clang  8.0.0svn
SemaDeclCXX.cpp
Go to the documentation of this file.
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"
22 #include "clang/AST/ExprCXX.h"
23 #include "clang/AST/RecordLayout.h"
25 #include "clang/AST/StmtVisitor.h"
26 #include "clang/AST/TypeLoc.h"
27 #include "clang/AST/TypeOrdering.h"
29 #include "clang/Basic/TargetInfo.h"
31 #include "clang/Lex/Preprocessor.h"
33 #include "clang/Sema/DeclSpec.h"
35 #include "clang/Sema/Lookup.h"
37 #include "clang/Sema/Scope.h"
38 #include "clang/Sema/ScopeInfo.h"
40 #include "clang/Sema/Template.h"
41 #include "llvm/ADT/STLExtras.h"
42 #include "llvm/ADT/SmallString.h"
43 #include "llvm/ADT/StringExtras.h"
44 #include <map>
45 #include <set>
46 
47 using namespace clang;
48 
49 //===----------------------------------------------------------------------===//
50 // CheckDefaultArgumentVisitor
51 //===----------------------------------------------------------------------===//
52 
53 namespace {
54  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
55  /// the default argument of a parameter to determine whether it
56  /// contains any ill-formed subexpressions. For example, this will
57  /// diagnose the use of local variables or parameters within the
58  /// default argument expression.
59  class CheckDefaultArgumentVisitor
60  : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
61  Expr *DefaultArg;
62  Sema *S;
63 
64  public:
65  CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
66  : DefaultArg(defarg), S(s) {}
67 
68  bool VisitExpr(Expr *Node);
69  bool VisitDeclRefExpr(DeclRefExpr *DRE);
70  bool VisitCXXThisExpr(CXXThisExpr *ThisE);
71  bool VisitLambdaExpr(LambdaExpr *Lambda);
72  bool VisitPseudoObjectExpr(PseudoObjectExpr *POE);
73  };
74 
75  /// VisitExpr - Visit all of the children of this expression.
76  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
77  bool IsInvalid = false;
78  for (Stmt *SubStmt : Node->children())
79  IsInvalid |= Visit(SubStmt);
80  return IsInvalid;
81  }
82 
83  /// VisitDeclRefExpr - Visit a reference to a declaration, to
84  /// determine whether this declaration can be used in the default
85  /// argument expression.
86  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
87  NamedDecl *Decl = DRE->getDecl();
88  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
89  // C++ [dcl.fct.default]p9
90  // Default arguments are evaluated each time the function is
91  // called. The order of evaluation of function arguments is
92  // unspecified. Consequently, parameters of a function shall not
93  // be used in default argument expressions, even if they are not
94  // evaluated. Parameters of a function declared before a default
95  // argument expression are in scope and can hide namespace and
96  // class member names.
97  return S->Diag(DRE->getBeginLoc(),
98  diag::err_param_default_argument_references_param)
99  << Param->getDeclName() << DefaultArg->getSourceRange();
100  } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
101  // C++ [dcl.fct.default]p7
102  // Local variables shall not be used in default argument
103  // expressions.
104  if (VDecl->isLocalVarDecl())
105  return S->Diag(DRE->getBeginLoc(),
106  diag::err_param_default_argument_references_local)
107  << VDecl->getDeclName() << DefaultArg->getSourceRange();
108  }
109 
110  return false;
111  }
112 
113  /// VisitCXXThisExpr - Visit a C++ "this" expression.
114  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
115  // C++ [dcl.fct.default]p8:
116  // The keyword this shall not be used in a default argument of a
117  // member function.
118  return S->Diag(ThisE->getBeginLoc(),
119  diag::err_param_default_argument_references_this)
120  << ThisE->getSourceRange();
121  }
122 
123  bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
124  bool Invalid = false;
126  i = POE->semantics_begin(), e = POE->semantics_end(); i != e; ++i) {
127  Expr *E = *i;
128 
129  // Look through bindings.
130  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
131  E = OVE->getSourceExpr();
132  assert(E && "pseudo-object binding without source expression?");
133  }
134 
135  Invalid |= Visit(E);
136  }
137  return Invalid;
138  }
139 
140  bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
141  // C++11 [expr.lambda.prim]p13:
142  // A lambda-expression appearing in a default argument shall not
143  // implicitly or explicitly capture any entity.
144  if (Lambda->capture_begin() == Lambda->capture_end())
145  return false;
146 
147  return S->Diag(Lambda->getBeginLoc(), 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  case EST_Unparsed:
175  case EST_Uninstantiated:
176  case EST_Unevaluated:
177  llvm_unreachable("should not see unresolved exception specs here");
178 
179  // If this function can throw any exceptions, make a note of that.
180  case EST_MSAny:
181  case EST_None:
182  // FIXME: Whichever we see last of MSAny and None determines our result.
183  // We should make a consistent, order-independent choice here.
184  ClearExceptions();
185  ComputedEST = EST;
186  return;
187  case EST_NoexceptFalse:
188  ClearExceptions();
189  ComputedEST = EST_None;
190  return;
191  // FIXME: If the call to this decl is using any of its default arguments, we
192  // need to search them for potentially-throwing calls.
193  // If this function has a basic noexcept, it doesn't affect the outcome.
194  case EST_BasicNoexcept:
195  case EST_NoexceptTrue:
196  return;
197  // If we're still at noexcept(true) and there's a throw() callee,
198  // change to that specification.
199  case EST_DynamicNone:
200  if (ComputedEST == EST_BasicNoexcept)
201  ComputedEST = EST_DynamicNone;
202  return;
204  llvm_unreachable(
205  "should not generate implicit declarations for dependent cases");
206  case EST_Dynamic:
207  break;
208  }
209  assert(EST == EST_Dynamic && "EST case not considered earlier.");
210  assert(ComputedEST != EST_None &&
211  "Shouldn't collect exceptions when throw-all is guaranteed.");
212  ComputedEST = EST_Dynamic;
213  // Record the exceptions in this function's exception specification.
214  for (const auto &E : Proto->exceptions())
215  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
216  Exceptions.push_back(E);
217 }
218 
220  if (!E || ComputedEST == EST_MSAny)
221  return;
222 
223  // FIXME:
224  //
225  // C++0x [except.spec]p14:
226  // [An] implicit exception-specification specifies the type-id T if and
227  // only if T is allowed by the exception-specification of a function directly
228  // invoked by f's implicit definition; f shall allow all exceptions if any
229  // function it directly invokes allows all exceptions, and f shall allow no
230  // exceptions if every function it directly invokes allows no exceptions.
231  //
232  // Note in particular that if an implicit exception-specification is generated
233  // for a function containing a throw-expression, that specification can still
234  // be noexcept(true).
235  //
236  // Note also that 'directly invoked' is not defined in the standard, and there
237  // is no indication that we should only consider potentially-evaluated calls.
238  //
239  // Ultimately we should implement the intent of the standard: the exception
240  // specification should be the set of exceptions which can be thrown by the
241  // implicit definition. For now, we assume that any non-nothrow expression can
242  // throw any exception.
243 
244  if (Self->canThrow(E))
245  ComputedEST = EST_None;
246 }
247 
248 bool
250  SourceLocation EqualLoc) {
251  if (RequireCompleteType(Param->getLocation(), Param->getType(),
252  diag::err_typecheck_decl_incomplete_type)) {
253  Param->setInvalidDecl();
254  return true;
255  }
256 
257  // C++ [dcl.fct.default]p5
258  // A default argument expression is implicitly converted (clause
259  // 4) to the parameter type. The default argument expression has
260  // the same semantic constraints as the initializer expression in
261  // a declaration of a variable of the parameter type, using the
262  // copy-initialization semantics (8.5).
264  Param);
266  EqualLoc);
267  InitializationSequence InitSeq(*this, Entity, Kind, Arg);
268  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
269  if (Result.isInvalid())
270  return true;
271  Arg = Result.getAs<Expr>();
272 
273  CheckCompletedExpr(Arg, EqualLoc);
274  Arg = MaybeCreateExprWithCleanups(Arg);
275 
276  // Okay: add the default argument to the parameter
277  Param->setDefaultArg(Arg);
278 
279  // We have already instantiated this parameter; provide each of the
280  // instantiations with the uninstantiated default argument.
281  UnparsedDefaultArgInstantiationsMap::iterator InstPos
282  = UnparsedDefaultArgInstantiations.find(Param);
283  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
284  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
285  InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
286 
287  // We're done tracking this parameter's instantiations.
288  UnparsedDefaultArgInstantiations.erase(InstPos);
289  }
290 
291  return false;
292 }
293 
294 /// ActOnParamDefaultArgument - Check whether the default argument
295 /// provided for a function parameter is well-formed. If so, attach it
296 /// to the parameter declaration.
297 void
299  Expr *DefaultArg) {
300  if (!param || !DefaultArg)
301  return;
302 
303  ParmVarDecl *Param = cast<ParmVarDecl>(param);
304  UnparsedDefaultArgLocs.erase(Param);
305 
306  // Default arguments are only permitted in C++
307  if (!getLangOpts().CPlusPlus) {
308  Diag(EqualLoc, diag::err_param_default_argument)
309  << DefaultArg->getSourceRange();
310  Param->setInvalidDecl();
311  return;
312  }
313 
314  // Check for unexpanded parameter packs.
315  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
316  Param->setInvalidDecl();
317  return;
318  }
319 
320  // C++11 [dcl.fct.default]p3
321  // A default argument expression [...] shall not be specified for a
322  // parameter pack.
323  if (Param->isParameterPack()) {
324  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
325  << DefaultArg->getSourceRange();
326  return;
327  }
328 
329  // Check that the default argument is well-formed
330  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
331  if (DefaultArgChecker.Visit(DefaultArg)) {
332  Param->setInvalidDecl();
333  return;
334  }
335 
336  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
337 }
338 
339 /// ActOnParamUnparsedDefaultArgument - We've seen a default
340 /// argument for a function parameter, but we can't parse it yet
341 /// because we're inside a class definition. Note that this default
342 /// argument will be parsed later.
344  SourceLocation EqualLoc,
345  SourceLocation ArgLoc) {
346  if (!param)
347  return;
348 
349  ParmVarDecl *Param = cast<ParmVarDecl>(param);
350  Param->setUnparsedDefaultArg();
351  UnparsedDefaultArgLocs[Param] = ArgLoc;
352 }
353 
354 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
355 /// the default argument for the parameter param failed.
357  SourceLocation EqualLoc) {
358  if (!param)
359  return;
360 
361  ParmVarDecl *Param = cast<ParmVarDecl>(param);
362  Param->setInvalidDecl();
363  UnparsedDefaultArgLocs.erase(Param);
364  Param->setDefaultArg(new(Context)
365  OpaqueValueExpr(EqualLoc,
366  Param->getType().getNonReferenceType(),
367  VK_RValue));
368 }
369 
370 /// CheckExtraCXXDefaultArguments - Check for any extra default
371 /// arguments in the declarator, which is not a function declaration
372 /// or definition and therefore is not permitted to have default
373 /// arguments. This routine should be invoked for every declarator
374 /// that is not a function declaration or definition.
376  // C++ [dcl.fct.default]p3
377  // A default argument expression shall be specified only in the
378  // parameter-declaration-clause of a function declaration or in a
379  // template-parameter (14.1). It shall not be specified for a
380  // parameter pack. If it is specified in a
381  // parameter-declaration-clause, it shall not occur within a
382  // declarator or abstract-declarator of a parameter-declaration.
383  bool MightBeFunction = D.isFunctionDeclarationContext();
384  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
385  DeclaratorChunk &chunk = D.getTypeObject(i);
386  if (chunk.Kind == DeclaratorChunk::Function) {
387  if (MightBeFunction) {
388  // This is a function declaration. It can have default arguments, but
389  // keep looking in case its return type is a function type with default
390  // arguments.
391  MightBeFunction = false;
392  continue;
393  }
394  for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
395  ++argIdx) {
396  ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
397  if (Param->hasUnparsedDefaultArg()) {
398  std::unique_ptr<CachedTokens> Toks =
399  std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
400  SourceRange SR;
401  if (Toks->size() > 1)
402  SR = SourceRange((*Toks)[1].getLocation(),
403  Toks->back().getLocation());
404  else
405  SR = UnparsedDefaultArgLocs[Param];
406  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
407  << SR;
408  } else if (Param->getDefaultArg()) {
409  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
410  << Param->getDefaultArg()->getSourceRange();
411  Param->setDefaultArg(nullptr);
412  }
413  }
414  } else if (chunk.Kind != DeclaratorChunk::Paren) {
415  MightBeFunction = false;
416  }
417  }
418 }
419 
421  for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) {
422  const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1);
423  if (!PVD->hasDefaultArg())
424  return false;
425  if (!PVD->hasInheritedDefaultArg())
426  return true;
427  }
428  return false;
429 }
430 
431 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
432 /// function, once we already know that they have the same
433 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
434 /// error, false otherwise.
436  Scope *S) {
437  bool Invalid = false;
438 
439  // The declaration context corresponding to the scope is the semantic
440  // parent, unless this is a local function declaration, in which case
441  // it is that surrounding function.
442  DeclContext *ScopeDC = New->isLocalExternDecl()
443  ? New->getLexicalDeclContext()
444  : New->getDeclContext();
445 
446  // Find the previous declaration for the purpose of default arguments.
447  FunctionDecl *PrevForDefaultArgs = Old;
448  for (/**/; PrevForDefaultArgs;
449  // Don't bother looking back past the latest decl if this is a local
450  // extern declaration; nothing else could work.
451  PrevForDefaultArgs = New->isLocalExternDecl()
452  ? nullptr
453  : PrevForDefaultArgs->getPreviousDecl()) {
454  // Ignore hidden declarations.
455  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
456  continue;
457 
458  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
459  !New->isCXXClassMember()) {
460  // Ignore default arguments of old decl if they are not in
461  // the same scope and this is not an out-of-line definition of
462  // a member function.
463  continue;
464  }
465 
466  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
467  // If only one of these is a local function declaration, then they are
468  // declared in different scopes, even though isDeclInScope may think
469  // they're in the same scope. (If both are local, the scope check is
470  // sufficient, and if neither is local, then they are in the same scope.)
471  continue;
472  }
473 
474  // We found the right previous declaration.
475  break;
476  }
477 
478  // C++ [dcl.fct.default]p4:
479  // For non-template functions, default arguments can be added in
480  // later declarations of a function in the same
481  // scope. Declarations in different scopes have completely
482  // distinct sets of default arguments. That is, declarations in
483  // inner scopes do not acquire default arguments from
484  // declarations in outer scopes, and vice versa. In a given
485  // function declaration, all parameters subsequent to a
486  // parameter with a default argument shall have default
487  // arguments supplied in this or previous declarations. A
488  // default argument shall not be redefined by a later
489  // declaration (not even to the same value).
490  //
491  // C++ [dcl.fct.default]p6:
492  // Except for member functions of class templates, the default arguments
493  // in a member function definition that appears outside of the class
494  // definition are added to the set of default arguments provided by the
495  // member function declaration in the class definition.
496  for (unsigned p = 0, NumParams = PrevForDefaultArgs
497  ? PrevForDefaultArgs->getNumParams()
498  : 0;
499  p < NumParams; ++p) {
500  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
501  ParmVarDecl *NewParam = New->getParamDecl(p);
502 
503  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
504  bool NewParamHasDfl = NewParam->hasDefaultArg();
505 
506  if (OldParamHasDfl && NewParamHasDfl) {
507  unsigned DiagDefaultParamID =
508  diag::err_param_default_argument_redefinition;
509 
510  // MSVC accepts that default parameters be redefined for member functions
511  // of template class. The new default parameter's value is ignored.
512  Invalid = true;
513  if (getLangOpts().MicrosoftExt) {
514  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
515  if (MD && MD->getParent()->getDescribedClassTemplate()) {
516  // Merge the old default argument into the new parameter.
517  NewParam->setHasInheritedDefaultArg();
518  if (OldParam->hasUninstantiatedDefaultArg())
519  NewParam->setUninstantiatedDefaultArg(
520  OldParam->getUninstantiatedDefaultArg());
521  else
522  NewParam->setDefaultArg(OldParam->getInit());
523  DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
524  Invalid = false;
525  }
526  }
527 
528  // FIXME: If we knew where the '=' was, we could easily provide a fix-it
529  // hint here. Alternatively, we could walk the type-source information
530  // for NewParam to find the last source location in the type... but it
531  // isn't worth the effort right now. This is the kind of test case that
532  // is hard to get right:
533  // int f(int);
534  // void g(int (*fp)(int) = f);
535  // void g(int (*fp)(int) = &f);
536  Diag(NewParam->getLocation(), DiagDefaultParamID)
537  << NewParam->getDefaultArgRange();
538 
539  // Look for the function declaration where the default argument was
540  // actually written, which may be a declaration prior to Old.
541  for (auto Older = PrevForDefaultArgs;
542  OldParam->hasInheritedDefaultArg(); /**/) {
543  Older = Older->getPreviousDecl();
544  OldParam = Older->getParamDecl(p);
545  }
546 
547  Diag(OldParam->getLocation(), diag::note_previous_definition)
548  << OldParam->getDefaultArgRange();
549  } else if (OldParamHasDfl) {
550  // Merge the old default argument into the new parameter unless the new
551  // function is a friend declaration in a template class. In the latter
552  // case the default arguments will be inherited when the friend
553  // declaration will be instantiated.
554  if (New->getFriendObjectKind() == Decl::FOK_None ||
556  // It's important to use getInit() here; getDefaultArg()
557  // strips off any top-level ExprWithCleanups.
558  NewParam->setHasInheritedDefaultArg();
559  if (OldParam->hasUnparsedDefaultArg())
560  NewParam->setUnparsedDefaultArg();
561  else if (OldParam->hasUninstantiatedDefaultArg())
562  NewParam->setUninstantiatedDefaultArg(
563  OldParam->getUninstantiatedDefaultArg());
564  else
565  NewParam->setDefaultArg(OldParam->getInit());
566  }
567  } else if (NewParamHasDfl) {
568  if (New->getDescribedFunctionTemplate()) {
569  // Paragraph 4, quoted above, only applies to non-template functions.
570  Diag(NewParam->getLocation(),
571  diag::err_param_default_argument_template_redecl)
572  << NewParam->getDefaultArgRange();
573  Diag(PrevForDefaultArgs->getLocation(),
574  diag::note_template_prev_declaration)
575  << false;
576  } else if (New->getTemplateSpecializationKind()
579  // C++ [temp.expr.spec]p21:
580  // Default function arguments shall not be specified in a declaration
581  // or a definition for one of the following explicit specializations:
582  // - the explicit specialization of a function template;
583  // - the explicit specialization of a member function template;
584  // - the explicit specialization of a member function of a class
585  // template where the class template specialization to which the
586  // member function specialization belongs is implicitly
587  // instantiated.
588  Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
590  << New->getDeclName()
591  << NewParam->getDefaultArgRange();
592  } else if (New->getDeclContext()->isDependentContext()) {
593  // C++ [dcl.fct.default]p6 (DR217):
594  // Default arguments for a member function of a class template shall
595  // be specified on the initial declaration of the member function
596  // within the class template.
597  //
598  // Reading the tea leaves a bit in DR217 and its reference to DR205
599  // leads me to the conclusion that one cannot add default function
600  // arguments for an out-of-line definition of a member function of a
601  // dependent type.
602  int WhichKind = 2;
603  if (CXXRecordDecl *Record
604  = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
605  if (Record->getDescribedClassTemplate())
606  WhichKind = 0;
607  else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
608  WhichKind = 1;
609  else
610  WhichKind = 2;
611  }
612 
613  Diag(NewParam->getLocation(),
614  diag::err_param_default_argument_member_template_redecl)
615  << WhichKind
616  << NewParam->getDefaultArgRange();
617  }
618  }
619  }
620 
621  // DR1344: If a default argument is added outside a class definition and that
622  // default argument makes the function a special member function, the program
623  // is ill-formed. This can only happen for constructors.
624  if (isa<CXXConstructorDecl>(New) &&
626  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
627  OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
628  if (NewSM != OldSM) {
629  ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
630  assert(NewParam->hasDefaultArg());
631  Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
632  << NewParam->getDefaultArgRange() << NewSM;
633  Diag(Old->getLocation(), diag::note_previous_declaration);
634  }
635  }
636 
637  const FunctionDecl *Def;
638  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
639  // template has a constexpr specifier then all its declarations shall
640  // contain the constexpr specifier.
641  if (New->isConstexpr() != Old->isConstexpr()) {
642  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
643  << New << New->isConstexpr();
644  Diag(Old->getLocation(), diag::note_previous_declaration);
645  Invalid = true;
646  } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
647  Old->isDefined(Def) &&
648  // If a friend function is inlined but does not have 'inline'
649  // specifier, it is a definition. Do not report attribute conflict
650  // in this case, redefinition will be diagnosed later.
651  (New->isInlineSpecified() ||
652  New->getFriendObjectKind() == Decl::FOK_None)) {
653  // C++11 [dcl.fcn.spec]p4:
654  // If the definition of a function appears in a translation unit before its
655  // first declaration as inline, the program is ill-formed.
656  Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
657  Diag(Def->getLocation(), diag::note_previous_definition);
658  Invalid = true;
659  }
660 
661  // FIXME: It's not clear what should happen if multiple declarations of a
662  // deduction guide have different explicitness. For now at least we simply
663  // reject any case where the explicitness changes.
664  auto *NewGuide = dyn_cast<CXXDeductionGuideDecl>(New);
665  if (NewGuide && NewGuide->isExplicitSpecified() !=
666  cast<CXXDeductionGuideDecl>(Old)->isExplicitSpecified()) {
667  Diag(New->getLocation(), diag::err_deduction_guide_explicit_mismatch)
668  << NewGuide->isExplicitSpecified();
669  Diag(Old->getLocation(), diag::note_previous_declaration);
670  }
671 
672  // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
673  // argument expression, that declaration shall be a definition and shall be
674  // the only declaration of the function or function template in the
675  // translation unit.
678  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
679  Diag(Old->getLocation(), diag::note_previous_declaration);
680  Invalid = true;
681  }
682 
683  return Invalid;
684 }
685 
686 NamedDecl *
688  MultiTemplateParamsArg TemplateParamLists) {
689  assert(D.isDecompositionDeclarator());
691 
692  // The syntax only allows a decomposition declarator as a simple-declaration,
693  // a for-range-declaration, or a condition in Clang, but we parse it in more
694  // cases than that.
696  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
697  << Decomp.getSourceRange();
698  return nullptr;
699  }
700 
701  if (!TemplateParamLists.empty()) {
702  // FIXME: There's no rule against this, but there are also no rules that
703  // would actually make it usable, so we reject it for now.
704  Diag(TemplateParamLists.front()->getTemplateLoc(),
705  diag::err_decomp_decl_template);
706  return nullptr;
707  }
708 
709  Diag(Decomp.getLSquareLoc(),
710  !getLangOpts().CPlusPlus17
711  ? diag::ext_decomp_decl
713  ? diag::ext_decomp_decl_cond
714  : diag::warn_cxx14_compat_decomp_decl)
715  << Decomp.getSourceRange();
716 
717  // The semantic context is always just the current context.
718  DeclContext *const DC = CurContext;
719 
720  // C++1z [dcl.dcl]/8:
721  // The decl-specifier-seq shall contain only the type-specifier auto
722  // and cv-qualifiers.
723  auto &DS = D.getDeclSpec();
724  {
725  SmallVector<StringRef, 8> BadSpecifiers;
726  SmallVector<SourceLocation, 8> BadSpecifierLocs;
727  if (auto SCS = DS.getStorageClassSpec()) {
728  BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
729  BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
730  }
731  if (auto TSCS = DS.getThreadStorageClassSpec()) {
732  BadSpecifiers.push_back(DeclSpec::getSpecifierName(TSCS));
733  BadSpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
734  }
735  if (DS.isConstexprSpecified()) {
736  BadSpecifiers.push_back("constexpr");
737  BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
738  }
739  if (DS.isInlineSpecified()) {
740  BadSpecifiers.push_back("inline");
741  BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
742  }
743  if (!BadSpecifiers.empty()) {
744  auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
745  Err << (int)BadSpecifiers.size()
746  << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
747  // Don't add FixItHints to remove the specifiers; we do still respect
748  // them when building the underlying variable.
749  for (auto Loc : BadSpecifierLocs)
750  Err << SourceRange(Loc, Loc);
751  }
752  // We can't recover from it being declared as a typedef.
753  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
754  return nullptr;
755  }
756 
757  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
758  QualType R = TInfo->getType();
759 
760  if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
761  UPPC_DeclarationType))
762  D.setInvalidType();
763 
764  // The syntax only allows a single ref-qualifier prior to the decomposition
765  // declarator. No other declarator chunks are permitted. Also check the type
766  // specifier here.
767  if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
768  D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
769  (D.getNumTypeObjects() == 1 &&
771  Diag(Decomp.getLSquareLoc(),
772  (D.hasGroupingParens() ||
773  (D.getNumTypeObjects() &&
775  ? diag::err_decomp_decl_parens
776  : diag::err_decomp_decl_type)
777  << R;
778 
779  // In most cases, there's no actual problem with an explicitly-specified
780  // type, but a function type won't work here, and ActOnVariableDeclarator
781  // shouldn't be called for such a type.
782  if (R->isFunctionType())
783  D.setInvalidType();
784  }
785 
786  // Build the BindingDecls.
788 
789  // Build the BindingDecls.
790  for (auto &B : D.getDecompositionDeclarator().bindings()) {
791  // Check for name conflicts.
792  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
793  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
794  ForVisibleRedeclaration);
795  LookupName(Previous, S,
796  /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
797 
798  // It's not permitted to shadow a template parameter name.
799  if (Previous.isSingleResult() &&
800  Previous.getFoundDecl()->isTemplateParameter()) {
801  DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
802  Previous.getFoundDecl());
803  Previous.clear();
804  }
805 
806  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
807  DS.getStorageClassSpec() == DeclSpec::SCS_extern;
808  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
809  /*AllowInlineNamespace*/false);
810  if (!Previous.empty()) {
811  auto *Old = Previous.getRepresentativeDecl();
812  Diag(B.NameLoc, diag::err_redefinition) << B.Name;
813  Diag(Old->getLocation(), diag::note_previous_definition);
814  }
815 
816  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
817  PushOnScopeChains(BD, S, true);
818  Bindings.push_back(BD);
819  ParsingInitForAutoVars.insert(BD);
820  }
821 
822  // There are no prior lookup results for the variable itself, because it
823  // is unnamed.
824  DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
825  Decomp.getLSquareLoc());
826  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
827  ForVisibleRedeclaration);
828 
829  // Build the variable that holds the non-decomposed object.
830  bool AddToScope = true;
831  NamedDecl *New =
832  ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
833  MultiTemplateParamsArg(), AddToScope, Bindings);
834  if (AddToScope) {
835  S->AddDecl(New);
836  CurContext->addHiddenDecl(New);
837  }
838 
839  if (isInOpenMPDeclareTargetContext())
840  checkDeclIsAllowedInOpenMPTarget(nullptr, New);
841 
842  return New;
843 }
844 
846  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
847  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
848  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
849  if ((int64_t)Bindings.size() != NumElems) {
850  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
851  << DecompType << (unsigned)Bindings.size() << NumElems.toString(10)
852  << (NumElems < Bindings.size());
853  return true;
854  }
855 
856  unsigned I = 0;
857  for (auto *B : Bindings) {
858  SourceLocation Loc = B->getLocation();
859  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
860  if (E.isInvalid())
861  return true;
862  E = GetInit(Loc, E.get(), I++);
863  if (E.isInvalid())
864  return true;
865  B->setBinding(ElemType, E.get());
866  }
867 
868  return false;
869 }
870 
872  ArrayRef<BindingDecl *> Bindings,
873  ValueDecl *Src, QualType DecompType,
874  const llvm::APSInt &NumElems,
875  QualType ElemType) {
877  S, Bindings, Src, DecompType, NumElems, ElemType,
878  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
879  ExprResult E = S.ActOnIntegerConstant(Loc, I);
880  if (E.isInvalid())
881  return ExprError();
882  return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
883  });
884 }
885 
887  ValueDecl *Src, QualType DecompType,
888  const ConstantArrayType *CAT) {
889  return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
890  llvm::APSInt(CAT->getSize()),
891  CAT->getElementType());
892 }
893 
895  ValueDecl *Src, QualType DecompType,
896  const VectorType *VT) {
898  S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
900  DecompType.getQualifiers()));
901 }
902 
904  ArrayRef<BindingDecl *> Bindings,
905  ValueDecl *Src, QualType DecompType,
906  const ComplexType *CT) {
908  S, Bindings, Src, DecompType, llvm::APSInt::get(2),
910  DecompType.getQualifiers()),
911  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
912  return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
913  });
914 }
915 
917  TemplateArgumentListInfo &Args) {
918  SmallString<128> SS;
919  llvm::raw_svector_ostream OS(SS);
920  bool First = true;
921  for (auto &Arg : Args.arguments()) {
922  if (!First)
923  OS << ", ";
924  Arg.getArgument().print(PrintingPolicy, OS);
925  First = false;
926  }
927  return OS.str();
928 }
929 
930 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
931  SourceLocation Loc, StringRef Trait,
933  unsigned DiagID) {
934  auto DiagnoseMissing = [&] {
935  if (DiagID)
936  S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
937  Args);
938  return true;
939  };
940 
941  // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
943  if (!Std)
944  return DiagnoseMissing();
945 
946  // Look up the trait itself, within namespace std. We can diagnose various
947  // problems with this lookup even if we've been asked to not diagnose a
948  // missing specialization, because this can only fail if the user has been
949  // declaring their own names in namespace std or we don't support the
950  // standard library implementation in use.
953  if (!S.LookupQualifiedName(Result, Std))
954  return DiagnoseMissing();
955  if (Result.isAmbiguous())
956  return true;
957 
958  ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
959  if (!TraitTD) {
960  Result.suppressDiagnostics();
961  NamedDecl *Found = *Result.begin();
962  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
963  S.Diag(Found->getLocation(), diag::note_declared_at);
964  return true;
965  }
966 
967  // Build the template-id.
968  QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
969  if (TraitTy.isNull())
970  return true;
971  if (!S.isCompleteType(Loc, TraitTy)) {
972  if (DiagID)
974  Loc, TraitTy, DiagID,
976  return true;
977  }
978 
979  CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
980  assert(RD && "specialization of class template is not a class?");
981 
982  // Look up the member of the trait type.
983  S.LookupQualifiedName(TraitMemberLookup, RD);
984  return TraitMemberLookup.isAmbiguous();
985 }
986 
987 static TemplateArgumentLoc
989  uint64_t I) {
990  TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
991  return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
992 }
993 
994 static TemplateArgumentLoc
997 }
998 
999 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1000 
1002  llvm::APSInt &Size) {
1005 
1007  LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1008 
1009  // Form template argument list for tuple_size<T>.
1010  TemplateArgumentListInfo Args(Loc, Loc);
1012 
1013  // If there's no tuple_size specialization, it's not tuple-like.
1014  if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/0))
1015  return IsTupleLike::NotTupleLike;
1016 
1017  // If we get this far, we've committed to the tuple interpretation, but
1018  // we can still fail if there actually isn't a usable ::value.
1019 
1020  struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1021  LookupResult &R;
1023  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1024  : R(R), Args(Args) {}
1025  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) {
1026  S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1028  }
1029  } Diagnoser(R, Args);
1030 
1031  if (R.empty()) {
1032  Diagnoser.diagnoseNotICE(S, Loc, SourceRange());
1033  return IsTupleLike::Error;
1034  }
1035 
1036  ExprResult E =
1037  S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1038  if (E.isInvalid())
1039  return IsTupleLike::Error;
1040 
1041  E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser, false);
1042  if (E.isInvalid())
1043  return IsTupleLike::Error;
1044 
1045  return IsTupleLike::TupleLike;
1046 }
1047 
1048 /// \return std::tuple_element<I, T>::type.
1050  unsigned I, QualType T) {
1051  // Form template argument list for tuple_element<I, T>.
1052  TemplateArgumentListInfo Args(Loc, Loc);
1053  Args.addArgument(
1056 
1057  DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1058  LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1060  S, R, Loc, "tuple_element", Args,
1061  diag::err_decomp_decl_std_tuple_element_not_specialized))
1062  return QualType();
1063 
1064  auto *TD = R.getAsSingle<TypeDecl>();
1065  if (!TD) {
1066  R.suppressDiagnostics();
1067  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1069  if (!R.empty())
1070  S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1071  return QualType();
1072  }
1073 
1074  return S.Context.getTypeDeclType(TD);
1075 }
1076 
1077 namespace {
1078 struct BindingDiagnosticTrap {
1079  Sema &S;
1080  DiagnosticErrorTrap Trap;
1081  BindingDecl *BD;
1082 
1083  BindingDiagnosticTrap(Sema &S, BindingDecl *BD)
1084  : S(S), Trap(S.Diags), BD(BD) {}
1085  ~BindingDiagnosticTrap() {
1086  if (Trap.hasErrorOccurred())
1087  S.Diag(BD->getLocation(), diag::note_in_binding_decl_init) << BD;
1088  }
1089 };
1090 }
1091 
1093  ArrayRef<BindingDecl *> Bindings,
1094  VarDecl *Src, QualType DecompType,
1095  const llvm::APSInt &TupleSize) {
1096  if ((int64_t)Bindings.size() != TupleSize) {
1097  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1098  << DecompType << (unsigned)Bindings.size() << TupleSize.toString(10)
1099  << (TupleSize < Bindings.size());
1100  return true;
1101  }
1102 
1103  if (Bindings.empty())
1104  return false;
1105 
1106  DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1107 
1108  // [dcl.decomp]p3:
1109  // The unqualified-id get is looked up in the scope of E by class member
1110  // access lookup ...
1111  LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1112  bool UseMemberGet = false;
1113  if (S.isCompleteType(Src->getLocation(), DecompType)) {
1114  if (auto *RD = DecompType->getAsCXXRecordDecl())
1115  S.LookupQualifiedName(MemberGet, RD);
1116  if (MemberGet.isAmbiguous())
1117  return true;
1118  // ... and if that finds at least one declaration that is a function
1119  // template whose first template parameter is a non-type parameter ...
1120  for (NamedDecl *D : MemberGet) {
1121  if (FunctionTemplateDecl *FTD =
1122  dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1123  TemplateParameterList *TPL = FTD->getTemplateParameters();
1124  if (TPL->size() != 0 &&
1125  isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1126  // ... the initializer is e.get<i>().
1127  UseMemberGet = true;
1128  break;
1129  }
1130  }
1131  }
1132  S.FilterAcceptableTemplateNames(MemberGet);
1133  }
1134 
1135  unsigned I = 0;
1136  for (auto *B : Bindings) {
1137  BindingDiagnosticTrap Trap(S, B);
1138  SourceLocation Loc = B->getLocation();
1139 
1140  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1141  if (E.isInvalid())
1142  return true;
1143 
1144  // e is an lvalue if the type of the entity is an lvalue reference and
1145  // an xvalue otherwise
1146  if (!Src->getType()->isLValueReferenceType())
1147  E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1148  E.get(), nullptr, VK_XValue);
1149 
1150  TemplateArgumentListInfo Args(Loc, Loc);
1151  Args.addArgument(
1153 
1154  if (UseMemberGet) {
1155  // if [lookup of member get] finds at least one declaration, the
1156  // initializer is e.get<i-1>().
1157  E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1158  CXXScopeSpec(), SourceLocation(), nullptr,
1159  MemberGet, &Args, nullptr);
1160  if (E.isInvalid())
1161  return true;
1162 
1163  E = S.ActOnCallExpr(nullptr, E.get(), Loc, None, Loc);
1164  } else {
1165  // Otherwise, the initializer is get<i-1>(e), where get is looked up
1166  // in the associated namespaces.
1169  DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1171 
1172  Expr *Arg = E.get();
1173  E = S.ActOnCallExpr(nullptr, Get, Loc, Arg, Loc);
1174  }
1175  if (E.isInvalid())
1176  return true;
1177  Expr *Init = E.get();
1178 
1179  // Given the type T designated by std::tuple_element<i - 1, E>::type,
1180  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1181  if (T.isNull())
1182  return true;
1183 
1184  // each vi is a variable of type "reference to T" initialized with the
1185  // initializer, where the reference is an lvalue reference if the
1186  // initializer is an lvalue and an rvalue reference otherwise
1187  QualType RefType =
1188  S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1189  if (RefType.isNull())
1190  return true;
1191  auto *RefVD = VarDecl::Create(
1192  S.Context, Src->getDeclContext(), Loc, Loc,
1193  B->getDeclName().getAsIdentifierInfo(), RefType,
1196  RefVD->setTSCSpec(Src->getTSCSpec());
1197  RefVD->setImplicit();
1198  if (Src->isInlineSpecified())
1199  RefVD->setInlineSpecified();
1200  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1201 
1204  InitializationSequence Seq(S, Entity, Kind, Init);
1205  E = Seq.Perform(S, Entity, Kind, Init);
1206  if (E.isInvalid())
1207  return true;
1208  E = S.ActOnFinishFullExpr(E.get(), Loc);
1209  if (E.isInvalid())
1210  return true;
1211  RefVD->setInit(E.get());
1212  RefVD->checkInitIsICE();
1213 
1215  DeclarationNameInfo(B->getDeclName(), Loc),
1216  RefVD);
1217  if (E.isInvalid())
1218  return true;
1219 
1220  B->setBinding(T, E.get());
1221  I++;
1222  }
1223 
1224  return false;
1225 }
1226 
1227 /// Find the base class to decompose in a built-in decomposition of a class type.
1228 /// This base class search is, unfortunately, not quite like any other that we
1229 /// perform anywhere else in C++.
1231  const CXXRecordDecl *RD,
1232  CXXCastPath &BasePath) {
1233  auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1234  CXXBasePath &Path) {
1235  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1236  };
1237 
1238  const CXXRecordDecl *ClassWithFields = nullptr;
1240  if (RD->hasDirectFields())
1241  // [dcl.decomp]p4:
1242  // Otherwise, all of E's non-static data members shall be public direct
1243  // members of E ...
1244  ClassWithFields = RD;
1245  else {
1246  // ... or of ...
1247  CXXBasePaths Paths;
1248  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1249  if (!RD->lookupInBases(BaseHasFields, Paths)) {
1250  // If no classes have fields, just decompose RD itself. (This will work
1251  // if and only if zero bindings were provided.)
1252  return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1253  }
1254 
1255  CXXBasePath *BestPath = nullptr;
1256  for (auto &P : Paths) {
1257  if (!BestPath)
1258  BestPath = &P;
1259  else if (!S.Context.hasSameType(P.back().Base->getType(),
1260  BestPath->back().Base->getType())) {
1261  // ... the same ...
1262  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1263  << false << RD << BestPath->back().Base->getType()
1264  << P.back().Base->getType();
1265  return DeclAccessPair();
1266  } else if (P.Access < BestPath->Access) {
1267  BestPath = &P;
1268  }
1269  }
1270 
1271  // ... unambiguous ...
1272  QualType BaseType = BestPath->back().Base->getType();
1273  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1274  S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1275  << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1276  return DeclAccessPair();
1277  }
1278 
1279  // ... [accessible, implied by other rules] base class of E.
1280  S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1281  *BestPath, diag::err_decomp_decl_inaccessible_base);
1282  AS = BestPath->Access;
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 DeclAccessPair();
1296  }
1297 
1298  return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1299 }
1300 
1302  ValueDecl *Src, QualType DecompType,
1303  const CXXRecordDecl *OrigRD) {
1304  CXXCastPath BasePath;
1305  DeclAccessPair BasePair =
1306  findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1307  const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1308  if (!RD)
1309  return true;
1311  DecompType.getQualifiers());
1312 
1313  auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1314  unsigned NumFields =
1315  std::count_if(RD->field_begin(), RD->field_end(),
1316  [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1317  assert(Bindings.size() != NumFields);
1318  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1319  << DecompType << (unsigned)Bindings.size() << NumFields
1320  << (NumFields < Bindings.size());
1321  return true;
1322  };
1323 
1324  // all of E's non-static data members shall be [...] well-formed
1325  // when named as e.name in the context of the structured binding,
1326  // E shall not have an anonymous union member, ...
1327  unsigned I = 0;
1328  for (auto *FD : RD->fields()) {
1329  if (FD->isUnnamedBitfield())
1330  continue;
1331 
1332  if (FD->isAnonymousStructOrUnion()) {
1333  S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1334  << DecompType << FD->getType()->isUnionType();
1335  S.Diag(FD->getLocation(), diag::note_declared_at);
1336  return true;
1337  }
1338 
1339  // We have a real field to bind.
1340  if (I >= Bindings.size())
1341  return DiagnoseBadNumberOfBindings();
1342  auto *B = Bindings[I++];
1343  SourceLocation Loc = B->getLocation();
1344 
1345  // The field must be accessible in the context of the structured binding.
1346  // We already checked that the base class is accessible.
1347  // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1348  // const_cast here.
1350  Loc, const_cast<CXXRecordDecl *>(OrigRD),
1352  BasePair.getAccess(), FD->getAccess())));
1353 
1354  // Initialize the binding to Src.FD.
1355  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1356  if (E.isInvalid())
1357  return true;
1358  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1359  VK_LValue, &BasePath);
1360  if (E.isInvalid())
1361  return true;
1362  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1363  CXXScopeSpec(), FD,
1364  DeclAccessPair::make(FD, FD->getAccess()),
1365  DeclarationNameInfo(FD->getDeclName(), Loc));
1366  if (E.isInvalid())
1367  return true;
1368 
1369  // If the type of the member is T, the referenced type is cv T, where cv is
1370  // the cv-qualification of the decomposition expression.
1371  //
1372  // FIXME: We resolve a defect here: if the field is mutable, we do not add
1373  // 'const' to the type of the field.
1374  Qualifiers Q = DecompType.getQualifiers();
1375  if (FD->isMutable())
1376  Q.removeConst();
1377  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1378  }
1379 
1380  if (I != Bindings.size())
1381  return DiagnoseBadNumberOfBindings();
1382 
1383  return false;
1384 }
1385 
1387  QualType DecompType = DD->getType();
1388 
1389  // If the type of the decomposition is dependent, then so is the type of
1390  // each binding.
1391  if (DecompType->isDependentType()) {
1392  for (auto *B : DD->bindings())
1393  B->setType(Context.DependentTy);
1394  return;
1395  }
1396 
1397  DecompType = DecompType.getNonReferenceType();
1398  ArrayRef<BindingDecl*> Bindings = DD->bindings();
1399 
1400  // C++1z [dcl.decomp]/2:
1401  // If E is an array type [...]
1402  // As an extension, we also support decomposition of built-in complex and
1403  // vector types.
1404  if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1405  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1406  DD->setInvalidDecl();
1407  return;
1408  }
1409  if (auto *VT = DecompType->getAs<VectorType>()) {
1410  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1411  DD->setInvalidDecl();
1412  return;
1413  }
1414  if (auto *CT = DecompType->getAs<ComplexType>()) {
1415  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1416  DD->setInvalidDecl();
1417  return;
1418  }
1419 
1420  // C++1z [dcl.decomp]/3:
1421  // if the expression std::tuple_size<E>::value is a well-formed integral
1422  // constant expression, [...]
1423  llvm::APSInt TupleSize(32);
1424  switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1425  case IsTupleLike::Error:
1426  DD->setInvalidDecl();
1427  return;
1428 
1429  case IsTupleLike::TupleLike:
1430  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1431  DD->setInvalidDecl();
1432  return;
1433 
1434  case IsTupleLike::NotTupleLike:
1435  break;
1436  }
1437 
1438  // C++1z [dcl.dcl]/8:
1439  // [E shall be of array or non-union class type]
1440  CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1441  if (!RD || RD->isUnion()) {
1442  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1443  << DD << !RD << DecompType;
1444  DD->setInvalidDecl();
1445  return;
1446  }
1447 
1448  // C++1z [dcl.decomp]/4:
1449  // all of E's non-static data members shall be [...] direct members of
1450  // E or of the same unambiguous public base class of E, ...
1451  if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1452  DD->setInvalidDecl();
1453 }
1454 
1455 /// Merge the exception specifications of two variable declarations.
1456 ///
1457 /// This is called when there's a redeclaration of a VarDecl. The function
1458 /// checks if the redeclaration might have an exception specification and
1459 /// validates compatibility and merges the specs if necessary.
1461  // Shortcut if exceptions are disabled.
1462  if (!getLangOpts().CXXExceptions)
1463  return;
1464 
1465  assert(Context.hasSameType(New->getType(), Old->getType()) &&
1466  "Should only be called if types are otherwise the same.");
1467 
1468  QualType NewType = New->getType();
1469  QualType OldType = Old->getType();
1470 
1471  // We're only interested in pointers and references to functions, as well
1472  // as pointers to member functions.
1473  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1474  NewType = R->getPointeeType();
1475  OldType = OldType->getAs<ReferenceType>()->getPointeeType();
1476  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1477  NewType = P->getPointeeType();
1478  OldType = OldType->getAs<PointerType>()->getPointeeType();
1479  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1480  NewType = M->getPointeeType();
1481  OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
1482  }
1483 
1484  if (!NewType->isFunctionProtoType())
1485  return;
1486 
1487  // There's lots of special cases for functions. For function pointers, system
1488  // libraries are hopefully not as broken so that we don't need these
1489  // workarounds.
1490  if (CheckEquivalentExceptionSpec(
1491  OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1492  NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1493  New->setInvalidDecl();
1494  }
1495 }
1496 
1497 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1498 /// function declaration are well-formed according to C++
1499 /// [dcl.fct.default].
1501  unsigned NumParams = FD->getNumParams();
1502  unsigned p;
1503 
1504  // Find first parameter with a default argument
1505  for (p = 0; p < NumParams; ++p) {
1506  ParmVarDecl *Param = FD->getParamDecl(p);
1507  if (Param->hasDefaultArg())
1508  break;
1509  }
1510 
1511  // C++11 [dcl.fct.default]p4:
1512  // In a given function declaration, each parameter subsequent to a parameter
1513  // with a default argument shall have a default argument supplied in this or
1514  // a previous declaration or shall be a function parameter pack. A default
1515  // argument shall not be redefined by a later declaration (not even to the
1516  // same value).
1517  unsigned LastMissingDefaultArg = 0;
1518  for (; p < NumParams; ++p) {
1519  ParmVarDecl *Param = FD->getParamDecl(p);
1520  if (!Param->hasDefaultArg() && !Param->isParameterPack()) {
1521  if (Param->isInvalidDecl())
1522  /* We already complained about this parameter. */;
1523  else if (Param->getIdentifier())
1524  Diag(Param->getLocation(),
1525  diag::err_param_default_argument_missing_name)
1526  << Param->getIdentifier();
1527  else
1528  Diag(Param->getLocation(),
1529  diag::err_param_default_argument_missing);
1530 
1531  LastMissingDefaultArg = p;
1532  }
1533  }
1534 
1535  if (LastMissingDefaultArg > 0) {
1536  // Some default arguments were missing. Clear out all of the
1537  // default arguments up to (and including) the last missing
1538  // default argument, so that we leave the function parameters
1539  // in a semantically valid state.
1540  for (p = 0; p <= LastMissingDefaultArg; ++p) {
1541  ParmVarDecl *Param = FD->getParamDecl(p);
1542  if (Param->hasDefaultArg()) {
1543  Param->setDefaultArg(nullptr);
1544  }
1545  }
1546  }
1547 }
1548 
1549 // CheckConstexprParameterTypes - Check whether a function's parameter types
1550 // are all literal types. If so, return true. If not, produce a suitable
1551 // diagnostic and return false.
1552 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1553  const FunctionDecl *FD) {
1554  unsigned ArgIndex = 0;
1555  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
1557  e = FT->param_type_end();
1558  i != e; ++i, ++ArgIndex) {
1559  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1560  SourceLocation ParamLoc = PD->getLocation();
1561  if (!(*i)->isDependentType() &&
1562  SemaRef.RequireLiteralType(ParamLoc, *i,
1563  diag::err_constexpr_non_literal_param,
1564  ArgIndex+1, PD->getSourceRange(),
1565  isa<CXXConstructorDecl>(FD)))
1566  return false;
1567  }
1568  return true;
1569 }
1570 
1571 /// Get diagnostic %select index for tag kind for
1572 /// record diagnostic message.
1573 /// WARNING: Indexes apply to particular diagnostics only!
1574 ///
1575 /// \returns diagnostic %select index.
1577  switch (Tag) {
1578  case TTK_Struct: return 0;
1579  case TTK_Interface: return 1;
1580  case TTK_Class: return 2;
1581  default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1582  }
1583 }
1584 
1585 // CheckConstexprFunctionDecl - Check whether a function declaration satisfies
1586 // the requirements of a constexpr function definition or a constexpr
1587 // constructor definition. If so, return true. If not, produce appropriate
1588 // diagnostics and return false.
1589 //
1590 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1592  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1593  if (MD && MD->isInstance()) {
1594  // C++11 [dcl.constexpr]p4:
1595  // The definition of a constexpr constructor shall satisfy the following
1596  // constraints:
1597  // - the class shall not have any virtual base classes;
1598  const CXXRecordDecl *RD = MD->getParent();
1599  if (RD->getNumVBases()) {
1600  Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1601  << isa<CXXConstructorDecl>(NewFD)
1603  for (const auto &I : RD->vbases())
1604  Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1605  << I.getSourceRange();
1606  return false;
1607  }
1608  }
1609 
1610  if (!isa<CXXConstructorDecl>(NewFD)) {
1611  // C++11 [dcl.constexpr]p3:
1612  // The definition of a constexpr function shall satisfy the following
1613  // constraints:
1614  // - it shall not be virtual;
1615  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1616  if (Method && Method->isVirtual()) {
1617  Method = Method->getCanonicalDecl();
1618  Diag(Method->getLocation(), diag::err_constexpr_virtual);
1619 
1620  // If it's not obvious why this function is virtual, find an overridden
1621  // function which uses the 'virtual' keyword.
1622  const CXXMethodDecl *WrittenVirtual = Method;
1623  while (!WrittenVirtual->isVirtualAsWritten())
1624  WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1625  if (WrittenVirtual != Method)
1626  Diag(WrittenVirtual->getLocation(),
1627  diag::note_overridden_virtual_function);
1628  return false;
1629  }
1630 
1631  // - its return type shall be a literal type;
1632  QualType RT = NewFD->getReturnType();
1633  if (!RT->isDependentType() &&
1634  RequireLiteralType(NewFD->getLocation(), RT,
1635  diag::err_constexpr_non_literal_return))
1636  return false;
1637  }
1638 
1639  // - each of its parameter types shall be a literal type;
1640  if (!CheckConstexprParameterTypes(*this, NewFD))
1641  return false;
1642 
1643  return true;
1644 }
1645 
1646 /// Check the given declaration statement is legal within a constexpr function
1647 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1648 ///
1649 /// \return true if the body is OK (maybe only as an extension), false if we
1650 /// have diagnosed a problem.
1651 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1652  DeclStmt *DS, SourceLocation &Cxx1yLoc) {
1653  // C++11 [dcl.constexpr]p3 and p4:
1654  // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1655  // contain only
1656  for (const auto *DclIt : DS->decls()) {
1657  switch (DclIt->getKind()) {
1658  case Decl::StaticAssert:
1659  case Decl::Using:
1660  case Decl::UsingShadow:
1661  case Decl::UsingDirective:
1662  case Decl::UnresolvedUsingTypename:
1663  case Decl::UnresolvedUsingValue:
1664  // - static_assert-declarations
1665  // - using-declarations,
1666  // - using-directives,
1667  continue;
1668 
1669  case Decl::Typedef:
1670  case Decl::TypeAlias: {
1671  // - typedef declarations and alias-declarations that do not define
1672  // classes or enumerations,
1673  const auto *TN = cast<TypedefNameDecl>(DclIt);
1674  if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1675  // Don't allow variably-modified types in constexpr functions.
1676  TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1677  SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1678  << TL.getSourceRange() << TL.getType()
1679  << isa<CXXConstructorDecl>(Dcl);
1680  return false;
1681  }
1682  continue;
1683  }
1684 
1685  case Decl::Enum:
1686  case Decl::CXXRecord:
1687  // C++1y allows types to be defined, not just declared.
1688  if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition())
1689  SemaRef.Diag(DS->getBeginLoc(),
1690  SemaRef.getLangOpts().CPlusPlus14
1691  ? diag::warn_cxx11_compat_constexpr_type_definition
1692  : diag::ext_constexpr_type_definition)
1693  << isa<CXXConstructorDecl>(Dcl);
1694  continue;
1695 
1696  case Decl::EnumConstant:
1697  case Decl::IndirectField:
1698  case Decl::ParmVar:
1699  // These can only appear with other declarations which are banned in
1700  // C++11 and permitted in C++1y, so ignore them.
1701  continue;
1702 
1703  case Decl::Var:
1704  case Decl::Decomposition: {
1705  // C++1y [dcl.constexpr]p3 allows anything except:
1706  // a definition of a variable of non-literal type or of static or
1707  // thread storage duration or for which no initialization is performed.
1708  const auto *VD = cast<VarDecl>(DclIt);
1709  if (VD->isThisDeclarationADefinition()) {
1710  if (VD->isStaticLocal()) {
1711  SemaRef.Diag(VD->getLocation(),
1712  diag::err_constexpr_local_var_static)
1713  << isa<CXXConstructorDecl>(Dcl)
1714  << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1715  return false;
1716  }
1717  if (!VD->getType()->isDependentType() &&
1718  SemaRef.RequireLiteralType(
1719  VD->getLocation(), VD->getType(),
1720  diag::err_constexpr_local_var_non_literal_type,
1721  isa<CXXConstructorDecl>(Dcl)))
1722  return false;
1723  if (!VD->getType()->isDependentType() &&
1724  !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1725  SemaRef.Diag(VD->getLocation(),
1726  diag::err_constexpr_local_var_no_init)
1727  << isa<CXXConstructorDecl>(Dcl);
1728  return false;
1729  }
1730  }
1731  SemaRef.Diag(VD->getLocation(),
1732  SemaRef.getLangOpts().CPlusPlus14
1733  ? diag::warn_cxx11_compat_constexpr_local_var
1734  : diag::ext_constexpr_local_var)
1735  << isa<CXXConstructorDecl>(Dcl);
1736  continue;
1737  }
1738 
1739  case Decl::NamespaceAlias:
1740  case Decl::Function:
1741  // These are disallowed in C++11 and permitted in C++1y. Allow them
1742  // everywhere as an extension.
1743  if (!Cxx1yLoc.isValid())
1744  Cxx1yLoc = DS->getBeginLoc();
1745  continue;
1746 
1747  default:
1748  SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1749  << isa<CXXConstructorDecl>(Dcl);
1750  return false;
1751  }
1752  }
1753 
1754  return true;
1755 }
1756 
1757 /// Check that the given field is initialized within a constexpr constructor.
1758 ///
1759 /// \param Dcl The constexpr constructor being checked.
1760 /// \param Field The field being checked. This may be a member of an anonymous
1761 /// struct or union nested within the class being checked.
1762 /// \param Inits All declarations, including anonymous struct/union members and
1763 /// indirect members, for which any initialization was provided.
1764 /// \param Diagnosed Set to true if an error is produced.
1766  const FunctionDecl *Dcl,
1767  FieldDecl *Field,
1768  llvm::SmallSet<Decl*, 16> &Inits,
1769  bool &Diagnosed) {
1770  if (Field->isInvalidDecl())
1771  return;
1772 
1773  if (Field->isUnnamedBitfield())
1774  return;
1775 
1776  // Anonymous unions with no variant members and empty anonymous structs do not
1777  // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1778  // indirect fields don't need initializing.
1779  if (Field->isAnonymousStructOrUnion() &&
1780  (Field->getType()->isUnionType()
1781  ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1782  : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1783  return;
1784 
1785  if (!Inits.count(Field)) {
1786  if (!Diagnosed) {
1787  SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
1788  Diagnosed = true;
1789  }
1790  SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
1791  } else if (Field->isAnonymousStructOrUnion()) {
1792  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1793  for (auto *I : RD->fields())
1794  // If an anonymous union contains an anonymous struct of which any member
1795  // is initialized, all members must be initialized.
1796  if (!RD->isUnion() || Inits.count(I))
1797  CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed);
1798  }
1799 }
1800 
1801 /// Check the provided statement is allowed in a constexpr function
1802 /// definition.
1803 static bool
1805  SmallVectorImpl<SourceLocation> &ReturnStmts,
1806  SourceLocation &Cxx1yLoc) {
1807  // - its function-body shall be [...] a compound-statement that contains only
1808  switch (S->getStmtClass()) {
1809  case Stmt::NullStmtClass:
1810  // - null statements,
1811  return true;
1812 
1813  case Stmt::DeclStmtClass:
1814  // - static_assert-declarations
1815  // - using-declarations,
1816  // - using-directives,
1817  // - typedef declarations and alias-declarations that do not define
1818  // classes or enumerations,
1819  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc))
1820  return false;
1821  return true;
1822 
1823  case Stmt::ReturnStmtClass:
1824  // - and exactly one return statement;
1825  if (isa<CXXConstructorDecl>(Dcl)) {
1826  // C++1y allows return statements in constexpr constructors.
1827  if (!Cxx1yLoc.isValid())
1828  Cxx1yLoc = S->getBeginLoc();
1829  return true;
1830  }
1831 
1832  ReturnStmts.push_back(S->getBeginLoc());
1833  return true;
1834 
1835  case Stmt::CompoundStmtClass: {
1836  // C++1y allows compound-statements.
1837  if (!Cxx1yLoc.isValid())
1838  Cxx1yLoc = S->getBeginLoc();
1839 
1840  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
1841  for (auto *BodyIt : CompStmt->body()) {
1842  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
1843  Cxx1yLoc))
1844  return false;
1845  }
1846  return true;
1847  }
1848 
1849  case Stmt::AttributedStmtClass:
1850  if (!Cxx1yLoc.isValid())
1851  Cxx1yLoc = S->getBeginLoc();
1852  return true;
1853 
1854  case Stmt::IfStmtClass: {
1855  // C++1y allows if-statements.
1856  if (!Cxx1yLoc.isValid())
1857  Cxx1yLoc = S->getBeginLoc();
1858 
1859  IfStmt *If = cast<IfStmt>(S);
1860  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
1861  Cxx1yLoc))
1862  return false;
1863  if (If->getElse() &&
1864  !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
1865  Cxx1yLoc))
1866  return false;
1867  return true;
1868  }
1869 
1870  case Stmt::WhileStmtClass:
1871  case Stmt::DoStmtClass:
1872  case Stmt::ForStmtClass:
1873  case Stmt::CXXForRangeStmtClass:
1874  case Stmt::ContinueStmtClass:
1875  // C++1y allows all of these. We don't allow them as extensions in C++11,
1876  // because they don't make sense without variable mutation.
1877  if (!SemaRef.getLangOpts().CPlusPlus14)
1878  break;
1879  if (!Cxx1yLoc.isValid())
1880  Cxx1yLoc = S->getBeginLoc();
1881  for (Stmt *SubStmt : S->children())
1882  if (SubStmt &&
1883  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1884  Cxx1yLoc))
1885  return false;
1886  return true;
1887 
1888  case Stmt::SwitchStmtClass:
1889  case Stmt::CaseStmtClass:
1890  case Stmt::DefaultStmtClass:
1891  case Stmt::BreakStmtClass:
1892  // C++1y allows switch-statements, and since they don't need variable
1893  // mutation, we can reasonably allow them in C++11 as an extension.
1894  if (!Cxx1yLoc.isValid())
1895  Cxx1yLoc = S->getBeginLoc();
1896  for (Stmt *SubStmt : S->children())
1897  if (SubStmt &&
1898  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1899  Cxx1yLoc))
1900  return false;
1901  return true;
1902 
1903  default:
1904  if (!isa<Expr>(S))
1905  break;
1906 
1907  // C++1y allows expression-statements.
1908  if (!Cxx1yLoc.isValid())
1909  Cxx1yLoc = S->getBeginLoc();
1910  return true;
1911  }
1912 
1913  SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1914  << isa<CXXConstructorDecl>(Dcl);
1915  return false;
1916 }
1917 
1918 /// Check the body for the given constexpr function declaration only contains
1919 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
1920 ///
1921 /// \return true if the body is OK, false if we have diagnosed a problem.
1923  if (isa<CXXTryStmt>(Body)) {
1924  // C++11 [dcl.constexpr]p3:
1925  // The definition of a constexpr function shall satisfy the following
1926  // constraints: [...]
1927  // - its function-body shall be = delete, = default, or a
1928  // compound-statement
1929  //
1930  // C++11 [dcl.constexpr]p4:
1931  // In the definition of a constexpr constructor, [...]
1932  // - its function-body shall not be a function-try-block;
1933  Diag(Body->getBeginLoc(), diag::err_constexpr_function_try_block)
1934  << isa<CXXConstructorDecl>(Dcl);
1935  return false;
1936  }
1937 
1938  SmallVector<SourceLocation, 4> ReturnStmts;
1939 
1940  // - its function-body shall be [...] a compound-statement that contains only
1941  // [... list of cases ...]
1942  CompoundStmt *CompBody = cast<CompoundStmt>(Body);
1943  SourceLocation Cxx1yLoc;
1944  for (auto *BodyIt : CompBody->body()) {
1945  if (!CheckConstexprFunctionStmt(*this, Dcl, BodyIt, ReturnStmts, Cxx1yLoc))
1946  return false;
1947  }
1948 
1949  if (Cxx1yLoc.isValid())
1950  Diag(Cxx1yLoc,
1951  getLangOpts().CPlusPlus14
1952  ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
1953  : diag::ext_constexpr_body_invalid_stmt)
1954  << isa<CXXConstructorDecl>(Dcl);
1955 
1956  if (const CXXConstructorDecl *Constructor
1957  = dyn_cast<CXXConstructorDecl>(Dcl)) {
1958  const CXXRecordDecl *RD = Constructor->getParent();
1959  // DR1359:
1960  // - every non-variant non-static data member and base class sub-object
1961  // shall be initialized;
1962  // DR1460:
1963  // - if the class is a union having variant members, exactly one of them
1964  // shall be initialized;
1965  if (RD->isUnion()) {
1966  if (Constructor->getNumCtorInitializers() == 0 &&
1967  RD->hasVariantMembers()) {
1968  Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
1969  return false;
1970  }
1971  } else if (!Constructor->isDependentContext() &&
1972  !Constructor->isDelegatingConstructor()) {
1973  assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
1974 
1975  // Skip detailed checking if we have enough initializers, and we would
1976  // allow at most one initializer per member.
1977  bool AnyAnonStructUnionMembers = false;
1978  unsigned Fields = 0;
1980  E = RD->field_end(); I != E; ++I, ++Fields) {
1981  if (I->isAnonymousStructOrUnion()) {
1982  AnyAnonStructUnionMembers = true;
1983  break;
1984  }
1985  }
1986  // DR1460:
1987  // - if the class is a union-like class, but is not a union, for each of
1988  // its anonymous union members having variant members, exactly one of
1989  // them shall be initialized;
1990  if (AnyAnonStructUnionMembers ||
1991  Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
1992  // Check initialization of non-static data members. Base classes are
1993  // always initialized so do not need to be checked. Dependent bases
1994  // might not have initializers in the member initializer list.
1995  llvm::SmallSet<Decl*, 16> Inits;
1996  for (const auto *I: Constructor->inits()) {
1997  if (FieldDecl *FD = I->getMember())
1998  Inits.insert(FD);
1999  else if (IndirectFieldDecl *ID = I->getIndirectMember())
2000  Inits.insert(ID->chain_begin(), ID->chain_end());
2001  }
2002 
2003  bool Diagnosed = false;
2004  for (auto *I : RD->fields())
2005  CheckConstexprCtorInitializer(*this, Dcl, I, Inits, Diagnosed);
2006  if (Diagnosed)
2007  return false;
2008  }
2009  }
2010  } else {
2011  if (ReturnStmts.empty()) {
2012  // C++1y doesn't require constexpr functions to contain a 'return'
2013  // statement. We still do, unless the return type might be void, because
2014  // otherwise if there's no return statement, the function cannot
2015  // be used in a core constant expression.
2016  bool OK = getLangOpts().CPlusPlus14 &&
2017  (Dcl->getReturnType()->isVoidType() ||
2018  Dcl->getReturnType()->isDependentType());
2019  Diag(Dcl->getLocation(),
2020  OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2021  : diag::err_constexpr_body_no_return);
2022  if (!OK)
2023  return false;
2024  } else if (ReturnStmts.size() > 1) {
2025  Diag(ReturnStmts.back(),
2026  getLangOpts().CPlusPlus14
2027  ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2028  : diag::ext_constexpr_body_multiple_return);
2029  for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2030  Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
2031  }
2032  }
2033 
2034  // C++11 [dcl.constexpr]p5:
2035  // if no function argument values exist such that the function invocation
2036  // substitution would produce a constant expression, the program is
2037  // ill-formed; no diagnostic required.
2038  // C++11 [dcl.constexpr]p3:
2039  // - every constructor call and implicit conversion used in initializing the
2040  // return value shall be one of those allowed in a constant expression.
2041  // C++11 [dcl.constexpr]p4:
2042  // - every constructor involved in initializing non-static data members and
2043  // base class sub-objects shall be a constexpr constructor.
2045  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
2046  Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr)
2047  << isa<CXXConstructorDecl>(Dcl);
2048  for (size_t I = 0, N = Diags.size(); I != N; ++I)
2049  Diag(Diags[I].first, Diags[I].second);
2050  // Don't return false here: we allow this for compatibility in
2051  // system headers.
2052  }
2053 
2054  return true;
2055 }
2056 
2057 /// Get the class that is directly named by the current context. This is the
2058 /// class for which an unqualified-id in this scope could name a constructor
2059 /// or destructor.
2060 ///
2061 /// If the scope specifier denotes a class, this will be that class.
2062 /// If the scope specifier is empty, this will be the class whose
2063 /// member-specification we are currently within. Otherwise, there
2064 /// is no such class.
2066  assert(getLangOpts().CPlusPlus && "No class names in C!");
2067 
2068  if (SS && SS->isInvalid())
2069  return nullptr;
2070 
2071  if (SS && SS->isNotEmpty()) {
2072  DeclContext *DC = computeDeclContext(*SS, true);
2073  return dyn_cast_or_null<CXXRecordDecl>(DC);
2074  }
2075 
2076  return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2077 }
2078 
2079 /// isCurrentClassName - Determine whether the identifier II is the
2080 /// name of the class type currently being defined. In the case of
2081 /// nested classes, this will only return true if II is the name of
2082 /// the innermost class.
2084  const CXXScopeSpec *SS) {
2085  CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2086  return CurDecl && &II == CurDecl->getIdentifier();
2087 }
2088 
2089 /// Determine whether the identifier II is a typo for the name of
2090 /// the class type currently being defined. If so, update it to the identifier
2091 /// that should have been used.
2093  assert(getLangOpts().CPlusPlus && "No class names in C!");
2094 
2095  if (!getLangOpts().SpellChecking)
2096  return false;
2097 
2098  CXXRecordDecl *CurDecl;
2099  if (SS && SS->isSet() && !SS->isInvalid()) {
2100  DeclContext *DC = computeDeclContext(*SS, true);
2101  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2102  } else
2103  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2104 
2105  if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2106  3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2107  < II->getLength()) {
2108  II = CurDecl->getIdentifier();
2109  return true;
2110  }
2111 
2112  return false;
2113 }
2114 
2115 /// Determine whether the given class is a base class of the given
2116 /// class, including looking at dependent bases.
2117 static bool findCircularInheritance(const CXXRecordDecl *Class,
2118  const CXXRecordDecl *Current) {
2120 
2121  Class = Class->getCanonicalDecl();
2122  while (true) {
2123  for (const auto &I : Current->bases()) {
2124  CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2125  if (!Base)
2126  continue;
2127 
2128  Base = Base->getDefinition();
2129  if (!Base)
2130  continue;
2131 
2132  if (Base->getCanonicalDecl() == Class)
2133  return true;
2134 
2135  Queue.push_back(Base);
2136  }
2137 
2138  if (Queue.empty())
2139  return false;
2140 
2141  Current = Queue.pop_back_val();
2142  }
2143 
2144  return false;
2145 }
2146 
2147 /// Check the validity of a C++ base class specifier.
2148 ///
2149 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2150 /// and returns NULL otherwise.
2153  SourceRange SpecifierRange,
2154  bool Virtual, AccessSpecifier Access,
2155  TypeSourceInfo *TInfo,
2156  SourceLocation EllipsisLoc) {
2157  QualType BaseType = TInfo->getType();
2158 
2159  // C++ [class.union]p1:
2160  // A union shall not have base classes.
2161  if (Class->isUnion()) {
2162  Diag(Class->getLocation(), diag::err_base_clause_on_union)
2163  << SpecifierRange;
2164  return nullptr;
2165  }
2166 
2167  if (EllipsisLoc.isValid() &&
2169  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2170  << TInfo->getTypeLoc().getSourceRange();
2171  EllipsisLoc = SourceLocation();
2172  }
2173 
2174  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2175 
2176  if (BaseType->isDependentType()) {
2177  // Make sure that we don't have circular inheritance among our dependent
2178  // bases. For non-dependent bases, the check for completeness below handles
2179  // this.
2180  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2181  if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2182  ((BaseDecl = BaseDecl->getDefinition()) &&
2183  findCircularInheritance(Class, BaseDecl))) {
2184  Diag(BaseLoc, diag::err_circular_inheritance)
2185  << BaseType << Context.getTypeDeclType(Class);
2186 
2187  if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2188  Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2189  << BaseType;
2190 
2191  return nullptr;
2192  }
2193  }
2194 
2195  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2196  Class->getTagKind() == TTK_Class,
2197  Access, TInfo, EllipsisLoc);
2198  }
2199 
2200  // Base specifiers must be record types.
2201  if (!BaseType->isRecordType()) {
2202  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2203  return nullptr;
2204  }
2205 
2206  // C++ [class.union]p1:
2207  // A union shall not be used as a base class.
2208  if (BaseType->isUnionType()) {
2209  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2210  return nullptr;
2211  }
2212 
2213  // For the MS ABI, propagate DLL attributes to base class templates.
2214  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2215  if (Attr *ClassAttr = getDLLAttr(Class)) {
2216  if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2217  BaseType->getAsCXXRecordDecl())) {
2218  propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2219  BaseLoc);
2220  }
2221  }
2222  }
2223 
2224  // C++ [class.derived]p2:
2225  // The class-name in a base-specifier shall not be an incompletely
2226  // defined class.
2227  if (RequireCompleteType(BaseLoc, BaseType,
2228  diag::err_incomplete_base_class, SpecifierRange)) {
2229  Class->setInvalidDecl();
2230  return nullptr;
2231  }
2232 
2233  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2234  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
2235  assert(BaseDecl && "Record type has no declaration");
2236  BaseDecl = BaseDecl->getDefinition();
2237  assert(BaseDecl && "Base type is not incomplete, but has no definition");
2238  CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2239  assert(CXXBaseDecl && "Base type is not a C++ type");
2240 
2241  // Microsoft docs say:
2242  // "If a base-class has a code_seg attribute, derived classes must have the
2243  // same attribute."
2244  const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2245  const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2246  if ((DerivedCSA || BaseCSA) &&
2247  (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2248  Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2249  Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2250  << CXXBaseDecl;
2251  return nullptr;
2252  }
2253 
2254  // A class which contains a flexible array member is not suitable for use as a
2255  // base class:
2256  // - If the layout determines that a base comes before another base,
2257  // the flexible array member would index into the subsequent base.
2258  // - If the layout determines that base comes before the derived class,
2259  // the flexible array member would index into the derived class.
2260  if (CXXBaseDecl->hasFlexibleArrayMember()) {
2261  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2262  << CXXBaseDecl->getDeclName();
2263  return nullptr;
2264  }
2265 
2266  // C++ [class]p3:
2267  // If a class is marked final and it appears as a base-type-specifier in
2268  // base-clause, the program is ill-formed.
2269  if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2270  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2271  << CXXBaseDecl->getDeclName()
2272  << FA->isSpelledAsSealed();
2273  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2274  << CXXBaseDecl->getDeclName() << FA->getRange();
2275  return nullptr;
2276  }
2277 
2278  if (BaseDecl->isInvalidDecl())
2279  Class->setInvalidDecl();
2280 
2281  // Create the base specifier.
2282  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2283  Class->getTagKind() == TTK_Class,
2284  Access, TInfo, EllipsisLoc);
2285 }
2286 
2287 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2288 /// one entry in the base class list of a class specifier, for
2289 /// example:
2290 /// class foo : public bar, virtual private baz {
2291 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2292 BaseResult
2293 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2294  ParsedAttributes &Attributes,
2295  bool Virtual, AccessSpecifier Access,
2296  ParsedType basetype, SourceLocation BaseLoc,
2297  SourceLocation EllipsisLoc) {
2298  if (!classdecl)
2299  return true;
2300 
2301  AdjustDeclIfTemplate(classdecl);
2302  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2303  if (!Class)
2304  return true;
2305 
2306  // We haven't yet attached the base specifiers.
2307  Class->setIsParsingBaseSpecifiers();
2308 
2309  // We do not support any C++11 attributes on base-specifiers yet.
2310  // Diagnose any attributes we see.
2311  for (const ParsedAttr &AL : Attributes) {
2312  if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2313  continue;
2314  Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2315  ? diag::warn_unknown_attribute_ignored
2316  : diag::err_base_specifier_attribute)
2317  << AL.getName();
2318  }
2319 
2320  TypeSourceInfo *TInfo = nullptr;
2321  GetTypeFromParser(basetype, &TInfo);
2322 
2323  if (EllipsisLoc.isInvalid() &&
2324  DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2325  UPPC_BaseType))
2326  return true;
2327 
2328  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2329  Virtual, Access, TInfo,
2330  EllipsisLoc))
2331  return BaseSpec;
2332  else
2333  Class->setInvalidDecl();
2334 
2335  return true;
2336 }
2337 
2338 /// Use small set to collect indirect bases. As this is only used
2339 /// locally, there's no need to abstract the small size parameter.
2340 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2341 
2342 /// Recursively add the bases of Type. Don't add Type itself.
2343 static void
2344 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2345  const QualType &Type)
2346 {
2347  // Even though the incoming type is a base, it might not be
2348  // a class -- it could be a template parm, for instance.
2349  if (auto Rec = Type->getAs<RecordType>()) {
2350  auto Decl = Rec->getAsCXXRecordDecl();
2351 
2352  // Iterate over its bases.
2353  for (const auto &BaseSpec : Decl->bases()) {
2354  QualType Base = Context.getCanonicalType(BaseSpec.getType())
2355  .getUnqualifiedType();
2356  if (Set.insert(Base).second)
2357  // If we've not already seen it, recurse.
2358  NoteIndirectBases(Context, Set, Base);
2359  }
2360  }
2361 }
2362 
2363 /// Performs the actual work of attaching the given base class
2364 /// specifiers to a C++ class.
2367  if (Bases.empty())
2368  return false;
2369 
2370  // Used to keep track of which base types we have already seen, so
2371  // that we can properly diagnose redundant direct base types. Note
2372  // that the key is always the unqualified canonical type of the base
2373  // class.
2374  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2375 
2376  // Used to track indirect bases so we can see if a direct base is
2377  // ambiguous.
2378  IndirectBaseSet IndirectBaseTypes;
2379 
2380  // Copy non-redundant base specifiers into permanent storage.
2381  unsigned NumGoodBases = 0;
2382  bool Invalid = false;
2383  for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2384  QualType NewBaseType
2385  = Context.getCanonicalType(Bases[idx]->getType());
2386  NewBaseType = NewBaseType.getLocalUnqualifiedType();
2387 
2388  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2389  if (KnownBase) {
2390  // C++ [class.mi]p3:
2391  // A class shall not be specified as a direct base class of a
2392  // derived class more than once.
2393  Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2394  << KnownBase->getType() << Bases[idx]->getSourceRange();
2395 
2396  // Delete the duplicate base class specifier; we're going to
2397  // overwrite its pointer later.
2398  Context.Deallocate(Bases[idx]);
2399 
2400  Invalid = true;
2401  } else {
2402  // Okay, add this new base class.
2403  KnownBase = Bases[idx];
2404  Bases[NumGoodBases++] = Bases[idx];
2405 
2406  // Note this base's direct & indirect bases, if there could be ambiguity.
2407  if (Bases.size() > 1)
2408  NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2409 
2410  if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2411  const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2412  if (Class->isInterface() &&
2413  (!RD->isInterfaceLike() ||
2414  KnownBase->getAccessSpecifier() != AS_public)) {
2415  // The Microsoft extension __interface does not permit bases that
2416  // are not themselves public interfaces.
2417  Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2418  << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2419  << RD->getSourceRange();
2420  Invalid = true;
2421  }
2422  if (RD->hasAttr<WeakAttr>())
2423  Class->addAttr(WeakAttr::CreateImplicit(Context));
2424  }
2425  }
2426  }
2427 
2428  // Attach the remaining base class specifiers to the derived class.
2429  Class->setBases(Bases.data(), NumGoodBases);
2430 
2431  // Check that the only base classes that are duplicate are virtual.
2432  for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2433  // Check whether this direct base is inaccessible due to ambiguity.
2434  QualType BaseType = Bases[idx]->getType();
2435 
2436  // Skip all dependent types in templates being used as base specifiers.
2437  // Checks below assume that the base specifier is a CXXRecord.
2438  if (BaseType->isDependentType())
2439  continue;
2440 
2441  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2442  .getUnqualifiedType();
2443 
2444  if (IndirectBaseTypes.count(CanonicalBase)) {
2445  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2446  /*DetectVirtual=*/true);
2447  bool found
2448  = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2449  assert(found);
2450  (void)found;
2451 
2452  if (Paths.isAmbiguous(CanonicalBase))
2453  Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2454  << BaseType << getAmbiguousPathsDisplayString(Paths)
2455  << Bases[idx]->getSourceRange();
2456  else
2457  assert(Bases[idx]->isVirtual());
2458  }
2459 
2460  // Delete the base class specifier, since its data has been copied
2461  // into the CXXRecordDecl.
2462  Context.Deallocate(Bases[idx]);
2463  }
2464 
2465  return Invalid;
2466 }
2467 
2468 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2469 /// class, after checking whether there are any duplicate base
2470 /// classes.
2471 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2473  if (!ClassDecl || Bases.empty())
2474  return;
2475 
2476  AdjustDeclIfTemplate(ClassDecl);
2477  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2478 }
2479 
2480 /// Determine whether the type \p Derived is a C++ class that is
2481 /// derived from the type \p Base.
2483  if (!getLangOpts().CPlusPlus)
2484  return false;
2485 
2486  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2487  if (!DerivedRD)
2488  return false;
2489 
2490  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2491  if (!BaseRD)
2492  return false;
2493 
2494  // If either the base or the derived type is invalid, don't try to
2495  // check whether one is derived from the other.
2496  if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2497  return false;
2498 
2499  // FIXME: In a modules build, do we need the entire path to be visible for us
2500  // to be able to use the inheritance relationship?
2501  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2502  return false;
2503 
2504  return DerivedRD->isDerivedFrom(BaseRD);
2505 }
2506 
2507 /// Determine whether the type \p Derived is a C++ class that is
2508 /// derived from the type \p Base.
2510  CXXBasePaths &Paths) {
2511  if (!getLangOpts().CPlusPlus)
2512  return false;
2513 
2514  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2515  if (!DerivedRD)
2516  return false;
2517 
2518  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2519  if (!BaseRD)
2520  return false;
2521 
2522  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2523  return false;
2524 
2525  return DerivedRD->isDerivedFrom(BaseRD, Paths);
2526 }
2527 
2528 static void BuildBasePathArray(const CXXBasePath &Path,
2529  CXXCastPath &BasePathArray) {
2530  // We first go backward and check if we have a virtual base.
2531  // FIXME: It would be better if CXXBasePath had the base specifier for
2532  // the nearest virtual base.
2533  unsigned Start = 0;
2534  for (unsigned I = Path.size(); I != 0; --I) {
2535  if (Path[I - 1].Base->isVirtual()) {
2536  Start = I - 1;
2537  break;
2538  }
2539  }
2540 
2541  // Now add all bases.
2542  for (unsigned I = Start, E = Path.size(); I != E; ++I)
2543  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2544 }
2545 
2546 
2548  CXXCastPath &BasePathArray) {
2549  assert(BasePathArray.empty() && "Base path array must be empty!");
2550  assert(Paths.isRecordingPaths() && "Must record paths!");
2551  return ::BuildBasePathArray(Paths.front(), BasePathArray);
2552 }
2553 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2554 /// conversion (where Derived and Base are class types) is
2555 /// well-formed, meaning that the conversion is unambiguous (and
2556 /// that all of the base classes are accessible). Returns true
2557 /// and emits a diagnostic if the code is ill-formed, returns false
2558 /// otherwise. Loc is the location where this routine should point to
2559 /// if there is an error, and Range is the source range to highlight
2560 /// if there is an error.
2561 ///
2562 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2563 /// diagnostic for the respective type of error will be suppressed, but the
2564 /// check for ill-formed code will still be performed.
2565 bool
2567  unsigned InaccessibleBaseID,
2568  unsigned AmbigiousBaseConvID,
2569  SourceLocation Loc, SourceRange Range,
2570  DeclarationName Name,
2571  CXXCastPath *BasePath,
2572  bool IgnoreAccess) {
2573  // First, determine whether the path from Derived to Base is
2574  // ambiguous. This is slightly more expensive than checking whether
2575  // the Derived to Base conversion exists, because here we need to
2576  // explore multiple paths to determine if there is an ambiguity.
2577  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2578  /*DetectVirtual=*/false);
2579  bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2580  if (!DerivationOkay)
2581  return true;
2582 
2583  const CXXBasePath *Path = nullptr;
2584  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2585  Path = &Paths.front();
2586 
2587  // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2588  // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2589  // user to access such bases.
2590  if (!Path && getLangOpts().MSVCCompat) {
2591  for (const CXXBasePath &PossiblePath : Paths) {
2592  if (PossiblePath.size() == 1) {
2593  Path = &PossiblePath;
2594  if (AmbigiousBaseConvID)
2595  Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2596  << Base << Derived << Range;
2597  break;
2598  }
2599  }
2600  }
2601 
2602  if (Path) {
2603  if (!IgnoreAccess) {
2604  // Check that the base class can be accessed.
2605  switch (
2606  CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2607  case AR_inaccessible:
2608  return true;
2609  case AR_accessible:
2610  case AR_dependent:
2611  case AR_delayed:
2612  break;
2613  }
2614  }
2615 
2616  // Build a base path if necessary.
2617  if (BasePath)
2618  ::BuildBasePathArray(*Path, *BasePath);
2619  return false;
2620  }
2621 
2622  if (AmbigiousBaseConvID) {
2623  // We know that the derived-to-base conversion is ambiguous, and
2624  // we're going to produce a diagnostic. Perform the derived-to-base
2625  // search just one more time to compute all of the possible paths so
2626  // that we can print them out. This is more expensive than any of
2627  // the previous derived-to-base checks we've done, but at this point
2628  // performance isn't as much of an issue.
2629  Paths.clear();
2630  Paths.setRecordingPaths(true);
2631  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2632  assert(StillOkay && "Can only be used with a derived-to-base conversion");
2633  (void)StillOkay;
2634 
2635  // Build up a textual representation of the ambiguous paths, e.g.,
2636  // D -> B -> A, that will be used to illustrate the ambiguous
2637  // conversions in the diagnostic. We only print one of the paths
2638  // to each base class subobject.
2639  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2640 
2641  Diag(Loc, AmbigiousBaseConvID)
2642  << Derived << Base << PathDisplayStr << Range << Name;
2643  }
2644  return true;
2645 }
2646 
2647 bool
2649  SourceLocation Loc, SourceRange Range,
2650  CXXCastPath *BasePath,
2651  bool IgnoreAccess) {
2652  return CheckDerivedToBaseConversion(
2653  Derived, Base, diag::err_upcast_to_inaccessible_base,
2654  diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2655  BasePath, IgnoreAccess);
2656 }
2657 
2658 
2659 /// Builds a string representing ambiguous paths from a
2660 /// specific derived class to different subobjects of the same base
2661 /// class.
2662 ///
2663 /// This function builds a string that can be used in error messages
2664 /// to show the different paths that one can take through the
2665 /// inheritance hierarchy to go from the derived class to different
2666 /// subobjects of a base class. The result looks something like this:
2667 /// @code
2668 /// struct D -> struct B -> struct A
2669 /// struct D -> struct C -> struct A
2670 /// @endcode
2672  std::string PathDisplayStr;
2673  std::set<unsigned> DisplayedPaths;
2674  for (CXXBasePaths::paths_iterator Path = Paths.begin();
2675  Path != Paths.end(); ++Path) {
2676  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2677  // We haven't displayed a path to this particular base
2678  // class subobject yet.
2679  PathDisplayStr += "\n ";
2680  PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2681  for (CXXBasePath::const_iterator Element = Path->begin();
2682  Element != Path->end(); ++Element)
2683  PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2684  }
2685  }
2686 
2687  return PathDisplayStr;
2688 }
2689 
2690 //===----------------------------------------------------------------------===//
2691 // C++ class member Handling
2692 //===----------------------------------------------------------------------===//
2693 
2694 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2697  const ParsedAttributesView &Attrs) {
2698  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2699  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2700  ASLoc, ColonLoc);
2701  CurContext->addHiddenDecl(ASDecl);
2702  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2703 }
2704 
2705 /// CheckOverrideControl - Check C++11 override control semantics.
2707  if (D->isInvalidDecl())
2708  return;
2709 
2710  // We only care about "override" and "final" declarations.
2711  if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2712  return;
2713 
2714  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2715 
2716  // We can't check dependent instance methods.
2717  if (MD && MD->isInstance() &&
2718  (MD->getParent()->hasAnyDependentBases() ||
2719  MD->getType()->isDependentType()))
2720  return;
2721 
2722  if (MD && !MD->isVirtual()) {
2723  // If we have a non-virtual method, check if if hides a virtual method.
2724  // (In that case, it's most likely the method has the wrong type.)
2725  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2726  FindHiddenVirtualMethods(MD, OverloadedMethods);
2727 
2728  if (!OverloadedMethods.empty()) {
2729  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2730  Diag(OA->getLocation(),
2731  diag::override_keyword_hides_virtual_member_function)
2732  << "override" << (OverloadedMethods.size() > 1);
2733  } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2734  Diag(FA->getLocation(),
2735  diag::override_keyword_hides_virtual_member_function)
2736  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2737  << (OverloadedMethods.size() > 1);
2738  }
2739  NoteHiddenVirtualMethods(MD, OverloadedMethods);
2740  MD->setInvalidDecl();
2741  return;
2742  }
2743  // Fall through into the general case diagnostic.
2744  // FIXME: We might want to attempt typo correction here.
2745  }
2746 
2747  if (!MD || !MD->isVirtual()) {
2748  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2749  Diag(OA->getLocation(),
2750  diag::override_keyword_only_allowed_on_virtual_member_functions)
2751  << "override" << FixItHint::CreateRemoval(OA->getLocation());
2752  D->dropAttr<OverrideAttr>();
2753  }
2754  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2755  Diag(FA->getLocation(),
2756  diag::override_keyword_only_allowed_on_virtual_member_functions)
2757  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2758  << FixItHint::CreateRemoval(FA->getLocation());
2759  D->dropAttr<FinalAttr>();
2760  }
2761  return;
2762  }
2763 
2764  // C++11 [class.virtual]p5:
2765  // If a function is marked with the virt-specifier override and
2766  // does not override a member function of a base class, the program is
2767  // ill-formed.
2768  bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
2769  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
2770  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
2771  << MD->getDeclName();
2772 }
2773 
2775  if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
2776  return;
2777  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2778  if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
2779  return;
2780 
2781  SourceLocation Loc = MD->getLocation();
2782  SourceLocation SpellingLoc = Loc;
2783  if (getSourceManager().isMacroArgExpansion(Loc))
2784  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
2785  SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
2786  if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
2787  return;
2788 
2789  if (MD->size_overridden_methods() > 0) {
2790  unsigned DiagID = isa<CXXDestructorDecl>(MD)
2791  ? diag::warn_destructor_marked_not_override_overriding
2792  : diag::warn_function_marked_not_override_overriding;
2793  Diag(MD->getLocation(), DiagID) << MD->getDeclName();
2794  const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
2795  Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
2796  }
2797 }
2798 
2799 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
2800 /// function overrides a virtual member function marked 'final', according to
2801 /// C++11 [class.virtual]p4.
2803  const CXXMethodDecl *Old) {
2804  FinalAttr *FA = Old->getAttr<FinalAttr>();
2805  if (!FA)
2806  return false;
2807 
2808  Diag(New->getLocation(), diag::err_final_function_overridden)
2809  << New->getDeclName()
2810  << FA->isSpelledAsSealed();
2811  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
2812  return true;
2813 }
2814 
2815 static bool InitializationHasSideEffects(const FieldDecl &FD) {
2816  const Type *T = FD.getType()->getBaseElementTypeUnsafe();
2817  // FIXME: Destruction of ObjC lifetime types has side-effects.
2818  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
2819  return !RD->isCompleteDefinition() ||
2820  !RD->hasTrivialDefaultConstructor() ||
2821  !RD->hasTrivialDestructor();
2822  return false;
2823 }
2824 
2827  llvm::find_if(list, [](const ParsedAttr &AL) {
2828  return AL.isDeclspecPropertyAttribute();
2829  });
2830  if (Itr != list.end())
2831  return &*Itr;
2832  return nullptr;
2833 }
2834 
2835 // Check if there is a field shadowing.
2836 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
2837  DeclarationName FieldName,
2838  const CXXRecordDecl *RD) {
2839  if (Diags.isIgnored(diag::warn_shadow_field, Loc))
2840  return;
2841 
2842  // To record a shadowed field in a base
2843  std::map<CXXRecordDecl*, NamedDecl*> Bases;
2844  auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
2845  CXXBasePath &Path) {
2846  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
2847  // Record an ambiguous path directly
2848  if (Bases.find(Base) != Bases.end())
2849  return true;
2850  for (const auto Field : Base->lookup(FieldName)) {
2851  if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
2852  Field->getAccess() != AS_private) {
2853  assert(Field->getAccess() != AS_none);
2854  assert(Bases.find(Base) == Bases.end());
2855  Bases[Base] = Field;
2856  return true;
2857  }
2858  }
2859  return false;
2860  };
2861 
2862  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2863  /*DetectVirtual=*/true);
2864  if (!RD->lookupInBases(FieldShadowed, Paths))
2865  return;
2866 
2867  for (const auto &P : Paths) {
2868  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
2869  auto It = Bases.find(Base);
2870  // Skip duplicated bases
2871  if (It == Bases.end())
2872  continue;
2873  auto BaseField = It->second;
2874  assert(BaseField->getAccess() != AS_private);
2875  if (AS_none !=
2876  CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
2877  Diag(Loc, diag::warn_shadow_field)
2878  << FieldName << RD << Base;
2879  Diag(BaseField->getLocation(), diag::note_shadow_field);
2880  Bases.erase(It);
2881  }
2882  }
2883 }
2884 
2885 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
2886 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
2887 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
2888 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
2889 /// present (but parsing it has been deferred).
2890 NamedDecl *
2892  MultiTemplateParamsArg TemplateParameterLists,
2893  Expr *BW, const VirtSpecifiers &VS,
2894  InClassInitStyle InitStyle) {
2895  const DeclSpec &DS = D.getDeclSpec();
2896  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
2897  DeclarationName Name = NameInfo.getName();
2898  SourceLocation Loc = NameInfo.getLoc();
2899 
2900  // For anonymous bitfields, the location should point to the type.
2901  if (Loc.isInvalid())
2902  Loc = D.getBeginLoc();
2903 
2904  Expr *BitWidth = static_cast<Expr*>(BW);
2905 
2906  assert(isa<CXXRecordDecl>(CurContext));
2907  assert(!DS.isFriendSpecified());
2908 
2909  bool isFunc = D.isDeclarationOfFunction();
2910  const ParsedAttr *MSPropertyAttr =
2912 
2913  if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
2914  // The Microsoft extension __interface only permits public member functions
2915  // and prohibits constructors, destructors, operators, non-public member
2916  // functions, static methods and data members.
2917  unsigned InvalidDecl;
2918  bool ShowDeclName = true;
2919  if (!isFunc &&
2920  (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
2921  InvalidDecl = 0;
2922  else if (!isFunc)
2923  InvalidDecl = 1;
2924  else if (AS != AS_public)
2925  InvalidDecl = 2;
2926  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
2927  InvalidDecl = 3;
2928  else switch (Name.getNameKind()) {
2930  InvalidDecl = 4;
2931  ShowDeclName = false;
2932  break;
2933 
2935  InvalidDecl = 5;
2936  ShowDeclName = false;
2937  break;
2938 
2941  InvalidDecl = 6;
2942  break;
2943 
2944  default:
2945  InvalidDecl = 0;
2946  break;
2947  }
2948 
2949  if (InvalidDecl) {
2950  if (ShowDeclName)
2951  Diag(Loc, diag::err_invalid_member_in_interface)
2952  << (InvalidDecl-1) << Name;
2953  else
2954  Diag(Loc, diag::err_invalid_member_in_interface)
2955  << (InvalidDecl-1) << "";
2956  return nullptr;
2957  }
2958  }
2959 
2960  // C++ 9.2p6: A member shall not be declared to have automatic storage
2961  // duration (auto, register) or with the extern storage-class-specifier.
2962  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
2963  // data members and cannot be applied to names declared const or static,
2964  // and cannot be applied to reference members.
2965  switch (DS.getStorageClassSpec()) {
2967  case DeclSpec::SCS_typedef:
2968  case DeclSpec::SCS_static:
2969  break;
2970  case DeclSpec::SCS_mutable:
2971  if (isFunc) {
2972  Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
2973 
2974  // FIXME: It would be nicer if the keyword was ignored only for this
2975  // declarator. Otherwise we could get follow-up errors.
2977  }
2978  break;
2979  default:
2981  diag::err_storageclass_invalid_for_member);
2983  break;
2984  }
2985 
2986  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
2988  !isFunc);
2989 
2990  if (DS.isConstexprSpecified() && isInstField) {
2992  Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
2993  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
2994  if (InitStyle == ICIS_NoInit) {
2995  B << 0 << 0;
2997  B << FixItHint::CreateRemoval(ConstexprLoc);
2998  else {
2999  B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3001  const char *PrevSpec;
3002  unsigned DiagID;
3003  bool Failed = D.getMutableDeclSpec().SetTypeQual(
3004  DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3005  (void)Failed;
3006  assert(!Failed && "Making a constexpr member const shouldn't fail");
3007  }
3008  } else {
3009  B << 1;
3010  const char *PrevSpec;
3011  unsigned DiagID;
3013  *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3014  Context.getPrintingPolicy())) {
3015  assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3016  "This is the only DeclSpec that should fail to be applied");
3017  B << 1;
3018  } else {
3019  B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3020  isInstField = false;
3021  }
3022  }
3023  }
3024 
3025  NamedDecl *Member;
3026  if (isInstField) {
3027  CXXScopeSpec &SS = D.getCXXScopeSpec();
3028 
3029  // Data members must have identifiers for names.
3030  if (!Name.isIdentifier()) {
3031  Diag(Loc, diag::err_bad_variable_name)
3032  << Name;
3033  return nullptr;
3034  }
3035 
3036  IdentifierInfo *II = Name.getAsIdentifierInfo();
3037 
3038  // Member field could not be with "template" keyword.
3039  // So TemplateParameterLists should be empty in this case.
3040  if (TemplateParameterLists.size()) {
3041  TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3042  if (TemplateParams->size()) {
3043  // There is no such thing as a member field template.
3044  Diag(D.getIdentifierLoc(), diag::err_template_member)
3045  << II
3046  << SourceRange(TemplateParams->getTemplateLoc(),
3047  TemplateParams->getRAngleLoc());
3048  } else {
3049  // There is an extraneous 'template<>' for this member.
3050  Diag(TemplateParams->getTemplateLoc(),
3051  diag::err_template_member_noparams)
3052  << II
3053  << SourceRange(TemplateParams->getTemplateLoc(),
3054  TemplateParams->getRAngleLoc());
3055  }
3056  return nullptr;
3057  }
3058 
3059  if (SS.isSet() && !SS.isInvalid()) {
3060  // The user provided a superfluous scope specifier inside a class
3061  // definition:
3062  //
3063  // class X {
3064  // int X::member;
3065  // };
3066  if (DeclContext *DC = computeDeclContext(SS, false))
3067  diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3068  D.getName().getKind() ==
3070  else
3071  Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3072  << Name << SS.getRange();
3073 
3074  SS.clear();
3075  }
3076 
3077  if (MSPropertyAttr) {
3078  Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3079  BitWidth, InitStyle, AS, *MSPropertyAttr);
3080  if (!Member)
3081  return nullptr;
3082  isInstField = false;
3083  } else {
3084  Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3085  BitWidth, InitStyle, AS);
3086  if (!Member)
3087  return nullptr;
3088  }
3089 
3090  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3091  } else {
3092  Member = HandleDeclarator(S, D, TemplateParameterLists);
3093  if (!Member)
3094  return nullptr;
3095 
3096  // Non-instance-fields can't have a bitfield.
3097  if (BitWidth) {
3098  if (Member->isInvalidDecl()) {
3099  // don't emit another diagnostic.
3100  } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3101  // C++ 9.6p3: A bit-field shall not be a static member.
3102  // "static member 'A' cannot be a bit-field"
3103  Diag(Loc, diag::err_static_not_bitfield)
3104  << Name << BitWidth->getSourceRange();
3105  } else if (isa<TypedefDecl>(Member)) {
3106  // "typedef member 'x' cannot be a bit-field"
3107  Diag(Loc, diag::err_typedef_not_bitfield)
3108  << Name << BitWidth->getSourceRange();
3109  } else {
3110  // A function typedef ("typedef int f(); f a;").
3111  // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3112  Diag(Loc, diag::err_not_integral_type_bitfield)
3113  << Name << cast<ValueDecl>(Member)->getType()
3114  << BitWidth->getSourceRange();
3115  }
3116 
3117  BitWidth = nullptr;
3118  Member->setInvalidDecl();
3119  }
3120 
3121  NamedDecl *NonTemplateMember = Member;
3122  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3123  NonTemplateMember = FunTmpl->getTemplatedDecl();
3124  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3125  NonTemplateMember = VarTmpl->getTemplatedDecl();
3126 
3127  Member->setAccess(AS);
3128 
3129  // If we have declared a member function template or static data member
3130  // template, set the access of the templated declaration as well.
3131  if (NonTemplateMember != Member)
3132  NonTemplateMember->setAccess(AS);
3133 
3134  // C++ [temp.deduct.guide]p3:
3135  // A deduction guide [...] for a member class template [shall be
3136  // declared] with the same access [as the template].
3137  if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3138  auto *TD = DG->getDeducedTemplate();
3139  if (AS != TD->getAccess()) {
3140  Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3141  Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3142  << TD->getAccess();
3143  const AccessSpecDecl *LastAccessSpec = nullptr;
3144  for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3145  if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3146  LastAccessSpec = AccessSpec;
3147  }
3148  assert(LastAccessSpec && "differing access with no access specifier");
3149  Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3150  << AS;
3151  }
3152  }
3153  }
3154 
3155  if (VS.isOverrideSpecified())
3156  Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context, 0));
3157  if (VS.isFinalSpecified())
3158  Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context,
3159  VS.isFinalSpelledSealed()));
3160 
3161  if (VS.getLastLocation().isValid()) {
3162  // Update the end location of a method that has a virt-specifiers.
3163  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3164  MD->setRangeEnd(VS.getLastLocation());
3165  }
3166 
3167  CheckOverrideControl(Member);
3168 
3169  assert((Name || isInstField) && "No identifier for non-field ?");
3170 
3171  if (isInstField) {
3172  FieldDecl *FD = cast<FieldDecl>(Member);
3173  FieldCollector->Add(FD);
3174 
3175  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3176  // Remember all explicit private FieldDecls that have a name, no side
3177  // effects and are not part of a dependent type declaration.
3178  if (!FD->isImplicit() && FD->getDeclName() &&
3179  FD->getAccess() == AS_private &&
3180  !FD->hasAttr<UnusedAttr>() &&
3181  !FD->getParent()->isDependentContext() &&
3183  UnusedPrivateFields.insert(FD);
3184  }
3185  }
3186 
3187  return Member;
3188 }
3189 
3190 namespace {
3191  class UninitializedFieldVisitor
3192  : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3193  Sema &S;
3194  // List of Decls to generate a warning on. Also remove Decls that become
3195  // initialized.
3196  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3197  // List of base classes of the record. Classes are removed after their
3198  // initializers.
3199  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3200  // Vector of decls to be removed from the Decl set prior to visiting the
3201  // nodes. These Decls may have been initialized in the prior initializer.
3202  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3203  // If non-null, add a note to the warning pointing back to the constructor.
3204  const CXXConstructorDecl *Constructor;
3205  // Variables to hold state when processing an initializer list. When
3206  // InitList is true, special case initialization of FieldDecls matching
3207  // InitListFieldDecl.
3208  bool InitList;
3209  FieldDecl *InitListFieldDecl;
3210  llvm::SmallVector<unsigned, 4> InitFieldIndex;
3211 
3212  public:
3214  UninitializedFieldVisitor(Sema &S,
3215  llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3216  llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3217  : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3218  Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3219 
3220  // Returns true if the use of ME is not an uninitialized use.
3221  bool IsInitListMemberExprInitialized(MemberExpr *ME,
3222  bool CheckReferenceOnly) {
3224  bool ReferenceField = false;
3225  while (ME) {
3226  FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3227  if (!FD)
3228  return false;
3229  Fields.push_back(FD);
3230  if (FD->getType()->isReferenceType())
3231  ReferenceField = true;
3232  ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3233  }
3234 
3235  // Binding a reference to an unintialized field is not an
3236  // uninitialized use.
3237  if (CheckReferenceOnly && !ReferenceField)
3238  return true;
3239 
3240  llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3241  // Discard the first field since it is the field decl that is being
3242  // initialized.
3243  for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3244  UsedFieldIndex.push_back((*I)->getFieldIndex());
3245  }
3246 
3247  for (auto UsedIter = UsedFieldIndex.begin(),
3248  UsedEnd = UsedFieldIndex.end(),
3249  OrigIter = InitFieldIndex.begin(),
3250  OrigEnd = InitFieldIndex.end();
3251  UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3252  if (*UsedIter < *OrigIter)
3253  return true;
3254  if (*UsedIter > *OrigIter)
3255  break;
3256  }
3257 
3258  return false;
3259  }
3260 
3261  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3262  bool AddressOf) {
3263  if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3264  return;
3265 
3266  // FieldME is the inner-most MemberExpr that is not an anonymous struct
3267  // or union.
3268  MemberExpr *FieldME = ME;
3269 
3270  bool AllPODFields = FieldME->getType().isPODType(S.Context);
3271 
3272  Expr *Base = ME;
3273  while (MemberExpr *SubME =
3274  dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3275 
3276  if (isa<VarDecl>(SubME->getMemberDecl()))
3277  return;
3278 
3279  if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3280  if (!FD->isAnonymousStructOrUnion())
3281  FieldME = SubME;
3282 
3283  if (!FieldME->getType().isPODType(S.Context))
3284  AllPODFields = false;
3285 
3286  Base = SubME->getBase();
3287  }
3288 
3289  if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3290  return;
3291 
3292  if (AddressOf && AllPODFields)
3293  return;
3294 
3295  ValueDecl* FoundVD = FieldME->getMemberDecl();
3296 
3297  if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3298  while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3299  BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3300  }
3301 
3302  if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3303  QualType T = BaseCast->getType();
3304  if (T->isPointerType() &&
3305  BaseClasses.count(T->getPointeeType())) {
3306  S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3307  << T->getPointeeType() << FoundVD;
3308  }
3309  }
3310  }
3311 
3312  if (!Decls.count(FoundVD))
3313  return;
3314 
3315  const bool IsReference = FoundVD->getType()->isReferenceType();
3316 
3317  if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3318  // Special checking for initializer lists.
3319  if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3320  return;
3321  }
3322  } else {
3323  // Prevent double warnings on use of unbounded references.
3324  if (CheckReferenceOnly && !IsReference)
3325  return;
3326  }
3327 
3328  unsigned diag = IsReference
3329  ? diag::warn_reference_field_is_uninit
3330  : diag::warn_field_is_uninit;
3331  S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3332  if (Constructor)
3333  S.Diag(Constructor->getLocation(),
3334  diag::note_uninit_in_this_constructor)
3335  << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3336 
3337  }
3338 
3339  void HandleValue(Expr *E, bool AddressOf) {
3340  E = E->IgnoreParens();
3341 
3342  if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3343  HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3344  AddressOf /*AddressOf*/);
3345  return;
3346  }
3347 
3348  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3349  Visit(CO->getCond());
3350  HandleValue(CO->getTrueExpr(), AddressOf);
3351  HandleValue(CO->getFalseExpr(), AddressOf);
3352  return;
3353  }
3354 
3355  if (BinaryConditionalOperator *BCO =
3356  dyn_cast<BinaryConditionalOperator>(E)) {
3357  Visit(BCO->getCond());
3358  HandleValue(BCO->getFalseExpr(), AddressOf);
3359  return;
3360  }
3361 
3362  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3363  HandleValue(OVE->getSourceExpr(), AddressOf);
3364  return;
3365  }
3366 
3367  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3368  switch (BO->getOpcode()) {
3369  default:
3370  break;
3371  case(BO_PtrMemD):
3372  case(BO_PtrMemI):
3373  HandleValue(BO->getLHS(), AddressOf);
3374  Visit(BO->getRHS());
3375  return;
3376  case(BO_Comma):
3377  Visit(BO->getLHS());
3378  HandleValue(BO->getRHS(), AddressOf);
3379  return;
3380  }
3381  }
3382 
3383  Visit(E);
3384  }
3385 
3386  void CheckInitListExpr(InitListExpr *ILE) {
3387  InitFieldIndex.push_back(0);
3388  for (auto Child : ILE->children()) {
3389  if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3390  CheckInitListExpr(SubList);
3391  } else {
3392  Visit(Child);
3393  }
3394  ++InitFieldIndex.back();
3395  }
3396  InitFieldIndex.pop_back();
3397  }
3398 
3399  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3400  FieldDecl *Field, const Type *BaseClass) {
3401  // Remove Decls that may have been initialized in the previous
3402  // initializer.
3403  for (ValueDecl* VD : DeclsToRemove)
3404  Decls.erase(VD);
3405  DeclsToRemove.clear();
3406 
3407  Constructor = FieldConstructor;
3408  InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3409 
3410  if (ILE && Field) {
3411  InitList = true;
3412  InitListFieldDecl = Field;
3413  InitFieldIndex.clear();
3414  CheckInitListExpr(ILE);
3415  } else {
3416  InitList = false;
3417  Visit(E);
3418  }
3419 
3420  if (Field)
3421  Decls.erase(Field);
3422  if (BaseClass)
3423  BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3424  }
3425 
3426  void VisitMemberExpr(MemberExpr *ME) {
3427  // All uses of unbounded reference fields will warn.
3428  HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3429  }
3430 
3431  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3432  if (E->getCastKind() == CK_LValueToRValue) {
3433  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3434  return;
3435  }
3436 
3437  Inherited::VisitImplicitCastExpr(E);
3438  }
3439 
3440  void VisitCXXConstructExpr(CXXConstructExpr *E) {
3441  if (E->getConstructor()->isCopyConstructor()) {
3442  Expr *ArgExpr = E->getArg(0);
3443  if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3444  if (ILE->getNumInits() == 1)
3445  ArgExpr = ILE->getInit(0);
3446  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3447  if (ICE->getCastKind() == CK_NoOp)
3448  ArgExpr = ICE->getSubExpr();
3449  HandleValue(ArgExpr, false /*AddressOf*/);
3450  return;
3451  }
3452  Inherited::VisitCXXConstructExpr(E);
3453  }
3454 
3455  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3456  Expr *Callee = E->getCallee();
3457  if (isa<MemberExpr>(Callee)) {
3458  HandleValue(Callee, false /*AddressOf*/);
3459  for (auto Arg : E->arguments())
3460  Visit(Arg);
3461  return;
3462  }
3463 
3464  Inherited::VisitCXXMemberCallExpr(E);
3465  }
3466 
3467  void VisitCallExpr(CallExpr *E) {
3468  // Treat std::move as a use.
3469  if (E->isCallToStdMove()) {
3470  HandleValue(E->getArg(0), /*AddressOf=*/false);
3471  return;
3472  }
3473 
3474  Inherited::VisitCallExpr(E);
3475  }
3476 
3477  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3478  Expr *Callee = E->getCallee();
3479 
3480  if (isa<UnresolvedLookupExpr>(Callee))
3481  return Inherited::VisitCXXOperatorCallExpr(E);
3482 
3483  Visit(Callee);
3484  for (auto Arg : E->arguments())
3485  HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3486  }
3487 
3488  void VisitBinaryOperator(BinaryOperator *E) {
3489  // If a field assignment is detected, remove the field from the
3490  // uninitiailized field set.
3491  if (E->getOpcode() == BO_Assign)
3492  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3493  if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3494  if (!FD->getType()->isReferenceType())
3495  DeclsToRemove.push_back(FD);
3496 
3497  if (E->isCompoundAssignmentOp()) {
3498  HandleValue(E->getLHS(), false /*AddressOf*/);
3499  Visit(E->getRHS());
3500  return;
3501  }
3502 
3503  Inherited::VisitBinaryOperator(E);
3504  }
3505 
3506  void VisitUnaryOperator(UnaryOperator *E) {
3507  if (E->isIncrementDecrementOp()) {
3508  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3509  return;
3510  }
3511  if (E->getOpcode() == UO_AddrOf) {
3512  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3513  HandleValue(ME->getBase(), true /*AddressOf*/);
3514  return;
3515  }
3516  }
3517 
3518  Inherited::VisitUnaryOperator(E);
3519  }
3520  };
3521 
3522  // Diagnose value-uses of fields to initialize themselves, e.g.
3523  // foo(foo)
3524  // where foo is not also a parameter to the constructor.
3525  // Also diagnose across field uninitialized use such as
3526  // x(y), y(x)
3527  // TODO: implement -Wuninitialized and fold this into that framework.
3528  static void DiagnoseUninitializedFields(
3529  Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3530 
3531  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3532  Constructor->getLocation())) {
3533  return;
3534  }
3535 
3536  if (Constructor->isInvalidDecl())
3537  return;
3538 
3539  const CXXRecordDecl *RD = Constructor->getParent();
3540 
3541  if (RD->getDescribedClassTemplate())
3542  return;
3543 
3544  // Holds fields that are uninitialized.
3545  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3546 
3547  // At the beginning, all fields are uninitialized.
3548  for (auto *I : RD->decls()) {
3549  if (auto *FD = dyn_cast<FieldDecl>(I)) {
3550  UninitializedFields.insert(FD);
3551  } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3552  UninitializedFields.insert(IFD->getAnonField());
3553  }
3554  }
3555 
3556  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3557  for (auto I : RD->bases())
3558  UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3559 
3560  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3561  return;
3562 
3563  UninitializedFieldVisitor UninitializedChecker(SemaRef,
3564  UninitializedFields,
3565  UninitializedBaseClasses);
3566 
3567  for (const auto *FieldInit : Constructor->inits()) {
3568  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3569  break;
3570 
3571  Expr *InitExpr = FieldInit->getInit();
3572  if (!InitExpr)
3573  continue;
3574 
3576  dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3577  InitExpr = Default->getExpr();
3578  if (!InitExpr)
3579  continue;
3580  // In class initializers will point to the constructor.
3581  UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3582  FieldInit->getAnyMember(),
3583  FieldInit->getBaseClass());
3584  } else {
3585  UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3586  FieldInit->getAnyMember(),
3587  FieldInit->getBaseClass());
3588  }
3589  }
3590  }
3591 } // namespace
3592 
3593 /// Enter a new C++ default initializer scope. After calling this, the
3594 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3595 /// parsing or instantiating the initializer failed.
3597  // Create a synthetic function scope to represent the call to the constructor
3598  // that notionally surrounds a use of this initializer.
3599  PushFunctionScope();
3600 }
3601 
3602 /// This is invoked after parsing an in-class initializer for a
3603 /// non-static C++ class member, and after instantiating an in-class initializer
3604 /// in a class template. Such actions are deferred until the class is complete.
3606  SourceLocation InitLoc,
3607  Expr *InitExpr) {
3608  // Pop the notional constructor scope we created earlier.
3609  PopFunctionScopeInfo(nullptr, D);
3610 
3611  FieldDecl *FD = dyn_cast<FieldDecl>(D);
3612  assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3613  "must set init style when field is created");
3614 
3615  if (!InitExpr) {
3616  D->setInvalidDecl();
3617  if (FD)
3619  return;
3620  }
3621 
3622  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3623  FD->setInvalidDecl();
3625  return;
3626  }
3627 
3628  ExprResult Init = InitExpr;
3629  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3630  InitializedEntity Entity =
3635  InitExpr->getBeginLoc(),
3636  InitExpr->getEndLoc())
3637  : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
3638  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3639  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3640  if (Init.isInvalid()) {
3641  FD->setInvalidDecl();
3642  return;
3643  }
3644  }
3645 
3646  // C++11 [class.base.init]p7:
3647  // The initialization of each base and member constitutes a
3648  // full-expression.
3649  Init = ActOnFinishFullExpr(Init.get(), InitLoc);
3650  if (Init.isInvalid()) {
3651  FD->setInvalidDecl();
3652  return;
3653  }
3654 
3655  InitExpr = Init.get();
3656 
3657  FD->setInClassInitializer(InitExpr);
3658 }
3659 
3660 /// Find the direct and/or virtual base specifiers that
3661 /// correspond to the given base type, for use in base initialization
3662 /// within a constructor.
3663 static bool FindBaseInitializer(Sema &SemaRef,
3664  CXXRecordDecl *ClassDecl,
3665  QualType BaseType,
3666  const CXXBaseSpecifier *&DirectBaseSpec,
3667  const CXXBaseSpecifier *&VirtualBaseSpec) {
3668  // First, check for a direct base class.
3669  DirectBaseSpec = nullptr;
3670  for (const auto &Base : ClassDecl->bases()) {
3671  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3672  // We found a direct base of this type. That's what we're
3673  // initializing.
3674  DirectBaseSpec = &Base;
3675  break;
3676  }
3677  }
3678 
3679  // Check for a virtual base class.
3680  // FIXME: We might be able to short-circuit this if we know in advance that
3681  // there are no virtual bases.
3682  VirtualBaseSpec = nullptr;
3683  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3684  // We haven't found a base yet; search the class hierarchy for a
3685  // virtual base class.
3686  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3687  /*DetectVirtual=*/false);
3688  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3689  SemaRef.Context.getTypeDeclType(ClassDecl),
3690  BaseType, Paths)) {
3691  for (CXXBasePaths::paths_iterator Path = Paths.begin();
3692  Path != Paths.end(); ++Path) {
3693  if (Path->back().Base->isVirtual()) {
3694  VirtualBaseSpec = Path->back().Base;
3695  break;
3696  }
3697  }
3698  }
3699  }
3700 
3701  return DirectBaseSpec || VirtualBaseSpec;
3702 }
3703 
3704 /// Handle a C++ member initializer using braced-init-list syntax.
3706 Sema::ActOnMemInitializer(Decl *ConstructorD,
3707  Scope *S,
3708  CXXScopeSpec &SS,
3709  IdentifierInfo *MemberOrBase,
3710  ParsedType TemplateTypeTy,
3711  const DeclSpec &DS,
3712  SourceLocation IdLoc,
3713  Expr *InitList,
3714  SourceLocation EllipsisLoc) {
3715  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3716  DS, IdLoc, InitList,
3717  EllipsisLoc);
3718 }
3719 
3720 /// Handle a C++ member initializer using parentheses syntax.
3722 Sema::ActOnMemInitializer(Decl *ConstructorD,
3723  Scope *S,
3724  CXXScopeSpec &SS,
3725  IdentifierInfo *MemberOrBase,
3726  ParsedType TemplateTypeTy,
3727  const DeclSpec &DS,
3728  SourceLocation IdLoc,
3729  SourceLocation LParenLoc,
3730  ArrayRef<Expr *> Args,
3731  SourceLocation RParenLoc,
3732  SourceLocation EllipsisLoc) {
3733  Expr *List = new (Context) ParenListExpr(Context, LParenLoc,
3734  Args, RParenLoc);
3735  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3736  DS, IdLoc, List, EllipsisLoc);
3737 }
3738 
3739 namespace {
3740 
3741 // Callback to only accept typo corrections that can be a valid C++ member
3742 // intializer: either a non-static field member or a base class.
3743 class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
3744 public:
3745  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
3746  : ClassDecl(ClassDecl) {}
3747 
3748  bool ValidateCandidate(const TypoCorrection &candidate) override {
3749  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
3750  if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
3751  return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
3752  return isa<TypeDecl>(ND);
3753  }
3754  return false;
3755  }
3756 
3757 private:
3758  CXXRecordDecl *ClassDecl;
3759 };
3760 
3761 }
3762 
3763 ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
3764  CXXScopeSpec &SS,
3765  ParsedType TemplateTypeTy,
3766  IdentifierInfo *MemberOrBase) {
3767  if (SS.getScopeRep() || TemplateTypeTy)
3768  return nullptr;
3769  DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
3770  if (Result.empty())
3771  return nullptr;
3772  ValueDecl *Member;
3773  if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
3774  (Member = dyn_cast<IndirectFieldDecl>(Result.front())))
3775  return Member;
3776  return nullptr;
3777 }
3778 
3779 /// Handle a C++ member initializer.
3781 Sema::BuildMemInitializer(Decl *ConstructorD,
3782  Scope *S,
3783  CXXScopeSpec &SS,
3784  IdentifierInfo *MemberOrBase,
3785  ParsedType TemplateTypeTy,
3786  const DeclSpec &DS,
3787  SourceLocation IdLoc,
3788  Expr *Init,
3789  SourceLocation EllipsisLoc) {
3790  ExprResult Res = CorrectDelayedTyposInExpr(Init);
3791  if (!Res.isUsable())
3792  return true;
3793  Init = Res.get();
3794 
3795  if (!ConstructorD)
3796  return true;
3797 
3798  AdjustDeclIfTemplate(ConstructorD);
3799 
3800  CXXConstructorDecl *Constructor
3801  = dyn_cast<CXXConstructorDecl>(ConstructorD);
3802  if (!Constructor) {
3803  // The user wrote a constructor initializer on a function that is
3804  // not a C++ constructor. Ignore the error for now, because we may
3805  // have more member initializers coming; we'll diagnose it just
3806  // once in ActOnMemInitializers.
3807  return true;
3808  }
3809 
3810  CXXRecordDecl *ClassDecl = Constructor->getParent();
3811 
3812  // C++ [class.base.init]p2:
3813  // Names in a mem-initializer-id are looked up in the scope of the
3814  // constructor's class and, if not found in that scope, are looked
3815  // up in the scope containing the constructor's definition.
3816  // [Note: if the constructor's class contains a member with the
3817  // same name as a direct or virtual base class of the class, a
3818  // mem-initializer-id naming the member or base class and composed
3819  // of a single identifier refers to the class member. A
3820  // mem-initializer-id for the hidden base class may be specified
3821  // using a qualified name. ]
3822 
3823  // Look for a member, first.
3824  if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
3825  ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
3826  if (EllipsisLoc.isValid())
3827  Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
3828  << MemberOrBase
3829  << SourceRange(IdLoc, Init->getSourceRange().getEnd());
3830 
3831  return BuildMemberInitializer(Member, Init, IdLoc);
3832  }
3833  // It didn't name a member, so see if it names a class.
3834  QualType BaseType;
3835  TypeSourceInfo *TInfo = nullptr;
3836 
3837  if (TemplateTypeTy) {
3838  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
3839  } else if (DS.getTypeSpecType() == TST_decltype) {
3840  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
3841  } else if (DS.getTypeSpecType() == TST_decltype_auto) {
3842  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
3843  return true;
3844  } else {
3845  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
3846  LookupParsedName(R, S, &SS);
3847 
3848  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
3849  if (!TyD) {
3850  if (R.isAmbiguous()) return true;
3851 
3852  // We don't want access-control diagnostics here.
3853  R.suppressDiagnostics();
3854 
3855  if (SS.isSet() && isDependentScopeSpecifier(SS)) {
3856  bool NotUnknownSpecialization = false;
3857  DeclContext *DC = computeDeclContext(SS, false);
3858  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
3859  NotUnknownSpecialization = !Record->hasAnyDependentBases();
3860 
3861  if (!NotUnknownSpecialization) {
3862  // When the scope specifier can refer to a member of an unknown
3863  // specialization, we take it as a type name.
3864  BaseType = CheckTypenameType(ETK_None, SourceLocation(),
3865  SS.getWithLocInContext(Context),
3866  *MemberOrBase, IdLoc);
3867  if (BaseType.isNull())
3868  return true;
3869 
3870  TInfo = Context.CreateTypeSourceInfo(BaseType);
3873  if (!TL.isNull()) {
3874  TL.setNameLoc(IdLoc);
3876  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3877  }
3878 
3879  R.clear();
3880  R.setLookupName(MemberOrBase);
3881  }
3882  }
3883 
3884  // If no results were found, try to correct typos.
3885  TypoCorrection Corr;
3886  if (R.empty() && BaseType.isNull() &&
3887  (Corr = CorrectTypo(
3888  R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
3889  llvm::make_unique<MemInitializerValidatorCCC>(ClassDecl),
3890  CTK_ErrorRecovery, ClassDecl))) {
3891  if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
3892  // We have found a non-static data member with a similar
3893  // name to what was typed; complain and initialize that
3894  // member.
3895  diagnoseTypo(Corr,
3896  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3897  << MemberOrBase << true);
3898  return BuildMemberInitializer(Member, Init, IdLoc);
3899  } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
3900  const CXXBaseSpecifier *DirectBaseSpec;
3901  const CXXBaseSpecifier *VirtualBaseSpec;
3902  if (FindBaseInitializer(*this, ClassDecl,
3903  Context.getTypeDeclType(Type),
3904  DirectBaseSpec, VirtualBaseSpec)) {
3905  // We have found a direct or virtual base class with a
3906  // similar name to what was typed; complain and initialize
3907  // that base class.
3908  diagnoseTypo(Corr,
3909  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3910  << MemberOrBase << false,
3911  PDiag() /*Suppress note, we provide our own.*/);
3912 
3913  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
3914  : VirtualBaseSpec;
3915  Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
3916  << BaseSpec->getType() << BaseSpec->getSourceRange();
3917 
3918  TyD = Type;
3919  }
3920  }
3921  }
3922 
3923  if (!TyD && BaseType.isNull()) {
3924  Diag(IdLoc, diag::err_mem_init_not_member_or_class)
3925  << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
3926  return true;
3927  }
3928  }
3929 
3930  if (BaseType.isNull()) {
3931  BaseType = Context.getTypeDeclType(TyD);
3932  MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
3933  if (SS.isSet()) {
3934  BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
3935  BaseType);
3936  TInfo = Context.CreateTypeSourceInfo(BaseType);
3938  TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
3940  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3941  }
3942  }
3943  }
3944 
3945  if (!TInfo)
3946  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
3947 
3948  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
3949 }
3950 
3953  SourceLocation IdLoc) {
3954  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
3955  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
3956  assert((DirectMember || IndirectMember) &&
3957  "Member must be a FieldDecl or IndirectFieldDecl");
3958 
3959  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
3960  return true;
3961 
3962  if (Member->isInvalidDecl())
3963  return true;
3964 
3965  MultiExprArg Args;
3966  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
3967  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
3968  } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
3969  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
3970  } else {
3971  // Template instantiation doesn't reconstruct ParenListExprs for us.
3972  Args = Init;
3973  }
3974 
3975  SourceRange InitRange = Init->getSourceRange();
3976 
3977  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
3978  // Can't check initialization for a member of dependent type or when
3979  // any of the arguments are type-dependent expressions.
3980  DiscardCleanupsInEvaluationContext();
3981  } else {
3982  bool InitList = false;
3983  if (isa<InitListExpr>(Init)) {
3984  InitList = true;
3985  Args = Init;
3986  }
3987 
3988  // Initialize the member.
3989  InitializedEntity MemberEntity =
3990  DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
3991  : InitializedEntity::InitializeMember(IndirectMember,
3992  nullptr);
3995  IdLoc, Init->getBeginLoc(), Init->getEndLoc())
3996  : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
3997  InitRange.getEnd());
3998 
3999  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4000  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4001  nullptr);
4002  if (MemberInit.isInvalid())
4003  return true;
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->getBeginLoc(), Init->getEndLoc())
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->getBeginLoc();
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->isZeroLengthBitField(SemaRef.Context))
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  /// 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 /// 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 
4617  auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4618  SemaRef.checkInitializerLifetime(Entity, DIE.get());
4619 
4620  CXXCtorInitializer *Init;
4621  if (Indirect)
4622  Init = new (SemaRef.Context)
4623  CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4624  SourceLocation(), DIE.get(), SourceLocation());
4625  else
4626  Init = new (SemaRef.Context)
4627  CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4628  SourceLocation(), DIE.get(), SourceLocation());
4629  return Info.addFieldInitializer(Init);
4630  }
4631 
4632  // Don't initialize incomplete or zero-length arrays.
4633  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4634  return false;
4635 
4636  // Don't try to build an implicit initializer if there were semantic
4637  // errors in any of the initializers (and therefore we might be
4638  // missing some that the user actually wrote).
4639  if (Info.AnyErrorsInInits)
4640  return false;
4641 
4642  CXXCtorInitializer *Init = nullptr;
4643  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4644  Indirect, Init))
4645  return true;
4646 
4647  if (!Init)
4648  return false;
4649 
4650  return Info.addFieldInitializer(Init);
4651 }
4652 
4653 bool
4655  CXXCtorInitializer *Initializer) {
4656  assert(Initializer->isDelegatingInitializer());
4657  Constructor->setNumCtorInitializers(1);
4658  CXXCtorInitializer **initializer =
4659  new (Context) CXXCtorInitializer*[1];
4660  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4661  Constructor->setCtorInitializers(initializer);
4662 
4663  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4664  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4665  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4666  }
4667 
4668  DelegatingCtorDecls.push_back(Constructor);
4669 
4670  DiagnoseUninitializedFields(*this, Constructor);
4671 
4672  return false;
4673 }
4674 
4675 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4676  ArrayRef<CXXCtorInitializer *> Initializers) {
4677  if (Constructor->isDependentContext()) {
4678  // Just store the initializers as written, they will be checked during
4679  // instantiation.
4680  if (!Initializers.empty()) {
4681  Constructor->setNumCtorInitializers(Initializers.size());
4682  CXXCtorInitializer **baseOrMemberInitializers =
4683  new (Context) CXXCtorInitializer*[Initializers.size()];
4684  memcpy(baseOrMemberInitializers, Initializers.data(),
4685  Initializers.size() * sizeof(CXXCtorInitializer*));
4686  Constructor->setCtorInitializers(baseOrMemberInitializers);
4687  }
4688 
4689  // Let template instantiation know whether we had errors.
4690  if (AnyErrors)
4691  Constructor->setInvalidDecl();
4692 
4693  return false;
4694  }
4695 
4696  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4697 
4698  // We need to build the initializer AST according to order of construction
4699  // and not what user specified in the Initializers list.
4700  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4701  if (!ClassDecl)
4702  return true;
4703 
4704  bool HadError = false;
4705 
4706  for (unsigned i = 0; i < Initializers.size(); i++) {
4707  CXXCtorInitializer *Member = Initializers[i];
4708 
4709  if (Member->isBaseInitializer())
4710  Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
4711  else {
4712  Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
4713 
4714  if (IndirectFieldDecl *F = Member->getIndirectMember()) {
4715  for (auto *C : F->chain()) {
4716  FieldDecl *FD = dyn_cast<FieldDecl>(C);
4717  if (FD && FD->getParent()->isUnion())
4718  Info.ActiveUnionMember.insert(std::make_pair(
4719  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4720  }
4721  } else if (FieldDecl *FD = Member->getMember()) {
4722  if (FD->getParent()->isUnion())
4723  Info.ActiveUnionMember.insert(std::make_pair(
4724  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4725  }
4726  }
4727  }
4728 
4729  // Keep track of the direct virtual bases.
4730  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
4731  for (auto &I : ClassDecl->bases()) {
4732  if (I.isVirtual())
4733  DirectVBases.insert(&I);
4734  }
4735 
4736  // Push virtual bases before others.
4737  for (auto &VBase : ClassDecl->vbases()) {
4739  = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
4740  // [class.base.init]p7, per DR257:
4741  // A mem-initializer where the mem-initializer-id names a virtual base
4742  // class is ignored during execution of a constructor of any class that
4743  // is not the most derived class.
4744  if (ClassDecl->isAbstract()) {
4745  // FIXME: Provide a fixit to remove the base specifier. This requires
4746  // tracking the location of the associated comma for a base specifier.
4747  Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
4748  << VBase.getType() << ClassDecl;
4749  DiagnoseAbstractType(ClassDecl);
4750  }
4751 
4752  Info.AllToInit.push_back(Value);
4753  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
4754  // [class.base.init]p8, per DR257:
4755  // If a given [...] base class is not named by a mem-initializer-id
4756  // [...] and the entity is not a virtual base class of an abstract
4757  // class, then [...] the entity is default-initialized.
4758  bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
4759  CXXCtorInitializer *CXXBaseInit;
4760  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4761  &VBase, IsInheritedVirtualBase,
4762  CXXBaseInit)) {
4763  HadError = true;
4764  continue;
4765  }
4766 
4767  Info.AllToInit.push_back(CXXBaseInit);
4768  }
4769  }
4770 
4771  // Non-virtual bases.
4772  for (auto &Base : ClassDecl->bases()) {
4773  // Virtuals are in the virtual base list and already constructed.
4774  if (Base.isVirtual())
4775  continue;
4776 
4778  = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
4779  Info.AllToInit.push_back(Value);
4780  } else if (!AnyErrors) {
4781  CXXCtorInitializer *CXXBaseInit;
4782  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4783  &Base, /*IsInheritedVirtualBase=*/false,
4784  CXXBaseInit)) {
4785  HadError = true;
4786  continue;
4787  }
4788 
4789  Info.AllToInit.push_back(CXXBaseInit);
4790  }
4791  }
4792 
4793  // Fields.
4794  for (auto *Mem : ClassDecl->decls()) {
4795  if (auto *F = dyn_cast<FieldDecl>(Mem)) {
4796  // C++ [class.bit]p2:
4797  // A declaration for a bit-field that omits the identifier declares an
4798  // unnamed bit-field. Unnamed bit-fields are not members and cannot be
4799  // initialized.
4800  if (F->isUnnamedBitfield())
4801  continue;
4802 
4803  // If we're not generating the implicit copy/move constructor, then we'll
4804  // handle anonymous struct/union fields based on their individual
4805  // indirect fields.
4806  if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
4807  continue;
4808 
4809  if (CollectFieldInitializer(*this, Info, F))
4810  HadError = true;
4811  continue;
4812  }
4813 
4814  // Beyond this point, we only consider default initialization.
4815  if (Info.isImplicitCopyOrMove())
4816  continue;
4817 
4818  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
4819  if (F->getType()->isIncompleteArrayType()) {
4820  assert(ClassDecl->hasFlexibleArrayMember() &&
4821  "Incomplete array type is not valid");
4822  continue;
4823  }
4824 
4825  // Initialize each field of an anonymous struct individually.
4826  if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
4827  HadError = true;
4828 
4829  continue;
4830  }
4831  }
4832 
4833  unsigned NumInitializers = Info.AllToInit.size();
4834  if (NumInitializers > 0) {
4835  Constructor->setNumCtorInitializers(NumInitializers);
4836  CXXCtorInitializer **baseOrMemberInitializers =
4837  new (Context) CXXCtorInitializer*[NumInitializers];
4838  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
4839  NumInitializers * sizeof(CXXCtorInitializer*));
4840  Constructor->setCtorInitializers(baseOrMemberInitializers);
4841 
4842  // Constructors implicitly reference the base and member
4843  // destructors.
4844  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
4845  Constructor->getParent());
4846  }
4847 
4848  return HadError;
4849 }
4850 
4852  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
4853  const RecordDecl *RD = RT->getDecl();
4854  if (RD->isAnonymousStructOrUnion()) {
4855  for (auto *Field : RD->fields())
4856  PopulateKeysForFields(Field, IdealInits);
4857  return;
4858  }
4859  }
4860  IdealInits.push_back(Field->getCanonicalDecl());
4861 }
4862 
4863 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
4864  return Context.getCanonicalType(BaseType).getTypePtr();
4865 }
4866 
4867 static const void *GetKeyForMember(ASTContext &Context,
4868  CXXCtorInitializer *Member) {
4869  if (!Member->isAnyMemberInitializer())
4870  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
4871 
4872  return Member->getAnyMember()->getCanonicalDecl();
4873 }
4874 
4876  Sema &SemaRef, const CXXConstructorDecl *Constructor,
4878  if (Constructor->getDeclContext()->isDependentContext())
4879  return;
4880 
4881  // Don't check initializers order unless the warning is enabled at the
4882  // location of at least one initializer.
4883  bool ShouldCheckOrder = false;
4884  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4885  CXXCtorInitializer *Init = Inits[InitIndex];
4886  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
4887  Init->getSourceLocation())) {
4888  ShouldCheckOrder = true;
4889  break;
4890  }
4891  }
4892  if (!ShouldCheckOrder)
4893  return;
4894 
4895  // Build the list of bases and members in the order that they'll
4896  // actually be initialized. The explicit initializers should be in
4897  // this same order but may be missing things.
4898  SmallVector<const void*, 32> IdealInitKeys;
4899 
4900  const CXXRecordDecl *ClassDecl = Constructor->getParent();
4901 
4902  // 1. Virtual bases.
4903  for (const auto &VBase : ClassDecl->vbases())
4904  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
4905 
4906  // 2. Non-virtual bases.
4907  for (const auto &Base : ClassDecl->bases()) {
4908  if (Base.isVirtual())
4909  continue;
4910  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
4911  }
4912 
4913  // 3. Direct fields.
4914  for (auto *Field : ClassDecl->fields()) {
4915  if (Field->isUnnamedBitfield())
4916  continue;
4917 
4918  PopulateKeysForFields(Field, IdealInitKeys);
4919  }
4920 
4921  unsigned NumIdealInits = IdealInitKeys.size();
4922  unsigned IdealIndex = 0;
4923 
4924  CXXCtorInitializer *PrevInit = nullptr;
4925  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4926  CXXCtorInitializer *Init = Inits[InitIndex];
4927  const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
4928 
4929  // Scan forward to try to find this initializer in the idealized
4930  // initializers list.
4931  for (; IdealIndex != NumIdealInits; ++IdealIndex)
4932  if (InitKey == IdealInitKeys[IdealIndex])
4933  break;
4934 
4935  // If we didn't find this initializer, it must be because we
4936  // scanned past it on a previous iteration. That can only
4937  // happen if we're out of order; emit a warning.
4938  if (IdealIndex == NumIdealInits && PrevInit) {
4940  SemaRef.Diag(PrevInit->getSourceLocation(),
4941  diag::warn_initializer_out_of_order);
4942 
4943  if (PrevInit->isAnyMemberInitializer())
4944  D << 0 << PrevInit->getAnyMember()->getDeclName();
4945  else
4946  D << 1 << PrevInit->getTypeSourceInfo()->getType();
4947 
4948  if (Init->isAnyMemberInitializer())
4949  D << 0 << Init->getAnyMember()->getDeclName();
4950  else
4951  D << 1 << Init->getTypeSourceInfo()->getType();
4952 
4953  // Move back to the initializer's location in the ideal list.
4954  for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
4955  if (InitKey == IdealInitKeys[IdealIndex])
4956  break;
4957 
4958  assert(IdealIndex < NumIdealInits &&
4959  "initializer not found in initializer list");
4960  }
4961 
4962  PrevInit = Init;
4963  }
4964 }
4965 
4966 namespace {
4967 bool CheckRedundantInit(Sema &S,
4968  CXXCtorInitializer *Init,
4969  CXXCtorInitializer *&PrevInit) {
4970  if (!PrevInit) {
4971  PrevInit = Init;
4972  return false;
4973  }
4974 
4975  if (FieldDecl *Field = Init->getAnyMember())
4976  S.Diag(Init->getSourceLocation(),
4977  diag::err_multiple_mem_initialization)
4978  << Field->getDeclName()
4979  << Init->getSourceRange();
4980  else {
4981  const Type *BaseClass = Init->getBaseClass();
4982  assert(BaseClass && "neither field nor base");
4983  S.Diag(Init->getSourceLocation(),
4984  diag::err_multiple_base_initialization)
4985  << QualType(BaseClass, 0)
4986  << Init->getSourceRange();
4987  }
4988  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
4989  << 0 << PrevInit->getSourceRange();
4990 
4991  return true;
4992 }
4993 
4994 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
4995 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
4996 
4997 bool CheckRedundantUnionInit(Sema &S,
4998  CXXCtorInitializer *Init,
4999  RedundantUnionMap &Unions) {
5000  FieldDecl *Field = Init->getAnyMember();
5001  RecordDecl *Parent = Field->getParent();
5002  NamedDecl *Child = Field;
5003 
5004  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5005  if (Parent->isUnion()) {
5006  UnionEntry &En = Unions[Parent];
5007  if (En.first && En.first != Child) {
5008  S.Diag(Init->getSourceLocation(),
5009  diag::err_multiple_mem_union_initialization)
5010  << Field->getDeclName()
5011  << Init->getSourceRange();
5012  S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5013  << 0 << En.second->getSourceRange();
5014  return true;
5015  }
5016  if (!En.first) {
5017  En.first = Child;
5018  En.second = Init;
5019  }
5020  if (!Parent->isAnonymousStructOrUnion())
5021  return false;
5022  }
5023 
5024  Child = Parent;
5025  Parent = cast<RecordDecl>(Parent->getDeclContext());
5026  }
5027 
5028  return false;
5029 }
5030 }
5031 
5032 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5033 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5036  bool AnyErrors) {
5037  if (!ConstructorDecl)
5038  return;
5039 
5040  AdjustDeclIfTemplate(ConstructorDecl);
5041 
5042  CXXConstructorDecl *Constructor
5043  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5044 
5045  if (!Constructor) {
5046  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5047  return;
5048  }
5049 
5050  // Mapping for the duplicate initializers check.
5051  // For member initializers, this is keyed with a FieldDecl*.
5052  // For base initializers, this is keyed with a Type*.
5053  llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5054 
5055  // Mapping for the inconsistent anonymous-union initializers check.
5056  RedundantUnionMap MemberUnions;
5057 
5058  bool HadError = false;
5059  for (unsigned i = 0; i < MemInits.size(); i++) {
5060  CXXCtorInitializer *Init = MemInits[i];
5061 
5062  // Set the source order index.
5063  Init->setSourceOrder(i);
5064 
5065  if (Init->isAnyMemberInitializer()) {
5066  const void *Key = GetKeyForMember(Context, Init);
5067  if (CheckRedundantInit(*this, Init, Members[Key]) ||
5068  CheckRedundantUnionInit(*this, Init, MemberUnions))
5069  HadError = true;
5070  } else if (Init->isBaseInitializer()) {
5071  const void *Key = GetKeyForMember(Context, Init);
5072  if (CheckRedundantInit(*this, Init, Members[Key]))
5073  HadError = true;
5074  } else {
5075  assert(Init->isDelegatingInitializer());
5076  // This must be the only initializer
5077  if (MemInits.size() != 1) {
5078  Diag(Init->getSourceLocation(),
5079  diag::err_delegating_initializer_alone)
5080  << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5081  // We will treat this as being the only initializer.
5082  }
5083  SetDelegatingInitializer(Constructor, MemInits[i]);
5084  // Return immediately as the initializer is set.
5085  return;
5086  }
5087  }
5088 
5089  if (HadError)
5090  return;
5091 
5092  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5093 
5094  SetCtorInitializers(Constructor, AnyErrors, MemInits);
5095 
5096  DiagnoseUninitializedFields(*this, Constructor);
5097 }
5098 
5099 void
5101  CXXRecordDecl *ClassDecl) {
5102  // Ignore dependent contexts. Also ignore unions, since their members never
5103  // have destructors implicitly called.
5104  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5105  return;
5106 
5107  // FIXME: all the access-control diagnostics are positioned on the
5108  // field/base declaration. That's probably good; that said, the
5109  // user might reasonably want to know why the destructor is being
5110  // emitted, and we currently don't say.
5111 
5112  // Non-static data members.
5113  for (auto *Field : ClassDecl->fields()) {
5114  if (Field->isInvalidDecl())
5115  continue;
5116 
5117  // Don't destroy incomplete or zero-length arrays.
5118  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5119  continue;
5120 
5121  QualType FieldType = Context.getBaseElementType(Field->getType());
5122 
5123  const RecordType* RT = FieldType->getAs<RecordType>();
5124  if (!RT)
5125  continue;
5126 
5127  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5128  if (FieldClassDecl->isInvalidDecl())
5129  continue;
5130  if (FieldClassDecl->hasIrrelevantDestructor())
5131  continue;
5132  // The destructor for an implicit anonymous union member is never invoked.
5133  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5134  continue;
5135 
5136  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5137  assert(Dtor && "No dtor found for FieldClassDecl!");
5138  CheckDestructorAccess(Field->getLocation(), Dtor,
5139  PDiag(diag::err_access_dtor_field)
5140  << Field->getDeclName()
5141  << FieldType);
5142 
5143  MarkFunctionReferenced(Location, Dtor);
5144  DiagnoseUseOfDecl(Dtor, Location);
5145  }
5146 
5147  // We only potentially invoke the destructors of potentially constructed
5148  // subobjects.
5149  bool VisitVirtualBases = !ClassDecl->isAbstract();
5150 
5151  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5152 
5153  // Bases.
5154  for (const auto &Base : ClassDecl->bases()) {
5155  // Bases are always records in a well-formed non-dependent class.
5156  const RecordType *RT = Base.getType()->getAs<RecordType>();
5157 
5158  // Remember direct virtual bases.
5159  if (Base.isVirtual()) {
5160  if (!VisitVirtualBases)
5161  continue;
5162  DirectVirtualBases.insert(RT);
5163  }
5164 
5165  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5166  // If our base class is invalid, we probably can't get its dtor anyway.
5167  if (BaseClassDecl->isInvalidDecl())
5168  continue;
5169  if (BaseClassDecl->hasIrrelevantDestructor())
5170  continue;
5171 
5172  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5173  assert(Dtor && "No dtor found for BaseClassDecl!");
5174 
5175  // FIXME: caret should be on the start of the class name
5176  CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5177  PDiag(diag::err_access_dtor_base)
5178  << Base.getType() << Base.getSourceRange(),
5179  Context.getTypeDeclType(ClassDecl));
5180 
5181  MarkFunctionReferenced(Location, Dtor);
5182  DiagnoseUseOfDecl(Dtor, Location);
5183  }
5184 
5185  if (!VisitVirtualBases)
5186  return;
5187 
5188  // Virtual bases.
5189  for (const auto &VBase : ClassDecl->vbases()) {
5190  // Bases are always records in a well-formed non-dependent class.
5191  const RecordType *RT = VBase.getType()->castAs<RecordType>();
5192 
5193  // Ignore direct virtual bases.
5194  if (DirectVirtualBases.count(RT))
5195  continue;
5196 
5197  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5198  // If our base class is invalid, we probably can't get its dtor anyway.
5199  if (BaseClassDecl->isInvalidDecl())
5200  continue;
5201  if (BaseClassDecl->hasIrrelevantDestructor())
5202  continue;
5203 
5204  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5205  assert(Dtor && "No dtor found for BaseClassDecl!");
5206  if (CheckDestructorAccess(
5207  ClassDecl->getLocation(), Dtor,
5208  PDiag(diag::err_access_dtor_vbase)
5209  << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5210  Context.getTypeDeclType(ClassDecl)) ==
5211  AR_accessible) {
5212  CheckDerivedToBaseConversion(
5213  Context.getTypeDeclType(ClassDecl), VBase.getType(),
5214  diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5215  SourceRange(), DeclarationName(), nullptr);
5216  }
5217 
5218  MarkFunctionReferenced(Location, Dtor);
5219  DiagnoseUseOfDecl(Dtor, Location);
5220  }
5221 }
5222 
5223 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5224  if (!CDtorDecl)
5225  return;
5226 
5227  if (CXXConstructorDecl *Constructor
5228  = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5229  SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5230  DiagnoseUninitializedFields(*this, Constructor);
5231  }
5232 }
5233 
5235  if (!getLangOpts().CPlusPlus)
5236  return false;
5237 
5238  const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5239  if (!RD)
5240  return false;
5241 
5242  // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5243  // class template specialization here, but doing so breaks a lot of code.
5244 
5245  // We can't answer whether something is abstract until it has a
5246  // definition. If it's currently being defined, we'll walk back
5247  // over all the declarations when we have a full definition.
5248  const CXXRecordDecl *Def = RD->getDefinition();
5249  if (!Def || Def->isBeingDefined())
5250  return false;
5251 
5252  return RD->isAbstract();
5253 }
5254 
5256  TypeDiagnoser &Diagnoser) {
5257  if (!isAbstractType(Loc, T))
5258  return false;
5259 
5260  T = Context.getBaseElementType(T);
5261  Diagnoser.diagnose(*this, Loc, T);
5262  DiagnoseAbstractType(T->getAsCXXRecordDecl());
5263  return true;
5264 }
5265 
5267  // Check if we've already emitted the list of pure virtual functions
5268  // for this class.
5269  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5270  return;
5271 
5272  // If the diagnostic is suppressed, don't emit the notes. We're only
5273  // going to emit them once, so try to attach them to a diagnostic we're
5274  // actually going to show.
5275  if (Diags.isLastDiagnosticIgnored())
5276  return;
5277 
5278  CXXFinalOverriderMap FinalOverriders;
5279  RD->getFinalOverriders(FinalOverriders);
5280 
5281  // Keep a set of seen pure methods so we won't diagnose the same method
5282  // more than once.
5283  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5284 
5285  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5286  MEnd = FinalOverriders.end();
5287  M != MEnd;
5288  ++M) {
5289  for (OverridingMethods::iterator SO = M->second.begin(),
5290  SOEnd = M->second.end();
5291  SO != SOEnd; ++SO) {
5292  // C++ [class.abstract]p4:
5293  // A class is abstract if it contains or inherits at least one
5294  // pure virtual function for which the final overrider is pure
5295  // virtual.
5296 
5297  //
5298  if (SO->second.size() != 1)
5299  continue;
5300 
5301  if (!SO->second.front().Method->isPure())
5302  continue;
5303 
5304  if (!SeenPureMethods.insert(SO->second.front().Method).second)
5305  continue;
5306 
5307  Diag(SO->second.front().Method->getLocation(),
5308  diag::note_pure_virtual_function)
5309  << SO->second.front().Method->getDeclName() << RD->getDeclName();
5310  }
5311  }
5312 
5313  if (!PureVirtualClassDiagSet)
5314  PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5315  PureVirtualClassDiagSet->insert(RD);
5316 }
5317 
5318 namespace {
5319 struct AbstractUsageInfo {
5320  Sema &S;
5321  CXXRecordDecl *Record;
5322  CanQualType AbstractType;
5323  bool Invalid;
5324 
5325  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5326  : S(S), Record(Record),
5327  AbstractType(S.Context.getCanonicalType(
5328  S.Context.getTypeDeclType(Record))),
5329  Invalid(false) {}
5330 
5331  void DiagnoseAbstractType() {
5332  if (Invalid) return;
5333  S.DiagnoseAbstractType(Record);
5334  Invalid = true;
5335  }
5336 
5337  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5338 };
5339 
5340 struct CheckAbstractUsage {
5341  AbstractUsageInfo &Info;
5342  const NamedDecl *Ctx;
5343 
5344  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5345  : Info(Info), Ctx(Ctx) {}
5346 
5347  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5348  switch (TL.getTypeLocClass()) {
5349 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5350 #define TYPELOC(CLASS, PARENT) \
5351  case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5352 #include "clang/AST/TypeLocNodes.def"
5353  }
5354  }
5355 
5356  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5358  for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5359  if (!TL.getParam(I))
5360  continue;
5361 
5362  TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5363  if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5364  }
5365  }
5366 
5367  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5369  }
5370 
5372  // Visit the type parameters from a permissive context.
5373  for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5374  TemplateArgumentLoc TAL = TL.getArgLoc(I);
5376  if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5377  Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5378  // TODO: other template argument types?
5379  }
5380  }
5381 
5382  // Visit pointee types from a permissive context.
5383 #define CheckPolymorphic(Type) \
5384  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5385  Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5386  }
5392 
5393  /// Handle all the types we haven't given a more specific
5394  /// implementation for above.
5395  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5396  // Every other kind of type that we haven't called out already
5397  // that has an inner type is either (1) sugar or (2) contains that
5398  // inner type in some way as a subobject.
5399  if (TypeLoc Next = TL.getNextTypeLoc())
5400  return Visit(Next, Sel);
5401 
5402  // If there's no inner type and we're in a permissive context,
5403  // don't diagnose.
5404  if (Sel == Sema::AbstractNone) return;
5405 
5406  // Check whether the type matches the abstract type.
5407  QualType T = TL.getType();
5408  if (T->isArrayType()) {
5410  T = Info.S.Context.getBaseElementType(T);
5411  }
5413  if (CT != Info.AbstractType) return;
5414 
5415  // It matched; do some magic.
5416  if (Sel == Sema::AbstractArrayType) {
5417  Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5418  << T << TL.getSourceRange();
5419  } else {
5420  Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5421  << Sel << T << TL.getSourceRange();
5422  }
5423  Info.DiagnoseAbstractType();
5424  }
5425 };
5426 
5427 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5429  CheckAbstractUsage(*this, D).Visit(TL, Sel);
5430 }
5431 
5432 }
5433 
5434 /// Check for invalid uses of an abstract type in a method declaration.
5435 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5436  CXXMethodDecl *MD) {
5437  // No need to do the check on definitions, which require that
5438  // the return/param types be complete.
5439  if (MD->doesThisDeclarationHaveABody())
5440  return;
5441 
5442  // For safety's sake, just ignore it if we don't have type source
5443  // information. This should never happen for non-implicit methods,
5444  // but...
5445  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5446  Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5447 }
5448 
5449 /// Check for invalid uses of an abstract type within a class definition.
5450 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5451  CXXRecordDecl *RD) {
5452  for (auto *D : RD->decls()) {
5453  if (D->isImplicit()) continue;
5454 
5455  // Methods and method templates.
5456  if (isa<CXXMethodDecl>(D)) {
5457  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5458  } else if (isa<FunctionTemplateDecl>(D)) {
5459  FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5460  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5461 
5462  // Fields and static variables.
5463  } else if (isa<FieldDecl>(D)) {
5464  FieldDecl *FD = cast<FieldDecl>(D);
5465  if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5466  Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5467  } else if (isa<VarDecl>(D)) {
5468  VarDecl *VD = cast<VarDecl>(D);
5469  if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5470  Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5471 
5472  // Nested classes and class templates.
5473  } else if (isa<CXXRecordDecl>(D)) {
5474  CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5475  } else if (isa<ClassTemplateDecl>(D)) {
5477  cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5478  }
5479  }
5480 }
5481 
5483  Attr *ClassAttr = getDLLAttr(Class);
5484  if (!ClassAttr)
5485  return;
5486 
5487  assert(ClassAttr->getKind() == attr::DLLExport);
5488 
5490 
5492  // Don't go any further if this is just an explicit instantiation
5493  // declaration.
5494  return;
5495 
5496  for (Decl *Member : Class->decls()) {
5497  // Defined static variables that are members of an exported base
5498  // class must be marked export too.
5499  auto *VD = dyn_cast<VarDecl>(Member);
5500  if (VD && Member->getAttr<DLLExportAttr>() &&
5501  VD->getStorageClass() == SC_Static &&
5503  S.MarkVariableReferenced(VD->getLocation(), VD);
5504 
5505  auto *MD = dyn_cast<CXXMethodDecl>(Member);
5506  if (!MD)
5507  continue;
5508 
5509  if (Member->getAttr<DLLExportAttr>()) {
5510  if (MD->isUserProvided()) {
5511  // Instantiate non-default class member functions ...
5512 
5513  // .. except for certain kinds of template specializations.
5514  if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5515  continue;
5516 
5517  S.MarkFunctionReferenced(Class->getLocation(), MD);
5518 
5519  // The function will be passed to the consumer when its definition is
5520  // encountered.
5521  } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5522  MD->isCopyAssignmentOperator() ||
5523  MD->isMoveAssignmentOperator()) {
5524  // Synthesize and instantiate non-trivial implicit methods, explicitly
5525  // defaulted methods, and the copy and move assignment operators. The
5526  // latter are exported even if they are trivial, because the address of
5527  // an operator can be taken and should compare equal across libraries.
5528  DiagnosticErrorTrap Trap(S.Diags);
5529  S.MarkFunctionReferenced(Class->getLocation(), MD);
5530  if (Trap.hasErrorOccurred()) {
5531  S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5532  << Class << !S.getLangOpts().CPlusPlus11;
5533  break;
5534  }
5535 
5536  // There is no later point when we will see the definition of this
5537  // function, so pass it to the consumer now.
5539  }
5540  }
5541  }
5542 }
5543 
5545  CXXRecordDecl *Class) {
5546  // Only the MS ABI has default constructor closures, so we don't need to do
5547  // this semantic checking anywhere else.
5549  return;
5550 
5551  CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5552  for (Decl *Member : Class->decls()) {
5553  // Look for exported default constructors.
5554  auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5555  if (!CD || !CD->isDefaultConstructor())
5556  continue;
5557  auto *Attr = CD->getAttr<DLLExportAttr>();
5558  if (!Attr)
5559  continue;
5560 
5561  // If the class is non-dependent, mark the default arguments as ODR-used so
5562  // that we can properly codegen the constructor closure.
5563  if (!Class->isDependentContext()) {
5564  for (ParmVarDecl *PD : CD->parameters()) {
5565  (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5567  }
5568  }
5569 
5570  if (LastExportedDefaultCtor) {
5571  S.Diag(LastExportedDefaultCtor->getLocation(),
5572  diag::err_attribute_dll_ambiguous_default_ctor)
5573  << Class;
5574  S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5575  << CD->getDeclName();
5576  return;
5577  }
5578  LastExportedDefaultCtor = CD;
5579  }
5580 }
5581 
5583  // Mark any compiler-generated routines with the implicit code_seg attribute.
5584  for (auto *Method : Class->methods()) {
5585  if (Method->isUserProvided())
5586  continue;
5587  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
5588  Method->addAttr(A);
5589  }
5590 }
5591 
5592 /// Check class-level dllimport/dllexport attribute.
5594  Attr *ClassAttr = getDLLAttr(Class);
5595 
5596  // MSVC inherits DLL attributes to partial class template specializations.
5597  if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5598  if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5599  if (Attr *TemplateAttr =
5600  getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5601  auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5602  A->setInherited(true);
5603  ClassAttr = A;
5604  }
5605  }
5606  }
5607 
5608  if (!ClassAttr)
5609  return;
5610 
5611  if (!Class->isExternallyVisible()) {
5612  Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5613  << Class << ClassAttr;
5614  return;
5615  }
5616 
5617  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5618  !ClassAttr->isInherited()) {
5619  // Diagnose dll attributes on members of class with dll attribute.
5620  for (Decl *Member : Class->decls()) {
5621  if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5622  continue;
5623  InheritableAttr *MemberAttr = getDLLAttr(Member);
5624  if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5625  continue;
5626 
5627  Diag(MemberAttr->getLocation(),
5628  diag::err_attribute_dll_member_of_dll_class)
5629  << MemberAttr << ClassAttr;
5630  Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5631  Member->setInvalidDecl();
5632  }
5633  }
5634 
5635  if (Class->getDescribedClassTemplate())
5636  // Don't inherit dll attribute until the template is instantiated.
5637  return;
5638 
5639  // The class is either imported or exported.
5640  const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5641 
5642  // Check if this was a dllimport attribute propagated from a derived class to
5643  // a base class template specialization. We don't apply these attributes to
5644  // static data members.
5645  const bool PropagatedImport =
5646  !ClassExported &&
5647  cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
5648 
5650 
5651  // Ignore explicit dllexport on explicit class template instantiation declarations.
5652  if (ClassExported && !ClassAttr->isInherited() &&
5654  Class->dropAttr<DLLExportAttr>();
5655  return;
5656  }
5657 
5658  // Force declaration of implicit members so they can inherit the attribute.
5659  ForceDeclarationOfImplicitMembers(Class);
5660 
5661  // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
5662  // seem to be true in practice?
5663 
5664  for (Decl *Member : Class->decls()) {
5665  VarDecl *VD = dyn_cast<VarDecl>(Member);
5666  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
5667 
5668  // Only methods and static fields inherit the attributes.
5669  if (!VD && !MD)
5670  continue;
5671 
5672  if (MD) {
5673  // Don't process deleted methods.
5674  if (MD->isDeleted())
5675  continue;
5676 
5677  if (MD->isInlined()) {
5678  // MinGW does not import or export inline methods.
5679  if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5680  !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())
5681  continue;
5682 
5683  // MSVC versions before 2015 don't export the move assignment operators
5684  // and move constructor, so don't attempt to import/export them if
5685  // we have a definition.
5686  auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
5687  if ((MD->isMoveAssignmentOperator() ||
5688  (Ctor && Ctor->isMoveConstructor())) &&
5689  !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
5690  continue;
5691 
5692  // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
5693  // operator is exported anyway.
5694  if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
5695  (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
5696  continue;
5697  }
5698  }
5699 
5700  // Don't apply dllimport attributes to static data members of class template
5701  // instantiations when the attribute is propagated from a derived class.
5702  if (VD && PropagatedImport)
5703  continue;
5704 
5705  if (!cast<NamedDecl>(Member)->isExternallyVisible())
5706  continue;
5707 
5708  if (!getDLLAttr(Member)) {
5709  auto *NewAttr =