clang  9.0.0svn
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 using namespace clang;
24 using namespace sema;
25 
26 /// Examines the FunctionScopeInfo stack to determine the nearest
27 /// enclosing lambda (to the current lambda) that is 'capture-ready' for
28 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
29 /// If successful, returns the index into Sema's FunctionScopeInfo stack
30 /// of the capture-ready lambda's LambdaScopeInfo.
31 ///
32 /// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
33 /// lambda - is on top) to determine the index of the nearest enclosing/outer
34 /// lambda that is ready to capture the \p VarToCapture being referenced in
35 /// the current lambda.
36 /// As we climb down the stack, we want the index of the first such lambda -
37 /// that is the lambda with the highest index that is 'capture-ready'.
38 ///
39 /// A lambda 'L' is capture-ready for 'V' (var or this) if:
40 /// - its enclosing context is non-dependent
41 /// - and if the chain of lambdas between L and the lambda in which
42 /// V is potentially used (i.e. the lambda at the top of the scope info
43 /// stack), can all capture or have already captured V.
44 /// If \p VarToCapture is 'null' then we are trying to capture 'this'.
45 ///
46 /// Note that a lambda that is deemed 'capture-ready' still needs to be checked
47 /// for whether it is 'capture-capable' (see
48 /// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
49 /// capture.
50 ///
51 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
52 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
53 /// is at the top of the stack and has the highest index.
54 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
55 ///
56 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
57 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
58 /// which is capture-ready. If the return value evaluates to 'false' then
59 /// no lambda is capture-ready for \p VarToCapture.
60 
61 static inline Optional<unsigned>
64  VarDecl *VarToCapture) {
65  // Label failure to capture.
66  const Optional<unsigned> NoLambdaIsCaptureReady;
67 
68  // Ignore all inner captured regions.
69  unsigned CurScopeIndex = FunctionScopes.size() - 1;
70  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
71  FunctionScopes[CurScopeIndex]))
72  --CurScopeIndex;
73  assert(
74  isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
75  "The function on the top of sema's function-info stack must be a lambda");
76 
77  // If VarToCapture is null, we are attempting to capture 'this'.
78  const bool IsCapturingThis = !VarToCapture;
79  const bool IsCapturingVariable = !IsCapturingThis;
80 
81  // Start with the current lambda at the top of the stack (highest index).
82  DeclContext *EnclosingDC =
83  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
84 
85  do {
86  const clang::sema::LambdaScopeInfo *LSI =
87  cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]);
88  // IF we have climbed down to an intervening enclosing lambda that contains
89  // the variable declaration - it obviously can/must not capture the
90  // variable.
91  // Since its enclosing DC is dependent, all the lambdas between it and the
92  // innermost nested lambda are dependent (otherwise we wouldn't have
93  // arrived here) - so we don't yet have a lambda that can capture the
94  // variable.
95  if (IsCapturingVariable &&
96  VarToCapture->getDeclContext()->Equals(EnclosingDC))
97  return NoLambdaIsCaptureReady;
98 
99  // For an enclosing lambda to be capture ready for an entity, all
100  // intervening lambda's have to be able to capture that entity. If even
101  // one of the intervening lambda's is not capable of capturing the entity
102  // then no enclosing lambda can ever capture that entity.
103  // For e.g.
104  // const int x = 10;
105  // [=](auto a) { #1
106  // [](auto b) { #2 <-- an intervening lambda that can never capture 'x'
107  // [=](auto c) { #3
108  // f(x, c); <-- can not lead to x's speculative capture by #1 or #2
109  // }; }; };
110  // If they do not have a default implicit capture, check to see
111  // if the entity has already been explicitly captured.
112  // If even a single dependent enclosing lambda lacks the capability
113  // to ever capture this variable, there is no further enclosing
114  // non-dependent lambda that can capture this variable.
116  if (IsCapturingVariable && !LSI->isCaptured(VarToCapture))
117  return NoLambdaIsCaptureReady;
118  if (IsCapturingThis && !LSI->isCXXThisCaptured())
119  return NoLambdaIsCaptureReady;
120  }
121  EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
122 
123  assert(CurScopeIndex);
124  --CurScopeIndex;
125  } while (!EnclosingDC->isTranslationUnit() &&
126  EnclosingDC->isDependentContext() &&
127  isLambdaCallOperator(EnclosingDC));
128 
129  assert(CurScopeIndex < (FunctionScopes.size() - 1));
130  // If the enclosingDC is not dependent, then the immediately nested lambda
131  // (one index above) is capture-ready.
132  if (!EnclosingDC->isDependentContext())
133  return CurScopeIndex + 1;
134  return NoLambdaIsCaptureReady;
135 }
136 
137 /// Examines the FunctionScopeInfo stack to determine the nearest
138 /// enclosing lambda (to the current lambda) that is 'capture-capable' for
139 /// the variable referenced in the current lambda (i.e. \p VarToCapture).
140 /// If successful, returns the index into Sema's FunctionScopeInfo stack
141 /// of the capture-capable lambda's LambdaScopeInfo.
142 ///
143 /// Given the current stack of lambdas being processed by Sema and
144 /// the variable of interest, to identify the nearest enclosing lambda (to the
145 /// current lambda at the top of the stack) that can truly capture
146 /// a variable, it has to have the following two properties:
147 /// a) 'capture-ready' - be the innermost lambda that is 'capture-ready':
148 /// - climb down the stack (i.e. starting from the innermost and examining
149 /// each outer lambda step by step) checking if each enclosing
150 /// lambda can either implicitly or explicitly capture the variable.
151 /// Record the first such lambda that is enclosed in a non-dependent
152 /// context. If no such lambda currently exists return failure.
153 /// b) 'capture-capable' - make sure the 'capture-ready' lambda can truly
154 /// capture the variable by checking all its enclosing lambdas:
155 /// - check if all outer lambdas enclosing the 'capture-ready' lambda
156 /// identified above in 'a' can also capture the variable (this is done
157 /// via tryCaptureVariable for variables and CheckCXXThisCapture for
158 /// 'this' by passing in the index of the Lambda identified in step 'a')
159 ///
160 /// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
161 /// LambdaScopeInfo inherits from). The current/deepest/innermost lambda
162 /// is at the top of the stack.
163 ///
164 /// \param VarToCapture - the variable to capture. If NULL, capture 'this'.
165 ///
166 ///
167 /// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
168 /// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
169 /// which is capture-capable. If the return value evaluates to 'false' then
170 /// no lambda is capture-capable for \p VarToCapture.
171 
174  VarDecl *VarToCapture, Sema &S) {
175 
176  const Optional<unsigned> NoLambdaIsCaptureCapable;
177 
178  const Optional<unsigned> OptionalStackIndex =
180  VarToCapture);
181  if (!OptionalStackIndex)
182  return NoLambdaIsCaptureCapable;
183 
184  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
185  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
186  S.getCurGenericLambda()) &&
187  "The capture ready lambda for a potential capture can only be the "
188  "current lambda if it is a generic lambda");
189 
190  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
191  cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
192 
193  // If VarToCapture is null, we are attempting to capture 'this'
194  const bool IsCapturingThis = !VarToCapture;
195  const bool IsCapturingVariable = !IsCapturingThis;
196 
197  if (IsCapturingVariable) {
198  // Check if the capture-ready lambda can truly capture the variable, by
199  // checking whether all enclosing lambdas of the capture-ready lambda allow
200  // the capture - i.e. make sure it is capture-capable.
201  QualType CaptureType, DeclRefType;
202  const bool CanCaptureVariable =
203  !S.tryCaptureVariable(VarToCapture,
204  /*ExprVarIsUsedInLoc*/ SourceLocation(),
206  /*EllipsisLoc*/ SourceLocation(),
207  /*BuildAndDiagnose*/ false, CaptureType,
208  DeclRefType, &IndexOfCaptureReadyLambda);
209  if (!CanCaptureVariable)
210  return NoLambdaIsCaptureCapable;
211  } else {
212  // Check if the capture-ready lambda can truly capture 'this' by checking
213  // whether all enclosing lambdas of the capture-ready lambda can capture
214  // 'this'.
215  const bool CanCaptureThis =
217  CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
218  /*Explicit*/ false, /*BuildAndDiagnose*/ false,
219  &IndexOfCaptureReadyLambda);
220  if (!CanCaptureThis)
221  return NoLambdaIsCaptureCapable;
222  }
223  return IndexOfCaptureReadyLambda;
224 }
225 
226 static inline TemplateParameterList *
228  if (LSI->GLTemplateParameterList)
229  return LSI->GLTemplateParameterList;
230 
231  if (!LSI->AutoTemplateParams.empty()) {
232  SourceRange IntroRange = LSI->IntroducerRange;
233  SourceLocation LAngleLoc = IntroRange.getBegin();
234  SourceLocation RAngleLoc = IntroRange.getEnd();
236  SemaRef.Context,
237  /*Template kw loc*/ SourceLocation(), LAngleLoc,
238  llvm::makeArrayRef((NamedDecl *const *)LSI->AutoTemplateParams.data(),
239  LSI->AutoTemplateParams.size()),
240  RAngleLoc, nullptr);
241  }
242  return LSI->GLTemplateParameterList;
243 }
244 
246  TypeSourceInfo *Info,
247  bool KnownDependent,
248  LambdaCaptureDefault CaptureDefault) {
249  DeclContext *DC = CurContext;
250  while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext()))
251  DC = DC->getParent();
252  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
253  *this);
254  // Start constructing the lambda class.
255  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
256  IntroducerRange.getBegin(),
257  KnownDependent,
258  IsGenericLambda,
259  CaptureDefault);
260  DC->addDecl(Class);
261 
262  return Class;
263 }
264 
265 /// Determine whether the given context is or is enclosed in an inline
266 /// function.
267 static bool isInInlineFunction(const DeclContext *DC) {
268  while (!DC->isFileContext()) {
269  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
270  if (FD->isInlined())
271  return true;
272 
273  DC = DC->getLexicalParent();
274  }
275 
276  return false;
277 }
278 
281  Decl *&ManglingContextDecl) {
282  // Compute the context for allocating mangling numbers in the current
283  // expression, if the ABI requires them.
284  ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
285 
286  enum ContextKind {
287  Normal,
288  DefaultArgument,
289  DataMember,
290  StaticDataMember,
291  InlineVariable,
292  VariableTemplate
293  } Kind = Normal;
294 
295  // Default arguments of member function parameters that appear in a class
296  // definition, as well as the initializers of data members, receive special
297  // treatment. Identify them.
298  if (ManglingContextDecl) {
299  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
300  if (const DeclContext *LexicalDC
301  = Param->getDeclContext()->getLexicalParent())
302  if (LexicalDC->isRecord())
303  Kind = DefaultArgument;
304  } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
305  if (Var->getDeclContext()->isRecord())
306  Kind = StaticDataMember;
307  else if (Var->getMostRecentDecl()->isInline())
308  Kind = InlineVariable;
309  else if (Var->getDescribedVarTemplate())
310  Kind = VariableTemplate;
311  else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
312  if (!VTS->isExplicitSpecialization())
313  Kind = VariableTemplate;
314  }
315  } else if (isa<FieldDecl>(ManglingContextDecl)) {
316  Kind = DataMember;
317  }
318  }
319 
320  // Itanium ABI [5.1.7]:
321  // In the following contexts [...] the one-definition rule requires closure
322  // types in different translation units to "correspond":
323  bool IsInNonspecializedTemplate =
324  inTemplateInstantiation() || CurContext->isDependentContext();
325  switch (Kind) {
326  case Normal: {
327  // -- the bodies of non-exported nonspecialized template functions
328  // -- the bodies of inline functions
329  if ((IsInNonspecializedTemplate &&
330  !(ManglingContextDecl && isa<ParmVarDecl>(ManglingContextDecl))) ||
331  isInInlineFunction(CurContext)) {
332  ManglingContextDecl = nullptr;
333  while (auto *CD = dyn_cast<CapturedDecl>(DC))
334  DC = CD->getParent();
335  return &Context.getManglingNumberContext(DC);
336  }
337 
338  ManglingContextDecl = nullptr;
339  return nullptr;
340  }
341 
342  case StaticDataMember:
343  // -- the initializers of nonspecialized static members of template classes
344  if (!IsInNonspecializedTemplate) {
345  ManglingContextDecl = nullptr;
346  return nullptr;
347  }
348  // Fall through to get the current context.
349  LLVM_FALLTHROUGH;
350 
351  case DataMember:
352  // -- the in-class initializers of class members
353  case DefaultArgument:
354  // -- default arguments appearing in class definitions
355  case InlineVariable:
356  // -- the initializers of inline variables
357  case VariableTemplate:
358  // -- the initializers of templated variables
359  return &ExprEvalContexts.back().getMangleNumberingContext(Context);
360  }
361 
362  llvm_unreachable("unexpected context");
363 }
364 
367  ASTContext &Ctx) {
368  assert(ManglingContextDecl && "Need to have a context declaration");
369  if (!MangleNumbering)
370  MangleNumbering = Ctx.createMangleNumberingContext();
371  return *MangleNumbering;
372 }
373 
375  SourceRange IntroducerRange,
376  TypeSourceInfo *MethodTypeInfo,
377  SourceLocation EndLoc,
379  const bool IsConstexprSpecified) {
380  QualType MethodType = MethodTypeInfo->getType();
381  TemplateParameterList *TemplateParams =
382  getGenericLambdaTemplateParameterList(getCurLambda(), *this);
383  // If a lambda appears in a dependent context or is a generic lambda (has
384  // template parameters) and has an 'auto' return type, deduce it to a
385  // dependent type.
386  if (Class->isDependentContext() || TemplateParams) {
387  const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
388  QualType Result = FPT->getReturnType();
389  if (Result->isUndeducedType()) {
390  Result = SubstAutoType(Result, Context.DependentTy);
391  MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
392  FPT->getExtProtoInfo());
393  }
394  }
395 
396  // C++11 [expr.prim.lambda]p5:
397  // The closure type for a lambda-expression has a public inline function
398  // call operator (13.5.4) whose parameters and return type are described by
399  // the lambda-expression's parameter-declaration-clause and
400  // trailing-return-type respectively.
401  DeclarationName MethodName
402  = Context.DeclarationNames.getCXXOperatorName(OO_Call);
403  DeclarationNameLoc MethodNameLoc;
404  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
405  = IntroducerRange.getBegin().getRawEncoding();
406  MethodNameLoc.CXXOperatorName.EndOpNameLoc
407  = IntroducerRange.getEnd().getRawEncoding();
408  CXXMethodDecl *Method
409  = CXXMethodDecl::Create(Context, Class, EndLoc,
410  DeclarationNameInfo(MethodName,
411  IntroducerRange.getBegin(),
412  MethodNameLoc),
413  MethodType, MethodTypeInfo,
414  SC_None,
415  /*isInline=*/true,
416  IsConstexprSpecified,
417  EndLoc);
418  Method->setAccess(AS_public);
419 
420  // Temporarily set the lexical declaration context to the current
421  // context, so that the Scope stack matches the lexical nesting.
422  Method->setLexicalDeclContext(CurContext);
423  // Create a function template if we have a template parameter list
424  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
425  FunctionTemplateDecl::Create(Context, Class,
426  Method->getLocation(), MethodName,
427  TemplateParams,
428  Method) : nullptr;
429  if (TemplateMethod) {
430  TemplateMethod->setLexicalDeclContext(CurContext);
431  TemplateMethod->setAccess(AS_public);
432  Method->setDescribedFunctionTemplate(TemplateMethod);
433  }
434 
435  // Add parameters.
436  if (!Params.empty()) {
437  Method->setParams(Params);
438  CheckParmsForFunctionDef(Params,
439  /*CheckParameterNames=*/false);
440 
441  for (auto P : Method->parameters())
442  P->setOwningFunction(Method);
443  }
444 
445  Decl *ManglingContextDecl;
446  if (MangleNumberingContext *MCtx =
447  getCurrentMangleNumberContext(Class->getDeclContext(),
448  ManglingContextDecl)) {
449  unsigned ManglingNumber = MCtx->getManglingNumber(Method);
450  Class->setLambdaMangling(ManglingNumber, ManglingContextDecl);
451  }
452 
453  return Method;
454 }
455 
457  CXXMethodDecl *CallOperator,
458  SourceRange IntroducerRange,
459  LambdaCaptureDefault CaptureDefault,
460  SourceLocation CaptureDefaultLoc,
461  bool ExplicitParams,
462  bool ExplicitResultType,
463  bool Mutable) {
464  LSI->CallOperator = CallOperator;
465  CXXRecordDecl *LambdaClass = CallOperator->getParent();
466  LSI->Lambda = LambdaClass;
467  if (CaptureDefault == LCD_ByCopy)
469  else if (CaptureDefault == LCD_ByRef)
471  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
472  LSI->IntroducerRange = IntroducerRange;
473  LSI->ExplicitParams = ExplicitParams;
474  LSI->Mutable = Mutable;
475 
476  if (ExplicitResultType) {
477  LSI->ReturnType = CallOperator->getReturnType();
478 
479  if (!LSI->ReturnType->isDependentType() &&
480  !LSI->ReturnType->isVoidType()) {
481  if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
482  diag::err_lambda_incomplete_result)) {
483  // Do nothing.
484  }
485  }
486  } else {
487  LSI->HasImplicitReturnType = true;
488  }
489 }
490 
493 }
494 
497  CXXMethodDecl *CallOperator, Scope *CurScope) {
498  // Introduce our parameters into the function scope
499  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
500  p < NumParams; ++p) {
501  ParmVarDecl *Param = CallOperator->getParamDecl(p);
502 
503  // If this has an identifier, add it to the scope stack.
504  if (CurScope && Param->getIdentifier()) {
505  bool Error = false;
506  // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
507  // retroactively apply it.
508  for (const auto &Capture : Captures) {
509  if (Capture.Id == Param->getIdentifier()) {
510  Error = true;
511  Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
512  Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
513  << Capture.Id << true;
514  }
515  }
516  if (!Error)
517  CheckShadow(CurScope, Param);
518 
519  PushOnScopeChains(Param, CurScope);
520  }
521  }
522 }
523 
524 /// If this expression is an enumerator-like expression of some type
525 /// T, return the type T; otherwise, return null.
526 ///
527 /// Pointer comparisons on the result here should always work because
528 /// it's derived from either the parent of an EnumConstantDecl
529 /// (i.e. the definition) or the declaration returned by
530 /// EnumType::getDecl() (i.e. the definition).
532  // An expression is an enumerator-like expression of type T if,
533  // ignoring parens and parens-like expressions:
534  E = E->IgnoreParens();
535 
536  // - it is an enumerator whose enum type is T or
537  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
538  if (EnumConstantDecl *D
539  = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
540  return cast<EnumDecl>(D->getDeclContext());
541  }
542  return nullptr;
543  }
544 
545  // - it is a comma expression whose RHS is an enumerator-like
546  // expression of type T or
547  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
548  if (BO->getOpcode() == BO_Comma)
549  return findEnumForBlockReturn(BO->getRHS());
550  return nullptr;
551  }
552 
553  // - it is a statement-expression whose value expression is an
554  // enumerator-like expression of type T or
555  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
556  if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
557  return findEnumForBlockReturn(last);
558  return nullptr;
559  }
560 
561  // - it is a ternary conditional operator (not the GNU ?:
562  // extension) whose second and third operands are
563  // enumerator-like expressions of type T or
564  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
565  if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
566  if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
567  return ED;
568  return nullptr;
569  }
570 
571  // (implicitly:)
572  // - it is an implicit integral conversion applied to an
573  // enumerator-like expression of type T or
574  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
575  // We can sometimes see integral conversions in valid
576  // enumerator-like expressions.
577  if (ICE->getCastKind() == CK_IntegralCast)
578  return findEnumForBlockReturn(ICE->getSubExpr());
579 
580  // Otherwise, just rely on the type.
581  }
582 
583  // - it is an expression of that formal enum type.
584  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
585  return ET->getDecl();
586  }
587 
588  // Otherwise, nope.
589  return nullptr;
590 }
591 
592 /// Attempt to find a type T for which the returned expression of the
593 /// given statement is an enumerator-like expression of that type.
595  if (Expr *retValue = ret->getRetValue())
596  return findEnumForBlockReturn(retValue);
597  return nullptr;
598 }
599 
600 /// Attempt to find a common type T for which all of the returned
601 /// expressions in a block are enumerator-like expressions of that
602 /// type.
604  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
605 
606  // Try to find one for the first return.
608  if (!ED) return nullptr;
609 
610  // Check that the rest of the returns have the same enum.
611  for (++i; i != e; ++i) {
612  if (findEnumForBlockReturn(*i) != ED)
613  return nullptr;
614  }
615 
616  // Never infer an anonymous enum type.
617  if (!ED->hasNameForLinkage()) return nullptr;
618 
619  return ED;
620 }
621 
622 /// Adjust the given return statements so that they formally return
623 /// the given type. It should require, at most, an IntegralCast.
625  QualType returnType) {
627  i = returns.begin(), e = returns.end(); i != e; ++i) {
628  ReturnStmt *ret = *i;
629  Expr *retValue = ret->getRetValue();
630  if (S.Context.hasSameType(retValue->getType(), returnType))
631  continue;
632 
633  // Right now we only support integral fixup casts.
634  assert(returnType->isIntegralOrUnscopedEnumerationType());
635  assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
636 
637  ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
638 
639  Expr *E = (cleanups ? cleanups->getSubExpr() : retValue);
640  E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast,
641  E, /*base path*/ nullptr, VK_RValue);
642  if (cleanups) {
643  cleanups->setSubExpr(E);
644  } else {
645  ret->setRetValue(E);
646  }
647  }
648 }
649 
651  assert(CSI.HasImplicitReturnType);
652  // If it was ever a placeholder, it had to been deduced to DependentTy.
653  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
654  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
655  "lambda expressions use auto deduction in C++14 onwards");
656 
657  // C++ core issue 975:
658  // If a lambda-expression does not include a trailing-return-type,
659  // it is as if the trailing-return-type denotes the following type:
660  // - if there are no return statements in the compound-statement,
661  // or all return statements return either an expression of type
662  // void or no expression or braced-init-list, the type void;
663  // - otherwise, if all return statements return an expression
664  // and the types of the returned expressions after
665  // lvalue-to-rvalue conversion (4.1 [conv.lval]),
666  // array-to-pointer conversion (4.2 [conv.array]), and
667  // function-to-pointer conversion (4.3 [conv.func]) are the
668  // same, that common type;
669  // - otherwise, the program is ill-formed.
670  //
671  // C++ core issue 1048 additionally removes top-level cv-qualifiers
672  // from the types of returned expressions to match the C++14 auto
673  // deduction rules.
674  //
675  // In addition, in blocks in non-C++ modes, if all of the return
676  // statements are enumerator-like expressions of some type T, where
677  // T has a name for linkage, then we infer the return type of the
678  // block to be that type.
679 
680  // First case: no return statements, implicit void return type.
681  ASTContext &Ctx = getASTContext();
682  if (CSI.Returns.empty()) {
683  // It's possible there were simply no /valid/ return statements.
684  // In this case, the first one we found may have at least given us a type.
685  if (CSI.ReturnType.isNull())
686  CSI.ReturnType = Ctx.VoidTy;
687  return;
688  }
689 
690  // Second case: at least one return statement has dependent type.
691  // Delay type checking until instantiation.
692  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
693  if (CSI.ReturnType->isDependentType())
694  return;
695 
696  // Try to apply the enum-fuzz rule.
697  if (!getLangOpts().CPlusPlus) {
698  assert(isa<BlockScopeInfo>(CSI));
700  if (ED) {
701  CSI.ReturnType = Context.getTypeDeclType(ED);
703  return;
704  }
705  }
706 
707  // Third case: only one return statement. Don't bother doing extra work!
708  if (CSI.Returns.size() == 1)
709  return;
710 
711  // General case: many return statements.
712  // Check that they all have compatible return types.
713 
714  // We require the return types to strictly match here.
715  // Note that we've already done the required promotions as part of
716  // processing the return statement.
717  for (const ReturnStmt *RS : CSI.Returns) {
718  const Expr *RetE = RS->getRetValue();
719 
720  QualType ReturnType =
721  (RetE ? RetE->getType() : Context.VoidTy).getUnqualifiedType();
722  if (Context.getCanonicalFunctionResultType(ReturnType) ==
724  // Use the return type with the strictest possible nullability annotation.
725  auto RetTyNullability = ReturnType->getNullability(Ctx);
726  auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
727  if (BlockNullability &&
728  (!RetTyNullability ||
729  hasWeakerNullability(*RetTyNullability, *BlockNullability)))
730  CSI.ReturnType = ReturnType;
731  continue;
732  }
733 
734  // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
735  // TODO: It's possible that the *first* return is the divergent one.
736  Diag(RS->getBeginLoc(),
737  diag::err_typecheck_missing_return_type_incompatible)
738  << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
739  // Continue iterating so that we keep emitting diagnostics.
740  }
741 }
742 
744  bool ByRef,
746  bool IsDirectInit,
747  Expr *&Init) {
748  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
749  // deduce against.
750  QualType DeductType = Context.getAutoDeductType();
751  TypeLocBuilder TLB;
752  TLB.pushTypeSpec(DeductType).setNameLoc(Loc);
753  if (ByRef) {
754  DeductType = BuildReferenceType(DeductType, true, Loc, Id);
755  assert(!DeductType.isNull() && "can't build reference to auto");
756  TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
757  }
758  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
759 
760  // Deduce the type of the init capture.
761  Expr *DeduceInit = Init;
762  QualType DeducedType = deduceVarTypeFromInitializer(
763  /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
764  SourceRange(Loc, Loc), IsDirectInit, DeduceInit);
765  if (DeducedType.isNull())
766  return QualType();
767 
768  // Are we a non-list direct initialization?
769  bool CXXDirectInit = isa<ParenListExpr>(Init);
770 
771  // Perform initialization analysis and ensure any implicit conversions
772  // (such as lvalue-to-rvalue) are enforced.
773  InitializedEntity Entity =
774  InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
776  IsDirectInit
777  ? (CXXDirectInit ? InitializationKind::CreateDirect(
778  Loc, Init->getBeginLoc(), Init->getEndLoc())
781 
782  MultiExprArg Args = DeduceInit;
783  QualType DclT;
784  InitializationSequence InitSeq(*this, Entity, Kind, Args);
785  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
786 
787  if (Result.isInvalid())
788  return QualType();
789 
790  Init = Result.getAs<Expr>();
791  return DeducedType;
792 }
793 
795  QualType InitCaptureType,
797  unsigned InitStyle, Expr *Init) {
798  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType,
799  Loc);
800  // Create a dummy variable representing the init-capture. This is not actually
801  // used as a variable, and only exists as a way to name and refer to the
802  // init-capture.
803  // FIXME: Pass in separate source locations for '&' and identifier.
804  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
805  Loc, Id, InitCaptureType, TSI, SC_Auto);
806  NewVD->setInitCapture(true);
807  NewVD->setReferenced(true);
808  // FIXME: Pass in a VarDecl::InitializationStyle.
809  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
810  NewVD->markUsed(Context);
811  NewVD->setInit(Init);
812  return NewVD;
813 }
814 
816  FieldDecl *Field = FieldDecl::Create(
817  Context, LSI->Lambda, Var->getLocation(), Var->getLocation(),
818  nullptr, Var->getType(), Var->getTypeSourceInfo(), nullptr, false,
819  ICIS_NoInit);
820  Field->setImplicit(true);
821  Field->setAccess(AS_private);
822  LSI->Lambda->addDecl(Field);
823 
824  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
825  /*isNested*/false, Var->getLocation(), SourceLocation(),
826  Var->getType(), Var->getInit());
827  return Field;
828 }
829 
831  Declarator &ParamInfo,
832  Scope *CurScope) {
833  // Determine if we're within a context where we know that the lambda will
834  // be dependent, because there are template parameters in scope.
835  bool KnownDependent = false;
836  LambdaScopeInfo *const LSI = getCurLambda();
837  assert(LSI && "LambdaScopeInfo should be on stack!");
838 
839  // The lambda-expression's closure type might be dependent even if its
840  // semantic context isn't, if it appears within a default argument of a
841  // function template.
842  if (CurScope->getTemplateParamParent())
843  KnownDependent = true;
844 
845  // Determine the signature of the call operator.
846  TypeSourceInfo *MethodTyInfo;
847  bool ExplicitParams = true;
848  bool ExplicitResultType = true;
849  bool ContainsUnexpandedParameterPack = false;
850  SourceLocation EndLoc;
852  if (ParamInfo.getNumTypeObjects() == 0) {
853  // C++11 [expr.prim.lambda]p4:
854  // If a lambda-expression does not include a lambda-declarator, it is as
855  // if the lambda-declarator were ().
857  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
858  EPI.HasTrailingReturn = true;
859  EPI.TypeQuals.addConst();
860  // C++1y [expr.prim.lambda]:
861  // The lambda return type is 'auto', which is replaced by the
862  // trailing-return type if provided and/or deduced from 'return'
863  // statements
864  // We don't do this before C++1y, because we don't support deduced return
865  // types there.
866  QualType DefaultTypeForNoTrailingReturn =
867  getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
868  : Context.DependentTy;
869  QualType MethodTy =
870  Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
871  MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
872  ExplicitParams = false;
873  ExplicitResultType = false;
874  EndLoc = Intro.Range.getEnd();
875  } else {
876  assert(ParamInfo.isFunctionDeclarator() &&
877  "lambda-declarator is a function");
879 
880  // C++11 [expr.prim.lambda]p5:
881  // This function call operator is declared const (9.3.1) if and only if
882  // the lambda-expression's parameter-declaration-clause is not followed
883  // by mutable. It is neither virtual nor declared volatile. [...]
884  if (!FTI.hasMutableQualifier()) {
886  SourceLocation());
887  }
888 
889  MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
890  assert(MethodTyInfo && "no type from lambda-declarator");
891  EndLoc = ParamInfo.getSourceRange().getEnd();
892 
893  ExplicitResultType = FTI.hasTrailingReturnType();
894 
895  if (FTIHasNonVoidParameters(FTI)) {
896  Params.reserve(FTI.NumParams);
897  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i)
898  Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
899  }
900 
901  // Check for unexpanded parameter packs in the method type.
902  if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
903  ContainsUnexpandedParameterPack = true;
904  }
905 
906  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
907  KnownDependent, Intro.Default);
908 
909  CXXMethodDecl *Method =
910  startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
911  ParamInfo.getDeclSpec().isConstexprSpecified());
912  if (ExplicitParams)
913  CheckCXXDefaultArguments(Method);
914 
915  // This represents the function body for the lambda function, check if we
916  // have to apply optnone due to a pragma.
917  AddRangeBasedOptnone(Method);
918 
919  // code_seg attribute on lambda apply to the method.
920  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
921  Method->addAttr(A);
922 
923  // Attributes on the lambda apply to the method.
924  ProcessDeclAttributes(CurScope, Method, ParamInfo);
925 
926  // CUDA lambdas get implicit attributes based on the scope in which they're
927  // declared.
928  if (getLangOpts().CUDA)
929  CUDASetLambdaAttrs(Method);
930 
931  // Introduce the function call operator as the current declaration context.
932  PushDeclContext(CurScope, Method);
933 
934  // Build the lambda scope.
935  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
936  ExplicitParams, ExplicitResultType, !Method->isConst());
937 
938  // C++11 [expr.prim.lambda]p9:
939  // A lambda-expression whose smallest enclosing scope is a block scope is a
940  // local lambda expression; any other lambda expression shall not have a
941  // capture-default or simple-capture in its lambda-introducer.
942  //
943  // For simple-captures, this is covered by the check below that any named
944  // entity is a variable that can be captured.
945  //
946  // For DR1632, we also allow a capture-default in any context where we can
947  // odr-use 'this' (in particular, in a default initializer for a non-static
948  // data member).
949  if (Intro.Default != LCD_None && !Class->getParent()->isFunctionOrMethod() &&
950  (getCurrentThisType().isNull() ||
951  CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
952  /*BuildAndDiagnose*/false)))
953  Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
954 
955  // Distinct capture names, for diagnostics.
956  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
957 
958  // Handle explicit captures.
959  SourceLocation PrevCaptureLoc
960  = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc;
961  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
962  PrevCaptureLoc = C->Loc, ++C) {
963  if (C->Kind == LCK_This || C->Kind == LCK_StarThis) {
964  if (C->Kind == LCK_StarThis)
965  Diag(C->Loc, !getLangOpts().CPlusPlus17
966  ? diag::ext_star_this_lambda_capture_cxx17
967  : diag::warn_cxx14_compat_star_this_lambda_capture);
968 
969  // C++11 [expr.prim.lambda]p8:
970  // An identifier or this shall not appear more than once in a
971  // lambda-capture.
972  if (LSI->isCXXThisCaptured()) {
973  Diag(C->Loc, diag::err_capture_more_than_once)
974  << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
976  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
977  continue;
978  }
979 
980  // C++2a [expr.prim.lambda]p8:
981  // If a lambda-capture includes a capture-default that is =,
982  // each simple-capture of that lambda-capture shall be of the form
983  // "&identifier", "this", or "* this". [ Note: The form [&,this] is
984  // redundant but accepted for compatibility with ISO C++14. --end note ]
985  if (Intro.Default == LCD_ByCopy && C->Kind != LCK_StarThis)
986  Diag(C->Loc, !getLangOpts().CPlusPlus2a
987  ? diag::ext_equals_this_lambda_capture_cxx2a
988  : diag::warn_cxx17_compat_equals_this_lambda_capture);
989 
990  // C++11 [expr.prim.lambda]p12:
991  // If this is captured by a local lambda expression, its nearest
992  // enclosing function shall be a non-static member function.
993  QualType ThisCaptureType = getCurrentThisType();
994  if (ThisCaptureType.isNull()) {
995  Diag(C->Loc, diag::err_this_capture) << true;
996  continue;
997  }
998 
999  CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1000  /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1001  C->Kind == LCK_StarThis);
1002  if (!LSI->Captures.empty())
1003  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1004  continue;
1005  }
1006 
1007  assert(C->Id && "missing identifier for capture");
1008 
1009  if (C->Init.isInvalid())
1010  continue;
1011 
1012  VarDecl *Var = nullptr;
1013  if (C->Init.isUsable()) {
1014  Diag(C->Loc, getLangOpts().CPlusPlus14
1015  ? diag::warn_cxx11_compat_init_capture
1016  : diag::ext_init_capture);
1017 
1018  if (C->Init.get()->containsUnexpandedParameterPack())
1019  ContainsUnexpandedParameterPack = true;
1020  // If the initializer expression is usable, but the InitCaptureType
1021  // is not, then an error has occurred - so ignore the capture for now.
1022  // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1023  // FIXME: we should create the init capture variable and mark it invalid
1024  // in this case.
1025  if (C->InitCaptureType.get().isNull())
1026  continue;
1027 
1028  unsigned InitStyle;
1029  switch (C->InitKind) {
1031  llvm_unreachable("not an init-capture?");
1033  InitStyle = VarDecl::CInit;
1034  break;
1036  InitStyle = VarDecl::CallInit;
1037  break;
1039  InitStyle = VarDecl::ListInit;
1040  break;
1041  }
1042  Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1043  C->Id, InitStyle, C->Init.get());
1044  // C++1y [expr.prim.lambda]p11:
1045  // An init-capture behaves as if it declares and explicitly
1046  // captures a variable [...] whose declarative region is the
1047  // lambda-expression's compound-statement
1048  if (Var)
1049  PushOnScopeChains(Var, CurScope, false);
1050  } else {
1051  assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1052  "init capture has valid but null init?");
1053 
1054  // C++11 [expr.prim.lambda]p8:
1055  // If a lambda-capture includes a capture-default that is &, the
1056  // identifiers in the lambda-capture shall not be preceded by &.
1057  // If a lambda-capture includes a capture-default that is =, [...]
1058  // each identifier it contains shall be preceded by &.
1059  if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) {
1060  Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1062  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1063  continue;
1064  } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) {
1065  Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1067  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1068  continue;
1069  }
1070 
1071  // C++11 [expr.prim.lambda]p10:
1072  // The identifiers in a capture-list are looked up using the usual
1073  // rules for unqualified name lookup (3.4.1)
1074  DeclarationNameInfo Name(C->Id, C->Loc);
1075  LookupResult R(*this, Name, LookupOrdinaryName);
1076  LookupName(R, CurScope);
1077  if (R.isAmbiguous())
1078  continue;
1079  if (R.empty()) {
1080  // FIXME: Disable corrections that would add qualification?
1081  CXXScopeSpec ScopeSpec;
1082  DeclFilterCCC<VarDecl> Validator{};
1083  if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1084  continue;
1085  }
1086 
1087  Var = R.getAsSingle<VarDecl>();
1088  if (Var && DiagnoseUseOfDecl(Var, C->Loc))
1089  continue;
1090  }
1091 
1092  // C++11 [expr.prim.lambda]p8:
1093  // An identifier or this shall not appear more than once in a
1094  // lambda-capture.
1095  if (!CaptureNames.insert(C->Id).second) {
1096  if (Var && LSI->isCaptured(Var)) {
1097  Diag(C->Loc, diag::err_capture_more_than_once)
1098  << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1100  SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1101  } else
1102  // Previous capture captured something different (one or both was
1103  // an init-cpature): no fixit.
1104  Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1105  continue;
1106  }
1107 
1108  // C++11 [expr.prim.lambda]p10:
1109  // [...] each such lookup shall find a variable with automatic storage
1110  // duration declared in the reaching scope of the local lambda expression.
1111  // Note that the 'reaching scope' check happens in tryCaptureVariable().
1112  if (!Var) {
1113  Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1114  continue;
1115  }
1116 
1117  // Ignore invalid decls; they'll just confuse the code later.
1118  if (Var->isInvalidDecl())
1119  continue;
1120 
1121  if (!Var->hasLocalStorage()) {
1122  Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1123  Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1124  continue;
1125  }
1126 
1127  // C++11 [expr.prim.lambda]p23:
1128  // A capture followed by an ellipsis is a pack expansion (14.5.3).
1129  SourceLocation EllipsisLoc;
1130  if (C->EllipsisLoc.isValid()) {
1131  if (Var->isParameterPack()) {
1132  EllipsisLoc = C->EllipsisLoc;
1133  } else {
1134  Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1135  << SourceRange(C->Loc);
1136 
1137  // Just ignore the ellipsis.
1138  }
1139  } else if (Var->isParameterPack()) {
1140  ContainsUnexpandedParameterPack = true;
1141  }
1142 
1143  if (C->Init.isUsable()) {
1144  buildInitCaptureField(LSI, Var);
1145  } else {
1146  TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1147  TryCapture_ExplicitByVal;
1148  tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1149  }
1150  if (!LSI->Captures.empty())
1151  LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1152  }
1153  finishLambdaExplicitCaptures(LSI);
1154 
1155  LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack;
1156 
1157  // Add lambda parameters into scope.
1158  addLambdaParameters(Intro.Captures, Method, CurScope);
1159 
1160  // Enter a new evaluation context to insulate the lambda from any
1161  // cleanups from the enclosing full-expression.
1162  PushExpressionEvaluationContext(
1163  ExpressionEvaluationContext::PotentiallyEvaluated);
1164 }
1165 
1167  bool IsInstantiation) {
1168  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1169 
1170  // Leave the expression-evaluation context.
1171  DiscardCleanupsInEvaluationContext();
1172  PopExpressionEvaluationContext();
1173 
1174  // Leave the context of the lambda.
1175  if (!IsInstantiation)
1176  PopDeclContext();
1177 
1178  // Finalize the lambda.
1179  CXXRecordDecl *Class = LSI->Lambda;
1180  Class->setInvalidDecl();
1181  SmallVector<Decl*, 4> Fields(Class->fields());
1182  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1184  CheckCompletedCXXClass(Class);
1185 
1186  PopFunctionScopeInfo();
1187 }
1188 
1190  const FunctionProtoType *CallOpProto) {
1191  // The function type inside the pointer type is the same as the call
1192  // operator with some tweaks. The calling convention is the default free
1193  // function convention, and the type qualifications are lost.
1194  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1195  CallOpProto->getExtProtoInfo();
1196  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1198  CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1199  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1200  InvokerExtInfo.TypeQuals = Qualifiers();
1201  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1202  "Lambda's call operator should not have a reference qualifier");
1203  return Context.getFunctionType(CallOpProto->getReturnType(),
1204  CallOpProto->getParamTypes(), InvokerExtInfo);
1205 }
1206 
1207 /// Add a lambda's conversion to function pointer, as described in
1208 /// C++11 [expr.prim.lambda]p6.
1210  SourceRange IntroducerRange,
1211  CXXRecordDecl *Class,
1212  CXXMethodDecl *CallOperator) {
1213  // This conversion is explicitly disabled if the lambda's function has
1214  // pass_object_size attributes on any of its parameters.
1215  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1216  return P->hasAttr<PassObjectSizeAttr>();
1217  };
1218  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1219  return;
1220 
1221  // Add the conversion to function pointer.
1222  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
1223  CallOperator->getType()->castAs<FunctionProtoType>());
1224  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1225 
1226  // Create the type of the conversion function.
1227  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1229  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1230  // The conversion function is always const and noexcept.
1231  ConvExtInfo.TypeQuals = Qualifiers();
1232  ConvExtInfo.TypeQuals.addConst();
1233  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1234  QualType ConvTy =
1235  S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1236 
1237  SourceLocation Loc = IntroducerRange.getBegin();
1238  DeclarationName ConversionName
1240  S.Context.getCanonicalType(PtrToFunctionTy));
1241  DeclarationNameLoc ConvNameLoc;
1242  // Construct a TypeSourceInfo for the conversion function, and wire
1243  // all the parameters appropriately for the FunctionProtoTypeLoc
1244  // so that everything works during transformation/instantiation of
1245  // generic lambdas.
1246  // The main reason for wiring up the parameters of the conversion
1247  // function with that of the call operator is so that constructs
1248  // like the following work:
1249  // auto L = [](auto b) { <-- 1
1250  // return [](auto a) -> decltype(a) { <-- 2
1251  // return a;
1252  // };
1253  // };
1254  // int (*fp)(int) = L(5);
1255  // Because the trailing return type can contain DeclRefExprs that refer
1256  // to the original call operator's variables, we hijack the call
1257  // operators ParmVarDecls below.
1258  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1259  S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1260  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1261 
1262  // The conversion function is a conversion to a pointer-to-function.
1263  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1264  FunctionProtoTypeLoc ConvTL =
1265  ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1266  // Get the result of the conversion function which is a pointer-to-function.
1267  PointerTypeLoc PtrToFunctionTL =
1268  ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1269  // Do the same for the TypeSourceInfo that is used to name the conversion
1270  // operator.
1271  PointerTypeLoc ConvNamePtrToFunctionTL =
1272  ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1273 
1274  // Get the underlying function types that the conversion function will
1275  // be converting to (should match the type of the call operator).
1276  FunctionProtoTypeLoc CallOpConvTL =
1277  PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1278  FunctionProtoTypeLoc CallOpConvNameTL =
1279  ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1280 
1281  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1282  // These parameter's are essentially used to transform the name and
1283  // the type of the conversion operator. By using the same parameters
1284  // as the call operator's we don't have to fix any back references that
1285  // the trailing return type of the call operator's uses (such as
1286  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1287  // - we can simply use the return type of the call operator, and
1288  // everything should work.
1289  SmallVector<ParmVarDecl *, 4> InvokerParams;
1290  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1291  ParmVarDecl *From = CallOperator->getParamDecl(I);
1292 
1293  InvokerParams.push_back(ParmVarDecl::Create(
1294  S.Context,
1295  // Temporarily add to the TU. This is set to the invoker below.
1297  From->getLocation(), From->getIdentifier(), From->getType(),
1298  From->getTypeSourceInfo(), From->getStorageClass(),
1299  /*DefaultArg=*/nullptr));
1300  CallOpConvTL.setParam(I, From);
1301  CallOpConvNameTL.setParam(I, From);
1302  }
1303 
1305  S.Context, Class, Loc,
1306  DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1307  /*isInline=*/true, /*isExplicit=*/false,
1308  /*isConstexpr=*/S.getLangOpts().CPlusPlus17,
1309  CallOperator->getBody()->getEndLoc());
1310  Conversion->setAccess(AS_public);
1311  Conversion->setImplicit(true);
1312 
1313  if (Class->isGenericLambda()) {
1314  // Create a template version of the conversion operator, using the template
1315  // parameter list of the function call operator.
1316  FunctionTemplateDecl *TemplateCallOperator =
1317  CallOperator->getDescribedFunctionTemplate();
1318  FunctionTemplateDecl *ConversionTemplate =
1320  Loc, ConversionName,
1321  TemplateCallOperator->getTemplateParameters(),
1322  Conversion);
1323  ConversionTemplate->setAccess(AS_public);
1324  ConversionTemplate->setImplicit(true);
1325  Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1326  Class->addDecl(ConversionTemplate);
1327  } else
1328  Class->addDecl(Conversion);
1329  // Add a non-static member function that will be the result of
1330  // the conversion with a certain unique ID.
1331  DeclarationName InvokerName = &S.Context.Idents.get(
1333  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1334  // we should get a prebuilt TrivialTypeSourceInfo from Context
1335  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1336  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1337  // loop below and then use its Params to set Invoke->setParams(...) below.
1338  // This would avoid the 'const' qualifier of the calloperator from
1339  // contaminating the type of the invoker, which is currently adjusted
1340  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments. Fixing the
1341  // trailing return type of the invoker would require a visitor to rebuild
1342  // the trailing return type and adjusting all back DeclRefExpr's to refer
1343  // to the new static invoker parameters - not the call operator's.
1345  S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1346  InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1347  /*IsInline=*/true,
1348  /*IsConstexpr=*/false, CallOperator->getBody()->getEndLoc());
1349  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I)
1350  InvokerParams[I]->setOwningFunction(Invoke);
1351  Invoke->setParams(InvokerParams);
1352  Invoke->setAccess(AS_private);
1353  Invoke->setImplicit(true);
1354  if (Class->isGenericLambda()) {
1355  FunctionTemplateDecl *TemplateCallOperator =
1356  CallOperator->getDescribedFunctionTemplate();
1357  FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1358  S.Context, Class, Loc, InvokerName,
1359  TemplateCallOperator->getTemplateParameters(),
1360  Invoke);
1361  StaticInvokerTemplate->setAccess(AS_private);
1362  StaticInvokerTemplate->setImplicit(true);
1363  Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1364  Class->addDecl(StaticInvokerTemplate);
1365  } else
1366  Class->addDecl(Invoke);
1367 }
1368 
1369 /// Add a lambda's conversion to block pointer.
1371  SourceRange IntroducerRange,
1372  CXXRecordDecl *Class,
1373  CXXMethodDecl *CallOperator) {
1375  CallOperator->getType()->castAs<FunctionProtoType>());
1376  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1377 
1378  FunctionProtoType::ExtProtoInfo ConversionEPI(
1380  /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1381  ConversionEPI.TypeQuals = Qualifiers();
1382  ConversionEPI.TypeQuals.addConst();
1383  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1384 
1385  SourceLocation Loc = IntroducerRange.getBegin();
1386  DeclarationName Name
1388  S.Context.getCanonicalType(BlockPtrTy));
1389  DeclarationNameLoc NameLoc;
1390  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1392  S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1393  S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1394  /*isInline=*/true, /*isExplicit=*/false,
1395  /*isConstexpr=*/false, CallOperator->getBody()->getEndLoc());
1396  Conversion->setAccess(AS_public);
1397  Conversion->setImplicit(true);
1398  Class->addDecl(Conversion);
1399 }
1400 
1402  Sema &S, const Capture &Capture, FieldDecl *Field,
1403  SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture) {
1404  assert(Capture.isVariableCapture() && "not a variable capture");
1405 
1406  auto *Var = Capture.getVariable();
1407  SourceLocation Loc =
1408  IsImplicitCapture ? ImplicitCaptureLoc : Capture.getLocation();
1409 
1410  // C++11 [expr.prim.lambda]p21:
1411  // When the lambda-expression is evaluated, the entities that
1412  // are captured by copy are used to direct-initialize each
1413  // corresponding non-static data member of the resulting closure
1414  // object. (For array members, the array elements are
1415  // direct-initialized in increasing subscript order.) These
1416  // initializations are performed in the (unspecified) order in
1417  // which the non-static data members are declared.
1418 
1419  // C++ [expr.prim.lambda]p12:
1420  // An entity captured by a lambda-expression is odr-used (3.2) in
1421  // the scope containing the lambda-expression.
1422  ExprResult RefResult = S.BuildDeclarationNameExpr(
1423  CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1424  if (RefResult.isInvalid())
1425  return ExprError();
1426  Expr *Ref = RefResult.get();
1427 
1429  Var->getIdentifier(), Field->getType(), Loc);
1430  InitializationKind InitKind = InitializationKind::CreateDirect(Loc, Loc, Loc);
1431  InitializationSequence Init(S, Entity, InitKind, Ref);
1432  return Init.Perform(S, Entity, InitKind, Ref);
1433 }
1434 
1436  Scope *CurScope) {
1437  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1438  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1439  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1440 }
1441 
1442 static LambdaCaptureDefault
1444  switch (ICS) {
1446  return LCD_None;
1448  return LCD_ByCopy;
1451  return LCD_ByRef;
1453  llvm_unreachable("block capture in lambda");
1454  }
1455  llvm_unreachable("Unknown implicit capture style");
1456 }
1457 
1459  if (!From.isVLATypeCapture()) {
1460  Expr *Init = From.getInitExpr();
1461  if (Init && Init->HasSideEffects(Context))
1462  return true;
1463  }
1464 
1465  if (!From.isCopyCapture())
1466  return false;
1467 
1468  const QualType T = From.isThisCapture()
1469  ? getCurrentThisType()->getPointeeType()
1470  : From.getCaptureType();
1471 
1472  if (T.isVolatileQualified())
1473  return true;
1474 
1475  const Type *BaseT = T->getBaseElementTypeUnsafe();
1476  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1477  return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1478  !RD->hasTrivialDestructor();
1479 
1480  return false;
1481 }
1482 
1484  const Capture &From) {
1485  if (CaptureHasSideEffects(From))
1486  return false;
1487 
1488  if (From.isVLATypeCapture())
1489  return false;
1490 
1491  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1492  if (From.isThisCapture())
1493  diag << "'this'";
1494  else
1495  diag << From.getVariable();
1496  diag << From.isNonODRUsed();
1497  diag << FixItHint::CreateRemoval(CaptureRange);
1498  return true;
1499 }
1500 
1502  LambdaScopeInfo *LSI) {
1503  // Collect information from the lambda scope.
1505  SmallVector<Expr *, 4> CaptureInits;
1506  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1507  LambdaCaptureDefault CaptureDefault =
1509  CXXRecordDecl *Class;
1510  CXXMethodDecl *CallOperator;
1511  SourceRange IntroducerRange;
1512  bool ExplicitParams;
1513  bool ExplicitResultType;
1514  CleanupInfo LambdaCleanup;
1515  bool ContainsUnexpandedParameterPack;
1516  bool IsGenericLambda;
1517  {
1518  CallOperator = LSI->CallOperator;
1519  Class = LSI->Lambda;
1520  IntroducerRange = LSI->IntroducerRange;
1521  ExplicitParams = LSI->ExplicitParams;
1522  ExplicitResultType = !LSI->HasImplicitReturnType;
1523  LambdaCleanup = LSI->Cleanup;
1524  ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1525  IsGenericLambda = Class->isGenericLambda();
1526 
1527  CallOperator->setLexicalDeclContext(Class);
1528  Decl *TemplateOrNonTemplateCallOperatorDecl =
1529  CallOperator->getDescribedFunctionTemplate()
1530  ? CallOperator->getDescribedFunctionTemplate()
1531  : cast<Decl>(CallOperator);
1532 
1533  TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1534  Class->addDecl(TemplateOrNonTemplateCallOperatorDecl);
1535 
1536  PopExpressionEvaluationContext();
1537 
1538  // Translate captures.
1539  auto CurField = Class->field_begin();
1540  // True if the current capture has a used capture or default before it.
1541  bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1542  SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1543  CaptureDefaultLoc : IntroducerRange.getBegin();
1544 
1545  for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I, ++CurField) {
1546  const Capture &From = LSI->Captures[I];
1547 
1548  assert(!From.isBlockCapture() && "Cannot capture __block variables");
1549  bool IsImplicit = I >= LSI->NumExplicitCaptures;
1550 
1551  // Use source ranges of explicit captures for fixits where available.
1552  SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1553 
1554  // Warn about unused explicit captures.
1555  bool IsCaptureUsed = true;
1556  if (!CurContext->isDependentContext() && !IsImplicit && !From.isODRUsed()) {
1557  // Initialized captures that are non-ODR used may not be eliminated.
1558  bool NonODRUsedInitCapture =
1559  IsGenericLambda && From.isNonODRUsed() && From.getInitExpr();
1560  if (!NonODRUsedInitCapture) {
1561  bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1562  SourceRange FixItRange;
1563  if (CaptureRange.isValid()) {
1564  if (!CurHasPreviousCapture && !IsLast) {
1565  // If there are no captures preceding this capture, remove the
1566  // following comma.
1567  FixItRange = SourceRange(CaptureRange.getBegin(),
1568  getLocForEndOfToken(CaptureRange.getEnd()));
1569  } else {
1570  // Otherwise, remove the comma since the last used capture.
1571  FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1572  CaptureRange.getEnd());
1573  }
1574  }
1575 
1576  IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1577  }
1578  }
1579 
1580  if (CaptureRange.isValid()) {
1581  CurHasPreviousCapture |= IsCaptureUsed;
1582  PrevCaptureLoc = CaptureRange.getEnd();
1583  }
1584 
1585  // Handle 'this' capture.
1586  if (From.isThisCapture()) {
1587  // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1588  // because it results in a reference capture. Don't warn prior to
1589  // C++2a; there's nothing that can be done about it before then.
1590  if (getLangOpts().CPlusPlus2a && IsImplicit &&
1591  CaptureDefault == LCD_ByCopy) {
1592  Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1593  Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1595  getLocForEndOfToken(CaptureDefaultLoc), ", this");
1596  }
1597 
1598  Captures.push_back(
1599  LambdaCapture(From.getLocation(), IsImplicit,
1600  From.isCopyCapture() ? LCK_StarThis : LCK_This));
1601  CaptureInits.push_back(From.getInitExpr());
1602  continue;
1603  }
1604  if (From.isVLATypeCapture()) {
1605  Captures.push_back(
1606  LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType));
1607  CaptureInits.push_back(nullptr);
1608  continue;
1609  }
1610 
1611  VarDecl *Var = From.getVariable();
1613  Captures.push_back(LambdaCapture(From.getLocation(), IsImplicit, Kind,
1614  Var, From.getEllipsisLoc()));
1615  Expr *Init = From.getInitExpr();
1616  if (!Init) {
1617  auto InitResult = performLambdaVarCaptureInitialization(
1618  *this, From, *CurField, CaptureDefaultLoc, IsImplicit);
1619  if (InitResult.isInvalid())
1620  return ExprError();
1621  Init = InitResult.get();
1622  }
1623  CaptureInits.push_back(Init);
1624  }
1625 
1626  // C++11 [expr.prim.lambda]p6:
1627  // The closure type for a lambda-expression with no lambda-capture
1628  // has a public non-virtual non-explicit const conversion function
1629  // to pointer to function having the same parameter and return
1630  // types as the closure type's function call operator.
1631  if (Captures.empty() && CaptureDefault == LCD_None)
1632  addFunctionPointerConversion(*this, IntroducerRange, Class,
1633  CallOperator);
1634 
1635  // Objective-C++:
1636  // The closure type for a lambda-expression has a public non-virtual
1637  // non-explicit const conversion function to a block pointer having the
1638  // same parameter and return types as the closure type's function call
1639  // operator.
1640  // FIXME: Fix generic lambda to block conversions.
1641  if (getLangOpts().Blocks && getLangOpts().ObjC && !IsGenericLambda)
1642  addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1643 
1644  // Finalize the lambda class.
1645  SmallVector<Decl*, 4> Fields(Class->fields());
1646  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1648  CheckCompletedCXXClass(Class);
1649  }
1650 
1651  Cleanup.mergeFrom(LambdaCleanup);
1652 
1653  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1654  CaptureDefault, CaptureDefaultLoc,
1655  Captures,
1656  ExplicitParams, ExplicitResultType,
1657  CaptureInits, EndLoc,
1658  ContainsUnexpandedParameterPack);
1659  // If the lambda expression's call operator is not explicitly marked constexpr
1660  // and we are not in a dependent context, analyze the call operator to infer
1661  // its constexpr-ness, suppressing diagnostics while doing so.
1662  if (getLangOpts().CPlusPlus17 && !CallOperator->isInvalidDecl() &&
1663  !CallOperator->isConstexpr() &&
1664  !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1665  !Class->getDeclContext()->isDependentContext()) {
1666  TentativeAnalysisScope DiagnosticScopeGuard(*this);
1667  CallOperator->setConstexpr(
1668  CheckConstexprFunctionDecl(CallOperator) &&
1669  CheckConstexprFunctionBody(CallOperator, CallOperator->getBody()));
1670  }
1671 
1672  // Emit delayed shadowing warnings now that the full capture list is known.
1673  DiagnoseShadowingLambdaDecls(LSI);
1674 
1675  if (!CurContext->isDependentContext()) {
1676  switch (ExprEvalContexts.back().Context) {
1677  // C++11 [expr.prim.lambda]p2:
1678  // A lambda-expression shall not appear in an unevaluated operand
1679  // (Clause 5).
1680  case ExpressionEvaluationContext::Unevaluated:
1681  case ExpressionEvaluationContext::UnevaluatedList:
1682  case ExpressionEvaluationContext::UnevaluatedAbstract:
1683  // C++1y [expr.const]p2:
1684  // A conditional-expression e is a core constant expression unless the
1685  // evaluation of e, following the rules of the abstract machine, would
1686  // evaluate [...] a lambda-expression.
1687  //
1688  // This is technically incorrect, there are some constant evaluated contexts
1689  // where this should be allowed. We should probably fix this when DR1607 is
1690  // ratified, it lays out the exact set of conditions where we shouldn't
1691  // allow a lambda-expression.
1692  case ExpressionEvaluationContext::ConstantEvaluated:
1693  // We don't actually diagnose this case immediately, because we
1694  // could be within a context where we might find out later that
1695  // the expression is potentially evaluated (e.g., for typeid).
1696  ExprEvalContexts.back().Lambdas.push_back(Lambda);
1697  break;
1698 
1699  case ExpressionEvaluationContext::DiscardedStatement:
1700  case ExpressionEvaluationContext::PotentiallyEvaluated:
1701  case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1702  break;
1703  }
1704  }
1705 
1706  return MaybeBindToTemporary(Lambda);
1707 }
1708 
1710  SourceLocation ConvLocation,
1711  CXXConversionDecl *Conv,
1712  Expr *Src) {
1713  // Make sure that the lambda call operator is marked used.
1714  CXXRecordDecl *Lambda = Conv->getParent();
1715  CXXMethodDecl *CallOperator
1716  = cast<CXXMethodDecl>(
1717  Lambda->lookup(
1718  Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1719  CallOperator->setReferenced();
1720  CallOperator->markUsed(Context);
1721 
1722  ExprResult Init = PerformCopyInitialization(
1724  /*NRVO=*/false),
1725  CurrentLocation, Src);
1726  if (!Init.isInvalid())
1727  Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1728 
1729  if (Init.isInvalid())
1730  return ExprError();
1731 
1732  // Create the new block to be returned.
1733  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1734 
1735  // Set the type information.
1736  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1737  Block->setIsVariadic(CallOperator->isVariadic());
1738  Block->setBlockMissingReturnType(false);
1739 
1740  // Add parameters.
1741  SmallVector<ParmVarDecl *, 4> BlockParams;
1742  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) {
1743  ParmVarDecl *From = CallOperator->getParamDecl(I);
1744  BlockParams.push_back(ParmVarDecl::Create(
1745  Context, Block, From->getBeginLoc(), From->getLocation(),
1746  From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1747  From->getStorageClass(),
1748  /*DefaultArg=*/nullptr));
1749  }
1750  Block->setParams(BlockParams);
1751 
1752  Block->setIsConversionFromLambda(true);
1753 
1754  // Add capture. The capture uses a fake variable, which doesn't correspond
1755  // to any actual memory location. However, the initializer copy-initializes
1756  // the lambda object.
1757  TypeSourceInfo *CapVarTSI =
1758  Context.getTrivialTypeSourceInfo(Src->getType());
1759  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
1760  ConvLocation, nullptr,
1761  Src->getType(), CapVarTSI,
1762  SC_None);
1763  BlockDecl::Capture Capture(/*Variable=*/CapVar, /*ByRef=*/false,
1764  /*Nested=*/false, /*Copy=*/Init.get());
1765  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
1766 
1767  // Add a fake function body to the block. IR generation is responsible
1768  // for filling in the actual body, which cannot be expressed as an AST.
1769  Block->setBody(new (Context) CompoundStmt(ConvLocation));
1770 
1771  // Create the block literal expression.
1772  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
1773  ExprCleanupObjects.push_back(Block);
1774  Cleanup.setExprNeedsCleanups(true);
1775 
1776  return BuildBlock;
1777 }
void setImplicit(bool I=true)
Definition: DeclBase.h:551
Represents a function declaration or definition.
Definition: Decl.h:1737
SourceRange IntroducerRange
Source range covering the lambda introducer [...].
Definition: ScopeInfo.h:793
DeclaratorChunk::FunctionTypeInfo & getFunctionTypeInfo()
getFunctionTypeInfo - Retrieves the function type info object (looking through parentheses).
Definition: DeclSpec.h:2267
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:2609
A class which contains all the information about a particular captured value.
Definition: Decl.h:3863
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:639
bool ExplicitParams
Whether the (empty) parameter list is explicit.
Definition: ScopeInfo.h:807
TemplateParameterList * GLTemplateParameterList
If this is a generic lambda, and the template parameter list has been created (from the AutoTemplateP...
Definition: ScopeInfo.h:829
bool SetTypeQual(TQ T, SourceLocation Loc)
Definition: DeclSpec.cpp:890
VarDecl * createLambdaInitCaptureVarDecl(SourceLocation Loc, QualType InitCaptureType, IdentifierInfo *Id, unsigned InitStyle, Expr *Init)
Create a dummy variable within the declcontext of the lambda&#39;s call operator, for name lookup purpose...
Definition: SemaLambda.cpp:794
Stmt - This represents one statement.
Definition: Stmt.h:65
An instance of this object exists for each enum constant that is defined.
Definition: Decl.h:2785
QualType ReturnType
ReturnType - The target type of return statements in this context, or null if unknown.
Definition: ScopeInfo.h:649
StorageClass getStorageClass() const
Returns the storage class as written in the source.
Definition: Decl.h:1019
bool isConstexpr() const
Whether this is a (C++11) constexpr function or constexpr constructor.
Definition: Decl.h:2093
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:607
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:87
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:4014
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:568
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:1414
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.cpp:4289
bool isFunctionDeclarator(unsigned &idx) const
isFunctionDeclarator - This method returns true if the declarator is a function declarator (looking t...
Definition: DeclSpec.h:2236
A container of type source information.
Definition: Decl.h:86
QualType getConversionType() const
Returns the type that this conversion function is converting to.
Definition: DeclCXX.h:2807
void setInitStyle(InitializationStyle Style)
Definition: Decl.h:1264
Describes the capture of a variable or of this, or of a C++1y init-capture.
Definition: LambdaCapture.h:25
This file provides some common utility functions for processing Lambda related AST Constructs...
bool isODRUsed() const
Definition: ScopeInfo.h:588
Represents a variable declaration or definition.
Definition: Decl.h:812
static CXXConversionDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, bool isInline, bool isExplicit, bool isConstexpr, SourceLocation EndLocation)
Definition: DeclCXX.cpp:2513
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:1764
QualType getReturnType() const
Definition: Decl.h:2301
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6768
Extra information about a function prototype.
Definition: Type.h:3779
bool isAmbiguous() const
Definition: Lookup.h:301
bool isInvalidDecl() const
Definition: DeclBase.h:545
Stores a list of template parameters for a TemplateDecl and its derived classes.
Definition: DeclTemplate.h:67
MangleNumberingContext & getMangleNumberingContext(ASTContext &Ctx)
Retrieve the mangling numbering context, used to consistently number constructs like lambdas for mang...
Definition: SemaLambda.cpp:366
static InitializationKind CreateDirectList(SourceLocation InitLoc)
bool isParameterPack() const
Whether this declaration is a parameter pack.
Definition: DeclBase.cpp:210
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:15401
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:3196
Represents a parameter to a function.
Definition: Decl.h:1549
CXXRecordDecl * createLambdaClosureType(SourceRange IntroducerRange, TypeSourceInfo *Info, bool KnownDependent, LambdaCaptureDefault CaptureDefault)
Create a new lambda closure type.
Definition: SemaLambda.cpp:245
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
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
Scope * getTemplateParamParent()
Definition: Scope.h:262
FunctionType::ExtInfo ExtInfo
Definition: Type.h:3780
One of these records is kept for each identifier that is lexed.
bool isConst() const
Definition: DeclCXX.h:2090
sema::LambdaScopeInfo * getCurGenericLambda()
Retrieve the current generic lambda info, if any.
Definition: Sema.cpp:1794
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
ArrayRef< QualType > getParamTypes() const
Definition: Type.h:3907
field_range fields() const
Definition: Decl.h:3783
TypeSourceInfo * getTypeSourceInfo(ASTContext &Context, QualType T)
Creates a TypeSourceInfo for the given type.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
std::unique_ptr< MangleNumberingContext > createMangleNumberingContext() const
LambdaCaptureKind
The different capture forms in a lambda introducer.
Definition: Lambda.h:33
Represents a member of a struct/union/class.
Definition: Decl.h:2578
bool isReferenceType() const
Definition: Type.h:6320
bool Equals(const DeclContext *DC) const
Determine whether this declaration context is equivalent to the declaration context DC...
Definition: DeclBase.h:1885
void setParams(ArrayRef< ParmVarDecl *> NewParamInfo)
Definition: Decl.h:2292
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Decl.h:738
static CXXRecordDecl * CreateLambda(const ASTContext &C, DeclContext *DC, TypeSourceInfo *Info, SourceLocation Loc, bool DependentLambda, bool IsGeneric, LambdaCaptureDefault CaptureDefault)
Definition: DeclCXX.cpp:139
bool ContainsUnexpandedParameterPack
Whether the lambda contains an unexpanded parameter pack.
Definition: ScopeInfo.h:813
IdentifierTable & Idents
Definition: ASTContext.h:565
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:109
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2261
DeclClass * getAsSingle() const
Definition: Lookup.h:507
bool isThisCapture() const
Definition: ScopeInfo.h:560
Expr * getInitExpr() const
Definition: ScopeInfo.h:612
void setNameLoc(SourceLocation Loc)
Definition: TypeLoc.h:520
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:2744
RAII class used to indicate that we are performing provisional semantic analysis to determine the val...
Definition: Sema.h:7713
< 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:3371
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:2174
bool containsUnexpandedParameterPack() const
Whether this type is or contains an unexpanded parameter pack, used to support C++0x variadic templat...
Definition: Type.h:1840
A builtin binary operation expression such as "x + y" or "x <= y".
Definition: Expr.h:3318
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6154
void setLambdaMangling(unsigned ManglingNumber, Decl *ContextDecl)
Set the mangling number and context declaration for a lambda class.
Definition: DeclCXX.h:1929
CXXMethodDecl * startLambdaDefinition(CXXRecordDecl *Class, SourceRange IntroducerRange, TypeSourceInfo *MethodType, SourceLocation EndLoc, ArrayRef< ParmVarDecl *> Params, bool IsConstexprSpecified)
Start the definition of a lambda expression.
Definition: SemaLambda.cpp:374
void finishedExplicitCaptures()
Note when all explicit captures have been added.
Definition: ScopeInfo.h:872
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:7340
field_iterator field_begin() const
Definition: Decl.cpp:4168
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:603
bool hasNameForLinkage() const
Is this tag type named, either directly or via being defined in a typedef of this type...
Definition: Decl.h:3269
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:62
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1715
static VarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S)
Definition: Decl.cpp:1931
const LangOptions & getLangOpts() const
Definition: Sema.h:1286
bool isLambdaCallOperator(const CXXMethodDecl *MD)
Definition: ASTLambda.h:27
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
ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl=false)
Definition: SemaExpr.cpp:2878
QualType getLambdaConversionFunctionResultType(const FunctionProtoType *CallOpType)
Get the return type to use for a lambda&#39;s conversion function(s) to function pointer type...
static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange, CXXRecordDecl *Class, CXXMethodDecl *CallOperator)
Add a lambda&#39;s conversion to function pointer, as described in C++11 [expr.prim.lambda]p6.
SmallVector< TemplateTypeParmDecl *, 4 > AutoTemplateParams
Store the list of the auto parameters for a generic lambda.
Definition: ScopeInfo.h:824
static ExprResult performLambdaVarCaptureInitialization(Sema &S, const Capture &Capture, FieldDecl *Field, SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture)
void addLambdaParameters(ArrayRef< LambdaIntroducer::LambdaCapture > Captures, CXXMethodDecl *CallOperator, Scope *CurScope)
Introduce the lambda parameters into scope.
Definition: SemaLambda.cpp:495
TypeSpecTypeLoc pushTypeSpec(QualType T)
Pushes space for a typespec TypeLoc.
CleanupInfo Cleanup
Whether any of the capture expressions requires cleanups.
Definition: ScopeInfo.h:810
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:1613
ExtInfo withCallingConv(CallingConv cc) const
Definition: Type.h:3583
ImplicitCaptureStyle ImpCaptureStyle
Definition: ScopeInfo.h:628
bool isIntegralOrUnscopedEnumerationType() const
Determine whether this type is an integral or unscoped enumeration type.
Definition: Type.cpp:1794
ConditionalOperator - The ?: ternary operator.
Definition: Expr.h:3616
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:328
CompoundStmt - This represents a group of statements like { stmt stmt }.
Definition: Stmt.h:1265
bool Mutable
Whether this is a mutable lambda.
Definition: ScopeInfo.h:804
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1635
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:189
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3699
static ImplicitCastExpr * Create(const ASTContext &Context, QualType T, CastKind Kind, Expr *Operand, const CXXCastPath *BasePath, ExprValueKind Cat)
Definition: Expr.cpp:1847
DeclarationNameTable DeclarationNames
Definition: ASTContext.h:568
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI)
Note that we have finished the explicit captures for the given lambda.
Definition: SemaLambda.cpp:491
SourceLocation getEllipsisLoc() const
Retrieve the source location of the ellipsis, whose presence indicates that the capture is a pack exp...
Definition: ScopeInfo.h:602
SmallVector< LambdaCapture, 4 > Captures
Definition: DeclSpec.h:2573
SourceLocation PotentialThisCaptureLocation
Definition: ScopeInfo.h:864
unsigned NumExplicitCaptures
The number of captures in the Captures list that are explicit captures.
Definition: ScopeInfo.h:801
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:564
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:3096
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
Definition: DeclTemplate.h:431
DeclContext * getLexicalParent()
getLexicalParent - Returns the containing lexical DeclContext.
Definition: DeclBase.h:1777
CXXMethodDecl * CallOperator
The lambda&#39;s compiler-generated operator().
Definition: ScopeInfo.h:790
Represents a block literal declaration, which is like an unnamed FunctionDecl.
Definition: Decl.h:3857
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:2702
int Id
Definition: ASTDiff.cpp:190
bool hasLocalStorage() const
Returns true if a variable with function scope is a non-static local variable.
Definition: Decl.h:1035
QualType buildLambdaInitCaptureInitialization(SourceLocation Loc, bool ByRef, IdentifierInfo *Id, bool DirectInit, Expr *&Init)
Definition: SemaLambda.cpp:743
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:6831
BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
Definition: Expr.h:5389
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:2218
void setInvalidDecl(bool Invalid=true)
setInvalidDecl - Indicates the Decl had a semantic error.
Definition: DeclBase.cpp:131
void setRetValue(Expr *E)
Definition: Stmt.h:2585
bool isFileContext() const
Definition: DeclBase.h:1831
DeclContext * getDeclContext()
Definition: DeclBase.h:430
bool isConstexprSpecified() const
Definition: DeclSpec.h:726
static TemplateParameterList * getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef)
Definition: SemaLambda.cpp:227
llvm::DenseMap< unsigned, SourceRange > ExplicitCaptureRanges
A map of explicit capture indices to their introducer source ranges.
Definition: ScopeInfo.h:853
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:456
bool isCaptured(VarDecl *Var) const
Determine whether the given variable has been captured.
Definition: ScopeInfo.h:682
QualType getType() const
Definition: Expr.h:130
bool isFunctionOrMethod() const
Definition: DeclBase.h:1813
Capture & getCapture(VarDecl *Var)
Retrieve the capture of the given variable, if it has been captured already.
Definition: ScopeInfo.h:691
Direct list-initialization (C++11)
Definition: Decl.h:823
static LambdaExpr * Create(const ASTContext &C, CXXRecordDecl *Class, SourceRange IntroducerRange, LambdaCaptureDefault CaptureDefault, SourceLocation CaptureDefaultLoc, ArrayRef< LambdaCapture > Captures, bool ExplicitParams, bool ExplicitResultType, ArrayRef< Expr *> CaptureInits, SourceLocation ClosingBrace, bool ContainsUnexpandedParameterPack)
Construct a new lambda expression.
Definition: ExprCXX.cpp:1127
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:267
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1761
ReturnStmt - This represents a return, optionally of an expression: return; return 4;...
Definition: Stmt.h:2550
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:1379
struct CXXOpName CXXOperatorName
bool isDependentContext() const
Determines whether this context is dependent on a template parameter.
Definition: DeclBase.cpp:1093
Common base class for placeholders for types that get replaced by placeholder type deduction: C++11 a...
Definition: Type.h:4721
const Type * getBaseElementTypeUnsafe() const
Get the base element type of this type, potentially discarding type qualifiers.
Definition: Type.h:6708
Represents a C++ conversion function within a class.
Definition: DeclCXX.h:2775
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:1395
SourceLocation getLocation() const
Retrieve the location at which this variable was captured.
Definition: ScopeInfo.h:598
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:704
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:235
TypeLoc getReturnLoc() const
Definition: TypeLoc.h:1410
static TemplateParameterList * Create(const ASTContext &C, SourceLocation TemplateLoc, SourceLocation LAngleLoc, ArrayRef< NamedDecl *> Params, SourceLocation RAngleLoc, Expr *RequiresClause)
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:276
static InitializationKind CreateCopy(SourceLocation InitLoc, SourceLocation EqualLoc, bool AllowExplicitConvs=false)
Create a copy initialization.
FieldDecl * buildInitCaptureField(sema::LambdaScopeInfo *LSI, VarDecl *Var)
Build the implicit field for an init-capture.
Definition: SemaLambda.cpp:815
void setIsVariadic(bool value)
Definition: Decl.h:3933
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc, sema::LambdaScopeInfo *LSI)
Complete a lambda-expression having processed and attached the lambda body.
void setIsConversionFromLambda(bool val=true)
Definition: Decl.h:4004
SourceLocation DefaultLoc
Definition: DeclSpec.h:2571
Kind
bool hasWeakerNullability(NullabilityKind L, NullabilityKind R)
Return true if L has a weaker nullability annotation than R.
Definition: Specifiers.h:299
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
VarDecl * getVariable() const
Definition: ScopeInfo.h:592
ExtProtoInfo getExtProtoInfo() const
Definition: Type.h:3911
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:3625
Expr * getRetValue()
Definition: Stmt.h:2583
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4408
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:787
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:62
void setReferenced(bool R=true)
Definition: DeclBase.h:580
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2048
No ref-qualifier was provided.
Definition: Type.h:1367
C-style initialization with assignment.
Definition: Decl.h:817
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2284
bool isVLATypeCapture() const
Definition: ScopeInfo.h:580
CanQualType VoidTy
Definition: ASTContext.h:1015
bool isGenericLambda() const
Determine whether this class describes a generic lambda function object (i.e.
Definition: DeclCXX.cpp:1358
Describes the kind of initialization being performed, along with location information for tokens rela...
SmallVector< Capture, 4 > Captures
Captures - The captures.
Definition: ScopeInfo.h:641
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3158
MangleNumberingContext * getCurrentMangleNumberContext(const DeclContext *DC, Decl *&ManglingContextDecl)
Compute the mangling number context for a lambda expression or block literal.
Definition: SemaLambda.cpp:280
SourceLocation CaptureDefaultLoc
Source location of the &#39;&&#39; or &#39;=&#39; specifying the default capture type, if any.
Definition: ScopeInfo.h:797
StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
Definition: Expr.h:3835
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:531
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:1888
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod) const
Retrieves the default calling convention for the current target.
This file provides some common utility functions for processing Lambdas.
static ParmVarDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, StorageClass S, Expr *DefArg)
Definition: Decl.cpp:2548
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:3937
LambdaCaptureDefault Default
Definition: DeclSpec.h:2572
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1266
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:650
bool isRecord() const
Definition: DeclBase.h:1840
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:172
static FixItHint CreateRemoval(CharSourceRange RemoveRange)
Create a code modification hint that removes the given source range.
Definition: Diagnostic.h:117
const Expr * getInit() const
Definition: Decl.h:1219
static void addBlockPointerConversion(Sema &S, SourceRange IntroducerRange, CXXRecordDecl *Class, CXXMethodDecl *CallOperator)
Add a lambda&#39;s conversion to block pointer.
The name of a declaration.
const CXXRecordDecl * getParent() const
Returns the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2173
MangleNumberingContext & getManglingNumberContext(const DeclContext *DC)
Retrieve the context for computing mangling numbers in the given DeclContext.
Represents an enum.
Definition: Decl.h:3325
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
bool isUndeducedType() const
Determine whether this type is an undeduced type, meaning that it somehow involves a C++11 &#39;auto&#39; typ...
Definition: Type.h:6683
void setInitCapture(bool IC)
Definition: Decl.h:1393
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:830
CanQualType DependentTy
Definition: ASTContext.h:1044
TypeSourceInfo * getTypeSourceInfo() const
Definition: Decl.h:715
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2282
Simple template class for restricting typo correction candidates to ones having a single Decl* of the...
QualType getAutoDeductType() const
C++11 deduction pattern for &#39;auto&#39; type.
static CXXMethodDecl * Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc, const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo, StorageClass SC, bool isInline, bool isConstexpr, SourceLocation EndLocation)
Definition: DeclCXX.cpp:1945
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:91
void addDecl(Decl *D)
Add the declaration D into this context.
Definition: DeclBase.cpp:1525
Optional< NullabilityKind > getNullability(const ASTContext &context) const
Determine the nullability of the given type.
Definition: Type.cpp:3775
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:411
Capture & getCXXThisCapture()
Retrieve the capture of C++ &#39;this&#39;, if it has been captured.
Definition: ScopeInfo.h:676
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2266
void setSignatureAsWritten(TypeSourceInfo *Sig)
Definition: Decl.h:3939
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:237
static BlockDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L)
Definition: Decl.cpp:4466
Call-style initialization (C++98)
Definition: Decl.h:820
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1008
Describes the sequence of initializations required to initialize a given object or reference with a s...
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
bool isValid() const
bool isVoidType() const
Definition: Type.h:6560
void setConstexpr(bool IC)
Definition: Decl.h:2094
Capturing by reference.
Definition: Lambda.h:37
TryCaptureKind
Definition: Sema.h:4172
const DeclSpec & getDeclSpec() const
getDeclSpec - Return the declaration-specifier that this declarator was declared with.
Definition: DeclSpec.h:1853
bool isCXXThisCaptured() const
Determine whether the C++ &#39;this&#39; is captured.
Definition: ScopeInfo.h:673
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
void addAttr(Attr *A)
Definition: DeclBase.cpp:843
Defines the clang::TargetInfo interface.
Represents a complete lambda introducer.
Definition: DeclSpec.h:2548
ExprResult ExprError()
Definition: Ownership.h:279
void setDescribedFunctionTemplate(FunctionTemplateDecl *Template)
Definition: Decl.cpp:3375
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2088
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1074
bool isNonODRUsed() const
Definition: ScopeInfo.h:589
void addCapture(VarDecl *Var, bool isBlock, bool isByref, bool isNested, SourceLocation Loc, SourceLocation EllipsisLoc, QualType CaptureType, Expr *Cpy)
Definition: ScopeInfo.h:651
QualType getType() const
Definition: Decl.h:647
bool empty() const
Return true if no decls were found.
Definition: Lookup.h:339
void setCaptures(ASTContext &Context, ArrayRef< Capture > Captures, bool CapturesCXXThis)
Definition: Decl.cpp:4300
A trivial tuple used to represent a source range.
void setLexicalDeclContext(DeclContext *DC)
Definition: DeclBase.cpp:298
ASTContext & Context
Definition: Sema.h:374
This represents a decl that may have a name.
Definition: Decl.h:248
bool isTranslationUnit() const
Definition: DeclBase.h:1836
void setAccess(AccessSpecifier AS)
Definition: DeclBase.h:460
void setBlockMissingReturnType(bool val=true)
Definition: Decl.h:3996
Describes an entity that is being initialized.
static FieldDecl * Create(const ASTContext &C, DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable, InClassInitStyle InitStyle)
Definition: Decl.cpp:3785
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3072
Wrapper for source info for pointers.
Definition: TypeLoc.h:1201
SourceLocation getBegin() const
bool isBlockCapture() const
Definition: ScopeInfo.h:576
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:624
No in-class initializer.
Definition: Specifiers.h:229
Declaration of a template function.
Definition: DeclTemplate.h:968
Attr - This represents one attribute.
Definition: Attr.h:43
SourceLocation getLocation() const
Definition: DeclBase.h:421
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:2719