall be one of those allowed in a constant expression.
2416 // C++11 [dcl.constexpr]p4:
2417 // - every constructor involved in initializing non-static data members and
2418 // base class sub-objects shall be a constexpr constructor.
2419 //
2420 // Note that this rule is distinct from the "requirements for a constexpr
2421 // function", so is not checked in CheckValid mode.
2422 SmallVector<PartialDiagnosticAt, 8> Diags;
2423 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2424 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2425 SemaRef.Diag(Dcl->getLocation(),
2426 diag::ext_constexpr_function_never_constant_expr)
2427 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2428 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2429 SemaRef.Diag(Diags[I].first, Diags[I].second);
2430 // Don't return false here: we allow this for compatibility in
2431 // system headers.
2432 }
2433
2434 return true;
2435}
2436
2437/// Get the class that is directly named by the current context. This is the
2438/// class for which an unqualified-id in this scope could name a constructor
2439/// or destructor.
2440///
2441/// If the scope specifier denotes a class, this will be that class.
2442/// If the scope specifier is empty, this will be the class whose
2443/// member-specification we are currently within. Otherwise, there
2444/// is no such class.
2445CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2446 assert(getLangOpts().CPlusPlus && "No class names in C!")(static_cast <bool> (getLangOpts().CPlusPlus &&
"No class names in C!") ? void (0) : __assert_fail ("getLangOpts().CPlusPlus && \"No class names in C!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2446, __extension__ __PRETTY_FUNCTION__
))
;
2447
2448 if (SS && SS->isInvalid())
2449 return nullptr;
2450
2451 if (SS && SS->isNotEmpty()) {
2452 DeclContext *DC = computeDeclContext(*SS, true);
2453 return dyn_cast_or_null<CXXRecordDecl>(DC);
2454 }
2455
2456 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2457}
2458
2459/// isCurrentClassName - Determine whether the identifier II is the
2460/// name of the class type currently being defined. In the case of
2461/// nested classes, this will only return true if II is the name of
2462/// the innermost class.
2463bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2464 const CXXScopeSpec *SS) {
2465 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2466 return CurDecl && &II == CurDecl->getIdentifier();
2467}
2468
2469/// Determine whether the identifier II is a typo for the name of
2470/// the class type currently being defined. If so, update it to the identifier
2471/// that should have been used.
2472bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2473 assert(getLangOpts().CPlusPlus && "No class names in C!")(static_cast <bool> (getLangOpts().CPlusPlus &&
"No class names in C!") ? void (0) : __assert_fail ("getLangOpts().CPlusPlus && \"No class names in C!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2473, __extension__ __PRETTY_FUNCTION__
))
;
2474
2475 if (!getLangOpts().SpellChecking)
2476 return false;
2477
2478 CXXRecordDecl *CurDecl;
2479 if (SS && SS->isSet() && !SS->isInvalid()) {
2480 DeclContext *DC = computeDeclContext(*SS, true);
2481 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2482 } else
2483 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2484
2485 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2486 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2487 < II->getLength()) {
2488 II = CurDecl->getIdentifier();
2489 return true;
2490 }
2491
2492 return false;
2493}
2494
2495/// Determine whether the given class is a base class of the given
2496/// class, including looking at dependent bases.
2497static bool findCircularInheritance(const CXXRecordDecl *Class,
2498 const CXXRecordDecl *Current) {
2499 SmallVector<const CXXRecordDecl*, 8> Queue;
2500
2501 Class = Class->getCanonicalDecl();
2502 while (true) {
2503 for (const auto &I : Current->bases()) {
2504 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2505 if (!Base)
2506 continue;
2507
2508 Base = Base->getDefinition();
2509 if (!Base)
2510 continue;
2511
2512 if (Base->getCanonicalDecl() == Class)
2513 return true;
2514
2515 Queue.push_back(Base);
2516 }
2517
2518 if (Queue.empty())
2519 return false;
2520
2521 Current = Queue.pop_back_val();
2522 }
2523
2524 return false;
2525}
2526
2527/// Check the validity of a C++ base class specifier.
2528///
2529/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2530/// and returns NULL otherwise.
2531CXXBaseSpecifier *
2532Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2533 SourceRange SpecifierRange,
2534 bool Virtual, AccessSpecifier Access,
2535 TypeSourceInfo *TInfo,
2536 SourceLocation EllipsisLoc) {
2537 // In HLSL, unspecified class access is public rather than private.
2538 if (getLangOpts().HLSL && Class->getTagKind() == TTK_Class &&
2539 Access == AS_none)
2540 Access = AS_public;
2541
2542 QualType BaseType = TInfo->getType();
2543 if (BaseType->containsErrors()) {
2544 // Already emitted a diagnostic when parsing the error type.
2545 return nullptr;
2546 }
2547 // C++ [class.union]p1:
2548 // A union shall not have base classes.
2549 if (Class->isUnion()) {
2550 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2551 << SpecifierRange;
2552 return nullptr;
2553 }
2554
2555 if (EllipsisLoc.isValid() &&
2556 !TInfo->getType()->containsUnexpandedParameterPack()) {
2557 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2558 << TInfo->getTypeLoc().getSourceRange();
2559 EllipsisLoc = SourceLocation();
2560 }
2561
2562 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2563
2564 if (BaseType->isDependentType()) {
2565 // Make sure that we don't have circular inheritance among our dependent
2566 // bases. For non-dependent bases, the check for completeness below handles
2567 // this.
2568 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2569 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2570 ((BaseDecl = BaseDecl->getDefinition()) &&
2571 findCircularInheritance(Class, BaseDecl))) {
2572 Diag(BaseLoc, diag::err_circular_inheritance)
2573 << BaseType << Context.getTypeDeclType(Class);
2574
2575 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2576 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2577 << BaseType;
2578
2579 return nullptr;
2580 }
2581 }
2582
2583 // Make sure that we don't make an ill-formed AST where the type of the
2584 // Class is non-dependent and its attached base class specifier is an
2585 // dependent type, which violates invariants in many clang code paths (e.g.
2586 // constexpr evaluator). If this case happens (in errory-recovery mode), we
2587 // explicitly mark the Class decl invalid. The diagnostic was already
2588 // emitted.
2589 if (!Class->getTypeForDecl()->isDependentType())
2590 Class->setInvalidDecl();
2591 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2592 Class->getTagKind() == TTK_Class,
2593 Access, TInfo, EllipsisLoc);
2594 }
2595
2596 // Base specifiers must be record types.
2597 if (!BaseType->isRecordType()) {
2598 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2599 return nullptr;
2600 }
2601
2602 // C++ [class.union]p1:
2603 // A union shall not be used as a base class.
2604 if (BaseType->isUnionType()) {
2605 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2606 return nullptr;
2607 }
2608
2609 // For the MS ABI, propagate DLL attributes to base class templates.
2610 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2611 if (Attr *ClassAttr = getDLLAttr(Class)) {
2612 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2613 BaseType->getAsCXXRecordDecl())) {
2614 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2615 BaseLoc);
2616 }
2617 }
2618 }
2619
2620 // C++ [class.derived]p2:
2621 // The class-name in a base-specifier shall not be an incompletely
2622 // defined class.
2623 if (RequireCompleteType(BaseLoc, BaseType,
2624 diag::err_incomplete_base_class, SpecifierRange)) {
2625 Class->setInvalidDecl();
2626 return nullptr;
2627 }
2628
2629 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2630 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2631 assert(BaseDecl && "Record type has no declaration")(static_cast <bool> (BaseDecl && "Record type has no declaration"
) ? void (0) : __assert_fail ("BaseDecl && \"Record type has no declaration\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2631, __extension__ __PRETTY_FUNCTION__
))
;
2632 BaseDecl = BaseDecl->getDefinition();
2633 assert(BaseDecl && "Base type is not incomplete, but has no definition")(static_cast <bool> (BaseDecl && "Base type is not incomplete, but has no definition"
) ? void (0) : __assert_fail ("BaseDecl && \"Base type is not incomplete, but has no definition\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2633, __extension__ __PRETTY_FUNCTION__
))
;
2634 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2635 assert(CXXBaseDecl && "Base type is not a C++ type")(static_cast <bool> (CXXBaseDecl && "Base type is not a C++ type"
) ? void (0) : __assert_fail ("CXXBaseDecl && \"Base type is not a C++ type\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2635, __extension__ __PRETTY_FUNCTION__
))
;
2636
2637 // Microsoft docs say:
2638 // "If a base-class has a code_seg attribute, derived classes must have the
2639 // same attribute."
2640 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2641 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2642 if ((DerivedCSA || BaseCSA) &&
2643 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2644 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2645 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2646 << CXXBaseDecl;
2647 return nullptr;
2648 }
2649
2650 // A class which contains a flexible array member is not suitable for use as a
2651 // base class:
2652 // - If the layout determines that a base comes before another base,
2653 // the flexible array member would index into the subsequent base.
2654 // - If the layout determines that base comes before the derived class,
2655 // the flexible array member would index into the derived class.
2656 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2657 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2658 << CXXBaseDecl->getDeclName();
2659 return nullptr;
2660 }
2661
2662 // C++ [class]p3:
2663 // If a class is marked final and it appears as a base-type-specifier in
2664 // base-clause, the program is ill-formed.
2665 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2666 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2667 << CXXBaseDecl->getDeclName()
2668 << FA->isSpelledAsSealed();
2669 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2670 << CXXBaseDecl->getDeclName() << FA->getRange();
2671 return nullptr;
2672 }
2673
2674 if (BaseDecl->isInvalidDecl())
2675 Class->setInvalidDecl();
2676
2677 // Create the base specifier.
2678 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2679 Class->getTagKind() == TTK_Class,
2680 Access, TInfo, EllipsisLoc);
2681}
2682
2683/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2684/// one entry in the base class list of a class specifier, for
2685/// example:
2686/// class foo : public bar, virtual private baz {
2687/// 'public bar' and 'virtual private baz' are each base-specifiers.
2688BaseResult Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2689 const ParsedAttributesView &Attributes,
2690 bool Virtual, AccessSpecifier Access,
2691 ParsedType basetype, SourceLocation BaseLoc,
2692 SourceLocation EllipsisLoc) {
2693 if (!classdecl)
2694 return true;
2695
2696 AdjustDeclIfTemplate(classdecl);
2697 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2698 if (!Class)
2699 return true;
2700
2701 // We haven't yet attached the base specifiers.
2702 Class->setIsParsingBaseSpecifiers();
2703
2704 // We do not support any C++11 attributes on base-specifiers yet.
2705 // Diagnose any attributes we see.
2706 for (const ParsedAttr &AL : Attributes) {
2707 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2708 continue;
2709 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2710 ? (unsigned)diag::warn_unknown_attribute_ignored
2711 : (unsigned)diag::err_base_specifier_attribute)
2712 << AL << AL.getRange();
2713 }
2714
2715 TypeSourceInfo *TInfo = nullptr;
2716 GetTypeFromParser(basetype, &TInfo);
2717
2718 if (EllipsisLoc.isInvalid() &&
2719 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2720 UPPC_BaseType))
2721 return true;
2722
2723 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2724 Virtual, Access, TInfo,
2725 EllipsisLoc))
2726 return BaseSpec;
2727 else
2728 Class->setInvalidDecl();
2729
2730 return true;
2731}
2732
2733/// Use small set to collect indirect bases. As this is only used
2734/// locally, there's no need to abstract the small size parameter.
2735typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2736
2737/// Recursively add the bases of Type. Don't add Type itself.
2738static void
2739NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2740 const QualType &Type)
2741{
2742 // Even though the incoming type is a base, it might not be
2743 // a class -- it could be a template parm, for instance.
2744 if (auto Rec = Type->getAs<RecordType>()) {
2745 auto Decl = Rec->getAsCXXRecordDecl();
2746
2747 // Iterate over its bases.
2748 for (const auto &BaseSpec : Decl->bases()) {
2749 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2750 .getUnqualifiedType();
2751 if (Set.insert(Base).second)
2752 // If we've not already seen it, recurse.
2753 NoteIndirectBases(Context, Set, Base);
2754 }
2755 }
2756}
2757
2758/// Performs the actual work of attaching the given base class
2759/// specifiers to a C++ class.
2760bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2761 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2762 if (Bases.empty())
2763 return false;
2764
2765 // Used to keep track of which base types we have already seen, so
2766 // that we can properly diagnose redundant direct base types. Note
2767 // that the key is always the unqualified canonical type of the base
2768 // class.
2769 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2770
2771 // Used to track indirect bases so we can see if a direct base is
2772 // ambiguous.
2773 IndirectBaseSet IndirectBaseTypes;
2774
2775 // Copy non-redundant base specifiers into permanent storage.
2776 unsigned NumGoodBases = 0;
2777 bool Invalid = false;
2778 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2779 QualType NewBaseType
2780 = Context.getCanonicalType(Bases[idx]->getType());
2781 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2782
2783 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2784 if (KnownBase) {
2785 // C++ [class.mi]p3:
2786 // A class shall not be specified as a direct base class of a
2787 // derived class more than once.
2788 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2789 << KnownBase->getType() << Bases[idx]->getSourceRange();
2790
2791 // Delete the duplicate base class specifier; we're going to
2792 // overwrite its pointer later.
2793 Context.Deallocate(Bases[idx]);
2794
2795 Invalid = true;
2796 } else {
2797 // Okay, add this new base class.
2798 KnownBase = Bases[idx];
2799 Bases[NumGoodBases++] = Bases[idx];
2800
2801 if (NewBaseType->isDependentType())
2802 continue;
2803 // Note this base's direct & indirect bases, if there could be ambiguity.
2804 if (Bases.size() > 1)
2805 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2806
2807 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2808 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2809 if (Class->isInterface() &&
2810 (!RD->isInterfaceLike() ||
2811 KnownBase->getAccessSpecifier() != AS_public)) {
2812 // The Microsoft extension __interface does not permit bases that
2813 // are not themselves public interfaces.
2814 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2815 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2816 << RD->getSourceRange();
2817 Invalid = true;
2818 }
2819 if (RD->hasAttr<WeakAttr>())
2820 Class->addAttr(WeakAttr::CreateImplicit(Context));
2821 }
2822 }
2823 }
2824
2825 // Attach the remaining base class specifiers to the derived class.
2826 Class->setBases(Bases.data(), NumGoodBases);
2827
2828 // Check that the only base classes that are duplicate are virtual.
2829 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2830 // Check whether this direct base is inaccessible due to ambiguity.
2831 QualType BaseType = Bases[idx]->getType();
2832
2833 // Skip all dependent types in templates being used as base specifiers.
2834 // Checks below assume that the base specifier is a CXXRecord.
2835 if (BaseType->isDependentType())
2836 continue;
2837
2838 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2839 .getUnqualifiedType();
2840
2841 if (IndirectBaseTypes.count(CanonicalBase)) {
2842 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2843 /*DetectVirtual=*/true);
2844 bool found
2845 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2846 assert(found)(static_cast <bool> (found) ? void (0) : __assert_fail (
"found", "clang/lib/Sema/SemaDeclCXX.cpp", 2846, __extension__
__PRETTY_FUNCTION__))
;
2847 (void)found;
2848
2849 if (Paths.isAmbiguous(CanonicalBase))
2850 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2851 << BaseType << getAmbiguousPathsDisplayString(Paths)
2852 << Bases[idx]->getSourceRange();
2853 else
2854 assert(Bases[idx]->isVirtual())(static_cast <bool> (Bases[idx]->isVirtual()) ? void
(0) : __assert_fail ("Bases[idx]->isVirtual()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 2854, __extension__ __PRETTY_FUNCTION__))
;
2855 }
2856
2857 // Delete the base class specifier, since its data has been copied
2858 // into the CXXRecordDecl.
2859 Context.Deallocate(Bases[idx]);
2860 }
2861
2862 return Invalid;
2863}
2864
2865/// ActOnBaseSpecifiers - Attach the given base specifiers to the
2866/// class, after checking whether there are any duplicate base
2867/// classes.
2868void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2869 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2870 if (!ClassDecl || Bases.empty())
2871 return;
2872
2873 AdjustDeclIfTemplate(ClassDecl);
2874 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2875}
2876
2877/// Determine whether the type \p Derived is a C++ class that is
2878/// derived from the type \p Base.
2879bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2880 if (!getLangOpts().CPlusPlus)
2881 return false;
2882
2883 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2884 if (!DerivedRD)
2885 return false;
2886
2887 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2888 if (!BaseRD)
2889 return false;
2890
2891 // If either the base or the derived type is invalid, don't try to
2892 // check whether one is derived from the other.
2893 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2894 return false;
2895
2896 // FIXME: In a modules build, do we need the entire path to be visible for us
2897 // to be able to use the inheritance relationship?
2898 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2899 return false;
2900
2901 return DerivedRD->isDerivedFrom(BaseRD);
2902}
2903
2904/// Determine whether the type \p Derived is a C++ class that is
2905/// derived from the type \p Base.
2906bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2907 CXXBasePaths &Paths) {
2908 if (!getLangOpts().CPlusPlus)
2909 return false;
2910
2911 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2912 if (!DerivedRD)
2913 return false;
2914
2915 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2916 if (!BaseRD)
2917 return false;
2918
2919 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2920 return false;
2921
2922 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2923}
2924
2925static void BuildBasePathArray(const CXXBasePath &Path,
2926 CXXCastPath &BasePathArray) {
2927 // We first go backward and check if we have a virtual base.
2928 // FIXME: It would be better if CXXBasePath had the base specifier for
2929 // the nearest virtual base.
2930 unsigned Start = 0;
2931 for (unsigned I = Path.size(); I != 0; --I) {
2932 if (Path[I - 1].Base->isVirtual()) {
2933 Start = I - 1;
2934 break;
2935 }
2936 }
2937
2938 // Now add all bases.
2939 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2940 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2941}
2942
2943
2944void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2945 CXXCastPath &BasePathArray) {
2946 assert(BasePathArray.empty() && "Base path array must be empty!")(static_cast <bool> (BasePathArray.empty() && "Base path array must be empty!"
) ? void (0) : __assert_fail ("BasePathArray.empty() && \"Base path array must be empty!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2946, __extension__ __PRETTY_FUNCTION__
))
;
2947 assert(Paths.isRecordingPaths() && "Must record paths!")(static_cast <bool> (Paths.isRecordingPaths() &&
"Must record paths!") ? void (0) : __assert_fail ("Paths.isRecordingPaths() && \"Must record paths!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 2947, __extension__ __PRETTY_FUNCTION__
))
;
2948 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2949}
2950/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2951/// conversion (where Derived and Base are class types) is
2952/// well-formed, meaning that the conversion is unambiguous (and
2953/// that all of the base classes are accessible). Returns true
2954/// and emits a diagnostic if the code is ill-formed, returns false
2955/// otherwise. Loc is the location where this routine should point to
2956/// if there is an error, and Range is the source range to highlight
2957/// if there is an error.
2958///
2959/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2960/// diagnostic for the respective type of error will be suppressed, but the
2961/// check for ill-formed code will still be performed.
2962bool
2963Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2964 unsigned InaccessibleBaseID,
2965 unsigned AmbiguousBaseConvID,
2966 SourceLocation Loc, SourceRange Range,
2967 DeclarationName Name,
2968 CXXCastPath *BasePath,
2969 bool IgnoreAccess) {
2970 // First, determine whether the path from Derived to Base is
2971 // ambiguous. This is slightly more expensive than checking whether
2972 // the Derived to Base conversion exists, because here we need to
2973 // explore multiple paths to determine if there is an ambiguity.
2974 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2975 /*DetectVirtual=*/false);
2976 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2977 if (!DerivationOkay)
2978 return true;
2979
2980 const CXXBasePath *Path = nullptr;
2981 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2982 Path = &Paths.front();
2983
2984 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2985 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2986 // user to access such bases.
2987 if (!Path && getLangOpts().MSVCCompat) {
2988 for (const CXXBasePath &PossiblePath : Paths) {
2989 if (PossiblePath.size() == 1) {
2990 Path = &PossiblePath;
2991 if (AmbiguousBaseConvID)
2992 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2993 << Base << Derived << Range;
2994 break;
2995 }
2996 }
2997 }
2998
2999 if (Path) {
3000 if (!IgnoreAccess) {
3001 // Check that the base class can be accessed.
3002 switch (
3003 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
3004 case AR_inaccessible:
3005 return true;
3006 case AR_accessible:
3007 case AR_dependent:
3008 case AR_delayed:
3009 break;
3010 }
3011 }
3012
3013 // Build a base path if necessary.
3014 if (BasePath)
3015 ::BuildBasePathArray(*Path, *BasePath);
3016 return false;
3017 }
3018
3019 if (AmbiguousBaseConvID) {
3020 // We know that the derived-to-base conversion is ambiguous, and
3021 // we're going to produce a diagnostic. Perform the derived-to-base
3022 // search just one more time to compute all of the possible paths so
3023 // that we can print them out. This is more expensive than any of
3024 // the previous derived-to-base checks we've done, but at this point
3025 // performance isn't as much of an issue.
3026 Paths.clear();
3027 Paths.setRecordingPaths(true);
3028 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
3029 assert(StillOkay && "Can only be used with a derived-to-base conversion")(static_cast <bool> (StillOkay && "Can only be used with a derived-to-base conversion"
) ? void (0) : __assert_fail ("StillOkay && \"Can only be used with a derived-to-base conversion\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3029, __extension__ __PRETTY_FUNCTION__
))
;
3030 (void)StillOkay;
3031
3032 // Build up a textual representation of the ambiguous paths, e.g.,
3033 // D -> B -> A, that will be used to illustrate the ambiguous
3034 // conversions in the diagnostic. We only print one of the paths
3035 // to each base class subobject.
3036 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3037
3038 Diag(Loc, AmbiguousBaseConvID)
3039 << Derived << Base << PathDisplayStr << Range << Name;
3040 }
3041 return true;
3042}
3043
3044bool
3045Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
3046 SourceLocation Loc, SourceRange Range,
3047 CXXCastPath *BasePath,
3048 bool IgnoreAccess) {
3049 return CheckDerivedToBaseConversion(
3050 Derived, Base, diag::err_upcast_to_inaccessible_base,
3051 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
3052 BasePath, IgnoreAccess);
3053}
3054
3055
3056/// Builds a string representing ambiguous paths from a
3057/// specific derived class to different subobjects of the same base
3058/// class.
3059///
3060/// This function builds a string that can be used in error messages
3061/// to show the different paths that one can take through the
3062/// inheritance hierarchy to go from the derived class to different
3063/// subobjects of a base class. The result looks something like this:
3064/// @code
3065/// struct D -> struct B -> struct A
3066/// struct D -> struct C -> struct A
3067/// @endcode
3068std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
3069 std::string PathDisplayStr;
3070 std::set<unsigned> DisplayedPaths;
3071 for (CXXBasePaths::paths_iterator Path = Paths.begin();
3072 Path != Paths.end(); ++Path) {
3073 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
3074 // We haven't displayed a path to this particular base
3075 // class subobject yet.
3076 PathDisplayStr += "\n ";
3077 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
3078 for (CXXBasePath::const_iterator Element = Path->begin();
3079 Element != Path->end(); ++Element)
3080 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
3081 }
3082 }
3083
3084 return PathDisplayStr;
3085}
3086
3087//===----------------------------------------------------------------------===//
3088// C++ class member Handling
3089//===----------------------------------------------------------------------===//
3090
3091/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
3092bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
3093 SourceLocation ColonLoc,
3094 const ParsedAttributesView &Attrs) {
3095 assert(Access != AS_none && "Invalid kind for syntactic access specifier!")(static_cast <bool> (Access != AS_none && "Invalid kind for syntactic access specifier!"
) ? void (0) : __assert_fail ("Access != AS_none && \"Invalid kind for syntactic access specifier!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3095, __extension__ __PRETTY_FUNCTION__
))
;
3096 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
3097 ASLoc, ColonLoc);
3098 CurContext->addHiddenDecl(ASDecl);
3099 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3100}
3101
3102/// CheckOverrideControl - Check C++11 override control semantics.
3103void Sema::CheckOverrideControl(NamedDecl *D) {
3104 if (D->isInvalidDecl())
3105 return;
3106
3107 // We only care about "override" and "final" declarations.
3108 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
3109 return;
3110
3111 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3112
3113 // We can't check dependent instance methods.
3114 if (MD && MD->isInstance() &&
3115 (MD->getParent()->hasAnyDependentBases() ||
3116 MD->getType()->isDependentType()))
3117 return;
3118
3119 if (MD && !MD->isVirtual()) {
3120 // If we have a non-virtual method, check if it hides a virtual method.
3121 // (In that case, it's most likely the method has the wrong type.)
3122 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
3123 FindHiddenVirtualMethods(MD, OverloadedMethods);
3124
3125 if (!OverloadedMethods.empty()) {
3126 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3127 Diag(OA->getLocation(),
3128 diag::override_keyword_hides_virtual_member_function)
3129 << "override" << (OverloadedMethods.size() > 1);
3130 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3131 Diag(FA->getLocation(),
3132 diag::override_keyword_hides_virtual_member_function)
3133 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3134 << (OverloadedMethods.size() > 1);
3135 }
3136 NoteHiddenVirtualMethods(MD, OverloadedMethods);
3137 MD->setInvalidDecl();
3138 return;
3139 }
3140 // Fall through into the general case diagnostic.
3141 // FIXME: We might want to attempt typo correction here.
3142 }
3143
3144 if (!MD || !MD->isVirtual()) {
3145 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3146 Diag(OA->getLocation(),
3147 diag::override_keyword_only_allowed_on_virtual_member_functions)
3148 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3149 D->dropAttr<OverrideAttr>();
3150 }
3151 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3152 Diag(FA->getLocation(),
3153 diag::override_keyword_only_allowed_on_virtual_member_functions)
3154 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3155 << FixItHint::CreateRemoval(FA->getLocation());
3156 D->dropAttr<FinalAttr>();
3157 }
3158 return;
3159 }
3160
3161 // C++11 [class.virtual]p5:
3162 // If a function is marked with the virt-specifier override and
3163 // does not override a member function of a base class, the program is
3164 // ill-formed.
3165 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3166 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3167 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3168 << MD->getDeclName();
3169}
3170
3171void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
3172 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3173 return;
3174 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3175 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3176 return;
3177
3178 SourceLocation Loc = MD->getLocation();
3179 SourceLocation SpellingLoc = Loc;
3180 if (getSourceManager().isMacroArgExpansion(Loc))
3181 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3182 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3183 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3184 return;
3185
3186 if (MD->size_overridden_methods() > 0) {
3187 auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
3188 unsigned DiagID =
3189 Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
3190 ? DiagInconsistent
3191 : DiagSuggest;
3192 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3193 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3194 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3195 };
3196 if (isa<CXXDestructorDecl>(MD))
3197 EmitDiag(
3198 diag::warn_inconsistent_destructor_marked_not_override_overriding,
3199 diag::warn_suggest_destructor_marked_not_override_overriding);
3200 else
3201 EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
3202 diag::warn_suggest_function_marked_not_override_overriding);
3203 }
3204}
3205
3206/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3207/// function overrides a virtual member function marked 'final', according to
3208/// C++11 [class.virtual]p4.
3209bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3210 const CXXMethodDecl *Old) {
3211 FinalAttr *FA = Old->getAttr<FinalAttr>();
3212 if (!FA)
3213 return false;
3214
3215 Diag(New->getLocation(), diag::err_final_function_overridden)
3216 << New->getDeclName()
3217 << FA->isSpelledAsSealed();
3218 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3219 return true;
3220}
3221
3222static bool InitializationHasSideEffects(const FieldDecl &FD) {
3223 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3224 // FIXME: Destruction of ObjC lifetime types has side-effects.
3225 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3226 return !RD->isCompleteDefinition() ||
3227 !RD->hasTrivialDefaultConstructor() ||
3228 !RD->hasTrivialDestructor();
3229 return false;
3230}
3231
3232static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3233 ParsedAttributesView::const_iterator Itr =
3234 llvm::find_if(list, [](const ParsedAttr &AL) {
3235 return AL.isDeclspecPropertyAttribute();
3236 });
3237 if (Itr != list.end())
3238 return &*Itr;
3239 return nullptr;
3240}
3241
3242// Check if there is a field shadowing.
3243void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3244 DeclarationName FieldName,
3245 const CXXRecordDecl *RD,
3246 bool DeclIsField) {
3247 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3248 return;
3249
3250 // To record a shadowed field in a base
3251 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3252 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3253 CXXBasePath &Path) {
3254 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3255 // Record an ambiguous path directly
3256 if (Bases.find(Base) != Bases.end())
3257 return true;
3258 for (const auto Field : Base->lookup(FieldName)) {
3259 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3260 Field->getAccess() != AS_private) {
3261 assert(Field->getAccess() != AS_none)(static_cast <bool> (Field->getAccess() != AS_none) ?
void (0) : __assert_fail ("Field->getAccess() != AS_none"
, "clang/lib/Sema/SemaDeclCXX.cpp", 3261, __extension__ __PRETTY_FUNCTION__
))
;
3262 assert(Bases.find(Base) == Bases.end())(static_cast <bool> (Bases.find(Base) == Bases.end()) ?
void (0) : __assert_fail ("Bases.find(Base) == Bases.end()",
"clang/lib/Sema/SemaDeclCXX.cpp", 3262, __extension__ __PRETTY_FUNCTION__
))
;
3263 Bases[Base] = Field;
3264 return true;
3265 }
3266 }
3267 return false;
3268 };
3269
3270 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3271 /*DetectVirtual=*/true);
3272 if (!RD->lookupInBases(FieldShadowed, Paths))
3273 return;
3274
3275 for (const auto &P : Paths) {
3276 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3277 auto It = Bases.find(Base);
3278 // Skip duplicated bases
3279 if (It == Bases.end())
3280 continue;
3281 auto BaseField = It->second;
3282 assert(BaseField->getAccess() != AS_private)(static_cast <bool> (BaseField->getAccess() != AS_private
) ? void (0) : __assert_fail ("BaseField->getAccess() != AS_private"
, "clang/lib/Sema/SemaDeclCXX.cpp", 3282, __extension__ __PRETTY_FUNCTION__
))
;
3283 if (AS_none !=
3284 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3285 Diag(Loc, diag::warn_shadow_field)
3286 << FieldName << RD << Base << DeclIsField;
3287 Diag(BaseField->getLocation(), diag::note_shadow_field);
3288 Bases.erase(It);
3289 }
3290 }
3291}
3292
3293/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3294/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3295/// bitfield width if there is one, 'InitExpr' specifies the initializer if
3296/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3297/// present (but parsing it has been deferred).
3298NamedDecl *
3299Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3300 MultiTemplateParamsArg TemplateParameterLists,
3301 Expr *BW, const VirtSpecifiers &VS,
3302 InClassInitStyle InitStyle) {
3303 const DeclSpec &DS = D.getDeclSpec();
3304 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3305 DeclarationName Name = NameInfo.getName();
3306 SourceLocation Loc = NameInfo.getLoc();
3307
3308 // For anonymous bitfields, the location should point to the type.
3309 if (Loc.isInvalid())
3310 Loc = D.getBeginLoc();
3311
3312 Expr *BitWidth = static_cast<Expr*>(BW);
3313
3314 assert(isa<CXXRecordDecl>(CurContext))(static_cast <bool> (isa<CXXRecordDecl>(CurContext
)) ? void (0) : __assert_fail ("isa<CXXRecordDecl>(CurContext)"
, "clang/lib/Sema/SemaDeclCXX.cpp", 3314, __extension__ __PRETTY_FUNCTION__
))
;
3315 assert(!DS.isFriendSpecified())(static_cast <bool> (!DS.isFriendSpecified()) ? void (0
) : __assert_fail ("!DS.isFriendSpecified()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 3315, __extension__ __PRETTY_FUNCTION__))
;
3316
3317 bool isFunc = D.isDeclarationOfFunction();
3318 const ParsedAttr *MSPropertyAttr =
3319 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3320
3321 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3322 // The Microsoft extension __interface only permits public member functions
3323 // and prohibits constructors, destructors, operators, non-public member
3324 // functions, static methods and data members.
3325 unsigned InvalidDecl;
3326 bool ShowDeclName = true;
3327 if (!isFunc &&
3328 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3329 InvalidDecl = 0;
3330 else if (!isFunc)
3331 InvalidDecl = 1;
3332 else if (AS != AS_public)
3333 InvalidDecl = 2;
3334 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3335 InvalidDecl = 3;
3336 else switch (Name.getNameKind()) {
3337 case DeclarationName::CXXConstructorName:
3338 InvalidDecl = 4;
3339 ShowDeclName = false;
3340 break;
3341
3342 case DeclarationName::CXXDestructorName:
3343 InvalidDecl = 5;
3344 ShowDeclName = false;
3345 break;
3346
3347 case DeclarationName::CXXOperatorName:
3348 case DeclarationName::CXXConversionFunctionName:
3349 InvalidDecl = 6;
3350 break;
3351
3352 default:
3353 InvalidDecl = 0;
3354 break;
3355 }
3356
3357 if (InvalidDecl) {
3358 if (ShowDeclName)
3359 Diag(Loc, diag::err_invalid_member_in_interface)
3360 << (InvalidDecl-1) << Name;
3361 else
3362 Diag(Loc, diag::err_invalid_member_in_interface)
3363 << (InvalidDecl-1) << "";
3364 return nullptr;
3365 }
3366 }
3367
3368 // C++ 9.2p6: A member shall not be declared to have automatic storage
3369 // duration (auto, register) or with the extern storage-class-specifier.
3370 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3371 // data members and cannot be applied to names declared const or static,
3372 // and cannot be applied to reference members.
3373 switch (DS.getStorageClassSpec()) {
3374 case DeclSpec::SCS_unspecified:
3375 case DeclSpec::SCS_typedef:
3376 case DeclSpec::SCS_static:
3377 break;
3378 case DeclSpec::SCS_mutable:
3379 if (isFunc) {
3380 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3381
3382 // FIXME: It would be nicer if the keyword was ignored only for this
3383 // declarator. Otherwise we could get follow-up errors.
3384 D.getMutableDeclSpec().ClearStorageClassSpecs();
3385 }
3386 break;
3387 default:
3388 Diag(DS.getStorageClassSpecLoc(),
3389 diag::err_storageclass_invalid_for_member);
3390 D.getMutableDeclSpec().ClearStorageClassSpecs();
3391 break;
3392 }
3393
3394 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3395 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3396 !isFunc);
3397
3398 if (DS.hasConstexprSpecifier() && isInstField) {
3399 SemaDiagnosticBuilder B =
3400 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3401 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3402 if (InitStyle == ICIS_NoInit) {
3403 B << 0 << 0;
3404 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3405 B << FixItHint::CreateRemoval(ConstexprLoc);
3406 else {
3407 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3408 D.getMutableDeclSpec().ClearConstexprSpec();
3409 const char *PrevSpec;
3410 unsigned DiagID;
3411 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3412 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3413 (void)Failed;
3414 assert(!Failed && "Making a constexpr member const shouldn't fail")(static_cast <bool> (!Failed && "Making a constexpr member const shouldn't fail"
) ? void (0) : __assert_fail ("!Failed && \"Making a constexpr member const shouldn't fail\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3414, __extension__ __PRETTY_FUNCTION__
))
;
3415 }
3416 } else {
3417 B << 1;
3418 const char *PrevSpec;
3419 unsigned DiagID;
3420 if (D.getMutableDeclSpec().SetStorageClassSpec(
3421 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3422 Context.getPrintingPolicy())) {
3423 assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&(static_cast <bool> (DS.getStorageClassSpec() == DeclSpec
::SCS_mutable && "This is the only DeclSpec that should fail to be applied"
) ? void (0) : __assert_fail ("DS.getStorageClassSpec() == DeclSpec::SCS_mutable && \"This is the only DeclSpec that should fail to be applied\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3424, __extension__ __PRETTY_FUNCTION__
))
3424 "This is the only DeclSpec that should fail to be applied")(static_cast <bool> (DS.getStorageClassSpec() == DeclSpec
::SCS_mutable && "This is the only DeclSpec that should fail to be applied"
) ? void (0) : __assert_fail ("DS.getStorageClassSpec() == DeclSpec::SCS_mutable && \"This is the only DeclSpec that should fail to be applied\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3424, __extension__ __PRETTY_FUNCTION__
))
;
3425 B << 1;
3426 } else {
3427 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3428 isInstField = false;
3429 }
3430 }
3431 }
3432
3433 NamedDecl *Member;
3434 if (isInstField) {
3435 CXXScopeSpec &SS = D.getCXXScopeSpec();
3436
3437 // Data members must have identifiers for names.
3438 if (!Name.isIdentifier()) {
3439 Diag(Loc, diag::err_bad_variable_name)
3440 << Name;
3441 return nullptr;
3442 }
3443
3444 IdentifierInfo *II = Name.getAsIdentifierInfo();
3445
3446 // Member field could not be with "template" keyword.
3447 // So TemplateParameterLists should be empty in this case.
3448 if (TemplateParameterLists.size()) {
3449 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3450 if (TemplateParams->size()) {
3451 // There is no such thing as a member field template.
3452 Diag(D.getIdentifierLoc(), diag::err_template_member)
3453 << II
3454 << SourceRange(TemplateParams->getTemplateLoc(),
3455 TemplateParams->getRAngleLoc());
3456 } else {
3457 // There is an extraneous 'template<>' for this member.
3458 Diag(TemplateParams->getTemplateLoc(),
3459 diag::err_template_member_noparams)
3460 << II
3461 << SourceRange(TemplateParams->getTemplateLoc(),
3462 TemplateParams->getRAngleLoc());
3463 }
3464 return nullptr;
3465 }
3466
3467 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
3468 Diag(D.getIdentifierLoc(), diag::err_member_with_template_arguments)
3469 << II
3470 << SourceRange(D.getName().TemplateId->LAngleLoc,
3471 D.getName().TemplateId->RAngleLoc)
3472 << D.getName().TemplateId->LAngleLoc;
3473 D.SetIdentifier(II, Loc);
3474 }
3475
3476 if (SS.isSet() && !SS.isInvalid()) {
3477 // The user provided a superfluous scope specifier inside a class
3478 // definition:
3479 //
3480 // class X {
3481 // int X::member;
3482 // };
3483 if (DeclContext *DC = computeDeclContext(SS, false))
3484 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3485 D.getName().getKind() ==
3486 UnqualifiedIdKind::IK_TemplateId);
3487 else
3488 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3489 << Name << SS.getRange();
3490
3491 SS.clear();
3492 }
3493
3494 if (MSPropertyAttr) {
3495 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3496 BitWidth, InitStyle, AS, *MSPropertyAttr);
3497 if (!Member)
3498 return nullptr;
3499 isInstField = false;
3500 } else {
3501 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3502 BitWidth, InitStyle, AS);
3503 if (!Member)
3504 return nullptr;
3505 }
3506
3507 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3508 } else {
3509 Member = HandleDeclarator(S, D, TemplateParameterLists);
3510 if (!Member)
3511 return nullptr;
3512
3513 // Non-instance-fields can't have a bitfield.
3514 if (BitWidth) {
3515 if (Member->isInvalidDecl()) {
3516 // don't emit another diagnostic.
3517 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3518 // C++ 9.6p3: A bit-field shall not be a static member.
3519 // "static member 'A' cannot be a bit-field"
3520 Diag(Loc, diag::err_static_not_bitfield)
3521 << Name << BitWidth->getSourceRange();
3522 } else if (isa<TypedefDecl>(Member)) {
3523 // "typedef member 'x' cannot be a bit-field"
3524 Diag(Loc, diag::err_typedef_not_bitfield)
3525 << Name << BitWidth->getSourceRange();
3526 } else {
3527 // A function typedef ("typedef int f(); f a;").
3528 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3529 Diag(Loc, diag::err_not_integral_type_bitfield)
3530 << Name << cast<ValueDecl>(Member)->getType()
3531 << BitWidth->getSourceRange();
3532 }
3533
3534 BitWidth = nullptr;
3535 Member->setInvalidDecl();
3536 }
3537
3538 NamedDecl *NonTemplateMember = Member;
3539 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3540 NonTemplateMember = FunTmpl->getTemplatedDecl();
3541 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3542 NonTemplateMember = VarTmpl->getTemplatedDecl();
3543
3544 Member->setAccess(AS);
3545
3546 // If we have declared a member function template or static data member
3547 // template, set the access of the templated declaration as well.
3548 if (NonTemplateMember != Member)
3549 NonTemplateMember->setAccess(AS);
3550
3551 // C++ [temp.deduct.guide]p3:
3552 // A deduction guide [...] for a member class template [shall be
3553 // declared] with the same access [as the template].
3554 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3555 auto *TD = DG->getDeducedTemplate();
3556 // Access specifiers are only meaningful if both the template and the
3557 // deduction guide are from the same scope.
3558 if (AS != TD->getAccess() &&
3559 TD->getDeclContext()->getRedeclContext()->Equals(
3560 DG->getDeclContext()->getRedeclContext())) {
3561 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3562 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3563 << TD->getAccess();
3564 const AccessSpecDecl *LastAccessSpec = nullptr;
3565 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3566 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3567 LastAccessSpec = AccessSpec;
3568 }
3569 assert(LastAccessSpec && "differing access with no access specifier")(static_cast <bool> (LastAccessSpec && "differing access with no access specifier"
) ? void (0) : __assert_fail ("LastAccessSpec && \"differing access with no access specifier\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3569, __extension__ __PRETTY_FUNCTION__
))
;
3570 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3571 << AS;
3572 }
3573 }
3574 }
3575
3576 if (VS.isOverrideSpecified())
3577 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3578 AttributeCommonInfo::AS_Keyword));
3579 if (VS.isFinalSpecified())
3580 Member->addAttr(FinalAttr::Create(
3581 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3582 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3583
3584 if (VS.getLastLocation().isValid()) {
3585 // Update the end location of a method that has a virt-specifiers.
3586 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3587 MD->setRangeEnd(VS.getLastLocation());
3588 }
3589
3590 CheckOverrideControl(Member);
3591
3592 assert((Name || isInstField) && "No identifier for non-field ?")(static_cast <bool> ((Name || isInstField) && "No identifier for non-field ?"
) ? void (0) : __assert_fail ("(Name || isInstField) && \"No identifier for non-field ?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 3592, __extension__ __PRETTY_FUNCTION__
))
;
3593
3594 if (isInstField) {
3595 FieldDecl *FD = cast<FieldDecl>(Member);
3596 FieldCollector->Add(FD);
3597
3598 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3599 // Remember all explicit private FieldDecls that have a name, no side
3600 // effects and are not part of a dependent type declaration.
3601 if (!FD->isImplicit() && FD->getDeclName() &&
3602 FD->getAccess() == AS_private &&
3603 !FD->hasAttr<UnusedAttr>() &&
3604 !FD->getParent()->isDependentContext() &&
3605 !InitializationHasSideEffects(*FD))
3606 UnusedPrivateFields.insert(FD);
3607 }
3608 }
3609
3610 return Member;
3611}
3612
3613namespace {
3614 class UninitializedFieldVisitor
3615 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3616 Sema &S;
3617 // List of Decls to generate a warning on. Also remove Decls that become
3618 // initialized.
3619 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3620 // List of base classes of the record. Classes are removed after their
3621 // initializers.
3622 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3623 // Vector of decls to be removed from the Decl set prior to visiting the
3624 // nodes. These Decls may have been initialized in the prior initializer.
3625 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3626 // If non-null, add a note to the warning pointing back to the constructor.
3627 const CXXConstructorDecl *Constructor;
3628 // Variables to hold state when processing an initializer list. When
3629 // InitList is true, special case initialization of FieldDecls matching
3630 // InitListFieldDecl.
3631 bool InitList;
3632 FieldDecl *InitListFieldDecl;
3633 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3634
3635 public:
3636 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
3637 UninitializedFieldVisitor(Sema &S,
3638 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3639 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3640 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3641 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3642
3643 // Returns true if the use of ME is not an uninitialized use.
3644 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3645 bool CheckReferenceOnly) {
3646 llvm::SmallVector<FieldDecl*, 4> Fields;
3647 bool ReferenceField = false;
3648 while (ME) {
3649 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3650 if (!FD)
3651 return false;
3652 Fields.push_back(FD);
3653 if (FD->getType()->isReferenceType())
3654 ReferenceField = true;
3655 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3656 }
3657
3658 // Binding a reference to an uninitialized field is not an
3659 // uninitialized use.
3660 if (CheckReferenceOnly && !ReferenceField)
3661 return true;
3662
3663 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3664 // Discard the first field since it is the field decl that is being
3665 // initialized.
3666 for (const FieldDecl *FD : llvm::drop_begin(llvm::reverse(Fields)))
3667 UsedFieldIndex.push_back(FD->getFieldIndex());
3668
3669 for (auto UsedIter = UsedFieldIndex.begin(),
3670 UsedEnd = UsedFieldIndex.end(),
3671 OrigIter = InitFieldIndex.begin(),
3672 OrigEnd = InitFieldIndex.end();
3673 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3674 if (*UsedIter < *OrigIter)
3675 return true;
3676 if (*UsedIter > *OrigIter)
3677 break;
3678 }
3679
3680 return false;
3681 }
3682
3683 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3684 bool AddressOf) {
3685 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3686 return;
3687
3688 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3689 // or union.
3690 MemberExpr *FieldME = ME;
3691
3692 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3693
3694 Expr *Base = ME;
3695 while (MemberExpr *SubME =
3696 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3697
3698 if (isa<VarDecl>(SubME->getMemberDecl()))
3699 return;
3700
3701 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3702 if (!FD->isAnonymousStructOrUnion())
3703 FieldME = SubME;
3704
3705 if (!FieldME->getType().isPODType(S.Context))
3706 AllPODFields = false;
3707
3708 Base = SubME->getBase();
3709 }
3710
3711 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
3712 Visit(Base);
3713 return;
3714 }
3715
3716 if (AddressOf && AllPODFields)
3717 return;
3718
3719 ValueDecl* FoundVD = FieldME->getMemberDecl();
3720
3721 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3722 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3723 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3724 }
3725
3726 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3727 QualType T = BaseCast->getType();
3728 if (T->isPointerType() &&
3729 BaseClasses.count(T->getPointeeType())) {
3730 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3731 << T->getPointeeType() << FoundVD;
3732 }
3733 }
3734 }
3735
3736 if (!Decls.count(FoundVD))
3737 return;
3738
3739 const bool IsReference = FoundVD->getType()->isReferenceType();
3740
3741 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3742 // Special checking for initializer lists.
3743 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3744 return;
3745 }
3746 } else {
3747 // Prevent double warnings on use of unbounded references.
3748 if (CheckReferenceOnly && !IsReference)
3749 return;
3750 }
3751
3752 unsigned diag = IsReference
3753 ? diag::warn_reference_field_is_uninit
3754 : diag::warn_field_is_uninit;
3755 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3756 if (Constructor)
3757 S.Diag(Constructor->getLocation(),
3758 diag::note_uninit_in_this_constructor)
3759 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3760
3761 }
3762
3763 void HandleValue(Expr *E, bool AddressOf) {
3764 E = E->IgnoreParens();
3765
3766 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3767 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3768 AddressOf /*AddressOf*/);
3769 return;
3770 }
3771
3772 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3773 Visit(CO->getCond());
3774 HandleValue(CO->getTrueExpr(), AddressOf);
3775 HandleValue(CO->getFalseExpr(), AddressOf);
3776 return;
3777 }
3778
3779 if (BinaryConditionalOperator *BCO =
3780 dyn_cast<BinaryConditionalOperator>(E)) {
3781 Visit(BCO->getCond());
3782 HandleValue(BCO->getFalseExpr(), AddressOf);
3783 return;
3784 }
3785
3786 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3787 HandleValue(OVE->getSourceExpr(), AddressOf);
3788 return;
3789 }
3790
3791 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3792 switch (BO->getOpcode()) {
3793 default:
3794 break;
3795 case(BO_PtrMemD):
3796 case(BO_PtrMemI):
3797 HandleValue(BO->getLHS(), AddressOf);
3798 Visit(BO->getRHS());
3799 return;
3800 case(BO_Comma):
3801 Visit(BO->getLHS());
3802 HandleValue(BO->getRHS(), AddressOf);
3803 return;
3804 }
3805 }
3806
3807 Visit(E);
3808 }
3809
3810 void CheckInitListExpr(InitListExpr *ILE) {
3811 InitFieldIndex.push_back(0);
3812 for (auto *Child : ILE->children()) {
3813 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3814 CheckInitListExpr(SubList);
3815 } else {
3816 Visit(Child);
3817 }
3818 ++InitFieldIndex.back();
3819 }
3820 InitFieldIndex.pop_back();
3821 }
3822
3823 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3824 FieldDecl *Field, const Type *BaseClass) {
3825 // Remove Decls that may have been initialized in the previous
3826 // initializer.
3827 for (ValueDecl* VD : DeclsToRemove)
3828 Decls.erase(VD);
3829 DeclsToRemove.clear();
3830
3831 Constructor = FieldConstructor;
3832 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3833
3834 if (ILE && Field) {
3835 InitList = true;
3836 InitListFieldDecl = Field;
3837 InitFieldIndex.clear();
3838 CheckInitListExpr(ILE);
3839 } else {
3840 InitList = false;
3841 Visit(E);
3842 }
3843
3844 if (Field)
3845 Decls.erase(Field);
3846 if (BaseClass)
3847 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3848 }
3849
3850 void VisitMemberExpr(MemberExpr *ME) {
3851 // All uses of unbounded reference fields will warn.
3852 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3853 }
3854
3855 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3856 if (E->getCastKind() == CK_LValueToRValue) {
3857 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3858 return;
3859 }
3860
3861 Inherited::VisitImplicitCastExpr(E);
3862 }
3863
3864 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3865 if (E->getConstructor()->isCopyConstructor()) {
3866 Expr *ArgExpr = E->getArg(0);
3867 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3868 if (ILE->getNumInits() == 1)
3869 ArgExpr = ILE->getInit(0);
3870 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3871 if (ICE->getCastKind() == CK_NoOp)
3872 ArgExpr = ICE->getSubExpr();
3873 HandleValue(ArgExpr, false /*AddressOf*/);
3874 return;
3875 }
3876 Inherited::VisitCXXConstructExpr(E);
3877 }
3878
3879 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3880 Expr *Callee = E->getCallee();
3881 if (isa<MemberExpr>(Callee)) {
3882 HandleValue(Callee, false /*AddressOf*/);
3883 for (auto *Arg : E->arguments())
3884 Visit(Arg);
3885 return;
3886 }
3887
3888 Inherited::VisitCXXMemberCallExpr(E);
3889 }
3890
3891 void VisitCallExpr(CallExpr *E) {
3892 // Treat std::move as a use.
3893 if (E->isCallToStdMove()) {
3894 HandleValue(E->getArg(0), /*AddressOf=*/false);
3895 return;
3896 }
3897
3898 Inherited::VisitCallExpr(E);
3899 }
3900
3901 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3902 Expr *Callee = E->getCallee();
3903
3904 if (isa<UnresolvedLookupExpr>(Callee))
3905 return Inherited::VisitCXXOperatorCallExpr(E);
3906
3907 Visit(Callee);
3908 for (auto *Arg : E->arguments())
3909 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3910 }
3911
3912 void VisitBinaryOperator(BinaryOperator *E) {
3913 // If a field assignment is detected, remove the field from the
3914 // uninitiailized field set.
3915 if (E->getOpcode() == BO_Assign)
3916 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3917 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3918 if (!FD->getType()->isReferenceType())
3919 DeclsToRemove.push_back(FD);
3920
3921 if (E->isCompoundAssignmentOp()) {
3922 HandleValue(E->getLHS(), false /*AddressOf*/);
3923 Visit(E->getRHS());
3924 return;
3925 }
3926
3927 Inherited::VisitBinaryOperator(E);
3928 }
3929
3930 void VisitUnaryOperator(UnaryOperator *E) {
3931 if (E->isIncrementDecrementOp()) {
3932 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3933 return;
3934 }
3935 if (E->getOpcode() == UO_AddrOf) {
3936 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3937 HandleValue(ME->getBase(), true /*AddressOf*/);
3938 return;
3939 }
3940 }
3941
3942 Inherited::VisitUnaryOperator(E);
3943 }
3944 };
3945
3946 // Diagnose value-uses of fields to initialize themselves, e.g.
3947 // foo(foo)
3948 // where foo is not also a parameter to the constructor.
3949 // Also diagnose across field uninitialized use such as
3950 // x(y), y(x)
3951 // TODO: implement -Wuninitialized and fold this into that framework.
3952 static void DiagnoseUninitializedFields(
3953 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3954
3955 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3956 Constructor->getLocation())) {
3957 return;
3958 }
3959
3960 if (Constructor->isInvalidDecl())
3961 return;
3962
3963 const CXXRecordDecl *RD = Constructor->getParent();
3964
3965 if (RD->isDependentContext())
3966 return;
3967
3968 // Holds fields that are uninitialized.
3969 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3970
3971 // At the beginning, all fields are uninitialized.
3972 for (auto *I : RD->decls()) {
3973 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3974 UninitializedFields.insert(FD);
3975 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3976 UninitializedFields.insert(IFD->getAnonField());
3977 }
3978 }
3979
3980 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3981 for (auto I : RD->bases())
3982 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3983
3984 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3985 return;
3986
3987 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3988 UninitializedFields,
3989 UninitializedBaseClasses);
3990
3991 for (const auto *FieldInit : Constructor->inits()) {
3992 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3993 break;
3994
3995 Expr *InitExpr = FieldInit->getInit();
3996 if (!InitExpr)
3997 continue;
3998
3999 if (CXXDefaultInitExpr *Default =
4000 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
4001 InitExpr = Default->getExpr();
4002 if (!InitExpr)
4003 continue;
4004 // In class initializers will point to the constructor.
4005 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
4006 FieldInit->getAnyMember(),
4007 FieldInit->getBaseClass());
4008 } else {
4009 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
4010 FieldInit->getAnyMember(),
4011 FieldInit->getBaseClass());
4012 }
4013 }
4014 }
4015} // namespace
4016
4017/// Enter a new C++ default initializer scope. After calling this, the
4018/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
4019/// parsing or instantiating the initializer failed.
4020void Sema::ActOnStartCXXInClassMemberInitializer() {
4021 // Create a synthetic function scope to represent the call to the constructor
4022 // that notionally surrounds a use of this initializer.
4023 PushFunctionScope();
4024}
4025
4026void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
4027 if (!D.isFunctionDeclarator())
4028 return;
4029 auto &FTI = D.getFunctionTypeInfo();
4030 if (!FTI.Params)
4031 return;
4032 for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
4033 FTI.NumParams)) {
4034 auto *ParamDecl = cast<NamedDecl>(Param.Param);
4035 if (ParamDecl->getDeclName())
4036 PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
4037 }
4038}
4039
4040ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
4041 return ActOnRequiresClause(ConstraintExpr);
4042}
4043
4044ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
4045 if (ConstraintExpr.isInvalid())
4046 return ExprError();
4047
4048 ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
4049 if (ConstraintExpr.isInvalid())
4050 return ExprError();
4051
4052 if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
4053 UPPC_RequiresClause))
4054 return ExprError();
4055
4056 return ConstraintExpr;
4057}
4058
4059ExprResult Sema::ConvertMemberDefaultInitExpression(FieldDecl *FD,
4060 Expr *InitExpr,
4061 SourceLocation InitLoc) {
4062 InitializedEntity Entity =
4063 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
4064 InitializationKind Kind =
4065 FD->getInClassInitStyle() == ICIS_ListInit
4066 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
4067 InitExpr->getBeginLoc(),
4068 InitExpr->getEndLoc())
4069 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
4070 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
4071 return Seq.Perform(*this, Entity, Kind, InitExpr);
4072}
4073
4074/// This is invoked after parsing an in-class initializer for a
4075/// non-static C++ class member, and after instantiating an in-class initializer
4076/// in a class template. Such actions are deferred until the class is complete.
4077void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
4078 SourceLocation InitLoc,
4079 Expr *InitExpr) {
4080 // Pop the notional constructor scope we created earlier.
4081 PopFunctionScopeInfo(nullptr, D);
4082
4083 FieldDecl *FD = dyn_cast<FieldDecl>(D);
4084 assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&(static_cast <bool> ((isa<MSPropertyDecl>(D) || FD
->getInClassInitStyle() != ICIS_NoInit) && "must set init style when field is created"
) ? void (0) : __assert_fail ("(isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) && \"must set init style when field is created\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4085, __extension__ __PRETTY_FUNCTION__
))
4085 "must set init style when field is created")(static_cast <bool> ((isa<MSPropertyDecl>(D) || FD
->getInClassInitStyle() != ICIS_NoInit) && "must set init style when field is created"
) ? void (0) : __assert_fail ("(isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) && \"must set init style when field is created\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4085, __extension__ __PRETTY_FUNCTION__
))
;
4086
4087 if (!InitExpr) {
4088 D->setInvalidDecl();
4089 if (FD)
4090 FD->removeInClassInitializer();
4091 return;
4092 }
4093
4094 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
4095 FD->setInvalidDecl();
4096 FD->removeInClassInitializer();
4097 return;
4098 }
4099
4100 ExprResult Init = InitExpr;
4101 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
4102 Init = ConvertMemberDefaultInitExpression(FD, InitExpr, InitLoc);
4103 // C++11 [class.base.init]p7:
4104 // The initialization of each base and member constitutes a
4105 // full-expression.
4106 if (!Init.isInvalid())
4107 Init = ActOnFinishFullExpr(Init.get(), /*DiscarededValue=*/false);
4108 if (Init.isInvalid()) {
4109 FD->setInvalidDecl();
4110 return;
4111 }
4112 }
4113
4114 InitExpr = Init.get();
4115
4116 FD->setInClassInitializer(InitExpr);
4117}
4118
4119/// Find the direct and/or virtual base specifiers that
4120/// correspond to the given base type, for use in base initialization
4121/// within a constructor.
4122static bool FindBaseInitializer(Sema &SemaRef,
4123 CXXRecordDecl *ClassDecl,
4124 QualType BaseType,
4125 const CXXBaseSpecifier *&DirectBaseSpec,
4126 const CXXBaseSpecifier *&VirtualBaseSpec) {
4127 // First, check for a direct base class.
4128 DirectBaseSpec = nullptr;
4129 for (const auto &Base : ClassDecl->bases()) {
4130 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
4131 // We found a direct base of this type. That's what we're
4132 // initializing.
4133 DirectBaseSpec = &Base;
4134 break;
4135 }
4136 }
4137
4138 // Check for a virtual base class.
4139 // FIXME: We might be able to short-circuit this if we know in advance that
4140 // there are no virtual bases.
4141 VirtualBaseSpec = nullptr;
4142 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
4143 // We haven't found a base yet; search the class hierarchy for a
4144 // virtual base class.
4145 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
4146 /*DetectVirtual=*/false);
4147 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
4148 SemaRef.Context.getTypeDeclType(ClassDecl),
4149 BaseType, Paths)) {
4150 for (CXXBasePaths::paths_iterator Path = Paths.begin();
4151 Path != Paths.end(); ++Path) {
4152 if (Path->back().Base->isVirtual()) {
4153 VirtualBaseSpec = Path->back().Base;
4154 break;
4155 }
4156 }
4157 }
4158 }
4159
4160 return DirectBaseSpec || VirtualBaseSpec;
4161}
4162
4163/// Handle a C++ member initializer using braced-init-list syntax.
4164MemInitResult
4165Sema::ActOnMemInitializer(Decl *ConstructorD,
4166 Scope *S,
4167 CXXScopeSpec &SS,
4168 IdentifierInfo *MemberOrBase,
4169 ParsedType TemplateTypeTy,
4170 const DeclSpec &DS,
4171 SourceLocation IdLoc,
4172 Expr *InitList,
4173 SourceLocation EllipsisLoc) {
4174 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4175 DS, IdLoc, InitList,
4176 EllipsisLoc);
4177}
4178
4179/// Handle a C++ member initializer using parentheses syntax.
4180MemInitResult
4181Sema::ActOnMemInitializer(Decl *ConstructorD,
4182 Scope *S,
4183 CXXScopeSpec &SS,
4184 IdentifierInfo *MemberOrBase,
4185 ParsedType TemplateTypeTy,
4186 const DeclSpec &DS,
4187 SourceLocation IdLoc,
4188 SourceLocation LParenLoc,
4189 ArrayRef<Expr *> Args,
4190 SourceLocation RParenLoc,
4191 SourceLocation EllipsisLoc) {
4192 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
4193 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4194 DS, IdLoc, List, EllipsisLoc);
4195}
4196
4197namespace {
4198
4199// Callback to only accept typo corrections that can be a valid C++ member
4200// initializer: either a non-static field member or a base class.
4201class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4202public:
4203 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4204 : ClassDecl(ClassDecl) {}
4205
4206 bool ValidateCandidate(const TypoCorrection &candidate) override {
4207 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4208 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4209 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4210 return isa<TypeDecl>(ND);
4211 }
4212 return false;
4213 }
4214
4215 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4216 return std::make_unique<MemInitializerValidatorCCC>(*this);
4217 }
4218
4219private:
4220 CXXRecordDecl *ClassDecl;
4221};
4222
4223}
4224
4225ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4226 CXXScopeSpec &SS,
4227 ParsedType TemplateTypeTy,
4228 IdentifierInfo *MemberOrBase) {
4229 if (SS.getScopeRep() || TemplateTypeTy)
4230 return nullptr;
4231 for (auto *D : ClassDecl->lookup(MemberOrBase))
4232 if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
4233 return cast<ValueDecl>(D);
4234 return nullptr;
4235}
4236
4237/// Handle a C++ member initializer.
4238MemInitResult
4239Sema::BuildMemInitializer(Decl *ConstructorD,
4240 Scope *S,
4241 CXXScopeSpec &SS,
4242 IdentifierInfo *MemberOrBase,
4243 ParsedType TemplateTypeTy,
4244 const DeclSpec &DS,
4245 SourceLocation IdLoc,
4246 Expr *Init,
4247 SourceLocation EllipsisLoc) {
4248 ExprResult Res = CorrectDelayedTyposInExpr(Init, /*InitDecl=*/nullptr,
4249 /*RecoverUncorrectedTypos=*/true);
4250 if (!Res.isUsable())
4251 return true;
4252 Init = Res.get();
4253
4254 if (!ConstructorD)
4255 return true;
4256
4257 AdjustDeclIfTemplate(ConstructorD);
4258
4259 CXXConstructorDecl *Constructor
4260 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4261 if (!Constructor) {
4262 // The user wrote a constructor initializer on a function that is
4263 // not a C++ constructor. Ignore the error for now, because we may
4264 // have more member initializers coming; we'll diagnose it just
4265 // once in ActOnMemInitializers.
4266 return true;
4267 }
4268
4269 CXXRecordDecl *ClassDecl = Constructor->getParent();
4270
4271 // C++ [class.base.init]p2:
4272 // Names in a mem-initializer-id are looked up in the scope of the
4273 // constructor's class and, if not found in that scope, are looked
4274 // up in the scope containing the constructor's definition.
4275 // [Note: if the constructor's class contains a member with the
4276 // same name as a direct or virtual base class of the class, a
4277 // mem-initializer-id naming the member or base class and composed
4278 // of a single identifier refers to the class member. A
4279 // mem-initializer-id for the hidden base class may be specified
4280 // using a qualified name. ]
4281
4282 // Look for a member, first.
4283 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4284 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4285 if (EllipsisLoc.isValid())
4286 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4287 << MemberOrBase
4288 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4289
4290 return BuildMemberInitializer(Member, Init, IdLoc);
4291 }
4292 // It didn't name a member, so see if it names a class.
4293 QualType BaseType;
4294 TypeSourceInfo *TInfo = nullptr;
4295
4296 if (TemplateTypeTy) {
4297 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4298 if (BaseType.isNull())
4299 return true;
4300 } else if (DS.getTypeSpecType() == TST_decltype) {
4301 BaseType = BuildDecltypeType(DS.getRepAsExpr());
4302 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4303 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4304 return true;
4305 } else {
4306 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4307 LookupParsedName(R, S, &SS);
4308
4309 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4310 if (!TyD) {
4311 if (R.isAmbiguous()) return true;
4312
4313 // We don't want access-control diagnostics here.
4314 R.suppressDiagnostics();
4315
4316 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4317 bool NotUnknownSpecialization = false;
4318 DeclContext *DC = computeDeclContext(SS, false);
4319 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4320 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4321
4322 if (!NotUnknownSpecialization) {
4323 // When the scope specifier can refer to a member of an unknown
4324 // specialization, we take it as a type name.
4325 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4326 SS.getWithLocInContext(Context),
4327 *MemberOrBase, IdLoc);
4328 if (BaseType.isNull())
4329 return true;
4330
4331 TInfo = Context.CreateTypeSourceInfo(BaseType);
4332 DependentNameTypeLoc TL =
4333 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4334 if (!TL.isNull()) {
4335 TL.setNameLoc(IdLoc);
4336 TL.setElaboratedKeywordLoc(SourceLocation());
4337 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4338 }
4339
4340 R.clear();
4341 R.setLookupName(MemberOrBase);
4342 }
4343 }
4344
4345 if (getLangOpts().MSVCCompat && !getLangOpts().CPlusPlus20) {
4346 if (auto UnqualifiedBase = R.getAsSingle<ClassTemplateDecl>()) {
4347 auto *TempSpec = cast<TemplateSpecializationType>(
4348 UnqualifiedBase->getInjectedClassNameSpecialization());
4349 TemplateName TN = TempSpec->getTemplateName();
4350 for (auto const &Base : ClassDecl->bases()) {
4351 auto BaseTemplate =
4352 Base.getType()->getAs<TemplateSpecializationType>();
4353 if (BaseTemplate && Context.hasSameTemplateName(
4354 BaseTemplate->getTemplateName(), TN)) {
4355 Diag(IdLoc, diag::ext_unqualified_base_class)
4356 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4357 BaseType = Base.getType();
4358 break;
4359 }
4360 }
4361 }
4362 }
4363
4364 // If no results were found, try to correct typos.
4365 TypoCorrection Corr;
4366 MemInitializerValidatorCCC CCC(ClassDecl);
4367 if (R.empty() && BaseType.isNull() &&
4368 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4369 CCC, CTK_ErrorRecovery, ClassDecl))) {
4370 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4371 // We have found a non-static data member with a similar
4372 // name to what was typed; complain and initialize that
4373 // member.
4374 diagnoseTypo(Corr,
4375 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4376 << MemberOrBase << true);
4377 return BuildMemberInitializer(Member, Init, IdLoc);
4378 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4379 const CXXBaseSpecifier *DirectBaseSpec;
4380 const CXXBaseSpecifier *VirtualBaseSpec;
4381 if (FindBaseInitializer(*this, ClassDecl,
4382 Context.getTypeDeclType(Type),
4383 DirectBaseSpec, VirtualBaseSpec)) {
4384 // We have found a direct or virtual base class with a
4385 // similar name to what was typed; complain and initialize
4386 // that base class.
4387 diagnoseTypo(Corr,
4388 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4389 << MemberOrBase << false,
4390 PDiag() /*Suppress note, we provide our own.*/);
4391
4392 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4393 : VirtualBaseSpec;
4394 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4395 << BaseSpec->getType() << BaseSpec->getSourceRange();
4396
4397 TyD = Type;
4398 }
4399 }
4400 }
4401
4402 if (!TyD && BaseType.isNull()) {
4403 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4404 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4405 return true;
4406 }
4407 }
4408
4409 if (BaseType.isNull()) {
4410 BaseType = getElaboratedType(ETK_None, SS, Context.getTypeDeclType(TyD));
4411 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4412 TInfo = Context.CreateTypeSourceInfo(BaseType);
4413 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4414 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4415 TL.setElaboratedKeywordLoc(SourceLocation());
4416 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4417 }
4418 }
4419
4420 if (!TInfo)
4421 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4422
4423 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4424}
4425
4426MemInitResult
4427Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4428 SourceLocation IdLoc) {
4429 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4430 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4431 assert((DirectMember || IndirectMember) &&(static_cast <bool> ((DirectMember || IndirectMember) &&
"Member must be a FieldDecl or IndirectFieldDecl") ? void (0
) : __assert_fail ("(DirectMember || IndirectMember) && \"Member must be a FieldDecl or IndirectFieldDecl\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4432, __extension__ __PRETTY_FUNCTION__
))
4432 "Member must be a FieldDecl or IndirectFieldDecl")(static_cast <bool> ((DirectMember || IndirectMember) &&
"Member must be a FieldDecl or IndirectFieldDecl") ? void (0
) : __assert_fail ("(DirectMember || IndirectMember) && \"Member must be a FieldDecl or IndirectFieldDecl\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4432, __extension__ __PRETTY_FUNCTION__
))
;
4433
4434 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4435 return true;
4436
4437 if (Member->isInvalidDecl())
4438 return true;
4439
4440 MultiExprArg Args;
4441 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4442 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4443 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4444 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4445 } else {
4446 // Template instantiation doesn't reconstruct ParenListExprs for us.
4447 Args = Init;
4448 }
4449
4450 SourceRange InitRange = Init->getSourceRange();
4451
4452 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4453 // Can't check initialization for a member of dependent type or when
4454 // any of the arguments are type-dependent expressions.
4455 DiscardCleanupsInEvaluationContext();
4456 } else {
4457 bool InitList = false;
4458 if (isa<InitListExpr>(Init)) {
4459 InitList = true;
4460 Args = Init;
4461 }
4462
4463 // Initialize the member.
4464 InitializedEntity MemberEntity =
4465 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4466 : InitializedEntity::InitializeMember(IndirectMember,
4467 nullptr);
4468 InitializationKind Kind =
4469 InitList ? InitializationKind::CreateDirectList(
4470 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4471 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4472 InitRange.getEnd());
4473
4474 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4475 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4476 nullptr);
4477 if (!MemberInit.isInvalid()) {
4478 // C++11 [class.base.init]p7:
4479 // The initialization of each base and member constitutes a
4480 // full-expression.
4481 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4482 /*DiscardedValue*/ false);
4483 }
4484
4485 if (MemberInit.isInvalid()) {
4486 // Args were sensible expressions but we couldn't initialize the member
4487 // from them. Preserve them in a RecoveryExpr instead.
4488 Init = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
4489 Member->getType())
4490 .get();
4491 if (!Init)
4492 return true;
4493 } else {
4494 Init = MemberInit.get();
4495 }
4496 }
4497
4498 if (DirectMember) {
4499 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4500 InitRange.getBegin(), Init,
4501 InitRange.getEnd());
4502 } else {
4503 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4504 InitRange.getBegin(), Init,
4505 InitRange.getEnd());
4506 }
4507}
4508
4509MemInitResult
4510Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4511 CXXRecordDecl *ClassDecl) {
4512 SourceLocation NameLoc = TInfo->getTypeLoc().getSourceRange().getBegin();
4513 if (!LangOpts.CPlusPlus11)
4514 return Diag(NameLoc, diag::err_delegating_ctor)
4515 << TInfo->getTypeLoc().getSourceRange();
4516 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4517
4518 bool InitList = true;
4519 MultiExprArg Args = Init;
4520 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4521 InitList = false;
4522 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4523 }
4524
4525 SourceRange InitRange = Init->getSourceRange();
4526 // Initialize the object.
4527 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4528 QualType(ClassDecl->getTypeForDecl(), 0));
4529 InitializationKind Kind =
4530 InitList ? InitializationKind::CreateDirectList(
4531 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4532 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4533 InitRange.getEnd());
4534 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4535 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4536 Args, nullptr);
4537 if (!DelegationInit.isInvalid()) {
4538 assert((DelegationInit.get()->containsErrors() ||(static_cast <bool> ((DelegationInit.get()->containsErrors
() || cast<CXXConstructExpr>(DelegationInit.get())->
getConstructor()) && "Delegating constructor with no target?"
) ? void (0) : __assert_fail ("(DelegationInit.get()->containsErrors() || cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) && \"Delegating constructor with no target?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4540, __extension__ __PRETTY_FUNCTION__
))
4539 cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) &&(static_cast <bool> ((DelegationInit.get()->containsErrors
() || cast<CXXConstructExpr>(DelegationInit.get())->
getConstructor()) && "Delegating constructor with no target?"
) ? void (0) : __assert_fail ("(DelegationInit.get()->containsErrors() || cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) && \"Delegating constructor with no target?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4540, __extension__ __PRETTY_FUNCTION__
))
4540 "Delegating constructor with no target?")(static_cast <bool> ((DelegationInit.get()->containsErrors
() || cast<CXXConstructExpr>(DelegationInit.get())->
getConstructor()) && "Delegating constructor with no target?"
) ? void (0) : __assert_fail ("(DelegationInit.get()->containsErrors() || cast<CXXConstructExpr>(DelegationInit.get())->getConstructor()) && \"Delegating constructor with no target?\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4540, __extension__ __PRETTY_FUNCTION__
))
;
4541
4542 // C++11 [class.base.init]p7:
4543 // The initialization of each base and member constitutes a
4544 // full-expression.
4545 DelegationInit = ActOnFinishFullExpr(
4546 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4547 }
4548
4549 if (DelegationInit.isInvalid()) {
4550 DelegationInit =
4551 CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
4552 QualType(ClassDecl->getTypeForDecl(), 0));
4553 if (DelegationInit.isInvalid())
4554 return true;
4555 } else {
4556 // If we are in a dependent context, template instantiation will
4557 // perform this type-checking again. Just save the arguments that we
4558 // received in a ParenListExpr.
4559 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4560 // of the information that we have about the base
4561 // initializer. However, deconstructing the ASTs is a dicey process,
4562 // and this approach is far more likely to get the corner cases right.
4563 if (CurContext->isDependentContext())
4564 DelegationInit = Init;
4565 }
4566
4567 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4568 DelegationInit.getAs<Expr>(),
4569 InitRange.getEnd());
4570}
4571
4572MemInitResult
4573Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4574 Expr *Init, CXXRecordDecl *ClassDecl,
4575 SourceLocation EllipsisLoc) {
4576 SourceLocation BaseLoc = BaseTInfo->getTypeLoc().getBeginLoc();
4577
4578 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4579 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4580 << BaseType << BaseTInfo->getTypeLoc().getSourceRange();
4581
4582 // C++ [class.base.init]p2:
4583 // [...] Unless the mem-initializer-id names a nonstatic data
4584 // member of the constructor's class or a direct or virtual base
4585 // of that class, the mem-initializer is ill-formed. A
4586 // mem-initializer-list can initialize a base class using any
4587 // name that denotes that base class type.
4588
4589 // We can store the initializers in "as-written" form and delay analysis until
4590 // instantiation if the constructor is dependent. But not for dependent
4591 // (broken) code in a non-template! SetCtorInitializers does not expect this.
4592 bool Dependent = CurContext->isDependentContext() &&
4593 (BaseType->isDependentType() || Init->isTypeDependent());
4594
4595 SourceRange InitRange = Init->getSourceRange();
4596 if (EllipsisLoc.isValid()) {
4597 // This is a pack expansion.
4598 if (!BaseType->containsUnexpandedParameterPack()) {
4599 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4600 << SourceRange(BaseLoc, InitRange.getEnd());
4601
4602 EllipsisLoc = SourceLocation();
4603 }
4604 } else {
4605 // Check for any unexpanded parameter packs.
4606 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4607 return true;
4608
4609 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4610 return true;
4611 }
4612
4613 // Check for direct and virtual base classes.
4614 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4615 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4616 if (!Dependent) {
4617 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4618 BaseType))
4619 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4620
4621 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4622 VirtualBaseSpec);
4623
4624 // C++ [base.class.init]p2:
4625 // Unless the mem-initializer-id names a nonstatic data member of the
4626 // constructor's class or a direct or virtual base of that class, the
4627 // mem-initializer is ill-formed.
4628 if (!DirectBaseSpec && !VirtualBaseSpec) {
4629 // If the class has any dependent bases, then it's possible that
4630 // one of those types will resolve to the same type as
4631 // BaseType. Therefore, just treat this as a dependent base
4632 // class initialization. FIXME: Should we try to check the
4633 // initialization anyway? It seems odd.
4634 if (ClassDecl->hasAnyDependentBases())
4635 Dependent = true;
4636 else
4637 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4638 << BaseType << Context.getTypeDeclType(ClassDecl)
4639 << BaseTInfo->getTypeLoc().getSourceRange();
4640 }
4641 }
4642
4643 if (Dependent) {
4644 DiscardCleanupsInEvaluationContext();
4645
4646 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4647 /*IsVirtual=*/false,
4648 InitRange.getBegin(), Init,
4649 InitRange.getEnd(), EllipsisLoc);
4650 }
4651
4652 // C++ [base.class.init]p2:
4653 // If a mem-initializer-id is ambiguous because it designates both
4654 // a direct non-virtual base class and an inherited virtual base
4655 // class, the mem-initializer is ill-formed.
4656 if (DirectBaseSpec && VirtualBaseSpec)
4657 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4658 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4659
4660 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4661 if (!BaseSpec)
4662 BaseSpec = VirtualBaseSpec;
4663
4664 // Initialize the base.
4665 bool InitList = true;
4666 MultiExprArg Args = Init;
4667 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4668 InitList = false;
4669 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4670 }
4671
4672 InitializedEntity BaseEntity =
4673 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4674 InitializationKind Kind =
4675 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4676 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4677 InitRange.getEnd());
4678 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4679 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4680 if (!BaseInit.isInvalid()) {
4681 // C++11 [class.base.init]p7:
4682 // The initialization of each base and member constitutes a
4683 // full-expression.
4684 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4685 /*DiscardedValue*/ false);
4686 }
4687
4688 if (BaseInit.isInvalid()) {
4689 BaseInit = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(),
4690 Args, BaseType);
4691 if (BaseInit.isInvalid())
4692 return true;
4693 } else {
4694 // If we are in a dependent context, template instantiation will
4695 // perform this type-checking again. Just save the arguments that we
4696 // received in a ParenListExpr.
4697 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4698 // of the information that we have about the base
4699 // initializer. However, deconstructing the ASTs is a dicey process,
4700 // and this approach is far more likely to get the corner cases right.
4701 if (CurContext->isDependentContext())
4702 BaseInit = Init;
4703 }
4704
4705 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4706 BaseSpec->isVirtual(),
4707 InitRange.getBegin(),
4708 BaseInit.getAs<Expr>(),
4709 InitRange.getEnd(), EllipsisLoc);
4710}
4711
4712// Create a static_cast\<T&&>(expr).
4713static Expr *CastForMoving(Sema &SemaRef, Expr *E) {
4714 QualType TargetType =
4715 SemaRef.BuildReferenceType(E->getType(), /*SpelledAsLValue*/ false,
4716 SourceLocation(), DeclarationName());
4717 SourceLocation ExprLoc = E->getBeginLoc();
4718 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4719 TargetType, ExprLoc);
4720
4721 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4722 SourceRange(ExprLoc, ExprLoc),
4723 E->getSourceRange()).get();
4724}
4725
4726/// ImplicitInitializerKind - How an implicit base or member initializer should
4727/// initialize its base or member.
4728enum ImplicitInitializerKind {
4729 IIK_Default,
4730 IIK_Copy,
4731 IIK_Move,
4732 IIK_Inherit
4733};
4734
4735static bool
4736BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4737 ImplicitInitializerKind ImplicitInitKind,
4738 CXXBaseSpecifier *BaseSpec,
4739 bool IsInheritedVirtualBase,
4740 CXXCtorInitializer *&CXXBaseInit) {
4741 InitializedEntity InitEntity
4742 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4743 IsInheritedVirtualBase);
4744
4745 ExprResult BaseInit;
4746
4747 switch (ImplicitInitKind) {
4748 case IIK_Inherit:
4749 case IIK_Default: {
4750 InitializationKind InitKind
4751 = InitializationKind::CreateDefault(Constructor->getLocation());
4752 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, std::nullopt);
4753 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, std::nullopt);
4754 break;
4755 }
4756
4757 case IIK_Move:
4758 case IIK_Copy: {
4759 bool Moving = ImplicitInitKind == IIK_Move;
4760 ParmVarDecl *Param = Constructor->getParamDecl(0);
4761 QualType ParamType = Param->getType().getNonReferenceType();
4762
4763 Expr *CopyCtorArg =
4764 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4765 SourceLocation(), Param, false,
4766 Constructor->getLocation(), ParamType,
4767 VK_LValue, nullptr);
4768
4769 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4770
4771 // Cast to the base class to avoid ambiguities.
4772 QualType ArgTy =
4773 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4774 ParamType.getQualifiers());
4775
4776 if (Moving) {
4777 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4778 }
4779
4780 CXXCastPath BasePath;
4781 BasePath.push_back(BaseSpec);
4782 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4783 CK_UncheckedDerivedToBase,
4784 Moving ? VK_XValue : VK_LValue,
4785 &BasePath).get();
4786
4787 InitializationKind InitKind
4788 = InitializationKind::CreateDirect(Constructor->getLocation(),
4789 SourceLocation(), SourceLocation());
4790 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4791 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4792 break;
4793 }
4794 }
4795
4796 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4797 if (BaseInit.isInvalid())
4798 return true;
4799
4800 CXXBaseInit =
4801 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4802 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4803 SourceLocation()),
4804 BaseSpec->isVirtual(),
4805 SourceLocation(),
4806 BaseInit.getAs<Expr>(),
4807 SourceLocation(),
4808 SourceLocation());
4809
4810 return false;
4811}
4812
4813static bool RefersToRValueRef(Expr *MemRef) {
4814 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4815 return Referenced->getType()->isRValueReferenceType();
4816}
4817
4818static bool
4819BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4820 ImplicitInitializerKind ImplicitInitKind,
4821 FieldDecl *Field, IndirectFieldDecl *Indirect,
4822 CXXCtorInitializer *&CXXMemberInit) {
4823 if (Field->isInvalidDecl())
4824 return true;
4825
4826 SourceLocation Loc = Constructor->getLocation();
4827
4828 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4829 bool Moving = ImplicitInitKind == IIK_Move;
4830 ParmVarDecl *Param = Constructor->getParamDecl(0);
4831 QualType ParamType = Param->getType().getNonReferenceType();
4832
4833 // Suppress copying zero-width bitfields.
4834 if (Field->isZeroLengthBitField(SemaRef.Context))
4835 return false;
4836
4837 Expr *MemberExprBase =
4838 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4839 SourceLocation(), Param, false,
4840 Loc, ParamType, VK_LValue, nullptr);
4841
4842 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4843
4844 if (Moving) {
4845 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4846 }
4847
4848 // Build a reference to this field within the parameter.
4849 CXXScopeSpec SS;
4850 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4851 Sema::LookupMemberName);
4852 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4853 : cast<ValueDecl>(Field), AS_public);
4854 MemberLookup.resolveKind();
4855 ExprResult CtorArg
4856 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4857 ParamType, Loc,
4858 /*IsArrow=*/false,
4859 SS,
4860 /*TemplateKWLoc=*/SourceLocation(),
4861 /*FirstQualifierInScope=*/nullptr,
4862 MemberLookup,
4863 /*TemplateArgs=*/nullptr,
4864 /*S*/nullptr);
4865 if (CtorArg.isInvalid())
4866 return true;
4867
4868 // C++11 [class.copy]p15:
4869 // - if a member m has rvalue reference type T&&, it is direct-initialized
4870 // with static_cast<T&&>(x.m);
4871 if (RefersToRValueRef(CtorArg.get())) {
4872 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4873 }
4874
4875 InitializedEntity Entity =
4876 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4877 /*Implicit*/ true)
4878 : InitializedEntity::InitializeMember(Field, nullptr,
4879 /*Implicit*/ true);
4880
4881 // Direct-initialize to use the copy constructor.
4882 InitializationKind InitKind =
4883 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4884
4885 Expr *CtorArgE = CtorArg.getAs<Expr>();
4886 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4887 ExprResult MemberInit =
4888 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4889 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4890 if (MemberInit.isInvalid())
4891 return true;
4892
4893 if (Indirect)
4894 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4895 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4896 else
4897 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4898 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4899 return false;
4900 }
4901
4902 assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&(static_cast <bool> ((ImplicitInitKind == IIK_Default ||
ImplicitInitKind == IIK_Inherit) && "Unhandled implicit init kind!"
) ? void (0) : __assert_fail ("(ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) && \"Unhandled implicit init kind!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4903, __extension__ __PRETTY_FUNCTION__
))
4903 "Unhandled implicit init kind!")(static_cast <bool> ((ImplicitInitKind == IIK_Default ||
ImplicitInitKind == IIK_Inherit) && "Unhandled implicit init kind!"
) ? void (0) : __assert_fail ("(ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) && \"Unhandled implicit init kind!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 4903, __extension__ __PRETTY_FUNCTION__
))
;
4904
4905 QualType FieldBaseElementType =
4906 SemaRef.Context.getBaseElementType(Field->getType());
4907
4908 if (FieldBaseElementType->isRecordType()) {
4909 InitializedEntity InitEntity =
4910 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4911 /*Implicit*/ true)
4912 : InitializedEntity::InitializeMember(Field, nullptr,
4913 /*Implicit*/ true);
4914 InitializationKind InitKind =
4915 InitializationKind::CreateDefault(Loc);
4916
4917 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, std::nullopt);
4918 ExprResult MemberInit =
4919 InitSeq.Perform(SemaRef, InitEntity, InitKind, std::nullopt);
4920
4921 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4922 if (MemberInit.isInvalid())
4923 return true;
4924
4925 if (Indirect)
4926 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4927 Indirect, Loc,
4928 Loc,
4929 MemberInit.get(),
4930 Loc);
4931 else
4932 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4933 Field, Loc, Loc,
4934 MemberInit.get(),
4935 Loc);
4936 return false;
4937 }
4938
4939 if (!Field->getParent()->isUnion()) {
4940 if (FieldBaseElementType->isReferenceType()) {
4941 SemaRef.Diag(Constructor->getLocation(),
4942 diag::err_uninitialized_member_in_ctor)
4943 << (int)Constructor->isImplicit()
4944 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4945 << 0 << Field->getDeclName();
4946 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4947 return true;
4948 }
4949
4950 if (FieldBaseElementType.isConstQualified()) {
4951 SemaRef.Diag(Constructor->getLocation(),
4952 diag::err_uninitialized_member_in_ctor)
4953 << (int)Constructor->isImplicit()
4954 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4955 << 1 << Field->getDeclName();
4956 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4957 return true;
4958 }
4959 }
4960
4961 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4962 // ARC and Weak:
4963 // Default-initialize Objective-C pointers to NULL.
4964 CXXMemberInit
4965 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4966 Loc, Loc,
4967 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4968 Loc);
4969 return false;
4970 }
4971
4972 // Nothing to initialize.
4973 CXXMemberInit = nullptr;
4974 return false;
4975}
4976
4977namespace {
4978struct BaseAndFieldInfo {
4979 Sema &S;
4980 CXXConstructorDecl *Ctor;
4981 bool AnyErrorsInInits;
4982 ImplicitInitializerKind IIK;
4983 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4984 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4985 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4986
4987 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4988 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4989 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4990 if (Ctor->getInheritedConstructor())
4991 IIK = IIK_Inherit;
4992 else if (Generated && Ctor->isCopyConstructor())
4993 IIK = IIK_Copy;
4994 else if (Generated && Ctor->isMoveConstructor())
4995 IIK = IIK_Move;
4996 else
4997 IIK = IIK_Default;
4998 }
4999
5000 bool isImplicitCopyOrMove() const {
5001 switch (IIK) {
5002 case IIK_Copy:
5003 case IIK_Move:
5004 return true;
5005
5006 case IIK_Default:
5007 case IIK_Inherit:
5008 return false;
5009 }
5010
5011 llvm_unreachable("Invalid ImplicitInitializerKind!")::llvm::llvm_unreachable_internal("Invalid ImplicitInitializerKind!"
, "clang/lib/Sema/SemaDeclCXX.cpp", 5011)
;
5012 }
5013
5014 bool addFieldInitializer(CXXCtorInitializer *Init) {
5015 AllToInit.push_back(Init);
5016
5017 // Check whether this initializer makes the field "used".
5018 if (Init->getInit()->HasSideEffects(S.Context))
5019 S.UnusedPrivateFields.remove(Init->getAnyMember());
5020
5021 return false;
5022 }
5023
5024 bool isInactiveUnionMember(FieldDecl *Field) {
5025 RecordDecl *Record = Field->getParent();
5026 if (!Record->isUnion())
5027 return false;
5028
5029 if (FieldDecl *Active =
5030 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
5031 return Active != Field->getCanonicalDecl();
5032
5033 // In an implicit copy or move constructor, ignore any in-class initializer.
5034 if (isImplicitCopyOrMove())
5035 return true;
5036
5037 // If there's no explicit initialization, the field is active only if it
5038 // has an in-class initializer...
5039 if (Field->hasInClassInitializer())
5040 return false;
5041 // ... or it's an anonymous struct or union whose class has an in-class
5042 // initializer.
5043 if (!Field->isAnonymousStructOrUnion())
5044 return true;
5045 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
5046 return !FieldRD->hasInClassInitializer();
5047 }
5048
5049 /// Determine whether the given field is, or is within, a union member
5050 /// that is inactive (because there was an initializer given for a different
5051 /// member of the union, or because the union was not initialized at all).
5052 bool isWithinInactiveUnionMember(FieldDecl *Field,
5053 IndirectFieldDecl *Indirect) {
5054 if (!Indirect)
5055 return isInactiveUnionMember(Field);
5056
5057 for (auto *C : Indirect->chain()) {
5058 FieldDecl *Field = dyn_cast<FieldDecl>(C);
5059 if (Field && isInactiveUnionMember(Field))
5060 return true;
5061 }
5062 return false;
5063 }
5064};
5065}
5066
5067/// Determine whether the given type is an incomplete or zero-lenfgth
5068/// array type.
5069static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
5070 if (T->isIncompleteArrayType())
5071 return true;
5072
5073 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
5074 if (!ArrayT->getSize())
5075 return true;
5076
5077 T = ArrayT->getElementType();
5078 }
5079
5080 return false;
5081}
5082
5083static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
5084 FieldDecl *Field,
5085 IndirectFieldDecl *Indirect = nullptr) {
5086 if (Field->isInvalidDecl())
5087 return false;
5088
5089 // Overwhelmingly common case: we have a direct initializer for this field.
5090 if (CXXCtorInitializer *Init =
5091 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
5092 return Info.addFieldInitializer(Init);
5093
5094 // C++11 [class.base.init]p8:
5095 // if the entity is a non-static data member that has a
5096 // brace-or-equal-initializer and either
5097 // -- the constructor's class is a union and no other variant member of that
5098 // union is designated by a mem-initializer-id or
5099 // -- the constructor's class is not a union, and, if the entity is a member
5100 // of an anonymous union, no other member of that union is designated by
5101 // a mem-initializer-id,
5102 // the entity is initialized as specified in [dcl.init].
5103 //
5104 // We also apply the same rules to handle anonymous structs within anonymous
5105 // unions.
5106 if (Info.isWithinInactiveUnionMember(Field, Indirect))
5107 return false;
5108
5109 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
5110 ExprResult DIE =
5111 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
5112 if (DIE.isInvalid())
5113 return true;
5114
5115 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
5116 SemaRef.checkInitializerLifetime(Entity, DIE.get());
5117
5118 CXXCtorInitializer *Init;
5119 if (Indirect)
5120 Init = new (SemaRef.Context)
5121 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
5122 SourceLocation(), DIE.get(), SourceLocation());
5123 else
5124 Init = new (SemaRef.Context)
5125 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
5126 SourceLocation(), DIE.get(), SourceLocation());
5127 return Info.addFieldInitializer(Init);
5128 }
5129
5130 // Don't initialize incomplete or zero-length arrays.
5131 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
5132 return false;
5133
5134 // Don't try to build an implicit initializer if there were semantic
5135 // errors in any of the initializers (and therefore we might be
5136 // missing some that the user actually wrote).
5137 if (Info.AnyErrorsInInits)
5138 return false;
5139
5140 CXXCtorInitializer *Init = nullptr;
5141 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
5142 Indirect, Init))
5143 return true;
5144
5145 if (!Init)
5146 return false;
5147
5148 return Info.addFieldInitializer(Init);
5149}
5150
5151bool
5152Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
5153 CXXCtorInitializer *Initializer) {
5154 assert(Initializer->isDelegatingInitializer())(static_cast <bool> (Initializer->isDelegatingInitializer
()) ? void (0) : __assert_fail ("Initializer->isDelegatingInitializer()"
, "clang/lib/Sema/SemaDeclCXX.cpp", 5154, __extension__ __PRETTY_FUNCTION__
))
;
5155 Constructor->setNumCtorInitializers(1);
5156 CXXCtorInitializer **initializer =
5157 new (Context) CXXCtorInitializer*[1];
5158 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
5159 Constructor->setCtorInitializers(initializer);
5160
5161 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
5162 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
5163 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
5164 }
5165
5166 DelegatingCtorDecls.push_back(Constructor);
5167
5168 DiagnoseUninitializedFields(*this, Constructor);
5169
5170 return false;
5171}
5172
5173bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
5174 ArrayRef<CXXCtorInitializer *> Initializers) {
5175 if (Constructor->isDependentContext()) {
5176 // Just store the initializers as written, they will be checked during
5177 // instantiation.
5178 if (!Initializers.empty()) {
5179 Constructor->setNumCtorInitializers(Initializers.size());
5180 CXXCtorInitializer **baseOrMemberInitializers =
5181 new (Context) CXXCtorInitializer*[Initializers.size()];
5182 memcpy(baseOrMemberInitializers, Initializers.data(),
5183 Initializers.size() * sizeof(CXXCtorInitializer*));
5184 Constructor->setCtorInitializers(baseOrMemberInitializers);
5185 }
5186
5187 // Let template instantiation know whether we had errors.
5188 if (AnyErrors)
5189 Constructor->setInvalidDecl();
5190
5191 return false;
5192 }
5193
5194 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
5195
5196 // We need to build the initializer AST according to order of construction
5197 // and not what user specified in the Initializers list.
5198 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
5199 if (!ClassDecl)
5200 return true;
5201
5202 bool HadError = false;
5203
5204 for (unsigned i = 0; i < Initializers.size(); i++) {
5205 CXXCtorInitializer *Member = Initializers[i];
5206
5207 if (Member->isBaseInitializer())
5208 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
5209 else {
5210 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
5211
5212 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
5213 for (auto *C : F->chain()) {
5214 FieldDecl *FD = dyn_cast<FieldDecl>(C);
5215 if (FD && FD->getParent()->isUnion())
5216 Info.ActiveUnionMember.insert(std::make_pair(
5217 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5218 }
5219 } else if (FieldDecl *FD = Member->getMember()) {
5220 if (FD->getParent()->isUnion())
5221 Info.ActiveUnionMember.insert(std::make_pair(
5222 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5223 }
5224 }
5225 }
5226
5227 // Keep track of the direct virtual bases.
5228 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
5229 for (auto &I : ClassDecl->bases()) {
5230 if (I.isVirtual())
5231 DirectVBases.insert(&I);
5232 }
5233
5234 // Push virtual bases before others.
5235 for (auto &VBase : ClassDecl->vbases()) {
5236 if (CXXCtorInitializer *Value
5237 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5238 // [class.base.init]p7, per DR257:
5239 // A mem-initializer where the mem-initializer-id names a virtual base
5240 // class is ignored during execution of a constructor of any class that
5241 // is not the most derived class.
5242 if (ClassDecl->isAbstract()) {
5243 // FIXME: Provide a fixit to remove the base specifier. This requires
5244 // tracking the location of the associated comma for a base specifier.
5245 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5246 << VBase.getType() << ClassDecl;
5247 DiagnoseAbstractType(ClassDecl);
5248 }
5249
5250 Info.AllToInit.push_back(Value);
5251 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5252 // [class.base.init]p8, per DR257:
5253 // If a given [...] base class is not named by a mem-initializer-id
5254 // [...] and the entity is not a virtual base class of an abstract
5255 // class, then [...] the entity is default-initialized.
5256 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5257 CXXCtorInitializer *CXXBaseInit;
5258 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5259 &VBase, IsInheritedVirtualBase,
5260 CXXBaseInit)) {
5261 HadError = true;
5262 continue;
5263 }
5264
5265 Info.AllToInit.push_back(CXXBaseInit);
5266 }
5267 }
5268
5269 // Non-virtual bases.
5270 for (auto &Base : ClassDecl->bases()) {
5271 // Virtuals are in the virtual base list and already constructed.
5272 if (Base.isVirtual())
5273 continue;
5274
5275 if (CXXCtorInitializer *Value
5276 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5277 Info.AllToInit.push_back(Value);
5278 } else if (!AnyErrors) {
5279 CXXCtorInitializer *CXXBaseInit;
5280 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5281 &Base, /*IsInheritedVirtualBase=*/false,
5282 CXXBaseInit)) {
5283 HadError = true;
5284 continue;
5285 }
5286
5287 Info.AllToInit.push_back(CXXBaseInit);
5288 }
5289 }
5290
5291 // Fields.
5292 for (auto *Mem : ClassDecl->decls()) {
5293 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5294 // C++ [class.bit]p2:
5295 // A declaration for a bit-field that omits the identifier declares an
5296 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5297 // initialized.
5298 if (F->isUnnamedBitfield())
5299 continue;
5300
5301 // If we're not generating the implicit copy/move constructor, then we'll
5302 // handle anonymous struct/union fields based on their individual
5303 // indirect fields.
5304 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5305 continue;
5306
5307 if (CollectFieldInitializer(*this, Info, F))
5308 HadError = true;
5309 continue;
5310 }
5311
5312 // Beyond this point, we only consider default initialization.
5313 if (Info.isImplicitCopyOrMove())
5314 continue;
5315
5316 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5317 if (F->getType()->isIncompleteArrayType()) {
5318 assert(ClassDecl->hasFlexibleArrayMember() &&(static_cast <bool> (ClassDecl->hasFlexibleArrayMember
() && "Incomplete array type is not valid") ? void (0
) : __assert_fail ("ClassDecl->hasFlexibleArrayMember() && \"Incomplete array type is not valid\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5319, __extension__ __PRETTY_FUNCTION__
))
5319 "Incomplete array type is not valid")(static_cast <bool> (ClassDecl->hasFlexibleArrayMember
() && "Incomplete array type is not valid") ? void (0
) : __assert_fail ("ClassDecl->hasFlexibleArrayMember() && \"Incomplete array type is not valid\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5319, __extension__ __PRETTY_FUNCTION__
))
;
5320 continue;
5321 }
5322
5323 // Initialize each field of an anonymous struct individually.
5324 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5325 HadError = true;
5326
5327 continue;
5328 }
5329 }
5330
5331 unsigned NumInitializers = Info.AllToInit.size();
5332 if (NumInitializers > 0) {
5333 Constructor->setNumCtorInitializers(NumInitializers);
5334 CXXCtorInitializer **baseOrMemberInitializers =
5335 new (Context) CXXCtorInitializer*[NumInitializers];
5336 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5337 NumInitializers * sizeof(CXXCtorInitializer*));
5338 Constructor->setCtorInitializers(baseOrMemberInitializers);
5339
5340 // Constructors implicitly reference the base and member
5341 // destructors.
5342 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5343 Constructor->getParent());
5344 }
5345
5346 return HadError;
5347}
5348
5349static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5350 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5351 const RecordDecl *RD = RT->getDecl();
5352 if (RD->isAnonymousStructOrUnion()) {
5353 for (auto *Field : RD->fields())
5354 PopulateKeysForFields(Field, IdealInits);
5355 return;
5356 }
5357 }
5358 IdealInits.push_back(Field->getCanonicalDecl());
5359}
5360
5361static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5362 return Context.getCanonicalType(BaseType).getTypePtr();
5363}
5364
5365static const void *GetKeyForMember(ASTContext &Context,
5366 CXXCtorInitializer *Member) {
5367 if (!Member->isAnyMemberInitializer())
5368 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5369
5370 return Member->getAnyMember()->getCanonicalDecl();
5371}
5372
5373static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
5374 const CXXCtorInitializer *Previous,
5375 const CXXCtorInitializer *Current) {
5376 if (Previous->isAnyMemberInitializer())
5377 Diag << 0 << Previous->getAnyMember();
5378 else
5379 Diag << 1 << Previous->getTypeSourceInfo()->getType();
5380
5381 if (Current->isAnyMemberInitializer())
5382 Diag << 0 << Current->getAnyMember();
5383 else
5384 Diag << 1 << Current->getTypeSourceInfo()->getType();
5385}
5386
5387static void DiagnoseBaseOrMemInitializerOrder(
5388 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5389 ArrayRef<CXXCtorInitializer *> Inits) {
5390 if (Constructor->getDeclContext()->isDependentContext())
5391 return;
5392
5393 // Don't check initializers order unless the warning is enabled at the
5394 // location of at least one initializer.
5395 bool ShouldCheckOrder = false;
5396 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5397 CXXCtorInitializer *Init = Inits[InitIndex];
5398 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5399 Init->getSourceLocation())) {
5400 ShouldCheckOrder = true;
5401 break;
5402 }
5403 }
5404 if (!ShouldCheckOrder)
5405 return;
5406
5407 // Build the list of bases and members in the order that they'll
5408 // actually be initialized. The explicit initializers should be in
5409 // this same order but may be missing things.
5410 SmallVector<const void*, 32> IdealInitKeys;
5411
5412 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5413
5414 // 1. Virtual bases.
5415 for (const auto &VBase : ClassDecl->vbases())
5416 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5417
5418 // 2. Non-virtual bases.
5419 for (const auto &Base : ClassDecl->bases()) {
5420 if (Base.isVirtual())
5421 continue;
5422 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5423 }
5424
5425 // 3. Direct fields.
5426 for (auto *Field : ClassDecl->fields()) {
5427 if (Field->isUnnamedBitfield())
5428 continue;
5429
5430 PopulateKeysForFields(Field, IdealInitKeys);
5431 }
5432
5433 unsigned NumIdealInits = IdealInitKeys.size();
5434 unsigned IdealIndex = 0;
5435
5436 // Track initializers that are in an incorrect order for either a warning or
5437 // note if multiple ones occur.
5438 SmallVector<unsigned> WarnIndexes;
5439 // Correlates the index of an initializer in the init-list to the index of
5440 // the field/base in the class.
5441 SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;
5442
5443 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5444 const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);
5445
5446 // Scan forward to try to find this initializer in the idealized
5447 // initializers list.
5448 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5449 if (InitKey == IdealInitKeys[IdealIndex])
5450 break;
5451
5452 // If we didn't find this initializer, it must be because we
5453 // scanned past it on a previous iteration. That can only
5454 // happen if we're out of order; emit a warning.
5455 if (IdealIndex == NumIdealInits && InitIndex) {
5456 WarnIndexes.push_back(InitIndex);
5457
5458 // Move back to the initializer's location in the ideal list.
5459 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5460 if (InitKey == IdealInitKeys[IdealIndex])
5461 break;
5462
5463 assert(IdealIndex < NumIdealInits &&(static_cast <bool> (IdealIndex < NumIdealInits &&
"initializer not found in initializer list") ? void (0) : __assert_fail
("IdealIndex < NumIdealInits && \"initializer not found in initializer list\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5464, __extension__ __PRETTY_FUNCTION__
))
5464 "initializer not found in initializer list")(static_cast <bool> (IdealIndex < NumIdealInits &&
"initializer not found in initializer list") ? void (0) : __assert_fail
("IdealIndex < NumIdealInits && \"initializer not found in initializer list\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5464, __extension__ __PRETTY_FUNCTION__
))
;
5465 }
5466 CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
5467 }
5468
5469 if (WarnIndexes.empty())
5470 return;
5471
5472 // Sort based on the ideal order, first in the pair.
5473 llvm::sort(CorrelatedInitOrder, llvm::less_first());
5474
5475 // Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
5476 // emit the diagnostic before we can try adding notes.
5477 {
5478 Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
5479 Inits[WarnIndexes.front() - 1]->getSourceLocation(),
5480 WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
5481 : diag::warn_some_initializers_out_of_order);
5482
5483 for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
5484 if (CorrelatedInitOrder[I].second == I)
5485 continue;
5486 // Ideally we would be using InsertFromRange here, but clang doesn't
5487 // appear to handle InsertFromRange correctly when the source range is
5488 // modified by another fix-it.
5489 D << FixItHint::CreateReplacement(
5490 Inits[I]->getSourceRange(),
5491 Lexer::getSourceText(
5492 CharSourceRange::getTokenRange(
5493 Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
5494 SemaRef.getSourceManager(), SemaRef.getLangOpts()));
5495 }
5496
5497 // If there is only 1 item out of order, the warning expects the name and
5498 // type of each being added to it.
5499 if (WarnIndexes.size() == 1) {
5500 AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
5501 Inits[WarnIndexes.front()]);
5502 return;
5503 }
5504 }
5505 // More than 1 item to warn, create notes letting the user know which ones
5506 // are bad.
5507 for (unsigned WarnIndex : WarnIndexes) {
5508 const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
5509 auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
5510 diag::note_initializer_out_of_order);
5511 AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
5512 D << PrevInit->getSourceRange();
5513 }
5514}
5515
5516namespace {
5517bool CheckRedundantInit(Sema &S,
5518 CXXCtorInitializer *Init,
5519 CXXCtorInitializer *&PrevInit) {
5520 if (!PrevInit) {
5521 PrevInit = Init;
5522 return false;
5523 }
5524
5525 if (FieldDecl *Field = Init->getAnyMember())
5526 S.Diag(Init->getSourceLocation(),
5527 diag::err_multiple_mem_initialization)
5528 << Field->getDeclName()
5529 << Init->getSourceRange();
5530 else {
5531 const Type *BaseClass = Init->getBaseClass();
5532 assert(BaseClass && "neither field nor base")(static_cast <bool> (BaseClass && "neither field nor base"
) ? void (0) : __assert_fail ("BaseClass && \"neither field nor base\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5532, __extension__ __PRETTY_FUNCTION__
))
;
5533 S.Diag(Init->getSourceLocation(),
5534 diag::err_multiple_base_initialization)
5535 << QualType(BaseClass, 0)
5536 << Init->getSourceRange();
5537 }
5538 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5539 << 0 << PrevInit->getSourceRange();
5540
5541 return true;
5542}
5543
5544typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5545typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5546
5547bool CheckRedundantUnionInit(Sema &S,
5548 CXXCtorInitializer *Init,
5549 RedundantUnionMap &Unions) {
5550 FieldDecl *Field = Init->getAnyMember();
5551 RecordDecl *Parent = Field->getParent();
5552 NamedDecl *Child = Field;
5553
5554 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5555 if (Parent->isUnion()) {
5556 UnionEntry &En = Unions[Parent];
5557 if (En.first && En.first != Child) {
5558 S.Diag(Init->getSourceLocation(),
5559 diag::err_multiple_mem_union_initialization)
5560 << Field->getDeclName()
5561 << Init->getSourceRange();
5562 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5563 << 0 << En.second->getSourceRange();
5564 return true;
5565 }
5566 if (!En.first) {
5567 En.first = Child;
5568 En.second = Init;
5569 }
5570 if (!Parent->isAnonymousStructOrUnion())
5571 return false;
5572 }
5573
5574 Child = Parent;
5575 Parent = cast<RecordDecl>(Parent->getDeclContext());
5576 }
5577
5578 return false;
5579}
5580} // namespace
5581
5582/// ActOnMemInitializers - Handle the member initializers for a constructor.
5583void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5584 SourceLocation ColonLoc,
5585 ArrayRef<CXXCtorInitializer*> MemInits,
5586 bool AnyErrors) {
5587 if (!ConstructorDecl)
5588 return;
5589
5590 AdjustDeclIfTemplate(ConstructorDecl);
5591
5592 CXXConstructorDecl *Constructor
5593 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5594
5595 if (!Constructor) {
5596 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5597 return;
5598 }
5599
5600 // Mapping for the duplicate initializers check.
5601 // For member initializers, this is keyed with a FieldDecl*.
5602 // For base initializers, this is keyed with a Type*.
5603 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5604
5605 // Mapping for the inconsistent anonymous-union initializers check.
5606 RedundantUnionMap MemberUnions;
5607
5608 bool HadError = false;
5609 for (unsigned i = 0; i < MemInits.size(); i++) {
5610 CXXCtorInitializer *Init = MemInits[i];
5611
5612 // Set the source order index.
5613 Init->setSourceOrder(i);
5614
5615 if (Init->isAnyMemberInitializer()) {
5616 const void *Key = GetKeyForMember(Context, Init);
5617 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5618 CheckRedundantUnionInit(*this, Init, MemberUnions))
5619 HadError = true;
5620 } else if (Init->isBaseInitializer()) {
5621 const void *Key = GetKeyForMember(Context, Init);
5622 if (CheckRedundantInit(*this, Init, Members[Key]))
5623 HadError = true;
5624 } else {
5625 assert(Init->isDelegatingInitializer())(static_cast <bool> (Init->isDelegatingInitializer()
) ? void (0) : __assert_fail ("Init->isDelegatingInitializer()"
, "clang/lib/Sema/SemaDeclCXX.cpp", 5625, __extension__ __PRETTY_FUNCTION__
))
;
5626 // This must be the only initializer
5627 if (MemInits.size() != 1) {
5628 Diag(Init->getSourceLocation(),
5629 diag::err_delegating_initializer_alone)
5630 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5631 // We will treat this as being the only initializer.
5632 }
5633 SetDelegatingInitializer(Constructor, MemInits[i]);
5634 // Return immediately as the initializer is set.
5635 return;
5636 }
5637 }
5638
5639 if (HadError)
5640 return;
5641
5642 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5643
5644 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5645
5646 DiagnoseUninitializedFields(*this, Constructor);
5647}
5648
5649void
5650Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5651 CXXRecordDecl *ClassDecl) {
5652 // Ignore dependent contexts. Also ignore unions, since their members never
5653 // have destructors implicitly called.
5654 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5655 return;
5656
5657 // FIXME: all the access-control diagnostics are positioned on the
5658 // field/base declaration. That's probably good; that said, the
5659 // user might reasonably want to know why the destructor is being
5660 // emitted, and we currently don't say.
5661
5662 // Non-static data members.
5663 for (auto *Field : ClassDecl->fields()) {
5664 if (Field->isInvalidDecl())
5665 continue;
5666
5667 // Don't destroy incomplete or zero-length arrays.
5668 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5669 continue;
5670
5671 QualType FieldType = Context.getBaseElementType(Field->getType());
5672
5673 const RecordType* RT = FieldType->getAs<RecordType>();
5674 if (!RT)
5675 continue;
5676
5677 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5678 if (FieldClassDecl->isInvalidDecl())
5679 continue;
5680 if (FieldClassDecl->hasIrrelevantDestructor())
5681 continue;
5682 // The destructor for an implicit anonymous union member is never invoked.
5683 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5684 continue;
5685
5686 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5687 // Dtor might still be missing, e.g because it's invalid.
5688 if (!Dtor)
5689 continue;
5690 CheckDestructorAccess(Field->getLocation(), Dtor,
5691 PDiag(diag::err_access_dtor_field)
5692 << Field->getDeclName()
5693 << FieldType);
5694
5695 MarkFunctionReferenced(Location, Dtor);
5696 DiagnoseUseOfDecl(Dtor, Location);
5697 }
5698
5699 // We only potentially invoke the destructors of potentially constructed
5700 // subobjects.
5701 bool VisitVirtualBases = !ClassDecl->isAbstract();
5702
5703 // If the destructor exists and has already been marked used in the MS ABI,
5704 // then virtual base destructors have already been checked and marked used.
5705 // Skip checking them again to avoid duplicate diagnostics.
5706 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5707 CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
5708 if (Dtor && Dtor->isUsed())
5709 VisitVirtualBases = false;
5710 }
5711
5712 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5713
5714 // Bases.
5715 for (const auto &Base : ClassDecl->bases()) {
5716 const RecordType *RT = Base.getType()->getAs<RecordType>();
5717 if (!RT)
5718 continue;
5719
5720 // Remember direct virtual bases.
5721 if (Base.isVirtual()) {
5722 if (!VisitVirtualBases)
5723 continue;
5724 DirectVirtualBases.insert(RT);
5725 }
5726
5727 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5728 // If our base class is invalid, we probably can't get its dtor anyway.
5729 if (BaseClassDecl->isInvalidDecl())
5730 continue;
5731 if (BaseClassDecl->hasIrrelevantDestructor())
5732 continue;
5733
5734 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5735 // Dtor might still be missing, e.g because it's invalid.
5736 if (!Dtor)
5737 continue;
5738
5739 // FIXME: caret should be on the start of the class name
5740 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5741 PDiag(diag::err_access_dtor_base)
5742 << Base.getType() << Base.getSourceRange(),
5743 Context.getTypeDeclType(ClassDecl));
5744
5745 MarkFunctionReferenced(Location, Dtor);
5746 DiagnoseUseOfDecl(Dtor, Location);
5747 }
5748
5749 if (VisitVirtualBases)
5750 MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
5751 &DirectVirtualBases);
5752}
5753
5754void Sema::MarkVirtualBaseDestructorsReferenced(
5755 SourceLocation Location, CXXRecordDecl *ClassDecl,
5756 llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
5757 // Virtual bases.
5758 for (const auto &VBase : ClassDecl->vbases()) {
5759 // Bases are always records in a well-formed non-dependent class.
5760 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5761
5762 // Ignore already visited direct virtual bases.
5763 if (DirectVirtualBases && DirectVirtualBases->count(RT))
5764 continue;
5765
5766 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5767 // If our base class is invalid, we probably can't get its dtor anyway.
5768 if (BaseClassDecl->isInvalidDecl())
5769 continue;
5770 if (BaseClassDecl->hasIrrelevantDestructor())
5771 continue;
5772
5773 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5774 // Dtor might still be missing, e.g because it's invalid.
5775 if (!Dtor)
5776 continue;
5777 if (CheckDestructorAccess(
5778 ClassDecl->getLocation(), Dtor,
5779 PDiag(diag::err_access_dtor_vbase)
5780 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5781 Context.getTypeDeclType(ClassDecl)) ==
5782 AR_accessible) {
5783 CheckDerivedToBaseConversion(
5784 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5785 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5786 SourceRange(), DeclarationName(), nullptr);
5787 }
5788
5789 MarkFunctionReferenced(Location, Dtor);
5790 DiagnoseUseOfDecl(Dtor, Location);
5791 }
5792}
5793
5794void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5795 if (!CDtorDecl)
5796 return;
5797
5798 if (CXXConstructorDecl *Constructor
5799 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5800 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5801 DiagnoseUninitializedFields(*this, Constructor);
5802 }
5803}
5804
5805bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5806 if (!getLangOpts().CPlusPlus)
5807 return false;
5808
5809 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5810 if (!RD)
5811 return false;
5812
5813 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5814 // class template specialization here, but doing so breaks a lot of code.
5815
5816 // We can't answer whether something is abstract until it has a
5817 // definition. If it's currently being defined, we'll walk back
5818 // over all the declarations when we have a full definition.
5819 const CXXRecordDecl *Def = RD->getDefinition();
5820 if (!Def || Def->isBeingDefined())
5821 return false;
5822
5823 return RD->isAbstract();
5824}
5825
5826bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5827 TypeDiagnoser &Diagnoser) {
5828 if (!isAbstractType(Loc, T))
5829 return false;
5830
5831 T = Context.getBaseElementType(T);
5832 Diagnoser.diagnose(*this, Loc, T);
5833 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5834 return true;
5835}
5836
5837void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5838 // Check if we've already emitted the list of pure virtual functions
5839 // for this class.
5840 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5841 return;
5842
5843 // If the diagnostic is suppressed, don't emit the notes. We're only
5844 // going to emit them once, so try to attach them to a diagnostic we're
5845 // actually going to show.
5846 if (Diags.isLastDiagnosticIgnored())
5847 return;
5848
5849 CXXFinalOverriderMap FinalOverriders;
5850 RD->getFinalOverriders(FinalOverriders);
5851
5852 // Keep a set of seen pure methods so we won't diagnose the same method
5853 // more than once.
5854 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5855
5856 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5857 MEnd = FinalOverriders.end();
5858 M != MEnd;
5859 ++M) {
5860 for (OverridingMethods::iterator SO = M->second.begin(),
5861 SOEnd = M->second.end();
5862 SO != SOEnd; ++SO) {
5863 // C++ [class.abstract]p4:
5864 // A class is abstract if it contains or inherits at least one
5865 // pure virtual function for which the final overrider is pure
5866 // virtual.
5867
5868 //
5869 if (SO->second.size() != 1)
5870 continue;
5871
5872 if (!SO->second.front().Method->isPure())
5873 continue;
5874
5875 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5876 continue;
5877
5878 Diag(SO->second.front().Method->getLocation(),
5879 diag::note_pure_virtual_function)
5880 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5881 }
5882 }
5883
5884 if (!PureVirtualClassDiagSet)
5885 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5886 PureVirtualClassDiagSet->insert(RD);
5887}
5888
5889namespace {
5890struct AbstractUsageInfo {
5891 Sema &S;
5892 CXXRecordDecl *Record;
5893 CanQualType AbstractType;
5894 bool Invalid;
5895
5896 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5897 : S(S), Record(Record),
5898 AbstractType(S.Context.getCanonicalType(
5899 S.Context.getTypeDeclType(Record))),
5900 Invalid(false) {}
5901
5902 void DiagnoseAbstractType() {
5903 if (Invalid) return;
5904 S.DiagnoseAbstractType(Record);
5905 Invalid = true;
5906 }
5907
5908 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5909};
5910
5911struct CheckAbstractUsage {
5912 AbstractUsageInfo &Info;
5913 const NamedDecl *Ctx;
5914
5915 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5916 : Info(Info), Ctx(Ctx) {}
5917
5918 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5919 switch (TL.getTypeLocClass()) {
5920#define ABSTRACT_TYPELOC(CLASS, PARENT)
5921#define TYPELOC(CLASS, PARENT) \
5922 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5923#include "clang/AST/TypeLocNodes.def"
5924 }
5925 }
5926
5927 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5928 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5929 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5930 if (!TL.getParam(I))
5931 continue;
5932
5933 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5934 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5935 }
5936 }
5937
5938 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5939 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5940 }
5941
5942 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5943 // Visit the type parameters from a permissive context.
5944 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5945 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5946 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5947 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5948 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5949 // TODO: other template argument types?
5950 }
5951 }
5952
5953 // Visit pointee types from a permissive context.
5954#define CheckPolymorphic(Type)void Check(Type TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getNextTypeLoc
(), Sema::AbstractNone); }
\
5955 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5956 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5957 }
5958 CheckPolymorphic(PointerTypeLoc)void Check(PointerTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5959 CheckPolymorphic(ReferenceTypeLoc)void Check(ReferenceTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5960 CheckPolymorphic(MemberPointerTypeLoc)void Check(MemberPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5961 CheckPolymorphic(BlockPointerTypeLoc)void Check(BlockPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5962 CheckPolymorphic(AtomicTypeLoc)void Check(AtomicTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5963
5964 /// Handle all the types we haven't given a more specific
5965 /// implementation for above.
5966 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5967 // Every other kind of type that we haven't called out already
5968 // that has an inner type is either (1) sugar or (2) contains that
5969 // inner type in some way as a subobject.
5970 if (TypeLoc Next = TL.getNextTypeLoc())
5971 return Visit(Next, Sel);
5972
5973 // If there's no inner type and we're in a permissive context,
5974 // don't diagnose.
5975 if (Sel == Sema::AbstractNone) return;
5976
5977 // Check whether the type matches the abstract type.
5978 QualType T = TL.getType();
5979 if (T->isArrayType()) {
5980 Sel = Sema::AbstractArrayType;
5981 T = Info.S.Context.getBaseElementType(T);
5982 }
5983 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5984 if (CT != Info.AbstractType) return;
5985
5986 // It matched; do some magic.
5987 // FIXME: These should be at most warnings. See P0929R2, CWG1640, CWG1646.
5988 if (Sel == Sema::AbstractArrayType) {
5989 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5990 << T << TL.getSourceRange();
5991 } else {
5992 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5993 << Sel << T << TL.getSourceRange();
5994 }
5995 Info.DiagnoseAbstractType();
5996 }
5997};
5998
5999void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
6000 Sema::AbstractDiagSelID Sel) {
6001 CheckAbstractUsage(*this, D).Visit(TL, Sel);
6002}
6003
6004}
6005
6006/// Check for invalid uses of an abstract type in a function declaration.
6007static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
6008 FunctionDecl *FD) {
6009 // No need to do the check on definitions, which require that
6010 // the return/param types be complete.
6011 if (FD->doesThisDeclarationHaveABody())
6012 return;
6013
6014 // For safety's sake, just ignore it if we don't have type source
6015 // information. This should never happen for non-implicit methods,
6016 // but...
6017 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
6018 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractNone);
6019}
6020
6021/// Check for invalid uses of an abstract type in a variable0 declaration.
6022static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
6023 VarDecl *VD) {
6024 // No need to do the check on definitions, which require that
6025 // the type is complete.
6026 if (VD->isThisDeclarationADefinition())
6027 return;
6028
6029 Info.CheckType(VD, VD->getTypeSourceInfo()->getTypeLoc(),
6030 Sema::AbstractVariableType);
6031}
6032
6033/// Check for invalid uses of an abstract type within a class definition.
6034static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
6035 CXXRecordDecl *RD) {
6036 for (auto *D : RD->decls()) {
6037 if (D->isImplicit()) continue;
6038
6039 // Step through friends to the befriended declaration.
6040 if (auto *FD = dyn_cast<FriendDecl>(D)) {
6041 D = FD->getFriendDecl();
6042 if (!D) continue;
6043 }
6044
6045 // Functions and function templates.
6046 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
6047 CheckAbstractClassUsage(Info, FD);
6048 } else if (auto *FTD = dyn_cast<FunctionTemplateDecl>(D)) {
6049 CheckAbstractClassUsage(Info, FTD->getTemplatedDecl());
6050
6051 // Fields and static variables.
6052 } else if (auto *FD = dyn_cast<FieldDecl>(D)) {
6053 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
6054 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
6055 } else if (auto *VD = dyn_cast<VarDecl>(D)) {
6056 CheckAbstractClassUsage(Info, VD);
6057 } else if (auto *VTD = dyn_cast<VarTemplateDecl>(D)) {
6058 CheckAbstractClassUsage(Info, VTD->getTemplatedDecl());
6059
6060 // Nested classes and class templates.
6061 } else if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
6062 CheckAbstractClassUsage(Info, RD);
6063 } else if (auto *CTD = dyn_cast<ClassTemplateDecl>(D)) {
6064 CheckAbstractClassUsage(Info, CTD->getTemplatedDecl());
6065 }
6066 }
6067}
6068 </