Coverage Report

Created: 2022-01-18 06:27

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/Sema/SemaLambda.cpp
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Count
Source (jump to first uncovered line)
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//===--- 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"
17
#include "clang/Sema/Initialization.h"
18
#include "clang/Sema/Lookup.h"
19
#include "clang/Sema/Scope.h"
20
#include "clang/Sema/ScopeInfo.h"
21
#include "clang/Sema/SemaInternal.h"
22
#include "clang/Sema/SemaLambda.h"
23
#include "llvm/ADT/STLExtras.h"
24
using namespace clang;
25
using namespace sema;
26
27
/// Examines the FunctionScopeInfo stack to determine the nearest
28
/// enclosing lambda (to the current lambda) that is 'capture-ready' for
29
/// the variable referenced in the current lambda (i.e. \p VarToCapture).
30
/// If successful, returns the index into Sema's FunctionScopeInfo stack
31
/// of the capture-ready lambda's LambdaScopeInfo.
32
///
33
/// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
34
/// lambda - is on top) to determine the index of the nearest enclosing/outer
35
/// lambda that is ready to capture the \p VarToCapture being referenced in
36
/// the current lambda.
37
/// As we climb down the stack, we want the index of the first such lambda -
38
/// that is the lambda with the highest index that is 'capture-ready'.
39
///
40
/// A lambda 'L' is capture-ready for 'V' (var or this) if:
41
///  - its enclosing context is non-dependent
42
///  - and if the chain of lambdas between L and the lambda in which
43
///    V is potentially used (i.e. the lambda at the top of the scope info
44
///    stack), can all capture or have already captured V.
45
/// If \p VarToCapture is 'null' then we are trying to capture 'this'.
46
///
47
/// Note that a lambda that is deemed 'capture-ready' still needs to be checked
48
/// for whether it is 'capture-capable' (see
49
/// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
50
/// capture.
51
///
52
/// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
53
///  LambdaScopeInfo inherits from).  The current/deepest/innermost lambda
54
///  is at the top of the stack and has the highest index.
55
/// \param VarToCapture - the variable to capture.  If NULL, capture 'this'.
56
///
57
/// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
58
/// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
59
/// which is capture-ready.  If the return value evaluates to 'false' then
60
/// no lambda is capture-ready for \p VarToCapture.
61
62
static inline Optional<unsigned>
63
getStackIndexOfNearestEnclosingCaptureReadyLambda(
64
    ArrayRef<const clang::sema::FunctionScopeInfo *> FunctionScopes,
65
1.01k
    VarDecl *VarToCapture) {
66
  // Label failure to capture.
67
1.01k
  const Optional<unsigned> NoLambdaIsCaptureReady;
68
69
  // Ignore all inner captured regions.
70
1.01k
  unsigned CurScopeIndex = FunctionScopes.size() - 1;
71
1.01k
  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
72
1.01k
                                  FunctionScopes[CurScopeIndex]))
73
5
    --CurScopeIndex;
74
1.01k
  assert(
75
1.01k
      isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
76
1.01k
      "The function on the top of sema's function-info stack must be a lambda");
77
78
  // If VarToCapture is null, we are attempting to capture 'this'.
79
0
  const bool IsCapturingThis = !VarToCapture;
80
1.01k
  const bool IsCapturingVariable = !IsCapturingThis;
81
82
  // Start with the current lambda at the top of the stack (highest index).
83
1.01k
  DeclContext *EnclosingDC =
84
1.01k
      cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
85
86
1.59k
  do {
87
1.59k
    const clang::sema::LambdaScopeInfo *LSI =
88
1.59k
        cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]);
89
    // IF we have climbed down to an intervening enclosing lambda that contains
90
    // the variable declaration - it obviously can/must not capture the
91
    // variable.
92
    // Since its enclosing DC is dependent, all the lambdas between it and the
93
    // innermost nested lambda are dependent (otherwise we wouldn't have
94
    // arrived here) - so we don't yet have a lambda that can capture the
95
    // variable.
96
1.59k
    if (IsCapturingVariable &&
97
1.59k
        
VarToCapture->getDeclContext()->Equals(EnclosingDC)1.43k
)
98
219
      return NoLambdaIsCaptureReady;
99
100
    // For an enclosing lambda to be capture ready for an entity, all
101
    // intervening lambda's have to be able to capture that entity. If even
102
    // one of the intervening lambda's is not capable of capturing the entity
103
    // then no enclosing lambda can ever capture that entity.
104
    // For e.g.
105
    // const int x = 10;
106
    // [=](auto a) {    #1
107
    //   [](auto b) {   #2 <-- an intervening lambda that can never capture 'x'
108
    //    [=](auto c) { #3
109
    //       f(x, c);  <-- can not lead to x's speculative capture by #1 or #2
110
    //    }; }; };
111
    // If they do not have a default implicit capture, check to see
112
    // if the entity has already been explicitly captured.
113
    // If even a single dependent enclosing lambda lacks the capability
114
    // to ever capture this variable, there is no further enclosing
115
    // non-dependent lambda that can capture this variable.
116
1.38k
    if (LSI->ImpCaptureStyle == sema::LambdaScopeInfo::ImpCap_None) {
117
307
      if (IsCapturingVariable && 
!LSI->isCaptured(VarToCapture)255
)
118
173
        return NoLambdaIsCaptureReady;
119
134
      if (IsCapturingThis && 
!LSI->isCXXThisCaptured()52
)
120
48
        return NoLambdaIsCaptureReady;
121
134
    }
122
1.15k
    EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
123
124
1.15k
    assert(CurScopeIndex);
125
0
    --CurScopeIndex;
126
1.15k
  } while (!EnclosingDC->isTranslationUnit() &&
127
1.15k
           EnclosingDC->isDependentContext() &&
128
1.15k
           
isLambdaCallOperator(EnclosingDC)758
);
129
130
573
  assert(CurScopeIndex < (FunctionScopes.size() - 1));
131
  // If the enclosingDC is not dependent, then the immediately nested lambda
132
  // (one index above) is capture-ready.
133
573
  if (!EnclosingDC->isDependentContext())
134
401
    return CurScopeIndex + 1;
135
172
  return NoLambdaIsCaptureReady;
136
573
}
137
138
/// Examines the FunctionScopeInfo stack to determine the nearest
139
/// enclosing lambda (to the current lambda) that is 'capture-capable' for
140
/// the variable referenced in the current lambda (i.e. \p VarToCapture).
141
/// If successful, returns the index into Sema's FunctionScopeInfo stack
142
/// of the capture-capable lambda's LambdaScopeInfo.
143
///
144
/// Given the current stack of lambdas being processed by Sema and
145
/// the variable of interest, to identify the nearest enclosing lambda (to the
146
/// current lambda at the top of the stack) that can truly capture
147
/// a variable, it has to have the following two properties:
148
///  a) 'capture-ready' - be the innermost lambda that is 'capture-ready':
149
///     - climb down the stack (i.e. starting from the innermost and examining
150
///       each outer lambda step by step) checking if each enclosing
151
///       lambda can either implicitly or explicitly capture the variable.
152
///       Record the first such lambda that is enclosed in a non-dependent
153
///       context. If no such lambda currently exists return failure.
154
///  b) 'capture-capable' - make sure the 'capture-ready' lambda can truly
155
///  capture the variable by checking all its enclosing lambdas:
156
///     - check if all outer lambdas enclosing the 'capture-ready' lambda
157
///       identified above in 'a' can also capture the variable (this is done
158
///       via tryCaptureVariable for variables and CheckCXXThisCapture for
159
///       'this' by passing in the index of the Lambda identified in step 'a')
160
///
161
/// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
162
/// LambdaScopeInfo inherits from).  The current/deepest/innermost lambda
163
/// is at the top of the stack.
164
///
165
/// \param VarToCapture - the variable to capture.  If NULL, capture 'this'.
166
///
167
///
168
/// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
169
/// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
170
/// which is capture-capable.  If the return value evaluates to 'false' then
171
/// no lambda is capture-capable for \p VarToCapture.
172
173
Optional<unsigned> clang::getStackIndexOfNearestEnclosingCaptureCapableLambda(
174
    ArrayRef<const sema::FunctionScopeInfo *> FunctionScopes,
175
1.01k
    VarDecl *VarToCapture, Sema &S) {
176
177
1.01k
  const Optional<unsigned> NoLambdaIsCaptureCapable;
178
179
1.01k
  const Optional<unsigned> OptionalStackIndex =
180
1.01k
      getStackIndexOfNearestEnclosingCaptureReadyLambda(FunctionScopes,
181
1.01k
                                                        VarToCapture);
182
1.01k
  if (!OptionalStackIndex)
183
612
    return NoLambdaIsCaptureCapable;
184
185
401
  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
186
401
  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
187
401
          S.getCurGenericLambda()) &&
188
401
         "The capture ready lambda for a potential capture can only be the "
189
401
         "current lambda if it is a generic lambda");
190
191
0
  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
192
401
      cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
193
194
  // If VarToCapture is null, we are attempting to capture 'this'
195
401
  const bool IsCapturingThis = !VarToCapture;
196
401
  const bool IsCapturingVariable = !IsCapturingThis;
197
198
401
  if (IsCapturingVariable) {
199
    // Check if the capture-ready lambda can truly capture the variable, by
200
    // checking whether all enclosing lambdas of the capture-ready lambda allow
201
    // the capture - i.e. make sure it is capture-capable.
202
381
    QualType CaptureType, DeclRefType;
203
381
    const bool CanCaptureVariable =
204
381
        !S.tryCaptureVariable(VarToCapture,
205
381
                              /*ExprVarIsUsedInLoc*/ SourceLocation(),
206
381
                              clang::Sema::TryCapture_Implicit,
207
381
                              /*EllipsisLoc*/ SourceLocation(),
208
381
                              /*BuildAndDiagnose*/ false, CaptureType,
209
381
                              DeclRefType, &IndexOfCaptureReadyLambda);
210
381
    if (!CanCaptureVariable)
211
28
      return NoLambdaIsCaptureCapable;
212
381
  } else {
213
    // Check if the capture-ready lambda can truly capture 'this' by checking
214
    // whether all enclosing lambdas of the capture-ready lambda can capture
215
    // 'this'.
216
20
    const bool CanCaptureThis =
217
20
        !S.CheckCXXThisCapture(
218
20
             CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
219
20
             /*Explicit*/ false, /*BuildAndDiagnose*/ false,
220
20
             &IndexOfCaptureReadyLambda);
221
20
    if (!CanCaptureThis)
222
4
      return NoLambdaIsCaptureCapable;
223
20
  }
224
369
  return IndexOfCaptureReadyLambda;
225
401
}
226
227
static inline TemplateParameterList *
228
21.3k
getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) {
229
21.3k
  if (!LSI->GLTemplateParameterList && 
!LSI->TemplateParams.empty()16.3k
) {
230
2.20k
    LSI->GLTemplateParameterList = TemplateParameterList::Create(
231
2.20k
        SemaRef.Context,
232
2.20k
        /*Template kw loc*/ SourceLocation(),
233
2.20k
        /*L angle loc*/ LSI->ExplicitTemplateParamsRange.getBegin(),
234
2.20k
        LSI->TemplateParams,
235
2.20k
        /*R angle loc*/LSI->ExplicitTemplateParamsRange.getEnd(),
236
2.20k
        LSI->RequiresClause.get());
237
2.20k
  }
238
21.3k
  return LSI->GLTemplateParameterList;
239
21.3k
}
240
241
CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange,
242
                                             TypeSourceInfo *Info,
243
                                             bool KnownDependent,
244
10.6k
                                             LambdaCaptureDefault CaptureDefault) {
245
10.6k
  DeclContext *DC = CurContext;
246
10.7k
  while (!(DC->isFunctionOrMethod() || 
DC->isRecord()1.59k
||
DC->isFileContext()1.06k
))
247
18
    DC = DC->getParent();
248
10.6k
  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
249
10.6k
                                                               *this);
250
  // Start constructing the lambda class.
251
10.6k
  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
252
10.6k
                                                     IntroducerRange.getBegin(),
253
10.6k
                                                     KnownDependent,
254
10.6k
                                                     IsGenericLambda,
255
10.6k
                                                     CaptureDefault);
256
10.6k
  DC->addDecl(Class);
257
258
10.6k
  return Class;
259
10.6k
}
260
261
/// Determine whether the given context is or is enclosed in an inline
262
/// function.
263
1.05M
static bool isInInlineFunction(const DeclContext *DC) {
264
1.52M
  while (!DC->isFileContext()) {
265
486k
    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
266
26.4k
      if (FD->isInlined())
267
11.0k
        return true;
268
269
475k
    DC = DC->getLexicalParent();
270
475k
  }
271
272
1.04M
  return false;
273
1.05M
}
274
275
std::tuple<MangleNumberingContext *, Decl *>
276
1.06M
Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
277
  // Compute the context for allocating mangling numbers in the current
278
  // expression, if the ABI requires them.
279
1.06M
  Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
280
281
1.06M
  enum ContextKind {
282
1.06M
    Normal,
283
1.06M
    DefaultArgument,
284
1.06M
    DataMember,
285
1.06M
    StaticDataMember,
286
1.06M
    InlineVariable,
287
1.06M
    VariableTemplate
288
1.06M
  } Kind = Normal;
289
290
  // Default arguments of member function parameters that appear in a class
291
  // definition, as well as the initializers of data members, receive special
292
  // treatment. Identify them.
293
1.06M
  if (ManglingContextDecl) {
294
2.64k
    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
295
792
      if (const DeclContext *LexicalDC
296
792
          = Param->getDeclContext()->getLexicalParent())
297
214
        if (LexicalDC->isRecord())
298
155
          Kind = DefaultArgument;
299
1.85k
    } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
300
1.63k
      if (Var->getDeclContext()->isRecord())
301
21
        Kind = StaticDataMember;
302
1.61k
      else if (Var->getMostRecentDecl()->isInline())
303
16
        Kind = InlineVariable;
304
1.60k
      else if (Var->getDescribedVarTemplate())
305
17
        Kind = VariableTemplate;
306
1.58k
      else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
307
8
        if (!VTS->isExplicitSpecialization())
308
8
          Kind = VariableTemplate;
309
8
      }
310
1.63k
    } else 
if (217
isa<FieldDecl>(ManglingContextDecl)217
) {
311
217
      Kind = DataMember;
312
217
    }
313
2.64k
  }
314
315
  // Itanium ABI [5.1.7]:
316
  //   In the following contexts [...] the one-definition rule requires closure
317
  //   types in different translation units to "correspond":
318
1.06M
  bool IsInNonspecializedTemplate =
319
1.06M
      inTemplateInstantiation() || 
CurContext->isDependentContext()1.06M
;
320
1.06M
  switch (Kind) {
321
1.06M
  case Normal: {
322
    //  -- the bodies of non-exported nonspecialized template functions
323
    //  -- the bodies of inline functions
324
1.06M
    if ((IsInNonspecializedTemplate &&
325
1.06M
         
!(16.0k
ManglingContextDecl16.0k
&&
isa<ParmVarDecl>(ManglingContextDecl)978
)) ||
326
1.06M
        
isInInlineFunction(CurContext)1.05M
) {
327
29.0k
      while (auto *CD = dyn_cast<CapturedDecl>(DC))
328
2.03k
        DC = CD->getParent();
329
27.0k
      return std::make_tuple(&Context.getManglingNumberContext(DC), nullptr);
330
27.0k
    }
331
332
1.04M
    return std::make_tuple(nullptr, nullptr);
333
1.06M
  }
334
335
21
  case StaticDataMember:
336
    //  -- the initializers of nonspecialized static members of template classes
337
21
    if (!IsInNonspecializedTemplate)
338
2
      return std::make_tuple(nullptr, ManglingContextDecl);
339
    // Fall through to get the current context.
340
21
    
LLVM_FALLTHROUGH19
;19
341
342
236
  case DataMember:
343
    //  -- the in-class initializers of class members
344
391
  case DefaultArgument:
345
    //  -- default arguments appearing in class definitions
346
407
  case InlineVariable:
347
    //  -- the initializers of inline variables
348
432
  case VariableTemplate:
349
    //  -- the initializers of templated variables
350
432
    return std::make_tuple(
351
432
        &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl,
352
432
                                          ManglingContextDecl),
353
432
        ManglingContextDecl);
354
1.06M
  }
355
356
0
  llvm_unreachable("unexpected context");
357
0
}
358
359
CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class,
360
                                           SourceRange IntroducerRange,
361
                                           TypeSourceInfo *MethodTypeInfo,
362
                                           SourceLocation EndLoc,
363
                                           ArrayRef<ParmVarDecl *> Params,
364
                                           ConstexprSpecKind ConstexprKind,
365
10.6k
                                           Expr *TrailingRequiresClause) {
366
10.6k
  QualType MethodType = MethodTypeInfo->getType();
367
10.6k
  TemplateParameterList *TemplateParams =
368
10.6k
      getGenericLambdaTemplateParameterList(getCurLambda(), *this);
369
  // If a lambda appears in a dependent context or is a generic lambda (has
370
  // template parameters) and has an 'auto' return type, deduce it to a
371
  // dependent type.
372
10.6k
  if (Class->isDependentContext() || 
TemplateParams8.13k
) {
373
4.91k
    const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
374
4.91k
    QualType Result = FPT->getReturnType();
375
4.91k
    if (Result->isUndeducedType()) {
376
3.50k
      Result = SubstAutoTypeDependent(Result);
377
3.50k
      MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
378
3.50k
                                           FPT->getExtProtoInfo());
379
3.50k
    }
380
4.91k
  }
381
382
  // C++11 [expr.prim.lambda]p5:
383
  //   The closure type for a lambda-expression has a public inline function
384
  //   call operator (13.5.4) whose parameters and return type are described by
385
  //   the lambda-expression's parameter-declaration-clause and
386
  //   trailing-return-type respectively.
387
10.6k
  DeclarationName MethodName
388
10.6k
    = Context.DeclarationNames.getCXXOperatorName(OO_Call);
389
10.6k
  DeclarationNameLoc MethodNameLoc =
390
10.6k
      DeclarationNameLoc::makeCXXOperatorNameLoc(IntroducerRange);
391
10.6k
  CXXMethodDecl *Method = CXXMethodDecl::Create(
392
10.6k
      Context, Class, EndLoc,
393
10.6k
      DeclarationNameInfo(MethodName, IntroducerRange.getBegin(),
394
10.6k
                          MethodNameLoc),
395
10.6k
      MethodType, MethodTypeInfo, SC_None, getCurFPFeatures().isFPConstrained(),
396
10.6k
      /*isInline=*/true, ConstexprKind, EndLoc, TrailingRequiresClause);
397
10.6k
  Method->setAccess(AS_public);
398
10.6k
  if (!TemplateParams)
399
7.09k
    Class->addDecl(Method);
400
401
  // Temporarily set the lexical declaration context to the current
402
  // context, so that the Scope stack matches the lexical nesting.
403
10.6k
  Method->setLexicalDeclContext(CurContext);
404
  // Create a function template if we have a template parameter list
405
10.6k
  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
406
3.60k
            FunctionTemplateDecl::Create(Context, Class,
407
3.60k
                                         Method->getLocation(), MethodName,
408
3.60k
                                         TemplateParams,
409
7.09k
                                         Method) : nullptr;
410
10.6k
  if (TemplateMethod) {
411
3.60k
    TemplateMethod->setAccess(AS_public);
412
3.60k
    Method->setDescribedFunctionTemplate(TemplateMethod);
413
3.60k
    Class->addDecl(TemplateMethod);
414
3.60k
    TemplateMethod->setLexicalDeclContext(CurContext);
415
3.60k
  }
416
417
  // Add parameters.
418
10.6k
  if (!Params.empty()) {
419
5.63k
    Method->setParams(Params);
420
5.63k
    CheckParmsForFunctionDef(Params,
421
5.63k
                             /*CheckParameterNames=*/false);
422
423
5.63k
    for (auto P : Method->parameters())
424
6.80k
      P->setOwningFunction(Method);
425
5.63k
  }
426
427
10.6k
  return Method;
428
10.6k
}
429
430
void Sema::handleLambdaNumbering(
431
    CXXRecordDecl *Class, CXXMethodDecl *Method,
432
10.6k
    Optional<std::tuple<bool, unsigned, unsigned, Decl *>> Mangling) {
433
10.6k
  if (Mangling) {
434
7
    bool HasKnownInternalLinkage;
435
7
    unsigned ManglingNumber, DeviceManglingNumber;
436
7
    Decl *ManglingContextDecl;
437
7
    std::tie(HasKnownInternalLinkage, ManglingNumber, DeviceManglingNumber,
438
7
             ManglingContextDecl) = Mangling.getValue();
439
7
    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
440
7
                             HasKnownInternalLinkage);
441
7
    Class->setDeviceLambdaManglingNumber(DeviceManglingNumber);
442
7
    return;
443
7
  }
444
445
10.6k
  auto getMangleNumberingContext =
446
10.6k
      [this](CXXRecordDecl *Class,
447
10.6k
             Decl *ManglingContextDecl) -> MangleNumberingContext * {
448
    // Get mangle numbering context if there's any extra decl context.
449
235
    if (ManglingContextDecl)
450
0
      return &Context.getManglingNumberContext(
451
0
          ASTContext::NeedExtraManglingDecl, ManglingContextDecl);
452
    // Otherwise, from that lambda's decl context.
453
235
    auto DC = Class->getDeclContext();
454
235
    while (auto *CD = dyn_cast<CapturedDecl>(DC))
455
0
      DC = CD->getParent();
456
235
    return &Context.getManglingNumberContext(DC);
457
235
  };
458
459
10.6k
  MangleNumberingContext *MCtx;
460
10.6k
  Decl *ManglingContextDecl;
461
10.6k
  std::tie(MCtx, ManglingContextDecl) =
462
10.6k
      getCurrentMangleNumberContext(Class->getDeclContext());
463
10.6k
  bool HasKnownInternalLinkage = false;
464
10.6k
  if (!MCtx && 
(4.46k
getLangOpts().CUDA4.46k
||
getLangOpts().SYCLIsDevice4.30k
||
465
4.46k
                
getLangOpts().SYCLIsHost4.23k
)) {
466
    // Force lambda numbering in CUDA/HIP as we need to name lambdas following
467
    // ODR. Both device- and host-compilation need to have a consistent naming
468
    // on kernel functions. As lambdas are potential part of these `__global__`
469
    // function names, they needs numbering following ODR.
470
    // Also force for SYCL, since we need this for the
471
    // __builtin_sycl_unique_stable_name implementation, which depends on lambda
472
    // mangling.
473
235
    MCtx = getMangleNumberingContext(Class, ManglingContextDecl);
474
235
    assert(MCtx && "Retrieving mangle numbering context failed!");
475
0
    HasKnownInternalLinkage = true;
476
235
  }
477
10.6k
  if (MCtx) {
478
6.45k
    unsigned ManglingNumber = MCtx->getManglingNumber(Method);
479
6.45k
    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
480
6.45k
                             HasKnownInternalLinkage);
481
6.45k
    Class->setDeviceLambdaManglingNumber(MCtx->getDeviceManglingNumber(Method));
482
6.45k
  }
483
10.6k
}
484
485
void Sema::buildLambdaScope(LambdaScopeInfo *LSI,
486
                                        CXXMethodDecl *CallOperator,
487
                                        SourceRange IntroducerRange,
488
                                        LambdaCaptureDefault CaptureDefault,
489
                                        SourceLocation CaptureDefaultLoc,
490
                                        bool ExplicitParams,
491
                                        bool ExplicitResultType,
492
10.6k
                                        bool Mutable) {
493
10.6k
  LSI->CallOperator = CallOperator;
494
10.6k
  CXXRecordDecl *LambdaClass = CallOperator->getParent();
495
10.6k
  LSI->Lambda = LambdaClass;
496
10.6k
  if (CaptureDefault == LCD_ByCopy)
497
1.30k
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
498
9.39k
  else if (CaptureDefault == LCD_ByRef)
499
2.05k
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
500
10.6k
  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
501
10.6k
  LSI->IntroducerRange = IntroducerRange;
502
10.6k
  LSI->ExplicitParams = ExplicitParams;
503
10.6k
  LSI->Mutable = Mutable;
504
505
10.6k
  if (ExplicitResultType) {
506
1.74k
    LSI->ReturnType = CallOperator->getReturnType();
507
508
1.74k
    if (!LSI->ReturnType->isDependentType() &&
509
1.74k
        
!LSI->ReturnType->isVoidType()1.29k
) {
510
810
      if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
511
810
                              diag::err_lambda_incomplete_result)) {
512
        // Do nothing.
513
2
      }
514
810
    }
515
8.95k
  } else {
516
8.95k
    LSI->HasImplicitReturnType = true;
517
8.95k
  }
518
10.6k
}
519
520
10.6k
void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) {
521
10.6k
  LSI->finishedExplicitCaptures();
522
10.6k
}
523
524
void Sema::ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc,
525
                                                    ArrayRef<NamedDecl *> TParams,
526
                                                    SourceLocation RAngleLoc,
527
166
                                                    ExprResult RequiresClause) {
528
166
  LambdaScopeInfo *LSI = getCurLambda();
529
166
  assert(LSI && "Expected a lambda scope");
530
0
  assert(LSI->NumExplicitTemplateParams == 0 &&
531
166
         "Already acted on explicit template parameters");
532
0
  assert(LSI->TemplateParams.empty() &&
533
166
         "Explicit template parameters should come "
534
166
         "before invented (auto) ones");
535
0
  assert(!TParams.empty() &&
536
166
         "No template parameters to act on");
537
0
  LSI->TemplateParams.append(TParams.begin(), TParams.end());
538
166
  LSI->NumExplicitTemplateParams = TParams.size();
539
166
  LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc};
540
166
  LSI->RequiresClause = RequiresClause;
541
166
}
542
543
void Sema::addLambdaParameters(
544
    ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
545
8.15k
    CXXMethodDecl *CallOperator, Scope *CurScope) {
546
  // Introduce our parameters into the function scope
547
8.15k
  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
548
12.3k
       p < NumParams; 
++p4.17k
) {
549
4.17k
    ParmVarDecl *Param = CallOperator->getParamDecl(p);
550
551
    // If this has an identifier, add it to the scope stack.
552
4.17k
    if (CurScope && Param->getIdentifier()) {
553
3.90k
      bool Error = false;
554
      // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
555
      // retroactively apply it.
556
3.90k
      for (const auto &Capture : Captures) {
557
361
        if (Capture.Id == Param->getIdentifier()) {
558
11
          Error = true;
559
11
          Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
560
11
          Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
561
11
              << Capture.Id << true;
562
11
        }
563
361
      }
564
3.90k
      if (!Error)
565
3.89k
        CheckShadow(CurScope, Param);
566
567
3.90k
      PushOnScopeChains(Param, CurScope);
568
3.90k
    }
569
4.17k
  }
570
8.15k
}
571
572
/// If this expression is an enumerator-like expression of some type
573
/// T, return the type T; otherwise, return null.
574
///
575
/// Pointer comparisons on the result here should always work because
576
/// it's derived from either the parent of an EnumConstantDecl
577
/// (i.e. the definition) or the declaration returned by
578
/// EnumType::getDecl() (i.e. the definition).
579
415
static EnumDecl *findEnumForBlockReturn(Expr *E) {
580
  // An expression is an enumerator-like expression of type T if,
581
  // ignoring parens and parens-like expressions:
582
415
  E = E->IgnoreParens();
583
584
  //  - it is an enumerator whose enum type is T or
585
415
  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
586
28
    if (EnumConstantDecl *D
587
28
          = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
588
28
      return cast<EnumDecl>(D->getDeclContext());
589
28
    }
590
0
    return nullptr;
591
28
  }
592
593
  //  - it is a comma expression whose RHS is an enumerator-like
594
  //    expression of type T or
595
387
  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
596
26
    if (BO->getOpcode() == BO_Comma)
597
1
      return findEnumForBlockReturn(BO->getRHS());
598
25
    return nullptr;
599
26
  }
600
601
  //  - it is a statement-expression whose value expression is an
602
  //    enumerator-like expression of type T or
603
361
  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
604
1
    if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
605
1
      return findEnumForBlockReturn(last);
606
0
    return nullptr;
607
1
  }
608
609
  //   - it is a ternary conditional operator (not the GNU ?:
610
  //     extension) whose second and third operands are
611
  //     enumerator-like expressions of type T or
612
360
  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
613
3
    if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
614
3
      if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
615
3
        return ED;
616
0
    return nullptr;
617
3
  }
618
619
  // (implicitly:)
620
  //   - it is an implicit integral conversion applied to an
621
  //     enumerator-like expression of type T or
622
357
  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
623
    // We can sometimes see integral conversions in valid
624
    // enumerator-like expressions.
625
146
    if (ICE->getCastKind() == CK_IntegralCast)
626
3
      return findEnumForBlockReturn(ICE->getSubExpr());
627
628
    // Otherwise, just rely on the type.
629
146
  }
630
631
  //   - it is an expression of that formal enum type.
632
354
  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
633
15
    return ET->getDecl();
634
15
  }
635
636
  // Otherwise, nope.
637
339
  return nullptr;
638
354
}
639
640
/// Attempt to find a type T for which the returned expression of the
641
/// given statement is an enumerator-like expression of that type.
642
505
static EnumDecl *findEnumForBlockReturn(ReturnStmt *ret) {
643
505
  if (Expr *retValue = ret->getRetValue())
644
404
    return findEnumForBlockReturn(retValue);
645
101
  return nullptr;
646
505
}
647
648
/// Attempt to find a common type T for which all of the returned
649
/// expressions in a block are enumerator-like expressions of that
650
/// type.
651
490
static EnumDecl *findCommonEnumForBlockReturns(ArrayRef<ReturnStmt*> returns) {
652
490
  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
653
654
  // Try to find one for the first return.
655
490
  EnumDecl *ED = findEnumForBlockReturn(*i);
656
490
  if (!ED) 
return nullptr463
;
657
658
  // Check that the rest of the returns have the same enum.
659
40
  
for (++i; 27
i != e;
++i13
) {
660
15
    if (findEnumForBlockReturn(*i) != ED)
661
2
      return nullptr;
662
15
  }
663
664
  // Never infer an anonymous enum type.
665
25
  if (!ED->hasNameForLinkage()) 
return nullptr3
;
666
667
22
  return ED;
668
25
}
669
670
/// Adjust the given return statements so that they formally return
671
/// the given type.  It should require, at most, an IntegralCast.
672
static void adjustBlockReturnsToEnum(Sema &S, ArrayRef<ReturnStmt*> returns,
673
22
                                     QualType returnType) {
674
22
  for (ArrayRef<ReturnStmt*>::iterator
675
57
         i = returns.begin(), e = returns.end(); i != e; 
++i35
) {
676
35
    ReturnStmt *ret = *i;
677
35
    Expr *retValue = ret->getRetValue();
678
35
    if (S.Context.hasSameType(retValue->getType(), returnType))
679
14
      continue;
680
681
    // Right now we only support integral fixup casts.
682
21
    assert(returnType->isIntegralOrUnscopedEnumerationType());
683
0
    assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
684
685
0
    ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
686
687
21
    Expr *E = (cleanups ? 
cleanups->getSubExpr()0
: retValue);
688
21
    E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast, E,
689
21
                                 /*base path*/ nullptr, VK_PRValue,
690
21
                                 FPOptionsOverride());
691
21
    if (cleanups) {
692
0
      cleanups->setSubExpr(E);
693
21
    } else {
694
21
      ret->setRetValue(E);
695
21
    }
696
21
  }
697
22
}
698
699
5.34k
void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) {
700
5.34k
  assert(CSI.HasImplicitReturnType);
701
  // If it was ever a placeholder, it had to been deduced to DependentTy.
702
0
  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
703
0
  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
704
5.34k
         "lambda expressions use auto deduction in C++14 onwards");
705
706
  // C++ core issue 975:
707
  //   If a lambda-expression does not include a trailing-return-type,
708
  //   it is as if the trailing-return-type denotes the following type:
709
  //     - if there are no return statements in the compound-statement,
710
  //       or all return statements return either an expression of type
711
  //       void or no expression or braced-init-list, the type void;
712
  //     - otherwise, if all return statements return an expression
713
  //       and the types of the returned expressions after
714
  //       lvalue-to-rvalue conversion (4.1 [conv.lval]),
715
  //       array-to-pointer conversion (4.2 [conv.array]), and
716
  //       function-to-pointer conversion (4.3 [conv.func]) are the
717
  //       same, that common type;
718
  //     - otherwise, the program is ill-formed.
719
  //
720
  // C++ core issue 1048 additionally removes top-level cv-qualifiers
721
  // from the types of returned expressions to match the C++14 auto
722
  // deduction rules.
723
  //
724
  // In addition, in blocks in non-C++ modes, if all of the return
725
  // statements are enumerator-like expressions of some type T, where
726
  // T has a name for linkage, then we infer the return type of the
727
  // block to be that type.
728
729
  // First case: no return statements, implicit void return type.
730
0
  ASTContext &Ctx = getASTContext();
731
5.34k
  if (CSI.Returns.empty()) {
732
    // It's possible there were simply no /valid/ return statements.
733
    // In this case, the first one we found may have at least given us a type.
734
4.23k
    if (CSI.ReturnType.isNull())
735
4.23k
      CSI.ReturnType = Ctx.VoidTy;
736
4.23k
    return;
737
4.23k
  }
738
739
  // Second case: at least one return statement has dependent type.
740
  // Delay type checking until instantiation.
741
1.10k
  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
742
1.10k
  if (CSI.ReturnType->isDependentType())
743
70
    return;
744
745
  // Try to apply the enum-fuzz rule.
746
1.03k
  if (!getLangOpts().CPlusPlus) {
747
490
    assert(isa<BlockScopeInfo>(CSI));
748
0
    const EnumDecl *ED = findCommonEnumForBlockReturns(CSI.Returns);
749
490
    if (ED) {
750
22
      CSI.ReturnType = Context.getTypeDeclType(ED);
751
22
      adjustBlockReturnsToEnum(*this, CSI.Returns, CSI.ReturnType);
752
22
      return;
753
22
    }
754
490
  }
755
756
  // Third case: only one return statement. Don't bother doing extra work!
757
1.01k
  if (CSI.Returns.size() == 1)
758
973
    return;
759
760
  // General case: many return statements.
761
  // Check that they all have compatible return types.
762
763
  // We require the return types to strictly match here.
764
  // Note that we've already done the required promotions as part of
765
  // processing the return statement.
766
111
  
for (const ReturnStmt *RS : CSI.Returns)43
{
767
111
    const Expr *RetE = RS->getRetValue();
768
769
111
    QualType ReturnType =
770
111
        (RetE ? 
RetE->getType()106
:
Context.VoidTy5
).getUnqualifiedType();
771
111
    if (Context.getCanonicalFunctionResultType(ReturnType) ==
772
111
          Context.getCanonicalFunctionResultType(CSI.ReturnType)) {
773
      // Use the return type with the strictest possible nullability annotation.
774
102
      auto RetTyNullability = ReturnType->getNullability(Ctx);
775
102
      auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
776
102
      if (BlockNullability &&
777
102
          
(4
!RetTyNullability4
||
778
4
           
hasWeakerNullability(*RetTyNullability, *BlockNullability)2
))
779
2
        CSI.ReturnType = ReturnType;
780
102
      continue;
781
102
    }
782
783
    // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
784
    // TODO: It's possible that the *first* return is the divergent one.
785
9
    Diag(RS->getBeginLoc(),
786
9
         diag::err_typecheck_missing_return_type_incompatible)
787
9
        << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
788
    // Continue iterating so that we keep emitting diagnostics.
789
9
  }
790
43
}
791
792
QualType Sema::buildLambdaInitCaptureInitialization(
793
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
794
    Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool IsDirectInit,
795
582
    Expr *&Init) {
796
  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
797
  // deduce against.
798
582
  QualType DeductType = Context.getAutoDeductType();
799
582
  TypeLocBuilder TLB;
800
582
  AutoTypeLoc TL = TLB.push<AutoTypeLoc>(DeductType);
801
582
  TL.setNameLoc(Loc);
802
582
  if (ByRef) {
803
115
    DeductType = BuildReferenceType(DeductType, true, Loc, Id);
804
115
    assert(!DeductType.isNull() && "can't build reference to auto");
805
0
    TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
806
115
  }
807
582
  if (EllipsisLoc.isValid()) {
808
64
    if (Init->containsUnexpandedParameterPack()) {
809
63
      Diag(EllipsisLoc, getLangOpts().CPlusPlus20
810
63
                            ? 
diag::warn_cxx17_compat_init_capture_pack32
811
63
                            : 
diag::ext_init_capture_pack31
);
812
63
      DeductType = Context.getPackExpansionType(DeductType, NumExpansions,
813
63
                                                /*ExpectPackInType=*/false);
814
63
      TLB.push<PackExpansionTypeLoc>(DeductType).setEllipsisLoc(EllipsisLoc);
815
63
    } else {
816
      // Just ignore the ellipsis for now and form a non-pack variable. We'll
817
      // diagnose this later when we try to capture it.
818
1
    }
819
64
  }
820
582
  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
821
822
  // Deduce the type of the init capture.
823
582
  QualType DeducedType = deduceVarTypeFromInitializer(
824
582
      /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
825
582
      SourceRange(Loc, Loc), IsDirectInit, Init);
826
582
  if (DeducedType.isNull())
827
37
    return QualType();
828
829
  // Are we a non-list direct initialization?
830
545
  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
831
832
  // Perform initialization analysis and ensure any implicit conversions
833
  // (such as lvalue-to-rvalue) are enforced.
834
545
  InitializedEntity Entity =
835
545
      InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
836
545
  InitializationKind Kind =
837
545
      IsDirectInit
838
545
          ? 
(160
CXXDirectInit160
? InitializationKind::CreateDirect(
839
140
                                 Loc, Init->getBeginLoc(), Init->getEndLoc())
840
160
                           : 
InitializationKind::CreateDirectList(Loc)20
)
841
545
          : 
InitializationKind::CreateCopy(Loc, Init->getBeginLoc())385
;
842
843
545
  MultiExprArg Args = Init;
844
545
  if (CXXDirectInit)
845
140
    Args =
846
140
        MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
847
545
  QualType DclT;
848
545
  InitializationSequence InitSeq(*this, Entity, Kind, Args);
849
545
  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
850
851
545
  if (Result.isInvalid())
852
4
    return QualType();
853
854
541
  Init = Result.getAs<Expr>();
855
541
  return DeducedType;
856
545
}
857
858
VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
859
                                              QualType InitCaptureType,
860
                                              SourceLocation EllipsisLoc,
861
                                              IdentifierInfo *Id,
862
539
                                              unsigned InitStyle, Expr *Init) {
863
  // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization
864
  // rather than reconstructing it here.
865
539
  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType, Loc);
866
539
  if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>())
867
61
    PETL.setEllipsisLoc(EllipsisLoc);
868
869
  // Create a dummy variable representing the init-capture. This is not actually
870
  // used as a variable, and only exists as a way to name and refer to the
871
  // init-capture.
872
  // FIXME: Pass in separate source locations for '&' and identifier.
873
539
  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
874
539
                                   Loc, Id, InitCaptureType, TSI, SC_Auto);
875
539
  NewVD->setInitCapture(true);
876
539
  NewVD->setReferenced(true);
877
  // FIXME: Pass in a VarDecl::InitializationStyle.
878
539
  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
879
539
  NewVD->markUsed(Context);
880
539
  NewVD->setInit(Init);
881
539
  if (NewVD->isParameterPack())
882
61
    getCurLambda()->LocalPacks.push_back(NewVD);
883
539
  return NewVD;
884
539
}
885
886
537
void Sema::addInitCapture(LambdaScopeInfo *LSI, VarDecl *Var) {
887
537
  assert(Var->isInitCapture() && "init capture flag should be set");
888
0
  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
889
537
                  /*isNested*/false, Var->getLocation(), SourceLocation(),
890
537
                  Var->getType(), /*Invalid*/false);
891
537
}
892
893
void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
894
                                        Declarator &ParamInfo,
895
8.15k
                                        Scope *CurScope) {
896
8.15k
  LambdaScopeInfo *const LSI = getCurLambda();
897
8.15k
  assert(LSI && "LambdaScopeInfo should be on stack!");
898
899
  // Determine if we're within a context where we know that the lambda will
900
  // be dependent, because there are template parameters in scope.
901
0
  bool KnownDependent;
902
8.15k
  if (LSI->NumExplicitTemplateParams > 0) {
903
166
    auto *TemplateParamScope = CurScope->getTemplateParamParent();
904
166
    assert(TemplateParamScope &&
905
166
           "Lambda with explicit template param list should establish a "
906
166
           "template param scope");
907
0
    assert(TemplateParamScope->getParent());
908
0
    KnownDependent = TemplateParamScope->getParent()
909
166
                                       ->getTemplateParamParent() != nullptr;
910
7.99k
  } else {
911
7.99k
    KnownDependent = CurScope->getTemplateParamParent() != nullptr;
912
7.99k
  }
913
914
  // Determine the signature of the call operator.
915
0
  TypeSourceInfo *MethodTyInfo;
916
8.15k
  bool ExplicitParams = true;
917
8.15k
  bool ExplicitResultType = true;
918
8.15k
  bool ContainsUnexpandedParameterPack = false;
919
8.15k
  SourceLocation EndLoc;
920
8.15k
  SmallVector<ParmVarDecl *, 8> Params;
921
8.15k
  if (ParamInfo.getNumTypeObjects() == 0) {
922
    // C++11 [expr.prim.lambda]p4:
923
    //   If a lambda-expression does not include a lambda-declarator, it is as
924
    //   if the lambda-declarator were ().
925
1.74k
    FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
926
1.74k
        /*IsVariadic=*/false, /*IsCXXMethod=*/true));
927
1.74k
    EPI.HasTrailingReturn = true;
928
1.74k
    EPI.TypeQuals.addConst();
929
1.74k
    LangAS AS = getDefaultCXXMethodAddrSpace();
930
1.74k
    if (AS != LangAS::Default)
931
2
      EPI.TypeQuals.addAddressSpace(AS);
932
933
    // C++1y [expr.prim.lambda]:
934
    //   The lambda return type is 'auto', which is replaced by the
935
    //   trailing-return type if provided and/or deduced from 'return'
936
    //   statements
937
    // We don't do this before C++1y, because we don't support deduced return
938
    // types there.
939
1.74k
    QualType DefaultTypeForNoTrailingReturn =
940
1.74k
        getLangOpts().CPlusPlus14 ? 
Context.getAutoDeductType()1.15k
941
1.74k
                                  : 
Context.DependentTy591
;
942
1.74k
    QualType MethodTy =
943
1.74k
        Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
944
1.74k
    MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
945
1.74k
    ExplicitParams = false;
946
1.74k
    ExplicitResultType = false;
947
1.74k
    EndLoc = Intro.Range.getEnd();
948
6.40k
  } else {
949
6.40k
    assert(ParamInfo.isFunctionDeclarator() &&
950
6.40k
           "lambda-declarator is a function");
951
0
    DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo();
952
953
    // C++11 [expr.prim.lambda]p5:
954
    //   This function call operator is declared const (9.3.1) if and only if
955
    //   the lambda-expression's parameter-declaration-clause is not followed
956
    //   by mutable. It is neither virtual nor declared volatile. [...]
957
6.40k
    if (!FTI.hasMutableQualifier()) {
958
6.21k
      FTI.getOrCreateMethodQualifiers().SetTypeQual(DeclSpec::TQ_const,
959
6.21k
                                                    SourceLocation());
960
6.21k
    }
961
962
6.40k
    MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
963
6.40k
    assert(MethodTyInfo && "no type from lambda-declarator");
964
0
    EndLoc = ParamInfo.getSourceRange().getEnd();
965
966
6.40k
    ExplicitResultType = FTI.hasTrailingReturnType();
967
968
6.40k
    if (FTIHasNonVoidParameters(FTI)) {
969
3.60k
      Params.reserve(FTI.NumParams);
970
7.78k
      for (unsigned i = 0, e = FTI.NumParams; i != e; 
++i4.17k
)
971
4.17k
        Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
972
3.60k
    }
973
974
    // Check for unexpanded parameter packs in the method type.
975
6.40k
    if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
976
50
      DiagnoseUnexpandedParameterPack(Intro.Range.getBegin(), MethodTyInfo,
977
50
                                      UPPC_DeclarationType);
978
6.40k
  }
979
980
0
  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
981
8.15k
                                                 KnownDependent, Intro.Default);
982
8.15k
  CXXMethodDecl *Method =
983
8.15k
      startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
984
8.15k
                            ParamInfo.getDeclSpec().getConstexprSpecifier(),
985
8.15k
                            ParamInfo.getTrailingRequiresClause());
986
8.15k
  if (ExplicitParams)
987
6.40k
    CheckCXXDefaultArguments(Method);
988
989
  // This represents the function body for the lambda function, check if we
990
  // have to apply optnone due to a pragma.
991
8.15k
  AddRangeBasedOptnone(Method);
992
993
  // code_seg attribute on lambda apply to the method.
994
8.15k
  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
995
2
    Method->addAttr(A);
996
997
  // Attributes on the lambda apply to the method.
998
8.15k
  ProcessDeclAttributes(CurScope, Method, ParamInfo);
999
1000
  // CUDA lambdas get implicit host and device attributes.
1001
8.15k
  if (getLangOpts().CUDA)
1002
214
    CUDASetLambdaAttrs(Method);
1003
1004
  // OpenMP lambdas might get assumumption attributes.
1005
8.15k
  if (LangOpts.OpenMP)
1006
1.39k
    ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Method);
1007
1008
  // Number the lambda for linkage purposes if necessary.
1009
8.15k
  handleLambdaNumbering(Class, Method);
1010
1011
  // Introduce the function call operator as the current declaration context.
1012
8.15k
  PushDeclContext(CurScope, Method);
1013
1014
  // Build the lambda scope.
1015
8.15k
  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
1016
8.15k
                   ExplicitParams, ExplicitResultType, !Method->isConst());
1017
1018
  // C++11 [expr.prim.lambda]p9:
1019
  //   A lambda-expression whose smallest enclosing scope is a block scope is a
1020
  //   local lambda expression; any other lambda expression shall not have a
1021
  //   capture-default or simple-capture in its lambda-introducer.
1022
  //
1023
  // For simple-captures, this is covered by the check below that any named
1024
  // entity is a variable that can be captured.
1025
  //
1026
  // For DR1632, we also allow a capture-default in any context where we can
1027
  // odr-use 'this' (in particular, in a default initializer for a non-static
1028
  // data member).
1029
8.15k
  if (Intro.Default != LCD_None && 
!Class->getParent()->isFunctionOrMethod()2.80k
&&
1030
8.15k
      
(37
getCurrentThisType().isNull()37
||
1031
37
       CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
1032
29
                           /*BuildAndDiagnose*/false)))
1033
8
    Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
1034
1035
  // Distinct capture names, for diagnostics.
1036
8.15k
  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
1037
1038
  // Handle explicit captures.
1039
8.15k
  SourceLocation PrevCaptureLoc
1040
8.15k
    = Intro.Default == LCD_None? 
Intro.Range.getBegin()5.35k
:
Intro.DefaultLoc2.80k
;
1041
9.86k
  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
1042
8.15k
       
PrevCaptureLoc = C->Loc, ++C1.70k
) {
1043
1.70k
    if (C->Kind == LCK_This || 
C->Kind == LCK_StarThis1.44k
) {
1044
382
      if (C->Kind == LCK_StarThis)
1045
121
        Diag(C->Loc, !getLangOpts().CPlusPlus17
1046
121
                             ? 
diag::ext_star_this_lambda_capture_cxx172
1047
121
                             : 
diag::warn_cxx14_compat_star_this_lambda_capture119
);
1048
1049
      // C++11 [expr.prim.lambda]p8:
1050
      //   An identifier or this shall not appear more than once in a
1051
      //   lambda-capture.
1052
382
      if (LSI->isCXXThisCaptured()) {
1053
5
        Diag(C->Loc, diag::err_capture_more_than_once)
1054
5
            << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
1055
5
            << FixItHint::CreateRemoval(
1056
5
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1057
5
        continue;
1058
5
      }
1059
1060
      // C++2a [expr.prim.lambda]p8:
1061
      //  If a lambda-capture includes a capture-default that is =,
1062
      //  each simple-capture of that lambda-capture shall be of the form
1063
      //  "&identifier", "this", or "* this". [ Note: The form [&,this] is
1064
      //  redundant but accepted for compatibility with ISO C++14. --end note ]
1065
377
      if (Intro.Default == LCD_ByCopy && 
C->Kind != LCK_StarThis9
)
1066
5
        Diag(C->Loc, !getLangOpts().CPlusPlus20
1067
5
                         ? 
diag::ext_equals_this_lambda_capture_cxx203
1068
5
                         : 
diag::warn_cxx17_compat_equals_this_lambda_capture2
);
1069
1070
      // C++11 [expr.prim.lambda]p12:
1071
      //   If this is captured by a local lambda expression, its nearest
1072
      //   enclosing function shall be a non-static member function.
1073
377
      QualType ThisCaptureType = getCurrentThisType();
1074
377
      if (ThisCaptureType.isNull()) {
1075
5
        Diag(C->Loc, diag::err_this_capture) << true;
1076
5
        continue;
1077
5
      }
1078
1079
372
      CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1080
372
                          /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1081
372
                          C->Kind == LCK_StarThis);
1082
372
      if (!LSI->Captures.empty())
1083
370
        LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1084
372
      continue;
1085
377
    }
1086
1087
1.32k
    assert(C->Id && "missing identifier for capture");
1088
1089
1.32k
    if (C->Init.isInvalid())
1090
7
      continue;
1091
1092
1.32k
    VarDecl *Var = nullptr;
1093
1.32k
    if (C->Init.isUsable()) {
1094
447
      Diag(C->Loc, getLangOpts().CPlusPlus14
1095
447
                       ? 
diag::warn_cxx11_compat_init_capture396
1096
447
                       : 
diag::ext_init_capture51
);
1097
1098
      // If the initializer expression is usable, but the InitCaptureType
1099
      // is not, then an error has occurred - so ignore the capture for now.
1100
      // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1101
      // FIXME: we should create the init capture variable and mark it invalid
1102
      // in this case.
1103
447
      if (C->InitCaptureType.get().isNull())
1104
33
        continue;
1105
1106
414
      if (C->Init.get()->containsUnexpandedParameterPack() &&
1107
414
          
!C->InitCaptureType.get()->getAs<PackExpansionType>()77
)
1108
16
        DiagnoseUnexpandedParameterPack(C->Init.get(), UPPC_Initializer);
1109
1110
414
      unsigned InitStyle;
1111
414
      switch (C->InitKind) {
1112
0
      case LambdaCaptureInitKind::NoInit:
1113
0
        llvm_unreachable("not an init-capture?");
1114
301
      case LambdaCaptureInitKind::CopyInit:
1115
301
        InitStyle = VarDecl::CInit;
1116
301
        break;
1117
94
      case LambdaCaptureInitKind::DirectInit:
1118
94
        InitStyle = VarDecl::CallInit;
1119
94
        break;
1120
19
      case LambdaCaptureInitKind::ListInit:
1121
19
        InitStyle = VarDecl::ListInit;
1122
19
        break;
1123
414
      }
1124
414
      Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1125
414
                                           C->EllipsisLoc, C->Id, InitStyle,
1126
414
                                           C->Init.get());
1127
      // C++1y [expr.prim.lambda]p11:
1128
      //   An init-capture behaves as if it declares and explicitly
1129
      //   captures a variable [...] whose declarative region is the
1130
      //   lambda-expression's compound-statement
1131
414
      if (Var)
1132
414
        PushOnScopeChains(Var, CurScope, false);
1133
873
    } else {
1134
873
      assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1135
873
             "init capture has valid but null init?");
1136
1137
      // C++11 [expr.prim.lambda]p8:
1138
      //   If a lambda-capture includes a capture-default that is &, the
1139
      //   identifiers in the lambda-capture shall not be preceded by &.
1140
      //   If a lambda-capture includes a capture-default that is =, [...]
1141
      //   each identifier it contains shall be preceded by &.
1142
873
      if (C->Kind == LCK_ByRef && 
Intro.Default == LCD_ByRef248
) {
1143
7
        Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1144
7
            << FixItHint::CreateRemoval(
1145
7
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1146
7
        continue;
1147
866
      } else if (C->Kind == LCK_ByCopy && 
Intro.Default == LCD_ByCopy625
) {
1148
1
        Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1149
1
            << FixItHint::CreateRemoval(
1150
1
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1151
1
        continue;
1152
1
      }
1153
1154
      // C++11 [expr.prim.lambda]p10:
1155
      //   The identifiers in a capture-list are looked up using the usual
1156
      //   rules for unqualified name lookup (3.4.1)
1157
865
      DeclarationNameInfo Name(C->Id, C->Loc);
1158
865
      LookupResult R(*this, Name, LookupOrdinaryName);
1159
865
      LookupName(R, CurScope);
1160
865
      if (R.isAmbiguous())
1161
1
        continue;
1162
864
      if (R.empty()) {
1163
        // FIXME: Disable corrections that would add qualification?
1164
1
        CXXScopeSpec ScopeSpec;
1165
1
        DeclFilterCCC<VarDecl> Validator{};
1166
1
        if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1167
0
          continue;
1168
1
      }
1169
1170
864
      Var = R.getAsSingle<VarDecl>();
1171
864
      if (Var && 
DiagnoseUseOfDecl(Var, C->Loc)850
)
1172
2
        continue;
1173
864
    }
1174
1175
    // C++11 [expr.prim.lambda]p8:
1176
    //   An identifier or this shall not appear more than once in a
1177
    //   lambda-capture.
1178
1.27k
    if (!CaptureNames.insert(C->Id).second) {
1179
9
      if (Var && LSI->isCaptured(Var)) {
1180
7
        Diag(C->Loc, diag::err_capture_more_than_once)
1181
7
            << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1182
7
            << FixItHint::CreateRemoval(
1183
7
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1184
7
      } else
1185
        // Previous capture captured something different (one or both was
1186
        // an init-cpature): no fixit.
1187
2
        Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1188
9
      continue;
1189
9
    }
1190
1191
    // C++11 [expr.prim.lambda]p10:
1192
    //   [...] each such lookup shall find a variable with automatic storage
1193
    //   duration declared in the reaching scope of the local lambda expression.
1194
    // Note that the 'reaching scope' check happens in tryCaptureVariable().
1195
1.26k
    if (!Var) {
1196
14
      Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1197
14
      continue;
1198
14
    }
1199
1200
    // Ignore invalid decls; they'll just confuse the code later.
1201
1.25k
    if (Var->isInvalidDecl())
1202
4
      continue;
1203
1204
1.24k
    if (!Var->hasLocalStorage()) {
1205
2
      Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1206
2
      Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1207
2
      continue;
1208
2
    }
1209
1210
    // C++11 [expr.prim.lambda]p23:
1211
    //   A capture followed by an ellipsis is a pack expansion (14.5.3).
1212
1.24k
    SourceLocation EllipsisLoc;
1213
1.24k
    if (C->EllipsisLoc.isValid()) {
1214
142
      if (Var->isParameterPack()) {
1215
138
        EllipsisLoc = C->EllipsisLoc;
1216
138
      } else {
1217
4
        Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1218
4
            << (C->Init.isUsable() ? 
C->Init.get()->getSourceRange()1
1219
4
                                   : 
SourceRange(C->Loc)3
);
1220
1221
        // Just ignore the ellipsis.
1222
4
      }
1223
1.10k
    } else if (Var->isParameterPack()) {
1224
13
      ContainsUnexpandedParameterPack = true;
1225
13
    }
1226
1227
1.24k
    if (C->Init.isUsable()) {
1228
412
      addInitCapture(LSI, Var);
1229
835
    } else {
1230
835
      TryCaptureKind Kind = C->Kind == LCK_ByRef ? 
TryCapture_ExplicitByRef236
:
1231
835
                                                   
TryCapture_ExplicitByVal599
;
1232
835
      tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1233
835
    }
1234
1.24k
    if (!LSI->Captures.empty())
1235
1.24k
      LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1236
1.24k
  }
1237
8.15k
  finishLambdaExplicitCaptures(LSI);
1238
1239
8.15k
  LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
1240
1241
  // Add lambda parameters into scope.
1242
8.15k
  addLambdaParameters(Intro.Captures, Method, CurScope);
1243
1244
  // Enter a new evaluation context to insulate the lambda from any
1245
  // cleanups from the enclosing full-expression.
1246
8.15k
  PushExpressionEvaluationContext(
1247
8.15k
      LSI->CallOperator->isConsteval()
1248
8.15k
          ? 
ExpressionEvaluationContext::ImmediateFunctionContext6
1249
8.15k
          : 
ExpressionEvaluationContext::PotentiallyEvaluated8.15k
);
1250
8.15k
}
1251
1252
void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
1253
208
                            bool IsInstantiation) {
1254
208
  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1255
1256
  // Leave the expression-evaluation context.
1257
208
  DiscardCleanupsInEvaluationContext();
1258
208
  PopExpressionEvaluationContext();
1259
1260
  // Leave the context of the lambda.
1261
208
  if (!IsInstantiation)
1262
187
    PopDeclContext();
1263
1264
  // Finalize the lambda.
1265
208
  CXXRecordDecl *Class = LSI->Lambda;
1266
208
  Class->setInvalidDecl();
1267
208
  SmallVector<Decl*, 4> Fields(Class->fields());
1268
208
  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1269
208
              SourceLocation(), ParsedAttributesView());
1270
208
  CheckCompletedCXXClass(nullptr, Class);
1271
1272
208
  PopFunctionScopeInfo();
1273
208
}
1274
1275
template <typename Func>
1276
static void repeatForLambdaConversionFunctionCallingConvs(
1277
5.57k
    Sema &S, const FunctionProtoType &CallOpProto, Func F) {
1278
5.57k
  CallingConv DefaultFree = S.Context.getDefaultCallingConvention(
1279
5.57k
      CallOpProto.isVariadic(), /*IsCXXMethod=*/false);
1280
5.57k
  CallingConv DefaultMember = S.Context.getDefaultCallingConvention(
1281
5.57k
      CallOpProto.isVariadic(), /*IsCXXMethod=*/true);
1282
5.57k
  CallingConv CallOpCC = CallOpProto.getCallConv();
1283
1284
  /// Implement emitting a version of the operator for many of the calling
1285
  /// conventions for MSVC, as described here:
1286
  /// https://devblogs.microsoft.com/oldnewthing/20150220-00/?p=44623.
1287
  /// Experimentally, we determined that cdecl, stdcall, fastcall, and
1288
  /// vectorcall are generated by MSVC when it is supported by the target.
1289
  /// Additionally, we are ensuring that the default-free/default-member and
1290
  /// call-operator calling convention are generated as well.
1291
  /// NOTE: We intentionally generate a 'thiscall' on Win32 implicitly from the
1292
  /// 'member default', despite MSVC not doing so. We do this in order to ensure
1293
  /// that someone who intentionally places 'thiscall' on the lambda call
1294
  /// operator will still get that overload, since we don't have the a way of
1295
  /// detecting the attribute by the time we get here.
1296
5.57k
  if (S.getLangOpts().MSVCCompat) {
1297
82
    CallingConv Convs[] = {
1298
82
        CC_C,        CC_X86StdCall, CC_X86FastCall, CC_X86VectorCall,
1299
82
        DefaultFree, DefaultMember, CallOpCC};
1300
82
    llvm::sort(Convs);
1301
82
    llvm::iterator_range<CallingConv *> Range(
1302
82
        std::begin(Convs), std::unique(std::begin(Convs), std::end(Convs)));
1303
82
    const TargetInfo &TI = S.getASTContext().getTargetInfo();
1304
1305
330
    for (CallingConv C : Range) {
1306
330
      if (TI.checkCallingConvention(C) == TargetInfo::CCCR_OK)
1307
170
        F(C);
1308
330
    }
1309
82
    return;
1310
82
  }
1311
1312
5.49k
  if (CallOpCC == DefaultMember && 
DefaultMember != DefaultFree5.47k
) {
1313
1.60k
    F(DefaultFree);
1314
1.60k
    F(DefaultMember);
1315
3.88k
  } else {
1316
3.88k
    F(CallOpCC);
1317
3.88k
  }
1318
5.49k
}
1319
1320
// Returns the 'standard' calling convention to be used for the lambda
1321
// conversion function, that is, the 'free' function calling convention unless
1322
// it is overridden by a non-default calling convention attribute.
1323
static CallingConv
1324
getLambdaConversionFunctionCallConv(Sema &S,
1325
162
                                    const FunctionProtoType *CallOpProto) {
1326
162
  CallingConv DefaultFree = S.Context.getDefaultCallingConvention(
1327
162
      CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1328
162
  CallingConv DefaultMember = S.Context.getDefaultCallingConvention(
1329
162
      CallOpProto->isVariadic(), /*IsCXXMethod=*/true);
1330
162
  CallingConv CallOpCC = CallOpProto->getCallConv();
1331
1332
  // If the call-operator hasn't been changed, return both the 'free' and
1333
  // 'member' function calling convention.
1334
162
  if (CallOpCC == DefaultMember && DefaultMember != DefaultFree)
1335
0
    return DefaultFree;
1336
162
  return CallOpCC;
1337
162
}
1338
1339
QualType Sema::getLambdaConversionFunctionResultType(
1340
7.82k
    const FunctionProtoType *CallOpProto, CallingConv CC) {
1341
7.82k
  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1342
7.82k
      CallOpProto->getExtProtoInfo();
1343
7.82k
  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1344
7.82k
  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1345
7.82k
  InvokerExtInfo.TypeQuals = Qualifiers();
1346
7.82k
  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1347
7.82k
         "Lambda's call operator should not have a reference qualifier");
1348
0
  return Context.getFunctionType(CallOpProto->getReturnType(),
1349
7.82k
                                 CallOpProto->getParamTypes(), InvokerExtInfo);
1350
7.82k
}
1351
1352
/// Add a lambda's conversion to function pointer, as described in
1353
/// C++11 [expr.prim.lambda]p6.
1354
static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange,
1355
                                         CXXRecordDecl *Class,
1356
                                         CXXMethodDecl *CallOperator,
1357
7.27k
                                         QualType InvokerFunctionTy) {
1358
  // This conversion is explicitly disabled if the lambda's function has
1359
  // pass_object_size attributes on any of its parameters.
1360
7.27k
  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1361
7.22k
    return P->hasAttr<PassObjectSizeAttr>();
1362
7.22k
  };
1363
7.27k
  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1364
2
    return;
1365
1366
  // Add the conversion to function pointer.
1367
7.26k
  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1368
1369
  // Create the type of the conversion function.
1370
7.26k
  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1371
7.26k
      S.Context.getDefaultCallingConvention(
1372
7.26k
      /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1373
  // The conversion function is always const and noexcept.
1374
7.26k
  ConvExtInfo.TypeQuals = Qualifiers();
1375
7.26k
  ConvExtInfo.TypeQuals.addConst();
1376
7.26k
  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1377
7.26k
  QualType ConvTy =
1378
7.26k
      S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1379
1380
7.26k
  SourceLocation Loc = IntroducerRange.getBegin();
1381
7.26k
  DeclarationName ConversionName
1382
7.26k
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1383
7.26k
        S.Context.getCanonicalType(PtrToFunctionTy));
1384
  // Construct a TypeSourceInfo for the conversion function, and wire
1385
  // all the parameters appropriately for the FunctionProtoTypeLoc
1386
  // so that everything works during transformation/instantiation of
1387
  // generic lambdas.
1388
  // The main reason for wiring up the parameters of the conversion
1389
  // function with that of the call operator is so that constructs
1390
  // like the following work:
1391
  // auto L = [](auto b) {                <-- 1
1392
  //   return [](auto a) -> decltype(a) { <-- 2
1393
  //      return a;
1394
  //   };
1395
  // };
1396
  // int (*fp)(int) = L(5);
1397
  // Because the trailing return type can contain DeclRefExprs that refer
1398
  // to the original call operator's variables, we hijack the call
1399
  // operators ParmVarDecls below.
1400
7.26k
  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1401
7.26k
      S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1402
7.26k
  DeclarationNameLoc ConvNameLoc =
1403
7.26k
      DeclarationNameLoc::makeNamedTypeLoc(ConvNamePtrToFunctionTSI);
1404
1405
  // The conversion function is a conversion to a pointer-to-function.
1406
7.26k
  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1407
7.26k
  FunctionProtoTypeLoc ConvTL =
1408
7.26k
      ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1409
  // Get the result of the conversion function which is a pointer-to-function.
1410
7.26k
  PointerTypeLoc PtrToFunctionTL =
1411
7.26k
      ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1412
  // Do the same for the TypeSourceInfo that is used to name the conversion
1413
  // operator.
1414
7.26k
  PointerTypeLoc ConvNamePtrToFunctionTL =
1415
7.26k
      ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1416
1417
  // Get the underlying function types that the conversion function will
1418
  // be converting to (should match the type of the call operator).
1419
7.26k
  FunctionProtoTypeLoc CallOpConvTL =
1420
7.26k
      PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1421
7.26k
  FunctionProtoTypeLoc CallOpConvNameTL =
1422
7.26k
    ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1423
1424
  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1425
  // These parameter's are essentially used to transform the name and
1426
  // the type of the conversion operator.  By using the same parameters
1427
  // as the call operator's we don't have to fix any back references that
1428
  // the trailing return type of the call operator's uses (such as
1429
  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1430
  // - we can simply use the return type of the call operator, and
1431
  // everything should work.
1432
7.26k
  SmallVector<ParmVarDecl *, 4> InvokerParams;
1433
14.4k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I7.22k
) {
1434
7.22k
    ParmVarDecl *From = CallOperator->getParamDecl(I);
1435
1436
7.22k
    InvokerParams.push_back(ParmVarDecl::Create(
1437
7.22k
        S.Context,
1438
        // Temporarily add to the TU. This is set to the invoker below.
1439
7.22k
        S.Context.getTranslationUnitDecl(), From->getBeginLoc(),
1440
7.22k
        From->getLocation(), From->getIdentifier(), From->getType(),
1441
7.22k
        From->getTypeSourceInfo(), From->getStorageClass(),
1442
7.22k
        /*DefArg=*/nullptr));
1443
7.22k
    CallOpConvTL.setParam(I, From);
1444
7.22k
    CallOpConvNameTL.setParam(I, From);
1445
7.22k
  }
1446
1447
7.26k
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1448
7.26k
      S.Context, Class, Loc,
1449
7.26k
      DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1450
7.26k
      S.getCurFPFeatures().isFPConstrained(),
1451
7.26k
      /*isInline=*/true, ExplicitSpecifier(),
1452
7.26k
      S.getLangOpts().CPlusPlus17 ? 
ConstexprSpecKind::Constexpr1.53k
1453
7.26k
                                  : 
ConstexprSpecKind::Unspecified5.73k
,
1454
7.26k
      CallOperator->getBody()->getEndLoc());
1455
7.26k
  Conversion->setAccess(AS_public);
1456
7.26k
  Conversion->setImplicit(true);
1457
1458
7.26k
  if (Class->isGenericLambda()) {
1459
    // Create a template version of the conversion operator, using the template
1460
    // parameter list of the function call operator.
1461
3.78k
    FunctionTemplateDecl *TemplateCallOperator =
1462
3.78k
            CallOperator->getDescribedFunctionTemplate();
1463
3.78k
    FunctionTemplateDecl *ConversionTemplate =
1464
3.78k
                  FunctionTemplateDecl::Create(S.Context, Class,
1465
3.78k
                                      Loc, ConversionName,
1466
3.78k
                                      TemplateCallOperator->getTemplateParameters(),
1467
3.78k
                                      Conversion);
1468
3.78k
    ConversionTemplate->setAccess(AS_public);
1469
3.78k
    ConversionTemplate->setImplicit(true);
1470
3.78k
    Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1471
3.78k
    Class->addDecl(ConversionTemplate);
1472
3.78k
  } else
1473
3.48k
    Class->addDecl(Conversion);
1474
  // Add a non-static member function that will be the result of
1475
  // the conversion with a certain unique ID.
1476
7.26k
  DeclarationName InvokerName = &S.Context.Idents.get(
1477
7.26k
                                                 getLambdaStaticInvokerName());
1478
  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1479
  // we should get a prebuilt TrivialTypeSourceInfo from Context
1480
  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1481
  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1482
  // loop below and then use its Params to set Invoke->setParams(...) below.
1483
  // This would avoid the 'const' qualifier of the calloperator from
1484
  // contaminating the type of the invoker, which is currently adjusted
1485
  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments.  Fixing the
1486
  // trailing return type of the invoker would require a visitor to rebuild
1487
  // the trailing return type and adjusting all back DeclRefExpr's to refer
1488
  // to the new static invoker parameters - not the call operator's.
1489
7.26k
  CXXMethodDecl *Invoke = CXXMethodDecl::Create(
1490
7.26k
      S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1491
7.26k
      InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1492
7.26k
      S.getCurFPFeatures().isFPConstrained(),
1493
7.26k
      /*isInline=*/true, ConstexprSpecKind::Unspecified,
1494
7.26k
      CallOperator->getBody()->getEndLoc());
1495
14.4k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I7.22k
)
1496
7.22k
    InvokerParams[I]->setOwningFunction(Invoke);
1497
7.26k
  Invoke->setParams(InvokerParams);
1498
7.26k
  Invoke->setAccess(AS_private);
1499
7.26k
  Invoke->setImplicit(true);
1500
7.26k
  if (Class->isGenericLambda()) {
1501
3.78k
    FunctionTemplateDecl *TemplateCallOperator =
1502
3.78k
            CallOperator->getDescribedFunctionTemplate();
1503
3.78k
    FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1504
3.78k
                          S.Context, Class, Loc, InvokerName,
1505
3.78k
                          TemplateCallOperator->getTemplateParameters(),
1506
3.78k
                          Invoke);
1507
3.78k
    StaticInvokerTemplate->setAccess(AS_private);
1508
3.78k
    StaticInvokerTemplate->setImplicit(true);
1509
3.78k
    Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1510
3.78k
    Class->addDecl(StaticInvokerTemplate);
1511
3.78k
  } else
1512
3.48k
    Class->addDecl(Invoke);
1513
7.26k
}
1514
1515
/// Add a lambda's conversion to function pointers, as described in
1516
/// C++11 [expr.prim.lambda]p6. Note that in most cases, this should emit only a
1517
/// single pointer conversion. In the event that the default calling convention
1518
/// for free and member functions is different, it will emit both conventions.
1519
static void addFunctionPointerConversions(Sema &S, SourceRange IntroducerRange,
1520
                                          CXXRecordDecl *Class,
1521
5.57k
                                          CXXMethodDecl *CallOperator) {
1522
5.57k
  const FunctionProtoType *CallOpProto =
1523
5.57k
      CallOperator->getType()->castAs<FunctionProtoType>();
1524
1525
5.57k
  repeatForLambdaConversionFunctionCallingConvs(
1526
7.27k
      S, *CallOpProto, [&](CallingConv CC) {
1527
7.27k
        QualType InvokerFunctionTy =
1528
7.27k
            S.getLambdaConversionFunctionResultType(CallOpProto, CC);
1529
7.27k
        addFunctionPointerConversion(S, IntroducerRange, Class, CallOperator,
1530
7.27k
                                     InvokerFunctionTy);
1531
7.27k
      });
1532
5.57k
}
1533
1534
/// Add a lambda's conversion to block pointer.
1535
static void addBlockPointerConversion(Sema &S,
1536
                                      SourceRange IntroducerRange,
1537
                                      CXXRecordDecl *Class,
1538
162
                                      CXXMethodDecl *CallOperator) {
1539
162
  const FunctionProtoType *CallOpProto =
1540
162
      CallOperator->getType()->castAs<FunctionProtoType>();
1541
162
  QualType FunctionTy = S.getLambdaConversionFunctionResultType(
1542
162
      CallOpProto, getLambdaConversionFunctionCallConv(S, CallOpProto));
1543
162
  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1544
1545
162
  FunctionProtoType::ExtProtoInfo ConversionEPI(
1546
162
      S.Context.getDefaultCallingConvention(
1547
162
          /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1548
162
  ConversionEPI.TypeQuals = Qualifiers();
1549
162
  ConversionEPI.TypeQuals.addConst();
1550
162
  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1551
1552
162
  SourceLocation Loc = IntroducerRange.getBegin();
1553
162
  DeclarationName Name
1554
162
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1555
162
        S.Context.getCanonicalType(BlockPtrTy));
1556
162
  DeclarationNameLoc NameLoc = DeclarationNameLoc::makeNamedTypeLoc(
1557
162
      S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc));
1558
162
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1559
162
      S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1560
162
      S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1561
162
      S.getCurFPFeatures().isFPConstrained(),
1562
162
      /*isInline=*/true, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
1563
162
      CallOperator->getBody()->getEndLoc());
1564
162
  Conversion->setAccess(AS_public);
1565
162
  Conversion->setImplicit(true);
1566
162
  Class->addDecl(Conversion);
1567
162
}
1568
1569
ExprResult Sema::BuildCaptureInit(const Capture &Cap,
1570
                                  SourceLocation ImplicitCaptureLoc,
1571
396k
                                  bool IsOpenMPMapping) {
1572
  // VLA captures don't have a stored initialization expression.
1573
396k
  if (Cap.isVLATypeCapture())
1574
8.94k
    return ExprResult();
1575
1576
  // An init-capture is initialized directly from its stored initializer.
1577
387k
  if (Cap.isInitCapture())
1578
533
    return Cap.getVariable()->getInit();
1579
1580
  // For anything else, build an initialization expression. For an implicit
1581
  // capture, the capture notionally happens at the capture-default, so use
1582
  // that location here.
1583
387k
  SourceLocation Loc =
1584
387k
      ImplicitCaptureLoc.isValid() ? 
ImplicitCaptureLoc385k
:
Cap.getLocation()1.54k
;
1585
1586
  // C++11 [expr.prim.lambda]p21:
1587
  //   When the lambda-expression is evaluated, the entities that
1588
  //   are captured by copy are used to direct-initialize each
1589
  //   corresponding non-static data member of the resulting closure
1590
  //   object. (For array members, the array elements are
1591
  //   direct-initialized in increasing subscript order.) These
1592
  //   initializations are performed in the (unspecified) order in
1593
  //   which the non-static data members are declared.
1594
1595
  // C++ [expr.prim.lambda]p12:
1596
  //   An entity captured by a lambda-expression is odr-used (3.2) in
1597
  //   the scope containing the lambda-expression.
1598
387k
  ExprResult Init;
1599
387k
  IdentifierInfo *Name = nullptr;
1600
387k
  if (Cap.isThisCapture()) {
1601
11.3k
    QualType ThisTy = getCurrentThisType();
1602
11.3k
    Expr *This = BuildCXXThisExpr(Loc, ThisTy, ImplicitCaptureLoc.isValid());
1603
11.3k
    if (Cap.isCopyCapture())
1604
137
      Init = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
1605
11.1k
    else
1606
11.1k
      Init = This;
1607
376k
  } else {
1608
376k
    assert(Cap.isVariableCapture() && "unknown kind of capture");
1609
0
    VarDecl *Var = Cap.getVariable();
1610
376k
    Name = Var->getIdentifier();
1611
376k
    Init = BuildDeclarationNameExpr(
1612
376k
      CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1613
376k
  }
1614
1615
  // In OpenMP, the capture kind doesn't actually describe how to capture:
1616
  // variables are "mapped" onto the device in a process that does not formally
1617
  // make a copy, even for a "copy capture".
1618
387k
  if (IsOpenMPMapping)
1619
381k
    return Init;
1620
1621
5.67k
  if (Init.isInvalid())
1622
0
    return ExprError();
1623
1624
5.67k
  Expr *InitExpr = Init.get();
1625
5.67k
  InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture(
1626
5.67k
      Name, Cap.getCaptureType(), Loc);
1627
5.67k
  InitializationKind InitKind =
1628
5.67k
      InitializationKind::CreateDirect(Loc, Loc, Loc);
1629
5.67k
  InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr);
1630
5.67k
  return InitSeq.Perform(*this, Entity, InitKind, InitExpr);
1631
5.67k
}
1632
1633
ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
1634
7.96k
                                 Scope *CurScope) {
1635
7.96k
  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1636
7.96k
  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1637
7.96k
  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1638
7.96k
}
1639
1640
static LambdaCaptureDefault
1641
10.4k
mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS) {
1642
10.4k
  switch (ICS) {
1643
7.13k
  case CapturingScopeInfo::ImpCap_None:
1644
7.13k
    return LCD_None;
1645
1.30k
  case CapturingScopeInfo::ImpCap_LambdaByval:
1646
1.30k
    return LCD_ByCopy;
1647
0
  case CapturingScopeInfo::ImpCap_CapturedRegion:
1648
2.04k
  case CapturingScopeInfo::ImpCap_LambdaByref:
1649
2.04k
    return LCD_ByRef;
1650
0
  case CapturingScopeInfo::ImpCap_Block:
1651
0
    llvm_unreachable("block capture in lambda");
1652
10.4k
  }
1653
0
  llvm_unreachable("Unknown implicit capture style");
1654
0
}
1655
1656
717
bool Sema::CaptureHasSideEffects(const Capture &From) {
1657
717
  if (From.isInitCapture()) {
1658
211
    Expr *Init = From.getVariable()->getInit();
1659
211
    if (Init && Init->HasSideEffects(Context))
1660
54
      return true;
1661
211
  }
1662
1663
663
  if (!From.isCopyCapture())
1664
168
    return false;
1665
1666
495
  const QualType T = From.isThisCapture()
1667
495
                         ? 
getCurrentThisType()->getPointeeType()42
1668
495
                         : 
From.getCaptureType()453
;
1669
1670
495
  if (T.isVolatileQualified())
1671
2
    return true;
1672
1673
493
  const Type *BaseT = T->getBaseElementTypeUnsafe();
1674
493
  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1675
102
    return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1676
102
           
!RD->hasTrivialDestructor()70
;
1677
1678
391
  return false;
1679
493
}
1680
1681
bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
1682
717
                                       const Capture &From) {
1683
717
  if (CaptureHasSideEffects(From))
1684
95
    return false;
1685
1686
622
  if (From.isVLATypeCapture())
1687
22
    return false;
1688
1689
600
  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1690
600
  if (From.isThisCapture())
1691
85
    diag << "'this'";
1692
515
  else
1693
515
    diag << From.getVariable();
1694
600
  diag << From.isNonODRUsed();
1695
600
  diag << FixItHint::CreateRemoval(CaptureRange);
1696
600
  return true;
1697
622
}
1698
1699
/// Create a field within the lambda class or captured statement record for the
1700
/// given capture.
1701
FieldDecl *Sema::BuildCaptureField(RecordDecl *RD,
1702
396k
                                   const sema::Capture &Capture) {
1703
396k
  SourceLocation Loc = Capture.getLocation();
1704
396k
  QualType FieldType = Capture.getCaptureType();
1705
1706
396k
  TypeSourceInfo *TSI = nullptr;
1707
396k
  if (Capture.isVariableCapture()) {
1708
376k
    auto *Var = Capture.getVariable();
1709
376k
    if (Var->isInitCapture())
1710
580
      TSI = Capture.getVariable()->getTypeSourceInfo();
1711
376k
  }
1712
1713
  // FIXME: Should we really be doing this? A null TypeSourceInfo seems more
1714
  // appropriate, at least for an implicit capture.
1715
396k
  if (!TSI)
1716
396k
    TSI = Context.getTrivialTypeSourceInfo(FieldType, Loc);
1717
1718
  // Build the non-static data member.
1719
396k
  FieldDecl *Field =
1720
396k
      FieldDecl::Create(Context, RD, /*StartLoc=*/Loc, /*IdLoc=*/Loc,
1721
396k
                        /*Id=*/nullptr, FieldType, TSI, /*BW=*/nullptr,
1722
396k
                        /*Mutable=*/false, ICIS_NoInit);
1723
  // If the variable being captured has an invalid type, mark the class as
1724
  // invalid as well.
1725
396k
  if (!FieldType->isDependentType()) {
1726
392k
    if (RequireCompleteSizedType(Loc, FieldType,
1727
392k
                                 diag::err_field_incomplete_or_sizeless)) {
1728
3
      RD->setInvalidDecl();
1729
3
      Field->setInvalidDecl();
1730
392k
    } else {
1731
392k
      NamedDecl *Def;
1732
392k
      FieldType->isIncompleteType(&Def);
1733
392k
      if (Def && 
Def->isInvalidDecl()317
) {
1734
2
        RD->setInvalidDecl();
1735
2
        Field->setInvalidDecl();
1736
2
      }
1737
392k
    }
1738
392k
  }
1739
396k
  Field->setImplicit(true);
1740
396k
  Field->setAccess(AS_private);
1741
396k
  RD->addDecl(Field);
1742
1743
396k
  if (Capture.isVLATypeCapture())
1744
8.94k
    Field->setCapturedVLAType(Capture.getCapturedVLAType());
1745
1746
396k
  return Field;
1747
396k
}
1748
1749
ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
1750
10.4k
                                 LambdaScopeInfo *LSI) {
1751
  // Collect information from the lambda scope.
1752
10.4k
  SmallVector<LambdaCapture, 4> Captures;
1753
10.4k
  SmallVector<Expr *, 4> CaptureInits;
1754
10.4k
  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1755
10.4k
  LambdaCaptureDefault CaptureDefault =
1756
10.4k
      mapImplicitCaptureStyle(LSI->ImpCaptureStyle);
1757
10.4k
  CXXRecordDecl *Class;
1758
10.4k
  CXXMethodDecl *CallOperator;
1759
10.4k
  SourceRange IntroducerRange;
1760
10.4k
  bool ExplicitParams;
1761
10.4k
  bool ExplicitResultType;
1762
10.4k
  CleanupInfo LambdaCleanup;
1763
10.4k
  bool ContainsUnexpandedParameterPack;
1764
10.4k
  bool IsGenericLambda;
1765
10.4k
  {
1766
10.4k
    CallOperator = LSI->CallOperator;
1767
10.4k
    Class = LSI->Lambda;
1768
10.4k
    IntroducerRange = LSI->IntroducerRange;
1769
10.4k
    ExplicitParams = LSI->ExplicitParams;
1770
10.4k
    ExplicitResultType = !LSI->HasImplicitReturnType;
1771
10.4k
    LambdaCleanup = LSI->Cleanup;
1772
10.4k
    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1773
10.4k
    IsGenericLambda = Class->isGenericLambda();
1774
1775
10.4k
    CallOperator->setLexicalDeclContext(Class);
1776
10.4k
    Decl *TemplateOrNonTemplateCallOperatorDecl =
1777
10.4k
        CallOperator->getDescribedFunctionTemplate()
1778
10.4k
        ? 
CallOperator->getDescribedFunctionTemplate()3.59k
1779
10.4k
        : 
cast<Decl>(CallOperator)6.89k
;
1780
1781
    // FIXME: Is this really the best choice? Keeping the lexical decl context
1782
    // set as CurContext seems more faithful to the source.
1783
10.4k
    TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1784
1785
10.4k
    PopExpressionEvaluationContext();
1786
1787
    // True if the current capture has a used capture or default before it.
1788
10.4k
    bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1789
10.4k
    SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1790
7.13k
        
CaptureDefaultLoc3.35k
: IntroducerRange.getBegin();
1791
1792
16.4k
    for (unsigned I = 0, N = LSI->Captures.size(); I != N; 
++I5.98k
) {
1793
6.00k
      const Capture &From = LSI->Captures[I];
1794
1795
6.00k
      if (From.isInvalid())
1796
24
        return ExprError();
1797
1798
5.98k
      assert(!From.isBlockCapture() && "Cannot capture __block variables");
1799
0
      bool IsImplicit = I >= LSI->NumExplicitCaptures;
1800
5.98k
      SourceLocation ImplicitCaptureLoc =
1801
5.98k
          IsImplicit ? 
CaptureDefaultLoc3.96k
:
SourceLocation()2.02k
;
1802
1803
      // Use source ranges of explicit captures for fixits where available.
1804
5.98k
      SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1805
1806
      // Warn about unused explicit captures.
1807
5.98k
      bool IsCaptureUsed = true;
1808
5.98k
      if (!CurContext->isDependentContext() && 
!IsImplicit5.41k
&&
1809
5.98k
          
!From.isODRUsed()1.58k
) {
1810
        // Initialized captures that are non-ODR used may not be eliminated.
1811
        // FIXME: Where did the IsGenericLambda here come from?
1812
728
        bool NonODRUsedInitCapture =
1813
728
            IsGenericLambda && 
From.isNonODRUsed()39
&&
From.isInitCapture()12
;
1814
728
        if (!NonODRUsedInitCapture) {
1815
717
          bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1816
717
          SourceRange FixItRange;
1817
717
          if (CaptureRange.isValid()) {
1818
550
            if (!CurHasPreviousCapture && 
!IsLast482
) {
1819
              // If there are no captures preceding this capture, remove the
1820
              // following comma.
1821
97
              FixItRange = SourceRange(CaptureRange.getBegin(),
1822
97
                                       getLocForEndOfToken(CaptureRange.getEnd()));
1823
453
            } else {
1824
              // Otherwise, remove the comma since the last used capture.
1825
453
              FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1826
453
                                       CaptureRange.getEnd());
1827
453
            }
1828
550
          }
1829
1830
717
          IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1831
717
        }
1832
728
      }
1833
1834
5.98k
      if (CaptureRange.isValid()) {
1835
1.58k
        CurHasPreviousCapture |= IsCaptureUsed;
1836
1.58k
        PrevCaptureLoc = CaptureRange.getEnd();
1837
1.58k
      }
1838
1839
      // Map the capture to our AST representation.
1840
5.98k
      LambdaCapture Capture = [&] {
1841
5.98k
        if (From.isThisCapture()) {
1842
          // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1843
          // because it results in a reference capture. Don't warn prior to
1844
          // C++2a; there's nothing that can be done about it before then.
1845
824
          if (getLangOpts().CPlusPlus20 && 
IsImplicit76
&&
1846
824
              
CaptureDefault == LCD_ByCopy48
) {
1847
41
            Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1848
41
            Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1849
41
                << FixItHint::CreateInsertion(
1850
41
                       getLocForEndOfToken(CaptureDefaultLoc), ", this");
1851
41
          }
1852
824
          return LambdaCapture(From.getLocation(), IsImplicit,
1853
824
                               From.isCopyCapture() ? 
LCK_StarThis137
:
LCK_This687
);
1854
5.15k
        } else if (From.isVLATypeCapture()) {
1855
50
          return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType);
1856
5.10k
        } else {
1857
5.10k
          assert(From.isVariableCapture() && "unknown kind of capture");
1858
0
          VarDecl *Var = From.getVariable();
1859
5.10k
          LambdaCaptureKind Kind =
1860
5.10k
              From.isCopyCapture() ? 
LCK_ByCopy1.85k
:
LCK_ByRef3.25k
;
1861
5.10k
          return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var,
1862
5.10k
                               From.getEllipsisLoc());
1863
5.10k
        }
1864
5.98k
      }();
1865
1866
      // Form the initializer for the capture field.
1867
5.98k
      ExprResult Init = BuildCaptureInit(From, ImplicitCaptureLoc);
1868
1869
      // FIXME: Skip this capture if the capture is not used, the initializer
1870
      // has no side-effects, the type of the capture is trivial, and the
1871
      // lambda is not externally visible.
1872
1873
      // Add a FieldDecl for the capture and form its initializer.
1874
5.98k
      BuildCaptureField(Class, From);
1875
5.98k
      Captures.push_back(Capture);
1876
5.98k
      CaptureInits.push_back(Init.get());
1877
1878
5.98k
      if (LangOpts.CUDA)
1879
98
        CUDACheckLambdaCapture(CallOperator, From);
1880
5.98k
    }
1881
1882
10.4k
    Class->setCaptures(Context, Captures);
1883
1884
    // C++11 [expr.prim.lambda]p6:
1885
    //   The closure type for a lambda-expression with no lambda-capture
1886
    //   has a public non-virtual non-explicit const conversion function
1887
    //   to pointer to function having the same parameter and return
1888
    //   types as the closure type's function call operator.
1889
10.4k
    if (Captures.empty() && 
CaptureDefault == LCD_None6.71k
)
1890
5.57k
      addFunctionPointerConversions(*this, IntroducerRange, Class,
1891
5.57k
                                    CallOperator);
1892
1893
    // Objective-C++:
1894
    //   The closure type for a lambda-expression has a public non-virtual
1895
    //   non-explicit const conversion function to a block pointer having the
1896
    //   same parameter and return types as the closure type's function call
1897
    //   operator.
1898
    // FIXME: Fix generic lambda to block conversions.
1899
10.4k
    if (getLangOpts().Blocks && 
getLangOpts().ObjC5.62k
&&
!IsGenericLambda171
)
1900
162
      addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1901
1902
    // Finalize the lambda class.
1903
10.4k
    SmallVector<Decl*, 4> Fields(Class->fields());
1904
10.4k
    ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1905
10.4k
                SourceLocation(), ParsedAttributesView());
1906
10.4k
    CheckCompletedCXXClass(nullptr, Class);
1907
10.4k
  }
1908
1909
0
  Cleanup.mergeFrom(LambdaCleanup);
1910
1911
10.4k
  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1912
10.4k
                                          CaptureDefault, CaptureDefaultLoc,
1913
10.4k
                                          ExplicitParams, ExplicitResultType,
1914
10.4k
                                          CaptureInits, EndLoc,
1915
10.4k
                                          ContainsUnexpandedParameterPack);
1916
  // If the lambda expression's call operator is not explicitly marked constexpr
1917
  // and we are not in a dependent context, analyze the call operator to infer
1918
  // its constexpr-ness, suppressing diagnostics while doing so.
1919
10.4k
  if (getLangOpts().CPlusPlus17 && 
!CallOperator->isInvalidDecl()3.00k
&&
1920
10.4k
      
!CallOperator->isConstexpr()2.99k
&&
1921
10.4k
      
!isa<CoroutineBodyStmt>(CallOperator->getBody())2.85k
&&
1922
10.4k
      
!Class->getDeclContext()->isDependentContext()2.80k
) {
1923
2.04k
    CallOperator->setConstexprKind(
1924
2.04k
        CheckConstexprFunctionDefinition(CallOperator,
1925
2.04k
                                         CheckConstexprKind::CheckValid)
1926
2.04k
            ? 
ConstexprSpecKind::Constexpr2.00k
1927
2.04k
            : 
ConstexprSpecKind::Unspecified39
);
1928
2.04k
  }
1929
1930
  // Emit delayed shadowing warnings now that the full capture list is known.
1931
10.4k
  DiagnoseShadowingLambdaDecls(LSI);
1932
1933
10.4k
  if (!CurContext->isDependentContext()) {
1934
7.97k
    switch (ExprEvalContexts.back().Context) {
1935
    // C++11 [expr.prim.lambda]p2:
1936
    //   A lambda-expression shall not appear in an unevaluated operand
1937
    //   (Clause 5).
1938
28
    case ExpressionEvaluationContext::Unevaluated:
1939
28
    case ExpressionEvaluationContext::UnevaluatedList:
1940
28
    case ExpressionEvaluationContext::UnevaluatedAbstract:
1941
    // C++1y [expr.const]p2:
1942
    //   A conditional-expression e is a core constant expression unless the
1943
    //   evaluation of e, following the rules of the abstract machine, would
1944
    //   evaluate [...] a lambda-expression.
1945
    //
1946
    // This is technically incorrect, there are some constant evaluated contexts
1947
    // where this should be allowed.  We should probably fix this when DR1607 is
1948
    // ratified, it lays out the exact set of conditions where we shouldn't
1949
    // allow a lambda-expression.
1950
209
    case ExpressionEvaluationContext::ConstantEvaluated:
1951
209
    case ExpressionEvaluationContext::ImmediateFunctionContext:
1952
      // We don't actually diagnose this case immediately, because we
1953
      // could be within a context where we might find out later that
1954
      // the expression is potentially evaluated (e.g., for typeid).
1955
209
      ExprEvalContexts.back().Lambdas.push_back(Lambda);
1956
209
      break;
1957
1958
0
    case ExpressionEvaluationContext::DiscardedStatement:
1959
7.48k
    case ExpressionEvaluationContext::PotentiallyEvaluated:
1960
7.76k
    case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1961
7.76k
      break;
1962
7.97k
    }
1963
7.97k
  }
1964
1965
10.4k
  return MaybeBindToTemporary(Lambda);
1966
10.4k
}
1967
1968
ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
1969
                                               SourceLocation ConvLocation,
1970
                                               CXXConversionDecl *Conv,
1971
31
                                               Expr *Src) {
1972
  // Make sure that the lambda call operator is marked used.
1973
31
  CXXRecordDecl *Lambda = Conv->getParent();
1974
31
  CXXMethodDecl *CallOperator
1975
31
    = cast<CXXMethodDecl>(
1976
31
        Lambda->lookup(
1977
31
          Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1978
31
  CallOperator->setReferenced();
1979
31
  CallOperator->markUsed(Context);
1980
1981
31
  ExprResult Init = PerformCopyInitialization(
1982
31
      InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType()),
1983
31
      CurrentLocation, Src);
1984
31
  if (!Init.isInvalid())
1985
31
    Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1986
1987
31
  if (Init.isInvalid())
1988
0
    return ExprError();
1989
1990
  // Create the new block to be returned.
1991
31
  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1992
1993
  // Set the type information.
1994
31
  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1995
31
  Block->setIsVariadic(CallOperator->isVariadic());
1996
31
  Block->setBlockMissingReturnType(false);
1997
1998
  // Add parameters.
1999
31
  SmallVector<ParmVarDecl *, 4> BlockParams;
2000
42
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I11
) {
2001
11
    ParmVarDecl *From = CallOperator->getParamDecl(I);
2002
11
    BlockParams.push_back(ParmVarDecl::Create(
2003
11
        Context, Block, From->getBeginLoc(), From->getLocation(),
2004
11
        From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
2005
11
        From->getStorageClass(),
2006
11
        /*DefArg=*/nullptr));
2007
11
  }
2008
31
  Block->setParams(BlockParams);
2009
2010
31
  Block->setIsConversionFromLambda(true);
2011
2012
  // Add capture. The capture uses a fake variable, which doesn't correspond
2013
  // to any actual memory location. However, the initializer copy-initializes
2014
  // the lambda object.
2015
31
  TypeSourceInfo *CapVarTSI =
2016
31
      Context.getTrivialTypeSourceInfo(Src->getType());
2017
31
  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
2018
31
                                    ConvLocation, nullptr,
2019
31
                                    Src->getType(), CapVarTSI,
2020
31
                                    SC_None);
2021
31
  BlockDecl::Capture Capture(/*variable=*/CapVar, /*byRef=*/false,
2022
31
                             /*nested=*/false, /*copy=*/Init.get());
2023
31
  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
2024
2025
  // Add a fake function body to the block. IR generation is responsible
2026
  // for filling in the actual body, which cannot be expressed as an AST.
2027
31
  Block->setBody(new (Context) CompoundStmt(ConvLocation));
2028
2029
  // Create the block literal expression.
2030
31
  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
2031
31
  ExprCleanupObjects.push_back(Block);
2032
31
  Cleanup.setExprNeedsCleanups(true);
2033
2034
31
  return BuildBlock;
2035
31
}