Bug Summary

File:build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/lib/Sema/SemaDeclCXX.cpp
Warning:line 7457, column 18
Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

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-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/lib/Sema -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/include -I tools/clang/include -I include -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -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 -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-04-20-140412-16051-1 -x c++ /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/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/EvaluatedExprVisitor.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/AST/TypeLoc.h"
26#include "clang/AST/TypeOrdering.h"
27#include "clang/Basic/AttributeCommonInfo.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/Specifiers.h"
30#include "clang/Basic/TargetInfo.h"
31#include "clang/Lex/LiteralSupport.h"
32#include "clang/Lex/Preprocessor.h"
33#include "clang/Sema/CXXFieldCollector.h"
34#include "clang/Sema/DeclSpec.h"
35#include "clang/Sema/Initialization.h"
36#include "clang/Sema/Lookup.h"
37#include "clang/Sema/ParsedTemplate.h"
38#include "clang/Sema/Scope.h"
39#include "clang/Sema/ScopeInfo.h"
40#include "clang/Sema/SemaInternal.h"
41#include "clang/Sema/Template.h"
42#include "llvm/ADT/ScopeExit.h"
43#include "llvm/ADT/SmallString.h"
44#include "llvm/ADT/STLExtras.h"
45#include "llvm/ADT/StringExtras.h"
46#include <map>
47#include <set>
48
49using namespace clang;
50
51//===----------------------------------------------------------------------===//
52// CheckDefaultArgumentVisitor
53//===----------------------------------------------------------------------===//
54
55namespace {
56/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
57/// the default argument of a parameter to determine whether it
58/// contains any ill-formed subexpressions. For example, this will
59/// diagnose the use of local variables or parameters within the
60/// default argument expression.
61class CheckDefaultArgumentVisitor
62 : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
63 Sema &S;
64 const Expr *DefaultArg;
65
66public:
67 CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
68 : S(S), DefaultArg(DefaultArg) {}
69
70 bool VisitExpr(const Expr *Node);
71 bool VisitDeclRefExpr(const DeclRefExpr *DRE);
72 bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
73 bool VisitLambdaExpr(const LambdaExpr *Lambda);
74 bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
75};
76
77/// VisitExpr - Visit all of the children of this expression.
78bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
79 bool IsInvalid = false;
80 for (const Stmt *SubStmt : Node->children())
81 IsInvalid |= Visit(SubStmt);
82 return IsInvalid;
83}
84
85/// VisitDeclRefExpr - Visit a reference to a declaration, to
86/// determine whether this declaration can be used in the default
87/// argument expression.
88bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
89 const NamedDecl *Decl = DRE->getDecl();
90 if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
91 // C++ [dcl.fct.default]p9:
92 // [...] parameters of a function shall not be used in default
93 // argument expressions, even if they are not evaluated. [...]
94 //
95 // C++17 [dcl.fct.default]p9 (by CWG 2082):
96 // [...] A parameter shall not appear as a potentially-evaluated
97 // expression in a default argument. [...]
98 //
99 if (DRE->isNonOdrUse() != NOUR_Unevaluated)
100 return S.Diag(DRE->getBeginLoc(),
101 diag::err_param_default_argument_references_param)
102 << Param->getDeclName() << DefaultArg->getSourceRange();
103 } else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
104 // C++ [dcl.fct.default]p7:
105 // Local variables shall not be used in default argument
106 // expressions.
107 //
108 // C++17 [dcl.fct.default]p7 (by CWG 2082):
109 // A local variable shall not appear as a potentially-evaluated
110 // expression in a default argument.
111 //
112 // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
113 // Note: A local variable cannot be odr-used (6.3) in a default argument.
114 //
115 if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
116 return S.Diag(DRE->getBeginLoc(),
117 diag::err_param_default_argument_references_local)
118 << VDecl->getDeclName() << DefaultArg->getSourceRange();
119 }
120
121 return false;
122}
123
124/// VisitCXXThisExpr - Visit a C++ "this" expression.
125bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
126 // C++ [dcl.fct.default]p8:
127 // The keyword this shall not be used in a default argument of a
128 // member function.
129 return S.Diag(ThisE->getBeginLoc(),
130 diag::err_param_default_argument_references_this)
131 << ThisE->getSourceRange();
132}
133
134bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
135 const PseudoObjectExpr *POE) {
136 bool Invalid = false;
137 for (const Expr *E : POE->semantics()) {
138 // Look through bindings.
139 if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
140 E = OVE->getSourceExpr();
141 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", 141, __extension__ __PRETTY_FUNCTION__
))
;
142 }
143
144 Invalid |= Visit(E);
145 }
146 return Invalid;
147}
148
149bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
150 // C++11 [expr.lambda.prim]p13:
151 // A lambda-expression appearing in a default argument shall not
152 // implicitly or explicitly capture any entity.
153 if (Lambda->capture_begin() == Lambda->capture_end())
154 return false;
155
156 return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
157}
158} // namespace
159
160void
161Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
162 const CXXMethodDecl *Method) {
163 // If we have an MSAny spec already, don't bother.
164 if (!Method || ComputedEST == EST_MSAny)
165 return;
166
167 const FunctionProtoType *Proto
168 = Method->getType()->getAs<FunctionProtoType>();
169 Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
170 if (!Proto)
171 return;
172
173 ExceptionSpecificationType EST = Proto->getExceptionSpecType();
174
175 // If we have a throw-all spec at this point, ignore the function.
176 if (ComputedEST == EST_None)
177 return;
178
179 if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
180 EST = EST_BasicNoexcept;
181
182 switch (EST) {
183 case EST_Unparsed:
184 case EST_Uninstantiated:
185 case EST_Unevaluated:
186 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", 186)
;
187
188 // If this function can throw any exceptions, make a note of that.
189 case EST_MSAny:
190 case EST_None:
191 // FIXME: Whichever we see last of MSAny and None determines our result.
192 // We should make a consistent, order-independent choice here.
193 ClearExceptions();
194 ComputedEST = EST;
195 return;
196 case EST_NoexceptFalse:
197 ClearExceptions();
198 ComputedEST = EST_None;
199 return;
200 // FIXME: If the call to this decl is using any of its default arguments, we
201 // need to search them for potentially-throwing calls.
202 // If this function has a basic noexcept, it doesn't affect the outcome.
203 case EST_BasicNoexcept:
204 case EST_NoexceptTrue:
205 case EST_NoThrow:
206 return;
207 // If we're still at noexcept(true) and there's a throw() callee,
208 // change to that specification.
209 case EST_DynamicNone:
210 if (ComputedEST == EST_BasicNoexcept)
211 ComputedEST = EST_DynamicNone;
212 return;
213 case EST_DependentNoexcept:
214 llvm_unreachable(::llvm::llvm_unreachable_internal("should not generate implicit declarations for dependent cases"
, "clang/lib/Sema/SemaDeclCXX.cpp", 215)
215 "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", 215)
;
216 case EST_Dynamic:
217 break;
218 }
219 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", 219, __extension__ __PRETTY_FUNCTION__
))
;
220 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", 221, __extension__ __PRETTY_FUNCTION__
))
221 "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", 221, __extension__ __PRETTY_FUNCTION__
))
;
222 ComputedEST = EST_Dynamic;
223 // Record the exceptions in this function's exception specification.
224 for (const auto &E : Proto->exceptions())
225 if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
226 Exceptions.push_back(E);
227}
228
229void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
230 if (!S || ComputedEST == EST_MSAny)
231 return;
232
233 // FIXME:
234 //
235 // C++0x [except.spec]p14:
236 // [An] implicit exception-specification specifies the type-id T if and
237 // only if T is allowed by the exception-specification of a function directly
238 // invoked by f's implicit definition; f shall allow all exceptions if any
239 // function it directly invokes allows all exceptions, and f shall allow no
240 // exceptions if every function it directly invokes allows no exceptions.
241 //
242 // Note in particular that if an implicit exception-specification is generated
243 // for a function containing a throw-expression, that specification can still
244 // be noexcept(true).
245 //
246 // Note also that 'directly invoked' is not defined in the standard, and there
247 // is no indication that we should only consider potentially-evaluated calls.
248 //
249 // Ultimately we should implement the intent of the standard: the exception
250 // specification should be the set of exceptions which can be thrown by the
251 // implicit definition. For now, we assume that any non-nothrow expression can
252 // throw any exception.
253
254 if (Self->canThrow(S))
255 ComputedEST = EST_None;
256}
257
258ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
259 SourceLocation EqualLoc) {
260 if (RequireCompleteType(Param->getLocation(), Param->getType(),
261 diag::err_typecheck_decl_incomplete_type))
262 return true;
263
264 // C++ [dcl.fct.default]p5
265 // A default argument expression is implicitly converted (clause
266 // 4) to the parameter type. The default argument expression has
267 // the same semantic constraints as the initializer expression in
268 // a declaration of a variable of the parameter type, using the
269 // copy-initialization semantics (8.5).
270 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
271 Param);
272 InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
273 EqualLoc);
274 InitializationSequence InitSeq(*this, Entity, Kind, Arg);
275 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
276 if (Result.isInvalid())
277 return true;
278 Arg = Result.getAs<Expr>();
279
280 CheckCompletedExpr(Arg, EqualLoc);
281 Arg = MaybeCreateExprWithCleanups(Arg);
282
283 return Arg;
284}
285
286void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
287 SourceLocation EqualLoc) {
288 // Add the default argument to the parameter
289 Param->setDefaultArg(Arg);
290
291 // We have already instantiated this parameter; provide each of the
292 // instantiations with the uninstantiated default argument.
293 UnparsedDefaultArgInstantiationsMap::iterator InstPos
294 = UnparsedDefaultArgInstantiations.find(Param);
295 if (InstPos != UnparsedDefaultArgInstantiations.end()) {
296 for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
297 InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
298
299 // We're done tracking this parameter's instantiations.
300 UnparsedDefaultArgInstantiations.erase(InstPos);
301 }
302}
303
304/// ActOnParamDefaultArgument - Check whether the default argument
305/// provided for a function parameter is well-formed. If so, attach it
306/// to the parameter declaration.
307void
308Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
309 Expr *DefaultArg) {
310 if (!param || !DefaultArg)
311 return;
312
313 ParmVarDecl *Param = cast<ParmVarDecl>(param);
314 UnparsedDefaultArgLocs.erase(Param);
315
316 auto Fail = [&] {
317 Param->setInvalidDecl();
318 Param->setDefaultArg(new (Context) OpaqueValueExpr(
319 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
320 };
321
322 // Default arguments are only permitted in C++
323 if (!getLangOpts().CPlusPlus) {
324 Diag(EqualLoc, diag::err_param_default_argument)
325 << DefaultArg->getSourceRange();
326 return Fail();
327 }
328
329 // Check for unexpanded parameter packs.
330 if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
331 return Fail();
332 }
333
334 // C++11 [dcl.fct.default]p3
335 // A default argument expression [...] shall not be specified for a
336 // parameter pack.
337 if (Param->isParameterPack()) {
338 Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
339 << DefaultArg->getSourceRange();
340 // Recover by discarding the default argument.
341 Param->setDefaultArg(nullptr);
342 return;
343 }
344
345 ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
346 if (Result.isInvalid())
347 return Fail();
348
349 DefaultArg = Result.getAs<Expr>();
350
351 // Check that the default argument is well-formed
352 CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
353 if (DefaultArgChecker.Visit(DefaultArg))
354 return Fail();
355
356 SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
357}
358
359/// ActOnParamUnparsedDefaultArgument - We've seen a default
360/// argument for a function parameter, but we can't parse it yet
361/// because we're inside a class definition. Note that this default
362/// argument will be parsed later.
363void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
364 SourceLocation EqualLoc,
365 SourceLocation ArgLoc) {
366 if (!param)
367 return;
368
369 ParmVarDecl *Param = cast<ParmVarDecl>(param);
370 Param->setUnparsedDefaultArg();
371 UnparsedDefaultArgLocs[Param] = ArgLoc;
372}
373
374/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
375/// the default argument for the parameter param failed.
376void Sema::ActOnParamDefaultArgumentError(Decl *param,
377 SourceLocation EqualLoc) {
378 if (!param)
379 return;
380
381 ParmVarDecl *Param = cast<ParmVarDecl>(param);
382 Param->setInvalidDecl();
383 UnparsedDefaultArgLocs.erase(Param);
384 Param->setDefaultArg(new (Context) OpaqueValueExpr(
385 EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
386}
387
388/// CheckExtraCXXDefaultArguments - Check for any extra default
389/// arguments in the declarator, which is not a function declaration
390/// or definition and therefore is not permitted to have default
391/// arguments. This routine should be invoked for every declarator
392/// that is not a function declaration or definition.
393void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
394 // C++ [dcl.fct.default]p3
395 // A default argument expression shall be specified only in the
396 // parameter-declaration-clause of a function declaration or in a
397 // template-parameter (14.1). It shall not be specified for a
398 // parameter pack. If it is specified in a
399 // parameter-declaration-clause, it shall not occur within a
400 // declarator or abstract-declarator of a parameter-declaration.
401 bool MightBeFunction = D.isFunctionDeclarationContext();
402 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
403 DeclaratorChunk &chunk = D.getTypeObject(i);
404 if (chunk.Kind == DeclaratorChunk::Function) {
405 if (MightBeFunction) {
406 // This is a function declaration. It can have default arguments, but
407 // keep looking in case its return type is a function type with default
408 // arguments.
409 MightBeFunction = false;
410 continue;
411 }
412 for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
413 ++argIdx) {
414 ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
415 if (Param->hasUnparsedDefaultArg()) {
416 std::unique_ptr<CachedTokens> Toks =
417 std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
418 SourceRange SR;
419 if (Toks->size() > 1)
420 SR = SourceRange((*Toks)[1].getLocation(),
421 Toks->back().getLocation());
422 else
423 SR = UnparsedDefaultArgLocs[Param];
424 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
425 << SR;
426 } else if (Param->getDefaultArg()) {
427 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
428 << Param->getDefaultArg()->getSourceRange();
429 Param->setDefaultArg(nullptr);
430 }
431 }
432 } else if (chunk.Kind != DeclaratorChunk::Paren) {
433 MightBeFunction = false;
434 }
435 }
436}
437
438static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
439 return llvm::any_of(FD->parameters(), [](ParmVarDecl *P) {
440 return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
441 });
442}
443
444/// MergeCXXFunctionDecl - Merge two declarations of the same C++
445/// function, once we already know that they have the same
446/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
447/// error, false otherwise.
448bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
449 Scope *S) {
450 bool Invalid = false;
451
452 // The declaration context corresponding to the scope is the semantic
453 // parent, unless this is a local function declaration, in which case
454 // it is that surrounding function.
455 DeclContext *ScopeDC = New->isLocalExternDecl()
456 ? New->getLexicalDeclContext()
457 : New->getDeclContext();
458
459 // Find the previous declaration for the purpose of default arguments.
460 FunctionDecl *PrevForDefaultArgs = Old;
461 for (/**/; PrevForDefaultArgs;
462 // Don't bother looking back past the latest decl if this is a local
463 // extern declaration; nothing else could work.
464 PrevForDefaultArgs = New->isLocalExternDecl()
465 ? nullptr
466 : PrevForDefaultArgs->getPreviousDecl()) {
467 // Ignore hidden declarations.
468 if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
469 continue;
470
471 if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
472 !New->isCXXClassMember()) {
473 // Ignore default arguments of old decl if they are not in
474 // the same scope and this is not an out-of-line definition of
475 // a member function.
476 continue;
477 }
478
479 if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
480 // If only one of these is a local function declaration, then they are
481 // declared in different scopes, even though isDeclInScope may think
482 // they're in the same scope. (If both are local, the scope check is
483 // sufficient, and if neither is local, then they are in the same scope.)
484 continue;
485 }
486
487 // We found the right previous declaration.
488 break;
489 }
490
491 // C++ [dcl.fct.default]p4:
492 // For non-template functions, default arguments can be added in
493 // later declarations of a function in the same
494 // scope. Declarations in different scopes have completely
495 // distinct sets of default arguments. That is, declarations in
496 // inner scopes do not acquire default arguments from
497 // declarations in outer scopes, and vice versa. In a given
498 // function declaration, all parameters subsequent to a
499 // parameter with a default argument shall have default
500 // arguments supplied in this or previous declarations. A
501 // default argument shall not be redefined by a later
502 // declaration (not even to the same value).
503 //
504 // C++ [dcl.fct.default]p6:
505 // Except for member functions of class templates, the default arguments
506 // in a member function definition that appears outside of the class
507 // definition are added to the set of default arguments provided by the
508 // member function declaration in the class definition.
509 for (unsigned p = 0, NumParams = PrevForDefaultArgs
510 ? PrevForDefaultArgs->getNumParams()
511 : 0;
512 p < NumParams; ++p) {
513 ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
514 ParmVarDecl *NewParam = New->getParamDecl(p);
515
516 bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
517 bool NewParamHasDfl = NewParam->hasDefaultArg();
518
519 if (OldParamHasDfl && NewParamHasDfl) {
520 unsigned DiagDefaultParamID =
521 diag::err_param_default_argument_redefinition;
522
523 // MSVC accepts that default parameters be redefined for member functions
524 // of template class. The new default parameter's value is ignored.
525 Invalid = true;
526 if (getLangOpts().MicrosoftExt) {
527 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
528 if (MD && MD->getParent()->getDescribedClassTemplate()) {
529 // Merge the old default argument into the new parameter.
530 NewParam->setHasInheritedDefaultArg();
531 if (OldParam->hasUninstantiatedDefaultArg())
532 NewParam->setUninstantiatedDefaultArg(
533 OldParam->getUninstantiatedDefaultArg());
534 else
535 NewParam->setDefaultArg(OldParam->getInit());
536 DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
537 Invalid = false;
538 }
539 }
540
541 // FIXME: If we knew where the '=' was, we could easily provide a fix-it
542 // hint here. Alternatively, we could walk the type-source information
543 // for NewParam to find the last source location in the type... but it
544 // isn't worth the effort right now. This is the kind of test case that
545 // is hard to get right:
546 // int f(int);
547 // void g(int (*fp)(int) = f);
548 // void g(int (*fp)(int) = &f);
549 Diag(NewParam->getLocation(), DiagDefaultParamID)
550 << NewParam->getDefaultArgRange();
551
552 // Look for the function declaration where the default argument was
553 // actually written, which may be a declaration prior to Old.
554 for (auto Older = PrevForDefaultArgs;
555 OldParam->hasInheritedDefaultArg(); /**/) {
556 Older = Older->getPreviousDecl();
557 OldParam = Older->getParamDecl(p);
558 }
559
560 Diag(OldParam->getLocation(), diag::note_previous_definition)
561 << OldParam->getDefaultArgRange();
562 } else if (OldParamHasDfl) {
563 // Merge the old default argument into the new parameter unless the new
564 // function is a friend declaration in a template class. In the latter
565 // case the default arguments will be inherited when the friend
566 // declaration will be instantiated.
567 if (New->getFriendObjectKind() == Decl::FOK_None ||
568 !New->getLexicalDeclContext()->isDependentContext()) {
569 // It's important to use getInit() here; getDefaultArg()
570 // strips off any top-level ExprWithCleanups.
571 NewParam->setHasInheritedDefaultArg();
572 if (OldParam->hasUnparsedDefaultArg())
573 NewParam->setUnparsedDefaultArg();
574 else if (OldParam->hasUninstantiatedDefaultArg())
575 NewParam->setUninstantiatedDefaultArg(
576 OldParam->getUninstantiatedDefaultArg());
577 else
578 NewParam->setDefaultArg(OldParam->getInit());
579 }
580 } else if (NewParamHasDfl) {
581 if (New->getDescribedFunctionTemplate()) {
582 // Paragraph 4, quoted above, only applies to non-template functions.
583 Diag(NewParam->getLocation(),
584 diag::err_param_default_argument_template_redecl)
585 << NewParam->getDefaultArgRange();
586 Diag(PrevForDefaultArgs->getLocation(),
587 diag::note_template_prev_declaration)
588 << false;
589 } else if (New->getTemplateSpecializationKind()
590 != TSK_ImplicitInstantiation &&
591 New->getTemplateSpecializationKind() != TSK_Undeclared) {
592 // C++ [temp.expr.spec]p21:
593 // Default function arguments shall not be specified in a declaration
594 // or a definition for one of the following explicit specializations:
595 // - the explicit specialization of a function template;
596 // - the explicit specialization of a member function template;
597 // - the explicit specialization of a member function of a class
598 // template where the class template specialization to which the
599 // member function specialization belongs is implicitly
600 // instantiated.
601 Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
602 << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
603 << New->getDeclName()
604 << NewParam->getDefaultArgRange();
605 } else if (New->getDeclContext()->isDependentContext()) {
606 // C++ [dcl.fct.default]p6 (DR217):
607 // Default arguments for a member function of a class template shall
608 // be specified on the initial declaration of the member function
609 // within the class template.
610 //
611 // Reading the tea leaves a bit in DR217 and its reference to DR205
612 // leads me to the conclusion that one cannot add default function
613 // arguments for an out-of-line definition of a member function of a
614 // dependent type.
615 int WhichKind = 2;
616 if (CXXRecordDecl *Record
617 = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
618 if (Record->getDescribedClassTemplate())
619 WhichKind = 0;
620 else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
621 WhichKind = 1;
622 else
623 WhichKind = 2;
624 }
625
626 Diag(NewParam->getLocation(),
627 diag::err_param_default_argument_member_template_redecl)
628 << WhichKind
629 << NewParam->getDefaultArgRange();
630 }
631 }
632 }
633
634 // DR1344: If a default argument is added outside a class definition and that
635 // default argument makes the function a special member function, the program
636 // is ill-formed. This can only happen for constructors.
637 if (isa<CXXConstructorDecl>(New) &&
638 New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
639 CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
640 OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
641 if (NewSM != OldSM) {
642 ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
643 assert(NewParam->hasDefaultArg())(static_cast <bool> (NewParam->hasDefaultArg()) ? void
(0) : __assert_fail ("NewParam->hasDefaultArg()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 643, __extension__ __PRETTY_FUNCTION__))
;
644 Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
645 << NewParam->getDefaultArgRange() << NewSM;
646 Diag(Old->getLocation(), diag::note_previous_declaration);
647 }
648 }
649
650 const FunctionDecl *Def;
651 // C++11 [dcl.constexpr]p1: If any declaration of a function or function
652 // template has a constexpr specifier then all its declarations shall
653 // contain the constexpr specifier.
654 if (New->getConstexprKind() != Old->getConstexprKind()) {
655 Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
656 << New << static_cast<int>(New->getConstexprKind())
657 << static_cast<int>(Old->getConstexprKind());
658 Diag(Old->getLocation(), diag::note_previous_declaration);
659 Invalid = true;
660 } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
661 Old->isDefined(Def) &&
662 // If a friend function is inlined but does not have 'inline'
663 // specifier, it is a definition. Do not report attribute conflict
664 // in this case, redefinition will be diagnosed later.
665 (New->isInlineSpecified() ||
666 New->getFriendObjectKind() == Decl::FOK_None)) {
667 // C++11 [dcl.fcn.spec]p4:
668 // If the definition of a function appears in a translation unit before its
669 // first declaration as inline, the program is ill-formed.
670 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
671 Diag(Def->getLocation(), diag::note_previous_definition);
672 Invalid = true;
673 }
674
675 // C++17 [temp.deduct.guide]p3:
676 // Two deduction guide declarations in the same translation unit
677 // for the same class template shall not have equivalent
678 // parameter-declaration-clauses.
679 if (isa<CXXDeductionGuideDecl>(New) &&
680 !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
681 Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
682 Diag(Old->getLocation(), diag::note_previous_declaration);
683 }
684
685 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
686 // argument expression, that declaration shall be a definition and shall be
687 // the only declaration of the function or function template in the
688 // translation unit.
689 if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
690 functionDeclHasDefaultArgument(Old)) {
691 Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
692 Diag(Old->getLocation(), diag::note_previous_declaration);
693 Invalid = true;
694 }
695
696 // C++11 [temp.friend]p4 (DR329):
697 // When a function is defined in a friend function declaration in a class
698 // template, the function is instantiated when the function is odr-used.
699 // The same restrictions on multiple declarations and definitions that
700 // apply to non-template function declarations and definitions also apply
701 // to these implicit definitions.
702 const FunctionDecl *OldDefinition = nullptr;
703 if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
704 Old->isDefined(OldDefinition, true))
705 CheckForFunctionRedefinition(New, OldDefinition);
706
707 return Invalid;
708}
709
710NamedDecl *
711Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
712 MultiTemplateParamsArg TemplateParamLists) {
713 assert(D.isDecompositionDeclarator())(static_cast <bool> (D.isDecompositionDeclarator()) ? void
(0) : __assert_fail ("D.isDecompositionDeclarator()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 713, __extension__ __PRETTY_FUNCTION__))
;
714 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
715
716 // The syntax only allows a decomposition declarator as a simple-declaration,
717 // a for-range-declaration, or a condition in Clang, but we parse it in more
718 // cases than that.
719 if (!D.mayHaveDecompositionDeclarator()) {
720 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
721 << Decomp.getSourceRange();
722 return nullptr;
723 }
724
725 if (!TemplateParamLists.empty()) {
726 // FIXME: There's no rule against this, but there are also no rules that
727 // would actually make it usable, so we reject it for now.
728 Diag(TemplateParamLists.front()->getTemplateLoc(),
729 diag::err_decomp_decl_template);
730 return nullptr;
731 }
732
733 Diag(Decomp.getLSquareLoc(),
734 !getLangOpts().CPlusPlus17
735 ? diag::ext_decomp_decl
736 : D.getContext() == DeclaratorContext::Condition
737 ? diag::ext_decomp_decl_cond
738 : diag::warn_cxx14_compat_decomp_decl)
739 << Decomp.getSourceRange();
740
741 // The semantic context is always just the current context.
742 DeclContext *const DC = CurContext;
743
744 // C++17 [dcl.dcl]/8:
745 // The decl-specifier-seq shall contain only the type-specifier auto
746 // and cv-qualifiers.
747 // C++2a [dcl.dcl]/8:
748 // If decl-specifier-seq contains any decl-specifier other than static,
749 // thread_local, auto, or cv-qualifiers, the program is ill-formed.
750 auto &DS = D.getDeclSpec();
751 {
752 SmallVector<StringRef, 8> BadSpecifiers;
753 SmallVector<SourceLocation, 8> BadSpecifierLocs;
754 SmallVector<StringRef, 8> CPlusPlus20Specifiers;
755 SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
756 if (auto SCS = DS.getStorageClassSpec()) {
757 if (SCS == DeclSpec::SCS_static) {
758 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
759 CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
760 } else {
761 BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
762 BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
763 }
764 }
765 if (auto TSCS = DS.getThreadStorageClassSpec()) {
766 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
767 CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
768 }
769 if (DS.hasConstexprSpecifier()) {
770 BadSpecifiers.push_back(
771 DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
772 BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
773 }
774 if (DS.isInlineSpecified()) {
775 BadSpecifiers.push_back("inline");
776 BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
777 }
778 if (!BadSpecifiers.empty()) {
779 auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
780 Err << (int)BadSpecifiers.size()
781 << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
782 // Don't add FixItHints to remove the specifiers; we do still respect
783 // them when building the underlying variable.
784 for (auto Loc : BadSpecifierLocs)
785 Err << SourceRange(Loc, Loc);
786 } else if (!CPlusPlus20Specifiers.empty()) {
787 auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
788 getLangOpts().CPlusPlus20
789 ? diag::warn_cxx17_compat_decomp_decl_spec
790 : diag::ext_decomp_decl_spec);
791 Warn << (int)CPlusPlus20Specifiers.size()
792 << llvm::join(CPlusPlus20Specifiers.begin(),
793 CPlusPlus20Specifiers.end(), " ");
794 for (auto Loc : CPlusPlus20SpecifierLocs)
795 Warn << SourceRange(Loc, Loc);
796 }
797 // We can't recover from it being declared as a typedef.
798 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
799 return nullptr;
800 }
801
802 // C++2a [dcl.struct.bind]p1:
803 // A cv that includes volatile is deprecated
804 if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
805 getLangOpts().CPlusPlus20)
806 Diag(DS.getVolatileSpecLoc(),
807 diag::warn_deprecated_volatile_structured_binding);
808
809 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
810 QualType R = TInfo->getType();
811
812 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
813 UPPC_DeclarationType))
814 D.setInvalidType();
815
816 // The syntax only allows a single ref-qualifier prior to the decomposition
817 // declarator. No other declarator chunks are permitted. Also check the type
818 // specifier here.
819 if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
820 D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
821 (D.getNumTypeObjects() == 1 &&
822 D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
823 Diag(Decomp.getLSquareLoc(),
824 (D.hasGroupingParens() ||
825 (D.getNumTypeObjects() &&
826 D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
827 ? diag::err_decomp_decl_parens
828 : diag::err_decomp_decl_type)
829 << R;
830
831 // In most cases, there's no actual problem with an explicitly-specified
832 // type, but a function type won't work here, and ActOnVariableDeclarator
833 // shouldn't be called for such a type.
834 if (R->isFunctionType())
835 D.setInvalidType();
836 }
837
838 // Build the BindingDecls.
839 SmallVector<BindingDecl*, 8> Bindings;
840
841 // Build the BindingDecls.
842 for (auto &B : D.getDecompositionDeclarator().bindings()) {
843 // Check for name conflicts.
844 DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
845 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
846 ForVisibleRedeclaration);
847 LookupName(Previous, S,
848 /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
849
850 // It's not permitted to shadow a template parameter name.
851 if (Previous.isSingleResult() &&
852 Previous.getFoundDecl()->isTemplateParameter()) {
853 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
854 Previous.getFoundDecl());
855 Previous.clear();
856 }
857
858 auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
859
860 // Find the shadowed declaration before filtering for scope.
861 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
862 ? getShadowedDeclaration(BD, Previous)
863 : nullptr;
864
865 bool ConsiderLinkage = DC->isFunctionOrMethod() &&
866 DS.getStorageClassSpec() == DeclSpec::SCS_extern;
867 FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
868 /*AllowInlineNamespace*/false);
869
870 if (!Previous.empty()) {
871 auto *Old = Previous.getRepresentativeDecl();
872 Diag(B.NameLoc, diag::err_redefinition) << B.Name;
873 Diag(Old->getLocation(), diag::note_previous_definition);
874 } else if (ShadowedDecl && !D.isRedeclaration()) {
875 CheckShadow(BD, ShadowedDecl, Previous);
876 }
877 PushOnScopeChains(BD, S, true);
878 Bindings.push_back(BD);
879 ParsingInitForAutoVars.insert(BD);
880 }
881
882 // There are no prior lookup results for the variable itself, because it
883 // is unnamed.
884 DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
885 Decomp.getLSquareLoc());
886 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
887 ForVisibleRedeclaration);
888
889 // Build the variable that holds the non-decomposed object.
890 bool AddToScope = true;
891 NamedDecl *New =
892 ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
893 MultiTemplateParamsArg(), AddToScope, Bindings);
894 if (AddToScope) {
895 S->AddDecl(New);
896 CurContext->addHiddenDecl(New);
897 }
898
899 if (isInOpenMPDeclareTargetContext())
900 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
901
902 return New;
903}
904
905static bool checkSimpleDecomposition(
906 Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
907 QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
908 llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
909 if ((int64_t)Bindings.size() != NumElems) {
910 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
911 << DecompType << (unsigned)Bindings.size()
912 << (unsigned)NumElems.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
913 << toString(NumElems, 10) << (NumElems < Bindings.size());
914 return true;
915 }
916
917 unsigned I = 0;
918 for (auto *B : Bindings) {
919 SourceLocation Loc = B->getLocation();
920 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
921 if (E.isInvalid())
922 return true;
923 E = GetInit(Loc, E.get(), I++);
924 if (E.isInvalid())
925 return true;
926 B->setBinding(ElemType, E.get());
927 }
928
929 return false;
930}
931
932static bool checkArrayLikeDecomposition(Sema &S,
933 ArrayRef<BindingDecl *> Bindings,
934 ValueDecl *Src, QualType DecompType,
935 const llvm::APSInt &NumElems,
936 QualType ElemType) {
937 return checkSimpleDecomposition(
938 S, Bindings, Src, DecompType, NumElems, ElemType,
939 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
940 ExprResult E = S.ActOnIntegerConstant(Loc, I);
941 if (E.isInvalid())
942 return ExprError();
943 return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
944 });
945}
946
947static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
948 ValueDecl *Src, QualType DecompType,
949 const ConstantArrayType *CAT) {
950 return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
951 llvm::APSInt(CAT->getSize()),
952 CAT->getElementType());
953}
954
955static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
956 ValueDecl *Src, QualType DecompType,
957 const VectorType *VT) {
958 return checkArrayLikeDecomposition(
959 S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
960 S.Context.getQualifiedType(VT->getElementType(),
961 DecompType.getQualifiers()));
962}
963
964static bool checkComplexDecomposition(Sema &S,
965 ArrayRef<BindingDecl *> Bindings,
966 ValueDecl *Src, QualType DecompType,
967 const ComplexType *CT) {
968 return checkSimpleDecomposition(
969 S, Bindings, Src, DecompType, llvm::APSInt::get(2),
970 S.Context.getQualifiedType(CT->getElementType(),
971 DecompType.getQualifiers()),
972 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
973 return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
974 });
975}
976
977static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
978 TemplateArgumentListInfo &Args,
979 const TemplateParameterList *Params) {
980 SmallString<128> SS;
981 llvm::raw_svector_ostream OS(SS);
982 bool First = true;
983 unsigned I = 0;
984 for (auto &Arg : Args.arguments()) {
985 if (!First)
986 OS << ", ";
987 Arg.getArgument().print(PrintingPolicy, OS,
988 TemplateParameterList::shouldIncludeTypeForArgument(
989 PrintingPolicy, Params, I));
990 First = false;
991 I++;
992 }
993 return std::string(OS.str());
994}
995
996static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
997 SourceLocation Loc, StringRef Trait,
998 TemplateArgumentListInfo &Args,
999 unsigned DiagID) {
1000 auto DiagnoseMissing = [&] {
1001 if (DiagID)
1002 S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
1003 Args, /*Params*/ nullptr);
1004 return true;
1005 };
1006
1007 // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
1008 NamespaceDecl *Std = S.getStdNamespace();
1009 if (!Std)
1010 return DiagnoseMissing();
1011
1012 // Look up the trait itself, within namespace std. We can diagnose various
1013 // problems with this lookup even if we've been asked to not diagnose a
1014 // missing specialization, because this can only fail if the user has been
1015 // declaring their own names in namespace std or we don't support the
1016 // standard library implementation in use.
1017 LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
1018 Loc, Sema::LookupOrdinaryName);
1019 if (!S.LookupQualifiedName(Result, Std))
1020 return DiagnoseMissing();
1021 if (Result.isAmbiguous())
1022 return true;
1023
1024 ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
1025 if (!TraitTD) {
1026 Result.suppressDiagnostics();
1027 NamedDecl *Found = *Result.begin();
1028 S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
1029 S.Diag(Found->getLocation(), diag::note_declared_at);
1030 return true;
1031 }
1032
1033 // Build the template-id.
1034 QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
1035 if (TraitTy.isNull())
1036 return true;
1037 if (!S.isCompleteType(Loc, TraitTy)) {
1038 if (DiagID)
1039 S.RequireCompleteType(
1040 Loc, TraitTy, DiagID,
1041 printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1042 TraitTD->getTemplateParameters()));
1043 return true;
1044 }
1045
1046 CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
1047 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", 1047, __extension__ __PRETTY_FUNCTION__
))
;
1048
1049 // Look up the member of the trait type.
1050 S.LookupQualifiedName(TraitMemberLookup, RD);
1051 return TraitMemberLookup.isAmbiguous();
1052}
1053
1054static TemplateArgumentLoc
1055getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
1056 uint64_t I) {
1057 TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
1058 return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1059}
1060
1061static TemplateArgumentLoc
1062getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
1063 return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1064}
1065
1066namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1067
1068static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
1069 llvm::APSInt &Size) {
1070 EnterExpressionEvaluationContext ContextRAII(
1071 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1072
1073 DeclarationName Value = S.PP.getIdentifierInfo("value");
1074 LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1075
1076 // Form template argument list for tuple_size<T>.
1077 TemplateArgumentListInfo Args(Loc, Loc);
1078 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1079
1080 // If there's no tuple_size specialization or the lookup of 'value' is empty,
1081 // it's not tuple-like.
1082 if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
1083 R.empty())
1084 return IsTupleLike::NotTupleLike;
1085
1086 // If we get this far, we've committed to the tuple interpretation, but
1087 // we can still fail if there actually isn't a usable ::value.
1088
1089 struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1090 LookupResult &R;
1091 TemplateArgumentListInfo &Args;
1092 ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1093 : R(R), Args(Args) {}
1094 Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
1095 SourceLocation Loc) override {
1096 return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1097 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1098 /*Params*/ nullptr);
1099 }
1100 } Diagnoser(R, Args);
1101
1102 ExprResult E =
1103 S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1104 if (E.isInvalid())
1105 return IsTupleLike::Error;
1106
1107 E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
1108 if (E.isInvalid())
1109 return IsTupleLike::Error;
1110
1111 return IsTupleLike::TupleLike;
1112}
1113
1114/// \return std::tuple_element<I, T>::type.
1115static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
1116 unsigned I, QualType T) {
1117 // Form template argument list for tuple_element<I, T>.
1118 TemplateArgumentListInfo Args(Loc, Loc);
1119 Args.addArgument(
1120 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1121 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1122
1123 DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1124 LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1125 if (lookupStdTypeTraitMember(
1126 S, R, Loc, "tuple_element", Args,
1127 diag::err_decomp_decl_std_tuple_element_not_specialized))
1128 return QualType();
1129
1130 auto *TD = R.getAsSingle<TypeDecl>();
1131 if (!TD) {
1132 R.suppressDiagnostics();
1133 S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1134 << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
1135 /*Params*/ nullptr);
1136 if (!R.empty())
1137 S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1138 return QualType();
1139 }
1140
1141 return S.Context.getTypeDeclType(TD);
1142}
1143
1144namespace {
1145struct InitializingBinding {
1146 Sema &S;
1147 InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
1148 Sema::CodeSynthesisContext Ctx;
1149 Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
1150 Ctx.PointOfInstantiation = BD->getLocation();
1151 Ctx.Entity = BD;
1152 S.pushCodeSynthesisContext(Ctx);
1153 }
1154 ~InitializingBinding() {
1155 S.popCodeSynthesisContext();
1156 }
1157};
1158}
1159
1160static bool checkTupleLikeDecomposition(Sema &S,
1161 ArrayRef<BindingDecl *> Bindings,
1162 VarDecl *Src, QualType DecompType,
1163 const llvm::APSInt &TupleSize) {
1164 if ((int64_t)Bindings.size() != TupleSize) {
1165 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1166 << DecompType << (unsigned)Bindings.size()
1167 << (unsigned)TupleSize.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
1168 << toString(TupleSize, 10) << (TupleSize < Bindings.size());
1169 return true;
1170 }
1171
1172 if (Bindings.empty())
1173 return false;
1174
1175 DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1176
1177 // [dcl.decomp]p3:
1178 // The unqualified-id get is looked up in the scope of E by class member
1179 // access lookup ...
1180 LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1181 bool UseMemberGet = false;
1182 if (S.isCompleteType(Src->getLocation(), DecompType)) {
1183 if (auto *RD = DecompType->getAsCXXRecordDecl())
1184 S.LookupQualifiedName(MemberGet, RD);
1185 if (MemberGet.isAmbiguous())
1186 return true;
1187 // ... and if that finds at least one declaration that is a function
1188 // template whose first template parameter is a non-type parameter ...
1189 for (NamedDecl *D : MemberGet) {
1190 if (FunctionTemplateDecl *FTD =
1191 dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1192 TemplateParameterList *TPL = FTD->getTemplateParameters();
1193 if (TPL->size() != 0 &&
1194 isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1195 // ... the initializer is e.get<i>().
1196 UseMemberGet = true;
1197 break;
1198 }
1199 }
1200 }
1201 }
1202
1203 unsigned I = 0;
1204 for (auto *B : Bindings) {
1205 InitializingBinding InitContext(S, B);
1206 SourceLocation Loc = B->getLocation();
1207
1208 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1209 if (E.isInvalid())
1210 return true;
1211
1212 // e is an lvalue if the type of the entity is an lvalue reference and
1213 // an xvalue otherwise
1214 if (!Src->getType()->isLValueReferenceType())
1215 E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1216 E.get(), nullptr, VK_XValue,
1217 FPOptionsOverride());
1218
1219 TemplateArgumentListInfo Args(Loc, Loc);
1220 Args.addArgument(
1221 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1222
1223 if (UseMemberGet) {
1224 // if [lookup of member get] finds at least one declaration, the
1225 // initializer is e.get<i-1>().
1226 E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1227 CXXScopeSpec(), SourceLocation(), nullptr,
1228 MemberGet, &Args, nullptr);
1229 if (E.isInvalid())
1230 return true;
1231
1232 E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
1233 } else {
1234 // Otherwise, the initializer is get<i-1>(e), where get is looked up
1235 // in the associated namespaces.
1236 Expr *Get = UnresolvedLookupExpr::Create(
1237 S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
1238 DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1239 UnresolvedSetIterator(), UnresolvedSetIterator());
1240
1241 Expr *Arg = E.get();
1242 E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
1243 }
1244 if (E.isInvalid())
1245 return true;
1246 Expr *Init = E.get();
1247
1248 // Given the type T designated by std::tuple_element<i - 1, E>::type,
1249 QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1250 if (T.isNull())
1251 return true;
1252
1253 // each vi is a variable of type "reference to T" initialized with the
1254 // initializer, where the reference is an lvalue reference if the
1255 // initializer is an lvalue and an rvalue reference otherwise
1256 QualType RefType =
1257 S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1258 if (RefType.isNull())
1259 return true;
1260 auto *RefVD = VarDecl::Create(
1261 S.Context, Src->getDeclContext(), Loc, Loc,
1262 B->getDeclName().getAsIdentifierInfo(), RefType,
1263 S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
1264 RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
1265 RefVD->setTSCSpec(Src->getTSCSpec());
1266 RefVD->setImplicit();
1267 if (Src->isInlineSpecified())
1268 RefVD->setInlineSpecified();
1269 RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1270
1271 InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
1272 InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
1273 InitializationSequence Seq(S, Entity, Kind, Init);
1274 E = Seq.Perform(S, Entity, Kind, Init);
1275 if (E.isInvalid())
1276 return true;
1277 E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1278 if (E.isInvalid())
1279 return true;
1280 RefVD->setInit(E.get());
1281 S.CheckCompleteVariableDeclaration(RefVD);
1282
1283 E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
1284 DeclarationNameInfo(B->getDeclName(), Loc),
1285 RefVD);
1286 if (E.isInvalid())
1287 return true;
1288
1289 B->setBinding(T, E.get());
1290 I++;
1291 }
1292
1293 return false;
1294}
1295
1296/// Find the base class to decompose in a built-in decomposition of a class type.
1297/// This base class search is, unfortunately, not quite like any other that we
1298/// perform anywhere else in C++.
1299static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
1300 const CXXRecordDecl *RD,
1301 CXXCastPath &BasePath) {
1302 auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1303 CXXBasePath &Path) {
1304 return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1305 };
1306
1307 const CXXRecordDecl *ClassWithFields = nullptr;
1308 AccessSpecifier AS = AS_public;
1309 if (RD->hasDirectFields())
1310 // [dcl.decomp]p4:
1311 // Otherwise, all of E's non-static data members shall be public direct
1312 // members of E ...
1313 ClassWithFields = RD;
1314 else {
1315 // ... or of ...
1316 CXXBasePaths Paths;
1317 Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1318 if (!RD->lookupInBases(BaseHasFields, Paths)) {
1319 // If no classes have fields, just decompose RD itself. (This will work
1320 // if and only if zero bindings were provided.)
1321 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1322 }
1323
1324 CXXBasePath *BestPath = nullptr;
1325 for (auto &P : Paths) {
1326 if (!BestPath)
1327 BestPath = &P;
1328 else if (!S.Context.hasSameType(P.back().Base->getType(),
1329 BestPath->back().Base->getType())) {
1330 // ... the same ...
1331 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1332 << false << RD << BestPath->back().Base->getType()
1333 << P.back().Base->getType();
1334 return DeclAccessPair();
1335 } else if (P.Access < BestPath->Access) {
1336 BestPath = &P;
1337 }
1338 }
1339
1340 // ... unambiguous ...
1341 QualType BaseType = BestPath->back().Base->getType();
1342 if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1343 S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1344 << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1345 return DeclAccessPair();
1346 }
1347
1348 // ... [accessible, implied by other rules] base class of E.
1349 S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1350 *BestPath, diag::err_decomp_decl_inaccessible_base);
1351 AS = BestPath->Access;
1352
1353 ClassWithFields = BaseType->getAsCXXRecordDecl();
1354 S.BuildBasePathArray(Paths, BasePath);
1355 }
1356
1357 // The above search did not check whether the selected class itself has base
1358 // classes with fields, so check that now.
1359 CXXBasePaths Paths;
1360 if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1361 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1362 << (ClassWithFields == RD) << RD << ClassWithFields
1363 << Paths.front().back().Base->getType();
1364 return DeclAccessPair();
1365 }
1366
1367 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1368}
1369
1370static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
1371 ValueDecl *Src, QualType DecompType,
1372 const CXXRecordDecl *OrigRD) {
1373 if (S.RequireCompleteType(Src->getLocation(), DecompType,
1374 diag::err_incomplete_type))
1375 return true;
1376
1377 CXXCastPath BasePath;
1378 DeclAccessPair BasePair =
1379 findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1380 const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1381 if (!RD)
1382 return true;
1383 QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
1384 DecompType.getQualifiers());
1385
1386 auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1387 unsigned NumFields = llvm::count_if(
1388 RD->fields(), [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1389 assert(Bindings.size() != NumFields)(static_cast <bool> (Bindings.size() != NumFields) ? void
(0) : __assert_fail ("Bindings.size() != NumFields", "clang/lib/Sema/SemaDeclCXX.cpp"
, 1389, __extension__ __PRETTY_FUNCTION__))
;
1390 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1391 << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
1392 << (NumFields < Bindings.size());
1393 return true;
1394 };
1395
1396 // all of E's non-static data members shall be [...] well-formed
1397 // when named as e.name in the context of the structured binding,
1398 // E shall not have an anonymous union member, ...
1399 unsigned I = 0;
1400 for (auto *FD : RD->fields()) {
1401 if (FD->isUnnamedBitfield())
1402 continue;
1403
1404 // All the non-static data members are required to be nameable, so they
1405 // must all have names.
1406 if (!FD->getDeclName()) {
1407 if (RD->isLambda()) {
1408 S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
1409 S.Diag(RD->getLocation(), diag::note_lambda_decl);
1410 return true;
1411 }
1412
1413 if (FD->isAnonymousStructOrUnion()) {
1414 S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1415 << DecompType << FD->getType()->isUnionType();
1416 S.Diag(FD->getLocation(), diag::note_declared_at);
1417 return true;
1418 }
1419
1420 // FIXME: Are there any other ways we could have an anonymous member?
1421 }
1422
1423 // We have a real field to bind.
1424 if (I >= Bindings.size())
1425 return DiagnoseBadNumberOfBindings();
1426 auto *B = Bindings[I++];
1427 SourceLocation Loc = B->getLocation();
1428
1429 // The field must be accessible in the context of the structured binding.
1430 // We already checked that the base class is accessible.
1431 // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1432 // const_cast here.
1433 S.CheckStructuredBindingMemberAccess(
1434 Loc, const_cast<CXXRecordDecl *>(OrigRD),
1435 DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
1436 BasePair.getAccess(), FD->getAccess())));
1437
1438 // Initialize the binding to Src.FD.
1439 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1440 if (E.isInvalid())
1441 return true;
1442 E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1443 VK_LValue, &BasePath);
1444 if (E.isInvalid())
1445 return true;
1446 E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1447 CXXScopeSpec(), FD,
1448 DeclAccessPair::make(FD, FD->getAccess()),
1449 DeclarationNameInfo(FD->getDeclName(), Loc));
1450 if (E.isInvalid())
1451 return true;
1452
1453 // If the type of the member is T, the referenced type is cv T, where cv is
1454 // the cv-qualification of the decomposition expression.
1455 //
1456 // FIXME: We resolve a defect here: if the field is mutable, we do not add
1457 // 'const' to the type of the field.
1458 Qualifiers Q = DecompType.getQualifiers();
1459 if (FD->isMutable())
1460 Q.removeConst();
1461 B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1462 }
1463
1464 if (I != Bindings.size())
1465 return DiagnoseBadNumberOfBindings();
1466
1467 return false;
1468}
1469
1470void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
1471 QualType DecompType = DD->getType();
1472
1473 // If the type of the decomposition is dependent, then so is the type of
1474 // each binding.
1475 if (DecompType->isDependentType()) {
1476 for (auto *B : DD->bindings())
1477 B->setType(Context.DependentTy);
1478 return;
1479 }
1480
1481 DecompType = DecompType.getNonReferenceType();
1482 ArrayRef<BindingDecl*> Bindings = DD->bindings();
1483
1484 // C++1z [dcl.decomp]/2:
1485 // If E is an array type [...]
1486 // As an extension, we also support decomposition of built-in complex and
1487 // vector types.
1488 if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1489 if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1490 DD->setInvalidDecl();
1491 return;
1492 }
1493 if (auto *VT = DecompType->getAs<VectorType>()) {
1494 if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1495 DD->setInvalidDecl();
1496 return;
1497 }
1498 if (auto *CT = DecompType->getAs<ComplexType>()) {
1499 if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1500 DD->setInvalidDecl();
1501 return;
1502 }
1503
1504 // C++1z [dcl.decomp]/3:
1505 // if the expression std::tuple_size<E>::value is a well-formed integral
1506 // constant expression, [...]
1507 llvm::APSInt TupleSize(32);
1508 switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1509 case IsTupleLike::Error:
1510 DD->setInvalidDecl();
1511 return;
1512
1513 case IsTupleLike::TupleLike:
1514 if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1515 DD->setInvalidDecl();
1516 return;
1517
1518 case IsTupleLike::NotTupleLike:
1519 break;
1520 }
1521
1522 // C++1z [dcl.dcl]/8:
1523 // [E shall be of array or non-union class type]
1524 CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1525 if (!RD || RD->isUnion()) {
1526 Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1527 << DD << !RD << DecompType;
1528 DD->setInvalidDecl();
1529 return;
1530 }
1531
1532 // C++1z [dcl.decomp]/4:
1533 // all of E's non-static data members shall be [...] direct members of
1534 // E or of the same unambiguous public base class of E, ...
1535 if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1536 DD->setInvalidDecl();
1537}
1538
1539/// Merge the exception specifications of two variable declarations.
1540///
1541/// This is called when there's a redeclaration of a VarDecl. The function
1542/// checks if the redeclaration might have an exception specification and
1543/// validates compatibility and merges the specs if necessary.
1544void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
1545 // Shortcut if exceptions are disabled.
1546 if (!getLangOpts().CXXExceptions)
1547 return;
1548
1549 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", 1550, __extension__ __PRETTY_FUNCTION__
))
1550 "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", 1550, __extension__ __PRETTY_FUNCTION__
))
;
1551
1552 QualType NewType = New->getType();
1553 QualType OldType = Old->getType();
1554
1555 // We're only interested in pointers and references to functions, as well
1556 // as pointers to member functions.
1557 if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1558 NewType = R->getPointeeType();
1559 OldType = OldType->castAs<ReferenceType>()->getPointeeType();
1560 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1561 NewType = P->getPointeeType();
1562 OldType = OldType->castAs<PointerType>()->getPointeeType();
1563 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1564 NewType = M->getPointeeType();
1565 OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
1566 }
1567
1568 if (!NewType->isFunctionProtoType())
1569 return;
1570
1571 // There's lots of special cases for functions. For function pointers, system
1572 // libraries are hopefully not as broken so that we don't need these
1573 // workarounds.
1574 if (CheckEquivalentExceptionSpec(
1575 OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1576 NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1577 New->setInvalidDecl();
1578 }
1579}
1580
1581/// CheckCXXDefaultArguments - Verify that the default arguments for a
1582/// function declaration are well-formed according to C++
1583/// [dcl.fct.default].
1584void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
1585 unsigned NumParams = FD->getNumParams();
1586 unsigned ParamIdx = 0;
1587
1588 // This checking doesn't make sense for explicit specializations; their
1589 // default arguments are determined by the declaration we're specializing,
1590 // not by FD.
1591 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
1592 return;
1593 if (auto *FTD = FD->getDescribedFunctionTemplate())
1594 if (FTD->isMemberSpecialization())
1595 return;
1596
1597 // Find first parameter with a default argument
1598 for (; ParamIdx < NumParams; ++ParamIdx) {
1599 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1600 if (Param->hasDefaultArg())
1601 break;
1602 }
1603
1604 // C++20 [dcl.fct.default]p4:
1605 // In a given function declaration, each parameter subsequent to a parameter
1606 // with a default argument shall have a default argument supplied in this or
1607 // a previous declaration, unless the parameter was expanded from a
1608 // parameter pack, or shall be a function parameter pack.
1609 for (; ParamIdx < NumParams; ++ParamIdx) {
1610 ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
1611 if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
1612 !(CurrentInstantiationScope &&
1613 CurrentInstantiationScope->isLocalPackExpansion(Param))) {
1614 if (Param->isInvalidDecl())
1615 /* We already complained about this parameter. */;
1616 else if (Param->getIdentifier())
1617 Diag(Param->getLocation(),
1618 diag::err_param_default_argument_missing_name)
1619 << Param->getIdentifier();
1620 else
1621 Diag(Param->getLocation(),
1622 diag::err_param_default_argument_missing);
1623 }
1624 }
1625}
1626
1627/// Check that the given type is a literal type. Issue a diagnostic if not,
1628/// if Kind is Diagnose.
1629/// \return \c true if a problem has been found (and optionally diagnosed).
1630template <typename... Ts>
1631static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
1632 SourceLocation Loc, QualType T, unsigned DiagID,
1633 Ts &&...DiagArgs) {
1634 if (T->isDependentType())
1635 return false;
1636
1637 switch (Kind) {
1638 case Sema::CheckConstexprKind::Diagnose:
1639 return SemaRef.RequireLiteralType(Loc, T, DiagID,
1640 std::forward<Ts>(DiagArgs)...);
1641
1642 case Sema::CheckConstexprKind::CheckValid:
1643 return !T->isLiteralType(SemaRef.Context);
1644 }
1645
1646 llvm_unreachable("unknown CheckConstexprKind")::llvm::llvm_unreachable_internal("unknown CheckConstexprKind"
, "clang/lib/Sema/SemaDeclCXX.cpp", 1646)
;
1647}
1648
1649/// Determine whether a destructor cannot be constexpr due to
1650static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
1651 const CXXDestructorDecl *DD,
1652 Sema::CheckConstexprKind Kind) {
1653 auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
1654 const CXXRecordDecl *RD =
1655 T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1656 if (!RD || RD->hasConstexprDestructor())
1657 return true;
1658
1659 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1660 SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
1661 << static_cast<int>(DD->getConstexprKind()) << !FD
1662 << (FD ? FD->getDeclName() : DeclarationName()) << T;
1663 SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
1664 << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
1665 }
1666 return false;
1667 };
1668
1669 const CXXRecordDecl *RD = DD->getParent();
1670 for (const CXXBaseSpecifier &B : RD->bases())
1671 if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
1672 return false;
1673 for (const FieldDecl *FD : RD->fields())
1674 if (!Check(FD->getLocation(), FD->getType(), FD))
1675 return false;
1676 return true;
1677}
1678
1679/// Check whether a function's parameter types are all literal types. If so,
1680/// return true. If not, produce a suitable diagnostic and return false.
1681static bool CheckConstexprParameterTypes(Sema &SemaRef,
1682 const FunctionDecl *FD,
1683 Sema::CheckConstexprKind Kind) {
1684 unsigned ArgIndex = 0;
1685 const auto *FT = FD->getType()->castAs<FunctionProtoType>();
1686 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1687 e = FT->param_type_end();
1688 i != e; ++i, ++ArgIndex) {
1689 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1690 SourceLocation ParamLoc = PD->getLocation();
1691 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1692 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1693 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1694 FD->isConsteval()))
1695 return false;
1696 }
1697 return true;
1698}
1699
1700/// Check whether a function's return type is a literal type. If so, return
1701/// true. If not, produce a suitable diagnostic and return false.
1702static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
1703 Sema::CheckConstexprKind Kind) {
1704 if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
1705 diag::err_constexpr_non_literal_return,
1706 FD->isConsteval()))
1707 return false;
1708 return true;
1709}
1710
1711/// Get diagnostic %select index for tag kind for
1712/// record diagnostic message.
1713/// WARNING: Indexes apply to particular diagnostics only!
1714///
1715/// \returns diagnostic %select index.
1716static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1717 switch (Tag) {
1718 case TTK_Struct: return 0;
1719 case TTK_Interface: return 1;
1720 case TTK_Class: return 2;
1721 default: llvm_unreachable("Invalid tag kind for record diagnostic!")::llvm::llvm_unreachable_internal("Invalid tag kind for record diagnostic!"
, "clang/lib/Sema/SemaDeclCXX.cpp", 1721)
;
1722 }
1723}
1724
1725static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1726 Stmt *Body,
1727 Sema::CheckConstexprKind Kind);
1728
1729// Check whether a function declaration satisfies the requirements of a
1730// constexpr function definition or a constexpr constructor definition. If so,
1731// return true. If not, produce appropriate diagnostics (unless asked not to by
1732// Kind) and return false.
1733//
1734// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1735bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1736 CheckConstexprKind Kind) {
1737 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1738 if (MD && MD->isInstance()) {
1739 // C++11 [dcl.constexpr]p4:
1740 // The definition of a constexpr constructor shall satisfy the following
1741 // constraints:
1742 // - the class shall not have any virtual base classes;
1743 //
1744 // FIXME: This only applies to constructors and destructors, not arbitrary
1745 // member functions.
1746 const CXXRecordDecl *RD = MD->getParent();
1747 if (RD->getNumVBases()) {
1748 if (Kind == CheckConstexprKind::CheckValid)
1749 return false;
1750
1751 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1752 << isa<CXXConstructorDecl>(NewFD)
1753 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1754 for (const auto &I : RD->vbases())
1755 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1756 << I.getSourceRange();
1757 return false;
1758 }
1759 }
1760
1761 if (!isa<CXXConstructorDecl>(NewFD)) {
1762 // C++11 [dcl.constexpr]p3:
1763 // The definition of a constexpr function shall satisfy the following
1764 // constraints:
1765 // - it shall not be virtual; (removed in C++20)
1766 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1767 if (Method && Method->isVirtual()) {
1768 if (getLangOpts().CPlusPlus20) {
1769 if (Kind == CheckConstexprKind::Diagnose)
1770 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1771 } else {
1772 if (Kind == CheckConstexprKind::CheckValid)
1773 return false;
1774
1775 Method = Method->getCanonicalDecl();
1776 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1777
1778 // If it's not obvious why this function is virtual, find an overridden
1779 // function which uses the 'virtual' keyword.
1780 const CXXMethodDecl *WrittenVirtual = Method;
1781 while (!WrittenVirtual->isVirtualAsWritten())
1782 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1783 if (WrittenVirtual != Method)
1784 Diag(WrittenVirtual->getLocation(),
1785 diag::note_overridden_virtual_function);
1786 return false;
1787 }
1788 }
1789
1790 // - its return type shall be a literal type;
1791 if (!CheckConstexprReturnType(*this, NewFD, Kind))
1792 return false;
1793 }
1794
1795 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1796 // A destructor can be constexpr only if the defaulted destructor could be;
1797 // we don't need to check the members and bases if we already know they all
1798 // have constexpr destructors.
1799 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1800 if (Kind == CheckConstexprKind::CheckValid)
1801 return false;
1802 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1803 return false;
1804 }
1805 }
1806
1807 // - each of its parameter types shall be a literal type;
1808 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1809 return false;
1810
1811 Stmt *Body = NewFD->getBody();
1812 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", 1813, __extension__ __PRETTY_FUNCTION__
))
1813 "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", 1813, __extension__ __PRETTY_FUNCTION__
))
;
1814 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1815}
1816
1817/// Check the given declaration statement is legal within a constexpr function
1818/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1819///
1820/// \return true if the body is OK (maybe only as an extension), false if we
1821/// have diagnosed a problem.
1822static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1823 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1824 Sema::CheckConstexprKind Kind) {
1825 // C++11 [dcl.constexpr]p3 and p4:
1826 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1827 // contain only
1828 for (const auto *DclIt : DS->decls()) {
1829 switch (DclIt->getKind()) {
1830 case Decl::StaticAssert:
1831 case Decl::Using:
1832 case Decl::UsingShadow:
1833 case Decl::UsingDirective:
1834 case Decl::UnresolvedUsingTypename:
1835 case Decl::UnresolvedUsingValue:
1836 case Decl::UsingEnum:
1837 // - static_assert-declarations
1838 // - using-declarations,
1839 // - using-directives,
1840 // - using-enum-declaration
1841 continue;
1842
1843 case Decl::Typedef:
1844 case Decl::TypeAlias: {
1845 // - typedef declarations and alias-declarations that do not define
1846 // classes or enumerations,
1847 const auto *TN = cast<TypedefNameDecl>(DclIt);
1848 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1849 // Don't allow variably-modified types in constexpr functions.
1850 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1851 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1852 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1853 << TL.getSourceRange() << TL.getType()
1854 << isa<CXXConstructorDecl>(Dcl);
1855 }
1856 return false;
1857 }
1858 continue;
1859 }
1860
1861 case Decl::Enum:
1862 case Decl::CXXRecord:
1863 // C++1y allows types to be defined, not just declared.
1864 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1865 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1866 SemaRef.Diag(DS->getBeginLoc(),
1867 SemaRef.getLangOpts().CPlusPlus14
1868 ? diag::warn_cxx11_compat_constexpr_type_definition
1869 : diag::ext_constexpr_type_definition)
1870 << isa<CXXConstructorDecl>(Dcl);
1871 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1872 return false;
1873 }
1874 }
1875 continue;
1876
1877 case Decl::EnumConstant:
1878 case Decl::IndirectField:
1879 case Decl::ParmVar:
1880 // These can only appear with other declarations which are banned in
1881 // C++11 and permitted in C++1y, so ignore them.
1882 continue;
1883
1884 case Decl::Var:
1885 case Decl::Decomposition: {
1886 // C++1y [dcl.constexpr]p3 allows anything except:
1887 // a definition of a variable of non-literal type or of static or
1888 // thread storage duration or [before C++2a] for which no
1889 // initialization is performed.
1890 const auto *VD = cast<VarDecl>(DclIt);
1891 if (VD->isThisDeclarationADefinition()) {
1892 if (VD->isStaticLocal()) {
1893 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1894 SemaRef.Diag(VD->getLocation(),
1895 SemaRef.getLangOpts().CPlusPlus2b
1896 ? diag::warn_cxx20_compat_constexpr_var
1897 : diag::ext_constexpr_static_var)
1898 << isa<CXXConstructorDecl>(Dcl)
1899 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1900 } else if (!SemaRef.getLangOpts().CPlusPlus2b) {
1901 return false;
1902 }
1903 }
1904 if (SemaRef.LangOpts.CPlusPlus2b) {
1905 CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1906 diag::warn_cxx20_compat_constexpr_var,
1907 isa<CXXConstructorDecl>(Dcl),
1908 /*variable of non-literal type*/ 2);
1909 } else if (CheckLiteralType(
1910 SemaRef, Kind, VD->getLocation(), VD->getType(),
1911 diag::err_constexpr_local_var_non_literal_type,
1912 isa<CXXConstructorDecl>(Dcl))) {
1913 return false;
1914 }
1915 if (!VD->getType()->isDependentType() &&
1916 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1917 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1918 SemaRef.Diag(
1919 VD->getLocation(),
1920 SemaRef.getLangOpts().CPlusPlus20
1921 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1922 : diag::ext_constexpr_local_var_no_init)
1923 << isa<CXXConstructorDecl>(Dcl);
1924 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
1925 return false;
1926 }
1927 continue;
1928 }
1929 }
1930 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1931 SemaRef.Diag(VD->getLocation(),
1932 SemaRef.getLangOpts().CPlusPlus14
1933 ? diag::warn_cxx11_compat_constexpr_local_var
1934 : diag::ext_constexpr_local_var)
1935 << isa<CXXConstructorDecl>(Dcl);
1936 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1937 return false;
1938 }
1939 continue;
1940 }
1941
1942 case Decl::NamespaceAlias:
1943 case Decl::Function:
1944 // These are disallowed in C++11 and permitted in C++1y. Allow them
1945 // everywhere as an extension.
1946 if (!Cxx1yLoc.isValid())
1947 Cxx1yLoc = DS->getBeginLoc();
1948 continue;
1949
1950 default:
1951 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1952 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1953 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1954 }
1955 return false;
1956 }
1957 }
1958
1959 return true;
1960}
1961
1962/// Check that the given field is initialized within a constexpr constructor.
1963///
1964/// \param Dcl The constexpr constructor being checked.
1965/// \param Field The field being checked. This may be a member of an anonymous
1966/// struct or union nested within the class being checked.
1967/// \param Inits All declarations, including anonymous struct/union members and
1968/// indirect members, for which any initialization was provided.
1969/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1970/// multiple notes for different members to the same error.
1971/// \param Kind Whether we're diagnosing a constructor as written or determining
1972/// whether the formal requirements are satisfied.
1973/// \return \c false if we're checking for validity and the constructor does
1974/// not satisfy the requirements on a constexpr constructor.
1975static bool CheckConstexprCtorInitializer(Sema &SemaRef,
1976 const FunctionDecl *Dcl,
1977 FieldDecl *Field,
1978 llvm::SmallSet<Decl*, 16> &Inits,
1979 bool &Diagnosed,
1980 Sema::CheckConstexprKind Kind) {
1981 // In C++20 onwards, there's nothing to check for validity.
1982 if (Kind == Sema::CheckConstexprKind::CheckValid &&
1983 SemaRef.getLangOpts().CPlusPlus20)
1984 return true;
1985
1986 if (Field->isInvalidDecl())
1987 return true;
1988
1989 if (Field->isUnnamedBitfield())
1990 return true;
1991
1992 // Anonymous unions with no variant members and empty anonymous structs do not
1993 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1994 // indirect fields don't need initializing.
1995 if (Field->isAnonymousStructOrUnion() &&
1996 (Field->getType()->isUnionType()
1997 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1998 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1999 return true;
2000
2001 if (!Inits.count(Field)) {
2002 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2003 if (!Diagnosed) {
2004 SemaRef.Diag(Dcl->getLocation(),
2005 SemaRef.getLangOpts().CPlusPlus20
2006 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
2007 : diag::ext_constexpr_ctor_missing_init);
2008 Diagnosed = true;
2009 }
2010 SemaRef.Diag(Field->getLocation(),
2011 diag::note_constexpr_ctor_missing_init);
2012 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2013 return false;
2014 }
2015 } else if (Field->isAnonymousStructOrUnion()) {
2016 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
2017 for (auto *I : RD->fields())
2018 // If an anonymous union contains an anonymous struct of which any member
2019 // is initialized, all members must be initialized.
2020 if (!RD->isUnion() || Inits.count(I))
2021 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2022 Kind))
2023 return false;
2024 }
2025 return true;
2026}
2027
2028/// Check the provided statement is allowed in a constexpr function
2029/// definition.
2030static bool
2031CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
2032 SmallVectorImpl<SourceLocation> &ReturnStmts,
2033 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
2034 SourceLocation &Cxx2bLoc,
2035 Sema::CheckConstexprKind Kind) {
2036 // - its function-body shall be [...] a compound-statement that contains only
2037 switch (S->getStmtClass()) {
2038 case Stmt::NullStmtClass:
2039 // - null statements,
2040 return true;
2041
2042 case Stmt::DeclStmtClass:
2043 // - static_assert-declarations
2044 // - using-declarations,
2045 // - using-directives,
2046 // - typedef declarations and alias-declarations that do not define
2047 // classes or enumerations,
2048 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
2049 return false;
2050 return true;
2051
2052 case Stmt::ReturnStmtClass:
2053 // - and exactly one return statement;
2054 if (isa<CXXConstructorDecl>(Dcl)) {
2055 // C++1y allows return statements in constexpr constructors.
2056 if (!Cxx1yLoc.isValid())
2057 Cxx1yLoc = S->getBeginLoc();
2058 return true;
2059 }
2060
2061 ReturnStmts.push_back(S->getBeginLoc());
2062 return true;
2063
2064 case Stmt::AttributedStmtClass:
2065 // Attributes on a statement don't affect its formal kind and hence don't
2066 // affect its validity in a constexpr function.
2067 return CheckConstexprFunctionStmt(
2068 SemaRef, Dcl, cast<AttributedStmt>(S)->getSubStmt(), ReturnStmts,
2069 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind);
2070
2071 case Stmt::CompoundStmtClass: {
2072 // C++1y allows compound-statements.
2073 if (!Cxx1yLoc.isValid())
2074 Cxx1yLoc = S->getBeginLoc();
2075
2076 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2077 for (auto *BodyIt : CompStmt->body()) {
2078 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2079 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2080 return false;
2081 }
2082 return true;
2083 }
2084
2085 case Stmt::IfStmtClass: {
2086 // C++1y allows if-statements.
2087 if (!Cxx1yLoc.isValid())
2088 Cxx1yLoc = S->getBeginLoc();
2089
2090 IfStmt *If = cast<IfStmt>(S);
2091 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2092 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2093 return false;
2094 if (If->getElse() &&
2095 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2096 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2097 return false;
2098 return true;
2099 }
2100
2101 case Stmt::WhileStmtClass:
2102 case Stmt::DoStmtClass:
2103 case Stmt::ForStmtClass:
2104 case Stmt::CXXForRangeStmtClass:
2105 case Stmt::ContinueStmtClass:
2106 // C++1y allows all of these. We don't allow them as extensions in C++11,
2107 // because they don't make sense without variable mutation.
2108 if (!SemaRef.getLangOpts().CPlusPlus14)
2109 break;
2110 if (!Cxx1yLoc.isValid())
2111 Cxx1yLoc = S->getBeginLoc();
2112 for (Stmt *SubStmt : S->children()) {
2113 if (SubStmt &&
2114 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2115 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2116 return false;
2117 }
2118 return true;
2119
2120 case Stmt::SwitchStmtClass:
2121 case Stmt::CaseStmtClass:
2122 case Stmt::DefaultStmtClass:
2123 case Stmt::BreakStmtClass:
2124 // C++1y allows switch-statements, and since they don't need variable
2125 // mutation, we can reasonably allow them in C++11 as an extension.
2126 if (!Cxx1yLoc.isValid())
2127 Cxx1yLoc = S->getBeginLoc();
2128 for (Stmt *SubStmt : S->children()) {
2129 if (SubStmt &&
2130 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2131 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2132 return false;
2133 }
2134 return true;
2135
2136 case Stmt::LabelStmtClass:
2137 case Stmt::GotoStmtClass:
2138 if (Cxx2bLoc.isInvalid())
2139 Cxx2bLoc = S->getBeginLoc();
2140 for (Stmt *SubStmt : S->children()) {
2141 if (SubStmt &&
2142 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2143 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2144 return false;
2145 }
2146 return true;
2147
2148 case Stmt::GCCAsmStmtClass:
2149 case Stmt::MSAsmStmtClass:
2150 // C++2a allows inline assembly statements.
2151 case Stmt::CXXTryStmtClass:
2152 if (Cxx2aLoc.isInvalid())
2153 Cxx2aLoc = S->getBeginLoc();
2154 for (Stmt *SubStmt : S->children()) {
2155 if (SubStmt &&
2156 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2157 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2158 return false;
2159 }
2160 return true;
2161
2162 case Stmt::CXXCatchStmtClass:
2163 // Do not bother checking the language mode (already covered by the
2164 // try block check).
2165 if (!CheckConstexprFunctionStmt(
2166 SemaRef, Dcl, cast<CXXCatchStmt>(S)->getHandlerBlock(), ReturnStmts,
2167 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2168 return false;
2169 return true;
2170
2171 default:
2172 if (!isa<Expr>(S))
2173 break;
2174
2175 // C++1y allows expression-statements.
2176 if (!Cxx1yLoc.isValid())
2177 Cxx1yLoc = S->getBeginLoc();
2178 return true;
2179 }
2180
2181 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2182 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2183 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2184 }
2185 return false;
2186}
2187
2188/// Check the body for the given constexpr function declaration only contains
2189/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2190///
2191/// \return true if the body is OK, false if we have found or diagnosed a
2192/// problem.
2193static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2194 Stmt *Body,
2195 Sema::CheckConstexprKind Kind) {
2196 SmallVector<SourceLocation, 4> ReturnStmts;
2197
2198 if (isa<CXXTryStmt>(Body)) {
2199 // C++11 [dcl.constexpr]p3:
2200 // The definition of a constexpr function shall satisfy the following
2201 // constraints: [...]
2202 // - its function-body shall be = delete, = default, or a
2203 // compound-statement
2204 //
2205 // C++11 [dcl.constexpr]p4:
2206 // In the definition of a constexpr constructor, [...]
2207 // - its function-body shall not be a function-try-block;
2208 //
2209 // This restriction is lifted in C++2a, as long as inner statements also
2210 // apply the general constexpr rules.
2211 switch (Kind) {
2212 case Sema::CheckConstexprKind::CheckValid:
2213 if (!SemaRef.getLangOpts().CPlusPlus20)
2214 return false;
2215 break;
2216
2217 case Sema::CheckConstexprKind::Diagnose:
2218 SemaRef.Diag(Body->getBeginLoc(),
2219 !SemaRef.getLangOpts().CPlusPlus20
2220 ? diag::ext_constexpr_function_try_block_cxx20
2221 : diag::warn_cxx17_compat_constexpr_function_try_block)
2222 << isa<CXXConstructorDecl>(Dcl);
2223 break;
2224 }
2225 }
2226
2227 // - its function-body shall be [...] a compound-statement that contains only
2228 // [... list of cases ...]
2229 //
2230 // Note that walking the children here is enough to properly check for
2231 // CompoundStmt and CXXTryStmt body.
2232 SourceLocation Cxx1yLoc, Cxx2aLoc, Cxx2bLoc;
2233 for (Stmt *SubStmt : Body->children()) {
2234 if (SubStmt &&
2235 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2236 Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
2237 return false;
2238 }
2239
2240 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2241 // If this is only valid as an extension, report that we don't satisfy the
2242 // constraints of the current language.
2243 if ((Cxx2bLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus2b) ||
2244 (Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
2245 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2246 return false;
2247 } else if (Cxx2bLoc.isValid()) {
2248 SemaRef.Diag(Cxx2bLoc,
2249 SemaRef.getLangOpts().CPlusPlus2b
2250 ? diag::warn_cxx20_compat_constexpr_body_invalid_stmt
2251 : diag::ext_constexpr_body_invalid_stmt_cxx2b)
2252 << isa<CXXConstructorDecl>(Dcl);
2253 } else if (Cxx2aLoc.isValid()) {
2254 SemaRef.Diag(Cxx2aLoc,
2255 SemaRef.getLangOpts().CPlusPlus20
2256 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2257 : diag::ext_constexpr_body_invalid_stmt_cxx20)
2258 << isa<CXXConstructorDecl>(Dcl);
2259 } else if (Cxx1yLoc.isValid()) {
2260 SemaRef.Diag(Cxx1yLoc,
2261 SemaRef.getLangOpts().CPlusPlus14
2262 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2263 : diag::ext_constexpr_body_invalid_stmt)
2264 << isa<CXXConstructorDecl>(Dcl);
2265 }
2266
2267 if (const CXXConstructorDecl *Constructor
2268 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2269 const CXXRecordDecl *RD = Constructor->getParent();
2270 // DR1359:
2271 // - every non-variant non-static data member and base class sub-object
2272 // shall be initialized;
2273 // DR1460:
2274 // - if the class is a union having variant members, exactly one of them
2275 // shall be initialized;
2276 if (RD->isUnion()) {
2277 if (Constructor->getNumCtorInitializers() == 0 &&
2278 RD->hasVariantMembers()) {
2279 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2280 SemaRef.Diag(
2281 Dcl->getLocation(),
2282 SemaRef.getLangOpts().CPlusPlus20
2283 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2284 : diag::ext_constexpr_union_ctor_no_init);
2285 } else if (!SemaRef.getLangOpts().CPlusPlus20) {
2286 return false;
2287 }
2288 }
2289 } else if (!Constructor->isDependentContext() &&
2290 !Constructor->isDelegatingConstructor()) {
2291 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", 2291, __extension__ __PRETTY_FUNCTION__
))
;
2292
2293 // Skip detailed checking if we have enough initializers, and we would
2294 // allow at most one initializer per member.
2295 bool AnyAnonStructUnionMembers = false;
2296 unsigned Fields = 0;
2297 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2298 E = RD->field_end(); I != E; ++I, ++Fields) {
2299 if (I->isAnonymousStructOrUnion()) {
2300 AnyAnonStructUnionMembers = true;
2301 break;
2302 }
2303 }
2304 // DR1460:
2305 // - if the class is a union-like class, but is not a union, for each of
2306 // its anonymous union members having variant members, exactly one of
2307 // them shall be initialized;
2308 if (AnyAnonStructUnionMembers ||
2309 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2310 // Check initialization of non-static data members. Base classes are
2311 // always initialized so do not need to be checked. Dependent bases
2312 // might not have initializers in the member initializer list.
2313 llvm::SmallSet<Decl*, 16> Inits;
2314 for (const auto *I: Constructor->inits()) {
2315 if (FieldDecl *FD = I->getMember())
2316 Inits.insert(FD);
2317 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2318 Inits.insert(ID->chain_begin(), ID->chain_end());
2319 }
2320
2321 bool Diagnosed = false;
2322 for (auto *I : RD->fields())
2323 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2324 Kind))
2325 return false;
2326 }
2327 }
2328 } else {
2329 if (ReturnStmts.empty()) {
2330 // C++1y doesn't require constexpr functions to contain a 'return'
2331 // statement. We still do, unless the return type might be void, because
2332 // otherwise if there's no return statement, the function cannot
2333 // be used in a core constant expression.
2334 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2335 (Dcl->getReturnType()->isVoidType() ||
2336 Dcl->getReturnType()->isDependentType());
2337 switch (Kind) {
2338 case Sema::CheckConstexprKind::Diagnose:
2339 SemaRef.Diag(Dcl->getLocation(),
2340 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2341 : diag::err_constexpr_body_no_return)
2342 << Dcl->isConsteval();
2343 if (!OK)
2344 return false;
2345 break;
2346
2347 case Sema::CheckConstexprKind::CheckValid:
2348 // The formal requirements don't include this rule in C++14, even
2349 // though the "must be able to produce a constant expression" rules
2350 // still imply it in some cases.
2351 if (!SemaRef.getLangOpts().CPlusPlus14)
2352 return false;
2353 break;
2354 }
2355 } else if (ReturnStmts.size() > 1) {
2356 switch (Kind) {
2357 case Sema::CheckConstexprKind::Diagnose:
2358 SemaRef.Diag(
2359 ReturnStmts.back(),
2360 SemaRef.getLangOpts().CPlusPlus14
2361 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2362 : diag::ext_constexpr_body_multiple_return);
2363 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2364 SemaRef.Diag(ReturnStmts[I],
2365 diag::note_constexpr_body_previous_return);
2366 break;
2367
2368 case Sema::CheckConstexprKind::CheckValid:
2369 if (!SemaRef.getLangOpts().CPlusPlus14)
2370 return false;
2371 break;
2372 }
2373 }
2374 }
2375
2376 // C++11 [dcl.constexpr]p5:
2377 // if no function argument values exist such that the function invocation
2378 // substitution would produce a constant expression, the program is
2379 // ill-formed; no diagnostic required.
2380 // C++11 [dcl.constexpr]p3:
2381 // - every constructor call and implicit conversion used in initializing the
2382 // return value shall be one of those allowed in a constant expression.
2383 // C++11 [dcl.constexpr]p4:
2384 // - every constructor involved in initializing non-static data members and
2385 // base class sub-objects shall be a constexpr constructor.
2386 //
2387 // Note that this rule is distinct from the "requirements for a constexpr
2388 // function", so is not checked in CheckValid mode.
2389 SmallVector<PartialDiagnosticAt, 8> Diags;
2390 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2391 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2392 SemaRef.Diag(Dcl->getLocation(),
2393 diag::ext_constexpr_function_never_constant_expr)
2394 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2395 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2396 SemaRef.Diag(Diags[I].first, Diags[I].second);
2397 // Don't return false here: we allow this for compatibility in
2398 // system headers.
2399 }
2400
2401 return true;
2402}
2403
2404/// Get the class that is directly named by the current context. This is the
2405/// class for which an unqualified-id in this scope could name a constructor
2406/// or destructor.
2407///
2408/// If the scope specifier denotes a class, this will be that class.
2409/// If the scope specifier is empty, this will be the class whose
2410/// member-specification we are currently within. Otherwise, there
2411/// is no such class.
2412CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2413 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", 2413, __extension__ __PRETTY_FUNCTION__
))
;
2414
2415 if (SS && SS->isInvalid())
2416 return nullptr;
2417
2418 if (SS && SS->isNotEmpty()) {
2419 DeclContext *DC = computeDeclContext(*SS, true);
2420 return dyn_cast_or_null<CXXRecordDecl>(DC);
2421 }
2422
2423 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2424}
2425
2426/// isCurrentClassName - Determine whether the identifier II is the
2427/// name of the class type currently being defined. In the case of
2428/// nested classes, this will only return true if II is the name of
2429/// the innermost class.
2430bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2431 const CXXScopeSpec *SS) {
2432 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2433 return CurDecl && &II == CurDecl->getIdentifier();
2434}
2435
2436/// Determine whether the identifier II is a typo for the name of
2437/// the class type currently being defined. If so, update it to the identifier
2438/// that should have been used.
2439bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2440 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", 2440, __extension__ __PRETTY_FUNCTION__
))
;
2441
2442 if (!getLangOpts().SpellChecking)
2443 return false;
2444
2445 CXXRecordDecl *CurDecl;
2446 if (SS && SS->isSet() && !SS->isInvalid()) {
2447 DeclContext *DC = computeDeclContext(*SS, true);
2448 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2449 } else
2450 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2451
2452 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2453 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2454 < II->getLength()) {
2455 II = CurDecl->getIdentifier();
2456 return true;
2457 }
2458
2459 return false;
2460}
2461
2462/// Determine whether the given class is a base class of the given
2463/// class, including looking at dependent bases.
2464static bool findCircularInheritance(const CXXRecordDecl *Class,
2465 const CXXRecordDecl *Current) {
2466 SmallVector<const CXXRecordDecl*, 8> Queue;
2467
2468 Class = Class->getCanonicalDecl();
2469 while (true) {
2470 for (const auto &I : Current->bases()) {
2471 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2472 if (!Base)
2473 continue;
2474
2475 Base = Base->getDefinition();
2476 if (!Base)
2477 continue;
2478
2479 if (Base->getCanonicalDecl() == Class)
2480 return true;
2481
2482 Queue.push_back(Base);
2483 }
2484
2485 if (Queue.empty())
2486 return false;
2487
2488 Current = Queue.pop_back_val();
2489 }
2490
2491 return false;
2492}
2493
2494/// Check the validity of a C++ base class specifier.
2495///
2496/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2497/// and returns NULL otherwise.
2498CXXBaseSpecifier *
2499Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2500 SourceRange SpecifierRange,
2501 bool Virtual, AccessSpecifier Access,
2502 TypeSourceInfo *TInfo,
2503 SourceLocation EllipsisLoc) {
2504 QualType BaseType = TInfo->getType();
2505 if (BaseType->containsErrors()) {
2506 // Already emitted a diagnostic when parsing the error type.
2507 return nullptr;
2508 }
2509 // C++ [class.union]p1:
2510 // A union shall not have base classes.
2511 if (Class->isUnion()) {
2512 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2513 << SpecifierRange;
2514 return nullptr;
2515 }
2516
2517 if (EllipsisLoc.isValid() &&
2518 !TInfo->getType()->containsUnexpandedParameterPack()) {
2519 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2520 << TInfo->getTypeLoc().getSourceRange();
2521 EllipsisLoc = SourceLocation();
2522 }
2523
2524 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2525
2526 if (BaseType->isDependentType()) {
2527 // Make sure that we don't have circular inheritance among our dependent
2528 // bases. For non-dependent bases, the check for completeness below handles
2529 // this.
2530 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2531 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2532 ((BaseDecl = BaseDecl->getDefinition()) &&
2533 findCircularInheritance(Class, BaseDecl))) {
2534 Diag(BaseLoc, diag::err_circular_inheritance)
2535 << BaseType << Context.getTypeDeclType(Class);
2536
2537 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2538 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2539 << BaseType;
2540
2541 return nullptr;
2542 }
2543 }
2544
2545 // Make sure that we don't make an ill-formed AST where the type of the
2546 // Class is non-dependent and its attached base class specifier is an
2547 // dependent type, which violates invariants in many clang code paths (e.g.
2548 // constexpr evaluator). If this case happens (in errory-recovery mode), we
2549 // explicitly mark the Class decl invalid. The diagnostic was already
2550 // emitted.
2551 if (!Class->getTypeForDecl()->isDependentType())
2552 Class->setInvalidDecl();
2553 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2554 Class->getTagKind() == TTK_Class,
2555 Access, TInfo, EllipsisLoc);
2556 }
2557
2558 // Base specifiers must be record types.
2559 if (!BaseType->isRecordType()) {
2560 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2561 return nullptr;
2562 }
2563
2564 // C++ [class.union]p1:
2565 // A union shall not be used as a base class.
2566 if (BaseType->isUnionType()) {
2567 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2568 return nullptr;
2569 }
2570
2571 // For the MS ABI, propagate DLL attributes to base class templates.
2572 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2573 if (Attr *ClassAttr = getDLLAttr(Class)) {
2574 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2575 BaseType->getAsCXXRecordDecl())) {
2576 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2577 BaseLoc);
2578 }
2579 }
2580 }
2581
2582 // C++ [class.derived]p2:
2583 // The class-name in a base-specifier shall not be an incompletely
2584 // defined class.
2585 if (RequireCompleteType(BaseLoc, BaseType,
2586 diag::err_incomplete_base_class, SpecifierRange)) {
2587 Class->setInvalidDecl();
2588 return nullptr;
2589 }
2590
2591 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2592 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2593 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", 2593, __extension__ __PRETTY_FUNCTION__
))
;
2594 BaseDecl = BaseDecl->getDefinition();
2595 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", 2595, __extension__ __PRETTY_FUNCTION__
))
;
2596 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2597 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", 2597, __extension__ __PRETTY_FUNCTION__
))
;
2598
2599 // Microsoft docs say:
2600 // "If a base-class has a code_seg attribute, derived classes must have the
2601 // same attribute."
2602 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2603 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2604 if ((DerivedCSA || BaseCSA) &&
2605 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2606 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2607 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2608 << CXXBaseDecl;
2609 return nullptr;
2610 }
2611
2612 // A class which contains a flexible array member is not suitable for use as a
2613 // base class:
2614 // - If the layout determines that a base comes before another base,
2615 // the flexible array member would index into the subsequent base.
2616 // - If the layout determines that base comes before the derived class,
2617 // the flexible array member would index into the derived class.
2618 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2619 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2620 << CXXBaseDecl->getDeclName();
2621 return nullptr;
2622 }
2623
2624 // C++ [class]p3:
2625 // If a class is marked final and it appears as a base-type-specifier in
2626 // base-clause, the program is ill-formed.
2627 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2628 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2629 << CXXBaseDecl->getDeclName()
2630 << FA->isSpelledAsSealed();
2631 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2632 << CXXBaseDecl->getDeclName() << FA->getRange();
2633 return nullptr;
2634 }
2635
2636 if (BaseDecl->isInvalidDecl())
2637 Class->setInvalidDecl();
2638
2639 // Create the base specifier.
2640 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2641 Class->getTagKind() == TTK_Class,
2642 Access, TInfo, EllipsisLoc);
2643}
2644
2645/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2646/// one entry in the base class list of a class specifier, for
2647/// example:
2648/// class foo : public bar, virtual private baz {
2649/// 'public bar' and 'virtual private baz' are each base-specifiers.
2650BaseResult Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2651 const ParsedAttributesView &Attributes,
2652 bool Virtual, AccessSpecifier Access,
2653 ParsedType basetype, SourceLocation BaseLoc,
2654 SourceLocation EllipsisLoc) {
2655 if (!classdecl)
2656 return true;
2657
2658 AdjustDeclIfTemplate(classdecl);
2659 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2660 if (!Class)
2661 return true;
2662
2663 // We haven't yet attached the base specifiers.
2664 Class->setIsParsingBaseSpecifiers();
2665
2666 // We do not support any C++11 attributes on base-specifiers yet.
2667 // Diagnose any attributes we see.
2668 for (const ParsedAttr &AL : Attributes) {
2669 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2670 continue;
2671 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2672 ? (unsigned)diag::warn_unknown_attribute_ignored
2673 : (unsigned)diag::err_base_specifier_attribute)
2674 << AL << AL.getRange();
2675 }
2676
2677 TypeSourceInfo *TInfo = nullptr;
2678 GetTypeFromParser(basetype, &TInfo);
2679
2680 if (EllipsisLoc.isInvalid() &&
2681 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2682 UPPC_BaseType))
2683 return true;
2684
2685 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2686 Virtual, Access, TInfo,
2687 EllipsisLoc))
2688 return BaseSpec;
2689 else
2690 Class->setInvalidDecl();
2691
2692 return true;
2693}
2694
2695/// Use small set to collect indirect bases. As this is only used
2696/// locally, there's no need to abstract the small size parameter.
2697typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2698
2699/// Recursively add the bases of Type. Don't add Type itself.
2700static void
2701NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2702 const QualType &Type)
2703{
2704 // Even though the incoming type is a base, it might not be
2705 // a class -- it could be a template parm, for instance.
2706 if (auto Rec = Type->getAs<RecordType>()) {
2707 auto Decl = Rec->getAsCXXRecordDecl();
2708
2709 // Iterate over its bases.
2710 for (const auto &BaseSpec : Decl->bases()) {
2711 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2712 .getUnqualifiedType();
2713 if (Set.insert(Base).second)
2714 // If we've not already seen it, recurse.
2715 NoteIndirectBases(Context, Set, Base);
2716 }
2717 }
2718}
2719
2720/// Performs the actual work of attaching the given base class
2721/// specifiers to a C++ class.
2722bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2723 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2724 if (Bases.empty())
2725 return false;
2726
2727 // Used to keep track of which base types we have already seen, so
2728 // that we can properly diagnose redundant direct base types. Note
2729 // that the key is always the unqualified canonical type of the base
2730 // class.
2731 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2732
2733 // Used to track indirect bases so we can see if a direct base is
2734 // ambiguous.
2735 IndirectBaseSet IndirectBaseTypes;
2736
2737 // Copy non-redundant base specifiers into permanent storage.
2738 unsigned NumGoodBases = 0;
2739 bool Invalid = false;
2740 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2741 QualType NewBaseType
2742 = Context.getCanonicalType(Bases[idx]->getType());
2743 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2744
2745 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2746 if (KnownBase) {
2747 // C++ [class.mi]p3:
2748 // A class shall not be specified as a direct base class of a
2749 // derived class more than once.
2750 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2751 << KnownBase->getType() << Bases[idx]->getSourceRange();
2752
2753 // Delete the duplicate base class specifier; we're going to
2754 // overwrite its pointer later.
2755 Context.Deallocate(Bases[idx]);
2756
2757 Invalid = true;
2758 } else {
2759 // Okay, add this new base class.
2760 KnownBase = Bases[idx];
2761 Bases[NumGoodBases++] = Bases[idx];
2762
2763 if (NewBaseType->isDependentType())
2764 continue;
2765 // Note this base's direct & indirect bases, if there could be ambiguity.
2766 if (Bases.size() > 1)
2767 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2768
2769 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2770 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2771 if (Class->isInterface() &&
2772 (!RD->isInterfaceLike() ||
2773 KnownBase->getAccessSpecifier() != AS_public)) {
2774 // The Microsoft extension __interface does not permit bases that
2775 // are not themselves public interfaces.
2776 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2777 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2778 << RD->getSourceRange();
2779 Invalid = true;
2780 }
2781 if (RD->hasAttr<WeakAttr>())
2782 Class->addAttr(WeakAttr::CreateImplicit(Context));
2783 }
2784 }
2785 }
2786
2787 // Attach the remaining base class specifiers to the derived class.
2788 Class->setBases(Bases.data(), NumGoodBases);
2789
2790 // Check that the only base classes that are duplicate are virtual.
2791 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2792 // Check whether this direct base is inaccessible due to ambiguity.
2793 QualType BaseType = Bases[idx]->getType();
2794
2795 // Skip all dependent types in templates being used as base specifiers.
2796 // Checks below assume that the base specifier is a CXXRecord.
2797 if (BaseType->isDependentType())
2798 continue;
2799
2800 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2801 .getUnqualifiedType();
2802
2803 if (IndirectBaseTypes.count(CanonicalBase)) {
2804 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2805 /*DetectVirtual=*/true);
2806 bool found
2807 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2808 assert(found)(static_cast <bool> (found) ? void (0) : __assert_fail (
"found", "clang/lib/Sema/SemaDeclCXX.cpp", 2808, __extension__
__PRETTY_FUNCTION__))
;
2809 (void)found;
2810
2811 if (Paths.isAmbiguous(CanonicalBase))
2812 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2813 << BaseType << getAmbiguousPathsDisplayString(Paths)
2814 << Bases[idx]->getSourceRange();
2815 else
2816 assert(Bases[idx]->isVirtual())(static_cast <bool> (Bases[idx]->isVirtual()) ? void
(0) : __assert_fail ("Bases[idx]->isVirtual()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 2816, __extension__ __PRETTY_FUNCTION__))
;
2817 }
2818
2819 // Delete the base class specifier, since its data has been copied
2820 // into the CXXRecordDecl.
2821 Context.Deallocate(Bases[idx]);
2822 }
2823
2824 return Invalid;
2825}
2826
2827/// ActOnBaseSpecifiers - Attach the given base specifiers to the
2828/// class, after checking whether there are any duplicate base
2829/// classes.
2830void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2831 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2832 if (!ClassDecl || Bases.empty())
2833 return;
2834
2835 AdjustDeclIfTemplate(ClassDecl);
2836 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2837}
2838
2839/// Determine whether the type \p Derived is a C++ class that is
2840/// derived from the type \p Base.
2841bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2842 if (!getLangOpts().CPlusPlus)
2843 return false;
2844
2845 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2846 if (!DerivedRD)
2847 return false;
2848
2849 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2850 if (!BaseRD)
2851 return false;
2852
2853 // If either the base or the derived type is invalid, don't try to
2854 // check whether one is derived from the other.
2855 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2856 return false;
2857
2858 // FIXME: In a modules build, do we need the entire path to be visible for us
2859 // to be able to use the inheritance relationship?
2860 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2861 return false;
2862
2863 return DerivedRD->isDerivedFrom(BaseRD);
2864}
2865
2866/// Determine whether the type \p Derived is a C++ class that is
2867/// derived from the type \p Base.
2868bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2869 CXXBasePaths &Paths) {
2870 if (!getLangOpts().CPlusPlus)
2871 return false;
2872
2873 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2874 if (!DerivedRD)
2875 return false;
2876
2877 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2878 if (!BaseRD)
2879 return false;
2880
2881 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2882 return false;
2883
2884 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2885}
2886
2887static void BuildBasePathArray(const CXXBasePath &Path,
2888 CXXCastPath &BasePathArray) {
2889 // We first go backward and check if we have a virtual base.
2890 // FIXME: It would be better if CXXBasePath had the base specifier for
2891 // the nearest virtual base.
2892 unsigned Start = 0;
2893 for (unsigned I = Path.size(); I != 0; --I) {
2894 if (Path[I - 1].Base->isVirtual()) {
2895 Start = I - 1;
2896 break;
2897 }
2898 }
2899
2900 // Now add all bases.
2901 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2902 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2903}
2904
2905
2906void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2907 CXXCastPath &BasePathArray) {
2908 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", 2908, __extension__ __PRETTY_FUNCTION__
))
;
2909 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", 2909, __extension__ __PRETTY_FUNCTION__
))
;
2910 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2911}
2912/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2913/// conversion (where Derived and Base are class types) is
2914/// well-formed, meaning that the conversion is unambiguous (and
2915/// that all of the base classes are accessible). Returns true
2916/// and emits a diagnostic if the code is ill-formed, returns false
2917/// otherwise. Loc is the location where this routine should point to
2918/// if there is an error, and Range is the source range to highlight
2919/// if there is an error.
2920///
2921/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2922/// diagnostic for the respective type of error will be suppressed, but the
2923/// check for ill-formed code will still be performed.
2924bool
2925Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2926 unsigned InaccessibleBaseID,
2927 unsigned AmbiguousBaseConvID,
2928 SourceLocation Loc, SourceRange Range,
2929 DeclarationName Name,
2930 CXXCastPath *BasePath,
2931 bool IgnoreAccess) {
2932 // First, determine whether the path from Derived to Base is
2933 // ambiguous. This is slightly more expensive than checking whether
2934 // the Derived to Base conversion exists, because here we need to
2935 // explore multiple paths to determine if there is an ambiguity.
2936 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2937 /*DetectVirtual=*/false);
2938 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2939 if (!DerivationOkay)
2940 return true;
2941
2942 const CXXBasePath *Path = nullptr;
2943 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2944 Path = &Paths.front();
2945
2946 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2947 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2948 // user to access such bases.
2949 if (!Path && getLangOpts().MSVCCompat) {
2950 for (const CXXBasePath &PossiblePath : Paths) {
2951 if (PossiblePath.size() == 1) {
2952 Path = &PossiblePath;
2953 if (AmbiguousBaseConvID)
2954 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2955 << Base << Derived << Range;
2956 break;
2957 }
2958 }
2959 }
2960
2961 if (Path) {
2962 if (!IgnoreAccess) {
2963 // Check that the base class can be accessed.
2964 switch (
2965 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2966 case AR_inaccessible:
2967 return true;
2968 case AR_accessible:
2969 case AR_dependent:
2970 case AR_delayed:
2971 break;
2972 }
2973 }
2974
2975 // Build a base path if necessary.
2976 if (BasePath)
2977 ::BuildBasePathArray(*Path, *BasePath);
2978 return false;
2979 }
2980
2981 if (AmbiguousBaseConvID) {
2982 // We know that the derived-to-base conversion is ambiguous, and
2983 // we're going to produce a diagnostic. Perform the derived-to-base
2984 // search just one more time to compute all of the possible paths so
2985 // that we can print them out. This is more expensive than any of
2986 // the previous derived-to-base checks we've done, but at this point
2987 // performance isn't as much of an issue.
2988 Paths.clear();
2989 Paths.setRecordingPaths(true);
2990 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2991 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", 2991, __extension__ __PRETTY_FUNCTION__
))
;
2992 (void)StillOkay;
2993
2994 // Build up a textual representation of the ambiguous paths, e.g.,
2995 // D -> B -> A, that will be used to illustrate the ambiguous
2996 // conversions in the diagnostic. We only print one of the paths
2997 // to each base class subobject.
2998 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2999
3000 Diag(Loc, AmbiguousBaseConvID)
3001 << Derived << Base << PathDisplayStr << Range << Name;
3002 }
3003 return true;
3004}
3005
3006bool
3007Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
3008 SourceLocation Loc, SourceRange Range,
3009 CXXCastPath *BasePath,
3010 bool IgnoreAccess) {
3011 return CheckDerivedToBaseConversion(
3012 Derived, Base, diag::err_upcast_to_inaccessible_base,
3013 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
3014 BasePath, IgnoreAccess);
3015}
3016
3017
3018/// Builds a string representing ambiguous paths from a
3019/// specific derived class to different subobjects of the same base
3020/// class.
3021///
3022/// This function builds a string that can be used in error messages
3023/// to show the different paths that one can take through the
3024/// inheritance hierarchy to go from the derived class to different
3025/// subobjects of a base class. The result looks something like this:
3026/// @code
3027/// struct D -> struct B -> struct A
3028/// struct D -> struct C -> struct A
3029/// @endcode
3030std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
3031 std::string PathDisplayStr;
3032 std::set<unsigned> DisplayedPaths;
3033 for (CXXBasePaths::paths_iterator Path = Paths.begin();
3034 Path != Paths.end(); ++Path) {
3035 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
3036 // We haven't displayed a path to this particular base
3037 // class subobject yet.
3038 PathDisplayStr += "\n ";
3039 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
3040 for (CXXBasePath::const_iterator Element = Path->begin();
3041 Element != Path->end(); ++Element)
3042 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
3043 }
3044 }
3045
3046 return PathDisplayStr;
3047}
3048
3049//===----------------------------------------------------------------------===//
3050// C++ class member Handling
3051//===----------------------------------------------------------------------===//
3052
3053/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
3054bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
3055 SourceLocation ColonLoc,
3056 const ParsedAttributesView &Attrs) {
3057 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", 3057, __extension__ __PRETTY_FUNCTION__
))
;
3058 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
3059 ASLoc, ColonLoc);
3060 CurContext->addHiddenDecl(ASDecl);
3061 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3062}
3063
3064/// CheckOverrideControl - Check C++11 override control semantics.
3065void Sema::CheckOverrideControl(NamedDecl *D) {
3066 if (D->isInvalidDecl())
3067 return;
3068
3069 // We only care about "override" and "final" declarations.
3070 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
3071 return;
3072
3073 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3074
3075 // We can't check dependent instance methods.
3076 if (MD && MD->isInstance() &&
3077 (MD->getParent()->hasAnyDependentBases() ||
3078 MD->getType()->isDependentType()))
3079 return;
3080
3081 if (MD && !MD->isVirtual()) {
3082 // If we have a non-virtual method, check if if hides a virtual method.
3083 // (In that case, it's most likely the method has the wrong type.)
3084 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
3085 FindHiddenVirtualMethods(MD, OverloadedMethods);
3086
3087 if (!OverloadedMethods.empty()) {
3088 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3089 Diag(OA->getLocation(),
3090 diag::override_keyword_hides_virtual_member_function)
3091 << "override" << (OverloadedMethods.size() > 1);
3092 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3093 Diag(FA->getLocation(),
3094 diag::override_keyword_hides_virtual_member_function)
3095 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3096 << (OverloadedMethods.size() > 1);
3097 }
3098 NoteHiddenVirtualMethods(MD, OverloadedMethods);
3099 MD->setInvalidDecl();
3100 return;
3101 }
3102 // Fall through into the general case diagnostic.
3103 // FIXME: We might want to attempt typo correction here.
3104 }
3105
3106 if (!MD || !MD->isVirtual()) {
3107 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3108 Diag(OA->getLocation(),
3109 diag::override_keyword_only_allowed_on_virtual_member_functions)
3110 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3111 D->dropAttr<OverrideAttr>();
3112 }
3113 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3114 Diag(FA->getLocation(),
3115 diag::override_keyword_only_allowed_on_virtual_member_functions)
3116 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3117 << FixItHint::CreateRemoval(FA->getLocation());
3118 D->dropAttr<FinalAttr>();
3119 }
3120 return;
3121 }
3122
3123 // C++11 [class.virtual]p5:
3124 // If a function is marked with the virt-specifier override and
3125 // does not override a member function of a base class, the program is
3126 // ill-formed.
3127 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3128 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3129 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3130 << MD->getDeclName();
3131}
3132
3133void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
3134 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3135 return;
3136 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3137 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3138 return;
3139
3140 SourceLocation Loc = MD->getLocation();
3141 SourceLocation SpellingLoc = Loc;
3142 if (getSourceManager().isMacroArgExpansion(Loc))
3143 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3144 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3145 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3146 return;
3147
3148 if (MD->size_overridden_methods() > 0) {
3149 auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
3150 unsigned DiagID =
3151 Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
3152 ? DiagInconsistent
3153 : DiagSuggest;
3154 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3155 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3156 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3157 };
3158 if (isa<CXXDestructorDecl>(MD))
3159 EmitDiag(
3160 diag::warn_inconsistent_destructor_marked_not_override_overriding,
3161 diag::warn_suggest_destructor_marked_not_override_overriding);
3162 else
3163 EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
3164 diag::warn_suggest_function_marked_not_override_overriding);
3165 }
3166}
3167
3168/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3169/// function overrides a virtual member function marked 'final', according to
3170/// C++11 [class.virtual]p4.
3171bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3172 const CXXMethodDecl *Old) {
3173 FinalAttr *FA = Old->getAttr<FinalAttr>();
3174 if (!FA)
3175 return false;
3176
3177 Diag(New->getLocation(), diag::err_final_function_overridden)
3178 << New->getDeclName()
3179 << FA->isSpelledAsSealed();
3180 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3181 return true;
3182}
3183
3184static bool InitializationHasSideEffects(const FieldDecl &FD) {
3185 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3186 // FIXME: Destruction of ObjC lifetime types has side-effects.
3187 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3188 return !RD->isCompleteDefinition() ||
3189 !RD->hasTrivialDefaultConstructor() ||
3190 !RD->hasTrivialDestructor();
3191 return false;
3192}
3193
3194static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3195 ParsedAttributesView::const_iterator Itr =
3196 llvm::find_if(list, [](const ParsedAttr &AL) {
3197 return AL.isDeclspecPropertyAttribute();
3198 });
3199 if (Itr != list.end())
3200 return &*Itr;
3201 return nullptr;
3202}
3203
3204// Check if there is a field shadowing.
3205void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3206 DeclarationName FieldName,
3207 const CXXRecordDecl *RD,
3208 bool DeclIsField) {
3209 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3210 return;
3211
3212 // To record a shadowed field in a base
3213 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3214 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3215 CXXBasePath &Path) {
3216 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3217 // Record an ambiguous path directly
3218 if (Bases.find(Base) != Bases.end())
3219 return true;
3220 for (const auto Field : Base->lookup(FieldName)) {
3221 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3222 Field->getAccess() != AS_private) {
3223 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", 3223, __extension__ __PRETTY_FUNCTION__
))
;
3224 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", 3224, __extension__ __PRETTY_FUNCTION__
))
;
3225 Bases[Base] = Field;
3226 return true;
3227 }
3228 }
3229 return false;
3230 };
3231
3232 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3233 /*DetectVirtual=*/true);
3234 if (!RD->lookupInBases(FieldShadowed, Paths))
3235 return;
3236
3237 for (const auto &P : Paths) {
3238 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3239 auto It = Bases.find(Base);
3240 // Skip duplicated bases
3241 if (It == Bases.end())
3242 continue;
3243 auto BaseField = It->second;
3244 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", 3244, __extension__ __PRETTY_FUNCTION__
))
;
3245 if (AS_none !=
3246 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3247 Diag(Loc, diag::warn_shadow_field)
3248 << FieldName << RD << Base << DeclIsField;
3249 Diag(BaseField->getLocation(), diag::note_shadow_field);
3250 Bases.erase(It);
3251 }
3252 }
3253}
3254
3255/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3256/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3257/// bitfield width if there is one, 'InitExpr' specifies the initializer if
3258/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3259/// present (but parsing it has been deferred).
3260NamedDecl *
3261Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3262 MultiTemplateParamsArg TemplateParameterLists,
3263 Expr *BW, const VirtSpecifiers &VS,
3264 InClassInitStyle InitStyle) {
3265 const DeclSpec &DS = D.getDeclSpec();
3266 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3267 DeclarationName Name = NameInfo.getName();
3268 SourceLocation Loc = NameInfo.getLoc();
3269
3270 // For anonymous bitfields, the location should point to the type.
3271 if (Loc.isInvalid())
3272 Loc = D.getBeginLoc();
3273
3274 Expr *BitWidth = static_cast<Expr*>(BW);
3275
3276 assert(isa<CXXRecordDecl>(CurContext))(static_cast <bool> (isa<CXXRecordDecl>(CurContext
)) ? void (0) : __assert_fail ("isa<CXXRecordDecl>(CurContext)"
, "clang/lib/Sema/SemaDeclCXX.cpp", 3276, __extension__ __PRETTY_FUNCTION__
))
;
3277 assert(!DS.isFriendSpecified())(static_cast <bool> (!DS.isFriendSpecified()) ? void (0
) : __assert_fail ("!DS.isFriendSpecified()", "clang/lib/Sema/SemaDeclCXX.cpp"
, 3277, __extension__ __PRETTY_FUNCTION__))
;
3278
3279 bool isFunc = D.isDeclarationOfFunction();
3280 const ParsedAttr *MSPropertyAttr =
3281 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3282
3283 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3284 // The Microsoft extension __interface only permits public member functions
3285 // and prohibits constructors, destructors, operators, non-public member
3286 // functions, static methods and data members.
3287 unsigned InvalidDecl;
3288 bool ShowDeclName = true;
3289 if (!isFunc &&
3290 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3291 InvalidDecl = 0;
3292 else if (!isFunc)
3293 InvalidDecl = 1;
3294 else if (AS != AS_public)
3295 InvalidDecl = 2;
3296 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3297 InvalidDecl = 3;
3298 else switch (Name.getNameKind()) {
3299 case DeclarationName::CXXConstructorName:
3300 InvalidDecl = 4;
3301 ShowDeclName = false;
3302 break;
3303
3304 case DeclarationName::CXXDestructorName:
3305 InvalidDecl = 5;
3306 ShowDeclName = false;
3307 break;
3308
3309 case DeclarationName::CXXOperatorName:
3310 case DeclarationName::CXXConversionFunctionName:
3311 InvalidDecl = 6;
3312 break;
3313
3314 default:
3315 InvalidDecl = 0;
3316 break;
3317 }
3318
3319 if (InvalidDecl) {
3320 if (ShowDeclName)
3321 Diag(Loc, diag::err_invalid_member_in_interface)
3322 << (InvalidDecl-1) << Name;
3323 else
3324 Diag(Loc, diag::err_invalid_member_in_interface)
3325 << (InvalidDecl-1) << "";
3326 return nullptr;
3327 }
3328 }
3329
3330 // C++ 9.2p6: A member shall not be declared to have automatic storage
3331 // duration (auto, register) or with the extern storage-class-specifier.
3332 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3333 // data members and cannot be applied to names declared const or static,
3334 // and cannot be applied to reference members.
3335 switch (DS.getStorageClassSpec()) {
3336 case DeclSpec::SCS_unspecified:
3337 case DeclSpec::SCS_typedef:
3338 case DeclSpec::SCS_static:
3339 break;
3340 case DeclSpec::SCS_mutable:
3341 if (isFunc) {
3342 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3343
3344 // FIXME: It would be nicer if the keyword was ignored only for this
3345 // declarator. Otherwise we could get follow-up errors.
3346 D.getMutableDeclSpec().ClearStorageClassSpecs();
3347 }
3348 break;
3349 default:
3350 Diag(DS.getStorageClassSpecLoc(),
3351 diag::err_storageclass_invalid_for_member);
3352 D.getMutableDeclSpec().ClearStorageClassSpecs();
3353 break;
3354 }
3355
3356 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3357 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3358 !isFunc);
3359
3360 if (DS.hasConstexprSpecifier() && isInstField) {
3361 SemaDiagnosticBuilder B =
3362 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3363 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3364 if (InitStyle == ICIS_NoInit) {
3365 B << 0 << 0;
3366 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3367 B << FixItHint::CreateRemoval(ConstexprLoc);
3368 else {
3369 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3370 D.getMutableDeclSpec().ClearConstexprSpec();
3371 const char *PrevSpec;
3372 unsigned DiagID;
3373 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3374 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3375 (void)Failed;
3376 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", 3376, __extension__ __PRETTY_FUNCTION__
))
;
3377 }
3378 } else {
3379 B << 1;
3380 const char *PrevSpec;
3381 unsigned DiagID;
3382 if (D.getMutableDeclSpec().SetStorageClassSpec(
3383 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3384 Context.getPrintingPolicy())) {
3385 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", 3386, __extension__ __PRETTY_FUNCTION__
))
3386 "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", 3386, __extension__ __PRETTY_FUNCTION__
))
;
3387 B << 1;
3388 } else {
3389 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3390 isInstField = false;
3391 }
3392 }
3393 }
3394
3395 NamedDecl *Member;
3396 if (isInstField) {
3397 CXXScopeSpec &SS = D.getCXXScopeSpec();
3398
3399 // Data members must have identifiers for names.
3400 if (!Name.isIdentifier()) {
3401 Diag(Loc, diag::err_bad_variable_name)
3402 << Name;
3403 return nullptr;
3404 }
3405
3406 IdentifierInfo *II = Name.getAsIdentifierInfo();
3407
3408 // Member field could not be with "template" keyword.
3409 // So TemplateParameterLists should be empty in this case.
3410 if (TemplateParameterLists.size()) {
3411 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3412 if (TemplateParams->size()) {
3413 // There is no such thing as a member field template.
3414 Diag(D.getIdentifierLoc(), diag::err_template_member)
3415 << II
3416 << SourceRange(TemplateParams->getTemplateLoc(),
3417 TemplateParams->getRAngleLoc());
3418 } else {
3419 // There is an extraneous 'template<>' for this member.
3420 Diag(TemplateParams->getTemplateLoc(),
3421 diag::err_template_member_noparams)
3422 << II
3423 << SourceRange(TemplateParams->getTemplateLoc(),
3424 TemplateParams->getRAngleLoc());
3425 }
3426 return nullptr;
3427 }
3428
3429 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
3430 Diag(D.getIdentifierLoc(), diag::err_member_with_template_arguments)
3431 << II
3432 << SourceRange(D.getName().TemplateId->LAngleLoc,
3433 D.getName().TemplateId->RAngleLoc)
3434 << D.getName().TemplateId->LAngleLoc;
3435 D.SetIdentifier(II, Loc);
3436 }
3437
3438 if (SS.isSet() && !SS.isInvalid()) {
3439 // The user provided a superfluous scope specifier inside a class
3440 // definition:
3441 //
3442 // class X {
3443 // int X::member;
3444 // };
3445 if (DeclContext *DC = computeDeclContext(SS, false))
3446 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3447 D.getName().getKind() ==
3448 UnqualifiedIdKind::IK_TemplateId);
3449 else
3450 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3451 << Name << SS.getRange();
3452
3453 SS.clear();
3454 }
3455
3456 if (MSPropertyAttr) {
3457 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3458 BitWidth, InitStyle, AS, *MSPropertyAttr);
3459 if (!Member)
3460 return nullptr;
3461 isInstField = false;
3462 } else {
3463 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3464 BitWidth, InitStyle, AS);
3465 if (!Member)
3466 return nullptr;
3467 }
3468
3469 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3470 } else {
3471 Member = HandleDeclarator(S, D, TemplateParameterLists);
3472 if (!Member)
3473 return nullptr;
3474
3475 // Non-instance-fields can't have a bitfield.
3476 if (BitWidth) {
3477 if (Member->isInvalidDecl()) {
3478 // don't emit another diagnostic.
3479 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3480 // C++ 9.6p3: A bit-field shall not be a static member.
3481 // "static member 'A' cannot be a bit-field"
3482 Diag(Loc, diag::err_static_not_bitfield)
3483 << Name << BitWidth->getSourceRange();
3484 } else if (isa<TypedefDecl>(Member)) {
3485 // "typedef member 'x' cannot be a bit-field"
3486 Diag(Loc, diag::err_typedef_not_bitfield)
3487 << Name << BitWidth->getSourceRange();
3488 } else {
3489 // A function typedef ("typedef int f(); f a;").
3490 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3491 Diag(Loc, diag::err_not_integral_type_bitfield)
3492 << Name << cast<ValueDecl>(Member)->getType()
3493 << BitWidth->getSourceRange();
3494 }
3495
3496 BitWidth = nullptr;
3497 Member->setInvalidDecl();
3498 }
3499
3500 NamedDecl *NonTemplateMember = Member;
3501 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3502 NonTemplateMember = FunTmpl->getTemplatedDecl();
3503 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3504 NonTemplateMember = VarTmpl->getTemplatedDecl();
3505
3506 Member->setAccess(AS);
3507
3508 // If we have declared a member function template or static data member
3509 // template, set the access of the templated declaration as well.
3510 if (NonTemplateMember != Member)
3511 NonTemplateMember->setAccess(AS);
3512
3513 // C++ [temp.deduct.guide]p3:
3514 // A deduction guide [...] for a member class template [shall be
3515 // declared] with the same access [as the template].
3516 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3517 auto *TD = DG->getDeducedTemplate();
3518 // Access specifiers are only meaningful if both the template and the
3519 // deduction guide are from the same scope.
3520 if (AS != TD->getAccess() &&
3521 TD->getDeclContext()->getRedeclContext()->Equals(
3522 DG->getDeclContext()->getRedeclContext())) {
3523 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3524 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3525 << TD->getAccess();
3526 const AccessSpecDecl *LastAccessSpec = nullptr;
3527 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3528 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3529 LastAccessSpec = AccessSpec;
3530 }
3531 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", 3531, __extension__ __PRETTY_FUNCTION__
))
;
3532 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3533 << AS;
3534 }
3535 }
3536 }
3537
3538 if (VS.isOverrideSpecified())
3539 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3540 AttributeCommonInfo::AS_Keyword));
3541 if (VS.isFinalSpecified())
3542 Member->addAttr(FinalAttr::Create(
3543 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3544 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3545
3546 if (VS.getLastLocation().isValid()) {
3547 // Update the end location of a method that has a virt-specifiers.
3548 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3549 MD->setRangeEnd(VS.getLastLocation());
3550 }
3551
3552 CheckOverrideControl(Member);
3553
3554 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", 3554, __extension__ __PRETTY_FUNCTION__
))
;
3555
3556 if (isInstField) {
3557 FieldDecl *FD = cast<FieldDecl>(Member);
3558 FieldCollector->Add(FD);
3559
3560 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3561 // Remember all explicit private FieldDecls that have a name, no side
3562 // effects and are not part of a dependent type declaration.
3563 if (!FD->isImplicit() && FD->getDeclName() &&
3564 FD->getAccess() == AS_private &&
3565 !FD->hasAttr<UnusedAttr>() &&
3566 !FD->getParent()->isDependentContext() &&
3567 !InitializationHasSideEffects(*FD))
3568 UnusedPrivateFields.insert(FD);
3569 }
3570 }
3571
3572 return Member;
3573}
3574
3575namespace {
3576 class UninitializedFieldVisitor
3577 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3578 Sema &S;
3579 // List of Decls to generate a warning on. Also remove Decls that become
3580 // initialized.
3581 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3582 // List of base classes of the record. Classes are removed after their
3583 // initializers.
3584 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3585 // Vector of decls to be removed from the Decl set prior to visiting the
3586 // nodes. These Decls may have been initialized in the prior initializer.
3587 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3588 // If non-null, add a note to the warning pointing back to the constructor.
3589 const CXXConstructorDecl *Constructor;
3590 // Variables to hold state when processing an initializer list. When
3591 // InitList is true, special case initialization of FieldDecls matching
3592 // InitListFieldDecl.
3593 bool InitList;
3594 FieldDecl *InitListFieldDecl;
3595 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3596
3597 public:
3598 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
3599 UninitializedFieldVisitor(Sema &S,
3600 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3601 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3602 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3603 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3604
3605 // Returns true if the use of ME is not an uninitialized use.
3606 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3607 bool CheckReferenceOnly) {
3608 llvm::SmallVector<FieldDecl*, 4> Fields;
3609 bool ReferenceField = false;
3610 while (ME) {
3611 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3612 if (!FD)
3613 return false;
3614 Fields.push_back(FD);
3615 if (FD->getType()->isReferenceType())
3616 ReferenceField = true;
3617 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3618 }
3619
3620 // Binding a reference to an uninitialized field is not an
3621 // uninitialized use.
3622 if (CheckReferenceOnly && !ReferenceField)
3623 return true;
3624
3625 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3626 // Discard the first field since it is the field decl that is being
3627 // initialized.
3628 for (const FieldDecl *FD : llvm::drop_begin(llvm::reverse(Fields)))
3629 UsedFieldIndex.push_back(FD->getFieldIndex());
3630
3631 for (auto UsedIter = UsedFieldIndex.begin(),
3632 UsedEnd = UsedFieldIndex.end(),
3633 OrigIter = InitFieldIndex.begin(),
3634 OrigEnd = InitFieldIndex.end();
3635 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3636 if (*UsedIter < *OrigIter)
3637 return true;
3638 if (*UsedIter > *OrigIter)
3639 break;
3640 }
3641
3642 return false;
3643 }
3644
3645 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3646 bool AddressOf) {
3647 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3648 return;
3649
3650 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3651 // or union.
3652 MemberExpr *FieldME = ME;
3653
3654 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3655
3656 Expr *Base = ME;
3657 while (MemberExpr *SubME =
3658 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3659
3660 if (isa<VarDecl>(SubME->getMemberDecl()))
3661 return;
3662
3663 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3664 if (!FD->isAnonymousStructOrUnion())
3665 FieldME = SubME;
3666
3667 if (!FieldME->getType().isPODType(S.Context))
3668 AllPODFields = false;
3669
3670 Base = SubME->getBase();
3671 }
3672
3673 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
3674 Visit(Base);
3675 return;
3676 }
3677
3678 if (AddressOf && AllPODFields)
3679 return;
3680
3681 ValueDecl* FoundVD = FieldME->getMemberDecl();
3682
3683 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3684 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3685 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3686 }
3687
3688 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3689 QualType T = BaseCast->getType();
3690 if (T->isPointerType() &&
3691 BaseClasses.count(T->getPointeeType())) {
3692 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3693 << T->getPointeeType() << FoundVD;
3694 }
3695 }
3696 }
3697
3698 if (!Decls.count(FoundVD))
3699 return;
3700
3701 const bool IsReference = FoundVD->getType()->isReferenceType();
3702
3703 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3704 // Special checking for initializer lists.
3705 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3706 return;
3707 }
3708 } else {
3709 // Prevent double warnings on use of unbounded references.
3710 if (CheckReferenceOnly && !IsReference)
3711 return;
3712 }
3713
3714 unsigned diag = IsReference
3715 ? diag::warn_reference_field_is_uninit
3716 : diag::warn_field_is_uninit;
3717 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3718 if (Constructor)
3719 S.Diag(Constructor->getLocation(),
3720 diag::note_uninit_in_this_constructor)
3721 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3722
3723 }
3724
3725 void HandleValue(Expr *E, bool AddressOf) {
3726 E = E->IgnoreParens();
3727
3728 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3729 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3730 AddressOf /*AddressOf*/);
3731 return;
3732 }
3733
3734 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3735 Visit(CO->getCond());
3736 HandleValue(CO->getTrueExpr(), AddressOf);
3737 HandleValue(CO->getFalseExpr(), AddressOf);
3738 return;
3739 }
3740
3741 if (BinaryConditionalOperator *BCO =
3742 dyn_cast<BinaryConditionalOperator>(E)) {
3743 Visit(BCO->getCond());
3744 HandleValue(BCO->getFalseExpr(), AddressOf);
3745 return;
3746 }
3747
3748 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3749 HandleValue(OVE->getSourceExpr(), AddressOf);
3750 return;
3751 }
3752
3753 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3754 switch (BO->getOpcode()) {
3755 default:
3756 break;
3757 case(BO_PtrMemD):
3758 case(BO_PtrMemI):
3759 HandleValue(BO->getLHS(), AddressOf);
3760 Visit(BO->getRHS());
3761 return;
3762 case(BO_Comma):
3763 Visit(BO->getLHS());
3764 HandleValue(BO->getRHS(), AddressOf);
3765 return;
3766 }
3767 }
3768
3769 Visit(E);
3770 }
3771
3772 void CheckInitListExpr(InitListExpr *ILE) {
3773 InitFieldIndex.push_back(0);
3774 for (auto Child : ILE->children()) {
3775 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3776 CheckInitListExpr(SubList);
3777 } else {
3778 Visit(Child);
3779 }
3780 ++InitFieldIndex.back();
3781 }
3782 InitFieldIndex.pop_back();
3783 }
3784
3785 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3786 FieldDecl *Field, const Type *BaseClass) {
3787 // Remove Decls that may have been initialized in the previous
3788 // initializer.
3789 for (ValueDecl* VD : DeclsToRemove)
3790 Decls.erase(VD);
3791 DeclsToRemove.clear();
3792
3793 Constructor = FieldConstructor;
3794 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3795
3796 if (ILE && Field) {
3797 InitList = true;
3798 InitListFieldDecl = Field;
3799 InitFieldIndex.clear();
3800 CheckInitListExpr(ILE);
3801 } else {
3802 InitList = false;
3803 Visit(E);
3804 }
3805
3806 if (Field)
3807 Decls.erase(Field);
3808 if (BaseClass)
3809 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3810 }
3811
3812 void VisitMemberExpr(MemberExpr *ME) {
3813 // All uses of unbounded reference fields will warn.
3814 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3815 }
3816
3817 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3818 if (E->getCastKind() == CK_LValueToRValue) {
3819 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3820 return;
3821 }
3822
3823 Inherited::VisitImplicitCastExpr(E);
3824 }
3825
3826 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3827 if (E->getConstructor()->isCopyConstructor()) {
3828 Expr *ArgExpr = E->getArg(0);
3829 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3830 if (ILE->getNumInits() == 1)
3831 ArgExpr = ILE->getInit(0);
3832 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3833 if (ICE->getCastKind() == CK_NoOp)
3834 ArgExpr = ICE->getSubExpr();
3835 HandleValue(ArgExpr, false /*AddressOf*/);
3836 return;
3837 }
3838 Inherited::VisitCXXConstructExpr(E);
3839 }
3840
3841 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3842 Expr *Callee = E->getCallee();
3843 if (isa<MemberExpr>(Callee)) {
3844 HandleValue(Callee, false /*AddressOf*/);
3845 for (auto Arg : E->arguments())
3846 Visit(Arg);
3847 return;
3848 }
3849
3850 Inherited::VisitCXXMemberCallExpr(E);
3851 }
3852
3853 void VisitCallExpr(CallExpr *E) {
3854 // Treat std::move as a use.
3855 if (E->isCallToStdMove()) {
3856 HandleValue(E->getArg(0), /*AddressOf=*/false);
3857 return;
3858 }
3859
3860 Inherited::VisitCallExpr(E);
3861 }
3862
3863 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3864 Expr *Callee = E->getCallee();
3865
3866 if (isa<UnresolvedLookupExpr>(Callee))
3867 return Inherited::VisitCXXOperatorCallExpr(E);
3868
3869 Visit(Callee);
3870 for (auto Arg : E->arguments())
3871 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3872 }
3873
3874 void VisitBinaryOperator(BinaryOperator *E) {
3875 // If a field assignment is detected, remove the field from the
3876 // uninitiailized field set.
3877 if (E->getOpcode() == BO_Assign)
3878 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3879 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3880 if (!FD->getType()->isReferenceType())
3881 DeclsToRemove.push_back(FD);
3882
3883 if (E->isCompoundAssignmentOp()) {
3884 HandleValue(E->getLHS(), false /*AddressOf*/);
3885 Visit(E->getRHS());
3886 return;
3887 }
3888
3889 Inherited::VisitBinaryOperator(E);
3890 }
3891
3892 void VisitUnaryOperator(UnaryOperator *E) {
3893 if (E->isIncrementDecrementOp()) {
3894 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3895 return;
3896 }
3897 if (E->getOpcode() == UO_AddrOf) {
3898 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3899 HandleValue(ME->getBase(), true /*AddressOf*/);
3900 return;
3901 }
3902 }
3903
3904 Inherited::VisitUnaryOperator(E);
3905 }
3906 };
3907
3908 // Diagnose value-uses of fields to initialize themselves, e.g.
3909 // foo(foo)
3910 // where foo is not also a parameter to the constructor.
3911 // Also diagnose across field uninitialized use such as
3912 // x(y), y(x)
3913 // TODO: implement -Wuninitialized and fold this into that framework.
3914 static void DiagnoseUninitializedFields(
3915 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3916
3917 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3918 Constructor->getLocation())) {
3919 return;
3920 }
3921
3922 if (Constructor->isInvalidDecl())
3923 return;
3924
3925 const CXXRecordDecl *RD = Constructor->getParent();
3926
3927 if (RD->isDependentContext())
3928 return;
3929
3930 // Holds fields that are uninitialized.
3931 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3932
3933 // At the beginning, all fields are uninitialized.
3934 for (auto *I : RD->decls()) {
3935 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3936 UninitializedFields.insert(FD);
3937 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3938 UninitializedFields.insert(IFD->getAnonField());
3939 }
3940 }
3941
3942 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3943 for (auto I : RD->bases())
3944 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3945
3946 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3947 return;
3948
3949 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3950 UninitializedFields,
3951 UninitializedBaseClasses);
3952
3953 for (const auto *FieldInit : Constructor->inits()) {
3954 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3955 break;
3956
3957 Expr *InitExpr = FieldInit->getInit();
3958 if (!InitExpr)
3959 continue;
3960
3961 if (CXXDefaultInitExpr *Default =
3962 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3963 InitExpr = Default->getExpr();
3964 if (!InitExpr)
3965 continue;
3966 // In class initializers will point to the constructor.
3967 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3968 FieldInit->getAnyMember(),
3969 FieldInit->getBaseClass());
3970 } else {
3971 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3972 FieldInit->getAnyMember(),
3973 FieldInit->getBaseClass());
3974 }
3975 }
3976 }
3977} // namespace
3978
3979/// Enter a new C++ default initializer scope. After calling this, the
3980/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3981/// parsing or instantiating the initializer failed.
3982void Sema::ActOnStartCXXInClassMemberInitializer() {
3983 // Create a synthetic function scope to represent the call to the constructor
3984 // that notionally surrounds a use of this initializer.
3985 PushFunctionScope();
3986}
3987
3988void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
3989 if (!D.isFunctionDeclarator())
3990 return;
3991 auto &FTI = D.getFunctionTypeInfo();
3992 if (!FTI.Params)
3993 return;
3994 for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
3995 FTI.NumParams)) {
3996 auto *ParamDecl = cast<NamedDecl>(Param.Param);
3997 if (ParamDecl->getDeclName())
3998 PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
3999 }
4000}
4001
4002ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
4003 return ActOnRequiresClause(ConstraintExpr);
4004}
4005
4006ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
4007 if (ConstraintExpr.isInvalid())
4008 return ExprError();
4009
4010 ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
4011 if (ConstraintExpr.isInvalid())
4012 return ExprError();
4013
4014 if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
4015 UPPC_RequiresClause))
4016 return ExprError();
4017
4018 return ConstraintExpr;
4019}
4020
4021/// This is invoked after parsing an in-class initializer for a
4022/// non-static C++ class member, and after instantiating an in-class initializer
4023/// in a class template. Such actions are deferred until the class is complete.
4024void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
4025 SourceLocation InitLoc,
4026 Expr *InitExpr) {
4027 // Pop the notional constructor scope we created earlier.
4028 PopFunctionScopeInfo(nullptr, D);
4029
4030 FieldDecl *FD = dyn_cast<FieldDecl>(D);
4031 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", 4032, __extension__ __PRETTY_FUNCTION__
))
4032 "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", 4032, __extension__ __PRETTY_FUNCTION__
))
;
4033
4034 if (!InitExpr) {
4035 D->setInvalidDecl();
4036 if (FD)
4037 FD->removeInClassInitializer();
4038 return;
4039 }
4040
4041 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
4042 FD->setInvalidDecl();
4043 FD->removeInClassInitializer();
4044 return;
4045 }
4046
4047 ExprResult Init = InitExpr;
4048 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
4049 InitializedEntity Entity =
4050 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
4051 InitializationKind Kind =
4052 FD->getInClassInitStyle() == ICIS_ListInit
4053 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
4054 InitExpr->getBeginLoc(),
4055 InitExpr->getEndLoc())
4056 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
4057 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
4058 Init = Seq.Perform(*this, Entity, Kind, InitExpr);
4059 if (Init.isInvalid()) {
4060 FD->setInvalidDecl();
4061 return;
4062 }
4063 }
4064
4065 // C++11 [class.base.init]p7:
4066 // The initialization of each base and member constitutes a
4067 // full-expression.
4068 Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
4069 if (Init.isInvalid()) {
4070 FD->setInvalidDecl();
4071 return;
4072 }
4073
4074 InitExpr = Init.get();
4075
4076 FD->setInClassInitializer(InitExpr);
4077}
4078
4079/// Find the direct and/or virtual base specifiers that
4080/// correspond to the given base type, for use in base initialization
4081/// within a constructor.
4082static bool FindBaseInitializer(Sema &SemaRef,
4083 CXXRecordDecl *ClassDecl,
4084 QualType BaseType,
4085 const CXXBaseSpecifier *&DirectBaseSpec,
4086 const CXXBaseSpecifier *&VirtualBaseSpec) {
4087 // First, check for a direct base class.
4088 DirectBaseSpec = nullptr;
4089 for (const auto &Base : ClassDecl->bases()) {
4090 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
4091 // We found a direct base of this type. That's what we're
4092 // initializing.
4093 DirectBaseSpec = &Base;
4094 break;
4095 }
4096 }
4097
4098 // Check for a virtual base class.
4099 // FIXME: We might be able to short-circuit this if we know in advance that
4100 // there are no virtual bases.
4101 VirtualBaseSpec = nullptr;
4102 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
4103 // We haven't found a base yet; search the class hierarchy for a
4104 // virtual base class.
4105 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
4106 /*DetectVirtual=*/false);
4107 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
4108 SemaRef.Context.getTypeDeclType(ClassDecl),
4109 BaseType, Paths)) {
4110 for (CXXBasePaths::paths_iterator Path = Paths.begin();
4111 Path != Paths.end(); ++Path) {
4112 if (Path->back().Base->isVirtual()) {
4113 VirtualBaseSpec = Path->back().Base;
4114 break;
4115 }
4116 }
4117 }
4118 }
4119
4120 return DirectBaseSpec || VirtualBaseSpec;
4121}
4122
4123/// Handle a C++ member initializer using braced-init-list syntax.
4124MemInitResult
4125Sema::ActOnMemInitializer(Decl *ConstructorD,
4126 Scope *S,
4127 CXXScopeSpec &SS,
4128 IdentifierInfo *MemberOrBase,
4129 ParsedType TemplateTypeTy,
4130 const DeclSpec &DS,
4131 SourceLocation IdLoc,
4132 Expr *InitList,
4133 SourceLocation EllipsisLoc) {
4134 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4135 DS, IdLoc, InitList,
4136 EllipsisLoc);
4137}
4138
4139/// Handle a C++ member initializer using parentheses syntax.
4140MemInitResult
4141Sema::ActOnMemInitializer(Decl *ConstructorD,
4142 Scope *S,
4143 CXXScopeSpec &SS,
4144 IdentifierInfo *MemberOrBase,
4145 ParsedType TemplateTypeTy,
4146 const DeclSpec &DS,
4147 SourceLocation IdLoc,
4148 SourceLocation LParenLoc,
4149 ArrayRef<Expr *> Args,
4150 SourceLocation RParenLoc,
4151 SourceLocation EllipsisLoc) {
4152 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
4153 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4154 DS, IdLoc, List, EllipsisLoc);
4155}
4156
4157namespace {
4158
4159// Callback to only accept typo corrections that can be a valid C++ member
4160// initializer: either a non-static field member or a base class.
4161class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4162public:
4163 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4164 : ClassDecl(ClassDecl) {}
4165
4166 bool ValidateCandidate(const TypoCorrection &candidate) override {
4167 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4168 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4169 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4170 return isa<TypeDecl>(ND);
4171 }
4172 return false;
4173 }
4174
4175 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4176 return std::make_unique<MemInitializerValidatorCCC>(*this);
4177 }
4178
4179private:
4180 CXXRecordDecl *ClassDecl;
4181};
4182
4183}
4184
4185ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4186 CXXScopeSpec &SS,
4187 ParsedType TemplateTypeTy,
4188 IdentifierInfo *MemberOrBase) {
4189 if (SS.getScopeRep() || TemplateTypeTy)
4190 return nullptr;
4191 for (auto *D : ClassDecl->lookup(MemberOrBase))
4192 if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
4193 return cast<ValueDecl>(D);
4194 return nullptr;
4195}
4196
4197/// Handle a C++ member initializer.
4198MemInitResult
4199Sema::BuildMemInitializer(Decl *ConstructorD,
4200 Scope *S,
4201 CXXScopeSpec &SS,
4202 IdentifierInfo *MemberOrBase,
4203 ParsedType TemplateTypeTy,
4204 const DeclSpec &DS,
4205 SourceLocation IdLoc,
4206 Expr *Init,
4207 SourceLocation EllipsisLoc) {
4208 ExprResult Res = CorrectDelayedTyposInExpr(Init, /*InitDecl=*/nullptr,
4209 /*RecoverUncorrectedTypos=*/true);
4210 if (!Res.isUsable())
4211 return true;
4212 Init = Res.get();
4213
4214 if (!ConstructorD)
4215 return true;
4216
4217 AdjustDeclIfTemplate(ConstructorD);
4218
4219 CXXConstructorDecl *Constructor
4220 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4221 if (!Constructor) {
4222 // The user wrote a constructor initializer on a function that is
4223 // not a C++ constructor. Ignore the error for now, because we may
4224 // have more member initializers coming; we'll diagnose it just
4225 // once in ActOnMemInitializers.
4226 return true;
4227 }
4228
4229 CXXRecordDecl *ClassDecl = Constructor->getParent();
4230
4231 // C++ [class.base.init]p2:
4232 // Names in a mem-initializer-id are looked up in the scope of the
4233 // constructor's class and, if not found in that scope, are looked
4234 // up in the scope containing the constructor's definition.
4235 // [Note: if the constructor's class contains a member with the
4236 // same name as a direct or virtual base class of the class, a
4237 // mem-initializer-id naming the member or base class and composed
4238 // of a single identifier refers to the class member. A
4239 // mem-initializer-id for the hidden base class may be specified
4240 // using a qualified name. ]
4241
4242 // Look for a member, first.
4243 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4244 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4245 if (EllipsisLoc.isValid())
4246 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4247 << MemberOrBase
4248 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4249
4250 return BuildMemberInitializer(Member, Init, IdLoc);
4251 }
4252 // It didn't name a member, so see if it names a class.
4253 QualType BaseType;
4254 TypeSourceInfo *TInfo = nullptr;
4255
4256 if (TemplateTypeTy) {
4257 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4258 if (BaseType.isNull())
4259 return true;
4260 } else if (DS.getTypeSpecType() == TST_decltype) {
4261 BaseType = BuildDecltypeType(DS.getRepAsExpr());
4262 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4263 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4264 return true;
4265 } else {
4266 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4267 LookupParsedName(R, S, &SS);
4268
4269 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4270 if (!TyD) {
4271 if (R.isAmbiguous()) return true;
4272
4273 // We don't want access-control diagnostics here.
4274 R.suppressDiagnostics();
4275
4276 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4277 bool NotUnknownSpecialization = false;
4278 DeclContext *DC = computeDeclContext(SS, false);
4279 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4280 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4281
4282 if (!NotUnknownSpecialization) {
4283 // When the scope specifier can refer to a member of an unknown
4284 // specialization, we take it as a type name.
4285 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4286 SS.getWithLocInContext(Context),
4287 *MemberOrBase, IdLoc);
4288 if (BaseType.isNull())
4289 return true;
4290
4291 TInfo = Context.CreateTypeSourceInfo(BaseType);
4292 DependentNameTypeLoc TL =
4293 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4294 if (!TL.isNull()) {
4295 TL.setNameLoc(IdLoc);
4296 TL.setElaboratedKeywordLoc(SourceLocation());
4297 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4298 }
4299
4300 R.clear();
4301 R.setLookupName(MemberOrBase);
4302 }
4303 }
4304
4305 // If no results were found, try to correct typos.
4306 TypoCorrection Corr;
4307 MemInitializerValidatorCCC CCC(ClassDecl);
4308 if (R.empty() && BaseType.isNull() &&
4309 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4310 CCC, CTK_ErrorRecovery, ClassDecl))) {
4311 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4312 // We have found a non-static data member with a similar
4313 // name to what was typed; complain and initialize that
4314 // member.
4315 diagnoseTypo(Corr,
4316 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4317 << MemberOrBase << true);
4318 return BuildMemberInitializer(Member, Init, IdLoc);
4319 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4320 const CXXBaseSpecifier *DirectBaseSpec;
4321 const CXXBaseSpecifier *VirtualBaseSpec;
4322 if (FindBaseInitializer(*this, ClassDecl,
4323 Context.getTypeDeclType(Type),
4324 DirectBaseSpec, VirtualBaseSpec)) {
4325 // We have found a direct or virtual base class with a
4326 // similar name to what was typed; complain and initialize
4327 // that base class.
4328 diagnoseTypo(Corr,
4329 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4330 << MemberOrBase << false,
4331 PDiag() /*Suppress note, we provide our own.*/);
4332
4333 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4334 : VirtualBaseSpec;
4335 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4336 << BaseSpec->getType() << BaseSpec->getSourceRange();
4337
4338 TyD = Type;
4339 }
4340 }
4341 }
4342
4343 if (!TyD && BaseType.isNull()) {
4344 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4345 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4346 return true;
4347 }
4348 }
4349
4350 if (BaseType.isNull()) {
4351 BaseType = Context.getTypeDeclType(TyD);
4352 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4353 if (SS.isSet()) {
4354 BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
4355 BaseType);
4356 TInfo = Context.CreateTypeSourceInfo(BaseType);
4357 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4358 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4359 TL.setElaboratedKeywordLoc(SourceLocation());
4360 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4361 }
4362 }
4363 }
4364
4365 if (!TInfo)
4366 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4367
4368 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4369}
4370
4371MemInitResult
4372Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4373 SourceLocation IdLoc) {
4374 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4375 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4376 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", 4377, __extension__ __PRETTY_FUNCTION__
))
4377 "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", 4377, __extension__ __PRETTY_FUNCTION__
))
;
4378
4379 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4380 return true;
4381
4382 if (Member->isInvalidDecl())
4383 return true;
4384
4385 MultiExprArg Args;
4386 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4387 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4388 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4389 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4390 } else {
4391 // Template instantiation doesn't reconstruct ParenListExprs for us.
4392 Args = Init;
4393 }
4394
4395 SourceRange InitRange = Init->getSourceRange();
4396
4397 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4398 // Can't check initialization for a member of dependent type or when
4399 // any of the arguments are type-dependent expressions.
4400 DiscardCleanupsInEvaluationContext();
4401 } else {
4402 bool InitList = false;
4403 if (isa<InitListExpr>(Init)) {
4404 InitList = true;
4405 Args = Init;
4406 }
4407
4408 // Initialize the member.
4409 InitializedEntity MemberEntity =
4410 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4411 : InitializedEntity::InitializeMember(IndirectMember,
4412 nullptr);
4413 InitializationKind Kind =
4414 InitList ? InitializationKind::CreateDirectList(
4415 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4416 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4417 InitRange.getEnd());
4418
4419 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4420 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4421 nullptr);
4422 if (!MemberInit.isInvalid()) {
4423 // C++11 [class.base.init]p7:
4424 // The initialization of each base and member constitutes a
4425 // full-expression.
4426 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4427 /*DiscardedValue*/ false);
4428 }
4429
4430 if (MemberInit.isInvalid()) {
4431 // Args were sensible expressions but we couldn't initialize the member
4432 // from them. Preserve them in a RecoveryExpr instead.
4433 Init = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
4434 Member->getType())
4435 .get();
4436 if (!Init)
4437 return true;
4438 } else {
4439 Init = MemberInit.get();
4440 }
4441 }
4442
4443 if (DirectMember) {
4444 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4445 InitRange.getBegin(), Init,
4446 InitRange.getEnd());
4447 } else {
4448 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4449 InitRange.getBegin(), Init,
4450 InitRange.getEnd());
4451 }
4452}
4453
4454MemInitResult
4455Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4456 CXXRecordDecl *ClassDecl) {
4457 SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4458 if (!LangOpts.CPlusPlus11)
4459 return Diag(NameLoc, diag::err_delegating_ctor)
4460 << TInfo->getTypeLoc().getLocalSourceRange();
4461 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4462
4463 bool InitList = true;
4464 MultiExprArg Args = Init;
4465 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4466 InitList = false;
4467 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4468 }
4469
4470 SourceRange InitRange = Init->getSourceRange();
4471 // Initialize the object.
4472 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4473 QualType(ClassDecl->getTypeForDecl(), 0));
4474 InitializationKind Kind =
4475 InitList ? InitializationKind::CreateDirectList(
4476 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4477 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4478 InitRange.getEnd());
4479 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4480 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4481 Args, nullptr);
4482 if (!DelegationInit.isInvalid()) {
4483 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", 4485, __extension__ __PRETTY_FUNCTION__
))
4484 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", 4485, __extension__ __PRETTY_FUNCTION__
))
4485 "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", 4485, __extension__ __PRETTY_FUNCTION__
))
;
4486
4487 // C++11 [class.base.init]p7:
4488 // The initialization of each base and member constitutes a
4489 // full-expression.
4490 DelegationInit = ActOnFinishFullExpr(
4491 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4492 }
4493
4494 if (DelegationInit.isInvalid()) {
4495 DelegationInit =
4496 CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(), Args,
4497 QualType(ClassDecl->getTypeForDecl(), 0));
4498 if (DelegationInit.isInvalid())
4499 return true;
4500 } else {
4501 // If we are in a dependent context, template instantiation will
4502 // perform this type-checking again. Just save the arguments that we
4503 // received in a ParenListExpr.
4504 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4505 // of the information that we have about the base
4506 // initializer. However, deconstructing the ASTs is a dicey process,
4507 // and this approach is far more likely to get the corner cases right.
4508 if (CurContext->isDependentContext())
4509 DelegationInit = Init;
4510 }
4511
4512 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4513 DelegationInit.getAs<Expr>(),
4514 InitRange.getEnd());
4515}
4516
4517MemInitResult
4518Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4519 Expr *Init, CXXRecordDecl *ClassDecl,
4520 SourceLocation EllipsisLoc) {
4521 SourceLocation BaseLoc
4522 = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4523
4524 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4525 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4526 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4527
4528 // C++ [class.base.init]p2:
4529 // [...] Unless the mem-initializer-id names a nonstatic data
4530 // member of the constructor's class or a direct or virtual base
4531 // of that class, the mem-initializer is ill-formed. A
4532 // mem-initializer-list can initialize a base class using any
4533 // name that denotes that base class type.
4534
4535 // We can store the initializers in "as-written" form and delay analysis until
4536 // instantiation if the constructor is dependent. But not for dependent
4537 // (broken) code in a non-template! SetCtorInitializers does not expect this.
4538 bool Dependent = CurContext->isDependentContext() &&
4539 (BaseType->isDependentType() || Init->isTypeDependent());
4540
4541 SourceRange InitRange = Init->getSourceRange();
4542 if (EllipsisLoc.isValid()) {
4543 // This is a pack expansion.
4544 if (!BaseType->containsUnexpandedParameterPack()) {
4545 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4546 << SourceRange(BaseLoc, InitRange.getEnd());
4547
4548 EllipsisLoc = SourceLocation();
4549 }
4550 } else {
4551 // Check for any unexpanded parameter packs.
4552 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4553 return true;
4554
4555 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4556 return true;
4557 }
4558
4559 // Check for direct and virtual base classes.
4560 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4561 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4562 if (!Dependent) {
4563 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4564 BaseType))
4565 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4566
4567 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4568 VirtualBaseSpec);
4569
4570 // C++ [base.class.init]p2:
4571 // Unless the mem-initializer-id names a nonstatic data member of the
4572 // constructor's class or a direct or virtual base of that class, the
4573 // mem-initializer is ill-formed.
4574 if (!DirectBaseSpec && !VirtualBaseSpec) {
4575 // If the class has any dependent bases, then it's possible that
4576 // one of those types will resolve to the same type as
4577 // BaseType. Therefore, just treat this as a dependent base
4578 // class initialization. FIXME: Should we try to check the
4579 // initialization anyway? It seems odd.
4580 if (ClassDecl->hasAnyDependentBases())
4581 Dependent = true;
4582 else
4583 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4584 << BaseType << Context.getTypeDeclType(ClassDecl)
4585 << BaseTInfo->getTypeLoc().getLocalSourceRange();
4586 }
4587 }
4588
4589 if (Dependent) {
4590 DiscardCleanupsInEvaluationContext();
4591
4592 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4593 /*IsVirtual=*/false,
4594 InitRange.getBegin(), Init,
4595 InitRange.getEnd(), EllipsisLoc);
4596 }
4597
4598 // C++ [base.class.init]p2:
4599 // If a mem-initializer-id is ambiguous because it designates both
4600 // a direct non-virtual base class and an inherited virtual base
4601 // class, the mem-initializer is ill-formed.
4602 if (DirectBaseSpec && VirtualBaseSpec)
4603 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4604 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4605
4606 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4607 if (!BaseSpec)
4608 BaseSpec = VirtualBaseSpec;
4609
4610 // Initialize the base.
4611 bool InitList = true;
4612 MultiExprArg Args = Init;
4613 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4614 InitList = false;
4615 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4616 }
4617
4618 InitializedEntity BaseEntity =
4619 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4620 InitializationKind Kind =
4621 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4622 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4623 InitRange.getEnd());
4624 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4625 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4626 if (!BaseInit.isInvalid()) {
4627 // C++11 [class.base.init]p7:
4628 // The initialization of each base and member constitutes a
4629 // full-expression.
4630 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4631 /*DiscardedValue*/ false);
4632 }
4633
4634 if (BaseInit.isInvalid()) {
4635 BaseInit = CreateRecoveryExpr(InitRange.getBegin(), InitRange.getEnd(),
4636 Args, BaseType);
4637 if (BaseInit.isInvalid())
4638 return true;
4639 } else {
4640 // If we are in a dependent context, template instantiation will
4641 // perform this type-checking again. Just save the arguments that we
4642 // received in a ParenListExpr.
4643 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4644 // of the information that we have about the base
4645 // initializer. However, deconstructing the ASTs is a dicey process,
4646 // and this approach is far more likely to get the corner cases right.
4647 if (CurContext->isDependentContext())
4648 BaseInit = Init;
4649 }
4650
4651 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4652 BaseSpec->isVirtual(),
4653 InitRange.getBegin(),
4654 BaseInit.getAs<Expr>(),
4655 InitRange.getEnd(), EllipsisLoc);
4656}
4657
4658// Create a static_cast\<T&&>(expr).
4659static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4660 if (T.isNull()) T = E->getType();
4661 QualType TargetType = SemaRef.BuildReferenceType(
4662 T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4663 SourceLocation ExprLoc = E->getBeginLoc();
4664 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4665 TargetType, ExprLoc);
4666
4667 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4668 SourceRange(ExprLoc, ExprLoc),
4669 E->getSourceRange()).get();
4670}
4671
4672/// ImplicitInitializerKind - How an implicit base or member initializer should
4673/// initialize its base or member.
4674enum ImplicitInitializerKind {
4675 IIK_Default,
4676 IIK_Copy,
4677 IIK_Move,
4678 IIK_Inherit
4679};
4680
4681static bool
4682BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4683 ImplicitInitializerKind ImplicitInitKind,
4684 CXXBaseSpecifier *BaseSpec,
4685 bool IsInheritedVirtualBase,
4686 CXXCtorInitializer *&CXXBaseInit) {
4687 InitializedEntity InitEntity
4688 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4689 IsInheritedVirtualBase);
4690
4691 ExprResult BaseInit;
4692
4693 switch (ImplicitInitKind) {
4694 case IIK_Inherit:
4695 case IIK_Default: {
4696 InitializationKind InitKind
4697 = InitializationKind::CreateDefault(Constructor->getLocation());
4698 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4699 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4700 break;
4701 }
4702
4703 case IIK_Move:
4704 case IIK_Copy: {
4705 bool Moving = ImplicitInitKind == IIK_Move;
4706 ParmVarDecl *Param = Constructor->getParamDecl(0);
4707 QualType ParamType = Param->getType().getNonReferenceType();
4708
4709 Expr *CopyCtorArg =
4710 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4711 SourceLocation(), Param, false,
4712 Constructor->getLocation(), ParamType,
4713 VK_LValue, nullptr);
4714
4715 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4716
4717 // Cast to the base class to avoid ambiguities.
4718 QualType ArgTy =
4719 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4720 ParamType.getQualifiers());
4721
4722 if (Moving) {
4723 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4724 }
4725
4726 CXXCastPath BasePath;
4727 BasePath.push_back(BaseSpec);
4728 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4729 CK_UncheckedDerivedToBase,
4730 Moving ? VK_XValue : VK_LValue,
4731 &BasePath).get();
4732
4733 InitializationKind InitKind
4734 = InitializationKind::CreateDirect(Constructor->getLocation(),
4735 SourceLocation(), SourceLocation());
4736 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4737 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4738 break;
4739 }
4740 }
4741
4742 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4743 if (BaseInit.isInvalid())
4744 return true;
4745
4746 CXXBaseInit =
4747 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4748 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4749 SourceLocation()),
4750 BaseSpec->isVirtual(),
4751 SourceLocation(),
4752 BaseInit.getAs<Expr>(),
4753 SourceLocation(),
4754 SourceLocation());
4755
4756 return false;
4757}
4758
4759static bool RefersToRValueRef(Expr *MemRef) {
4760 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4761 return Referenced->getType()->isRValueReferenceType();
4762}
4763
4764static bool
4765BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4766 ImplicitInitializerKind ImplicitInitKind,
4767 FieldDecl *Field, IndirectFieldDecl *Indirect,
4768 CXXCtorInitializer *&CXXMemberInit) {
4769 if (Field->isInvalidDecl())
4770 return true;
4771
4772 SourceLocation Loc = Constructor->getLocation();
4773
4774 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4775 bool Moving = ImplicitInitKind == IIK_Move;
4776 ParmVarDecl *Param = Constructor->getParamDecl(0);
4777 QualType ParamType = Param->getType().getNonReferenceType();
4778
4779 // Suppress copying zero-width bitfields.
4780 if (Field->isZeroLengthBitField(SemaRef.Context))
4781 return false;
4782
4783 Expr *MemberExprBase =
4784 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4785 SourceLocation(), Param, false,
4786 Loc, ParamType, VK_LValue, nullptr);
4787
4788 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4789
4790 if (Moving) {
4791 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4792 }
4793
4794 // Build a reference to this field within the parameter.
4795 CXXScopeSpec SS;
4796 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4797 Sema::LookupMemberName);
4798 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4799 : cast<ValueDecl>(Field), AS_public);
4800 MemberLookup.resolveKind();
4801 ExprResult CtorArg
4802 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4803 ParamType, Loc,
4804 /*IsArrow=*/false,
4805 SS,
4806 /*TemplateKWLoc=*/SourceLocation(),
4807 /*FirstQualifierInScope=*/nullptr,
4808 MemberLookup,
4809 /*TemplateArgs=*/nullptr,
4810 /*S*/nullptr);
4811 if (CtorArg.isInvalid())
4812 return true;
4813
4814 // C++11 [class.copy]p15:
4815 // - if a member m has rvalue reference type T&&, it is direct-initialized
4816 // with static_cast<T&&>(x.m);
4817 if (RefersToRValueRef(CtorArg.get())) {
4818 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4819 }
4820
4821 InitializedEntity Entity =
4822 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4823 /*Implicit*/ true)
4824 : InitializedEntity::InitializeMember(Field, nullptr,
4825 /*Implicit*/ true);
4826
4827 // Direct-initialize to use the copy constructor.
4828 InitializationKind InitKind =
4829 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4830
4831 Expr *CtorArgE = CtorArg.getAs<Expr>();
4832 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4833 ExprResult MemberInit =
4834 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4835 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4836 if (MemberInit.isInvalid())
4837 return true;
4838
4839 if (Indirect)
4840 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4841 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4842 else
4843 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4844 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4845 return false;
4846 }
4847
4848 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", 4849, __extension__ __PRETTY_FUNCTION__
))
4849 "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", 4849, __extension__ __PRETTY_FUNCTION__
))
;
4850
4851 QualType FieldBaseElementType =
4852 SemaRef.Context.getBaseElementType(Field->getType());
4853
4854 if (FieldBaseElementType->isRecordType()) {
4855 InitializedEntity InitEntity =
4856 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4857 /*Implicit*/ true)
4858 : InitializedEntity::InitializeMember(Field, nullptr,
4859 /*Implicit*/ true);
4860 InitializationKind InitKind =
4861 InitializationKind::CreateDefault(Loc);
4862
4863 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4864 ExprResult MemberInit =
4865 InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4866
4867 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4868 if (MemberInit.isInvalid())
4869 return true;
4870
4871 if (Indirect)
4872 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4873 Indirect, Loc,
4874 Loc,
4875 MemberInit.get(),
4876 Loc);
4877 else
4878 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4879 Field, Loc, Loc,
4880 MemberInit.get(),
4881 Loc);
4882 return false;
4883 }
4884
4885 if (!Field->getParent()->isUnion()) {
4886 if (FieldBaseElementType->isReferenceType()) {
4887 SemaRef.Diag(Constructor->getLocation(),
4888 diag::err_uninitialized_member_in_ctor)
4889 << (int)Constructor->isImplicit()
4890 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4891 << 0 << Field->getDeclName();
4892 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4893 return true;
4894 }
4895
4896 if (FieldBaseElementType.isConstQualified()) {
4897 SemaRef.Diag(Constructor->getLocation(),
4898 diag::err_uninitialized_member_in_ctor)
4899 << (int)Constructor->isImplicit()
4900 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4901 << 1 << Field->getDeclName();
4902 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4903 return true;
4904 }
4905 }
4906
4907 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4908 // ARC and Weak:
4909 // Default-initialize Objective-C pointers to NULL.
4910 CXXMemberInit
4911 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4912 Loc, Loc,
4913 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4914 Loc);
4915 return false;
4916 }
4917
4918 // Nothing to initialize.
4919 CXXMemberInit = nullptr;
4920 return false;
4921}
4922
4923namespace {
4924struct BaseAndFieldInfo {
4925 Sema &S;
4926 CXXConstructorDecl *Ctor;
4927 bool AnyErrorsInInits;
4928 ImplicitInitializerKind IIK;
4929 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4930 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4931 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4932
4933 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4934 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4935 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4936 if (Ctor->getInheritedConstructor())
4937 IIK = IIK_Inherit;
4938 else if (Generated && Ctor->isCopyConstructor())
4939 IIK = IIK_Copy;
4940 else if (Generated && Ctor->isMoveConstructor())
4941 IIK = IIK_Move;
4942 else
4943 IIK = IIK_Default;
4944 }
4945
4946 bool isImplicitCopyOrMove() const {
4947 switch (IIK) {
4948 case IIK_Copy:
4949 case IIK_Move:
4950 return true;
4951
4952 case IIK_Default:
4953 case IIK_Inherit:
4954 return false;
4955 }
4956
4957 llvm_unreachable("Invalid ImplicitInitializerKind!")::llvm::llvm_unreachable_internal("Invalid ImplicitInitializerKind!"
, "clang/lib/Sema/SemaDeclCXX.cpp", 4957)
;
4958 }
4959
4960 bool addFieldInitializer(CXXCtorInitializer *Init) {
4961 AllToInit.push_back(Init);
4962
4963 // Check whether this initializer makes the field "used".
4964 if (Init->getInit()->HasSideEffects(S.Context))
4965 S.UnusedPrivateFields.remove(Init->getAnyMember());
4966
4967 return false;
4968 }
4969
4970 bool isInactiveUnionMember(FieldDecl *Field) {
4971 RecordDecl *Record = Field->getParent();
4972 if (!Record->isUnion())
4973 return false;
4974
4975 if (FieldDecl *Active =
4976 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4977 return Active != Field->getCanonicalDecl();
4978
4979 // In an implicit copy or move constructor, ignore any in-class initializer.
4980 if (isImplicitCopyOrMove())
4981 return true;
4982
4983 // If there's no explicit initialization, the field is active only if it
4984 // has an in-class initializer...
4985 if (Field->hasInClassInitializer())
4986 return false;
4987 // ... or it's an anonymous struct or union whose class has an in-class
4988 // initializer.
4989 if (!Field->isAnonymousStructOrUnion())
4990 return true;
4991 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4992 return !FieldRD->hasInClassInitializer();
4993 }
4994
4995 /// Determine whether the given field is, or is within, a union member
4996 /// that is inactive (because there was an initializer given for a different
4997 /// member of the union, or because the union was not initialized at all).
4998 bool isWithinInactiveUnionMember(FieldDecl *Field,
4999 IndirectFieldDecl *Indirect) {
5000 if (!Indirect)
5001 return isInactiveUnionMember(Field);
5002
5003 for (auto *C : Indirect->chain()) {
5004 FieldDecl *Field = dyn_cast<FieldDecl>(C);
5005 if (Field && isInactiveUnionMember(Field))
5006 return true;
5007 }
5008 return false;
5009 }
5010};
5011}
5012
5013/// Determine whether the given type is an incomplete or zero-lenfgth
5014/// array type.
5015static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
5016 if (T->isIncompleteArrayType())
5017 return true;
5018
5019 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
5020 if (!ArrayT->getSize())
5021 return true;
5022
5023 T = ArrayT->getElementType();
5024 }
5025
5026 return false;
5027}
5028
5029static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
5030 FieldDecl *Field,
5031 IndirectFieldDecl *Indirect = nullptr) {
5032 if (Field->isInvalidDecl())
5033 return false;
5034
5035 // Overwhelmingly common case: we have a direct initializer for this field.
5036 if (CXXCtorInitializer *Init =
5037 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
5038 return Info.addFieldInitializer(Init);
5039
5040 // C++11 [class.base.init]p8:
5041 // if the entity is a non-static data member that has a
5042 // brace-or-equal-initializer and either
5043 // -- the constructor's class is a union and no other variant member of that
5044 // union is designated by a mem-initializer-id or
5045 // -- the constructor's class is not a union, and, if the entity is a member
5046 // of an anonymous union, no other member of that union is designated by
5047 // a mem-initializer-id,
5048 // the entity is initialized as specified in [dcl.init].
5049 //
5050 // We also apply the same rules to handle anonymous structs within anonymous
5051 // unions.
5052 if (Info.isWithinInactiveUnionMember(Field, Indirect))
5053 return false;
5054
5055 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
5056 ExprResult DIE =
5057 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
5058 if (DIE.isInvalid())
5059 return true;
5060
5061 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
5062 SemaRef.checkInitializerLifetime(Entity, DIE.get());
5063
5064 CXXCtorInitializer *Init;
5065 if (Indirect)
5066 Init = new (SemaRef.Context)
5067 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
5068 SourceLocation(), DIE.get(), SourceLocation());
5069 else
5070 Init = new (SemaRef.Context)
5071 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
5072 SourceLocation(), DIE.get(), SourceLocation());
5073 return Info.addFieldInitializer(Init);
5074 }
5075
5076 // Don't initialize incomplete or zero-length arrays.
5077 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
5078 return false;
5079
5080 // Don't try to build an implicit initializer if there were semantic
5081 // errors in any of the initializers (and therefore we might be
5082 // missing some that the user actually wrote).
5083 if (Info.AnyErrorsInInits)
5084 return false;
5085
5086 CXXCtorInitializer *Init = nullptr;
5087 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
5088 Indirect, Init))
5089 return true;
5090
5091 if (!Init)
5092 return false;
5093
5094 return Info.addFieldInitializer(Init);
5095}
5096
5097bool
5098Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
5099 CXXCtorInitializer *Initializer) {
5100 assert(Initializer->isDelegatingInitializer())(static_cast <bool> (Initializer->isDelegatingInitializer
()) ? void (0) : __assert_fail ("Initializer->isDelegatingInitializer()"
, "clang/lib/Sema/SemaDeclCXX.cpp", 5100, __extension__ __PRETTY_FUNCTION__
))
;
5101 Constructor->setNumCtorInitializers(1);
5102 CXXCtorInitializer **initializer =
5103 new (Context) CXXCtorInitializer*[1];
5104 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
5105 Constructor->setCtorInitializers(initializer);
5106
5107 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
5108 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
5109 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
5110 }
5111
5112 DelegatingCtorDecls.push_back(Constructor);
5113
5114 DiagnoseUninitializedFields(*this, Constructor);
5115
5116 return false;
5117}
5118
5119bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
5120 ArrayRef<CXXCtorInitializer *> Initializers) {
5121 if (Constructor->isDependentContext()) {
5122 // Just store the initializers as written, they will be checked during
5123 // instantiation.
5124 if (!Initializers.empty()) {
5125 Constructor->setNumCtorInitializers(Initializers.size());
5126 CXXCtorInitializer **baseOrMemberInitializers =
5127 new (Context) CXXCtorInitializer*[Initializers.size()];
5128 memcpy(baseOrMemberInitializers, Initializers.data(),
5129 Initializers.size() * sizeof(CXXCtorInitializer*));
5130 Constructor->setCtorInitializers(baseOrMemberInitializers);
5131 }
5132
5133 // Let template instantiation know whether we had errors.
5134 if (AnyErrors)
5135 Constructor->setInvalidDecl();
5136
5137 return false;
5138 }
5139
5140 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
5141
5142 // We need to build the initializer AST according to order of construction
5143 // and not what user specified in the Initializers list.
5144 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
5145 if (!ClassDecl)
5146 return true;
5147
5148 bool HadError = false;
5149
5150 for (unsigned i = 0; i < Initializers.size(); i++) {
5151 CXXCtorInitializer *Member = Initializers[i];
5152
5153 if (Member->isBaseInitializer())
5154 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
5155 else {
5156 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
5157
5158 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
5159 for (auto *C : F->chain()) {
5160 FieldDecl *FD = dyn_cast<FieldDecl>(C);
5161 if (FD && FD->getParent()->isUnion())
5162 Info.ActiveUnionMember.insert(std::make_pair(
5163 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5164 }
5165 } else if (FieldDecl *FD = Member->getMember()) {
5166 if (FD->getParent()->isUnion())
5167 Info.ActiveUnionMember.insert(std::make_pair(
5168 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5169 }
5170 }
5171 }
5172
5173 // Keep track of the direct virtual bases.
5174 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
5175 for (auto &I : ClassDecl->bases()) {
5176 if (I.isVirtual())
5177 DirectVBases.insert(&I);
5178 }
5179
5180 // Push virtual bases before others.
5181 for (auto &VBase : ClassDecl->vbases()) {
5182 if (CXXCtorInitializer *Value
5183 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5184 // [class.base.init]p7, per DR257:
5185 // A mem-initializer where the mem-initializer-id names a virtual base
5186 // class is ignored during execution of a constructor of any class that
5187 // is not the most derived class.
5188 if (ClassDecl->isAbstract()) {
5189 // FIXME: Provide a fixit to remove the base specifier. This requires
5190 // tracking the location of the associated comma for a base specifier.
5191 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5192 << VBase.getType() << ClassDecl;
5193 DiagnoseAbstractType(ClassDecl);
5194 }
5195
5196 Info.AllToInit.push_back(Value);
5197 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5198 // [class.base.init]p8, per DR257:
5199 // If a given [...] base class is not named by a mem-initializer-id
5200 // [...] and the entity is not a virtual base class of an abstract
5201 // class, then [...] the entity is default-initialized.
5202 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5203 CXXCtorInitializer *CXXBaseInit;
5204 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5205 &VBase, IsInheritedVirtualBase,
5206 CXXBaseInit)) {
5207 HadError = true;
5208 continue;
5209 }
5210
5211 Info.AllToInit.push_back(CXXBaseInit);
5212 }
5213 }
5214
5215 // Non-virtual bases.
5216 for (auto &Base : ClassDecl->bases()) {
5217 // Virtuals are in the virtual base list and already constructed.
5218 if (Base.isVirtual())
5219 continue;
5220
5221 if (CXXCtorInitializer *Value
5222 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5223 Info.AllToInit.push_back(Value);
5224 } else if (!AnyErrors) {
5225 CXXCtorInitializer *CXXBaseInit;
5226 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5227 &Base, /*IsInheritedVirtualBase=*/false,
5228 CXXBaseInit)) {
5229 HadError = true;
5230 continue;
5231 }
5232
5233 Info.AllToInit.push_back(CXXBaseInit);
5234 }
5235 }
5236
5237 // Fields.
5238 for (auto *Mem : ClassDecl->decls()) {
5239 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5240 // C++ [class.bit]p2:
5241 // A declaration for a bit-field that omits the identifier declares an
5242 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5243 // initialized.
5244 if (F->isUnnamedBitfield())
5245 continue;
5246
5247 // If we're not generating the implicit copy/move constructor, then we'll
5248 // handle anonymous struct/union fields based on their individual
5249 // indirect fields.
5250 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5251 continue;
5252
5253 if (CollectFieldInitializer(*this, Info, F))
5254 HadError = true;
5255 continue;
5256 }
5257
5258 // Beyond this point, we only consider default initialization.
5259 if (Info.isImplicitCopyOrMove())
5260 continue;
5261
5262 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5263 if (F->getType()->isIncompleteArrayType()) {
5264 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", 5265, __extension__ __PRETTY_FUNCTION__
))
5265 "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", 5265, __extension__ __PRETTY_FUNCTION__
))
;
5266 continue;
5267 }
5268
5269 // Initialize each field of an anonymous struct individually.
5270 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5271 HadError = true;
5272
5273 continue;
5274 }
5275 }
5276
5277 unsigned NumInitializers = Info.AllToInit.size();
5278 if (NumInitializers > 0) {
5279 Constructor->setNumCtorInitializers(NumInitializers);
5280 CXXCtorInitializer **baseOrMemberInitializers =
5281 new (Context) CXXCtorInitializer*[NumInitializers];
5282 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5283 NumInitializers * sizeof(CXXCtorInitializer*));
5284 Constructor->setCtorInitializers(baseOrMemberInitializers);
5285
5286 // Constructors implicitly reference the base and member
5287 // destructors.
5288 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5289 Constructor->getParent());
5290 }
5291
5292 return HadError;
5293}
5294
5295static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5296 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5297 const RecordDecl *RD = RT->getDecl();
5298 if (RD->isAnonymousStructOrUnion()) {
5299 for (auto *Field : RD->fields())
5300 PopulateKeysForFields(Field, IdealInits);
5301 return;
5302 }
5303 }
5304 IdealInits.push_back(Field->getCanonicalDecl());
5305}
5306
5307static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5308 return Context.getCanonicalType(BaseType).getTypePtr();
5309}
5310
5311static const void *GetKeyForMember(ASTContext &Context,
5312 CXXCtorInitializer *Member) {
5313 if (!Member->isAnyMemberInitializer())
5314 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5315
5316 return Member->getAnyMember()->getCanonicalDecl();
5317}
5318
5319static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
5320 const CXXCtorInitializer *Previous,
5321 const CXXCtorInitializer *Current) {
5322 if (Previous->isAnyMemberInitializer())
5323 Diag << 0 << Previous->getAnyMember();
5324 else
5325 Diag << 1 << Previous->getTypeSourceInfo()->getType();
5326
5327 if (Current->isAnyMemberInitializer())
5328 Diag << 0 << Current->getAnyMember();
5329 else
5330 Diag << 1 << Current->getTypeSourceInfo()->getType();
5331}
5332
5333static void DiagnoseBaseOrMemInitializerOrder(
5334 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5335 ArrayRef<CXXCtorInitializer *> Inits) {
5336 if (Constructor->getDeclContext()->isDependentContext())
5337 return;
5338
5339 // Don't check initializers order unless the warning is enabled at the
5340 // location of at least one initializer.
5341 bool ShouldCheckOrder = false;
5342 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5343 CXXCtorInitializer *Init = Inits[InitIndex];
5344 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5345 Init->getSourceLocation())) {
5346 ShouldCheckOrder = true;
5347 break;
5348 }
5349 }
5350 if (!ShouldCheckOrder)
5351 return;
5352
5353 // Build the list of bases and members in the order that they'll
5354 // actually be initialized. The explicit initializers should be in
5355 // this same order but may be missing things.
5356 SmallVector<const void*, 32> IdealInitKeys;
5357
5358 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5359
5360 // 1. Virtual bases.
5361 for (const auto &VBase : ClassDecl->vbases())
5362 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5363
5364 // 2. Non-virtual bases.
5365 for (const auto &Base : ClassDecl->bases()) {
5366 if (Base.isVirtual())
5367 continue;
5368 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5369 }
5370
5371 // 3. Direct fields.
5372 for (auto *Field : ClassDecl->fields()) {
5373 if (Field->isUnnamedBitfield())
5374 continue;
5375
5376 PopulateKeysForFields(Field, IdealInitKeys);
5377 }
5378
5379 unsigned NumIdealInits = IdealInitKeys.size();
5380 unsigned IdealIndex = 0;
5381
5382 // Track initializers that are in an incorrect order for either a warning or
5383 // note if multiple ones occur.
5384 SmallVector<unsigned> WarnIndexes;
5385 // Correlates the index of an initializer in the init-list to the index of
5386 // the field/base in the class.
5387 SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;
5388
5389 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5390 const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);
5391
5392 // Scan forward to try to find this initializer in the idealized
5393 // initializers list.
5394 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5395 if (InitKey == IdealInitKeys[IdealIndex])
5396 break;
5397
5398 // If we didn't find this initializer, it must be because we
5399 // scanned past it on a previous iteration. That can only
5400 // happen if we're out of order; emit a warning.
5401 if (IdealIndex == NumIdealInits && InitIndex) {
5402 WarnIndexes.push_back(InitIndex);
5403
5404 // Move back to the initializer's location in the ideal list.
5405 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5406 if (InitKey == IdealInitKeys[IdealIndex])
5407 break;
5408
5409 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", 5410, __extension__ __PRETTY_FUNCTION__
))
5410 "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", 5410, __extension__ __PRETTY_FUNCTION__
))
;
5411 }
5412 CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
5413 }
5414
5415 if (WarnIndexes.empty())
5416 return;
5417
5418 // Sort based on the ideal order, first in the pair.
5419 llvm::sort(CorrelatedInitOrder,
5420 [](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });
5421
5422 // Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
5423 // emit the diagnostic before we can try adding notes.
5424 {
5425 Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
5426 Inits[WarnIndexes.front() - 1]->getSourceLocation(),
5427 WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
5428 : diag::warn_some_initializers_out_of_order);
5429
5430 for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
5431 if (CorrelatedInitOrder[I].second == I)
5432 continue;
5433 // Ideally we would be using InsertFromRange here, but clang doesn't
5434 // appear to handle InsertFromRange correctly when the source range is
5435 // modified by another fix-it.
5436 D << FixItHint::CreateReplacement(
5437 Inits[I]->getSourceRange(),
5438 Lexer::getSourceText(
5439 CharSourceRange::getTokenRange(
5440 Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
5441 SemaRef.getSourceManager(), SemaRef.getLangOpts()));
5442 }
5443
5444 // If there is only 1 item out of order, the warning expects the name and
5445 // type of each being added to it.
5446 if (WarnIndexes.size() == 1) {
5447 AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
5448 Inits[WarnIndexes.front()]);
5449 return;
5450 }
5451 }
5452 // More than 1 item to warn, create notes letting the user know which ones
5453 // are bad.
5454 for (unsigned WarnIndex : WarnIndexes) {
5455 const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
5456 auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
5457 diag::note_initializer_out_of_order);
5458 AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
5459 D << PrevInit->getSourceRange();
5460 }
5461}
5462
5463namespace {
5464bool CheckRedundantInit(Sema &S,
5465 CXXCtorInitializer *Init,
5466 CXXCtorInitializer *&PrevInit) {
5467 if (!PrevInit) {
5468 PrevInit = Init;
5469 return false;
5470 }
5471
5472 if (FieldDecl *Field = Init->getAnyMember())
5473 S.Diag(Init->getSourceLocation(),
5474 diag::err_multiple_mem_initialization)
5475 << Field->getDeclName()
5476 << Init->getSourceRange();
5477 else {
5478 const Type *BaseClass = Init->getBaseClass();
5479 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", 5479, __extension__ __PRETTY_FUNCTION__
))
;
5480 S.Diag(Init->getSourceLocation(),
5481 diag::err_multiple_base_initialization)
5482 << QualType(BaseClass, 0)
5483 << Init->getSourceRange();
5484 }
5485 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5486 << 0 << PrevInit->getSourceRange();
5487
5488 return true;
5489}
5490
5491typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5492typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5493
5494bool CheckRedundantUnionInit(Sema &S,
5495 CXXCtorInitializer *Init,
5496 RedundantUnionMap &Unions) {
5497 FieldDecl *Field = Init->getAnyMember();
5498 RecordDecl *Parent = Field->getParent();
5499 NamedDecl *Child = Field;
5500
5501 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5502 if (Parent->isUnion()) {
5503 UnionEntry &En = Unions[Parent];
5504 if (En.first && En.first != Child) {
5505 S.Diag(Init->getSourceLocation(),
5506 diag::err_multiple_mem_union_initialization)
5507 << Field->getDeclName()
5508 << Init->getSourceRange();
5509 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5510 << 0 << En.second->getSourceRange();
5511 return true;
5512 }
5513 if (!En.first) {
5514 En.first = Child;
5515 En.second = Init;
5516 }
5517 if (!Parent->isAnonymousStructOrUnion())
5518 return false;
5519 }
5520
5521 Child = Parent;
5522 Parent = cast<RecordDecl>(Parent->getDeclContext());
5523 }
5524
5525 return false;
5526}
5527} // namespace
5528
5529/// ActOnMemInitializers - Handle the member initializers for a constructor.
5530void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5531 SourceLocation ColonLoc,
5532 ArrayRef<CXXCtorInitializer*> MemInits,
5533 bool AnyErrors) {
5534 if (!ConstructorDecl)
5535 return;
5536
5537 AdjustDeclIfTemplate(ConstructorDecl);
5538
5539 CXXConstructorDecl *Constructor
5540 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5541
5542 if (!Constructor) {
5543 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5544 return;
5545 }
5546
5547 // Mapping for the duplicate initializers check.
5548 // For member initializers, this is keyed with a FieldDecl*.
5549 // For base initializers, this is keyed with a Type*.
5550 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5551
5552 // Mapping for the inconsistent anonymous-union initializers check.
5553 RedundantUnionMap MemberUnions;
5554
5555 bool HadError = false;
5556 for (unsigned i = 0; i < MemInits.size(); i++) {
5557 CXXCtorInitializer *Init = MemInits[i];
5558
5559 // Set the source order index.
5560 Init->setSourceOrder(i);
5561
5562 if (Init->isAnyMemberInitializer()) {
5563 const void *Key = GetKeyForMember(Context, Init);
5564 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5565 CheckRedundantUnionInit(*this, Init, MemberUnions))
5566 HadError = true;
5567 } else if (Init->isBaseInitializer()) {
5568 const void *Key = GetKeyForMember(Context, Init);
5569 if (CheckRedundantInit(*this, Init, Members[Key]))
5570 HadError = true;
5571 } else {
5572 assert(Init->isDelegatingInitializer())(static_cast <bool> (Init->isDelegatingInitializer()
) ? void (0) : __assert_fail ("Init->isDelegatingInitializer()"
, "clang/lib/Sema/SemaDeclCXX.cpp", 5572, __extension__ __PRETTY_FUNCTION__
))
;
5573 // This must be the only initializer
5574 if (MemInits.size() != 1) {
5575 Diag(Init->getSourceLocation(),
5576 diag::err_delegating_initializer_alone)
5577 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5578 // We will treat this as being the only initializer.
5579 }
5580 SetDelegatingInitializer(Constructor, MemInits[i]);
5581 // Return immediately as the initializer is set.
5582 return;
5583 }
5584 }
5585
5586 if (HadError)
5587 return;
5588
5589 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5590
5591 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5592
5593 DiagnoseUninitializedFields(*this, Constructor);
5594}
5595
5596void
5597Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5598 CXXRecordDecl *ClassDecl) {
5599 // Ignore dependent contexts. Also ignore unions, since their members never
5600 // have destructors implicitly called.
5601 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5602 return;
5603
5604 // FIXME: all the access-control diagnostics are positioned on the
5605 // field/base declaration. That's probably good; that said, the
5606 // user might reasonably want to know why the destructor is being
5607 // emitted, and we currently don't say.
5608
5609 // Non-static data members.
5610 for (auto *Field : ClassDecl->fields()) {
5611 if (Field->isInvalidDecl())
5612 continue;
5613
5614 // Don't destroy incomplete or zero-length arrays.
5615 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5616 continue;
5617
5618 QualType FieldType = Context.getBaseElementType(Field->getType());
5619
5620 const RecordType* RT = FieldType->getAs<RecordType>();
5621 if (!RT)
5622 continue;
5623
5624 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5625 if (FieldClassDecl->isInvalidDecl())
5626 continue;
5627 if (FieldClassDecl->hasIrrelevantDestructor())
5628 continue;
5629 // The destructor for an implicit anonymous union member is never invoked.
5630 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5631 continue;
5632
5633 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5634 assert(Dtor && "No dtor found for FieldClassDecl!")(static_cast <bool> (Dtor && "No dtor found for FieldClassDecl!"
) ? void (0) : __assert_fail ("Dtor && \"No dtor found for FieldClassDecl!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5634, __extension__ __PRETTY_FUNCTION__
))
;
5635 CheckDestructorAccess(Field->getLocation(), Dtor,
5636 PDiag(diag::err_access_dtor_field)
5637 << Field->getDeclName()
5638 << FieldType);
5639
5640 MarkFunctionReferenced(Location, Dtor);
5641 DiagnoseUseOfDecl(Dtor, Location);
5642 }
5643
5644 // We only potentially invoke the destructors of potentially constructed
5645 // subobjects.
5646 bool VisitVirtualBases = !ClassDecl->isAbstract();
5647
5648 // If the destructor exists and has already been marked used in the MS ABI,
5649 // then virtual base destructors have already been checked and marked used.
5650 // Skip checking them again to avoid duplicate diagnostics.
5651 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5652 CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
5653 if (Dtor && Dtor->isUsed())
5654 VisitVirtualBases = false;
5655 }
5656
5657 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5658
5659 // Bases.
5660 for (const auto &Base : ClassDecl->bases()) {
5661 const RecordType *RT = Base.getType()->getAs<RecordType>();
5662 if (!RT)
5663 continue;
5664
5665 // Remember direct virtual bases.
5666 if (Base.isVirtual()) {
5667 if (!VisitVirtualBases)
5668 continue;
5669 DirectVirtualBases.insert(RT);
5670 }
5671
5672 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5673 // If our base class is invalid, we probably can't get its dtor anyway.
5674 if (BaseClassDecl->isInvalidDecl())
5675 continue;
5676 if (BaseClassDecl->hasIrrelevantDestructor())
5677 continue;
5678
5679 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5680 assert(Dtor && "No dtor found for BaseClassDecl!")(static_cast <bool> (Dtor && "No dtor found for BaseClassDecl!"
) ? void (0) : __assert_fail ("Dtor && \"No dtor found for BaseClassDecl!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5680, __extension__ __PRETTY_FUNCTION__
))
;
5681
5682 // FIXME: caret should be on the start of the class name
5683 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5684 PDiag(diag::err_access_dtor_base)
5685 << Base.getType() << Base.getSourceRange(),
5686 Context.getTypeDeclType(ClassDecl));
5687
5688 MarkFunctionReferenced(Location, Dtor);
5689 DiagnoseUseOfDecl(Dtor, Location);
5690 }
5691
5692 if (VisitVirtualBases)
5693 MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
5694 &DirectVirtualBases);
5695}
5696
5697void Sema::MarkVirtualBaseDestructorsReferenced(
5698 SourceLocation Location, CXXRecordDecl *ClassDecl,
5699 llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
5700 // Virtual bases.
5701 for (const auto &VBase : ClassDecl->vbases()) {
5702 // Bases are always records in a well-formed non-dependent class.
5703 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5704
5705 // Ignore already visited direct virtual bases.
5706 if (DirectVirtualBases && DirectVirtualBases->count(RT))
5707 continue;
5708
5709 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5710 // If our base class is invalid, we probably can't get its dtor anyway.
5711 if (BaseClassDecl->isInvalidDecl())
5712 continue;
5713 if (BaseClassDecl->hasIrrelevantDestructor())
5714 continue;
5715
5716 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5717 assert(Dtor && "No dtor found for BaseClassDecl!")(static_cast <bool> (Dtor && "No dtor found for BaseClassDecl!"
) ? void (0) : __assert_fail ("Dtor && \"No dtor found for BaseClassDecl!\""
, "clang/lib/Sema/SemaDeclCXX.cpp", 5717, __extension__ __PRETTY_FUNCTION__
))
;
5718 if (CheckDestructorAccess(
5719 ClassDecl->getLocation(), Dtor,
5720 PDiag(diag::err_access_dtor_vbase)
5721 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5722 Context.getTypeDeclType(ClassDecl)) ==
5723 AR_accessible) {
5724 CheckDerivedToBaseConversion(
5725 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5726 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5727 SourceRange(), DeclarationName(), nullptr);
5728 }
5729
5730 MarkFunctionReferenced(Location, Dtor);
5731 DiagnoseUseOfDecl(Dtor, Location);
5732 }
5733}
5734
5735void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5736 if (!CDtorDecl)
5737 return;
5738
5739 if (CXXConstructorDecl *Constructor
5740 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5741 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5742 DiagnoseUninitializedFields(*this, Constructor);
5743 }
5744}
5745
5746bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5747 if (!getLangOpts().CPlusPlus)
5748 return false;
5749
5750 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5751 if (!RD)
5752 return false;
5753
5754 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5755 // class template specialization here, but doing so breaks a lot of code.
5756
5757 // We can't answer whether something is abstract until it has a
5758 // definition. If it's currently being defined, we'll walk back
5759 // over all the declarations when we have a full definition.
5760 const CXXRecordDecl *Def = RD->getDefinition();
5761 if (!Def || Def->isBeingDefined())
5762 return false;
5763
5764 return RD->isAbstract();
5765}
5766
5767bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5768 TypeDiagnoser &Diagnoser) {
5769 if (!isAbstractType(Loc, T))
5770 return false;
5771
5772 T = Context.getBaseElementType(T);
5773 Diagnoser.diagnose(*this, Loc, T);
5774 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5775 return true;
5776}
5777
5778void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5779 // Check if we've already emitted the list of pure virtual functions
5780 // for this class.
5781 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5782 return;
5783
5784 // If the diagnostic is suppressed, don't emit the notes. We're only
5785 // going to emit them once, so try to attach them to a diagnostic we're
5786 // actually going to show.
5787 if (Diags.isLastDiagnosticIgnored())
5788 return;
5789
5790 CXXFinalOverriderMap FinalOverriders;
5791 RD->getFinalOverriders(FinalOverriders);
5792
5793 // Keep a set of seen pure methods so we won't diagnose the same method
5794 // more than once.
5795 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5796
5797 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5798 MEnd = FinalOverriders.end();
5799 M != MEnd;
5800 ++M) {
5801 for (OverridingMethods::iterator SO = M->second.begin(),
5802 SOEnd = M->second.end();
5803 SO != SOEnd; ++SO) {
5804 // C++ [class.abstract]p4:
5805 // A class is abstract if it contains or inherits at least one
5806 // pure virtual function for which the final overrider is pure
5807 // virtual.
5808
5809 //
5810 if (SO->second.size() != 1)
5811 continue;
5812
5813 if (!SO->second.front().Method->isPure())
5814 continue;
5815
5816 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5817 continue;
5818
5819 Diag(SO->second.front().Method->getLocation(),
5820 diag::note_pure_virtual_function)
5821 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5822 }
5823 }
5824
5825 if (!PureVirtualClassDiagSet)
5826 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5827 PureVirtualClassDiagSet->insert(RD);
5828}
5829
5830namespace {
5831struct AbstractUsageInfo {
5832 Sema &S;
5833 CXXRecordDecl *Record;
5834 CanQualType AbstractType;
5835 bool Invalid;
5836
5837 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5838 : S(S), Record(Record),
5839 AbstractType(S.Context.getCanonicalType(
5840 S.Context.getTypeDeclType(Record))),
5841 Invalid(false) {}
5842
5843 void DiagnoseAbstractType() {
5844 if (Invalid) return;
5845 S.DiagnoseAbstractType(Record);
5846 Invalid = true;
5847 }
5848
5849 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5850};
5851
5852struct CheckAbstractUsage {
5853 AbstractUsageInfo &Info;
5854 const NamedDecl *Ctx;
5855
5856 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5857 : Info(Info), Ctx(Ctx) {}
5858
5859 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5860 switch (TL.getTypeLocClass()) {
5861#define ABSTRACT_TYPELOC(CLASS, PARENT)
5862#define TYPELOC(CLASS, PARENT) \
5863 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5864#include "clang/AST/TypeLocNodes.def"
5865 }
5866 }
5867
5868 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5869 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5870 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5871 if (!TL.getParam(I))
5872 continue;
5873
5874 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5875 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5876 }
5877 }
5878
5879 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5880 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5881 }
5882
5883 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5884 // Visit the type parameters from a permissive context.
5885 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5886 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5887 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5888 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5889 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5890 // TODO: other template argument types?
5891 }
5892 }
5893
5894 // Visit pointee types from a permissive context.
5895#define CheckPolymorphic(Type)void Check(Type TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getNextTypeLoc
(), Sema::AbstractNone); }
\
5896 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5897 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5898 }
5899 CheckPolymorphic(PointerTypeLoc)void Check(PointerTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5900 CheckPolymorphic(ReferenceTypeLoc)void Check(ReferenceTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5901 CheckPolymorphic(MemberPointerTypeLoc)void Check(MemberPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5902 CheckPolymorphic(BlockPointerTypeLoc)void Check(BlockPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); }
5903 CheckPolymorphic(AtomicTypeLoc)void Check(AtomicTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); }
5904
5905 /// Handle all the types we haven't given a more specific
5906 /// implementation for above.
5907 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5908 // Every other kind of type that we haven't called out already
5909 // that has an inner type is either (1) sugar or (2) contains that
5910 // inner type in some way as a subobject.
5911 if (TypeLoc Next = TL.getNextTypeLoc())
5912 return Visit(Next, Sel);
5913
5914 // If there's no inner type and we're in a permissive context,
5915 // don't diagnose.
5916 if (Sel == Sema::AbstractNone) return;
5917
5918 // Check whether the type matches the abstract type.
5919 QualType T = TL.getType();
5920 if (T->isArrayType()) {
5921 Sel = Sema::AbstractArrayType;
5922 T = Info.S.Context.getBaseElementType(T);
5923 }
5924 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5925 if (CT != Info.AbstractType) return;
5926
5927 // It matched; do some magic.
5928 // FIXME: These should be at most warnings. See P0929R2, CWG1640, CWG1646.
5929 if (Sel == Sema::AbstractArrayType) {
5930 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5931 << T << TL.getSourceRange();
5932 } else {
5933 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5934 << Sel << T << TL.getSourceRange();
5935 }
5936 Info.DiagnoseAbstractType();
5937 }
5938};
5939
5940void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5941 Sema::AbstractDiagSelID Sel) {
5942 CheckAbstractUsage(*this, D).Visit(TL, Sel);
5943}
5944
5945}
5946
5947/// Check for invalid uses of an abstract type in a function declaration.
5948static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5949 FunctionDecl *FD) {
5950 // No need to do the check on definitions, which require that
5951 // the return/param types be complete.
5952 if (FD->doesThisDeclarationHaveABody())
5953 return;
5954
5955 // For safety's sake, just ignore it if we don't have type source
5956 // information. This should never happen for non-implicit methods,
5957 // but...
5958 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5959 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractNone);
5960}
5961
5962/// Check for invalid uses of an abstract type in a variable0 declaration.
5963static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5964 VarDecl *VD) {
5965 // No need to do the check on definitions, which require that
5966 // the type is complete.
5967 if (VD->isThisDeclarationADefinition())
5968 return;
5969
5970 Info.CheckType(VD, VD->getTypeSourceInfo()->getTypeLoc(),
5971 Sema::AbstractVariableType);
5972}
5973
5974/// Check for invalid uses of an abstract type within a class definition.
5975static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5976 CXXRecordDecl *RD) {
5977 for (auto *D : RD->decls()) {
5978 if (D->isImplicit()) continue;
5979
5980 // Step through friends to the befriended declaration.
5981 if (auto *FD = dyn_cast<FriendDecl>(D)) {
5982 D = FD->getFriendDecl();
5983 if (!D) continue;
5984 }
5985
5986 // Functions and function templates.
5987 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
5988 CheckAbstractClassUsage(Info, FD);
5989 } else if (auto *FTD = dyn_cast<FunctionTemplateDecl>(D)) {
5990 CheckAbstractClassUsage(Info, FTD->getTemplatedDecl());
5991
5992 // Fields and static variables.
5993 } else if (auto *FD = dyn_cast<FieldDecl>(D)) {
5994 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5995 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5996 } else if (auto *VD = dyn_cast<VarDecl>(D)) {
5997 CheckAbstractClassUsage(Info, VD);
5998 } else if (auto *VTD = dyn_cast<VarTemplateDecl>(D)) {
5999 CheckAbstractClassUsage(Info, VTD->getTemplatedDecl());
6000
6001 // Nested classes and class templates.
6002 } else if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
6003 CheckAbstractClassUsage(Info, RD);
6004 } else if (auto *CTD = dyn_cast<ClassTemplateDecl>(D)) {
6005 CheckAbstractClassUsage(Info, CTD->getTemplatedDecl());
6006 }
6007 }
6008}
6009
6010static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
6011 Attr *ClassAttr = getDLLAttr(Class);
6012 if (!ClassAttr)
6013 return;
6014
6015 assert(ClassAttr->getKind() == attr::DLLExport)(static_cast <bool> (ClassAttr->getKind() == attr::DLLExport
) ? void (0) : __assert_fail ("ClassAttr->getKind() == attr::DLLExport"
, "clang/lib/Sema/SemaDeclCXX.cpp", 6015, __extension__ __PRETTY_FUNCTION__
))
;
6016
6017 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
6018
6019 if (TSK == TSK_ExplicitInstantiationDeclaration)
6020 // Don't go any further if this is just an explicit instantiation
6021 // declaration.
6022 return;
6023
6024 // Add a context note to explain how we got to any diagnostics produced below.
6025 struct MarkingClassDllexported {
6026 Sema &S;
6027 MarkingClassDllexported(Sema &S, CXXRecordDecl *Class,
6028 SourceLocation AttrLoc)
6029 : S(S) {
6030 Sema::CodeSynthesisContext Ctx;
6031 Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported;
6032 Ctx.PointOfInstantiation = AttrLoc;
6033 Ctx.Entity = Class;
6034 S.pushCodeSynthesisContext(Ctx);
6035 }
6036 ~MarkingClassDllexported() {
6037 S.popCodeSynthesisContext();
6038 }
6039 } MarkingDllexportedContext(S, Class, ClassAttr->getLocation());
6040
6041 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
6042 S.MarkVTableUsed(Class->getLocation(), Class, true);
6043
6044