clang  10.0.0svn
SemaLambda.cpp
Go to the documentation of this file.
1 //===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements semantic analysis for C++ lambda expressions.
10 //
11 //===----------------------------------------------------------------------===//
12 #include "clang/Sema/DeclSpec.h"
13 #include "TypeLocBuilder.h"
14 #include "clang/AST/ASTLambda.h"
15 #include "clang/AST/ExprCXX.h"
16 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Sema/Lookup.h"
19 #include "clang/Sema/Scope.h"
20 #include "clang/Sema/ScopeInfo.h"
22 #include "clang/Sema/SemaLambda.h"
23 #include "llvm/ADT/STLExtras.h"
24 using namespace clang;
25 using namespace sema;
26 
27 /// Examines the FunctionScopeInfo stack to determine the nearest
28 /// enclosing lambda (to the current lambda) that is 'capture-ready' for
29 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
30 /// If successful, returns the index into Sema's FunctionScopeInfo stack
31 /// of the capture-ready lambda's LambdaScopeInfo.
32 ///
33 /// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
34 /// lambda - is on top) to determine the index of the nearest enclosing/outer
35 /// lambda that is ready to capture the \p VarToCapture being referenced in
36 /// the current lambda.
37 /// As we climb down the stack, we want the index of the first such lambda -
38 /// that is the lambda with the highest index that is 'capture-ready'.
39 ///
40 /// A lambda 'L' is capture-ready for 'V' (var or this) if:
41 /// - its enclosing context is non-dependent
42 /// - and if the chain of lambdas between L and the lambda in which
43 /// V is potentially used (i.e. the lambda at the top of the scope info
44 /// stack), can all capture or have already captured V.
45 /// If \p VarToCapture is 'null' then we are trying to capture 'this'.
46 ///
47 /// Note that a lambda that is deemed 'capture-ready' still needs to be checked
48 /// for whether it is 'capture-capable' (see
49 /// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
50 /// capture.
51 ///
52 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
53 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
54 /// is at the top of the stack and has the highest index.
55 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
56 ///
57 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
58 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
59 /// which is capture-ready. If the return value evaluates to 'false' then
60 /// no lambda is capture-ready for \p VarToCapture.
61 
62 static inline Optional<unsigned>
65  VarDecl *VarToCapture) {
66  // Label failure to capture.
67  const Optional<unsigned> NoLambdaIsCaptureReady;
68 
69  // Ignore all inner captured regions.
70  unsigned CurScopeIndex = FunctionScopes.size() - 1;
71  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
72  FunctionScopes[CurScopeIndex]))
73  --CurScopeIndex;
74  assert(
75  isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
76  "The function on the top of sema's function-info stack must be a lambda");
77 
78  // If VarToCapture is null, we are attempting to capture 'this'.
79  const bool IsCapturingThis = !VarToCapture;
80  const bool IsCapturingVariable = !IsCapturingThis;
81 
82  // Start with the current lambda at the top of the stack (highest index).
83  DeclContext *EnclosingDC =
84  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
85 
86  do {
87  const clang::sema::LambdaScopeInfo *LSI =
88  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]);
89  // IF we have climbed down to an intervening enclosing lambda that contains
90  // the variable declaration - it obviously can/must not capture the
91  // variable.
92  // Since its enclosing DC is dependent, all the lambdas between it and the
93  // innermost nested lambda are dependent (otherwise we wouldn't have
94  // arrived here) - so we don't yet have a lambda that can capture the
95  // variable.
96  if (IsCapturingVariable &&
97  VarToCapture->getDeclContext()->Equals(EnclosingDC))
98  return NoLambdaIsCaptureReady;
99 
100  // For an enclosing lambda to be capture ready for an entity, all
101  // intervening lambda's have to be able to capture that entity. If even
102  // one of the intervening lambda's is not capable of capturing the entity
103  // then no enclosing lambda can ever capture that entity.
104  // For e.g.
105  // const int x = 10;
106  // [=](auto a) { #1
107  // [](auto b) { #2 <-- an intervening lambda that can never capture 'x'
108  // [=](auto c) { #3
109  // f(x, c); <-- can not lead to x's speculative capture by #1 or #2
110  // }; }; };
111  // If they do not have a default implicit capture, check to see
112  // if the entity has already been explicitly captured.
113  // If even a single dependent enclosing lambda lacks the capability
114  // to ever capture this variable, there is no further enclosing
115  // non-dependent lambda that can capture this variable.
117  if (IsCapturingVariable && !LSI->isCaptured(VarToCapture))
118  return NoLambdaIsCaptureReady;
119  if (IsCapturingThis && !LSI->isCXXThisCaptured())
120  return NoLambdaIsCaptureReady;
121  }
122  EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
123 
124  assert(CurScopeIndex);
125  --CurScopeIndex;
126  } while (!EnclosingDC->isTranslationUnit() &&
127  EnclosingDC->isDependentContext() &&
128  isLambdaCallOperator(EnclosingDC));
129 
130  assert(CurScopeIndex < (FunctionScopes.size() - 1));
131  // If the enclosingDC is not dependent, then the immediately nested lambda
132  // (one index above) is capture-ready.
133  if (!EnclosingDC->isDependentContext())
134  return CurScopeIndex + 1;
135  return NoLambdaIsCaptureReady;
136 }
137 
138 /// Examines the FunctionScopeInfo stack to determine the nearest
139 /// enclosing lambda (to the current lambda) that is 'capture-capable' for
140 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
141 /// If successful, returns the index into Sema's FunctionScopeInfo stack
142 /// of the capture-capable lambda's LambdaScopeInfo.
143 ///
144 /// Given the current stack of lambdas being processed by Sema and
145 /// the variable of interest, to identify the nearest enclosing lambda (to the
146 /// current lambda at the top of the stack) that can truly capture
147 /// a variable, it has to have the following two properties:
148 /// a) 'capture-ready' - be the innermost lambda that is 'capture-ready':
149 /// - climb down the stack (i.e. starting from the innermost and examining
150 /// each outer lambda step by step) checking if each enclosing
151 /// lambda can either implicitly or explicitly capture the variable.
152 /// Record the first such lambda that is enclosed in a non-dependent
153 /// context. If no such lambda currently exists return failure.
154 /// b) 'capture-capable' - make sure the 'capture-ready' lambda can truly
155 /// capture the variable by checking all its enclosing lambdas:
156 /// - check if all outer lambdas enclosing the 'capture-ready' lambda
157 /// identified above in 'a' can also capture the variable (this is done
158 /// via tryCaptureVariable for variables and CheckCXXThisCapture for
159 /// 'this' by passing in the index of the Lambda identified in step 'a')
160 ///
161 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
162 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
163 /// is at the top of the stack.
164 ///
165 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
166 ///
167 ///
168 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
169 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
170 /// which is capture-capable. If the return value evaluates to 'false' then
171 /// no lambda is capture-capable for \p VarToCapture.
172 
175  VarDecl *VarToCapture, Sema &S) {
176 
177  const Optional<unsigned> NoLambdaIsCaptureCapable;
178 
179  const Optional<unsigned> OptionalStackIndex =
181  VarToCapture);
182  if (!OptionalStackIndex)
183  return NoLambdaIsCaptureCapable;
184 
185  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
186  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
187  S.getCurGenericLambda()) &&
188  "The capture ready lambda for a potential capture can only be the "
189  "current lambda if it is a generic lambda");
190 
191  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
192  cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
193 
194  // If VarToCapture is null, we are attempting to capture 'this'
195  const bool IsCapturingThis = !VarToCapture;
196  const bool IsCapturingVariable = !IsCapturingThis;
197 
198  if (IsCapturingVariable) {
199  // Check if the capture-ready lambda can truly capture the variable, by
200  // checking whether all enclosing lambdas of the capture-ready lambda allow
201  // the capture - i.e. make sure it is capture-capable.
202  QualType CaptureType, DeclRefType;
203  const bool CanCaptureVariable =
204  !S.tryCaptureVariable(VarToCapture,
205  /*ExprVarIsUsedInLoc*/ SourceLocation(),
207  /*EllipsisLoc*/ SourceLocation(),
208  /*BuildAndDiagnose*/ false, CaptureType,
209  DeclRefType, &IndexOfCaptureReadyLambda);
210  if (!CanCaptureVariable)
211  return NoLambdaIsCaptureCapable;
212  } else {
213  // Check if the capture-ready lambda can truly capture 'this' by checking
214  // whether all enclosing lambdas of the capture-ready lambda can capture
215  // 'this'.
216  const bool CanCaptureThis =
218  CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
219  /*Explicit*/ false, /*BuildAndDiagnose*/ false,
220  &IndexOfCaptureReadyLambda);
221  if (!CanCaptureThis)
222  return NoLambdaIsCaptureCapable;
223  }
224  return IndexOfCaptureReadyLambda;
225 }
226 
227 static inline TemplateParameterList *
229  if (!LSI->GLTemplateParameterList && !LSI->TemplateParams.empty()) {
231  SemaRef.Context,
232  /*Template kw loc*/ SourceLocation(),
233  /*L angle loc*/ LSI->ExplicitTemplateParamsRange.getBegin(),
234  LSI->TemplateParams,
235  /*R angle loc*/LSI->ExplicitTemplateParamsRange.getEnd(),
236  nullptr);
237  }
238  return LSI->GLTemplateParameterList;
239 }
240 
242  TypeSourceInfo *Info,
243  bool KnownDependent,
244  LambdaCaptureDefault CaptureDefault) {
245  DeclContext *DC = CurContext;
246  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
247  DC = DC->getParent();
248  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
249  *this);
250  // Start constructing the lambda class.
251  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
252  IntroducerRange.getBegin(),
253  KnownDependent,
254  IsGenericLambda,
255  CaptureDefault);
256  DC->addDecl(Class);
257 
258  return Class;
259 }
260 
261 /// Determine whether the given context is or is enclosed in an inline
262 /// function.
263 static bool isInInlineFunction(const DeclContext *DC) {
264  while (!DC->isFileContext()) {
265  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
266  if (FD->isInlined())
267  return true;
268 
269  DC = DC->getLexicalParent();
270  }
271 
272  return false;
273 }
274 
275 std::tuple<MangleNumberingContext *, Decl *>
277  // Compute the context for allocating mangling numbers in the current
278  // expression, if the ABI requires them.
279  Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
280 
281  enum ContextKind {
282  Normal,
283  DefaultArgument,
284  DataMember,
285  StaticDataMember,
286  InlineVariable,
287  VariableTemplate
288  } Kind = Normal;
289 
290  // Default arguments of member function parameters that appear in a class
291  // definition, as well as the initializers of data members, receive special
292  // treatment. Identify them.
293  if (ManglingContextDecl) {
294  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
295  if (const DeclContext *LexicalDC
296  = Param->getDeclContext()->getLexicalParent())
297  if (LexicalDC->isRecord())
298  Kind = DefaultArgument;
299  } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
300  if (Var->getDeclContext()->isRecord())
301  Kind = StaticDataMember;
302  else if (Var->getMostRecentDecl()->isInline())
303  Kind = InlineVariable;
304  else if (Var->getDescribedVarTemplate())
305  Kind = VariableTemplate;
306  else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
307  if (!VTS->isExplicitSpecialization())
308  Kind = VariableTemplate;
309  }
310  } else if (isa<FieldDecl>(ManglingContextDecl)) {
311  Kind = DataMember;
312  }
313  }
314 
315  // Itanium ABI [5.1.7]:
316  // In the following contexts [...] the one-definition rule requires closure
317  // types in different translation units to "correspond":
318  bool IsInNonspecializedTemplate =
319  inTemplateInstantiation() || CurContext->isDependentContext();
320  switch (Kind) {
321  case Normal: {
322  // -- the bodies of non-exported nonspecialized template functions
323  // -- the bodies of inline functions
324  if ((IsInNonspecializedTemplate &&
325  !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
326  isInInlineFunction(CurContext)) {
327  while (auto *CD = dyn_cast<CapturedDecl>(DC))
328  DC = CD->getParent();
329  return std::make_tuple(&Context.getManglingNumberContext(DC), nullptr);
330  }
331 
332  return std::make_tuple(nullptr, nullptr);
333  }
334 
335  case StaticDataMember:
336  // -- the initializers of nonspecialized static members of template classes
337  if (!IsInNonspecializedTemplate)
338  return std::make_tuple(nullptr, ManglingContextDecl);
339  // Fall through to get the current context.
340  LLVM_FALLTHROUGH;
341 
342  case DataMember:
343  // -- the in-class initializers of class members
344  case DefaultArgument:
345  // -- default arguments appearing in class definitions
346  case InlineVariable:
347  // -- the initializers of inline variables
348  case VariableTemplate:
349  // -- the initializers of templated variables
350  return std::make_tuple(
352  ManglingContextDecl),
353  ManglingContextDecl);
354  }
355 
356  llvm_unreachable("unexpected context");
357 }
358 
360  SourceRange IntroducerRange,
361  TypeSourceInfo *MethodTypeInfo,
362  SourceLocation EndLoc,
364  ConstexprSpecKind ConstexprKind) {
365  QualType MethodType = MethodTypeInfo->getType();
366  TemplateParameterList *TemplateParams =
367  getGenericLambdaTemplateParameterList(getCurLambda(), *this);
368  // If a lambda appears in a dependent context or is a generic lambda (has
369  // template parameters) and has an 'auto' return type, deduce it to a
370  // dependent type.
371  if (Class->isDependentContext() || TemplateParams) {
372  const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
373  QualType Result = FPT->getReturnType();
374  if (Result->isUndeducedType()) {
375  Result = SubstAutoType(Result, Context.DependentTy);
376  MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
377  FPT->getExtProtoInfo());
378  }
379  }
380 
381  // C++11 [expr.prim.lambda]p5:
382  // The closure type for a lambda-expression has a public inline function
383  // call operator (13.5.4) whose parameters and return type are described by
384  // the lambda-expression's parameter-declaration-clause and
385  // trailing-return-type respectively.
386  DeclarationName MethodName
387  = Context.DeclarationNames.getCXXOperatorName(OO_Call);
388  DeclarationNameLoc MethodNameLoc;
389  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
390  = IntroducerRange.getBegin().getRawEncoding();
391  MethodNameLoc.CXXOperatorName.EndOpNameLoc
392  = IntroducerRange.getEnd().getRawEncoding();
394  Context, Class, EndLoc,
395  DeclarationNameInfo(MethodName, IntroducerRange.getBegin(),
396  MethodNameLoc),
397  MethodType, MethodTypeInfo, SC_None,
398  /*isInline=*/true, ConstexprKind, EndLoc);
399  Method->setAccess(AS_public);
400  if (!TemplateParams)
401  Class->addDecl(Method);
402 
403  // Temporarily set the lexical declaration context to the current
404  // context, so that the Scope stack matches the lexical nesting.
405  Method->setLexicalDeclContext(CurContext);
406  // Create a function template if we have a template parameter list
407  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
408  FunctionTemplateDecl::Create(Context, Class,
409  Method->getLocation(), MethodName,
410  TemplateParams,
411  Method) : nullptr;
412  if (TemplateMethod) {
413  TemplateMethod->setAccess(AS_public);
414  Method->setDescribedFunctionTemplate(TemplateMethod);
415  Class->addDecl(TemplateMethod);
416  TemplateMethod->setLexicalDeclContext(CurContext);
417  }
418 
419  // Add parameters.
420  if (!Params.empty()) {
421  Method->setParams(Params);
422  CheckParmsForFunctionDef(Params,
423  /*CheckParameterNames=*/false);
424 
425  for (auto P : Method->parameters())
426  P->setOwningFunction(Method);
427  }
428 
429  return Method;
430 }
431 
433  CXXRecordDecl *Class, CXXMethodDecl *Method,
434  Optional<std::tuple<unsigned, bool, Decl *>> Mangling) {
435  if (Mangling) {
436  unsigned ManglingNumber;
437  bool HasKnownInternalLinkage;
438  Decl *ManglingContextDecl;
439  std::tie(ManglingNumber, HasKnownInternalLinkage, ManglingContextDecl) =
440  Mangling.getValue();
441  Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
442  HasKnownInternalLinkage);
443  return;
444  }
445 
446  auto getMangleNumberingContext =
447  [this](CXXRecordDecl *Class, Decl *ManglingContextDecl) -> MangleNumberingContext * {
448  // Get mangle numbering context if there's any extra decl context.
449  if (ManglingContextDecl)
450  return &Context.getManglingNumberContext(
451  ASTContext::NeedExtraManglingDecl, ManglingContextDecl);
452  // Otherwise, from that lambda's decl context.
453  auto DC = Class->getDeclContext();
454  while (auto *CD = dyn_cast<CapturedDecl>(DC))
455  DC = CD->getParent();
456  return &Context.getManglingNumberContext(DC);
457  };
458 
460  Decl *ManglingContextDecl;
461  std::tie(MCtx, ManglingContextDecl) =
462  getCurrentMangleNumberContext(Class->getDeclContext());
463  bool HasKnownInternalLinkage = false;
464  if (!MCtx && getLangOpts().CUDA) {
465  // Force lambda numbering in CUDA/HIP as we need to name lambdas following
466  // ODR. Both device- and host-compilation need to have a consistent naming
467  // on kernel functions. As lambdas are potential part of these `__global__`
468  // function names, they needs numbering following ODR.
469  MCtx = getMangleNumberingContext(Class, ManglingContextDecl);
470  assert(MCtx && "Retrieving mangle numbering context failed!");
471  HasKnownInternalLinkage = true;
472  }
473  if (MCtx) {
474  unsigned ManglingNumber = MCtx->getManglingNumber(Method);
475  Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
476  HasKnownInternalLinkage);
477  }
478 }
479 
481  CXXMethodDecl *CallOperator,
482  SourceRange IntroducerRange,
483  LambdaCaptureDefault CaptureDefault,
484  SourceLocation CaptureDefaultLoc,
485  bool ExplicitParams,
486  bool ExplicitResultType,
487  bool Mutable) {
488  LSI->CallOperator = CallOperator;
489  CXXRecordDecl *LambdaClass = CallOperator->getParent();
490  LSI->Lambda = LambdaClass;
491  if (CaptureDefault == LCD_ByCopy)
493  else if (CaptureDefault == LCD_ByRef)
495  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
496  LSI->IntroducerRange = IntroducerRange;
497  LSI->ExplicitParams = ExplicitParams;
498  LSI->Mutable = Mutable;
499 
500  if (ExplicitResultType) {
501  LSI->ReturnType = CallOperator->getReturnType();
502 
503  if (!LSI->ReturnType->isDependentType() &&
504  !LSI->ReturnType->isVoidType()) {
505  if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
506  diag::err_lambda_incomplete_result)) {
507  // Do nothing.
508  }
509  }
510  } else {
511  LSI->HasImplicitReturnType = true;
512  }
513 }
514 
517 }
518 
520  ArrayRef<NamedDecl *> TParams,
521  SourceLocation RAngleLoc) {
522  LambdaScopeInfo *LSI = getCurLambda();
523  assert(LSI && "Expected a lambda scope");
524  assert(LSI->NumExplicitTemplateParams == 0 &&
525  "Already acted on explicit template parameters");
526  assert(LSI->TemplateParams.empty() &&
527  "Explicit template parameters should come "
528  "before invented (auto) ones");
529  assert(!TParams.empty() &&
530  "No template parameters to act on");
531  LSI->TemplateParams.append(TParams.begin(), TParams.end());
532  LSI->NumExplicitTemplateParams = TParams.size();
533  LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc};
534 }
535 
538  CXXMethodDecl *CallOperator, Scope *CurScope) {
539  // Introduce our parameters into the function scope
540  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
541  p < NumParams; ++p) {
542  ParmVarDecl *Param = CallOperator->getParamDecl(p);
543 
544  // If this has an identifier, add it to the scope stack.
545  if (CurScope && Param->getIdentifier()) {
546  bool Error = false;
547  // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
548  // retroactively apply it.
549  for (const auto &Capture : Captures) {
550  if (Capture.Id == Param->getIdentifier()) {
551  Error = true;
552  Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
553  Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
554  << Capture.Id << true;
555  }
556  }
557  if (!Error)
558  CheckShadow(CurScope, Param);
559 
560  PushOnScopeChains(Param, CurScope);
561  }
562  }
563 }
564 
565 /// If this expression is an enumerator-like expression of some type
566 /// T, return the type T; otherwise, return null.
567 ///
568 /// Pointer comparisons on the result here should always work because
569 /// it's derived from either the parent of an EnumConstantDecl
570 /// (i.e. the definition) or the declaration returned by
571 /// EnumType::getDecl() (i.e. the definition).
573  // An expression is an enumerator-like expression of type T if,
574  // ignoring parens and parens-like expressions:
575  E = E->IgnoreParens();
576 
577  // - it is an enumerator whose enum type is T or
578  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
579  if (EnumConstantDecl *D
580  = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
581  return cast<EnumDecl>(D->getDeclContext());
582  }
583  return nullptr;
584  }
585 
586  // - it is a comma expression whose RHS is an enumerator-like
587  // expression of type T or
588  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
589  if (BO->getOpcode() == BO_Comma)
590  return findEnumForBlockReturn(BO->getRHS());
591  return nullptr;
592  }
593 
594  // - it is a statement-expression whose value expression is an
595  // enumerator-like expression of type T or
596  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
597  if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
598  return findEnumForBlockReturn(last);
599  return nullptr;
600  }
601 
602  // - it is a ternary conditional operator (not the GNU ?:
603  // extension) whose second and third operands are
604  // enumerator-like expressions of type T or
605  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
606  if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
607  if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
608  return ED;
609  return nullptr;
610  }
611 
612  // (implicitly:)
613  // - it is an implicit integral conversion applied to an
614  // enumerator-like expression of type T or
615  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
616  // We can sometimes see integral conversions in valid
617  // enumerator-like expressions.
618  if (ICE->getCastKind() == CK_IntegralCast)
619  return findEnumForBlockReturn(ICE->getSubExpr());
620 
621  // Otherwise, just rely on the type.
622  }
623 
624  // - it is an expression of that formal enum type.
625  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
626  return ET->getDecl();
627  }
628 
629  // Otherwise, nope.
630  return nullptr;
631 }
632 
633 /// Attempt to find a type T for which the returned expression of the
634 /// given statement is an enumerator-like expression of that type.
636  if (Expr *retValue = ret->getRetValue())
637  return findEnumForBlockReturn(retValue);
638  return nullptr;
639 }
640 
641 /// Attempt to find a common type T for which all of the returned
642 /// expressions in a block are enumerator-like expressions of that
643 /// type.
645  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
646 
647  // Try to find one for the first return.
649  if (!ED) return nullptr;
650 
651  // Check that the rest of the returns have the same enum.
652  for (++i; i != e; ++i) {
653  if (findEnumForBlockReturn(*i) != ED)
654  return nullptr;
655  }
656 
657  // Never infer an anonymous enum type.
658  if (!ED->hasNameForLinkage()) return nullptr;
659 
660  return ED;
661 }
662 
663 /// Adjust the given return statements so that they formally return
664 /// the given type. It should require, at most, an IntegralCast.
666  QualType returnType) {
668  i = returns.begin(), e = returns.end(); i != e; ++i) {
669  ReturnStmt *ret = *i;
670  Expr *retValue = ret->getRetValue();
671  if (S.Context.hasSameType(retValue->getType(), returnType))
672  continue;
673 
674  // Right now we only support integral fixup casts.
675  assert(returnType->isIntegralOrUnscopedEnumerationType());
676  assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
677 
678  ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
679 
680  Expr *E = (cleanups ? cleanups->getSubExpr() : retValue);
681  E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast,
682  E, /*base path*/ nullptr, VK_RValue);
683  if (cleanups) {
684  cleanups->setSubExpr(E);
685  } else {
686  ret->setRetValue(E);
687  }
688  }
689 }
690 
692  assert(CSI.HasImplicitReturnType);
693  // If it was ever a placeholder, it had to been deduced to DependentTy.
694  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
695  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
696  "lambda expressions use auto deduction in C++14 onwards");
697 
698  // C++ core issue 975:
699  // If a lambda-expression does not include a trailing-return-type,
700  // it is as if the trailing-return-type denotes the following type:
701  // - if there are no return statements in the compound-statement,
702  // or all return statements return either an expression of type
703  // void or no expression or braced-init-list, the type void;
704  // - otherwise, if all return statements return an expression
705  // and the types of the returned expressions after
706  // lvalue-to-rvalue conversion (4.1 [conv.lval]),
707  // array-to-pointer conversion (4.2 [conv.array]), and
708  // function-to-pointer conversion (4.3 [conv.func]) are the
709  // same, that common type;
710  // - otherwise, the program is ill-formed.
711  //
712  // C++ core issue 1048 additionally removes top-level cv-qualifiers
713  // from the types of returned expressions to match the C++14 auto
714  // deduction rules.
715  //
716  // In addition, in blocks in non-C++ modes, if all of the return
717  // statements are enumerator-like expressions of some type T, where
718  // T has a name for linkage, then we infer the return type of the
719  // block to be that type.
720 
721  // First case: no return statements, implicit void return type.
722  ASTContext &Ctx = getASTContext();
723  if (CSI.Returns.empty()) {
724  // It's possible there were simply no /valid/ return statements.
725  // In this case, the first one we found may have at least given us a type.
726  if (CSI.ReturnType.isNull())
727  CSI.ReturnType = Ctx.VoidTy;
728  return;
729  }
730 
731  // Second case: at least one return statement has dependent type.
732  // Delay type checking until instantiation.
733  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
734  if (CSI.ReturnType->isDependentType())
735  return;
736 
737  // Try to apply the enum-fuzz rule.
738  if (!getLangOpts().CPlusPlus) {
739  assert(isa<BlockScopeInfo>(CSI));
741  if (ED) {
742  CSI.ReturnType = Context.getTypeDeclType(ED);
744  return;
745  }
746  }
747 
748  // Third case: only one return statement. Don't bother doing extra work!
749  if (CSI.Returns.size() == 1)
750  return;
751 
752  // General case: many return statements.
753  // Check that they all have compatible return types.
754 
755  // We require the return types to strictly match here.
756  // Note that we've already done the required promotions as part of
757  // processing the return statement.
758  for (const ReturnStmt *RS : CSI.Returns) {
759  const Expr *RetE = RS->getRetValue();
760 
761  QualType ReturnType =
762  (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType();
763  if (Context.getCanonicalFunctionResultType(ReturnType) ==
765  // Use the return type with the strictest possible nullability annotation.
766  auto RetTyNullability = ReturnType->getNullability(Ctx);
767  auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
768  if (BlockNullability &&
769  (!RetTyNullability ||
770  hasWeakerNullability(*RetTyNullability, *BlockNullability)))
771  CSI.ReturnType = ReturnType;
772  continue;
773  }
774 
775  // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
776  // TODO: It's possible that the *first* return is the divergent one.
777  Diag(RS->getBeginLoc(),
778  diag::err_typecheck_missing_return_type_incompatible)
779  << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
780  // Continue iterating so that we keep emitting diagnostics.
781  }
782 }
783 
785  SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
786  Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool IsDirectInit,
787  Expr *&Init) {
788  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
789  // deduce against.
790  QualType DeductType = Context.getAutoDeductType();
791  TypeLocBuilder TLB;
792  TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
793  if (ByRef) {
794  DeductType = BuildReferenceType(DeductType, true, Loc, Id);
795  assert(!DeductType.isNull() && "can't build reference to auto");
796  TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
797  }
798  if (EllipsisLoc.isValid()) {
799  if (Init->containsUnexpandedParameterPack()) {
800  Diag(EllipsisLoc, getLangOpts().CPlusPlus2a
801  ? diag::warn_cxx17_compat_init_capture_pack
802  : diag::ext_init_capture_pack);
803  DeductType = Context.getPackExpansionType(DeductType, NumExpansions);
804  TLB.push<PackExpansionTypeLoc>(DeductType).setEllipsisLoc(EllipsisLoc);
805  } else {
806  // Just ignore the ellipsis for now and form a non-pack variable. We'll
807  // diagnose this later when we try to capture it.
808  }
809  }
810  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
811 
812  // Deduce the type of the init capture.
813  QualType DeducedType = deduceVarTypeFromInitializer(
814  /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
815  SourceRange(Loc, Loc), IsDirectInit, Init);
816  if (DeducedType.isNull())
817  return QualType();
818 
819  // Are we a non-list direct initialization?
820  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
821 
822  // Perform initialization analysis and ensure any implicit conversions
823  // (such as lvalue-to-rvalue) are enforced.
824  InitializedEntity Entity =
825  InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
827  IsDirectInit
828  ? (CXXDirectInit ? InitializationKind::CreateDirect(
829  Loc, Init->getBeginLoc(), Init->getEndLoc())
832 
833  MultiExprArg Args = Init;
834  if (CXXDirectInit)
835  Args =
836  MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
837  QualType DclT;
838  InitializationSequence InitSeq(*this, Entity, Kind, Args);
839  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
840 
841  if (Result.isInvalid())
842  return QualType();
843 
844  Init = Result.getAs<Expr>();
845  return DeducedType;
846 }
847 
849  QualType InitCaptureType,
850  SourceLocation EllipsisLoc,
852  unsigned InitStyle, Expr *Init) {
853  // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization
854  // rather than reconstructing it here.
855  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType, Loc);
856  if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>())
857  PETL.setEllipsisLoc(EllipsisLoc);
858 
859  // Create a dummy variable representing the init-capture. This is not actually
860  // used as a variable, and only exists as a way to name and refer to the
861  // init-capture.
862  // FIXME: Pass in separate source locations for '&' and identifier.
863  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
864  Loc, Id, InitCaptureType, TSI, SC_Auto);
865  NewVD->setInitCapture(true);
866  NewVD->setReferenced(true);
867  // FIXME: Pass in a VarDecl::InitializationStyle.
868  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
869  NewVD->markUsed(Context);
870  NewVD->setInit(Init);
871  if (NewVD->isParameterPack())
872  getCurLambda()->LocalPacks.push_back(NewVD);
873  return NewVD;
874 }
875 
877  assert(Var->isInitCapture() && "init capture flag should be set");
878  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
879  /*isNested*/false, Var->getLocation(), SourceLocation(),
880  Var->getType(), /*Invalid*/false);
881 }
882 
884  Declarator &ParamInfo,
885  Scope *CurScope) {
886  LambdaScopeInfo *const LSI = getCurLambda();
887  assert(LSI && "LambdaScopeInfo should be on stack!");
888 
889  // Determine if we're within a context where we know that the lambda will
890  // be dependent, because there are template parameters in scope.
891  bool KnownDependent;
892  if (LSI->NumExplicitTemplateParams > 0) {
893  auto *TemplateParamScope = CurScope->getTemplateParamParent();
894  assert(TemplateParamScope &&
895  "Lambda with explicit template param list should establish a "
896  "template param scope");
897  assert(TemplateParamScope->getParent());
898  KnownDependent = TemplateParamScope->getParent()
899  ->getTemplateParamParent() != nullptr;
900  } else {
901  KnownDependent = CurScope->getTemplateParamParent() != nullptr;
902  }
903 
904  // Determine the signature of the call operator.
905  TypeSourceInfo *MethodTyInfo;
906  bool ExplicitParams = true;
907  bool ExplicitResultType = true;
908  bool ContainsUnexpandedParameterPack = false;
909  SourceLocation EndLoc;
911  if (ParamInfo.getNumTypeObjects() == 0) {
912  // C++11 [expr.prim.lambda]p4:
913  // If a lambda-expression does not include a lambda-declarator, it is as
914  // if the lambda-declarator were ().
916  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
917  EPI.HasTrailingReturn = true;
918  EPI.TypeQuals.addConst();
919  // C++1y [expr.prim.lambda]:
920  // The lambda return type is 'auto', which is replaced by the
921  // trailing-return type if provided and/or deduced from 'return'
922  // statements
923  // We don't do this before C++1y, because we don't support deduced return
924  // types there.
925  QualType DefaultTypeForNoTrailingReturn =
926  getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
927  : Context.DependentTy;
928  QualType MethodTy =
929  Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
930  MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
931  ExplicitParams = false;
932  ExplicitResultType = false;
933  EndLoc = Intro.Range.getEnd();
934  } else {
935  assert(ParamInfo.isFunctionDeclarator() &&
936  "lambda-declarator is a function");
938 
939  // C++11 [expr.prim.lambda]p5:
940  // This function call operator is declared const (9.3.1) if and only if
941  // the lambda-expression's parameter-declaration-clause is not followed
942  // by mutable. It is neither virtual nor declared volatile. [...]
943  if (!FTI.hasMutableQualifier()) {
945  SourceLocation());
946  }
947 
948  MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
949  assert(MethodTyInfo && "no type from lambda-declarator");
950  EndLoc = ParamInfo.getSourceRange().getEnd();
951 
952  ExplicitResultType = FTI.hasTrailingReturnType();
953 
954  if (FTIHasNonVoidParameters(FTI)) {
955  Params.reserve(FTI.NumParams);
956  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i)
957  Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
958  }
959 
960  // Check for unexpanded parameter packs in the method type.
961  if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
962  DiagnoseUnexpandedParameterPack(Intro.Range.getBegin(), MethodTyInfo,
963  UPPC_DeclarationType);
964  }
965 
966  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
967  KnownDependent, Intro.Default);
968  CXXMethodDecl *Method =
969  startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
970  ParamInfo.getDeclSpec().getConstexprSpecifier());
971  if (ExplicitParams)
972  CheckCXXDefaultArguments(Method);
973 
974  // This represents the function body for the lambda function, check if we
975  // have to apply optnone due to a pragma.
976  AddRangeBasedOptnone(Method);
977 
978  // code_seg attribute on lambda apply to the method.
979  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
980  Method->addAttr(A);
981 
982  // Attributes on the lambda apply to the method.
983  ProcessDeclAttributes(CurScope, Method, ParamInfo);
984 
985  // CUDA lambdas get implicit attributes based on the scope in which they're
986  // declared.
987  if (getLangOpts().CUDA)
988  CUDASetLambdaAttrs(Method);
989 
990  // Number the lambda for linkage purposes if necessary.
991  handleLambdaNumbering(Class, Method);
992 
993  // Introduce the function call operator as the current declaration context.
994  PushDeclContext(CurScope, Method);
995 
996  // Build the lambda scope.
997  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
998  ExplicitParams, ExplicitResultType, !Method->isConst());
999 
1000  // C++11 [expr.prim.lambda]p9:
1001  // A lambda-expression whose smallest enclosing scope is a block scope is a
1002  // local lambda expression; any other lambda expression shall not have a
1003  // capture-default or simple-capture in its lambda-introducer.
1004  //
1005  // For simple-captures, this is covered by the check below that any named
1006  // entity is a variable that can be captured.
1007  //
1008  // For DR1632, we also allow a capture-default in any context where we can
1009  // odr-use 'this' (in particular, in a default initializer for a non-static
1010  // data member).
1011  if (Intro.Default != LCD_None && !Class->getParent()->isFunctionOrMethod() &&
1012  (getCurrentThisType().isNull() ||
1013  CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
1014  /*BuildAndDiagnose*/false)))
1015  Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
1016 
1017  // Distinct capture names, for diagnostics.
1018  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
1019 
1020  // Handle explicit captures.
1021  SourceLocation PrevCaptureLoc
1022  = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc;
1023  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
1024  PrevCaptureLoc = C->Loc, ++C) {
1025  if (C->Kind == LCK_This || C->Kind == LCK_StarThis) {
1026  if (C->Kind == LCK_StarThis)
1027  Diag(C->Loc, !getLangOpts().CPlusPlus17
1028  ? diag::ext_star_this_lambda_capture_cxx17
1029  : diag::warn_cxx14_compat_star_this_lambda_capture);
1030 
1031  // C++11 [expr.prim.lambda]p8:
1032  // An identifier or this shall not appear more than once in a
1033  // lambda-capture.
1034  if (LSI->isCXXThisCaptured()) {
1035  Diag(C->Loc, diag::err_capture_more_than_once)
1036  << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
1038  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1039  continue;
1040  }
1041 
1042  // C++2a [expr.prim.lambda]p8:
1043  // If a lambda-capture includes a capture-default that is =,
1044  // each simple-capture of that lambda-capture shall be of the form
1045  // "&identifier", "this", or "* this". [ Note: The form [&,this] is
1046  // redundant but accepted for compatibility with ISO C++14. --end note ]
1047  if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis)
1048  Diag(C->Loc, !getLangOpts().CPlusPlus2a
1049  ? diag::ext_equals_this_lambda_capture_cxx2a
1050  : diag::warn_cxx17_compat_equals_this_lambda_capture);
1051 
1052  // C++11 [expr.prim.lambda]p12:
1053  // If this is captured by a local lambda expression, its nearest
1054  // enclosing function shall be a non-static member function.
1055  QualType ThisCaptureType = getCurrentThisType();
1056  if (ThisCaptureType.isNull()) {
1057  Diag(C->Loc, diag::err_this_capture) << true;
1058  continue;
1059  }
1060 
1061  CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1062  /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1063  C->Kind == LCK_StarThis);
1064  if (!LSI->Captures.empty())
1065  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1066  continue;
1067  }
1068 
1069  assert(C->Id && "missing identifier for capture");
1070 
1071  if (C->Init.isInvalid())
1072  continue;
1073 
1074  VarDecl *Var = nullptr;
1075  if (C->Init.isUsable()) {
1076  Diag(C->Loc, getLangOpts().CPlusPlus14
1077  ? diag::warn_cxx11_compat_init_capture
1078  : diag::ext_init_capture);
1079 
1080  // If the initializer expression is usable, but the InitCaptureType
1081  // is not, then an error has occurred - so ignore the capture for now.
1082  // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1083  // FIXME: we should create the init capture variable and mark it invalid
1084  // in this case.
1085  if (C->InitCaptureType.get().isNull())
1086  continue;
1087 
1088  if (C->Init.get()->containsUnexpandedParameterPack() &&
1089  !C->InitCaptureType.get()->getAs<PackExpansionType>())
1090  DiagnoseUnexpandedParameterPack(C->Init.get(), UPPC_Initializer);
1091 
1092  unsigned InitStyle;
1093  switch (C->InitKind) {
1095  llvm_unreachable("not an init-capture?");
1097  InitStyle = VarDecl::CInit;
1098  break;
1100  InitStyle = VarDecl::CallInit;
1101  break;
1103  InitStyle = VarDecl::ListInit;
1104  break;
1105  }
1106  Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1107  C->EllipsisLoc, C->Id, InitStyle,
1108  C->Init.get());
1109  // C++1y [expr.prim.lambda]p11:
1110  // An init-capture behaves as if it declares and explicitly
1111  // captures a variable [...] whose declarative region is the
1112  // lambda-expression's compound-statement
1113  if (Var)
1114  PushOnScopeChains(Var, CurScope, false);
1115  } else {
1116  assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1117  "init capture has valid but null init?");
1118 
1119  // C++11 [expr.prim.lambda]p8:
1120  // If a lambda-capture includes a capture-default that is &, the
1121  // identifiers in the lambda-capture shall not be preceded by &.
1122  // If a lambda-capture includes a capture-default that is =, [...]
1123  // each identifier it contains shall be preceded by &.
1124  if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) {
1125  Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1127  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1128  continue;
1129  } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) {
1130  Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1132  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1133  continue;
1134  }
1135 
1136  // C++11 [expr.prim.lambda]p10:
1137  // The identifiers in a capture-list are looked up using the usual
1138  // rules for unqualified name lookup (3.4.1)
1139  DeclarationNameInfo Name(C->Id, C->Loc);
1140  LookupResult R(*this, Name, LookupOrdinaryName);
1141  LookupName(R, CurScope);
1142  if (R.isAmbiguous())
1143  continue;
1144  if (R.empty()) {
1145  // FIXME: Disable corrections that would add qualification?
1146  CXXScopeSpec ScopeSpec;
1147  DeclFilterCCC<VarDecl> Validator{};
1148  if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1149  continue;
1150  }
1151 
1152  Var = R.getAsSingle<VarDecl>();
1153  if (Var && DiagnoseUseOfDecl(Var, C->Loc))
1154  continue;
1155  }
1156 
1157  // C++11 [expr.prim.lambda]p8:
1158  // An identifier or this shall not appear more than once in a
1159  // lambda-capture.
1160  if (!CaptureNames.insert(C->Id).second) {
1161  if (Var && LSI->isCaptured(Var)) {
1162  Diag(C->Loc, diag::err_capture_more_than_once)
1163  << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1165  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1166  } else
1167  // Previous capture captured something different (one or both was
1168  // an init-cpature): no fixit.
1169  Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1170  continue;
1171  }
1172 
1173  // C++11 [expr.prim.lambda]p10:
1174  // [...] each such lookup shall find a variable with automatic storage
1175  // duration declared in the reaching scope of the local lambda expression.
1176  // Note that the 'reaching scope' check happens in tryCaptureVariable().
1177  if (!Var) {
1178  Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1179  continue;
1180  }
1181 
1182  // Ignore invalid decls; they'll just confuse the code later.
1183  if (Var->isInvalidDecl())
1184  continue;
1185 
1186  if (!Var->hasLocalStorage()) {
1187  Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1188  Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1189  continue;
1190  }
1191 
1192  // C++11 [expr.prim.lambda]p23:
1193  // A capture followed by an ellipsis is a pack expansion (14.5.3).
1194  SourceLocation EllipsisLoc;
1195  if (C->EllipsisLoc.isValid()) {
1196  if (Var->isParameterPack()) {
1197  EllipsisLoc = C->EllipsisLoc;
1198  } else {
1199  Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1200  << (C->Init.isUsable() ? C->Init.get()->getSourceRange()
1201  : SourceRange(C->Loc));
1202 
1203  // Just ignore the ellipsis.
1204  }
1205  } else if (Var->isParameterPack()) {
1206  ContainsUnexpandedParameterPack = true;
1207  }
1208 
1209  if (C->Init.isUsable()) {
1210  addInitCapture(LSI, Var);
1211  } else {
1212  TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1213  TryCapture_ExplicitByVal;
1214  tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1215  }
1216  if (!LSI->Captures.empty())
1217  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1218  }
1219  finishLambdaExplicitCaptures(LSI);
1220 
1221  LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
1222 
1223  // Add lambda parameters into scope.
1224  addLambdaParameters(Intro.Captures, Method, CurScope);
1225 
1226  // Enter a new evaluation context to insulate the lambda from any
1227  // cleanups from the enclosing full-expression.
1228  PushExpressionEvaluationContext(
1229  ExpressionEvaluationContext::PotentiallyEvaluated);
1230 }
1231 
1233  bool IsInstantiation) {
1234  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1235 
1236  // Leave the expression-evaluation context.
1237  DiscardCleanupsInEvaluationContext();
1238  PopExpressionEvaluationContext();
1239 
1240  // Leave the context of the lambda.
1241  if (!IsInstantiation)
1242  PopDeclContext();
1243 
1244  // Finalize the lambda.
1245  CXXRecordDecl *Class = LSI->Lambda;
1246  Class->setInvalidDecl();
1247  SmallVector<Decl*, 4> Fields(Class->fields());
1248  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1250  CheckCompletedCXXClass(Class);
1251 
1252  PopFunctionScopeInfo();
1253 }
1254 
1256  const FunctionProtoType *CallOpProto) {
1257  // The function type inside the pointer type is the same as the call
1258  // operator with some tweaks. The calling convention is the default free
1259  // function convention, and the type qualifications are lost.
1260  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1261  CallOpProto->getExtProtoInfo();
1262  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1264  CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1265  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1266  InvokerExtInfo.TypeQuals = Qualifiers();
1267  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1268  "Lambda's call operator should not have a reference qualifier");
1269  return Context.getFunctionType(CallOpProto->getReturnType(),
1270  CallOpProto->getParamTypes(), InvokerExtInfo);
1271 }
1272 
1273 /// Add a lambda's conversion to function pointer, as described in
1274 /// C++11 [expr.prim.lambda]p6.
1276  SourceRange IntroducerRange,
1277  CXXRecordDecl *Class,
1278  CXXMethodDecl *CallOperator) {
1279  // This conversion is explicitly disabled if the lambda's function has
1280  // pass_object_size attributes on any of its parameters.
1281  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1282  return P->hasAttr<PassObjectSizeAttr>();
1283  };
1284  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1285  return;
1286 
1287  // Add the conversion to function pointer.
1288  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
1289  CallOperator->getType()->castAs<FunctionProtoType>());
1290  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1291 
1292  // Create the type of the conversion function.
1293  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1295  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1296  // The conversion function is always const and noexcept.
1297  ConvExtInfo.TypeQuals = Qualifiers();
1298  ConvExtInfo.TypeQuals.addConst();
1299  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1300  QualType ConvTy =
1301  S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1302 
1303  SourceLocation Loc = IntroducerRange.getBegin();
1304  DeclarationName ConversionName
1306  S.Context.getCanonicalType(PtrToFunctionTy));
1307  DeclarationNameLoc ConvNameLoc;
1308  // Construct a TypeSourceInfo for the conversion function, and wire
1309  // all the parameters appropriately for the FunctionProtoTypeLoc
1310  // so that everything works during transformation/instantiation of
1311  // generic lambdas.
1312  // The main reason for wiring up the parameters of the conversion
1313  // function with that of the call operator is so that constructs
1314  // like the following work:
1315  // auto L = [](auto b) { <-- 1
1316  // return [](auto a) -> decltype(a) { <-- 2
1317  // return a;
1318  // };
1319  // };
1320  // int (*fp)(int) = L(5);
1321  // Because the trailing return type can contain DeclRefExprs that refer
1322  // to the original call operator's variables, we hijack the call
1323  // operators ParmVarDecls below.
1324  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1325  S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1326  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1327 
1328  // The conversion function is a conversion to a pointer-to-function.
1329  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1330  FunctionProtoTypeLoc ConvTL =
1331  ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1332  // Get the result of the conversion function which is a pointer-to-function.
1333  PointerTypeLoc PtrToFunctionTL =
1334  ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1335  // Do the same for the TypeSourceInfo that is used to name the conversion
1336  // operator.
1337  PointerTypeLoc ConvNamePtrToFunctionTL =
1338  ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1339 
1340  // Get the underlying function types that the conversion function will
1341  // be converting to (should match the type of the call operator).
1342  FunctionProtoTypeLoc CallOpConvTL =
1343  PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1344  FunctionProtoTypeLoc CallOpConvNameTL =
1345  ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1346 
1347  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1348  // These parameter's are essentially used to transform the name and
1349  // the type of the conversion operator. By using the same parameters
1350  // as the call operator's we don't have to fix any back references that
1351  // the trailing return type of the call operator's uses (such as
1352  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1353  // - we can simply use the return type of the call operator, and
1354  // everything should work.
1355  SmallVector<ParmVarDecl *, 4> InvokerParams;
1356  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1357  ParmVarDecl *From = CallOperator->getParamDecl(I);
1358 
1359  InvokerParams.push_back(ParmVarDecl::Create(
1360  S.Context,
1361  // Temporarily add to the TU. This is set to the invoker below.
1363  From->getLocation(), From->getIdentifier(), From->getType(),
1364  From->getTypeSourceInfo(), From->getStorageClass(),
1365  /*DefArg=*/nullptr));
1366  CallOpConvTL.setParam(I, From);
1367  CallOpConvNameTL.setParam(I, From);
1368  }
1369 
1371  S.Context, Class, Loc,
1372  DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1373  /*isInline=*/true, ExplicitSpecifier(),
1374  S.getLangOpts().CPlusPlus17 ? CSK_constexpr : CSK_unspecified,
1375  CallOperator->getBody()->getEndLoc());
1376  Conversion->setAccess(AS_public);
1377  Conversion->setImplicit(true);
1378 
1379  if (Class->isGenericLambda()) {
1380  // Create a template version of the conversion operator, using the template
1381  // parameter list of the function call operator.
1382  FunctionTemplateDecl *TemplateCallOperator =
1383  CallOperator->getDescribedFunctionTemplate();
1384  FunctionTemplateDecl *ConversionTemplate =
1386  Loc, ConversionName,
1387  TemplateCallOperator->getTemplateParameters(),
1388  Conversion);
1389  ConversionTemplate->setAccess(AS_public);
1390  ConversionTemplate->setImplicit(true);
1391  Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1392  Class->addDecl(ConversionTemplate);
1393  } else
1394  Class->addDecl(Conversion);
1395  // Add a non-static member function that will be the result of
1396  // the conversion with a certain unique ID.
1397  DeclarationName InvokerName = &S.Context.Idents.get(
1399  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1400  // we should get a prebuilt TrivialTypeSourceInfo from Context
1401  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1402  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1403  // loop below and then use its Params to set Invoke->setParams(...) below.
1404  // This would avoid the 'const' qualifier of the calloperator from
1405  // contaminating the type of the invoker, which is currently adjusted
1406  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments. Fixing the
1407  // trailing return type of the invoker would require a visitor to rebuild
1408  // the trailing return type and adjusting all back DeclRefExpr's to refer
1409  // to the new static invoker parameters - not the call operator's.
1411  S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1412  InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1413  /*isInline=*/true, CSK_unspecified, CallOperator->getBody()->getEndLoc());
1414  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I)
1415  InvokerParams[I]->setOwningFunction(Invoke);
1416  Invoke->setParams(InvokerParams);
1417  Invoke->setAccess(AS_private);
1418  Invoke->setImplicit(true);
1419  if (Class->isGenericLambda()) {
1420  FunctionTemplateDecl *TemplateCallOperator =
1421  CallOperator->getDescribedFunctionTemplate();
1422  FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1423  S.Context, Class, Loc, InvokerName,
1424  TemplateCallOperator->getTemplateParameters(),
1425  Invoke);
1426  StaticInvokerTemplate->setAccess(AS_private);
1427  StaticInvokerTemplate->setImplicit(true);
1428  Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1429  Class->addDecl(StaticInvokerTemplate);
1430  } else
1431  Class->addDecl(Invoke);
1432 }
1433 
1434 /// Add a lambda's conversion to block pointer.
1436  SourceRange IntroducerRange,
1437  CXXRecordDecl *Class,
1438  CXXMethodDecl *CallOperator) {
1440  CallOperator->getType()->castAs<FunctionProtoType>());
1441  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1442 
1443  FunctionProtoType::ExtProtoInfo ConversionEPI(
1445  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1446  ConversionEPI.TypeQuals = Qualifiers();
1447  ConversionEPI.TypeQuals.addConst();
1448  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1449 
1450  SourceLocation Loc = IntroducerRange.getBegin();
1451  DeclarationName Name
1453  S.Context.getCanonicalType(BlockPtrTy));
1454  DeclarationNameLoc NameLoc;
1455  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1457  S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1458  S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1459  /*isInline=*/true, ExplicitSpecifier(), CSK_unspecified,
1460  CallOperator->getBody()->getEndLoc());
1461  Conversion->setAccess(AS_public);
1462  Conversion->setImplicit(true);
1463  Class->addDecl(Conversion);
1464 }
1465 
1467  SourceLocation ImplicitCaptureLoc,
1468  bool IsOpenMPMapping) {
1469  // VLA captures don't have a stored initialization expression.
1470  if (Cap.isVLATypeCapture())
1471  return ExprResult();
1472 
1473  // An init-capture is initialized directly from its stored initializer.
1474  if (Cap.isInitCapture())
1475  return Cap.getVariable()->getInit();
1476 
1477  // For anything else, build an initialization expression. For an implicit
1478  // capture, the capture notionally happens at the capture-default, so use
1479  // that location here.
1480  SourceLocation Loc =
1481  ImplicitCaptureLoc.isValid() ? ImplicitCaptureLoc : Cap.getLocation();
1482 
1483  // C++11 [expr.prim.lambda]p21:
1484  // When the lambda-expression is evaluated, the entities that
1485  // are captured by copy are used to direct-initialize each
1486  // corresponding non-static data member of the resulting closure
1487  // object. (For array members, the array elements are
1488  // direct-initialized in increasing subscript order.) These
1489  // initializations are performed in the (unspecified) order in
1490  // which the non-static data members are declared.
1491 
1492  // C++ [expr.prim.lambda]p12:
1493  // An entity captured by a lambda-expression is odr-used (3.2) in
1494  // the scope containing the lambda-expression.
1495  ExprResult Init;
1496  IdentifierInfo *Name = nullptr;
1497  if (Cap.isThisCapture()) {
1498  QualType ThisTy = getCurrentThisType();
1499  Expr *This = BuildCXXThisExpr(Loc, ThisTy, ImplicitCaptureLoc.isValid());
1500  if (Cap.isCopyCapture())
1501  Init = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
1502  else
1503  Init = This;
1504  } else {
1505  assert(Cap.isVariableCapture() && "unknown kind of capture");
1506  VarDecl *Var = Cap.getVariable();
1507  Name = Var->getIdentifier();
1508  Init = BuildDeclarationNameExpr(
1509  CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1510  }
1511 
1512  // In OpenMP, the capture kind doesn't actually describe how to capture:
1513  // variables are "mapped" onto the device in a process that does not formally
1514  // make a copy, even for a "copy capture".
1515  if (IsOpenMPMapping)
1516  return Init;
1517 
1518  if (Init.isInvalid())
1519  return ExprError();
1520 
1521  Expr *InitExpr = Init.get();
1523  Name, Cap.getCaptureType(), Loc);
1524  InitializationKind InitKind =
1525  InitializationKind::CreateDirect(Loc, Loc, Loc);
1526  InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr);
1527  return InitSeq.Perform(*this, Entity, InitKind, InitExpr);
1528 }
1529 
1531  Scope *CurScope) {
1532  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1533  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1534  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1535 }
1536 
1537 static LambdaCaptureDefault
1539  switch (ICS) {
1541  return LCD_None;
1543  return LCD_ByCopy;
1546  return LCD_ByRef;
1548  llvm_unreachable("block capture in lambda");
1549  }
1550  llvm_unreachable("Unknown implicit capture style");
1551 }
1552 
1554  if (From.isInitCapture()) {
1555  Expr *Init = From.getVariable()->getInit();
1556  if (Init && Init->HasSideEffects(Context))
1557  return true;
1558  }
1559 
1560  if (!From.isCopyCapture())
1561  return false;
1562 
1563  const QualType T = From.isThisCapture()
1564  ? getCurrentThisType()->getPointeeType()
1565  : From.getCaptureType();
1566 
1567  if (T.isVolatileQualified())
1568  return true;
1569 
1570  const Type *BaseT = T->getBaseElementTypeUnsafe();
1571  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1572  return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1573  !RD->hasTrivialDestructor();
1574 
1575  return false;
1576 }
1577 
1579  const Capture &From) {
1580  if (CaptureHasSideEffects(From))
1581  return false;
1582 
1583  if (From.isVLATypeCapture())
1584  return false;
1585 
1586  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1587  if (From.isThisCapture())
1588  diag << "'this'";
1589  else
1590  diag << From.getVariable();
1591  diag << From.isNonODRUsed();
1592  diag << FixItHint::CreateRemoval(CaptureRange);
1593  return true;
1594 }
1595 
1596 /// Create a field within the lambda class or captured statement record for the
1597 /// given capture.
1599  const sema::Capture &Capture) {
1600  SourceLocation Loc = Capture.getLocation();
1601  QualType FieldType = Capture.getCaptureType();
1602 
1603  TypeSourceInfo *TSI = nullptr;
1604  if (Capture.isVariableCapture()) {
1605  auto *Var = Capture.getVariable();
1606  if (Var->isInitCapture())
1607  TSI = Capture.getVariable()->getTypeSourceInfo();
1608  }
1609 
1610  // FIXME: Should we really be doing this? A null TypeSourceInfo seems more
1611  // appropriate, at least for an implicit capture.
1612  if (!TSI)
1613  TSI = Context.getTrivialTypeSourceInfo(FieldType, Loc);
1614 
1615  // Build the non-static data member.
1616  FieldDecl *Field =
1617  FieldDecl::Create(Context, RD, Loc, Loc, nullptr, FieldType, TSI, nullptr,
1618  false, ICIS_NoInit);
1619  // If the variable being captured has an invalid type, mark the class as
1620  // invalid as well.
1621  if (!FieldType->isDependentType()) {
1622  if (RequireCompleteType(Loc, FieldType, diag::err_field_incomplete)) {
1623  RD->setInvalidDecl();
1624  Field->setInvalidDecl();
1625  } else {
1626  NamedDecl *Def;
1627  FieldType->isIncompleteType(&Def);
1628  if (Def && Def->isInvalidDecl()) {
1629  RD->setInvalidDecl();
1630  Field->setInvalidDecl();
1631  }
1632  }
1633  }
1634  Field->setImplicit(true);
1635  Field->setAccess(AS_private);
1636  RD->addDecl(Field);
1637 
1638  if (Capture.isVLATypeCapture())
1639  Field->setCapturedVLAType(Capture.getCapturedVLAType());
1640 
1641  return Field;
1642 }
1643 
1645  LambdaScopeInfo *LSI) {
1646  // Collect information from the lambda scope.
1648  SmallVector<Expr *, 4> CaptureInits;
1649  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1650  LambdaCaptureDefault CaptureDefault =
1652  CXXRecordDecl *Class;
1653  CXXMethodDecl *CallOperator;
1654  SourceRange IntroducerRange;
1655  bool ExplicitParams;
1656  bool ExplicitResultType;
1657  CleanupInfo LambdaCleanup;
1658  bool ContainsUnexpandedParameterPack;
1659  bool IsGenericLambda;
1660  {
1661  CallOperator = LSI->CallOperator;
1662  Class = LSI->Lambda;
1663  IntroducerRange = LSI->IntroducerRange;
1664  ExplicitParams = LSI->ExplicitParams;
1665  ExplicitResultType = !LSI->HasImplicitReturnType;
1666  LambdaCleanup = LSI->Cleanup;
1667  ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1668  IsGenericLambda = Class->isGenericLambda();
1669 
1670  CallOperator->setLexicalDeclContext(Class);
1671  Decl *TemplateOrNonTemplateCallOperatorDecl =
1672  CallOperator->getDescribedFunctionTemplate()
1673  ? CallOperator->getDescribedFunctionTemplate()
1674  : cast<Decl>(CallOperator);
1675 
1676  // FIXME: Is this really the best choice? Keeping the lexical decl context
1677  // set as CurContext seems more faithful to the source.
1678  TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1679 
1680  PopExpressionEvaluationContext();
1681 
1682  // True if the current capture has a used capture or default before it.
1683  bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1684  SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1685  CaptureDefaultLoc : IntroducerRange.getBegin();
1686 
1687  for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) {
1688  const Capture &From = LSI->Captures[I];
1689 
1690  if (From.isInvalid())
1691  return ExprError();
1692 
1693  assert(!From.isBlockCapture() && "Cannot capture __block variables");
1694  bool IsImplicit = I >= LSI->NumExplicitCaptures;
1695  SourceLocation ImplicitCaptureLoc =
1696  IsImplicit ? CaptureDefaultLoc : SourceLocation();
1697 
1698  // Use source ranges of explicit captures for fixits where available.
1699  SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1700 
1701  // Warn about unused explicit captures.
1702  bool IsCaptureUsed = true;
1703  if (!CurContext->isDependentContext() && !IsImplicit &&
1704  !From.isODRUsed()) {
1705  // Initialized captures that are non-ODR used may not be eliminated.
1706  // FIXME: Where did the IsGenericLambda here come from?
1707  bool NonODRUsedInitCapture =
1708  IsGenericLambda && From.isNonODRUsed() && From.isInitCapture();
1709  if (!NonODRUsedInitCapture) {
1710  bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1711  SourceRange FixItRange;
1712  if (CaptureRange.isValid()) {
1713  if (!CurHasPreviousCapture && !IsLast) {
1714  // If there are no captures preceding this capture, remove the
1715  // following comma.
1716  FixItRange = SourceRange(CaptureRange.getBegin(),
1717  getLocForEndOfToken(CaptureRange.getEnd()));
1718  } else {
1719  // Otherwise, remove the comma since the last used capture.
1720  FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1721  CaptureRange.getEnd());
1722  }
1723  }
1724 
1725  IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1726  }
1727  }
1728 
1729  if (CaptureRange.isValid()) {
1730  CurHasPreviousCapture |= IsCaptureUsed;
1731  PrevCaptureLoc = CaptureRange.getEnd();
1732  }
1733 
1734  // Map the capture to our AST representation.
1735  LambdaCapture Capture = [&] {
1736  if (From.isThisCapture()) {
1737  // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1738  // because it results in a reference capture. Don't warn prior to
1739  // C++2a; there's nothing that can be done about it before then.
1740  if (getLangOpts().CPlusPlus2a && IsImplicit &&
1741  CaptureDefault == LCD_ByCopy) {
1742  Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1743  Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1745  getLocForEndOfToken(CaptureDefaultLoc), ", this");
1746  }
1747  return LambdaCapture(From.getLocation(), IsImplicit,
1748  From.isCopyCapture() ? LCK_StarThis : LCK_This);
1749  } else if (From.isVLATypeCapture()) {
1750  return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType);
1751  } else {
1752  assert(From.isVariableCapture() && "unknown kind of capture");
1753  VarDecl *Var = From.getVariable();
1755  From.isCopyCapture() ? LCK_ByCopy : LCK_ByRef;
1756  return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var,
1757  From.getEllipsisLoc());
1758  }
1759  }();
1760 
1761  // Form the initializer for the capture field.
1762  ExprResult Init = BuildCaptureInit(From, ImplicitCaptureLoc);
1763 
1764  // FIXME: Skip this capture if the capture is not used, the initializer
1765  // has no side-effects, the type of the capture is trivial, and the
1766  // lambda is not externally visible.
1767 
1768  // Add a FieldDecl for the capture and form its initializer.
1769  BuildCaptureField(Class, From);
1770  Captures.push_back(Capture);
1771  CaptureInits.push_back(Init.get());
1772  }
1773 
1774  // C++11 [expr.prim.lambda]p6:
1775  // The closure type for a lambda-expression with no lambda-capture
1776  // has a public non-virtual non-explicit const conversion function
1777  // to pointer to function having the same parameter and return
1778  // types as the closure type's function call operator.
1779  if (Captures.empty() && CaptureDefault == LCD_None)
1780  addFunctionPointerConversion(*this, IntroducerRange, Class,
1781  CallOperator);
1782 
1783  // Objective-C++:
1784  // The closure type for a lambda-expression has a public non-virtual
1785  // non-explicit const conversion function to a block pointer having the
1786  // same parameter and return types as the closure type's function call
1787  // operator.
1788  // FIXME: Fix generic lambda to block conversions.
1789  if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda)
1790  addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1791 
1792  // Finalize the lambda class.
1793  SmallVector<Decl*, 4> Fields(Class->fields());
1794  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1796  CheckCompletedCXXClass(Class);
1797  }
1798 
1799  Cleanup.mergeFrom(LambdaCleanup);
1800 
1801  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1802  CaptureDefault, CaptureDefaultLoc,
1803  Captures,
1804  ExplicitParams, ExplicitResultType,
1805  CaptureInits, EndLoc,
1806  ContainsUnexpandedParameterPack);
1807  // If the lambda expression's call operator is not explicitly marked constexpr
1808  // and we are not in a dependent context, analyze the call operator to infer
1809  // its constexpr-ness, suppressing diagnostics while doing so.
1810  if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() &&
1811  !CallOperator->isConstexpr() &&
1812  !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1813  !Class->getDeclContext()->isDependentContext()) {
1814  CallOperator->setConstexprKind(
1815  CheckConstexprFunctionDefinition(CallOperator,
1816  CheckConstexprKind::CheckValid)
1817  ? CSK_constexpr
1818  : CSK_unspecified);
1819  }
1820 
1821  // Emit delayed shadowing warnings now that the full capture list is known.
1822  DiagnoseShadowingLambdaDecls(LSI);
1823 
1824  if (!CurContext->isDependentContext()) {
1825  switch (ExprEvalContexts.back().Context) {
1826  // C++11 [expr.prim.lambda]p2:
1827  // A lambda-expression shall not appear in an unevaluated operand
1828  // (Clause 5).
1829  case ExpressionEvaluationContext::Unevaluated:
1830  case ExpressionEvaluationContext::UnevaluatedList:
1831  case ExpressionEvaluationContext::UnevaluatedAbstract:
1832  // C++1y [expr.const]p2:
1833  // A conditional-expression e is a core constant expression unless the
1834  // evaluation of e, following the rules of the abstract machine, would
1835  // evaluate [...] a lambda-expression.
1836  //
1837  // This is technically incorrect, there are some constant evaluated contexts
1838  // where this should be allowed. We should probably fix this when DR1607 is
1839  // ratified, it lays out the exact set of conditions where we shouldn't
1840  // allow a lambda-expression.
1841  case ExpressionEvaluationContext::ConstantEvaluated:
1842  // We don't actually diagnose this case immediately, because we
1843  // could be within a context where we might find out later that
1844  // the expression is potentially evaluated (e.g., for typeid).
1845  ExprEvalContexts.back().Lambdas.push_back(Lambda);
1846  break;
1847 
1848  case ExpressionEvaluationContext::DiscardedStatement:
1849  case ExpressionEvaluationContext::PotentiallyEvaluated:
1850  case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1851  break;
1852  }
1853  }
1854 
1855  return MaybeBindToTemporary(Lambda);
1856 }
1857 
1859  SourceLocation ConvLocation,
1860  CXXConversionDecl *Conv,
1861  Expr *Src) {
1862  // Make sure that the lambda call operator is marked used.
1863  CXXRecordDecl *Lambda = Conv->getParent();
1864  CXXMethodDecl *CallOperator
1865  = cast<CXXMethodDecl>(
1866  Lambda->lookup(
1867  Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1868  CallOperator->setReferenced();
1869  CallOperator->markUsed(Context);
1870 
1871  ExprResult Init = PerformCopyInitialization(
1873  /*NRVO=*/false),
1874  CurrentLocation, Src);
1875  if (!Init.isInvalid())
1876  Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1877 
1878  if (Init.isInvalid())
1879  return ExprError();
1880 
1881  // Create the new block to be returned.
1882  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1883 
1884  // Set the type information.
1885  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1886  Block->setIsVariadic(CallOperator->isVariadic());
1887  Block->setBlockMissingReturnType(false);
1888 
1889  // Add parameters.
1890  SmallVector<ParmVarDecl *, 4> BlockParams;
1891  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1892  ParmVarDecl *From = CallOperator->getParamDecl(I);
1893  BlockParams.push_back(ParmVarDecl::Create(
1894  Context, Block, From->getBeginLoc(), From->getLocation(),
1895  From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1896  From->getStorageClass(),
1897  /*DefArg=*/nullptr));
1898  }
1899  Block->setParams(BlockParams);
1900 
1901  Block->setIsConversionFromLambda(true);
1902 
1903  // Add capture. The capture uses a fake variable, which doesn't correspond
1904  // to any actual memory location. However, the initializer copy-initializes
1905  // the lambda object.
1906  TypeSourceInfo *CapVarTSI =
1907  Context.getTrivialTypeSourceInfo(Src->getType());
1908  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
1909  ConvLocation, nullptr,
1910  Src->getType(), CapVarTSI,
1911  SC_None);
1912  BlockDecl::Capture Capture(/*variable=*/CapVar, /*byRef=*/false,
1913  /*nested=*/false, /*copy=*/Init.get());
1914  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
1915 
1916  // Add a fake function body to the block. IR generation is responsible
1917  // for filling in the actual body, which cannot be expressed as an AST.
1918  Block->setBody(new (Context) CompoundStmt(ConvLocation));
1919 
1920  // Create the block literal expression.
1921  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
1922  ExprCleanupObjects.push_back(Block);
1923  Cleanup.setExprNeedsCleanups(true);
1924 
1925  return BuildBlock;
1926 }
void setImplicit(bool I=true)
Definition: DeclBase.h:559
Represents a function declaration or definition.
Definition: Decl.h:1784
SourceRange IntroducerRange
Source range covering the lambda introducer [...].
Definition: ScopeInfo.h:801
DeclaratorChunk::FunctionTypeInfo & getFunctionTypeInfo()
getFunctionTypeInfo - Retrieves the function type info object (looking through parentheses).
Definition: DeclSpec.h:2278
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
SourceLocation getBeginLoc() const
Definition: Stmt.h:2679
A class which contains all the information about a particular captured value.
Definition: Decl.h:3957
if(T->getSizeExpr()) TRY_TO(TraverseStmt(T -> getSizeExpr()))
unsigned getRawEncoding() const
When a SourceLocation itself cannot be used, this returns an (opaque) 32-bit integer encoding for it...
A (possibly-)qualified type.
Definition: Type.h:643
bool ExplicitParams
Whether the (empty) parameter list is explicit.
Definition: ScopeInfo.h:815
virtual unsigned getManglingNumber(const CXXMethodDecl *CallOperator)=0
Retrieve the mangling number of a new lambda expression with the given call operator within this cont...
TemplateParameterList * GLTemplateParameterList
If this is a generic lambda, and the template parameter list has been created (from the TemplateParam...
Definition: ScopeInfo.h:848
bool SetTypeQual(TQ T, SourceLocation Loc)
Definition: DeclSpec.cpp:914
Stmt - This represents one statement.
Definition: Stmt.h:66
An instance of this object exists for each enum constant that is defined.
Definition: Decl.h:2855
QualType ReturnType
ReturnType - The target type of return statements in this context, or null if unknown.
Definition: ScopeInfo.h:658
StorageClass getStorageClass() const
Returns the storage class as written in the source.
Definition: Decl.h:1034
bool isConstexpr() const
Whether this is a (C++11) constexpr function or constexpr constructor.
Definition: Decl.h:2144
DeclarationName getCXXConversionFunctionName(CanQualType Ty)
Returns the name of a C++ conversion function for the given Type.
QualType getCaptureType() const
Retrieve the capture type for this capture, which is effectively the type of the non-static data memb...
Definition: ScopeInfo.h:624
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:4041
LambdaCaptureDefault
The default, if any, capture method for a lambda expression.
Definition: Lambda.h:22
CanQualType getCanonicalFunctionResultType(QualType ResultType) const
Adjust the given function result type.
StringRef P
ExprResult BuildBlockForLambdaConversion(SourceLocation CurrentLocation, SourceLocation ConvLocation, CXXConversionDecl *Conv, Expr *Src)
bool isCopyCapture() const
Definition: ScopeInfo.h:583
static InitializationKind CreateDirect(SourceLocation InitLoc, SourceLocation LParenLoc, SourceLocation RParenLoc)
Create a direct initialization.
QualType getBlockPointerType(QualType T) const
Return the uniqued reference to the type for a block of the specified type.
The base class of the type hierarchy.
Definition: Type.h:1436
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.cpp:4464
bool isFunctionDeclarator(unsigned &idx) const
isFunctionDeclarator - This method returns true if the declarator is a function declarator (looking t...
Definition: DeclSpec.h:2247
A container of type source information.
Definition: Decl.h:86
Store information needed for an explicit specifier.
Definition: DeclCXX.h:1792
QualType getConversionType() const
Returns the type that this conversion function is converting to.
Definition: DeclCXX.h:2727
void setInitStyle(InitializationStyle Style)
Definition: Decl.h:1300
Describes the capture of a variable or of this, or of a C++1y init-capture.
Definition: LambdaCapture.h:25
This file provides some common utility functions for processing Lambda related AST Constructs...
bool isODRUsed() const
Definition: ScopeInfo.h:595
Represents a variable declaration or definition.
Definition: Decl.h:827
bool DiagnoseUnusedLambdaCapture(SourceRange CaptureRange, const sema::Capture &From)
Diagnose if an explicit lambda capture is unused.
Information about one declarator, including the parsed type information and the identifier.
Definition: DeclSpec.h:1775
QualType getReturnType() const
Definition: Decl.h:2365
VarDecl * createLambdaInitCaptureVarDecl(SourceLocation Loc, QualType InitCaptureType, SourceLocation EllipsisLoc, IdentifierInfo *Id, unsigned InitStyle, Expr *Init)
Create a dummy variable within the declcontext of the lambda&#39;s call operator, for name lookup purpose...
Definition: SemaLambda.cpp:848
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6858
bool This(InterpState &S, CodePtr OpPC)
Definition: Interp.h:830
Extra information about a function prototype.
Definition: Type.h:3805
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:553
Stores a list of template parameters for a TemplateDecl and its derived classes.
Definition: DeclTemplate.h:67
static InitializationKind CreateDirectList(SourceLocation InitLoc)
bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc, TryCaptureKind Kind, SourceLocation EllipsisLoc, bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const unsigned *const FunctionScopeIndexToStopAt)
Try to capture the given variable.
Definition: SemaExpr.cpp:16021
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:3306
Represents a parameter to a function.
Definition: Decl.h:1600
CXXRecordDecl * createLambdaClosureType(SourceRange IntroducerRange, TypeSourceInfo *Info, bool KnownDependent, LambdaCaptureDefault CaptureDefault)
Create a new lambda closure type.
Definition: SemaLambda.cpp:241
Defines the clang::Expr interface and subclasses for C++ expressions.
The collection of all-type qualifiers we support.
Definition: Type.h:137
tok::TokenKind ContextKind
static CXXMethodDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInline, ConstexprSpecKind ConstexprKind, SourceLocation EndLocation)
Definition: DeclCXX.cpp:2039
bool FTIHasNonVoidParameters(const DeclaratorChunk::FunctionTypeInfo &FTI)
Definition: SemaInternal.h:36
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Represents a struct/union/class.
Definition: Decl.h:3662
Scope * getTemplateParamParent()
Definition: Scope.h:262
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3806
One of these records is kept for each identifier that is lexed.
bool isConst() const
Definition: DeclCXX.h:1945
sema::LambdaScopeInfo * getCurGenericLambda()
Retrieve the current generic lambda info, if any.
Definition: Sema.cpp:1868
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:160
ArrayRef< QualType > getParamTypes() const
Definition: Type.h:3934
field_range fields() const
Definition: Decl.h:3877
TypeSourceInfo * getTypeSourceInfo(ASTContext &Context, QualType T)
Creates a TypeSourceInfo for the given type.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:274
LambdaCaptureKind
The different capture forms in a lambda introducer.
Definition: Lambda.h:33
Represents a member of a struct/union/class.
Definition: Decl.h:2643
bool isReferenceType() const
Definition: Type.h:6403
bool Equals(const DeclContext *DC) const
Determine whether this declaration context is equivalent to the declaration context DC...
Definition: DeclBase.h:1903
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.h:2356
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:746
static CXXRecordDecl * CreateLambda(const ASTContext &C, DeclContext *DC, TypeSourceInfo *Info, SourceLocation Loc, bool DependentLambda, bool IsGeneric, LambdaCaptureDefault CaptureDefault)
Definition: DeclCXX.cpp:141
bool ContainsUnexpandedParameterPack
Whether the lambda contains an unexpanded parameter pack.
Definition: ScopeInfo.h:821
IdentifierTable & Idents
Definition: ASTContext.h:579
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:125
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2325
DeclClass * getAsSingle() const
Definition: Lookup.h:507
bool isThisCapture() const
Definition: ScopeInfo.h:578
void setNameLoc(SourceLocation Loc)
Definition: TypeLoc.h:523
Represents the results of name lookup.
Definition: Lookup.h:46
PtrTy get() const
Definition: Ownership.h:170
Stmt * getBody(const FunctionDecl *&Definition) const
Retrieve the body (definition) of the function.
Definition: Decl.cpp:2849
< Capturing the *this object by copy
Definition: Lambda.h:36
static LambdaCaptureDefault mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS)
static InitializedEntity InitializeLambdaToBlock(SourceLocation BlockVarLoc, QualType Type, bool NRVO)
Keeps track of the mangled names of lambda expressions and block literals within a particular context...
FunctionTemplateDecl * getDescribedFunctionTemplate() const
Retrieves the function template that is described by this function declaration.
Definition: Decl.cpp:3486
bool CheckCXXThisCapture(SourceLocation Loc, bool Explicit=false, bool BuildAndDiagnose=true, const unsigned *const FunctionScopeIndexToStopAt=nullptr, bool ByCopy=false)
Make sure the value of &#39;this&#39; is actually available in the current context, if it is a potentially ev...
unsigned getNumTypeObjects() const
Return the number of types applied to this declarator.
Definition: DeclSpec.h:2185
const VariableArrayType * getCapturedVLAType() const
Definition: ScopeInfo.h:609
bool containsUnexpandedParameterPack() const
Whether this type is or contains an unexpanded parameter pack, used to support C++0x variadic templat...
Definition: Type.h:1871
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3409
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6218
void finishedExplicitCaptures()
Note when all explicit captures have been added.
Definition: ScopeInfo.h:891
llvm::Error Error
DeclContext * getLambdaAwareParentOfDeclContext(DeclContext *DC)
Definition: ASTLambda.h:70
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
ExprResult Perform(Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind, MultiExprArg Args, QualType *ResultType=nullptr)
Perform the actual initialization of the given entity based on the computed initialization sequence...
Definition: SemaInit.cpp:7744
void addInitCapture(sema::LambdaScopeInfo *LSI, VarDecl *Var)
Add an init-capture to a lambda scope.
Definition: SemaLambda.cpp:876
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:644
bool hasNameForLinkage() const
Is this tag type named, either directly or via being defined in a typedef of this type...
Definition: Decl.h:3339
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:1818
unsigned NumExplicitTemplateParams
The number of parameters in the template parameter list that were explicitly specified by the user...
Definition: ScopeInfo.h:833
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1965
const LangOptions & getLangOpts() const
Definition: Sema.h:1288
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:27
ExprResult BuildCaptureInit(const sema::Capture &Capture, SourceLocation ImplicitCaptureLoc, bool IsOpenMPMapping=false)
Initialize the given capture with a suitable expression.
static FunctionTemplateDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L, DeclarationName Name, TemplateParameterList *Params, NamedDecl *Decl)
Create a function template node.
StringRef getLambdaStaticInvokerName()
Definition: ASTLambda.h:22
QualType getLambdaConversionFunctionResultType(const FunctionProtoType *CallOpType)
Get the return type to use for a lambda&#39;s conversion function(s) to function pointer type...
static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange, CXXRecordDecl *Class, CXXMethodDecl *CallOperator)
Add a lambda&#39;s conversion to function pointer, as described in C++11 [expr.prim.lambda]p6.
void addLambdaParameters(ArrayRef< LambdaIntroducer::LambdaCapture > Captures, CXXMethodDecl *CallOperator, Scope *CurScope)
Introduce the lambda parameters into scope.
Definition: SemaLambda.cpp:536
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod, bool IsBuiltin=false) const
Retrieves the default calling convention for the current target.
TypeSpecTypeLoc pushTypeSpec(QualType T)
Pushes space for a typespec TypeLoc.
CleanupInfo Cleanup
Whether any of the capture expressions requires cleanups.
Definition: ScopeInfo.h:818
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:1609
ExtInfo withCallingConv(CallingConv cc) const
Definition: Type.h:3609
ImplicitCaptureStyle ImpCaptureStyle
Definition: ScopeInfo.h:637
bool isIntegralOrUnscopedEnumerationType() const
Determine whether this type is an integral or unscoped enumeration type.
Definition: Type.cpp:1859
ConditionalOperator - The ?: ternary operator.
Definition: Expr.h:3707
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:331
CompoundStmt - This represents a group of statements like { stmt stmt }.
Definition: Stmt.h:1320
bool Mutable
Whether this is a mutable lambda.
Definition: ScopeInfo.h:812
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1692
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:3725
static ImplicitCastExpr * Create(const ASTContext &Context, QualType T, CastKind Kind, Expr *Operand, const CXXCastPath *BasePath, ExprValueKind Cat)
Definition: Expr.cpp:1981
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:582
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI)
Note that we have finished the explicit captures for the given lambda.
Definition: SemaLambda.cpp:515
SourceLocation getEllipsisLoc() const
Retrieve the source location of the ellipsis, whose presence indicates that the capture is a pack exp...
Definition: ScopeInfo.h:619
SmallVector< LambdaCapture, 4 > Captures
Definition: DeclSpec.h:2584
SourceLocation PotentialThisCaptureLocation
Definition: ScopeInfo.h:883
unsigned NumExplicitCaptures
The number of captures in the Captures list that are explicit captures.
Definition: ScopeInfo.h:809
TypeSourceInfo * getTrivialTypeSourceInfo(QualType T, SourceLocation Loc=SourceLocation()) const
Allocate a TypeSourceInfo where all locations have been initialized to a given location, which defaults to the empty location.
bool isVariableCapture() const
Definition: ScopeInfo.h:579
bool HasSideEffects(const ASTContext &Ctx, bool IncludePossibleEffects=true) const
HasSideEffects - This routine returns true for all those expressions which have any effect other than...
Definition: Expr.cpp:3343
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
Definition: DeclTemplate.h:406
static CXXConversionDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, bool isInline, ExplicitSpecifier ES, ConstexprSpecKind ConstexprKind, SourceLocation EndLocation)
Definition: DeclCXX.cpp:2637
DeclContext * getLexicalParent()
getLexicalParent - Returns the containing lexical DeclContext.
Definition: DeclBase.h:1795
CXXMethodDecl * CallOperator
The lambda&#39;s compiler-generated operator().
Definition: ScopeInfo.h:798
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3951
bool isInvalid() const
Definition: ScopeInfo.h:590
ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, Scope *CurScope)
ActOnLambdaExpr - This is called when the body of a lambda expression was successfully completed...
This represents one expression.
Definition: Expr.h:108
bool isVariadic() const
Whether this function is variadic.
Definition: Decl.cpp:2807
int Id
Definition: ASTDiff.cpp:190
bool hasLocalStorage() const
Returns true if a variable with function scope is a non-static local variable.
Definition: Decl.h:1050
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:6923
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5551
T getAs() const
Convert to the specified TypeLoc type, returning a null TypeLoc if this TypeLoc is not of the desired...
Definition: TypeLoc.h:86
void setInit(Expr *I)
Definition: Decl.cpp:2268
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:132
void setRetValue(Expr *E)
Definition: Stmt.h:2655
bool isFileContext() const
Definition: DeclBase.h:1849
DeclContext * getDeclContext()
Definition: DeclBase.h:438
static TemplateParameterList * getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef)
Definition: SemaLambda.cpp:228
llvm::DenseMap< unsigned, SourceRange > ExplicitCaptureRanges
A map of explicit capture indices to their introducer source ranges.
Definition: ScopeInfo.h:872
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:480
bool isCaptured(VarDecl *Var) const
Determine whether the given variable has been captured.
Definition: ScopeInfo.h:687
QualType getType() const
Definition: Expr.h:137
bool isFunctionOrMethod() const
Definition: DeclBase.h:1831
Capture & getCapture(VarDecl *Var)
Retrieve the capture of the given variable, if it has been captured already.
Definition: ScopeInfo.h:696
Direct list-initialization (C++11)
Definition: Decl.h:838
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:1214
DeclarationName getCXXOperatorName(OverloadedOperatorKind Op)
Get the name of the overloadable C++ operator corresponding to Op.
static bool isInInlineFunction(const DeclContext *DC)
Determine whether the given context is or is enclosed in an inline function.
Definition: SemaLambda.cpp:263
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1779
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2620
bool isInvalid() const
Definition: Ownership.h:166
SourceLocation getEnd() const
QualType getFunctionType(QualType ResultTy, ArrayRef< QualType > Args, const FunctionProtoType::ExtProtoInfo &EPI) const
Return a normal function type with a typed argument list.
Definition: ASTContext.h:1387
struct CXXOpName CXXOperatorName
bool isDependentContext() const
Determines whether this context is dependent on a template parameter.
Definition: DeclBase.cpp:1089
Common base class for placeholders for types that get replaced by placeholder type deduction: C++11 a...
Definition: Type.h:4783
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6798
Represents a C++ conversion function within a class.
Definition: DeclCXX.h:2690
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:1403
SourceLocation getLocation() const
Retrieve the location at which this variable was captured.
Definition: ScopeInfo.h:615
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:708
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:265
TypeLoc getReturnLoc() const
Definition: TypeLoc.h:1446
static TemplateParameterList * Create(const ASTContext &C, SourceLocation TemplateLoc, SourceLocation LAngleLoc, ArrayRef< NamedDecl *> Params, SourceLocation RAngleLoc, Expr *RequiresClause)
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:287
static InitializationKind CreateCopy(SourceLocation InitLoc, SourceLocation EqualLoc, bool AllowExplicitConvs=false)
Create a copy initialization.
ConstexprSpecKind getConstexprSpecifier() const
Definition: DeclSpec.h:731
void setIsVariadic(bool value)
Definition: Decl.h:4027
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, sema::LambdaScopeInfo *LSI)
Complete a lambda-expression having processed and attached the lambda body.
QualType getPackExpansionType(QualType Pattern, Optional< unsigned > NumExpansions)
SmallVector< NamedDecl *, 4 > TemplateParams
Store the list of the template parameters for a generic lambda.
Definition: ScopeInfo.h:843
void setIsConversionFromLambda(bool val=true)
Definition: Decl.h:4098
SourceLocation DefaultLoc
Definition: DeclSpec.h:2582
Kind
bool hasWeakerNullability(NullabilityKind L, NullabilityKind R)
Return true if L has a weaker nullability annotation than R.
Definition: Specifiers.h:329
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
VarDecl * getVariable() const
Definition: ScopeInfo.h:604
ExtProtoInfo getExtProtoInfo() const
Definition: Type.h:3938
unsigned getNumExprs() const
Return the number of expressions in this paren list.
Definition: Expr.h:5141
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:3651
Expr * getRetValue()
Definition: Stmt.h:2653
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4470
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:795
static Optional< unsigned > getStackIndexOfNearestEnclosingCaptureReadyLambda(ArrayRef< const clang::sema::FunctionScopeInfo *> FunctionScopes, VarDecl *VarToCapture)
Examines the FunctionScopeInfo stack to determine the nearest enclosing lambda (to the current lambda...
Definition: SemaLambda.cpp:63
SourceRange ExplicitTemplateParamsRange
Source range covering the explicit template parameter list (if it exists).
Definition: ScopeInfo.h:836
MutableArrayRef< Expr * > MultiExprArg
Definition: Ownership.h:273
void setReferenced(bool R=true)
Definition: DeclBase.h:588
void setLambdaMangling(unsigned ManglingNumber, Decl *ContextDecl, bool HasKnownInternalLinkage=false)
Set the mangling number and context declaration for a lambda class.
Definition: DeclCXX.h:1731
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1905
void handleLambdaNumbering(CXXRecordDecl *Class, CXXMethodDecl *Method, Optional< std::tuple< unsigned, bool, Decl *>> Mangling=None)
Number lambda for linkage purposes if necessary.
Definition: SemaLambda.cpp:432
No ref-qualifier was provided.
Definition: Type.h:1389
C-style initialization with assignment.
Definition: Decl.h:832
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2348
bool isVLATypeCapture() const
Definition: ScopeInfo.h:586
CanQualType VoidTy
Definition: ASTContext.h:1015
bool isGenericLambda() const
Determine whether this class describes a generic lambda function object (i.e.
Definition: DeclCXX.cpp:1389
Describes the kind of initialization being performed, along with location information for tokens rela...
SmallVector< Capture, 4 > Captures
Captures - The captures.
Definition: ScopeInfo.h:650
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3249
SourceLocation CaptureDefaultLoc
Source location of the &#39;&&#39; or &#39;=&#39; specifying the default capture type, if any.
Definition: ScopeInfo.h:805
Expr ** getExprs()
Definition: Expr.h:5152
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3926
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:572
Represents a pack expansion of types.
Definition: Type.h:5431
DeclarationNameLoc - Additional source/type location info for a declaration name. ...
SourceRange getSourceRange() const LLVM_READONLY
Get the source range that spans this declarator.
Definition: DeclSpec.h:1899
This file provides some common utility functions for processing Lambdas.
static ParmVarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S, Expr *DefArg)
Definition: Decl.cpp:2657
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:4031
ConstexprSpecKind
Define the kind of constexpr specifier.
Definition: Specifiers.h:32
bool isValid() const
Return true if this is a valid SourceLocation object.
LambdaCaptureDefault Default
Definition: DeclSpec.h:2583
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1271
void deduceClosureReturnType(sema::CapturingScopeInfo &CSI)
Deduce a block or lambda&#39;s return type based on the return statements present in the body...
Definition: SemaLambda.cpp:691
bool isRecord() const
Definition: DeclBase.h:1858
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:1234
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
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2028
MangleNumberingContext & getManglingNumberContext(const DeclContext *DC)
Retrieve the context for computing mangling numbers in the given DeclContext.
Represents an enum.
Definition: Decl.h:3395
bool isParameterPack() const
Determine whether this variable is actually a function parameter pack or init-capture pack...
Definition: Decl.cpp:2449
bool isInitCapture() const
Whether this variable is the implicit variable for a lambda init-capture.
Definition: Decl.h:1426
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
void ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc, ArrayRef< NamedDecl *> TParams, SourceLocation RAngleLoc)
This is called after parsing the explicit template parameter list on a lambda (if it exists) in C++2a...
Definition: SemaLambda.cpp:519
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:6773
void setInitCapture(bool IC)
Definition: Decl.h:1429
Capturing variable-length array type.
Definition: Lambda.h:38
void ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, Declarator &ParamInfo, Scope *CurScope)
ActOnStartOfLambdaDefinition - This is called just before we start parsing the body of a lambda; it a...
Definition: SemaLambda.cpp:883
void setConstexprKind(ConstexprSpecKind CSK)
Definition: Decl.h:2147
CanQualType DependentTy
Definition: ASTContext.h:1044
std::tuple< MangleNumberingContext *, Decl * > getCurrentMangleNumberContext(const DeclContext *DC)
Compute the mangling number context for a lambda expression or block literal.
Definition: SemaLambda.cpp:276
TypeSourceInfo * getTypeSourceInfo() const
Definition: Decl.h:723
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2305
Simple template class for restricting typo correction candidates to ones having a single Decl* of the...
QualType getAutoDeductType() const
C++11 deduction pattern for &#39;auto&#39; type.
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:92
void addDecl(Decl *D)
Add the declaration D into this context.
Definition: DeclBase.cpp:1521
Optional< NullabilityKind > getNullability(const ASTContext &context) const
Determine the nullability of the given type.
Definition: Type.cpp:3825
Capturing the *this object by reference.
Definition: Lambda.h:34
void markUsed(ASTContext &C)
Mark the declaration used, in the sense of odr-use.
Definition: DeclBase.cpp:413
Capture & getCXXThisCapture()
Retrieve the capture of C++ &#39;this&#39;, if it has been captured.
Definition: ScopeInfo.h:681
bool isIncompleteType(NamedDecl **Def=nullptr) const
Types are partitioned into 3 broad categories (C99 6.2.5p1): object types, function types...
Definition: Type.cpp:2118
FieldDecl * BuildCaptureField(RecordDecl *RD, const sema::Capture &Capture)
Build a FieldDecl suitable to hold the given capture.
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2289
void setSignatureAsWritten(TypeSourceInfo *Sig)
Definition: Decl.h:4033
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:240
bool isInitCapture() const
Determine whether this capture is an init-capture.
Definition: ScopeInfo.cpp:219
static BlockDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L)
Definition: Decl.cpp:4640
Call-style initialization (C++98)
Definition: Decl.h:835
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1008
void addCapture(VarDecl *Var, bool isBlock, bool isByref, bool isNested, SourceLocation Loc, SourceLocation EllipsisLoc, QualType CaptureType, bool Invalid)
Definition: ScopeInfo.h:660
Describes the sequence of initializations required to initialize a given object or reference with a s...
ActionResult< Expr * > ExprResult
Definition: Ownership.h:263
Represents a C++ struct/union/class.
Definition: DeclCXX.h:255
bool isValid() const
bool isVoidType() const
Definition: Type.h:6650
Capturing by reference.
Definition: Lambda.h:37
TryCaptureKind
Definition: Sema.h:4354
const DeclSpec & getDeclSpec() const
getDeclSpec - Return the declaration-specifier that this declarator was declared with.
Definition: DeclSpec.h:1864
bool isCXXThisCaptured() const
Determine whether the C++ &#39;this&#39; is captured.
Definition: ScopeInfo.h:678
bool containsUnexpandedParameterPack() const
Whether this expression contains an unexpanded parameter pack (for C++11 variadic templates)...
Definition: Expr.h:223
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
void setCapturedVLAType(const VariableArrayType *VLAType)
Set the captured variable length array type for this field.
Definition: Decl.cpp:4021
void addAttr(Attr *A)
Definition: DeclBase.cpp:830
Defines the clang::TargetInfo interface.
Represents a complete lambda introducer.
Definition: DeclSpec.h:2559
ExprResult ExprError()
Definition: Ownership.h:279
void setDescribedFunctionTemplate(FunctionTemplateDecl *Template)
Definition: Decl.cpp:3490
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2121
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1146
bool isNonODRUsed() const
Definition: ScopeInfo.h:596
CXXMethodDecl * startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange, TypeSourceInfo *MethodType, SourceLocation EndLoc, ArrayRef< ParmVarDecl *> Params, ConstexprSpecKind ConstexprKind)
Start the definition of a lambda expression.
Definition: SemaLambda.cpp:359
QualType getType() const
Definition: Decl.h:655
bool empty() const
Return true if no decls were found.
Definition: Lookup.h:339
void setCaptures(ASTContext &Context, ArrayRef< Capture > Captures, bool CapturesCXXThis)
Definition: Decl.cpp:4475
A trivial tuple used to represent a source range.
void setLexicalDeclContext(DeclContext *DC)
Definition: DeclBase.cpp:299
ASTContext & Context
Definition: Sema.h:377
This represents a decl that may have a name.
Definition: Decl.h:248
bool isTranslationUnit() const
Definition: DeclBase.h:1854
void setAccess(AccessSpecifier AS)
Definition: DeclBase.h:468
void setBlockMissingReturnType(bool val=true)
Definition: Decl.h:4090
Describes an entity that is being initialized.
QualType buildLambdaInitCaptureInitialization(SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc, Optional< unsigned > NumExpansions, IdentifierInfo *Id, bool DirectInit, Expr *&Init)
Definition: SemaLambda.cpp:784
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:3924
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3178
Wrapper for source info for pointers.
Definition: TypeLoc.h:1237
SourceLocation getBegin() const
bool isBlockCapture() const
Definition: ScopeInfo.h:585
static void adjustBlockReturnsToEnum(Sema &S, ArrayRef< ReturnStmt *> returns, QualType returnType)
Adjust the given return statements so that they formally return the given type.
Definition: SemaLambda.cpp:665
No in-class initializer.
Definition: Specifiers.h:259
Declaration of a template function.
Definition: DeclTemplate.h:961
Attr - This represents one attribute.
Definition: Attr.h:45
SourceLocation getLocation() const
Definition: DeclBase.h:429
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97
Expr * IgnoreParens() LLVM_READONLY
Skip past any parentheses which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2962