Coverage Report

Created: 2021-01-26 06:56

/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
//
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//===----------------------------------------------------------------------===//
8
//
9
//  This file implements semantic analysis for C++ lambda expressions.
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//
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//===----------------------------------------------------------------------===//
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#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
989
    VarDecl *VarToCapture) {
66
  // Label failure to capture.
67
989
  const Optional<unsigned> NoLambdaIsCaptureReady;
68
69
  // Ignore all inner captured regions.
70
989
  unsigned CurScopeIndex = FunctionScopes.size() - 1;
71
994
  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
72
994
                                  FunctionScopes[CurScopeIndex]))
73
5
    --CurScopeIndex;
74
989
  assert(
75
989
      isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
76
989
      "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
989
  const bool IsCapturingThis = !VarToCapture;
80
989
  const bool IsCapturingVariable = !IsCapturingThis;
81
82
  // Start with the current lambda at the top of the stack (highest index).
83
989
  DeclContext *EnclosingDC =
84
989
      cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
85
86
1.57k
  do {
87
1.57k
    const clang::sema::LambdaScopeInfo *LSI =
88
1.57k
        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
1.57k
    if (IsCapturingVariable &&
97
1.41k
        VarToCapture->getDeclContext()->Equals(EnclosingDC))
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
1.35k
    if (LSI->ImpCaptureStyle == sema::LambdaScopeInfo::ImpCap_None) {
117
304
      if (IsCapturingVariable && 
!LSI->isCaptured(VarToCapture)252
)
118
173
        return NoLambdaIsCaptureReady;
119
131
      if (IsCapturingThis && 
!LSI->isCXXThisCaptured()52
)
120
48
        return NoLambdaIsCaptureReady;
121
1.13k
    }
122
1.13k
    EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
123
124
1.13k
    assert(CurScopeIndex);
125
1.13k
    --CurScopeIndex;
126
1.13k
  } while (!EnclosingDC->isTranslationUnit() &&
127
1.13k
           EnclosingDC->isDependentContext() &&
128
745
           isLambdaCallOperator(EnclosingDC));
129
130
549
  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
549
  if (!EnclosingDC->isDependentContext())
134
390
    return CurScopeIndex + 1;
135
159
  return NoLambdaIsCaptureReady;
136
159
}
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
989
    VarDecl *VarToCapture, Sema &S) {
176
177
989
  const Optional<unsigned> NoLambdaIsCaptureCapable;
178
179
989
  const Optional<unsigned> OptionalStackIndex =
180
989
      getStackIndexOfNearestEnclosingCaptureReadyLambda(FunctionScopes,
181
989
                                                        VarToCapture);
182
989
  if (!OptionalStackIndex)
183
599
    return NoLambdaIsCaptureCapable;
184
185
390
  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
186
390
  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
187
390
          S.getCurGenericLambda()) &&
188
390
         "The capture ready lambda for a potential capture can only be the "
189
390
         "current lambda if it is a generic lambda");
190
191
390
  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
192
390
      cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
193
194
  // If VarToCapture is null, we are attempting to capture 'this'
195
390
  const bool IsCapturingThis = !VarToCapture;
196
390
  const bool IsCapturingVariable = !IsCapturingThis;
197
198
390
  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
370
    QualType CaptureType, DeclRefType;
203
370
    const bool CanCaptureVariable =
204
370
        !S.tryCaptureVariable(VarToCapture,
205
370
                              /*ExprVarIsUsedInLoc*/ SourceLocation(),
206
370
                              clang::Sema::TryCapture_Implicit,
207
370
                              /*EllipsisLoc*/ SourceLocation(),
208
370
                              /*BuildAndDiagnose*/ false, CaptureType,
209
370
                              DeclRefType, &IndexOfCaptureReadyLambda);
210
370
    if (!CanCaptureVariable)
211
28
      return NoLambdaIsCaptureCapable;
212
20
  } 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
358
  }
224
358
  return IndexOfCaptureReadyLambda;
225
358
}
226
227
static inline TemplateParameterList *
228
19.3k
getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) {
229
19.3k
  if (!LSI->GLTemplateParameterList && 
!LSI->TemplateParams.empty()14.6k
) {
230
2.01k
    LSI->GLTemplateParameterList = TemplateParameterList::Create(
231
2.01k
        SemaRef.Context,
232
2.01k
        /*Template kw loc*/ SourceLocation(),
233
2.01k
        /*L angle loc*/ LSI->ExplicitTemplateParamsRange.getBegin(),
234
2.01k
        LSI->TemplateParams,
235
2.01k
        /*R angle loc*/LSI->ExplicitTemplateParamsRange.getEnd(),
236
2.01k
        LSI->RequiresClause.get());
237
2.01k
  }
238
19.3k
  return LSI->GLTemplateParameterList;
239
19.3k
}
240
241
CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange,
242
                                             TypeSourceInfo *Info,
243
                                             bool KnownDependent,
244
9.68k
                                             LambdaCaptureDefault CaptureDefault) {
245
9.68k
  DeclContext *DC = CurContext;
246
9.70k
  while (!(DC->isFunctionOrMethod() || 
DC->isRecord()1.45k
||
DC->isFileContext()923
))
247
19
    DC = DC->getParent();
248
9.68k
  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
249
9.68k
                                                               *this);
250
  // Start constructing the lambda class.
251
9.68k
  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
252
9.68k
                                                     IntroducerRange.getBegin(),
253
9.68k
                                                     KnownDependent,
254
9.68k
                                                     IsGenericLambda,
255
9.68k
                                                     CaptureDefault);
256
9.68k
  DC->addDecl(Class);
257
258
9.68k
  return Class;
259
9.68k
}
260
261
/// Determine whether the given context is or is enclosed in an inline
262
/// function.
263
1.01M
static bool isInInlineFunction(const DeclContext *DC) {
264
1.40M
  while (!DC->isFileContext()) {
265
398k
    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
266
20.5k
      if (FD->isInlined())
267
7.87k
        return true;
268
269
390k
    DC = DC->getLexicalParent();
270
390k
  }
271
272
1.00M
  return false;
273
1.01M
}
274
275
std::tuple<MangleNumberingContext *, Decl *>
276
1.02M
Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
277
  // Compute the context for allocating mangling numbers in the current
278
  // expression, if the ABI requires them.
279
1.02M
  Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
280
281
1.02M
  enum ContextKind {
282
1.02M
    Normal,
283
1.02M
    DefaultArgument,
284
1.02M
    DataMember,
285
1.02M
    StaticDataMember,
286
1.02M
    InlineVariable,
287
1.02M
    VariableTemplate
288
1.02M
  } 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
1.02M
  if (ManglingContextDecl) {
294
2.50k
    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
295
790
      if (const DeclContext *LexicalDC
296
212
          = Param->getDeclContext()->getLexicalParent())
297
212
        if (LexicalDC->isRecord())
298
153
          Kind = DefaultArgument;
299
1.71k
    } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
300
1.49k
      if (Var->getDeclContext()->isRecord())
301
21
        Kind = StaticDataMember;
302
1.47k
      else if (Var->getMostRecentDecl()->isInline())
303
8
        Kind = InlineVariable;
304
1.47k
      else if (Var->getDescribedVarTemplate())
305
17
        Kind = VariableTemplate;
306
1.45k
      else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
307
7
        if (!VTS->isExplicitSpecialization())
308
7
          Kind = VariableTemplate;
309
7
      }
310
217
    } else if (isa<FieldDecl>(ManglingContextDecl)) {
311
217
      Kind = DataMember;
312
217
    }
313
2.50k
  }
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
1.02M
  bool IsInNonspecializedTemplate =
319
1.02M
      inTemplateInstantiation() || 
CurContext->isDependentContext()1.02M
;
320
1.02M
  switch (Kind) {
321
1.02M
  case Normal: {
322
    //  -- the bodies of non-exported nonspecialized template functions
323
    //  -- the bodies of inline functions
324
1.02M
    if ((IsInNonspecializedTemplate &&
325
15.5k
         !(ManglingContextDecl && 
isa<ParmVarDecl>(ManglingContextDecl)963
)) ||
326
1.01M
        isInInlineFunction(CurContext)) {
327
25.3k
      while (auto *CD = dyn_cast<CapturedDecl>(DC))
328
2.03k
        DC = CD->getParent();
329
23.3k
      return std::make_tuple(&Context.getManglingNumberContext(DC), nullptr);
330
23.3k
    }
331
332
1.00M
    return std::make_tuple(nullptr, nullptr);
333
1.00M
  }
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
19
    LLVM_FALLTHROUGH;
341
342
236
  case DataMember:
343
    //  -- the in-class initializers of class members
344
389
  case DefaultArgument:
345
    //  -- default arguments appearing in class definitions
346
397
  case InlineVariable:
347
    //  -- the initializers of inline variables
348
421
  case VariableTemplate:
349
    //  -- the initializers of templated variables
350
421
    return std::make_tuple(
351
421
        &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl,
352
421
                                          ManglingContextDecl),
353
421
        ManglingContextDecl);
354
0
  }
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
9.68k
                                           Expr *TrailingRequiresClause) {
366
9.68k
  QualType MethodType = MethodTypeInfo->getType();
367
9.68k
  TemplateParameterList *TemplateParams =
368
9.68k
      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
9.68k
  if (Class->isDependentContext() || 
TemplateParams7.21k
) {
373
4.65k
    const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
374
4.65k
    QualType Result = FPT->getReturnType();
375
4.65k
    if (Result->isUndeducedType()) {
376
3.28k
      Result = SubstAutoType(Result, Context.DependentTy);
377
3.28k
      MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
378
3.28k
                                           FPT->getExtProtoInfo());
379
3.28k
    }
380
4.65k
  }
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
9.68k
  DeclarationName MethodName
388
9.68k
    = Context.DeclarationNames.getCXXOperatorName(OO_Call);
389
9.68k
  DeclarationNameLoc MethodNameLoc;
390
9.68k
  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
391
9.68k
    = IntroducerRange.getBegin().getRawEncoding();
392
9.68k
  MethodNameLoc.CXXOperatorName.EndOpNameLoc
393
9.68k
    = IntroducerRange.getEnd().getRawEncoding();
394
9.68k
  CXXMethodDecl *Method = CXXMethodDecl::Create(
395
9.68k
      Context, Class, EndLoc,
396
9.68k
      DeclarationNameInfo(MethodName, IntroducerRange.getBegin(),
397
9.68k
                          MethodNameLoc),
398
9.68k
      MethodType, MethodTypeInfo, SC_None,
399
9.68k
      /*isInline=*/true, ConstexprKind, EndLoc, TrailingRequiresClause);
400
9.68k
  Method->setAccess(AS_public);
401
9.68k
  if (!TemplateParams)
402
6.29k
    Class->addDecl(Method);
403
404
  // Temporarily set the lexical declaration context to the current
405
  // context, so that the Scope stack matches the lexical nesting.
406
9.68k
  Method->setLexicalDeclContext(CurContext);
407
  // Create a function template if we have a template parameter list
408
9.68k
  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
409
3.38k
            FunctionTemplateDecl::Create(Context, Class,
410
3.38k
                                         Method->getLocation(), MethodName,
411
3.38k
                                         TemplateParams,
412
6.29k
                                         Method) : nullptr;
413
9.68k
  if (TemplateMethod) {
414
3.38k
    TemplateMethod->setAccess(AS_public);
415
3.38k
    Method->setDescribedFunctionTemplate(TemplateMethod);
416
3.38k
    Class->addDecl(TemplateMethod);
417
3.38k
    TemplateMethod->setLexicalDeclContext(CurContext);
418
3.38k
  }
419
420
  // Add parameters.
421
9.68k
  if (!Params.empty()) {
422
5.39k
    Method->setParams(Params);
423
5.39k
    CheckParmsForFunctionDef(Params,
424
5.39k
                             /*CheckParameterNames=*/false);
425
426
5.39k
    for (auto P : Method->parameters())
427
6.51k
      P->setOwningFunction(Method);
428
5.39k
  }
429
430
9.68k
  return Method;
431
9.68k
}
432
433
void Sema::handleLambdaNumbering(
434
    CXXRecordDecl *Class, CXXMethodDecl *Method,
435
9.68k
    Optional<std::tuple<unsigned, bool, Decl *>> Mangling) {
436
9.68k
  if (Mangling) {
437
7
    unsigned ManglingNumber;
438
7
    bool HasKnownInternalLinkage;
439
7
    Decl *ManglingContextDecl;
440
7
    std::tie(ManglingNumber, HasKnownInternalLinkage, ManglingContextDecl) =
441
7
        Mangling.getValue();
442
7
    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
443
7
                             HasKnownInternalLinkage);
444
7
    return;
445
7
  }
446
447
9.67k
  auto getMangleNumberingContext =
448
9.67k
      [this](CXXRecordDecl *Class,
449
138
             Decl *ManglingContextDecl) -> MangleNumberingContext * {
450
    // Get mangle numbering context if there's any extra decl context.
451
138
    if (ManglingContextDecl)
452
0
      return &Context.getManglingNumberContext(
453
0
          ASTContext::NeedExtraManglingDecl, ManglingContextDecl);
454
    // Otherwise, from that lambda's decl context.
455
138
    auto DC = Class->getDeclContext();
456
138
    while (auto *CD = dyn_cast<CapturedDecl>(DC))
457
0
      DC = CD->getParent();
458
138
    return &Context.getManglingNumberContext(DC);
459
138
  };
460
461
9.67k
  MangleNumberingContext *MCtx;
462
9.67k
  Decl *ManglingContextDecl;
463
9.67k
  std::tie(MCtx, ManglingContextDecl) =
464
9.67k
      getCurrentMangleNumberContext(Class->getDeclContext());
465
9.67k
  bool HasKnownInternalLinkage = false;
466
9.67k
  if (!MCtx && 
getLangOpts().CUDA3.80k
) {
467
    // Force lambda numbering in CUDA/HIP as we need to name lambdas following
468
    // ODR. Both device- and host-compilation need to have a consistent naming
469
    // on kernel functions. As lambdas are potential part of these `__global__`
470
    // function names, they needs numbering following ODR.
471
138
    MCtx = getMangleNumberingContext(Class, ManglingContextDecl);
472
138
    assert(MCtx && "Retrieving mangle numbering context failed!");
473
138
    HasKnownInternalLinkage = true;
474
138
  }
475
9.67k
  if (MCtx) {
476
6.01k
    unsigned ManglingNumber = MCtx->getManglingNumber(Method);
477
6.01k
    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
478
6.01k
                             HasKnownInternalLinkage);
479
6.01k
  }
480
9.67k
}
481
482
void Sema::buildLambdaScope(LambdaScopeInfo *LSI,
483
                                        CXXMethodDecl *CallOperator,
484
                                        SourceRange IntroducerRange,
485
                                        LambdaCaptureDefault CaptureDefault,
486
                                        SourceLocation CaptureDefaultLoc,
487
                                        bool ExplicitParams,
488
                                        bool ExplicitResultType,
489
9.68k
                                        bool Mutable) {
490
9.68k
  LSI->CallOperator = CallOperator;
491
9.68k
  CXXRecordDecl *LambdaClass = CallOperator->getParent();
492
9.68k
  LSI->Lambda = LambdaClass;
493
9.68k
  if (CaptureDefault == LCD_ByCopy)
494
1.13k
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
495
8.54k
  else if (CaptureDefault == LCD_ByRef)
496
1.93k
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
497
9.68k
  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
498
9.68k
  LSI->IntroducerRange = IntroducerRange;
499
9.68k
  LSI->ExplicitParams = ExplicitParams;
500
9.68k
  LSI->Mutable = Mutable;
501
502
9.68k
  if (ExplicitResultType) {
503
1.61k
    LSI->ReturnType = CallOperator->getReturnType();
504
505
1.61k
    if (!LSI->ReturnType->isDependentType() &&
506
1.20k
        !LSI->ReturnType->isVoidType()) {
507
730
      if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
508
2
                              diag::err_lambda_incomplete_result)) {
509
        // Do nothing.
510
2
      }
511
730
    }
512
8.07k
  } else {
513
8.07k
    LSI->HasImplicitReturnType = true;
514
8.07k
  }
515
9.68k
}
516
517
9.68k
void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) {
518
9.68k
  LSI->finishedExplicitCaptures();
519
9.68k
}
520
521
void Sema::ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc,
522
                                                    ArrayRef<NamedDecl *> TParams,
523
                                                    SourceLocation RAngleLoc,
524
90
                                                    ExprResult RequiresClause) {
525
90
  LambdaScopeInfo *LSI = getCurLambda();
526
90
  assert(LSI && "Expected a lambda scope");
527
90
  assert(LSI->NumExplicitTemplateParams == 0 &&
528
90
         "Already acted on explicit template parameters");
529
90
  assert(LSI->TemplateParams.empty() &&
530
90
         "Explicit template parameters should come "
531
90
         "before invented (auto) ones");
532
90
  assert(!TParams.empty() &&
533
90
         "No template parameters to act on");
534
90
  LSI->TemplateParams.append(TParams.begin(), TParams.end());
535
90
  LSI->NumExplicitTemplateParams = TParams.size();
536
90
  LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc};
537
90
  LSI->RequiresClause = RequiresClause;
538
90
}
539
540
void Sema::addLambdaParameters(
541
    ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
542
7.21k
    CXXMethodDecl *CallOperator, Scope *CurScope) {
543
  // Introduce our parameters into the function scope
544
7.21k
  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
545
11.1k
       p < NumParams; 
++p3.92k
) {
546
3.92k
    ParmVarDecl *Param = CallOperator->getParamDecl(p);
547
548
    // If this has an identifier, add it to the scope stack.
549
3.92k
    if (CurScope && Param->getIdentifier()) {
550
3.69k
      bool Error = false;
551
      // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
552
      // retroactively apply it.
553
335
      for (const auto &Capture : Captures) {
554
335
        if (Capture.Id == Param->getIdentifier()) {
555
11
          Error = true;
556
11
          Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
557
11
          Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
558
11
              << Capture.Id << true;
559
11
        }
560
335
      }
561
3.69k
      if (!Error)
562
3.68k
        CheckShadow(CurScope, Param);
563
564
3.69k
      PushOnScopeChains(Param, CurScope);
565
3.69k
    }
566
3.92k
  }
567
7.21k
}
568
569
/// If this expression is an enumerator-like expression of some type
570
/// T, return the type T; otherwise, return null.
571
///
572
/// Pointer comparisons on the result here should always work because
573
/// it's derived from either the parent of an EnumConstantDecl
574
/// (i.e. the definition) or the declaration returned by
575
/// EnumType::getDecl() (i.e. the definition).
576
384
static EnumDecl *findEnumForBlockReturn(Expr *E) {
577
  // An expression is an enumerator-like expression of type T if,
578
  // ignoring parens and parens-like expressions:
579
384
  E = E->IgnoreParens();
580
581
  //  - it is an enumerator whose enum type is T or
582
384
  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
583
28
    if (EnumConstantDecl *D
584
28
          = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
585
28
      return cast<EnumDecl>(D->getDeclContext());
586
28
    }
587
0
    return nullptr;
588
0
  }
589
590
  //  - it is a comma expression whose RHS is an enumerator-like
591
  //    expression of type T or
592
356
  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
593
26
    if (BO->getOpcode() == BO_Comma)
594
1
      return findEnumForBlockReturn(BO->getRHS());
595
25
    return nullptr;
596
25
  }
597
598
  //  - it is a statement-expression whose value expression is an
599
  //    enumerator-like expression of type T or
600
330
  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
601
1
    if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
602
1
      return findEnumForBlockReturn(last);
603
0
    return nullptr;
604
0
  }
605
606
  //   - it is a ternary conditional operator (not the GNU ?:
607
  //     extension) whose second and third operands are
608
  //     enumerator-like expressions of type T or
609
329
  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
610
3
    if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
611
3
      if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
612
3
        return ED;
613
0
    return nullptr;
614
0
  }
615
616
  // (implicitly:)
617
  //   - it is an implicit integral conversion applied to an
618
  //     enumerator-like expression of type T or
619
326
  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
620
    // We can sometimes see integral conversions in valid
621
    // enumerator-like expressions.
622
137
    if (ICE->getCastKind() == CK_IntegralCast)
623
3
      return findEnumForBlockReturn(ICE->getSubExpr());
624
625
    // Otherwise, just rely on the type.
626
137
  }
627
628
  //   - it is an expression of that formal enum type.
629
323
  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
630
15
    return ET->getDecl();
631
15
  }
632
633
  // Otherwise, nope.
634
308
  return nullptr;
635
308
}
636
637
/// Attempt to find a type T for which the returned expression of the
638
/// given statement is an enumerator-like expression of that type.
639
464
static EnumDecl *findEnumForBlockReturn(ReturnStmt *ret) {
640
464
  if (Expr *retValue = ret->getRetValue())
641
373
    return findEnumForBlockReturn(retValue);
642
91
  return nullptr;
643
91
}
644
645
/// Attempt to find a common type T for which all of the returned
646
/// expressions in a block are enumerator-like expressions of that
647
/// type.
648
449
static EnumDecl *findCommonEnumForBlockReturns(ArrayRef<ReturnStmt*> returns) {
649
449
  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
650
651
  // Try to find one for the first return.
652
449
  EnumDecl *ED = findEnumForBlockReturn(*i);
653
449
  if (!ED) 
return nullptr422
;
654
655
  // Check that the rest of the returns have the same enum.
656
40
  
for (++i; 27
i != e;
++i13
) {
657
15
    if (findEnumForBlockReturn(*i) != ED)
658
2
      return nullptr;
659
15
  }
660
661
  // Never infer an anonymous enum type.
662
25
  if (!ED->hasNameForLinkage()) 
return nullptr3
;
663
664
22
  return ED;
665
22
}
666
667
/// Adjust the given return statements so that they formally return
668
/// the given type.  It should require, at most, an IntegralCast.
669
static void adjustBlockReturnsToEnum(Sema &S, ArrayRef<ReturnStmt*> returns,
670
22
                                     QualType returnType) {
671
22
  for (ArrayRef<ReturnStmt*>::iterator
672
57
         i = returns.begin(), e = returns.end(); i != e; 
++i35
) {
673
35
    ReturnStmt *ret = *i;
674
35
    Expr *retValue = ret->getRetValue();
675
35
    if (S.Context.hasSameType(retValue->getType(), returnType))
676
14
      continue;
677
678
    // Right now we only support integral fixup casts.
679
21
    assert(returnType->isIntegralOrUnscopedEnumerationType());
680
21
    assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
681
682
21
    ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
683
684
21
    Expr *E = (cleanups ? 
cleanups->getSubExpr()0
: retValue);
685
21
    E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast, E,
686
21
                                 /*base path*/ nullptr, VK_RValue,
687
21
                                 FPOptionsOverride());
688
21
    if (cleanups) {
689
0
      cleanups->setSubExpr(E);
690
21
    } else {
691
21
      ret->setRetValue(E);
692
21
    }
693
21
  }
694
22
}
695
696
4.99k
void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) {
697
4.99k
  assert(CSI.HasImplicitReturnType);
698
  // If it was ever a placeholder, it had to been deduced to DependentTy.
699
4.99k
  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
700
4.99k
  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
701
4.99k
         "lambda expressions use auto deduction in C++14 onwards");
702
703
  // C++ core issue 975:
704
  //   If a lambda-expression does not include a trailing-return-type,
705
  //   it is as if the trailing-return-type denotes the following type:
706
  //     - if there are no return statements in the compound-statement,
707
  //       or all return statements return either an expression of type
708
  //       void or no expression or braced-init-list, the type void;
709
  //     - otherwise, if all return statements return an expression
710
  //       and the types of the returned expressions after
711
  //       lvalue-to-rvalue conversion (4.1 [conv.lval]),
712
  //       array-to-pointer conversion (4.2 [conv.array]), and
713
  //       function-to-pointer conversion (4.3 [conv.func]) are the
714
  //       same, that common type;
715
  //     - otherwise, the program is ill-formed.
716
  //
717
  // C++ core issue 1048 additionally removes top-level cv-qualifiers
718
  // from the types of returned expressions to match the C++14 auto
719
  // deduction rules.
720
  //
721
  // In addition, in blocks in non-C++ modes, if all of the return
722
  // statements are enumerator-like expressions of some type T, where
723
  // T has a name for linkage, then we infer the return type of the
724
  // block to be that type.
725
726
  // First case: no return statements, implicit void return type.
727
4.99k
  ASTContext &Ctx = getASTContext();
728
4.99k
  if (CSI.Returns.empty()) {
729
    // It's possible there were simply no /valid/ return statements.
730
    // In this case, the first one we found may have at least given us a type.
731
3.99k
    if (CSI.ReturnType.isNull())
732
3.99k
      CSI.ReturnType = Ctx.VoidTy;
733
3.99k
    return;
734
3.99k
  }
735
736
  // Second case: at least one return statement has dependent type.
737
  // Delay type checking until instantiation.
738
1.00k
  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
739
1.00k
  if (CSI.ReturnType->isDependentType())
740
70
    return;
741
742
  // Try to apply the enum-fuzz rule.
743
931
  if (!getLangOpts().CPlusPlus) {
744
449
    assert(isa<BlockScopeInfo>(CSI));
745
449
    const EnumDecl *ED = findCommonEnumForBlockReturns(CSI.Returns);
746
449
    if (ED) {
747
22
      CSI.ReturnType = Context.getTypeDeclType(ED);
748
22
      adjustBlockReturnsToEnum(*this, CSI.Returns, CSI.ReturnType);
749
22
      return;
750
22
    }
751
909
  }
752
753
  // Third case: only one return statement. Don't bother doing extra work!
754
909
  if (CSI.Returns.size() == 1)
755
866
    return;
756
757
  // General case: many return statements.
758
  // Check that they all have compatible return types.
759
760
  // We require the return types to strictly match here.
761
  // Note that we've already done the required promotions as part of
762
  // processing the return statement.
763
111
  
for (const ReturnStmt *RS : CSI.Returns)43
{
764
111
    const Expr *RetE = RS->getRetValue();
765
766
111
    QualType ReturnType =
767
106
        (RetE ? RetE->getType() : 
Context.VoidTy5
).getUnqualifiedType();
768
111
    if (Context.getCanonicalFunctionResultType(ReturnType) ==
769
102
          Context.getCanonicalFunctionResultType(CSI.ReturnType)) {
770
      // Use the return type with the strictest possible nullability annotation.
771
102
      auto RetTyNullability = ReturnType->getNullability(Ctx);
772
102
      auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
773
102
      if (BlockNullability &&
774
4
          (!RetTyNullability ||
775
2
           hasWeakerNullability(*RetTyNullability, *BlockNullability)))
776
2
        CSI.ReturnType = ReturnType;
777
102
      continue;
778
102
    }
779
780
    // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
781
    // TODO: It's possible that the *first* return is the divergent one.
782
9
    Diag(RS->getBeginLoc(),
783
9
         diag::err_typecheck_missing_return_type_incompatible)
784
9
        << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
785
    // Continue iterating so that we keep emitting diagnostics.
786
9
  }
787
43
}
788
789
QualType Sema::buildLambdaInitCaptureInitialization(
790
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
791
    Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool IsDirectInit,
792
525
    Expr *&Init) {
793
  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
794
  // deduce against.
795
525
  QualType DeductType = Context.getAutoDeductType();
796
525
  TypeLocBuilder TLB;
797
525
  AutoTypeLoc TL = TLB.push<AutoTypeLoc>(DeductType);
798
525
  TL.setNameLoc(Loc);
799
525
  if (ByRef) {
800
109
    DeductType = BuildReferenceType(DeductType, true, Loc, Id);
801
109
    assert(!DeductType.isNull() && "can't build reference to auto");
802
109
    TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
803
109
  }
804
525
  if (EllipsisLoc.isValid()) {
805
64
    if (Init->containsUnexpandedParameterPack()) {
806
63
      Diag(EllipsisLoc, getLangOpts().CPlusPlus20
807
32
                            ? diag::warn_cxx17_compat_init_capture_pack
808
31
                            : diag::ext_init_capture_pack);
809
63
      DeductType = Context.getPackExpansionType(DeductType, NumExpansions,
810
63
                                                /*ExpectPackInType=*/false);
811
63
      TLB.push<PackExpansionTypeLoc>(DeductType).setEllipsisLoc(EllipsisLoc);
812
1
    } else {
813
      // Just ignore the ellipsis for now and form a non-pack variable. We'll
814
      // diagnose this later when we try to capture it.
815
1
    }
816
64
  }
817
525
  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
818
819
  // Deduce the type of the init capture.
820
525
  QualType DeducedType = deduceVarTypeFromInitializer(
821
525
      /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
822
525
      SourceRange(Loc, Loc), IsDirectInit, Init);
823
525
  if (DeducedType.isNull())
824
36
    return QualType();
825
826
  // Are we a non-list direct initialization?
827
489
  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
828
829
  // Perform initialization analysis and ensure any implicit conversions
830
  // (such as lvalue-to-rvalue) are enforced.
831
489
  InitializedEntity Entity =
832
489
      InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
833
489
  InitializationKind Kind =
834
489
      IsDirectInit
835
155
          ? (CXXDirectInit ? InitializationKind::CreateDirect(
836
136
                                 Loc, Init->getBeginLoc(), Init->getEndLoc())
837
19
                           : InitializationKind::CreateDirectList(Loc))
838
334
          : InitializationKind::CreateCopy(Loc, Init->getBeginLoc());
839
840
489
  MultiExprArg Args = Init;
841
489
  if (CXXDirectInit)
842
136
    Args =
843
136
        MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
844
489
  QualType DclT;
845
489
  InitializationSequence InitSeq(*this, Entity, Kind, Args);
846
489
  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
847
848
489
  if (Result.isInvalid())
849
4
    return QualType();
850
851
485
  Init = Result.getAs<Expr>();
852
485
  return DeducedType;
853
485
}
854
855
VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
856
                                              QualType InitCaptureType,
857
                                              SourceLocation EllipsisLoc,
858
                                              IdentifierInfo *Id,
859
483
                                              unsigned InitStyle, Expr *Init) {
860
  // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization
861
  // rather than reconstructing it here.
862
483
  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType, Loc);
863
483
  if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>())
864
61
    PETL.setEllipsisLoc(EllipsisLoc);
865
866
  // Create a dummy variable representing the init-capture. This is not actually
867
  // used as a variable, and only exists as a way to name and refer to the
868
  // init-capture.
869
  // FIXME: Pass in separate source locations for '&' and identifier.
870
483
  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
871
483
                                   Loc, Id, InitCaptureType, TSI, SC_Auto);
872
483
  NewVD->setInitCapture(true);
873
483
  NewVD->setReferenced(true);
874
  // FIXME: Pass in a VarDecl::InitializationStyle.
875
483
  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
876
483
  NewVD->markUsed(Context);
877
483
  NewVD->setInit(Init);
878
483
  if (NewVD->isParameterPack())
879
61
    getCurLambda()->LocalPacks.push_back(NewVD);
880
483
  return NewVD;
881
483
}
882
883
481
void Sema::addInitCapture(LambdaScopeInfo *LSI, VarDecl *Var) {
884
481
  assert(Var->isInitCapture() && "init capture flag should be set");
885
481
  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
886
481
                  /*isNested*/false, Var->getLocation(), SourceLocation(),
887
481
                  Var->getType(), /*Invalid*/false);
888
481
}
889
890
void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
891
                                        Declarator &ParamInfo,
892
7.21k
                                        Scope *CurScope) {
893
7.21k
  LambdaScopeInfo *const LSI = getCurLambda();
894
7.21k
  assert(LSI && "LambdaScopeInfo should be on stack!");
895
896
  // Determine if we're within a context where we know that the lambda will
897
  // be dependent, because there are template parameters in scope.
898
7.21k
  bool KnownDependent;
899
7.21k
  if (LSI->NumExplicitTemplateParams > 0) {
900
90
    auto *TemplateParamScope = CurScope->getTemplateParamParent();
901
90
    assert(TemplateParamScope &&
902
90
           "Lambda with explicit template param list should establish a "
903
90
           "template param scope");
904
90
    assert(TemplateParamScope->getParent());
905
90
    KnownDependent = TemplateParamScope->getParent()
906
90
                                       ->getTemplateParamParent() != nullptr;
907
7.12k
  } else {
908
7.12k
    KnownDependent = CurScope->getTemplateParamParent() != nullptr;
909
7.12k
  }
910
911
  // Determine the signature of the call operator.
912
7.21k
  TypeSourceInfo *MethodTyInfo;
913
7.21k
  bool ExplicitParams = true;
914
7.21k
  bool ExplicitResultType = true;
915
7.21k
  bool ContainsUnexpandedParameterPack = false;
916
7.21k
  SourceLocation EndLoc;
917
7.21k
  SmallVector<ParmVarDecl *, 8> Params;
918
7.21k
  if (ParamInfo.getNumTypeObjects() == 0) {
919
    // C++11 [expr.prim.lambda]p4:
920
    //   If a lambda-expression does not include a lambda-declarator, it is as
921
    //   if the lambda-declarator were ().
922
1.51k
    FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
923
1.51k
        /*IsVariadic=*/false, /*IsCXXMethod=*/true));
924
1.51k
    EPI.HasTrailingReturn = true;
925
1.51k
    EPI.TypeQuals.addConst();
926
1.51k
    LangAS AS = getDefaultCXXMethodAddrSpace();
927
1.51k
    if (AS != LangAS::Default)
928
2
      EPI.TypeQuals.addAddressSpace(AS);
929
930
    // C++1y [expr.prim.lambda]:
931
    //   The lambda return type is 'auto', which is replaced by the
932
    //   trailing-return type if provided and/or deduced from 'return'
933
    //   statements
934
    // We don't do this before C++1y, because we don't support deduced return
935
    // types there.
936
1.51k
    QualType DefaultTypeForNoTrailingReturn =
937
997
        getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
938
518
                                  : Context.DependentTy;
939
1.51k
    QualType MethodTy =
940
1.51k
        Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
941
1.51k
    MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
942
1.51k
    ExplicitParams = false;
943
1.51k
    ExplicitResultType = false;
944
1.51k
    EndLoc = Intro.Range.getEnd();
945
5.70k
  } else {
946
5.70k
    assert(ParamInfo.isFunctionDeclarator() &&
947
5.70k
           "lambda-declarator is a function");
948
5.70k
    DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo();
949
950
    // C++11 [expr.prim.lambda]p5:
951
    //   This function call operator is declared const (9.3.1) if and only if
952
    //   the lambda-expression's parameter-declaration-clause is not followed
953
    //   by mutable. It is neither virtual nor declared volatile. [...]
954
5.70k
    if (!FTI.hasMutableQualifier()) {
955
5.54k
      FTI.getOrCreateMethodQualifiers().SetTypeQual(DeclSpec::TQ_const,
956
5.54k
                                                    SourceLocation());
957
5.54k
    }
958
959
5.70k
    MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
960
5.70k
    assert(MethodTyInfo && "no type from lambda-declarator");
961
5.70k
    EndLoc = ParamInfo.getSourceRange().getEnd();
962
963
5.70k
    ExplicitResultType = FTI.hasTrailingReturnType();
964
965
5.70k
    if (FTIHasNonVoidParameters(FTI)) {
966
3.40k
      Params.reserve(FTI.NumParams);
967
7.33k
      for (unsigned i = 0, e = FTI.NumParams; i != e; 
++i3.92k
)
968
3.92k
        Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
969
3.40k
    }
970
971
    // Check for unexpanded parameter packs in the method type.
972
5.70k
    if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
973
47
      DiagnoseUnexpandedParameterPack(Intro.Range.getBegin(), MethodTyInfo,
974
47
                                      UPPC_DeclarationType);
975
5.70k
  }
976
977
7.21k
  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
978
7.21k
                                                 KnownDependent, Intro.Default);
979
7.21k
  CXXMethodDecl *Method =
980
7.21k
      startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
981
7.21k
                            ParamInfo.getDeclSpec().getConstexprSpecifier(),
982
7.21k
                            ParamInfo.getTrailingRequiresClause());
983
7.21k
  if (ExplicitParams)
984
5.70k
    CheckCXXDefaultArguments(Method);
985
986
  // This represents the function body for the lambda function, check if we
987
  // have to apply optnone due to a pragma.
988
7.21k
  AddRangeBasedOptnone(Method);
989
990
  // code_seg attribute on lambda apply to the method.
991
7.21k
  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
992
2
    Method->addAttr(A);
993
994
  // Attributes on the lambda apply to the method.
995
7.21k
  ProcessDeclAttributes(CurScope, Method, ParamInfo);
996
997
  // CUDA lambdas get implicit host and device attributes.
998
7.21k
  if (getLangOpts().CUDA)
999
164
    CUDASetLambdaAttrs(Method);
1000
1001
  // OpenMP lambdas might get assumumption attributes.
1002
7.21k
  if (LangOpts.OpenMP)
1003
1.30k
    ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Method);
1004
1005
  // Number the lambda for linkage purposes if necessary.
1006
7.21k
  handleLambdaNumbering(Class, Method);
1007
1008
  // Introduce the function call operator as the current declaration context.
1009
7.21k
  PushDeclContext(CurScope, Method);
1010
1011
  // Build the lambda scope.
1012
7.21k
  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
1013
7.21k
                   ExplicitParams, ExplicitResultType, !Method->isConst());
1014
1015
  // C++11 [expr.prim.lambda]p9:
1016
  //   A lambda-expression whose smallest enclosing scope is a block scope is a
1017
  //   local lambda expression; any other lambda expression shall not have a
1018
  //   capture-default or simple-capture in its lambda-introducer.
1019
  //
1020
  // For simple-captures, this is covered by the check below that any named
1021
  // entity is a variable that can be captured.
1022
  //
1023
  // For DR1632, we also allow a capture-default in any context where we can
1024
  // odr-use 'this' (in particular, in a default initializer for a non-static
1025
  // data member).
1026
7.21k
  if (Intro.Default != LCD_None && 
!Class->getParent()->isFunctionOrMethod()2.53k
&&
1027
37
      (getCurrentThisType().isNull() ||
1028
29
       CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
1029
29
                           /*BuildAndDiagnose*/false)))
1030
8
    Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
1031
1032
  // Distinct capture names, for diagnostics.
1033
7.21k
  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
1034
1035
  // Handle explicit captures.
1036
7.21k
  SourceLocation PrevCaptureLoc
1037
4.68k
    = Intro.Default == LCD_None? Intro.Range.getBegin() : 
Intro.DefaultLoc2.53k
;
1038
8.71k
  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
1039
1.49k
       PrevCaptureLoc = C->Loc, ++C) {
1040
1.49k
    if (C->Kind == LCK_This || 
C->Kind == LCK_StarThis1.26k
) {
1041
343
      if (C->Kind == LCK_StarThis)
1042
112
        Diag(C->Loc, !getLangOpts().CPlusPlus17
1043
2
                             ? diag::ext_star_this_lambda_capture_cxx17
1044
110
                             : diag::warn_cxx14_compat_star_this_lambda_capture);
1045
1046
      // C++11 [expr.prim.lambda]p8:
1047
      //   An identifier or this shall not appear more than once in a
1048
      //   lambda-capture.
1049
343
      if (LSI->isCXXThisCaptured()) {
1050
5
        Diag(C->Loc, diag::err_capture_more_than_once)
1051
5
            << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
1052
5
            << FixItHint::CreateRemoval(
1053
5
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1054
5
        continue;
1055
5
      }
1056
1057
      // C++2a [expr.prim.lambda]p8:
1058
      //  If a lambda-capture includes a capture-default that is =,
1059
      //  each simple-capture of that lambda-capture shall be of the form
1060
      //  "&identifier", "this", or "* this". [ Note: The form [&,this] is
1061
      //  redundant but accepted for compatibility with ISO C++14. --end note ]
1062
338
      if (Intro.Default == LCD_ByCopy && 
C->Kind != LCK_StarThis9
)
1063
5
        Diag(C->Loc, !getLangOpts().CPlusPlus20
1064
3
                         ? diag::ext_equals_this_lambda_capture_cxx20
1065
2
                         : diag::warn_cxx17_compat_equals_this_lambda_capture);
1066
1067
      // C++11 [expr.prim.lambda]p12:
1068
      //   If this is captured by a local lambda expression, its nearest
1069
      //   enclosing function shall be a non-static member function.
1070
338
      QualType ThisCaptureType = getCurrentThisType();
1071
338
      if (ThisCaptureType.isNull()) {
1072
5
        Diag(C->Loc, diag::err_this_capture) << true;
1073
5
        continue;
1074
5
      }
1075
1076
333
      CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1077
333
                          /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1078
333
                          C->Kind == LCK_StarThis);
1079
333
      if (!LSI->Captures.empty())
1080
331
        LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1081
333
      continue;
1082
333
    }
1083
1084
1.15k
    assert(C->Id && "missing identifier for capture");
1085
1086
1.15k
    if (C->Init.isInvalid())
1087
7
      continue;
1088
1089
1.14k
    VarDecl *Var = nullptr;
1090
1.14k
    if (C->Init.isUsable()) {
1091
390
      Diag(C->Loc, getLangOpts().CPlusPlus14
1092
339
                       ? diag::warn_cxx11_compat_init_capture
1093
51
                       : diag::ext_init_capture);
1094
1095
      // If the initializer expression is usable, but the InitCaptureType
1096
      // is not, then an error has occurred - so ignore the capture for now.
1097
      // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1098
      // FIXME: we should create the init capture variable and mark it invalid
1099
      // in this case.
1100
390
      if (C->InitCaptureType.get().isNull())
1101
32
        continue;
1102
1103
358
      if (C->Init.get()->containsUnexpandedParameterPack() &&
1104
77
          !C->InitCaptureType.get()->getAs<PackExpansionType>())
1105
16
        DiagnoseUnexpandedParameterPack(C->Init.get(), UPPC_Initializer);
1106
1107
358
      unsigned InitStyle;
1108
358
      switch (C->InitKind) {
1109
0
      case LambdaCaptureInitKind::NoInit:
1110
0
        llvm_unreachable("not an init-capture?");
1111
250
      case LambdaCaptureInitKind::CopyInit:
1112
250
        InitStyle = VarDecl::CInit;
1113
250
        break;
1114
90
      case LambdaCaptureInitKind::DirectInit:
1115
90
        InitStyle = VarDecl::CallInit;
1116
90
        break;
1117
18
      case LambdaCaptureInitKind::ListInit:
1118
18
        InitStyle = VarDecl::ListInit;
1119
18
        break;
1120
358
      }
1121
358
      Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1122
358
                                           C->EllipsisLoc, C->Id, InitStyle,
1123
358
                                           C->Init.get());
1124
      // C++1y [expr.prim.lambda]p11:
1125
      //   An init-capture behaves as if it declares and explicitly
1126
      //   captures a variable [...] whose declarative region is the
1127
      //   lambda-expression's compound-statement
1128
358
      if (Var)
1129
358
        PushOnScopeChains(Var, CurScope, false);
1130
758
    } else {
1131
758
      assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1132
758
             "init capture has valid but null init?");
1133
1134
      // C++11 [expr.prim.lambda]p8:
1135
      //   If a lambda-capture includes a capture-default that is &, the
1136
      //   identifiers in the lambda-capture shall not be preceded by &.
1137
      //   If a lambda-capture includes a capture-default that is =, [...]
1138
      //   each identifier it contains shall be preceded by &.
1139
758
      if (C->Kind == LCK_ByRef && 
Intro.Default == LCD_ByRef225
) {
1140
7
        Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1141
7
            << FixItHint::CreateRemoval(
1142
7
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1143
7
        continue;
1144
751
      } else if (C->Kind == LCK_ByCopy && 
Intro.Default == LCD_ByCopy533
) {
1145
1
        Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1146
1
            << FixItHint::CreateRemoval(
1147
1
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1148
1
        continue;
1149
1
      }
1150
1151
      // C++11 [expr.prim.lambda]p10:
1152
      //   The identifiers in a capture-list are looked up using the usual
1153
      //   rules for unqualified name lookup (3.4.1)
1154
750
      DeclarationNameInfo Name(C->Id, C->Loc);
1155
750
      LookupResult R(*this, Name, LookupOrdinaryName);
1156
750
      LookupName(R, CurScope);
1157
750
      if (R.isAmbiguous())
1158
1
        continue;
1159
749
      if (R.empty()) {
1160
        // FIXME: Disable corrections that would add qualification?
1161
1
        CXXScopeSpec ScopeSpec;
1162
1
        DeclFilterCCC<VarDecl> Validator{};
1163
1
        if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1164
0
          continue;
1165
749
      }
1166
1167
749
      Var = R.getAsSingle<VarDecl>();
1168
749
      if (Var && 
DiagnoseUseOfDecl(Var, C->Loc)743
)
1169
2
        continue;
1170
1.10k
    }
1171
1172
    // C++11 [expr.prim.lambda]p8:
1173
    //   An identifier or this shall not appear more than once in a
1174
    //   lambda-capture.
1175
1.10k
    if (!CaptureNames.insert(C->Id).second) {
1176
9
      if (Var && LSI->isCaptured(Var)) {
1177
7
        Diag(C->Loc, diag::err_capture_more_than_once)
1178
7
            << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1179
7
            << FixItHint::CreateRemoval(
1180
7
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1181
7
      } else
1182
        // Previous capture captured something different (one or both was
1183
        // an init-cpature): no fixit.
1184
2
        Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1185
9
      continue;
1186
9
    }
1187
1188
    // C++11 [expr.prim.lambda]p10:
1189
    //   [...] each such lookup shall find a variable with automatic storage
1190
    //   duration declared in the reaching scope of the local lambda expression.
1191
    // Note that the 'reaching scope' check happens in tryCaptureVariable().
1192
1.09k
    if (!Var) {
1193
6
      Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1194
6
      continue;
1195
6
    }
1196
1197
    // Ignore invalid decls; they'll just confuse the code later.
1198
1.09k
    if (Var->isInvalidDecl())
1199
4
      continue;
1200
1201
1.08k
    if (!Var->hasLocalStorage()) {
1202
2
      Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1203
2
      Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1204
2
      continue;
1205
2
    }
1206
1207
    // C++11 [expr.prim.lambda]p23:
1208
    //   A capture followed by an ellipsis is a pack expansion (14.5.3).
1209
1.08k
    SourceLocation EllipsisLoc;
1210
1.08k
    if (C->EllipsisLoc.isValid()) {
1211
142
      if (Var->isParameterPack()) {
1212
138
        EllipsisLoc = C->EllipsisLoc;
1213
4
      } else {
1214
4
        Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1215
1
            << (C->Init.isUsable() ? C->Init.get()->getSourceRange()
1216
3
                                   : SourceRange(C->Loc));
1217
1218
        // Just ignore the ellipsis.
1219
4
      }
1220
942
    } else if (Var->isParameterPack()) {
1221
13
      ContainsUnexpandedParameterPack = true;
1222
13
    }
1223
1224
1.08k
    if (C->Init.isUsable()) {
1225
356
      addInitCapture(LSI, Var);
1226
728
    } else {
1227
213
      TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1228
515
                                                   TryCapture_ExplicitByVal;
1229
728
      tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1230
728
    }
1231
1.08k
    if (!LSI->Captures.empty())
1232
1.07k
      LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1233
1.08k
  }
1234
7.21k
  finishLambdaExplicitCaptures(LSI);
1235
1236
7.21k
  LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
1237
1238
  // Add lambda parameters into scope.
1239
7.21k
  addLambdaParameters(Intro.Captures, Method, CurScope);
1240
1241
  // Enter a new evaluation context to insulate the lambda from any
1242
  // cleanups from the enclosing full-expression.
1243
7.21k
  PushExpressionEvaluationContext(
1244
7.21k
      LSI->CallOperator->isConsteval()
1245
4
          ? ExpressionEvaluationContext::ConstantEvaluated
1246
7.21k
          : ExpressionEvaluationContext::PotentiallyEvaluated);
1247
7.21k
}
1248
1249
void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
1250
195
                            bool IsInstantiation) {
1251
195
  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1252
1253
  // Leave the expression-evaluation context.
1254
195
  DiscardCleanupsInEvaluationContext();
1255
195
  PopExpressionEvaluationContext();
1256
1257
  // Leave the context of the lambda.
1258
195
  if (!IsInstantiation)
1259
176
    PopDeclContext();
1260
1261
  // Finalize the lambda.
1262
195
  CXXRecordDecl *Class = LSI->Lambda;
1263
195
  Class->setInvalidDecl();
1264
195
  SmallVector<Decl*, 4> Fields(Class->fields());
1265
195
  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1266
195
              SourceLocation(), ParsedAttributesView());
1267
195
  CheckCompletedCXXClass(nullptr, Class);
1268
1269
195
  PopFunctionScopeInfo();
1270
195
}
1271
1272
template <typename Func>
1273
static void repeatForLambdaConversionFunctionCallingConvs(
1274
5.02k
    Sema &S, const FunctionProtoType &CallOpProto, Func F) {
1275
5.02k
  CallingConv DefaultFree = S.Context.getDefaultCallingConvention(
1276
5.02k
      CallOpProto.isVariadic(), /*IsCXXMethod=*/false);
1277
5.02k
  CallingConv DefaultMember = S.Context.getDefaultCallingConvention(
1278
5.02k
      CallOpProto.isVariadic(), /*IsCXXMethod=*/true);
1279
5.02k
  CallingConv CallOpCC = CallOpProto.getCallConv();
1280
1281
  /// Implement emitting a version of the operator for many of the calling
1282
  /// conventions for MSVC, as described here:
1283
  /// https://devblogs.microsoft.com/oldnewthing/20150220-00/?p=44623.
1284
  /// Experimentally, we determined that cdecl, stdcall, fastcall, and
1285
  /// vectorcall are generated by MSVC when it is supported by the target.
1286
  /// Additionally, we are ensuring that the default-free/default-member and
1287
  /// call-operator calling convention are generated as well.
1288
  /// NOTE: We intentionally generate a 'thiscall' on Win32 implicitly from the
1289
  /// 'member default', despite MSVC not doing so. We do this in order to ensure
1290
  /// that someone who intentionally places 'thiscall' on the lambda call
1291
  /// operator will still get that overload, since we don't have the a way of
1292
  /// detecting the attribute by the time we get here.
1293
5.02k
  if (S.getLangOpts().MSVCCompat) {
1294
70
    CallingConv Convs[] = {
1295
70
        CC_C,        CC_X86StdCall, CC_X86FastCall, CC_X86VectorCall,
1296
70
        DefaultFree, DefaultMember, CallOpCC};
1297
70
    llvm::sort(Convs);
1298
70
    llvm::iterator_range<CallingConv *> Range(
1299
70
        std::begin(Convs), std::unique(std::begin(Convs), std::end(Convs)));
1300
70
    const TargetInfo &TI = S.getASTContext().getTargetInfo();
1301
1302
282
    for (CallingConv C : Range) {
1303
282
      if (TI.checkCallingConvention(C) == TargetInfo::CCCR_OK)
1304
146
        F(C);
1305
282
    }
1306
70
    return;
1307
70
  }
1308
1309
4.95k
  if (CallOpCC == DefaultMember && 
DefaultMember != DefaultFree4.93k
) {
1310
1.60k
    F(DefaultFree);
1311
1.60k
    F(DefaultMember);
1312
3.35k
  } else {
1313
3.35k
    F(CallOpCC);
1314
3.35k
  }
1315
4.95k
}
1316
1317
// Returns the 'standard' calling convention to be used for the lambda
1318
// conversion function, that is, the 'free' function calling convention unless
1319
// it is overridden by a non-default calling convention attribute.
1320
static CallingConv
1321
getLambdaConversionFunctionCallConv(Sema &S,
1322
159
                                    const FunctionProtoType *CallOpProto) {
1323
159
  CallingConv DefaultFree = S.Context.getDefaultCallingConvention(
1324
159
      CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1325
159
  CallingConv DefaultMember = S.Context.getDefaultCallingConvention(
1326
159
      CallOpProto->isVariadic(), /*IsCXXMethod=*/true);
1327
159
  CallingConv CallOpCC = CallOpProto->getCallConv();
1328
1329
  // If the call-operator hasn't been changed, return both the 'free' and
1330
  // 'member' function calling convention.
1331
159
  if (CallOpCC == DefaultMember && DefaultMember != DefaultFree)
1332
0
    return DefaultFree;
1333
159
  return CallOpCC;
1334
159
}
1335
1336
QualType Sema::getLambdaConversionFunctionResultType(
1337
7.25k
    const FunctionProtoType *CallOpProto, CallingConv CC) {
1338
7.25k
  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1339
7.25k
      CallOpProto->getExtProtoInfo();
1340
7.25k
  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1341
7.25k
  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1342
7.25k
  InvokerExtInfo.TypeQuals = Qualifiers();
1343
7.25k
  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1344
7.25k
         "Lambda's call operator should not have a reference qualifier");
1345
7.25k
  return Context.getFunctionType(CallOpProto->getReturnType(),
1346
7.25k
                                 CallOpProto->getParamTypes(), InvokerExtInfo);
1347
7.25k
}
1348
1349
/// Add a lambda's conversion to function pointer, as described in
1350
/// C++11 [expr.prim.lambda]p6.
1351
static void addFunctionPointerConversion(Sema &S, SourceRange IntroducerRange,
1352
                                         CXXRecordDecl *Class,
1353
                                         CXXMethodDecl *CallOperator,
1354
6.70k
                                         QualType InvokerFunctionTy) {
1355
  // This conversion is explicitly disabled if the lambda's function has
1356
  // pass_object_size attributes on any of its parameters.
1357
7.02k
  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1358
7.02k
    return P->hasAttr<PassObjectSizeAttr>();
1359
7.02k
  };
1360
6.70k
  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1361
2
    return;
1362
1363
  // Add the conversion to function pointer.
1364
6.70k
  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1365
1366
  // Create the type of the conversion function.
1367
6.70k
  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1368
6.70k
      S.Context.getDefaultCallingConvention(
1369
6.70k
      /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1370
  // The conversion function is always const and noexcept.
1371
6.70k
  ConvExtInfo.TypeQuals = Qualifiers();
1372
6.70k
  ConvExtInfo.TypeQuals.addConst();
1373
6.70k
  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1374
6.70k
  QualType ConvTy =
1375
6.70k
      S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1376
1377
6.70k
  SourceLocation Loc = IntroducerRange.getBegin();
1378
6.70k
  DeclarationName ConversionName
1379
6.70k
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1380
6.70k
        S.Context.getCanonicalType(PtrToFunctionTy));
1381
6.70k
  DeclarationNameLoc ConvNameLoc;
1382
  // Construct a TypeSourceInfo for the conversion function, and wire
1383
  // all the parameters appropriately for the FunctionProtoTypeLoc
1384
  // so that everything works during transformation/instantiation of
1385
  // generic lambdas.
1386
  // The main reason for wiring up the parameters of the conversion
1387
  // function with that of the call operator is so that constructs
1388
  // like the following work:
1389
  // auto L = [](auto b) {                <-- 1
1390
  //   return [](auto a) -> decltype(a) { <-- 2
1391
  //      return a;
1392
  //   };
1393
  // };
1394
  // int (*fp)(int) = L(5);
1395
  // Because the trailing return type can contain DeclRefExprs that refer
1396
  // to the original call operator's variables, we hijack the call
1397
  // operators ParmVarDecls below.
1398
6.70k
  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1399
6.70k
      S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1400
6.70k
  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1401
1402
  // The conversion function is a conversion to a pointer-to-function.
1403
6.70k
  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1404
6.70k
  FunctionProtoTypeLoc ConvTL =
1405
6.70k
      ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1406
  // Get the result of the conversion function which is a pointer-to-function.
1407
6.70k
  PointerTypeLoc PtrToFunctionTL =
1408
6.70k
      ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1409
  // Do the same for the TypeSourceInfo that is used to name the conversion
1410
  // operator.
1411
6.70k
  PointerTypeLoc ConvNamePtrToFunctionTL =
1412
6.70k
      ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1413
1414
  // Get the underlying function types that the conversion function will
1415
  // be converting to (should match the type of the call operator).
1416
6.70k
  FunctionProtoTypeLoc CallOpConvTL =
1417
6.70k
      PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1418
6.70k
  FunctionProtoTypeLoc CallOpConvNameTL =
1419
6.70k
    ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1420
1421
  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1422
  // These parameter's are essentially used to transform the name and
1423
  // the type of the conversion operator.  By using the same parameters
1424
  // as the call operator's we don't have to fix any back references that
1425
  // the trailing return type of the call operator's uses (such as
1426
  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1427
  // - we can simply use the return type of the call operator, and
1428
  // everything should work.
1429
6.70k
  SmallVector<ParmVarDecl *, 4> InvokerParams;
1430
13.7k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I7.02k
) {
1431
7.02k
    ParmVarDecl *From = CallOperator->getParamDecl(I);
1432
1433
7.02k
    InvokerParams.push_back(ParmVarDecl::Create(
1434
7.02k
        S.Context,
1435
        // Temporarily add to the TU. This is set to the invoker below.
1436
7.02k
        S.Context.getTranslationUnitDecl(), From->getBeginLoc(),
1437
7.02k
        From->getLocation(), From->getIdentifier(), From->getType(),
1438
7.02k
        From->getTypeSourceInfo(), From->getStorageClass(),
1439
7.02k
        /*DefArg=*/nullptr));
1440
7.02k
    CallOpConvTL.setParam(I, From);
1441
7.02k
    CallOpConvNameTL.setParam(I, From);
1442
7.02k
  }
1443
1444
6.70k
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1445
6.70k
      S.Context, Class, Loc,
1446
6.70k
      DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1447
6.70k
      /*isInline=*/true, ExplicitSpecifier(),
1448
1.16k
      S.getLangOpts().CPlusPlus17 ? ConstexprSpecKind::Constexpr
1449
5.54k
                                  : ConstexprSpecKind::Unspecified,
1450
6.70k
      CallOperator->getBody()->getEndLoc());
1451
6.70k
  Conversion->setAccess(AS_public);
1452
6.70k
  Conversion->setImplicit(true);
1453
1454
6.70k
  if (Class->isGenericLambda()) {
1455
    // Create a template version of the conversion operator, using the template
1456
    // parameter list of the function call operator.
1457
3.60k
    FunctionTemplateDecl *TemplateCallOperator =
1458
3.60k
            CallOperator->getDescribedFunctionTemplate();
1459
3.60k
    FunctionTemplateDecl *ConversionTemplate =
1460
3.60k
                  FunctionTemplateDecl::Create(S.Context, Class,
1461
3.60k
                                      Loc, ConversionName,
1462
3.60k
                                      TemplateCallOperator->getTemplateParameters(),
1463
3.60k
                                      Conversion);
1464
3.60k
    ConversionTemplate->setAccess(AS_public);
1465
3.60k
    ConversionTemplate->setImplicit(true);
1466
3.60k
    Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1467
3.60k
    Class->addDecl(ConversionTemplate);
1468
3.60k
  } else
1469
3.09k
    Class->addDecl(Conversion);
1470
  // Add a non-static member function that will be the result of
1471
  // the conversion with a certain unique ID.
1472
6.70k
  DeclarationName InvokerName = &S.Context.Idents.get(
1473
6.70k
                                                 getLambdaStaticInvokerName());
1474
  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1475
  // we should get a prebuilt TrivialTypeSourceInfo from Context
1476
  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1477
  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1478
  // loop below and then use its Params to set Invoke->setParams(...) below.
1479
  // This would avoid the 'const' qualifier of the calloperator from
1480
  // contaminating the type of the invoker, which is currently adjusted
1481
  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments.  Fixing the
1482
  // trailing return type of the invoker would require a visitor to rebuild
1483
  // the trailing return type and adjusting all back DeclRefExpr's to refer
1484
  // to the new static invoker parameters - not the call operator's.
1485
6.70k
  CXXMethodDecl *Invoke = CXXMethodDecl::Create(
1486
6.70k
      S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1487
6.70k
      InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1488
6.70k
      /*isInline=*/true, ConstexprSpecKind::Unspecified,
1489
6.70k
      CallOperator->getBody()->getEndLoc());
1490
13.7k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I7.02k
)
1491
7.02k
    InvokerParams[I]->setOwningFunction(Invoke);
1492
6.70k
  Invoke->setParams(InvokerParams);
1493
6.70k
  Invoke->setAccess(AS_private);
1494
6.70k
  Invoke->setImplicit(true);
1495
6.70k
  if (Class->isGenericLambda()) {
1496
3.60k
    FunctionTemplateDecl *TemplateCallOperator =
1497
3.60k
            CallOperator->getDescribedFunctionTemplate();
1498
3.60k
    FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1499
3.60k
                          S.Context, Class, Loc, InvokerName,
1500
3.60k
                          TemplateCallOperator->getTemplateParameters(),
1501
3.60k
                          Invoke);
1502
3.60k
    StaticInvokerTemplate->setAccess(AS_private);
1503
3.60k
    StaticInvokerTemplate->setImplicit(true);
1504
3.60k
    Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1505
3.60k
    Class->addDecl(StaticInvokerTemplate);
1506
3.60k
  } else
1507
3.09k
    Class->addDecl(Invoke);
1508
6.70k
}
1509
1510
/// Add a lambda's conversion to function pointers, as described in
1511
/// C++11 [expr.prim.lambda]p6. Note that in most cases, this should emit only a
1512
/// single pointer conversion. In the event that the default calling convention
1513
/// for free and member functions is different, it will emit both conventions.
1514
static void addFunctionPointerConversions(Sema &S, SourceRange IntroducerRange,
1515
                                          CXXRecordDecl *Class,
1516
5.02k
                                          CXXMethodDecl *CallOperator) {
1517
5.02k
  const FunctionProtoType *CallOpProto =
1518
5.02k
      CallOperator->getType()->castAs<FunctionProtoType>();
1519
1520
5.02k
  repeatForLambdaConversionFunctionCallingConvs(
1521
6.70k
      S, *CallOpProto, [&](CallingConv CC) {
1522
6.70k
        QualType InvokerFunctionTy =
1523
6.70k
            S.getLambdaConversionFunctionResultType(CallOpProto, CC);
1524
6.70k
        addFunctionPointerConversion(S, IntroducerRange, Class, CallOperator,
1525
6.70k
                                     InvokerFunctionTy);
1526
6.70k
      });
1527
5.02k
}
1528
1529
/// Add a lambda's conversion to block pointer.
1530
static void addBlockPointerConversion(Sema &S,
1531
                                      SourceRange IntroducerRange,
1532
                                      CXXRecordDecl *Class,
1533
159
                                      CXXMethodDecl *CallOperator) {
1534
159
  const FunctionProtoType *CallOpProto =
1535
159
      CallOperator->getType()->castAs<FunctionProtoType>();
1536
159
  QualType FunctionTy = S.getLambdaConversionFunctionResultType(
1537
159
      CallOpProto, getLambdaConversionFunctionCallConv(S, CallOpProto));
1538
159
  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1539
1540
159
  FunctionProtoType::ExtProtoInfo ConversionEPI(
1541
159
      S.Context.getDefaultCallingConvention(
1542
159
          /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1543
159
  ConversionEPI.TypeQuals = Qualifiers();
1544
159
  ConversionEPI.TypeQuals.addConst();
1545
159
  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1546
1547
159
  SourceLocation Loc = IntroducerRange.getBegin();
1548
159
  DeclarationName Name
1549
159
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1550
159
        S.Context.getCanonicalType(BlockPtrTy));
1551
159
  DeclarationNameLoc NameLoc;
1552
159
  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1553
159
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1554
159
      S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1555
159
      S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1556
159
      /*isInline=*/true, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
1557
159
      CallOperator->getBody()->getEndLoc());
1558
159
  Conversion->setAccess(AS_public);
1559
159
  Conversion->setImplicit(true);
1560
159
  Class->addDecl(Conversion);
1561
159
}
1562
1563
ExprResult Sema::BuildCaptureInit(const Capture &Cap,
1564
                                  SourceLocation ImplicitCaptureLoc,
1565
389k
                                  bool IsOpenMPMapping) {
1566
  // VLA captures don't have a stored initialization expression.
1567
389k
  if (Cap.isVLATypeCapture())
1568
8.82k
    return ExprResult();
1569
1570
  // An init-capture is initialized directly from its stored initializer.
1571
381k
  if (Cap.isInitCapture())
1572
477
    return Cap.getVariable()->getInit();
1573
1574
  // For anything else, build an initialization expression. For an implicit
1575
  // capture, the capture notionally happens at the capture-default, so use
1576
  // that location here.
1577
380k
  SourceLocation Loc =
1578
379k
      ImplicitCaptureLoc.isValid() ? ImplicitCaptureLoc : 
Cap.getLocation()1.31k
;
1579
1580
  // C++11 [expr.prim.lambda]p21:
1581
  //   When the lambda-expression is evaluated, the entities that
1582
  //   are captured by copy are used to direct-initialize each
1583
  //   corresponding non-static data member of the resulting closure
1584
  //   object. (For array members, the array elements are
1585
  //   direct-initialized in increasing subscript order.) These
1586
  //   initializations are performed in the (unspecified) order in
1587
  //   which the non-static data members are declared.
1588
1589
  // C++ [expr.prim.lambda]p12:
1590
  //   An entity captured by a lambda-expression is odr-used (3.2) in
1591
  //   the scope containing the lambda-expression.
1592
380k
  ExprResult Init;
1593
380k
  IdentifierInfo *Name = nullptr;
1594
380k
  if (Cap.isThisCapture()) {
1595
11.1k
    QualType ThisTy = getCurrentThisType();
1596
11.1k
    Expr *This = BuildCXXThisExpr(Loc, ThisTy, ImplicitCaptureLoc.isValid());
1597
11.1k
    if (Cap.isCopyCapture())
1598
128
      Init = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
1599
11.0k
    else
1600
11.0k
      Init = This;
1601
369k
  } else {
1602
369k
    assert(Cap.isVariableCapture() && "unknown kind of capture");
1603
369k
    VarDecl *Var = Cap.getVariable();
1604
369k
    Name = Var->getIdentifier();
1605
369k
    Init = BuildDeclarationNameExpr(
1606
369k
      CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1607
369k
  }
1608
1609
  // In OpenMP, the capture kind doesn't actually describe how to capture:
1610
  // variables are "mapped" onto the device in a process that does not formally
1611
  // make a copy, even for a "copy capture".
1612
380k
  if (IsOpenMPMapping)
1613
375k
    return Init;
1614
1615
5.00k
  if (Init.isInvalid())
1616
0
    return ExprError();
1617
1618
5.00k
  Expr *InitExpr = Init.get();
1619
5.00k
  InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture(
1620
5.00k
      Name, Cap.getCaptureType(), Loc);
1621
5.00k
  InitializationKind InitKind =
1622
5.00k
      InitializationKind::CreateDirect(Loc, Loc, Loc);
1623
5.00k
  InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr);
1624
5.00k
  return InitSeq.Perform(*this, Entity, InitKind, InitExpr);
1625
5.00k
}
1626
1627
ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
1628
7.03k
                                 Scope *CurScope) {
1629
7.03k
  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1630
7.03k
  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1631
7.03k
  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1632
7.03k
}
1633
1634
static LambdaCaptureDefault
1635
9.48k
mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS) {
1636
9.48k
  switch (ICS) {
1637
6.42k
  case CapturingScopeInfo::ImpCap_None:
1638
6.42k
    return LCD_None;
1639
1.13k
  case CapturingScopeInfo::ImpCap_LambdaByval:
1640
1.13k
    return LCD_ByCopy;
1641
0
  case CapturingScopeInfo::ImpCap_CapturedRegion:
1642
1.93k
  case CapturingScopeInfo::ImpCap_LambdaByref:
1643
1.93k
    return LCD_ByRef;
1644
0
  case CapturingScopeInfo::ImpCap_Block:
1645
0
    llvm_unreachable("block capture in lambda");
1646
0
  }
1647
0
  llvm_unreachable("Unknown implicit capture style");
1648
0
}
1649
1650
671
bool Sema::CaptureHasSideEffects(const Capture &From) {
1651
671
  if (From.isInitCapture()) {
1652
199
    Expr *Init = From.getVariable()->getInit();
1653
199
    if (Init && Init->HasSideEffects(Context))
1654
54
      return true;
1655
617
  }
1656
1657
617
  if (!From.isCopyCapture())
1658
159
    return false;
1659
1660
458
  const QualType T = From.isThisCapture()
1661
33
                         ? getCurrentThisType()->getPointeeType()
1662
425
                         : From.getCaptureType();
1663
1664
458
  if (T.isVolatileQualified())
1665
2
    return true;
1666
1667
456
  const Type *BaseT = T->getBaseElementTypeUnsafe();
1668
456
  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1669
82
    return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1670
50
           !RD->hasTrivialDestructor();
1671
1672
374
  return false;
1673
374
}
1674
1675
bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
1676
671
                                       const Capture &From) {
1677
671
  if (CaptureHasSideEffects(From))
1678
91
    return false;
1679
1680
580
  if (From.isVLATypeCapture())
1681
18
    return false;
1682
1683
562
  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1684
562
  if (From.isThisCapture())
1685
77
    diag << "'this'";
1686
485
  else
1687
485
    diag << From.getVariable();
1688
562
  diag << From.isNonODRUsed();
1689
562
  diag << FixItHint::CreateRemoval(CaptureRange);
1690
562
  return true;
1691
562
}
1692
1693
/// Create a field within the lambda class or captured statement record for the
1694
/// given capture.
1695
FieldDecl *Sema::BuildCaptureField(RecordDecl *RD,
1696
389k
                                   const sema::Capture &Capture) {
1697
389k
  SourceLocation Loc = Capture.getLocation();
1698
389k
  QualType FieldType = Capture.getCaptureType();
1699
1700
389k
  TypeSourceInfo *TSI = nullptr;
1701
389k
  if (Capture.isVariableCapture()) {
1702
370k
    auto *Var = Capture.getVariable();
1703
370k
    if (Var->isInitCapture())
1704
524
      TSI = Capture.getVariable()->getTypeSourceInfo();
1705
370k
  }
1706
1707
  // FIXME: Should we really be doing this? A null TypeSourceInfo seems more
1708
  // appropriate, at least for an implicit capture.
1709
389k
  if (!TSI)
1710
389k
    TSI = Context.getTrivialTypeSourceInfo(FieldType, Loc);
1711
1712
  // Build the non-static data member.
1713
389k
  FieldDecl *Field =
1714
389k
      FieldDecl::Create(Context, RD, /*StartLoc=*/Loc, /*IdLoc=*/Loc,
1715
389k
                        /*Id=*/nullptr, FieldType, TSI, /*BW=*/nullptr,
1716
389k
                        /*Mutable=*/false, ICIS_NoInit);
1717
  // If the variable being captured has an invalid type, mark the class as
1718
  // invalid as well.
1719
389k
  if (!FieldType->isDependentType()) {
1720
385k
    if (RequireCompleteSizedType(Loc, FieldType,
1721
3
                                 diag::err_field_incomplete_or_sizeless)) {
1722
3
      RD->setInvalidDecl();
1723
3
      Field->setInvalidDecl();
1724
385k
    } else {
1725
385k
      NamedDecl *Def;
1726
385k
      FieldType->isIncompleteType(&Def);
1727
385k
      if (Def && 
Def->isInvalidDecl()280
) {
1728
2
        RD->setInvalidDecl();
1729
2
        Field->setInvalidDecl();
1730
2
      }
1731
385k
    }
1732
385k
  }
1733
389k
  Field->setImplicit(true);
1734
389k
  Field->setAccess(AS_private);
1735
389k
  RD->addDecl(Field);
1736
1737
389k
  if (Capture.isVLATypeCapture())
1738
8.82k
    Field->setCapturedVLAType(Capture.getCapturedVLAType());
1739
1740
389k
  return Field;
1741
389k
}
1742
1743
ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
1744
9.48k
                                 LambdaScopeInfo *LSI) {
1745
  // Collect information from the lambda scope.
1746
9.48k
  SmallVector<LambdaCapture, 4> Captures;
1747
9.48k
  SmallVector<Expr *, 4> CaptureInits;
1748
9.48k
  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1749
9.48k
  LambdaCaptureDefault CaptureDefault =
1750
9.48k
      mapImplicitCaptureStyle(LSI->ImpCaptureStyle);
1751
9.48k
  CXXRecordDecl *Class;
1752
9.48k
  CXXMethodDecl *CallOperator;
1753
9.48k
  SourceRange IntroducerRange;
1754
9.48k
  bool ExplicitParams;
1755
9.48k
  bool ExplicitResultType;
1756
9.48k
  CleanupInfo LambdaCleanup;
1757
9.48k
  bool ContainsUnexpandedParameterPack;
1758
9.48k
  bool IsGenericLambda;
1759
9.48k
  {
1760
9.48k
    CallOperator = LSI->CallOperator;
1761
9.48k
    Class = LSI->Lambda;
1762
9.48k
    IntroducerRange = LSI->IntroducerRange;
1763
9.48k
    ExplicitParams = LSI->ExplicitParams;
1764
9.48k
    ExplicitResultType = !LSI->HasImplicitReturnType;
1765
9.48k
    LambdaCleanup = LSI->Cleanup;
1766
9.48k
    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1767
9.48k
    IsGenericLambda = Class->isGenericLambda();
1768
1769
9.48k
    CallOperator->setLexicalDeclContext(Class);
1770
9.48k
    Decl *TemplateOrNonTemplateCallOperatorDecl =
1771
9.48k
        CallOperator->getDescribedFunctionTemplate()
1772
3.38k
        ? CallOperator->getDescribedFunctionTemplate()
1773
6.10k
        : cast<Decl>(CallOperator);
1774
1775
    // FIXME: Is this really the best choice? Keeping the lexical decl context
1776
    // set as CurContext seems more faithful to the source.
1777
9.48k
    TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1778
1779
9.48k
    PopExpressionEvaluationContext();
1780
1781
    // True if the current capture has a used capture or default before it.
1782
9.48k
    bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1783
9.48k
    SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1784
6.42k
        
CaptureDefaultLoc3.06k
: IntroducerRange.getBegin();
1785
1786
14.9k
    for (unsigned I = 0, N = LSI->Captures.size(); I != N; 
++I5.43k
) {
1787
5.46k
      const Capture &From = LSI->Captures[I];
1788
1789
5.46k
      if (From.isInvalid())
1790
24
        return ExprError();
1791
1792
5.43k
      assert(!From.isBlockCapture() && "Cannot capture __block variables");
1793
5.43k
      bool IsImplicit = I >= LSI->NumExplicitCaptures;
1794
5.43k
      SourceLocation ImplicitCaptureLoc =
1795
3.62k
          IsImplicit ? CaptureDefaultLoc : 
SourceLocation()1.81k
;
1796
1797
      // Use source ranges of explicit captures for fixits where available.
1798
5.43k
      SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1799
1800
      // Warn about unused explicit captures.
1801
5.43k
      bool IsCaptureUsed = true;
1802
5.43k
      if (!CurContext->isDependentContext() && 
!IsImplicit4.87k
&&
1803
1.39k
          !From.isODRUsed()) {
1804
        // Initialized captures that are non-ODR used may not be eliminated.
1805
        // FIXME: Where did the IsGenericLambda here come from?
1806
682
        bool NonODRUsedInitCapture =
1807
682
            IsGenericLambda && 
From.isNonODRUsed()31
&&
From.isInitCapture()12
;
1808
682
        if (!NonODRUsedInitCapture) {
1809
671
          bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1810
671
          SourceRange FixItRange;
1811
671
          if (CaptureRange.isValid()) {
1812
510
            if (!CurHasPreviousCapture && 
!IsLast444
) {
1813
              // If there are no captures preceding this capture, remove the
1814
              // following comma.
1815
93
              FixItRange = SourceRange(CaptureRange.getBegin(),
1816
93
                                       getLocForEndOfToken(CaptureRange.getEnd()));
1817
417
            } else {
1818
              // Otherwise, remove the comma since the last used capture.
1819
417
              FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1820
417
                                       CaptureRange.getEnd());
1821
417
            }
1822
510
          }
1823
1824
671
          IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1825
671
        }
1826
682
      }
1827
1828
5.43k
      if (CaptureRange.isValid()) {
1829
1.38k
        CurHasPreviousCapture |= IsCaptureUsed;
1830
1.38k
        PrevCaptureLoc = CaptureRange.getEnd();
1831
1.38k
      }
1832
1833
      // Map the capture to our AST representation.
1834
5.43k
      LambdaCapture Capture = [&] {
1835
5.43k
        if (From.isThisCapture()) {
1836
          // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1837
          // because it results in a reference capture. Don't warn prior to
1838
          // C++2a; there's nothing that can be done about it before then.
1839
767
          if (getLangOpts().CPlusPlus20 && 
IsImplicit62
&&
1840
44
              CaptureDefault == LCD_ByCopy) {
1841
39
            Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1842
39
            Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1843
39
                << FixItHint::CreateInsertion(
1844
39
                       getLocForEndOfToken(CaptureDefaultLoc), ", this");
1845
39
          }
1846
767
          return LambdaCapture(From.getLocation(), IsImplicit,
1847
639
                               From.isCopyCapture() ? 
LCK_StarThis128
: LCK_This);
1848
4.66k
        } else if (From.isVLATypeCapture()) {
1849
46
          return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType);
1850
4.62k
        } else {
1851
4.62k
          assert(From.isVariableCapture() && "unknown kind of capture");
1852
4.62k
          VarDecl *Var = From.getVariable();
1853
4.62k
          LambdaCaptureKind Kind =
1854
3.14k
              From.isCopyCapture() ? 
LCK_ByCopy1.48k
: LCK_ByRef;
1855
4.62k
          return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var,
1856
4.62k
                               From.getEllipsisLoc());
1857
4.62k
        }
1858
5.43k
      }();
1859
1860
      // Form the initializer for the capture field.
1861
5.43k
      ExprResult Init = BuildCaptureInit(From, ImplicitCaptureLoc);
1862
1863
      // FIXME: Skip this capture if the capture is not used, the initializer
1864
      // has no side-effects, the type of the capture is trivial, and the
1865
      // lambda is not externally visible.
1866
1867
      // Add a FieldDecl for the capture and form its initializer.
1868
5.43k
      BuildCaptureField(Class, From);
1869
5.43k
      Captures.push_back(Capture);
1870
5.43k
      CaptureInits.push_back(Init.get());
1871
1872
5.43k
      if (LangOpts.CUDA)
1873
62
        CUDACheckLambdaCapture(CallOperator, From);
1874
5.43k
    }
1875
1876
9.46k
    Class->setCaptures(Context, Captures);
1877
1878
    // C++11 [expr.prim.lambda]p6:
1879
    //   The closure type for a lambda-expression with no lambda-capture
1880
    //   has a public non-virtual non-explicit const conversion function
1881
    //   to pointer to function having the same parameter and return
1882
    //   types as the closure type's function call operator.
1883
9.46k
    if (Captures.empty() && 
CaptureDefault == LCD_None6.12k
)
1884
5.02k
      addFunctionPointerConversions(*this, IntroducerRange, Class,
1885
5.02k
                                    CallOperator);
1886
1887
    // Objective-C++:
1888
    //   The closure type for a lambda-expression has a public non-virtual
1889
    //   non-explicit const conversion function to a block pointer having the
1890
    //   same parameter and return types as the closure type's function call
1891
    //   operator.
1892
    // FIXME: Fix generic lambda to block conversions.
1893
9.46k
    if (getLangOpts().Blocks && 
getLangOpts().ObjC5.54k
&&
!IsGenericLambda168
)
1894
159
      addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1895
1896
    // Finalize the lambda class.
1897
9.46k
    SmallVector<Decl*, 4> Fields(Class->fields());
1898
9.46k
    ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1899
9.46k
                SourceLocation(), ParsedAttributesView());
1900
9.46k
    CheckCompletedCXXClass(nullptr, Class);
1901
9.46k
  }
1902
1903
9.46k
  Cleanup.mergeFrom(LambdaCleanup);
1904
1905
9.46k
  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1906
9.46k
                                          CaptureDefault, CaptureDefaultLoc,
1907
9.46k
                                          ExplicitParams, ExplicitResultType,
1908
9.46k
                                          CaptureInits, EndLoc,
1909
9.46k
                                          ContainsUnexpandedParameterPack);
1910
  // If the lambda expression's call operator is not explicitly marked constexpr
1911
  // and we are not in a dependent context, analyze the call operator to infer
1912
  // its constexpr-ness, suppressing diagnostics while doing so.
1913
9.46k
  if (getLangOpts().CPlusPlus17 && 
!CallOperator->isInvalidDecl()2.40k
&&
1914
2.39k
      !CallOperator->isConstexpr() &&
1915
2.28k
      !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1916
2.28k
      !Class->getDeclContext()->isDependentContext()) {
1917
1.56k
    CallOperator->setConstexprKind(
1918
1.56k
        CheckConstexprFunctionDefinition(CallOperator,
1919
1.56k
                                         CheckConstexprKind::CheckValid)
1920
1.53k
            ? ConstexprSpecKind::Constexpr
1921
38
            : ConstexprSpecKind::Unspecified);
1922
1.56k
  }
1923
1924
  // Emit delayed shadowing warnings now that the full capture list is known.
1925
9.46k
  DiagnoseShadowingLambdaDecls(LSI);
1926
1927
9.46k
  if (!CurContext->isDependentContext()) {
1928
7.05k
    switch (ExprEvalContexts.back().Context) {
1929
    // C++11 [expr.prim.lambda]p2:
1930
    //   A lambda-expression shall not appear in an unevaluated operand
1931
    //   (Clause 5).
1932
16
    case ExpressionEvaluationContext::Unevaluated:
1933
16
    case ExpressionEvaluationContext::UnevaluatedList:
1934
16
    case ExpressionEvaluationContext::UnevaluatedAbstract:
1935
    // C++1y [expr.const]p2:
1936
    //   A conditional-expression e is a core constant expression unless the
1937
    //   evaluation of e, following the rules of the abstract machine, would
1938
    //   evaluate [...] a lambda-expression.
1939
    //
1940
    // This is technically incorrect, there are some constant evaluated contexts
1941
    // where this should be allowed.  We should probably fix this when DR1607 is
1942
    // ratified, it lays out the exact set of conditions where we shouldn't
1943
    // allow a lambda-expression.
1944
189
    case ExpressionEvaluationContext::ConstantEvaluated:
1945
      // We don't actually diagnose this case immediately, because we
1946
      // could be within a context where we might find out later that
1947
      // the expression is potentially evaluated (e.g., for typeid).
1948
189
      ExprEvalContexts.back().Lambdas.push_back(Lambda);
1949
189
      break;
1950
1951
0
    case ExpressionEvaluationContext::DiscardedStatement:
1952
6.59k
    case ExpressionEvaluationContext::PotentiallyEvaluated:
1953
6.87k
    case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1954
6.87k
      break;
1955
9.46k
    }
1956
9.46k
  }
1957
1958
9.46k
  return MaybeBindToTemporary(Lambda);
1959
9.46k
}
1960
1961
ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
1962
                                               SourceLocation ConvLocation,
1963
                                               CXXConversionDecl *Conv,
1964
31
                                               Expr *Src) {
1965
  // Make sure that the lambda call operator is marked used.
1966
31
  CXXRecordDecl *Lambda = Conv->getParent();
1967
31
  CXXMethodDecl *CallOperator
1968
31
    = cast<CXXMethodDecl>(
1969
31
        Lambda->lookup(
1970
31
          Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1971
31
  CallOperator->setReferenced();
1972
31
  CallOperator->markUsed(Context);
1973
1974
31
  ExprResult Init = PerformCopyInitialization(
1975
31
      InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType(),
1976
31
                                                 /*NRVO=*/false),
1977
31
      CurrentLocation, Src);
1978
31
  if (!Init.isInvalid())
1979
31
    Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1980
1981
31
  if (Init.isInvalid())
1982
0
    return ExprError();
1983
1984
  // Create the new block to be returned.
1985
31
  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1986
1987
  // Set the type information.
1988
31
  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1989
31
  Block->setIsVariadic(CallOperator->isVariadic());
1990
31
  Block->setBlockMissingReturnType(false);
1991
1992
  // Add parameters.
1993
31
  SmallVector<ParmVarDecl *, 4> BlockParams;
1994
42
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I11
) {
1995
11
    ParmVarDecl *From = CallOperator->getParamDecl(I);
1996
11
    BlockParams.push_back(ParmVarDecl::Create(
1997
11
        Context, Block, From->getBeginLoc(), From->getLocation(),
1998
11
        From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1999
11
        From->getStorageClass(),
2000
11
        /*DefArg=*/nullptr));
2001
11
  }
2002
31
  Block->setParams(BlockParams);
2003
2004
31
  Block->setIsConversionFromLambda(true);
2005
2006
  // Add capture. The capture uses a fake variable, which doesn't correspond
2007
  // to any actual memory location. However, the initializer copy-initializes
2008
  // the lambda object.
2009
31
  TypeSourceInfo *CapVarTSI =
2010
31
      Context.getTrivialTypeSourceInfo(Src->getType());
2011
31
  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
2012
31
                                    ConvLocation, nullptr,
2013
31
                                    Src->getType(), CapVarTSI,
2014
31
                                    SC_None);
2015
31
  BlockDecl::Capture Capture(/*variable=*/CapVar, /*byRef=*/false,
2016
31
                             /*nested=*/false, /*copy=*/Init.get());
2017
31
  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
2018
2019
  // Add a fake function body to the block. IR generation is responsible
2020
  // for filling in the actual body, which cannot be expressed as an AST.
2021
31
  Block->setBody(new (Context) CompoundStmt(ConvLocation));
2022
2023
  // Create the block literal expression.
2024
31
  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
2025
31
  ExprCleanupObjects.push_back(Block);
2026
31
  Cleanup.setExprNeedsCleanups(true);
2027
2028
31
  return BuildBlock;
2029
31
}