clang  8.0.0svn
SemaLambda.cpp
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1 //===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements semantic analysis for C++ lambda expressions.
11 //
12 //===----------------------------------------------------------------------===//
13 #include "clang/Sema/DeclSpec.h"
14 #include "TypeLocBuilder.h"
15 #include "clang/AST/ASTLambda.h"
16 #include "clang/AST/ExprCXX.h"
17 #include "clang/Basic/TargetInfo.h"
19 #include "clang/Sema/Lookup.h"
20 #include "clang/Sema/Scope.h"
21 #include "clang/Sema/ScopeInfo.h"
23 #include "clang/Sema/SemaLambda.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)
230  return LSI->GLTemplateParameterList;
231 
232  if (!LSI->AutoTemplateParams.empty()) {
233  SourceRange IntroRange = LSI->IntroducerRange;
234  SourceLocation LAngleLoc = IntroRange.getBegin();
235  SourceLocation RAngleLoc = IntroRange.getEnd();
237  SemaRef.Context,
238  /*Template kw loc*/ SourceLocation(), LAngleLoc,
239  llvm::makeArrayRef((NamedDecl *const *)LSI->AutoTemplateParams.data(),
240  LSI->AutoTemplateParams.size()),
241  RAngleLoc, nullptr);
242  }
243  return LSI->GLTemplateParameterList;
244 }
245 
247  TypeSourceInfo *Info,
248  bool KnownDependent,
249  LambdaCaptureDefault CaptureDefault) {
250  DeclContext *DC = CurContext;
251  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
252  DC = DC->getParent();
253  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
254  *this);
255  // Start constructing the lambda class.
256  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
257  IntroducerRange.getBegin(),
258  KnownDependent,
259  IsGenericLambda,
260  CaptureDefault);
261  DC->addDecl(Class);
262 
263  return Class;
264 }
265 
266 /// Determine whether the given context is or is enclosed in an inline
267 /// function.
268 static bool isInInlineFunction(const DeclContext *DC) {
269  while (!DC->isFileContext()) {
270  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
271  if (FD->isInlined())
272  return true;
273 
274  DC = DC->getLexicalParent();
275  }
276 
277  return false;
278 }
279 
282  Decl *&ManglingContextDecl) {
283  // Compute the context for allocating mangling numbers in the current
284  // expression, if the ABI requires them.
285  ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
286 
287  enum ContextKind {
288  Normal,
289  DefaultArgument,
290  DataMember,
291  StaticDataMember,
292  InlineVariable,
293  VariableTemplate
294  } Kind = Normal;
295 
296  // Default arguments of member function parameters that appear in a class
297  // definition, as well as the initializers of data members, receive special
298  // treatment. Identify them.
299  if (ManglingContextDecl) {
300  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
301  if (const DeclContext *LexicalDC
302  = Param->getDeclContext()->getLexicalParent())
303  if (LexicalDC->isRecord())
304  Kind = DefaultArgument;
305  } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
306  if (Var->getDeclContext()->isRecord())
307  Kind = StaticDataMember;
308  else if (Var->getMostRecentDecl()->isInline())
309  Kind = InlineVariable;
310  else if (Var->getDescribedVarTemplate())
311  Kind = VariableTemplate;
312  else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
313  if (!VTS->isExplicitSpecialization())
314  Kind = VariableTemplate;
315  }
316  } else if (isa<FieldDecl>(ManglingContextDecl)) {
317  Kind = DataMember;
318  }
319  }
320 
321  // Itanium ABI [5.1.7]:
322  // In the following contexts [...] the one-definition rule requires closure
323  // types in different translation units to "correspond":
324  bool IsInNonspecializedTemplate =
325  inTemplateInstantiation() || CurContext->isDependentContext();
326  switch (Kind) {
327  case Normal: {
328  // -- the bodies of non-exported nonspecialized template functions
329  // -- the bodies of inline functions
330  if ((IsInNonspecializedTemplate &&
331  !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
332  isInInlineFunction(CurContext)) {
333  ManglingContextDecl = nullptr;
334  while (auto *CD = dyn_cast<CapturedDecl>(DC))
335  DC = CD->getParent();
336  return &Context.getManglingNumberContext(DC);
337  }
338 
339  ManglingContextDecl = nullptr;
340  return nullptr;
341  }
342 
343  case StaticDataMember:
344  // -- the initializers of nonspecialized static members of template classes
345  if (!IsInNonspecializedTemplate) {
346  ManglingContextDecl = nullptr;
347  return nullptr;
348  }
349  // Fall through to get the current context.
350  LLVM_FALLTHROUGH;
351 
352  case DataMember:
353  // -- the in-class initializers of class members
354  case DefaultArgument:
355  // -- default arguments appearing in class definitions
356  case InlineVariable:
357  // -- the initializers of inline variables
358  case VariableTemplate:
359  // -- the initializers of templated variables
360  return &ExprEvalContexts.back().getMangleNumberingContext(Context);
361  }
362 
363  llvm_unreachable("unexpected context");
364 }
365 
368  ASTContext &Ctx) {
369  assert(ManglingContextDecl && "Need to have a context declaration");
370  if (!MangleNumbering)
371  MangleNumbering = Ctx.createMangleNumberingContext();
372  return *MangleNumbering;
373 }
374 
376  SourceRange IntroducerRange,
377  TypeSourceInfo *MethodTypeInfo,
378  SourceLocation EndLoc,
380  const bool IsConstexprSpecified) {
381  QualType MethodType = MethodTypeInfo->getType();
382  TemplateParameterList *TemplateParams =
383  getGenericLambdaTemplateParameterList(getCurLambda(), *this);
384  // If a lambda appears in a dependent context or is a generic lambda (has
385  // template parameters) and has an 'auto' return type, deduce it to a
386  // dependent type.
387  if (Class->isDependentContext() || TemplateParams) {
388  const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
389  QualType Result = FPT->getReturnType();
390  if (Result->isUndeducedType()) {
391  Result = SubstAutoType(Result, Context.DependentTy);
392  MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
393  FPT->getExtProtoInfo());
394  }
395  }
396 
397  // C++11 [expr.prim.lambda]p5:
398  // The closure type for a lambda-expression has a public inline function
399  // call operator (13.5.4) whose parameters and return type are described by
400  // the lambda-expression's parameter-declaration-clause and
401  // trailing-return-type respectively.
402  DeclarationName MethodName
403  = Context.DeclarationNames.getCXXOperatorName(OO_Call);
404  DeclarationNameLoc MethodNameLoc;
405  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
406  = IntroducerRange.getBegin().getRawEncoding();
407  MethodNameLoc.CXXOperatorName.EndOpNameLoc
408  = IntroducerRange.getEnd().getRawEncoding();
409  CXXMethodDecl *Method
410  = CXXMethodDecl::Create(Context, Class, EndLoc,
411  DeclarationNameInfo(MethodName,
412  IntroducerRange.getBegin(),
413  MethodNameLoc),
414  MethodType, MethodTypeInfo,
415  SC_None,
416  /*isInline=*/true,
417  IsConstexprSpecified,
418  EndLoc);
419  Method->setAccess(AS_public);
420 
421  // Temporarily set the lexical declaration context to the current
422  // context, so that the Scope stack matches the lexical nesting.
423  Method->setLexicalDeclContext(CurContext);
424  // Create a function template if we have a template parameter list
425  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
426  FunctionTemplateDecl::Create(Context, Class,
427  Method->getLocation(), MethodName,
428  TemplateParams,
429  Method) : nullptr;
430  if (TemplateMethod) {
431  TemplateMethod->setLexicalDeclContext(CurContext);
432  TemplateMethod->setAccess(AS_public);
433  Method->setDescribedFunctionTemplate(TemplateMethod);
434  }
435 
436  // Add parameters.
437  if (!Params.empty()) {
438  Method->setParams(Params);
439  CheckParmsForFunctionDef(Params,
440  /*CheckParameterNames=*/false);
441 
442  for (auto P : Method->parameters())
443  P->setOwningFunction(Method);
444  }
445 
446  Decl *ManglingContextDecl;
447  if (MangleNumberingContext *MCtx =
448  getCurrentMangleNumberContext(Class->getDeclContext(),
449  ManglingContextDecl)) {
450  unsigned ManglingNumber = MCtx->getManglingNumber(Method);
451  Class->setLambdaMangling(ManglingNumber, ManglingContextDecl);
452  }
453 
454  return Method;
455 }
456 
458  CXXMethodDecl *CallOperator,
459  SourceRange IntroducerRange,
460  LambdaCaptureDefault CaptureDefault,
461  SourceLocation CaptureDefaultLoc,
462  bool ExplicitParams,
463  bool ExplicitResultType,
464  bool Mutable) {
465  LSI->CallOperator = CallOperator;
466  CXXRecordDecl *LambdaClass = CallOperator->getParent();
467  LSI->Lambda = LambdaClass;
468  if (CaptureDefault == LCD_ByCopy)
470  else if (CaptureDefault == LCD_ByRef)
472  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
473  LSI->IntroducerRange = IntroducerRange;
474  LSI->ExplicitParams = ExplicitParams;
475  LSI->Mutable = Mutable;
476 
477  if (ExplicitResultType) {
478  LSI->ReturnType = CallOperator->getReturnType();
479 
480  if (!LSI->ReturnType->isDependentType() &&
481  !LSI->ReturnType->isVoidType()) {
482  if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
483  diag::err_lambda_incomplete_result)) {
484  // Do nothing.
485  }
486  }
487  } else {
488  LSI->HasImplicitReturnType = true;
489  }
490 }
491 
494 }
495 
498  CXXMethodDecl *CallOperator, Scope *CurScope) {
499  // Introduce our parameters into the function scope
500  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
501  p < NumParams; ++p) {
502  ParmVarDecl *Param = CallOperator->getParamDecl(p);
503 
504  // If this has an identifier, add it to the scope stack.
505  if (CurScope && Param->getIdentifier()) {
506  bool Error = false;
507  // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
508  // retroactively apply it.
509  for (const auto &Capture : Captures) {
510  if (Capture.Id == Param->getIdentifier()) {
511  Error = true;
512  Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
513  Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
514  << Capture.Id << true;
515  }
516  }
517  if (!Error)
518  CheckShadow(CurScope, Param);
519 
520  PushOnScopeChains(Param, CurScope);
521  }
522  }
523 }
524 
525 /// If this expression is an enumerator-like expression of some type
526 /// T, return the type T; otherwise, return null.
527 ///
528 /// Pointer comparisons on the result here should always work because
529 /// it's derived from either the parent of an EnumConstantDecl
530 /// (i.e. the definition) or the declaration returned by
531 /// EnumType::getDecl() (i.e. the definition).
533  // An expression is an enumerator-like expression of type T if,
534  // ignoring parens and parens-like expressions:
535  E = E->IgnoreParens();
536 
537  // - it is an enumerator whose enum type is T or
538  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
539  if (EnumConstantDecl *D
540  = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
541  return cast<EnumDecl>(D->getDeclContext());
542  }
543  return nullptr;
544  }
545 
546  // - it is a comma expression whose RHS is an enumerator-like
547  // expression of type T or
548  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
549  if (BO->getOpcode() == BO_Comma)
550  return findEnumForBlockReturn(BO->getRHS());
551  return nullptr;
552  }
553 
554  // - it is a statement-expression whose value expression is an
555  // enumerator-like expression of type T or
556  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
557  if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
558  return findEnumForBlockReturn(last);
559  return nullptr;
560  }
561 
562  // - it is a ternary conditional operator (not the GNU ?:
563  // extension) whose second and third operands are
564  // enumerator-like expressions of type T or
565  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
566  if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
567  if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
568  return ED;
569  return nullptr;
570  }
571 
572  // (implicitly:)
573  // - it is an implicit integral conversion applied to an
574  // enumerator-like expression of type T or
575  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
576  // We can sometimes see integral conversions in valid
577  // enumerator-like expressions.
578  if (ICE->getCastKind() == CK_IntegralCast)
579  return findEnumForBlockReturn(ICE->getSubExpr());
580 
581  // Otherwise, just rely on the type.
582  }
583 
584  // - it is an expression of that formal enum type.
585  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
586  return ET->getDecl();
587  }
588 
589  // Otherwise, nope.
590  return nullptr;
591 }
592 
593 /// Attempt to find a type T for which the returned expression of the
594 /// given statement is an enumerator-like expression of that type.
596  if (Expr *retValue = ret->getRetValue())
597  return findEnumForBlockReturn(retValue);
598  return nullptr;
599 }
600 
601 /// Attempt to find a common type T for which all of the returned
602 /// expressions in a block are enumerator-like expressions of that
603 /// type.
605  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
606 
607  // Try to find one for the first return.
609  if (!ED) return nullptr;
610 
611  // Check that the rest of the returns have the same enum.
612  for (++i; i != e; ++i) {
613  if (findEnumForBlockReturn(*i) != ED)
614  return nullptr;
615  }
616 
617  // Never infer an anonymous enum type.
618  if (!ED->hasNameForLinkage()) return nullptr;
619 
620  return ED;
621 }
622 
623 /// Adjust the given return statements so that they formally return
624 /// the given type. It should require, at most, an IntegralCast.
626  QualType returnType) {
628  i = returns.begin(), e = returns.end(); i != e; ++i) {
629  ReturnStmt *ret = *i;
630  Expr *retValue = ret->getRetValue();
631  if (S.Context.hasSameType(retValue->getType(), returnType))
632  continue;
633 
634  // Right now we only support integral fixup casts.
635  assert(returnType->isIntegralOrUnscopedEnumerationType());
636  assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
637 
638  ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
639 
640  Expr *E = (cleanups ? cleanups->getSubExpr() : retValue);
641  E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast,
642  E, /*base path*/ nullptr, VK_RValue);
643  if (cleanups) {
644  cleanups->setSubExpr(E);
645  } else {
646  ret->setRetValue(E);
647  }
648  }
649 }
650 
652  assert(CSI.HasImplicitReturnType);
653  // If it was ever a placeholder, it had to been deduced to DependentTy.
654  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
655  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
656  "lambda expressions use auto deduction in C++14 onwards");
657 
658  // C++ core issue 975:
659  // If a lambda-expression does not include a trailing-return-type,
660  // it is as if the trailing-return-type denotes the following type:
661  // - if there are no return statements in the compound-statement,
662  // or all return statements return either an expression of type
663  // void or no expression or braced-init-list, the type void;
664  // - otherwise, if all return statements return an expression
665  // and the types of the returned expressions after
666  // lvalue-to-rvalue conversion (4.1 [conv.lval]),
667  // array-to-pointer conversion (4.2 [conv.array]), and
668  // function-to-pointer conversion (4.3 [conv.func]) are the
669  // same, that common type;
670  // - otherwise, the program is ill-formed.
671  //
672  // C++ core issue 1048 additionally removes top-level cv-qualifiers
673  // from the types of returned expressions to match the C++14 auto
674  // deduction rules.
675  //
676  // In addition, in blocks in non-C++ modes, if all of the return
677  // statements are enumerator-like expressions of some type T, where
678  // T has a name for linkage, then we infer the return type of the
679  // block to be that type.
680 
681  // First case: no return statements, implicit void return type.
682  ASTContext &Ctx = getASTContext();
683  if (CSI.Returns.empty()) {
684  // It's possible there were simply no /valid/ return statements.
685  // In this case, the first one we found may have at least given us a type.
686  if (CSI.ReturnType.isNull())
687  CSI.ReturnType = Ctx.VoidTy;
688  return;
689  }
690 
691  // Second case: at least one return statement has dependent type.
692  // Delay type checking until instantiation.
693  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
694  if (CSI.ReturnType->isDependentType())
695  return;
696 
697  // Try to apply the enum-fuzz rule.
698  if (!getLangOpts().CPlusPlus) {
699  assert(isa<BlockScopeInfo>(CSI));
701  if (ED) {
702  CSI.ReturnType = Context.getTypeDeclType(ED);
704  return;
705  }
706  }
707 
708  // Third case: only one return statement. Don't bother doing extra work!
709  if (CSI.Returns.size() == 1)
710  return;
711 
712  // General case: many return statements.
713  // Check that they all have compatible return types.
714 
715  // We require the return types to strictly match here.
716  // Note that we've already done the required promotions as part of
717  // processing the return statement.
718  for (const ReturnStmt *RS : CSI.Returns) {
719  const Expr *RetE = RS->getRetValue();
720 
721  QualType ReturnType =
722  (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType();
723  if (Context.getCanonicalFunctionResultType(ReturnType) ==
725  // Use the return type with the strictest possible nullability annotation.
726  auto RetTyNullability = ReturnType->getNullability(Ctx);
727  auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
728  if (BlockNullability &&
729  (!RetTyNullability ||
730  hasWeakerNullability(*RetTyNullability, *BlockNullability)))
731  CSI.ReturnType = ReturnType;
732  continue;
733  }
734 
735  // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
736  // TODO: It's possible that the *first* return is the divergent one.
737  Diag(RS->getBeginLoc(),
738  diag::err_typecheck_missing_return_type_incompatible)
739  << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
740  // Continue iterating so that we keep emitting diagnostics.
741  }
742 }
743 
745  bool ByRef,
747  bool IsDirectInit,
748  Expr *&Init) {
749  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
750  // deduce against.
751  QualType DeductType = Context.getAutoDeductType();
752  TypeLocBuilder TLB;
753  TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
754  if (ByRef) {
755  DeductType = BuildReferenceType(DeductType, true, Loc, Id);
756  assert(!DeductType.isNull() && "can't build reference to auto");
757  TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
758  }
759  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
760 
761  // Deduce the type of the init capture.
762  QualType DeducedType = deduceVarTypeFromInitializer(
763  /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
764  SourceRange(Loc, Loc), IsDirectInit, Init);
765  if (DeducedType.isNull())
766  return QualType();
767 
768  // Are we a non-list direct initialization?
769  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
770 
771  // Perform initialization analysis and ensure any implicit conversions
772  // (such as lvalue-to-rvalue) are enforced.
773  InitializedEntity Entity =
774  InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
776  IsDirectInit
777  ? (CXXDirectInit ? InitializationKind::CreateDirect(
778  Loc, Init->getBeginLoc(), Init->getEndLoc())
781 
782  MultiExprArg Args = Init;
783  if (CXXDirectInit)
784  Args =
785  MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
786  QualType DclT;
787  InitializationSequence InitSeq(*this, Entity, Kind, Args);
788  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
789 
790  if (Result.isInvalid())
791  return QualType();
792 
793  Init = Result.getAs<Expr>();
794  return DeducedType;
795 }
796 
798  QualType InitCaptureType,
800  unsigned InitStyle, Expr *Init) {
801  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType,
802  Loc);
803  // Create a dummy variable representing the init-capture. This is not actually
804  // used as a variable, and only exists as a way to name and refer to the
805  // init-capture.
806  // FIXME: Pass in separate source locations for '&' and identifier.
807  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
808  Loc, Id, InitCaptureType, TSI, SC_Auto);
809  NewVD->setInitCapture(true);
810  NewVD->setReferenced(true);
811  // FIXME: Pass in a VarDecl::InitializationStyle.
812  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
813  NewVD->markUsed(Context);
814  NewVD->setInit(Init);
815  return NewVD;
816 }
817 
819  FieldDecl *Field = FieldDecl::Create(
820  Context, LSI->Lambda, Var->getLocation(), Var->getLocation(),
821  nullptr, Var->getType(), Var->getTypeSourceInfo(), nullptr, false,
822  ICIS_NoInit);
823  Field->setImplicit(true);
824  Field->setAccess(AS_private);
825  LSI->Lambda->addDecl(Field);
826 
827  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
828  /*isNested*/false, Var->getLocation(), SourceLocation(),
829  Var->getType(), Var->getInit());
830  return Field;
831 }
832 
834  Declarator &ParamInfo,
835  Scope *CurScope) {
836  // Determine if we're within a context where we know that the lambda will
837  // be dependent, because there are template parameters in scope.
838  bool KnownDependent = false;
839  LambdaScopeInfo *const LSI = getCurLambda();
840  assert(LSI && "LambdaScopeInfo should be on stack!");
841 
842  // The lambda-expression's closure type might be dependent even if its
843  // semantic context isn't, if it appears within a default argument of a
844  // function template.
845  if (CurScope->getTemplateParamParent())
846  KnownDependent = true;
847 
848  // Determine the signature of the call operator.
849  TypeSourceInfo *MethodTyInfo;
850  bool ExplicitParams = true;
851  bool ExplicitResultType = true;
852  bool ContainsUnexpandedParameterPack = false;
853  SourceLocation EndLoc;
855  if (ParamInfo.getNumTypeObjects() == 0) {
856  // C++11 [expr.prim.lambda]p4:
857  // If a lambda-expression does not include a lambda-declarator, it is as
858  // if the lambda-declarator were ().
860  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
861  EPI.HasTrailingReturn = true;
862  EPI.TypeQuals |= DeclSpec::TQ_const;
863  // C++1y [expr.prim.lambda]:
864  // The lambda return type is 'auto', which is replaced by the
865  // trailing-return type if provided and/or deduced from 'return'
866  // statements
867  // We don't do this before C++1y, because we don't support deduced return
868  // types there.
869  QualType DefaultTypeForNoTrailingReturn =
870  getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
871  : Context.DependentTy;
872  QualType MethodTy =
873  Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
874  MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
875  ExplicitParams = false;
876  ExplicitResultType = false;
877  EndLoc = Intro.Range.getEnd();
878  } else {
879  assert(ParamInfo.isFunctionDeclarator() &&
880  "lambda-declarator is a function");
882 
883  // C++11 [expr.prim.lambda]p5:
884  // This function call operator is declared const (9.3.1) if and only if
885  // the lambda-expression's parameter-declaration-clause is not followed
886  // by mutable. It is neither virtual nor declared volatile. [...]
887  if (!FTI.hasMutableQualifier())
889 
890  MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
891  assert(MethodTyInfo && "no type from lambda-declarator");
892  EndLoc = ParamInfo.getSourceRange().getEnd();
893 
894  ExplicitResultType = FTI.hasTrailingReturnType();
895 
896  if (FTIHasNonVoidParameters(FTI)) {
897  Params.reserve(FTI.NumParams);
898  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i)
899  Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
900  }
901 
902  // Check for unexpanded parameter packs in the method type.
903  if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
904  ContainsUnexpandedParameterPack = true;
905  }
906 
907  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
908  KnownDependent, Intro.Default);
909 
910  CXXMethodDecl *Method =
911  startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
912  ParamInfo.getDeclSpec().isConstexprSpecified());
913  if (ExplicitParams)
914  CheckCXXDefaultArguments(Method);
915 
916  // This represents the function body for the lambda function, check if we
917  // have to apply optnone due to a pragma.
918  AddRangeBasedOptnone(Method);
919 
920  // code_seg attribute on lambda apply to the method.
921  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
922  Method->addAttr(A);
923 
924  // Attributes on the lambda apply to the method.
925  ProcessDeclAttributes(CurScope, Method, ParamInfo);
926 
927  // CUDA lambdas get implicit attributes based on the scope in which they're
928  // declared.
929  if (getLangOpts().CUDA)
930  CUDASetLambdaAttrs(Method);
931 
932  // Introduce the function call operator as the current declaration context.
933  PushDeclContext(CurScope, Method);
934 
935  // Build the lambda scope.
936  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
937  ExplicitParams, ExplicitResultType, !Method->isConst());
938 
939  // C++11 [expr.prim.lambda]p9:
940  // A lambda-expression whose smallest enclosing scope is a block scope is a
941  // local lambda expression; any other lambda expression shall not have a
942  // capture-default or simple-capture in its lambda-introducer.
943  //
944  // For simple-captures, this is covered by the check below that any named
945  // entity is a variable that can be captured.
946  //
947  // For DR1632, we also allow a capture-default in any context where we can
948  // odr-use 'this' (in particular, in a default initializer for a non-static
949  // data member).
950  if (Intro.Default != LCD_None && !Class->getParent()->isFunctionOrMethod() &&
951  (getCurrentThisType().isNull() ||
952  CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
953  /*BuildAndDiagnose*/false)))
954  Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
955 
956  // Distinct capture names, for diagnostics.
957  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
958 
959  // Handle explicit captures.
960  SourceLocation PrevCaptureLoc
961  = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc;
962  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
963  PrevCaptureLoc = C->Loc, ++C) {
964  if (C->Kind == LCK_This || C->Kind == LCK_StarThis) {
965  if (C->Kind == LCK_StarThis)
966  Diag(C->Loc, !getLangOpts().CPlusPlus17
967  ? diag::ext_star_this_lambda_capture_cxx17
968  : diag::warn_cxx14_compat_star_this_lambda_capture);
969 
970  // C++11 [expr.prim.lambda]p8:
971  // An identifier or this shall not appear more than once in a
972  // lambda-capture.
973  if (LSI->isCXXThisCaptured()) {
974  Diag(C->Loc, diag::err_capture_more_than_once)
975  << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
977  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
978  continue;
979  }
980 
981  // C++2a [expr.prim.lambda]p8:
982  // If a lambda-capture includes a capture-default that is =,
983  // each simple-capture of that lambda-capture shall be of the form
984  // "&identifier", "this", or "* this". [ Note: The form [&,this] is
985  // redundant but accepted for compatibility with ISO C++14. --end note ]
986  if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis)
987  Diag(C->Loc, !getLangOpts().CPlusPlus2a
988  ? diag::ext_equals_this_lambda_capture_cxx2a
989  : diag::warn_cxx17_compat_equals_this_lambda_capture);
990 
991  // C++11 [expr.prim.lambda]p12:
992  // If this is captured by a local lambda expression, its nearest
993  // enclosing function shall be a non-static member function.
994  QualType ThisCaptureType = getCurrentThisType();
995  if (ThisCaptureType.isNull()) {
996  Diag(C->Loc, diag::err_this_capture) << true;
997  continue;
998  }
999 
1000  CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1001  /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1002  C->Kind == LCK_StarThis);
1003  if (!LSI->Captures.empty())
1004  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1005  continue;
1006  }
1007 
1008  assert(C->Id && "missing identifier for capture");
1009 
1010  if (C->Init.isInvalid())
1011  continue;
1012 
1013  VarDecl *Var = nullptr;
1014  if (C->Init.isUsable()) {
1015  Diag(C->Loc, getLangOpts().CPlusPlus14
1016  ? diag::warn_cxx11_compat_init_capture
1017  : diag::ext_init_capture);
1018 
1019  if (C->Init.get()->containsUnexpandedParameterPack())
1020  ContainsUnexpandedParameterPack = true;
1021  // If the initializer expression is usable, but the InitCaptureType
1022  // is not, then an error has occurred - so ignore the capture for now.
1023  // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1024  // FIXME: we should create the init capture variable and mark it invalid
1025  // in this case.
1026  if (C->InitCaptureType.get().isNull())
1027  continue;
1028 
1029  unsigned InitStyle;
1030  switch (C->InitKind) {
1032  llvm_unreachable("not an init-capture?");
1034  InitStyle = VarDecl::CInit;
1035  break;
1037  InitStyle = VarDecl::CallInit;
1038  break;
1040  InitStyle = VarDecl::ListInit;
1041  break;
1042  }
1043  Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1044  C->Id, InitStyle, C->Init.get());
1045  // C++1y [expr.prim.lambda]p11:
1046  // An init-capture behaves as if it declares and explicitly
1047  // captures a variable [...] whose declarative region is the
1048  // lambda-expression's compound-statement
1049  if (Var)
1050  PushOnScopeChains(Var, CurScope, false);
1051  } else {
1052  assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1053  "init capture has valid but null init?");
1054 
1055  // C++11 [expr.prim.lambda]p8:
1056  // If a lambda-capture includes a capture-default that is &, the
1057  // identifiers in the lambda-capture shall not be preceded by &.
1058  // If a lambda-capture includes a capture-default that is =, [...]
1059  // each identifier it contains shall be preceded by &.
1060  if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) {
1061  Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1063  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1064  continue;
1065  } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) {
1066  Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1068  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1069  continue;
1070  }
1071 
1072  // C++11 [expr.prim.lambda]p10:
1073  // The identifiers in a capture-list are looked up using the usual
1074  // rules for unqualified name lookup (3.4.1)
1075  DeclarationNameInfo Name(C->Id, C->Loc);
1076  LookupResult R(*this, Name, LookupOrdinaryName);
1077  LookupName(R, CurScope);
1078  if (R.isAmbiguous())
1079  continue;
1080  if (R.empty()) {
1081  // FIXME: Disable corrections that would add qualification?
1082  CXXScopeSpec ScopeSpec;
1083  if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R,
1084  llvm::make_unique<DeclFilterCCC<VarDecl>>()))
1085  continue;
1086  }
1087 
1088  Var = R.getAsSingle<VarDecl>();
1089  if (Var && DiagnoseUseOfDecl(Var, C->Loc))
1090  continue;
1091  }
1092 
1093  // C++11 [expr.prim.lambda]p8:
1094  // An identifier or this shall not appear more than once in a
1095  // lambda-capture.
1096  if (!CaptureNames.insert(C->Id).second) {
1097  if (Var && LSI->isCaptured(Var)) {
1098  Diag(C->Loc, diag::err_capture_more_than_once)
1099  << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1101  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1102  } else
1103  // Previous capture captured something different (one or both was
1104  // an init-cpature): no fixit.
1105  Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1106  continue;
1107  }
1108 
1109  // C++11 [expr.prim.lambda]p10:
1110  // [...] each such lookup shall find a variable with automatic storage
1111  // duration declared in the reaching scope of the local lambda expression.
1112  // Note that the 'reaching scope' check happens in tryCaptureVariable().
1113  if (!Var) {
1114  Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1115  continue;
1116  }
1117 
1118  // Ignore invalid decls; they'll just confuse the code later.
1119  if (Var->isInvalidDecl())
1120  continue;
1121 
1122  if (!Var->hasLocalStorage()) {
1123  Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1124  Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1125  continue;
1126  }
1127 
1128  // C++11 [expr.prim.lambda]p23:
1129  // A capture followed by an ellipsis is a pack expansion (14.5.3).
1130  SourceLocation EllipsisLoc;
1131  if (C->EllipsisLoc.isValid()) {
1132  if (Var->isParameterPack()) {
1133  EllipsisLoc = C->EllipsisLoc;
1134  } else {
1135  Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1136  << SourceRange(C->Loc);
1137 
1138  // Just ignore the ellipsis.
1139  }
1140  } else if (Var->isParameterPack()) {
1141  ContainsUnexpandedParameterPack = true;
1142  }
1143 
1144  if (C->Init.isUsable()) {
1145  buildInitCaptureField(LSI, Var);
1146  } else {
1147  TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1148  TryCapture_ExplicitByVal;
1149  tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1150  }
1151  if (!LSI->Captures.empty())
1152  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1153  }
1154  finishLambdaExplicitCaptures(LSI);
1155 
1156  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
1157 
1158  // Add lambda parameters into scope.
1159  addLambdaParameters(Intro.Captures, Method, CurScope);
1160 
1161  // Enter a new evaluation context to insulate the lambda from any
1162  // cleanups from the enclosing full-expression.
1163  PushExpressionEvaluationContext(
1164  ExpressionEvaluationContext::PotentiallyEvaluated);
1165 }
1166 
1168  bool IsInstantiation) {
1169  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1170 
1171  // Leave the expression-evaluation context.
1172  DiscardCleanupsInEvaluationContext();
1173  PopExpressionEvaluationContext();
1174 
1175  // Leave the context of the lambda.
1176  if (!IsInstantiation)
1177  PopDeclContext();
1178 
1179  // Finalize the lambda.
1180  CXXRecordDecl *Class = LSI->Lambda;
1181  Class->setInvalidDecl();
1182  SmallVector<Decl*, 4> Fields(Class->fields());
1183  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1185  CheckCompletedCXXClass(Class);
1186 
1187  PopFunctionScopeInfo();
1188 }
1189 
1191  const FunctionProtoType *CallOpProto) {
1192  // The function type inside the pointer type is the same as the call
1193  // operator with some tweaks. The calling convention is the default free
1194  // function convention, and the type qualifications are lost.
1195  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1196  CallOpProto->getExtProtoInfo();
1197  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1199  CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1200  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1201  InvokerExtInfo.TypeQuals = 0;
1202  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1203  "Lambda's call operator should not have a reference qualifier");
1204  return Context.getFunctionType(CallOpProto->getReturnType(),
1205  CallOpProto->getParamTypes(), InvokerExtInfo);
1206 }
1207 
1208 /// Add a lambda's conversion to function pointer, as described in
1209 /// C++11 [expr.prim.lambda]p6.
1211  SourceRange IntroducerRange,
1212  CXXRecordDecl *Class,
1213  CXXMethodDecl *CallOperator) {
1214  // This conversion is explicitly disabled if the lambda's function has
1215  // pass_object_size attributes on any of its parameters.
1216  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1217  return P->hasAttr<PassObjectSizeAttr>();
1218  };
1219  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1220  return;
1221 
1222  // Add the conversion to function pointer.
1223  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
1224  CallOperator->getType()->castAs<FunctionProtoType>());
1225  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1226 
1227  // Create the type of the conversion function.
1228  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1230  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1231  // The conversion function is always const.
1232  ConvExtInfo.TypeQuals = Qualifiers::Const;
1233  QualType ConvTy =
1234  S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1235 
1236  SourceLocation Loc = IntroducerRange.getBegin();
1237  DeclarationName ConversionName
1239  S.Context.getCanonicalType(PtrToFunctionTy));
1240  DeclarationNameLoc ConvNameLoc;
1241  // Construct a TypeSourceInfo for the conversion function, and wire
1242  // all the parameters appropriately for the FunctionProtoTypeLoc
1243  // so that everything works during transformation/instantiation of
1244  // generic lambdas.
1245  // The main reason for wiring up the parameters of the conversion
1246  // function with that of the call operator is so that constructs
1247  // like the following work:
1248  // auto L = [](auto b) { <-- 1
1249  // return [](auto a) -> decltype(a) { <-- 2
1250  // return a;
1251  // };
1252  // };
1253  // int (*fp)(int) = L(5);
1254  // Because the trailing return type can contain DeclRefExprs that refer
1255  // to the original call operator's variables, we hijack the call
1256  // operators ParmVarDecls below.
1257  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1258  S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1259  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1260 
1261  // The conversion function is a conversion to a pointer-to-function.
1262  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1263  FunctionProtoTypeLoc ConvTL =
1264  ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1265  // Get the result of the conversion function which is a pointer-to-function.
1266  PointerTypeLoc PtrToFunctionTL =
1267  ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1268  // Do the same for the TypeSourceInfo that is used to name the conversion
1269  // operator.
1270  PointerTypeLoc ConvNamePtrToFunctionTL =
1271  ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1272 
1273  // Get the underlying function types that the conversion function will
1274  // be converting to (should match the type of the call operator).
1275  FunctionProtoTypeLoc CallOpConvTL =
1276  PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1277  FunctionProtoTypeLoc CallOpConvNameTL =
1278  ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1279 
1280  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1281  // These parameter's are essentially used to transform the name and
1282  // the type of the conversion operator. By using the same parameters
1283  // as the call operator's we don't have to fix any back references that
1284  // the trailing return type of the call operator's uses (such as
1285  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1286  // - we can simply use the return type of the call operator, and
1287  // everything should work.
1288  SmallVector<ParmVarDecl *, 4> InvokerParams;
1289  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1290  ParmVarDecl *From = CallOperator->getParamDecl(I);
1291 
1292  InvokerParams.push_back(ParmVarDecl::Create(
1293  S.Context,
1294  // Temporarily add to the TU. This is set to the invoker below.
1296  From->getLocation(), From->getIdentifier(), From->getType(),
1297  From->getTypeSourceInfo(), From->getStorageClass(),
1298  /*DefaultArg=*/nullptr));
1299  CallOpConvTL.setParam(I, From);
1300  CallOpConvNameTL.setParam(I, From);
1301  }
1302 
1304  S.Context, Class, Loc,
1305  DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1306  /*isInline=*/true, /*isExplicit=*/false,
1307  /*isConstexpr=*/S.getLangOpts().CPlusPlus17,
1308  CallOperator->getBody()->getEndLoc());
1309  Conversion->setAccess(AS_public);
1310  Conversion->setImplicit(true);
1311 
1312  if (Class->isGenericLambda()) {
1313  // Create a template version of the conversion operator, using the template
1314  // parameter list of the function call operator.
1315  FunctionTemplateDecl *TemplateCallOperator =
1316  CallOperator->getDescribedFunctionTemplate();
1317  FunctionTemplateDecl *ConversionTemplate =
1319  Loc, ConversionName,
1320  TemplateCallOperator->getTemplateParameters(),
1321  Conversion);
1322  ConversionTemplate->setAccess(AS_public);
1323  ConversionTemplate->setImplicit(true);
1324  Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1325  Class->addDecl(ConversionTemplate);
1326  } else
1327  Class->addDecl(Conversion);
1328  // Add a non-static member function that will be the result of
1329  // the conversion with a certain unique ID.
1330  DeclarationName InvokerName = &S.Context.Idents.get(
1332  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1333  // we should get a prebuilt TrivialTypeSourceInfo from Context
1334  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1335  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1336  // loop below and then use its Params to set Invoke->setParams(...) below.
1337  // This would avoid the 'const' qualifier of the calloperator from
1338  // contaminating the type of the invoker, which is currently adjusted
1339  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments. Fixing the
1340  // trailing return type of the invoker would require a visitor to rebuild
1341  // the trailing return type and adjusting all back DeclRefExpr's to refer
1342  // to the new static invoker parameters - not the call operator's.
1344  S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1345  InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1346  /*IsInline=*/true,
1347  /*IsConstexpr=*/false, CallOperator->getBody()->getEndLoc());
1348  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I)
1349  InvokerParams[I]->setOwningFunction(Invoke);
1350  Invoke->setParams(InvokerParams);
1351  Invoke->setAccess(AS_private);
1352  Invoke->setImplicit(true);
1353  if (Class->isGenericLambda()) {
1354  FunctionTemplateDecl *TemplateCallOperator =
1355  CallOperator->getDescribedFunctionTemplate();
1356  FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1357  S.Context, Class, Loc, InvokerName,
1358  TemplateCallOperator->getTemplateParameters(),
1359  Invoke);
1360  StaticInvokerTemplate->setAccess(AS_private);
1361  StaticInvokerTemplate->setImplicit(true);
1362  Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1363  Class->addDecl(StaticInvokerTemplate);
1364  } else
1365  Class->addDecl(Invoke);
1366 }
1367 
1368 /// Add a lambda's conversion to block pointer.
1370  SourceRange IntroducerRange,
1371  CXXRecordDecl *Class,
1372  CXXMethodDecl *CallOperator) {
1374  CallOperator->getType()->castAs<FunctionProtoType>());
1375  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1376 
1377  FunctionProtoType::ExtProtoInfo ConversionEPI(
1379  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1380  ConversionEPI.TypeQuals = Qualifiers::Const;
1381  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1382 
1383  SourceLocation Loc = IntroducerRange.getBegin();
1384  DeclarationName Name
1386  S.Context.getCanonicalType(BlockPtrTy));
1387  DeclarationNameLoc NameLoc;
1388  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1390  S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1391  S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1392  /*isInline=*/true, /*isExplicit=*/false,
1393  /*isConstexpr=*/false, CallOperator->getBody()->getEndLoc());
1394  Conversion->setAccess(AS_public);
1395  Conversion->setImplicit(true);
1396  Class->addDecl(Conversion);
1397 }
1398 
1400  Sema &S, const Capture &Capture, FieldDecl *Field,
1401  SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture) {
1402  assert(Capture.isVariableCapture() && "not a variable capture");
1403 
1404  auto *Var = Capture.getVariable();
1405  SourceLocation Loc =
1406  IsImplicitCapture ? ImplicitCaptureLoc : Capture.getLocation();
1407 
1408  // C++11 [expr.prim.lambda]p21:
1409  // When the lambda-expression is evaluated, the entities that
1410  // are captured by copy are used to direct-initialize each
1411  // corresponding non-static data member of the resulting closure
1412  // object. (For array members, the array elements are
1413  // direct-initialized in increasing subscript order.) These
1414  // initializations are performed in the (unspecified) order in
1415  // which the non-static data members are declared.
1416 
1417  // C++ [expr.prim.lambda]p12:
1418  // An entity captured by a lambda-expression is odr-used (3.2) in
1419  // the scope containing the lambda-expression.
1420  ExprResult RefResult = S.BuildDeclarationNameExpr(
1421  CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1422  if (RefResult.isInvalid())
1423  return ExprError();
1424  Expr *Ref = RefResult.get();
1425 
1427  Var->getIdentifier(), Field->getType(), Loc);
1428  InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
1429  InitializationSequence Init(S, Entity, InitKind, Ref);
1430  return Init.Perform(S, Entity, InitKind, Ref);
1431 }
1432 
1434  Scope *CurScope) {
1435  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1436  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1437  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1438 }
1439 
1440 static LambdaCaptureDefault
1442  switch (ICS) {
1444  return LCD_None;
1446  return LCD_ByCopy;
1449  return LCD_ByRef;
1451  llvm_unreachable("block capture in lambda");
1452  }
1453  llvm_unreachable("Unknown implicit capture style");
1454 }
1455 
1457  if (!From.isVLATypeCapture()) {
1458  Expr *Init = From.getInitExpr();
1459  if (Init && Init->HasSideEffects(Context))
1460  return true;
1461  }
1462 
1463  if (!From.isCopyCapture())
1464  return false;
1465 
1466  const QualType T = From.isThisCapture()
1467  ? getCurrentThisType()->getPointeeType()
1468  : From.getCaptureType();
1469 
1470  if (T.isVolatileQualified())
1471  return true;
1472 
1473  const Type *BaseT = T->getBaseElementTypeUnsafe();
1474  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1475  return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1476  !RD->hasTrivialDestructor();
1477 
1478  return false;
1479 }
1480 
1482  const Capture &From) {
1483  if (CaptureHasSideEffects(From))
1484  return false;
1485 
1486  if (From.isVLATypeCapture())
1487  return false;
1488 
1489  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1490  if (From.isThisCapture())
1491  diag << "'this'";
1492  else
1493  diag << From.getVariable();
1494  diag << From.isNonODRUsed();
1495  diag << FixItHint::CreateRemoval(CaptureRange);
1496  return true;
1497 }
1498 
1500  LambdaScopeInfo *LSI) {
1501  // Collect information from the lambda scope.
1503  SmallVector<Expr *, 4> CaptureInits;
1504  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1505  LambdaCaptureDefault CaptureDefault =
1507  CXXRecordDecl *Class;
1508  CXXMethodDecl *CallOperator;
1509  SourceRange IntroducerRange;
1510  bool ExplicitParams;
1511  bool ExplicitResultType;
1512  CleanupInfo LambdaCleanup;
1513  bool ContainsUnexpandedParameterPack;
1514  bool IsGenericLambda;
1515  {
1516  CallOperator = LSI->CallOperator;
1517  Class = LSI->Lambda;
1518  IntroducerRange = LSI->IntroducerRange;
1519  ExplicitParams = LSI->ExplicitParams;
1520  ExplicitResultType = !LSI->HasImplicitReturnType;
1521  LambdaCleanup = LSI->Cleanup;
1522  ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1523  IsGenericLambda = Class->isGenericLambda();
1524 
1525  CallOperator->setLexicalDeclContext(Class);
1526  Decl *TemplateOrNonTemplateCallOperatorDecl =
1527  CallOperator->getDescribedFunctionTemplate()
1528  ? CallOperator->getDescribedFunctionTemplate()
1529  : cast<Decl>(CallOperator);
1530 
1531  TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1532  Class->addDecl(TemplateOrNonTemplateCallOperatorDecl);
1533 
1534  PopExpressionEvaluationContext();
1535 
1536  // Translate captures.
1537  auto CurField = Class->field_begin();
1538  // True if the current capture has a used capture or default before it.
1539  bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1540  SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1541  CaptureDefaultLoc : IntroducerRange.getBegin();
1542 
1543  for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I, ++CurField) {
1544  const Capture &From = LSI->Captures[I];
1545 
1546  assert(!From.isBlockCapture() && "Cannot capture __block variables");
1547  bool IsImplicit = I >= LSI->NumExplicitCaptures;
1548 
1549  // Use source ranges of explicit captures for fixits where available.
1550  SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1551 
1552  // Warn about unused explicit captures.
1553  bool IsCaptureUsed = true;
1554  if (!CurContext->isDependentContext() && !IsImplicit && !From.isODRUsed()) {
1555  // Initialized captures that are non-ODR used may not be eliminated.
1556  bool NonODRUsedInitCapture =
1557  IsGenericLambda && From.isNonODRUsed() && From.getInitExpr();
1558  if (!NonODRUsedInitCapture) {
1559  bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1560  SourceRange FixItRange;
1561  if (CaptureRange.isValid()) {
1562  if (!CurHasPreviousCapture && !IsLast) {
1563  // If there are no captures preceding this capture, remove the
1564  // following comma.
1565  FixItRange = SourceRange(CaptureRange.getBegin(),
1566  getLocForEndOfToken(CaptureRange.getEnd()));
1567  } else {
1568  // Otherwise, remove the comma since the last used capture.
1569  FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1570  CaptureRange.getEnd());
1571  }
1572  }
1573 
1574  IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1575  }
1576  }
1577 
1578  if (CaptureRange.isValid()) {
1579  CurHasPreviousCapture |= IsCaptureUsed;
1580  PrevCaptureLoc = CaptureRange.getEnd();
1581  }
1582 
1583  // Handle 'this' capture.
1584  if (From.isThisCapture()) {
1585  // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1586  // because it results in a reference capture. Don't warn prior to
1587  // C++2a; there's nothing that can be done about it before then.
1588  if (getLangOpts().CPlusPlus2a && IsImplicit &&
1589  CaptureDefault == LCD_ByCopy) {
1590  Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1591  Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1593  getLocForEndOfToken(CaptureDefaultLoc), ", this");
1594  }
1595 
1596  Captures.push_back(
1597  LambdaCapture(From.getLocation(), IsImplicit,
1598  From.isCopyCapture() ? LCK_StarThis : LCK_This));
1599  CaptureInits.push_back(From.getInitExpr());
1600  continue;
1601  }
1602  if (From.isVLATypeCapture()) {
1603  Captures.push_back(
1604  LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType));
1605  CaptureInits.push_back(nullptr);
1606  continue;
1607  }
1608 
1609  VarDecl *Var = From.getVariable();
1611  Captures.push_back(LambdaCapture(From.getLocation(), IsImplicit, Kind,
1612  Var, From.getEllipsisLoc()));
1613  Expr *Init = From.getInitExpr();
1614  if (!Init) {
1615  auto InitResult = performLambdaVarCaptureInitialization(
1616  *this, From, *CurField, CaptureDefaultLoc, IsImplicit);
1617  if (InitResult.isInvalid())
1618  return ExprError();
1619  Init = InitResult.get();
1620  }
1621  CaptureInits.push_back(Init);
1622  }
1623 
1624  // C++11 [expr.prim.lambda]p6:
1625  // The closure type for a lambda-expression with no lambda-capture
1626  // has a public non-virtual non-explicit const conversion function
1627  // to pointer to function having the same parameter and return
1628  // types as the closure type's function call operator.
1629  if (Captures.empty() && CaptureDefault == LCD_None)
1630  addFunctionPointerConversion(*this, IntroducerRange, Class,
1631  CallOperator);
1632 
1633  // Objective-C++:
1634  // The closure type for a lambda-expression has a public non-virtual
1635  // non-explicit const conversion function to a block pointer having the
1636  // same parameter and return types as the closure type's function call
1637  // operator.
1638  // FIXME: Fix generic lambda to block conversions.
1639  if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda)
1640  addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1641 
1642  // Finalize the lambda class.
1643  SmallVector<Decl*, 4> Fields(Class->fields());
1644  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1646  CheckCompletedCXXClass(Class);
1647  }
1648 
1649  Cleanup.mergeFrom(LambdaCleanup);
1650 
1651  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1652  CaptureDefault, CaptureDefaultLoc,
1653  Captures,
1654  ExplicitParams, ExplicitResultType,
1655  CaptureInits, EndLoc,
1656  ContainsUnexpandedParameterPack);
1657  // If the lambda expression's call operator is not explicitly marked constexpr
1658  // and we are not in a dependent context, analyze the call operator to infer
1659  // its constexpr-ness, suppressing diagnostics while doing so.
1660  if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() &&
1661  !CallOperator->isConstexpr() &&
1662  !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1663  !Class->getDeclContext()->isDependentContext()) {
1664  TentativeAnalysisScope DiagnosticScopeGuard(*this);
1665  CallOperator->setConstexpr(
1666  CheckConstexprFunctionDecl(CallOperator) &&
1667  CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()));
1668  }
1669 
1670  // Emit delayed shadowing warnings now that the full capture list is known.
1671  DiagnoseShadowingLambdaDecls(LSI);
1672 
1673  if (!CurContext->isDependentContext()) {
1674  switch (ExprEvalContexts.back().Context) {
1675  // C++11 [expr.prim.lambda]p2:
1676  // A lambda-expression shall not appear in an unevaluated operand
1677  // (Clause 5).
1678  case ExpressionEvaluationContext::Unevaluated:
1679  case ExpressionEvaluationContext::UnevaluatedList:
1680  case ExpressionEvaluationContext::UnevaluatedAbstract:
1681  // C++1y [expr.const]p2:
1682  // A conditional-expression e is a core constant expression unless the
1683  // evaluation of e, following the rules of the abstract machine, would
1684  // evaluate [...] a lambda-expression.
1685  //
1686  // This is technically incorrect, there are some constant evaluated contexts
1687  // where this should be allowed. We should probably fix this when DR1607 is
1688  // ratified, it lays out the exact set of conditions where we shouldn't
1689  // allow a lambda-expression.
1690  case ExpressionEvaluationContext::ConstantEvaluated:
1691  // We don't actually diagnose this case immediately, because we
1692  // could be within a context where we might find out later that
1693  // the expression is potentially evaluated (e.g., for typeid).
1694  ExprEvalContexts.back().Lambdas.push_back(Lambda);
1695  break;
1696 
1697  case ExpressionEvaluationContext::DiscardedStatement:
1698  case ExpressionEvaluationContext::PotentiallyEvaluated:
1699  case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1700  break;
1701  }
1702  }
1703 
1704  return MaybeBindToTemporary(Lambda);
1705 }
1706 
1708  SourceLocation ConvLocation,
1709  CXXConversionDecl *Conv,
1710  Expr *Src) {
1711  // Make sure that the lambda call operator is marked used.
1712  CXXRecordDecl *Lambda = Conv->getParent();
1713  CXXMethodDecl *CallOperator
1714  = cast<CXXMethodDecl>(
1715  Lambda->lookup(
1716  Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1717  CallOperator->setReferenced();
1718  CallOperator->markUsed(Context);
1719 
1720  ExprResult Init = PerformCopyInitialization(
1722  /*NRVO=*/false),
1723  CurrentLocation, Src);
1724  if (!Init.isInvalid())
1725  Init = ActOnFinishFullExpr(Init.get());
1726 
1727  if (Init.isInvalid())
1728  return ExprError();
1729 
1730  // Create the new block to be returned.
1731  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1732 
1733  // Set the type information.
1734  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1735  Block->setIsVariadic(CallOperator->isVariadic());
1736  Block->setBlockMissingReturnType(false);
1737 
1738  // Add parameters.
1739  SmallVector<ParmVarDecl *, 4> BlockParams;
1740  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1741  ParmVarDecl *From = CallOperator->getParamDecl(I);
1742  BlockParams.push_back(ParmVarDecl::Create(
1743  Context, Block, From->getBeginLoc(), From->getLocation(),
1744  From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1745  From->getStorageClass(),
1746  /*DefaultArg=*/nullptr));
1747  }
1748  Block->setParams(BlockParams);
1749 
1750  Block->setIsConversionFromLambda(true);
1751 
1752  // Add capture. The capture uses a fake variable, which doesn't correspond
1753  // to any actual memory location. However, the initializer copy-initializes
1754  // the lambda object.
1755  TypeSourceInfo *CapVarTSI =
1756  Context.getTrivialTypeSourceInfo(Src->getType());
1757  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
1758  ConvLocation, nullptr,
1759  Src->getType(), CapVarTSI,
1760  SC_None);
1761  BlockDecl::Capture Capture(/*Variable=*/CapVar, /*ByRef=*/false,
1762  /*Nested=*/false, /*Copy=*/Init.get());
1763  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
1764 
1765  // Add a fake function body to the block. IR generation is responsible
1766  // for filling in the actual body, which cannot be expressed as an AST.
1767  Block->setBody(new (Context) CompoundStmt(ConvLocation));
1768 
1769  // Create the block literal expression.
1770  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
1771  ExprCleanupObjects.push_back(Block);
1772  Cleanup.setExprNeedsCleanups(true);
1773 
1774  return BuildBlock;
1775 }
void setImplicit(bool I=true)
Definition: DeclBase.h:548
Represents a function declaration or definition.
Definition: Decl.h:1732
SourceRange IntroducerRange
Source range covering the lambda introducer [...].
Definition: ScopeInfo.h:794
DeclaratorChunk::FunctionTypeInfo & getFunctionTypeInfo()
getFunctionTypeInfo - Retrieves the function type info object (looking through parentheses).
Definition: DeclSpec.h:2251
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:2064
A class which contains all the information about a particular captured value.
Definition: Decl.h:3860
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:642
bool ExplicitParams
Whether the (empty) parameter list is explicit.
Definition: ScopeInfo.h:808
TemplateParameterList * GLTemplateParameterList
If this is a generic lambda, and the template parameter list has been created (from the AutoTemplateP...
Definition: ScopeInfo.h:830
VarDecl * createLambdaInitCaptureVarDecl(SourceLocation Loc, QualType InitCaptureType, 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:797
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:2782
QualType ReturnType
ReturnType - The target type of return statements in this context, or null if unknown.
Definition: ScopeInfo.h:650
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:2088
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:608
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:3993
LambdaCaptureDefault
The default, if any, capture method for a lambda expression.
Definition: Lambda.h:23
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:569
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:1415
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.cpp:4266
bool isFunctionDeclarator(unsigned &idx) const
isFunctionDeclarator - This method returns true if the declarator is a function declarator (looking t...
Definition: DeclSpec.h:2220
A container of type source information.
Definition: Decl.h:86
QualType getConversionType() const
Returns the type that this conversion function is converting to.
Definition: DeclCXX.h:2794
void setInitStyle(InitializationStyle Style)
Definition: Decl.h:1264
Describes the capture of a variable or of this, or of a C++1y init-capture.
Definition: LambdaCapture.h:26
This file provides some common utility functions for processing Lambda related AST Constructs...
bool isODRUsed() const
Definition: ScopeInfo.h:589
Represents a variable declaration or definition.
Definition: Decl.h:812
static CXXConversionDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, bool isInline, bool isExplicit, bool isConstexpr, SourceLocation EndLocation)
Definition: DeclCXX.cpp:2488
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:1748
QualType getReturnType() const
Definition: Decl.h:2290
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6716
Extra information about a function prototype.
Definition: Type.h:3762
bool isAmbiguous() const
Definition: Lookup.h:290
bool isInvalidDecl() const
Definition: DeclBase.h:542
Stores a list of template parameters for a TemplateDecl and its derived classes.
Definition: DeclTemplate.h:68
MangleNumberingContext & getMangleNumberingContext(ASTContext &Ctx)
Retrieve the mangling numbering context, used to consistently number constructs like lambdas for mang...
Definition: SemaLambda.cpp:367
static InitializationKind CreateDirectList(SourceLocation InitLoc)
bool isParameterPack() const
Whether this declaration is a parameter pack.
Definition: DeclBase.cpp:211
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:15052
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:3033
Represents a parameter to a function.
Definition: Decl.h:1551
CXXRecordDecl * createLambdaClosureType(SourceRange IntroducerRange, TypeSourceInfo *Info, bool KnownDependent, LambdaCaptureDefault CaptureDefault)
Create a new lambda closure type.
Definition: SemaLambda.cpp:246
Defines the clang::Expr interface and subclasses for C++ expressions.
tok::TokenKind ContextKind
bool FTIHasNonVoidParameters(const DeclaratorChunk::FunctionTypeInfo &FTI)
Definition: SemaInternal.h:37
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Scope * getTemplateParamParent()
Definition: Scope.h:259
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3763
One of these records is kept for each identifier that is lexed.
bool isConst() const
Definition: DeclCXX.h:2083
sema::LambdaScopeInfo * getCurGenericLambda()
Retrieve the current generic lambda info, if any.
Definition: Sema.cpp:1573
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:3886
field_range fields() const
Definition: Decl.h:3780
TypeSourceInfo * getTypeSourceInfo(ASTContext &Context, QualType T)
Creates a TypeSourceInfo for the given type.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:280
std::unique_ptr< MangleNumberingContext > createMangleNumberingContext() const
LambdaCaptureKind
The different capture forms in a lambda introducer.
Definition: Lambda.h:34
Represents a member of a struct/union/class.
Definition: Decl.h:2575
unsigned TypeQuals
The type qualifiers: const/volatile/restrict/__unaligned The qualifier bitmask values are the same as...
Definition: DeclSpec.h:1255
bool isReferenceType() const
Definition: Type.h:6294
bool Equals(const DeclContext *DC) const
Determine whether this declaration context is equivalent to the declaration context DC...
Definition: DeclBase.h:1871
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.h:2281
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:140
bool ContainsUnexpandedParameterPack
Whether the lambda contains an unexpanded parameter pack.
Definition: ScopeInfo.h:814
IdentifierTable & Idents
Definition: ASTContext.h:565
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:110
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2250
DeclClass * getAsSingle() const
Definition: Lookup.h:496
bool isThisCapture() const
Definition: ScopeInfo.h:561
Expr * getInitExpr() const
Definition: ScopeInfo.h:613
void setNameLoc(SourceLocation Loc)
Definition: TypeLoc.h:521
Represents the results of name lookup.
Definition: Lookup.h:47
PtrTy get() const
Definition: Ownership.h:174
Stmt * getBody(const FunctionDecl *&Definition) const
Retrieve the body (definition) of the function.
Definition: Decl.cpp:2729
RAII class used to indicate that we are performing provisional semantic analysis to determine the val...
Definition: Sema.h:7569
< Capturing the *this object by copy
Definition: Lambda.h:37
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:3355
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:2158
bool containsUnexpandedParameterPack() const
Whether this type is or contains an unexpanded parameter pack, used to support C++0x variadic templat...
Definition: Type.h:1837
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3198
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6128
void setLambdaMangling(unsigned ManglingNumber, Decl *ContextDecl)
Set the mangling number and context declaration for a lambda class.
Definition: DeclCXX.h:1922
CXXMethodDecl * startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange, TypeSourceInfo *MethodType, SourceLocation EndLoc, ArrayRef< ParmVarDecl *> Params, bool IsConstexprSpecified)
Start the definition of a lambda expression.
Definition: SemaLambda.cpp:375
void finishedExplicitCaptures()
Note when all explicit captures have been added.
Definition: ScopeInfo.h:873
DeclContext * getLambdaAwareParentOfDeclContext(DeclContext *DC)
Definition: ASTLambda.h:71
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:7262
field_iterator field_begin() const
Definition: Decl.cpp:4146
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:604
bool hasNameForLinkage() const
Is this tag type named, either directly or via being defined in a typedef of this type...
Definition: Decl.h:3266
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:1611
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1918
const LangOptions & getLangOpts() const
Definition: Sema.h:1220
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:28
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:23
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2750
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.
SmallVector< TemplateTypeParmDecl *, 4 > AutoTemplateParams
Store the list of the auto parameters for a generic lambda.
Definition: ScopeInfo.h:825
static ExprResult performLambdaVarCaptureInitialization(Sema &S, const Capture &Capture, FieldDecl *Field, SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture)
void addLambdaParameters(ArrayRef< LambdaIntroducer::LambdaCapture > Captures, CXXMethodDecl *CallOperator, Scope *CurScope)
Introduce the lambda parameters into scope.
Definition: SemaLambda.cpp:496
TypeSpecTypeLoc pushTypeSpec(QualType T)
Pushes space for a typespec TypeLoc.
CleanupInfo Cleanup
Whether any of the capture expressions requires cleanups.
Definition: ScopeInfo.h:811
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:1590
ExtInfo withCallingConv(CallingConv cc) const
Definition: Type.h:3577
ImplicitCaptureStyle ImpCaptureStyle
Definition: ScopeInfo.h:629
bool isIntegralOrUnscopedEnumerationType() const
Determine whether this type is an integral or unscoped enumeration type.
Definition: Type.cpp:1764
ConditionalOperator - The ?: ternary operator.
Definition: Expr.h:3488
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:278
CompoundStmt - This represents a group of statements like { stmt stmt }.
Definition: Stmt.h:803
bool Mutable
Whether this is a mutable lambda.
Definition: ScopeInfo.h:805
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1605
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:3686
static ImplicitCastExpr * Create(const ASTContext &Context, QualType T, CastKind Kind, Expr *Operand, const CXXCastPath *BasePath, ExprValueKind Cat)
Definition: Expr.cpp:1811
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:568
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI)
Note that we have finished the explicit captures for the given lambda.
Definition: SemaLambda.cpp:492
SourceLocation getEllipsisLoc() const
Retrieve the source location of the ellipsis, whose presence indicates that the capture is a pack exp...
Definition: ScopeInfo.h:603
SmallVector< LambdaCapture, 4 > Captures
Definition: DeclSpec.h:2557
SourceLocation PotentialThisCaptureLocation
Definition: ScopeInfo.h:865
unsigned NumExplicitCaptures
The number of captures in the Captures list that are explicit captures.
Definition: ScopeInfo.h:802
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:565
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:3074
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
Definition: DeclTemplate.h:432
DeclContext * getLexicalParent()
getLexicalParent - Returns the containing lexical DeclContext.
Definition: DeclBase.h:1767
CXXMethodDecl * CallOperator
The lambda&#39;s compiler-generated operator().
Definition: ScopeInfo.h:791
Pepresents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3854
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:106
bool isVariadic() const
Whether this function is variadic.
Definition: Decl.cpp:2687
int Id
Definition: ASTDiff.cpp:191
bool hasLocalStorage() const
Returns true if a variable with function scope is a non-static local variable.
Definition: Decl.h:1035
QualType buildLambdaInitCaptureInitialization(SourceLocation Loc, bool ByRef, IdentifierInfo *Id, bool DirectInit, Expr *&Init)
Definition: SemaLambda.cpp:744
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:6779
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5070
T getAs() const
Convert to the specified TypeLoc type, returning a null TypeLoc if this TypeLoc is not of the desired...
Definition: TypeLoc.h:87
void setInit(Expr *I)
Definition: Decl.cpp:2205
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:132
void setRetValue(Expr *E)
Definition: Stmt.h:2040
bool isFileContext() const
Definition: DeclBase.h:1817
DeclContext * getDeclContext()
Definition: DeclBase.h:427
bool isConstexprSpecified() const
Definition: DeclSpec.h:713
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:854
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:457
bool isCaptured(VarDecl *Var) const
Determine whether the given variable has been captured.
Definition: ScopeInfo.h:683
QualType getType() const
Definition: Expr.h:128
bool isFunctionOrMethod() const
Definition: DeclBase.h:1799
Capture & getCapture(VarDecl *Var)
Retrieve the capture of the given variable, if it has been captured already.
Definition: ScopeInfo.h:692
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:946
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:268
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1751
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2005
bool isInvalid() const
Definition: Ownership.h:170
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:1389
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:4695
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6674
Represents a C++ conversion function within a class.
Definition: DeclCXX.h:2762
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:1405
SourceLocation getLocation() const
Retrieve the location at which this variable was captured.
Definition: ScopeInfo.h:599
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:707
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:236
TypeLoc getReturnLoc() const
Definition: TypeLoc.h:1411
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:293
static InitializationKind CreateCopy(SourceLocation InitLoc, SourceLocation EqualLoc, bool AllowExplicitConvs=false)
Create a copy initialization.
FieldDecl * buildInitCaptureField(sema::LambdaScopeInfo *LSI, VarDecl *Var)
Build the implicit field for an init-capture.
Definition: SemaLambda.cpp:818
void setIsVariadic(bool value)
Definition: Decl.h:3930
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, sema::LambdaScopeInfo *LSI)
Complete a lambda-expression having processed and attached the lambda body.
void setIsConversionFromLambda(bool val=true)
Definition: Decl.h:4001
SourceLocation DefaultLoc
Definition: DeclSpec.h:2555
Kind
bool hasWeakerNullability(NullabilityKind L, NullabilityKind R)
Return true if L has a weaker nullability annotation than R.
Definition: Specifiers.h:299
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:157
VarDecl * getVariable() const
Definition: ScopeInfo.h:593
ExtProtoInfo getExtProtoInfo() const
Definition: Type.h:3890
unsigned getNumExprs() const
Definition: Expr.h:4837
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:3617
Expr * getRetValue()
Definition: Stmt.h:2038
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4382
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:788
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
MutableArrayRef< Expr * > MultiExprArg
Definition: Ownership.h:277
void setReferenced(bool R=true)
Definition: DeclBase.h:577
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2041
No ref-qualifier was provided.
Definition: Type.h:1368
C-style initialization with assignment.
Definition: Decl.h:817
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2273
bool isVLATypeCapture() const
Definition: ScopeInfo.h:581
CanQualType VoidTy
Definition: ASTContext.h:1025
bool isGenericLambda() const
Determine whether this class describes a generic lambda function object (i.e.
Definition: DeclCXX.cpp:1348
Describes the kind of initialization being performed, along with location information for tokens rela...
SmallVector< Capture, 4 > Captures
Captures - The captures.
Definition: ScopeInfo.h:642
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3016
MangleNumberingContext * getCurrentMangleNumberContext(const DeclContext *DC, Decl *&ManglingContextDecl)
Compute the mangling number context for a lambda expression or block literal.
Definition: SemaLambda.cpp:281
SourceLocation CaptureDefaultLoc
Source location of the &#39;&&#39; or &#39;=&#39; specifying the default capture type, if any.
Definition: ScopeInfo.h:798
Expr ** getExprs()
Definition: Expr.h:4849
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3707
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:532
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:1872
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod) const
Retrieves the default calling convention for the current target.
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:2535
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:3934
LambdaCaptureDefault Default
Definition: DeclSpec.h:2556
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1261
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:651
bool isRecord() const
Definition: DeclBase.h:1826
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:118
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:2166
MangleNumberingContext & getManglingNumberContext(const DeclContext *DC)
Retrieve the context for computing mangling numbers in the given DeclContext.
Represents an enum.
Definition: Decl.h:3322
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
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:6649
void setInitCapture(bool IC)
Definition: Decl.h:1395
Capturing variable-length array type.
Definition: Lambda.h:39
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:833
CanQualType DependentTy
Definition: ASTContext.h:1054
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:2278
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 CXXMethodDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInline, bool isConstexpr, SourceLocation EndLocation)
Definition: DeclCXX.cpp:1935
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:92
void addDecl(Decl *D)
Add the declaration D into this context.
Definition: DeclBase.cpp:1502
Optional< NullabilityKind > getNullability(const ASTContext &context) const
Determine the nullability of the given type.
Definition: Type.cpp:3671
Capturing the *this object by reference.
Definition: Lambda.h:35
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:677
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2262
void setSignatureAsWritten(TypeSourceInfo *Sig)
Definition: Decl.h:3936
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:238
static BlockDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L)
Definition: Decl.cpp:4443
Call-style initialization (C++98)
Definition: Decl.h:820
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1018
Describes the sequence of initializations required to initialize a given object or reference with a s...
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
bool isValid() const
bool isVoidType() const
Definition: Type.h:6530
void setConstexpr(bool IC)
Definition: Decl.h:2089
Capturing by reference.
Definition: Lambda.h:38
TryCaptureKind
Definition: Sema.h:4050
const DeclSpec & getDeclSpec() const
getDeclSpec - Return the declaration-specifier that this declarator was declared with.
Definition: DeclSpec.h:1837
bool isCXXThisCaptured() const
Determine whether the C++ &#39;this&#39; is captured.
Definition: ScopeInfo.h:674
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
void addAttr(Attr *A)
Definition: DeclBase.cpp:840
Defines the clang::TargetInfo interface.
Represents a complete lambda introducer.
Definition: DeclSpec.h:2532
ExprResult ExprError()
Definition: Ownership.h:283
void setDescribedFunctionTemplate(FunctionTemplateDecl *Template)
Definition: Decl.cpp:3359
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2085
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1036
bool isNonODRUsed() const
Definition: ScopeInfo.h:590
void addCapture(VarDecl *Var, bool isBlock, bool isByref, bool isNested, SourceLocation Loc, SourceLocation EllipsisLoc, QualType CaptureType, Expr *Cpy)
Definition: ScopeInfo.h:652
QualType getType() const
Definition: Decl.h:647
bool empty() const
Return true if no decls were found.
Definition: Lookup.h:328
void setCaptures(ASTContext &Context, ArrayRef< Capture > Captures, bool CapturesCXXThis)
Definition: Decl.cpp:4277
A trivial tuple used to represent a source range.
void setLexicalDeclContext(DeclContext *DC)
Definition: DeclBase.cpp:299
ASTContext & Context
Definition: Sema.h:320
This represents a decl that may have a name.
Definition: Decl.h:248
bool isTranslationUnit() const
Definition: DeclBase.h:1822
void setAccess(AccessSpecifier AS)
Definition: DeclBase.h:457
void setBlockMissingReturnType(bool val=true)
Definition: Decl.h:3993
Describes an entity that is being initialized.
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:3763
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3042
Wrapper for source info for pointers.
Definition: TypeLoc.h:1202
SourceLocation getBegin() const
bool isBlockCapture() const
Definition: ScopeInfo.h:577
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:625
No in-class initializer.
Definition: Specifiers.h:230
Declaration of a template function.
Definition: DeclTemplate.h:968
Attr - This represents one attribute.
Definition: Attr.h:43
SourceLocation getLocation() const
Definition: DeclBase.h:418
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97
Expr * IgnoreParens() LLVM_READONLY
IgnoreParens - Ignore parentheses.
Definition: Expr.cpp:2539