Coverage Report

Created: 2020-09-22 08:39

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/Sema/SemaLambda.cpp
Line
Count
Source (jump to first uncovered line)
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//===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//
7
//===----------------------------------------------------------------------===//
8
//
9
//  This file implements semantic analysis for C++ lambda expressions.
10
//
11
//===----------------------------------------------------------------------===//
12
#include "clang/Sema/DeclSpec.h"
13
#include "TypeLocBuilder.h"
14
#include "clang/AST/ASTLambda.h"
15
#include "clang/AST/ExprCXX.h"
16
#include "clang/Basic/TargetInfo.h"
17
#include "clang/Sema/Initialization.h"
18
#include "clang/Sema/Lookup.h"
19
#include "clang/Sema/Scope.h"
20
#include "clang/Sema/ScopeInfo.h"
21
#include "clang/Sema/SemaInternal.h"
22
#include "clang/Sema/SemaLambda.h"
23
#include "llvm/ADT/STLExtras.h"
24
using namespace clang;
25
using namespace sema;
26
27
/// Examines the FunctionScopeInfo stack to determine the nearest
28
/// enclosing lambda (to the current lambda) that is 'capture-ready' for
29
/// the variable referenced in the current lambda (i.e. \p VarToCapture).
30
/// If successful, returns the index into Sema's FunctionScopeInfo stack
31
/// of the capture-ready lambda's LambdaScopeInfo.
32
///
33
/// Climbs down the stack of lambdas (deepest nested lambda - i.e. current
34
/// lambda - is on top) to determine the index of the nearest enclosing/outer
35
/// lambda that is ready to capture the \p VarToCapture being referenced in
36
/// the current lambda.
37
/// As we climb down the stack, we want the index of the first such lambda -
38
/// that is the lambda with the highest index that is 'capture-ready'.
39
///
40
/// A lambda 'L' is capture-ready for 'V' (var or this) if:
41
///  - its enclosing context is non-dependent
42
///  - and if the chain of lambdas between L and the lambda in which
43
///    V is potentially used (i.e. the lambda at the top of the scope info
44
///    stack), can all capture or have already captured V.
45
/// If \p VarToCapture is 'null' then we are trying to capture 'this'.
46
///
47
/// Note that a lambda that is deemed 'capture-ready' still needs to be checked
48
/// for whether it is 'capture-capable' (see
49
/// getStackIndexOfNearestEnclosingCaptureCapableLambda), before it can truly
50
/// capture.
51
///
52
/// \param FunctionScopes - Sema's stack of nested FunctionScopeInfo's (which a
53
///  LambdaScopeInfo inherits from).  The current/deepest/innermost lambda
54
///  is at the top of the stack and has the highest index.
55
/// \param VarToCapture - the variable to capture.  If NULL, capture 'this'.
56
///
57
/// \returns An Optional<unsigned> Index that if evaluates to 'true' contains
58
/// the index (into Sema's FunctionScopeInfo stack) of the innermost lambda
59
/// which is capture-ready.  If the return value evaluates to 'false' then
60
/// no lambda is capture-ready for \p VarToCapture.
61
62
static inline Optional<unsigned>
63
getStackIndexOfNearestEnclosingCaptureReadyLambda(
64
    ArrayRef<const clang::sema::FunctionScopeInfo *> FunctionScopes,
65
604
    VarDecl *VarToCapture) {
66
  // Label failure to capture.
67
604
  const Optional<unsigned> NoLambdaIsCaptureReady;
68
69
  // Ignore all inner captured regions.
70
604
  unsigned CurScopeIndex = FunctionScopes.size() - 1;
71
609
  while (CurScopeIndex > 0 && isa<clang::sema::CapturedRegionScopeInfo>(
72
609
                                  FunctionScopes[CurScopeIndex]))
73
5
    --CurScopeIndex;
74
604
  assert(
75
604
      isa<clang::sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex]) &&
76
604
      "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
604
  const bool IsCapturingThis = !VarToCapture;
80
604
  const bool IsCapturingVariable = !IsCapturingThis;
81
82
  // Start with the current lambda at the top of the stack (highest index).
83
604
  DeclContext *EnclosingDC =
84
604
      cast<sema::LambdaScopeInfo>(FunctionScopes[CurScopeIndex])->CallOperator;
85
86
922
  do {
87
922
    const clang::sema::LambdaScopeInfo *LSI =
88
922
        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
922
    if (IsCapturingVariable &&
97
842
        VarToCapture->getDeclContext()->Equals(EnclosingDC))
98
129
      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
793
    if (LSI->ImpCaptureStyle == sema::LambdaScopeInfo::ImpCap_None) {
117
192
      if (IsCapturingVariable && 
!LSI->isCaptured(VarToCapture)166
)
118
91
        return NoLambdaIsCaptureReady;
119
101
      if (IsCapturingThis && 
!LSI->isCXXThisCaptured()26
)
120
24
        return NoLambdaIsCaptureReady;
121
678
    }
122
678
    EnclosingDC = getLambdaAwareParentOfDeclContext(EnclosingDC);
123
124
678
    assert(CurScopeIndex);
125
678
    --CurScopeIndex;
126
678
  } while (!EnclosingDC->isTranslationUnit() &&
127
678
           EnclosingDC->isDependentContext() &&
128
463
           isLambdaCallOperator(EnclosingDC));
129
130
360
  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
360
  if (!EnclosingDC->isDependentContext())
134
215
    return CurScopeIndex + 1;
135
145
  return NoLambdaIsCaptureReady;
136
145
}
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
604
    VarDecl *VarToCapture, Sema &S) {
176
177
604
  const Optional<unsigned> NoLambdaIsCaptureCapable;
178
179
604
  const Optional<unsigned> OptionalStackIndex =
180
604
      getStackIndexOfNearestEnclosingCaptureReadyLambda(FunctionScopes,
181
604
                                                        VarToCapture);
182
604
  if (!OptionalStackIndex)
183
389
    return NoLambdaIsCaptureCapable;
184
185
215
  const unsigned IndexOfCaptureReadyLambda = OptionalStackIndex.getValue();
186
215
  assert(((IndexOfCaptureReadyLambda != (FunctionScopes.size() - 1)) ||
187
215
          S.getCurGenericLambda()) &&
188
215
         "The capture ready lambda for a potential capture can only be the "
189
215
         "current lambda if it is a generic lambda");
190
191
215
  const sema::LambdaScopeInfo *const CaptureReadyLambdaLSI =
192
215
      cast<sema::LambdaScopeInfo>(FunctionScopes[IndexOfCaptureReadyLambda]);
193
194
  // If VarToCapture is null, we are attempting to capture 'this'
195
215
  const bool IsCapturingThis = !VarToCapture;
196
215
  const bool IsCapturingVariable = !IsCapturingThis;
197
198
215
  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
205
    QualType CaptureType, DeclRefType;
203
205
    const bool CanCaptureVariable =
204
205
        !S.tryCaptureVariable(VarToCapture,
205
205
                              /*ExprVarIsUsedInLoc*/ SourceLocation(),
206
205
                              clang::Sema::TryCapture_Implicit,
207
205
                              /*EllipsisLoc*/ SourceLocation(),
208
205
                              /*BuildAndDiagnose*/ false, CaptureType,
209
205
                              DeclRefType, &IndexOfCaptureReadyLambda);
210
205
    if (!CanCaptureVariable)
211
14
      return NoLambdaIsCaptureCapable;
212
10
  } 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
10
    const bool CanCaptureThis =
217
10
        !S.CheckCXXThisCapture(
218
10
             CaptureReadyLambdaLSI->PotentialThisCaptureLocation,
219
10
             /*Explicit*/ false, /*BuildAndDiagnose*/ false,
220
10
             &IndexOfCaptureReadyLambda);
221
10
    if (!CanCaptureThis)
222
2
      return NoLambdaIsCaptureCapable;
223
199
  }
224
199
  return IndexOfCaptureReadyLambda;
225
199
}
226
227
static inline TemplateParameterList *
228
15.0k
getGenericLambdaTemplateParameterList(LambdaScopeInfo *LSI, Sema &SemaRef) {
229
15.0k
  if (!LSI->GLTemplateParameterList && 
!LSI->TemplateParams.empty()12.3k
) {
230
1.17k
    LSI->GLTemplateParameterList = TemplateParameterList::Create(
231
1.17k
        SemaRef.Context,
232
1.17k
        /*Template kw loc*/ SourceLocation(),
233
1.17k
        /*L angle loc*/ LSI->ExplicitTemplateParamsRange.getBegin(),
234
1.17k
        LSI->TemplateParams,
235
1.17k
        /*R angle loc*/LSI->ExplicitTemplateParamsRange.getEnd(),
236
1.17k
        nullptr);
237
1.17k
  }
238
15.0k
  return LSI->GLTemplateParameterList;
239
15.0k
}
240
241
CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange,
242
                                             TypeSourceInfo *Info,
243
                                             bool KnownDependent,
244
7.52k
                                             LambdaCaptureDefault CaptureDefault) {
245
7.52k
  DeclContext *DC = CurContext;
246
7.53k
  while (!(DC->isFunctionOrMethod() || 
DC->isRecord()1.14k
||
DC->isFileContext()817
))
247
15
    DC = DC->getParent();
248
7.52k
  bool IsGenericLambda = getGenericLambdaTemplateParameterList(getCurLambda(),
249
7.52k
                                                               *this);
250
  // Start constructing the lambda class.
251
7.52k
  CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info,
252
7.52k
                                                     IntroducerRange.getBegin(),
253
7.52k
                                                     KnownDependent,
254
7.52k
                                                     IsGenericLambda,
255
7.52k
                                                     CaptureDefault);
256
7.52k
  DC->addDecl(Class);
257
258
7.52k
  return Class;
259
7.52k
}
260
261
/// Determine whether the given context is or is enclosed in an inline
262
/// function.
263
971k
static bool isInInlineFunction(const DeclContext *DC) {
264
1.35M
  while (!DC->isFileContext()) {
265
390k
    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
266
19.6k
      if (FD->isInlined())
267
7.73k
        return true;
268
269
382k
    DC = DC->getLexicalParent();
270
382k
  }
271
272
963k
  return false;
273
971k
}
274
275
std::tuple<MangleNumberingContext *, Decl *>
276
985k
Sema::getCurrentMangleNumberContext(const DeclContext *DC) {
277
  // Compute the context for allocating mangling numbers in the current
278
  // expression, if the ABI requires them.
279
985k
  Decl *ManglingContextDecl = ExprEvalContexts.back().ManglingContextDecl;
280
281
985k
  enum ContextKind {
282
985k
    Normal,
283
985k
    DefaultArgument,
284
985k
    DataMember,
285
985k
    StaticDataMember,
286
985k
    InlineVariable,
287
985k
    VariableTemplate
288
985k
  } 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
985k
  if (ManglingContextDecl) {
294
1.92k
    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ManglingContextDecl)) {
295
700
      if (const DeclContext *LexicalDC
296
136
          = Param->getDeclContext()->getLexicalParent())
297
136
        if (LexicalDC->isRecord())
298
101
          Kind = DefaultArgument;
299
1.22k
    } else if (VarDecl *Var = dyn_cast<VarDecl>(ManglingContextDecl)) {
300
1.08k
      if (Var->getDeclContext()->isRecord())
301
21
        Kind = StaticDataMember;
302
1.06k
      else if (Var->getMostRecentDecl()->isInline())
303
8
        Kind = InlineVariable;
304
1.05k
      else if (Var->getDescribedVarTemplate())
305
13
        Kind = VariableTemplate;
306
1.04k
      else if (auto *VTS = dyn_cast<VarTemplateSpecializationDecl>(Var)) {
307
7
        if (!VTS->isExplicitSpecialization())
308
7
          Kind = VariableTemplate;
309
7
      }
310
143
    } else if (isa<FieldDecl>(ManglingContextDecl)) {
311
143
      Kind = DataMember;
312
143
    }
313
1.92k
  }
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
985k
  bool IsInNonspecializedTemplate =
319
985k
      inTemplateInstantiation() || 
CurContext->isDependentContext()983k
;
320
985k
  switch (Kind) {
321
984k
  case Normal: {
322
    //  -- the bodies of non-exported nonspecialized template functions
323
    //  -- the bodies of inline functions
324
984k
    if ((IsInNonspecializedTemplate &&
325
13.6k
         !(ManglingContextDecl && 
isa<ParmVarDecl>(ManglingContextDecl)593
)) ||
326
971k
        isInInlineFunction(CurContext)) {
327
23.4k
      while (auto *CD = dyn_cast<CapturedDecl>(DC))
328
2.03k
        DC = CD->getParent();
329
21.4k
      return std::make_tuple(&Context.getManglingNumberContext(DC), nullptr);
330
21.4k
    }
331
332
963k
    return std::make_tuple(nullptr, nullptr);
333
963k
  }
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
291
  case DataMember:
343
    //  -- the in-class initializers of class members
344
291
  case DefaultArgument:
345
    //  -- default arguments appearing in class definitions
346
291
  case InlineVariable:
347
    //  -- the initializers of inline variables
348
291
  case VariableTemplate:
349
    //  -- the initializers of templated variables
350
291
    return std::make_tuple(
351
291
        &Context.getManglingNumberContext(ASTContext::NeedExtraManglingDecl,
352
291
                                          ManglingContextDecl),
353
291
        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
7.52k
                                           Expr *TrailingRequiresClause) {
366
7.52k
  QualType MethodType = MethodTypeInfo->getType();
367
7.52k
  TemplateParameterList *TemplateParams =
368
7.52k
      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
7.52k
  if (Class->isDependentContext() || 
TemplateParams5.87k
) {
373
2.90k
    const FunctionProtoType *FPT = MethodType->castAs<FunctionProtoType>();
374
2.90k
    QualType Result = FPT->getReturnType();
375
2.90k
    if (Result->isUndeducedType()) {
376
2.05k
      Result = SubstAutoType(Result, Context.DependentTy);
377
2.05k
      MethodType = Context.getFunctionType(Result, FPT->getParamTypes(),
378
2.05k
                                           FPT->getExtProtoInfo());
379
2.05k
    }
380
2.90k
  }
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
7.52k
  DeclarationName MethodName
388
7.52k
    = Context.DeclarationNames.getCXXOperatorName(OO_Call);
389
7.52k
  DeclarationNameLoc MethodNameLoc;
390
7.52k
  MethodNameLoc.CXXOperatorName.BeginOpNameLoc
391
7.52k
    = IntroducerRange.getBegin().getRawEncoding();
392
7.52k
  MethodNameLoc.CXXOperatorName.EndOpNameLoc
393
7.52k
    = IntroducerRange.getEnd().getRawEncoding();
394
7.52k
  CXXMethodDecl *Method = CXXMethodDecl::Create(
395
7.52k
      Context, Class, EndLoc,
396
7.52k
      DeclarationNameInfo(MethodName, IntroducerRange.getBegin(),
397
7.52k
                          MethodNameLoc),
398
7.52k
      MethodType, MethodTypeInfo, SC_None,
399
7.52k
      /*isInline=*/true, ConstexprKind, EndLoc, TrailingRequiresClause);
400
7.52k
  Method->setAccess(AS_public);
401
7.52k
  if (!TemplateParams)
402
5.60k
    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
7.52k
  Method->setLexicalDeclContext(CurContext);
407
  // Create a function template if we have a template parameter list
408
7.52k
  FunctionTemplateDecl *const TemplateMethod = TemplateParams ?
409
1.92k
            FunctionTemplateDecl::Create(Context, Class,
410
1.92k
                                         Method->getLocation(), MethodName,
411
1.92k
                                         TemplateParams,
412
5.60k
                                         Method) : nullptr;
413
7.52k
  if (TemplateMethod) {
414
1.92k
    TemplateMethod->setAccess(AS_public);
415
1.92k
    Method->setDescribedFunctionTemplate(TemplateMethod);
416
1.92k
    Class->addDecl(TemplateMethod);
417
1.92k
    TemplateMethod->setLexicalDeclContext(CurContext);
418
1.92k
  }
419
420
  // Add parameters.
421
7.52k
  if (!Params.empty()) {
422
3.39k
    Method->setParams(Params);
423
3.39k
    CheckParmsForFunctionDef(Params,
424
3.39k
                             /*CheckParameterNames=*/false);
425
426
3.39k
    for (auto P : Method->parameters())
427
4.09k
      P->setOwningFunction(Method);
428
3.39k
  }
429
430
7.52k
  return Method;
431
7.52k
}
432
433
void Sema::handleLambdaNumbering(
434
    CXXRecordDecl *Class, CXXMethodDecl *Method,
435
7.52k
    Optional<std::tuple<unsigned, bool, Decl *>> Mangling) {
436
7.52k
  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
7.51k
  auto getMangleNumberingContext =
448
7.51k
      [this](CXXRecordDecl *Class,
449
114
             Decl *ManglingContextDecl) -> MangleNumberingContext * {
450
    // Get mangle numbering context if there's any extra decl context.
451
114
    if (ManglingContextDecl)
452
0
      return &Context.getManglingNumberContext(
453
0
          ASTContext::NeedExtraManglingDecl, ManglingContextDecl);
454
    // Otherwise, from that lambda's decl context.
455
114
    auto DC = Class->getDeclContext();
456
114
    while (auto *CD = dyn_cast<CapturedDecl>(DC))
457
0
      DC = CD->getParent();
458
114
    return &Context.getManglingNumberContext(DC);
459
114
  };
460
461
7.51k
  MangleNumberingContext *MCtx;
462
7.51k
  Decl *ManglingContextDecl;
463
7.51k
  std::tie(MCtx, ManglingContextDecl) =
464
7.51k
      getCurrentMangleNumberContext(Class->getDeclContext());
465
7.51k
  bool HasKnownInternalLinkage = false;
466
7.51k
  if (!MCtx && 
getLangOpts().CUDA3.23k
) {
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
114
    MCtx = getMangleNumberingContext(Class, ManglingContextDecl);
472
114
    assert(MCtx && "Retrieving mangle numbering context failed!");
473
114
    HasKnownInternalLinkage = true;
474
114
  }
475
7.51k
  if (MCtx) {
476
4.39k
    unsigned ManglingNumber = MCtx->getManglingNumber(Method);
477
4.39k
    Class->setLambdaMangling(ManglingNumber, ManglingContextDecl,
478
4.39k
                             HasKnownInternalLinkage);
479
4.39k
  }
480
7.51k
}
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
7.52k
                                        bool Mutable) {
490
7.52k
  LSI->CallOperator = CallOperator;
491
7.52k
  CXXRecordDecl *LambdaClass = CallOperator->getParent();
492
7.52k
  LSI->Lambda = LambdaClass;
493
7.52k
  if (CaptureDefault == LCD_ByCopy)
494
748
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval;
495
6.77k
  else if (CaptureDefault == LCD_ByRef)
496
1.88k
    LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref;
497
7.52k
  LSI->CaptureDefaultLoc = CaptureDefaultLoc;
498
7.52k
  LSI->IntroducerRange = IntroducerRange;
499
7.52k
  LSI->ExplicitParams = ExplicitParams;
500
7.52k
  LSI->Mutable = Mutable;
501
502
7.52k
  if (ExplicitResultType) {
503
981
    LSI->ReturnType = CallOperator->getReturnType();
504
505
981
    if (!LSI->ReturnType->isDependentType() &&
506
758
        !LSI->ReturnType->isVoidType()) {
507
492
      if (RequireCompleteType(CallOperator->getBeginLoc(), LSI->ReturnType,
508
2
                              diag::err_lambda_incomplete_result)) {
509
        // Do nothing.
510
2
      }
511
492
    }
512
6.54k
  } else {
513
6.54k
    LSI->HasImplicitReturnType = true;
514
6.54k
  }
515
7.52k
}
516
517
7.52k
void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) {
518
7.52k
  LSI->finishedExplicitCaptures();
519
7.52k
}
520
521
void Sema::ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc,
522
                                                    ArrayRef<NamedDecl *> TParams,
523
75
                                                    SourceLocation RAngleLoc) {
524
75
  LambdaScopeInfo *LSI = getCurLambda();
525
75
  assert(LSI && "Expected a lambda scope");
526
75
  assert(LSI->NumExplicitTemplateParams == 0 &&
527
75
         "Already acted on explicit template parameters");
528
75
  assert(LSI->TemplateParams.empty() &&
529
75
         "Explicit template parameters should come "
530
75
         "before invented (auto) ones");
531
75
  assert(!TParams.empty() &&
532
75
         "No template parameters to act on");
533
75
  LSI->TemplateParams.append(TParams.begin(), TParams.end());
534
75
  LSI->NumExplicitTemplateParams = TParams.size();
535
75
  LSI->ExplicitTemplateParamsRange = {LAngleLoc, RAngleLoc};
536
75
}
537
538
void Sema::addLambdaParameters(
539
    ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
540
5.97k
    CXXMethodDecl *CallOperator, Scope *CurScope) {
541
  // Introduce our parameters into the function scope
542
5.97k
  for (unsigned p = 0, NumParams = CallOperator->getNumParams();
543
8.66k
       p < NumParams; 
++p2.68k
) {
544
2.68k
    ParmVarDecl *Param = CallOperator->getParamDecl(p);
545
546
    // If this has an identifier, add it to the scope stack.
547
2.68k
    if (CurScope && Param->getIdentifier()) {
548
2.55k
      bool Error = false;
549
      // Resolution of CWG 2211 in C++17 renders shadowing ill-formed, but we
550
      // retroactively apply it.
551
319
      for (const auto &Capture : Captures) {
552
319
        if (Capture.Id == Param->getIdentifier()) {
553
11
          Error = true;
554
11
          Diag(Param->getLocation(), diag::err_parameter_shadow_capture);
555
11
          Diag(Capture.Loc, diag::note_var_explicitly_captured_here)
556
11
              << Capture.Id << true;
557
11
        }
558
319
      }
559
2.55k
      if (!Error)
560
2.54k
        CheckShadow(CurScope, Param);
561
562
2.55k
      PushOnScopeChains(Param, CurScope);
563
2.55k
    }
564
2.68k
  }
565
5.97k
}
566
567
/// If this expression is an enumerator-like expression of some type
568
/// T, return the type T; otherwise, return null.
569
///
570
/// Pointer comparisons on the result here should always work because
571
/// it's derived from either the parent of an EnumConstantDecl
572
/// (i.e. the definition) or the declaration returned by
573
/// EnumType::getDecl() (i.e. the definition).
574
384
static EnumDecl *findEnumForBlockReturn(Expr *E) {
575
  // An expression is an enumerator-like expression of type T if,
576
  // ignoring parens and parens-like expressions:
577
384
  E = E->IgnoreParens();
578
579
  //  - it is an enumerator whose enum type is T or
580
384
  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
581
28
    if (EnumConstantDecl *D
582
28
          = dyn_cast<EnumConstantDecl>(DRE->getDecl())) {
583
28
      return cast<EnumDecl>(D->getDeclContext());
584
28
    }
585
0
    return nullptr;
586
0
  }
587
588
  //  - it is a comma expression whose RHS is an enumerator-like
589
  //    expression of type T or
590
356
  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
591
26
    if (BO->getOpcode() == BO_Comma)
592
1
      return findEnumForBlockReturn(BO->getRHS());
593
25
    return nullptr;
594
25
  }
595
596
  //  - it is a statement-expression whose value expression is an
597
  //    enumerator-like expression of type T or
598
330
  if (StmtExpr *SE = dyn_cast<StmtExpr>(E)) {
599
1
    if (Expr *last = dyn_cast_or_null<Expr>(SE->getSubStmt()->body_back()))
600
1
      return findEnumForBlockReturn(last);
601
0
    return nullptr;
602
0
  }
603
604
  //   - it is a ternary conditional operator (not the GNU ?:
605
  //     extension) whose second and third operands are
606
  //     enumerator-like expressions of type T or
607
329
  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
608
3
    if (EnumDecl *ED = findEnumForBlockReturn(CO->getTrueExpr()))
609
3
      if (ED == findEnumForBlockReturn(CO->getFalseExpr()))
610
3
        return ED;
611
0
    return nullptr;
612
0
  }
613
614
  // (implicitly:)
615
  //   - it is an implicit integral conversion applied to an
616
  //     enumerator-like expression of type T or
617
326
  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
618
    // We can sometimes see integral conversions in valid
619
    // enumerator-like expressions.
620
137
    if (ICE->getCastKind() == CK_IntegralCast)
621
3
      return findEnumForBlockReturn(ICE->getSubExpr());
622
623
    // Otherwise, just rely on the type.
624
137
  }
625
626
  //   - it is an expression of that formal enum type.
627
323
  if (const EnumType *ET = E->getType()->getAs<EnumType>()) {
628
15
    return ET->getDecl();
629
15
  }
630
631
  // Otherwise, nope.
632
308
  return nullptr;
633
308
}
634
635
/// Attempt to find a type T for which the returned expression of the
636
/// given statement is an enumerator-like expression of that type.
637
464
static EnumDecl *findEnumForBlockReturn(ReturnStmt *ret) {
638
464
  if (Expr *retValue = ret->getRetValue())
639
373
    return findEnumForBlockReturn(retValue);
640
91
  return nullptr;
641
91
}
642
643
/// Attempt to find a common type T for which all of the returned
644
/// expressions in a block are enumerator-like expressions of that
645
/// type.
646
449
static EnumDecl *findCommonEnumForBlockReturns(ArrayRef<ReturnStmt*> returns) {
647
449
  ArrayRef<ReturnStmt*>::iterator i = returns.begin(), e = returns.end();
648
649
  // Try to find one for the first return.
650
449
  EnumDecl *ED = findEnumForBlockReturn(*i);
651
449
  if (!ED) 
return nullptr422
;
652
653
  // Check that the rest of the returns have the same enum.
654
40
  
for (++i; 27
i != e;
++i13
) {
655
15
    if (findEnumForBlockReturn(*i) != ED)
656
2
      return nullptr;
657
15
  }
658
659
  // Never infer an anonymous enum type.
660
25
  if (!ED->hasNameForLinkage()) 
return nullptr3
;
661
662
22
  return ED;
663
22
}
664
665
/// Adjust the given return statements so that they formally return
666
/// the given type.  It should require, at most, an IntegralCast.
667
static void adjustBlockReturnsToEnum(Sema &S, ArrayRef<ReturnStmt*> returns,
668
22
                                     QualType returnType) {
669
22
  for (ArrayRef<ReturnStmt*>::iterator
670
57
         i = returns.begin(), e = returns.end(); i != e; 
++i35
) {
671
35
    ReturnStmt *ret = *i;
672
35
    Expr *retValue = ret->getRetValue();
673
35
    if (S.Context.hasSameType(retValue->getType(), returnType))
674
14
      continue;
675
676
    // Right now we only support integral fixup casts.
677
21
    assert(returnType->isIntegralOrUnscopedEnumerationType());
678
21
    assert(retValue->getType()->isIntegralOrUnscopedEnumerationType());
679
680
21
    ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(retValue);
681
682
21
    Expr *E = (cleanups ? 
cleanups->getSubExpr()0
: retValue);
683
21
    E = ImplicitCastExpr::Create(S.Context, returnType, CK_IntegralCast, E,
684
21
                                 /*base path*/ nullptr, VK_RValue,
685
21
                                 FPOptionsOverride());
686
21
    if (cleanups) {
687
0
      cleanups->setSubExpr(E);
688
21
    } else {
689
21
      ret->setRetValue(E);
690
21
    }
691
21
  }
692
22
}
693
694
4.90k
void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) {
695
4.90k
  assert(CSI.HasImplicitReturnType);
696
  // If it was ever a placeholder, it had to been deduced to DependentTy.
697
4.90k
  assert(CSI.ReturnType.isNull() || !CSI.ReturnType->isUndeducedType());
698
4.90k
  assert((!isa<LambdaScopeInfo>(CSI) || !getLangOpts().CPlusPlus14) &&
699
4.90k
         "lambda expressions use auto deduction in C++14 onwards");
700
701
  // C++ core issue 975:
702
  //   If a lambda-expression does not include a trailing-return-type,
703
  //   it is as if the trailing-return-type denotes the following type:
704
  //     - if there are no return statements in the compound-statement,
705
  //       or all return statements return either an expression of type
706
  //       void or no expression or braced-init-list, the type void;
707
  //     - otherwise, if all return statements return an expression
708
  //       and the types of the returned expressions after
709
  //       lvalue-to-rvalue conversion (4.1 [conv.lval]),
710
  //       array-to-pointer conversion (4.2 [conv.array]), and
711
  //       function-to-pointer conversion (4.3 [conv.func]) are the
712
  //       same, that common type;
713
  //     - otherwise, the program is ill-formed.
714
  //
715
  // C++ core issue 1048 additionally removes top-level cv-qualifiers
716
  // from the types of returned expressions to match the C++14 auto
717
  // deduction rules.
718
  //
719
  // In addition, in blocks in non-C++ modes, if all of the return
720
  // statements are enumerator-like expressions of some type T, where
721
  // T has a name for linkage, then we infer the return type of the
722
  // block to be that type.
723
724
  // First case: no return statements, implicit void return type.
725
4.90k
  ASTContext &Ctx = getASTContext();
726
4.90k
  if (CSI.Returns.empty()) {
727
    // It's possible there were simply no /valid/ return statements.
728
    // In this case, the first one we found may have at least given us a type.
729
3.93k
    if (CSI.ReturnType.isNull())
730
3.93k
      CSI.ReturnType = Ctx.VoidTy;
731
3.93k
    return;
732
3.93k
  }
733
734
  // Second case: at least one return statement has dependent type.
735
  // Delay type checking until instantiation.
736
970
  assert(!CSI.ReturnType.isNull() && "We should have a tentative return type.");
737
970
  if (CSI.ReturnType->isDependentType())
738
64
    return;
739
740
  // Try to apply the enum-fuzz rule.
741
906
  if (!getLangOpts().CPlusPlus) {
742
449
    assert(isa<BlockScopeInfo>(CSI));
743
449
    const EnumDecl *ED = findCommonEnumForBlockReturns(CSI.Returns);
744
449
    if (ED) {
745
22
      CSI.ReturnType = Context.getTypeDeclType(ED);
746
22
      adjustBlockReturnsToEnum(*this, CSI.Returns, CSI.ReturnType);
747
22
      return;
748
22
    }
749
884
  }
750
751
  // Third case: only one return statement. Don't bother doing extra work!
752
884
  if (CSI.Returns.size() == 1)
753
841
    return;
754
755
  // General case: many return statements.
756
  // Check that they all have compatible return types.
757
758
  // We require the return types to strictly match here.
759
  // Note that we've already done the required promotions as part of
760
  // processing the return statement.
761
111
  
for (const ReturnStmt *RS : CSI.Returns)43
{
762
111
    const Expr *RetE = RS->getRetValue();
763
764
111
    QualType ReturnType =
765
106
        (RetE ? RetE->getType() : 
Context.VoidTy5
).getUnqualifiedType();
766
111
    if (Context.getCanonicalFunctionResultType(ReturnType) ==
767
102
          Context.getCanonicalFunctionResultType(CSI.ReturnType)) {
768
      // Use the return type with the strictest possible nullability annotation.
769
102
      auto RetTyNullability = ReturnType->getNullability(Ctx);
770
102
      auto BlockNullability = CSI.ReturnType->getNullability(Ctx);
771
102
      if (BlockNullability &&
772
4
          (!RetTyNullability ||
773
2
           hasWeakerNullability(*RetTyNullability, *BlockNullability)))
774
2
        CSI.ReturnType = ReturnType;
775
102
      continue;
776
102
    }
777
778
    // FIXME: This is a poor diagnostic for ReturnStmts without expressions.
779
    // TODO: It's possible that the *first* return is the divergent one.
780
9
    Diag(RS->getBeginLoc(),
781
9
         diag::err_typecheck_missing_return_type_incompatible)
782
9
        << ReturnType << CSI.ReturnType << isa<LambdaScopeInfo>(CSI);
783
    // Continue iterating so that we keep emitting diagnostics.
784
9
  }
785
43
}
786
787
QualType Sema::buildLambdaInitCaptureInitialization(
788
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
789
    Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool IsDirectInit,
790
518
    Expr *&Init) {
791
  // Create an 'auto' or 'auto&' TypeSourceInfo that we can use to
792
  // deduce against.
793
518
  QualType DeductType = Context.getAutoDeductType();
794
518
  TypeLocBuilder TLB;
795
518
  AutoTypeLoc TL = TLB.push<AutoTypeLoc>(DeductType);
796
518
  TL.setNameLoc(Loc);
797
518
  if (ByRef) {
798
107
    DeductType = BuildReferenceType(DeductType, true, Loc, Id);
799
107
    assert(!DeductType.isNull() && "can't build reference to auto");
800
107
    TLB.push<ReferenceTypeLoc>(DeductType).setSigilLoc(Loc);
801
107
  }
802
518
  if (EllipsisLoc.isValid()) {
803
60
    if (Init->containsUnexpandedParameterPack()) {
804
59
      Diag(EllipsisLoc, getLangOpts().CPlusPlus20
805
32
                            ? diag::warn_cxx17_compat_init_capture_pack
806
27
                            : diag::ext_init_capture_pack);
807
59
      DeductType = Context.getPackExpansionType(DeductType, NumExpansions,
808
59
                                                /*ExpectPackInType=*/false);
809
59
      TLB.push<PackExpansionTypeLoc>(DeductType).setEllipsisLoc(EllipsisLoc);
810
1
    } else {
811
      // Just ignore the ellipsis for now and form a non-pack variable. We'll
812
      // diagnose this later when we try to capture it.
813
1
    }
814
60
  }
815
518
  TypeSourceInfo *TSI = TLB.getTypeSourceInfo(Context, DeductType);
816
817
  // Deduce the type of the init capture.
818
518
  QualType DeducedType = deduceVarTypeFromInitializer(
819
518
      /*VarDecl*/nullptr, DeclarationName(Id), DeductType, TSI,
820
518
      SourceRange(Loc, Loc), IsDirectInit, Init);
821
518
  if (DeducedType.isNull())
822
36
    return QualType();
823
824
  // Are we a non-list direct initialization?
825
482
  ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
826
827
  // Perform initialization analysis and ensure any implicit conversions
828
  // (such as lvalue-to-rvalue) are enforced.
829
482
  InitializedEntity Entity =
830
482
      InitializedEntity::InitializeLambdaCapture(Id, DeducedType, Loc);
831
482
  InitializationKind Kind =
832
482
      IsDirectInit
833
155
          ? (CXXDirectInit ? InitializationKind::CreateDirect(
834
136
                                 Loc, Init->getBeginLoc(), Init->getEndLoc())
835
19
                           : InitializationKind::CreateDirectList(Loc))
836
327
          : InitializationKind::CreateCopy(Loc, Init->getBeginLoc());
837
838
482
  MultiExprArg Args = Init;
839
482
  if (CXXDirectInit)
840
136
    Args =
841
136
        MultiExprArg(CXXDirectInit->getExprs(), CXXDirectInit->getNumExprs());
842
482
  QualType DclT;
843
482
  InitializationSequence InitSeq(*this, Entity, Kind, Args);
844
482
  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
845
846
482
  if (Result.isInvalid())
847
4
    return QualType();
848
849
478
  Init = Result.getAs<Expr>();
850
478
  return DeducedType;
851
478
}
852
853
VarDecl *Sema::createLambdaInitCaptureVarDecl(SourceLocation Loc,
854
                                              QualType InitCaptureType,
855
                                              SourceLocation EllipsisLoc,
856
                                              IdentifierInfo *Id,
857
476
                                              unsigned InitStyle, Expr *Init) {
858
  // FIXME: Retain the TypeSourceInfo from buildLambdaInitCaptureInitialization
859
  // rather than reconstructing it here.
860
476
  TypeSourceInfo *TSI = Context.getTrivialTypeSourceInfo(InitCaptureType, Loc);
861
476
  if (auto PETL = TSI->getTypeLoc().getAs<PackExpansionTypeLoc>())
862
57
    PETL.setEllipsisLoc(EllipsisLoc);
863
864
  // Create a dummy variable representing the init-capture. This is not actually
865
  // used as a variable, and only exists as a way to name and refer to the
866
  // init-capture.
867
  // FIXME: Pass in separate source locations for '&' and identifier.
868
476
  VarDecl *NewVD = VarDecl::Create(Context, CurContext, Loc,
869
476
                                   Loc, Id, InitCaptureType, TSI, SC_Auto);
870
476
  NewVD->setInitCapture(true);
871
476
  NewVD->setReferenced(true);
872
  // FIXME: Pass in a VarDecl::InitializationStyle.
873
476
  NewVD->setInitStyle(static_cast<VarDecl::InitializationStyle>(InitStyle));
874
476
  NewVD->markUsed(Context);
875
476
  NewVD->setInit(Init);
876
476
  if (NewVD->isParameterPack())
877
57
    getCurLambda()->LocalPacks.push_back(NewVD);
878
476
  return NewVD;
879
476
}
880
881
474
void Sema::addInitCapture(LambdaScopeInfo *LSI, VarDecl *Var) {
882
474
  assert(Var->isInitCapture() && "init capture flag should be set");
883
474
  LSI->addCapture(Var, /*isBlock*/false, Var->getType()->isReferenceType(),
884
474
                  /*isNested*/false, Var->getLocation(), SourceLocation(),
885
474
                  Var->getType(), /*Invalid*/false);
886
474
}
887
888
void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
889
                                        Declarator &ParamInfo,
890
5.97k
                                        Scope *CurScope) {
891
5.97k
  LambdaScopeInfo *const LSI = getCurLambda();
892
5.97k
  assert(LSI && "LambdaScopeInfo should be on stack!");
893
894
  // Determine if we're within a context where we know that the lambda will
895
  // be dependent, because there are template parameters in scope.
896
5.97k
  bool KnownDependent;
897
5.97k
  if (LSI->NumExplicitTemplateParams > 0) {
898
75
    auto *TemplateParamScope = CurScope->getTemplateParamParent();
899
75
    assert(TemplateParamScope &&
900
75
           "Lambda with explicit template param list should establish a "
901
75
           "template param scope");
902
75
    assert(TemplateParamScope->getParent());
903
75
    KnownDependent = TemplateParamScope->getParent()
904
75
                                       ->getTemplateParamParent() != nullptr;
905
5.89k
  } else {
906
5.89k
    KnownDependent = CurScope->getTemplateParamParent() != nullptr;
907
5.89k
  }
908
909
  // Determine the signature of the call operator.
910
5.97k
  TypeSourceInfo *MethodTyInfo;
911
5.97k
  bool ExplicitParams = true;
912
5.97k
  bool ExplicitResultType = true;
913
5.97k
  bool ContainsUnexpandedParameterPack = false;
914
5.97k
  SourceLocation EndLoc;
915
5.97k
  SmallVector<ParmVarDecl *, 8> Params;
916
5.97k
  if (ParamInfo.getNumTypeObjects() == 0) {
917
    // C++11 [expr.prim.lambda]p4:
918
    //   If a lambda-expression does not include a lambda-declarator, it is as
919
    //   if the lambda-declarator were ().
920
1.46k
    FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention(
921
1.46k
        /*IsVariadic=*/false, /*IsCXXMethod=*/true));
922
1.46k
    EPI.HasTrailingReturn = true;
923
1.46k
    EPI.TypeQuals.addConst();
924
1.46k
    LangAS AS = getDefaultCXXMethodAddrSpace();
925
1.46k
    if (AS != LangAS::Default)
926
1
      EPI.TypeQuals.addAddressSpace(AS);
927
928
    // C++1y [expr.prim.lambda]:
929
    //   The lambda return type is 'auto', which is replaced by the
930
    //   trailing-return type if provided and/or deduced from 'return'
931
    //   statements
932
    // We don't do this before C++1y, because we don't support deduced return
933
    // types there.
934
1.46k
    QualType DefaultTypeForNoTrailingReturn =
935
960
        getLangOpts().CPlusPlus14 ? Context.getAutoDeductType()
936
503
                                  : Context.DependentTy;
937
1.46k
    QualType MethodTy =
938
1.46k
        Context.getFunctionType(DefaultTypeForNoTrailingReturn, None, EPI);
939
1.46k
    MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy);
940
1.46k
    ExplicitParams = false;
941
1.46k
    ExplicitResultType = false;
942
1.46k
    EndLoc = Intro.Range.getEnd();
943
4.51k
  } else {
944
4.51k
    assert(ParamInfo.isFunctionDeclarator() &&
945
4.51k
           "lambda-declarator is a function");
946
4.51k
    DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo();
947
948
    // C++11 [expr.prim.lambda]p5:
949
    //   This function call operator is declared const (9.3.1) if and only if
950
    //   the lambda-expression's parameter-declaration-clause is not followed
951
    //   by mutable. It is neither virtual nor declared volatile. [...]
952
4.51k
    if (!FTI.hasMutableQualifier()) {
953
4.36k
      FTI.getOrCreateMethodQualifiers().SetTypeQual(DeclSpec::TQ_const,
954
4.36k
                                                    SourceLocation());
955
4.36k
    }
956
957
4.51k
    MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope);
958
4.51k
    assert(MethodTyInfo && "no type from lambda-declarator");
959
4.51k
    EndLoc = ParamInfo.getSourceRange().getEnd();
960
961
4.51k
    ExplicitResultType = FTI.hasTrailingReturnType();
962
963
4.51k
    if (FTIHasNonVoidParameters(FTI)) {
964
2.29k
      Params.reserve(FTI.NumParams);
965
4.98k
      for (unsigned i = 0, e = FTI.NumParams; i != e; 
++i2.68k
)
966
2.68k
        Params.push_back(cast<ParmVarDecl>(FTI.Params[i].Param));
967
2.29k
    }
968
969
    // Check for unexpanded parameter packs in the method type.
970
4.51k
    if (MethodTyInfo->getType()->containsUnexpandedParameterPack())
971
27
      DiagnoseUnexpandedParameterPack(Intro.Range.getBegin(), MethodTyInfo,
972
27
                                      UPPC_DeclarationType);
973
4.51k
  }
974
975
5.97k
  CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo,
976
5.97k
                                                 KnownDependent, Intro.Default);
977
5.97k
  CXXMethodDecl *Method =
978
5.97k
      startLambdaDefinition(Class, Intro.Range, MethodTyInfo, EndLoc, Params,
979
5.97k
                            ParamInfo.getDeclSpec().getConstexprSpecifier(),
980
5.97k
                            ParamInfo.getTrailingRequiresClause());
981
5.97k
  if (ExplicitParams)
982
4.51k
    CheckCXXDefaultArguments(Method);
983
984
  // This represents the function body for the lambda function, check if we
985
  // have to apply optnone due to a pragma.
986
5.97k
  AddRangeBasedOptnone(Method);
987
988
  // code_seg attribute on lambda apply to the method.
989
5.97k
  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
990
2
    Method->addAttr(A);
991
992
  // Attributes on the lambda apply to the method.
993
5.97k
  ProcessDeclAttributes(CurScope, Method, ParamInfo);
994
995
  // CUDA lambdas get implicit host and device attributes.
996
5.97k
  if (getLangOpts().CUDA)
997
136
    CUDASetLambdaAttrs(Method);
998
999
  // Number the lambda for linkage purposes if necessary.
1000
5.97k
  handleLambdaNumbering(Class, Method);
1001
1002
  // Introduce the function call operator as the current declaration context.
1003
5.97k
  PushDeclContext(CurScope, Method);
1004
1005
  // Build the lambda scope.
1006
5.97k
  buildLambdaScope(LSI, Method, Intro.Range, Intro.Default, Intro.DefaultLoc,
1007
5.97k
                   ExplicitParams, ExplicitResultType, !Method->isConst());
1008
1009
  // C++11 [expr.prim.lambda]p9:
1010
  //   A lambda-expression whose smallest enclosing scope is a block scope is a
1011
  //   local lambda expression; any other lambda expression shall not have a
1012
  //   capture-default or simple-capture in its lambda-introducer.
1013
  //
1014
  // For simple-captures, this is covered by the check below that any named
1015
  // entity is a variable that can be captured.
1016
  //
1017
  // For DR1632, we also allow a capture-default in any context where we can
1018
  // odr-use 'this' (in particular, in a default initializer for a non-static
1019
  // data member).
1020
5.97k
  if (Intro.Default != LCD_None && 
!Class->getParent()->isFunctionOrMethod()2.27k
&&
1021
31
      (getCurrentThisType().isNull() ||
1022
23
       CheckCXXThisCapture(SourceLocation(), /*Explicit*/true,
1023
23
                           /*BuildAndDiagnose*/false)))
1024
8
    Diag(Intro.DefaultLoc, diag::err_capture_default_non_local);
1025
1026
  // Distinct capture names, for diagnostics.
1027
5.97k
  llvm::SmallSet<IdentifierInfo*, 8> CaptureNames;
1028
1029
  // Handle explicit captures.
1030
5.97k
  SourceLocation PrevCaptureLoc
1031
3.69k
    = Intro.Default == LCD_None? Intro.Range.getBegin() : 
Intro.DefaultLoc2.27k
;
1032
7.42k
  for (auto C = Intro.Captures.begin(), E = Intro.Captures.end(); C != E;
1033
1.45k
       PrevCaptureLoc = C->Loc, ++C) {
1034
1.45k
    if (C->Kind == LCK_This || 
C->Kind == LCK_StarThis1.23k
) {
1035
331
      if (C->Kind == LCK_StarThis)
1036
112
        Diag(C->Loc, !getLangOpts().CPlusPlus17
1037
2
                             ? diag::ext_star_this_lambda_capture_cxx17
1038
110
                             : diag::warn_cxx14_compat_star_this_lambda_capture);
1039
1040
      // C++11 [expr.prim.lambda]p8:
1041
      //   An identifier or this shall not appear more than once in a
1042
      //   lambda-capture.
1043
331
      if (LSI->isCXXThisCaptured()) {
1044
5
        Diag(C->Loc, diag::err_capture_more_than_once)
1045
5
            << "'this'" << SourceRange(LSI->getCXXThisCapture().getLocation())
1046
5
            << FixItHint::CreateRemoval(
1047
5
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1048
5
        continue;
1049
5
      }
1050
1051
      // C++2a [expr.prim.lambda]p8:
1052
      //  If a lambda-capture includes a capture-default that is =,
1053
      //  each simple-capture of that lambda-capture shall be of the form
1054
      //  "&identifier", "this", or "* this". [ Note: The form [&,this] is
1055
      //  redundant but accepted for compatibility with ISO C++14. --end note ]
1056
326
      if (Intro.Default == LCD_ByCopy && 
C->Kind != LCK_StarThis9
)
1057
5
        Diag(C->Loc, !getLangOpts().CPlusPlus20
1058
3
                         ? diag::ext_equals_this_lambda_capture_cxx20
1059
2
                         : diag::warn_cxx17_compat_equals_this_lambda_capture);
1060
1061
      // C++11 [expr.prim.lambda]p12:
1062
      //   If this is captured by a local lambda expression, its nearest
1063
      //   enclosing function shall be a non-static member function.
1064
326
      QualType ThisCaptureType = getCurrentThisType();
1065
326
      if (ThisCaptureType.isNull()) {
1066
5
        Diag(C->Loc, diag::err_this_capture) << true;
1067
5
        continue;
1068
5
      }
1069
1070
321
      CheckCXXThisCapture(C->Loc, /*Explicit=*/true, /*BuildAndDiagnose*/ true,
1071
321
                          /*FunctionScopeIndexToStopAtPtr*/ nullptr,
1072
321
                          C->Kind == LCK_StarThis);
1073
321
      if (!LSI->Captures.empty())
1074
319
        LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1075
321
      continue;
1076
321
    }
1077
1078
1.12k
    assert(C->Id && "missing identifier for capture");
1079
1080
1.12k
    if (C->Init.isInvalid())
1081
7
      continue;
1082
1083
1.11k
    VarDecl *Var = nullptr;
1084
1.11k
    if (C->Init.isUsable()) {
1085
383
      Diag(C->Loc, getLangOpts().CPlusPlus14
1086
334
                       ? diag::warn_cxx11_compat_init_capture
1087
49
                       : diag::ext_init_capture);
1088
1089
      // If the initializer expression is usable, but the InitCaptureType
1090
      // is not, then an error has occurred - so ignore the capture for now.
1091
      // for e.g., [n{0}] { }; <-- if no <initializer_list> is included.
1092
      // FIXME: we should create the init capture variable and mark it invalid
1093
      // in this case.
1094
383
      if (C->InitCaptureType.get().isNull())
1095
32
        continue;
1096
1097
351
      if (C->Init.get()->containsUnexpandedParameterPack() &&
1098
73
          !C->InitCaptureType.get()->getAs<PackExpansionType>())
1099
16
        DiagnoseUnexpandedParameterPack(C->Init.get(), UPPC_Initializer);
1100
1101
351
      unsigned InitStyle;
1102
351
      switch (C->InitKind) {
1103
0
      case LambdaCaptureInitKind::NoInit:
1104
0
        llvm_unreachable("not an init-capture?");
1105
243
      case LambdaCaptureInitKind::CopyInit:
1106
243
        InitStyle = VarDecl::CInit;
1107
243
        break;
1108
90
      case LambdaCaptureInitKind::DirectInit:
1109
90
        InitStyle = VarDecl::CallInit;
1110
90
        break;
1111
18
      case LambdaCaptureInitKind::ListInit:
1112
18
        InitStyle = VarDecl::ListInit;
1113
18
        break;
1114
351
      }
1115
351
      Var = createLambdaInitCaptureVarDecl(C->Loc, C->InitCaptureType.get(),
1116
351
                                           C->EllipsisLoc, C->Id, InitStyle,
1117
351
                                           C->Init.get());
1118
      // C++1y [expr.prim.lambda]p11:
1119
      //   An init-capture behaves as if it declares and explicitly
1120
      //   captures a variable [...] whose declarative region is the
1121
      //   lambda-expression's compound-statement
1122
351
      if (Var)
1123
351
        PushOnScopeChains(Var, CurScope, false);
1124
730
    } else {
1125
730
      assert(C->InitKind == LambdaCaptureInitKind::NoInit &&
1126
730
             "init capture has valid but null init?");
1127
1128
      // C++11 [expr.prim.lambda]p8:
1129
      //   If a lambda-capture includes a capture-default that is &, the
1130
      //   identifiers in the lambda-capture shall not be preceded by &.
1131
      //   If a lambda-capture includes a capture-default that is =, [...]
1132
      //   each identifier it contains shall be preceded by &.
1133
730
      if (C->Kind == LCK_ByRef && 
Intro.Default == LCD_ByRef222
) {
1134
7
        Diag(C->Loc, diag::err_reference_capture_with_reference_default)
1135
7
            << FixItHint::CreateRemoval(
1136
7
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1137
7
        continue;
1138
723
      } else if (C->Kind == LCK_ByCopy && 
Intro.Default == LCD_ByCopy508
) {
1139
1
        Diag(C->Loc, diag::err_copy_capture_with_copy_default)
1140
1
            << FixItHint::CreateRemoval(
1141
1
                SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1142
1
        continue;
1143
1
      }
1144
1145
      // C++11 [expr.prim.lambda]p10:
1146
      //   The identifiers in a capture-list are looked up using the usual
1147
      //   rules for unqualified name lookup (3.4.1)
1148
722
      DeclarationNameInfo Name(C->Id, C->Loc);
1149
722
      LookupResult R(*this, Name, LookupOrdinaryName);
1150
722
      LookupName(R, CurScope);
1151
722
      if (R.isAmbiguous())
1152
1
        continue;
1153
721
      if (R.empty()) {
1154
        // FIXME: Disable corrections that would add qualification?
1155
1
        CXXScopeSpec ScopeSpec;
1156
1
        DeclFilterCCC<VarDecl> Validator{};
1157
1
        if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator))
1158
0
          continue;
1159
721
      }
1160
1161
721
      Var = R.getAsSingle<VarDecl>();
1162
721
      if (Var && 
DiagnoseUseOfDecl(Var, C->Loc)715
)
1163
2
        continue;
1164
1.07k
    }
1165
1166
    // C++11 [expr.prim.lambda]p8:
1167
    //   An identifier or this shall not appear more than once in a
1168
    //   lambda-capture.
1169
1.07k
    if (!CaptureNames.insert(C->Id).second) {
1170
9
      if (Var && LSI->isCaptured(Var)) {
1171
7
        Diag(C->Loc, diag::err_capture_more_than_once)
1172
7
            << C->Id << SourceRange(LSI->getCapture(Var).getLocation())
1173
7
            << FixItHint::CreateRemoval(
1174
7
                   SourceRange(getLocForEndOfToken(PrevCaptureLoc), C->Loc));
1175
7
      } else
1176
        // Previous capture captured something different (one or both was
1177
        // an init-cpature): no fixit.
1178
2
        Diag(C->Loc, diag::err_capture_more_than_once) << C->Id;
1179
9
      continue;
1180
9
    }
1181
1182
    // C++11 [expr.prim.lambda]p10:
1183
    //   [...] each such lookup shall find a variable with automatic storage
1184
    //   duration declared in the reaching scope of the local lambda expression.
1185
    // Note that the 'reaching scope' check happens in tryCaptureVariable().
1186
1.06k
    if (!Var) {
1187
6
      Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id;
1188
6
      continue;
1189
6
    }
1190
1191
    // Ignore invalid decls; they'll just confuse the code later.
1192
1.05k
    if (Var->isInvalidDecl())
1193
4
      continue;
1194
1195
1.05k
    if (!Var->hasLocalStorage()) {
1196
2
      Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id;
1197
2
      Diag(Var->getLocation(), diag::note_previous_decl) << C->Id;
1198
2
      continue;
1199
2
    }
1200
1201
    // C++11 [expr.prim.lambda]p23:
1202
    //   A capture followed by an ellipsis is a pack expansion (14.5.3).
1203
1.04k
    SourceLocation EllipsisLoc;
1204
1.04k
    if (C->EllipsisLoc.isValid()) {
1205
130
      if (Var->isParameterPack()) {
1206
126
        EllipsisLoc = C->EllipsisLoc;
1207
4
      } else {
1208
4
        Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1209
1
            << (C->Init.isUsable() ? C->Init.get()->getSourceRange()
1210
3
                                   : SourceRange(C->Loc));
1211
1212
        // Just ignore the ellipsis.
1213
4
      }
1214
919
    } else if (Var->isParameterPack()) {
1215
13
      ContainsUnexpandedParameterPack = true;
1216
13
    }
1217
1218
1.04k
    if (C->Init.isUsable()) {
1219
349
      addInitCapture(LSI, Var);
1220
700
    } else {
1221
210
      TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef :
1222
490
                                                   TryCapture_ExplicitByVal;
1223
700
      tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc);
1224
700
    }
1225
1.04k
    if (!LSI->Captures.empty())
1226
1.04k
      LSI->ExplicitCaptureRanges[LSI->Captures.size() - 1] = C->ExplicitRange;
1227
1.04k
  }
1228
5.97k
  finishLambdaExplicitCaptures(LSI);
1229
1230
5.97k
  LSI->ContainsUnexpandedParameterPack |= ContainsUnexpandedParameterPack;
1231
1232
  // Add lambda parameters into scope.
1233
5.97k
  addLambdaParameters(Intro.Captures, Method, CurScope);
1234
1235
  // Enter a new evaluation context to insulate the lambda from any
1236
  // cleanups from the enclosing full-expression.
1237
5.97k
  PushExpressionEvaluationContext(
1238
5.97k
      LSI->CallOperator->isConsteval()
1239
4
          ? ExpressionEvaluationContext::ConstantEvaluated
1240
5.97k
          : ExpressionEvaluationContext::PotentiallyEvaluated);
1241
5.97k
}
1242
1243
void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
1244
193
                            bool IsInstantiation) {
1245
193
  LambdaScopeInfo *LSI = cast<LambdaScopeInfo>(FunctionScopes.back());
1246
1247
  // Leave the expression-evaluation context.
1248
193
  DiscardCleanupsInEvaluationContext();
1249
193
  PopExpressionEvaluationContext();
1250
1251
  // Leave the context of the lambda.
1252
193
  if (!IsInstantiation)
1253
174
    PopDeclContext();
1254
1255
  // Finalize the lambda.
1256
193
  CXXRecordDecl *Class = LSI->Lambda;
1257
193
  Class->setInvalidDecl();
1258
193
  SmallVector<Decl*, 4> Fields(Class->fields());
1259
193
  ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1260
193
              SourceLocation(), ParsedAttributesView());
1261
193
  CheckCompletedCXXClass(nullptr, Class);
1262
1263
193
  PopFunctionScopeInfo();
1264
193
}
1265
1266
QualType Sema::getLambdaConversionFunctionResultType(
1267
3.64k
    const FunctionProtoType *CallOpProto) {
1268
  // The function type inside the pointer type is the same as the call
1269
  // operator with some tweaks. The calling convention is the default free
1270
  // function convention, and the type qualifications are lost.
1271
3.64k
  const FunctionProtoType::ExtProtoInfo CallOpExtInfo =
1272
3.64k
      CallOpProto->getExtProtoInfo();
1273
3.64k
  FunctionProtoType::ExtProtoInfo InvokerExtInfo = CallOpExtInfo;
1274
3.64k
  CallingConv CC = Context.getDefaultCallingConvention(
1275
3.64k
      CallOpProto->isVariadic(), /*IsCXXMethod=*/false);
1276
3.64k
  InvokerExtInfo.ExtInfo = InvokerExtInfo.ExtInfo.withCallingConv(CC);
1277
3.64k
  InvokerExtInfo.TypeQuals = Qualifiers();
1278
3.64k
  assert(InvokerExtInfo.RefQualifier == RQ_None &&
1279
3.64k
      "Lambda's call operator should not have a reference qualifier");
1280
3.64k
  return Context.getFunctionType(CallOpProto->getReturnType(),
1281
3.64k
                                 CallOpProto->getParamTypes(), InvokerExtInfo);
1282
3.64k
}
1283
1284
/// Add a lambda's conversion to function pointer, as described in
1285
/// C++11 [expr.prim.lambda]p6.
1286
static void addFunctionPointerConversion(Sema &S,
1287
                                         SourceRange IntroducerRange,
1288
                                         CXXRecordDecl *Class,
1289
3.36k
                                         CXXMethodDecl *CallOperator) {
1290
  // This conversion is explicitly disabled if the lambda's function has
1291
  // pass_object_size attributes on any of its parameters.
1292
3.03k
  auto HasPassObjectSizeAttr = [](const ParmVarDecl *P) {
1293
3.03k
    return P->hasAttr<PassObjectSizeAttr>();
1294
3.03k
  };
1295
3.36k
  if (llvm::any_of(CallOperator->parameters(), HasPassObjectSizeAttr))
1296
2
    return;
1297
1298
  // Add the conversion to function pointer.
1299
3.36k
  QualType InvokerFunctionTy = S.getLambdaConversionFunctionResultType(
1300
3.36k
      CallOperator->getType()->castAs<FunctionProtoType>());
1301
3.36k
  QualType PtrToFunctionTy = S.Context.getPointerType(InvokerFunctionTy);
1302
1303
  // Create the type of the conversion function.
1304
3.36k
  FunctionProtoType::ExtProtoInfo ConvExtInfo(
1305
3.36k
      S.Context.getDefaultCallingConvention(
1306
3.36k
      /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1307
  // The conversion function is always const and noexcept.
1308
3.36k
  ConvExtInfo.TypeQuals = Qualifiers();
1309
3.36k
  ConvExtInfo.TypeQuals.addConst();
1310
3.36k
  ConvExtInfo.ExceptionSpec.Type = EST_BasicNoexcept;
1311
3.36k
  QualType ConvTy =
1312
3.36k
      S.Context.getFunctionType(PtrToFunctionTy, None, ConvExtInfo);
1313
1314
3.36k
  SourceLocation Loc = IntroducerRange.getBegin();
1315
3.36k
  DeclarationName ConversionName
1316
3.36k
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1317
3.36k
        S.Context.getCanonicalType(PtrToFunctionTy));
1318
3.36k
  DeclarationNameLoc ConvNameLoc;
1319
  // Construct a TypeSourceInfo for the conversion function, and wire
1320
  // all the parameters appropriately for the FunctionProtoTypeLoc
1321
  // so that everything works during transformation/instantiation of
1322
  // generic lambdas.
1323
  // The main reason for wiring up the parameters of the conversion
1324
  // function with that of the call operator is so that constructs
1325
  // like the following work:
1326
  // auto L = [](auto b) {                <-- 1
1327
  //   return [](auto a) -> decltype(a) { <-- 2
1328
  //      return a;
1329
  //   };
1330
  // };
1331
  // int (*fp)(int) = L(5);
1332
  // Because the trailing return type can contain DeclRefExprs that refer
1333
  // to the original call operator's variables, we hijack the call
1334
  // operators ParmVarDecls below.
1335
3.36k
  TypeSourceInfo *ConvNamePtrToFunctionTSI =
1336
3.36k
      S.Context.getTrivialTypeSourceInfo(PtrToFunctionTy, Loc);
1337
3.36k
  ConvNameLoc.NamedType.TInfo = ConvNamePtrToFunctionTSI;
1338
1339
  // The conversion function is a conversion to a pointer-to-function.
1340
3.36k
  TypeSourceInfo *ConvTSI = S.Context.getTrivialTypeSourceInfo(ConvTy, Loc);
1341
3.36k
  FunctionProtoTypeLoc ConvTL =
1342
3.36k
      ConvTSI->getTypeLoc().getAs<FunctionProtoTypeLoc>();
1343
  // Get the result of the conversion function which is a pointer-to-function.
1344
3.36k
  PointerTypeLoc PtrToFunctionTL =
1345
3.36k
      ConvTL.getReturnLoc().getAs<PointerTypeLoc>();
1346
  // Do the same for the TypeSourceInfo that is used to name the conversion
1347
  // operator.
1348
3.36k
  PointerTypeLoc ConvNamePtrToFunctionTL =
1349
3.36k
      ConvNamePtrToFunctionTSI->getTypeLoc().getAs<PointerTypeLoc>();
1350
1351
  // Get the underlying function types that the conversion function will
1352
  // be converting to (should match the type of the call operator).
1353
3.36k
  FunctionProtoTypeLoc CallOpConvTL =
1354
3.36k
      PtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1355
3.36k
  FunctionProtoTypeLoc CallOpConvNameTL =
1356
3.36k
    ConvNamePtrToFunctionTL.getPointeeLoc().getAs<FunctionProtoTypeLoc>();
1357
1358
  // Wire up the FunctionProtoTypeLocs with the call operator's parameters.
1359
  // These parameter's are essentially used to transform the name and
1360
  // the type of the conversion operator.  By using the same parameters
1361
  // as the call operator's we don't have to fix any back references that
1362
  // the trailing return type of the call operator's uses (such as
1363
  // decltype(some_type<decltype(a)>::type{} + decltype(a){}) etc.)
1364
  // - we can simply use the return type of the call operator, and
1365
  // everything should work.
1366
3.36k
  SmallVector<ParmVarDecl *, 4> InvokerParams;
1367
6.39k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I3.03k
) {
1368
3.03k
    ParmVarDecl *From = CallOperator->getParamDecl(I);
1369
1370
3.03k
    InvokerParams.push_back(ParmVarDecl::Create(
1371
3.03k
        S.Context,
1372
        // Temporarily add to the TU. This is set to the invoker below.
1373
3.03k
        S.Context.getTranslationUnitDecl(), From->getBeginLoc(),
1374
3.03k
        From->getLocation(), From->getIdentifier(), From->getType(),
1375
3.03k
        From->getTypeSourceInfo(), From->getStorageClass(),
1376
3.03k
        /*DefArg=*/nullptr));
1377
3.03k
    CallOpConvTL.setParam(I, From);
1378
3.03k
    CallOpConvNameTL.setParam(I, From);
1379
3.03k
  }
1380
1381
3.36k
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1382
3.36k
      S.Context, Class, Loc,
1383
3.36k
      DeclarationNameInfo(ConversionName, Loc, ConvNameLoc), ConvTy, ConvTSI,
1384
3.36k
      /*isInline=*/true, ExplicitSpecifier(),
1385
2.57k
      S.getLangOpts().CPlusPlus17 ? 
CSK_constexpr781
: CSK_unspecified,
1386
3.36k
      CallOperator->getBody()->getEndLoc());
1387
3.36k
  Conversion->setAccess(AS_public);
1388
3.36k
  Conversion->setImplicit(true);
1389
1390
3.36k
  if (Class->isGenericLambda()) {
1391
    // Create a template version of the conversion operator, using the template
1392
    // parameter list of the function call operator.
1393
1.38k
    FunctionTemplateDecl *TemplateCallOperator =
1394
1.38k
            CallOperator->getDescribedFunctionTemplate();
1395
1.38k
    FunctionTemplateDecl *ConversionTemplate =
1396
1.38k
                  FunctionTemplateDecl::Create(S.Context, Class,
1397
1.38k
                                      Loc, ConversionName,
1398
1.38k
                                      TemplateCallOperator->getTemplateParameters(),
1399
1.38k
                                      Conversion);
1400
1.38k
    ConversionTemplate->setAccess(AS_public);
1401
1.38k
    ConversionTemplate->setImplicit(true);
1402
1.38k
    Conversion->setDescribedFunctionTemplate(ConversionTemplate);
1403
1.38k
    Class->addDecl(ConversionTemplate);
1404
1.38k
  } else
1405
1.97k
    Class->addDecl(Conversion);
1406
  // Add a non-static member function that will be the result of
1407
  // the conversion with a certain unique ID.
1408
3.36k
  DeclarationName InvokerName = &S.Context.Idents.get(
1409
3.36k
                                                 getLambdaStaticInvokerName());
1410
  // FIXME: Instead of passing in the CallOperator->getTypeSourceInfo()
1411
  // we should get a prebuilt TrivialTypeSourceInfo from Context
1412
  // using FunctionTy & Loc and get its TypeLoc as a FunctionProtoTypeLoc
1413
  // then rewire the parameters accordingly, by hoisting up the InvokeParams
1414
  // loop below and then use its Params to set Invoke->setParams(...) below.
1415
  // This would avoid the 'const' qualifier of the calloperator from
1416
  // contaminating the type of the invoker, which is currently adjusted
1417
  // in SemaTemplateDeduction.cpp:DeduceTemplateArguments.  Fixing the
1418
  // trailing return type of the invoker would require a visitor to rebuild
1419
  // the trailing return type and adjusting all back DeclRefExpr's to refer
1420
  // to the new static invoker parameters - not the call operator's.
1421
3.36k
  CXXMethodDecl *Invoke = CXXMethodDecl::Create(
1422
3.36k
      S.Context, Class, Loc, DeclarationNameInfo(InvokerName, Loc),
1423
3.36k
      InvokerFunctionTy, CallOperator->getTypeSourceInfo(), SC_Static,
1424
3.36k
      /*isInline=*/true, CSK_unspecified, CallOperator->getBody()->getEndLoc());
1425
6.39k
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I3.03k
)
1426
3.03k
    InvokerParams[I]->setOwningFunction(Invoke);
1427
3.36k
  Invoke->setParams(InvokerParams);
1428
3.36k
  Invoke->setAccess(AS_private);
1429
3.36k
  Invoke->setImplicit(true);
1430
3.36k
  if (Class->isGenericLambda()) {
1431
1.38k
    FunctionTemplateDecl *TemplateCallOperator =
1432
1.38k
            CallOperator->getDescribedFunctionTemplate();
1433
1.38k
    FunctionTemplateDecl *StaticInvokerTemplate = FunctionTemplateDecl::Create(
1434
1.38k
                          S.Context, Class, Loc, InvokerName,
1435
1.38k
                          TemplateCallOperator->getTemplateParameters(),
1436
1.38k
                          Invoke);
1437
1.38k
    StaticInvokerTemplate->setAccess(AS_private);
1438
1.38k
    StaticInvokerTemplate->setImplicit(true);
1439
1.38k
    Invoke->setDescribedFunctionTemplate(StaticInvokerTemplate);
1440
1.38k
    Class->addDecl(StaticInvokerTemplate);
1441
1.38k
  } else
1442
1.97k
    Class->addDecl(Invoke);
1443
3.36k
}
1444
1445
/// Add a lambda's conversion to block pointer.
1446
static void addBlockPointerConversion(Sema &S,
1447
                                      SourceRange IntroducerRange,
1448
                                      CXXRecordDecl *Class,
1449
159
                                      CXXMethodDecl *CallOperator) {
1450
159
  QualType FunctionTy = S.getLambdaConversionFunctionResultType(
1451
159
      CallOperator->getType()->castAs<FunctionProtoType>());
1452
159
  QualType BlockPtrTy = S.Context.getBlockPointerType(FunctionTy);
1453
1454
159
  FunctionProtoType::ExtProtoInfo ConversionEPI(
1455
159
      S.Context.getDefaultCallingConvention(
1456
159
          /*IsVariadic=*/false, /*IsCXXMethod=*/true));
1457
159
  ConversionEPI.TypeQuals = Qualifiers();
1458
159
  ConversionEPI.TypeQuals.addConst();
1459
159
  QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, None, ConversionEPI);
1460
1461
159
  SourceLocation Loc = IntroducerRange.getBegin();
1462
159
  DeclarationName Name
1463
159
    = S.Context.DeclarationNames.getCXXConversionFunctionName(
1464
159
        S.Context.getCanonicalType(BlockPtrTy));
1465
159
  DeclarationNameLoc NameLoc;
1466
159
  NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc);
1467
159
  CXXConversionDecl *Conversion = CXXConversionDecl::Create(
1468
159
      S.Context, Class, Loc, DeclarationNameInfo(Name, Loc, NameLoc), ConvTy,
1469
159
      S.Context.getTrivialTypeSourceInfo(ConvTy, Loc),
1470
159
      /*isInline=*/true, ExplicitSpecifier(), CSK_unspecified,
1471
159
      CallOperator->getBody()->getEndLoc());
1472
159
  Conversion->setAccess(AS_public);
1473
159
  Conversion->setImplicit(true);
1474
159
  Class->addDecl(Conversion);
1475
159
}
1476
1477
ExprResult Sema::BuildCaptureInit(const Capture &Cap,
1478
                                  SourceLocation ImplicitCaptureLoc,
1479
387k
                                  bool IsOpenMPMapping) {
1480
  // VLA captures don't have a stored initialization expression.
1481
387k
  if (Cap.isVLATypeCapture())
1482
8.81k
    return ExprResult();
1483
1484
  // An init-capture is initialized directly from its stored initializer.
1485
379k
  if (Cap.isInitCapture())
1486
470
    return Cap.getVariable()->getInit();
1487
1488
  // For anything else, build an initialization expression. For an implicit
1489
  // capture, the capture notionally happens at the capture-default, so use
1490
  // that location here.
1491
378k
  SourceLocation Loc =
1492
377k
      ImplicitCaptureLoc.isValid() ? ImplicitCaptureLoc : 
Cap.getLocation()1.23k
;
1493
1494
  // C++11 [expr.prim.lambda]p21:
1495
  //   When the lambda-expression is evaluated, the entities that
1496
  //   are captured by copy are used to direct-initialize each
1497
  //   corresponding non-static data member of the resulting closure
1498
  //   object. (For array members, the array elements are
1499
  //   direct-initialized in increasing subscript order.) These
1500
  //   initializations are performed in the (unspecified) order in
1501
  //   which the non-static data members are declared.
1502
1503
  // C++ [expr.prim.lambda]p12:
1504
  //   An entity captured by a lambda-expression is odr-used (3.2) in
1505
  //   the scope containing the lambda-expression.
1506
378k
  ExprResult Init;
1507
378k
  IdentifierInfo *Name = nullptr;
1508
378k
  if (Cap.isThisCapture()) {
1509
11.0k
    QualType ThisTy = getCurrentThisType();
1510
11.0k
    Expr *This = BuildCXXThisExpr(Loc, ThisTy, ImplicitCaptureLoc.isValid());
1511
11.0k
    if (Cap.isCopyCapture())
1512
128
      Init = CreateBuiltinUnaryOp(Loc, UO_Deref, This);
1513
10.9k
    else
1514
10.9k
      Init = This;
1515
367k
  } else {
1516
367k
    assert(Cap.isVariableCapture() && "unknown kind of capture");
1517
367k
    VarDecl *Var = Cap.getVariable();
1518
367k
    Name = Var->getIdentifier();
1519
367k
    Init = BuildDeclarationNameExpr(
1520
367k
      CXXScopeSpec(), DeclarationNameInfo(Var->getDeclName(), Loc), Var);
1521
367k
  }
1522
1523
  // In OpenMP, the capture kind doesn't actually describe how to capture:
1524
  // variables are "mapped" onto the device in a process that does not formally
1525
  // make a copy, even for a "copy capture".
1526
378k
  if (IsOpenMPMapping)
1527
373k
    return Init;
1528
1529
4.70k
  if (Init.isInvalid())
1530
0
    return ExprError();
1531
1532
4.70k
  Expr *InitExpr = Init.get();
1533
4.70k
  InitializedEntity Entity = InitializedEntity::InitializeLambdaCapture(
1534
4.70k
      Name, Cap.getCaptureType(), Loc);
1535
4.70k
  InitializationKind InitKind =
1536
4.70k
      InitializationKind::CreateDirect(Loc, Loc, Loc);
1537
4.70k
  InitializationSequence InitSeq(*this, Entity, InitKind, InitExpr);
1538
4.70k
  return InitSeq.Perform(*this, Entity, InitKind, InitExpr);
1539
4.70k
}
1540
1541
ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
1542
5.80k
                                 Scope *CurScope) {
1543
5.80k
  LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
1544
5.80k
  ActOnFinishFunctionBody(LSI.CallOperator, Body);
1545
5.80k
  return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
1546
5.80k
}
1547
1548
static LambdaCaptureDefault
1549
7.33k
mapImplicitCaptureStyle(CapturingScopeInfo::ImplicitCaptureStyle ICS) {
1550
7.33k
  switch (ICS) {
1551
4.70k
  case CapturingScopeInfo::ImpCap_None:
1552
4.70k
    return LCD_None;
1553
748
  case CapturingScopeInfo::ImpCap_LambdaByval:
1554
748
    return LCD_ByCopy;
1555
1.88k
  case CapturingScopeInfo::ImpCap_CapturedRegion:
1556
1.88k
  case CapturingScopeInfo::ImpCap_LambdaByref:
1557
1.88k
    return LCD_ByRef;
1558
0
  case CapturingScopeInfo::ImpCap_Block:
1559
0
    llvm_unreachable("block capture in lambda");
1560
0
  }
1561
0
  llvm_unreachable("Unknown implicit capture style");
1562
0
}
1563
1564
634
bool Sema::CaptureHasSideEffects(const Capture &From) {
1565
634
  if (From.isInitCapture()) {
1566
192
    Expr *Init = From.getVariable()->getInit();
1567
192
    if (Init && Init->HasSideEffects(Context))
1568
50
      return true;
1569
584
  }
1570
1571
584
  if (!From.isCopyCapture())
1572
156
    return false;
1573
1574
428
  const QualType T = From.isThisCapture()
1575
33
                         ? getCurrentThisType()->getPointeeType()
1576
395
                         : From.getCaptureType();
1577
1578
428
  if (T.isVolatileQualified())
1579
2
    return true;
1580
1581
426
  const Type *BaseT = T->getBaseElementTypeUnsafe();
1582
426
  if (const CXXRecordDecl *RD = BaseT->getAsCXXRecordDecl())
1583
82
    return !RD->isCompleteDefinition() || !RD->hasTrivialCopyConstructor() ||
1584
50
           !RD->hasTrivialDestructor();
1585
1586
344
  return false;
1587
344
}
1588
1589
bool Sema::DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
1590
634
                                       const Capture &From) {
1591
634
  if (CaptureHasSideEffects(From))
1592
87
    return false;
1593
1594
547
  if (From.isVLATypeCapture())
1595
18
    return false;
1596
1597
529
  auto diag = Diag(From.getLocation(), diag::warn_unused_lambda_capture);
1598
529
  if (From.isThisCapture())
1599
77
    diag << "'this'";
1600
452
  else
1601
452
    diag << From.getVariable();
1602
529
  diag << From.isNonODRUsed();
1603
529
  diag << FixItHint::CreateRemoval(CaptureRange);
1604
529
  return true;
1605
529
}
1606
1607
/// Create a field within the lambda class or captured statement record for the
1608
/// given capture.
1609
FieldDecl *Sema::BuildCaptureField(RecordDecl *RD,
1610
387k
                                   const sema::Capture &Capture) {
1611
387k
  SourceLocation Loc = Capture.getLocation();
1612
387k
  QualType FieldType = Capture.getCaptureType();
1613
1614
387k
  TypeSourceInfo *TSI = nullptr;
1615
387k
  if (Capture.isVariableCapture()) {
1616
368k
    auto *Var = Capture.getVariable();
1617
368k
    if (Var->isInitCapture())
1618
517
      TSI = Capture.getVariable()->getTypeSourceInfo();
1619
368k
  }
1620
1621
  // FIXME: Should we really be doing this? A null TypeSourceInfo seems more
1622
  // appropriate, at least for an implicit capture.
1623
387k
  if (!TSI)
1624
387k
    TSI = Context.getTrivialTypeSourceInfo(FieldType, Loc);
1625
1626
  // Build the non-static data member.
1627
387k
  FieldDecl *Field =
1628
387k
      FieldDecl::Create(Context, RD, /*StartLoc=*/Loc, /*IdLoc=*/Loc,
1629
387k
                        /*Id=*/nullptr, FieldType, TSI, /*BW=*/nullptr,
1630
387k
                        /*Mutable=*/false, ICIS_NoInit);
1631
  // If the variable being captured has an invalid type, mark the class as
1632
  // invalid as well.
1633
387k
  if (!FieldType->isDependentType()) {
1634
383k
    if (RequireCompleteSizedType(Loc, FieldType,
1635
3
                                 diag::err_field_incomplete_or_sizeless)) {
1636
3
      RD->setInvalidDecl();
1637
3
      Field->setInvalidDecl();
1638
383k
    } else {
1639
383k
      NamedDecl *Def;
1640
383k
      FieldType->isIncompleteType(&Def);
1641
383k
      if (Def && 
Def->isInvalidDecl()276
) {
1642
2
        RD->setInvalidDecl();
1643
2
        Field->setInvalidDecl();
1644
2
      }
1645
383k
    }
1646
383k
  }
1647
387k
  Field->setImplicit(true);
1648
387k
  Field->setAccess(AS_private);
1649
387k
  RD->addDecl(Field);
1650
1651
387k
  if (Capture.isVLATypeCapture())
1652
8.81k
    Field->setCapturedVLAType(Capture.getCapturedVLAType());
1653
1654
387k
  return Field;
1655
387k
}
1656
1657
ExprResult Sema::BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
1658
7.33k
                                 LambdaScopeInfo *LSI) {
1659
  // Collect information from the lambda scope.
1660
7.33k
  SmallVector<LambdaCapture, 4> Captures;
1661
7.33k
  SmallVector<Expr *, 4> CaptureInits;
1662
7.33k
  SourceLocation CaptureDefaultLoc = LSI->CaptureDefaultLoc;
1663
7.33k
  LambdaCaptureDefault CaptureDefault =
1664
7.33k
      mapImplicitCaptureStyle(LSI->ImpCaptureStyle);
1665
7.33k
  CXXRecordDecl *Class;
1666
7.33k
  CXXMethodDecl *CallOperator;
1667
7.33k
  SourceRange IntroducerRange;
1668
7.33k
  bool ExplicitParams;
1669
7.33k
  bool ExplicitResultType;
1670
7.33k
  CleanupInfo LambdaCleanup;
1671
7.33k
  bool ContainsUnexpandedParameterPack;
1672
7.33k
  bool IsGenericLambda;
1673
7.33k
  {
1674
7.33k
    CallOperator = LSI->CallOperator;
1675
7.33k
    Class = LSI->Lambda;
1676
7.33k
    IntroducerRange = LSI->IntroducerRange;
1677
7.33k
    ExplicitParams = LSI->ExplicitParams;
1678
7.33k
    ExplicitResultType = !LSI->HasImplicitReturnType;
1679
7.33k
    LambdaCleanup = LSI->Cleanup;
1680
7.33k
    ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack;
1681
7.33k
    IsGenericLambda = Class->isGenericLambda();
1682
1683
7.33k
    CallOperator->setLexicalDeclContext(Class);
1684
7.33k
    Decl *TemplateOrNonTemplateCallOperatorDecl =
1685
7.33k
        CallOperator->getDescribedFunctionTemplate()
1686
1.91k
        ? CallOperator->getDescribedFunctionTemplate()
1687
5.41k
        : cast<Decl>(CallOperator);
1688
1689
    // FIXME: Is this really the best choice? Keeping the lexical decl context
1690
    // set as CurContext seems more faithful to the source.
1691
7.33k
    TemplateOrNonTemplateCallOperatorDecl->setLexicalDeclContext(Class);
1692
1693
7.33k
    PopExpressionEvaluationContext();
1694
1695
    // True if the current capture has a used capture or default before it.
1696
7.33k
    bool CurHasPreviousCapture = CaptureDefault != LCD_None;
1697
7.33k
    SourceLocation PrevCaptureLoc = CurHasPreviousCapture ?
1698
4.70k
        
CaptureDefaultLoc2.62k
: IntroducerRange.getBegin();
1699
1700
12.4k
    for (unsigned I = 0, N = LSI->Captures.size(); I != N; 
++I5.12k
) {
1701
5.14k
      const Capture &From = LSI->Captures[I];
1702
1703
5.14k
      if (From.isInvalid())
1704
24
        return ExprError();
1705
1706
5.12k
      assert(!From.isBlockCapture() && "Cannot capture __block variables");
1707
5.12k
      bool IsImplicit = I >= LSI->NumExplicitCaptures;
1708
5.12k
      SourceLocation ImplicitCaptureLoc =
1709
3.40k
          IsImplicit ? CaptureDefaultLoc : 
SourceLocation()1.72k
;
1710
1711
      // Use source ranges of explicit captures for fixits where available.
1712
5.12k
      SourceRange CaptureRange = LSI->ExplicitCaptureRanges[I];
1713
1714
      // Warn about unused explicit captures.
1715
5.12k
      bool IsCaptureUsed = true;
1716
5.12k
      if (!CurContext->isDependentContext() && 
!IsImplicit4.60k
&&
1717
1.33k
          !From.isODRUsed()) {
1718
        // Initialized captures that are non-ODR used may not be eliminated.
1719
        // FIXME: Where did the IsGenericLambda here come from?
1720
645
        bool NonODRUsedInitCapture =
1721
645
            IsGenericLambda && 
From.isNonODRUsed()29
&&
From.isInitCapture()12
;
1722
645
        if (!NonODRUsedInitCapture) {
1723
634
          bool IsLast = (I + 1) == LSI->NumExplicitCaptures;
1724
634
          SourceRange FixItRange;
1725
634
          if (CaptureRange.isValid()) {
1726
499
            if (!CurHasPreviousCapture && 
!IsLast433
) {
1727
              // If there are no captures preceding this capture, remove the
1728
              // following comma.
1729
93
              FixItRange = SourceRange(CaptureRange.getBegin(),
1730
93
                                       getLocForEndOfToken(CaptureRange.getEnd()));
1731
406
            } else {
1732
              // Otherwise, remove the comma since the last used capture.
1733
406
              FixItRange = SourceRange(getLocForEndOfToken(PrevCaptureLoc),
1734
406
                                       CaptureRange.getEnd());
1735
406
            }
1736
499
          }
1737
1738
634
          IsCaptureUsed = !DiagnoseUnusedLambdaCapture(FixItRange, From);
1739
634
        }
1740
645
      }
1741
1742
5.12k
      if (CaptureRange.isValid()) {
1743
1.33k
        CurHasPreviousCapture |= IsCaptureUsed;
1744
1.33k
        PrevCaptureLoc = CaptureRange.getEnd();
1745
1.33k
      }
1746
1747
      // Map the capture to our AST representation.
1748
5.12k
      LambdaCapture Capture = [&] {
1749
5.12k
        if (From.isThisCapture()) {
1750
          // Capturing 'this' implicitly with a default of '[=]' is deprecated,
1751
          // because it results in a reference capture. Don't warn prior to
1752
          // C++2a; there's nothing that can be done about it before then.
1753
705
          if (getLangOpts().CPlusPlus20 && 
IsImplicit35
&&
1754
23
              CaptureDefault == LCD_ByCopy) {
1755
20
            Diag(From.getLocation(), diag::warn_deprecated_this_capture);
1756
20
            Diag(CaptureDefaultLoc, diag::note_deprecated_this_capture)
1757
20
                << FixItHint::CreateInsertion(
1758
20
                       getLocForEndOfToken(CaptureDefaultLoc), ", this");
1759
20
          }
1760
705
          return LambdaCapture(From.getLocation(), IsImplicit,
1761
577
                               From.isCopyCapture() ? 
LCK_StarThis128
: LCK_This);
1762
4.41k
        } else if (From.isVLATypeCapture()) {
1763
46
          return LambdaCapture(From.getLocation(), IsImplicit, LCK_VLAType);
1764
4.37k
        } else {
1765
4.37k
          assert(From.isVariableCapture() && "unknown kind of capture");
1766
4.37k
          VarDecl *Var = From.getVariable();
1767
4.37k
          LambdaCaptureKind Kind =
1768
3.09k
              From.isCopyCapture() ? 
LCK_ByCopy1.27k
: LCK_ByRef;
1769
4.37k
          return LambdaCapture(From.getLocation(), IsImplicit, Kind, Var,
1770
4.37k
                               From.getEllipsisLoc());
1771
4.37k
        }
1772
5.12k
      }();
1773
1774
      // Form the initializer for the capture field.
1775
5.12k
      ExprResult Init = BuildCaptureInit(From, ImplicitCaptureLoc);
1776
1777
      // FIXME: Skip this capture if the capture is not used, the initializer
1778
      // has no side-effects, the type of the capture is trivial, and the
1779
      // lambda is not externally visible.
1780
1781
      // Add a FieldDecl for the capture and form its initializer.
1782
5.12k
      BuildCaptureField(Class, From);
1783
5.12k
      Captures.push_back(Capture);
1784
5.12k
      CaptureInits.push_back(Init.get());
1785
1786
5.12k
      if (LangOpts.CUDA)
1787
32
        CUDACheckLambdaCapture(CallOperator, From);
1788
5.12k
    }
1789
1790
7.30k
    Class->setCaptures(Context, Captures);
1791
1792
    // C++11 [expr.prim.lambda]p6:
1793
    //   The closure type for a lambda-expression with no lambda-capture
1794
    //   has a public non-virtual non-explicit const conversion function
1795
    //   to pointer to function having the same parameter and return
1796
    //   types as the closure type's function call operator.
1797
7.30k
    if (Captures.empty() && 
CaptureDefault == LCD_None4.19k
)
1798
3.36k
      addFunctionPointerConversion(*this, IntroducerRange, Class,
1799
3.36k
                                   CallOperator);
1800
1801
    // Objective-C++:
1802
    //   The closure type for a lambda-expression has a public non-virtual
1803
    //   non-explicit const conversion function to a block pointer having the
1804
    //   same parameter and return types as the closure type's function call
1805
    //   operator.
1806
    // FIXME: Fix generic lambda to block conversions.
1807
7.30k
    if (getLangOpts().Blocks && 
getLangOpts().ObjC3.59k
&&
!IsGenericLambda168
)
1808
159
      addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator);
1809
1810
    // Finalize the lambda class.
1811
7.30k
    SmallVector<Decl*, 4> Fields(Class->fields());
1812
7.30k
    ActOnFields(nullptr, Class->getLocation(), Class, Fields, SourceLocation(),
1813
7.30k
                SourceLocation(), ParsedAttributesView());
1814
7.30k
    CheckCompletedCXXClass(nullptr, Class);
1815
7.30k
  }
1816
1817
7.30k
  Cleanup.mergeFrom(LambdaCleanup);
1818
1819
7.30k
  LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange,
1820
7.30k
                                          CaptureDefault, CaptureDefaultLoc,
1821
7.30k
                                          ExplicitParams, ExplicitResultType,
1822
7.30k
                                          CaptureInits, EndLoc,
1823
7.30k
                                          ContainsUnexpandedParameterPack);
1824
  // If the lambda expression's call operator is not explicitly marked constexpr
1825
  // and we are not in a dependent context, analyze the call operator to infer
1826
  // its constexpr-ness, suppressing diagnostics while doing so.
1827
7.30k
  if (getLangOpts().CPlusPlus17 && 
!CallOperator->isInvalidDecl()2.01k
&&
1828
2.00k
      !CallOperator->isConstexpr() &&
1829
1.90k
      !isa<CoroutineBodyStmt>(CallOperator->getBody()) &&
1830
1.89k
      !Class->getDeclContext()->isDependentContext()) {
1831
1.33k
    CallOperator->setConstexprKind(
1832
1.33k
        CheckConstexprFunctionDefinition(CallOperator,
1833
1.33k
                                         CheckConstexprKind::CheckValid)
1834
1.29k
            ? CSK_constexpr
1835
38
            : CSK_unspecified);
1836
1.33k
  }
1837
1838
  // Emit delayed shadowing warnings now that the full capture list is known.
1839
7.30k
  DiagnoseShadowingLambdaDecls(LSI);
1840
1841
7.30k
  if (!CurContext->isDependentContext()) {
1842
5.71k
    switch (ExprEvalContexts.back().Context) {
1843
    // C++11 [expr.prim.lambda]p2:
1844
    //   A lambda-expression shall not appear in an unevaluated operand
1845
    //   (Clause 5).
1846
125
    case ExpressionEvaluationContext::Unevaluated:
1847
125
    case ExpressionEvaluationContext::UnevaluatedList:
1848
125
    case ExpressionEvaluationContext::UnevaluatedAbstract:
1849
    // C++1y [expr.const]p2:
1850
    //   A conditional-expression e is a core constant expression unless the
1851
    //   evaluation of e, following the rules of the abstract machine, would
1852
    //   evaluate [...] a lambda-expression.
1853
    //
1854
    // This is technically incorrect, there are some constant evaluated contexts
1855
    // where this should be allowed.  We should probably fix this when DR1607 is
1856
    // ratified, it lays out the exact set of conditions where we shouldn't
1857
    // allow a lambda-expression.
1858
125
    case ExpressionEvaluationContext::ConstantEvaluated:
1859
      // We don't actually diagnose this case immediately, because we
1860
      // could be within a context where we might find out later that
1861
      // the expression is potentially evaluated (e.g., for typeid).
1862
125
      ExprEvalContexts.back().Lambdas.push_back(Lambda);
1863
125
      break;
1864
1865
5.58k
    case ExpressionEvaluationContext::DiscardedStatement:
1866
5.58k
    case ExpressionEvaluationContext::PotentiallyEvaluated:
1867
5.58k
    case ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed:
1868
5.58k
      break;
1869
7.30k
    }
1870
7.30k
  }
1871
1872
7.30k
  return MaybeBindToTemporary(Lambda);
1873
7.30k
}
1874
1875
ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
1876
                                               SourceLocation ConvLocation,
1877
                                               CXXConversionDecl *Conv,
1878
31
                                               Expr *Src) {
1879
  // Make sure that the lambda call operator is marked used.
1880
31
  CXXRecordDecl *Lambda = Conv->getParent();
1881
31
  CXXMethodDecl *CallOperator
1882
31
    = cast<CXXMethodDecl>(
1883
31
        Lambda->lookup(
1884
31
          Context.DeclarationNames.getCXXOperatorName(OO_Call)).front());
1885
31
  CallOperator->setReferenced();
1886
31
  CallOperator->markUsed(Context);
1887
1888
31
  ExprResult Init = PerformCopyInitialization(
1889
31
      InitializedEntity::InitializeLambdaToBlock(ConvLocation, Src->getType(),
1890
31
                                                 /*NRVO=*/false),
1891
31
      CurrentLocation, Src);
1892
31
  if (!Init.isInvalid())
1893
31
    Init = ActOnFinishFullExpr(Init.get(), /*DiscardedValue*/ false);
1894
1895
31
  if (Init.isInvalid())
1896
0
    return ExprError();
1897
1898
  // Create the new block to be returned.
1899
31
  BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation);
1900
1901
  // Set the type information.
1902
31
  Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo());
1903
31
  Block->setIsVariadic(CallOperator->isVariadic());
1904
31
  Block->setBlockMissingReturnType(false);
1905
1906
  // Add parameters.
1907
31
  SmallVector<ParmVarDecl *, 4> BlockParams;
1908
42
  for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; 
++I11
) {
1909
11
    ParmVarDecl *From = CallOperator->getParamDecl(I);
1910
11
    BlockParams.push_back(ParmVarDecl::Create(
1911
11
        Context, Block, From->getBeginLoc(), From->getLocation(),
1912
11
        From->getIdentifier(), From->getType(), From->getTypeSourceInfo(),
1913
11
        From->getStorageClass(),
1914
11
        /*DefArg=*/nullptr));
1915
11
  }
1916
31
  Block->setParams(BlockParams);
1917
1918
31
  Block->setIsConversionFromLambda(true);
1919
1920
  // Add capture. The capture uses a fake variable, which doesn't correspond
1921
  // to any actual memory location. However, the initializer copy-initializes
1922
  // the lambda object.
1923
31
  TypeSourceInfo *CapVarTSI =
1924
31
      Context.getTrivialTypeSourceInfo(Src->getType());
1925
31
  VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation,
1926
31
                                    ConvLocation, nullptr,
1927
31
                                    Src->getType(), CapVarTSI,
1928
31
                                    SC_None);
1929
31
  BlockDecl::Capture Capture(/*variable=*/CapVar, /*byRef=*/false,
1930
31
                             /*nested=*/false, /*copy=*/Init.get());
1931
31
  Block->setCaptures(Context, Capture, /*CapturesCXXThis=*/false);
1932
1933
  // Add a fake function body to the block. IR generation is responsible
1934
  // for filling in the actual body, which cannot be expressed as an AST.
1935
31
  Block->setBody(new (Context) CompoundStmt(ConvLocation));
1936
1937
  // Create the block literal expression.
1938
31
  Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType());
1939
31
  ExprCleanupObjects.push_back(Block);
1940
31
  Cleanup.setExprNeedsCleanups(true);
1941
1942
31
  return BuildBlock;
1943
31
}