clang  7.0.0svn
SemaDeclCXX.cpp
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1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements semantic analysis for C++ declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ASTLambda.h"
19 #include "clang/AST/CharUnits.h"
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->getLocStart(),
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->getLocStart(),
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->getLocStart(),
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->getLocStart(),
148  diag::err_lambda_capture_default_arg);
149  }
150 }
151 
152 void
154  const CXXMethodDecl *Method) {
155  // If we have an MSAny spec already, don't bother.
156  if (!Method || ComputedEST == EST_MSAny)
157  return;
158 
159  const FunctionProtoType *Proto
160  = Method->getType()->getAs<FunctionProtoType>();
161  Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
162  if (!Proto)
163  return;
164 
166 
167  // If we have a throw-all spec at this point, ignore the function.
168  if (ComputedEST == EST_None)
169  return;
170 
171  if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
172  EST = EST_BasicNoexcept;
173 
174  switch (EST) {
175  case EST_Unparsed:
176  case EST_Uninstantiated:
177  case EST_Unevaluated:
178  llvm_unreachable("should not see unresolved exception specs here");
179 
180  // If this function can throw any exceptions, make a note of that.
181  case EST_MSAny:
182  case EST_None:
183  // FIXME: Whichever we see last of MSAny and None determines our result.
184  // We should make a consistent, order-independent choice here.
185  ClearExceptions();
186  ComputedEST = EST;
187  return;
188  case EST_NoexceptFalse:
189  ClearExceptions();
190  ComputedEST = EST_None;
191  return;
192  // FIXME: If the call to this decl is using any of its default arguments, we
193  // need to search them for potentially-throwing calls.
194  // If this function has a basic noexcept, it doesn't affect the outcome.
195  case EST_BasicNoexcept:
196  case EST_NoexceptTrue:
197  return;
198  // If we're still at noexcept(true) and there's a throw() callee,
199  // change to that specification.
200  case EST_DynamicNone:
201  if (ComputedEST == EST_BasicNoexcept)
202  ComputedEST = EST_DynamicNone;
203  return;
205  llvm_unreachable(
206  "should not generate implicit declarations for dependent cases");
207  case EST_Dynamic:
208  break;
209  }
210  assert(EST == EST_Dynamic && "EST case not considered earlier.");
211  assert(ComputedEST != EST_None &&
212  "Shouldn't collect exceptions when throw-all is guaranteed.");
213  ComputedEST = EST_Dynamic;
214  // Record the exceptions in this function's exception specification.
215  for (const auto &E : Proto->exceptions())
216  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
217  Exceptions.push_back(E);
218 }
219 
221  if (!E || ComputedEST == EST_MSAny)
222  return;
223 
224  // FIXME:
225  //
226  // C++0x [except.spec]p14:
227  // [An] implicit exception-specification specifies the type-id T if and
228  // only if T is allowed by the exception-specification of a function directly
229  // invoked by f's implicit definition; f shall allow all exceptions if any
230  // function it directly invokes allows all exceptions, and f shall allow no
231  // exceptions if every function it directly invokes allows no exceptions.
232  //
233  // Note in particular that if an implicit exception-specification is generated
234  // for a function containing a throw-expression, that specification can still
235  // be noexcept(true).
236  //
237  // Note also that 'directly invoked' is not defined in the standard, and there
238  // is no indication that we should only consider potentially-evaluated calls.
239  //
240  // Ultimately we should implement the intent of the standard: the exception
241  // specification should be the set of exceptions which can be thrown by the
242  // implicit definition. For now, we assume that any non-nothrow expression can
243  // throw any exception.
244 
245  if (Self->canThrow(E))
246  ComputedEST = EST_None;
247 }
248 
249 bool
251  SourceLocation EqualLoc) {
252  if (RequireCompleteType(Param->getLocation(), Param->getType(),
253  diag::err_typecheck_decl_incomplete_type)) {
254  Param->setInvalidDecl();
255  return true;
256  }
257 
258  // C++ [dcl.fct.default]p5
259  // A default argument expression is implicitly converted (clause
260  // 4) to the parameter type. The default argument expression has
261  // the same semantic constraints as the initializer expression in
262  // a declaration of a variable of the parameter type, using the
263  // copy-initialization semantics (8.5).
265  Param);
267  EqualLoc);
268  InitializationSequence InitSeq(*this, Entity, Kind, Arg);
269  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
270  if (Result.isInvalid())
271  return true;
272  Arg = Result.getAs<Expr>();
273 
274  CheckCompletedExpr(Arg, EqualLoc);
275  Arg = MaybeCreateExprWithCleanups(Arg);
276 
277  // Okay: add the default argument to the parameter
278  Param->setDefaultArg(Arg);
279 
280  // We have already instantiated this parameter; provide each of the
281  // instantiations with the uninstantiated default argument.
282  UnparsedDefaultArgInstantiationsMap::iterator InstPos
283  = UnparsedDefaultArgInstantiations.find(Param);
284  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
285  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
286  InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
287 
288  // We're done tracking this parameter's instantiations.
289  UnparsedDefaultArgInstantiations.erase(InstPos);
290  }
291 
292  return false;
293 }
294 
295 /// ActOnParamDefaultArgument - Check whether the default argument
296 /// provided for a function parameter is well-formed. If so, attach it
297 /// to the parameter declaration.
298 void
300  Expr *DefaultArg) {
301  if (!param || !DefaultArg)
302  return;
303 
304  ParmVarDecl *Param = cast<ParmVarDecl>(param);
305  UnparsedDefaultArgLocs.erase(Param);
306 
307  // Default arguments are only permitted in C++
308  if (!getLangOpts().CPlusPlus) {
309  Diag(EqualLoc, diag::err_param_default_argument)
310  << DefaultArg->getSourceRange();
311  Param->setInvalidDecl();
312  return;
313  }
314 
315  // Check for unexpanded parameter packs.
316  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
317  Param->setInvalidDecl();
318  return;
319  }
320 
321  // C++11 [dcl.fct.default]p3
322  // A default argument expression [...] shall not be specified for a
323  // parameter pack.
324  if (Param->isParameterPack()) {
325  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
326  << DefaultArg->getSourceRange();
327  return;
328  }
329 
330  // Check that the default argument is well-formed
331  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
332  if (DefaultArgChecker.Visit(DefaultArg)) {
333  Param->setInvalidDecl();
334  return;
335  }
336 
337  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
338 }
339 
340 /// ActOnParamUnparsedDefaultArgument - We've seen a default
341 /// argument for a function parameter, but we can't parse it yet
342 /// because we're inside a class definition. Note that this default
343 /// argument will be parsed later.
345  SourceLocation EqualLoc,
346  SourceLocation ArgLoc) {
347  if (!param)
348  return;
349 
350  ParmVarDecl *Param = cast<ParmVarDecl>(param);
351  Param->setUnparsedDefaultArg();
352  UnparsedDefaultArgLocs[Param] = ArgLoc;
353 }
354 
355 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
356 /// the default argument for the parameter param failed.
358  SourceLocation EqualLoc) {
359  if (!param)
360  return;
361 
362  ParmVarDecl *Param = cast<ParmVarDecl>(param);
363  Param->setInvalidDecl();
364  UnparsedDefaultArgLocs.erase(Param);
365  Param->setDefaultArg(new(Context)
366  OpaqueValueExpr(EqualLoc,
367  Param->getType().getNonReferenceType(),
368  VK_RValue));
369 }
370 
371 /// CheckExtraCXXDefaultArguments - Check for any extra default
372 /// arguments in the declarator, which is not a function declaration
373 /// or definition and therefore is not permitted to have default
374 /// arguments. This routine should be invoked for every declarator
375 /// that is not a function declaration or definition.
377  // C++ [dcl.fct.default]p3
378  // A default argument expression shall be specified only in the
379  // parameter-declaration-clause of a function declaration or in a
380  // template-parameter (14.1). It shall not be specified for a
381  // parameter pack. If it is specified in a
382  // parameter-declaration-clause, it shall not occur within a
383  // declarator or abstract-declarator of a parameter-declaration.
384  bool MightBeFunction = D.isFunctionDeclarationContext();
385  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
386  DeclaratorChunk &chunk = D.getTypeObject(i);
387  if (chunk.Kind == DeclaratorChunk::Function) {
388  if (MightBeFunction) {
389  // This is a function declaration. It can have default arguments, but
390  // keep looking in case its return type is a function type with default
391  // arguments.
392  MightBeFunction = false;
393  continue;
394  }
395  for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
396  ++argIdx) {
397  ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
398  if (Param->hasUnparsedDefaultArg()) {
399  std::unique_ptr<CachedTokens> Toks =
400  std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
401  SourceRange SR;
402  if (Toks->size() > 1)
403  SR = SourceRange((*Toks)[1].getLocation(),
404  Toks->back().getLocation());
405  else
406  SR = UnparsedDefaultArgLocs[Param];
407  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
408  << SR;
409  } else if (Param->getDefaultArg()) {
410  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
411  << Param->getDefaultArg()->getSourceRange();
412  Param->setDefaultArg(nullptr);
413  }
414  }
415  } else if (chunk.Kind != DeclaratorChunk::Paren) {
416  MightBeFunction = false;
417  }
418  }
419 }
420 
422  for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) {
423  const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1);
424  if (!PVD->hasDefaultArg())
425  return false;
426  if (!PVD->hasInheritedDefaultArg())
427  return true;
428  }
429  return false;
430 }
431 
432 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
433 /// function, once we already know that they have the same
434 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
435 /// error, false otherwise.
437  Scope *S) {
438  bool Invalid = false;
439 
440  // The declaration context corresponding to the scope is the semantic
441  // parent, unless this is a local function declaration, in which case
442  // it is that surrounding function.
443  DeclContext *ScopeDC = New->isLocalExternDecl()
444  ? New->getLexicalDeclContext()
445  : New->getDeclContext();
446 
447  // Find the previous declaration for the purpose of default arguments.
448  FunctionDecl *PrevForDefaultArgs = Old;
449  for (/**/; PrevForDefaultArgs;
450  // Don't bother looking back past the latest decl if this is a local
451  // extern declaration; nothing else could work.
452  PrevForDefaultArgs = New->isLocalExternDecl()
453  ? nullptr
454  : PrevForDefaultArgs->getPreviousDecl()) {
455  // Ignore hidden declarations.
456  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
457  continue;
458 
459  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
460  !New->isCXXClassMember()) {
461  // Ignore default arguments of old decl if they are not in
462  // the same scope and this is not an out-of-line definition of
463  // a member function.
464  continue;
465  }
466 
467  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
468  // If only one of these is a local function declaration, then they are
469  // declared in different scopes, even though isDeclInScope may think
470  // they're in the same scope. (If both are local, the scope check is
471  // sufficient, and if neither is local, then they are in the same scope.)
472  continue;
473  }
474 
475  // We found the right previous declaration.
476  break;
477  }
478 
479  // C++ [dcl.fct.default]p4:
480  // For non-template functions, default arguments can be added in
481  // later declarations of a function in the same
482  // scope. Declarations in different scopes have completely
483  // distinct sets of default arguments. That is, declarations in
484  // inner scopes do not acquire default arguments from
485  // declarations in outer scopes, and vice versa. In a given
486  // function declaration, all parameters subsequent to a
487  // parameter with a default argument shall have default
488  // arguments supplied in this or previous declarations. A
489  // default argument shall not be redefined by a later
490  // declaration (not even to the same value).
491  //
492  // C++ [dcl.fct.default]p6:
493  // Except for member functions of class templates, the default arguments
494  // in a member function definition that appears outside of the class
495  // definition are added to the set of default arguments provided by the
496  // member function declaration in the class definition.
497  for (unsigned p = 0, NumParams = PrevForDefaultArgs
498  ? PrevForDefaultArgs->getNumParams()
499  : 0;
500  p < NumParams; ++p) {
501  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
502  ParmVarDecl *NewParam = New->getParamDecl(p);
503 
504  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
505  bool NewParamHasDfl = NewParam->hasDefaultArg();
506 
507  if (OldParamHasDfl && NewParamHasDfl) {
508  unsigned DiagDefaultParamID =
509  diag::err_param_default_argument_redefinition;
510 
511  // MSVC accepts that default parameters be redefined for member functions
512  // of template class. The new default parameter's value is ignored.
513  Invalid = true;
514  if (getLangOpts().MicrosoftExt) {
515  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
516  if (MD && MD->getParent()->getDescribedClassTemplate()) {
517  // Merge the old default argument into the new parameter.
518  NewParam->setHasInheritedDefaultArg();
519  if (OldParam->hasUninstantiatedDefaultArg())
520  NewParam->setUninstantiatedDefaultArg(
521  OldParam->getUninstantiatedDefaultArg());
522  else
523  NewParam->setDefaultArg(OldParam->getInit());
524  DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
525  Invalid = false;
526  }
527  }
528 
529  // FIXME: If we knew where the '=' was, we could easily provide a fix-it
530  // hint here. Alternatively, we could walk the type-source information
531  // for NewParam to find the last source location in the type... but it
532  // isn't worth the effort right now. This is the kind of test case that
533  // is hard to get right:
534  // int f(int);
535  // void g(int (*fp)(int) = f);
536  // void g(int (*fp)(int) = &f);
537  Diag(NewParam->getLocation(), DiagDefaultParamID)
538  << NewParam->getDefaultArgRange();
539 
540  // Look for the function declaration where the default argument was
541  // actually written, which may be a declaration prior to Old.
542  for (auto Older = PrevForDefaultArgs;
543  OldParam->hasInheritedDefaultArg(); /**/) {
544  Older = Older->getPreviousDecl();
545  OldParam = Older->getParamDecl(p);
546  }
547 
548  Diag(OldParam->getLocation(), diag::note_previous_definition)
549  << OldParam->getDefaultArgRange();
550  } else if (OldParamHasDfl) {
551  // Merge the old default argument into the new parameter unless the new
552  // function is a friend declaration in a template class. In the latter
553  // case the default arguments will be inherited when the friend
554  // declaration will be instantiated.
555  if (New->getFriendObjectKind() == Decl::FOK_None ||
557  // It's important to use getInit() here; getDefaultArg()
558  // strips off any top-level ExprWithCleanups.
559  NewParam->setHasInheritedDefaultArg();
560  if (OldParam->hasUnparsedDefaultArg())
561  NewParam->setUnparsedDefaultArg();
562  else if (OldParam->hasUninstantiatedDefaultArg())
563  NewParam->setUninstantiatedDefaultArg(
564  OldParam->getUninstantiatedDefaultArg());
565  else
566  NewParam->setDefaultArg(OldParam->getInit());
567  }
568  } else if (NewParamHasDfl) {
569  if (New->getDescribedFunctionTemplate()) {
570  // Paragraph 4, quoted above, only applies to non-template functions.
571  Diag(NewParam->getLocation(),
572  diag::err_param_default_argument_template_redecl)
573  << NewParam->getDefaultArgRange();
574  Diag(PrevForDefaultArgs->getLocation(),
575  diag::note_template_prev_declaration)
576  << false;
577  } else if (New->getTemplateSpecializationKind()
580  // C++ [temp.expr.spec]p21:
581  // Default function arguments shall not be specified in a declaration
582  // or a definition for one of the following explicit specializations:
583  // - the explicit specialization of a function template;
584  // - the explicit specialization of a member function template;
585  // - the explicit specialization of a member function of a class
586  // template where the class template specialization to which the
587  // member function specialization belongs is implicitly
588  // instantiated.
589  Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
591  << New->getDeclName()
592  << NewParam->getDefaultArgRange();
593  } else if (New->getDeclContext()->isDependentContext()) {
594  // C++ [dcl.fct.default]p6 (DR217):
595  // Default arguments for a member function of a class template shall
596  // be specified on the initial declaration of the member function
597  // within the class template.
598  //
599  // Reading the tea leaves a bit in DR217 and its reference to DR205
600  // leads me to the conclusion that one cannot add default function
601  // arguments for an out-of-line definition of a member function of a
602  // dependent type.
603  int WhichKind = 2;
604  if (CXXRecordDecl *Record
605  = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
606  if (Record->getDescribedClassTemplate())
607  WhichKind = 0;
608  else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
609  WhichKind = 1;
610  else
611  WhichKind = 2;
612  }
613 
614  Diag(NewParam->getLocation(),
615  diag::err_param_default_argument_member_template_redecl)
616  << WhichKind
617  << NewParam->getDefaultArgRange();
618  }
619  }
620  }
621 
622  // DR1344: If a default argument is added outside a class definition and that
623  // default argument makes the function a special member function, the program
624  // is ill-formed. This can only happen for constructors.
625  if (isa<CXXConstructorDecl>(New) &&
627  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
628  OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
629  if (NewSM != OldSM) {
630  ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
631  assert(NewParam->hasDefaultArg());
632  Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
633  << NewParam->getDefaultArgRange() << NewSM;
634  Diag(Old->getLocation(), diag::note_previous_declaration);
635  }
636  }
637 
638  const FunctionDecl *Def;
639  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
640  // template has a constexpr specifier then all its declarations shall
641  // contain the constexpr specifier.
642  if (New->isConstexpr() != Old->isConstexpr()) {
643  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
644  << New << New->isConstexpr();
645  Diag(Old->getLocation(), diag::note_previous_declaration);
646  Invalid = true;
647  } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
648  Old->isDefined(Def) &&
649  // If a friend function is inlined but does not have 'inline'
650  // specifier, it is a definition. Do not report attribute conflict
651  // in this case, redefinition will be diagnosed later.
652  (New->isInlineSpecified() ||
653  New->getFriendObjectKind() == Decl::FOK_None)) {
654  // C++11 [dcl.fcn.spec]p4:
655  // If the definition of a function appears in a translation unit before its
656  // first declaration as inline, the program is ill-formed.
657  Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
658  Diag(Def->getLocation(), diag::note_previous_definition);
659  Invalid = true;
660  }
661 
662  // FIXME: It's not clear what should happen if multiple declarations of a
663  // deduction guide have different explicitness. For now at least we simply
664  // reject any case where the explicitness changes.
665  auto *NewGuide = dyn_cast<CXXDeductionGuideDecl>(New);
666  if (NewGuide && NewGuide->isExplicitSpecified() !=
667  cast<CXXDeductionGuideDecl>(Old)->isExplicitSpecified()) {
668  Diag(New->getLocation(), diag::err_deduction_guide_explicit_mismatch)
669  << NewGuide->isExplicitSpecified();
670  Diag(Old->getLocation(), diag::note_previous_declaration);
671  }
672 
673  // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
674  // argument expression, that declaration shall be a definition and shall be
675  // the only declaration of the function or function template in the
676  // translation unit.
679  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
680  Diag(Old->getLocation(), diag::note_previous_declaration);
681  Invalid = true;
682  }
683 
684  return Invalid;
685 }
686 
687 NamedDecl *
689  MultiTemplateParamsArg TemplateParamLists) {
690  assert(D.isDecompositionDeclarator());
692 
693  // The syntax only allows a decomposition declarator as a simple-declaration,
694  // a for-range-declaration, or a condition in Clang, but we parse it in more
695  // cases than that.
697  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
698  << Decomp.getSourceRange();
699  return nullptr;
700  }
701 
702  if (!TemplateParamLists.empty()) {
703  // FIXME: There's no rule against this, but there are also no rules that
704  // would actually make it usable, so we reject it for now.
705  Diag(TemplateParamLists.front()->getTemplateLoc(),
706  diag::err_decomp_decl_template);
707  return nullptr;
708  }
709 
710  Diag(Decomp.getLSquareLoc(),
711  !getLangOpts().CPlusPlus17
712  ? diag::ext_decomp_decl
714  ? diag::ext_decomp_decl_cond
715  : diag::warn_cxx14_compat_decomp_decl)
716  << Decomp.getSourceRange();
717 
718  // The semantic context is always just the current context.
719  DeclContext *const DC = CurContext;
720 
721  // C++1z [dcl.dcl]/8:
722  // The decl-specifier-seq shall contain only the type-specifier auto
723  // and cv-qualifiers.
724  auto &DS = D.getDeclSpec();
725  {
726  SmallVector<StringRef, 8> BadSpecifiers;
727  SmallVector<SourceLocation, 8> BadSpecifierLocs;
728  if (auto SCS = DS.getStorageClassSpec()) {
729  BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
730  BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
731  }
732  if (auto TSCS = DS.getThreadStorageClassSpec()) {
733  BadSpecifiers.push_back(DeclSpec::getSpecifierName(TSCS));
734  BadSpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
735  }
736  if (DS.isConstexprSpecified()) {
737  BadSpecifiers.push_back("constexpr");
738  BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
739  }
740  if (DS.isInlineSpecified()) {
741  BadSpecifiers.push_back("inline");
742  BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
743  }
744  if (!BadSpecifiers.empty()) {
745  auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
746  Err << (int)BadSpecifiers.size()
747  << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
748  // Don't add FixItHints to remove the specifiers; we do still respect
749  // them when building the underlying variable.
750  for (auto Loc : BadSpecifierLocs)
751  Err << SourceRange(Loc, Loc);
752  }
753  // We can't recover from it being declared as a typedef.
754  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
755  return nullptr;
756  }
757 
758  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
759  QualType R = TInfo->getType();
760 
761  if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
762  UPPC_DeclarationType))
763  D.setInvalidType();
764 
765  // The syntax only allows a single ref-qualifier prior to the decomposition
766  // declarator. No other declarator chunks are permitted. Also check the type
767  // specifier here.
768  if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
769  D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
770  (D.getNumTypeObjects() == 1 &&
772  Diag(Decomp.getLSquareLoc(),
773  (D.hasGroupingParens() ||
774  (D.getNumTypeObjects() &&
776  ? diag::err_decomp_decl_parens
777  : diag::err_decomp_decl_type)
778  << R;
779 
780  // In most cases, there's no actual problem with an explicitly-specified
781  // type, but a function type won't work here, and ActOnVariableDeclarator
782  // shouldn't be called for such a type.
783  if (R->isFunctionType())
784  D.setInvalidType();
785  }
786 
787  // Build the BindingDecls.
789 
790  // Build the BindingDecls.
791  for (auto &B : D.getDecompositionDeclarator().bindings()) {
792  // Check for name conflicts.
793  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
794  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
795  ForVisibleRedeclaration);
796  LookupName(Previous, S,
797  /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
798 
799  // It's not permitted to shadow a template parameter name.
800  if (Previous.isSingleResult() &&
801  Previous.getFoundDecl()->isTemplateParameter()) {
802  DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
803  Previous.getFoundDecl());
804  Previous.clear();
805  }
806 
807  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
808  DS.getStorageClassSpec() == DeclSpec::SCS_extern;
809  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
810  /*AllowInlineNamespace*/false);
811  if (!Previous.empty()) {
812  auto *Old = Previous.getRepresentativeDecl();
813  Diag(B.NameLoc, diag::err_redefinition) << B.Name;
814  Diag(Old->getLocation(), diag::note_previous_definition);
815  }
816 
817  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
818  PushOnScopeChains(BD, S, true);
819  Bindings.push_back(BD);
820  ParsingInitForAutoVars.insert(BD);
821  }
822 
823  // There are no prior lookup results for the variable itself, because it
824  // is unnamed.
825  DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
826  Decomp.getLSquareLoc());
827  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
828  ForVisibleRedeclaration);
829 
830  // Build the variable that holds the non-decomposed object.
831  bool AddToScope = true;
832  NamedDecl *New =
833  ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
834  MultiTemplateParamsArg(), AddToScope, Bindings);
835  if (AddToScope) {
836  S->AddDecl(New);
837  CurContext->addHiddenDecl(New);
838  }
839 
840  if (isInOpenMPDeclareTargetContext())
841  checkDeclIsAllowedInOpenMPTarget(nullptr, New);
842 
843  return New;
844 }
845 
847  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
848  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
849  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
850  if ((int64_t)Bindings.size() != NumElems) {
851  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
852  << DecompType << (unsigned)Bindings.size() << NumElems.toString(10)
853  << (NumElems < Bindings.size());
854  return true;
855  }
856 
857  unsigned I = 0;
858  for (auto *B : Bindings) {
859  SourceLocation Loc = B->getLocation();
860  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
861  if (E.isInvalid())
862  return true;
863  E = GetInit(Loc, E.get(), I++);
864  if (E.isInvalid())
865  return true;
866  B->setBinding(ElemType, E.get());
867  }
868 
869  return false;
870 }
871 
873  ArrayRef<BindingDecl *> Bindings,
874  ValueDecl *Src, QualType DecompType,
875  const llvm::APSInt &NumElems,
876  QualType ElemType) {
878  S, Bindings, Src, DecompType, NumElems, ElemType,
879  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
880  ExprResult E = S.ActOnIntegerConstant(Loc, I);
881  if (E.isInvalid())
882  return ExprError();
883  return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
884  });
885 }
886 
888  ValueDecl *Src, QualType DecompType,
889  const ConstantArrayType *CAT) {
890  return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
891  llvm::APSInt(CAT->getSize()),
892  CAT->getElementType());
893 }
894 
896  ValueDecl *Src, QualType DecompType,
897  const VectorType *VT) {
899  S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
901  DecompType.getQualifiers()));
902 }
903 
905  ArrayRef<BindingDecl *> Bindings,
906  ValueDecl *Src, QualType DecompType,
907  const ComplexType *CT) {
909  S, Bindings, Src, DecompType, llvm::APSInt::get(2),
911  DecompType.getQualifiers()),
912  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
913  return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
914  });
915 }
916 
918  TemplateArgumentListInfo &Args) {
919  SmallString<128> SS;
920  llvm::raw_svector_ostream OS(SS);
921  bool First = true;
922  for (auto &Arg : Args.arguments()) {
923  if (!First)
924  OS << ", ";
925  Arg.getArgument().print(PrintingPolicy, OS);
926  First = false;
927  }
928  return OS.str();
929 }
930 
931 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
932  SourceLocation Loc, StringRef Trait,
934  unsigned DiagID) {
935  auto DiagnoseMissing = [&] {
936  if (DiagID)
937  S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
938  Args);
939  return true;
940  };
941 
942  // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
944  if (!Std)
945  return DiagnoseMissing();
946 
947  // Look up the trait itself, within namespace std. We can diagnose various
948  // problems with this lookup even if we've been asked to not diagnose a
949  // missing specialization, because this can only fail if the user has been
950  // declaring their own names in namespace std or we don't support the
951  // standard library implementation in use.
954  if (!S.LookupQualifiedName(Result, Std))
955  return DiagnoseMissing();
956  if (Result.isAmbiguous())
957  return true;
958 
959  ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
960  if (!TraitTD) {
961  Result.suppressDiagnostics();
962  NamedDecl *Found = *Result.begin();
963  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
964  S.Diag(Found->getLocation(), diag::note_declared_at);
965  return true;
966  }
967 
968  // Build the template-id.
969  QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
970  if (TraitTy.isNull())
971  return true;
972  if (!S.isCompleteType(Loc, TraitTy)) {
973  if (DiagID)
975  Loc, TraitTy, DiagID,
977  return true;
978  }
979 
980  CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
981  assert(RD && "specialization of class template is not a class?");
982 
983  // Look up the member of the trait type.
984  S.LookupQualifiedName(TraitMemberLookup, RD);
985  return TraitMemberLookup.isAmbiguous();
986 }
987 
988 static TemplateArgumentLoc
990  uint64_t I) {
991  TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
992  return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
993 }
994 
995 static TemplateArgumentLoc
998 }
999 
1000 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1001 
1003  llvm::APSInt &Size) {
1006 
1008  LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1009 
1010  // Form template argument list for tuple_size<T>.
1011  TemplateArgumentListInfo Args(Loc, Loc);
1013 
1014  // If there's no tuple_size specialization, it's not tuple-like.
1015  if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/0))
1016  return IsTupleLike::NotTupleLike;
1017 
1018  // If we get this far, we've committed to the tuple interpretation, but
1019  // we can still fail if there actually isn't a usable ::value.
1020 
1021  struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1022  LookupResult &R;
1024  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1025  : R(R), Args(Args) {}
1026  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) {
1027  S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1029  }
1030  } Diagnoser(R, Args);
1031 
1032  if (R.empty()) {
1033  Diagnoser.diagnoseNotICE(S, Loc, SourceRange());
1034  return IsTupleLike::Error;
1035  }
1036 
1037  ExprResult E =
1038  S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1039  if (E.isInvalid())
1040  return IsTupleLike::Error;
1041 
1042  E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser, false);
1043  if (E.isInvalid())
1044  return IsTupleLike::Error;
1045 
1046  return IsTupleLike::TupleLike;
1047 }
1048 
1049 /// \return std::tuple_element<I, T>::type.
1051  unsigned I, QualType T) {
1052  // Form template argument list for tuple_element<I, T>.
1053  TemplateArgumentListInfo Args(Loc, Loc);
1054  Args.addArgument(
1057 
1058  DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1059  LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1061  S, R, Loc, "tuple_element", Args,
1062  diag::err_decomp_decl_std_tuple_element_not_specialized))
1063  return QualType();
1064 
1065  auto *TD = R.getAsSingle<TypeDecl>();
1066  if (!TD) {
1067  R.suppressDiagnostics();
1068  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1070  if (!R.empty())
1071  S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1072  return QualType();
1073  }
1074 
1075  return S.Context.getTypeDeclType(TD);
1076 }
1077 
1078 namespace {
1079 struct BindingDiagnosticTrap {
1080  Sema &S;
1081  DiagnosticErrorTrap Trap;
1082  BindingDecl *BD;
1083 
1084  BindingDiagnosticTrap(Sema &S, BindingDecl *BD)
1085  : S(S), Trap(S.Diags), BD(BD) {}
1086  ~BindingDiagnosticTrap() {
1087  if (Trap.hasErrorOccurred())
1088  S.Diag(BD->getLocation(), diag::note_in_binding_decl_init) << BD;
1089  }
1090 };
1091 }
1092 
1094  ArrayRef<BindingDecl *> Bindings,
1095  VarDecl *Src, QualType DecompType,
1096  const llvm::APSInt &TupleSize) {
1097  if ((int64_t)Bindings.size() != TupleSize) {
1098  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1099  << DecompType << (unsigned)Bindings.size() << TupleSize.toString(10)
1100  << (TupleSize < Bindings.size());
1101  return true;
1102  }
1103 
1104  if (Bindings.empty())
1105  return false;
1106 
1107  DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1108 
1109  // [dcl.decomp]p3:
1110  // The unqualified-id get is looked up in the scope of E by class member
1111  // access lookup
1112  LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1113  bool UseMemberGet = false;
1114  if (S.isCompleteType(Src->getLocation(), DecompType)) {
1115  if (auto *RD = DecompType->getAsCXXRecordDecl())
1116  S.LookupQualifiedName(MemberGet, RD);
1117  if (MemberGet.isAmbiguous())
1118  return true;
1119  UseMemberGet = !MemberGet.empty();
1120  S.FilterAcceptableTemplateNames(MemberGet);
1121  }
1122 
1123  unsigned I = 0;
1124  for (auto *B : Bindings) {
1125  BindingDiagnosticTrap Trap(S, B);
1126  SourceLocation Loc = B->getLocation();
1127 
1128  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1129  if (E.isInvalid())
1130  return true;
1131 
1132  // e is an lvalue if the type of the entity is an lvalue reference and
1133  // an xvalue otherwise
1134  if (!Src->getType()->isLValueReferenceType())
1135  E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1136  E.get(), nullptr, VK_XValue);
1137 
1138  TemplateArgumentListInfo Args(Loc, Loc);
1139  Args.addArgument(
1141 
1142  if (UseMemberGet) {
1143  // if [lookup of member get] finds at least one declaration, the
1144  // initializer is e.get<i-1>().
1145  E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1146  CXXScopeSpec(), SourceLocation(), nullptr,
1147  MemberGet, &Args, nullptr);
1148  if (E.isInvalid())
1149  return true;
1150 
1151  E = S.ActOnCallExpr(nullptr, E.get(), Loc, None, Loc);
1152  } else {
1153  // Otherwise, the initializer is get<i-1>(e), where get is looked up
1154  // in the associated namespaces.
1157  DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1159 
1160  Expr *Arg = E.get();
1161  E = S.ActOnCallExpr(nullptr, Get, Loc, Arg, Loc);
1162  }
1163  if (E.isInvalid())
1164  return true;
1165  Expr *Init = E.get();
1166 
1167  // Given the type T designated by std::tuple_element<i - 1, E>::type,
1168  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1169  if (T.isNull())
1170  return true;
1171 
1172  // each vi is a variable of type "reference to T" initialized with the
1173  // initializer, where the reference is an lvalue reference if the
1174  // initializer is an lvalue and an rvalue reference otherwise
1175  QualType RefType =
1176  S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1177  if (RefType.isNull())
1178  return true;
1179  auto *RefVD = VarDecl::Create(
1180  S.Context, Src->getDeclContext(), Loc, Loc,
1181  B->getDeclName().getAsIdentifierInfo(), RefType,
1184  RefVD->setTSCSpec(Src->getTSCSpec());
1185  RefVD->setImplicit();
1186  if (Src->isInlineSpecified())
1187  RefVD->setInlineSpecified();
1188  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1189 
1192  InitializationSequence Seq(S, Entity, Kind, Init);
1193  E = Seq.Perform(S, Entity, Kind, Init);
1194  if (E.isInvalid())
1195  return true;
1196  E = S.ActOnFinishFullExpr(E.get(), Loc);
1197  if (E.isInvalid())
1198  return true;
1199  RefVD->setInit(E.get());
1200  RefVD->checkInitIsICE();
1201 
1203  DeclarationNameInfo(B->getDeclName(), Loc),
1204  RefVD);
1205  if (E.isInvalid())
1206  return true;
1207 
1208  B->setBinding(T, E.get());
1209  I++;
1210  }
1211 
1212  return false;
1213 }
1214 
1215 /// Find the base class to decompose in a built-in decomposition of a class type.
1216 /// This base class search is, unfortunately, not quite like any other that we
1217 /// perform anywhere else in C++.
1219  SourceLocation Loc,
1220  const CXXRecordDecl *RD,
1221  CXXCastPath &BasePath) {
1222  auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1223  CXXBasePath &Path) {
1224  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1225  };
1226 
1227  const CXXRecordDecl *ClassWithFields = nullptr;
1228  if (RD->hasDirectFields())
1229  // [dcl.decomp]p4:
1230  // Otherwise, all of E's non-static data members shall be public direct
1231  // members of E ...
1232  ClassWithFields = RD;
1233  else {
1234  // ... or of ...
1235  CXXBasePaths Paths;
1236  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1237  if (!RD->lookupInBases(BaseHasFields, Paths)) {
1238  // If no classes have fields, just decompose RD itself. (This will work
1239  // if and only if zero bindings were provided.)
1240  return RD;
1241  }
1242 
1243  CXXBasePath *BestPath = nullptr;
1244  for (auto &P : Paths) {
1245  if (!BestPath)
1246  BestPath = &P;
1247  else if (!S.Context.hasSameType(P.back().Base->getType(),
1248  BestPath->back().Base->getType())) {
1249  // ... the same ...
1250  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1251  << false << RD << BestPath->back().Base->getType()
1252  << P.back().Base->getType();
1253  return nullptr;
1254  } else if (P.Access < BestPath->Access) {
1255  BestPath = &P;
1256  }
1257  }
1258 
1259  // ... unambiguous ...
1260  QualType BaseType = BestPath->back().Base->getType();
1261  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1262  S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1263  << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1264  return nullptr;
1265  }
1266 
1267  // ... public base class of E.
1268  if (BestPath->Access != AS_public) {
1269  S.Diag(Loc, diag::err_decomp_decl_non_public_base)
1270  << RD << BaseType;
1271  for (auto &BS : *BestPath) {
1272  if (BS.Base->getAccessSpecifier() != AS_public) {
1273  S.Diag(BS.Base->getLocStart(), diag::note_access_constrained_by_path)
1274  << (BS.Base->getAccessSpecifier() == AS_protected)
1275  << (BS.Base->getAccessSpecifierAsWritten() == AS_none);
1276  break;
1277  }
1278  }
1279  return nullptr;
1280  }
1281 
1282  ClassWithFields = BaseType->getAsCXXRecordDecl();
1283  S.BuildBasePathArray(Paths, BasePath);
1284  }
1285 
1286  // The above search did not check whether the selected class itself has base
1287  // classes with fields, so check that now.
1288  CXXBasePaths Paths;
1289  if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1290  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1291  << (ClassWithFields == RD) << RD << ClassWithFields
1292  << Paths.front().back().Base->getType();
1293  return nullptr;
1294  }
1295 
1296  return ClassWithFields;
1297 }
1298 
1300  ValueDecl *Src, QualType DecompType,
1301  const CXXRecordDecl *RD) {
1302  CXXCastPath BasePath;
1303  RD = findDecomposableBaseClass(S, Src->getLocation(), RD, BasePath);
1304  if (!RD)
1305  return true;
1307  DecompType.getQualifiers());
1308 
1309  auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1310  unsigned NumFields =
1311  std::count_if(RD->field_begin(), RD->field_end(),
1312  [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1313  assert(Bindings.size() != NumFields);
1314  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1315  << DecompType << (unsigned)Bindings.size() << NumFields
1316  << (NumFields < Bindings.size());
1317  return true;
1318  };
1319 
1320  // all of E's non-static data members shall be public [...] members,
1321  // E shall not have an anonymous union member, ...
1322  unsigned I = 0;
1323  for (auto *FD : RD->fields()) {
1324  if (FD->isUnnamedBitfield())
1325  continue;
1326 
1327  if (FD->isAnonymousStructOrUnion()) {
1328  S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1329  << DecompType << FD->getType()->isUnionType();
1330  S.Diag(FD->getLocation(), diag::note_declared_at);
1331  return true;
1332  }
1333 
1334  // We have a real field to bind.
1335  if (I >= Bindings.size())
1336  return DiagnoseBadNumberOfBindings();
1337  auto *B = Bindings[I++];
1338 
1339  SourceLocation Loc = B->getLocation();
1340  if (FD->getAccess() != AS_public) {
1341  S.Diag(Loc, diag::err_decomp_decl_non_public_member) << FD << DecompType;
1342 
1343  // Determine whether the access specifier was explicit.
1344  bool Implicit = true;
1345  for (const auto *D : RD->decls()) {
1346  if (declaresSameEntity(D, FD))
1347  break;
1348  if (isa<AccessSpecDecl>(D)) {
1349  Implicit = false;
1350  break;
1351  }
1352  }
1353 
1354  S.Diag(FD->getLocation(), diag::note_access_natural)
1355  << (FD->getAccess() == AS_protected) << Implicit;
1356  return true;
1357  }
1358 
1359  // Initialize the binding to Src.FD.
1360  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1361  if (E.isInvalid())
1362  return true;
1363  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1364  VK_LValue, &BasePath);
1365  if (E.isInvalid())
1366  return true;
1367  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1368  CXXScopeSpec(), FD,
1369  DeclAccessPair::make(FD, FD->getAccess()),
1370  DeclarationNameInfo(FD->getDeclName(), Loc));
1371  if (E.isInvalid())
1372  return true;
1373 
1374  // If the type of the member is T, the referenced type is cv T, where cv is
1375  // the cv-qualification of the decomposition expression.
1376  //
1377  // FIXME: We resolve a defect here: if the field is mutable, we do not add
1378  // 'const' to the type of the field.
1379  Qualifiers Q = DecompType.getQualifiers();
1380  if (FD->isMutable())
1381  Q.removeConst();
1382  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1383  }
1384 
1385  if (I != Bindings.size())
1386  return DiagnoseBadNumberOfBindings();
1387 
1388  return false;
1389 }
1390 
1392  QualType DecompType = DD->getType();
1393 
1394  // If the type of the decomposition is dependent, then so is the type of
1395  // each binding.
1396  if (DecompType->isDependentType()) {
1397  for (auto *B : DD->bindings())
1398  B->setType(Context.DependentTy);
1399  return;
1400  }
1401 
1402  DecompType = DecompType.getNonReferenceType();
1403  ArrayRef<BindingDecl*> Bindings = DD->bindings();
1404 
1405  // C++1z [dcl.decomp]/2:
1406  // If E is an array type [...]
1407  // As an extension, we also support decomposition of built-in complex and
1408  // vector types.
1409  if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1410  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1411  DD->setInvalidDecl();
1412  return;
1413  }
1414  if (auto *VT = DecompType->getAs<VectorType>()) {
1415  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1416  DD->setInvalidDecl();
1417  return;
1418  }
1419  if (auto *CT = DecompType->getAs<ComplexType>()) {
1420  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1421  DD->setInvalidDecl();
1422  return;
1423  }
1424 
1425  // C++1z [dcl.decomp]/3:
1426  // if the expression std::tuple_size<E>::value is a well-formed integral
1427  // constant expression, [...]
1428  llvm::APSInt TupleSize(32);
1429  switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1430  case IsTupleLike::Error:
1431  DD->setInvalidDecl();
1432  return;
1433 
1434  case IsTupleLike::TupleLike:
1435  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1436  DD->setInvalidDecl();
1437  return;
1438 
1439  case IsTupleLike::NotTupleLike:
1440  break;
1441  }
1442 
1443  // C++1z [dcl.dcl]/8:
1444  // [E shall be of array or non-union class type]
1445  CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1446  if (!RD || RD->isUnion()) {
1447  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1448  << DD << !RD << DecompType;
1449  DD->setInvalidDecl();
1450  return;
1451  }
1452 
1453  // C++1z [dcl.decomp]/4:
1454  // all of E's non-static data members shall be [...] direct members of
1455  // E or of the same unambiguous public base class of E, ...
1456  if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1457  DD->setInvalidDecl();
1458 }
1459 
1460 /// Merge the exception specifications of two variable declarations.
1461 ///
1462 /// This is called when there's a redeclaration of a VarDecl. The function
1463 /// checks if the redeclaration might have an exception specification and
1464 /// validates compatibility and merges the specs if necessary.
1466  // Shortcut if exceptions are disabled.
1467  if (!getLangOpts().CXXExceptions)
1468  return;
1469 
1470  assert(Context.hasSameType(New->getType(), Old->getType()) &&
1471  "Should only be called if types are otherwise the same.");
1472 
1473  QualType NewType = New->getType();
1474  QualType OldType = Old->getType();
1475 
1476  // We're only interested in pointers and references to functions, as well
1477  // as pointers to member functions.
1478  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1479  NewType = R->getPointeeType();
1480  OldType = OldType->getAs<ReferenceType>()->getPointeeType();
1481  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1482  NewType = P->getPointeeType();
1483  OldType = OldType->getAs<PointerType>()->getPointeeType();
1484  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1485  NewType = M->getPointeeType();
1486  OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
1487  }
1488 
1489  if (!NewType->isFunctionProtoType())
1490  return;
1491 
1492  // There's lots of special cases for functions. For function pointers, system
1493  // libraries are hopefully not as broken so that we don't need these
1494  // workarounds.
1495  if (CheckEquivalentExceptionSpec(
1496  OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1497  NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1498  New->setInvalidDecl();
1499  }
1500 }
1501 
1502 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1503 /// function declaration are well-formed according to C++
1504 /// [dcl.fct.default].
1506  unsigned NumParams = FD->getNumParams();
1507  unsigned p;
1508 
1509  // Find first parameter with a default argument
1510  for (p = 0; p < NumParams; ++p) {
1511  ParmVarDecl *Param = FD->getParamDecl(p);
1512  if (Param->hasDefaultArg())
1513  break;
1514  }
1515 
1516  // C++11 [dcl.fct.default]p4:
1517  // In a given function declaration, each parameter subsequent to a parameter
1518  // with a default argument shall have a default argument supplied in this or
1519  // a previous declaration or shall be a function parameter pack. A default
1520  // argument shall not be redefined by a later declaration (not even to the
1521  // same value).
1522  unsigned LastMissingDefaultArg = 0;
1523  for (; p < NumParams; ++p) {
1524  ParmVarDecl *Param = FD->getParamDecl(p);
1525  if (!Param->hasDefaultArg() && !Param->isParameterPack()) {
1526  if (Param->isInvalidDecl())
1527  /* We already complained about this parameter. */;
1528  else if (Param->getIdentifier())
1529  Diag(Param->getLocation(),
1530  diag::err_param_default_argument_missing_name)
1531  << Param->getIdentifier();
1532  else
1533  Diag(Param->getLocation(),
1534  diag::err_param_default_argument_missing);
1535 
1536  LastMissingDefaultArg = p;
1537  }
1538  }
1539 
1540  if (LastMissingDefaultArg > 0) {
1541  // Some default arguments were missing. Clear out all of the
1542  // default arguments up to (and including) the last missing
1543  // default argument, so that we leave the function parameters
1544  // in a semantically valid state.
1545  for (p = 0; p <= LastMissingDefaultArg; ++p) {
1546  ParmVarDecl *Param = FD->getParamDecl(p);
1547  if (Param->hasDefaultArg()) {
1548  Param->setDefaultArg(nullptr);
1549  }
1550  }
1551  }
1552 }
1553 
1554 // CheckConstexprParameterTypes - Check whether a function's parameter types
1555 // are all literal types. If so, return true. If not, produce a suitable
1556 // diagnostic and return false.
1557 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1558  const FunctionDecl *FD) {
1559  unsigned ArgIndex = 0;
1560  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
1562  e = FT->param_type_end();
1563  i != e; ++i, ++ArgIndex) {
1564  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1565  SourceLocation ParamLoc = PD->getLocation();
1566  if (!(*i)->isDependentType() &&
1567  SemaRef.RequireLiteralType(ParamLoc, *i,
1568  diag::err_constexpr_non_literal_param,
1569  ArgIndex+1, PD->getSourceRange(),
1570  isa<CXXConstructorDecl>(FD)))
1571  return false;
1572  }
1573  return true;
1574 }
1575 
1576 /// Get diagnostic %select index for tag kind for
1577 /// record diagnostic message.
1578 /// WARNING: Indexes apply to particular diagnostics only!
1579 ///
1580 /// \returns diagnostic %select index.
1582  switch (Tag) {
1583  case TTK_Struct: return 0;
1584  case TTK_Interface: return 1;
1585  case TTK_Class: return 2;
1586  default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1587  }
1588 }
1589 
1590 // CheckConstexprFunctionDecl - Check whether a function declaration satisfies
1591 // the requirements of a constexpr function definition or a constexpr
1592 // constructor definition. If so, return true. If not, produce appropriate
1593 // diagnostics and return false.
1594 //
1595 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1597  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1598  if (MD && MD->isInstance()) {
1599  // C++11 [dcl.constexpr]p4:
1600  // The definition of a constexpr constructor shall satisfy the following
1601  // constraints:
1602  // - the class shall not have any virtual base classes;
1603  const CXXRecordDecl *RD = MD->getParent();
1604  if (RD->getNumVBases()) {
1605  Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1606  << isa<CXXConstructorDecl>(NewFD)
1608  for (const auto &I : RD->vbases())
1609  Diag(I.getLocStart(),
1610  diag::note_constexpr_virtual_base_here) << I.getSourceRange();
1611  return false;
1612  }
1613  }
1614 
1615  if (!isa<CXXConstructorDecl>(NewFD)) {
1616  // C++11 [dcl.constexpr]p3:
1617  // The definition of a constexpr function shall satisfy the following
1618  // constraints:
1619  // - it shall not be virtual;
1620  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1621  if (Method && Method->isVirtual()) {
1622  Method = Method->getCanonicalDecl();
1623  Diag(Method->getLocation(), diag::err_constexpr_virtual);
1624 
1625  // If it's not obvious why this function is virtual, find an overridden
1626  // function which uses the 'virtual' keyword.
1627  const CXXMethodDecl *WrittenVirtual = Method;
1628  while (!WrittenVirtual->isVirtualAsWritten())
1629  WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1630  if (WrittenVirtual != Method)
1631  Diag(WrittenVirtual->getLocation(),
1632  diag::note_overridden_virtual_function);
1633  return false;
1634  }
1635 
1636  // - its return type shall be a literal type;
1637  QualType RT = NewFD->getReturnType();
1638  if (!RT->isDependentType() &&
1639  RequireLiteralType(NewFD->getLocation(), RT,
1640  diag::err_constexpr_non_literal_return))
1641  return false;
1642  }
1643 
1644  // - each of its parameter types shall be a literal type;
1645  if (!CheckConstexprParameterTypes(*this, NewFD))
1646  return false;
1647 
1648  return true;
1649 }
1650 
1651 /// Check the given declaration statement is legal within a constexpr function
1652 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1653 ///
1654 /// \return true if the body is OK (maybe only as an extension), false if we
1655 /// have diagnosed a problem.
1656 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1657  DeclStmt *DS, SourceLocation &Cxx1yLoc) {
1658  // C++11 [dcl.constexpr]p3 and p4:
1659  // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1660  // contain only
1661  for (const auto *DclIt : DS->decls()) {
1662  switch (DclIt->getKind()) {
1663  case Decl::StaticAssert:
1664  case Decl::Using:
1665  case Decl::UsingShadow:
1666  case Decl::UsingDirective:
1667  case Decl::UnresolvedUsingTypename:
1668  case Decl::UnresolvedUsingValue:
1669  // - static_assert-declarations
1670  // - using-declarations,
1671  // - using-directives,
1672  continue;
1673 
1674  case Decl::Typedef:
1675  case Decl::TypeAlias: {
1676  // - typedef declarations and alias-declarations that do not define
1677  // classes or enumerations,
1678  const auto *TN = cast<TypedefNameDecl>(DclIt);
1679  if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1680  // Don't allow variably-modified types in constexpr functions.
1681  TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1682  SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1683  << TL.getSourceRange() << TL.getType()
1684  << isa<CXXConstructorDecl>(Dcl);
1685  return false;
1686  }
1687  continue;
1688  }
1689 
1690  case Decl::Enum:
1691  case Decl::CXXRecord:
1692  // C++1y allows types to be defined, not just declared.
1693  if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition())
1694  SemaRef.Diag(DS->getLocStart(),
1695  SemaRef.getLangOpts().CPlusPlus14
1696  ? diag::warn_cxx11_compat_constexpr_type_definition
1697  : diag::ext_constexpr_type_definition)
1698  << isa<CXXConstructorDecl>(Dcl);
1699  continue;
1700 
1701  case Decl::EnumConstant:
1702  case Decl::IndirectField:
1703  case Decl::ParmVar:
1704  // These can only appear with other declarations which are banned in
1705  // C++11 and permitted in C++1y, so ignore them.
1706  continue;
1707 
1708  case Decl::Var:
1709  case Decl::Decomposition: {
1710  // C++1y [dcl.constexpr]p3 allows anything except:
1711  // a definition of a variable of non-literal type or of static or
1712  // thread storage duration or for which no initialization is performed.
1713  const auto *VD = cast<VarDecl>(DclIt);
1714  if (VD->isThisDeclarationADefinition()) {
1715  if (VD->isStaticLocal()) {
1716  SemaRef.Diag(VD->getLocation(),
1717  diag::err_constexpr_local_var_static)
1718  << isa<CXXConstructorDecl>(Dcl)
1719  << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1720  return false;
1721  }
1722  if (!VD->getType()->isDependentType() &&
1723  SemaRef.RequireLiteralType(
1724  VD->getLocation(), VD->getType(),
1725  diag::err_constexpr_local_var_non_literal_type,
1726  isa<CXXConstructorDecl>(Dcl)))
1727  return false;
1728  if (!VD->getType()->isDependentType() &&
1729  !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1730  SemaRef.Diag(VD->getLocation(),
1731  diag::err_constexpr_local_var_no_init)
1732  << isa<CXXConstructorDecl>(Dcl);
1733  return false;
1734  }
1735  }
1736  SemaRef.Diag(VD->getLocation(),
1737  SemaRef.getLangOpts().CPlusPlus14
1738  ? diag::warn_cxx11_compat_constexpr_local_var
1739  : diag::ext_constexpr_local_var)
1740  << isa<CXXConstructorDecl>(Dcl);
1741  continue;
1742  }
1743 
1744  case Decl::NamespaceAlias:
1745  case Decl::Function:
1746  // These are disallowed in C++11 and permitted in C++1y. Allow them
1747  // everywhere as an extension.
1748  if (!Cxx1yLoc.isValid())
1749  Cxx1yLoc = DS->getLocStart();
1750  continue;
1751 
1752  default:
1753  SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt)
1754  << isa<CXXConstructorDecl>(Dcl);
1755  return false;
1756  }
1757  }
1758 
1759  return true;
1760 }
1761 
1762 /// Check that the given field is initialized within a constexpr constructor.
1763 ///
1764 /// \param Dcl The constexpr constructor being checked.
1765 /// \param Field The field being checked. This may be a member of an anonymous
1766 /// struct or union nested within the class being checked.
1767 /// \param Inits All declarations, including anonymous struct/union members and
1768 /// indirect members, for which any initialization was provided.
1769 /// \param Diagnosed Set to true if an error is produced.
1771  const FunctionDecl *Dcl,
1772  FieldDecl *Field,
1773  llvm::SmallSet<Decl*, 16> &Inits,
1774  bool &Diagnosed) {
1775  if (Field->isInvalidDecl())
1776  return;
1777 
1778  if (Field->isUnnamedBitfield())
1779  return;
1780 
1781  // Anonymous unions with no variant members and empty anonymous structs do not
1782  // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1783  // indirect fields don't need initializing.
1784  if (Field->isAnonymousStructOrUnion() &&
1785  (Field->getType()->isUnionType()
1786  ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1787  : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1788  return;
1789 
1790  if (!Inits.count(Field)) {
1791  if (!Diagnosed) {
1792  SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
1793  Diagnosed = true;
1794  }
1795  SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
1796  } else if (Field->isAnonymousStructOrUnion()) {
1797  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1798  for (auto *I : RD->fields())
1799  // If an anonymous union contains an anonymous struct of which any member
1800  // is initialized, all members must be initialized.
1801  if (!RD->isUnion() || Inits.count(I))
1802  CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed);
1803  }
1804 }
1805 
1806 /// Check the provided statement is allowed in a constexpr function
1807 /// definition.
1808 static bool
1810  SmallVectorImpl<SourceLocation> &ReturnStmts,
1811  SourceLocation &Cxx1yLoc) {
1812  // - its function-body shall be [...] a compound-statement that contains only
1813  switch (S->getStmtClass()) {
1814  case Stmt::NullStmtClass:
1815  // - null statements,
1816  return true;
1817 
1818  case Stmt::DeclStmtClass:
1819  // - static_assert-declarations
1820  // - using-declarations,
1821  // - using-directives,
1822  // - typedef declarations and alias-declarations that do not define
1823  // classes or enumerations,
1824  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc))
1825  return false;
1826  return true;
1827 
1828  case Stmt::ReturnStmtClass:
1829  // - and exactly one return statement;
1830  if (isa<CXXConstructorDecl>(Dcl)) {
1831  // C++1y allows return statements in constexpr constructors.
1832  if (!Cxx1yLoc.isValid())
1833  Cxx1yLoc = S->getLocStart();
1834  return true;
1835  }
1836 
1837  ReturnStmts.push_back(S->getLocStart());
1838  return true;
1839 
1840  case Stmt::CompoundStmtClass: {
1841  // C++1y allows compound-statements.
1842  if (!Cxx1yLoc.isValid())
1843  Cxx1yLoc = S->getLocStart();
1844 
1845  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
1846  for (auto *BodyIt : CompStmt->body()) {
1847  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
1848  Cxx1yLoc))
1849  return false;
1850  }
1851  return true;
1852  }
1853 
1854  case Stmt::AttributedStmtClass:
1855  if (!Cxx1yLoc.isValid())
1856  Cxx1yLoc = S->getLocStart();
1857  return true;
1858 
1859  case Stmt::IfStmtClass: {
1860  // C++1y allows if-statements.
1861  if (!Cxx1yLoc.isValid())
1862  Cxx1yLoc = S->getLocStart();
1863 
1864  IfStmt *If = cast<IfStmt>(S);
1865  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
1866  Cxx1yLoc))
1867  return false;
1868  if (If->getElse() &&
1869  !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
1870  Cxx1yLoc))
1871  return false;
1872  return true;
1873  }
1874 
1875  case Stmt::WhileStmtClass:
1876  case Stmt::DoStmtClass:
1877  case Stmt::ForStmtClass:
1878  case Stmt::CXXForRangeStmtClass:
1879  case Stmt::ContinueStmtClass:
1880  // C++1y allows all of these. We don't allow them as extensions in C++11,
1881  // because they don't make sense without variable mutation.
1882  if (!SemaRef.getLangOpts().CPlusPlus14)
1883  break;
1884  if (!Cxx1yLoc.isValid())
1885  Cxx1yLoc = S->getLocStart();
1886  for (Stmt *SubStmt : S->children())
1887  if (SubStmt &&
1888  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1889  Cxx1yLoc))
1890  return false;
1891  return true;
1892 
1893  case Stmt::SwitchStmtClass:
1894  case Stmt::CaseStmtClass:
1895  case Stmt::DefaultStmtClass:
1896  case Stmt::BreakStmtClass:
1897  // C++1y allows switch-statements, and since they don't need variable
1898  // mutation, we can reasonably allow them in C++11 as an extension.
1899  if (!Cxx1yLoc.isValid())
1900  Cxx1yLoc = S->getLocStart();
1901  for (Stmt *SubStmt : S->children())
1902  if (SubStmt &&
1903  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1904  Cxx1yLoc))
1905  return false;
1906  return true;
1907 
1908  default:
1909  if (!isa<Expr>(S))
1910  break;
1911 
1912  // C++1y allows expression-statements.
1913  if (!Cxx1yLoc.isValid())
1914  Cxx1yLoc = S->getLocStart();
1915  return true;
1916  }
1917 
1918  SemaRef.Diag(S->getLocStart(), diag::err_constexpr_body_invalid_stmt)
1919  << isa<CXXConstructorDecl>(Dcl);
1920  return false;
1921 }
1922 
1923 /// Check the body for the given constexpr function declaration only contains
1924 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
1925 ///
1926 /// \return true if the body is OK, false if we have diagnosed a problem.
1928  if (isa<CXXTryStmt>(Body)) {
1929  // C++11 [dcl.constexpr]p3:
1930  // The definition of a constexpr function shall satisfy the following
1931  // constraints: [...]
1932  // - its function-body shall be = delete, = default, or a
1933  // compound-statement
1934  //
1935  // C++11 [dcl.constexpr]p4:
1936  // In the definition of a constexpr constructor, [...]
1937  // - its function-body shall not be a function-try-block;
1938  Diag(Body->getLocStart(), diag::err_constexpr_function_try_block)
1939  << isa<CXXConstructorDecl>(Dcl);
1940  return false;
1941  }
1942 
1943  SmallVector<SourceLocation, 4> ReturnStmts;
1944 
1945  // - its function-body shall be [...] a compound-statement that contains only
1946  // [... list of cases ...]
1947  CompoundStmt *CompBody = cast<CompoundStmt>(Body);
1948  SourceLocation Cxx1yLoc;
1949  for (auto *BodyIt : CompBody->body()) {
1950  if (!CheckConstexprFunctionStmt(*this, Dcl, BodyIt, ReturnStmts, Cxx1yLoc))
1951  return false;
1952  }
1953 
1954  if (Cxx1yLoc.isValid())
1955  Diag(Cxx1yLoc,
1956  getLangOpts().CPlusPlus14
1957  ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
1958  : diag::ext_constexpr_body_invalid_stmt)
1959  << isa<CXXConstructorDecl>(Dcl);
1960 
1961  if (const CXXConstructorDecl *Constructor
1962  = dyn_cast<CXXConstructorDecl>(Dcl)) {
1963  const CXXRecordDecl *RD = Constructor->getParent();
1964  // DR1359:
1965  // - every non-variant non-static data member and base class sub-object
1966  // shall be initialized;
1967  // DR1460:
1968  // - if the class is a union having variant members, exactly one of them
1969  // shall be initialized;
1970  if (RD->isUnion()) {
1971  if (Constructor->getNumCtorInitializers() == 0 &&
1972  RD->hasVariantMembers()) {
1973  Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
1974  return false;
1975  }
1976  } else if (!Constructor->isDependentContext() &&
1977  !Constructor->isDelegatingConstructor()) {
1978  assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
1979 
1980  // Skip detailed checking if we have enough initializers, and we would
1981  // allow at most one initializer per member.
1982  bool AnyAnonStructUnionMembers = false;
1983  unsigned Fields = 0;
1985  E = RD->field_end(); I != E; ++I, ++Fields) {
1986  if (I->isAnonymousStructOrUnion()) {
1987  AnyAnonStructUnionMembers = true;
1988  break;
1989  }
1990  }
1991  // DR1460:
1992  // - if the class is a union-like class, but is not a union, for each of
1993  // its anonymous union members having variant members, exactly one of
1994  // them shall be initialized;
1995  if (AnyAnonStructUnionMembers ||
1996  Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
1997  // Check initialization of non-static data members. Base classes are
1998  // always initialized so do not need to be checked. Dependent bases
1999  // might not have initializers in the member initializer list.
2000  llvm::SmallSet<Decl*, 16> Inits;
2001  for (const auto *I: Constructor->inits()) {
2002  if (FieldDecl *FD = I->getMember())
2003  Inits.insert(FD);
2004  else if (IndirectFieldDecl *ID = I->getIndirectMember())
2005  Inits.insert(ID->chain_begin(), ID->chain_end());
2006  }
2007 
2008  bool Diagnosed = false;
2009  for (auto *I : RD->fields())
2010  CheckConstexprCtorInitializer(*this, Dcl, I, Inits, Diagnosed);
2011  if (Diagnosed)
2012  return false;
2013  }
2014  }
2015  } else {
2016  if (ReturnStmts.empty()) {
2017  // C++1y doesn't require constexpr functions to contain a 'return'
2018  // statement. We still do, unless the return type might be void, because
2019  // otherwise if there's no return statement, the function cannot
2020  // be used in a core constant expression.
2021  bool OK = getLangOpts().CPlusPlus14 &&
2022  (Dcl->getReturnType()->isVoidType() ||
2023  Dcl->getReturnType()->isDependentType());
2024  Diag(Dcl->getLocation(),
2025  OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2026  : diag::err_constexpr_body_no_return);
2027  if (!OK)
2028  return false;
2029  } else if (ReturnStmts.size() > 1) {
2030  Diag(ReturnStmts.back(),
2031  getLangOpts().CPlusPlus14
2032  ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2033  : diag::ext_constexpr_body_multiple_return);
2034  for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2035  Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
2036  }
2037  }
2038 
2039  // C++11 [dcl.constexpr]p5:
2040  // if no function argument values exist such that the function invocation
2041  // substitution would produce a constant expression, the program is
2042  // ill-formed; no diagnostic required.
2043  // C++11 [dcl.constexpr]p3:
2044  // - every constructor call and implicit conversion used in initializing the
2045  // return value shall be one of those allowed in a constant expression.
2046  // C++11 [dcl.constexpr]p4:
2047  // - every constructor involved in initializing non-static data members and
2048  // base class sub-objects shall be a constexpr constructor.
2050  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
2051  Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr)
2052  << isa<CXXConstructorDecl>(Dcl);
2053  for (size_t I = 0, N = Diags.size(); I != N; ++I)
2054  Diag(Diags[I].first, Diags[I].second);
2055  // Don't return false here: we allow this for compatibility in
2056  // system headers.
2057  }
2058 
2059  return true;
2060 }
2061 
2062 /// Get the class that is directly named by the current context. This is the
2063 /// class for which an unqualified-id in this scope could name a constructor
2064 /// or destructor.
2065 ///
2066 /// If the scope specifier denotes a class, this will be that class.
2067 /// If the scope specifier is empty, this will be the class whose
2068 /// member-specification we are currently within. Otherwise, there
2069 /// is no such class.
2071  assert(getLangOpts().CPlusPlus && "No class names in C!");
2072 
2073  if (SS && SS->isInvalid())
2074  return nullptr;
2075 
2076  if (SS && SS->isNotEmpty()) {
2077  DeclContext *DC = computeDeclContext(*SS, true);
2078  return dyn_cast_or_null<CXXRecordDecl>(DC);
2079  }
2080 
2081  return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2082 }
2083 
2084 /// isCurrentClassName - Determine whether the identifier II is the
2085 /// name of the class type currently being defined. In the case of
2086 /// nested classes, this will only return true if II is the name of
2087 /// the innermost class.
2089  const CXXScopeSpec *SS) {
2090  CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2091  return CurDecl && &II == CurDecl->getIdentifier();
2092 }
2093 
2094 /// Determine whether the identifier II is a typo for the name of
2095 /// the class type currently being defined. If so, update it to the identifier
2096 /// that should have been used.
2098  assert(getLangOpts().CPlusPlus && "No class names in C!");
2099 
2100  if (!getLangOpts().SpellChecking)
2101  return false;
2102 
2103  CXXRecordDecl *CurDecl;
2104  if (SS && SS->isSet() && !SS->isInvalid()) {
2105  DeclContext *DC = computeDeclContext(*SS, true);
2106  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2107  } else
2108  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2109 
2110  if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2111  3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2112  < II->getLength()) {
2113  II = CurDecl->getIdentifier();
2114  return true;
2115  }
2116 
2117  return false;
2118 }
2119 
2120 /// Determine whether the given class is a base class of the given
2121 /// class, including looking at dependent bases.
2122 static bool findCircularInheritance(const CXXRecordDecl *Class,
2123  const CXXRecordDecl *Current) {
2125 
2126  Class = Class->getCanonicalDecl();
2127  while (true) {
2128  for (const auto &I : Current->bases()) {
2129  CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2130  if (!Base)
2131  continue;
2132 
2133  Base = Base->getDefinition();
2134  if (!Base)
2135  continue;
2136 
2137  if (Base->getCanonicalDecl() == Class)
2138  return true;
2139 
2140  Queue.push_back(Base);
2141  }
2142 
2143  if (Queue.empty())
2144  return false;
2145 
2146  Current = Queue.pop_back_val();
2147  }
2148 
2149  return false;
2150 }
2151 
2152 /// Check the validity of a C++ base class specifier.
2153 ///
2154 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2155 /// and returns NULL otherwise.
2158  SourceRange SpecifierRange,
2159  bool Virtual, AccessSpecifier Access,
2160  TypeSourceInfo *TInfo,
2161  SourceLocation EllipsisLoc) {
2162  QualType BaseType = TInfo->getType();
2163 
2164  // C++ [class.union]p1:
2165  // A union shall not have base classes.
2166  if (Class->isUnion()) {
2167  Diag(Class->getLocation(), diag::err_base_clause_on_union)
2168  << SpecifierRange;
2169  return nullptr;
2170  }
2171 
2172  if (EllipsisLoc.isValid() &&
2174  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2175  << TInfo->getTypeLoc().getSourceRange();
2176  EllipsisLoc = SourceLocation();
2177  }
2178 
2179  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2180 
2181  if (BaseType->isDependentType()) {
2182  // Make sure that we don't have circular inheritance among our dependent
2183  // bases. For non-dependent bases, the check for completeness below handles
2184  // this.
2185  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2186  if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2187  ((BaseDecl = BaseDecl->getDefinition()) &&
2188  findCircularInheritance(Class, BaseDecl))) {
2189  Diag(BaseLoc, diag::err_circular_inheritance)
2190  << BaseType << Context.getTypeDeclType(Class);
2191 
2192  if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2193  Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2194  << BaseType;
2195 
2196  return nullptr;
2197  }
2198  }
2199 
2200  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2201  Class->getTagKind() == TTK_Class,
2202  Access, TInfo, EllipsisLoc);
2203  }
2204 
2205  // Base specifiers must be record types.
2206  if (!BaseType->isRecordType()) {
2207  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2208  return nullptr;
2209  }
2210 
2211  // C++ [class.union]p1:
2212  // A union shall not be used as a base class.
2213  if (BaseType->isUnionType()) {
2214  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2215  return nullptr;
2216  }
2217 
2218  // For the MS ABI, propagate DLL attributes to base class templates.
2219  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2220  if (Attr *ClassAttr = getDLLAttr(Class)) {
2221  if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2222  BaseType->getAsCXXRecordDecl())) {
2223  propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2224  BaseLoc);
2225  }
2226  }
2227  }
2228 
2229  // C++ [class.derived]p2:
2230  // The class-name in a base-specifier shall not be an incompletely
2231  // defined class.
2232  if (RequireCompleteType(BaseLoc, BaseType,
2233  diag::err_incomplete_base_class, SpecifierRange)) {
2234  Class->setInvalidDecl();
2235  return nullptr;
2236  }
2237 
2238  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2239  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
2240  assert(BaseDecl && "Record type has no declaration");
2241  BaseDecl = BaseDecl->getDefinition();
2242  assert(BaseDecl && "Base type is not incomplete, but has no definition");
2243  CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2244  assert(CXXBaseDecl && "Base type is not a C++ type");
2245 
2246  // A class which contains a flexible array member is not suitable for use as a
2247  // base class:
2248  // - If the layout determines that a base comes before another base,
2249  // the flexible array member would index into the subsequent base.
2250  // - If the layout determines that base comes before the derived class,
2251  // the flexible array member would index into the derived class.
2252  if (CXXBaseDecl->hasFlexibleArrayMember()) {
2253  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2254  << CXXBaseDecl->getDeclName();
2255  return nullptr;
2256  }
2257 
2258  // C++ [class]p3:
2259  // If a class is marked final and it appears as a base-type-specifier in
2260  // base-clause, the program is ill-formed.
2261  if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2262  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2263  << CXXBaseDecl->getDeclName()
2264  << FA->isSpelledAsSealed();
2265  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2266  << CXXBaseDecl->getDeclName() << FA->getRange();
2267  return nullptr;
2268  }
2269 
2270  if (BaseDecl->isInvalidDecl())
2271  Class->setInvalidDecl();
2272 
2273  // Create the base specifier.
2274  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2275  Class->getTagKind() == TTK_Class,
2276  Access, TInfo, EllipsisLoc);
2277 }
2278 
2279 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2280 /// one entry in the base class list of a class specifier, for
2281 /// example:
2282 /// class foo : public bar, virtual private baz {
2283 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2284 BaseResult
2285 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2286  ParsedAttributes &Attributes,
2287  bool Virtual, AccessSpecifier Access,
2288  ParsedType basetype, SourceLocation BaseLoc,
2289  SourceLocation EllipsisLoc) {
2290  if (!classdecl)
2291  return true;
2292 
2293  AdjustDeclIfTemplate(classdecl);
2294  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2295  if (!Class)
2296  return true;
2297 
2298  // We haven't yet attached the base specifiers.
2299  Class->setIsParsingBaseSpecifiers();
2300 
2301  // We do not support any C++11 attributes on base-specifiers yet.
2302  // Diagnose any attributes we see.
2303  for (const ParsedAttr &AL : Attributes) {
2304  if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2305  continue;
2306  Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2307  ? diag::warn_unknown_attribute_ignored
2308  : diag::err_base_specifier_attribute)
2309  << AL.getName();
2310  }
2311 
2312  TypeSourceInfo *TInfo = nullptr;
2313  GetTypeFromParser(basetype, &TInfo);
2314 
2315  if (EllipsisLoc.isInvalid() &&
2316  DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2317  UPPC_BaseType))
2318  return true;
2319 
2320  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2321  Virtual, Access, TInfo,
2322  EllipsisLoc))
2323  return BaseSpec;
2324  else
2325  Class->setInvalidDecl();
2326 
2327  return true;
2328 }
2329 
2330 /// Use small set to collect indirect bases. As this is only used
2331 /// locally, there's no need to abstract the small size parameter.
2332 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2333 
2334 /// Recursively add the bases of Type. Don't add Type itself.
2335 static void
2336 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2337  const QualType &Type)
2338 {
2339  // Even though the incoming type is a base, it might not be
2340  // a class -- it could be a template parm, for instance.
2341  if (auto Rec = Type->getAs<RecordType>()) {
2342  auto Decl = Rec->getAsCXXRecordDecl();
2343 
2344  // Iterate over its bases.
2345  for (const auto &BaseSpec : Decl->bases()) {
2346  QualType Base = Context.getCanonicalType(BaseSpec.getType())
2347  .getUnqualifiedType();
2348  if (Set.insert(Base).second)
2349  // If we've not already seen it, recurse.
2350  NoteIndirectBases(Context, Set, Base);
2351  }
2352  }
2353 }
2354 
2355 /// Performs the actual work of attaching the given base class
2356 /// specifiers to a C++ class.
2359  if (Bases.empty())
2360  return false;
2361 
2362  // Used to keep track of which base types we have already seen, so
2363  // that we can properly diagnose redundant direct base types. Note
2364  // that the key is always the unqualified canonical type of the base
2365  // class.
2366  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2367 
2368  // Used to track indirect bases so we can see if a direct base is
2369  // ambiguous.
2370  IndirectBaseSet IndirectBaseTypes;
2371 
2372  // Copy non-redundant base specifiers into permanent storage.
2373  unsigned NumGoodBases = 0;
2374  bool Invalid = false;
2375  for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2376  QualType NewBaseType
2377  = Context.getCanonicalType(Bases[idx]->getType());
2378  NewBaseType = NewBaseType.getLocalUnqualifiedType();
2379 
2380  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2381  if (KnownBase) {
2382  // C++ [class.mi]p3:
2383  // A class shall not be specified as a direct base class of a
2384  // derived class more than once.
2385  Diag(Bases[idx]->getLocStart(),
2386  diag::err_duplicate_base_class)
2387  << KnownBase->getType()
2388  << Bases[idx]->getSourceRange();
2389 
2390  // Delete the duplicate base class specifier; we're going to
2391  // overwrite its pointer later.
2392  Context.Deallocate(Bases[idx]);
2393 
2394  Invalid = true;
2395  } else {
2396  // Okay, add this new base class.
2397  KnownBase = Bases[idx];
2398  Bases[NumGoodBases++] = Bases[idx];
2399 
2400  // Note this base's direct & indirect bases, if there could be ambiguity.
2401  if (Bases.size() > 1)
2402  NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2403 
2404  if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2405  const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2406  if (Class->isInterface() &&
2407  (!RD->isInterfaceLike() ||
2408  KnownBase->getAccessSpecifier() != AS_public)) {
2409  // The Microsoft extension __interface does not permit bases that
2410  // are not themselves public interfaces.
2411  Diag(KnownBase->getLocStart(), diag::err_invalid_base_in_interface)
2412  << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2413  << RD->getSourceRange();
2414  Invalid = true;
2415  }
2416  if (RD->hasAttr<WeakAttr>())
2417  Class->addAttr(WeakAttr::CreateImplicit(Context));
2418  }
2419  }
2420  }
2421 
2422  // Attach the remaining base class specifiers to the derived class.
2423  Class->setBases(Bases.data(), NumGoodBases);
2424 
2425  // Check that the only base classes that are duplicate are virtual.
2426  for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2427  // Check whether this direct base is inaccessible due to ambiguity.
2428  QualType BaseType = Bases[idx]->getType();
2429 
2430  // Skip all dependent types in templates being used as base specifiers.
2431  // Checks below assume that the base specifier is a CXXRecord.
2432  if (BaseType->isDependentType())
2433  continue;
2434 
2435  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2436  .getUnqualifiedType();
2437 
2438  if (IndirectBaseTypes.count(CanonicalBase)) {
2439  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2440  /*DetectVirtual=*/true);
2441  bool found
2442  = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2443  assert(found);
2444  (void)found;
2445 
2446  if (Paths.isAmbiguous(CanonicalBase))
2447  Diag(Bases[idx]->getLocStart (), diag::warn_inaccessible_base_class)
2448  << BaseType << getAmbiguousPathsDisplayString(Paths)
2449  << Bases[idx]->getSourceRange();
2450  else
2451  assert(Bases[idx]->isVirtual());
2452  }
2453 
2454  // Delete the base class specifier, since its data has been copied
2455  // into the CXXRecordDecl.
2456  Context.Deallocate(Bases[idx]);
2457  }
2458 
2459  return Invalid;
2460 }
2461 
2462 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2463 /// class, after checking whether there are any duplicate base
2464 /// classes.
2465 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2467  if (!ClassDecl || Bases.empty())
2468  return;
2469 
2470  AdjustDeclIfTemplate(ClassDecl);
2471  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2472 }
2473 
2474 /// Determine whether the type \p Derived is a C++ class that is
2475 /// derived from the type \p Base.
2477  if (!getLangOpts().CPlusPlus)
2478  return false;
2479 
2480  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2481  if (!DerivedRD)
2482  return false;
2483 
2484  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2485  if (!BaseRD)
2486  return false;
2487 
2488  // If either the base or the derived type is invalid, don't try to
2489  // check whether one is derived from the other.
2490  if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2491  return false;
2492 
2493  // FIXME: In a modules build, do we need the entire path to be visible for us
2494  // to be able to use the inheritance relationship?
2495  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2496  return false;
2497 
2498  return DerivedRD->isDerivedFrom(BaseRD);
2499 }
2500 
2501 /// Determine whether the type \p Derived is a C++ class that is
2502 /// derived from the type \p Base.
2504  CXXBasePaths &Paths) {
2505  if (!getLangOpts().CPlusPlus)
2506  return false;
2507 
2508  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2509  if (!DerivedRD)
2510  return false;
2511 
2512  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2513  if (!BaseRD)
2514  return false;
2515 
2516  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2517  return false;
2518 
2519  return DerivedRD->isDerivedFrom(BaseRD, Paths);
2520 }
2521 
2522 static void BuildBasePathArray(const CXXBasePath &Path,
2523  CXXCastPath &BasePathArray) {
2524  // We first go backward and check if we have a virtual base.
2525  // FIXME: It would be better if CXXBasePath had the base specifier for
2526  // the nearest virtual base.
2527  unsigned Start = 0;
2528  for (unsigned I = Path.size(); I != 0; --I) {
2529  if (Path[I - 1].Base->isVirtual()) {
2530  Start = I - 1;
2531  break;
2532  }
2533  }
2534 
2535  // Now add all bases.
2536  for (unsigned I = Start, E = Path.size(); I != E; ++I)
2537  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2538 }
2539 
2540 
2542  CXXCastPath &BasePathArray) {
2543  assert(BasePathArray.empty() && "Base path array must be empty!");
2544  assert(Paths.isRecordingPaths() && "Must record paths!");
2545  return ::BuildBasePathArray(Paths.front(), BasePathArray);
2546 }
2547 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2548 /// conversion (where Derived and Base are class types) is
2549 /// well-formed, meaning that the conversion is unambiguous (and
2550 /// that all of the base classes are accessible). Returns true
2551 /// and emits a diagnostic if the code is ill-formed, returns false
2552 /// otherwise. Loc is the location where this routine should point to
2553 /// if there is an error, and Range is the source range to highlight
2554 /// if there is an error.
2555 ///
2556 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2557 /// diagnostic for the respective type of error will be suppressed, but the
2558 /// check for ill-formed code will still be performed.
2559 bool
2561  unsigned InaccessibleBaseID,
2562  unsigned AmbigiousBaseConvID,
2563  SourceLocation Loc, SourceRange Range,
2564  DeclarationName Name,
2565  CXXCastPath *BasePath,
2566  bool IgnoreAccess) {
2567  // First, determine whether the path from Derived to Base is
2568  // ambiguous. This is slightly more expensive than checking whether
2569  // the Derived to Base conversion exists, because here we need to
2570  // explore multiple paths to determine if there is an ambiguity.
2571  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2572  /*DetectVirtual=*/false);
2573  bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2574  if (!DerivationOkay)
2575  return true;
2576 
2577  const CXXBasePath *Path = nullptr;
2578  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2579  Path = &Paths.front();
2580 
2581  // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2582  // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2583  // user to access such bases.
2584  if (!Path && getLangOpts().MSVCCompat) {
2585  for (const CXXBasePath &PossiblePath : Paths) {
2586  if (PossiblePath.size() == 1) {
2587  Path = &PossiblePath;
2588  if (AmbigiousBaseConvID)
2589  Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2590  << Base << Derived << Range;
2591  break;
2592  }
2593  }
2594  }
2595 
2596  if (Path) {
2597  if (!IgnoreAccess) {
2598  // Check that the base class can be accessed.
2599  switch (
2600  CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2601  case AR_inaccessible:
2602  return true;
2603  case AR_accessible:
2604  case AR_dependent:
2605  case AR_delayed:
2606  break;
2607  }
2608  }
2609 
2610  // Build a base path if necessary.
2611  if (BasePath)
2612  ::BuildBasePathArray(*Path, *BasePath);
2613  return false;
2614  }
2615 
2616  if (AmbigiousBaseConvID) {
2617  // We know that the derived-to-base conversion is ambiguous, and
2618  // we're going to produce a diagnostic. Perform the derived-to-base
2619  // search just one more time to compute all of the possible paths so
2620  // that we can print them out. This is more expensive than any of
2621  // the previous derived-to-base checks we've done, but at this point
2622  // performance isn't as much of an issue.
2623  Paths.clear();
2624  Paths.setRecordingPaths(true);
2625  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2626  assert(StillOkay && "Can only be used with a derived-to-base conversion");
2627  (void)StillOkay;
2628 
2629  // Build up a textual representation of the ambiguous paths, e.g.,
2630  // D -> B -> A, that will be used to illustrate the ambiguous
2631  // conversions in the diagnostic. We only print one of the paths
2632  // to each base class subobject.
2633  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2634 
2635  Diag(Loc, AmbigiousBaseConvID)
2636  << Derived << Base << PathDisplayStr << Range << Name;
2637  }
2638  return true;
2639 }
2640 
2641 bool
2643  SourceLocation Loc, SourceRange Range,
2644  CXXCastPath *BasePath,
2645  bool IgnoreAccess) {
2646  return CheckDerivedToBaseConversion(
2647  Derived, Base, diag::err_upcast_to_inaccessible_base,
2648  diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2649  BasePath, IgnoreAccess);
2650 }
2651 
2652 
2653 /// Builds a string representing ambiguous paths from a
2654 /// specific derived class to different subobjects of the same base
2655 /// class.
2656 ///
2657 /// This function builds a string that can be used in error messages
2658 /// to show the different paths that one can take through the
2659 /// inheritance hierarchy to go from the derived class to different
2660 /// subobjects of a base class. The result looks something like this:
2661 /// @code
2662 /// struct D -> struct B -> struct A
2663 /// struct D -> struct C -> struct A
2664 /// @endcode
2666  std::string PathDisplayStr;
2667  std::set<unsigned> DisplayedPaths;
2668  for (CXXBasePaths::paths_iterator Path = Paths.begin();
2669  Path != Paths.end(); ++Path) {
2670  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2671  // We haven't displayed a path to this particular base
2672  // class subobject yet.
2673  PathDisplayStr += "\n ";
2674  PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2675  for (CXXBasePath::const_iterator Element = Path->begin();
2676  Element != Path->end(); ++Element)
2677  PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2678  }
2679  }
2680 
2681  return PathDisplayStr;
2682 }
2683 
2684 //===----------------------------------------------------------------------===//
2685 // C++ class member Handling
2686 //===----------------------------------------------------------------------===//
2687 
2688 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2691  const ParsedAttributesView &Attrs) {
2692  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2693  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2694  ASLoc, ColonLoc);
2695  CurContext->addHiddenDecl(ASDecl);
2696  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2697 }
2698 
2699 /// CheckOverrideControl - Check C++11 override control semantics.
2701  if (D->isInvalidDecl())
2702  return;
2703 
2704  // We only care about "override" and "final" declarations.
2705  if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2706  return;
2707 
2708  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2709 
2710  // We can't check dependent instance methods.
2711  if (MD && MD->isInstance() &&
2712  (MD->getParent()->hasAnyDependentBases() ||
2713  MD->getType()->isDependentType()))
2714  return;
2715 
2716  if (MD && !MD->isVirtual()) {
2717  // If we have a non-virtual method, check if if hides a virtual method.
2718  // (In that case, it's most likely the method has the wrong type.)
2719  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2720  FindHiddenVirtualMethods(MD, OverloadedMethods);
2721 
2722  if (!OverloadedMethods.empty()) {
2723  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2724  Diag(OA->getLocation(),
2725  diag::override_keyword_hides_virtual_member_function)
2726  << "override" << (OverloadedMethods.size() > 1);
2727  } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2728  Diag(FA->getLocation(),
2729  diag::override_keyword_hides_virtual_member_function)
2730  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2731  << (OverloadedMethods.size() > 1);
2732  }
2733  NoteHiddenVirtualMethods(MD, OverloadedMethods);
2734  MD->setInvalidDecl();
2735  return;
2736  }
2737  // Fall through into the general case diagnostic.
2738  // FIXME: We might want to attempt typo correction here.
2739  }
2740 
2741  if (!MD || !MD->isVirtual()) {
2742  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2743  Diag(OA->getLocation(),
2744  diag::override_keyword_only_allowed_on_virtual_member_functions)
2745  << "override" << FixItHint::CreateRemoval(OA->getLocation());
2746  D->dropAttr<OverrideAttr>();
2747  }
2748  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2749  Diag(FA->getLocation(),
2750  diag::override_keyword_only_allowed_on_virtual_member_functions)
2751  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2752  << FixItHint::CreateRemoval(FA->getLocation());
2753  D->dropAttr<FinalAttr>();
2754  }
2755  return;
2756  }
2757 
2758  // C++11 [class.virtual]p5:
2759  // If a function is marked with the virt-specifier override and
2760  // does not override a member function of a base class, the program is
2761  // ill-formed.
2762  bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
2763  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
2764  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
2765  << MD->getDeclName();
2766 }
2767 
2769  if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
2770  return;
2771  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2772  if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
2773  return;
2774 
2775  SourceLocation Loc = MD->getLocation();
2776  SourceLocation SpellingLoc = Loc;
2777  if (getSourceManager().isMacroArgExpansion(Loc))
2778  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
2779  SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
2780  if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
2781  return;
2782 
2783  if (MD->size_overridden_methods() > 0) {
2784  unsigned DiagID = isa<CXXDestructorDecl>(MD)
2785  ? diag::warn_destructor_marked_not_override_overriding
2786  : diag::warn_function_marked_not_override_overriding;
2787  Diag(MD->getLocation(), DiagID) << MD->getDeclName();
2788  const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
2789  Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
2790  }
2791 }
2792 
2793 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
2794 /// function overrides a virtual member function marked 'final', according to
2795 /// C++11 [class.virtual]p4.
2797  const CXXMethodDecl *Old) {
2798  FinalAttr *FA = Old->getAttr<FinalAttr>();
2799  if (!FA)
2800  return false;
2801 
2802  Diag(New->getLocation(), diag::err_final_function_overridden)
2803  << New->getDeclName()
2804  << FA->isSpelledAsSealed();
2805  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
2806  return true;
2807 }
2808 
2809 static bool InitializationHasSideEffects(const FieldDecl &FD) {
2810  const Type *T = FD.getType()->getBaseElementTypeUnsafe();
2811  // FIXME: Destruction of ObjC lifetime types has side-effects.
2812  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
2813  return !RD->isCompleteDefinition() ||
2814  !RD->hasTrivialDefaultConstructor() ||
2815  !RD->hasTrivialDestructor();
2816  return false;
2817 }
2818 
2821  llvm::find_if(list, [](const ParsedAttr &AL) {
2822  return AL.isDeclspecPropertyAttribute();
2823  });
2824  if (Itr != list.end())
2825  return &*Itr;
2826  return nullptr;
2827 }
2828 
2829 // Check if there is a field shadowing.
2830 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
2831  DeclarationName FieldName,
2832  const CXXRecordDecl *RD) {
2833  if (Diags.isIgnored(diag::warn_shadow_field, Loc))
2834  return;
2835 
2836  // To record a shadowed field in a base
2837  std::map<CXXRecordDecl*, NamedDecl*> Bases;
2838  auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
2839  CXXBasePath &Path) {
2840  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
2841  // Record an ambiguous path directly
2842  if (Bases.find(Base) != Bases.end())
2843  return true;
2844  for (const auto Field : Base->lookup(FieldName)) {
2845  if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
2846  Field->getAccess() != AS_private) {
2847  assert(Field->getAccess() != AS_none);
2848  assert(Bases.find(Base) == Bases.end());
2849  Bases[Base] = Field;
2850  return true;
2851  }
2852  }
2853  return false;
2854  };
2855 
2856  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2857  /*DetectVirtual=*/true);
2858  if (!RD->lookupInBases(FieldShadowed, Paths))
2859  return;
2860 
2861  for (const auto &P : Paths) {
2862  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
2863  auto It = Bases.find(Base);
2864  // Skip duplicated bases
2865  if (It == Bases.end())
2866  continue;
2867  auto BaseField = It->second;
2868  assert(BaseField->getAccess() != AS_private);
2869  if (AS_none !=
2870  CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
2871  Diag(Loc, diag::warn_shadow_field)
2872  << FieldName << RD << Base;
2873  Diag(BaseField->getLocation(), diag::note_shadow_field);
2874  Bases.erase(It);
2875  }
2876  }
2877 }
2878 
2879 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
2880 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
2881 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
2882 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
2883 /// present (but parsing it has been deferred).
2884 NamedDecl *
2886  MultiTemplateParamsArg TemplateParameterLists,
2887  Expr *BW, const VirtSpecifiers &VS,
2888  InClassInitStyle InitStyle) {
2889  const DeclSpec &DS = D.getDeclSpec();
2890  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
2891  DeclarationName Name = NameInfo.getName();
2892  SourceLocation Loc = NameInfo.getLoc();
2893 
2894  // For anonymous bitfields, the location should point to the type.
2895  if (Loc.isInvalid())
2896  Loc = D.getLocStart();
2897 
2898  Expr *BitWidth = static_cast<Expr*>(BW);
2899 
2900  assert(isa<CXXRecordDecl>(CurContext));
2901  assert(!DS.isFriendSpecified());
2902 
2903  bool isFunc = D.isDeclarationOfFunction();
2904  const ParsedAttr *MSPropertyAttr =
2906 
2907  if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
2908  // The Microsoft extension __interface only permits public member functions
2909  // and prohibits constructors, destructors, operators, non-public member
2910  // functions, static methods and data members.
2911  unsigned InvalidDecl;
2912  bool ShowDeclName = true;
2913  if (!isFunc &&
2914  (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
2915  InvalidDecl = 0;
2916  else if (!isFunc)
2917  InvalidDecl = 1;
2918  else if (AS != AS_public)
2919  InvalidDecl = 2;
2920  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
2921  InvalidDecl = 3;
2922  else switch (Name.getNameKind()) {
2924  InvalidDecl = 4;
2925  ShowDeclName = false;
2926  break;
2927 
2929  InvalidDecl = 5;
2930  ShowDeclName = false;
2931  break;
2932 
2935  InvalidDecl = 6;
2936  break;
2937 
2938  default:
2939  InvalidDecl = 0;
2940  break;
2941  }
2942 
2943  if (InvalidDecl) {
2944  if (ShowDeclName)
2945  Diag(Loc, diag::err_invalid_member_in_interface)
2946  << (InvalidDecl-1) << Name;
2947  else
2948  Diag(Loc, diag::err_invalid_member_in_interface)
2949  << (InvalidDecl-1) << "";
2950  return nullptr;
2951  }
2952  }
2953 
2954  // C++ 9.2p6: A member shall not be declared to have automatic storage
2955  // duration (auto, register) or with the extern storage-class-specifier.
2956  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
2957  // data members and cannot be applied to names declared const or static,
2958  // and cannot be applied to reference members.
2959  switch (DS.getStorageClassSpec()) {
2961  case DeclSpec::SCS_typedef:
2962  case DeclSpec::SCS_static:
2963  break;
2964  case DeclSpec::SCS_mutable:
2965  if (isFunc) {
2966  Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
2967 
2968  // FIXME: It would be nicer if the keyword was ignored only for this
2969  // declarator. Otherwise we could get follow-up errors.
2971  }
2972  break;
2973  default:
2975  diag::err_storageclass_invalid_for_member);
2977  break;
2978  }
2979 
2980  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
2982  !isFunc);
2983 
2984  if (DS.isConstexprSpecified() && isInstField) {
2986  Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
2987  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
2988  if (InitStyle == ICIS_NoInit) {
2989  B << 0 << 0;
2991  B << FixItHint::CreateRemoval(ConstexprLoc);
2992  else {
2993  B << FixItHint::CreateReplacement(ConstexprLoc, "const");
2995  const char *PrevSpec;
2996  unsigned DiagID;
2997  bool Failed = D.getMutableDeclSpec().SetTypeQual(
2998  DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
2999  (void)Failed;
3000  assert(!Failed && "Making a constexpr member const shouldn't fail");
3001  }
3002  } else {
3003  B << 1;
3004  const char *PrevSpec;
3005  unsigned DiagID;
3007  *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3008  Context.getPrintingPolicy())) {
3009  assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3010  "This is the only DeclSpec that should fail to be applied");
3011  B << 1;
3012  } else {
3013  B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3014  isInstField = false;
3015  }
3016  }
3017  }
3018 
3019  NamedDecl *Member;
3020  if (isInstField) {
3021  CXXScopeSpec &SS = D.getCXXScopeSpec();
3022 
3023  // Data members must have identifiers for names.
3024  if (!Name.isIdentifier()) {
3025  Diag(Loc, diag::err_bad_variable_name)
3026  << Name;
3027  return nullptr;
3028  }
3029 
3030  IdentifierInfo *II = Name.getAsIdentifierInfo();
3031 
3032  // Member field could not be with "template" keyword.
3033  // So TemplateParameterLists should be empty in this case.
3034  if (TemplateParameterLists.size()) {
3035  TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3036  if (TemplateParams->size()) {
3037  // There is no such thing as a member field template.
3038  Diag(D.getIdentifierLoc(), diag::err_template_member)
3039  << II
3040  << SourceRange(TemplateParams->getTemplateLoc(),
3041  TemplateParams->getRAngleLoc());
3042  } else {
3043  // There is an extraneous 'template<>' for this member.
3044  Diag(TemplateParams->getTemplateLoc(),
3045  diag::err_template_member_noparams)
3046  << II
3047  << SourceRange(TemplateParams->getTemplateLoc(),
3048  TemplateParams->getRAngleLoc());
3049  }
3050  return nullptr;
3051  }
3052 
3053  if (SS.isSet() && !SS.isInvalid()) {
3054  // The user provided a superfluous scope specifier inside a class
3055  // definition:
3056  //
3057  // class X {
3058  // int X::member;
3059  // };
3060  if (DeclContext *DC = computeDeclContext(SS, false))
3061  diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3062  D.getName().getKind() ==
3064  else
3065  Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3066  << Name << SS.getRange();
3067 
3068  SS.clear();
3069  }
3070 
3071  if (MSPropertyAttr) {
3072  Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3073  BitWidth, InitStyle, AS, *MSPropertyAttr);
3074  if (!Member)
3075  return nullptr;
3076  isInstField = false;
3077  } else {
3078  Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3079  BitWidth, InitStyle, AS);
3080  if (!Member)
3081  return nullptr;
3082  }
3083 
3084  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3085  } else {
3086  Member = HandleDeclarator(S, D, TemplateParameterLists);
3087  if (!Member)
3088  return nullptr;
3089 
3090  // Non-instance-fields can't have a bitfield.
3091  if (BitWidth) {
3092  if (Member->isInvalidDecl()) {
3093  // don't emit another diagnostic.
3094  } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3095  // C++ 9.6p3: A bit-field shall not be a static member.
3096  // "static member 'A' cannot be a bit-field"
3097  Diag(Loc, diag::err_static_not_bitfield)
3098  << Name << BitWidth->getSourceRange();
3099  } else if (isa<TypedefDecl>(Member)) {
3100  // "typedef member 'x' cannot be a bit-field"
3101  Diag(Loc, diag::err_typedef_not_bitfield)
3102  << Name << BitWidth->getSourceRange();
3103  } else {
3104  // A function typedef ("typedef int f(); f a;").
3105  // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3106  Diag(Loc, diag::err_not_integral_type_bitfield)
3107  << Name << cast<ValueDecl>(Member)->getType()
3108  << BitWidth->getSourceRange();
3109  }
3110 
3111  BitWidth = nullptr;
3112  Member->setInvalidDecl();
3113  }
3114 
3115  NamedDecl *NonTemplateMember = Member;
3116  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3117  NonTemplateMember = FunTmpl->getTemplatedDecl();
3118  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3119  NonTemplateMember = VarTmpl->getTemplatedDecl();
3120 
3121  Member->setAccess(AS);
3122 
3123  // If we have declared a member function template or static data member
3124  // template, set the access of the templated declaration as well.
3125  if (NonTemplateMember != Member)
3126  NonTemplateMember->setAccess(AS);
3127 
3128  // C++ [temp.deduct.guide]p3:
3129  // A deduction guide [...] for a member class template [shall be
3130  // declared] with the same access [as the template].
3131  if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3132  auto *TD = DG->getDeducedTemplate();
3133  if (AS != TD->getAccess()) {
3134  Diag(DG->getLocStart(), diag::err_deduction_guide_wrong_access);
3135  Diag(TD->getLocStart(), diag::note_deduction_guide_template_access)
3136  << TD->getAccess();
3137  const AccessSpecDecl *LastAccessSpec = nullptr;
3138  for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3139  if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3140  LastAccessSpec = AccessSpec;
3141  }
3142  assert(LastAccessSpec && "differing access with no access specifier");
3143  Diag(LastAccessSpec->getLocStart(), diag::note_deduction_guide_access)
3144  << AS;
3145  }
3146  }
3147  }
3148 
3149  if (VS.isOverrideSpecified())
3150  Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context, 0));
3151  if (VS.isFinalSpecified())
3152  Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context,
3153  VS.isFinalSpelledSealed()));
3154 
3155  if (VS.getLastLocation().isValid()) {
3156  // Update the end location of a method that has a virt-specifiers.
3157  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3158  MD->setRangeEnd(VS.getLastLocation());
3159  }
3160 
3161  CheckOverrideControl(Member);
3162 
3163  assert((Name || isInstField) && "No identifier for non-field ?");
3164 
3165  if (isInstField) {
3166  FieldDecl *FD = cast<FieldDecl>(Member);
3167  FieldCollector->Add(FD);
3168 
3169  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3170  // Remember all explicit private FieldDecls that have a name, no side
3171  // effects and are not part of a dependent type declaration.
3172  if (!FD->isImplicit() && FD->getDeclName() &&
3173  FD->getAccess() == AS_private &&
3174  !FD->hasAttr<UnusedAttr>() &&
3175  !FD->getParent()->isDependentContext() &&
3177  UnusedPrivateFields.insert(FD);
3178  }
3179  }
3180 
3181  return Member;
3182 }
3183 
3184 namespace {
3185  class UninitializedFieldVisitor
3186  : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3187  Sema &S;
3188  // List of Decls to generate a warning on. Also remove Decls that become
3189  // initialized.
3190  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3191  // List of base classes of the record. Classes are removed after their
3192  // initializers.
3193  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3194  // Vector of decls to be removed from the Decl set prior to visiting the
3195  // nodes. These Decls may have been initialized in the prior initializer.
3196  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3197  // If non-null, add a note to the warning pointing back to the constructor.
3198  const CXXConstructorDecl *Constructor;
3199  // Variables to hold state when processing an initializer list. When
3200  // InitList is true, special case initialization of FieldDecls matching
3201  // InitListFieldDecl.
3202  bool InitList;
3203  FieldDecl *InitListFieldDecl;
3204  llvm::SmallVector<unsigned, 4> InitFieldIndex;
3205 
3206  public:
3208  UninitializedFieldVisitor(Sema &S,
3209  llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3210  llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3211  : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3212  Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3213 
3214  // Returns true if the use of ME is not an uninitialized use.
3215  bool IsInitListMemberExprInitialized(MemberExpr *ME,
3216  bool CheckReferenceOnly) {
3218  bool ReferenceField = false;
3219  while (ME) {
3220  FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3221  if (!FD)
3222  return false;
3223  Fields.push_back(FD);
3224  if (FD->getType()->isReferenceType())
3225  ReferenceField = true;
3226  ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3227  }
3228 
3229  // Binding a reference to an unintialized field is not an
3230  // uninitialized use.
3231  if (CheckReferenceOnly && !ReferenceField)
3232  return true;
3233 
3234  llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3235  // Discard the first field since it is the field decl that is being
3236  // initialized.
3237  for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3238  UsedFieldIndex.push_back((*I)->getFieldIndex());
3239  }
3240 
3241  for (auto UsedIter = UsedFieldIndex.begin(),
3242  UsedEnd = UsedFieldIndex.end(),
3243  OrigIter = InitFieldIndex.begin(),
3244  OrigEnd = InitFieldIndex.end();
3245  UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3246  if (*UsedIter < *OrigIter)
3247  return true;
3248  if (*UsedIter > *OrigIter)
3249  break;
3250  }
3251 
3252  return false;
3253  }
3254 
3255  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3256  bool AddressOf) {
3257  if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3258  return;
3259 
3260  // FieldME is the inner-most MemberExpr that is not an anonymous struct
3261  // or union.
3262  MemberExpr *FieldME = ME;
3263 
3264  bool AllPODFields = FieldME->getType().isPODType(S.Context);
3265 
3266  Expr *Base = ME;
3267  while (MemberExpr *SubME =
3268  dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3269 
3270  if (isa<VarDecl>(SubME->getMemberDecl()))
3271  return;
3272 
3273  if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3274  if (!FD->isAnonymousStructOrUnion())
3275  FieldME = SubME;
3276 
3277  if (!FieldME->getType().isPODType(S.Context))
3278  AllPODFields = false;
3279 
3280  Base = SubME->getBase();
3281  }
3282 
3283  if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3284  return;
3285 
3286  if (AddressOf && AllPODFields)
3287  return;
3288 
3289  ValueDecl* FoundVD = FieldME->getMemberDecl();
3290 
3291  if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3292  while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3293  BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3294  }
3295 
3296  if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3297  QualType T = BaseCast->getType();
3298  if (T->isPointerType() &&
3299  BaseClasses.count(T->getPointeeType())) {
3300  S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3301  << T->getPointeeType() << FoundVD;
3302  }
3303  }
3304  }
3305 
3306  if (!Decls.count(FoundVD))
3307  return;
3308 
3309  const bool IsReference = FoundVD->getType()->isReferenceType();
3310 
3311  if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3312  // Special checking for initializer lists.
3313  if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3314  return;
3315  }
3316  } else {
3317  // Prevent double warnings on use of unbounded references.
3318  if (CheckReferenceOnly && !IsReference)
3319  return;
3320  }
3321 
3322  unsigned diag = IsReference
3323  ? diag::warn_reference_field_is_uninit
3324  : diag::warn_field_is_uninit;
3325  S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3326  if (Constructor)
3327  S.Diag(Constructor->getLocation(),
3328  diag::note_uninit_in_this_constructor)
3329  << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3330 
3331  }
3332 
3333  void HandleValue(Expr *E, bool AddressOf) {
3334  E = E->IgnoreParens();
3335 
3336  if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3337  HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3338  AddressOf /*AddressOf*/);
3339  return;
3340  }
3341 
3342  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3343  Visit(CO->getCond());
3344  HandleValue(CO->getTrueExpr(), AddressOf);
3345  HandleValue(CO->getFalseExpr(), AddressOf);
3346  return;
3347  }
3348 
3349  if (BinaryConditionalOperator *BCO =
3350  dyn_cast<BinaryConditionalOperator>(E)) {
3351  Visit(BCO->getCond());
3352  HandleValue(BCO->getFalseExpr(), AddressOf);
3353  return;
3354  }
3355 
3356  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3357  HandleValue(OVE->getSourceExpr(), AddressOf);
3358  return;
3359  }
3360 
3361  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3362  switch (BO->getOpcode()) {
3363  default:
3364  break;
3365  case(BO_PtrMemD):
3366  case(BO_PtrMemI):
3367  HandleValue(BO->getLHS(), AddressOf);
3368  Visit(BO->getRHS());
3369  return;
3370  case(BO_Comma):
3371  Visit(BO->getLHS());
3372  HandleValue(BO->getRHS(), AddressOf);
3373  return;
3374  }
3375  }
3376 
3377  Visit(E);
3378  }
3379 
3380  void CheckInitListExpr(InitListExpr *ILE) {
3381  InitFieldIndex.push_back(0);
3382  for (auto Child : ILE->children()) {
3383  if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3384  CheckInitListExpr(SubList);
3385  } else {
3386  Visit(Child);
3387  }
3388  ++InitFieldIndex.back();
3389  }
3390  InitFieldIndex.pop_back();
3391  }
3392 
3393  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3394  FieldDecl *Field, const Type *BaseClass) {
3395  // Remove Decls that may have been initialized in the previous
3396  // initializer.
3397  for (ValueDecl* VD : DeclsToRemove)
3398  Decls.erase(VD);
3399  DeclsToRemove.clear();
3400 
3401  Constructor = FieldConstructor;
3402  InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3403 
3404  if (ILE && Field) {
3405  InitList = true;
3406  InitListFieldDecl = Field;
3407  InitFieldIndex.clear();
3408  CheckInitListExpr(ILE);
3409  } else {
3410  InitList = false;
3411  Visit(E);
3412  }
3413 
3414  if (Field)
3415  Decls.erase(Field);
3416  if (BaseClass)
3417  BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3418  }
3419 
3420  void VisitMemberExpr(MemberExpr *ME) {
3421  // All uses of unbounded reference fields will warn.
3422  HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3423  }
3424 
3425  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3426  if (E->getCastKind() == CK_LValueToRValue) {
3427  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3428  return;
3429  }
3430 
3431  Inherited::VisitImplicitCastExpr(E);
3432  }
3433 
3434  void VisitCXXConstructExpr(CXXConstructExpr *E) {
3435  if (E->getConstructor()->isCopyConstructor()) {
3436  Expr *ArgExpr = E->getArg(0);
3437  if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3438  if (ILE->getNumInits() == 1)
3439  ArgExpr = ILE->getInit(0);
3440  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3441  if (ICE->getCastKind() == CK_NoOp)
3442  ArgExpr = ICE->getSubExpr();
3443  HandleValue(ArgExpr, false /*AddressOf*/);
3444  return;
3445  }
3446  Inherited::VisitCXXConstructExpr(E);
3447  }
3448 
3449  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3450  Expr *Callee = E->getCallee();
3451  if (isa<MemberExpr>(Callee)) {
3452  HandleValue(Callee, false /*AddressOf*/);
3453  for (auto Arg : E->arguments())
3454  Visit(Arg);
3455  return;
3456  }
3457 
3458  Inherited::VisitCXXMemberCallExpr(E);
3459  }
3460 
3461  void VisitCallExpr(CallExpr *E) {
3462  // Treat std::move as a use.
3463  if (E->isCallToStdMove()) {
3464  HandleValue(E->getArg(0), /*AddressOf=*/false);
3465  return;
3466  }
3467 
3468  Inherited::VisitCallExpr(E);
3469  }
3470 
3471  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3472  Expr *Callee = E->getCallee();
3473 
3474  if (isa<UnresolvedLookupExpr>(Callee))
3475  return Inherited::VisitCXXOperatorCallExpr(E);
3476 
3477  Visit(Callee);
3478  for (auto Arg : E->arguments())
3479  HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3480  }
3481 
3482  void VisitBinaryOperator(BinaryOperator *E) {
3483  // If a field assignment is detected, remove the field from the
3484  // uninitiailized field set.
3485  if (E->getOpcode() == BO_Assign)
3486  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3487  if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3488  if (!FD->getType()->isReferenceType())
3489  DeclsToRemove.push_back(FD);
3490 
3491  if (E->isCompoundAssignmentOp()) {
3492  HandleValue(E->getLHS(), false /*AddressOf*/);
3493  Visit(E->getRHS());
3494  return;
3495  }
3496 
3497  Inherited::VisitBinaryOperator(E);
3498  }
3499 
3500  void VisitUnaryOperator(UnaryOperator *E) {
3501  if (E->isIncrementDecrementOp()) {
3502  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3503  return;
3504  }
3505  if (E->getOpcode() == UO_AddrOf) {
3506  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3507  HandleValue(ME->getBase(), true /*AddressOf*/);
3508  return;
3509  }
3510  }
3511 
3512  Inherited::VisitUnaryOperator(E);
3513  }
3514  };
3515 
3516  // Diagnose value-uses of fields to initialize themselves, e.g.
3517  // foo(foo)
3518  // where foo is not also a parameter to the constructor.
3519  // Also diagnose across field uninitialized use such as
3520  // x(y), y(x)
3521  // TODO: implement -Wuninitialized and fold this into that framework.
3522  static void DiagnoseUninitializedFields(
3523  Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3524 
3525  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3526  Constructor->getLocation())) {
3527  return;
3528  }
3529 
3530  if (Constructor->isInvalidDecl())
3531  return;
3532 
3533  const CXXRecordDecl *RD = Constructor->getParent();
3534 
3535  if (RD->getDescribedClassTemplate())
3536  return;
3537 
3538  // Holds fields that are uninitialized.
3539  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3540 
3541  // At the beginning, all fields are uninitialized.
3542  for (auto *I : RD->decls()) {
3543  if (auto *FD = dyn_cast<FieldDecl>(I)) {
3544  UninitializedFields.insert(FD);
3545  } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3546  UninitializedFields.insert(IFD->getAnonField());
3547  }
3548  }
3549 
3550  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3551  for (auto I : RD->bases())
3552  UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3553 
3554  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3555  return;
3556 
3557  UninitializedFieldVisitor UninitializedChecker(SemaRef,
3558  UninitializedFields,
3559  UninitializedBaseClasses);
3560 
3561  for (const auto *FieldInit : Constructor->inits()) {
3562  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3563  break;
3564 
3565  Expr *InitExpr = FieldInit->getInit();
3566  if (!InitExpr)
3567  continue;
3568 
3570  dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3571  InitExpr = Default->getExpr();
3572  if (!InitExpr)
3573  continue;
3574  // In class initializers will point to the constructor.
3575  UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3576  FieldInit->getAnyMember(),
3577  FieldInit->getBaseClass());
3578  } else {
3579  UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3580  FieldInit->getAnyMember(),
3581  FieldInit->getBaseClass());
3582  }
3583  }
3584  }
3585 } // namespace
3586 
3587 /// Enter a new C++ default initializer scope. After calling this, the
3588 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3589 /// parsing or instantiating the initializer failed.
3591  // Create a synthetic function scope to represent the call to the constructor
3592  // that notionally surrounds a use of this initializer.
3593  PushFunctionScope();
3594 }
3595 
3596 /// This is invoked after parsing an in-class initializer for a
3597 /// non-static C++ class member, and after instantiating an in-class initializer
3598 /// in a class template. Such actions are deferred until the class is complete.
3600  SourceLocation InitLoc,
3601  Expr *InitExpr) {
3602  // Pop the notional constructor scope we created earlier.
3603  PopFunctionScopeInfo(nullptr, D);
3604 
3605  FieldDecl *FD = dyn_cast<FieldDecl>(D);
3606  assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3607  "must set init style when field is created");
3608 
3609  if (!InitExpr) {
3610  D->setInvalidDecl();
3611  if (FD)
3613  return;
3614  }
3615 
3616  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3617  FD->setInvalidDecl();
3619  return;
3620  }
3621 
3622  ExprResult Init = InitExpr;
3623  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3628  InitExpr->getLocStart(),
3629  InitExpr->getLocEnd())
3630  : InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc);
3631  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3632  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3633  if (Init.isInvalid()) {
3634  FD->setInvalidDecl();
3635  return;
3636  }
3637  }
3638 
3639  // C++11 [class.base.init]p7:
3640  // The initialization of each base and member constitutes a
3641  // full-expression.
3642  Init = ActOnFinishFullExpr(Init.get(), InitLoc);
3643  if (Init.isInvalid()) {
3644  FD->setInvalidDecl();
3645  return;
3646  }
3647 
3648  InitExpr = Init.get();
3649 
3650  FD->setInClassInitializer(InitExpr);
3651 }
3652 
3653 /// Find the direct and/or virtual base specifiers that
3654 /// correspond to the given base type, for use in base initialization
3655 /// within a constructor.
3656 static bool FindBaseInitializer(Sema &SemaRef,
3657  CXXRecordDecl *ClassDecl,
3658  QualType BaseType,
3659  const CXXBaseSpecifier *&DirectBaseSpec,
3660  const CXXBaseSpecifier *&VirtualBaseSpec) {
3661  // First, check for a direct base class.
3662  DirectBaseSpec = nullptr;
3663  for (const auto &Base : ClassDecl->bases()) {
3664  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3665  // We found a direct base of this type. That's what we're
3666  // initializing.
3667  DirectBaseSpec = &Base;
3668  break;
3669  }
3670  }
3671 
3672  // Check for a virtual base class.
3673  // FIXME: We might be able to short-circuit this if we know in advance that
3674  // there are no virtual bases.
3675  VirtualBaseSpec = nullptr;
3676  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3677  // We haven't found a base yet; search the class hierarchy for a
3678  // virtual base class.
3679  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3680  /*DetectVirtual=*/false);
3681  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3682  SemaRef.Context.getTypeDeclType(ClassDecl),
3683  BaseType, Paths)) {
3684  for (CXXBasePaths::paths_iterator Path = Paths.begin();
3685  Path != Paths.end(); ++Path) {
3686  if (Path->back().Base->isVirtual()) {
3687  VirtualBaseSpec = Path->back().Base;
3688  break;
3689  }
3690  }
3691  }
3692  }
3693 
3694  return DirectBaseSpec || VirtualBaseSpec;
3695 }
3696 
3697 /// Handle a C++ member initializer using braced-init-list syntax.
3699 Sema::ActOnMemInitializer(Decl *ConstructorD,
3700  Scope *S,
3701  CXXScopeSpec &SS,
3702  IdentifierInfo *MemberOrBase,
3703  ParsedType TemplateTypeTy,
3704  const DeclSpec &DS,
3705  SourceLocation IdLoc,
3706  Expr *InitList,
3707  SourceLocation EllipsisLoc) {
3708  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3709  DS, IdLoc, InitList,
3710  EllipsisLoc);
3711 }
3712 
3713 /// Handle a C++ member initializer using parentheses syntax.
3715 Sema::ActOnMemInitializer(Decl *ConstructorD,
3716  Scope *S,
3717  CXXScopeSpec &SS,
3718  IdentifierInfo *MemberOrBase,
3719  ParsedType TemplateTypeTy,
3720  const DeclSpec &DS,
3721  SourceLocation IdLoc,
3722  SourceLocation LParenLoc,
3723  ArrayRef<Expr *> Args,
3724  SourceLocation RParenLoc,
3725  SourceLocation EllipsisLoc) {
3726  Expr *List = new (Context) ParenListExpr(Context, LParenLoc,
3727  Args, RParenLoc);
3728  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3729  DS, IdLoc, List, EllipsisLoc);
3730 }
3731 
3732 namespace {
3733 
3734 // Callback to only accept typo corrections that can be a valid C++ member
3735 // intializer: either a non-static field member or a base class.
3736 class MemInitializerValidatorCCC : public CorrectionCandidateCallback {
3737 public:
3738  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
3739  : ClassDecl(ClassDecl) {}
3740 
3741  bool ValidateCandidate(const TypoCorrection &candidate) override {
3742  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
3743  if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
3744  return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
3745  return isa<TypeDecl>(ND);
3746  }
3747  return false;
3748  }
3749 
3750 private:
3751  CXXRecordDecl *ClassDecl;
3752 };
3753 
3754 }
3755 
3756 /// Handle a C++ member initializer.
3758 Sema::BuildMemInitializer(Decl *ConstructorD,
3759  Scope *S,
3760  CXXScopeSpec &SS,
3761  IdentifierInfo *MemberOrBase,
3762  ParsedType TemplateTypeTy,
3763  const DeclSpec &DS,
3764  SourceLocation IdLoc,
3765  Expr *Init,
3766  SourceLocation EllipsisLoc) {
3767  ExprResult Res = CorrectDelayedTyposInExpr(Init);
3768  if (!Res.isUsable())
3769  return true;
3770  Init = Res.get();
3771 
3772  if (!ConstructorD)
3773  return true;
3774 
3775  AdjustDeclIfTemplate(ConstructorD);
3776 
3777  CXXConstructorDecl *Constructor
3778  = dyn_cast<CXXConstructorDecl>(ConstructorD);
3779  if (!Constructor) {
3780  // The user wrote a constructor initializer on a function that is
3781  // not a C++ constructor. Ignore the error for now, because we may
3782  // have more member initializers coming; we'll diagnose it just
3783  // once in ActOnMemInitializers.
3784  return true;
3785  }
3786 
3787  CXXRecordDecl *ClassDecl = Constructor->getParent();
3788 
3789  // C++ [class.base.init]p2:
3790  // Names in a mem-initializer-id are looked up in the scope of the
3791  // constructor's class and, if not found in that scope, are looked
3792  // up in the scope containing the constructor's definition.
3793  // [Note: if the constructor's class contains a member with the
3794  // same name as a direct or virtual base class of the class, a
3795  // mem-initializer-id naming the member or base class and composed
3796  // of a single identifier refers to the class member. A
3797  // mem-initializer-id for the hidden base class may be specified
3798  // using a qualified name. ]
3799  if (!SS.getScopeRep() && !TemplateTypeTy) {
3800  // Look for a member, first.
3801  DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
3802  if (!Result.empty()) {
3803  ValueDecl *Member;
3804  if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
3805  (Member = dyn_cast<IndirectFieldDecl>(Result.front()))) {
3806  if (EllipsisLoc.isValid())
3807  Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
3808  << MemberOrBase
3809  << SourceRange(IdLoc, Init->getSourceRange().getEnd());
3810 
3811  return BuildMemberInitializer(Member, Init, IdLoc);
3812  }
3813  }
3814  }
3815  // It didn't name a member, so see if it names a class.
3816  QualType BaseType;
3817  TypeSourceInfo *TInfo = nullptr;
3818 
3819  if (TemplateTypeTy) {
3820  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
3821  } else if (DS.getTypeSpecType() == TST_decltype) {
3822  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
3823  } else if (DS.getTypeSpecType() == TST_decltype_auto) {
3824  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
3825  return true;
3826  } else {
3827  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
3828  LookupParsedName(R, S, &SS);
3829 
3830  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
3831  if (!TyD) {
3832  if (R.isAmbiguous()) return true;
3833 
3834  // We don't want access-control diagnostics here.
3835  R.suppressDiagnostics();
3836 
3837  if (SS.isSet() && isDependentScopeSpecifier(SS)) {
3838  bool NotUnknownSpecialization = false;
3839  DeclContext *DC = computeDeclContext(SS, false);
3840  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
3841  NotUnknownSpecialization = !Record->hasAnyDependentBases();
3842 
3843  if (!NotUnknownSpecialization) {
3844  // When the scope specifier can refer to a member of an unknown
3845  // specialization, we take it as a type name.
3846  BaseType = CheckTypenameType(ETK_None, SourceLocation(),
3847  SS.getWithLocInContext(Context),
3848  *MemberOrBase, IdLoc);
3849  if (BaseType.isNull())
3850  return true;
3851 
3852  TInfo = Context.CreateTypeSourceInfo(BaseType);
3855  if (!TL.isNull()) {
3856  TL.setNameLoc(IdLoc);
3858  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3859  }
3860 
3861  R.clear();
3862  R.setLookupName(MemberOrBase);
3863  }
3864  }
3865 
3866  // If no results were found, try to correct typos.
3867  TypoCorrection Corr;
3868  if (R.empty() && BaseType.isNull() &&
3869  (Corr = CorrectTypo(
3870  R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
3871  llvm::make_unique<MemInitializerValidatorCCC>(ClassDecl),
3872  CTK_ErrorRecovery, ClassDecl))) {
3873  if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
3874  // We have found a non-static data member with a similar
3875  // name to what was typed; complain and initialize that
3876  // member.
3877  diagnoseTypo(Corr,
3878  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3879  << MemberOrBase << true);
3880  return BuildMemberInitializer(Member, Init, IdLoc);
3881  } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
3882  const CXXBaseSpecifier *DirectBaseSpec;
3883  const CXXBaseSpecifier *VirtualBaseSpec;
3884  if (FindBaseInitializer(*this, ClassDecl,
3885  Context.getTypeDeclType(Type),
3886  DirectBaseSpec, VirtualBaseSpec)) {
3887  // We have found a direct or virtual base class with a
3888  // similar name to what was typed; complain and initialize
3889  // that base class.
3890  diagnoseTypo(Corr,
3891  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3892  << MemberOrBase << false,
3893  PDiag() /*Suppress note, we provide our own.*/);
3894 
3895  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
3896  : VirtualBaseSpec;
3897  Diag(BaseSpec->getLocStart(),
3898  diag::note_base_class_specified_here)
3899  << BaseSpec->getType()
3900  << BaseSpec->getSourceRange();
3901 
3902  TyD = Type;
3903  }
3904  }
3905  }
3906 
3907  if (!TyD && BaseType.isNull()) {
3908  Diag(IdLoc, diag::err_mem_init_not_member_or_class)
3909  << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
3910  return true;
3911  }
3912  }
3913 
3914  if (BaseType.isNull()) {
3915  BaseType = Context.getTypeDeclType(TyD);
3916  MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
3917  if (SS.isSet()) {
3918  BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
3919  BaseType);
3920  TInfo = Context.CreateTypeSourceInfo(BaseType);
3922  TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
3924  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3925  }
3926  }
3927  }
3928 
3929  if (!TInfo)
3930  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
3931 
3932  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
3933 }
3934 
3935 /// Checks a member initializer expression for cases where reference (or
3936 /// pointer) members are bound to by-value parameters (or their addresses).
3938  Expr *Init,
3939  SourceLocation IdLoc) {
3940  QualType MemberTy = Member->getType();
3941 
3942  // We only handle pointers and references currently.
3943  // FIXME: Would this be relevant for ObjC object pointers? Or block pointers?
3944  if (!MemberTy->isReferenceType() && !MemberTy->isPointerType())
3945  return;
3946 
3947  const bool IsPointer = MemberTy->isPointerType();
3948  if (IsPointer) {
3949  if (const UnaryOperator *Op
3950  = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) {
3951  // The only case we're worried about with pointers requires taking the
3952  // address.
3953  if (Op->getOpcode() != UO_AddrOf)
3954  return;
3955 
3956  Init = Op->getSubExpr();
3957  } else {
3958  // We only handle address-of expression initializers for pointers.
3959  return;
3960  }
3961  }
3962 
3963  if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) {
3964  // We only warn when referring to a non-reference parameter declaration.
3965  const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl());
3966  if (!Parameter || Parameter->getType()->isReferenceType())
3967  return;
3968 
3969  S.Diag(Init->getExprLoc(),
3970  IsPointer ? diag::warn_init_ptr_member_to_parameter_addr
3971  : diag::warn_bind_ref_member_to_parameter)
3972  << Member << Parameter << Init->getSourceRange();
3973  } else {
3974  // Other initializers are fine.
3975  return;
3976  }
3977 
3978  S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here)
3979  << (unsigned)IsPointer;
3980 }
3981 
3984  SourceLocation IdLoc) {
3985  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
3986  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
3987  assert((DirectMember || IndirectMember) &&
3988  "Member must be a FieldDecl or IndirectFieldDecl");
3989 
3990  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
3991  return true;
3992 
3993  if (Member->isInvalidDecl())
3994  return true;
3995 
3996  MultiExprArg Args;
3997  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
3998  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
3999  } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4000  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4001  } else {
4002  // Template instantiation doesn't reconstruct ParenListExprs for us.
4003  Args = Init;
4004  }
4005 
4006  SourceRange InitRange = Init->getSourceRange();
4007 
4008  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4009  // Can't check initialization for a member of dependent type or when
4010  // any of the arguments are type-dependent expressions.
4011  DiscardCleanupsInEvaluationContext();
4012  } else {
4013  bool InitList = false;
4014  if (isa<InitListExpr>(Init)) {
4015  InitList = true;
4016  Args = Init;
4017  }
4018 
4019  // Initialize the member.
4020  InitializedEntity MemberEntity =
4021  DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4022  : InitializedEntity::InitializeMember(IndirectMember,
4023  nullptr);
4026  IdLoc, Init->getLocStart(), Init->getLocEnd())
4027  : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4028  InitRange.getEnd());
4029 
4030  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4031  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4032  nullptr);
4033  if (MemberInit.isInvalid())
4034  return true;
4035 
4036  CheckForDanglingReferenceOrPointer(*this, Member, MemberInit.get(), IdLoc);
4037 
4038  // C++11 [class.base.init]p7:
4039  // The initialization of each base and member constitutes a
4040  // full-expression.
4041  MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin());
4042  if (MemberInit.isInvalid())
4043  return true;
4044 
4045  Init = MemberInit.get();
4046  }
4047 
4048  if (DirectMember) {
4049  return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4050  InitRange.getBegin(), Init,
4051  InitRange.getEnd());
4052  } else {
4053  return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4054  InitRange.getBegin(), Init,
4055  InitRange.getEnd());
4056  }
4057 }
4058 
4061  CXXRecordDecl *ClassDecl) {
4062  SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4063  if (!LangOpts.CPlusPlus11)
4064  return Diag(NameLoc, diag::err_delegating_ctor)
4065  << TInfo->getTypeLoc().getLocalSourceRange();
4066  Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4067 
4068  bool InitList = true;
4069  MultiExprArg Args = Init;
4070  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4071  InitList = false;
4072  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4073  }
4074 
4075  SourceRange InitRange = Init->getSourceRange();
4076  // Initialize the object.
4078  QualType(ClassDecl->getTypeForDecl(), 0));
4081  NameLoc, Init->getLocStart(), Init->getLocEnd())
4082  : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4083  InitRange.getEnd());
4084  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4085  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4086  Args, nullptr);
4087  if (DelegationInit.isInvalid())
4088  return true;
4089 
4090  assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4091  "Delegating constructor with no target?");
4092 
4093  // C++11 [class.base.init]p7:
4094  // The initialization of each base and member constitutes a
4095  // full-expression.
4096  DelegationInit = ActOnFinishFullExpr(DelegationInit.get(),
4097  InitRange.getBegin());
4098  if (DelegationInit.isInvalid())
4099  return true;
4100 
4101  // If we are in a dependent context, template instantiation will
4102  // perform this type-checking again. Just save the arguments that we
4103  // received in a ParenListExpr.
4104  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4105  // of the information that we have about the base
4106  // initializer. However, deconstructing the ASTs is a dicey process,
4107  // and this approach is far more likely to get the corner cases right.
4108  if (CurContext->isDependentContext())
4109  DelegationInit = Init;
4110 
4111  return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4112  DelegationInit.getAs<Expr>(),
4113  InitRange.getEnd());
4114 }
4115 
4118  Expr *Init, CXXRecordDecl *ClassDecl,
4119  SourceLocation EllipsisLoc) {
4120  SourceLocation BaseLoc
4121  = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4122 
4123  if (!BaseType->isDependentType() && !BaseType->isRecordType())
4124  return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4125  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4126 
4127  // C++ [class.base.init]p2:
4128  // [...] Unless the mem-initializer-id names a nonstatic data
4129  // member of the constructor's class or a direct or virtual base
4130  // of that class, the mem-initializer is ill-formed. A
4131  // mem-initializer-list can initialize a base class using any
4132  // name that denotes that base class type.
4133  bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4134 
4135  SourceRange InitRange = Init->getSourceRange();
4136  if (EllipsisLoc.isValid()) {
4137  // This is a pack expansion.
4138  if (!BaseType->containsUnexpandedParameterPack()) {
4139  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4140  << SourceRange(BaseLoc, InitRange.getEnd());
4141 
4142  EllipsisLoc = SourceLocation();
4143  }
4144  } else {
4145  // Check for any unexpanded parameter packs.
4146  if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4147  return true;
4148 
4149  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4150  return true;
4151  }
4152 
4153  // Check for direct and virtual base classes.
4154  const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4155  const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4156  if (!Dependent) {
4157  if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4158  BaseType))
4159  return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4160 
4161  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4162  VirtualBaseSpec);
4163 
4164  // C++ [base.class.init]p2:
4165  // Unless the mem-initializer-id names a nonstatic data member of the
4166  // constructor's class or a direct or virtual base of that class, the
4167  // mem-initializer is ill-formed.
4168  if (!DirectBaseSpec && !VirtualBaseSpec) {
4169  // If the class has any dependent bases, then it's possible that
4170  // one of those types will resolve to the same type as
4171  // BaseType. Therefore, just treat this as a dependent base
4172  // class initialization. FIXME: Should we try to check the
4173  // initialization anyway? It seems odd.
4174  if (ClassDecl->hasAnyDependentBases())
4175  Dependent = true;
4176  else
4177  return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4178  << BaseType << Context.getTypeDeclType(ClassDecl)
4179  << BaseTInfo->getTypeLoc().getLocalSourceRange();
4180  }
4181  }
4182 
4183  if (Dependent) {
4184  DiscardCleanupsInEvaluationContext();
4185 
4186  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4187  /*IsVirtual=*/false,
4188  InitRange.getBegin(), Init,
4189  InitRange.getEnd(), EllipsisLoc);
4190  }
4191 
4192  // C++ [base.class.init]p2:
4193  // If a mem-initializer-id is ambiguous because it designates both
4194  // a direct non-virtual base class and an inherited virtual base
4195  // class, the mem-initializer is ill-formed.
4196  if (DirectBaseSpec && VirtualBaseSpec)
4197  return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4198  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4199 
4200  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4201  if (!BaseSpec)
4202  BaseSpec = VirtualBaseSpec;
4203 
4204  // Initialize the base.
4205  bool InitList = true;
4206  MultiExprArg Args = Init;
4207  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4208  InitList = false;
4209  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4210  }
4211 
4212  InitializedEntity BaseEntity =
4213  InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4215  InitList ? InitializationKind::CreateDirectList(BaseLoc)
4216  : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4217  InitRange.getEnd());
4218  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4219  ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4220  if (BaseInit.isInvalid())
4221  return true;
4222 
4223  // C++11 [class.base.init]p7:
4224  // The initialization of each base and member constitutes a
4225  // full-expression.
4226  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin());
4227  if (BaseInit.isInvalid())
4228  return true;
4229 
4230  // If we are in a dependent context, template instantiation will
4231  // perform this type-checking again. Just save the arguments that we
4232  // received in a ParenListExpr.
4233  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4234  // of the information that we have about the base
4235  // initializer. However, deconstructing the ASTs is a dicey process,
4236  // and this approach is far more likely to get the corner cases right.
4237  if (CurContext->isDependentContext())
4238  BaseInit = Init;
4239 
4240  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4241  BaseSpec->isVirtual(),
4242  InitRange.getBegin(),
4243  BaseInit.getAs<Expr>(),
4244  InitRange.getEnd(), EllipsisLoc);
4245 }
4246 
4247 // Create a static_cast<T&&>(expr).
4248 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4249  if (T.isNull()) T = E->getType();
4250  QualType TargetType = SemaRef.BuildReferenceType(
4251  T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4252  SourceLocation ExprLoc = E->getLocStart();
4253  TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4254  TargetType, ExprLoc);
4255 
4256  return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4257  SourceRange(ExprLoc, ExprLoc),
4258  E->getSourceRange()).get();
4259 }
4260 
4261 /// ImplicitInitializerKind - How an implicit base or member initializer should
4262 /// initialize its base or member.
4268 };
4269 
4270 static bool
4272  ImplicitInitializerKind ImplicitInitKind,
4273  CXXBaseSpecifier *BaseSpec,
4274  bool IsInheritedVirtualBase,
4275  CXXCtorInitializer *&CXXBaseInit) {
4276  InitializedEntity InitEntity
4277  = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4278  IsInheritedVirtualBase);
4279 
4280  ExprResult BaseInit;
4281 
4282  switch (ImplicitInitKind) {
4283  case IIK_Inherit:
4284  case IIK_Default: {
4285  InitializationKind InitKind
4287  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4288  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4289  break;
4290  }
4291 
4292  case IIK_Move:
4293  case IIK_Copy: {
4294  bool Moving = ImplicitInitKind == IIK_Move;
4295  ParmVarDecl *Param = Constructor->getParamDecl(0);
4296  QualType ParamType = Param->getType().getNonReferenceType();
4297 
4298  Expr *CopyCtorArg =
4300  SourceLocation(), Param, false,
4301  Constructor->getLocation(), ParamType,
4302  VK_LValue, nullptr);
4303 
4304  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4305 
4306  // Cast to the base class to avoid ambiguities.
4307  QualType ArgTy =
4308  SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4309  ParamType.getQualifiers());
4310 
4311  if (Moving) {
4312  CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4313  }
4314 
4315  CXXCastPath BasePath;
4316  BasePath.push_back(BaseSpec);
4317  CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4318  CK_UncheckedDerivedToBase,
4319  Moving ? VK_XValue : VK_LValue,
4320  &BasePath).get();
4321 
4322  InitializationKind InitKind
4325  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4326  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4327  break;
4328  }
4329  }
4330 
4331  BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4332  if (BaseInit.isInvalid())
4333  return true;
4334 
4335  CXXBaseInit =
4336  new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4337  SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4338  SourceLocation()),
4339  BaseSpec->isVirtual(),
4340  SourceLocation(),
4341  BaseInit.getAs<Expr>(),
4342  SourceLocation(),
4343  SourceLocation());
4344 
4345  return false;
4346 }
4347 
4348 static bool RefersToRValueRef(Expr *MemRef) {
4349  ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4350  return Referenced->getType()->isRValueReferenceType();
4351 }
4352 
4353 static bool
4355  ImplicitInitializerKind ImplicitInitKind,
4356  FieldDecl *Field, IndirectFieldDecl *Indirect,
4357  CXXCtorInitializer *&CXXMemberInit) {
4358  if (Field->isInvalidDecl())
4359  return true;
4360 
4361  SourceLocation Loc = Constructor->getLocation();
4362 
4363  if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4364  bool Moving = ImplicitInitKind == IIK_Move;
4365  ParmVarDecl *Param = Constructor->getParamDecl(0);
4366  QualType ParamType = Param->getType().getNonReferenceType();
4367 
4368  // Suppress copying zero-width bitfields.
4369  if (Field->isZeroLengthBitField(SemaRef.Context))
4370  return false;
4371 
4372  Expr *MemberExprBase =
4374  SourceLocation(), Param, false,
4375  Loc, ParamType, VK_LValue, nullptr);
4376 
4377  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4378 
4379  if (Moving) {
4380  MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4381  }
4382 
4383  // Build a reference to this field within the parameter.
4384  CXXScopeSpec SS;
4385  LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4387  MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4388  : cast<ValueDecl>(Field), AS_public);
4389  MemberLookup.resolveKind();
4390  ExprResult CtorArg
4391  = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4392  ParamType, Loc,
4393  /*IsArrow=*/false,
4394  SS,
4395  /*TemplateKWLoc=*/SourceLocation(),
4396  /*FirstQualifierInScope=*/nullptr,
4397  MemberLookup,
4398  /*TemplateArgs=*/nullptr,
4399  /*S*/nullptr);
4400  if (CtorArg.isInvalid())
4401  return true;
4402 
4403  // C++11 [class.copy]p15:
4404  // - if a member m has rvalue reference type T&&, it is direct-initialized
4405  // with static_cast<T&&>(x.m);
4406  if (RefersToRValueRef(CtorArg.get())) {
4407  CtorArg = CastForMoving(SemaRef, CtorArg.get());
4408  }
4409 
4410  InitializedEntity Entity =
4411  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4412  /*Implicit*/ true)
4413  : InitializedEntity::InitializeMember(Field, nullptr,
4414  /*Implicit*/ true);
4415 
4416  // Direct-initialize to use the copy constructor.
4417  InitializationKind InitKind =
4419 
4420  Expr *CtorArgE = CtorArg.getAs<Expr>();
4421  InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4422  ExprResult MemberInit =
4423  InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4424  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4425  if (MemberInit.isInvalid())
4426  return true;
4427 
4428  if (Indirect)
4429  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4430  SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4431  else
4432  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4433  SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4434  return false;
4435  }
4436 
4437  assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4438  "Unhandled implicit init kind!");
4439 
4440  QualType FieldBaseElementType =
4441  SemaRef.Context.getBaseElementType(Field->getType());
4442 
4443  if (FieldBaseElementType->isRecordType()) {
4444  InitializedEntity InitEntity =
4445  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4446  /*Implicit*/ true)
4447  : InitializedEntity::InitializeMember(Field, nullptr,
4448  /*Implicit*/ true);
4449  InitializationKind InitKind =
4451 
4452  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4453  ExprResult MemberInit =
4454  InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4455 
4456  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4457  if (MemberInit.isInvalid())
4458  return true;
4459 
4460  if (Indirect)
4461  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4462  Indirect, Loc,
4463  Loc,
4464  MemberInit.get(),
4465  Loc);
4466  else
4467  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4468  Field, Loc, Loc,
4469  MemberInit.get(),
4470  Loc);
4471  return false;
4472  }
4473 
4474  if (!Field->getParent()->isUnion()) {
4475  if (FieldBaseElementType->isReferenceType()) {
4476  SemaRef.Diag(Constructor->getLocation(),
4477  diag::err_uninitialized_member_in_ctor)
4478  << (int)Constructor->isImplicit()
4479  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4480  << 0 << Field->getDeclName();
4481  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4482  return true;
4483  }
4484 
4485  if (FieldBaseElementType.isConstQualified()) {
4486  SemaRef.Diag(Constructor->getLocation(),
4487  diag::err_uninitialized_member_in_ctor)
4488  << (int)Constructor->isImplicit()
4489  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4490  << 1 << Field->getDeclName();
4491  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4492  return true;
4493  }
4494  }
4495 
4496  if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4497  // ARC and Weak:
4498  // Default-initialize Objective-C pointers to NULL.
4499  CXXMemberInit
4500  = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4501  Loc, Loc,
4502  new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4503  Loc);
4504  return false;
4505  }
4506 
4507  // Nothing to initialize.
4508  CXXMemberInit = nullptr;
4509  return false;
4510 }
4511 
4512 namespace {
4513 struct BaseAndFieldInfo {
4514  Sema &S;
4515  CXXConstructorDecl *Ctor;
4516  bool AnyErrorsInInits;
4518  llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4520  llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4521 
4522  BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4523  : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4524  bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4525  if (Ctor->getInheritedConstructor())
4526  IIK = IIK_Inherit;
4527  else if (Generated && Ctor->isCopyConstructor())
4528  IIK = IIK_Copy;
4529  else if (Generated && Ctor->isMoveConstructor())
4530  IIK = IIK_Move;
4531  else
4532  IIK = IIK_Default;
4533  }
4534 
4535  bool isImplicitCopyOrMove() const {
4536  switch (IIK) {
4537  case IIK_Copy:
4538  case IIK_Move:
4539  return true;
4540 
4541  case IIK_Default:
4542  case IIK_Inherit:
4543  return false;
4544  }
4545 
4546  llvm_unreachable("Invalid ImplicitInitializerKind!");
4547  }
4548 
4549  bool addFieldInitializer(CXXCtorInitializer *Init) {
4550  AllToInit.push_back(Init);
4551 
4552  // Check whether this initializer makes the field "used".
4553  if (Init->getInit()->HasSideEffects(S.Context))
4554  S.UnusedPrivateFields.remove(Init->getAnyMember());
4555 
4556  return false;
4557  }
4558 
4559  bool isInactiveUnionMember(FieldDecl *Field) {
4560  RecordDecl *Record = Field->getParent();
4561  if (!Record->isUnion())
4562  return false;
4563 
4564  if (FieldDecl *Active =
4565  ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4566  return Active != Field->getCanonicalDecl();
4567 
4568  // In an implicit copy or move constructor, ignore any in-class initializer.
4569  if (isImplicitCopyOrMove())
4570  return true;
4571 
4572  // If there's no explicit initialization, the field is active only if it
4573  // has an in-class initializer...
4574  if (Field->hasInClassInitializer())
4575  return false;
4576  // ... or it's an anonymous struct or union whose class has an in-class
4577  // initializer.
4578  if (!Field->isAnonymousStructOrUnion())
4579  return true;
4580  CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4581  return !FieldRD->hasInClassInitializer();
4582  }
4583 
4584  /// Determine whether the given field is, or is within, a union member
4585  /// that is inactive (because there was an initializer given for a different
4586  /// member of the union, or because the union was not initialized at all).
4587  bool isWithinInactiveUnionMember(FieldDecl *Field,
4588  IndirectFieldDecl *Indirect) {
4589  if (!Indirect)
4590  return isInactiveUnionMember(Field);
4591 
4592  for (auto *C : Indirect->chain()) {
4593  FieldDecl *Field = dyn_cast<FieldDecl>(C);
4594  if (Field && isInactiveUnionMember(Field))
4595  return true;
4596  }
4597  return false;
4598  }
4599 };
4600 }
4601 
4602 /// Determine whether the given type is an incomplete or zero-lenfgth
4603 /// array type.
4605  if (T->isIncompleteArrayType())
4606  return true;
4607 
4608  while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4609  if (!ArrayT->getSize())
4610  return true;
4611 
4612  T = ArrayT->getElementType();
4613  }
4614 
4615  return false;
4616 }
4617 
4618 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4619  FieldDecl *Field,
4620  IndirectFieldDecl *Indirect = nullptr) {
4621  if (Field->isInvalidDecl())
4622  return false;
4623 
4624  // Overwhelmingly common case: we have a direct initializer for this field.
4625  if (CXXCtorInitializer *Init =
4626  Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4627  return Info.addFieldInitializer(Init);
4628 
4629  // C++11 [class.base.init]p8:
4630  // if the entity is a non-static data member that has a
4631  // brace-or-equal-initializer and either
4632  // -- the constructor's class is a union and no other variant member of that
4633  // union is designated by a mem-initializer-id or
4634  // -- the constructor's class is not a union, and, if the entity is a member
4635  // of an anonymous union, no other member of that union is designated by
4636  // a mem-initializer-id,
4637  // the entity is initialized as specified in [dcl.init].
4638  //
4639  // We also apply the same rules to handle anonymous structs within anonymous
4640  // unions.
4641  if (Info.isWithinInactiveUnionMember(Field, Indirect))
4642  return false;
4643 
4644  if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4645  ExprResult DIE =
4646  SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4647  if (DIE.isInvalid())
4648  return true;
4649  CXXCtorInitializer *Init;
4650  if (Indirect)
4651  Init = new (SemaRef.Context)
4652  CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4653  SourceLocation(), DIE.get(), SourceLocation());
4654  else
4655  Init = new (SemaRef.Context)
4656  CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4657  SourceLocation(), DIE.get(), SourceLocation());
4658  return Info.addFieldInitializer(Init);
4659  }
4660 
4661  // Don't initialize incomplete or zero-length arrays.
4662  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4663  return false;
4664 
4665  // Don't try to build an implicit initializer if there were semantic
4666  // errors in any of the initializers (and therefore we might be
4667  // missing some that the user actually wrote).
4668  if (Info.AnyErrorsInInits)
4669  return false;
4670 
4671  CXXCtorInitializer *Init = nullptr;
4672  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4673  Indirect, Init))
4674  return true;
4675 
4676  if (!Init)
4677  return false;
4678 
4679  return Info.addFieldInitializer(Init);
4680 }
4681 
4682 bool
4684  CXXCtorInitializer *Initializer) {
4685  assert(Initializer->isDelegatingInitializer());
4686  Constructor->setNumCtorInitializers(1);
4687  CXXCtorInitializer **initializer =
4688  new (Context) CXXCtorInitializer*[1];
4689  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4690  Constructor->setCtorInitializers(initializer);
4691 
4692  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4693  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4694  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4695  }
4696 
4697  DelegatingCtorDecls.push_back(Constructor);
4698 
4699  DiagnoseUninitializedFields(*this, Constructor);
4700 
4701  return false;
4702 }
4703 
4704 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4705  ArrayRef<CXXCtorInitializer *> Initializers) {
4706  if (Constructor->isDependentContext()) {
4707  // Just store the initializers as written, they will be checked during
4708  // instantiation.
4709  if (!Initializers.empty()) {
4710  Constructor->setNumCtorInitializers(Initializers.size());
4711  CXXCtorInitializer **baseOrMemberInitializers =
4712  new (Context) CXXCtorInitializer*[Initializers.size()];
4713  memcpy(baseOrMemberInitializers, Initializers.data(),
4714  Initializers.size() * sizeof(CXXCtorInitializer*));
4715  Constructor->setCtorInitializers(baseOrMemberInitializers);
4716  }
4717 
4718  // Let template instantiation know whether we had errors.
4719  if (AnyErrors)
4720  Constructor->setInvalidDecl();
4721 
4722  return false;
4723  }
4724 
4725  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4726 
4727  // We need to build the initializer AST according to order of construction
4728  // and not what user specified in the Initializers list.
4729  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4730  if (!ClassDecl)
4731  return true;
4732 
4733  bool HadError = false;
4734 
4735  for (unsigned i = 0; i < Initializers.size(); i++) {
4736  CXXCtorInitializer *Member = Initializers[i];
4737 
4738  if (Member->isBaseInitializer())
4739  Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
4740  else {
4741  Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
4742 
4743  if (IndirectFieldDecl *F = Member->getIndirectMember()) {
4744  for (auto *C : F->chain()) {
4745  FieldDecl *FD = dyn_cast<FieldDecl>(C);
4746  if (FD && FD->getParent()->isUnion())
4747  Info.ActiveUnionMember.insert(std::make_pair(
4748  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4749  }
4750  } else if (FieldDecl *FD = Member->getMember()) {
4751  if (FD->getParent()->isUnion())
4752  Info.ActiveUnionMember.insert(std::make_pair(
4753  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4754  }
4755  }
4756  }
4757 
4758  // Keep track of the direct virtual bases.
4759  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
4760  for (auto &I : ClassDecl->bases()) {
4761  if (I.isVirtual())
4762  DirectVBases.insert(&I);
4763  }
4764 
4765  // Push virtual bases before others.
4766  for (auto &VBase : ClassDecl->vbases()) {
4768  = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
4769  // [class.base.init]p7, per DR257:
4770  // A mem-initializer where the mem-initializer-id names a virtual base
4771  // class is ignored during execution of a constructor of any class that
4772  // is not the most derived class.
4773  if (ClassDecl->isAbstract()) {
4774  // FIXME: Provide a fixit to remove the base specifier. This requires
4775  // tracking the location of the associated comma for a base specifier.
4776  Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
4777  << VBase.getType() << ClassDecl;
4778  DiagnoseAbstractType(ClassDecl);
4779  }
4780 
4781  Info.AllToInit.push_back(Value);
4782  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
4783  // [class.base.init]p8, per DR257:
4784  // If a given [...] base class is not named by a mem-initializer-id
4785  // [...] and the entity is not a virtual base class of an abstract
4786  // class, then [...] the entity is default-initialized.
4787  bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
4788  CXXCtorInitializer *CXXBaseInit;
4789  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4790  &VBase, IsInheritedVirtualBase,
4791  CXXBaseInit)) {
4792  HadError = true;
4793  continue;
4794  }
4795 
4796  Info.AllToInit.push_back(CXXBaseInit);
4797  }
4798  }
4799 
4800  // Non-virtual bases.
4801  for (auto &Base : ClassDecl->bases()) {
4802  // Virtuals are in the virtual base list and already constructed.
4803  if (Base.isVirtual())
4804  continue;
4805 
4807  = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
4808  Info.AllToInit.push_back(Value);
4809  } else if (!AnyErrors) {
4810  CXXCtorInitializer *CXXBaseInit;
4811  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4812  &Base, /*IsInheritedVirtualBase=*/false,
4813  CXXBaseInit)) {
4814  HadError = true;
4815  continue;
4816  }
4817 
4818  Info.AllToInit.push_back(CXXBaseInit);
4819  }
4820  }
4821 
4822  // Fields.
4823  for (auto *Mem : ClassDecl->decls()) {
4824  if (auto *F = dyn_cast<FieldDecl>(Mem)) {
4825  // C++ [class.bit]p2:
4826  // A declaration for a bit-field that omits the identifier declares an
4827  // unnamed bit-field. Unnamed bit-fields are not members and cannot be
4828  // initialized.
4829  if (F->isUnnamedBitfield())
4830  continue;
4831 
4832  // If we're not generating the implicit copy/move constructor, then we'll
4833  // handle anonymous struct/union fields based on their individual
4834  // indirect fields.
4835  if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
4836  continue;
4837 
4838  if (CollectFieldInitializer(*this, Info, F))
4839  HadError = true;
4840  continue;
4841  }
4842 
4843  // Beyond this point, we only consider default initialization.
4844  if (Info.isImplicitCopyOrMove())
4845  continue;
4846 
4847  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
4848  if (F->getType()->isIncompleteArrayType()) {
4849  assert(ClassDecl->hasFlexibleArrayMember() &&
4850  "Incomplete array type is not valid");
4851  continue;
4852  }
4853 
4854  // Initialize each field of an anonymous struct individually.
4855  if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
4856  HadError = true;
4857 
4858  continue;
4859  }
4860  }
4861 
4862  unsigned NumInitializers = Info.AllToInit.size();
4863  if (NumInitializers > 0) {
4864  Constructor->setNumCtorInitializers(NumInitializers);
4865  CXXCtorInitializer **baseOrMemberInitializers =
4866  new (Context) CXXCtorInitializer*[NumInitializers];
4867  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
4868  NumInitializers * sizeof(CXXCtorInitializer*));
4869  Constructor->setCtorInitializers(baseOrMemberInitializers);
4870 
4871  // Constructors implicitly reference the base and member
4872  // destructors.
4873  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
4874  Constructor->getParent());
4875  }
4876 
4877  return HadError;
4878 }
4879 
4881  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
4882  const RecordDecl *RD = RT->getDecl();
4883  if (RD->isAnonymousStructOrUnion()) {
4884  for (auto *Field : RD->fields())
4885  PopulateKeysForFields(Field, IdealInits);
4886  return;
4887  }
4888  }
4889  IdealInits.push_back(Field->getCanonicalDecl());
4890 }
4891 
4892 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
4893  return Context.getCanonicalType(BaseType).getTypePtr();
4894 }
4895 
4896 static const void *GetKeyForMember(ASTContext &Context,
4897  CXXCtorInitializer *Member) {
4898  if (!Member->isAnyMemberInitializer())
4899  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
4900 
4901  return Member->getAnyMember()->getCanonicalDecl();
4902 }
4903 
4905  Sema &SemaRef, const CXXConstructorDecl *Constructor,
4907  if (Constructor->getDeclContext()->isDependentContext())
4908  return;
4909 
4910  // Don't check initializers order unless the warning is enabled at the
4911  // location of at least one initializer.
4912  bool ShouldCheckOrder = false;
4913  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4914  CXXCtorInitializer *Init = Inits[InitIndex];
4915  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
4916  Init->getSourceLocation())) {
4917  ShouldCheckOrder = true;
4918  break;
4919  }
4920  }
4921  if (!ShouldCheckOrder)
4922  return;
4923 
4924  // Build the list of bases and members in the order that they'll
4925  // actually be initialized. The explicit initializers should be in
4926  // this same order but may be missing things.
4927  SmallVector<const void*, 32> IdealInitKeys;
4928 
4929  const CXXRecordDecl *ClassDecl = Constructor->getParent();
4930 
4931  // 1. Virtual bases.
4932  for (const auto &VBase : ClassDecl->vbases())
4933  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
4934 
4935  // 2. Non-virtual bases.
4936  for (const auto &Base : ClassDecl->bases()) {
4937  if (Base.isVirtual())
4938  continue;
4939  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
4940  }
4941 
4942  // 3. Direct fields.
4943  for (auto *Field : ClassDecl->fields()) {
4944  if (Field->isUnnamedBitfield())
4945  continue;
4946 
4947  PopulateKeysForFields(Field, IdealInitKeys);
4948  }
4949 
4950  unsigned NumIdealInits = IdealInitKeys.size();
4951  unsigned IdealIndex = 0;
4952 
4953  CXXCtorInitializer *PrevInit = nullptr;
4954  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4955  CXXCtorInitializer *Init = Inits[InitIndex];
4956  const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
4957 
4958  // Scan forward to try to find this initializer in the idealized
4959  // initializers list.
4960  for (; IdealIndex != NumIdealInits; ++IdealIndex)
4961  if (InitKey == IdealInitKeys[IdealIndex])
4962  break;
4963 
4964  // If we didn't find this initializer, it must be because we
4965  // scanned past it on a previous iteration. That can only
4966  // happen if we're out of order; emit a warning.
4967  if (IdealIndex == NumIdealInits && PrevInit) {
4969  SemaRef.Diag(PrevInit->getSourceLocation(),
4970  diag::warn_initializer_out_of_order);
4971 
4972  if (PrevInit->isAnyMemberInitializer())
4973  D << 0 << PrevInit->getAnyMember()->getDeclName();
4974  else
4975  D << 1 << PrevInit->getTypeSourceInfo()->getType();
4976 
4977  if (Init->isAnyMemberInitializer())
4978  D << 0 << Init->getAnyMember()->getDeclName();
4979  else
4980  D << 1 << Init->getTypeSourceInfo()->getType();
4981 
4982  // Move back to the initializer's location in the ideal list.
4983  for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
4984  if (InitKey == IdealInitKeys[IdealIndex])
4985  break;
4986 
4987  assert(IdealIndex < NumIdealInits &&
4988  "initializer not found in initializer list");
4989  }
4990 
4991  PrevInit = Init;
4992  }
4993 }
4994 
4995 namespace {
4996 bool CheckRedundantInit(Sema &S,
4997  CXXCtorInitializer *Init,
4998  CXXCtorInitializer *&PrevInit) {
4999  if (!PrevInit) {
5000  PrevInit = Init;
5001  return false;
5002  }
5003 
5004  if (FieldDecl *Field = Init->getAnyMember())
5005  S.Diag(Init->getSourceLocation(),
5006  diag::err_multiple_mem_initialization)
5007  << Field->getDeclName()
5008  << Init->getSourceRange();
5009  else {
5010  const Type *BaseClass = Init->getBaseClass();
5011  assert(BaseClass && "neither field nor base");
5012  S.Diag(Init->getSourceLocation(),
5013  diag::err_multiple_base_initialization)
5014  << QualType(BaseClass, 0)
5015  << Init->getSourceRange();
5016  }
5017  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5018  << 0 << PrevInit->getSourceRange();
5019 
5020  return true;
5021 }
5022 
5023 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5024 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5025 
5026 bool CheckRedundantUnionInit(Sema &S,
5027  CXXCtorInitializer *Init,
5028  RedundantUnionMap &Unions) {
5029  FieldDecl *Field = Init->getAnyMember();
5030  RecordDecl *Parent = Field->getParent();
5031  NamedDecl *Child = Field;
5032 
5033  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5034  if (Parent->isUnion()) {
5035  UnionEntry &En = Unions[Parent];
5036  if (En.first && En.first != Child) {
5037  S.Diag(Init->getSourceLocation(),
5038  diag::err_multiple_mem_union_initialization)
5039  << Field->getDeclName()
5040  << Init->getSourceRange();
5041  S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5042  << 0 << En.second->getSourceRange();
5043  return true;
5044  }
5045  if (!En.first) {
5046  En.first = Child;
5047  En.second = Init;
5048  }
5049  if (!Parent->isAnonymousStructOrUnion())
5050  return false;
5051  }
5052 
5053  Child = Parent;
5054  Parent = cast<RecordDecl>(Parent->getDeclContext());
5055  }
5056 
5057  return false;
5058 }
5059 }
5060 
5061 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5062 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5065  bool AnyErrors) {
5066  if (!ConstructorDecl)
5067  return;
5068 
5069  AdjustDeclIfTemplate(ConstructorDecl);
5070 
5071  CXXConstructorDecl *Constructor
5072  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5073 
5074  if (!Constructor) {
5075  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5076  return;
5077  }
5078 
5079  // Mapping for the duplicate initializers check.
5080  // For member initializers, this is keyed with a FieldDecl*.
5081  // For base initializers, this is keyed with a Type*.
5082  llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5083 
5084  // Mapping for the inconsistent anonymous-union initializers check.
5085  RedundantUnionMap MemberUnions;
5086 
5087  bool HadError = false;
5088  for (unsigned i = 0; i < MemInits.size(); i++) {
5089  CXXCtorInitializer *Init = MemInits[i];
5090 
5091  // Set the source order index.
5092  Init->setSourceOrder(i);
5093 
5094  if (Init->isAnyMemberInitializer()) {
5095  const void *Key = GetKeyForMember(Context, Init);
5096  if (CheckRedundantInit(*this, Init, Members[Key]) ||
5097  CheckRedundantUnionInit(*this, Init, MemberUnions))
5098  HadError = true;
5099  } else if (Init->isBaseInitializer()) {
5100  const void *Key = GetKeyForMember(Context, Init);
5101  if (CheckRedundantInit(*this, Init, Members[Key]))
5102  HadError = true;
5103  } else {
5104  assert(Init->isDelegatingInitializer());
5105  // This must be the only initializer
5106  if (MemInits.size() != 1) {
5107  Diag(Init->getSourceLocation(),
5108  diag::err_delegating_initializer_alone)
5109  << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5110  // We will treat this as being the only initializer.
5111  }
5112  SetDelegatingInitializer(Constructor, MemInits[i]);
5113  // Return immediately as the initializer is set.
5114  return;
5115  }
5116  }
5117 
5118  if (HadError)
5119  return;
5120 
5121  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5122 
5123  SetCtorInitializers(Constructor, AnyErrors, MemInits);
5124 
5125  DiagnoseUninitializedFields(*this, Constructor);
5126 }
5127 
5128 void
5130  CXXRecordDecl *ClassDecl) {
5131  // Ignore dependent contexts. Also ignore unions, since their members never
5132  // have destructors implicitly called.
5133  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5134  return;
5135 
5136  // FIXME: all the access-control diagnostics are positioned on the
5137  // field/base declaration. That's probably good; that said, the
5138  // user might reasonably want to know why the destructor is being
5139  // emitted, and we currently don't say.
5140 
5141  // Non-static data members.
5142  for (auto *Field : ClassDecl->fields()) {
5143  if (Field->isInvalidDecl())
5144  continue;
5145 
5146  // Don't destroy incomplete or zero-length arrays.
5147  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5148  continue;
5149 
5150  QualType FieldType = Context.getBaseElementType(Field->getType());
5151 
5152  const RecordType* RT = FieldType->getAs<RecordType>();
5153  if (!RT)
5154  continue;
5155 
5156  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5157  if (FieldClassDecl->isInvalidDecl())
5158  continue;
5159  if (FieldClassDecl->hasIrrelevantDestructor())
5160  continue;
5161  // The destructor for an implicit anonymous union member is never invoked.
5162  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5163  continue;
5164 
5165  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5166  assert(Dtor && "No dtor found for FieldClassDecl!");
5167  CheckDestructorAccess(Field->getLocation(), Dtor,
5168  PDiag(diag::err_access_dtor_field)
5169  << Field->getDeclName()
5170  << FieldType);
5171 
5172  MarkFunctionReferenced(Location, Dtor);
5173  DiagnoseUseOfDecl(Dtor, Location);
5174  }
5175 
5176  // We only potentially invoke the destructors of potentially constructed
5177  // subobjects.
5178  bool VisitVirtualBases = !ClassDecl->isAbstract();
5179 
5180  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5181 
5182  // Bases.
5183  for (const auto &Base : ClassDecl->bases()) {
5184  // Bases are always records in a well-formed non-dependent class.
5185  const RecordType *RT = Base.getType()->getAs<RecordType>();
5186 
5187  // Remember direct virtual bases.
5188  if (Base.isVirtual()) {
5189  if (!VisitVirtualBases)
5190  continue;
5191  DirectVirtualBases.insert(RT);
5192  }
5193 
5194  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5195  // If our base class is invalid, we probably can't get its dtor anyway.
5196  if (BaseClassDecl->isInvalidDecl())
5197  continue;
5198  if (BaseClassDecl->hasIrrelevantDestructor())
5199  continue;
5200 
5201  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5202  assert(Dtor && "No dtor found for BaseClassDecl!");
5203 
5204  // FIXME: caret should be on the start of the class name
5205  CheckDestructorAccess(Base.getLocStart(), Dtor,
5206  PDiag(diag::err_access_dtor_base)
5207  << Base.getType()
5208  << Base.getSourceRange(),
5209  Context.getTypeDeclType(ClassDecl));
5210 
5211  MarkFunctionReferenced(Location, Dtor);
5212  DiagnoseUseOfDecl(Dtor, Location);
5213  }
5214 
5215  if (!VisitVirtualBases)
5216  return;
5217 
5218  // Virtual bases.
5219  for (const auto &VBase : ClassDecl->vbases()) {
5220  // Bases are always records in a well-formed non-dependent class.
5221  const RecordType *RT = VBase.getType()->castAs<RecordType>();
5222 
5223  // Ignore direct virtual bases.
5224  if (DirectVirtualBases.count(RT))
5225  continue;
5226 
5227  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5228  // If our base class is invalid, we probably can't get its dtor anyway.
5229  if (BaseClassDecl->isInvalidDecl())
5230  continue;
5231  if (BaseClassDecl->hasIrrelevantDestructor())
5232  continue;
5233 
5234  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5235  assert(Dtor && "No dtor found for BaseClassDecl!");
5236  if (CheckDestructorAccess(
5237  ClassDecl->getLocation(), Dtor,
5238  PDiag(diag::err_access_dtor_vbase)
5239  << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5240  Context.getTypeDeclType(ClassDecl)) ==
5241  AR_accessible) {
5242  CheckDerivedToBaseConversion(
5243  Context.getTypeDeclType(ClassDecl), VBase.getType(),
5244  diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5245  SourceRange(), DeclarationName(), nullptr);
5246  }
5247 
5248  MarkFunctionReferenced(Location, Dtor);
5249  DiagnoseUseOfDecl(Dtor, Location);
5250  }
5251 }
5252 
5253 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5254  if (!CDtorDecl)
5255  return;
5256 
5257  if (CXXConstructorDecl *Constructor
5258  = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5259  SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5260  DiagnoseUninitializedFields(*this, Constructor);
5261  }
5262 }
5263 
5265  if (!getLangOpts().CPlusPlus)
5266  return false;
5267 
5268  const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5269  if (!RD)
5270  return false;
5271 
5272  // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5273  // class template specialization here, but doing so breaks a lot of code.
5274 
5275  // We can't answer whether something is abstract until it has a
5276  // definition. If it's currently being defined, we'll walk back
5277  // over all the declarations when we have a full definition.
5278  const CXXRecordDecl *Def = RD->getDefinition();
5279  if (!Def || Def->isBeingDefined())
5280  return false;
5281 
5282  return RD->isAbstract();
5283 }
5284 
5286  TypeDiagnoser &Diagnoser) {
5287  if (!isAbstractType(Loc, T))
5288  return false;
5289 
5290  T = Context.getBaseElementType(T);
5291  Diagnoser.diagnose(*this, Loc, T);
5292  DiagnoseAbstractType(T->getAsCXXRecordDecl());
5293  return true;
5294 }
5295 
5297  // Check if we've already emitted the list of pure virtual functions
5298  // for this class.
5299  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5300  return;
5301 
5302  // If the diagnostic is suppressed, don't emit the notes. We're only
5303  // going to emit them once, so try to attach them to a diagnostic we're
5304  // actually going to show.
5305  if (Diags.isLastDiagnosticIgnored())
5306  return;
5307 
5308  CXXFinalOverriderMap FinalOverriders;
5309  RD->getFinalOverriders(FinalOverriders);
5310 
5311  // Keep a set of seen pure methods so we won't diagnose the same method
5312  // more than once.
5313  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5314 
5315  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5316  MEnd = FinalOverriders.end();
5317  M != MEnd;
5318  ++M) {
5319  for (OverridingMethods::iterator SO = M->second.begin(),
5320  SOEnd = M->second.end();
5321  SO != SOEnd; ++SO) {
5322  // C++ [class.abstract]p4:
5323  // A class is abstract if it contains or inherits at least one
5324  // pure virtual function for which the final overrider is pure
5325  // virtual.
5326 
5327  //
5328  if (SO->second.size() != 1)
5329  continue;
5330 
5331  if (!SO->second.front().Method->isPure())
5332  continue;
5333 
5334  if (!SeenPureMethods.insert(SO->second.front().Method).second)
5335  continue;
5336 
5337  Diag(SO->second.front().Method->getLocation(),
5338  diag::note_pure_virtual_function)
5339  << SO->second.front().Method->getDeclName() << RD->getDeclName();
5340  }
5341  }
5342 
5343  if (!PureVirtualClassDiagSet)
5344  PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5345  PureVirtualClassDiagSet->insert(RD);
5346 }
5347 
5348 namespace {
5349 struct AbstractUsageInfo {
5350  Sema &S;
5351  CXXRecordDecl *Record;
5352  CanQualType AbstractType;
5353  bool Invalid;
5354 
5355  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5356  : S(S), Record(Record),
5357  AbstractType(S.Context.getCanonicalType(
5358  S.Context.getTypeDeclType(Record))),
5359  Invalid(false) {}
5360 
5361  void DiagnoseAbstractType() {
5362  if (Invalid) return;
5363  S.DiagnoseAbstractType(Record);
5364  Invalid = true;
5365  }
5366 
5367  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5368 };
5369 
5370 struct CheckAbstractUsage {
5371  AbstractUsageInfo &Info;
5372  const NamedDecl *Ctx;
5373 
5374  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5375  : Info(Info), Ctx(Ctx) {}
5376 
5377  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5378  switch (TL.getTypeLocClass()) {
5379 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5380 #define TYPELOC(CLASS, PARENT) \
5381  case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5382 #include "clang/AST/TypeLocNodes.def"
5383  }
5384  }
5385 
5386  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5388  for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5389  if (!TL.getParam(I))
5390  continue;
5391 
5392  TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5393  if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5394  }
5395  }
5396 
5397  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5399  }
5400 
5402  // Visit the type parameters from a permissive context.
5403  for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5404  TemplateArgumentLoc TAL = TL.getArgLoc(I);
5406  if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5407  Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5408  // TODO: other template argument types?
5409  }
5410  }
5411 
5412  // Visit pointee types from a permissive context.
5413 #define CheckPolymorphic(Type) \
5414  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5415  Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5416  }
5422 
5423  /// Handle all the types we haven't given a more specific
5424  /// implementation for above.
5425  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5426  // Every other kind of type that we haven't called out already
5427  // that has an inner type is either (1) sugar or (2) contains that
5428  // inner type in some way as a subobject.
5429  if (TypeLoc Next = TL.getNextTypeLoc())
5430  return Visit(Next, Sel);
5431 
5432  // If there's no inner type and we're in a permissive context,
5433  // don't diagnose.
5434  if (Sel == Sema::AbstractNone) return;
5435 
5436  // Check whether the type matches the abstract type.
5437  QualType T = TL.getType();
5438  if (T->isArrayType()) {
5440  T = Info.S.Context.getBaseElementType(T);
5441  }
5443  if (CT != Info.AbstractType) return;
5444 
5445  // It matched; do some magic.
5446  if (Sel == Sema::AbstractArrayType) {
5447  Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5448  << T << TL.getSourceRange();
5449  } else {
5450  Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5451  << Sel << T << TL.getSourceRange();
5452  }
5453  Info.DiagnoseAbstractType();
5454  }
5455 };
5456 
5457 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5459  CheckAbstractUsage(*this, D).Visit(TL, Sel);
5460 }
5461 
5462 }
5463 
5464 /// Check for invalid uses of an abstract type in a method declaration.
5465 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5466  CXXMethodDecl *MD) {
5467  // No need to do the check on definitions, which require that
5468  // the return/param types be complete.
5469  if (MD->doesThisDeclarationHaveABody())
5470  return;
5471 
5472  // For safety's sake, just ignore it if we don't have type source
5473  // information. This should never happen for non-implicit methods,
5474  // but...
5475  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5476  Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5477 }
5478 
5479 /// Check for invalid uses of an abstract type within a class definition.
5480 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5481  CXXRecordDecl *RD) {
5482  for (auto *D : RD->decls()) {
5483  if (D->isImplicit()) continue;
5484 
5485  // Methods and method templates.
5486  if (isa<CXXMethodDecl>(D)) {
5487  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5488  } else if (isa<FunctionTemplateDecl>(D)) {
5489  FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5490  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5491 
5492  // Fields and static variables.
5493  } else if (isa<FieldDecl>(D)) {
5494  FieldDecl *FD = cast<FieldDecl>(D);
5495  if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5496  Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5497  } else if (isa<VarDecl>(D)) {
5498  VarDecl *VD = cast<VarDecl>(D);
5499  if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5500  Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5501 
5502  // Nested classes and class templates.
5503  } else if (isa<CXXRecordDecl>(D)) {
5504  CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5505  } else if (isa<ClassTemplateDecl>(D)) {
5507  cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5508  }
5509  }
5510 }
5511 
5513  Attr *ClassAttr = getDLLAttr(Class);
5514  if (!ClassAttr)
5515  return;
5516 
5517  assert(ClassAttr->getKind() == attr::DLLExport);
5518 
5520 
5522  // Don't go any further if this is just an explicit instantiation
5523  // declaration.
5524  return;
5525 
5526  for (Decl *Member : Class->decls()) {
5527  // Defined static variables that are members of an exported base
5528  // class must be marked export too.
5529  auto *VD = dyn_cast<VarDecl>(Member);
5530  if (VD && Member->getAttr<DLLExportAttr>() &&
5531  VD->getStorageClass() == SC_Static &&
5533  S.MarkVariableReferenced(VD->getLocation(), VD);
5534 
5535  auto *MD = dyn_cast<CXXMethodDecl>(Member);
5536  if (!MD)
5537  continue;
5538 
5539  if (Member->getAttr<DLLExportAttr>()) {
5540  if (MD->isUserProvided()) {
5541  // Instantiate non-default class member functions ...
5542 
5543  // .. except for certain kinds of template specializations.
5544  if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5545  continue;
5546 
5547  S.MarkFunctionReferenced(Class->getLocation(), MD);
5548 
5549  // The function will be passed to the consumer when its definition is
5550  // encountered.
5551  } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5552  MD->isCopyAssignmentOperator() ||
5553  MD->isMoveAssignmentOperator()) {
5554  // Synthesize and instantiate non-trivial implicit methods, explicitly
5555  // defaulted methods, and the copy and move assignment operators. The
5556  // latter are exported even if they are trivial, because the address of
5557  // an operator can be taken and should compare equal across libraries.
5558  DiagnosticErrorTrap Trap(S.Diags);
5559  S.MarkFunctionReferenced(Class->getLocation(), MD);
5560  if (Trap.hasErrorOccurred()) {
5561  S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5562  << Class << !S.getLangOpts().CPlusPlus11;
5563  break;
5564  }
5565 
5566  // There is no later point when we will see the definition of this
5567  // function, so pass it to the consumer now.
5569  }
5570  }
5571  }
5572 }
5573 
5575  CXXRecordDecl *Class) {
5576  // Only the MS ABI has default constructor closures, so we don't need to do
5577  // this semantic checking anywhere else.
5579  return;
5580 
5581  CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5582  for (Decl *Member : Class->decls()) {
5583  // Look for exported default constructors.
5584  auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5585  if (!CD || !CD->isDefaultConstructor())
5586  continue;
5587  auto *Attr = CD->getAttr<DLLExportAttr>();
5588  if (!Attr)
5589  continue;
5590 
5591  // If the class is non-dependent, mark the default arguments as ODR-used so
5592  // that we can properly codegen the constructor closure.
5593  if (!Class->isDependentContext()) {
5594  for (ParmVarDecl *PD : CD->parameters()) {
5595  (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5597  }
5598  }
5599 
5600  if (LastExportedDefaultCtor) {
5601  S.Diag(LastExportedDefaultCtor->getLocation(),
5602  diag::err_attribute_dll_ambiguous_default_ctor)
5603  << Class;
5604  S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5605  << CD->getDeclName();
5606  return;
5607  }
5608  LastExportedDefaultCtor = CD;
5609  }
5610 }
5611 
5612 /// Check class-level dllimport/dllexport attribute.
5614  Attr *ClassAttr = getDLLAttr(Class);
5615 
5616  // MSVC inherits DLL attributes to partial class template specializations.
5617  if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5618  if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5619  if (Attr *TemplateAttr =
5620  getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5621  auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5622  A->setInherited(true);
5623  ClassAttr = A;
5624  }
5625  }
5626  }
5627 
5628  if (!ClassAttr)
5629  return;
5630 
5631  if (!Class->isExternallyVisible()) {
5632  Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5633  << Class << ClassAttr;
5634  return;
5635  }
5636 
5637  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5638  !ClassAttr->isInherited()) {
5639  // Diagnose dll attributes on members of class with dll attribute.
5640  for (Decl *Member : Class->decls()) {
5641  if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5642  continue;
5643  InheritableAttr *MemberAttr = getDLLAttr(Member);
5644  if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5645  continue;
5646 
5647  Diag(MemberAttr->getLocation(),
5648  diag::err_attribute_dll_member_of_dll_class)
5649  << MemberAttr << ClassAttr;
5650  Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5651  Member->setInvalidDecl();
5652  }
5653  }
5654 
5655  if (Class->getDescribedClassTemplate())
5656  // Don't inherit dll attribute until the template is instantiated.
5657  return;
5658 
5659  // The class is either imported or exported.
5660  const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5661 
5662  // Check if this was a dllimport attribute propagated from a derived class to
5663  // a base class template specialization. We don't apply these attributes to
5664  // static data members.
5665  const bool PropagatedImport =
5666  !ClassExported &&
5667  cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
5668 
5670 
5671  // Ignore explicit dllexport on explicit class template instantiation declarations.
5672  if (ClassExported && !ClassAttr->isInherited() &&
5674  Class->dropAttr<DLLExportAttr>();
5675  return;
5676  }
5677 
5678  // Force declaration of implicit members so they can inherit the attribute.
5679  ForceDeclarationOfImplicitMembers(Class);
5680 
5681  // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
5682  // seem to be true in practice?
5683 
5684  for (Decl *Member : Class->decls()) {
5685  VarDecl *VD = dyn_cast<VarDecl>(Member);
5686  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
5687 
5688  // Only methods and static fields inherit the attributes.
5689  if (!VD && !MD)
5690  continue;
5691 
5692  if (MD) {
5693  // Don't process deleted methods.
5694  if (MD->isDeleted())
5695  continue;
5696 
5697  if (MD->isInlined()) {
5698  // MinGW does not import or export inline methods.
5699  if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5700  !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment())
5701  continue;
5702 
5703  // MSVC versions before 2015 don't export the move assignment operators
5704  // and move constructor, so don't attempt to import/export them if
5705  // we have a definition.
5706  auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
5707  if ((MD->isMoveAssignmentOperator() ||
5708  (Ctor && Ctor->isMoveConstructor())) &&
5709  !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
5710  continue;
5711 
5712  // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
5713  // operator is exported anyway.
5714  if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&