clang  7.0.0svn
SemaDeclCXX.cpp
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1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements semantic analysis for C++ declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ASTLambda.h"
19 #include "clang/AST/CharUnits.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/RecordLayout.h"
24 #include "clang/AST/StmtVisitor.h"
25 #include "clang/AST/TypeLoc.h"
26 #include "clang/AST/TypeOrdering.h"
28 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/Preprocessor.h"
32 #include "clang/Sema/DeclSpec.h"
34 #include "clang/Sema/Lookup.h"
36 #include "clang/Sema/Scope.h"
37 #include "clang/Sema/ScopeInfo.h"
39 #include "clang/Sema/Template.h"
40 #include "llvm/ADT/STLExtras.h"
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/StringExtras.h"
43 #include <map>
44 #include <set>
45 
46 using namespace clang;
47 
48 //===----------------------------------------------------------------------===//
49 // CheckDefaultArgumentVisitor
50 //===----------------------------------------------------------------------===//
51 
52 namespace {
53  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
54  /// the default argument of a parameter to determine whether it
55  /// contains any ill-formed subexpressions. For example, this will
56  /// diagnose the use of local variables or parameters within the
57  /// default argument expression.
58  class CheckDefaultArgumentVisitor
59  : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
60  Expr *DefaultArg;
61  Sema *S;
62 
63  public:
64  CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
65  : DefaultArg(defarg), S(s) {}
66 
67  bool VisitExpr(Expr *Node);
68  bool VisitDeclRefExpr(DeclRefExpr *DRE);
69  bool VisitCXXThisExpr(CXXThisExpr *ThisE);
70  bool VisitLambdaExpr(LambdaExpr *Lambda);
71  bool VisitPseudoObjectExpr(PseudoObjectExpr *POE);
72  };
73 
74  /// VisitExpr - Visit all of the children of this expression.
75  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
76  bool IsInvalid = false;
77  for (Stmt *SubStmt : Node->children())
78  IsInvalid |= Visit(SubStmt);
79  return IsInvalid;
80  }
81 
82  /// VisitDeclRefExpr - Visit a reference to a declaration, to
83  /// determine whether this declaration can be used in the default
84  /// argument expression.
85  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
86  NamedDecl *Decl = DRE->getDecl();
87  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
88  // C++ [dcl.fct.default]p9
89  // Default arguments are evaluated each time the function is
90  // called. The order of evaluation of function arguments is
91  // unspecified. Consequently, parameters of a function shall not
92  // be used in default argument expressions, even if they are not
93  // evaluated. Parameters of a function declared before a default
94  // argument expression are in scope and can hide namespace and
95  // class member names.
96  return S->Diag(DRE->getLocStart(),
97  diag::err_param_default_argument_references_param)
98  << Param->getDeclName() << DefaultArg->getSourceRange();
99  } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
100  // C++ [dcl.fct.default]p7
101  // Local variables shall not be used in default argument
102  // expressions.
103  if (VDecl->isLocalVarDecl())
104  return S->Diag(DRE->getLocStart(),
105  diag::err_param_default_argument_references_local)
106  << VDecl->getDeclName() << DefaultArg->getSourceRange();
107  }
108 
109  return false;
110  }
111 
112  /// VisitCXXThisExpr - Visit a C++ "this" expression.
113  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
114  // C++ [dcl.fct.default]p8:
115  // The keyword this shall not be used in a default argument of a
116  // member function.
117  return S->Diag(ThisE->getLocStart(),
118  diag::err_param_default_argument_references_this)
119  << ThisE->getSourceRange();
120  }
121 
122  bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
123  bool Invalid = false;
125  i = POE->semantics_begin(), e = POE->semantics_end(); i != e; ++i) {
126  Expr *E = *i;
127 
128  // Look through bindings.
129  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
130  E = OVE->getSourceExpr();
131  assert(E && "pseudo-object binding without source expression?");
132  }
133 
134  Invalid |= Visit(E);
135  }
136  return Invalid;
137  }
138 
139  bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
140  // C++11 [expr.lambda.prim]p13:
141  // A lambda-expression appearing in a default argument shall not
142  // implicitly or explicitly capture any entity.
143  if (Lambda->capture_begin() == Lambda->capture_end())
144  return false;
145 
146  return S->Diag(Lambda->getLocStart(),
147  diag::err_lambda_capture_default_arg);
148  }
149 }
150 
151 void
153  const CXXMethodDecl *Method) {
154  // If we have an MSAny spec already, don't bother.
155  if (!Method || ComputedEST == EST_MSAny)
156  return;
157 
158  const FunctionProtoType *Proto
159  = Method->getType()->getAs<FunctionProtoType>();
160  Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
161  if (!Proto)
162  return;
163 
165 
166  // If we have a throw-all spec at this point, ignore the function.
167  if (ComputedEST == EST_None)
168  return;
169 
170  if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
171  EST = EST_BasicNoexcept;
172 
173  switch(EST) {
174  // If this function can throw any exceptions, make a note of that.
175  case EST_MSAny:
176  case EST_None:
177  ClearExceptions();
178  ComputedEST = EST;
179  return;
180  // FIXME: If the call to this decl is using any of its default arguments, we
181  // need to search them for potentially-throwing calls.
182  // If this function has a basic noexcept, it doesn't affect the outcome.
183  case EST_BasicNoexcept:
184  return;
185  // If we're still at noexcept(true) and there's a nothrow() callee,
186  // change to that specification.
187  case EST_DynamicNone:
188  if (ComputedEST == EST_BasicNoexcept)
189  ComputedEST = EST_DynamicNone;
190  return;
191  // Check out noexcept specs.
193  {
195  Proto->getNoexceptSpec(Self->Context);
196  assert(NR != FunctionProtoType::NR_NoNoexcept &&
197  "Must have noexcept result for EST_ComputedNoexcept.");
198  assert(NR != FunctionProtoType::NR_Dependent &&
199  "Should not generate implicit declarations for dependent cases, "
200  "and don't know how to handle them anyway.");
201  // noexcept(false) -> no spec on the new function
202  if (NR == FunctionProtoType::NR_Throw) {
203  ClearExceptions();
204  ComputedEST = EST_None;
205  }
206  // noexcept(true) won't change anything either.
207  return;
208  }
209  default:
210  break;
211  }
212  assert(EST == EST_Dynamic && "EST case not considered earlier.");
213  assert(ComputedEST != EST_None &&
214  "Shouldn't collect exceptions when throw-all is guaranteed.");
215  ComputedEST = EST_Dynamic;
216  // Record the exceptions in this function's exception specification.
217  for (const auto &E : Proto->exceptions())
218  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
219  Exceptions.push_back(E);
220 }
221 
223  if (!E || ComputedEST == EST_MSAny)
224  return;
225 
226  // FIXME:
227  //
228  // C++0x [except.spec]p14:
229  // [An] implicit exception-specification specifies the type-id T if and
230  // only if T is allowed by the exception-specification of a function directly
231  // invoked by f's implicit definition; f shall allow all exceptions if any
232  // function it directly invokes allows all exceptions, and f shall allow no
233  // exceptions if every function it directly invokes allows no exceptions.
234  //
235  // Note in particular that if an implicit exception-specification is generated
236  // for a function containing a throw-expression, that specification can still
237  // be noexcept(true).
238  //
239  // Note also that 'directly invoked' is not defined in the standard, and there
240  // is no indication that we should only consider potentially-evaluated calls.
241  //
242  // Ultimately we should implement the intent of the standard: the exception
243  // specification should be the set of exceptions which can be thrown by the
244  // implicit definition. For now, we assume that any non-nothrow expression can
245  // throw any exception.
246 
247  if (Self->canThrow(E))
248  ComputedEST = EST_None;
249 }
250 
251 bool
253  SourceLocation EqualLoc) {
254  if (RequireCompleteType(Param->getLocation(), Param->getType(),
255  diag::err_typecheck_decl_incomplete_type)) {
256  Param->setInvalidDecl();
257  return true;
258  }
259 
260  // C++ [dcl.fct.default]p5
261  // A default argument expression is implicitly converted (clause
262  // 4) to the parameter type. The default argument expression has
263  // the same semantic constraints as the initializer expression in
264  // a declaration of a variable of the parameter type, using the
265  // copy-initialization semantics (8.5).
267  Param);
269  EqualLoc);
270  InitializationSequence InitSeq(*this, Entity, Kind, Arg);
271  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
272  if (Result.isInvalid())
273  return true;
274  Arg = Result.getAs<Expr>();
275 
276  CheckCompletedExpr(Arg, EqualLoc);
277  Arg = MaybeCreateExprWithCleanups(Arg);
278 
279  // Okay: add the default argument to the parameter
280  Param->setDefaultArg(Arg);
281 
282  // We have already instantiated this parameter; provide each of the
283  // instantiations with the uninstantiated default argument.
284  UnparsedDefaultArgInstantiationsMap::iterator InstPos
285  = UnparsedDefaultArgInstantiations.find(Param);
286  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
287  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
288  InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
289 
290  // We're done tracking this parameter's instantiations.
291  UnparsedDefaultArgInstantiations.erase(InstPos);
292  }
293 
294  return false;
295 }
296 
297 /// ActOnParamDefaultArgument - Check whether the default argument
298 /// provided for a function parameter is well-formed. If so, attach it
299 /// to the parameter declaration.
300 void
302  Expr *DefaultArg) {
303  if (!param || !DefaultArg)
304  return;
305 
306  ParmVarDecl *Param = cast<ParmVarDecl>(param);
307  UnparsedDefaultArgLocs.erase(Param);
308 
309  // Default arguments are only permitted in C++
310  if (!getLangOpts().CPlusPlus) {
311  Diag(EqualLoc, diag::err_param_default_argument)
312  << DefaultArg->getSourceRange();
313  Param->setInvalidDecl();
314  return;
315  }
316 
317  // Check for unexpanded parameter packs.
318  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
319  Param->setInvalidDecl();
320  return;
321  }
322 
323  // C++11 [dcl.fct.default]p3
324  // A default argument expression [...] shall not be specified for a
325  // parameter pack.
326  if (Param->isParameterPack()) {
327  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
328  << DefaultArg->getSourceRange();
329  return;
330  }
331 
332  // Check that the default argument is well-formed
333  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
334  if (DefaultArgChecker.Visit(DefaultArg)) {
335  Param->setInvalidDecl();
336  return;
337  }
338 
339  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
340 }
341 
342 /// ActOnParamUnparsedDefaultArgument - We've seen a default
343 /// argument for a function parameter, but we can't parse it yet
344 /// because we're inside a class definition. Note that this default
345 /// argument will be parsed later.
347  SourceLocation EqualLoc,
348  SourceLocation ArgLoc) {
349  if (!param)
350  return;
351 
352  ParmVarDecl *Param = cast<ParmVarDecl>(param);
353  Param->setUnparsedDefaultArg();
354  UnparsedDefaultArgLocs[Param] = ArgLoc;
355 }
356 
357 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
358 /// the default argument for the parameter param failed.
360  SourceLocation EqualLoc) {
361  if (!param)
362  return;
363 
364  ParmVarDecl *Param = cast<ParmVarDecl>(param);
365  Param->setInvalidDecl();
366  UnparsedDefaultArgLocs.erase(Param);
367  Param->setDefaultArg(new(Context)
368  OpaqueValueExpr(EqualLoc,
369  Param->getType().getNonReferenceType(),
370  VK_RValue));
371 }
372 
373 /// CheckExtraCXXDefaultArguments - Check for any extra default
374 /// arguments in the declarator, which is not a function declaration
375 /// or definition and therefore is not permitted to have default
376 /// arguments. This routine should be invoked for every declarator
377 /// that is not a function declaration or definition.
379  // C++ [dcl.fct.default]p3
380  // A default argument expression shall be specified only in the
381  // parameter-declaration-clause of a function declaration or in a
382  // template-parameter (14.1). It shall not be specified for a
383  // parameter pack. If it is specified in a
384  // parameter-declaration-clause, it shall not occur within a
385  // declarator or abstract-declarator of a parameter-declaration.
386  bool MightBeFunction = D.isFunctionDeclarationContext();
387  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
388  DeclaratorChunk &chunk = D.getTypeObject(i);
389  if (chunk.Kind == DeclaratorChunk::Function) {
390  if (MightBeFunction) {
391  // This is a function declaration. It can have default arguments, but
392  // keep looking in case its return type is a function type with default
393  // arguments.
394  MightBeFunction = false;
395  continue;
396  }
397  for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
398  ++argIdx) {
399  ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
400  if (Param->hasUnparsedDefaultArg()) {
401  std::unique_ptr<CachedTokens> Toks =
402  std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
403  SourceRange SR;
404  if (Toks->size() > 1)
405  SR = SourceRange((*Toks)[1].getLocation(),
406  Toks->back().getLocation());
407  else
408  SR = UnparsedDefaultArgLocs[Param];
409  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
410  << SR;
411  } else if (Param->getDefaultArg()) {
412  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
413  << Param->getDefaultArg()->getSourceRange();
414  Param->setDefaultArg(nullptr);
415  }
416  }
417  } else if (chunk.Kind != DeclaratorChunk::Paren) {
418  MightBeFunction = false;
419  }
420  }
421 }
422 
424  for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) {
425  const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1);
426  if (!PVD->hasDefaultArg())
427  return false;
428  if (!PVD->hasInheritedDefaultArg())
429  return true;
430  }
431  return false;
432 }
433 
434 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
435 /// function, once we already know that they have the same
436 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
437 /// error, false otherwise.
439  Scope *S) {
440  bool Invalid = false;
441 
442  // The declaration context corresponding to the scope is the semantic
443  // parent, unless this is a local function declaration, in which case
444  // it is that surrounding function.
445  DeclContext *ScopeDC = New->isLocalExternDecl()
446  ? New->getLexicalDeclContext()
447  : New->getDeclContext();
448 
449  // Find the previous declaration for the purpose of default arguments.
450  FunctionDecl *PrevForDefaultArgs = Old;
451  for (/**/; PrevForDefaultArgs;
452  // Don't bother looking back past the latest decl if this is a local
453  // extern declaration; nothing else could work.
454  PrevForDefaultArgs = New->isLocalExternDecl()
455  ? nullptr
456  : PrevForDefaultArgs->getPreviousDecl()) {
457  // Ignore hidden declarations.
458  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
459  continue;
460 
461  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
462  !New->isCXXClassMember()) {
463  // Ignore default arguments of old decl if they are not in
464  // the same scope and this is not an out-of-line definition of
465  // a member function.
466  continue;
467  }
468 
469  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
470  // If only one of these is a local function declaration, then they are
471  // declared in different scopes, even though isDeclInScope may think
472  // they're in the same scope. (If both are local, the scope check is
473  // sufficient, and if neither is local, then they are in the same scope.)
474  continue;
475  }
476 
477  // We found the right previous declaration.
478  break;
479  }
480 
481  // C++ [dcl.fct.default]p4:
482  // For non-template functions, default arguments can be added in
483  // later declarations of a function in the same
484  // scope. Declarations in different scopes have completely
485  // distinct sets of default arguments. That is, declarations in
486  // inner scopes do not acquire default arguments from
487  // declarations in outer scopes, and vice versa. In a given
488  // function declaration, all parameters subsequent to a
489  // parameter with a default argument shall have default
490  // arguments supplied in this or previous declarations. A
491  // default argument shall not be redefined by a later
492  // declaration (not even to the same value).
493  //
494  // C++ [dcl.fct.default]p6:
495  // Except for member functions of class templates, the default arguments
496  // in a member function definition that appears outside of the class
497  // definition are added to the set of default arguments provided by the
498  // member function declaration in the class definition.
499  for (unsigned p = 0, NumParams = PrevForDefaultArgs
500  ? PrevForDefaultArgs->getNumParams()
501  : 0;
502  p < NumParams; ++p) {
503  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
504  ParmVarDecl *NewParam = New->getParamDecl(p);
505 
506  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
507  bool NewParamHasDfl = NewParam->hasDefaultArg();
508 
509  if (OldParamHasDfl && NewParamHasDfl) {
510  unsigned DiagDefaultParamID =
511  diag::err_param_default_argument_redefinition;
512 
513  // MSVC accepts that default parameters be redefined for member functions
514  // of template class. The new default parameter's value is ignored.
515  Invalid = true;
516  if (getLangOpts().MicrosoftExt) {
517  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
518  if (MD && MD->getParent()->getDescribedClassTemplate()) {
519  // Merge the old default argument into the new parameter.
520  NewParam->setHasInheritedDefaultArg();
521  if (OldParam->hasUninstantiatedDefaultArg())
522  NewParam->setUninstantiatedDefaultArg(
523  OldParam->getUninstantiatedDefaultArg());
524  else
525  NewParam->setDefaultArg(OldParam->getInit());
526  DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
527  Invalid = false;
528  }
529  }
530 
531  // FIXME: If we knew where the '=' was, we could easily provide a fix-it
532  // hint here. Alternatively, we could walk the type-source information
533  // for NewParam to find the last source location in the type... but it
534  // isn't worth the effort right now. This is the kind of test case that
535  // is hard to get right:
536  // int f(int);
537  // void g(int (*fp)(int) = f);
538  // void g(int (*fp)(int) = &f);
539  Diag(NewParam->getLocation(), DiagDefaultParamID)
540  << NewParam->getDefaultArgRange();
541 
542  // Look for the function declaration where the default argument was
543  // actually written, which may be a declaration prior to Old.
544  for (auto Older = PrevForDefaultArgs;
545  OldParam->hasInheritedDefaultArg(); /**/) {
546  Older = Older->getPreviousDecl();
547  OldParam = Older->getParamDecl(p);
548  }
549 
550  Diag(OldParam->getLocation(), diag::note_previous_definition)
551  << OldParam->getDefaultArgRange();
552  } else if (OldParamHasDfl) {
553  // Merge the old default argument into the new parameter unless the new
554  // function is a friend declaration in a template class. In the latter
555  // case the default arguments will be inherited when the friend
556  // declaration will be instantiated.
557  if (New->getFriendObjectKind() == Decl::FOK_None ||
559  // It's important to use getInit() here; getDefaultArg()
560  // strips off any top-level ExprWithCleanups.
561  NewParam->setHasInheritedDefaultArg();
562  if (OldParam->hasUnparsedDefaultArg())
563  NewParam->setUnparsedDefaultArg();
564  else if (OldParam->hasUninstantiatedDefaultArg())
565  NewParam->setUninstantiatedDefaultArg(
566  OldParam->getUninstantiatedDefaultArg());
567  else
568  NewParam->setDefaultArg(OldParam->getInit());
569  }
570  } else if (NewParamHasDfl) {
571  if (New->getDescribedFunctionTemplate()) {
572  // Paragraph 4, quoted above, only applies to non-template functions.
573  Diag(NewParam->getLocation(),
574  diag::err_param_default_argument_template_redecl)
575  << NewParam->getDefaultArgRange();
576  Diag(PrevForDefaultArgs->getLocation(),
577  diag::note_template_prev_declaration)
578  << false;
579  } else if (New->getTemplateSpecializationKind()
582  // C++ [temp.expr.spec]p21:
583  // Default function arguments shall not be specified in a declaration
584  // or a definition for one of the following explicit specializations:
585  // - the explicit specialization of a function template;
586  // - the explicit specialization of a member function template;
587  // - the explicit specialization of a member function of a class
588  // template where the class template specialization to which the
589  // member function specialization belongs is implicitly
590  // instantiated.
591  Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
593  << New->getDeclName()
594  << NewParam->getDefaultArgRange();
595  } else if (New->getDeclContext()->isDependentContext()) {
596  // C++ [dcl.fct.default]p6 (DR217):
597  // Default arguments for a member function of a class template shall
598  // be specified on the initial declaration of the member function
599  // within the class template.
600  //
601  // Reading the tea leaves a bit in DR217 and its reference to DR205
602  // leads me to the conclusion that one cannot add default function
603  // arguments for an out-of-line definition of a member function of a
604  // dependent type.
605  int WhichKind = 2;
606  if (CXXRecordDecl *Record
607  = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
608  if (Record->getDescribedClassTemplate())
609  WhichKind = 0;
610  else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
611  WhichKind = 1;
612  else
613  WhichKind = 2;
614  }
615 
616  Diag(NewParam->getLocation(),
617  diag::err_param_default_argument_member_template_redecl)
618  << WhichKind
619  << NewParam->getDefaultArgRange();
620  }
621  }
622  }
623 
624  // DR1344: If a default argument is added outside a class definition and that
625  // default argument makes the function a special member function, the program
626  // is ill-formed. This can only happen for constructors.
627  if (isa<CXXConstructorDecl>(New) &&
629  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
630  OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
631  if (NewSM != OldSM) {
632  ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
633  assert(NewParam->hasDefaultArg());
634  Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
635  << NewParam->getDefaultArgRange() << NewSM;
636  Diag(Old->getLocation(), diag::note_previous_declaration);
637  }
638  }
639 
640  const FunctionDecl *Def;
641  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
642  // template has a constexpr specifier then all its declarations shall
643  // contain the constexpr specifier.
644  if (New->isConstexpr() != Old->isConstexpr()) {
645  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
646  << New << New->isConstexpr();
647  Diag(Old->getLocation(), diag::note_previous_declaration);
648  Invalid = true;
649  } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
650  Old->isDefined(Def) &&
651  // If a friend function is inlined but does not have 'inline'
652  // specifier, it is a definition. Do not report attribute conflict
653  // in this case, redefinition will be diagnosed later.
654  (New->isInlineSpecified() ||
655  New->getFriendObjectKind() == Decl::FOK_None)) {
656  // C++11 [dcl.fcn.spec]p4:
657  // If the definition of a function appears in a translation unit before its
658  // first declaration as inline, the program is ill-formed.
659  Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
660  Diag(Def->getLocation(), diag::note_previous_definition);
661  Invalid = true;
662  }
663 
664  // FIXME: It's not clear what should happen if multiple declarations of a
665  // deduction guide have different explicitness. For now at least we simply
666  // reject any case where the explicitness changes.
667  auto *NewGuide = dyn_cast<CXXDeductionGuideDecl>(New);
668  if (NewGuide && NewGuide->isExplicitSpecified() !=
669  cast<CXXDeductionGuideDecl>(Old)->isExplicitSpecified()) {
670  Diag(New->getLocation(), diag::err_deduction_guide_explicit_mismatch)
671  << NewGuide->isExplicitSpecified();
672  Diag(Old->getLocation(), diag::note_previous_declaration);
673  }
674 
675  // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
676  // argument expression, that declaration shall be a definition and shall be
677  // the only declaration of the function or function template in the
678  // translation unit.
681  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
682  Diag(Old->getLocation(), diag::note_previous_declaration);
683  Invalid = true;
684  }
685 
686  return Invalid;
687 }
688 
689 NamedDecl *
691  MultiTemplateParamsArg TemplateParamLists) {
692  assert(D.isDecompositionDeclarator());
694 
695  // The syntax only allows a decomposition declarator as a simple-declaration,
696  // a for-range-declaration, or a condition in Clang, but we parse it in more
697  // cases than that.
699  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
700  << Decomp.getSourceRange();
701  return nullptr;
702  }
703 
704  if (!TemplateParamLists.empty()) {
705  // FIXME: There's no rule against this, but there are also no rules that
706  // would actually make it usable, so we reject it for now.
707  Diag(TemplateParamLists.front()->getTemplateLoc(),
708  diag::err_decomp_decl_template);
709  return nullptr;
710  }
711 
712  Diag(Decomp.getLSquareLoc(),
713  !getLangOpts().CPlusPlus17
714  ? diag::ext_decomp_decl
716  ? diag::ext_decomp_decl_cond
717  : diag::warn_cxx14_compat_decomp_decl)
718  << Decomp.getSourceRange();
719 
720  // The semantic context is always just the current context.
721  DeclContext *const DC = CurContext;
722 
723  // C++1z [dcl.dcl]/8:
724  // The decl-specifier-seq shall contain only the type-specifier auto
725  // and cv-qualifiers.
726  auto &DS = D.getDeclSpec();
727  {
728  SmallVector<StringRef, 8> BadSpecifiers;
729  SmallVector<SourceLocation, 8> BadSpecifierLocs;
730  if (auto SCS = DS.getStorageClassSpec()) {
731  BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
732  BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
733  }
734  if (auto TSCS = DS.getThreadStorageClassSpec()) {
735  BadSpecifiers.push_back(DeclSpec::getSpecifierName(TSCS));
736  BadSpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
737  }
738  if (DS.isConstexprSpecified()) {
739  BadSpecifiers.push_back("constexpr");
740  BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
741  }
742  if (DS.isInlineSpecified()) {
743  BadSpecifiers.push_back("inline");
744  BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
745  }
746  if (!BadSpecifiers.empty()) {
747  auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
748  Err << (int)BadSpecifiers.size()
749  << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
750  // Don't add FixItHints to remove the specifiers; we do still respect
751  // them when building the underlying variable.
752  for (auto Loc : BadSpecifierLocs)
753  Err << SourceRange(Loc, Loc);
754  }
755  // We can't recover from it being declared as a typedef.
756  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
757  return nullptr;
758  }
759 
760  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
761  QualType R = TInfo->getType();
762 
763  if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
764  UPPC_DeclarationType))
765  D.setInvalidType();
766 
767  // The syntax only allows a single ref-qualifier prior to the decomposition
768  // declarator. No other declarator chunks are permitted. Also check the type
769  // specifier here.
770  if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
771  D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
772  (D.getNumTypeObjects() == 1 &&
774  Diag(Decomp.getLSquareLoc(),
775  (D.hasGroupingParens() ||
776  (D.getNumTypeObjects() &&
778  ? diag::err_decomp_decl_parens
779  : diag::err_decomp_decl_type)
780  << R;
781 
782  // In most cases, there's no actual problem with an explicitly-specified
783  // type, but a function type won't work here, and ActOnVariableDeclarator
784  // shouldn't be called for such a type.
785  if (R->isFunctionType())
786  D.setInvalidType();
787  }
788 
789  // Build the BindingDecls.
791 
792  // Build the BindingDecls.
793  for (auto &B : D.getDecompositionDeclarator().bindings()) {
794  // Check for name conflicts.
795  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
796  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
797  ForVisibleRedeclaration);
798  LookupName(Previous, S,
799  /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
800 
801  // It's not permitted to shadow a template parameter name.
802  if (Previous.isSingleResult() &&
803  Previous.getFoundDecl()->isTemplateParameter()) {
804  DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
805  Previous.getFoundDecl());
806  Previous.clear();
807  }
808 
809  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
810  DS.getStorageClassSpec() == DeclSpec::SCS_extern;
811  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
812  /*AllowInlineNamespace*/false);
813  if (!Previous.empty()) {
814  auto *Old = Previous.getRepresentativeDecl();
815  Diag(B.NameLoc, diag::err_redefinition) << B.Name;
816  Diag(Old->getLocation(), diag::note_previous_definition);
817  }
818 
819  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
820  PushOnScopeChains(BD, S, true);
821  Bindings.push_back(BD);
822  ParsingInitForAutoVars.insert(BD);
823  }
824 
825  // There are no prior lookup results for the variable itself, because it
826  // is unnamed.
827  DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
828  Decomp.getLSquareLoc());
829  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
830  ForVisibleRedeclaration);
831 
832  // Build the variable that holds the non-decomposed object.
833  bool AddToScope = true;
834  NamedDecl *New =
835  ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
836  MultiTemplateParamsArg(), AddToScope, Bindings);
837  if (AddToScope) {
838  S->AddDecl(New);
839  CurContext->addHiddenDecl(New);
840  }
841 
842  if (isInOpenMPDeclareTargetContext())
843  checkDeclIsAllowedInOpenMPTarget(nullptr, New);
844 
845  return New;
846 }
847 
849  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
850  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
851  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
852  if ((int64_t)Bindings.size() != NumElems) {
853  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
854  << DecompType << (unsigned)Bindings.size() << NumElems.toString(10)
855  << (NumElems < Bindings.size());
856  return true;
857  }
858 
859  unsigned I = 0;
860  for (auto *B : Bindings) {
861  SourceLocation Loc = B->getLocation();
862  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
863  if (E.isInvalid())
864  return true;
865  E = GetInit(Loc, E.get(), I++);
866  if (E.isInvalid())
867  return true;
868  B->setBinding(ElemType, E.get());
869  }
870 
871  return false;
872 }
873 
875  ArrayRef<BindingDecl *> Bindings,
876  ValueDecl *Src, QualType DecompType,
877  const llvm::APSInt &NumElems,
878  QualType ElemType) {
880  S, Bindings, Src, DecompType, NumElems, ElemType,
881  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
882  ExprResult E = S.ActOnIntegerConstant(Loc, I);
883  if (E.isInvalid())
884  return ExprError();
885  return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
886  });
887 }
888 
890  ValueDecl *Src, QualType DecompType,
891  const ConstantArrayType *CAT) {
892  return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
893  llvm::APSInt(CAT->getSize()),
894  CAT->getElementType());
895 }
896 
898  ValueDecl *Src, QualType DecompType,
899  const VectorType *VT) {
901  S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
903  DecompType.getQualifiers()));
904 }
905 
907  ArrayRef<BindingDecl *> Bindings,
908  ValueDecl *Src, QualType DecompType,
909  const ComplexType *CT) {
911  S, Bindings, Src, DecompType, llvm::APSInt::get(2),
913  DecompType.getQualifiers()),
914  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
915  return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
916  });
917 }
918 
920  TemplateArgumentListInfo &Args) {
921  SmallString<128> SS;
922  llvm::raw_svector_ostream OS(SS);
923  bool First = true;
924  for (auto &Arg : Args.arguments()) {
925  if (!First)
926  OS << ", ";
927  Arg.getArgument().print(PrintingPolicy, OS);
928  First = false;
929  }
930  return OS.str();
931 }
932 
933 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
934  SourceLocation Loc, StringRef Trait,
936  unsigned DiagID) {
937  auto DiagnoseMissing = [&] {
938  if (DiagID)
939  S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
940  Args);
941  return true;
942  };
943 
944  // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
945  NamespaceDecl *Std = S.getStdNamespace();
946  if (!Std)
947  return DiagnoseMissing();
948 
949  // Look up the trait itself, within namespace std. We can diagnose various
950  // problems with this lookup even if we've been asked to not diagnose a
951  // missing specialization, because this can only fail if the user has been
952  // declaring their own names in namespace std or we don't support the
953  // standard library implementation in use.
956  if (!S.LookupQualifiedName(Result, Std))
957  return DiagnoseMissing();
958  if (Result.isAmbiguous())
959  return true;
960 
961  ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
962  if (!TraitTD) {
963  Result.suppressDiagnostics();
964  NamedDecl *Found = *Result.begin();
965  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
966  S.Diag(Found->getLocation(), diag::note_declared_at);
967  return true;
968  }
969 
970  // Build the template-id.
971  QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
972  if (TraitTy.isNull())
973  return true;
974  if (!S.isCompleteType(Loc, TraitTy)) {
975  if (DiagID)
977  Loc, TraitTy, DiagID,
979  return true;
980  }
981 
982  CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
983  assert(RD && "specialization of class template is not a class?");
984 
985  // Look up the member of the trait type.
986  S.LookupQualifiedName(TraitMemberLookup, RD);
987  return TraitMemberLookup.isAmbiguous();
988 }
989 
990 static TemplateArgumentLoc
992  uint64_t I) {
993  TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
994  return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
995 }
996 
997 static TemplateArgumentLoc
1000 }
1001 
1002 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1003 
1005  llvm::APSInt &Size) {
1008 
1010  LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1011 
1012  // Form template argument list for tuple_size<T>.
1013  TemplateArgumentListInfo Args(Loc, Loc);
1015 
1016  // If there's no tuple_size specialization, it's not tuple-like.
1017  if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/0))
1018  return IsTupleLike::NotTupleLike;
1019 
1020  // If we get this far, we've committed to the tuple interpretation, but
1021  // we can still fail if there actually isn't a usable ::value.
1022 
1023  struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1024  LookupResult &R;
1026  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1027  : R(R), Args(Args) {}
1028  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) {
1029  S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1031  }
1032  } Diagnoser(R, Args);
1033 
1034  if (R.empty()) {
1035  Diagnoser.diagnoseNotICE(S, Loc, SourceRange());
1036  return IsTupleLike::Error;
1037  }
1038 
1039  ExprResult E =
1040  S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1041  if (E.isInvalid())
1042  return IsTupleLike::Error;
1043 
1044  E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser, false);
1045  if (E.isInvalid())
1046  return IsTupleLike::Error;
1047 
1048  return IsTupleLike::TupleLike;
1049 }
1050 
1051 /// \return std::tuple_element<I, T>::type.
1053  unsigned I, QualType T) {
1054  // Form template argument list for tuple_element<I, T>.
1055  TemplateArgumentListInfo Args(Loc, Loc);
1056  Args.addArgument(
1059 
1060  DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1061  LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1063  S, R, Loc, "tuple_element", Args,
1064  diag::err_decomp_decl_std_tuple_element_not_specialized))
1065  return QualType();
1066 
1067  auto *TD = R.getAsSingle<TypeDecl>();
1068  if (!TD) {
1069  R.suppressDiagnostics();
1070  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1072  if (!R.empty())
1073  S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1074  return QualType();
1075  }
1076 
1077  return S.Context.getTypeDeclType(TD);
1078 }
1079 
1080 namespace {
1081 struct BindingDiagnosticTrap {
1082  Sema &S;
1083  DiagnosticErrorTrap Trap;
1084  BindingDecl *BD;
1085 
1086  BindingDiagnosticTrap(Sema &S, BindingDecl *BD)
1087  : S(S), Trap(S.Diags), BD(BD) {}
1088  ~BindingDiagnosticTrap() {
1089  if (Trap.hasErrorOccurred())
1090  S.Diag(BD->getLocation(), diag::note_in_binding_decl_init) << BD;
1091  }
1092 };
1093 }
1094 
1096  ArrayRef<BindingDecl *> Bindings,
1097  VarDecl *Src, QualType DecompType,
1098  const llvm::APSInt &TupleSize) {
1099  if ((int64_t)Bindings.size() != TupleSize) {
1100  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1101  << DecompType << (unsigned)Bindings.size() << TupleSize.toString(10)
1102  << (TupleSize < Bindings.size());
1103  return true;
1104  }
1105 
1106  if (Bindings.empty())
1107  return false;
1108 
1109  DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1110 
1111  // [dcl.decomp]p3:
1112  // The unqualified-id get is looked up in the scope of E by class member
1113  // access lookup
1114  LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1115  bool UseMemberGet = false;
1116  if (S.isCompleteType(Src->getLocation(), DecompType)) {
1117  if (auto *RD = DecompType->getAsCXXRecordDecl())
1118  S.LookupQualifiedName(MemberGet, RD);
1119  if (MemberGet.isAmbiguous())
1120  return true;
1121  UseMemberGet = !MemberGet.empty();
1122  S.FilterAcceptableTemplateNames(MemberGet);
1123  }
1124 
1125  unsigned I = 0;
1126  for (auto *B : Bindings) {
1127  BindingDiagnosticTrap Trap(S, B);
1128  SourceLocation Loc = B->getLocation();
1129 
1130  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1131  if (E.isInvalid())
1132  return true;
1133 
1134  // e is an lvalue if the type of the entity is an lvalue reference and
1135  // an xvalue otherwise
1136  if (!Src->getType()->isLValueReferenceType())
1137  E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1138  E.get(), nullptr, VK_XValue);
1139 
1140  TemplateArgumentListInfo Args(Loc, Loc);
1141  Args.addArgument(
1143 
1144  if (UseMemberGet) {
1145  // if [lookup of member get] finds at least one declaration, the
1146  // initializer is e.get<i-1>().
1147  E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1148  CXXScopeSpec(), SourceLocation(), nullptr,
1149  MemberGet, &Args, nullptr);
1150  if (E.isInvalid())
1151  return true;
1152 
1153  E = S.ActOnCallExpr(nullptr, E.get(), Loc, None, Loc);
1154  } else {
1155  // Otherwise, the initializer is get<i-1>(e), where get is looked up
1156  // in the associated namespaces.
1159  DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1161 
1162  Expr *Arg = E.get();
1163  E = S.ActOnCallExpr(nullptr, Get, Loc, Arg, Loc);
1164  }
1165  if (E.isInvalid())
1166  return true;
1167  Expr *Init = E.get();
1168 
1169  // Given the type T designated by std::tuple_element<i - 1, E>::type,
1170  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1171  if (T.isNull())
1172  return true;
1173 
1174  // each vi is a variable of type "reference to T" initialized with the
1175  // initializer, where the reference is an lvalue reference if the
1176  // initializer is an lvalue and an rvalue reference otherwise
1177  QualType RefType =
1178  S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1179  if (RefType.isNull())
1180  return true;
1181  auto *RefVD = VarDecl::Create(
1182  S.Context, Src->getDeclContext(), Loc, Loc,
1183  B->getDeclName().getAsIdentifierInfo(), RefType,
1186  RefVD->setTSCSpec(Src->getTSCSpec());
1187  RefVD->setImplicit();
1188  if (Src->isInlineSpecified())
1189  RefVD->setInlineSpecified();
1190  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1191 
1194  InitializationSequence Seq(S, Entity, Kind, Init);
1195  E = Seq.Perform(S, Entity, Kind, Init);
1196  if (E.isInvalid())
1197  return true;
1198  E = S.ActOnFinishFullExpr(E.get(), Loc);
1199  if (E.isInvalid())
1200  return true;
1201  RefVD->setInit(E.get());
1202  RefVD->checkInitIsICE();
1203 
1205  DeclarationNameInfo(B->getDeclName(), Loc),
1206  RefVD);
1207  if (E.isInvalid())
1208  return true;
1209 
1210  B->setBinding(T, E.get());
1211  I++;
1212  }
1213 
1214  return false;
1215 }
1216 
1217 /// Find the base class to decompose in a built-in decomposition of a class type.
1218 /// This base class search is, unfortunately, not quite like any other that we
1219 /// perform anywhere else in C++.
1221  SourceLocation Loc,
1222  const CXXRecordDecl *RD,
1223  CXXCastPath &BasePath) {
1224  auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1225  CXXBasePath &Path) {
1226  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1227  };
1228 
1229  const CXXRecordDecl *ClassWithFields = nullptr;
1230  if (RD->hasDirectFields())
1231  // [dcl.decomp]p4:
1232  // Otherwise, all of E's non-static data members shall be public direct
1233  // members of E ...
1234  ClassWithFields = RD;
1235  else {
1236  // ... or of ...
1237  CXXBasePaths Paths;
1238  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1239  if (!RD->lookupInBases(BaseHasFields, Paths)) {
1240  // If no classes have fields, just decompose RD itself. (This will work
1241  // if and only if zero bindings were provided.)
1242  return RD;
1243  }
1244 
1245  CXXBasePath *BestPath = nullptr;
1246  for (auto &P : Paths) {
1247  if (!BestPath)
1248  BestPath = &P;
1249  else if (!S.Context.hasSameType(P.back().Base->getType(),
1250  BestPath->back().Base->getType())) {
1251  // ... the same ...
1252  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1253  << false << RD << BestPath->back().Base->getType()
1254  << P.back().Base->getType();
1255  return nullptr;
1256  } else if (P.Access < BestPath->Access) {
1257  BestPath = &P;
1258  }
1259  }
1260 
1261  // ... unambiguous ...
1262  QualType BaseType = BestPath->back().Base->getType();
1263  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1264  S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1265  << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1266  return nullptr;
1267  }
1268 
1269  // ... public base class of E.
1270  if (BestPath->Access != AS_public) {
1271  S.Diag(Loc, diag::err_decomp_decl_non_public_base)
1272  << RD << BaseType;
1273  for (auto &BS : *BestPath) {
1274  if (BS.Base->getAccessSpecifier() != AS_public) {
1275  S.Diag(BS.Base->getLocStart(), diag::note_access_constrained_by_path)
1276  << (BS.Base->getAccessSpecifier() == AS_protected)
1277  << (BS.Base->getAccessSpecifierAsWritten() == AS_none);
1278  break;
1279  }
1280  }
1281  return nullptr;
1282  }
1283 
1284  ClassWithFields = BaseType->getAsCXXRecordDecl();
1285  S.BuildBasePathArray(Paths, BasePath);
1286  }
1287 
1288  // The above search did not check whether the selected class itself has base
1289  // classes with fields, so check that now.
1290  CXXBasePaths Paths;
1291  if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1292  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1293  << (ClassWithFields == RD) << RD << ClassWithFields
1294  << Paths.front().back().Base->getType();
1295  return nullptr;
1296  }
1297 
1298  return ClassWithFields;
1299 }
1300 
1302  ValueDecl *Src, QualType DecompType,
1303  const CXXRecordDecl *RD) {
1304  CXXCastPath BasePath;
1305  RD = findDecomposableBaseClass(S, Src->getLocation(), RD, BasePath);
1306  if (!RD)
1307  return true;
1309  DecompType.getQualifiers());
1310 
1311  auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1312  unsigned NumFields =
1313  std::count_if(RD->field_begin(), RD->field_end(),
1314  [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1315  assert(Bindings.size() != NumFields);
1316  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1317  << DecompType << (unsigned)Bindings.size() << NumFields
1318  << (NumFields < Bindings.size());
1319  return true;
1320  };
1321 
1322  // all of E's non-static data members shall be public [...] members,
1323  // E shall not have an anonymous union member, ...
1324  unsigned I = 0;
1325  for (auto *FD : RD->fields()) {
1326  if (FD->isUnnamedBitfield())
1327  continue;
1328 
1329  if (FD->isAnonymousStructOrUnion()) {
1330  S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1331  << DecompType << FD->getType()->isUnionType();
1332  S.Diag(FD->getLocation(), diag::note_declared_at);
1333  return true;
1334  }
1335 
1336  // We have a real field to bind.
1337  if (I >= Bindings.size())
1338  return DiagnoseBadNumberOfBindings();
1339  auto *B = Bindings[I++];
1340 
1341  SourceLocation Loc = B->getLocation();
1342  if (FD->getAccess() != AS_public) {
1343  S.Diag(Loc, diag::err_decomp_decl_non_public_member) << FD << DecompType;
1344 
1345  // Determine whether the access specifier was explicit.
1346  bool Implicit = true;
1347  for (const auto *D : RD->decls()) {
1348  if (declaresSameEntity(D, FD))
1349  break;
1350  if (isa<AccessSpecDecl>(D)) {
1351  Implicit = false;
1352  break;
1353  }
1354  }
1355 
1356  S.Diag(FD->getLocation(), diag::note_access_natural)
1357  << (FD->getAccess() == AS_protected) << Implicit;
1358  return true;
1359  }
1360 
1361  // Initialize the binding to Src.FD.
1362  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1363  if (E.isInvalid())
1364  return true;
1365  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1366  VK_LValue, &BasePath);
1367  if (E.isInvalid())
1368  return true;
1369  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1370  CXXScopeSpec(), FD,
1371  DeclAccessPair::make(FD, FD->getAccess()),
1372  DeclarationNameInfo(FD->getDeclName(), Loc));
1373  if (E.isInvalid())
1374  return true;
1375 
1376  // If the type of the member is T, the referenced type is cv T, where cv is
1377  // the cv-qualification of the decomposition expression.
1378  //
1379  // FIXME: We resolve a defect here: if the field is mutable, we do not add
1380  // 'const' to the type of the field.
1381  Qualifiers Q = DecompType.getQualifiers();
1382  if (FD->isMutable())
1383  Q.removeConst();
1384  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1385  }
1386 
1387  if (I != Bindings.size())
1388  return DiagnoseBadNumberOfBindings();
1389 
1390  return false;
1391 }
1392 
1394  QualType DecompType = DD->getType();
1395 
1396  // If the type of the decomposition is dependent, then so is the type of
1397  // each binding.
1398  if (DecompType->isDependentType()) {
1399  for (auto *B : DD->bindings())
1400  B->setType(Context.DependentTy);
1401  return;
1402  }
1403 
1404  DecompType = DecompType.getNonReferenceType();
1405  ArrayRef<BindingDecl*> Bindings = DD->bindings();
1406 
1407  // C++1z [dcl.decomp]/2:
1408  // If E is an array type [...]
1409  // As an extension, we also support decomposition of built-in complex and
1410  // vector types.
1411  if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1412  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1413  DD->setInvalidDecl();
1414  return;
1415  }
1416  if (auto *VT = DecompType->getAs<VectorType>()) {
1417  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1418  DD->setInvalidDecl();
1419  return;
1420  }
1421  if (auto *CT = DecompType->getAs<ComplexType>()) {
1422  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1423  DD->setInvalidDecl();
1424  return;
1425  }
1426 
1427  // C++1z [dcl.decomp]/3:
1428  // if the expression std::tuple_size<E>::value is a well-formed integral
1429  // constant expression, [...]
1430  llvm::APSInt TupleSize(32);
1431  switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1432  case IsTupleLike::Error:
1433  DD->setInvalidDecl();
1434  return;
1435 
1436  case IsTupleLike::TupleLike:
1437  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1438  DD->setInvalidDecl();
1439  return;
1440 
1441  case IsTupleLike::NotTupleLike:
1442  break;
1443  }
1444 
1445  // C++1z [dcl.dcl]/8:
1446  // [E shall be of array or non-union class type]
1447  CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1448  if (!RD || RD->isUnion()) {
1449  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1450  << DD << !RD << DecompType;
1451  DD->setInvalidDecl();
1452  return;
1453  }
1454 
1455  // C++1z [dcl.decomp]/4:
1456  // all of E's non-static data members shall be [...] direct members of
1457  // E or of the same unambiguous public base class of E, ...
1458  if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1459  DD->setInvalidDecl();
1460 }
1461 
1462 /// \brief Merge the exception specifications of two variable declarations.
1463 ///
1464 /// This is called when there's a redeclaration of a VarDecl. The function
1465 /// checks if the redeclaration might have an exception specification and
1466 /// validates compatibility and merges the specs if necessary.
1468  // Shortcut if exceptions are disabled.
1469  if (!getLangOpts().CXXExceptions)
1470  return;
1471 
1472  assert(Context.hasSameType(New->getType(), Old->getType()) &&
1473  "Should only be called if types are otherwise the same.");
1474 
1475  QualType NewType = New->getType();
1476  QualType OldType = Old->getType();
1477 
1478  // We're only interested in pointers and references to functions, as well
1479  // as pointers to member functions.
1480  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1481  NewType = R->getPointeeType();
1482  OldType = OldType->getAs<ReferenceType>()->getPointeeType();
1483  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1484  NewType = P->getPointeeType();
1485  OldType = OldType->getAs<PointerType>()->getPointeeType();
1486  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1487  NewType = M->getPointeeType();
1488  OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
1489  }
1490 
1491  if (!NewType->isFunctionProtoType())
1492  return;
1493 
1494  // There's lots of special cases for functions. For function pointers, system
1495  // libraries are hopefully not as broken so that we don't need these
1496  // workarounds.
1497  if (CheckEquivalentExceptionSpec(
1498  OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1499  NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1500  New->setInvalidDecl();
1501  }
1502 }
1503 
1504 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1505 /// function declaration are well-formed according to C++
1506 /// [dcl.fct.default].
1508  unsigned NumParams = FD->getNumParams();
1509  unsigned p;
1510 
1511  // Find first parameter with a default argument
1512  for (p = 0; p < NumParams; ++p) {
1513  ParmVarDecl *Param = FD->getParamDecl(p);
1514  if (Param->hasDefaultArg())
1515  break;
1516  }
1517 
1518  // C++11 [dcl.fct.default]p4:
1519  // In a given function declaration, each parameter subsequent to a parameter
1520  // with a default argument shall have a default argument supplied in this or
1521  // a previous declaration or shall be a function parameter pack. A default
1522  // argument shall not be redefined by a later declaration (not even to the
1523  // same value).
1524  unsigned LastMissingDefaultArg = 0;
1525  for (; p < NumParams; ++p) {
1526  ParmVarDecl *Param = FD->getParamDecl(p);
1527  if (!Param->hasDefaultArg() && !Param->isParameterPack()) {
1528  if (Param->isInvalidDecl())
1529  /* We already complained about this parameter. */;
1530  else if (Param->getIdentifier())
1531  Diag(Param->getLocation(),
1532  diag::err_param_default_argument_missing_name)
1533  << Param->getIdentifier();
1534  else
1535  Diag(Param->getLocation(),
1536  diag::err_param_default_argument_missing);
1537 
1538  LastMissingDefaultArg = p;
1539  }
1540  }
1541 
1542  if (LastMissingDefaultArg > 0) {
1543  // Some default arguments were missing. Clear out all of the
1544  // default arguments up to (and including) the last missing
1545  // default argument, so that we leave the function parameters
1546  // in a semantically valid state.
1547  for (p = 0; p <= LastMissingDefaultArg; ++p) {
1548  ParmVarDecl *Param = FD->getParamDecl(p);
1549  if (Param->hasDefaultArg()) {
1550  Param->setDefaultArg(nullptr);
1551  }
1552  }
1553  }
1554 }
1555 
1556 // CheckConstexprParameterTypes - Check whether a function's parameter types
1557 // are all literal types. If so, return true. If not, produce a suitable
1558 // diagnostic and return false.
1559 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1560  const FunctionDecl *FD) {
1561  unsigned ArgIndex = 0;
1562  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
1564  e = FT->param_type_end();
1565  i != e; ++i, ++ArgIndex) {
1566  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1567  SourceLocation ParamLoc = PD->getLocation();
1568  if (!(*i)->isDependentType() &&
1569  SemaRef.RequireLiteralType(ParamLoc, *i,
1570  diag::err_constexpr_non_literal_param,
1571  ArgIndex+1, PD->getSourceRange(),
1572  isa<CXXConstructorDecl>(FD)))
1573  return false;
1574  }
1575  return true;
1576 }
1577 
1578 /// \brief Get diagnostic %select index for tag kind for
1579 /// record diagnostic message.
1580 /// WARNING: Indexes apply to particular diagnostics only!
1581 ///
1582 /// \returns diagnostic %select index.
1584  switch (Tag) {
1585  case TTK_Struct: return 0;
1586  case TTK_Interface: return 1;
1587  case TTK_Class: return 2;
1588  default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1589  }
1590 }
1591 
1592 // CheckConstexprFunctionDecl - Check whether a function declaration satisfies
1593 // the requirements of a constexpr function definition or a constexpr
1594 // constructor definition. If so, return true. If not, produce appropriate
1595 // diagnostics and return false.
1596 //
1597 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1599  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1600  if (MD && MD->isInstance()) {
1601  // C++11 [dcl.constexpr]p4:
1602  // The definition of a constexpr constructor shall satisfy the following
1603  // constraints:
1604  // - the class shall not have any virtual base classes;
1605  const CXXRecordDecl *RD = MD->getParent();
1606  if (RD->getNumVBases()) {
1607  Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1608  << isa<CXXConstructorDecl>(NewFD)
1610  for (const auto &I : RD->vbases())
1611  Diag(I.getLocStart(),
1612  diag::note_constexpr_virtual_base_here) << I.getSourceRange();
1613  return false;
1614  }
1615  }
1616 
1617  if (!isa<CXXConstructorDecl>(NewFD)) {
1618  // C++11 [dcl.constexpr]p3:
1619  // The definition of a constexpr function shall satisfy the following
1620  // constraints:
1621  // - it shall not be virtual;
1622  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1623  if (Method && Method->isVirtual()) {
1624  Method = Method->getCanonicalDecl();
1625  Diag(Method->getLocation(), diag::err_constexpr_virtual);
1626 
1627  // If it's not obvious why this function is virtual, find an overridden
1628  // function which uses the 'virtual' keyword.
1629  const CXXMethodDecl *WrittenVirtual = Method;
1630  while (!WrittenVirtual->isVirtualAsWritten())
1631  WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1632  if (WrittenVirtual != Method)
1633  Diag(WrittenVirtual->getLocation(),
1634  diag::note_overridden_virtual_function);
1635  return false;
1636  }
1637 
1638  // - its return type shall be a literal type;
1639  QualType RT = NewFD->getReturnType();
1640  if (!RT->isDependentType() &&
1641  RequireLiteralType(NewFD->getLocation(), RT,
1642  diag::err_constexpr_non_literal_return))
1643  return false;
1644  }
1645 
1646  // - each of its parameter types shall be a literal type;
1647  if (!CheckConstexprParameterTypes(*this, NewFD))
1648  return false;
1649 
1650  return true;
1651 }
1652 
1653 /// Check the given declaration statement is legal within a constexpr function
1654 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1655 ///
1656 /// \return true if the body is OK (maybe only as an extension), false if we
1657 /// have diagnosed a problem.
1658 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1659  DeclStmt *DS, SourceLocation &Cxx1yLoc) {
1660  // C++11 [dcl.constexpr]p3 and p4:
1661  // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1662  // contain only
1663  for (const auto *DclIt : DS->decls()) {
1664  switch (DclIt->getKind()) {
1665  case Decl::StaticAssert:
1666  case Decl::Using:
1667  case Decl::UsingShadow:
1668  case Decl::UsingDirective:
1669  case Decl::UnresolvedUsingTypename:
1670  case Decl::UnresolvedUsingValue:
1671  // - static_assert-declarations
1672  // - using-declarations,
1673  // - using-directives,
1674  continue;
1675 
1676  case Decl::Typedef:
1677  case Decl::TypeAlias: {
1678  // - typedef declarations and alias-declarations that do not define
1679  // classes or enumerations,
1680  const auto *TN = cast<TypedefNameDecl>(DclIt);
1681  if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1682  // Don't allow variably-modified types in constexpr functions.
1683  TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1684  SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1685  << TL.getSourceRange() << TL.getType()
1686  << isa<CXXConstructorDecl>(Dcl);
1687  return false;
1688  }
1689  continue;
1690  }
1691 
1692  case Decl::Enum:
1693  case Decl::CXXRecord:
1694  // C++1y allows types to be defined, not just declared.
1695  if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition())
1696  SemaRef.Diag(DS->getLocStart(),
1697  SemaRef.getLangOpts().CPlusPlus14
1698  ? diag::warn_cxx11_compat_constexpr_type_definition
1699  : diag::ext_constexpr_type_definition)
1700  << isa<CXXConstructorDecl>(Dcl);
1701  continue;
1702 
1703  case Decl::EnumConstant:
1704  case Decl::IndirectField:
1705  case Decl::ParmVar:
1706  // These can only appear with other declarations which are banned in
1707  // C++11 and permitted in C++1y, so ignore them.
1708  continue;
1709 
1710  case Decl::Var:
1711  case Decl::Decomposition: {
1712  // C++1y [dcl.constexpr]p3 allows anything except:
1713  // a definition of a variable of non-literal type or of static or
1714  // thread storage duration or for which no initialization is performed.
1715  const auto *VD = cast<VarDecl>(DclIt);
1716  if (VD->isThisDeclarationADefinition()) {
1717  if (VD->isStaticLocal()) {
1718  SemaRef.Diag(VD->getLocation(),
1719  diag::err_constexpr_local_var_static)
1720  << isa<CXXConstructorDecl>(Dcl)
1721  << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1722  return false;
1723  }
1724  if (!VD->getType()->isDependentType() &&
1725  SemaRef.RequireLiteralType(
1726  VD->getLocation(), VD->getType(),
1727  diag::err_constexpr_local_var_non_literal_type,
1728  isa<CXXConstructorDecl>(Dcl)))
1729  return false;
1730  if (!VD->getType()->isDependentType() &&
1731  !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1732  SemaRef.Diag(VD->getLocation(),
1733  diag::err_constexpr_local_var_no_init)
1734  << isa<CXXConstructorDecl>(Dcl);
1735  return false;
1736  }
1737  }
1738  SemaRef.Diag(VD->getLocation(),
1739  SemaRef.getLangOpts().CPlusPlus14
1740  ? diag::warn_cxx11_compat_constexpr_local_var
1741  : diag::ext_constexpr_local_var)
1742  << isa<CXXConstructorDecl>(Dcl);
1743  continue;
1744  }
1745 
1746  case Decl::NamespaceAlias:
1747  case Decl::Function:
1748  // These are disallowed in C++11 and permitted in C++1y. Allow them
1749  // everywhere as an extension.
1750  if (!Cxx1yLoc.isValid())
1751  Cxx1yLoc = DS->getLocStart();
1752  continue;
1753 
1754  default:
1755  SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
1756  << isa<CXXConstructorDecl>(Dcl);
1757  return false;
1758  }
1759  }
1760 
1761  return true;
1762 }
1763 
1764 /// Check that the given field is initialized within a constexpr constructor.
1765 ///
1766 /// \param Dcl The constexpr constructor being checked.
1767 /// \param Field The field being checked. This may be a member of an anonymous
1768 /// struct or union nested within the class being checked.
1769 /// \param Inits All declarations, including anonymous struct/union members and
1770 /// indirect members, for which any initialization was provided.
1771 /// \param Diagnosed Set to true if an error is produced.
1773  const FunctionDecl *Dcl,
1774  FieldDecl *Field,
1775  llvm::SmallSet<Decl*, 16> &Inits,
1776  bool &Diagnosed) {
1777  if (Field->isInvalidDecl())
1778  return;
1779 
1780  if (Field->isUnnamedBitfield())
1781  return;
1782 
1783  // Anonymous unions with no variant members and empty anonymous structs do not
1784  // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1785  // indirect fields don't need initializing.
1786  if (Field->isAnonymousStructOrUnion() &&
1787  (Field->getType()->isUnionType()
1788  ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1789  : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1790  return;
1791 
1792  if (!Inits.count(Field)) {
1793  if (!Diagnosed) {
1794  SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
1795  Diagnosed = true;
1796  }
1797  SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
1798  } else if (Field->isAnonymousStructOrUnion()) {
1799  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1800  for (auto *I : RD->fields())
1801  // If an anonymous union contains an anonymous struct of which any member
1802  // is initialized, all members must be initialized.
1803  if (!RD->isUnion() || Inits.count(I))
1804  CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed);
1805  }
1806 }
1807 
1808 /// Check the provided statement is allowed in a constexpr function
1809 /// definition.
1810 static bool
1812  SmallVectorImpl<SourceLocation> &ReturnStmts,
1813  SourceLocation &Cxx1yLoc) {
1814  // - its function-body shall be [...] a compound-statement that contains only
1815  switch (S->getStmtClass()) {
1816  case Stmt::NullStmtClass:
1817  // - null statements,
1818  return true;
1819 
1820  case Stmt::DeclStmtClass:
1821  // - static_assert-declarations
1822  // - using-declarations,
1823  // - using-directives,
1824  // - typedef declarations and alias-declarations that do not define
1825  // classes or enumerations,
1826  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc))
1827  return false;
1828  return true;
1829 
1830  case Stmt::ReturnStmtClass:
1831  // - and exactly one return statement;
1832  if (isa<CXXConstructorDecl>(Dcl)) {
1833  // C++1y allows return statements in constexpr constructors.
1834  if (!Cxx1yLoc.isValid())
1835  Cxx1yLoc = S->getLocStart();
1836  return true;
1837  }
1838 
1839  ReturnStmts.push_back(S->getLocStart());
1840  return true;
1841 
1842  case Stmt::CompoundStmtClass: {
1843  // C++1y allows compound-statements.
1844  if (!Cxx1yLoc.isValid())
1845  Cxx1yLoc = S->getLocStart();
1846 
1847  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
1848  for (auto *BodyIt : CompStmt->body()) {
1849  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
1850  Cxx1yLoc))
1851  return false;
1852  }
1853  return true;
1854  }
1855 
1856  case Stmt::AttributedStmtClass:
1857  if (!Cxx1yLoc.isValid())
1858  Cxx1yLoc = S->getLocStart();
1859  return true;
1860 
1861  case Stmt::IfStmtClass: {
1862  // C++1y allows if-statements.
1863  if (!Cxx1yLoc.isValid())
1864  Cxx1yLoc = S->getLocStart();
1865 
1866  IfStmt *If = cast<IfStmt>(S);
1867  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
1868  Cxx1yLoc))
1869  return false;
1870  if (If->getElse() &&
1871  !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
1872  Cxx1yLoc))
1873  return false;
1874  return true;
1875  }
1876 
1877  case Stmt::WhileStmtClass:
1878  case Stmt::DoStmtClass:
1879  case Stmt::ForStmtClass:
1880  case Stmt::CXXForRangeStmtClass:
1881  case Stmt::ContinueStmtClass:
1882  // C++1y allows all of these. We don't allow them as extensions in C++11,
1883  // because they don't make sense without variable mutation.
1884  if (!SemaRef.getLangOpts().CPlusPlus14)
1885  break;
1886  if (!Cxx1yLoc.isValid())
1887  Cxx1yLoc = S->getLocStart();
1888  for (Stmt *SubStmt : S->children())
1889  if (SubStmt &&
1890  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1891  Cxx1yLoc))
1892  return false;
1893  return true;
1894 
1895  case Stmt::SwitchStmtClass:
1896  case Stmt::CaseStmtClass:
1897  case Stmt::DefaultStmtClass:
1898  case Stmt::BreakStmtClass:
1899  // C++1y allows switch-statements, and since they don't need variable
1900  // mutation, we can reasonably allow them in C++11 as an extension.
1901  if (!Cxx1yLoc.isValid())
1902  Cxx1yLoc = S->getLocStart();
1903  for (Stmt *SubStmt : S->children())
1904  if (SubStmt &&
1905  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1906  Cxx1yLoc))
1907  return false;
1908  return true;
1909 
1910  default:
1911  if (!isa<Expr>(S))
1912  break;
1913 
1914  // C++1y allows expression-statements.
1915  if (!Cxx1yLoc.isValid())
1916  Cxx1yLoc = S->getLocStart();
1917  return true;
1918  }
1919 
1920  SemaRef.Diag(S->getLocStart(), diag::err_constexpr_body_invalid_stmt)
1921  << isa<CXXConstructorDecl>(Dcl);
1922  return false;
1923 }
1924 
1925 /// Check the body for the given constexpr function declaration only contains
1926 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
1927 ///
1928 /// \return true if the body is OK, false if we have diagnosed a problem.
1930  if (isa<CXXTryStmt>(Body)) {
1931  // C++11 [dcl.constexpr]p3:
1932  // The definition of a constexpr function shall satisfy the following
1933  // constraints: [...]
1934  // - its function-body shall be = delete, = default, or a
1935  // compound-statement
1936  //
1937  // C++11 [dcl.constexpr]p4:
1938  // In the definition of a constexpr constructor, [...]
1939  // - its function-body shall not be a function-try-block;
1940  Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
1941  << isa<CXXConstructorDecl>(Dcl);
1942  return false;
1943  }
1944 
1945  SmallVector<SourceLocation, 4> ReturnStmts;
1946 
1947  // - its function-body shall be [...] a compound-statement that contains only
1948  // [... list of cases ...]
1949  CompoundStmt *CompBody = cast<CompoundStmt>(Body);
1950  SourceLocation Cxx1yLoc;
1951  for (auto *BodyIt : CompBody->body()) {
1952  if (!CheckConstexprFunctionStmt(*this, Dcl, BodyIt, ReturnStmts, Cxx1yLoc))
1953  return false;
1954  }
1955 
1956  if (Cxx1yLoc.isValid())
1957  Diag(Cxx1yLoc,
1958  getLangOpts().CPlusPlus14
1959  ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
1960  : diag::ext_constexpr_body_invalid_stmt)
1961  << isa<CXXConstructorDecl>(Dcl);
1962 
1963  if (const CXXConstructorDecl *Constructor
1964  = dyn_cast<CXXConstructorDecl>(Dcl)) {
1965  const CXXRecordDecl *RD = Constructor->getParent();
1966  // DR1359:
1967  // - every non-variant non-static data member and base class sub-object
1968  // shall be initialized;
1969  // DR1460:
1970  // - if the class is a union having variant members, exactly one of them
1971  // shall be initialized;
1972  if (RD->isUnion()) {
1973  if (Constructor->getNumCtorInitializers() == 0 &&
1974  RD->hasVariantMembers()) {
1975  Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
1976  return false;
1977  }
1978  } else if (!Constructor->isDependentContext() &&
1979  !Constructor->isDelegatingConstructor()) {
1980  assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
1981 
1982  // Skip detailed checking if we have enough initializers, and we would
1983  // allow at most one initializer per member.
1984  bool AnyAnonStructUnionMembers = false;
1985  unsigned Fields = 0;
1987  E = RD->field_end(); I != E; ++I, ++Fields) {
1988  if (I->isAnonymousStructOrUnion()) {
1989  AnyAnonStructUnionMembers = true;
1990  break;
1991  }
1992  }
1993  // DR1460:
1994  // - if the class is a union-like class, but is not a union, for each of
1995  // its anonymous union members having variant members, exactly one of
1996  // them shall be initialized;
1997  if (AnyAnonStructUnionMembers ||
1998  Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
1999  // Check initialization of non-static data members. Base classes are
2000  // always initialized so do not need to be checked. Dependent bases
2001  // might not have initializers in the member initializer list.
2002  llvm::SmallSet<Decl*, 16> Inits;
2003  for (const auto *I: Constructor->inits()) {
2004  if (FieldDecl *FD = I->getMember())
2005  Inits.insert(FD);
2006  else if (IndirectFieldDecl *ID = I->getIndirectMember())
2007  Inits.insert(ID->chain_begin(), ID->chain_end());
2008  }
2009 
2010  bool Diagnosed = false;
2011  for (auto *I : RD->fields())
2012  CheckConstexprCtorInitializer(*this, Dcl, I, Inits, Diagnosed);
2013  if (Diagnosed)
2014  return false;
2015  }
2016  }
2017  } else {
2018  if (ReturnStmts.empty()) {
2019  // C++1y doesn't require constexpr functions to contain a 'return'
2020  // statement. We still do, unless the return type might be void, because
2021  // otherwise if there's no return statement, the function cannot
2022  // be used in a core constant expression.
2023  bool OK = getLangOpts().CPlusPlus14 &&
2024  (Dcl->getReturnType()->isVoidType() ||
2025  Dcl->getReturnType()->isDependentType());
2026  Diag(Dcl->getLocation(),
2027  OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2028  : diag::err_constexpr_body_no_return);
2029  if (!OK)
2030  return false;
2031  } else if (ReturnStmts.size() > 1) {
2032  Diag(ReturnStmts.back(),
2033  getLangOpts().CPlusPlus14
2034  ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2035  : diag::ext_constexpr_body_multiple_return);
2036  for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2037  Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
2038  }
2039  }
2040 
2041  // C++11 [dcl.constexpr]p5:
2042  // if no function argument values exist such that the function invocation
2043  // substitution would produce a constant expression, the program is
2044  // ill-formed; no diagnostic required.
2045  // C++11 [dcl.constexpr]p3:
2046  // - every constructor call and implicit conversion used in initializing the
2047  // return value shall be one of those allowed in a constant expression.
2048  // C++11 [dcl.constexpr]p4:
2049  // - every constructor involved in initializing non-static data members and
2050  // base class sub-objects shall be a constexpr constructor.
2052  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
2053  Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr)
2054  << isa<CXXConstructorDecl>(Dcl);
2055  for (size_t I = 0, N = Diags.size(); I != N; ++I)
2056  Diag(Diags[I].first, Diags[I].second);
2057  // Don't return false here: we allow this for compatibility in
2058  // system headers.
2059  }
2060 
2061  return true;
2062 }
2063 
2064 /// isCurrentClassName - Determine whether the identifier II is the
2065 /// name of the class type currently being defined. In the case of
2066 /// nested classes, this will only return true if II is the name of
2067 /// the innermost class.
2069  const CXXScopeSpec *SS) {
2070  assert(getLangOpts().CPlusPlus && "No class names in C!");
2071 
2072  CXXRecordDecl *CurDecl;
2073  if (SS && SS->isSet() && !SS->isInvalid()) {
2074  DeclContext *DC = computeDeclContext(*SS, true);
2075  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2076  } else
2077  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2078 
2079  if (CurDecl && CurDecl->getIdentifier())
2080  return &II == CurDecl->getIdentifier();
2081  return false;
2082 }
2083 
2084 /// \brief Determine whether the identifier II is a typo for the name of
2085 /// the class type currently being defined. If so, update it to the identifier
2086 /// that should have been used.
2088  assert(getLangOpts().CPlusPlus && "No class names in C!");
2089 
2090  if (!getLangOpts().SpellChecking)
2091  return false;
2092 
2093  CXXRecordDecl *CurDecl;
2094  if (SS && SS->isSet() && !SS->isInvalid()) {
2095  DeclContext *DC = computeDeclContext(*SS, true);
2096  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2097  } else
2098  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2099 
2100  if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2101  3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2102  < II->getLength()) {
2103  II = CurDecl->getIdentifier();
2104  return true;
2105  }
2106 
2107  return false;
2108 }
2109 
2110 /// \brief Determine whether the given class is a base class of the given
2111 /// class, including looking at dependent bases.
2112 static bool findCircularInheritance(const CXXRecordDecl *Class,
2113  const CXXRecordDecl *Current) {
2115 
2116  Class = Class->getCanonicalDecl();
2117  while (true) {
2118  for (const auto &I : Current->bases()) {
2119  CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2120  if (!Base)
2121  continue;
2122 
2123  Base = Base->getDefinition();
2124  if (!Base)
2125  continue;
2126 
2127  if (Base->getCanonicalDecl() == Class)
2128  return true;
2129 
2130  Queue.push_back(Base);
2131  }
2132 
2133  if (Queue.empty())
2134  return false;
2135 
2136  Current = Queue.pop_back_val();
2137  }
2138 
2139  return false;
2140 }
2141 
2142 /// \brief Check the validity of a C++ base class specifier.
2143 ///
2144 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2145 /// and returns NULL otherwise.
2148  SourceRange SpecifierRange,
2149  bool Virtual, AccessSpecifier Access,
2150  TypeSourceInfo *TInfo,
2151  SourceLocation EllipsisLoc) {
2152  QualType BaseType = TInfo->getType();
2153 
2154  // C++ [class.union]p1:
2155  // A union shall not have base classes.
2156  if (Class->isUnion()) {
2157  Diag(Class->getLocation(), diag::err_base_clause_on_union)
2158  << SpecifierRange;
2159  return nullptr;
2160  }
2161 
2162  if (EllipsisLoc.isValid() &&
2164  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2165  << TInfo->getTypeLoc().getSourceRange();
2166  EllipsisLoc = SourceLocation();
2167  }
2168 
2169  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2170 
2171  if (BaseType->isDependentType()) {
2172  // Make sure that we don't have circular inheritance among our dependent
2173  // bases. For non-dependent bases, the check for completeness below handles
2174  // this.
2175  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2176  if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2177  ((BaseDecl = BaseDecl->getDefinition()) &&
2178  findCircularInheritance(Class, BaseDecl))) {
2179  Diag(BaseLoc, diag::err_circular_inheritance)
2180  << BaseType << Context.getTypeDeclType(Class);
2181 
2182  if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2183  Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2184  << BaseType;
2185 
2186  return nullptr;
2187  }
2188  }
2189 
2190  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2191  Class->getTagKind() == TTK_Class,
2192  Access, TInfo, EllipsisLoc);
2193  }
2194 
2195  // Base specifiers must be record types.
2196  if (!BaseType->isRecordType()) {
2197  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2198  return nullptr;
2199  }
2200 
2201  // C++ [class.union]p1:
2202  // A union shall not be used as a base class.
2203  if (BaseType->isUnionType()) {
2204  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2205  return nullptr;
2206  }
2207 
2208  // For the MS ABI, propagate DLL attributes to base class templates.
2209  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2210  if (Attr *ClassAttr = getDLLAttr(Class)) {
2211  if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2212  BaseType->getAsCXXRecordDecl())) {
2213  propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2214  BaseLoc);
2215  }
2216  }
2217  }
2218 
2219  // C++ [class.derived]p2:
2220  // The class-name in a base-specifier shall not be an incompletely
2221  // defined class.
2222  if (RequireCompleteType(BaseLoc, BaseType,
2223  diag::err_incomplete_base_class, SpecifierRange)) {
2224  Class->setInvalidDecl();
2225  return nullptr;
2226  }
2227 
2228  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2229  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
2230  assert(BaseDecl && "Record type has no declaration");
2231  BaseDecl = BaseDecl->getDefinition();
2232  assert(BaseDecl && "Base type is not incomplete, but has no definition");
2233  CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2234  assert(CXXBaseDecl && "Base type is not a C++ type");
2235 
2236  // A class which contains a flexible array member is not suitable for use as a
2237  // base class:
2238  // - If the layout determines that a base comes before another base,
2239  // the flexible array member would index into the subsequent base.
2240  // - If the layout determines that base comes before the derived class,
2241  // the flexible array member would index into the derived class.
2242  if (CXXBaseDecl->hasFlexibleArrayMember()) {
2243  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2244  << CXXBaseDecl->getDeclName();
2245  return nullptr;
2246  }
2247 
2248  // C++ [class]p3:
2249  // If a class is marked final and it appears as a base-type-specifier in
2250  // base-clause, the program is ill-formed.
2251  if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2252  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2253  << CXXBaseDecl->getDeclName()
2254  << FA->isSpelledAsSealed();
2255  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2256  << CXXBaseDecl->getDeclName() << FA->getRange();
2257  return nullptr;
2258  }
2259 
2260  if (BaseDecl->isInvalidDecl())
2261  Class->setInvalidDecl();
2262 
2263  // Create the base specifier.
2264  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2265  Class->getTagKind() == TTK_Class,
2266  Access, TInfo, EllipsisLoc);
2267 }
2268 
2269 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2270 /// one entry in the base class list of a class specifier, for
2271 /// example:
2272 /// class foo : public bar, virtual private baz {
2273 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2274 BaseResult
2275 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2276  ParsedAttributes &Attributes,
2277  bool Virtual, AccessSpecifier Access,
2278  ParsedType basetype, SourceLocation BaseLoc,
2279  SourceLocation EllipsisLoc) {
2280  if (!classdecl)
2281  return true;
2282 
2283  AdjustDeclIfTemplate(classdecl);
2284  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2285  if (!Class)
2286  return true;
2287 
2288  // We haven't yet attached the base specifiers.
2289  Class->setIsParsingBaseSpecifiers();
2290 
2291  // We do not support any C++11 attributes on base-specifiers yet.
2292  // Diagnose any attributes we see.
2293  if (!Attributes.empty()) {
2294  for (AttributeList *Attr = Attributes.getList(); Attr;
2295  Attr = Attr->getNext()) {
2296  if (Attr->isInvalid() ||
2298  continue;
2299  Diag(Attr->getLoc(),
2301  ? diag::warn_unknown_attribute_ignored
2302  : diag::err_base_specifier_attribute)
2303  << Attr->getName();
2304  }
2305  }
2306 
2307  TypeSourceInfo *TInfo = nullptr;
2308  GetTypeFromParser(basetype, &TInfo);
2309 
2310  if (EllipsisLoc.isInvalid() &&
2311  DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2312  UPPC_BaseType))
2313  return true;
2314 
2315  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2316  Virtual, Access, TInfo,
2317  EllipsisLoc))
2318  return BaseSpec;
2319  else
2320  Class->setInvalidDecl();
2321 
2322  return true;
2323 }
2324 
2325 /// Use small set to collect indirect bases. As this is only used
2326 /// locally, there's no need to abstract the small size parameter.
2327 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2328 
2329 /// \brief Recursively add the bases of Type. Don't add Type itself.
2330 static void
2331 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2332  const QualType &Type)
2333 {
2334  // Even though the incoming type is a base, it might not be
2335  // a class -- it could be a template parm, for instance.
2336  if (auto Rec = Type->getAs<RecordType>()) {
2337  auto Decl = Rec->getAsCXXRecordDecl();
2338 
2339  // Iterate over its bases.
2340  for (const auto &BaseSpec : Decl->bases()) {
2341  QualType Base = Context.getCanonicalType(BaseSpec.getType())
2342  .getUnqualifiedType();
2343  if (Set.insert(Base).second)
2344  // If we've not already seen it, recurse.
2345  NoteIndirectBases(Context, Set, Base);
2346  }
2347  }
2348 }
2349 
2350 /// \brief Performs the actual work of attaching the given base class
2351 /// specifiers to a C++ class.
2354  if (Bases.empty())
2355  return false;
2356 
2357  // Used to keep track of which base types we have already seen, so
2358  // that we can properly diagnose redundant direct base types. Note
2359  // that the key is always the unqualified canonical type of the base
2360  // class.
2361  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2362 
2363  // Used to track indirect bases so we can see if a direct base is
2364  // ambiguous.
2365  IndirectBaseSet IndirectBaseTypes;
2366 
2367  // Copy non-redundant base specifiers into permanent storage.
2368  unsigned NumGoodBases = 0;
2369  bool Invalid = false;
2370  for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2371  QualType NewBaseType
2372  = Context.getCanonicalType(Bases[idx]->getType());
2373  NewBaseType = NewBaseType.getLocalUnqualifiedType();
2374 
2375  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2376  if (KnownBase) {
2377  // C++ [class.mi]p3:
2378  // A class shall not be specified as a direct base class of a
2379  // derived class more than once.
2380  Diag(Bases[idx]->getLocStart(),
2381  diag::err_duplicate_base_class)
2382  << KnownBase->getType()
2383  << Bases[idx]->getSourceRange();
2384 
2385  // Delete the duplicate base class specifier; we're going to
2386  // overwrite its pointer later.
2387  Context.Deallocate(Bases[idx]);
2388 
2389  Invalid = true;
2390  } else {
2391  // Okay, add this new base class.
2392  KnownBase = Bases[idx];
2393  Bases[NumGoodBases++] = Bases[idx];
2394 
2395  // Note this base's direct & indirect bases, if there could be ambiguity.
2396  if (Bases.size() > 1)
2397  NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2398 
2399  if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2400  const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2401  if (Class->isInterface() &&
2402  (!RD->isInterfaceLike() ||
2403  KnownBase->getAccessSpecifier() != AS_public)) {
2404  // The Microsoft extension __interface does not permit bases that
2405  // are not themselves public interfaces.
2406  Diag(KnownBase->getLocStart(), diag::err_invalid_base_in_interface)
2407  << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getName()
2408  << RD->getSourceRange();
2409  Invalid = true;
2410  }
2411  if (RD->hasAttr<WeakAttr>())
2412  Class->addAttr(WeakAttr::CreateImplicit(Context));
2413  }
2414  }
2415  }
2416 
2417  // Attach the remaining base class specifiers to the derived class.
2418  Class->setBases(Bases.data(), NumGoodBases);
2419 
2420  // Check that the only base classes that are duplicate are virtual.
2421  for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2422  // Check whether this direct base is inaccessible due to ambiguity.
2423  QualType BaseType = Bases[idx]->getType();
2424 
2425  // Skip all dependent types in templates being used as base specifiers.
2426  // Checks below assume that the base specifier is a CXXRecord.
2427  if (BaseType->isDependentType())
2428  continue;
2429 
2430  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2431  .getUnqualifiedType();
2432 
2433  if (IndirectBaseTypes.count(CanonicalBase)) {
2434  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2435  /*DetectVirtual=*/true);
2436  bool found
2437  = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2438  assert(found);
2439  (void)found;
2440 
2441  if (Paths.isAmbiguous(CanonicalBase))
2442  Diag(Bases[idx]->getLocStart (), diag::warn_inaccessible_base_class)
2443  << BaseType << getAmbiguousPathsDisplayString(Paths)
2444  << Bases[idx]->getSourceRange();
2445  else
2446  assert(Bases[idx]->isVirtual());
2447  }
2448 
2449  // Delete the base class specifier, since its data has been copied
2450  // into the CXXRecordDecl.
2451  Context.Deallocate(Bases[idx]);
2452  }
2453 
2454  return Invalid;
2455 }
2456 
2457 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2458 /// class, after checking whether there are any duplicate base
2459 /// classes.
2460 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2462  if (!ClassDecl || Bases.empty())
2463  return;
2464 
2465  AdjustDeclIfTemplate(ClassDecl);
2466  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2467 }
2468 
2469 /// \brief Determine whether the type \p Derived is a C++ class that is
2470 /// derived from the type \p Base.
2472  if (!getLangOpts().CPlusPlus)
2473  return false;
2474 
2475  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2476  if (!DerivedRD)
2477  return false;
2478 
2479  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2480  if (!BaseRD)
2481  return false;
2482 
2483  // If either the base or the derived type is invalid, don't try to
2484  // check whether one is derived from the other.
2485  if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2486  return false;
2487 
2488  // FIXME: In a modules build, do we need the entire path to be visible for us
2489  // to be able to use the inheritance relationship?
2490  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2491  return false;
2492 
2493  return DerivedRD->isDerivedFrom(BaseRD);
2494 }
2495 
2496 /// \brief Determine whether the type \p Derived is a C++ class that is
2497 /// derived from the type \p Base.
2499  CXXBasePaths &Paths) {
2500  if (!getLangOpts().CPlusPlus)
2501  return false;
2502 
2503  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2504  if (!DerivedRD)
2505  return false;
2506 
2507  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2508  if (!BaseRD)
2509  return false;
2510 
2511  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2512  return false;
2513 
2514  return DerivedRD->isDerivedFrom(BaseRD, Paths);
2515 }
2516 
2517 static void BuildBasePathArray(const CXXBasePath &Path,
2518  CXXCastPath &BasePathArray) {
2519  // We first go backward and check if we have a virtual base.
2520  // FIXME: It would be better if CXXBasePath had the base specifier for
2521  // the nearest virtual base.
2522  unsigned Start = 0;
2523  for (unsigned I = Path.size(); I != 0; --I) {
2524  if (Path[I - 1].Base->isVirtual()) {
2525  Start = I - 1;
2526  break;
2527  }
2528  }
2529 
2530  // Now add all bases.
2531  for (unsigned I = Start, E = Path.size(); I != E; ++I)
2532  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2533 }
2534 
2535 
2537  CXXCastPath &BasePathArray) {
2538  assert(BasePathArray.empty() && "Base path array must be empty!");
2539  assert(Paths.isRecordingPaths() && "Must record paths!");
2540  return ::BuildBasePathArray(Paths.front(), BasePathArray);
2541 }
2542 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2543 /// conversion (where Derived and Base are class types) is
2544 /// well-formed, meaning that the conversion is unambiguous (and
2545 /// that all of the base classes are accessible). Returns true
2546 /// and emits a diagnostic if the code is ill-formed, returns false
2547 /// otherwise. Loc is the location where this routine should point to
2548 /// if there is an error, and Range is the source range to highlight
2549 /// if there is an error.
2550 ///
2551 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2552 /// diagnostic for the respective type of error will be suppressed, but the
2553 /// check for ill-formed code will still be performed.
2554 bool
2556  unsigned InaccessibleBaseID,
2557  unsigned AmbigiousBaseConvID,
2558  SourceLocation Loc, SourceRange Range,
2559  DeclarationName Name,
2560  CXXCastPath *BasePath,
2561  bool IgnoreAccess) {
2562  // First, determine whether the path from Derived to Base is
2563  // ambiguous. This is slightly more expensive than checking whether
2564  // the Derived to Base conversion exists, because here we need to
2565  // explore multiple paths to determine if there is an ambiguity.
2566  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2567  /*DetectVirtual=*/false);
2568  bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2569  if (!DerivationOkay)
2570  return true;
2571 
2572  const CXXBasePath *Path = nullptr;
2573  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2574  Path = &Paths.front();
2575 
2576  // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2577  // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2578  // user to access such bases.
2579  if (!Path && getLangOpts().MSVCCompat) {
2580  for (const CXXBasePath &PossiblePath : Paths) {
2581  if (PossiblePath.size() == 1) {
2582  Path = &PossiblePath;
2583  if (AmbigiousBaseConvID)
2584  Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2585  << Base << Derived << Range;
2586  break;
2587  }
2588  }
2589  }
2590 
2591  if (Path) {
2592  if (!IgnoreAccess) {
2593  // Check that the base class can be accessed.
2594  switch (
2595  CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2596  case AR_inaccessible:
2597  return true;
2598  case AR_accessible:
2599  case AR_dependent:
2600  case AR_delayed:
2601  break;
2602  }
2603  }
2604 
2605  // Build a base path if necessary.
2606  if (BasePath)
2607  ::BuildBasePathArray(*Path, *BasePath);
2608  return false;
2609  }
2610 
2611  if (AmbigiousBaseConvID) {
2612  // We know that the derived-to-base conversion is ambiguous, and
2613  // we're going to produce a diagnostic. Perform the derived-to-base
2614  // search just one more time to compute all of the possible paths so
2615  // that we can print them out. This is more expensive than any of
2616  // the previous derived-to-base checks we've done, but at this point
2617  // performance isn't as much of an issue.
2618  Paths.clear();
2619  Paths.setRecordingPaths(true);
2620  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2621  assert(StillOkay && "Can only be used with a derived-to-base conversion");
2622  (void)StillOkay;
2623 
2624  // Build up a textual representation of the ambiguous paths, e.g.,
2625  // D -> B -> A, that will be used to illustrate the ambiguous
2626  // conversions in the diagnostic. We only print one of the paths
2627  // to each base class subobject.
2628  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2629 
2630  Diag(Loc, AmbigiousBaseConvID)
2631  << Derived << Base << PathDisplayStr << Range << Name;
2632  }
2633  return true;
2634 }
2635 
2636 bool
2638  SourceLocation Loc, SourceRange Range,
2639  CXXCastPath *BasePath,
2640  bool IgnoreAccess) {
2641  return CheckDerivedToBaseConversion(
2642  Derived, Base, diag::err_upcast_to_inaccessible_base,
2643  diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2644  BasePath, IgnoreAccess);
2645 }
2646 
2647 
2648 /// @brief Builds a string representing ambiguous paths from a
2649 /// specific derived class to different subobjects of the same base
2650 /// class.
2651 ///
2652 /// This function builds a string that can be used in error messages
2653 /// to show the different paths that one can take through the
2654 /// inheritance hierarchy to go from the derived class to different
2655 /// subobjects of a base class. The result looks something like this:
2656 /// @code
2657 /// struct D -> struct B -> struct A
2658 /// struct D -> struct C -> struct A
2659 /// @endcode
2661  std::string PathDisplayStr;
2662  std::set<unsigned> DisplayedPaths;
2663  for (CXXBasePaths::paths_iterator Path = Paths.begin();
2664  Path != Paths.end(); ++Path) {
2665  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2666  // We haven't displayed a path to this particular base
2667  // class subobject yet.
2668  PathDisplayStr += "\n ";
2669  PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2670  for (CXXBasePath::const_iterator Element = Path->begin();
2671  Element != Path->end(); ++Element)
2672  PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2673  }
2674  }
2675 
2676  return PathDisplayStr;
2677 }
2678 
2679 //===----------------------------------------------------------------------===//
2680 // C++ class member Handling
2681 //===----------------------------------------------------------------------===//
2682 
2683 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2685  SourceLocation ASLoc,
2687  AttributeList *Attrs) {
2688  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2689  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2690  ASLoc, ColonLoc);
2691  CurContext->addHiddenDecl(ASDecl);
2692  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2693 }
2694 
2695 /// CheckOverrideControl - Check C++11 override control semantics.
2697  if (D->isInvalidDecl())
2698  return;
2699 
2700  // We only care about "override" and "final" declarations.
2701  if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2702  return;
2703 
2704  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2705 
2706  // We can't check dependent instance methods.
2707  if (MD && MD->isInstance() &&
2708  (MD->getParent()->hasAnyDependentBases() ||
2709  MD->getType()->isDependentType()))
2710  return;
2711 
2712  if (MD && !MD->isVirtual()) {
2713  // If we have a non-virtual method, check if if hides a virtual method.
2714  // (In that case, it's most likely the method has the wrong type.)
2715  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2716  FindHiddenVirtualMethods(MD, OverloadedMethods);
2717 
2718  if (!OverloadedMethods.empty()) {
2719  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2720  Diag(OA->getLocation(),
2721  diag::override_keyword_hides_virtual_member_function)
2722  << "override" << (OverloadedMethods.size() > 1);
2723  } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2724  Diag(FA->getLocation(),
2725  diag::override_keyword_hides_virtual_member_function)
2726  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2727  << (OverloadedMethods.size() > 1);
2728  }
2729  NoteHiddenVirtualMethods(MD, OverloadedMethods);
2730  MD->setInvalidDecl();
2731  return;
2732  }
2733  // Fall through into the general case diagnostic.
2734  // FIXME: We might want to attempt typo correction here.
2735  }
2736 
2737  if (!MD || !MD->isVirtual()) {
2738  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2739  Diag(OA->getLocation(),
2740  diag::override_keyword_only_allowed_on_virtual_member_functions)
2741  << "override" << FixItHint::CreateRemoval(OA->getLocation());
2742  D->dropAttr<OverrideAttr>();
2743  }
2744  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2745  Diag(FA->getLocation(),
2746  diag::override_keyword_only_allowed_on_virtual_member_functions)
2747  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2748  << FixItHint::CreateRemoval(FA->getLocation());
2749  D->dropAttr<FinalAttr>();
2750  }
2751  return;
2752  }
2753 
2754  // C++11 [class.virtual]p5:
2755  // If a function is marked with the virt-specifier override and
2756  // does not override a member function of a base class, the program is
2757  // ill-formed.
2758  bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
2759  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
2760  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
2761  << MD->getDeclName();
2762 }
2763 
2765  if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
2766  return;
2767  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2768  if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
2769  return;
2770 
2771  SourceLocation Loc = MD->getLocation();
2772  SourceLocation SpellingLoc = Loc;
2773  if (getSourceManager().isMacroArgExpansion(Loc))
2774  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).first;
2775  SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
2776  if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
2777  return;
2778 
2779  if (MD->size_overridden_methods() > 0) {
2780  unsigned DiagID = isa<CXXDestructorDecl>(MD)
2781  ? diag::warn_destructor_marked_not_override_overriding
2782  : diag::warn_function_marked_not_override_overriding;
2783  Diag(MD->getLocation(), DiagID) << MD->getDeclName();
2784  const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
2785  Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
2786  }
2787 }
2788 
2789 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
2790 /// function overrides a virtual member function marked 'final', according to
2791 /// C++11 [class.virtual]p4.
2793  const CXXMethodDecl *Old) {
2794  FinalAttr *FA = Old->getAttr<FinalAttr>();
2795  if (!FA)
2796  return false;
2797 
2798  Diag(New->getLocation(), diag::err_final_function_overridden)
2799  << New->getDeclName()
2800  << FA->isSpelledAsSealed();
2801  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
2802  return true;
2803 }
2804 
2805 static bool InitializationHasSideEffects(const FieldDecl &FD) {
2806  const Type *T = FD.getType()->getBaseElementTypeUnsafe();
2807  // FIXME: Destruction of ObjC lifetime types has side-effects.
2808  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
2809  return !RD->isCompleteDefinition() ||
2810  !RD->hasTrivialDefaultConstructor() ||
2811  !RD->hasTrivialDestructor();
2812  return false;
2813 }
2814 
2816  for (AttributeList *it = list; it != nullptr; it = it->getNext())
2817  if (it->isDeclspecPropertyAttribute())
2818  return it;
2819  return nullptr;
2820 }
2821 
2822 // Check if there is a field shadowing.
2823 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
2824  DeclarationName FieldName,
2825  const CXXRecordDecl *RD) {
2826  if (Diags.isIgnored(diag::warn_shadow_field, Loc))
2827  return;
2828 
2829  // To record a shadowed field in a base
2830  std::map<CXXRecordDecl*, NamedDecl*> Bases;
2831  auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
2832  CXXBasePath &Path) {
2833  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
2834  // Record an ambiguous path directly
2835  if (Bases.find(Base) != Bases.end())
2836  return true;
2837  for (const auto Field : Base->lookup(FieldName)) {
2838  if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
2839  Field->getAccess() != AS_private) {
2840  assert(Field->getAccess() != AS_none);
2841  assert(Bases.find(Base) == Bases.end());
2842  Bases[Base] = Field;
2843  return true;
2844  }
2845  }
2846  return false;
2847  };
2848 
2849  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2850  /*DetectVirtual=*/true);
2851  if (!RD->lookupInBases(FieldShadowed, Paths))
2852  return;
2853 
2854  for (const auto &P : Paths) {
2855  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
2856  auto It = Bases.find(Base);
2857  // Skip duplicated bases
2858  if (It == Bases.end())
2859  continue;
2860  auto BaseField = It->second;
2861  assert(BaseField->getAccess() != AS_private);
2862  if (AS_none !=
2863  CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
2864  Diag(Loc, diag::warn_shadow_field)
2865  << FieldName.getAsString() << RD->getName() << Base->getName();
2866  Diag(BaseField->getLocation(), diag::note_shadow_field);
2867  Bases.erase(It);
2868  }
2869  }
2870 }
2871 
2872 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
2873 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
2874 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
2875 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
2876 /// present (but parsing it has been deferred).
2877 NamedDecl *
2879  MultiTemplateParamsArg TemplateParameterLists,
2880  Expr *BW, const VirtSpecifiers &VS,
2881  InClassInitStyle InitStyle) {
2882  const DeclSpec &DS = D.getDeclSpec();
2883  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
2884  DeclarationName Name = NameInfo.getName();
2885  SourceLocation Loc = NameInfo.getLoc();
2886 
2887  // For anonymous bitfields, the location should point to the type.
2888  if (Loc.isInvalid())
2889  Loc = D.getLocStart();
2890 
2891  Expr *BitWidth = static_cast<Expr*>(BW);
2892 
2893  assert(isa<CXXRecordDecl>(CurContext));
2894  assert(!DS.isFriendSpecified());
2895 
2896  bool isFunc = D.isDeclarationOfFunction();
2897  AttributeList *MSPropertyAttr =
2899 
2900  if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
2901  // The Microsoft extension __interface only permits public member functions
2902  // and prohibits constructors, destructors, operators, non-public member
2903  // functions, static methods and data members.
2904  unsigned InvalidDecl;
2905  bool ShowDeclName = true;
2906  if (!isFunc &&
2907  (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
2908  InvalidDecl = 0;
2909  else if (!isFunc)
2910  InvalidDecl = 1;
2911  else if (AS != AS_public)
2912  InvalidDecl = 2;
2913  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
2914  InvalidDecl = 3;
2915  else switch (Name.getNameKind()) {
2917  InvalidDecl = 4;
2918  ShowDeclName = false;
2919  break;
2920 
2922  InvalidDecl = 5;
2923  ShowDeclName = false;
2924  break;
2925 
2928  InvalidDecl = 6;
2929  break;
2930 
2931  default:
2932  InvalidDecl = 0;
2933  break;
2934  }
2935 
2936  if (InvalidDecl) {
2937  if (ShowDeclName)
2938  Diag(Loc, diag::err_invalid_member_in_interface)
2939  << (InvalidDecl-1) << Name;
2940  else
2941  Diag(Loc, diag::err_invalid_member_in_interface)
2942  << (InvalidDecl-1) << "";
2943  return nullptr;
2944  }
2945  }
2946 
2947  // C++ 9.2p6: A member shall not be declared to have automatic storage
2948  // duration (auto, register) or with the extern storage-class-specifier.
2949  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
2950  // data members and cannot be applied to names declared const or static,
2951  // and cannot be applied to reference members.
2952  switch (DS.getStorageClassSpec()) {
2954  case DeclSpec::SCS_typedef:
2955  case DeclSpec::SCS_static:
2956  break;
2957  case DeclSpec::SCS_mutable:
2958  if (isFunc) {
2959  Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
2960 
2961  // FIXME: It would be nicer if the keyword was ignored only for this
2962  // declarator. Otherwise we could get follow-up errors.
2964  }
2965  break;
2966  default:
2968  diag::err_storageclass_invalid_for_member);
2970  break;
2971  }
2972 
2973  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
2975  !isFunc);
2976 
2977  if (DS.isConstexprSpecified() && isInstField) {
2979  Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
2980  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
2981  if (InitStyle == ICIS_NoInit) {
2982  B << 0 << 0;
2984  B << FixItHint::CreateRemoval(ConstexprLoc);
2985  else {
2986  B << FixItHint::CreateReplacement(ConstexprLoc, "const");
2988  const char *PrevSpec;
2989  unsigned DiagID;
2990  bool Failed = D.getMutableDeclSpec().SetTypeQual(
2991  DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
2992  (void)Failed;
2993  assert(!Failed && "Making a constexpr member const shouldn't fail");
2994  }
2995  } else {
2996  B << 1;
2997  const char *PrevSpec;
2998  unsigned DiagID;
3000  *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3001  Context.getPrintingPolicy())) {
3002  assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3003  "This is the only DeclSpec that should fail to be applied");
3004  B << 1;
3005  } else {
3006  B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3007  isInstField = false;
3008  }
3009  }
3010  }
3011 
3012  NamedDecl *Member;
3013  if (isInstField) {
3014  CXXScopeSpec &SS = D.getCXXScopeSpec();
3015 
3016  // Data members must have identifiers for names.
3017  if (!Name.isIdentifier()) {
3018  Diag(Loc, diag::err_bad_variable_name)
3019  << Name;
3020  return nullptr;
3021  }
3022 
3023  IdentifierInfo *II = Name.getAsIdentifierInfo();
3024 
3025  // Member field could not be with "template" keyword.
3026  // So TemplateParameterLists should be empty in this case.
3027  if (TemplateParameterLists.size()) {
3028  TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3029  if (TemplateParams->size()) {
3030  // There is no such thing as a member field template.
3031  Diag(D.getIdentifierLoc(), diag::err_template_member)
3032  << II
3033  << SourceRange(TemplateParams->getTemplateLoc(),
3034  TemplateParams->getRAngleLoc());
3035  } else {
3036  // There is an extraneous 'template<>' for this member.
3037  Diag(TemplateParams->getTemplateLoc(),
3038  diag::err_template_member_noparams)
3039  << II
3040  << SourceRange(TemplateParams->getTemplateLoc(),
3041  TemplateParams->getRAngleLoc());
3042  }
3043  return nullptr;
3044  }
3045 
3046  if (SS.isSet() && !SS.isInvalid()) {
3047  // The user provided a superfluous scope specifier inside a class
3048  // definition:
3049  //
3050  // class X {
3051  // int X::member;
3052  // };
3053  if (DeclContext *DC = computeDeclContext(SS, false))
3054  diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc());
3055  else
3056  Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3057  << Name << SS.getRange();
3058 
3059  SS.clear();
3060  }
3061 
3062  if (MSPropertyAttr) {
3063  Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3064  BitWidth, InitStyle, AS, MSPropertyAttr);
3065  if (!Member)
3066  return nullptr;
3067  isInstField = false;
3068  } else {
3069  Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3070  BitWidth, InitStyle, AS);
3071  if (!Member)
3072  return nullptr;
3073  }
3074 
3075  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3076  } else {
3077  Member = HandleDeclarator(S, D, TemplateParameterLists);
3078  if (!Member)
3079  return nullptr;
3080 
3081  // Non-instance-fields can't have a bitfield.
3082  if (BitWidth) {
3083  if (Member->isInvalidDecl()) {
3084  // don't emit another diagnostic.
3085  } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3086  // C++ 9.6p3: A bit-field shall not be a static member.
3087  // "static member 'A' cannot be a bit-field"
3088  Diag(Loc, diag::err_static_not_bitfield)
3089  << Name << BitWidth->getSourceRange();
3090  } else if (isa<TypedefDecl>(Member)) {
3091  // "typedef member 'x' cannot be a bit-field"
3092  Diag(Loc, diag::err_typedef_not_bitfield)
3093  << Name << BitWidth->getSourceRange();
3094  } else {
3095  // A function typedef ("typedef int f(); f a;").
3096  // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3097  Diag(Loc, diag::err_not_integral_type_bitfield)
3098  << Name << cast<ValueDecl>(Member)->getType()
3099  << BitWidth->getSourceRange();
3100  }
3101 
3102  BitWidth = nullptr;
3103  Member->setInvalidDecl();
3104  }
3105 
3106  Member->setAccess(AS);
3107 
3108  // If we have declared a member function template or static data member
3109  // template, set the access of the templated declaration as well.
3110  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3111  FunTmpl->getTemplatedDecl()->setAccess(AS);
3112  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3113  VarTmpl->getTemplatedDecl()->setAccess(AS);
3114  }
3115 
3116  if (VS.isOverrideSpecified())
3117  Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context, 0));
3118  if (VS.isFinalSpecified())
3119  Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context,
3120  VS.isFinalSpelledSealed()));
3121 
3122  if (VS.getLastLocation().isValid()) {
3123  // Update the end location of a method that has a virt-specifiers.
3124  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3125  MD->setRangeEnd(VS.getLastLocation());
3126  }
3127 
3128  CheckOverrideControl(Member);
3129 
3130  assert((Name || isInstField) && "No identifier for non-field ?");
3131 
3132  if (isInstField) {
3133  FieldDecl *FD = cast<FieldDecl>(Member);
3134  FieldCollector->Add(FD);
3135 
3136  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3137  // Remember all explicit private FieldDecls that have a name, no side
3138  // effects and are not part of a dependent type declaration.
3139  if (!FD->isImplicit() && FD->getDeclName() &&
3140  FD->getAccess() == AS_private &&
3141  !FD->hasAttr<UnusedAttr>() &&
3142  !FD->getParent()->isDependentContext() &&
3144  UnusedPrivateFields.insert(FD);
3145  }
3146  }
3147 
3148  return Member;
3149 }
3150 
3151 namespace {
3152  class UninitializedFieldVisitor
3153  : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3154  Sema &S;
3155  // List of Decls to generate a warning on. Also remove Decls that become
3156  // initialized.
3157  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3158  // List of base classes of the record. Classes are removed after their
3159  // initializers.
3160  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3161  // Vector of decls to be removed from the Decl set prior to visiting the
3162  // nodes. These Decls may have been initialized in the prior initializer.
3163  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3164  // If non-null, add a note to the warning pointing back to the constructor.
3165  const CXXConstructorDecl *Constructor;
3166  // Variables to hold state when processing an initializer list. When
3167  // InitList is true, special case initialization of FieldDecls matching
3168  // InitListFieldDecl.
3169  bool InitList;
3170  FieldDecl *InitListFieldDecl;
3171  llvm::SmallVector<unsigned, 4> InitFieldIndex;
3172 
3173  public:
3175  UninitializedFieldVisitor(Sema &S,
3176  llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3177  llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3178  : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3179  Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3180 
3181  // Returns true if the use of ME is not an uninitialized use.
3182  bool IsInitListMemberExprInitialized(MemberExpr *ME,
3183  bool CheckReferenceOnly) {
3185  bool ReferenceField = false;
3186  while (ME) {
3187  FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3188  if (!FD)
3189  return false;
3190  Fields.push_back(FD);
3191  if (FD->getType()->isReferenceType())
3192  ReferenceField = true;
3193  ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3194  }
3195 
3196  // Binding a reference to an unintialized field is not an
3197  // uninitialized use.
3198  if (CheckReferenceOnly && !ReferenceField)
3199  return true;
3200 
3201  llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3202  // Discard the first field since it is the field decl that is being
3203  // initialized.
3204  for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3205  UsedFieldIndex.push_back((*I)->getFieldIndex());
3206  }
3207 
3208  for (auto UsedIter = UsedFieldIndex.begin(),
3209  UsedEnd = UsedFieldIndex.end(),
3210  OrigIter = InitFieldIndex.begin(),
3211  OrigEnd = InitFieldIndex.end();
3212  UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3213  if (*UsedIter < *OrigIter)
3214  return true;
3215  if (*UsedIter > *OrigIter)
3216  break;
3217  }
3218 
3219  return false;
3220  }
3221 
3222  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3223  bool AddressOf) {
3224  if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3225  return;
3226 
3227  // FieldME is the inner-most MemberExpr that is not an anonymous struct
3228  // or union.
3229  MemberExpr *FieldME = ME;
3230 
3231  bool AllPODFields = FieldME->getType().isPODType(S.Context);
3232 
3233  Expr *Base = ME;
3234  while (MemberExpr *SubME =
3235  dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3236 
3237  if (isa<VarDecl>(SubME->getMemberDecl()))
3238  return;
3239 
3240  if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3241  if (!FD->isAnonymousStructOrUnion())
3242  FieldME = SubME;
3243 
3244  if (!FieldME->getType().isPODType(S.Context))
3245  AllPODFields = false;
3246 
3247  Base = SubME->getBase();
3248  }
3249 
3250  if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3251  return;
3252 
3253  if (AddressOf && AllPODFields)
3254  return;
3255 
3256  ValueDecl* FoundVD = FieldME->getMemberDecl();
3257 
3258  if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3259  while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3260  BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3261  }
3262 
3263  if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3264  QualType T = BaseCast->getType();
3265  if (T->isPointerType() &&
3266  BaseClasses.count(T->getPointeeType())) {
3267  S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3268  << T->getPointeeType() << FoundVD;
3269  }
3270  }
3271  }
3272 
3273  if (!Decls.count(FoundVD))
3274  return;
3275 
3276  const bool IsReference = FoundVD->getType()->isReferenceType();
3277 
3278  if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3279  // Special checking for initializer lists.
3280  if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3281  return;
3282  }
3283  } else {
3284  // Prevent double warnings on use of unbounded references.
3285  if (CheckReferenceOnly && !IsReference)
3286  return;
3287  }
3288 
3289  unsigned diag = IsReference
3290  ? diag::warn_reference_field_is_uninit
3291  : diag::warn_field_is_uninit;
3292  S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3293  if (Constructor)
3294  S.Diag(Constructor->getLocation(),
3295  diag::note_uninit_in_this_constructor)
3296  << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3297 
3298  }
3299 
3300  void HandleValue(Expr *E, bool AddressOf) {
3301  E = E->IgnoreParens();
3302 
3303  if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3304  HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3305  AddressOf /*AddressOf*/);
3306  return;
3307  }
3308 
3309  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3310  Visit(CO->getCond());
3311  HandleValue(CO->getTrueExpr(), AddressOf);
3312  HandleValue(CO->getFalseExpr(), AddressOf);
3313  return;
3314  }
3315 
3316  if (BinaryConditionalOperator *BCO =
3317  dyn_cast<BinaryConditionalOperator>(E)) {
3318  Visit(BCO->getCond());
3319  HandleValue(BCO->getFalseExpr(), AddressOf);
3320  return;
3321  }
3322 
3323  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3324  HandleValue(OVE->getSourceExpr(), AddressOf);
3325  return;
3326  }
3327 
3328  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3329  switch (BO->getOpcode()) {
3330  default:
3331  break;
3332  case(BO_PtrMemD):
3333  case(BO_PtrMemI):
3334  HandleValue(BO->getLHS(), AddressOf);
3335  Visit(BO->getRHS());
3336  return;
3337  case(BO_Comma):
3338  Visit(BO->getLHS());
3339  HandleValue(BO->getRHS(), AddressOf);
3340  return;
3341  }
3342  }
3343 
3344  Visit(E);
3345  }
3346 
3347  void CheckInitListExpr(InitListExpr *ILE) {
3348  InitFieldIndex.push_back(0);
3349  for (auto Child : ILE->children()) {
3350  if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3351  CheckInitListExpr(SubList);
3352  } else {
3353  Visit(Child);
3354  }
3355  ++InitFieldIndex.back();
3356  }
3357  InitFieldIndex.pop_back();
3358  }
3359 
3360  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3361  FieldDecl *Field, const Type *BaseClass) {
3362  // Remove Decls that may have been initialized in the previous
3363  // initializer.
3364  for (ValueDecl* VD : DeclsToRemove)
3365  Decls.erase(VD);
3366  DeclsToRemove.clear();
3367 
3368  Constructor = FieldConstructor;
3369  InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3370 
3371  if (ILE && Field) {
3372  InitList = true;
3373  InitListFieldDecl = Field;
3374  InitFieldIndex.clear();
3375  CheckInitListExpr(ILE);
3376  } else {
3377  InitList = false;
3378  Visit(E);
3379  }
3380 
3381  if (Field)
3382  Decls.erase(Field);
3383  if (BaseClass)
3384  BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3385  }
3386 
3387  void VisitMemberExpr(MemberExpr *ME) {
3388  // All uses of unbounded reference fields will warn.
3389  HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3390  }
3391 
3392  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3393  if (E->getCastKind() == CK_LValueToRValue) {
3394  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3395  return;
3396  }
3397 
3398  Inherited::VisitImplicitCastExpr(E);
3399  }
3400 
3401  void VisitCXXConstructExpr(CXXConstructExpr *E) {
3402  if (E->getConstructor()->isCopyConstructor()) {
3403  Expr *ArgExpr = E->getArg(0);
3404  if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3405  if (ILE->getNumInits() == 1)
3406  ArgExpr = ILE->getInit(0);
3407  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3408  if (ICE->getCastKind() == CK_NoOp)
3409  ArgExpr = ICE->getSubExpr();
3410  HandleValue(ArgExpr, false /*AddressOf*/);
3411  return;
3412  }
3413  Inherited::VisitCXXConstructExpr(E);
3414  }
3415 
3416  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3417  Expr *Callee = E->getCallee();
3418  if (isa<MemberExpr>(Callee)) {
3419  HandleValue(Callee, false /*AddressOf*/);
3420  for (auto Arg : E->arguments())
3421  Visit(Arg);
3422  return;
3423  }
3424 
3425  Inherited::VisitCXXMemberCallExpr(E);
3426  }
3427 
3428  void VisitCallExpr(CallExpr *E) {
3429  // Treat std::move as a use.
3430  if (E->isCallToStdMove()) {
3431  HandleValue(E->getArg(0), /*AddressOf=*/false);
3432  return;
3433  }
3434 
3435  Inherited::VisitCallExpr(E);
3436  }
3437 
3438  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3439  Expr *Callee = E->getCallee();
3440 
3441  if (isa<UnresolvedLookupExpr>(Callee))
3442  return Inherited::VisitCXXOperatorCallExpr(E);
3443 
3444  Visit(Callee);
3445  for (auto Arg : E->arguments())
3446  HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3447  }
3448 
3449  void VisitBinaryOperator(BinaryOperator *E) {
3450  // If a field assignment is detected, remove the field from the
3451  // uninitiailized field set.
3452  if (E->getOpcode() == BO_Assign)
3453  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3454  if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3455  if (!FD->getType()->isReferenceType())
3456  DeclsToRemove.push_back(FD);
3457 
3458  if (E->isCompoundAssignmentOp()) {
3459  HandleValue(E->getLHS(), false /*AddressOf*/);
3460  Visit(E->getRHS());
3461  return;
3462  }
3463 
3464  Inherited::VisitBinaryOperator(E);
3465  }
3466 
3467  void VisitUnaryOperator(UnaryOperator *E) {
3468  if (E->isIncrementDecrementOp()) {
3469  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3470  return;
3471  }
3472  if (E->getOpcode() == UO_AddrOf) {
3473  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3474  HandleValue(ME->getBase(), true /*AddressOf*/);
3475  return;
3476  }
3477  }
3478 
3479  Inherited::VisitUnaryOperator(E);
3480  }
3481  };
3482 
3483  // Diagnose value-uses of fields to initialize themselves, e.g.
3484  // foo(foo)
3485  // where foo is not also a parameter to the constructor.
3486  // Also diagnose across field uninitialized use such as
3487  // x(y), y(x)
3488  // TODO: implement -Wuninitialized and fold this into that framework.
3489  static void DiagnoseUninitializedFields(
3490  Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3491 
3492  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3493  Constructor->getLocation())) {
3494  return;
3495  }
3496 
3497  if (Constructor->isInvalidDecl())
3498  return;
3499 
3500  const CXXRecordDecl *RD = Constructor->getParent();
3501 
3502  if (RD->getDescribedClassTemplate())
3503  return;
3504 
3505  // Holds fields that are uninitialized.
3506  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3507 
3508  // At the beginning, all fields are uninitialized.
3509  for (auto *I : RD->decls()) {
3510  if (auto *FD = dyn_cast<FieldDecl>(I)) {
3511  UninitializedFields.insert(FD);
3512  } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3513  UninitializedFields.insert(IFD->getAnonField());
3514  }
3515  }
3516 
3517  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3518  for (auto I : RD->bases())
3519  UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3520 
3521  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3522  return;
3523 
3524  UninitializedFieldVisitor UninitializedChecker(SemaRef,
3525  UninitializedFields,
3526  UninitializedBaseClasses);
3527 
3528  for (const auto *FieldInit : Constructor->inits()) {
3529  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3530  break;
3531 
3532  Expr *InitExpr = FieldInit->getInit();
3533  if (!InitExpr)
3534  continue;
3535 
3537  dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3538  InitExpr = Default->getExpr();
3539  if (!InitExpr)
3540  continue;
3541  // In class initializers will point to the constructor.
3542  UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3543  FieldInit->getAnyMember(),
3544  FieldInit->getBaseClass());
3545  } else {
3546  UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3547  FieldInit->getAnyMember(),
3548  FieldInit->getBaseClass());
3549  }
3550  }
3551  }
3552 } // namespace
3553 
3554 /// \brief Enter a new C++ default initializer scope. After calling this, the
3555 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3556 /// parsing or instantiating the initializer failed.
3558  // Create a synthetic function scope to represent the call to the constructor
3559  // that notionally surrounds a use of this initializer.
3560  PushFunctionScope();
3561 }
3562 
3563 /// \brief This is invoked after parsing an in-class initializer for a
3564 /// non-static C++ class member, and after instantiating an in-class initializer
3565 /// in a class template. Such actions are deferred until the class is complete.
3567  SourceLocation InitLoc,
3568  Expr *InitExpr) {
3569  // Pop the notional constructor scope we created earlier.
3570  PopFunctionScopeInfo(nullptr, D);
3571 
3572  FieldDecl *FD = dyn_cast<FieldDecl>(D);
3573  assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3574  "must set init style when field is created");
3575 
3576  if (!InitExpr) {
3577  D->setInvalidDecl();
3578  if (FD)
3580  return;
3581  }
3582 
3583  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3584  FD->setInvalidDecl();
3586  return;
3587  }
3588 
3589  ExprResult Init = InitExpr;
3590  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3595  InitExpr->getLocStart(),
3596  InitExpr->getLocEnd())
3597  : InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc);
3598  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3599  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3600  if (Init.isInvalid()) {
3601  FD->setInvalidDecl();
3602  return;
3603  }
3604  }
3605 
3606  // C++11 [class.base.init]p7:
3607  // The initialization of each base and member constitutes a
3608  // full-expression.
3609  Init = ActOnFinishFullExpr(Init.get(), InitLoc);
3610  if (Init.isInvalid()) {
3611  FD->setInvalidDecl();
3612  return;
3613  }
3614 
3615  InitExpr = Init.get();
3616 
3617  FD->setInClassInitializer(InitExpr);
3618 }
3619 
3620 /// \brief Find the direct and/or virtual base specifiers that
3621 /// correspond to the given base type, for use in base initialization
3622 /// within a constructor.
3623 static bool FindBaseInitializer(Sema &SemaRef,
3624  CXXRecordDecl *ClassDecl,
3625  QualType BaseType,
3626  const CXXBaseSpecifier *&DirectBaseSpec,
3627  const CXXBaseSpecifier *&VirtualBaseSpec) {
3628  // First, check for a direct base class.
3629  DirectBaseSpec = nullptr;
3630  for (const auto &Base : ClassDecl->bases()) {
3631  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3632  // We found a direct base of this type. That's what we're
3633  // initializing.
3634  DirectBaseSpec = &Base;
3635  break;
3636  }
3637  }
3638 
3639  // Check for a virtual base class.
3640  // FIXME: We might be able to short-circuit this if we know in advance that
3641  // there are no virtual bases.
3642  VirtualBaseSpec = nullptr;
3643  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3644  // We haven't found a base yet; search the class hierarchy for a
3645  // virtual base class.
3646  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3647  /*DetectVirtual=*/false);
3648  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3649  SemaRef.Context.getTypeDeclType(ClassDecl),
3650  BaseType, Paths)) {
3651  for (CXXBasePaths::paths_iterator Path = Paths.begin();
3652  Path != Paths.end(); ++Path) {
3653  if (Path->back().Base->isVirtual()) {
3654  VirtualBaseSpec = Path->back().Base;
3655  break;
3656  }
3657  }
3658  }
3659  }
3660 
3661  return DirectBaseSpec || VirtualBaseSpec;
3662 }
3663 
3664 /// \brief Handle a C++ member initializer using braced-init-list syntax.
3666 Sema::ActOnMemInitializer(Decl *ConstructorD,
3667  Scope *S,
3668  CXXScopeSpec &SS,
3669  IdentifierInfo *MemberOrBase,
3670  ParsedType TemplateTypeTy,
3671  const DeclSpec &DS,
3672  SourceLocation IdLoc,
3673  Expr *InitList,
3674  SourceLocation EllipsisLoc) {
3675  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3676  DS, IdLoc, InitList,
3677  EllipsisLoc);
3678 }
3679 
3680 /// \brief Handle a C++ member initializer using parentheses syntax.
3682 Sema::ActOnMemInitializer(Decl *ConstructorD,
3683  Scope *S,
3684  CXXScopeSpec &SS,
3685  IdentifierInfo *MemberOrBase,
3686  ParsedType TemplateTypeTy,
3687  const DeclSpec &DS,
3688  SourceLocation IdLoc,
3689  SourceLocation LParenLoc,
3690  ArrayRef<Expr *> Args,
3691  SourceLocation RParenLoc,
3692  SourceLocation EllipsisLoc) {
3693  Expr *List = new (Context) ParenListExpr(Context, LParenLoc,
3694  Args, RParenLoc);
3695  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3696  DS, IdLoc, List, EllipsisLoc);
3697 }
3698 
3699 namespace {
3700 
3701 // Callback to only accept typo corrections that can be a valid C++ member
3702 // intializer: either a non-static field member or a base class.
3703 class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
3704 public:
3705  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
3706  : ClassDecl(ClassDecl) {}
3707 
3708  bool ValidateCandidate(const TypoCorrection &candidate) override {
3709  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
3710  if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
3711  return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
3712  return isa<TypeDecl>(ND);
3713  }
3714  return false;
3715  }
3716 
3717 private:
3718  CXXRecordDecl *ClassDecl;
3719 };
3720 
3721 }
3722 
3723 /// \brief Handle a C++ member initializer.
3725 Sema::BuildMemInitializer(Decl *ConstructorD,
3726  Scope *S,
3727  CXXScopeSpec &SS,
3728  IdentifierInfo *MemberOrBase,
3729  ParsedType TemplateTypeTy,
3730  const DeclSpec &DS,
3731  SourceLocation IdLoc,
3732  Expr *Init,
3733  SourceLocation EllipsisLoc) {
3734  ExprResult Res = CorrectDelayedTyposInExpr(Init);
3735  if (!Res.isUsable())
3736  return true;
3737  Init = Res.get();
3738 
3739  if (!ConstructorD)
3740  return true;
3741 
3742  AdjustDeclIfTemplate(ConstructorD);
3743 
3744  CXXConstructorDecl *Constructor
3745  = dyn_cast<CXXConstructorDecl>(ConstructorD);
3746  if (!Constructor) {
3747  // The user wrote a constructor initializer on a function that is
3748  // not a C++ constructor. Ignore the error for now, because we may
3749  // have more member initializers coming; we'll diagnose it just
3750  // once in ActOnMemInitializers.
3751  return true;
3752  }
3753 
3754  CXXRecordDecl *ClassDecl = Constructor->getParent();
3755 
3756  // C++ [class.base.init]p2:
3757  // Names in a mem-initializer-id are looked up in the scope of the
3758  // constructor's class and, if not found in that scope, are looked
3759  // up in the scope containing the constructor's definition.
3760  // [Note: if the constructor's class contains a member with the
3761  // same name as a direct or virtual base class of the class, a
3762  // mem-initializer-id naming the member or base class and composed
3763  // of a single identifier refers to the class member. A
3764  // mem-initializer-id for the hidden base class may be specified
3765  // using a qualified name. ]
3766  if (!SS.getScopeRep() && !TemplateTypeTy) {
3767  // Look for a member, first.
3768  DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
3769  if (!Result.empty()) {
3770  ValueDecl *Member;
3771  if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
3772  (Member = dyn_cast<IndirectFieldDecl>(Result.front()))) {
3773  if (EllipsisLoc.isValid())
3774  Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
3775  << MemberOrBase
3776  << SourceRange(IdLoc, Init->getSourceRange().getEnd());
3777 
3778  return BuildMemberInitializer(Member, Init, IdLoc);
3779  }
3780  }
3781  }
3782  // It didn't name a member, so see if it names a class.
3783  QualType BaseType;
3784  TypeSourceInfo *TInfo = nullptr;
3785 
3786  if (TemplateTypeTy) {
3787  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
3788  } else if (DS.getTypeSpecType() == TST_decltype) {
3789  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
3790  } else if (DS.getTypeSpecType() == TST_decltype_auto) {
3791  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
3792  return true;
3793  } else {
3794  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
3795  LookupParsedName(R, S, &SS);
3796 
3797  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
3798  if (!TyD) {
3799  if (R.isAmbiguous()) return true;
3800 
3801  // We don't want access-control diagnostics here.
3802  R.suppressDiagnostics();
3803 
3804  if (SS.isSet() && isDependentScopeSpecifier(SS)) {
3805  bool NotUnknownSpecialization = false;
3806  DeclContext *DC = computeDeclContext(SS, false);
3807  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
3808  NotUnknownSpecialization = !Record->hasAnyDependentBases();
3809 
3810  if (!NotUnknownSpecialization) {
3811  // When the scope specifier can refer to a member of an unknown
3812  // specialization, we take it as a type name.
3813  BaseType = CheckTypenameType(ETK_None, SourceLocation(),
3814  SS.getWithLocInContext(Context),
3815  *MemberOrBase, IdLoc);
3816  if (BaseType.isNull())
3817  return true;
3818 
3819  TInfo = Context.CreateTypeSourceInfo(BaseType);
3822  if (!TL.isNull()) {
3823  TL.setNameLoc(IdLoc);
3825  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3826  }
3827 
3828  R.clear();
3829  R.setLookupName(MemberOrBase);
3830  }
3831  }
3832 
3833  // If no results were found, try to correct typos.
3834  TypoCorrection Corr;
3835  if (R.empty() && BaseType.isNull() &&
3836  (Corr = CorrectTypo(
3837  R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
3838  llvm::make_unique<MemInitializerValidatorCCC>(ClassDecl),
3839  CTK_ErrorRecovery, ClassDecl))) {
3840  if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
3841  // We have found a non-static data member with a similar
3842  // name to what was typed; complain and initialize that
3843  // member.
3844  diagnoseTypo(Corr,
3845  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3846  << MemberOrBase << true);
3847  return BuildMemberInitializer(Member, Init, IdLoc);
3848  } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
3849  const CXXBaseSpecifier *DirectBaseSpec;
3850  const CXXBaseSpecifier *VirtualBaseSpec;
3851  if (FindBaseInitializer(*this, ClassDecl,
3852  Context.getTypeDeclType(Type),
3853  DirectBaseSpec, VirtualBaseSpec)) {
3854  // We have found a direct or virtual base class with a
3855  // similar name to what was typed; complain and initialize
3856  // that base class.
3857  diagnoseTypo(Corr,
3858  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3859  << MemberOrBase << false,
3860  PDiag() /*Suppress note, we provide our own.*/);
3861 
3862  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
3863  : VirtualBaseSpec;
3864  Diag(BaseSpec->getLocStart(),
3865  diag::note_base_class_specified_here)
3866  << BaseSpec->getType()
3867  << BaseSpec->getSourceRange();
3868 
3869  TyD = Type;
3870  }
3871  }
3872  }
3873 
3874  if (!TyD && BaseType.isNull()) {
3875  Diag(IdLoc, diag::err_mem_init_not_member_or_class)
3876  << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
3877  return true;
3878  }
3879  }
3880 
3881  if (BaseType.isNull()) {
3882  BaseType = Context.getTypeDeclType(TyD);
3883  MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
3884  if (SS.isSet()) {
3885  BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
3886  BaseType);
3887  TInfo = Context.CreateTypeSourceInfo(BaseType);
3889  TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
3891  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3892  }
3893  }
3894  }
3895 
3896  if (!TInfo)
3897  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
3898 
3899  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
3900 }
3901 
3902 /// Checks a member initializer expression for cases where reference (or
3903 /// pointer) members are bound to by-value parameters (or their addresses).
3905  Expr *Init,
3906  SourceLocation IdLoc) {
3907  QualType MemberTy = Member->getType();
3908 
3909  // We only handle pointers and references currently.
3910  // FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
3911  if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
3912  return;
3913 
3914  const bool IsPointer = MemberTy->isPointerType();
3915  if (IsPointer) {
3916  if (const UnaryOperator *Op
3917  = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
3918  // The only case we're worried about with pointers requires taking the
3919  // address.
3920  if (Op->getOpcode() != UO_AddrOf)
3921  return;
3922 
3923  Init = Op->getSubExpr();
3924  } else {
3925  // We only handle address-of expression initializers for pointers.
3926  return;
3927  }
3928  }
3929 
3930  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
3931  // We only warn when referring to a non-reference parameter declaration.
3932  const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
3933  if (!Parameter || Parameter->getType()->isReferenceType())
3934  return;
3935 
3936  S.Diag(Init->getExprLoc(),
3937  IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
3938  : diag::warn_bind_ref_member_to_parameter)
3939  << Member << Parameter << Init->getSourceRange();
3940  } else {
3941  // Other initializers are fine.
3942  return;
3943  }
3944 
3945  S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
3946  << (unsigned)IsPointer;
3947 }
3948 
3951  SourceLocation IdLoc) {
3952  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
3953  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
3954  assert((DirectMember || IndirectMember) &&
3955  "Member must be a FieldDecl or IndirectFieldDecl");
3956 
3957  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
3958  return true;
3959 
3960  if (Member->isInvalidDecl())
3961  return true;
3962 
3963  MultiExprArg Args;
3964  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
3965  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
3966  } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
3967  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
3968  } else {
3969  // Template instantiation doesn't reconstruct ParenListExprs for us.
3970  Args = Init;
3971  }
3972 
3973  SourceRange InitRange = Init->getSourceRange();
3974 
3975  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
3976  // Can't check initialization for a member of dependent type or when
3977  // any of the arguments are type-dependent expressions.
3978  DiscardCleanupsInEvaluationContext();
3979  } else {
3980  bool InitList = false;
3981  if (isa<InitListExpr>(Init)) {
3982  InitList = true;
3983  Args = Init;
3984  }
3985 
3986  // Initialize the member.
3987  InitializedEntity MemberEntity =
3988  DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
3989  : InitializedEntity::InitializeMember(IndirectMember,
3990  nullptr);
3993  IdLoc, Init->getLocStart(), Init->getLocEnd())
3994  : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
3995  InitRange.getEnd());
3996 
3997  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
3998  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
3999  nullptr);
4000  if (MemberInit.isInvalid())
4001  return true;
4002 
4003  CheckForDanglingReferenceOrPointer(*this, Member, MemberInit.get(), IdLoc);
4004 
4005  // C++11 [class.base.init]p7:
4006  // The initialization of each base and member constitutes a
4007  // full-expression.
4008  MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin());
4009  if (MemberInit.isInvalid())
4010  return true;
4011 
4012  Init = MemberInit.get();
4013  }
4014 
4015  if (DirectMember) {
4016  return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4017  InitRange.getBegin(), Init,
4018  InitRange.getEnd());
4019  } else {
4020  return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4021  InitRange.getBegin(), Init,
4022  InitRange.getEnd());
4023  }
4024 }
4025 
4028  CXXRecordDecl *ClassDecl) {
4029  SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4030  if (!LangOpts.CPlusPlus11)
4031  return Diag(NameLoc, diag::err_delegating_ctor)
4032  << TInfo->getTypeLoc().getLocalSourceRange();
4033  Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4034 
4035  bool InitList = true;
4036  MultiExprArg Args = Init;
4037  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4038  InitList = false;
4039  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4040  }
4041 
4042  SourceRange InitRange = Init->getSourceRange();
4043  // Initialize the object.
4045  QualType(ClassDecl->getTypeForDecl(), 0));
4048  NameLoc, Init->getLocStart(), Init->getLocEnd())
4049  : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4050  InitRange.getEnd());
4051  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4052  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4053  Args, nullptr);
4054  if (DelegationInit.isInvalid())
4055  return true;
4056 
4057  assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4058  "Delegating constructor with no target?");
4059 
4060  // C++11 [class.base.init]p7:
4061  // The initialization of each base and member constitutes a
4062  // full-expression.
4063  DelegationInit = ActOnFinishFullExpr(DelegationInit.get(),
4064  InitRange.getBegin());
4065  if (DelegationInit.isInvalid())
4066  return true;
4067 
4068  // If we are in a dependent context, template instantiation will
4069  // perform this type-checking again. Just save the arguments that we
4070  // received in a ParenListExpr.
4071  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4072  // of the information that we have about the base
4073  // initializer. However, deconstructing the ASTs is a dicey process,
4074  // and this approach is far more likely to get the corner cases right.
4075  if (CurContext->isDependentContext())
4076  DelegationInit = Init;
4077 
4078  return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4079  DelegationInit.getAs<Expr>(),
4080  InitRange.getEnd());
4081 }
4082 
4085  Expr *Init, CXXRecordDecl *ClassDecl,
4086  SourceLocation EllipsisLoc) {
4087  SourceLocation BaseLoc
4088  = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4089 
4090  if (!BaseType->isDependentType() && !BaseType->isRecordType())
4091  return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4092  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4093 
4094  // C++ [class.base.init]p2:
4095  // [...] Unless the mem-initializer-id names a nonstatic data
4096  // member of the constructor's class or a direct or virtual base
4097  // of that class, the mem-initializer is ill-formed. A
4098  // mem-initializer-list can initialize a base class using any
4099  // name that denotes that base class type.
4100  bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4101 
4102  SourceRange InitRange = Init->getSourceRange();
4103  if (EllipsisLoc.isValid()) {
4104  // This is a pack expansion.
4105  if (!BaseType->containsUnexpandedParameterPack()) {
4106  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4107  << SourceRange(BaseLoc, InitRange.getEnd());
4108 
4109  EllipsisLoc = SourceLocation();
4110  }
4111  } else {
4112  // Check for any unexpanded parameter packs.
4113  if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4114  return true;
4115 
4116  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4117  return true;
4118  }
4119 
4120  // Check for direct and virtual base classes.
4121  const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4122  const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4123  if (!Dependent) {
4124  if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4125  BaseType))
4126  return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4127 
4128  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4129  VirtualBaseSpec);
4130 
4131  // C++ [base.class.init]p2:
4132  // Unless the mem-initializer-id names a nonstatic data member of the
4133  // constructor's class or a direct or virtual base of that class, the
4134  // mem-initializer is ill-formed.
4135  if (!DirectBaseSpec && !VirtualBaseSpec) {
4136  // If the class has any dependent bases, then it's possible that
4137  // one of those types will resolve to the same type as
4138  // BaseType. Therefore, just treat this as a dependent base
4139  // class initialization. FIXME: Should we try to check the
4140  // initialization anyway? It seems odd.
4141  if (ClassDecl->hasAnyDependentBases())
4142  Dependent = true;
4143  else
4144  return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4145  << BaseType << Context.getTypeDeclType(ClassDecl)
4146  << BaseTInfo->getTypeLoc().getLocalSourceRange();
4147  }
4148  }
4149 
4150  if (Dependent) {
4151  DiscardCleanupsInEvaluationContext();
4152 
4153  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4154  /*IsVirtual=*/false,
4155  InitRange.getBegin(), Init,
4156  InitRange.getEnd(), EllipsisLoc);
4157  }
4158 
4159  // C++ [base.class.init]p2:
4160  // If a mem-initializer-id is ambiguous because it designates both
4161  // a direct non-virtual base class and an inherited virtual base
4162  // class, the mem-initializer is ill-formed.
4163  if (DirectBaseSpec && VirtualBaseSpec)
4164  return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4165  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4166 
4167  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4168  if (!BaseSpec)
4169  BaseSpec = VirtualBaseSpec;
4170 
4171  // Initialize the base.
4172  bool InitList = true;
4173  MultiExprArg Args = Init;
4174  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4175  InitList = false;
4176  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4177  }
4178 
4179  InitializedEntity BaseEntity =
4180  InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4182  InitList ? InitializationKind::CreateDirectList(BaseLoc)
4183  : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4184  InitRange.getEnd());
4185  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4186  ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4187  if (BaseInit.isInvalid())
4188  return true;
4189 
4190  // C++11 [class.base.init]p7:
4191  // The initialization of each base and member constitutes a
4192  // full-expression.
4193  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin());
4194  if (BaseInit.isInvalid())
4195  return true;
4196 
4197  // If we are in a dependent context, template instantiation will
4198  // perform this type-checking again. Just save the arguments that we
4199  // received in a ParenListExpr.
4200  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4201  // of the information that we have about the base
4202  // initializer. However, deconstructing the ASTs is a dicey process,
4203  // and this approach is far more likely to get the corner cases right.
4204  if (CurContext->isDependentContext())
4205  BaseInit = Init;
4206 
4207  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4208  BaseSpec->isVirtual(),
4209  InitRange.getBegin(),
4210  BaseInit.getAs<Expr>(),
4211  InitRange.getEnd(), EllipsisLoc);
4212 }
4213 
4214 // Create a static_cast<T&&>(expr).
4215 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4216  if (T.isNull()) T = E->getType();
4217  QualType TargetType = SemaRef.BuildReferenceType(
4218  T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4219  SourceLocation ExprLoc = E->getLocStart();
4220  TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4221  TargetType, ExprLoc);
4222 
4223  return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4224  SourceRange(ExprLoc, ExprLoc),
4225  E->getSourceRange()).get();
4226 }
4227 
4228 /// ImplicitInitializerKind - How an implicit base or member initializer should
4229 /// initialize its base or member.
4235 };
4236 
4237 static bool
4239  ImplicitInitializerKind ImplicitInitKind,
4240  CXXBaseSpecifier *BaseSpec,
4241  bool IsInheritedVirtualBase,
4242  CXXCtorInitializer *&CXXBaseInit) {
4243  InitializedEntity InitEntity
4244  = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4245  IsInheritedVirtualBase);
4246 
4247  ExprResult BaseInit;
4248 
4249  switch (ImplicitInitKind) {
4250  case IIK_Inherit:
4251  case IIK_Default: {
4252  InitializationKind InitKind
4254  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4255  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4256  break;
4257  }
4258 
4259  case IIK_Move:
4260  case IIK_Copy: {
4261  bool Moving = ImplicitInitKind == IIK_Move;
4262  ParmVarDecl *Param = Constructor->getParamDecl(0);
4263  QualType ParamType = Param->getType().getNonReferenceType();
4264 
4265  Expr *CopyCtorArg =
4267  SourceLocation(), Param, false,
4268  Constructor->getLocation(), ParamType,
4269  VK_LValue, nullptr);
4270 
4271  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4272 
4273  // Cast to the base class to avoid ambiguities.
4274  QualType ArgTy =
4275  SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4276  ParamType.getQualifiers());
4277 
4278  if (Moving) {
4279  CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4280  }
4281 
4282  CXXCastPath BasePath;
4283  BasePath.push_back(BaseSpec);
4284  CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4285  CK_UncheckedDerivedToBase,
4286  Moving ? VK_XValue : VK_LValue,
4287  &BasePath).get();
4288 
4289  InitializationKind InitKind
4292  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4293  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4294  break;
4295  }
4296  }
4297 
4298  BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4299  if (BaseInit.isInvalid())
4300  return true;
4301 
4302  CXXBaseInit =
4303  new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4304  SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4305  SourceLocation()),
4306  BaseSpec->isVirtual(),
4307  SourceLocation(),
4308  BaseInit.getAs<Expr>(),
4309  SourceLocation(),
4310  SourceLocation());
4311 
4312  return false;
4313 }
4314 
4315 static bool RefersToRValueRef(Expr *MemRef) {
4316  ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4317  return Referenced->getType()->isRValueReferenceType();
4318 }
4319 
4320 static bool
4322  ImplicitInitializerKind ImplicitInitKind,
4323  FieldDecl *Field, IndirectFieldDecl *Indirect,
4324  CXXCtorInitializer *&CXXMemberInit) {
4325  if (Field->isInvalidDecl())
4326  return true;
4327 
4328  SourceLocation Loc = Constructor->getLocation();
4329 
4330  if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4331  bool Moving = ImplicitInitKind == IIK_Move;
4332  ParmVarDecl *Param = Constructor->getParamDecl(0);
4333  QualType ParamType = Param->getType().getNonReferenceType();
4334 
4335  // Suppress copying zero-width bitfields.
4336  if (Field->isBitField() && Field->getBitWidthValue(SemaRef.Context) == 0)
4337  return false;
4338 
4339  Expr *MemberExprBase =
4341  SourceLocation(), Param, false,
4342  Loc, ParamType, VK_LValue, nullptr);
4343 
4344  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4345 
4346  if (Moving) {
4347  MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4348  }
4349 
4350  // Build a reference to this field within the parameter.
4351  CXXScopeSpec SS;
4352  LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4354  MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4355  : cast<ValueDecl>(Field), AS_public);
4356  MemberLookup.resolveKind();
4357  ExprResult CtorArg
4358  = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4359  ParamType, Loc,
4360  /*IsArrow=*/false,
4361  SS,
4362  /*TemplateKWLoc=*/SourceLocation(),
4363  /*FirstQualifierInScope=*/nullptr,
4364  MemberLookup,
4365  /*TemplateArgs=*/nullptr,
4366  /*S*/nullptr);
4367  if (CtorArg.isInvalid())
4368  return true;
4369 
4370  // C++11 [class.copy]p15:
4371  // - if a member m has rvalue reference type T&&, it is direct-initialized
4372  // with static_cast<T&&>(x.m);
4373  if (RefersToRValueRef(CtorArg.get())) {
4374  CtorArg = CastForMoving(SemaRef, CtorArg.get());
4375  }
4376 
4377  InitializedEntity Entity =
4378  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4379  /*Implicit*/ true)
4380  : InitializedEntity::InitializeMember(Field, nullptr,
4381  /*Implicit*/ true);
4382 
4383  // Direct-initialize to use the copy constructor.
4384  InitializationKind InitKind =
4386 
4387  Expr *CtorArgE = CtorArg.getAs<Expr>();
4388  InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4389  ExprResult MemberInit =
4390  InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4391  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4392  if (MemberInit.isInvalid())
4393  return true;
4394 
4395  if (Indirect)
4396  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4397  SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4398  else
4399  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4400  SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4401  return false;
4402  }
4403 
4404  assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4405  "Unhandled implicit init kind!");
4406 
4407  QualType FieldBaseElementType =
4408  SemaRef.Context.getBaseElementType(Field->getType());
4409 
4410  if (FieldBaseElementType->isRecordType()) {
4411  InitializedEntity InitEntity =
4412  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4413  /*Implicit*/ true)
4414  : InitializedEntity::InitializeMember(Field, nullptr,
4415  /*Implicit*/ true);
4416  InitializationKind InitKind =
4418 
4419  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4420  ExprResult MemberInit =
4421  InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4422 
4423  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4424  if (MemberInit.isInvalid())
4425  return true;
4426 
4427  if (Indirect)
4428  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4429  Indirect, Loc,
4430  Loc,
4431  MemberInit.get(),
4432  Loc);
4433  else
4434  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4435  Field, Loc, Loc,
4436  MemberInit.get(),
4437  Loc);
4438  return false;
4439  }
4440 
4441  if (!Field->getParent()->isUnion()) {
4442  if (FieldBaseElementType->isReferenceType()) {
4443  SemaRef.Diag(Constructor->getLocation(),
4444  diag::err_uninitialized_member_in_ctor)
4445  << (int)Constructor->isImplicit()
4446  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4447  << 0 << Field->getDeclName();
4448  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4449  return true;
4450  }
4451 
4452  if (FieldBaseElementType.isConstQualified()) {
4453  SemaRef.Diag(Constructor->getLocation(),
4454  diag::err_uninitialized_member_in_ctor)
4455  << (int)Constructor->isImplicit()
4456  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4457  << 1 << Field->getDeclName();
4458  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4459  return true;
4460  }
4461  }
4462 
4463  if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4464  // ARC and Weak:
4465  // Default-initialize Objective-C pointers to NULL.
4466  CXXMemberInit
4467  = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4468  Loc, Loc,
4469  new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4470  Loc);
4471  return false;
4472  }
4473 
4474  // Nothing to initialize.
4475  CXXMemberInit = nullptr;
4476  return false;
4477 }
4478 
4479 namespace {
4480 struct BaseAndFieldInfo {
4481  Sema &S;
4482  CXXConstructorDecl *Ctor;
4483  bool AnyErrorsInInits;
4485  llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4487  llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4488 
4489  BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4490  : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4491  bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4492  if (Ctor->getInheritedConstructor())
4493  IIK = IIK_Inherit;
4494  else if (Generated && Ctor->isCopyConstructor())
4495  IIK = IIK_Copy;
4496  else if (Generated && Ctor->isMoveConstructor())
4497  IIK = IIK_Move;
4498  else
4499  IIK = IIK_Default;
4500  }
4501 
4502  bool isImplicitCopyOrMove() const {
4503  switch (IIK) {
4504  case IIK_Copy:
4505  case IIK_Move:
4506  return true;
4507 
4508  case IIK_Default:
4509  case IIK_Inherit:
4510  return false;
4511  }
4512 
4513  llvm_unreachable("Invalid ImplicitInitializerKind!");
4514  }
4515 
4516  bool addFieldInitializer(CXXCtorInitializer *Init) {
4517  AllToInit.push_back(Init);
4518 
4519  // Check whether this initializer makes the field "used".
4520  if (Init->getInit()->HasSideEffects(S.Context))
4521  S.UnusedPrivateFields.remove(Init->getAnyMember());
4522 
4523  return false;
4524  }
4525 
4526  bool isInactiveUnionMember(FieldDecl *Field) {
4527  RecordDecl *Record = Field->getParent();
4528  if (!Record->isUnion())
4529  return false;
4530 
4531  if (FieldDecl *Active =
4532  ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4533  return Active != Field->getCanonicalDecl();
4534 
4535  // In an implicit copy or move constructor, ignore any in-class initializer.
4536  if (isImplicitCopyOrMove())
4537  return true;
4538 
4539  // If there's no explicit initialization, the field is active only if it
4540  // has an in-class initializer...
4541  if (Field->hasInClassInitializer())
4542  return false;
4543  // ... or it's an anonymous struct or union whose class has an in-class
4544  // initializer.
4545  if (!Field->isAnonymousStructOrUnion())
4546  return true;
4547  CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4548  return !FieldRD->hasInClassInitializer();
4549  }
4550 
4551  /// \brief Determine whether the given field is, or is within, a union member
4552  /// that is inactive (because there was an initializer given for a different
4553  /// member of the union, or because the union was not initialized at all).
4554  bool isWithinInactiveUnionMember(FieldDecl *Field,
4555  IndirectFieldDecl *Indirect) {
4556  if (!Indirect)
4557  return isInactiveUnionMember(Field);
4558 
4559  for (auto *C : Indirect->chain()) {
4560  FieldDecl *Field = dyn_cast<FieldDecl>(C);
4561  if (Field && isInactiveUnionMember(Field))
4562  return true;
4563  }
4564  return false;
4565  }
4566 };
4567 }
4568 
4569 /// \brief Determine whether the given type is an incomplete or zero-lenfgth
4570 /// array type.
4572  if (T->isIncompleteArrayType())
4573  return true;
4574 
4575  while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4576  if (!ArrayT->getSize())
4577  return true;
4578 
4579  T = ArrayT->getElementType();
4580  }
4581 
4582  return false;
4583 }
4584 
4585 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4586  FieldDecl *Field,
4587  IndirectFieldDecl *Indirect = nullptr) {
4588  if (Field->isInvalidDecl())
4589  return false;
4590 
4591  // Overwhelmingly common case: we have a direct initializer for this field.
4592  if (CXXCtorInitializer *Init =
4593  Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4594  return Info.addFieldInitializer(Init);
4595 
4596  // C++11 [class.base.init]p8:
4597  // if the entity is a non-static data member that has a
4598  // brace-or-equal-initializer and either
4599  // -- the constructor's class is a union and no other variant member of that
4600  // union is designated by a mem-initializer-id or
4601  // -- the constructor's class is not a union, and, if the entity is a member
4602  // of an anonymous union, no other member of that union is designated by
4603  // a mem-initializer-id,
4604  // the entity is initialized as specified in [dcl.init].
4605  //
4606  // We also apply the same rules to handle anonymous structs within anonymous
4607  // unions.
4608  if (Info.isWithinInactiveUnionMember(Field, Indirect))
4609  return false;
4610 
4611  if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4612  ExprResult DIE =
4613  SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4614  if (DIE.isInvalid())
4615  return true;
4616  CXXCtorInitializer *Init;
4617  if (Indirect)
4618  Init = new (SemaRef.Context)
4619  CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4620  SourceLocation(), DIE.get(), SourceLocation());
4621  else
4622  Init = new (SemaRef.Context)
4623  CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4624  SourceLocation(), DIE.get(), SourceLocation());
4625  return Info.addFieldInitializer(Init);
4626  }
4627 
4628  // Don't initialize incomplete or zero-length arrays.
4629  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4630  return false;
4631 
4632  // Don't try to build an implicit initializer if there were semantic
4633  // errors in any of the initializers (and therefore we might be
4634  // missing some that the user actually wrote).
4635  if (Info.AnyErrorsInInits)
4636  return false;
4637 
4638  CXXCtorInitializer *Init = nullptr;
4639  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4640  Indirect, Init))
4641  return true;
4642 
4643  if (!Init)
4644  return false;
4645 
4646  return Info.addFieldInitializer(Init);
4647 }
4648 
4649 bool
4651  CXXCtorInitializer *Initializer) {
4652  assert(Initializer->isDelegatingInitializer());
4653  Constructor->setNumCtorInitializers(1);
4654  CXXCtorInitializer **initializer =
4655  new (Context) CXXCtorInitializer*[1];
4656  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4657  Constructor->setCtorInitializers(initializer);
4658 
4659  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4660  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4661  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4662  }
4663 
4664  DelegatingCtorDecls.push_back(Constructor);
4665 
4666  DiagnoseUninitializedFields(*this, Constructor);
4667 
4668  return false;
4669 }
4670 
4671 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4672  ArrayRef<CXXCtorInitializer *> Initializers) {
4673  if (Constructor->isDependentContext()) {
4674  // Just store the initializers as written, they will be checked during
4675  // instantiation.
4676  if (!Initializers.empty()) {
4677  Constructor->setNumCtorInitializers(Initializers.size());
4678  CXXCtorInitializer **baseOrMemberInitializers =
4679  new (Context) CXXCtorInitializer*[Initializers.size()];
4680  memcpy(baseOrMemberInitializers, Initializers.data(),
4681  Initializers.size() * sizeof(CXXCtorInitializer*));
4682  Constructor->setCtorInitializers(baseOrMemberInitializers);
4683  }
4684 
4685  // Let template instantiation know whether we had errors.
4686  if (AnyErrors)
4687  Constructor->setInvalidDecl();
4688 
4689  return false;
4690  }
4691 
4692  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4693 
4694  // We need to build the initializer AST according to order of construction
4695  // and not what user specified in the Initializers list.
4696  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4697  if (!ClassDecl)
4698  return true;
4699 
4700  bool HadError = false;
4701 
4702  for (unsigned i = 0; i < Initializers.size(); i++) {
4703  CXXCtorInitializer *Member = Initializers[i];
4704 
4705  if (Member->isBaseInitializer())
4706  Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
4707  else {
4708  Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
4709 
4710  if (IndirectFieldDecl *F = Member->getIndirectMember()) {
4711  for (auto *C : F->chain()) {
4712  FieldDecl *FD = dyn_cast<FieldDecl>(C);
4713  if (FD && FD->getParent()->isUnion())
4714  Info.ActiveUnionMember.insert(std::make_pair(
4715  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4716  }
4717  } else if (FieldDecl *FD = Member->getMember()) {
4718  if (FD->getParent()->isUnion())
4719  Info.ActiveUnionMember.insert(std::make_pair(
4720  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4721  }
4722  }
4723  }
4724 
4725  // Keep track of the direct virtual bases.
4726  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
4727  for (auto &I : ClassDecl->bases()) {
4728  if (I.isVirtual())
4729  DirectVBases.insert(&I);
4730  }
4731 
4732  // Push virtual bases before others.
4733  for (auto &VBase : ClassDecl->vbases()) {
4735  = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
4736  // [class.base.init]p7, per DR257:
4737  // A mem-initializer where the mem-initializer-id names a virtual base
4738  // class is ignored during execution of a constructor of any class that
4739  // is not the most derived class.
4740  if (ClassDecl->isAbstract()) {
4741  // FIXME: Provide a fixit to remove the base specifier. This requires
4742  // tracking the location of the associated comma for a base specifier.
4743  Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
4744  << VBase.getType() << ClassDecl;
4745  DiagnoseAbstractType(ClassDecl);
4746  }
4747 
4748  Info.AllToInit.push_back(Value);
4749  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
4750  // [class.base.init]p8, per DR257:
4751  // If a given [...] base class is not named by a mem-initializer-id
4752  // [...] and the entity is not a virtual base class of an abstract
4753  // class, then [...] the entity is default-initialized.
4754  bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
4755  CXXCtorInitializer *CXXBaseInit;
4756  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4757  &VBase, IsInheritedVirtualBase,
4758  CXXBaseInit)) {
4759  HadError = true;
4760  continue;
4761  }
4762 
4763  Info.AllToInit.push_back(CXXBaseInit);
4764  }
4765  }
4766 
4767  // Non-virtual bases.
4768  for (auto &Base : ClassDecl->bases()) {
4769  // Virtuals are in the virtual base list and already constructed.
4770  if (Base.isVirtual())
4771  continue;
4772 
4774  = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
4775  Info.AllToInit.push_back(Value);
4776  } else if (!AnyErrors) {
4777  CXXCtorInitializer *CXXBaseInit;
4778  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4779  &Base, /*IsInheritedVirtualBase=*/false,
4780  CXXBaseInit)) {
4781  HadError = true;
4782  continue;
4783  }
4784 
4785  Info.AllToInit.push_back(CXXBaseInit);
4786  }
4787  }
4788 
4789  // Fields.
4790  for (auto *Mem : ClassDecl->decls()) {
4791  if (auto *F = dyn_cast<FieldDecl>(Mem)) {
4792  // C++ [class.bit]p2:
4793  // A declaration for a bit-field that omits the identifier declares an
4794  // unnamed bit-field. Unnamed bit-fields are not members and cannot be
4795  // initialized.
4796  if (F->isUnnamedBitfield())
4797  continue;
4798 
4799  // If we're not generating the implicit copy/move constructor, then we'll
4800  // handle anonymous struct/union fields based on their individual
4801  // indirect fields.
4802  if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
4803  continue;
4804 
4805  if (CollectFieldInitializer(*this, Info, F))
4806  HadError = true;
4807  continue;
4808  }
4809 
4810  // Beyond this point, we only consider default initialization.
4811  if (Info.isImplicitCopyOrMove())
4812  continue;
4813 
4814  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
4815  if (F->getType()->isIncompleteArrayType()) {
4816  assert(ClassDecl->hasFlexibleArrayMember() &&
4817  "Incomplete array type is not valid");
4818  continue;
4819  }
4820 
4821  // Initialize each field of an anonymous struct individually.
4822  if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
4823  HadError = true;
4824 
4825  continue;
4826  }
4827  }
4828 
4829  unsigned NumInitializers = Info.AllToInit.size();
4830  if (NumInitializers > 0) {
4831  Constructor->setNumCtorInitializers(NumInitializers);
4832  CXXCtorInitializer **baseOrMemberInitializers =
4833  new (Context) CXXCtorInitializer*[NumInitializers];
4834  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
4835  NumInitializers * sizeof(CXXCtorInitializer*));
4836  Constructor->setCtorInitializers(baseOrMemberInitializers);
4837 
4838  // Constructors implicitly reference the base and member
4839  // destructors.
4840  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
4841  Constructor->getParent());
4842  }
4843 
4844  return HadError;
4845 }
4846 
4848  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
4849  const RecordDecl *RD = RT->getDecl();
4850  if (RD->isAnonymousStructOrUnion()) {
4851  for (auto *Field : RD->fields())
4852  PopulateKeysForFields(Field, IdealInits);
4853  return;
4854  }
4855  }
4856  IdealInits.push_back(Field->getCanonicalDecl());
4857 }
4858 
4859 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
4860  return Context.getCanonicalType(BaseType).getTypePtr();
4861 }
4862 
4863 static const void *GetKeyForMember(ASTContext &Context,
4864  CXXCtorInitializer *Member) {
4865  if (!Member->isAnyMemberInitializer())
4866  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
4867 
4868  return Member->getAnyMember()->getCanonicalDecl();
4869 }
4870 
4872  Sema &SemaRef, const CXXConstructorDecl *Constructor,
4874  if (Constructor->getDeclContext()->isDependentContext())
4875  return;
4876 
4877  // Don't check initializers order unless the warning is enabled at the
4878  // location of at least one initializer.
4879  bool ShouldCheckOrder = false;
4880  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4881  CXXCtorInitializer *Init = Inits[InitIndex];
4882  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
4883  Init->getSourceLocation())) {
4884  ShouldCheckOrder = true;
4885  break;
4886  }
4887  }
4888  if (!ShouldCheckOrder)
4889  return;
4890 
4891  // Build the list of bases and members in the order that they'll
4892  // actually be initialized. The explicit initializers should be in
4893  // this same order but may be missing things.
4894  SmallVector<const void*, 32> IdealInitKeys;
4895 
4896  const CXXRecordDecl *ClassDecl = Constructor->getParent();
4897 
4898  // 1. Virtual bases.
4899  for (const auto &VBase : ClassDecl->vbases())
4900  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
4901 
4902  // 2. Non-virtual bases.
4903  for (const auto &Base : ClassDecl->bases()) {
4904  if (Base.isVirtual())
4905  continue;
4906  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
4907  }
4908 
4909  // 3. Direct fields.
4910  for (auto *Field : ClassDecl->fields()) {
4911  if (Field->isUnnamedBitfield())
4912  continue;
4913 
4914  PopulateKeysForFields(Field, IdealInitKeys);
4915  }
4916 
4917  unsigned NumIdealInits = IdealInitKeys.size();
4918  unsigned IdealIndex = 0;
4919 
4920  CXXCtorInitializer *PrevInit = nullptr;
4921  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4922  CXXCtorInitializer *Init = Inits[InitIndex];
4923  const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
4924 
4925  // Scan forward to try to find this initializer in the idealized
4926  // initializers list.
4927  for (; IdealIndex != NumIdealInits; ++IdealIndex)
4928  if (InitKey == IdealInitKeys[IdealIndex])
4929  break;
4930 
4931  // If we didn't find this initializer, it must be because we
4932  // scanned past it on a previous iteration. That can only
4933  // happen if we're out of order; emit a warning.
4934  if (IdealIndex == NumIdealInits && PrevInit) {
4936  SemaRef.Diag(PrevInit->getSourceLocation(),
4937  diag::warn_initializer_out_of_order);
4938 
4939  if (PrevInit->isAnyMemberInitializer())
4940  D << 0 << PrevInit->getAnyMember()->getDeclName();
4941  else
4942  D << 1 << PrevInit->getTypeSourceInfo()->getType();
4943 
4944  if (Init->isAnyMemberInitializer())
4945  D << 0 << Init->getAnyMember()->getDeclName();
4946  else
4947  D << 1 << Init->getTypeSourceInfo()->getType();
4948 
4949  // Move back to the initializer's location in the ideal list.
4950  for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
4951  if (InitKey == IdealInitKeys[IdealIndex])
4952  break;
4953 
4954  assert(IdealIndex < NumIdealInits &&
4955  "initializer not found in initializer list");
4956  }
4957 
4958  PrevInit = Init;
4959  }
4960 }
4961 
4962 namespace {
4963 bool CheckRedundantInit(Sema &S,
4964  CXXCtorInitializer *Init,
4965  CXXCtorInitializer *&PrevInit) {
4966  if (!PrevInit) {
4967  PrevInit = Init;
4968  return false;
4969  }
4970 
4971  if (FieldDecl *Field = Init->getAnyMember())
4972  S.Diag(Init->getSourceLocation(),
4973  diag::err_multiple_mem_initialization)
4974  << Field->getDeclName()
4975  << Init->getSourceRange();
4976  else {
4977  const Type *BaseClass = Init->getBaseClass();
4978  assert(BaseClass && "neither field nor base");
4979  S.Diag(Init->getSourceLocation(),
4980  diag::err_multiple_base_initialization)
4981  << QualType(BaseClass, 0)
4982  << Init->getSourceRange();
4983  }
4984  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
4985  << 0 << PrevInit->getSourceRange();
4986 
4987  return true;
4988 }
4989 
4990 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
4991 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
4992 
4993 bool CheckRedundantUnionInit(Sema &S,
4994  CXXCtorInitializer *Init,
4995  RedundantUnionMap &Unions) {
4996  FieldDecl *Field = Init->getAnyMember();
4997  RecordDecl *Parent = Field->getParent();
4998  NamedDecl *Child = Field;
4999 
5000  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5001  if (Parent->isUnion()) {
5002  UnionEntry &En = Unions[Parent];
5003  if (En.first && En.first != Child) {
5004  S.Diag(Init->getSourceLocation(),
5005  diag::err_multiple_mem_union_initialization)
5006  << Field->getDeclName()
5007  << Init->getSourceRange();
5008  S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5009  << 0 << En.second->getSourceRange();
5010  return true;
5011  }
5012  if (!En.first) {
5013  En.first = Child;
5014  En.second = Init;
5015  }
5016  if (!Parent->isAnonymousStructOrUnion())
5017  return false;
5018  }
5019 
5020  Child = Parent;
5021  Parent = cast<RecordDecl>(Parent->getDeclContext());
5022  }
5023 
5024  return false;
5025 }
5026 }
5027 
5028 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5029 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5032  bool AnyErrors) {
5033  if (!ConstructorDecl)
5034  return;
5035 
5036  AdjustDeclIfTemplate(ConstructorDecl);
5037 
5038  CXXConstructorDecl *Constructor
5039  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5040 
5041  if (!Constructor) {
5042  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5043  return;
5044  }
5045 
5046  // Mapping for the duplicate initializers check.
5047  // For member initializers, this is keyed with a FieldDecl*.
5048  // For base initializers, this is keyed with a Type*.
5049  llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5050 
5051  // Mapping for the inconsistent anonymous-union initializers check.
5052  RedundantUnionMap MemberUnions;
5053 
5054  bool HadError = false;
5055  for (unsigned i = 0; i < MemInits.size(); i++) {
5056  CXXCtorInitializer *Init = MemInits[i];
5057 
5058  // Set the source order index.
5059  Init->setSourceOrder(i);
5060 
5061  if (Init->isAnyMemberInitializer()) {
5062  const void *Key = GetKeyForMember(Context, Init);
5063  if (CheckRedundantInit(*this, Init, Members[Key]) ||
5064  CheckRedundantUnionInit(*this, Init, MemberUnions))
5065  HadError = true;
5066  } else if (Init->isBaseInitializer()) {
5067  const void *Key = GetKeyForMember(Context, Init);
5068  if (CheckRedundantInit(*this, Init, Members[Key]))
5069  HadError = true;
5070  } else {
5071  assert(Init->isDelegatingInitializer());
5072  // This must be the only initializer
5073  if (MemInits.size() != 1) {
5074  Diag(Init->getSourceLocation(),
5075  diag::err_delegating_initializer_alone)
5076  << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5077  // We will treat this as being the only initializer.
5078  }
5079  SetDelegatingInitializer(Constructor, MemInits[i]);
5080  // Return immediately as the initializer is set.
5081  return;
5082  }
5083  }
5084 
5085  if (HadError)
5086  return;
5087 
5088  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5089 
5090  SetCtorInitializers(Constructor, AnyErrors, MemInits);
5091 
5092  DiagnoseUninitializedFields(*this, Constructor);
5093 }
5094 
5095 void
5097  CXXRecordDecl *ClassDecl) {
5098  // Ignore dependent contexts. Also ignore unions, since their members never
5099  // have destructors implicitly called.
5100  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5101  return;
5102 
5103  // FIXME: all the access-control diagnostics are positioned on the
5104  // field/base declaration. That's probably good; that said, the
5105  // user might reasonably want to know why the destructor is being
5106  // emitted, and we currently don't say.
5107 
5108  // Non-static data members.
5109  for (auto *Field : ClassDecl->fields()) {
5110  if (Field->isInvalidDecl())
5111  continue;
5112 
5113  // Don't destroy incomplete or zero-length arrays.
5114  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5115  continue;
5116 
5117  QualType FieldType = Context.getBaseElementType(Field->getType());
5118 
5119  const RecordType* RT = FieldType->getAs<RecordType>();
5120  if (!RT)
5121  continue;
5122 
5123  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5124  if (FieldClassDecl->isInvalidDecl())
5125  continue;
5126  if (FieldClassDecl->hasIrrelevantDestructor())
5127  continue;
5128  // The destructor for an implicit anonymous union member is never invoked.
5129  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5130  continue;
5131 
5132  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5133  assert(Dtor && "No dtor found for FieldClassDecl!");
5134  CheckDestructorAccess(Field->getLocation(), Dtor,
5135  PDiag(diag::err_access_dtor_field)
5136  << Field->getDeclName()
5137  << FieldType);
5138 
5139  MarkFunctionReferenced(Location, Dtor);
5140  DiagnoseUseOfDecl(Dtor, Location);
5141  }
5142 
5143  // We only potentially invoke the destructors of potentially constructed
5144  // subobjects.
5145  bool VisitVirtualBases = !ClassDecl->isAbstract();
5146 
5147  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5148 
5149  // Bases.
5150  for (const auto &Base : ClassDecl->bases()) {
5151  // Bases are always records in a well-formed non-dependent class.
5152  const RecordType *RT = Base.getType()->getAs<RecordType>();
5153 
5154  // Remember direct virtual bases.
5155  if (Base.isVirtual()) {
5156  if (!VisitVirtualBases)
5157  continue;
5158  DirectVirtualBases.insert(RT);
5159  }
5160 
5161  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5162  // If our base class is invalid, we probably can't get its dtor anyway.
5163  if (BaseClassDecl->isInvalidDecl())
5164  continue;
5165  if (BaseClassDecl->hasIrrelevantDestructor())
5166  continue;
5167 
5168  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5169  assert(Dtor && "No dtor found for BaseClassDecl!");
5170 
5171  // FIXME: caret should be on the start of the class name
5172  CheckDestructorAccess(Base.getLocStart(), Dtor,
5173  PDiag(diag::err_access_dtor_base)
5174  << Base.getType()
5175  << Base.getSourceRange(),
5176  Context.getTypeDeclType(ClassDecl));
5177 
5178  MarkFunctionReferenced(Location, Dtor);
5179  DiagnoseUseOfDecl(Dtor, Location);
5180  }
5181 
5182  if (!VisitVirtualBases)
5183  return;
5184 
5185  // Virtual bases.
5186  for (const auto &VBase : ClassDecl->vbases()) {
5187  // Bases are always records in a well-formed non-dependent class.
5188  const RecordType *RT = VBase.getType()->castAs<RecordType>();
5189 
5190  // Ignore direct virtual bases.
5191  if (DirectVirtualBases.count(RT))
5192  continue;
5193 
5194  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5195  // If our base class is invalid, we probably can't get its dtor anyway.
5196  if (BaseClassDecl->isInvalidDecl())
5197  continue;
5198  if (BaseClassDecl->hasIrrelevantDestructor())
5199  continue;
5200 
5201  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5202  assert(Dtor && "No dtor found for BaseClassDecl!");
5203  if (CheckDestructorAccess(
5204  ClassDecl->getLocation(), Dtor,
5205  PDiag(diag::err_access_dtor_vbase)
5206  << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5207  Context.getTypeDeclType(ClassDecl)) ==
5208  AR_accessible) {
5209  CheckDerivedToBaseConversion(
5210  Context.getTypeDeclType(ClassDecl), VBase.getType(),
5211  diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5212  SourceRange(), DeclarationName(), nullptr);
5213  }
5214 
5215  MarkFunctionReferenced(Location, Dtor);
5216  DiagnoseUseOfDecl(Dtor, Location);
5217  }
5218 }
5219 
5220 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5221  if (!CDtorDecl)
5222  return;
5223 
5224  if (CXXConstructorDecl *Constructor
5225  = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5226  SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5227  DiagnoseUninitializedFields(*this, Constructor);
5228  }
5229 }
5230 
5232  if (!getLangOpts().CPlusPlus)
5233  return false;
5234 
5235  const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5236  if (!RD)
5237  return false;
5238 
5239  // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5240  // class template specialization here, but doing so breaks a lot of code.
5241 
5242  // We can't answer whether something is abstract until it has a
5243  // definition. If it's currently being defined, we'll walk back
5244  // over all the declarations when we have a full definition.
5245  const CXXRecordDecl *Def = RD->getDefinition();
5246  if (!Def || Def->isBeingDefined())
5247  return false;
5248 
5249  return RD->isAbstract();
5250 }
5251 
5253  TypeDiagnoser &Diagnoser) {
5254  if (!isAbstractType(Loc, T))
5255  return false;
5256 
5257  T = Context.getBaseElementType(T);
5258  Diagnoser.diagnose(*this, Loc, T);
5259  DiagnoseAbstractType(T->getAsCXXRecordDecl());
5260  return true;
5261 }
5262 
5264  // Check if we've already emitted the list of pure virtual functions
5265  // for this class.
5266  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5267  return;
5268 
5269  // If the diagnostic is suppressed, don't emit the notes. We're only
5270  // going to emit them once, so try to attach them to a diagnostic we're
5271  // actually going to show.
5272  if (Diags.isLastDiagnosticIgnored())
5273  return;
5274 
5275  CXXFinalOverriderMap FinalOverriders;
5276  RD->getFinalOverriders(FinalOverriders);
5277 
5278  // Keep a set of seen pure methods so we won't diagnose the same method
5279  // more than once.
5280  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5281 
5282  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5283  MEnd = FinalOverriders.end();
5284  M != MEnd;
5285  ++M) {
5286  for (OverridingMethods::iterator SO = M->second.begin(),
5287  SOEnd = M->second.end();
5288  SO != SOEnd; ++SO) {
5289  // C++ [class.abstract]p4:
5290  // A class is abstract if it contains or inherits at least one
5291  // pure virtual function for which the final overrider is pure
5292  // virtual.
5293 
5294  //
5295  if (SO->second.size() != 1)
5296  continue;
5297 
5298  if (!SO->second.front().Method->isPure())
5299  continue;
5300 
5301  if (!SeenPureMethods.insert(SO->second.front().Method).second)
5302  continue;
5303 
5304  Diag(SO->second.front().Method->getLocation(),
5305  diag::note_pure_virtual_function)
5306  << SO->second.front().Method->getDeclName() << RD->getDeclName();
5307  }
5308  }
5309 
5310  if (!PureVirtualClassDiagSet)
5311  PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5312  PureVirtualClassDiagSet->insert(RD);
5313 }
5314 
5315 namespace {
5316 struct AbstractUsageInfo {
5317  Sema &S;
5318  CXXRecordDecl *Record;
5319  CanQualType AbstractType;
5320  bool Invalid;
5321 
5322  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5323  : S(S), Record(Record),
5324  AbstractType(S.Context.getCanonicalType(
5325  S.Context.getTypeDeclType(Record))),
5326  Invalid(false) {}
5327 
5328  void DiagnoseAbstractType() {
5329  if (Invalid) return;
5330  S.DiagnoseAbstractType(Record);
5331  Invalid = true;
5332  }
5333 
5334  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5335 };
5336 
5337 struct CheckAbstractUsage {
5338  AbstractUsageInfo &Info;
5339  const NamedDecl *Ctx;
5340 
5341  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5342  : Info(Info), Ctx(Ctx) {}
5343 
5344  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5345  switch (TL.getTypeLocClass()) {
5346 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5347 #define TYPELOC(CLASS, PARENT) \
5348  case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5349 #include "clang/AST/TypeLocNodes.def"
5350  }
5351  }
5352 
5353  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5355  for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5356  if (!TL.getParam(I))
5357  continue;
5358 
5359  TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5360  if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5361  }
5362  }
5363 
5364  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5366  }
5367 
5369  // Visit the type parameters from a permissive context.
5370  for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5371  TemplateArgumentLoc TAL = TL.getArgLoc(I);
5373  if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5374  Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5375  // TODO: other template argument types?
5376  }
5377  }
5378 
5379  // Visit pointee types from a permissive context.
5380 #define CheckPolymorphic(Type) \
5381  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5382  Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5383  }
5389 
5390  /// Handle all the types we haven't given a more specific
5391  /// implementation for above.
5392  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5393  // Every other kind of type that we haven't called out already
5394  // that has an inner type is either (1) sugar or (2) contains that
5395  // inner type in some way as a subobject.
5396  if (TypeLoc Next = TL.getNextTypeLoc())
5397  return Visit(Next, Sel);
5398 
5399  // If there's no inner type and we're in a permissive context,
5400  // don't diagnose.
5401  if (Sel == Sema::AbstractNone) return;
5402 
5403  // Check whether the type matches the abstract type.
5404  QualType T = TL.getType();
5405  if (T->isArrayType()) {
5407  T = Info.S.Context.getBaseElementType(T);
5408  }
5410  if (CT != Info.AbstractType) return;
5411 
5412  // It matched; do some magic.
5413  if (Sel == Sema::AbstractArrayType) {
5414  Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5415  << T << TL.getSourceRange();
5416  } else {
5417  Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5418  << Sel << T << TL.getSourceRange();
5419  }
5420  Info.DiagnoseAbstractType();
5421  }
5422 };
5423 
5424 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5426  CheckAbstractUsage(*this, D).Visit(TL, Sel);
5427 }
5428 
5429 }
5430 
5431 /// Check for invalid uses of an abstract type in a method declaration.
5432 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5433  CXXMethodDecl *MD) {
5434  // No need to do the check on definitions, which require that
5435  // the return/param types be complete.
5436  if (MD->doesThisDeclarationHaveABody())
5437  return;
5438 
5439  // For safety's sake, just ignore it if we don't have type source
5440  // information. This should never happen for non-implicit methods,
5441  // but...
5442  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5443  Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5444 }
5445 
5446 /// Check for invalid uses of an abstract type within a class definition.
5447 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5448  CXXRecordDecl *RD) {
5449  for (auto *D : RD->decls()) {
5450  if (D->isImplicit()) continue;
5451 
5452  // Methods and method templates.
5453  if (isa<CXXMethodDecl>(D)) {
5454  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5455  } else if (isa<FunctionTemplateDecl>(D)) {
5456  FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5457  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5458 
5459  // Fields and static variables.
5460  } else if (isa<FieldDecl>(D)) {
5461  FieldDecl *FD = cast<FieldDecl>(D);
5462  if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5463  Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5464  } else if (isa<VarDecl>(D)) {
5465  VarDecl *VD = cast<VarDecl>(D);
5466  if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5467  Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5468 
5469  // Nested classes and class templates.
5470  } else if (isa<CXXRecordDecl>(D)) {
5471  CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5472  } else if (isa<ClassTemplateDecl>(D)) {
5474  cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5475  }
5476  }
5477 }
5478 
5480  Attr *ClassAttr = getDLLAttr(Class);
5481  if (!ClassAttr)
5482  return;
5483 
5484  assert(ClassAttr->getKind() == attr::DLLExport);
5485 
5487 
5489  // Don't go any further if this is just an explicit instantiation
5490  // declaration.
5491  return;
5492 
5493  for (Decl *Member : Class->decls()) {
5494  auto *MD = dyn_cast<CXXMethodDecl>(Member);
5495  if (!MD)
5496  continue;
5497 
5498  if (Member->getAttr<DLLExportAttr>()) {
5499  if (MD->isUserProvided()) {
5500  // Instantiate non-default class member functions ...
5501 
5502  // .. except for certain kinds of template specializations.
5503  if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5504  continue;
5505 
5506  S.MarkFunctionReferenced(Class->getLocation(), MD);
5507 
5508  // The function will be passed to the consumer when its definition is
5509  // encountered.
5510  } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5511  MD->isCopyAssignmentOperator() ||
5512  MD->isMoveAssignmentOperator()) {
5513  // Synthesize and instantiate non-trivial implicit methods, explicitly
5514  // defaulted methods, and the copy and move assignment operators. The
5515  // latter are exported even if they are trivial, because the address of
5516  // an operator can be taken and should compare equal across libraries.
5517  DiagnosticErrorTrap Trap(S.Diags);
5518  S.MarkFunctionReferenced(Class->getLocation(), MD);
5519  if (Trap.hasErrorOccurred()) {
5520  S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5521  << Class->getName() << !S.getLangOpts().CPlusPlus11;
5522  break;
5523  }
5524 
5525  // There is no later point when we will see the definition of this
5526  // function, so pass it to the consumer now.
5528  }
5529  }
5530  }
5531 }
5532 
5534  CXXRecordDecl *Class) {
5535  // Only the MS ABI has default constructor closures, so we don't need to do
5536  // this semantic checking anywhere else.
5538  return;
5539 
5540  CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5541  for (Decl *Member : Class->decls()) {
5542  // Look for exported default constructors.
5543  auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5544  if (!CD || !CD->isDefaultConstructor())
5545  continue;
5546  auto *Attr = CD->getAttr<DLLExportAttr>();
5547  if (!Attr)
5548  continue;
5549 
5550  // If the class is non-dependent, mark the default arguments as ODR-used so
5551  // that we can properly codegen the constructor closure.
5552  if (!Class->isDependentContext()) {
5553  for (ParmVarDecl *PD : CD->parameters()) {
5554  (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5556  }
5557  }
5558 
5559  if (LastExportedDefaultCtor) {
5560  S.Diag(LastExportedDefaultCtor->getLocation(),
5561  diag::err_attribute_dll_ambiguous_default_ctor)
5562  << Class;
5563  S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5564  << CD->getDeclName();
5565  return;
5566  }
5567  LastExportedDefaultCtor = CD;
5568  }
5569 }
5570 
5571 /// \brief Check class-level dllimport/dllexport attribute.
5573  Attr *ClassAttr = getDLLAttr(Class);
5574 
5575  // MSVC inherits DLL attributes to partial class template specializations.
5576  if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5577  if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5578  if (Attr *TemplateAttr =
5579  getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5580  auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5581  A->setInherited(true);
5582  ClassAttr = A;
5583  }
5584  }
5585  }
5586 
5587  if (!ClassAttr)
5588  return;
5589 
5590  if (!Class->isExternallyVisible()) {
5591  Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5592  << Class << ClassAttr;
5593  return;
5594  }
5595 
5596  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5597  !ClassAttr->isInherited()) {
5598  // Diagnose dll attributes on members of class with dll attribute.
5599  for (Decl *Member : Class->decls()) {
5600  if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5601  continue;
5602  InheritableAttr *MemberAttr = getDLLAttr(Member);
5603  if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5604  continue;
5605 
5606  Diag(MemberAttr->getLocation(),
5607  diag::err_attribute_dll_member_of_dll_class)
5608  << MemberAttr << ClassAttr;
5609  Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5610  Member->setInvalidDecl();
5611  }
5612  }
5613 
5614  if (Class->getDescribedClassTemplate())
5615  // Don't inherit dll attribute until the template is instantiated.
5616  return;
5617 
5618  // The class is either imported or exported.
5619  const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5620 
5622 
5623  // Ignore explicit dllexport on explicit class template instantiation declarations.
5624  if (ClassExported && !ClassAttr->isInherited() &&
5626  Class->dropAttr<DLLExportAttr>();
5627  return;
5628  }
5629 
5630  // Force declaration of implicit members so they can inherit the attribute.
5631  ForceDeclarationOfImplicitMembers(Class);
5632 
5633  // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
5634  // seem to be true in practice?
5635 
5636  for (Decl *Member : Class->decls()) {
5637  VarDecl *VD = dyn_cast<VarDecl>(Member);
5638  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
5639 
5640  // Only methods and static fields inherit the attributes.
5641  if (!VD && !MD)
5642  continue;
5643 
5644  if (MD) {
5645  // Don't process deleted methods.
5646  if (MD->isDeleted())
5647  continue;
5648 
5649  if (MD->isInlined()) {
5650  // MinGW does not import or export inline methods.
5651  if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5652  !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())
5653  continue;
5654 
5655  // MSVC versions before 2015 don't export the move assignment operators
5656  // and move constructor, so don't attempt to import/export them if
5657  // we have a definition.
5658  auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
5659  if ((MD->isMoveAssignmentOperator() ||
5660  (Ctor && Ctor->isMoveConstructor())) &&
5661  !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
5662  continue;
5663 
5664  // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
5665  // operator is exported anyway.
5666  if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
5667  (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
5668  continue;
5669  }
5670  }
5671 
5672  if (!cast<NamedDecl>(Member)->isExternallyVisible())
5673  continue;
5674 
5675  if (!getDLLAttr(Member)) {
5676  auto *NewAttr =
5677  cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
5678  NewAttr->setInherited(true);
5679  Member->addAttr(NewAttr);
5680  }
5681  }
5682 
5683  if (ClassExported)
5684  DelayedDllExportClasses.push_back(Class);
5685 }
5686 
5687 /// \brief Perform propagation of DLL attributes from a derived class to a
5688 /// templated base class for MS compatibility.
5690  CXXRecordDecl *Class, Attr *ClassAttr,
5691  ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
5692  if (getDLLAttr(
5693  BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
5694  // If the base class template has a DLL attribute, don't try to change it.
5695  return;
5696  }
5697 
5698  auto TSK = BaseTemplateSpec->getSpecializationKind();
5699  if (!getDLLAttr(BaseTemplateSpec) &&
5701  TSK == TSK_ImplicitInstantiation)) {
5702  // The template hasn't been instantiated yet (or it has, but only as an
5703  // explicit instantiation declaration or implicit instantiation, which means
5704  // we haven't codegenned any members yet), so propagate the attribute.
5705  auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
5706  NewAttr->setInherited(true);
5707  BaseTemplateSpec->addAttr(Ne