clang  9.0.0svn
SemaLambda.cpp
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1 //===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
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++ lambda expressions.
10 //
11 //===----------------------------------------------------------------------===//
12 #include "clang/Sema/DeclSpec.h"
13 #include "TypeLocBuilder.h"
14 #include "clang/AST/ASTLambda.h"
15 #include "clang/AST/ExprCXX.h"
16 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Sema/Lookup.h"
19 #include "clang/Sema/Scope.h"
20 #include "clang/Sema/ScopeInfo.h"
22 #include "clang/Sema/SemaLambda.h"
23 #include "llvm/ADT/STLExtras.h"
24 using namespace clang;
25 using namespace sema;
26 
27 /// Examines the FunctionScopeInfo stack to determine the nearest
28 /// enclosing lambda (to the current lambda) that is 'capture-ready' for
29 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
30 /// If successful, returns the index into Sema's FunctionScopeInfo stack
31 /// of the capture-ready lambda's LambdaScopeInfo.
32 ///
33 /// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
34 /// lambda - is on top) to determine the index of the nearest enclosing/outer
35 /// lambda that is ready to capture the \p VarToCapture being referenced in
36 /// the current lambda.
37 /// As we climb down the stack, we want the index of the first such lambda -
38 /// that is the lambda with the highest index that is 'capture-ready'.
39 ///
40 /// A lambda 'L' is capture-ready for 'V' (var or this) if:
41 /// - its enclosing context is non-dependent
42 /// - and if the chain of lambdas between L and the lambda in which
43 /// V is potentially used (i.e. the lambda at the top of the scope info
44 /// stack), can all capture or have already captured V.
45 /// If \p VarToCapture is 'null' then we are trying to capture 'this'.
46 ///
47 /// Note that a lambda that is deemed 'capture-ready' still needs to be checked
48 /// for whether it is 'capture-capable' (see
49 /// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
50 /// capture.
51 ///
52 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
53 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
54 /// is at the top of the stack and has the highest index.
55 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
56 ///
57 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
58 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
59 /// which is capture-ready. If the return value evaluates to 'false' then
60 /// no lambda is capture-ready for \p VarToCapture.
61 
62 static inline Optional<unsigned>
65  VarDecl *VarToCapture) {
66  // Label failure to capture.
67  const Optional<unsigned> NoLambdaIsCaptureReady;
68 
69  // Ignore all inner captured regions.
70  unsigned CurScopeIndex = FunctionScopes.size() - 1;
71  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
72  FunctionScopes[CurScopeIndex]))
73  --CurScopeIndex;
74  assert(
75  isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
76  "The function on the top of sema's function-info stack must be a lambda");
77 
78  // If VarToCapture is null, we are attempting to capture 'this'.
79  const bool IsCapturingThis = !VarToCapture;
80  const bool IsCapturingVariable = !IsCapturingThis;
81 
82  // Start with the current lambda at the top of the stack (highest index).
83  DeclContext *EnclosingDC =
84  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
85 
86  do {
87  const clang::sema::LambdaScopeInfo *LSI =
88  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]);
89  // IF we have climbed down to an intervening enclosing lambda that contains
90  // the variable declaration - it obviously can/must not capture the
91  // variable.
92  // Since its enclosing DC is dependent, all the lambdas between it and the
93  // innermost nested lambda are dependent (otherwise we wouldn't have
94  // arrived here) - so we don't yet have a lambda that can capture the
95  // variable.
96  if (IsCapturingVariable &&
97  VarToCapture->getDeclContext()->Equals(EnclosingDC))
98  return NoLambdaIsCaptureReady;
99 
100  // For an enclosing lambda to be capture ready for an entity, all
101  // intervening lambda's have to be able to capture that entity. If even
102  // one of the intervening lambda's is not capable of capturing the entity
103  // then no enclosing lambda can ever capture that entity.
104  // For e.g.
105  // const int x = 10;
106  // [=](auto a) { #1
107  // [](auto b) { #2 <-- an intervening lambda that can never capture 'x'
108  // [=](auto c) { #3
109  // f(x, c); <-- can not lead to x's speculative capture by #1 or #2
110  // }; }; };
111  // If they do not have a default implicit capture, check to see
112  // if the entity has already been explicitly captured.
113  // If even a single dependent enclosing lambda lacks the capability
114  // to ever capture this variable, there is no further enclosing
115  // non-dependent lambda that can capture this variable.
117  if (IsCapturingVariable && !LSI->isCaptured(VarToCapture))
118  return NoLambdaIsCaptureReady;
119  if (IsCapturingThis && !LSI->isCXXThisCaptured())
120  return NoLambdaIsCaptureReady;
121  }
122  EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
123 
124  assert(CurScopeIndex);
125  --CurScopeIndex;
126  } while (!EnclosingDC->isTranslationUnit() &&
127  EnclosingDC->isDependentContext() &&
128  isLambdaCallOperator(EnclosingDC));
129 
130  assert(CurScopeIndex < (FunctionScopes.size() - 1));
131  // If the enclosingDC is not dependent, then the immediately nested lambda
132  // (one index above) is capture-ready.
133  if (!EnclosingDC->isDependentContext())
134  return CurScopeIndex + 1;
135  return NoLambdaIsCaptureReady;
136 }
137 
138 /// Examines the FunctionScopeInfo stack to determine the nearest
139 /// enclosing lambda (to the current lambda) that is 'capture-capable' for
140 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
141 /// If successful, returns the index into Sema's FunctionScopeInfo stack
142 /// of the capture-capable lambda's LambdaScopeInfo.
143 ///
144 /// Given the current stack of lambdas being processed by Sema and
145 /// the variable of interest, to identify the nearest enclosing lambda (to the
146 /// current lambda at the top of the stack) that can truly capture
147 /// a variable, it has to have the following two properties:
148 /// a) 'capture-ready' - be the innermost lambda that is 'capture-ready':
149 /// - climb down the stack (i.e. starting from the innermost and examining
150 /// each outer lambda step by step) checking if each enclosing
151 /// lambda can either implicitly or explicitly capture the variable.
152 /// Record the first such lambda that is enclosed in a non-dependent
153 /// context. If no such lambda currently exists return failure.
154 /// b) 'capture-capable' - make sure the 'capture-ready' lambda can truly
155 /// capture the variable by checking all its enclosing lambdas:
156 /// - check if all outer lambdas enclosing the 'capture-ready' lambda
157 /// identified above in 'a' can also capture the variable (this is done
158 /// via tryCaptureVariable for variables and CheckCXXThisCapture for
159 /// 'this' by passing in the index of the Lambda identified in step 'a')
160 ///
161 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
162 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
163 /// is at the top of the stack.
164 ///
165 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
166 ///
167 ///
168 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
169 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
170 /// which is capture-capable. If the return value evaluates to 'false' then
171 /// no lambda is capture-capable for \p VarToCapture.
172 
175  VarDecl *VarToCapture, Sema &S) {
176 
177  const Optional<unsigned> NoLambdaIsCaptureCapable;
178 
179  const Optional<unsigned> OptionalStackIndex =
181  VarToCapture);
182  if (!OptionalStackIndex)
183  return NoLambdaIsCaptureCapable;
184 
185  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
186  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
187  S.getCurGenericLambda()) &&
188  "The capture ready lambda for a potential capture can only be the "
189  "current lambda if it is a generic lambda");
190 
191  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
192  cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
193 
194  // If VarToCapture is null, we are attempting to capture 'this'
195  const bool IsCapturingThis = !VarToCapture;
196  const bool IsCapturingVariable = !IsCapturingThis;
197 
198  if (IsCapturingVariable) {
199  // Check if the capture-ready lambda can truly capture the variable, by
200  // checking whether all enclosing lambdas of the capture-ready lambda allow
201  // the capture - i.e. make sure it is capture-capable.
202  QualType CaptureType, DeclRefType;
203  const bool CanCaptureVariable =
204  !S.tryCaptureVariable(VarToCapture,
205  /*ExprVarIsUsedInLoc*/ SourceLocation(),
207  /*EllipsisLoc*/ SourceLocation(),
208  /*BuildAndDiagnose*/ false, CaptureType,
209  DeclRefType, &IndexOfCaptureReadyLambda);
210  if (!CanCaptureVariable)
211  return NoLambdaIsCaptureCapable;
212  } else {
213  // Check if the capture-ready lambda can truly capture 'this' by checking
214  // whether all enclosing lambdas of the capture-ready lambda can capture
215  // 'this'.
216  const bool CanCaptureThis =
218  CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
219  /*Explicit*/ false, /*BuildAndDiagnose*/ false,
220  &IndexOfCaptureReadyLambda);
221  if (!CanCaptureThis)
222  return NoLambdaIsCaptureCapable;
223  }
224  return IndexOfCaptureReadyLambda;
225 }
226 
227 static inline TemplateParameterList *
229  if (!LSI->GLTemplateParameterList && !LSI->TemplateParams.empty()) {
231  SemaRef.Context,
232  /*Template kw loc*/ SourceLocation(),
233  /*L angle loc*/ LSI->ExplicitTemplateParamsRange.getBegin(),
234  LSI->TemplateParams,
235  /*R angle loc*/LSI->ExplicitTemplateParamsRange.getEnd(),
236  nullptr);
237  }
238  return LSI->GLTemplateParameterList;
239 }
240 
242  TypeSourceInfo *Info,
243  bool KnownDependent,
244  LambdaCaptureDefault CaptureDefault) {
245  DeclContext *DC = CurContext;
246  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
247  DC = DC->getParent();
248  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
249  *this);
250  // Start constructing the lambda class.
251  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
252  IntroducerRange.getBegin(),
253  KnownDependent,
254  IsGenericLambda,
255  CaptureDefault);
256  DC->addDecl(Class);
257 
258  return Class;
259 }
260 
261 /// Determine whether the given context is or is enclosed in an inline
262 /// function.
263 static bool isInInlineFunction(const DeclContext *DC) {
264  while (!DC->isFileContext()) {
265  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
266  if (FD->isInlined())
267  return true;
268 
269  DC = DC->getLexicalParent();
270  }
271 
272  return false;
273 }
274 
277  Decl *&ManglingContextDecl) {
278  // Compute the context for allocating mangling numbers in the current
279  // expression, if the ABI requires them.
280  ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
281 
282  enum ContextKind {
283  Normal,
284  DefaultArgument,
285  DataMember,
286  StaticDataMember,
287  InlineVariable,
288  VariableTemplate
289  } Kind = Normal;
290 
291  // Default arguments of member function parameters that appear in a class
292  // definition, as well as the initializers of data members, receive special
293  // treatment. Identify them.
294  if (ManglingContextDecl) {
295  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
296  if (const DeclContext *LexicalDC
297  = Param->getDeclContext()->getLexicalParent())
298  if (LexicalDC->isRecord())
299  Kind = DefaultArgument;
300  } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
301  if (Var->getDeclContext()->isRecord())
302  Kind = StaticDataMember;
303  else if (Var->getMostRecentDecl()->isInline())
304  Kind = InlineVariable;
305  else if (Var->getDescribedVarTemplate())
306  Kind = VariableTemplate;
307  else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
308  if (!VTS->isExplicitSpecialization())
309  Kind = VariableTemplate;
310  }
311  } else if (isa<FieldDecl>(ManglingContextDecl)) {
312  Kind = DataMember;
313  }
314  }
315 
316  // Itanium ABI [5.1.7]:
317  // In the following contexts [...] the one-definition rule requires closure
318  // types in different translation units to "correspond":
319  bool IsInNonspecializedTemplate =
320  inTemplateInstantiation() || CurContext->isDependentContext();
321  switch (Kind) {
322  case Normal: {
323  // -- the bodies of non-exported nonspecialized template functions
324  // -- the bodies of inline functions
325  if ((IsInNonspecializedTemplate &&
326  !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
327  isInInlineFunction(CurContext)) {
328  ManglingContextDecl = nullptr;
329  while (auto *CD = dyn_cast<CapturedDecl>(DC))
330  DC = CD->getParent();
331  return &Context.getManglingNumberContext(DC);
332  }
333 
334  ManglingContextDecl = nullptr;
335  return nullptr;
336  }
337 
338  case StaticDataMember:
339  // -- the initializers of nonspecialized static members of template classes
340  if (!IsInNonspecializedTemplate) {
341  ManglingContextDecl = nullptr;
342  return nullptr;
343  }
344  // Fall through to get the current context.
345  LLVM_FALLTHROUGH;
346 
347  case DataMember:
348  // -- the in-class initializers of class members
349  case DefaultArgument:
350  // -- default arguments appearing in class definitions
351  case InlineVariable:
352  // -- the initializers of inline variables
353  case VariableTemplate:
354  // -- the initializers of templated variables
355  return &ExprEvalContexts.back().getMangleNumberingContext(Context);
356  }
357 
358  llvm_unreachable("unexpected context");
359 }
360 
363  ASTContext &Ctx) {
364  assert(ManglingContextDecl && "Need to have a context declaration");
365  if (!MangleNumbering)
366  MangleNumbering = Ctx.createMangleNumberingContext();
367  return *MangleNumbering;
368 }
369 
371  CXXRecordDecl *Class, SourceRange IntroducerRange,
372  TypeSourceInfo *MethodTypeInfo, SourceLocation EndLoc,
373  ArrayRef<ParmVarDecl *> Params, ConstexprSpecKind ConstexprKind,
374  Optional<std::pair<unsigned, Decl *>> Mangling) {
375  QualType MethodType = MethodTypeInfo->getType();
376  TemplateParameterList *TemplateParams =
377  getGenericLambdaTemplateParameterList(getCurLambda(), *this);
378  // If a lambda appears in a dependent context or is a generic lambda (has
379  // template parameters) and has an 'auto' return type, deduce it to a
380  // dependent type.
381  if (Class->isDependentContext() || TemplateParams) {
382  const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
383  QualType Result = FPT->getReturnType();
384  if (Result->isUndeducedType()) {
385  Result = SubstAutoType(Result, Context.DependentTy);
386  MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
387  FPT->getExtProtoInfo());
388  }
389  }
390 
391  // C++11 [expr.prim.lambda]p5:
392  // The closure type for a lambda-expression has a public inline function
393  // call operator (13.5.4) whose parameters and return type are described by
394  // the lambda-expression's parameter-declaration-clause and
395  // trailing-return-type respectively.
396  DeclarationName MethodName
397  = Context.DeclarationNames.getCXXOperatorName(OO_Call);
398  DeclarationNameLoc MethodNameLoc;
399  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
400  = IntroducerRange.getBegin().getRawEncoding();
401  MethodNameLoc.CXXOperatorName.EndOpNameLoc
402  = IntroducerRange.getEnd().getRawEncoding();
404  Context, Class, EndLoc,
405  DeclarationNameInfo(MethodName, IntroducerRange.getBegin(),
406  MethodNameLoc),
407  MethodType, MethodTypeInfo, SC_None,
408  /*isInline=*/true, ConstexprKind, EndLoc);
409  Method->setAccess(AS_public);
410 
411  // Temporarily set the lexical declaration context to the current
412  // context, so that the Scope stack matches the lexical nesting.
413  Method->setLexicalDeclContext(CurContext);
414  // Create a function template if we have a template parameter list
415  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
416  FunctionTemplateDecl::Create(Context, Class,
417  Method->getLocation(), MethodName,
418  TemplateParams,
419  Method) : nullptr;
420  if (TemplateMethod) {
421  TemplateMethod->setLexicalDeclContext(CurContext);
422  TemplateMethod->setAccess(AS_public);
423  Method->setDescribedFunctionTemplate(TemplateMethod);
424  }
425 
426  // Add parameters.
427  if (!Params.empty()) {
428  Method->setParams(Params);
429  CheckParmsForFunctionDef(Params,
430  /*CheckParameterNames=*/false);
431 
432  for (auto P : Method->parameters())
433  P->setOwningFunction(Method);
434  }
435 
436  if (Mangling) {
437  Class->setLambdaMangling(Mangling->first, Mangling->second);
438  } else {
439  Decl *ManglingContextDecl;
440  if (MangleNumberingContext *MCtx =
441  getCurrentMangleNumberContext(Class->getDeclContext(),
442  ManglingContextDecl)) {
443  unsigned ManglingNumber = MCtx->getManglingNumber(Method);
444  Class->setLambdaMangling(ManglingNumber, ManglingContextDecl);
445  }
446  }
447 
448  return Method;
449 }
450 
452  CXXMethodDecl *CallOperator,
453  SourceRange IntroducerRange,
454  LambdaCaptureDefault CaptureDefault,
455  SourceLocation CaptureDefaultLoc,
456  bool ExplicitParams,
457  bool ExplicitResultType,
458  bool Mutable) {
459  LSI->CallOperator = CallOperator;
460  CXXRecordDecl *LambdaClass = CallOperator->getParent();
461  LSI->Lambda = LambdaClass;
462  if (CaptureDefault == LCD_ByCopy)
464  else if (CaptureDefault == LCD_ByRef)
466  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
467  LSI->IntroducerRange = IntroducerRange;
468  LSI->ExplicitParams = ExplicitParams;
469  LSI->Mutable = Mutable;
470 
471  if (ExplicitResultType) {
472  LSI->ReturnType = CallOperator->getReturnType();
473 
474  if (!LSI->ReturnType->isDependentType() &&
475  !LSI->ReturnType->isVoidType()) {
476  if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
477  diag::err_lambda_incomplete_result)) {
478  // Do nothing.
479  }
480  }
481  } else {
482  LSI->HasImplicitReturnType = true;
483  }
484 }
485 
488 }
489 
491  ArrayRef<NamedDecl *> TParams,
492  SourceLocation RAngleLoc) {
493  LambdaScopeInfo *LSI = getCurLambda();
494  assert(LSI && "Expected a lambda scope");
495  assert(LSI->NumExplicitTemplateParams == 0 &&
496  "Already acted on explicit template parameters");
497  assert(LSI->TemplateParams.empty() &&
498  "Explicit template parameters should come "
499  "before invented (auto) ones");
500  assert(!TParams.empty() &&
501  "No template parameters to act on");
502  LSI->TemplateParams.append(TParams.begin(), TParams.end());
503  LSI->NumExplicitTemplateParams = TParams.size();
504  LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc};
505 }
506 
509  CXXMethodDecl *CallOperator, Scope *CurScope) {
510  // Introduce our parameters into the function scope
511  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
512  p < NumParams; ++p) {
513  ParmVarDecl *Param = CallOperator->getParamDecl(p);
514 
515  // If this has an identifier, add it to the scope stack.
516  if (CurScope && Param->getIdentifier()) {
517  bool Error = false;
518  // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
519  // retroactively apply it.
520  for (const auto &Capture : Captures) {
521  if (Capture.Id == Param->getIdentifier()) {
522  Error = true;
523  Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
524  Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
525  << Capture.Id << true;
526  }
527  }
528  if (!Error)
529  CheckShadow(CurScope, Param);
530 
531  PushOnScopeChains(Param, CurScope);
532  }
533  }
534 }
535 
536 /// If this expression is an enumerator-like expression of some type
537 /// T, return the type T; otherwise, return null.
538 ///
539 /// Pointer comparisons on the result here should always work because
540 /// it's derived from either the parent of an EnumConstantDecl
541 /// (i.e. the definition) or the declaration returned by
542 /// EnumType::getDecl() (i.e. the definition).
544  // An expression is an enumerator-like expression of type T if,
545  // ignoring parens and parens-like expressions:
546  E = E->IgnoreParens();
547 
548  // - it is an enumerator whose enum type is T or
549  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
550  if (EnumConstantDecl *D
551  = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
552  return cast<EnumDecl>(D->getDeclContext());
553  }
554  return nullptr;
555  }
556 
557  // - it is a comma expression whose RHS is an enumerator-like
558  // expression of type T or
559  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
560  if (BO->getOpcode() == BO_Comma)
561  return findEnumForBlockReturn(BO->getRHS());
562  return nullptr;
563  }
564 
565  // - it is a statement-expression whose value expression is an
566  // enumerator-like expression of type T or
567  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
568  if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
569  return findEnumForBlockReturn(last);
570  return nullptr;
571  }
572 
573  // - it is a ternary conditional operator (not the GNU ?:
574  // extension) whose second and third operands are
575  // enumerator-like expressions of type T or
576  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
577  if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
578  if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
579  return ED;
580  return nullptr;
581  }
582 
583  // (implicitly:)
584  // - it is an implicit integral conversion applied to an
585  // enumerator-like expression of type T or
586  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
587  // We can sometimes see integral conversions in valid
588  // enumerator-like expressions.
589  if (ICE->getCastKind() == CK_IntegralCast)
590  return findEnumForBlockReturn(ICE->getSubExpr());
591 
592  // Otherwise, just rely on the type.
593  }
594 
595  // - it is an expression of that formal enum type.
596  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
597  return ET->getDecl();
598  }
599 
600  // Otherwise, nope.
601  return nullptr;
602 }
603 
604 /// Attempt to find a type T for which the returned expression of the
605 /// given statement is an enumerator-like expression of that type.
607  if (Expr *retValue = ret->getRetValue())
608  return findEnumForBlockReturn(retValue);
609  return nullptr;
610 }
611 
612 /// Attempt to find a common type T for which all of the returned
613 /// expressions in a block are enumerator-like expressions of that
614 /// type.
616  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
617 
618  // Try to find one for the first return.
620  if (!ED) return nullptr;
621 
622  // Check that the rest of the returns have the same enum.
623  for (++i; i != e; ++i) {
624  if (findEnumForBlockReturn(*i) != ED)
625  return nullptr;
626  }
627 
628  // Never infer an anonymous enum type.
629  if (!ED->hasNameForLinkage()) return nullptr;
630 
631  return ED;
632 }
633 
634 /// Adjust the given return statements so that they formally return
635 /// the given type. It should require, at most, an IntegralCast.
637  QualType returnType) {
639  i = returns.begin(), e = returns.end(); i != e; ++i) {
640  ReturnStmt *ret = *i;
641  Expr *retValue = ret->getRetValue();
642  if (S.Context.hasSameType(retValue->getType(), returnType))
643  continue;
644 
645  // Right now we only support integral fixup casts.
646  assert(returnType->isIntegralOrUnscopedEnumerationType());
647  assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
648 
649  ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
650 
651  Expr *E = (cleanups ? cleanups->getSubExpr() : retValue);
652  E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast,
653  E, /*base path*/ nullptr, VK_RValue);
654  if (cleanups) {
655  cleanups->setSubExpr(E);
656  } else {
657  ret->setRetValue(E);
658  }
659  }
660 }
661 
663  assert(CSI.HasImplicitReturnType);
664  // If it was ever a placeholder, it had to been deduced to DependentTy.
665  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
666  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
667  "lambda expressions use auto deduction in C++14 onwards");
668 
669  // C++ core issue 975:
670  // If a lambda-expression does not include a trailing-return-type,
671  // it is as if the trailing-return-type denotes the following type:
672  // - if there are no return statements in the compound-statement,
673  // or all return statements return either an expression of type
674  // void or no expression or braced-init-list, the type void;
675  // - otherwise, if all return statements return an expression
676  // and the types of the returned expressions after
677  // lvalue-to-rvalue conversion (4.1 [conv.lval]),
678  // array-to-pointer conversion (4.2 [conv.array]), and
679  // function-to-pointer conversion (4.3 [conv.func]) are the
680  // same, that common type;
681  // - otherwise, the program is ill-formed.
682  //
683  // C++ core issue 1048 additionally removes top-level cv-qualifiers
684  // from the types of returned expressions to match the C++14 auto
685  // deduction rules.
686  //
687  // In addition, in blocks in non-C++ modes, if all of the return
688  // statements are enumerator-like expressions of some type T, where
689  // T has a name for linkage, then we infer the return type of the
690  // block to be that type.
691 
692  // First case: no return statements, implicit void return type.
693  ASTContext &Ctx = getASTContext();
694  if (CSI.Returns.empty()) {
695  // It's possible there were simply no /valid/ return statements.
696  // In this case, the first one we found may have at least given us a type.
697  if (CSI.ReturnType.isNull())
698  CSI.ReturnType = Ctx.VoidTy;
699  return;
700  }
701 
702  // Second case: at least one return statement has dependent type.
703  // Delay type checking until instantiation.
704  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
705  if (CSI.ReturnType->isDependentType())
706  return;
707 
708  // Try to apply the enum-fuzz rule.
709  if (!getLangOpts().CPlusPlus) {
710  assert(isa<BlockScopeInfo>(CSI));
712  if (ED) {
713  CSI.ReturnType = Context.getTypeDeclType(ED);
715  return;
716  }
717  }
718 
719  // Third case: only one return statement. Don't bother doing extra work!
720  if (CSI.Returns.size() == 1)
721  return;
722 
723  // General case: many return statements.
724  // Check that they all have compatible return types.
725 
726  // We require the return types to strictly match here.
727  // Note that we've already done the required promotions as part of
728  // processing the return statement.
729  for (const ReturnStmt *RS : CSI.Returns) {
730  const Expr *RetE = RS->getRetValue();
731 
732  QualType ReturnType =
733  (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType();
734  if (Context.getCanonicalFunctionResultType(ReturnType) ==
736  // Use the return type with the strictest possible nullability annotation.
737  auto RetTyNullability = ReturnType->getNullability(Ctx);
738  auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
739  if (BlockNullability &&
740  (!RetTyNullability ||
741  hasWeakerNullability(*RetTyNullability, *BlockNullability)))
742  CSI.ReturnType = ReturnType;
743  continue;
744  }
745 
746  // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
747  // TODO: It's possible that the *first* return is the divergent one.
748  Diag(RS->getBeginLoc(),
749  diag::err_typecheck_missing_return_type_incompatible)
750  << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
751  // Continue iterating so that we keep emitting diagnostics.
752  }
753 }
754 
756  SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
757  Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool IsDirectInit,
758  Expr *&Init) {
759  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
760  // deduce against.
761  QualType DeductType = Context.getAutoDeductType();
762  TypeLocBuilder TLB;
763  TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
764  if (ByRef) {
765  DeductType = BuildReferenceType(DeductType, true, Loc, Id);
766  assert(!DeductType.isNull() && "can't build reference to auto");
767  TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
768  }
769  if (EllipsisLoc.isValid()) {
770  if (Init->containsUnexpandedParameterPack()) {
771  Diag(EllipsisLoc, getLangOpts().CPlusPlus2a
772  ? diag::warn_cxx17_compat_init_capture_pack
773  : diag::ext_init_capture_pack);
774  DeductType = Context.getPackExpansionType(DeductType, NumExpansions);
775  TLB.push<PackExpansionTypeLoc>(DeductType).setEllipsisLoc(EllipsisLoc);
776  } else {
777  // Just ignore the ellipsis for now and form a non-pack variable. We'll
778  // diagnose this later when we try to capture it.
779  }
780  }
781  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
782 
783  // Deduce the type of the init capture.
784  QualType DeducedType = deduceVarTypeFromInitializer(
785  /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
786  SourceRange(Loc, Loc), IsDirectInit, Init);
787  if (DeducedType.isNull())
788  return QualType();
789 
790  // Are we a non-list direct initialization?
791  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
792 
793  // Perform initialization analysis and ensure any implicit conversions
794  // (such as lvalue-to-rvalue) are enforced.
795  InitializedEntity Entity =
796  InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
798  IsDirectInit
799  ? (CXXDirectInit ? InitializationKind::CreateDirect(
800  Loc, Init->getBeginLoc(), Init->getEndLoc())
803 
804  MultiExprArg Args = Init;
805  if (CXXDirectInit)
806  Args =
807  MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
808  QualType DclT;
809  InitializationSequence InitSeq(*this, Entity, Kind, Args);
810  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
811 
812  if (Result.isInvalid())
813  return QualType();
814 
815  Init = Result.getAs<Expr>();
816  return DeducedType;
817 }
818 
820  QualType InitCaptureType,
821  SourceLocation EllipsisLoc,
823  unsigned InitStyle, Expr *Init) {
824  // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization
825  // rather than reconstructing it here.
826  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType, Loc);
827  if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>())
828  PETL.setEllipsisLoc(EllipsisLoc);
829 
830  // Create a dummy variable representing the init-capture. This is not actually
831  // used as a variable, and only exists as a way to name and refer to the
832  // init-capture.
833  // FIXME: Pass in separate source locations for '&' and identifier.
834  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
835  Loc, Id, InitCaptureType, TSI, SC_Auto);
836  NewVD->setInitCapture(true);
837  NewVD->setReferenced(true);
838  // FIXME: Pass in a VarDecl::InitializationStyle.
839  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
840  NewVD->markUsed(Context);
841  NewVD->setInit(Init);
842  return NewVD;
843 }
844 
846  assert(Var->isInitCapture() && "init capture flag should be set");
847  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
848  /*isNested*/false, Var->getLocation(), SourceLocation(),
849  Var->getType(), /*Invalid*/false);
850 }
851 
853  Declarator &ParamInfo,
854  Scope *CurScope) {
855  LambdaScopeInfo *const LSI = getCurLambda();
856  assert(LSI && "LambdaScopeInfo should be on stack!");
857 
858  // Determine if we're within a context where we know that the lambda will
859  // be dependent, because there are template parameters in scope.
860  bool KnownDependent;
861  if (LSI->NumExplicitTemplateParams > 0) {
862  auto *TemplateParamScope = CurScope->getTemplateParamParent();
863  assert(TemplateParamScope &&
864  "Lambda with explicit template param list should establish a "
865  "template param scope");
866  assert(TemplateParamScope->getParent());
867  KnownDependent = TemplateParamScope->getParent()
868  ->getTemplateParamParent() != nullptr;
869  } else {
870  KnownDependent = CurScope->getTemplateParamParent() != nullptr;
871  }
872 
873  // Determine the signature of the call operator.
874  TypeSourceInfo *MethodTyInfo;
875  bool ExplicitParams = true;
876  bool ExplicitResultType = true;
877  bool ContainsUnexpandedParameterPack = false;
878  SourceLocation EndLoc;
880  if (ParamInfo.getNumTypeObjects() == 0) {
881  // C++11 [expr.prim.lambda]p4:
882  // If a lambda-expression does not include a lambda-declarator, it is as
883  // if the lambda-declarator were ().
885  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
886  EPI.HasTrailingReturn = true;
887  EPI.TypeQuals.addConst();
888  // C++1y [expr.prim.lambda]:
889  // The lambda return type is 'auto', which is replaced by the
890  // trailing-return type if provided and/or deduced from 'return'
891  // statements
892  // We don't do this before C++1y, because we don't support deduced return
893  // types there.
894  QualType DefaultTypeForNoTrailingReturn =
895  getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
896  : Context.DependentTy;
897  QualType MethodTy =
898  Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
899  MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
900  ExplicitParams = false;
901  ExplicitResultType = false;
902  EndLoc = Intro.Range.getEnd();
903  } else {
904  assert(ParamInfo.isFunctionDeclarator() &&
905  "lambda-declarator is a function");
907 
908  // C++11 [expr.prim.lambda]p5:
909  // This function call operator is declared const (9.3.1) if and only if
910  // the lambda-expression's parameter-declaration-clause is not followed
911  // by mutable. It is neither virtual nor declared volatile. [...]
912  if (!FTI.hasMutableQualifier()) {
914  SourceLocation());
915  }
916 
917  MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
918  assert(MethodTyInfo && "no type from lambda-declarator");
919  EndLoc = ParamInfo.getSourceRange().getEnd();
920 
921  ExplicitResultType = FTI.hasTrailingReturnType();
922 
923  if (FTIHasNonVoidParameters(FTI)) {
924  Params.reserve(FTI.NumParams);
925  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i)
926  Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
927  }
928 
929  // Check for unexpanded parameter packs in the method type.
930  if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
931  ContainsUnexpandedParameterPack = true;
932  }
933 
934  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
935  KnownDependent, Intro.Default);
936 
937  CXXMethodDecl *Method =
938  startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
939  ParamInfo.getDeclSpec().getConstexprSpecifier());
940  if (ExplicitParams)
941  CheckCXXDefaultArguments(Method);
942 
943  // This represents the function body for the lambda function, check if we
944  // have to apply optnone due to a pragma.
945  AddRangeBasedOptnone(Method);
946 
947  // code_seg attribute on lambda apply to the method.
948  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
949  Method->addAttr(A);
950 
951  // Attributes on the lambda apply to the method.
952  ProcessDeclAttributes(CurScope, Method, ParamInfo);
953 
954  // CUDA lambdas get implicit attributes based on the scope in which they're
955  // declared.
956  if (getLangOpts().CUDA)
957  CUDASetLambdaAttrs(Method);
958 
959  // Introduce the function call operator as the current declaration context.
960  PushDeclContext(CurScope, Method);
961 
962  // Build the lambda scope.
963  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
964  ExplicitParams, ExplicitResultType, !Method->isConst());
965 
966  // C++11 [expr.prim.lambda]p9:
967  // A lambda-expression whose smallest enclosing scope is a block scope is a
968  // local lambda expression; any other lambda expression shall not have a
969  // capture-default or simple-capture in its lambda-introducer.
970  //
971  // For simple-captures, this is covered by the check below that any named
972  // entity is a variable that can be captured.
973  //
974  // For DR1632, we also allow a capture-default in any context where we can
975  // odr-use 'this' (in particular, in a default initializer for a non-static
976  // data member).
977  if (Intro.Default != LCD_None && !Class->getParent()->isFunctionOrMethod() &&
978  (getCurrentThisType().isNull() ||
979  CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
980  /*BuildAndDiagnose*/false)))
981  Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
982 
983  // Distinct capture names, for diagnostics.
984  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
985 
986  // Handle explicit captures.
987  SourceLocation PrevCaptureLoc
988  = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc;
989  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
990  PrevCaptureLoc = C->Loc, ++C) {
991  if (C->Kind == LCK_This || C->Kind == LCK_StarThis) {
992  if (C->Kind == LCK_StarThis)
993  Diag(C->Loc, !getLangOpts().CPlusPlus17
994  ? diag::ext_star_this_lambda_capture_cxx17
995  : diag::warn_cxx14_compat_star_this_lambda_capture);
996 
997  // C++11 [expr.prim.lambda]p8:
998  // An identifier or this shall not appear more than once in a
999  // lambda-capture.
1000  if (LSI->isCXXThisCaptured()) {
1001  Diag(C->Loc, diag::err_capture_more_than_once)
1002  << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
1004  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1005  continue;
1006  }
1007 
1008  // C++2a [expr.prim.lambda]p8:
1009  // If a lambda-capture includes a capture-default that is =,
1010  // each simple-capture of that lambda-capture shall be of the form
1011  // "&identifier", "this", or "* this". [ Note: The form [&,this] is
1012  // redundant but accepted for compatibility with ISO C++14. --end note ]
1013  if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis)
1014  Diag(C->Loc, !getLangOpts().CPlusPlus2a
1015  ? diag::ext_equals_this_lambda_capture_cxx2a
1016  : diag::warn_cxx17_compat_equals_this_lambda_capture);
1017 
1018  // C++11 [expr.prim.lambda]p12:
1019  // If this is captured by a local lambda expression, its nearest
1020  // enclosing function shall be a non-static member function.
1021  QualType ThisCaptureType = getCurrentThisType();
1022  if (ThisCaptureType.isNull()) {
1023  Diag(C->Loc, diag::err_this_capture) << true;
1024  continue;
1025  }
1026 
1027  CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1028  /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1029  C->Kind == LCK_StarThis);
1030  if (!LSI->Captures.empty())
1031  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1032  continue;
1033  }
1034 
1035  assert(C->Id && "missing identifier for capture");
1036 
1037  if (C->Init.isInvalid())
1038  continue;
1039 
1040  VarDecl *Var = nullptr;
1041  if (C->Init.isUsable()) {
1042  Diag(C->Loc, getLangOpts().CPlusPlus14
1043  ? diag::warn_cxx11_compat_init_capture
1044  : diag::ext_init_capture);
1045 
1046  // If the initializer expression is usable, but the InitCaptureType
1047  // is not, then an error has occurred - so ignore the capture for now.
1048  // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1049  // FIXME: we should create the init capture variable and mark it invalid
1050  // in this case.
1051  if (C->InitCaptureType.get().isNull())
1052  continue;
1053 
1054  if (C->Init.get()->containsUnexpandedParameterPack() &&
1055  !C->InitCaptureType.get()->getAs<PackExpansionType>())
1056  ContainsUnexpandedParameterPack = true;
1057 
1058  unsigned InitStyle;
1059  switch (C->InitKind) {
1061  llvm_unreachable("not an init-capture?");
1063  InitStyle = VarDecl::CInit;
1064  break;
1066  InitStyle = VarDecl::CallInit;
1067  break;
1069  InitStyle = VarDecl::ListInit;
1070  break;
1071  }
1072  Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1073  C->EllipsisLoc, C->Id, InitStyle,
1074  C->Init.get());
1075  // C++1y [expr.prim.lambda]p11:
1076  // An init-capture behaves as if it declares and explicitly
1077  // captures a variable [...] whose declarative region is the
1078  // lambda-expression's compound-statement
1079  if (Var)
1080  PushOnScopeChains(Var, CurScope, false);
1081  } else {
1082  assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1083  "init capture has valid but null init?");
1084 
1085  // C++11 [expr.prim.lambda]p8:
1086  // If a lambda-capture includes a capture-default that is &, the
1087  // identifiers in the lambda-capture shall not be preceded by &.
1088  // If a lambda-capture includes a capture-default that is =, [...]
1089  // each identifier it contains shall be preceded by &.
1090  if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) {
1091  Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1093  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1094  continue;
1095  } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) {
1096  Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1098  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1099  continue;
1100  }
1101 
1102  // C++11 [expr.prim.lambda]p10:
1103  // The identifiers in a capture-list are looked up using the usual
1104  // rules for unqualified name lookup (3.4.1)
1105  DeclarationNameInfo Name(C->Id, C->Loc);
1106  LookupResult R(*this, Name, LookupOrdinaryName);
1107  LookupName(R, CurScope);
1108  if (R.isAmbiguous())
1109  continue;
1110  if (R.empty()) {
1111  // FIXME: Disable corrections that would add qualification?
1112  CXXScopeSpec ScopeSpec;
1113  DeclFilterCCC<VarDecl> Validator{};
1114  if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1115  continue;
1116  }
1117 
1118  Var = R.getAsSingle<VarDecl>();
1119  if (Var && DiagnoseUseOfDecl(Var, C->Loc))
1120  continue;
1121  }
1122 
1123  // C++11 [expr.prim.lambda]p8:
1124  // An identifier or this shall not appear more than once in a
1125  // lambda-capture.
1126  if (!CaptureNames.insert(C->Id).second) {
1127  if (Var && LSI->isCaptured(Var)) {
1128  Diag(C->Loc, diag::err_capture_more_than_once)
1129  << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1131  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1132  } else
1133  // Previous capture captured something different (one or both was
1134  // an init-cpature): no fixit.
1135  Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1136  continue;
1137  }
1138 
1139  // C++11 [expr.prim.lambda]p10:
1140  // [...] each such lookup shall find a variable with automatic storage
1141  // duration declared in the reaching scope of the local lambda expression.
1142  // Note that the 'reaching scope' check happens in tryCaptureVariable().
1143  if (!Var) {
1144  Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1145  continue;
1146  }
1147 
1148  // Ignore invalid decls; they'll just confuse the code later.
1149  if (Var->isInvalidDecl())
1150  continue;
1151 
1152  if (!Var->hasLocalStorage()) {
1153  Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1154  Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1155  continue;
1156  }
1157 
1158  // C++11 [expr.prim.lambda]p23:
1159  // A capture followed by an ellipsis is a pack expansion (14.5.3).
1160  SourceLocation EllipsisLoc;
1161  if (C->EllipsisLoc.isValid()) {
1162  if (Var->isParameterPack()) {
1163  EllipsisLoc = C->EllipsisLoc;
1164  } else {
1165  Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1166  << (C->Init.isUsable() ? C->Init.get()->getSourceRange()
1167  : SourceRange(C->Loc));
1168 
1169  // Just ignore the ellipsis.
1170  }
1171  } else if (Var->isParameterPack()) {
1172  ContainsUnexpandedParameterPack = true;
1173  }
1174 
1175  if (C->Init.isUsable()) {
1176  addInitCapture(LSI, Var);
1177  } else {
1178  TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1179  TryCapture_ExplicitByVal;
1180  tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1181  }
1182  if (!LSI->Captures.empty())
1183  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1184  }
1185  finishLambdaExplicitCaptures(LSI);
1186 
1187  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
1188 
1189  // Add lambda parameters into scope.
1190  addLambdaParameters(Intro.Captures, Method, CurScope);
1191 
1192  // Enter a new evaluation context to insulate the lambda from any
1193  // cleanups from the enclosing full-expression.
1194  PushExpressionEvaluationContext(
1195  ExpressionEvaluationContext::PotentiallyEvaluated);
1196 }
1197 
1199  bool IsInstantiation) {
1200  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1201 
1202  // Leave the expression-evaluation context.
1203  DiscardCleanupsInEvaluationContext();
1204  PopExpressionEvaluationContext();
1205 
1206  // Leave the context of the lambda.
1207  if (!IsInstantiation)
1208  PopDeclContext();
1209 
1210  // Finalize the lambda.
1211  CXXRecordDecl *Class = LSI->Lambda;
1212  Class->setInvalidDecl();
1213  SmallVector<Decl*, 4> Fields(Class->fields());
1214  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1216  CheckCompletedCXXClass(Class);
1217 
1218  PopFunctionScopeInfo();
1219 }
1220 
1222  const FunctionProtoType *CallOpProto) {
1223  // The function type inside the pointer type is the same as the call
1224  // operator with some tweaks. The calling convention is the default free
1225  // function convention, and the type qualifications are lost.
1226  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1227  CallOpProto->getExtProtoInfo();
1228  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1230  CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1231  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1232  InvokerExtInfo.TypeQuals = Qualifiers();
1233  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1234  "Lambda's call operator should not have a reference qualifier");
1235  return Context.getFunctionType(CallOpProto->getReturnType(),
1236  CallOpProto->getParamTypes(), InvokerExtInfo);
1237 }
1238 
1239 /// Add a lambda's conversion to function pointer, as described in
1240 /// C++11 [expr.prim.lambda]p6.
1242  SourceRange IntroducerRange,
1243  CXXRecordDecl *Class,
1244  CXXMethodDecl *CallOperator) {
1245  // This conversion is explicitly disabled if the lambda's function has
1246  // pass_object_size attributes on any of its parameters.
1247  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1248  return P->hasAttr<PassObjectSizeAttr>();
1249  };
1250  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1251  return;
1252 
1253  // Add the conversion to function pointer.
1254  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
1255  CallOperator->getType()->castAs<FunctionProtoType>());
1256  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1257 
1258  // Create the type of the conversion function.
1259  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1261  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1262  // The conversion function is always const and noexcept.
1263  ConvExtInfo.TypeQuals = Qualifiers();
1264  ConvExtInfo.TypeQuals.addConst();
1265  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1266  QualType ConvTy =
1267  S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1268 
1269  SourceLocation Loc = IntroducerRange.getBegin();
1270  DeclarationName ConversionName
1272  S.Context.getCanonicalType(PtrToFunctionTy));
1273  DeclarationNameLoc ConvNameLoc;
1274  // Construct a TypeSourceInfo for the conversion function, and wire
1275  // all the parameters appropriately for the FunctionProtoTypeLoc
1276  // so that everything works during transformation/instantiation of
1277  // generic lambdas.
1278  // The main reason for wiring up the parameters of the conversion
1279  // function with that of the call operator is so that constructs
1280  // like the following work:
1281  // auto L = [](auto b) { <-- 1
1282  // return [](auto a) -> decltype(a) { <-- 2
1283  // return a;
1284  // };
1285  // };
1286  // int (*fp)(int) = L(5);
1287  // Because the trailing return type can contain DeclRefExprs that refer
1288  // to the original call operator's variables, we hijack the call
1289  // operators ParmVarDecls below.
1290  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1291  S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1292  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1293 
1294  // The conversion function is a conversion to a pointer-to-function.
1295  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1296  FunctionProtoTypeLoc ConvTL =
1297  ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1298  // Get the result of the conversion function which is a pointer-to-function.
1299  PointerTypeLoc PtrToFunctionTL =
1300  ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1301  // Do the same for the TypeSourceInfo that is used to name the conversion
1302  // operator.
1303  PointerTypeLoc ConvNamePtrToFunctionTL =
1304  ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1305 
1306  // Get the underlying function types that the conversion function will
1307  // be converting to (should match the type of the call operator).
1308  FunctionProtoTypeLoc CallOpConvTL =
1309  PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1310  FunctionProtoTypeLoc CallOpConvNameTL =
1311  ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1312 
1313  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1314  // These parameter's are essentially used to transform the name and
1315  // the type of the conversion operator. By using the same parameters
1316  // as the call operator's we don't have to fix any back references that
1317  // the trailing return type of the call operator's uses (such as
1318  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1319  // - we can simply use the return type of the call operator, and
1320  // everything should work.
1321  SmallVector<ParmVarDecl *, 4> InvokerParams;
1322  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1323  ParmVarDecl *From = CallOperator->getParamDecl(I);
1324 
1325  InvokerParams.push_back(ParmVarDecl::Create(
1326  S.Context,
1327  // Temporarily add to the TU. This is set to the invoker below.
1329  From->getLocation(), From->getIdentifier(), From->getType(),
1330  From->getTypeSourceInfo(), From->getStorageClass(),
1331  /*DefaultArg=*/nullptr));
1332  CallOpConvTL.setParam(I, From);
1333  CallOpConvNameTL.setParam(I, From);
1334  }
1335 
1337  S.Context, Class, Loc,
1338  DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1339  /*isInline=*/true, ExplicitSpecifier(),
1340  S.getLangOpts().CPlusPlus17 ? CSK_constexpr : CSK_unspecified,
1341  CallOperator->getBody()->getEndLoc());
1342  Conversion->setAccess(AS_public);
1343  Conversion->setImplicit(true);
1344 
1345  if (Class->isGenericLambda()) {
1346  // Create a template version of the conversion operator, using the template
1347  // parameter list of the function call operator.
1348  FunctionTemplateDecl *TemplateCallOperator =
1349  CallOperator->getDescribedFunctionTemplate();
1350  FunctionTemplateDecl *ConversionTemplate =
1352  Loc, ConversionName,
1353  TemplateCallOperator->getTemplateParameters(),
1354  Conversion);
1355  ConversionTemplate->setAccess(AS_public);
1356  ConversionTemplate->setImplicit(true);
1357  Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1358  Class->addDecl(ConversionTemplate);
1359  } else
1360  Class->addDecl(Conversion);
1361  // Add a non-static member function that will be the result of
1362  // the conversion with a certain unique ID.
1363  DeclarationName InvokerName = &S.Context.Idents.get(
1365  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1366  // we should get a prebuilt TrivialTypeSourceInfo from Context
1367  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1368  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1369  // loop below and then use its Params to set Invoke->setParams(...) below.
1370  // This would avoid the 'const' qualifier of the calloperator from
1371  // contaminating the type of the invoker, which is currently adjusted
1372  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments. Fixing the
1373  // trailing return type of the invoker would require a visitor to rebuild
1374  // the trailing return type and adjusting all back DeclRefExpr's to refer
1375  // to the new static invoker parameters - not the call operator's.
1377  S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1378  InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1379  /*IsInline=*/true, CSK_unspecified, CallOperator->getBody()->getEndLoc());
1380  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I)
1381  InvokerParams[I]->setOwningFunction(Invoke);
1382  Invoke->setParams(InvokerParams);
1383  Invoke->setAccess(AS_private);
1384  Invoke->setImplicit(true);
1385  if (Class->isGenericLambda()) {
1386  FunctionTemplateDecl *TemplateCallOperator =
1387  CallOperator->getDescribedFunctionTemplate();
1388  FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1389  S.Context, Class, Loc, InvokerName,
1390  TemplateCallOperator->getTemplateParameters(),
1391  Invoke);
1392  StaticInvokerTemplate->setAccess(AS_private);
1393  StaticInvokerTemplate->setImplicit(true);
1394  Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1395  Class->addDecl(StaticInvokerTemplate);
1396  } else
1397  Class->addDecl(Invoke);
1398 }
1399 
1400 /// Add a lambda's conversion to block pointer.
1402  SourceRange IntroducerRange,
1403  CXXRecordDecl *Class,
1404  CXXMethodDecl *CallOperator) {
1406  CallOperator->getType()->castAs<FunctionProtoType>());
1407  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1408 
1409  FunctionProtoType::ExtProtoInfo ConversionEPI(
1411  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1412  ConversionEPI.TypeQuals = Qualifiers();
1413  ConversionEPI.TypeQuals.addConst();
1414  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1415 
1416  SourceLocation Loc = IntroducerRange.getBegin();
1417  DeclarationName Name
1419  S.Context.getCanonicalType(BlockPtrTy));
1420  DeclarationNameLoc NameLoc;
1421  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1423  S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1424  S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1425  /*isInline=*/true, ExplicitSpecifier(), CSK_unspecified,
1426  CallOperator->getBody()->getEndLoc());
1427  Conversion->setAccess(AS_public);
1428  Conversion->setImplicit(true);
1429  Class->addDecl(Conversion);
1430 }
1431 
1433  SourceLocation ImplicitCaptureLoc,
1434  bool IsOpenMPMapping) {
1435  // VLA captures don't have a stored initialization expression.
1436  if (Cap.isVLATypeCapture())
1437  return ExprResult();
1438 
1439  // An init-capture is initialized directly from its stored initializer.
1440  if (Cap.isInitCapture())
1441  return Cap.getVariable()->getInit();
1442 
1443  // For anything else, build an initialization expression. For an implicit
1444  // capture, the capture notionally happens at the capture-default, so use
1445  // that location here.
1446  SourceLocation Loc =
1447  ImplicitCaptureLoc.isValid() ? ImplicitCaptureLoc : Cap.getLocation();
1448 
1449  // C++11 [expr.prim.lambda]p21:
1450  // When the lambda-expression is evaluated, the entities that
1451  // are captured by copy are used to direct-initialize each
1452  // corresponding non-static data member of the resulting closure
1453  // object. (For array members, the array elements are
1454  // direct-initialized in increasing subscript order.) These
1455  // initializations are performed in the (unspecified) order in
1456  // which the non-static data members are declared.
1457 
1458  // C++ [expr.prim.lambda]p12:
1459  // An entity captured by a lambda-expression is odr-used (3.2) in
1460  // the scope containing the lambda-expression.
1461  ExprResult Init;
1462  IdentifierInfo *Name = nullptr;
1463  if (Cap.isThisCapture()) {
1464  QualType ThisTy = getCurrentThisType();
1465  Expr *This = BuildCXXThisExpr(Loc, ThisTy, ImplicitCaptureLoc.isValid());
1466  if (Cap.isCopyCapture())
1467  Init = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
1468  else
1469  Init = This;
1470  } else {
1471  assert(Cap.isVariableCapture() && "unknown kind of capture");
1472  VarDecl *Var = Cap.getVariable();
1473  Name = Var->getIdentifier();
1474  Init = BuildDeclarationNameExpr(
1475  CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1476  }
1477 
1478  // In OpenMP, the capture kind doesn't actually describe how to capture:
1479  // variables are "mapped" onto the device in a process that does not formally
1480  // make a copy, even for a "copy capture".
1481  if (IsOpenMPMapping)
1482  return Init;
1483 
1484  if (Init.isInvalid())
1485  return ExprError();
1486 
1487  Expr *InitExpr = Init.get();
1489  Name, Cap.getCaptureType(), Loc);
1490  InitializationKind InitKind =
1491  InitializationKind::CreateDirect(Loc, Loc, Loc);
1492  InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr);
1493  return InitSeq.Perform(*this, Entity, InitKind, InitExpr);
1494 }
1495 
1497  Scope *CurScope) {
1498  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1499  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1500  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1501 }
1502 
1503 static LambdaCaptureDefault
1505  switch (ICS) {
1507  return LCD_None;
1509  return LCD_ByCopy;
1512  return LCD_ByRef;
1514  llvm_unreachable("block capture in lambda");
1515  }
1516  llvm_unreachable("Unknown implicit capture style");
1517 }
1518 
1520  if (From.isInitCapture()) {
1521  Expr *Init = From.getVariable()->getInit();
1522  if (Init && Init->HasSideEffects(Context))
1523  return true;
1524  }
1525 
1526  if (!From.isCopyCapture())
1527  return false;
1528 
1529  const QualType T = From.isThisCapture()
1530  ? getCurrentThisType()->getPointeeType()
1531  : From.getCaptureType();
1532 
1533  if (T.isVolatileQualified())
1534  return true;
1535 
1536  const Type *BaseT = T->getBaseElementTypeUnsafe();
1537  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1538  return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1539  !RD->hasTrivialDestructor();
1540 
1541  return false;
1542 }
1543 
1545  const Capture &From) {
1546  if (CaptureHasSideEffects(From))
1547  return false;
1548 
1549  if (From.isVLATypeCapture())
1550  return false;
1551 
1552  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1553  if (From.isThisCapture())
1554  diag << "'this'";
1555  else
1556  diag << From.getVariable();
1557  diag << From.isNonODRUsed();
1558  diag << FixItHint::CreateRemoval(CaptureRange);
1559  return true;
1560 }
1561 
1562 /// Create a field within the lambda class or captured statement record for the
1563 /// given capture.
1565  const sema::Capture &Capture) {
1566  SourceLocation Loc = Capture.getLocation();
1567  QualType FieldType = Capture.getCaptureType();
1568 
1569  TypeSourceInfo *TSI = nullptr;
1570  if (Capture.isVariableCapture()) {
1571  auto *Var = Capture.getVariable();
1572  if (Var->isInitCapture())
1573  TSI = Capture.getVariable()->getTypeSourceInfo();
1574  }
1575 
1576  // FIXME: Should we really be doing this? A null TypeSourceInfo seems more
1577  // appropriate, at least for an implicit capture.
1578  if (!TSI)
1579  TSI = Context.getTrivialTypeSourceInfo(FieldType, Loc);
1580 
1581  // Build the non-static data member.
1582  FieldDecl *Field =
1583  FieldDecl::Create(Context, RD, Loc, Loc, nullptr, FieldType, TSI, nullptr,
1584  false, ICIS_NoInit);
1585  // If the variable being captured has an invalid type, mark the class as
1586  // invalid as well.
1587  if (!FieldType->isDependentType()) {
1588  if (RequireCompleteType(Loc, FieldType, diag::err_field_incomplete)) {
1589  RD->setInvalidDecl();
1590  Field->setInvalidDecl();
1591  } else {
1592  NamedDecl *Def;
1593  FieldType->isIncompleteType(&Def);
1594  if (Def && Def->isInvalidDecl()) {
1595  RD->setInvalidDecl();
1596  Field->setInvalidDecl();
1597  }
1598  }
1599  }
1600  Field->setImplicit(true);
1601  Field->setAccess(AS_private);
1602  RD->addDecl(Field);
1603 
1604  if (Capture.isVLATypeCapture())
1605  Field->setCapturedVLAType(Capture.getCapturedVLAType());
1606 
1607  return Field;
1608 }
1609 
1611  LambdaScopeInfo *LSI) {
1612  // Collect information from the lambda scope.
1614  SmallVector<Expr *, 4> CaptureInits;
1615  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1616  LambdaCaptureDefault CaptureDefault =
1618  CXXRecordDecl *Class;
1619  CXXMethodDecl *CallOperator;
1620  SourceRange IntroducerRange;
1621  bool ExplicitParams;
1622  bool ExplicitResultType;
1623  CleanupInfo LambdaCleanup;
1624  bool ContainsUnexpandedParameterPack;
1625  bool IsGenericLambda;
1626  {
1627  CallOperator = LSI->CallOperator;
1628  Class = LSI->Lambda;
1629  IntroducerRange = LSI->IntroducerRange;
1630  ExplicitParams = LSI->ExplicitParams;
1631  ExplicitResultType = !LSI->HasImplicitReturnType;
1632  LambdaCleanup = LSI->Cleanup;
1633  ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1634  IsGenericLambda = Class->isGenericLambda();
1635 
1636  CallOperator->setLexicalDeclContext(Class);
1637  Decl *TemplateOrNonTemplateCallOperatorDecl =
1638  CallOperator->getDescribedFunctionTemplate()
1639  ? CallOperator->getDescribedFunctionTemplate()
1640  : cast<Decl>(CallOperator);
1641 
1642  TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1643  Class->addDecl(TemplateOrNonTemplateCallOperatorDecl);
1644 
1645  PopExpressionEvaluationContext();
1646 
1647  // True if the current capture has a used capture or default before it.
1648  bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1649  SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1650  CaptureDefaultLoc : IntroducerRange.getBegin();
1651 
1652  for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) {
1653  const Capture &From = LSI->Captures[I];
1654 
1655  if (From.isInvalid())
1656  return ExprError();
1657 
1658  assert(!From.isBlockCapture() && "Cannot capture __block variables");
1659  bool IsImplicit = I >= LSI->NumExplicitCaptures;
1660  SourceLocation ImplicitCaptureLoc =
1661  IsImplicit ? CaptureDefaultLoc : SourceLocation();
1662 
1663  // Use source ranges of explicit captures for fixits where available.
1664  SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1665 
1666  // Warn about unused explicit captures.
1667  bool IsCaptureUsed = true;
1668  if (!CurContext->isDependentContext() && !IsImplicit &&
1669  !From.isODRUsed()) {
1670  // Initialized captures that are non-ODR used may not be eliminated.
1671  // FIXME: Where did the IsGenericLambda here come from?
1672  bool NonODRUsedInitCapture =
1673  IsGenericLambda && From.isNonODRUsed() && From.isInitCapture();
1674  if (!NonODRUsedInitCapture) {
1675  bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1676  SourceRange FixItRange;
1677  if (CaptureRange.isValid()) {
1678  if (!CurHasPreviousCapture && !IsLast) {
1679  // If there are no captures preceding this capture, remove the
1680  // following comma.
1681  FixItRange = SourceRange(CaptureRange.getBegin(),
1682  getLocForEndOfToken(CaptureRange.getEnd()));
1683  } else {
1684  // Otherwise, remove the comma since the last used capture.
1685  FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1686  CaptureRange.getEnd());
1687  }
1688  }
1689 
1690  IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1691  }
1692  }
1693 
1694  if (CaptureRange.isValid()) {
1695  CurHasPreviousCapture |= IsCaptureUsed;
1696  PrevCaptureLoc = CaptureRange.getEnd();
1697  }
1698 
1699  // Map the capture to our AST representation.
1700  LambdaCapture Capture = [&] {
1701  if (From.isThisCapture()) {
1702  // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1703  // because it results in a reference capture. Don't warn prior to
1704  // C++2a; there's nothing that can be done about it before then.
1705  if (getLangOpts().CPlusPlus2a && IsImplicit &&
1706  CaptureDefault == LCD_ByCopy) {
1707  Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1708  Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1710  getLocForEndOfToken(CaptureDefaultLoc), ", this");
1711  }
1712  return LambdaCapture(From.getLocation(), IsImplicit,
1713  From.isCopyCapture() ? LCK_StarThis : LCK_This);
1714  } else if (From.isVLATypeCapture()) {
1715  return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType);
1716  } else {
1717  assert(From.isVariableCapture() && "unknown kind of capture");
1718  VarDecl *Var = From.getVariable();
1720  From.isCopyCapture() ? LCK_ByCopy : LCK_ByRef;
1721  return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var,
1722  From.getEllipsisLoc());
1723  }
1724  }();
1725 
1726  // Form the initializer for the capture field.
1727  ExprResult Init = BuildCaptureInit(From, ImplicitCaptureLoc);
1728 
1729  // FIXME: Skip this capture if the capture is not used, the initializer
1730  // has no side-effects, the type of the capture is trivial, and the
1731  // lambda is not externally visible.
1732 
1733  // Add a FieldDecl for the capture and form its initializer.
1734  BuildCaptureField(Class, From);
1735  Captures.push_back(Capture);
1736  CaptureInits.push_back(Init.get());
1737  }
1738 
1739  // C++11 [expr.prim.lambda]p6:
1740  // The closure type for a lambda-expression with no lambda-capture
1741  // has a public non-virtual non-explicit const conversion function
1742  // to pointer to function having the same parameter and return
1743  // types as the closure type's function call operator.
1744  if (Captures.empty() && CaptureDefault == LCD_None)
1745  addFunctionPointerConversion(*this, IntroducerRange, Class,
1746  CallOperator);
1747 
1748  // Objective-C++:
1749  // The closure type for a lambda-expression has a public non-virtual
1750  // non-explicit const conversion function to a block pointer having the
1751  // same parameter and return types as the closure type's function call
1752  // operator.
1753  // FIXME: Fix generic lambda to block conversions.
1754  if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda)
1755  addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1756 
1757  // Finalize the lambda class.
1758  SmallVector<Decl*, 4> Fields(Class->fields());
1759  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1761  CheckCompletedCXXClass(Class);
1762  }
1763 
1764  Cleanup.mergeFrom(LambdaCleanup);
1765 
1766  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1767  CaptureDefault, CaptureDefaultLoc,
1768  Captures,
1769  ExplicitParams, ExplicitResultType,
1770  CaptureInits, EndLoc,
1771  ContainsUnexpandedParameterPack);
1772  // If the lambda expression's call operator is not explicitly marked constexpr
1773  // and we are not in a dependent context, analyze the call operator to infer
1774  // its constexpr-ness, suppressing diagnostics while doing so.
1775  if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() &&
1776  !CallOperator->isConstexpr() &&
1777  !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1778  !Class->getDeclContext()->isDependentContext()) {
1779  TentativeAnalysisScope DiagnosticScopeGuard(*this);
1780  CallOperator->setConstexprKind(
1781  (CheckConstexprFunctionDecl(CallOperator) &&
1782  CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()))
1783  ? CSK_constexpr
1784  : CSK_unspecified);
1785  }
1786 
1787  // Emit delayed shadowing warnings now that the full capture list is known.
1788  DiagnoseShadowingLambdaDecls(LSI);
1789 
1790  if (!CurContext->isDependentContext()) {
1791  switch (ExprEvalContexts.back().Context) {
1792  // C++11 [expr.prim.lambda]p2:
1793  // A lambda-expression shall not appear in an unevaluated operand
1794  // (Clause 5).
1795  case ExpressionEvaluationContext::Unevaluated:
1796  case ExpressionEvaluationContext::UnevaluatedList:
1797  case ExpressionEvaluationContext::UnevaluatedAbstract:
1798  // C++1y [expr.const]p2:
1799  // A conditional-expression e is a core constant expression unless the
1800  // evaluation of e, following the rules of the abstract machine, would
1801  // evaluate [...] a lambda-expression.
1802  //
1803  // This is technically incorrect, there are some constant evaluated contexts
1804  // where this should be allowed. We should probably fix this when DR1607 is
1805  // ratified, it lays out the exact set of conditions where we shouldn't
1806  // allow a lambda-expression.
1807  case ExpressionEvaluationContext::ConstantEvaluated:
1808  // We don't actually diagnose this case immediately, because we
1809  // could be within a context where we might find out later that
1810  // the expression is potentially evaluated (e.g., for typeid).
1811  ExprEvalContexts.back().Lambdas.push_back(Lambda);
1812  break;
1813 
1814  case ExpressionEvaluationContext::DiscardedStatement:
1815  case ExpressionEvaluationContext::PotentiallyEvaluated:
1816  case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1817  break;
1818  }
1819  }
1820 
1821  return MaybeBindToTemporary(Lambda);
1822 }
1823 
1825  SourceLocation ConvLocation,
1826  CXXConversionDecl *Conv,
1827  Expr *Src) {
1828  // Make sure that the lambda call operator is marked used.
1829  CXXRecordDecl *Lambda = Conv->getParent();
1830  CXXMethodDecl *CallOperator
1831  = cast<CXXMethodDecl>(
1832  Lambda->lookup(
1833  Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1834  CallOperator->setReferenced();
1835  CallOperator->markUsed(Context);
1836 
1837  ExprResult Init = PerformCopyInitialization(
1839  /*NRVO=*/false),
1840  CurrentLocation, Src);
1841  if (!Init.isInvalid())
1842  Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1843 
1844  if (Init.isInvalid())
1845  return ExprError();
1846 
1847  // Create the new block to be returned.
1848  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1849 
1850  // Set the type information.
1851  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1852  Block->setIsVariadic(CallOperator->isVariadic());
1853  Block->setBlockMissingReturnType(false);
1854 
1855  // Add parameters.
1856  SmallVector<ParmVarDecl *, 4> BlockParams;
1857  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1858  ParmVarDecl *From = CallOperator->getParamDecl(I);
1859  BlockParams.push_back(ParmVarDecl::Create(
1860  Context, Block, From->getBeginLoc(), From->getLocation(),
1861  From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1862  From->getStorageClass(),
1863  /*DefaultArg=*/nullptr));
1864  }
1865  Block->setParams(BlockParams);
1866 
1867  Block->setIsConversionFromLambda(true);
1868 
1869  // Add capture. The capture uses a fake variable, which doesn't correspond
1870  // to any actual memory location. However, the initializer copy-initializes
1871  // the lambda object.
1872  TypeSourceInfo *CapVarTSI =
1873  Context.getTrivialTypeSourceInfo(Src->getType());
1874  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
1875  ConvLocation, nullptr,
1876  Src->getType(), CapVarTSI,
1877  SC_None);
1878  BlockDecl::Capture Capture(/*Variable=*/CapVar, /*ByRef=*/false,
1879  /*Nested=*/false, /*Copy=*/Init.get());
1880  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
1881 
1882  // Add a fake function body to the block. IR generation is responsible
1883  // for filling in the actual body, which cannot be expressed as an AST.
1884  Block->setBody(new (Context) CompoundStmt(ConvLocation));
1885 
1886  // Create the block literal expression.
1887  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
1888  ExprCleanupObjects.push_back(Block);
1889  Cleanup.setExprNeedsCleanups(true);
1890 
1891  return BuildBlock;
1892 }
void setImplicit(bool I=true)
Definition: DeclBase.h:559
Represents a function declaration or definition.
Definition: Decl.h:1748
SourceRange IntroducerRange
Source range covering the lambda introducer [...].
Definition: ScopeInfo.h:798
DeclaratorChunk::FunctionTypeInfo & getFunctionTypeInfo()
getFunctionTypeInfo - Retrieves the function type info object (looking through parentheses).
Definition: DeclSpec.h:2278
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
SourceLocation getBeginLoc() const
Definition: Stmt.h:2647
A class which contains all the information about a particular captured value.
Definition: Decl.h:3890
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T -> getSizeExpr()))
unsigned getRawEncoding() const
When a SourceLocation itself cannot be used, this returns an (opaque) 32-bit integer encoding for it...
A (possibly-)qualified type.
Definition: Type.h:643
bool ExplicitParams
Whether the (empty) parameter list is explicit.
Definition: ScopeInfo.h:812
TemplateParameterList * GLTemplateParameterList
If this is a generic lambda, and the template parameter list has been created (from the TemplateParam...
Definition: ScopeInfo.h:842
bool SetTypeQual(TQ T, SourceLocation Loc)
Definition: DeclSpec.cpp:914
Stmt - This represents one statement.
Definition: Stmt.h:66
An instance of this object exists for each enum constant that is defined.
Definition: Decl.h:2812
QualType ReturnType
ReturnType - The target type of return statements in this context, or null if unknown.
Definition: ScopeInfo.h:658
StorageClass getStorageClass() const
Returns the storage class as written in the source.
Definition: Decl.h:1019
bool isConstexpr() const
Whether this is a (C++11) constexpr function or constexpr constructor.
Definition: Decl.h:2108
DeclarationName getCXXConversionFunctionName(CanQualType Ty)
Returns the name of a C++ conversion function for the given Type.
QualType getCaptureType() const
Retrieve the capture type for this capture, which is effectively the type of the non-static data memb...
Definition: ScopeInfo.h:624
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:4020
LambdaCaptureDefault
The default, if any, capture method for a lambda expression.
Definition: Lambda.h:22
CanQualType getCanonicalFunctionResultType(QualType ResultType) const
Adjust the given function result type.
StringRef P
ExprResult BuildBlockForLambdaConversion(SourceLocation CurrentLocation, SourceLocation ConvLocation, CXXConversionDecl *Conv, Expr *Src)
bool isCopyCapture() const
Definition: ScopeInfo.h:583
static InitializationKind CreateDirect(SourceLocation InitLoc, SourceLocation LParenLoc, SourceLocation RParenLoc)
Create a direct initialization.
QualType getBlockPointerType(QualType T) const
Return the uniqued reference to the type for a block of the specified type.
The base class of the type hierarchy.
Definition: Type.h:1418
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.cpp:4385
bool isFunctionDeclarator(unsigned &idx) const
isFunctionDeclarator - This method returns true if the declarator is a function declarator (looking t...
Definition: DeclSpec.h:2247
A container of type source information.
Definition: Decl.h:86
Store information needed for an explicit specifier.
Definition: DeclCXX.h:1999
QualType getConversionType() const
Returns the type that this conversion function is converting to.
Definition: DeclCXX.h:2923
void setInitStyle(InitializationStyle Style)
Definition: Decl.h:1269
Describes the capture of a variable or of this, or of a C++1y init-capture.
Definition: LambdaCapture.h:25
__m128i_u * p
Definition: emmintrin.h:2134
This file provides some common utility functions for processing Lambda related AST Constructs...
bool isODRUsed() const
Definition: ScopeInfo.h:595
Represents a variable declaration or definition.
Definition: Decl.h:812
bool DiagnoseUnusedLambdaCapture(SourceRange CaptureRange, const sema::Capture &From)
Diagnose if an explicit lambda capture is unused.
Information about one declarator, including the parsed type information and the identifier.
Definition: DeclSpec.h:1775
QualType getReturnType() const
Definition: Decl.h:2329
VarDecl * createLambdaInitCaptureVarDecl(SourceLocation Loc, QualType InitCaptureType, SourceLocation EllipsisLoc, IdentifierInfo *Id, unsigned InitStyle, Expr *Init)
Create a dummy variable within the declcontext of the lambda&#39;s call operator, for name lookup purpose...
Definition: SemaLambda.cpp:819
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6818
Extra information about a function prototype.
Definition: Type.h:3784
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:553
Stores a list of template parameters for a TemplateDecl and its derived classes.
Definition: DeclTemplate.h:67
MangleNumberingContext & getMangleNumberingContext(ASTContext &Ctx)
Retrieve the mangling numbering context, used to consistently number constructs like lambdas for mang...
Definition: SemaLambda.cpp:362
static InitializationKind CreateDirectList(SourceLocation InitLoc)
bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc, TryCaptureKind Kind, SourceLocation EllipsisLoc, bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const unsigned *const FunctionScopeIndexToStopAt)
Try to capture the given variable.
Definition: SemaExpr.cpp:15575
bool CaptureHasSideEffects(const sema::Capture &From)
Does copying/destroying the captured variable have side effects?
Represents an expression – generally a full-expression – that introduces cleanups to be run at the ...
Definition: ExprCXX.h:3207
Represents a parameter to a function.
Definition: Decl.h:1564
CXXRecordDecl * createLambdaClosureType(SourceRange IntroducerRange, TypeSourceInfo *Info, bool KnownDependent, LambdaCaptureDefault CaptureDefault)
Create a new lambda closure type.
Definition: SemaLambda.cpp:241
Defines the clang::Expr interface and subclasses for C++ expressions.
long i
Definition: xmmintrin.h:1456
The collection of all-type qualifiers we support.
Definition: Type.h:137
tok::TokenKind ContextKind
static CXXMethodDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInline, ConstexprSpecKind ConstexprKind, SourceLocation EndLocation)
Definition: DeclCXX.cpp:1998
bool FTIHasNonVoidParameters(const DeclaratorChunk::FunctionTypeInfo &FTI)
Definition: SemaInternal.h:36
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Represents a struct/union/class.
Definition: Decl.h:3619
Scope * getTemplateParamParent()
Definition: Scope.h:262
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3785
One of these records is kept for each identifier that is lexed.
bool isConst() const
Definition: DeclCXX.h:2149
sema::LambdaScopeInfo * getCurGenericLambda()
Retrieve the current generic lambda info, if any.
Definition: Sema.cpp:1803
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
ArrayRef< QualType > getParamTypes() const
Definition: Type.h:3913
field_range fields() const
Definition: Decl.h:3810
TypeSourceInfo * getTypeSourceInfo(ASTContext &Context, QualType T)
Creates a TypeSourceInfo for the given type.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
std::unique_ptr< MangleNumberingContext > createMangleNumberingContext() const
LambdaCaptureKind
The different capture forms in a lambda introducer.
Definition: Lambda.h:33
Represents a member of a struct/union/class.
Definition: Decl.h:2605
bool isReferenceType() const
Definition: Type.h:6363
bool Equals(const DeclContext *DC) const
Determine whether this declaration context is equivalent to the declaration context DC...
Definition: DeclBase.h:1896
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.h:2320
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:738
static CXXRecordDecl * CreateLambda(const ASTContext &C, DeclContext *DC, TypeSourceInfo *Info, SourceLocation Loc, bool DependentLambda, bool IsGeneric, LambdaCaptureDefault CaptureDefault)
Definition: DeclCXX.cpp:139
bool ContainsUnexpandedParameterPack
Whether the lambda contains an unexpanded parameter pack.
Definition: ScopeInfo.h:818
IdentifierTable & Idents
Definition: ASTContext.h:569
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:124
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2289
DeclClass * getAsSingle() const
Definition: Lookup.h:507
bool isThisCapture() const
Definition: ScopeInfo.h:578
void setNameLoc(SourceLocation Loc)
Definition: TypeLoc.h:523
Represents the results of name lookup.
Definition: Lookup.h:46
PtrTy get() const
Definition: Ownership.h:170
Stmt * getBody(const FunctionDecl *&Definition) const
Retrieve the body (definition) of the function.
Definition: Decl.cpp:2808
RAII class used to indicate that we are performing provisional semantic analysis to determine the val...
Definition: Sema.h:7834
< Capturing the *this object by copy
Definition: Lambda.h:36
static LambdaCaptureDefault mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS)
static InitializedEntity InitializeLambdaToBlock(SourceLocation BlockVarLoc, QualType Type, bool NRVO)
Keeps track of the mangled names of lambda expressions and block literals within a particular context...
FunctionTemplateDecl * getDescribedFunctionTemplate() const
Retrieves the function template that is described by this function declaration.
Definition: Decl.cpp:3443
bool CheckCXXThisCapture(SourceLocation Loc, bool Explicit=false, bool BuildAndDiagnose=true, const unsigned *const FunctionScopeIndexToStopAt=nullptr, bool ByCopy=false)
Make sure the value of &#39;this&#39; is actually available in the current context, if it is a potentially ev...
unsigned getNumTypeObjects() const
Return the number of types applied to this declarator.
Definition: DeclSpec.h:2185
const VariableArrayType * getCapturedVLAType() const
Definition: ScopeInfo.h:609
bool containsUnexpandedParameterPack() const
Whether this type is or contains an unexpanded parameter pack, used to support C++0x variadic templat...
Definition: Type.h:1844
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3407
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6197
void setLambdaMangling(unsigned ManglingNumber, Decl *ContextDecl)
Set the mangling number and context declaration for a lambda class.
Definition: DeclCXX.h:1941
void finishedExplicitCaptures()
Note when all explicit captures have been added.
Definition: ScopeInfo.h:885
DeclContext * getLambdaAwareParentOfDeclContext(DeclContext *DC)
Definition: ASTLambda.h:70
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
ExprResult Perform(Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind, MultiExprArg Args, QualType *ResultType=nullptr)
Perform the actual initialization of the given entity based on the computed initialization sequence...
Definition: SemaInit.cpp:7363
void addInitCapture(sema::LambdaScopeInfo *LSI, VarDecl *Var)
Add an init-capture to a lambda scope.
Definition: SemaLambda.cpp:845
static EnumDecl * findCommonEnumForBlockReturns(ArrayRef< ReturnStmt *> returns)
Attempt to find a common type T for which all of the returned expressions in a block are enumerator-l...
Definition: SemaLambda.cpp:615
bool hasNameForLinkage() const
Is this tag type named, either directly or via being defined in a typedef of this type...
Definition: Decl.h:3296
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:63
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1722
unsigned NumExplicitTemplateParams
The number of parameters in the template parameter list that were explicitly specified by the user...
Definition: ScopeInfo.h:827
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1952
const LangOptions & getLangOpts() const
Definition: Sema.h:1285
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:27
ExprResult BuildCaptureInit(const sema::Capture &Capture, SourceLocation ImplicitCaptureLoc, bool IsOpenMPMapping=false)
Initialize the given capture with a suitable expression.
static FunctionTemplateDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L, DeclarationName Name, TemplateParameterList *Params, NamedDecl *Decl)
Create a function template node.
StringRef getLambdaStaticInvokerName()
Definition: ASTLambda.h:22
QualType getLambdaConversionFunctionResultType(const FunctionProtoType *CallOpType)
Get the return type to use for a lambda&#39;s conversion function(s) to function pointer type...
static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange, CXXRecordDecl *Class, CXXMethodDecl *CallOperator)
Add a lambda&#39;s conversion to function pointer, as described in C++11 [expr.prim.lambda]p6.
void addLambdaParameters(ArrayRef< LambdaIntroducer::LambdaCapture > Captures, CXXMethodDecl *CallOperator, Scope *CurScope)
Introduce the lambda parameters into scope.
Definition: SemaLambda.cpp:507
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod, bool IsBuiltin=false) const
Retrieves the default calling convention for the current target.
TypeSpecTypeLoc pushTypeSpec(QualType T)
Pushes space for a typespec TypeLoc.
CleanupInfo Cleanup
Whether any of the capture expressions requires cleanups.
Definition: ScopeInfo.h:815
TyLocType push(QualType T)
Pushes space for a new TypeLoc of the given type.
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1601
ExtInfo withCallingConv(CallingConv cc) const
Definition: Type.h:3588
ImplicitCaptureStyle ImpCaptureStyle
Definition: ScopeInfo.h:637
bool isIntegralOrUnscopedEnumerationType() const
Determine whether this type is an integral or unscoped enumeration type.
Definition: Type.cpp:1803
ConditionalOperator - The ?: ternary operator.
Definition: Expr.h:3705
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:328
CompoundStmt - This represents a group of statements like { stmt stmt }.
Definition: Stmt.h:1303
bool Mutable
Whether this is a mutable lambda.
Definition: ScopeInfo.h:809
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1636
SmallVector< ReturnStmt *, 4 > Returns
The list of return statements that occur within the function or block, if there is any chance of appl...
Definition: ScopeInfo.h:190
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3704
static ImplicitCastExpr * Create(const ASTContext &Context, QualType T, CastKind Kind, Expr *Operand, const CXXCastPath *BasePath, ExprValueKind Cat)
Definition: Expr.cpp:1951
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:572
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI)
Note that we have finished the explicit captures for the given lambda.
Definition: SemaLambda.cpp:486
SourceLocation getEllipsisLoc() const
Retrieve the source location of the ellipsis, whose presence indicates that the capture is a pack exp...
Definition: ScopeInfo.h:619
SmallVector< LambdaCapture, 4 > Captures
Definition: DeclSpec.h:2584
SourceLocation PotentialThisCaptureLocation
Definition: ScopeInfo.h:877
unsigned NumExplicitCaptures
The number of captures in the Captures list that are explicit captures.
Definition: ScopeInfo.h:806
TypeSourceInfo * getTrivialTypeSourceInfo(QualType T, SourceLocation Loc=SourceLocation()) const
Allocate a TypeSourceInfo where all locations have been initialized to a given location, which defaults to the empty location.
bool isVariableCapture() const
Definition: ScopeInfo.h:579
bool HasSideEffects(const ASTContext &Ctx, bool IncludePossibleEffects=true) const
HasSideEffects - This routine returns true for all those expressions which have any effect other than...
Definition: Expr.cpp:3294
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
Definition: DeclTemplate.h:436
static CXXConversionDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, bool isInline, ExplicitSpecifier ES, ConstexprSpecKind ConstexprKind, SourceLocation EndLocation)
Definition: DeclCXX.cpp:2573
DeclContext * getLexicalParent()
getLexicalParent - Returns the containing lexical DeclContext.
Definition: DeclBase.h:1788
CXXMethodDecl * CallOperator
The lambda&#39;s compiler-generated operator().
Definition: ScopeInfo.h:795
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3884
bool isInvalid() const
Definition: ScopeInfo.h:590
ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, Scope *CurScope)
ActOnLambdaExpr - This is called when the body of a lambda expression was successfully completed...
This represents one expression.
Definition: Expr.h:108
bool isVariadic() const
Whether this function is variadic.
Definition: Decl.cpp:2766
int Id
Definition: ASTDiff.cpp:190
bool hasLocalStorage() const
Returns true if a variable with function scope is a non-static local variable.
Definition: Decl.h:1035
This file defines the classes used to store parsed information about declaration-specifiers and decla...
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6883
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5543
T getAs() const
Convert to the specified TypeLoc type, returning a null TypeLoc if this TypeLoc is not of the desired...
Definition: TypeLoc.h:86
void setInit(Expr *I)
Definition: Decl.cpp:2239
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:131
void setRetValue(Expr *E)
Definition: Stmt.h:2623
bool isFileContext() const
Definition: DeclBase.h:1842
DeclContext * getDeclContext()
Definition: DeclBase.h:438
static TemplateParameterList * getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef)
Definition: SemaLambda.cpp:228
llvm::DenseMap< unsigned, SourceRange > ExplicitCaptureRanges
A map of explicit capture indices to their introducer source ranges.
Definition: ScopeInfo.h:866
void buildLambdaScope(sema::LambdaScopeInfo *LSI, CXXMethodDecl *CallOperator, SourceRange IntroducerRange, LambdaCaptureDefault CaptureDefault, SourceLocation CaptureDefaultLoc, bool ExplicitParams, bool ExplicitResultType, bool Mutable)
Endow the lambda scope info with the relevant properties.
Definition: SemaLambda.cpp:451
bool isCaptured(VarDecl *Var) const
Determine whether the given variable has been captured.
Definition: ScopeInfo.h:687
QualType getType() const
Definition: Expr.h:137
bool isFunctionOrMethod() const
Definition: DeclBase.h:1824
Capture & getCapture(VarDecl *Var)
Retrieve the capture of the given variable, if it has been captured already.
Definition: ScopeInfo.h:696
Direct list-initialization (C++11)
Definition: Decl.h:823
static LambdaExpr * Create(const ASTContext &C, CXXRecordDecl *Class, SourceRange IntroducerRange, LambdaCaptureDefault CaptureDefault, SourceLocation CaptureDefaultLoc, ArrayRef< LambdaCapture > Captures, bool ExplicitParams, bool ExplicitResultType, ArrayRef< Expr *> CaptureInits, SourceLocation ClosingBrace, bool ContainsUnexpandedParameterPack)
Construct a new lambda expression.
Definition: ExprCXX.cpp:1131
DeclarationName getCXXOperatorName(OverloadedOperatorKind Op)
Get the name of the overloadable C++ operator corresponding to Op.
static bool isInInlineFunction(const DeclContext *DC)
Determine whether the given context is or is enclosed in an inline function.
Definition: SemaLambda.cpp:263
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1772
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2588
bool isInvalid() const
Definition: Ownership.h:166
SourceLocation getEnd() const
QualType getFunctionType(QualType ResultTy, ArrayRef< QualType > Args, const FunctionProtoType::ExtProtoInfo &EPI) const
Return a normal function type with a typed argument list.
Definition: ASTContext.h:1382
struct CXXOpName CXXOperatorName
bool isDependentContext() const
Determines whether this context is dependent on a template parameter.
Definition: DeclBase.cpp:1081
Common base class for placeholders for types that get replaced by placeholder type deduction: C++11 a...
Definition: Type.h:4762
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6758
Represents a C++ conversion function within a class.
Definition: DeclCXX.h:2886
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h:1398
SourceLocation getLocation() const
Retrieve the location at which this variable was captured.
Definition: ScopeInfo.h:615
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:708
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:264
TypeLoc getReturnLoc() const
Definition: TypeLoc.h:1446
static TemplateParameterList * Create(const ASTContext &C, SourceLocation TemplateLoc, SourceLocation LAngleLoc, ArrayRef< NamedDecl *> Params, SourceLocation RAngleLoc, Expr *RequiresClause)
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:276
static InitializationKind CreateCopy(SourceLocation InitLoc, SourceLocation EqualLoc, bool AllowExplicitConvs=false)
Create a copy initialization.
ConstexprSpecKind getConstexprSpecifier() const
Definition: DeclSpec.h:731
void setIsVariadic(bool value)
Definition: Decl.h:3960
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, sema::LambdaScopeInfo *LSI)
Complete a lambda-expression having processed and attached the lambda body.
QualType getPackExpansionType(QualType Pattern, Optional< unsigned > NumExpansions)
SmallVector< NamedDecl *, 4 > TemplateParams
Store the list of the template parameters for a generic lambda.
Definition: ScopeInfo.h:837
void setIsConversionFromLambda(bool val=true)
Definition: Decl.h:4031
SourceLocation DefaultLoc
Definition: DeclSpec.h:2582
Kind
bool hasWeakerNullability(NullabilityKind L, NullabilityKind R)
Return true if L has a weaker nullability annotation than R.
Definition: Specifiers.h:328
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
VarDecl * getVariable() const
Definition: ScopeInfo.h:604
ExtProtoInfo getExtProtoInfo() const
Definition: Type.h:3917
unsigned getNumExprs() const
Return the number of expressions in this paren list.
Definition: Expr.h:5133
Encodes a location in the source.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
QualType getReturnType() const
Definition: Type.h:3630
Expr * getRetValue()
Definition: Stmt.h:2621
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4449
static InitializedEntity InitializeLambdaCapture(IdentifierInfo *VarID, QualType FieldType, SourceLocation Loc)
Create the initialization entity for a lambda capture.
CXXRecordDecl * Lambda
The class that describes the lambda.
Definition: ScopeInfo.h:792
static Optional< unsigned > getStackIndexOfNearestEnclosingCaptureReadyLambda(ArrayRef< const clang::sema::FunctionScopeInfo *> FunctionScopes, VarDecl *VarToCapture)
Examines the FunctionScopeInfo stack to determine the nearest enclosing lambda (to the current lambda...
Definition: SemaLambda.cpp:63
SourceRange ExplicitTemplateParamsRange
Source range covering the explicit template parameter list (if it exists).
Definition: ScopeInfo.h:830
MutableArrayRef< Expr * > MultiExprArg
Definition: Ownership.h:273
void setReferenced(bool R=true)
Definition: DeclBase.h:588
CXXMethodDecl * startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange, TypeSourceInfo *MethodType, SourceLocation EndLoc, ArrayRef< ParmVarDecl *> Params, ConstexprSpecKind ConstexprKind, Optional< std::pair< unsigned, Decl *>> Mangling=None)
Start the definition of a lambda expression.
Definition: SemaLambda.cpp:370
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2109
No ref-qualifier was provided.
Definition: Type.h:1371
C-style initialization with assignment.
Definition: Decl.h:817
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2312
bool isVLATypeCapture() const
Definition: ScopeInfo.h:586
CanQualType VoidTy
Definition: ASTContext.h:1014
bool isGenericLambda() const
Determine whether this class describes a generic lambda function object (i.e.
Definition: DeclCXX.cpp:1358
Describes the kind of initialization being performed, along with location information for tokens rela...
SmallVector< Capture, 4 > Captures
Captures - The captures.
Definition: ScopeInfo.h:650
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3247
MangleNumberingContext * getCurrentMangleNumberContext(const DeclContext *DC, Decl *&ManglingContextDecl)
Compute the mangling number context for a lambda expression or block literal.
Definition: SemaLambda.cpp:276
SourceLocation CaptureDefaultLoc
Source location of the &#39;&&#39; or &#39;=&#39; specifying the default capture type, if any.
Definition: ScopeInfo.h:802
Expr ** getExprs()
Definition: Expr.h:5144
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3924
static EnumDecl * findEnumForBlockReturn(Expr *E)
If this expression is an enumerator-like expression of some type T, return the type T; otherwise...
Definition: SemaLambda.cpp:543
Represents a pack expansion of types.
Definition: Type.h:5410
DeclarationNameLoc - Additional source/type location info for a declaration name. ...
SourceRange getSourceRange() const LLVM_READONLY
Get the source range that spans this declarator.
Definition: DeclSpec.h:1899
This file provides some common utility functions for processing Lambdas.
static ParmVarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S, Expr *DefArg)
Definition: Decl.cpp:2616
Dataflow Directional Tag Classes.
void ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope, bool IsInstantiation=false)
ActOnLambdaError - If there is an error parsing a lambda, this callback is invoked to pop the informa...
void setBody(CompoundStmt *B)
Definition: Decl.h:3964
ConstexprSpecKind
Define the kind of constexpr specifier.
Definition: Specifiers.h:32
bool isValid() const
Return true if this is a valid SourceLocation object.
LambdaCaptureDefault Default
Definition: DeclSpec.h:2583
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1271
void deduceClosureReturnType(sema::CapturingScopeInfo &CSI)
Deduce a block or lambda&#39;s return type based on the return statements present in the body...
Definition: SemaLambda.cpp:662
bool isRecord() const
Definition: DeclBase.h:1851
Optional< unsigned > getStackIndexOfNearestEnclosingCaptureCapableLambda(ArrayRef< const sema::FunctionScopeInfo *> FunctionScopes, VarDecl *VarToCapture, Sema &S)
Examines the FunctionScopeInfo stack to determine the nearest enclosing lambda (to the current lambda...
Definition: SemaLambda.cpp:173
static FixItHint CreateRemoval(CharSourceRange RemoveRange)
Create a code modification hint that removes the given source range.
Definition: Diagnostic.h:117
const Expr * getInit() const
Definition: Decl.h:1219
static void addBlockPointerConversion(Sema &S, SourceRange IntroducerRange, CXXRecordDecl *Class, CXXMethodDecl *CallOperator)
Add a lambda&#39;s conversion to block pointer.
The name of a declaration.
const CXXRecordDecl * getParent() const
Returns the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2232
MangleNumberingContext & getManglingNumberContext(const DeclContext *DC)
Retrieve the context for computing mangling numbers in the given DeclContext.
Represents an enum.
Definition: Decl.h:3352
bool isParameterPack() const
Determine whether this variable is actually a function parameter pack or init-capture pack...
Definition: Decl.cpp:2420
bool isInitCapture() const
Whether this variable is the implicit variable for a lambda init-capture.
Definition: Decl.h:1395
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
void ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc, ArrayRef< NamedDecl *> TParams, SourceLocation RAngleLoc)
This is called after parsing the explicit template parameter list on a lambda (if it exists) in C++2a...
Definition: SemaLambda.cpp:490
bool isUndeducedType() const
Determine whether this type is an undeduced type, meaning that it somehow involves a C++11 &#39;auto&#39; typ...
Definition: Type.h:6733
void setInitCapture(bool IC)
Definition: Decl.h:1398
Capturing variable-length array type.
Definition: Lambda.h:38
void ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, Declarator &ParamInfo, Scope *CurScope)
ActOnStartOfLambdaDefinition - This is called just before we start parsing the body of a lambda; it a...
Definition: SemaLambda.cpp:852
void setConstexprKind(ConstexprSpecKind CSK)
Definition: Decl.h:2111
CanQualType DependentTy
Definition: ASTContext.h:1043
TypeSourceInfo * getTypeSourceInfo() const
Definition: Decl.h:715
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2296
Simple template class for restricting typo correction candidates to ones having a single Decl* of the...
QualType getAutoDeductType() const
C++11 deduction pattern for &#39;auto&#39; type.
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:91
void addDecl(Decl *D)
Add the declaration D into this context.
Definition: DeclBase.cpp:1513
Optional< NullabilityKind > getNullability(const ASTContext &context) const
Determine the nullability of the given type.
Definition: Type.cpp:3799
Capturing the *this object by reference.
Definition: Lambda.h:34
void markUsed(ASTContext &C)
Mark the declaration used, in the sense of odr-use.
Definition: DeclBase.cpp:412
Capture & getCXXThisCapture()
Retrieve the capture of C++ &#39;this&#39;, if it has been captured.
Definition: ScopeInfo.h:681
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types...
Definition: Type.cpp:2062
FieldDecl * BuildCaptureField(RecordDecl *RD, const sema::Capture &Capture)
Build a FieldDecl suitable to hold the given capture.
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2280
void setSignatureAsWritten(TypeSourceInfo *Sig)
Definition: Decl.h:3966
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:240
bool isInitCapture() const
Determine whether this capture is an init-capture.
Definition: ScopeInfo.cpp:219
static BlockDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L)
Definition: Decl.cpp:4561
Call-style initialization (C++98)
Definition: Decl.h:820
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1007
void addCapture(VarDecl *Var, bool isBlock, bool isByref, bool isNested, SourceLocation Loc, SourceLocation EllipsisLoc, QualType CaptureType, bool Invalid)
Definition: ScopeInfo.h:660
Describes the sequence of initializations required to initialize a given object or reference with a s...
ActionResult< Expr * > ExprResult
Definition: Ownership.h:263
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
bool isValid() const
bool isVoidType() const
Definition: Type.h:6610
Capturing by reference.
Definition: Lambda.h:37
TryCaptureKind
Definition: Sema.h:4202
const DeclSpec & getDeclSpec() const
getDeclSpec - Return the declaration-specifier that this declarator was declared with.
Definition: DeclSpec.h:1864
bool isCXXThisCaptured() const
Determine whether the C++ &#39;this&#39; is captured.
Definition: ScopeInfo.h:678
bool containsUnexpandedParameterPack() const
Whether this expression contains an unexpanded parameter pack (for C++11 variadic templates)...
Definition: Expr.h:223
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
void setCapturedVLAType(const VariableArrayType *VLAType)
Set the captured variable length array type for this field.
Definition: Decl.cpp:3945
void addAttr(Attr *A)
Definition: DeclBase.cpp:828
Defines the clang::TargetInfo interface.
Represents a complete lambda introducer.
Definition: DeclSpec.h:2559
ExprResult ExprError()
Definition: Ownership.h:279
void setDescribedFunctionTemplate(FunctionTemplateDecl *Template)
Definition: Decl.cpp:3447
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2093
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1143
bool isNonODRUsed() const
Definition: ScopeInfo.h:596
QualType getType() const
Definition: Decl.h:647
bool empty() const
Return true if no decls were found.
Definition: Lookup.h:339
void setCaptures(ASTContext &Context, ArrayRef< Capture > Captures, bool CapturesCXXThis)
Definition: Decl.cpp:4396
A trivial tuple used to represent a source range.
void setLexicalDeclContext(DeclContext *DC)
Definition: DeclBase.cpp:298
ASTContext & Context
Definition: Sema.h:374
This represents a decl that may have a name.
Definition: Decl.h:248
bool isTranslationUnit() const
Definition: DeclBase.h:1847
void setAccess(AccessSpecifier AS)
Definition: DeclBase.h:468
void setBlockMissingReturnType(bool val=true)
Definition: Decl.h:4023
Describes an entity that is being initialized.
QualType buildLambdaInitCaptureInitialization(SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc, Optional< unsigned > NumExpansions, IdentifierInfo *Id, bool DirectInit, Expr *&Init)
Definition: SemaLambda.cpp:755
static FieldDecl * Create(const ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable, InClassInitStyle InitStyle)
Definition: Decl.cpp:3881
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3138
Wrapper for source info for pointers.
Definition: TypeLoc.h:1237
SourceLocation getBegin() const
bool isBlockCapture() const
Definition: ScopeInfo.h:585
static void adjustBlockReturnsToEnum(Sema &S, ArrayRef< ReturnStmt *> returns, QualType returnType)
Adjust the given return statements so that they formally return the given type.
Definition: SemaLambda.cpp:636
No in-class initializer.
Definition: Specifiers.h:258
Declaration of a template function.
Attr - This represents one attribute.
Definition: Attr.h:43
SourceLocation getLocation() const
Definition: DeclBase.h:429
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97
Expr * IgnoreParens() LLVM_READONLY
Skip past any parentheses which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2913