clang  9.0.0svn
SemaDeclCXX.cpp
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1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements semantic analysis for C++ declarations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTLambda.h"
18 #include "clang/AST/CharUnits.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/RecordLayout.h"
24 #include "clang/AST/StmtVisitor.h"
25 #include "clang/AST/TypeLoc.h"
26 #include "clang/AST/TypeOrdering.h"
28 #include "clang/Basic/TargetInfo.h"
30 #include "clang/Lex/Preprocessor.h"
32 #include "clang/Sema/DeclSpec.h"
34 #include "clang/Sema/Lookup.h"
36 #include "clang/Sema/Scope.h"
37 #include "clang/Sema/ScopeInfo.h"
39 #include "clang/Sema/Template.h"
40 #include "llvm/ADT/STLExtras.h"
41 #include "llvm/ADT/SmallString.h"
42 #include "llvm/ADT/StringExtras.h"
43 #include <map>
44 #include <set>
45 
46 using namespace clang;
47 
48 //===----------------------------------------------------------------------===//
49 // CheckDefaultArgumentVisitor
50 //===----------------------------------------------------------------------===//
51 
52 namespace {
53  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
54  /// the default argument of a parameter to determine whether it
55  /// contains any ill-formed subexpressions. For example, this will
56  /// diagnose the use of local variables or parameters within the
57  /// default argument expression.
58  class CheckDefaultArgumentVisitor
59  : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
60  Expr *DefaultArg;
61  Sema *S;
62 
63  public:
64  CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
65  : DefaultArg(defarg), S(s) {}
66 
67  bool VisitExpr(Expr *Node);
68  bool VisitDeclRefExpr(DeclRefExpr *DRE);
69  bool VisitCXXThisExpr(CXXThisExpr *ThisE);
70  bool VisitLambdaExpr(LambdaExpr *Lambda);
71  bool VisitPseudoObjectExpr(PseudoObjectExpr *POE);
72  };
73 
74  /// VisitExpr - Visit all of the children of this expression.
75  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
76  bool IsInvalid = false;
77  for (Stmt *SubStmt : Node->children())
78  IsInvalid |= Visit(SubStmt);
79  return IsInvalid;
80  }
81 
82  /// VisitDeclRefExpr - Visit a reference to a declaration, to
83  /// determine whether this declaration can be used in the default
84  /// argument expression.
85  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
86  NamedDecl *Decl = DRE->getDecl();
87  if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
88  // C++ [dcl.fct.default]p9
89  // Default arguments are evaluated each time the function is
90  // called. The order of evaluation of function arguments is
91  // unspecified. Consequently, parameters of a function shall not
92  // be used in default argument expressions, even if they are not
93  // evaluated. Parameters of a function declared before a default
94  // argument expression are in scope and can hide namespace and
95  // class member names.
96  return S->Diag(DRE->getBeginLoc(),
97  diag::err_param_default_argument_references_param)
98  << Param->getDeclName() << DefaultArg->getSourceRange();
99  } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
100  // C++ [dcl.fct.default]p7
101  // Local variables shall not be used in default argument
102  // expressions.
103  if (VDecl->isLocalVarDecl())
104  return S->Diag(DRE->getBeginLoc(),
105  diag::err_param_default_argument_references_local)
106  << VDecl->getDeclName() << DefaultArg->getSourceRange();
107  }
108 
109  return false;
110  }
111 
112  /// VisitCXXThisExpr - Visit a C++ "this" expression.
113  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
114  // C++ [dcl.fct.default]p8:
115  // The keyword this shall not be used in a default argument of a
116  // member function.
117  return S->Diag(ThisE->getBeginLoc(),
118  diag::err_param_default_argument_references_this)
119  << ThisE->getSourceRange();
120  }
121 
122  bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
123  bool Invalid = false;
125  i = POE->semantics_begin(), e = POE->semantics_end(); i != e; ++i) {
126  Expr *E = *i;
127 
128  // Look through bindings.
129  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
130  E = OVE->getSourceExpr();
131  assert(E && "pseudo-object binding without source expression?");
132  }
133 
134  Invalid |= Visit(E);
135  }
136  return Invalid;
137  }
138 
139  bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
140  // C++11 [expr.lambda.prim]p13:
141  // A lambda-expression appearing in a default argument shall not
142  // implicitly or explicitly capture any entity.
143  if (Lambda->capture_begin() == Lambda->capture_end())
144  return false;
145 
146  return S->Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
147  }
148 }
149 
150 void
152  const CXXMethodDecl *Method) {
153  // If we have an MSAny spec already, don't bother.
154  if (!Method || ComputedEST == EST_MSAny)
155  return;
156 
157  const FunctionProtoType *Proto
158  = Method->getType()->getAs<FunctionProtoType>();
159  Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
160  if (!Proto)
161  return;
162 
164 
165  // If we have a throw-all spec at this point, ignore the function.
166  if (ComputedEST == EST_None)
167  return;
168 
169  if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
170  EST = EST_BasicNoexcept;
171 
172  switch (EST) {
173  case EST_Unparsed:
174  case EST_Uninstantiated:
175  case EST_Unevaluated:
176  llvm_unreachable("should not see unresolved exception specs here");
177 
178  // If this function can throw any exceptions, make a note of that.
179  case EST_MSAny:
180  case EST_None:
181  // FIXME: Whichever we see last of MSAny and None determines our result.
182  // We should make a consistent, order-independent choice here.
183  ClearExceptions();
184  ComputedEST = EST;
185  return;
186  case EST_NoexceptFalse:
187  ClearExceptions();
188  ComputedEST = EST_None;
189  return;
190  // FIXME: If the call to this decl is using any of its default arguments, we
191  // need to search them for potentially-throwing calls.
192  // If this function has a basic noexcept, it doesn't affect the outcome.
193  case EST_BasicNoexcept:
194  case EST_NoexceptTrue:
195  return;
196  // If we're still at noexcept(true) and there's a throw() callee,
197  // change to that specification.
198  case EST_DynamicNone:
199  if (ComputedEST == EST_BasicNoexcept)
200  ComputedEST = EST_DynamicNone;
201  return;
203  llvm_unreachable(
204  "should not generate implicit declarations for dependent cases");
205  case EST_Dynamic:
206  break;
207  }
208  assert(EST == EST_Dynamic && "EST case not considered earlier.");
209  assert(ComputedEST != EST_None &&
210  "Shouldn't collect exceptions when throw-all is guaranteed.");
211  ComputedEST = EST_Dynamic;
212  // Record the exceptions in this function's exception specification.
213  for (const auto &E : Proto->exceptions())
214  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
215  Exceptions.push_back(E);
216 }
217 
219  if (!E || ComputedEST == EST_MSAny)
220  return;
221 
222  // FIXME:
223  //
224  // C++0x [except.spec]p14:
225  // [An] implicit exception-specification specifies the type-id T if and
226  // only if T is allowed by the exception-specification of a function directly
227  // invoked by f's implicit definition; f shall allow all exceptions if any
228  // function it directly invokes allows all exceptions, and f shall allow no
229  // exceptions if every function it directly invokes allows no exceptions.
230  //
231  // Note in particular that if an implicit exception-specification is generated
232  // for a function containing a throw-expression, that specification can still
233  // be noexcept(true).
234  //
235  // Note also that 'directly invoked' is not defined in the standard, and there
236  // is no indication that we should only consider potentially-evaluated calls.
237  //
238  // Ultimately we should implement the intent of the standard: the exception
239  // specification should be the set of exceptions which can be thrown by the
240  // implicit definition. For now, we assume that any non-nothrow expression can
241  // throw any exception.
242 
243  if (Self->canThrow(E))
244  ComputedEST = EST_None;
245 }
246 
247 bool
249  SourceLocation EqualLoc) {
250  if (RequireCompleteType(Param->getLocation(), Param->getType(),
251  diag::err_typecheck_decl_incomplete_type)) {
252  Param->setInvalidDecl();
253  return true;
254  }
255 
256  // C++ [dcl.fct.default]p5
257  // A default argument expression is implicitly converted (clause
258  // 4) to the parameter type. The default argument expression has
259  // the same semantic constraints as the initializer expression in
260  // a declaration of a variable of the parameter type, using the
261  // copy-initialization semantics (8.5).
263  Param);
265  EqualLoc);
266  InitializationSequence InitSeq(*this, Entity, Kind, Arg);
267  ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
268  if (Result.isInvalid())
269  return true;
270  Arg = Result.getAs<Expr>();
271 
272  CheckCompletedExpr(Arg, EqualLoc);
273  Arg = MaybeCreateExprWithCleanups(Arg);
274 
275  // Okay: add the default argument to the parameter
276  Param->setDefaultArg(Arg);
277 
278  // We have already instantiated this parameter; provide each of the
279  // instantiations with the uninstantiated default argument.
280  UnparsedDefaultArgInstantiationsMap::iterator InstPos
281  = UnparsedDefaultArgInstantiations.find(Param);
282  if (InstPos != UnparsedDefaultArgInstantiations.end()) {
283  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
284  InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
285 
286  // We're done tracking this parameter's instantiations.
287  UnparsedDefaultArgInstantiations.erase(InstPos);
288  }
289 
290  return false;
291 }
292 
293 /// ActOnParamDefaultArgument - Check whether the default argument
294 /// provided for a function parameter is well-formed. If so, attach it
295 /// to the parameter declaration.
296 void
298  Expr *DefaultArg) {
299  if (!param || !DefaultArg)
300  return;
301 
302  ParmVarDecl *Param = cast<ParmVarDecl>(param);
303  UnparsedDefaultArgLocs.erase(Param);
304 
305  // Default arguments are only permitted in C++
306  if (!getLangOpts().CPlusPlus) {
307  Diag(EqualLoc, diag::err_param_default_argument)
308  << DefaultArg->getSourceRange();
309  Param->setInvalidDecl();
310  return;
311  }
312 
313  // Check for unexpanded parameter packs.
314  if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
315  Param->setInvalidDecl();
316  return;
317  }
318 
319  // C++11 [dcl.fct.default]p3
320  // A default argument expression [...] shall not be specified for a
321  // parameter pack.
322  if (Param->isParameterPack()) {
323  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
324  << DefaultArg->getSourceRange();
325  return;
326  }
327 
328  // Check that the default argument is well-formed
329  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
330  if (DefaultArgChecker.Visit(DefaultArg)) {
331  Param->setInvalidDecl();
332  return;
333  }
334 
335  SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
336 }
337 
338 /// ActOnParamUnparsedDefaultArgument - We've seen a default
339 /// argument for a function parameter, but we can't parse it yet
340 /// because we're inside a class definition. Note that this default
341 /// argument will be parsed later.
343  SourceLocation EqualLoc,
344  SourceLocation ArgLoc) {
345  if (!param)
346  return;
347 
348  ParmVarDecl *Param = cast<ParmVarDecl>(param);
349  Param->setUnparsedDefaultArg();
350  UnparsedDefaultArgLocs[Param] = ArgLoc;
351 }
352 
353 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
354 /// the default argument for the parameter param failed.
356  SourceLocation EqualLoc) {
357  if (!param)
358  return;
359 
360  ParmVarDecl *Param = cast<ParmVarDecl>(param);
361  Param->setInvalidDecl();
362  UnparsedDefaultArgLocs.erase(Param);
363  Param->setDefaultArg(new(Context)
364  OpaqueValueExpr(EqualLoc,
365  Param->getType().getNonReferenceType(),
366  VK_RValue));
367 }
368 
369 /// CheckExtraCXXDefaultArguments - Check for any extra default
370 /// arguments in the declarator, which is not a function declaration
371 /// or definition and therefore is not permitted to have default
372 /// arguments. This routine should be invoked for every declarator
373 /// that is not a function declaration or definition.
375  // C++ [dcl.fct.default]p3
376  // A default argument expression shall be specified only in the
377  // parameter-declaration-clause of a function declaration or in a
378  // template-parameter (14.1). It shall not be specified for a
379  // parameter pack. If it is specified in a
380  // parameter-declaration-clause, it shall not occur within a
381  // declarator or abstract-declarator of a parameter-declaration.
382  bool MightBeFunction = D.isFunctionDeclarationContext();
383  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
384  DeclaratorChunk &chunk = D.getTypeObject(i);
385  if (chunk.Kind == DeclaratorChunk::Function) {
386  if (MightBeFunction) {
387  // This is a function declaration. It can have default arguments, but
388  // keep looking in case its return type is a function type with default
389  // arguments.
390  MightBeFunction = false;
391  continue;
392  }
393  for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
394  ++argIdx) {
395  ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
396  if (Param->hasUnparsedDefaultArg()) {
397  std::unique_ptr<CachedTokens> Toks =
398  std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
399  SourceRange SR;
400  if (Toks->size() > 1)
401  SR = SourceRange((*Toks)[1].getLocation(),
402  Toks->back().getLocation());
403  else
404  SR = UnparsedDefaultArgLocs[Param];
405  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
406  << SR;
407  } else if (Param->getDefaultArg()) {
408  Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
409  << Param->getDefaultArg()->getSourceRange();
410  Param->setDefaultArg(nullptr);
411  }
412  }
413  } else if (chunk.Kind != DeclaratorChunk::Paren) {
414  MightBeFunction = false;
415  }
416  }
417 }
418 
420  for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) {
421  const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1);
422  if (!PVD->hasDefaultArg())
423  return false;
424  if (!PVD->hasInheritedDefaultArg())
425  return true;
426  }
427  return false;
428 }
429 
430 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
431 /// function, once we already know that they have the same
432 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
433 /// error, false otherwise.
435  Scope *S) {
436  bool Invalid = false;
437 
438  // The declaration context corresponding to the scope is the semantic
439  // parent, unless this is a local function declaration, in which case
440  // it is that surrounding function.
441  DeclContext *ScopeDC = New->isLocalExternDecl()
442  ? New->getLexicalDeclContext()
443  : New->getDeclContext();
444 
445  // Find the previous declaration for the purpose of default arguments.
446  FunctionDecl *PrevForDefaultArgs = Old;
447  for (/**/; PrevForDefaultArgs;
448  // Don't bother looking back past the latest decl if this is a local
449  // extern declaration; nothing else could work.
450  PrevForDefaultArgs = New->isLocalExternDecl()
451  ? nullptr
452  : PrevForDefaultArgs->getPreviousDecl()) {
453  // Ignore hidden declarations.
454  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
455  continue;
456 
457  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
458  !New->isCXXClassMember()) {
459  // Ignore default arguments of old decl if they are not in
460  // the same scope and this is not an out-of-line definition of
461  // a member function.
462  continue;
463  }
464 
465  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
466  // If only one of these is a local function declaration, then they are
467  // declared in different scopes, even though isDeclInScope may think
468  // they're in the same scope. (If both are local, the scope check is
469  // sufficient, and if neither is local, then they are in the same scope.)
470  continue;
471  }
472 
473  // We found the right previous declaration.
474  break;
475  }
476 
477  // C++ [dcl.fct.default]p4:
478  // For non-template functions, default arguments can be added in
479  // later declarations of a function in the same
480  // scope. Declarations in different scopes have completely
481  // distinct sets of default arguments. That is, declarations in
482  // inner scopes do not acquire default arguments from
483  // declarations in outer scopes, and vice versa. In a given
484  // function declaration, all parameters subsequent to a
485  // parameter with a default argument shall have default
486  // arguments supplied in this or previous declarations. A
487  // default argument shall not be redefined by a later
488  // declaration (not even to the same value).
489  //
490  // C++ [dcl.fct.default]p6:
491  // Except for member functions of class templates, the default arguments
492  // in a member function definition that appears outside of the class
493  // definition are added to the set of default arguments provided by the
494  // member function declaration in the class definition.
495  for (unsigned p = 0, NumParams = PrevForDefaultArgs
496  ? PrevForDefaultArgs->getNumParams()
497  : 0;
498  p < NumParams; ++p) {
499  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
500  ParmVarDecl *NewParam = New->getParamDecl(p);
501 
502  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
503  bool NewParamHasDfl = NewParam->hasDefaultArg();
504 
505  if (OldParamHasDfl && NewParamHasDfl) {
506  unsigned DiagDefaultParamID =
507  diag::err_param_default_argument_redefinition;
508 
509  // MSVC accepts that default parameters be redefined for member functions
510  // of template class. The new default parameter's value is ignored.
511  Invalid = true;
512  if (getLangOpts().MicrosoftExt) {
513  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
514  if (MD && MD->getParent()->getDescribedClassTemplate()) {
515  // Merge the old default argument into the new parameter.
516  NewParam->setHasInheritedDefaultArg();
517  if (OldParam->hasUninstantiatedDefaultArg())
518  NewParam->setUninstantiatedDefaultArg(
519  OldParam->getUninstantiatedDefaultArg());
520  else
521  NewParam->setDefaultArg(OldParam->getInit());
522  DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
523  Invalid = false;
524  }
525  }
526 
527  // FIXME: If we knew where the '=' was, we could easily provide a fix-it
528  // hint here. Alternatively, we could walk the type-source information
529  // for NewParam to find the last source location in the type... but it
530  // isn't worth the effort right now. This is the kind of test case that
531  // is hard to get right:
532  // int f(int);
533  // void g(int (*fp)(int) = f);
534  // void g(int (*fp)(int) = &f);
535  Diag(NewParam->getLocation(), DiagDefaultParamID)
536  << NewParam->getDefaultArgRange();
537 
538  // Look for the function declaration where the default argument was
539  // actually written, which may be a declaration prior to Old.
540  for (auto Older = PrevForDefaultArgs;
541  OldParam->hasInheritedDefaultArg(); /**/) {
542  Older = Older->getPreviousDecl();
543  OldParam = Older->getParamDecl(p);
544  }
545 
546  Diag(OldParam->getLocation(), diag::note_previous_definition)
547  << OldParam->getDefaultArgRange();
548  } else if (OldParamHasDfl) {
549  // Merge the old default argument into the new parameter unless the new
550  // function is a friend declaration in a template class. In the latter
551  // case the default arguments will be inherited when the friend
552  // declaration will be instantiated.
553  if (New->getFriendObjectKind() == Decl::FOK_None ||
555  // It's important to use getInit() here; getDefaultArg()
556  // strips off any top-level ExprWithCleanups.
557  NewParam->setHasInheritedDefaultArg();
558  if (OldParam->hasUnparsedDefaultArg())
559  NewParam->setUnparsedDefaultArg();
560  else if (OldParam->hasUninstantiatedDefaultArg())
561  NewParam->setUninstantiatedDefaultArg(
562  OldParam->getUninstantiatedDefaultArg());
563  else
564  NewParam->setDefaultArg(OldParam->getInit());
565  }
566  } else if (NewParamHasDfl) {
567  if (New->getDescribedFunctionTemplate()) {
568  // Paragraph 4, quoted above, only applies to non-template functions.
569  Diag(NewParam->getLocation(),
570  diag::err_param_default_argument_template_redecl)
571  << NewParam->getDefaultArgRange();
572  Diag(PrevForDefaultArgs->getLocation(),
573  diag::note_template_prev_declaration)
574  << false;
575  } else if (New->getTemplateSpecializationKind()
578  // C++ [temp.expr.spec]p21:
579  // Default function arguments shall not be specified in a declaration
580  // or a definition for one of the following explicit specializations:
581  // - the explicit specialization of a function template;
582  // - the explicit specialization of a member function template;
583  // - the explicit specialization of a member function of a class
584  // template where the class template specialization to which the
585  // member function specialization belongs is implicitly
586  // instantiated.
587  Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
589  << New->getDeclName()
590  << NewParam->getDefaultArgRange();
591  } else if (New->getDeclContext()->isDependentContext()) {
592  // C++ [dcl.fct.default]p6 (DR217):
593  // Default arguments for a member function of a class template shall
594  // be specified on the initial declaration of the member function
595  // within the class template.
596  //
597  // Reading the tea leaves a bit in DR217 and its reference to DR205
598  // leads me to the conclusion that one cannot add default function
599  // arguments for an out-of-line definition of a member function of a
600  // dependent type.
601  int WhichKind = 2;
602  if (CXXRecordDecl *Record
603  = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
604  if (Record->getDescribedClassTemplate())
605  WhichKind = 0;
606  else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
607  WhichKind = 1;
608  else
609  WhichKind = 2;
610  }
611 
612  Diag(NewParam->getLocation(),
613  diag::err_param_default_argument_member_template_redecl)
614  << WhichKind
615  << NewParam->getDefaultArgRange();
616  }
617  }
618  }
619 
620  // DR1344: If a default argument is added outside a class definition and that
621  // default argument makes the function a special member function, the program
622  // is ill-formed. This can only happen for constructors.
623  if (isa<CXXConstructorDecl>(New) &&
625  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
626  OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
627  if (NewSM != OldSM) {
628  ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
629  assert(NewParam->hasDefaultArg());
630  Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
631  << NewParam->getDefaultArgRange() << NewSM;
632  Diag(Old->getLocation(), diag::note_previous_declaration);
633  }
634  }
635 
636  const FunctionDecl *Def;
637  // C++11 [dcl.constexpr]p1: If any declaration of a function or function
638  // template has a constexpr specifier then all its declarations shall
639  // contain the constexpr specifier.
640  if (New->isConstexpr() != Old->isConstexpr()) {
641  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
642  << New << New->isConstexpr();
643  Diag(Old->getLocation(), diag::note_previous_declaration);
644  Invalid = true;
645  } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
646  Old->isDefined(Def) &&
647  // If a friend function is inlined but does not have 'inline'
648  // specifier, it is a definition. Do not report attribute conflict
649  // in this case, redefinition will be diagnosed later.
650  (New->isInlineSpecified() ||
651  New->getFriendObjectKind() == Decl::FOK_None)) {
652  // C++11 [dcl.fcn.spec]p4:
653  // If the definition of a function appears in a translation unit before its
654  // first declaration as inline, the program is ill-formed.
655  Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
656  Diag(Def->getLocation(), diag::note_previous_definition);
657  Invalid = true;
658  }
659 
660  // FIXME: It's not clear what should happen if multiple declarations of a
661  // deduction guide have different explicitness. For now at least we simply
662  // reject any case where the explicitness changes.
663  auto *NewGuide = dyn_cast<CXXDeductionGuideDecl>(New);
664  if (NewGuide && NewGuide->isExplicitSpecified() !=
665  cast<CXXDeductionGuideDecl>(Old)->isExplicitSpecified()) {
666  Diag(New->getLocation(), diag::err_deduction_guide_explicit_mismatch)
667  << NewGuide->isExplicitSpecified();
668  Diag(Old->getLocation(), diag::note_previous_declaration);
669  }
670 
671  // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
672  // argument expression, that declaration shall be a definition and shall be
673  // the only declaration of the function or function template in the
674  // translation unit.
677  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
678  Diag(Old->getLocation(), diag::note_previous_declaration);
679  Invalid = true;
680  }
681 
682  return Invalid;
683 }
684 
685 NamedDecl *
687  MultiTemplateParamsArg TemplateParamLists) {
688  assert(D.isDecompositionDeclarator());
690 
691  // The syntax only allows a decomposition declarator as a simple-declaration,
692  // a for-range-declaration, or a condition in Clang, but we parse it in more
693  // cases than that.
695  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
696  << Decomp.getSourceRange();
697  return nullptr;
698  }
699 
700  if (!TemplateParamLists.empty()) {
701  // FIXME: There's no rule against this, but there are also no rules that
702  // would actually make it usable, so we reject it for now.
703  Diag(TemplateParamLists.front()->getTemplateLoc(),
704  diag::err_decomp_decl_template);
705  return nullptr;
706  }
707 
708  Diag(Decomp.getLSquareLoc(),
709  !getLangOpts().CPlusPlus17
710  ? diag::ext_decomp_decl
712  ? diag::ext_decomp_decl_cond
713  : diag::warn_cxx14_compat_decomp_decl)
714  << Decomp.getSourceRange();
715 
716  // The semantic context is always just the current context.
717  DeclContext *const DC = CurContext;
718 
719  // C++1z [dcl.dcl]/8:
720  // The decl-specifier-seq shall contain only the type-specifier auto
721  // and cv-qualifiers.
722  auto &DS = D.getDeclSpec();
723  {
724  SmallVector<StringRef, 8> BadSpecifiers;
725  SmallVector<SourceLocation, 8> BadSpecifierLocs;
726  if (auto SCS = DS.getStorageClassSpec()) {
727  BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
728  BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
729  }
730  if (auto TSCS = DS.getThreadStorageClassSpec()) {
731  BadSpecifiers.push_back(DeclSpec::getSpecifierName(TSCS));
732  BadSpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
733  }
734  if (DS.isConstexprSpecified()) {
735  BadSpecifiers.push_back("constexpr");
736  BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
737  }
738  if (DS.isInlineSpecified()) {
739  BadSpecifiers.push_back("inline");
740  BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
741  }
742  if (!BadSpecifiers.empty()) {
743  auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
744  Err << (int)BadSpecifiers.size()
745  << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
746  // Don't add FixItHints to remove the specifiers; we do still respect
747  // them when building the underlying variable.
748  for (auto Loc : BadSpecifierLocs)
749  Err << SourceRange(Loc, Loc);
750  }
751  // We can't recover from it being declared as a typedef.
752  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
753  return nullptr;
754  }
755 
756  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
757  QualType R = TInfo->getType();
758 
759  if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
760  UPPC_DeclarationType))
761  D.setInvalidType();
762 
763  // The syntax only allows a single ref-qualifier prior to the decomposition
764  // declarator. No other declarator chunks are permitted. Also check the type
765  // specifier here.
766  if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
767  D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
768  (D.getNumTypeObjects() == 1 &&
770  Diag(Decomp.getLSquareLoc(),
771  (D.hasGroupingParens() ||
772  (D.getNumTypeObjects() &&
774  ? diag::err_decomp_decl_parens
775  : diag::err_decomp_decl_type)
776  << R;
777 
778  // In most cases, there's no actual problem with an explicitly-specified
779  // type, but a function type won't work here, and ActOnVariableDeclarator
780  // shouldn't be called for such a type.
781  if (R->isFunctionType())
782  D.setInvalidType();
783  }
784 
785  // Build the BindingDecls.
787 
788  // Build the BindingDecls.
789  for (auto &B : D.getDecompositionDeclarator().bindings()) {
790  // Check for name conflicts.
791  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
792  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
793  ForVisibleRedeclaration);
794  LookupName(Previous, S,
795  /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
796 
797  // It's not permitted to shadow a template parameter name.
798  if (Previous.isSingleResult() &&
799  Previous.getFoundDecl()->isTemplateParameter()) {
800  DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
801  Previous.getFoundDecl());
802  Previous.clear();
803  }
804 
805  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
806  DS.getStorageClassSpec() == DeclSpec::SCS_extern;
807  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
808  /*AllowInlineNamespace*/false);
809  if (!Previous.empty()) {
810  auto *Old = Previous.getRepresentativeDecl();
811  Diag(B.NameLoc, diag::err_redefinition) << B.Name;
812  Diag(Old->getLocation(), diag::note_previous_definition);
813  }
814 
815  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
816  PushOnScopeChains(BD, S, true);
817  Bindings.push_back(BD);
818  ParsingInitForAutoVars.insert(BD);
819  }
820 
821  // There are no prior lookup results for the variable itself, because it
822  // is unnamed.
823  DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
824  Decomp.getLSquareLoc());
825  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
826  ForVisibleRedeclaration);
827 
828  // Build the variable that holds the non-decomposed object.
829  bool AddToScope = true;
830  NamedDecl *New =
831  ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
832  MultiTemplateParamsArg(), AddToScope, Bindings);
833  if (AddToScope) {
834  S->AddDecl(New);
835  CurContext->addHiddenDecl(New);
836  }
837 
838  if (isInOpenMPDeclareTargetContext())
839  checkDeclIsAllowedInOpenMPTarget(nullptr, New);
840 
841  return New;
842 }
843 
845  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
846  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
847  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
848  if ((int64_t)Bindings.size() != NumElems) {
849  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
850  << DecompType << (unsigned)Bindings.size() << NumElems.toString(10)
851  << (NumElems < Bindings.size());
852  return true;
853  }
854 
855  unsigned I = 0;
856  for (auto *B : Bindings) {
857  SourceLocation Loc = B->getLocation();
858  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
859  if (E.isInvalid())
860  return true;
861  E = GetInit(Loc, E.get(), I++);
862  if (E.isInvalid())
863  return true;
864  B->setBinding(ElemType, E.get());
865  }
866 
867  return false;
868 }
869 
871  ArrayRef<BindingDecl *> Bindings,
872  ValueDecl *Src, QualType DecompType,
873  const llvm::APSInt &NumElems,
874  QualType ElemType) {
876  S, Bindings, Src, DecompType, NumElems, ElemType,
877  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
878  ExprResult E = S.ActOnIntegerConstant(Loc, I);
879  if (E.isInvalid())
880  return ExprError();
881  return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
882  });
883 }
884 
886  ValueDecl *Src, QualType DecompType,
887  const ConstantArrayType *CAT) {
888  return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
889  llvm::APSInt(CAT->getSize()),
890  CAT->getElementType());
891 }
892 
894  ValueDecl *Src, QualType DecompType,
895  const VectorType *VT) {
897  S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
899  DecompType.getQualifiers()));
900 }
901 
903  ArrayRef<BindingDecl *> Bindings,
904  ValueDecl *Src, QualType DecompType,
905  const ComplexType *CT) {
907  S, Bindings, Src, DecompType, llvm::APSInt::get(2),
909  DecompType.getQualifiers()),
910  [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
911  return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
912  });
913 }
914 
916  TemplateArgumentListInfo &Args) {
917  SmallString<128> SS;
918  llvm::raw_svector_ostream OS(SS);
919  bool First = true;
920  for (auto &Arg : Args.arguments()) {
921  if (!First)
922  OS << ", ";
923  Arg.getArgument().print(PrintingPolicy, OS);
924  First = false;
925  }
926  return OS.str();
927 }
928 
929 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
930  SourceLocation Loc, StringRef Trait,
932  unsigned DiagID) {
933  auto DiagnoseMissing = [&] {
934  if (DiagID)
935  S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
936  Args);
937  return true;
938  };
939 
940  // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
942  if (!Std)
943  return DiagnoseMissing();
944 
945  // Look up the trait itself, within namespace std. We can diagnose various
946  // problems with this lookup even if we've been asked to not diagnose a
947  // missing specialization, because this can only fail if the user has been
948  // declaring their own names in namespace std or we don't support the
949  // standard library implementation in use.
952  if (!S.LookupQualifiedName(Result, Std))
953  return DiagnoseMissing();
954  if (Result.isAmbiguous())
955  return true;
956 
957  ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
958  if (!TraitTD) {
959  Result.suppressDiagnostics();
960  NamedDecl *Found = *Result.begin();
961  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
962  S.Diag(Found->getLocation(), diag::note_declared_at);
963  return true;
964  }
965 
966  // Build the template-id.
967  QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
968  if (TraitTy.isNull())
969  return true;
970  if (!S.isCompleteType(Loc, TraitTy)) {
971  if (DiagID)
973  Loc, TraitTy, DiagID,
975  return true;
976  }
977 
978  CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
979  assert(RD && "specialization of class template is not a class?");
980 
981  // Look up the member of the trait type.
982  S.LookupQualifiedName(TraitMemberLookup, RD);
983  return TraitMemberLookup.isAmbiguous();
984 }
985 
986 static TemplateArgumentLoc
988  uint64_t I) {
989  TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
990  return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
991 }
992 
993 static TemplateArgumentLoc
996 }
997 
998 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
999 
1001  llvm::APSInt &Size) {
1004 
1006  LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1007 
1008  // Form template argument list for tuple_size<T>.
1009  TemplateArgumentListInfo Args(Loc, Loc);
1011 
1012  // If there's no tuple_size specialization, it's not tuple-like.
1013  if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/0))
1014  return IsTupleLike::NotTupleLike;
1015 
1016  // If we get this far, we've committed to the tuple interpretation, but
1017  // we can still fail if there actually isn't a usable ::value.
1018 
1019  struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1020  LookupResult &R;
1022  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1023  : R(R), Args(Args) {}
1024  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) {
1025  S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1027  }
1028  } Diagnoser(R, Args);
1029 
1030  if (R.empty()) {
1031  Diagnoser.diagnoseNotICE(S, Loc, SourceRange());
1032  return IsTupleLike::Error;
1033  }
1034 
1035  ExprResult E =
1036  S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1037  if (E.isInvalid())
1038  return IsTupleLike::Error;
1039 
1040  E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser, false);
1041  if (E.isInvalid())
1042  return IsTupleLike::Error;
1043 
1044  return IsTupleLike::TupleLike;
1045 }
1046 
1047 /// \return std::tuple_element<I, T>::type.
1049  unsigned I, QualType T) {
1050  // Form template argument list for tuple_element<I, T>.
1051  TemplateArgumentListInfo Args(Loc, Loc);
1052  Args.addArgument(
1055 
1056  DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1057  LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1059  S, R, Loc, "tuple_element", Args,
1060  diag::err_decomp_decl_std_tuple_element_not_specialized))
1061  return QualType();
1062 
1063  auto *TD = R.getAsSingle<TypeDecl>();
1064  if (!TD) {
1065  R.suppressDiagnostics();
1066  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1068  if (!R.empty())
1069  S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1070  return QualType();
1071  }
1072 
1073  return S.Context.getTypeDeclType(TD);
1074 }
1075 
1076 namespace {
1077 struct BindingDiagnosticTrap {
1078  Sema &S;
1079  DiagnosticErrorTrap Trap;
1080  BindingDecl *BD;
1081 
1082  BindingDiagnosticTrap(Sema &S, BindingDecl *BD)
1083  : S(S), Trap(S.Diags), BD(BD) {}
1084  ~BindingDiagnosticTrap() {
1085  if (Trap.hasErrorOccurred())
1086  S.Diag(BD->getLocation(), diag::note_in_binding_decl_init) << BD;
1087  }
1088 };
1089 }
1090 
1092  ArrayRef<BindingDecl *> Bindings,
1093  VarDecl *Src, QualType DecompType,
1094  const llvm::APSInt &TupleSize) {
1095  if ((int64_t)Bindings.size() != TupleSize) {
1096  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1097  << DecompType << (unsigned)Bindings.size() << TupleSize.toString(10)
1098  << (TupleSize < Bindings.size());
1099  return true;
1100  }
1101 
1102  if (Bindings.empty())
1103  return false;
1104 
1105  DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1106 
1107  // [dcl.decomp]p3:
1108  // The unqualified-id get is looked up in the scope of E by class member
1109  // access lookup ...
1110  LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1111  bool UseMemberGet = false;
1112  if (S.isCompleteType(Src->getLocation(), DecompType)) {
1113  if (auto *RD = DecompType->getAsCXXRecordDecl())
1114  S.LookupQualifiedName(MemberGet, RD);
1115  if (MemberGet.isAmbiguous())
1116  return true;
1117  // ... and if that finds at least one declaration that is a function
1118  // template whose first template parameter is a non-type parameter ...
1119  for (NamedDecl *D : MemberGet) {
1120  if (FunctionTemplateDecl *FTD =
1121  dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1122  TemplateParameterList *TPL = FTD->getTemplateParameters();
1123  if (TPL->size() != 0 &&
1124  isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1125  // ... the initializer is e.get<i>().
1126  UseMemberGet = true;
1127  break;
1128  }
1129  }
1130  }
1131  }
1132 
1133  unsigned I = 0;
1134  for (auto *B : Bindings) {
1135  BindingDiagnosticTrap Trap(S, B);
1136  SourceLocation Loc = B->getLocation();
1137 
1138  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1139  if (E.isInvalid())
1140  return true;
1141 
1142  // e is an lvalue if the type of the entity is an lvalue reference and
1143  // an xvalue otherwise
1144  if (!Src->getType()->isLValueReferenceType())
1145  E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1146  E.get(), nullptr, VK_XValue);
1147 
1148  TemplateArgumentListInfo Args(Loc, Loc);
1149  Args.addArgument(
1151 
1152  if (UseMemberGet) {
1153  // if [lookup of member get] finds at least one declaration, the
1154  // initializer is e.get<i-1>().
1155  E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1156  CXXScopeSpec(), SourceLocation(), nullptr,
1157  MemberGet, &Args, nullptr);
1158  if (E.isInvalid())
1159  return true;
1160 
1161  E = S.ActOnCallExpr(nullptr, E.get(), Loc, None, Loc);
1162  } else {
1163  // Otherwise, the initializer is get<i-1>(e), where get is looked up
1164  // in the associated namespaces.
1167  DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1169 
1170  Expr *Arg = E.get();
1171  E = S.ActOnCallExpr(nullptr, Get, Loc, Arg, Loc);
1172  }
1173  if (E.isInvalid())
1174  return true;
1175  Expr *Init = E.get();
1176 
1177  // Given the type T designated by std::tuple_element<i - 1, E>::type,
1178  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1179  if (T.isNull())
1180  return true;
1181 
1182  // each vi is a variable of type "reference to T" initialized with the
1183  // initializer, where the reference is an lvalue reference if the
1184  // initializer is an lvalue and an rvalue reference otherwise
1185  QualType RefType =
1186  S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1187  if (RefType.isNull())
1188  return true;
1189  auto *RefVD = VarDecl::Create(
1190  S.Context, Src->getDeclContext(), Loc, Loc,
1191  B->getDeclName().getAsIdentifierInfo(), RefType,
1194  RefVD->setTSCSpec(Src->getTSCSpec());
1195  RefVD->setImplicit();
1196  if (Src->isInlineSpecified())
1197  RefVD->setInlineSpecified();
1198  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1199 
1202  InitializationSequence Seq(S, Entity, Kind, Init);
1203  E = Seq.Perform(S, Entity, Kind, Init);
1204  if (E.isInvalid())
1205  return true;
1206  E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1207  if (E.isInvalid())
1208  return true;
1209  RefVD->setInit(E.get());
1210  RefVD->checkInitIsICE();
1211 
1213  DeclarationNameInfo(B->getDeclName(), Loc),
1214  RefVD);
1215  if (E.isInvalid())
1216  return true;
1217 
1218  B->setBinding(T, E.get());
1219  I++;
1220  }
1221 
1222  return false;
1223 }
1224 
1225 /// Find the base class to decompose in a built-in decomposition of a class type.
1226 /// This base class search is, unfortunately, not quite like any other that we
1227 /// perform anywhere else in C++.
1229  const CXXRecordDecl *RD,
1230  CXXCastPath &BasePath) {
1231  auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1232  CXXBasePath &Path) {
1233  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1234  };
1235 
1236  const CXXRecordDecl *ClassWithFields = nullptr;
1238  if (RD->hasDirectFields())
1239  // [dcl.decomp]p4:
1240  // Otherwise, all of E's non-static data members shall be public direct
1241  // members of E ...
1242  ClassWithFields = RD;
1243  else {
1244  // ... or of ...
1245  CXXBasePaths Paths;
1246  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1247  if (!RD->lookupInBases(BaseHasFields, Paths)) {
1248  // If no classes have fields, just decompose RD itself. (This will work
1249  // if and only if zero bindings were provided.)
1250  return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1251  }
1252 
1253  CXXBasePath *BestPath = nullptr;
1254  for (auto &P : Paths) {
1255  if (!BestPath)
1256  BestPath = &P;
1257  else if (!S.Context.hasSameType(P.back().Base->getType(),
1258  BestPath->back().Base->getType())) {
1259  // ... the same ...
1260  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1261  << false << RD << BestPath->back().Base->getType()
1262  << P.back().Base->getType();
1263  return DeclAccessPair();
1264  } else if (P.Access < BestPath->Access) {
1265  BestPath = &P;
1266  }
1267  }
1268 
1269  // ... unambiguous ...
1270  QualType BaseType = BestPath->back().Base->getType();
1271  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1272  S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1273  << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1274  return DeclAccessPair();
1275  }
1276 
1277  // ... [accessible, implied by other rules] base class of E.
1278  S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1279  *BestPath, diag::err_decomp_decl_inaccessible_base);
1280  AS = BestPath->Access;
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 DeclAccessPair();
1294  }
1295 
1296  return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1297 }
1298 
1300  ValueDecl *Src, QualType DecompType,
1301  const CXXRecordDecl *OrigRD) {
1302  if (S.RequireCompleteType(Src->getLocation(), DecompType,
1303  diag::err_incomplete_type))
1304  return true;
1305 
1306  CXXCastPath BasePath;
1307  DeclAccessPair BasePair =
1308  findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1309  const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1310  if (!RD)
1311  return true;
1313  DecompType.getQualifiers());
1314 
1315  auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1316  unsigned NumFields =
1317  std::count_if(RD->field_begin(), RD->field_end(),
1318  [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1319  assert(Bindings.size() != NumFields);
1320  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1321  << DecompType << (unsigned)Bindings.size() << NumFields
1322  << (NumFields < Bindings.size());
1323  return true;
1324  };
1325 
1326  // all of E's non-static data members shall be [...] well-formed
1327  // when named as e.name in the context of the structured binding,
1328  // E shall not have an anonymous union member, ...
1329  unsigned I = 0;
1330  for (auto *FD : RD->fields()) {
1331  if (FD->isUnnamedBitfield())
1332  continue;
1333 
1334  if (FD->isAnonymousStructOrUnion()) {
1335  S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1336  << DecompType << FD->getType()->isUnionType();
1337  S.Diag(FD->getLocation(), diag::note_declared_at);
1338  return true;
1339  }
1340 
1341  // We have a real field to bind.
1342  if (I >= Bindings.size())
1343  return DiagnoseBadNumberOfBindings();
1344  auto *B = Bindings[I++];
1345  SourceLocation Loc = B->getLocation();
1346 
1347  // The field must be accessible in the context of the structured binding.
1348  // We already checked that the base class is accessible.
1349  // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1350  // const_cast here.
1352  Loc, const_cast<CXXRecordDecl *>(OrigRD),
1354  BasePair.getAccess(), FD->getAccess())));
1355 
1356  // Initialize the binding to Src.FD.
1357  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1358  if (E.isInvalid())
1359  return true;
1360  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1361  VK_LValue, &BasePath);
1362  if (E.isInvalid())
1363  return true;
1364  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1365  CXXScopeSpec(), FD,
1366  DeclAccessPair::make(FD, FD->getAccess()),
1367  DeclarationNameInfo(FD->getDeclName(), Loc));
1368  if (E.isInvalid())
1369  return true;
1370 
1371  // If the type of the member is T, the referenced type is cv T, where cv is
1372  // the cv-qualification of the decomposition expression.
1373  //
1374  // FIXME: We resolve a defect here: if the field is mutable, we do not add
1375  // 'const' to the type of the field.
1376  Qualifiers Q = DecompType.getQualifiers();
1377  if (FD->isMutable())
1378  Q.removeConst();
1379  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1380  }
1381 
1382  if (I != Bindings.size())
1383  return DiagnoseBadNumberOfBindings();
1384 
1385  return false;
1386 }
1387 
1389  QualType DecompType = DD->getType();
1390 
1391  // If the type of the decomposition is dependent, then so is the type of
1392  // each binding.
1393  if (DecompType->isDependentType()) {
1394  for (auto *B : DD->bindings())
1395  B->setType(Context.DependentTy);
1396  return;
1397  }
1398 
1399  DecompType = DecompType.getNonReferenceType();
1400  ArrayRef<BindingDecl*> Bindings = DD->bindings();
1401 
1402  // C++1z [dcl.decomp]/2:
1403  // If E is an array type [...]
1404  // As an extension, we also support decomposition of built-in complex and
1405  // vector types.
1406  if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1407  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1408  DD->setInvalidDecl();
1409  return;
1410  }
1411  if (auto *VT = DecompType->getAs<VectorType>()) {
1412  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1413  DD->setInvalidDecl();
1414  return;
1415  }
1416  if (auto *CT = DecompType->getAs<ComplexType>()) {
1417  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1418  DD->setInvalidDecl();
1419  return;
1420  }
1421 
1422  // C++1z [dcl.decomp]/3:
1423  // if the expression std::tuple_size<E>::value is a well-formed integral
1424  // constant expression, [...]
1425  llvm::APSInt TupleSize(32);
1426  switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1427  case IsTupleLike::Error:
1428  DD->setInvalidDecl();
1429  return;
1430 
1431  case IsTupleLike::TupleLike:
1432  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1433  DD->setInvalidDecl();
1434  return;
1435 
1436  case IsTupleLike::NotTupleLike:
1437  break;
1438  }
1439 
1440  // C++1z [dcl.dcl]/8:
1441  // [E shall be of array or non-union class type]
1442  CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1443  if (!RD || RD->isUnion()) {
1444  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1445  << DD << !RD << DecompType;
1446  DD->setInvalidDecl();
1447  return;
1448  }
1449 
1450  // C++1z [dcl.decomp]/4:
1451  // all of E's non-static data members shall be [...] direct members of
1452  // E or of the same unambiguous public base class of E, ...
1453  if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1454  DD->setInvalidDecl();
1455 }
1456 
1457 /// Merge the exception specifications of two variable declarations.
1458 ///
1459 /// This is called when there's a redeclaration of a VarDecl. The function
1460 /// checks if the redeclaration might have an exception specification and
1461 /// validates compatibility and merges the specs if necessary.
1463  // Shortcut if exceptions are disabled.
1464  if (!getLangOpts().CXXExceptions)
1465  return;
1466 
1467  assert(Context.hasSameType(New->getType(), Old->getType()) &&
1468  "Should only be called if types are otherwise the same.");
1469 
1470  QualType NewType = New->getType();
1471  QualType OldType = Old->getType();
1472 
1473  // We're only interested in pointers and references to functions, as well
1474  // as pointers to member functions.
1475  if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1476  NewType = R->getPointeeType();
1477  OldType = OldType->getAs<ReferenceType>()->getPointeeType();
1478  } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1479  NewType = P->getPointeeType();
1480  OldType = OldType->getAs<PointerType>()->getPointeeType();
1481  } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1482  NewType = M->getPointeeType();
1483  OldType = OldType->getAs<MemberPointerType>()->getPointeeType();
1484  }
1485 
1486  if (!NewType->isFunctionProtoType())
1487  return;
1488 
1489  // There's lots of special cases for functions. For function pointers, system
1490  // libraries are hopefully not as broken so that we don't need these
1491  // workarounds.
1492  if (CheckEquivalentExceptionSpec(
1493  OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1494  NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1495  New->setInvalidDecl();
1496  }
1497 }
1498 
1499 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1500 /// function declaration are well-formed according to C++
1501 /// [dcl.fct.default].
1503  unsigned NumParams = FD->getNumParams();
1504  unsigned p;
1505 
1506  // Find first parameter with a default argument
1507  for (p = 0; p < NumParams; ++p) {
1508  ParmVarDecl *Param = FD->getParamDecl(p);
1509  if (Param->hasDefaultArg())
1510  break;
1511  }
1512 
1513  // C++11 [dcl.fct.default]p4:
1514  // In a given function declaration, each parameter subsequent to a parameter
1515  // with a default argument shall have a default argument supplied in this or
1516  // a previous declaration or shall be a function parameter pack. A default
1517  // argument shall not be redefined by a later declaration (not even to the
1518  // same value).
1519  unsigned LastMissingDefaultArg = 0;
1520  for (; p < NumParams; ++p) {
1521  ParmVarDecl *Param = FD->getParamDecl(p);
1522  if (!Param->hasDefaultArg() && !Param->isParameterPack()) {
1523  if (Param->isInvalidDecl())
1524  /* We already complained about this parameter. */;
1525  else if (Param->getIdentifier())
1526  Diag(Param->getLocation(),
1527  diag::err_param_default_argument_missing_name)
1528  << Param->getIdentifier();
1529  else
1530  Diag(Param->getLocation(),
1531  diag::err_param_default_argument_missing);
1532 
1533  LastMissingDefaultArg = p;
1534  }
1535  }
1536 
1537  if (LastMissingDefaultArg > 0) {
1538  // Some default arguments were missing. Clear out all of the
1539  // default arguments up to (and including) the last missing
1540  // default argument, so that we leave the function parameters
1541  // in a semantically valid state.
1542  for (p = 0; p <= LastMissingDefaultArg; ++p) {
1543  ParmVarDecl *Param = FD->getParamDecl(p);
1544  if (Param->hasDefaultArg()) {
1545  Param->setDefaultArg(nullptr);
1546  }
1547  }
1548  }
1549 }
1550 
1551 // CheckConstexprParameterTypes - Check whether a function's parameter types
1552 // are all literal types. If so, return true. If not, produce a suitable
1553 // diagnostic and return false.
1554 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1555  const FunctionDecl *FD) {
1556  unsigned ArgIndex = 0;
1557  const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
1559  e = FT->param_type_end();
1560  i != e; ++i, ++ArgIndex) {
1561  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1562  SourceLocation ParamLoc = PD->getLocation();
1563  if (!(*i)->isDependentType() &&
1564  SemaRef.RequireLiteralType(ParamLoc, *i,
1565  diag::err_constexpr_non_literal_param,
1566  ArgIndex+1, PD->getSourceRange(),
1567  isa<CXXConstructorDecl>(FD)))
1568  return false;
1569  }
1570  return true;
1571 }
1572 
1573 /// Get diagnostic %select index for tag kind for
1574 /// record diagnostic message.
1575 /// WARNING: Indexes apply to particular diagnostics only!
1576 ///
1577 /// \returns diagnostic %select index.
1579  switch (Tag) {
1580  case TTK_Struct: return 0;
1581  case TTK_Interface: return 1;
1582  case TTK_Class: return 2;
1583  default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1584  }
1585 }
1586 
1587 // CheckConstexprFunctionDecl - Check whether a function declaration satisfies
1588 // the requirements of a constexpr function definition or a constexpr
1589 // constructor definition. If so, return true. If not, produce appropriate
1590 // diagnostics and return false.
1591 //
1592 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1594  const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1595  if (MD && MD->isInstance()) {
1596  // C++11 [dcl.constexpr]p4:
1597  // The definition of a constexpr constructor shall satisfy the following
1598  // constraints:
1599  // - the class shall not have any virtual base classes;
1600  const CXXRecordDecl *RD = MD->getParent();
1601  if (RD->getNumVBases()) {
1602  Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1603  << isa<CXXConstructorDecl>(NewFD)
1605  for (const auto &I : RD->vbases())
1606  Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1607  << I.getSourceRange();
1608  return false;
1609  }
1610  }
1611 
1612  if (!isa<CXXConstructorDecl>(NewFD)) {
1613  // C++11 [dcl.constexpr]p3:
1614  // The definition of a constexpr function shall satisfy the following
1615  // constraints:
1616  // - it shall not be virtual;
1617  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1618  if (Method && Method->isVirtual()) {
1619  Method = Method->getCanonicalDecl();
1620  Diag(Method->getLocation(), diag::err_constexpr_virtual);
1621 
1622  // If it's not obvious why this function is virtual, find an overridden
1623  // function which uses the 'virtual' keyword.
1624  const CXXMethodDecl *WrittenVirtual = Method;
1625  while (!WrittenVirtual->isVirtualAsWritten())
1626  WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1627  if (WrittenVirtual != Method)
1628  Diag(WrittenVirtual->getLocation(),
1629  diag::note_overridden_virtual_function);
1630  return false;
1631  }
1632 
1633  // - its return type shall be a literal type;
1634  QualType RT = NewFD->getReturnType();
1635  if (!RT->isDependentType() &&
1636  RequireLiteralType(NewFD->getLocation(), RT,
1637  diag::err_constexpr_non_literal_return))
1638  return false;
1639  }
1640 
1641  // - each of its parameter types shall be a literal type;
1642  if (!CheckConstexprParameterTypes(*this, NewFD))
1643  return false;
1644 
1645  return true;
1646 }
1647 
1648 /// Check the given declaration statement is legal within a constexpr function
1649 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1650 ///
1651 /// \return true if the body is OK (maybe only as an extension), false if we
1652 /// have diagnosed a problem.
1653 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1654  DeclStmt *DS, SourceLocation &Cxx1yLoc) {
1655  // C++11 [dcl.constexpr]p3 and p4:
1656  // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1657  // contain only
1658  for (const auto *DclIt : DS->decls()) {
1659  switch (DclIt->getKind()) {
1660  case Decl::StaticAssert:
1661  case Decl::Using:
1662  case Decl::UsingShadow:
1663  case Decl::UsingDirective:
1664  case Decl::UnresolvedUsingTypename:
1665  case Decl::UnresolvedUsingValue:
1666  // - static_assert-declarations
1667  // - using-declarations,
1668  // - using-directives,
1669  continue;
1670 
1671  case Decl::Typedef:
1672  case Decl::TypeAlias: {
1673  // - typedef declarations and alias-declarations that do not define
1674  // classes or enumerations,
1675  const auto *TN = cast<TypedefNameDecl>(DclIt);
1676  if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1677  // Don't allow variably-modified types in constexpr functions.
1678  TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1679  SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1680  << TL.getSourceRange() << TL.getType()
1681  << isa<CXXConstructorDecl>(Dcl);
1682  return false;
1683  }
1684  continue;
1685  }
1686 
1687  case Decl::Enum:
1688  case Decl::CXXRecord:
1689  // C++1y allows types to be defined, not just declared.
1690  if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition())
1691  SemaRef.Diag(DS->getBeginLoc(),
1692  SemaRef.getLangOpts().CPlusPlus14
1693  ? diag::warn_cxx11_compat_constexpr_type_definition
1694  : diag::ext_constexpr_type_definition)
1695  << isa<CXXConstructorDecl>(Dcl);
1696  continue;
1697 
1698  case Decl::EnumConstant:
1699  case Decl::IndirectField:
1700  case Decl::ParmVar:
1701  // These can only appear with other declarations which are banned in
1702  // C++11 and permitted in C++1y, so ignore them.
1703  continue;
1704 
1705  case Decl::Var:
1706  case Decl::Decomposition: {
1707  // C++1y [dcl.constexpr]p3 allows anything except:
1708  // a definition of a variable of non-literal type or of static or
1709  // thread storage duration or for which no initialization is performed.
1710  const auto *VD = cast<VarDecl>(DclIt);
1711  if (VD->isThisDeclarationADefinition()) {
1712  if (VD->isStaticLocal()) {
1713  SemaRef.Diag(VD->getLocation(),
1714  diag::err_constexpr_local_var_static)
1715  << isa<CXXConstructorDecl>(Dcl)
1716  << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1717  return false;
1718  }
1719  if (!VD->getType()->isDependentType() &&
1720  SemaRef.RequireLiteralType(
1721  VD->getLocation(), VD->getType(),
1722  diag::err_constexpr_local_var_non_literal_type,
1723  isa<CXXConstructorDecl>(Dcl)))
1724  return false;
1725  if (!VD->getType()->isDependentType() &&
1726  !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1727  SemaRef.Diag(VD->getLocation(),
1728  diag::err_constexpr_local_var_no_init)
1729  << isa<CXXConstructorDecl>(Dcl);
1730  return false;
1731  }
1732  }
1733  SemaRef.Diag(VD->getLocation(),
1734  SemaRef.getLangOpts().CPlusPlus14
1735  ? diag::warn_cxx11_compat_constexpr_local_var
1736  : diag::ext_constexpr_local_var)
1737  << isa<CXXConstructorDecl>(Dcl);
1738  continue;
1739  }
1740 
1741  case Decl::NamespaceAlias:
1742  case Decl::Function:
1743  // These are disallowed in C++11 and permitted in C++1y. Allow them
1744  // everywhere as an extension.
1745  if (!Cxx1yLoc.isValid())
1746  Cxx1yLoc = DS->getBeginLoc();
1747  continue;
1748 
1749  default:
1750  SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1751  << isa<CXXConstructorDecl>(Dcl);
1752  return false;
1753  }
1754  }
1755 
1756  return true;
1757 }
1758 
1759 /// Check that the given field is initialized within a constexpr constructor.
1760 ///
1761 /// \param Dcl The constexpr constructor being checked.
1762 /// \param Field The field being checked. This may be a member of an anonymous
1763 /// struct or union nested within the class being checked.
1764 /// \param Inits All declarations, including anonymous struct/union members and
1765 /// indirect members, for which any initialization was provided.
1766 /// \param Diagnosed Set to true if an error is produced.
1768  const FunctionDecl *Dcl,
1769  FieldDecl *Field,
1770  llvm::SmallSet<Decl*, 16> &Inits,
1771  bool &Diagnosed) {
1772  if (Field->isInvalidDecl())
1773  return;
1774 
1775  if (Field->isUnnamedBitfield())
1776  return;
1777 
1778  // Anonymous unions with no variant members and empty anonymous structs do not
1779  // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1780  // indirect fields don't need initializing.
1781  if (Field->isAnonymousStructOrUnion() &&
1782  (Field->getType()->isUnionType()
1783  ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1784  : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1785  return;
1786 
1787  if (!Inits.count(Field)) {
1788  if (!Diagnosed) {
1789  SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init);
1790  Diagnosed = true;
1791  }
1792  SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init);
1793  } else if (Field->isAnonymousStructOrUnion()) {
1794  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1795  for (auto *I : RD->fields())
1796  // If an anonymous union contains an anonymous struct of which any member
1797  // is initialized, all members must be initialized.
1798  if (!RD->isUnion() || Inits.count(I))
1799  CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed);
1800  }
1801 }
1802 
1803 /// Check the provided statement is allowed in a constexpr function
1804 /// definition.
1805 static bool
1807  SmallVectorImpl<SourceLocation> &ReturnStmts,
1808  SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc) {
1809  // - its function-body shall be [...] a compound-statement that contains only
1810  switch (S->getStmtClass()) {
1811  case Stmt::NullStmtClass:
1812  // - null statements,
1813  return true;
1814 
1815  case Stmt::DeclStmtClass:
1816  // - static_assert-declarations
1817  // - using-declarations,
1818  // - using-directives,
1819  // - typedef declarations and alias-declarations that do not define
1820  // classes or enumerations,
1821  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc))
1822  return false;
1823  return true;
1824 
1825  case Stmt::ReturnStmtClass:
1826  // - and exactly one return statement;
1827  if (isa<CXXConstructorDecl>(Dcl)) {
1828  // C++1y allows return statements in constexpr constructors.
1829  if (!Cxx1yLoc.isValid())
1830  Cxx1yLoc = S->getBeginLoc();
1831  return true;
1832  }
1833 
1834  ReturnStmts.push_back(S->getBeginLoc());
1835  return true;
1836 
1837  case Stmt::CompoundStmtClass: {
1838  // C++1y allows compound-statements.
1839  if (!Cxx1yLoc.isValid())
1840  Cxx1yLoc = S->getBeginLoc();
1841 
1842  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
1843  for (auto *BodyIt : CompStmt->body()) {
1844  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
1845  Cxx1yLoc, Cxx2aLoc))
1846  return false;
1847  }
1848  return true;
1849  }
1850 
1851  case Stmt::AttributedStmtClass:
1852  if (!Cxx1yLoc.isValid())
1853  Cxx1yLoc = S->getBeginLoc();
1854  return true;
1855 
1856  case Stmt::IfStmtClass: {
1857  // C++1y allows if-statements.
1858  if (!Cxx1yLoc.isValid())
1859  Cxx1yLoc = S->getBeginLoc();
1860 
1861  IfStmt *If = cast<IfStmt>(S);
1862  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
1863  Cxx1yLoc, Cxx2aLoc))
1864  return false;
1865  if (If->getElse() &&
1866  !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
1867  Cxx1yLoc, Cxx2aLoc))
1868  return false;
1869  return true;
1870  }
1871 
1872  case Stmt::WhileStmtClass:
1873  case Stmt::DoStmtClass:
1874  case Stmt::ForStmtClass:
1875  case Stmt::CXXForRangeStmtClass:
1876  case Stmt::ContinueStmtClass:
1877  // C++1y allows all of these. We don't allow them as extensions in C++11,
1878  // because they don't make sense without variable mutation.
1879  if (!SemaRef.getLangOpts().CPlusPlus14)
1880  break;
1881  if (!Cxx1yLoc.isValid())
1882  Cxx1yLoc = S->getBeginLoc();
1883  for (Stmt *SubStmt : S->children())
1884  if (SubStmt &&
1885  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1886  Cxx1yLoc, Cxx2aLoc))
1887  return false;
1888  return true;
1889 
1890  case Stmt::SwitchStmtClass:
1891  case Stmt::CaseStmtClass:
1892  case Stmt::DefaultStmtClass:
1893  case Stmt::BreakStmtClass:
1894  // C++1y allows switch-statements, and since they don't need variable
1895  // mutation, we can reasonably allow them in C++11 as an extension.
1896  if (!Cxx1yLoc.isValid())
1897  Cxx1yLoc = S->getBeginLoc();
1898  for (Stmt *SubStmt : S->children())
1899  if (SubStmt &&
1900  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1901  Cxx1yLoc, Cxx2aLoc))
1902  return false;
1903  return true;
1904 
1905  case Stmt::CXXTryStmtClass:
1906  if (Cxx2aLoc.isInvalid())
1907  Cxx2aLoc = S->getBeginLoc();
1908  for (Stmt *SubStmt : S->children()) {
1909  if (SubStmt &&
1910  !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
1911  Cxx1yLoc, Cxx2aLoc))
1912  return false;
1913  }
1914  return true;
1915 
1916  case Stmt::CXXCatchStmtClass:
1917  // Do not bother checking the language mode (already covered by the
1918  // try block check).
1919  if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
1920  cast<CXXCatchStmt>(S)->getHandlerBlock(),
1921  ReturnStmts, Cxx1yLoc, Cxx2aLoc))
1922  return false;
1923  return true;
1924 
1925  default:
1926  if (!isa<Expr>(S))
1927  break;
1928 
1929  // C++1y allows expression-statements.
1930  if (!Cxx1yLoc.isValid())
1931  Cxx1yLoc = S->getBeginLoc();
1932  return true;
1933  }
1934 
1935  SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1936  << isa<CXXConstructorDecl>(Dcl);
1937  return false;
1938 }
1939 
1940 /// Check the body for the given constexpr function declaration only contains
1941 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
1942 ///
1943 /// \return true if the body is OK, false if we have diagnosed a problem.
1945  SmallVector<SourceLocation, 4> ReturnStmts;
1946 
1947  if (isa<CXXTryStmt>(Body)) {
1948  // C++11 [dcl.constexpr]p3:
1949  // The definition of a constexpr function shall satisfy the following
1950  // constraints: [...]
1951  // - its function-body shall be = delete, = default, or a
1952  // compound-statement
1953  //
1954  // C++11 [dcl.constexpr]p4:
1955  // In the definition of a constexpr constructor, [...]
1956  // - its function-body shall not be a function-try-block;
1957  //
1958  // This restriction is lifted in C++2a, as long as inner statements also
1959  // apply the general constexpr rules.
1960  Diag(Body->getBeginLoc(),
1961  !getLangOpts().CPlusPlus2a
1962  ? diag::ext_constexpr_function_try_block_cxx2a
1963  : diag::warn_cxx17_compat_constexpr_function_try_block)
1964  << isa<CXXConstructorDecl>(Dcl);
1965  }
1966 
1967  // - its function-body shall be [...] a compound-statement that contains only
1968  // [... list of cases ...]
1969  //
1970  // Note that walking the children here is enough to properly check for
1971  // CompoundStmt and CXXTryStmt body.
1972  SourceLocation Cxx1yLoc, Cxx2aLoc;
1973  for (Stmt *SubStmt : Body->children()) {
1974  if (SubStmt &&
1975  !CheckConstexprFunctionStmt(*this, Dcl, SubStmt, ReturnStmts,
1976  Cxx1yLoc, Cxx2aLoc))
1977  return false;
1978  }
1979 
1980  if (Cxx2aLoc.isValid())
1981  Diag(Cxx2aLoc,
1982  getLangOpts().CPlusPlus2a
1983  ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
1984  : diag::ext_constexpr_body_invalid_stmt_cxx2a)
1985  << isa<CXXConstructorDecl>(Dcl);
1986  if (Cxx1yLoc.isValid())
1987  Diag(Cxx1yLoc,
1988  getLangOpts().CPlusPlus14
1989  ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
1990  : diag::ext_constexpr_body_invalid_stmt)
1991  << isa<CXXConstructorDecl>(Dcl);
1992 
1993  if (const CXXConstructorDecl *Constructor
1994  = dyn_cast<CXXConstructorDecl>(Dcl)) {
1995  const CXXRecordDecl *RD = Constructor->getParent();
1996  // DR1359:
1997  // - every non-variant non-static data member and base class sub-object
1998  // shall be initialized;
1999  // DR1460:
2000  // - if the class is a union having variant members, exactly one of them
2001  // shall be initialized;
2002  if (RD->isUnion()) {
2003  if (Constructor->getNumCtorInitializers() == 0 &&
2004  RD->hasVariantMembers()) {
2005  Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init);
2006  return false;
2007  }
2008  } else if (!Constructor->isDependentContext() &&
2009  !Constructor->isDelegatingConstructor()) {
2010  assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
2011 
2012  // Skip detailed checking if we have enough initializers, and we would
2013  // allow at most one initializer per member.
2014  bool AnyAnonStructUnionMembers = false;
2015  unsigned Fields = 0;
2017  E = RD->field_end(); I != E; ++I, ++Fields) {
2018  if (I->isAnonymousStructOrUnion()) {
2019  AnyAnonStructUnionMembers = true;
2020  break;
2021  }
2022  }
2023  // DR1460:
2024  // - if the class is a union-like class, but is not a union, for each of
2025  // its anonymous union members having variant members, exactly one of
2026  // them shall be initialized;
2027  if (AnyAnonStructUnionMembers ||
2028  Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2029  // Check initialization of non-static data members. Base classes are
2030  // always initialized so do not need to be checked. Dependent bases
2031  // might not have initializers in the member initializer list.
2032  llvm::SmallSet<Decl*, 16> Inits;
2033  for (const auto *I: Constructor->inits()) {
2034  if (FieldDecl *FD = I->getMember())
2035  Inits.insert(FD);
2036  else if (IndirectFieldDecl *ID = I->getIndirectMember())
2037  Inits.insert(ID->chain_begin(), ID->chain_end());
2038  }
2039 
2040  bool Diagnosed = false;
2041  for (auto *I : RD->fields())
2042  CheckConstexprCtorInitializer(*this, Dcl, I, Inits, Diagnosed);
2043  if (Diagnosed)
2044  return false;
2045  }
2046  }
2047  } else {
2048  if (ReturnStmts.empty()) {
2049  // C++1y doesn't require constexpr functions to contain a 'return'
2050  // statement. We still do, unless the return type might be void, because
2051  // otherwise if there's no return statement, the function cannot
2052  // be used in a core constant expression.
2053  bool OK = getLangOpts().CPlusPlus14 &&
2054  (Dcl->getReturnType()->isVoidType() ||
2055  Dcl->getReturnType()->isDependentType());
2056  Diag(Dcl->getLocation(),
2057  OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2058  : diag::err_constexpr_body_no_return);
2059  if (!OK)
2060  return false;
2061  } else if (ReturnStmts.size() > 1) {
2062  Diag(ReturnStmts.back(),
2063  getLangOpts().CPlusPlus14
2064  ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2065  : diag::ext_constexpr_body_multiple_return);
2066  for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2067  Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return);
2068  }
2069  }
2070 
2071  // C++11 [dcl.constexpr]p5:
2072  // if no function argument values exist such that the function invocation
2073  // substitution would produce a constant expression, the program is
2074  // ill-formed; no diagnostic required.
2075  // C++11 [dcl.constexpr]p3:
2076  // - every constructor call and implicit conversion used in initializing the
2077  // return value shall be one of those allowed in a constant expression.
2078  // C++11 [dcl.constexpr]p4:
2079  // - every constructor involved in initializing non-static data members and
2080  // base class sub-objects shall be a constexpr constructor.
2082  if (!Expr::isPotentialConstantExpr(Dcl, Diags)) {
2083  Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr)
2084  << isa<CXXConstructorDecl>(Dcl);
2085  for (size_t I = 0, N = Diags.size(); I != N; ++I)
2086  Diag(Diags[I].first, Diags[I].second);
2087  // Don't return false here: we allow this for compatibility in
2088  // system headers.
2089  }
2090 
2091  return true;
2092 }
2093 
2094 /// Get the class that is directly named by the current context. This is the
2095 /// class for which an unqualified-id in this scope could name a constructor
2096 /// or destructor.
2097 ///
2098 /// If the scope specifier denotes a class, this will be that class.
2099 /// If the scope specifier is empty, this will be the class whose
2100 /// member-specification we are currently within. Otherwise, there
2101 /// is no such class.
2103  assert(getLangOpts().CPlusPlus && "No class names in C!");
2104 
2105  if (SS && SS->isInvalid())
2106  return nullptr;
2107 
2108  if (SS && SS->isNotEmpty()) {
2109  DeclContext *DC = computeDeclContext(*SS, true);
2110  return dyn_cast_or_null<CXXRecordDecl>(DC);
2111  }
2112 
2113  return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2114 }
2115 
2116 /// isCurrentClassName - Determine whether the identifier II is the
2117 /// name of the class type currently being defined. In the case of
2118 /// nested classes, this will only return true if II is the name of
2119 /// the innermost class.
2121  const CXXScopeSpec *SS) {
2122  CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2123  return CurDecl && &II == CurDecl->getIdentifier();
2124 }
2125 
2126 /// Determine whether the identifier II is a typo for the name of
2127 /// the class type currently being defined. If so, update it to the identifier
2128 /// that should have been used.
2130  assert(getLangOpts().CPlusPlus && "No class names in C!");
2131 
2132  if (!getLangOpts().SpellChecking)
2133  return false;
2134 
2135  CXXRecordDecl *CurDecl;
2136  if (SS && SS->isSet() && !SS->isInvalid()) {
2137  DeclContext *DC = computeDeclContext(*SS, true);
2138  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2139  } else
2140  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2141 
2142  if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2143  3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2144  < II->getLength()) {
2145  II = CurDecl->getIdentifier();
2146  return true;
2147  }
2148 
2149  return false;
2150 }
2151 
2152 /// Determine whether the given class is a base class of the given
2153 /// class, including looking at dependent bases.
2154 static bool findCircularInheritance(const CXXRecordDecl *Class,
2155  const CXXRecordDecl *Current) {
2157 
2158  Class = Class->getCanonicalDecl();
2159  while (true) {
2160  for (const auto &I : Current->bases()) {
2161  CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2162  if (!Base)
2163  continue;
2164 
2165  Base = Base->getDefinition();
2166  if (!Base)
2167  continue;
2168 
2169  if (Base->getCanonicalDecl() == Class)
2170  return true;
2171 
2172  Queue.push_back(Base);
2173  }
2174 
2175  if (Queue.empty())
2176  return false;
2177 
2178  Current = Queue.pop_back_val();
2179  }
2180 
2181  return false;
2182 }
2183 
2184 /// Check the validity of a C++ base class specifier.
2185 ///
2186 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2187 /// and returns NULL otherwise.
2190  SourceRange SpecifierRange,
2191  bool Virtual, AccessSpecifier Access,
2192  TypeSourceInfo *TInfo,
2193  SourceLocation EllipsisLoc) {
2194  QualType BaseType = TInfo->getType();
2195 
2196  // C++ [class.union]p1:
2197  // A union shall not have base classes.
2198  if (Class->isUnion()) {
2199  Diag(Class->getLocation(), diag::err_base_clause_on_union)
2200  << SpecifierRange;
2201  return nullptr;
2202  }
2203 
2204  if (EllipsisLoc.isValid() &&
2206  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2207  << TInfo->getTypeLoc().getSourceRange();
2208  EllipsisLoc = SourceLocation();
2209  }
2210 
2211  SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2212 
2213  if (BaseType->isDependentType()) {
2214  // Make sure that we don't have circular inheritance among our dependent
2215  // bases. For non-dependent bases, the check for completeness below handles
2216  // this.
2217  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2218  if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2219  ((BaseDecl = BaseDecl->getDefinition()) &&
2220  findCircularInheritance(Class, BaseDecl))) {
2221  Diag(BaseLoc, diag::err_circular_inheritance)
2222  << BaseType << Context.getTypeDeclType(Class);
2223 
2224  if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2225  Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2226  << BaseType;
2227 
2228  return nullptr;
2229  }
2230  }
2231 
2232  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2233  Class->getTagKind() == TTK_Class,
2234  Access, TInfo, EllipsisLoc);
2235  }
2236 
2237  // Base specifiers must be record types.
2238  if (!BaseType->isRecordType()) {
2239  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2240  return nullptr;
2241  }
2242 
2243  // C++ [class.union]p1:
2244  // A union shall not be used as a base class.
2245  if (BaseType->isUnionType()) {
2246  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2247  return nullptr;
2248  }
2249 
2250  // For the MS ABI, propagate DLL attributes to base class templates.
2251  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2252  if (Attr *ClassAttr = getDLLAttr(Class)) {
2253  if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2254  BaseType->getAsCXXRecordDecl())) {
2255  propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2256  BaseLoc);
2257  }
2258  }
2259  }
2260 
2261  // C++ [class.derived]p2:
2262  // The class-name in a base-specifier shall not be an incompletely
2263  // defined class.
2264  if (RequireCompleteType(BaseLoc, BaseType,
2265  diag::err_incomplete_base_class, SpecifierRange)) {
2266  Class->setInvalidDecl();
2267  return nullptr;
2268  }
2269 
2270  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2271  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
2272  assert(BaseDecl && "Record type has no declaration");
2273  BaseDecl = BaseDecl->getDefinition();
2274  assert(BaseDecl && "Base type is not incomplete, but has no definition");
2275  CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2276  assert(CXXBaseDecl && "Base type is not a C++ type");
2277 
2278  // Microsoft docs say:
2279  // "If a base-class has a code_seg attribute, derived classes must have the
2280  // same attribute."
2281  const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2282  const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2283  if ((DerivedCSA || BaseCSA) &&
2284  (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2285  Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2286  Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2287  << CXXBaseDecl;
2288  return nullptr;
2289  }
2290 
2291  // A class which contains a flexible array member is not suitable for use as a
2292  // base class:
2293  // - If the layout determines that a base comes before another base,
2294  // the flexible array member would index into the subsequent base.
2295  // - If the layout determines that base comes before the derived class,
2296  // the flexible array member would index into the derived class.
2297  if (CXXBaseDecl->hasFlexibleArrayMember()) {
2298  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2299  << CXXBaseDecl->getDeclName();
2300  return nullptr;
2301  }
2302 
2303  // C++ [class]p3:
2304  // If a class is marked final and it appears as a base-type-specifier in
2305  // base-clause, the program is ill-formed.
2306  if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2307  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2308  << CXXBaseDecl->getDeclName()
2309  << FA->isSpelledAsSealed();
2310  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2311  << CXXBaseDecl->getDeclName() << FA->getRange();
2312  return nullptr;
2313  }
2314 
2315  if (BaseDecl->isInvalidDecl())
2316  Class->setInvalidDecl();
2317 
2318  // Create the base specifier.
2319  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2320  Class->getTagKind() == TTK_Class,
2321  Access, TInfo, EllipsisLoc);
2322 }
2323 
2324 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2325 /// one entry in the base class list of a class specifier, for
2326 /// example:
2327 /// class foo : public bar, virtual private baz {
2328 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2329 BaseResult
2330 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2331  ParsedAttributes &Attributes,
2332  bool Virtual, AccessSpecifier Access,
2333  ParsedType basetype, SourceLocation BaseLoc,
2334  SourceLocation EllipsisLoc) {
2335  if (!classdecl)
2336  return true;
2337 
2338  AdjustDeclIfTemplate(classdecl);
2339  CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2340  if (!Class)
2341  return true;
2342 
2343  // We haven't yet attached the base specifiers.
2344  Class->setIsParsingBaseSpecifiers();
2345 
2346  // We do not support any C++11 attributes on base-specifiers yet.
2347  // Diagnose any attributes we see.
2348  for (const ParsedAttr &AL : Attributes) {
2349  if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2350  continue;
2351  Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2352  ? (unsigned)diag::warn_unknown_attribute_ignored
2353  : (unsigned)diag::err_base_specifier_attribute)
2354  << AL.getName();
2355  }
2356 
2357  TypeSourceInfo *TInfo = nullptr;
2358  GetTypeFromParser(basetype, &TInfo);
2359 
2360  if (EllipsisLoc.isInvalid() &&
2361  DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2362  UPPC_BaseType))
2363  return true;
2364 
2365  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2366  Virtual, Access, TInfo,
2367  EllipsisLoc))
2368  return BaseSpec;
2369  else
2370  Class->setInvalidDecl();
2371 
2372  return true;
2373 }
2374 
2375 /// Use small set to collect indirect bases. As this is only used
2376 /// locally, there's no need to abstract the small size parameter.
2377 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2378 
2379 /// Recursively add the bases of Type. Don't add Type itself.
2380 static void
2381 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2382  const QualType &Type)
2383 {
2384  // Even though the incoming type is a base, it might not be
2385  // a class -- it could be a template parm, for instance.
2386  if (auto Rec = Type->getAs<RecordType>()) {
2387  auto Decl = Rec->getAsCXXRecordDecl();
2388 
2389  // Iterate over its bases.
2390  for (const auto &BaseSpec : Decl->bases()) {
2391  QualType Base = Context.getCanonicalType(BaseSpec.getType())
2392  .getUnqualifiedType();
2393  if (Set.insert(Base).second)
2394  // If we've not already seen it, recurse.
2395  NoteIndirectBases(Context, Set, Base);
2396  }
2397  }
2398 }
2399 
2400 /// Performs the actual work of attaching the given base class
2401 /// specifiers to a C++ class.
2404  if (Bases.empty())
2405  return false;
2406 
2407  // Used to keep track of which base types we have already seen, so
2408  // that we can properly diagnose redundant direct base types. Note
2409  // that the key is always the unqualified canonical type of the base
2410  // class.
2411  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2412 
2413  // Used to track indirect bases so we can see if a direct base is
2414  // ambiguous.
2415  IndirectBaseSet IndirectBaseTypes;
2416 
2417  // Copy non-redundant base specifiers into permanent storage.
2418  unsigned NumGoodBases = 0;
2419  bool Invalid = false;
2420  for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2421  QualType NewBaseType
2422  = Context.getCanonicalType(Bases[idx]->getType());
2423  NewBaseType = NewBaseType.getLocalUnqualifiedType();
2424 
2425  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2426  if (KnownBase) {
2427  // C++ [class.mi]p3:
2428  // A class shall not be specified as a direct base class of a
2429  // derived class more than once.
2430  Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2431  << KnownBase->getType() << Bases[idx]->getSourceRange();
2432 
2433  // Delete the duplicate base class specifier; we're going to
2434  // overwrite its pointer later.
2435  Context.Deallocate(Bases[idx]);
2436 
2437  Invalid = true;
2438  } else {
2439  // Okay, add this new base class.
2440  KnownBase = Bases[idx];
2441  Bases[NumGoodBases++] = Bases[idx];
2442 
2443  // Note this base's direct & indirect bases, if there could be ambiguity.
2444  if (Bases.size() > 1)
2445  NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2446 
2447  if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2448  const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2449  if (Class->isInterface() &&
2450  (!RD->isInterfaceLike() ||
2451  KnownBase->getAccessSpecifier() != AS_public)) {
2452  // The Microsoft extension __interface does not permit bases that
2453  // are not themselves public interfaces.
2454  Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2455  << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2456  << RD->getSourceRange();
2457  Invalid = true;
2458  }
2459  if (RD->hasAttr<WeakAttr>())
2460  Class->addAttr(WeakAttr::CreateImplicit(Context));
2461  }
2462  }
2463  }
2464 
2465  // Attach the remaining base class specifiers to the derived class.
2466  Class->setBases(Bases.data(), NumGoodBases);
2467 
2468  // Check that the only base classes that are duplicate are virtual.
2469  for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2470  // Check whether this direct base is inaccessible due to ambiguity.
2471  QualType BaseType = Bases[idx]->getType();
2472 
2473  // Skip all dependent types in templates being used as base specifiers.
2474  // Checks below assume that the base specifier is a CXXRecord.
2475  if (BaseType->isDependentType())
2476  continue;
2477 
2478  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2479  .getUnqualifiedType();
2480 
2481  if (IndirectBaseTypes.count(CanonicalBase)) {
2482  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2483  /*DetectVirtual=*/true);
2484  bool found
2485  = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2486  assert(found);
2487  (void)found;
2488 
2489  if (Paths.isAmbiguous(CanonicalBase))
2490  Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2491  << BaseType << getAmbiguousPathsDisplayString(Paths)
2492  << Bases[idx]->getSourceRange();
2493  else
2494  assert(Bases[idx]->isVirtual());
2495  }
2496 
2497  // Delete the base class specifier, since its data has been copied
2498  // into the CXXRecordDecl.
2499  Context.Deallocate(Bases[idx]);
2500  }
2501 
2502  return Invalid;
2503 }
2504 
2505 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2506 /// class, after checking whether there are any duplicate base
2507 /// classes.
2508 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2510  if (!ClassDecl || Bases.empty())
2511  return;
2512 
2513  AdjustDeclIfTemplate(ClassDecl);
2514  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2515 }
2516 
2517 /// Determine whether the type \p Derived is a C++ class that is
2518 /// derived from the type \p Base.
2520  if (!getLangOpts().CPlusPlus)
2521  return false;
2522 
2523  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2524  if (!DerivedRD)
2525  return false;
2526 
2527  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2528  if (!BaseRD)
2529  return false;
2530 
2531  // If either the base or the derived type is invalid, don't try to
2532  // check whether one is derived from the other.
2533  if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2534  return false;
2535 
2536  // FIXME: In a modules build, do we need the entire path to be visible for us
2537  // to be able to use the inheritance relationship?
2538  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2539  return false;
2540 
2541  return DerivedRD->isDerivedFrom(BaseRD);
2542 }
2543 
2544 /// Determine whether the type \p Derived is a C++ class that is
2545 /// derived from the type \p Base.
2547  CXXBasePaths &Paths) {
2548  if (!getLangOpts().CPlusPlus)
2549  return false;
2550 
2551  CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2552  if (!DerivedRD)
2553  return false;
2554 
2555  CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2556  if (!BaseRD)
2557  return false;
2558 
2559  if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2560  return false;
2561 
2562  return DerivedRD->isDerivedFrom(BaseRD, Paths);
2563 }
2564 
2565 static void BuildBasePathArray(const CXXBasePath &Path,
2566  CXXCastPath &BasePathArray) {
2567  // We first go backward and check if we have a virtual base.
2568  // FIXME: It would be better if CXXBasePath had the base specifier for
2569  // the nearest virtual base.
2570  unsigned Start = 0;
2571  for (unsigned I = Path.size(); I != 0; --I) {
2572  if (Path[I - 1].Base->isVirtual()) {
2573  Start = I - 1;
2574  break;
2575  }
2576  }
2577 
2578  // Now add all bases.
2579  for (unsigned I = Start, E = Path.size(); I != E; ++I)
2580  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2581 }
2582 
2583 
2585  CXXCastPath &BasePathArray) {
2586  assert(BasePathArray.empty() && "Base path array must be empty!");
2587  assert(Paths.isRecordingPaths() && "Must record paths!");
2588  return ::BuildBasePathArray(Paths.front(), BasePathArray);
2589 }
2590 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2591 /// conversion (where Derived and Base are class types) is
2592 /// well-formed, meaning that the conversion is unambiguous (and
2593 /// that all of the base classes are accessible). Returns true
2594 /// and emits a diagnostic if the code is ill-formed, returns false
2595 /// otherwise. Loc is the location where this routine should point to
2596 /// if there is an error, and Range is the source range to highlight
2597 /// if there is an error.
2598 ///
2599 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2600 /// diagnostic for the respective type of error will be suppressed, but the
2601 /// check for ill-formed code will still be performed.
2602 bool
2604  unsigned InaccessibleBaseID,
2605  unsigned AmbigiousBaseConvID,
2606  SourceLocation Loc, SourceRange Range,
2607  DeclarationName Name,
2608  CXXCastPath *BasePath,
2609  bool IgnoreAccess) {
2610  // First, determine whether the path from Derived to Base is
2611  // ambiguous. This is slightly more expensive than checking whether
2612  // the Derived to Base conversion exists, because here we need to
2613  // explore multiple paths to determine if there is an ambiguity.
2614  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2615  /*DetectVirtual=*/false);
2616  bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2617  if (!DerivationOkay)
2618  return true;
2619 
2620  const CXXBasePath *Path = nullptr;
2621  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2622  Path = &Paths.front();
2623 
2624  // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2625  // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2626  // user to access such bases.
2627  if (!Path && getLangOpts().MSVCCompat) {
2628  for (const CXXBasePath &PossiblePath : Paths) {
2629  if (PossiblePath.size() == 1) {
2630  Path = &PossiblePath;
2631  if (AmbigiousBaseConvID)
2632  Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2633  << Base << Derived << Range;
2634  break;
2635  }
2636  }
2637  }
2638 
2639  if (Path) {
2640  if (!IgnoreAccess) {
2641  // Check that the base class can be accessed.
2642  switch (
2643  CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2644  case AR_inaccessible:
2645  return true;
2646  case AR_accessible:
2647  case AR_dependent:
2648  case AR_delayed:
2649  break;
2650  }
2651  }
2652 
2653  // Build a base path if necessary.
2654  if (BasePath)
2655  ::BuildBasePathArray(*Path, *BasePath);
2656  return false;
2657  }
2658 
2659  if (AmbigiousBaseConvID) {
2660  // We know that the derived-to-base conversion is ambiguous, and
2661  // we're going to produce a diagnostic. Perform the derived-to-base
2662  // search just one more time to compute all of the possible paths so
2663  // that we can print them out. This is more expensive than any of
2664  // the previous derived-to-base checks we've done, but at this point
2665  // performance isn't as much of an issue.
2666  Paths.clear();
2667  Paths.setRecordingPaths(true);
2668  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2669  assert(StillOkay && "Can only be used with a derived-to-base conversion");
2670  (void)StillOkay;
2671 
2672  // Build up a textual representation of the ambiguous paths, e.g.,
2673  // D -> B -> A, that will be used to illustrate the ambiguous
2674  // conversions in the diagnostic. We only print one of the paths
2675  // to each base class subobject.
2676  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2677 
2678  Diag(Loc, AmbigiousBaseConvID)
2679  << Derived << Base << PathDisplayStr << Range << Name;
2680  }
2681  return true;
2682 }
2683 
2684 bool
2686  SourceLocation Loc, SourceRange Range,
2687  CXXCastPath *BasePath,
2688  bool IgnoreAccess) {
2689  return CheckDerivedToBaseConversion(
2690  Derived, Base, diag::err_upcast_to_inaccessible_base,
2691  diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2692  BasePath, IgnoreAccess);
2693 }
2694 
2695 
2696 /// Builds a string representing ambiguous paths from a
2697 /// specific derived class to different subobjects of the same base
2698 /// class.
2699 ///
2700 /// This function builds a string that can be used in error messages
2701 /// to show the different paths that one can take through the
2702 /// inheritance hierarchy to go from the derived class to different
2703 /// subobjects of a base class. The result looks something like this:
2704 /// @code
2705 /// struct D -> struct B -> struct A
2706 /// struct D -> struct C -> struct A
2707 /// @endcode
2709  std::string PathDisplayStr;
2710  std::set<unsigned> DisplayedPaths;
2711  for (CXXBasePaths::paths_iterator Path = Paths.begin();
2712  Path != Paths.end(); ++Path) {
2713  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2714  // We haven't displayed a path to this particular base
2715  // class subobject yet.
2716  PathDisplayStr += "\n ";
2717  PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2718  for (CXXBasePath::const_iterator Element = Path->begin();
2719  Element != Path->end(); ++Element)
2720  PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2721  }
2722  }
2723 
2724  return PathDisplayStr;
2725 }
2726 
2727 //===----------------------------------------------------------------------===//
2728 // C++ class member Handling
2729 //===----------------------------------------------------------------------===//
2730 
2731 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2734  const ParsedAttributesView &Attrs) {
2735  assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2736  AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2737  ASLoc, ColonLoc);
2738  CurContext->addHiddenDecl(ASDecl);
2739  return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2740 }
2741 
2742 /// CheckOverrideControl - Check C++11 override control semantics.
2744  if (D->isInvalidDecl())
2745  return;
2746 
2747  // We only care about "override" and "final" declarations.
2748  if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2749  return;
2750 
2751  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2752 
2753  // We can't check dependent instance methods.
2754  if (MD && MD->isInstance() &&
2755  (MD->getParent()->hasAnyDependentBases() ||
2756  MD->getType()->isDependentType()))
2757  return;
2758 
2759  if (MD && !MD->isVirtual()) {
2760  // If we have a non-virtual method, check if if hides a virtual method.
2761  // (In that case, it's most likely the method has the wrong type.)
2762  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2763  FindHiddenVirtualMethods(MD, OverloadedMethods);
2764 
2765  if (!OverloadedMethods.empty()) {
2766  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2767  Diag(OA->getLocation(),
2768  diag::override_keyword_hides_virtual_member_function)
2769  << "override" << (OverloadedMethods.size() > 1);
2770  } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2771  Diag(FA->getLocation(),
2772  diag::override_keyword_hides_virtual_member_function)
2773  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2774  << (OverloadedMethods.size() > 1);
2775  }
2776  NoteHiddenVirtualMethods(MD, OverloadedMethods);
2777  MD->setInvalidDecl();
2778  return;
2779  }
2780  // Fall through into the general case diagnostic.
2781  // FIXME: We might want to attempt typo correction here.
2782  }
2783 
2784  if (!MD || !MD->isVirtual()) {
2785  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2786  Diag(OA->getLocation(),
2787  diag::override_keyword_only_allowed_on_virtual_member_functions)
2788  << "override" << FixItHint::CreateRemoval(OA->getLocation());
2789  D->dropAttr<OverrideAttr>();
2790  }
2791  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2792  Diag(FA->getLocation(),
2793  diag::override_keyword_only_allowed_on_virtual_member_functions)
2794  << (FA->isSpelledAsSealed() ? "sealed" : "final")
2795  << FixItHint::CreateRemoval(FA->getLocation());
2796  D->dropAttr<FinalAttr>();
2797  }
2798  return;
2799  }
2800 
2801  // C++11 [class.virtual]p5:
2802  // If a function is marked with the virt-specifier override and
2803  // does not override a member function of a base class, the program is
2804  // ill-formed.
2805  bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
2806  if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
2807  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
2808  << MD->getDeclName();
2809 }
2810 
2812  if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
2813  return;
2814  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2815  if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
2816  return;
2817 
2818  SourceLocation Loc = MD->getLocation();
2819  SourceLocation SpellingLoc = Loc;
2820  if (getSourceManager().isMacroArgExpansion(Loc))
2821  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
2822  SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
2823  if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
2824  return;
2825 
2826  if (MD->size_overridden_methods() > 0) {
2827  unsigned DiagID = isa<CXXDestructorDecl>(MD)
2828  ? diag::warn_destructor_marked_not_override_overriding
2829  : diag::warn_function_marked_not_override_overriding;
2830  Diag(MD->getLocation(), DiagID) << MD->getDeclName();
2831  const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
2832  Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
2833  }
2834 }
2835 
2836 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
2837 /// function overrides a virtual member function marked 'final', according to
2838 /// C++11 [class.virtual]p4.
2840  const CXXMethodDecl *Old) {
2841  FinalAttr *FA = Old->getAttr<FinalAttr>();
2842  if (!FA)
2843  return false;
2844 
2845  Diag(New->getLocation(), diag::err_final_function_overridden)
2846  << New->getDeclName()
2847  << FA->isSpelledAsSealed();
2848  Diag(Old->getLocation(), diag::note_overridden_virtual_function);
2849  return true;
2850 }
2851 
2852 static bool InitializationHasSideEffects(const FieldDecl &FD) {
2853  const Type *T = FD.getType()->getBaseElementTypeUnsafe();
2854  // FIXME: Destruction of ObjC lifetime types has side-effects.
2855  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
2856  return !RD->isCompleteDefinition() ||
2857  !RD->hasTrivialDefaultConstructor() ||
2858  !RD->hasTrivialDestructor();
2859  return false;
2860 }
2861 
2864  llvm::find_if(list, [](const ParsedAttr &AL) {
2865  return AL.isDeclspecPropertyAttribute();
2866  });
2867  if (Itr != list.end())
2868  return &*Itr;
2869  return nullptr;
2870 }
2871 
2872 // Check if there is a field shadowing.
2873 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
2874  DeclarationName FieldName,
2875  const CXXRecordDecl *RD,
2876  bool DeclIsField) {
2877  if (Diags.isIgnored(diag::warn_shadow_field, Loc))
2878  return;
2879 
2880  // To record a shadowed field in a base
2881  std::map<CXXRecordDecl*, NamedDecl*> Bases;
2882  auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
2883  CXXBasePath &Path) {
2884  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
2885  // Record an ambiguous path directly
2886  if (Bases.find(Base) != Bases.end())
2887  return true;
2888  for (const auto Field : Base->lookup(FieldName)) {
2889  if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
2890  Field->getAccess() != AS_private) {
2891  assert(Field->getAccess() != AS_none);
2892  assert(Bases.find(Base) == Bases.end());
2893  Bases[Base] = Field;
2894  return true;
2895  }
2896  }
2897  return false;
2898  };
2899 
2900  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2901  /*DetectVirtual=*/true);
2902  if (!RD->lookupInBases(FieldShadowed, Paths))
2903  return;
2904 
2905  for (const auto &P : Paths) {
2906  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
2907  auto It = Bases.find(Base);
2908  // Skip duplicated bases
2909  if (It == Bases.end())
2910  continue;
2911  auto BaseField = It->second;
2912  assert(BaseField->getAccess() != AS_private);
2913  if (AS_none !=
2914  CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
2915  Diag(Loc, diag::warn_shadow_field)
2916  << FieldName << RD << Base << DeclIsField;
2917  Diag(BaseField->getLocation(), diag::note_shadow_field);
2918  Bases.erase(It);
2919  }
2920  }
2921 }
2922 
2923 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
2924 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
2925 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
2926 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
2927 /// present (but parsing it has been deferred).
2928 NamedDecl *
2930  MultiTemplateParamsArg TemplateParameterLists,
2931  Expr *BW, const VirtSpecifiers &VS,
2932  InClassInitStyle InitStyle) {
2933  const DeclSpec &DS = D.getDeclSpec();
2934  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
2935  DeclarationName Name = NameInfo.getName();
2936  SourceLocation Loc = NameInfo.getLoc();
2937 
2938  // For anonymous bitfields, the location should point to the type.
2939  if (Loc.isInvalid())
2940  Loc = D.getBeginLoc();
2941 
2942  Expr *BitWidth = static_cast<Expr*>(BW);
2943 
2944  assert(isa<CXXRecordDecl>(CurContext));
2945  assert(!DS.isFriendSpecified());
2946 
2947  bool isFunc = D.isDeclarationOfFunction();
2948  const ParsedAttr *MSPropertyAttr =
2950 
2951  if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
2952  // The Microsoft extension __interface only permits public member functions
2953  // and prohibits constructors, destructors, operators, non-public member
2954  // functions, static methods and data members.
2955  unsigned InvalidDecl;
2956  bool ShowDeclName = true;
2957  if (!isFunc &&
2958  (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
2959  InvalidDecl = 0;
2960  else if (!isFunc)
2961  InvalidDecl = 1;
2962  else if (AS != AS_public)
2963  InvalidDecl = 2;
2964  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
2965  InvalidDecl = 3;
2966  else switch (Name.getNameKind()) {
2968  InvalidDecl = 4;
2969  ShowDeclName = false;
2970  break;
2971 
2973  InvalidDecl = 5;
2974  ShowDeclName = false;
2975  break;
2976 
2979  InvalidDecl = 6;
2980  break;
2981 
2982  default:
2983  InvalidDecl = 0;
2984  break;
2985  }
2986 
2987  if (InvalidDecl) {
2988  if (ShowDeclName)
2989  Diag(Loc, diag::err_invalid_member_in_interface)
2990  << (InvalidDecl-1) << Name;
2991  else
2992  Diag(Loc, diag::err_invalid_member_in_interface)
2993  << (InvalidDecl-1) << "";
2994  return nullptr;
2995  }
2996  }
2997 
2998  // C++ 9.2p6: A member shall not be declared to have automatic storage
2999  // duration (auto, register) or with the extern storage-class-specifier.
3000  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3001  // data members and cannot be applied to names declared const or static,
3002  // and cannot be applied to reference members.
3003  switch (DS.getStorageClassSpec()) {
3005  case DeclSpec::SCS_typedef:
3006  case DeclSpec::SCS_static:
3007  break;
3008  case DeclSpec::SCS_mutable:
3009  if (isFunc) {
3010  Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3011 
3012  // FIXME: It would be nicer if the keyword was ignored only for this
3013  // declarator. Otherwise we could get follow-up errors.
3015  }
3016  break;
3017  default:
3019  diag::err_storageclass_invalid_for_member);
3021  break;
3022  }
3023 
3024  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3026  !isFunc);
3027 
3028  if (DS.isConstexprSpecified() && isInstField) {
3030  Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3031  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3032  if (InitStyle == ICIS_NoInit) {
3033  B << 0 << 0;
3035  B << FixItHint::CreateRemoval(ConstexprLoc);
3036  else {
3037  B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3039  const char *PrevSpec;
3040  unsigned DiagID;
3041  bool Failed = D.getMutableDeclSpec().SetTypeQual(
3042  DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3043  (void)Failed;
3044  assert(!Failed && "Making a constexpr member const shouldn't fail");
3045  }
3046  } else {
3047  B << 1;
3048  const char *PrevSpec;
3049  unsigned DiagID;
3051  *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3052  Context.getPrintingPolicy())) {
3053  assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3054  "This is the only DeclSpec that should fail to be applied");
3055  B << 1;
3056  } else {
3057  B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3058  isInstField = false;
3059  }
3060  }
3061  }
3062 
3063  NamedDecl *Member;
3064  if (isInstField) {
3065  CXXScopeSpec &SS = D.getCXXScopeSpec();
3066 
3067  // Data members must have identifiers for names.
3068  if (!Name.isIdentifier()) {
3069  Diag(Loc, diag::err_bad_variable_name)
3070  << Name;
3071  return nullptr;
3072  }
3073 
3074  IdentifierInfo *II = Name.getAsIdentifierInfo();
3075 
3076  // Member field could not be with "template" keyword.
3077  // So TemplateParameterLists should be empty in this case.
3078  if (TemplateParameterLists.size()) {
3079  TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3080  if (TemplateParams->size()) {
3081  // There is no such thing as a member field template.
3082  Diag(D.getIdentifierLoc(), diag::err_template_member)
3083  << II
3084  << SourceRange(TemplateParams->getTemplateLoc(),
3085  TemplateParams->getRAngleLoc());
3086  } else {
3087  // There is an extraneous 'template<>' for this member.
3088  Diag(TemplateParams->getTemplateLoc(),
3089  diag::err_template_member_noparams)
3090  << II
3091  << SourceRange(TemplateParams->getTemplateLoc(),
3092  TemplateParams->getRAngleLoc());
3093  }
3094  return nullptr;
3095  }
3096 
3097  if (SS.isSet() && !SS.isInvalid()) {
3098  // The user provided a superfluous scope specifier inside a class
3099  // definition:
3100  //
3101  // class X {
3102  // int X::member;
3103  // };
3104  if (DeclContext *DC = computeDeclContext(SS, false))
3105  diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3106  D.getName().getKind() ==
3108  else
3109  Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3110  << Name << SS.getRange();
3111 
3112  SS.clear();
3113  }
3114 
3115  if (MSPropertyAttr) {
3116  Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3117  BitWidth, InitStyle, AS, *MSPropertyAttr);
3118  if (!Member)
3119  return nullptr;
3120  isInstField = false;
3121  } else {
3122  Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3123  BitWidth, InitStyle, AS);
3124  if (!Member)
3125  return nullptr;
3126  }
3127 
3128  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3129  } else {
3130  Member = HandleDeclarator(S, D, TemplateParameterLists);
3131  if (!Member)
3132  return nullptr;
3133 
3134  // Non-instance-fields can't have a bitfield.
3135  if (BitWidth) {
3136  if (Member->isInvalidDecl()) {
3137  // don't emit another diagnostic.
3138  } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3139  // C++ 9.6p3: A bit-field shall not be a static member.
3140  // "static member 'A' cannot be a bit-field"
3141  Diag(Loc, diag::err_static_not_bitfield)
3142  << Name << BitWidth->getSourceRange();
3143  } else if (isa<TypedefDecl>(Member)) {
3144  // "typedef member 'x' cannot be a bit-field"
3145  Diag(Loc, diag::err_typedef_not_bitfield)
3146  << Name << BitWidth->getSourceRange();
3147  } else {
3148  // A function typedef ("typedef int f(); f a;").
3149  // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3150  Diag(Loc, diag::err_not_integral_type_bitfield)
3151  << Name << cast<ValueDecl>(Member)->getType()
3152  << BitWidth->getSourceRange();
3153  }
3154 
3155  BitWidth = nullptr;
3156  Member->setInvalidDecl();
3157  }
3158 
3159  NamedDecl *NonTemplateMember = Member;
3160  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3161  NonTemplateMember = FunTmpl->getTemplatedDecl();
3162  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3163  NonTemplateMember = VarTmpl->getTemplatedDecl();
3164 
3165  Member->setAccess(AS);
3166 
3167  // If we have declared a member function template or static data member
3168  // template, set the access of the templated declaration as well.
3169  if (NonTemplateMember != Member)
3170  NonTemplateMember->setAccess(AS);
3171 
3172  // C++ [temp.deduct.guide]p3:
3173  // A deduction guide [...] for a member class template [shall be
3174  // declared] with the same access [as the template].
3175  if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3176  auto *TD = DG->getDeducedTemplate();
3177  // Access specifiers are only meaningful if both the template and the
3178  // deduction guide are from the same scope.
3179  if (AS != TD->getAccess() &&
3180  TD->getDeclContext()->getRedeclContext()->Equals(
3181  DG->getDeclContext()->getRedeclContext())) {
3182  Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3183  Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3184  << TD->getAccess();
3185  const AccessSpecDecl *LastAccessSpec = nullptr;
3186  for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3187  if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3188  LastAccessSpec = AccessSpec;
3189  }
3190  assert(LastAccessSpec && "differing access with no access specifier");
3191  Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3192  << AS;
3193  }
3194  }
3195  }
3196 
3197  if (VS.isOverrideSpecified())
3198  Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context, 0));
3199  if (VS.isFinalSpecified())
3200  Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context,
3201  VS.isFinalSpelledSealed()));
3202 
3203  if (VS.getLastLocation().isValid()) {
3204  // Update the end location of a method that has a virt-specifiers.
3205  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3206  MD->setRangeEnd(VS.getLastLocation());
3207  }
3208 
3209  CheckOverrideControl(Member);
3210 
3211  assert((Name || isInstField) && "No identifier for non-field ?");
3212 
3213  if (isInstField) {
3214  FieldDecl *FD = cast<FieldDecl>(Member);
3215  FieldCollector->Add(FD);
3216 
3217  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3218  // Remember all explicit private FieldDecls that have a name, no side
3219  // effects and are not part of a dependent type declaration.
3220  if (!FD->isImplicit() && FD->getDeclName() &&
3221  FD->getAccess() == AS_private &&
3222  !FD->hasAttr<UnusedAttr>() &&
3223  !FD->getParent()->isDependentContext() &&
3225  UnusedPrivateFields.insert(FD);
3226  }
3227  }
3228 
3229  return Member;
3230 }
3231 
3232 namespace {
3233  class UninitializedFieldVisitor
3234  : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3235  Sema &S;
3236  // List of Decls to generate a warning on. Also remove Decls that become
3237  // initialized.
3238  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3239  // List of base classes of the record. Classes are removed after their
3240  // initializers.
3241  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3242  // Vector of decls to be removed from the Decl set prior to visiting the
3243  // nodes. These Decls may have been initialized in the prior initializer.
3244  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3245  // If non-null, add a note to the warning pointing back to the constructor.
3246  const CXXConstructorDecl *Constructor;
3247  // Variables to hold state when processing an initializer list. When
3248  // InitList is true, special case initialization of FieldDecls matching
3249  // InitListFieldDecl.
3250  bool InitList;
3251  FieldDecl *InitListFieldDecl;
3252  llvm::SmallVector<unsigned, 4> InitFieldIndex;
3253 
3254  public:
3256  UninitializedFieldVisitor(Sema &S,
3257  llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3258  llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3259  : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3260  Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3261 
3262  // Returns true if the use of ME is not an uninitialized use.
3263  bool IsInitListMemberExprInitialized(MemberExpr *ME,
3264  bool CheckReferenceOnly) {
3266  bool ReferenceField = false;
3267  while (ME) {
3268  FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3269  if (!FD)
3270  return false;
3271  Fields.push_back(FD);
3272  if (FD->getType()->isReferenceType())
3273  ReferenceField = true;
3274  ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3275  }
3276 
3277  // Binding a reference to an uninitialized field is not an
3278  // uninitialized use.
3279  if (CheckReferenceOnly && !ReferenceField)
3280  return true;
3281 
3282  llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3283  // Discard the first field since it is the field decl that is being
3284  // initialized.
3285  for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3286  UsedFieldIndex.push_back((*I)->getFieldIndex());
3287  }
3288 
3289  for (auto UsedIter = UsedFieldIndex.begin(),
3290  UsedEnd = UsedFieldIndex.end(),
3291  OrigIter = InitFieldIndex.begin(),
3292  OrigEnd = InitFieldIndex.end();
3293  UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3294  if (*UsedIter < *OrigIter)
3295  return true;
3296  if (*UsedIter > *OrigIter)
3297  break;
3298  }
3299 
3300  return false;
3301  }
3302 
3303  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3304  bool AddressOf) {
3305  if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3306  return;
3307 
3308  // FieldME is the inner-most MemberExpr that is not an anonymous struct
3309  // or union.
3310  MemberExpr *FieldME = ME;
3311 
3312  bool AllPODFields = FieldME->getType().isPODType(S.Context);
3313 
3314  Expr *Base = ME;
3315  while (MemberExpr *SubME =
3316  dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3317 
3318  if (isa<VarDecl>(SubME->getMemberDecl()))
3319  return;
3320 
3321  if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3322  if (!FD->isAnonymousStructOrUnion())
3323  FieldME = SubME;
3324 
3325  if (!FieldME->getType().isPODType(S.Context))
3326  AllPODFields = false;
3327 
3328  Base = SubME->getBase();
3329  }
3330 
3331  if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3332  return;
3333 
3334  if (AddressOf && AllPODFields)
3335  return;
3336 
3337  ValueDecl* FoundVD = FieldME->getMemberDecl();
3338 
3339  if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3340  while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3341  BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3342  }
3343 
3344  if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3345  QualType T = BaseCast->getType();
3346  if (T->isPointerType() &&
3347  BaseClasses.count(T->getPointeeType())) {
3348  S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3349  << T->getPointeeType() << FoundVD;
3350  }
3351  }
3352  }
3353 
3354  if (!Decls.count(FoundVD))
3355  return;
3356 
3357  const bool IsReference = FoundVD->getType()->isReferenceType();
3358 
3359  if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3360  // Special checking for initializer lists.
3361  if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3362  return;
3363  }
3364  } else {
3365  // Prevent double warnings on use of unbounded references.
3366  if (CheckReferenceOnly && !IsReference)
3367  return;
3368  }
3369 
3370  unsigned diag = IsReference
3371  ? diag::warn_reference_field_is_uninit
3372  : diag::warn_field_is_uninit;
3373  S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3374  if (Constructor)
3375  S.Diag(Constructor->getLocation(),
3376  diag::note_uninit_in_this_constructor)
3377  << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3378 
3379  }
3380 
3381  void HandleValue(Expr *E, bool AddressOf) {
3382  E = E->IgnoreParens();
3383 
3384  if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3385  HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3386  AddressOf /*AddressOf*/);
3387  return;
3388  }
3389 
3390  if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3391  Visit(CO->getCond());
3392  HandleValue(CO->getTrueExpr(), AddressOf);
3393  HandleValue(CO->getFalseExpr(), AddressOf);
3394  return;
3395  }
3396 
3397  if (BinaryConditionalOperator *BCO =
3398  dyn_cast<BinaryConditionalOperator>(E)) {
3399  Visit(BCO->getCond());
3400  HandleValue(BCO->getFalseExpr(), AddressOf);
3401  return;
3402  }
3403 
3404  if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3405  HandleValue(OVE->getSourceExpr(), AddressOf);
3406  return;
3407  }
3408 
3409  if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3410  switch (BO->getOpcode()) {
3411  default:
3412  break;
3413  case(BO_PtrMemD):
3414  case(BO_PtrMemI):
3415  HandleValue(BO->getLHS(), AddressOf);
3416  Visit(BO->getRHS());
3417  return;
3418  case(BO_Comma):
3419  Visit(BO->getLHS());
3420  HandleValue(BO->getRHS(), AddressOf);
3421  return;
3422  }
3423  }
3424 
3425  Visit(E);
3426  }
3427 
3428  void CheckInitListExpr(InitListExpr *ILE) {
3429  InitFieldIndex.push_back(0);
3430  for (auto Child : ILE->children()) {
3431  if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3432  CheckInitListExpr(SubList);
3433  } else {
3434  Visit(Child);
3435  }
3436  ++InitFieldIndex.back();
3437  }
3438  InitFieldIndex.pop_back();
3439  }
3440 
3441  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3442  FieldDecl *Field, const Type *BaseClass) {
3443  // Remove Decls that may have been initialized in the previous
3444  // initializer.
3445  for (ValueDecl* VD : DeclsToRemove)
3446  Decls.erase(VD);
3447  DeclsToRemove.clear();
3448 
3449  Constructor = FieldConstructor;
3450  InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3451 
3452  if (ILE && Field) {
3453  InitList = true;
3454  InitListFieldDecl = Field;
3455  InitFieldIndex.clear();
3456  CheckInitListExpr(ILE);
3457  } else {
3458  InitList = false;
3459  Visit(E);
3460  }
3461 
3462  if (Field)
3463  Decls.erase(Field);
3464  if (BaseClass)
3465  BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3466  }
3467 
3468  void VisitMemberExpr(MemberExpr *ME) {
3469  // All uses of unbounded reference fields will warn.
3470  HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3471  }
3472 
3473  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3474  if (E->getCastKind() == CK_LValueToRValue) {
3475  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3476  return;
3477  }
3478 
3479  Inherited::VisitImplicitCastExpr(E);
3480  }
3481 
3482  void VisitCXXConstructExpr(CXXConstructExpr *E) {
3483  if (E->getConstructor()->isCopyConstructor()) {
3484  Expr *ArgExpr = E->getArg(0);
3485  if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3486  if (ILE->getNumInits() == 1)
3487  ArgExpr = ILE->getInit(0);
3488  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3489  if (ICE->getCastKind() == CK_NoOp)
3490  ArgExpr = ICE->getSubExpr();
3491  HandleValue(ArgExpr, false /*AddressOf*/);
3492  return;
3493  }
3494  Inherited::VisitCXXConstructExpr(E);
3495  }
3496 
3497  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3498  Expr *Callee = E->getCallee();
3499  if (isa<MemberExpr>(Callee)) {
3500  HandleValue(Callee, false /*AddressOf*/);
3501  for (auto Arg : E->arguments())
3502  Visit(Arg);
3503  return;
3504  }
3505 
3506  Inherited::VisitCXXMemberCallExpr(E);
3507  }
3508 
3509  void VisitCallExpr(CallExpr *E) {
3510  // Treat std::move as a use.
3511  if (E->isCallToStdMove()) {
3512  HandleValue(E->getArg(0), /*AddressOf=*/false);
3513  return;
3514  }
3515 
3516  Inherited::VisitCallExpr(E);
3517  }
3518 
3519  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3520  Expr *Callee = E->getCallee();
3521 
3522  if (isa<UnresolvedLookupExpr>(Callee))
3523  return Inherited::VisitCXXOperatorCallExpr(E);
3524 
3525  Visit(Callee);
3526  for (auto Arg : E->arguments())
3527  HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3528  }
3529 
3530  void VisitBinaryOperator(BinaryOperator *E) {
3531  // If a field assignment is detected, remove the field from the
3532  // uninitiailized field set.
3533  if (E->getOpcode() == BO_Assign)
3534  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3535  if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3536  if (!FD->getType()->isReferenceType())
3537  DeclsToRemove.push_back(FD);
3538 
3539  if (E->isCompoundAssignmentOp()) {
3540  HandleValue(E->getLHS(), false /*AddressOf*/);
3541  Visit(E->getRHS());
3542  return;
3543  }
3544 
3545  Inherited::VisitBinaryOperator(E);
3546  }
3547 
3548  void VisitUnaryOperator(UnaryOperator *E) {
3549  if (E->isIncrementDecrementOp()) {
3550  HandleValue(E->getSubExpr(), false /*AddressOf*/);
3551  return;
3552  }
3553  if (E->getOpcode() == UO_AddrOf) {
3554  if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3555  HandleValue(ME->getBase(), true /*AddressOf*/);
3556  return;
3557  }
3558  }
3559 
3560  Inherited::VisitUnaryOperator(E);
3561  }
3562  };
3563 
3564  // Diagnose value-uses of fields to initialize themselves, e.g.
3565  // foo(foo)
3566  // where foo is not also a parameter to the constructor.
3567  // Also diagnose across field uninitialized use such as
3568  // x(y), y(x)
3569  // TODO: implement -Wuninitialized and fold this into that framework.
3570  static void DiagnoseUninitializedFields(
3571  Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3572 
3573  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3574  Constructor->getLocation())) {
3575  return;
3576  }
3577 
3578  if (Constructor->isInvalidDecl())
3579  return;
3580 
3581  const CXXRecordDecl *RD = Constructor->getParent();
3582 
3583  if (RD->getDescribedClassTemplate())
3584  return;
3585 
3586  // Holds fields that are uninitialized.
3587  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3588 
3589  // At the beginning, all fields are uninitialized.
3590  for (auto *I : RD->decls()) {
3591  if (auto *FD = dyn_cast<FieldDecl>(I)) {
3592  UninitializedFields.insert(FD);
3593  } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3594  UninitializedFields.insert(IFD->getAnonField());
3595  }
3596  }
3597 
3598  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3599  for (auto I : RD->bases())
3600  UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3601 
3602  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3603  return;
3604 
3605  UninitializedFieldVisitor UninitializedChecker(SemaRef,
3606  UninitializedFields,
3607  UninitializedBaseClasses);
3608 
3609  for (const auto *FieldInit : Constructor->inits()) {
3610  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3611  break;
3612 
3613  Expr *InitExpr = FieldInit->getInit();
3614  if (!InitExpr)
3615  continue;
3616 
3618  dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3619  InitExpr = Default->getExpr();
3620  if (!InitExpr)
3621  continue;
3622  // In class initializers will point to the constructor.
3623  UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3624  FieldInit->getAnyMember(),
3625  FieldInit->getBaseClass());
3626  } else {
3627  UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3628  FieldInit->getAnyMember(),
3629  FieldInit->getBaseClass());
3630  }
3631  }
3632  }
3633 } // namespace
3634 
3635 /// Enter a new C++ default initializer scope. After calling this, the
3636 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3637 /// parsing or instantiating the initializer failed.
3639  // Create a synthetic function scope to represent the call to the constructor
3640  // that notionally surrounds a use of this initializer.
3641  PushFunctionScope();
3642 }
3643 
3644 /// This is invoked after parsing an in-class initializer for a
3645 /// non-static C++ class member, and after instantiating an in-class initializer
3646 /// in a class template. Such actions are deferred until the class is complete.
3648  SourceLocation InitLoc,
3649  Expr *InitExpr) {
3650  // Pop the notional constructor scope we created earlier.
3651  PopFunctionScopeInfo(nullptr, D);
3652 
3653  FieldDecl *FD = dyn_cast<FieldDecl>(D);
3654  assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3655  "must set init style when field is created");
3656 
3657  if (!InitExpr) {
3658  D->setInvalidDecl();
3659  if (FD)
3661  return;
3662  }
3663 
3664  if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3665  FD->setInvalidDecl();
3667  return;
3668  }
3669 
3670  ExprResult Init = InitExpr;
3671  if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3672  InitializedEntity Entity =
3677  InitExpr->getBeginLoc(),
3678  InitExpr->getEndLoc())
3679  : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
3680  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3681  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3682  if (Init.isInvalid()) {
3683  FD->setInvalidDecl();
3684  return;
3685  }
3686  }
3687 
3688  // C++11 [class.base.init]p7:
3689  // The initialization of each base and member constitutes a
3690  // full-expression.
3691  Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
3692  if (Init.isInvalid()) {
3693  FD->setInvalidDecl();
3694  return;
3695  }
3696 
3697  InitExpr = Init.get();
3698 
3699  FD->setInClassInitializer(InitExpr);
3700 }
3701 
3702 /// Find the direct and/or virtual base specifiers that
3703 /// correspond to the given base type, for use in base initialization
3704 /// within a constructor.
3705 static bool FindBaseInitializer(Sema &SemaRef,
3706  CXXRecordDecl *ClassDecl,
3707  QualType BaseType,
3708  const CXXBaseSpecifier *&DirectBaseSpec,
3709  const CXXBaseSpecifier *&VirtualBaseSpec) {
3710  // First, check for a direct base class.
3711  DirectBaseSpec = nullptr;
3712  for (const auto &Base : ClassDecl->bases()) {
3713  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3714  // We found a direct base of this type. That's what we're
3715  // initializing.
3716  DirectBaseSpec = &Base;
3717  break;
3718  }
3719  }
3720 
3721  // Check for a virtual base class.
3722  // FIXME: We might be able to short-circuit this if we know in advance that
3723  // there are no virtual bases.
3724  VirtualBaseSpec = nullptr;
3725  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3726  // We haven't found a base yet; search the class hierarchy for a
3727  // virtual base class.
3728  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3729  /*DetectVirtual=*/false);
3730  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3731  SemaRef.Context.getTypeDeclType(ClassDecl),
3732  BaseType, Paths)) {
3733  for (CXXBasePaths::paths_iterator Path = Paths.begin();
3734  Path != Paths.end(); ++Path) {
3735  if (Path->back().Base->isVirtual()) {
3736  VirtualBaseSpec = Path->back().Base;
3737  break;
3738  }
3739  }
3740  }
3741  }
3742 
3743  return DirectBaseSpec || VirtualBaseSpec;
3744 }
3745 
3746 /// Handle a C++ member initializer using braced-init-list syntax.
3748 Sema::ActOnMemInitializer(Decl *ConstructorD,
3749  Scope *S,
3750  CXXScopeSpec &SS,
3751  IdentifierInfo *MemberOrBase,
3752  ParsedType TemplateTypeTy,
3753  const DeclSpec &DS,
3754  SourceLocation IdLoc,
3755  Expr *InitList,
3756  SourceLocation EllipsisLoc) {
3757  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3758  DS, IdLoc, InitList,
3759  EllipsisLoc);
3760 }
3761 
3762 /// Handle a C++ member initializer using parentheses syntax.
3764 Sema::ActOnMemInitializer(Decl *ConstructorD,
3765  Scope *S,
3766  CXXScopeSpec &SS,
3767  IdentifierInfo *MemberOrBase,
3768  ParsedType TemplateTypeTy,
3769  const DeclSpec &DS,
3770  SourceLocation IdLoc,
3771  SourceLocation LParenLoc,
3772  ArrayRef<Expr *> Args,
3773  SourceLocation RParenLoc,
3774  SourceLocation EllipsisLoc) {
3775  Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
3776  return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3777  DS, IdLoc, List, EllipsisLoc);
3778 }
3779 
3780 namespace {
3781 
3782 // Callback to only accept typo corrections that can be a valid C++ member
3783 // intializer: either a non-static field member or a base class.
3784 class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
3785 public:
3786  explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
3787  : ClassDecl(ClassDecl) {}
3788 
3789  bool ValidateCandidate(const TypoCorrection &candidate) override {
3790  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
3791  if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
3792  return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
3793  return isa<TypeDecl>(ND);
3794  }
3795  return false;
3796  }
3797 
3798  std::unique_ptr<CorrectionCandidateCallback> clone() override {
3799  return llvm::make_unique<MemInitializerValidatorCCC>(*this);
3800  }
3801 
3802 private:
3803  CXXRecordDecl *ClassDecl;
3804 };
3805 
3806 }
3807 
3808 ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
3809  CXXScopeSpec &SS,
3810  ParsedType TemplateTypeTy,
3811  IdentifierInfo *MemberOrBase) {
3812  if (SS.getScopeRep() || TemplateTypeTy)
3813  return nullptr;
3814  DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
3815  if (Result.empty())
3816  return nullptr;
3817  ValueDecl *Member;
3818  if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
3819  (Member = dyn_cast<IndirectFieldDecl>(Result.front())))
3820  return Member;
3821  return nullptr;
3822 }
3823 
3824 /// Handle a C++ member initializer.
3826 Sema::BuildMemInitializer(Decl *ConstructorD,
3827  Scope *S,
3828  CXXScopeSpec &SS,
3829  IdentifierInfo *MemberOrBase,
3830  ParsedType TemplateTypeTy,
3831  const DeclSpec &DS,
3832  SourceLocation IdLoc,
3833  Expr *Init,
3834  SourceLocation EllipsisLoc) {
3835  ExprResult Res = CorrectDelayedTyposInExpr(Init);
3836  if (!Res.isUsable())
3837  return true;
3838  Init = Res.get();
3839 
3840  if (!ConstructorD)
3841  return true;
3842 
3843  AdjustDeclIfTemplate(ConstructorD);
3844 
3845  CXXConstructorDecl *Constructor
3846  = dyn_cast<CXXConstructorDecl>(ConstructorD);
3847  if (!Constructor) {
3848  // The user wrote a constructor initializer on a function that is
3849  // not a C++ constructor. Ignore the error for now, because we may
3850  // have more member initializers coming; we'll diagnose it just
3851  // once in ActOnMemInitializers.
3852  return true;
3853  }
3854 
3855  CXXRecordDecl *ClassDecl = Constructor->getParent();
3856 
3857  // C++ [class.base.init]p2:
3858  // Names in a mem-initializer-id are looked up in the scope of the
3859  // constructor's class and, if not found in that scope, are looked
3860  // up in the scope containing the constructor's definition.
3861  // [Note: if the constructor's class contains a member with the
3862  // same name as a direct or virtual base class of the class, a
3863  // mem-initializer-id naming the member or base class and composed
3864  // of a single identifier refers to the class member. A
3865  // mem-initializer-id for the hidden base class may be specified
3866  // using a qualified name. ]
3867 
3868  // Look for a member, first.
3869  if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
3870  ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
3871  if (EllipsisLoc.isValid())
3872  Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
3873  << MemberOrBase
3874  << SourceRange(IdLoc, Init->getSourceRange().getEnd());
3875 
3876  return BuildMemberInitializer(Member, Init, IdLoc);
3877  }
3878  // It didn't name a member, so see if it names a class.
3879  QualType BaseType;
3880  TypeSourceInfo *TInfo = nullptr;
3881 
3882  if (TemplateTypeTy) {
3883  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
3884  } else if (DS.getTypeSpecType() == TST_decltype) {
3885  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
3886  } else if (DS.getTypeSpecType() == TST_decltype_auto) {
3887  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
3888  return true;
3889  } else {
3890  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
3891  LookupParsedName(R, S, &SS);
3892 
3893  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
3894  if (!TyD) {
3895  if (R.isAmbiguous()) return true;
3896 
3897  // We don't want access-control diagnostics here.
3898  R.suppressDiagnostics();
3899 
3900  if (SS.isSet() && isDependentScopeSpecifier(SS)) {
3901  bool NotUnknownSpecialization = false;
3902  DeclContext *DC = computeDeclContext(SS, false);
3903  if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
3904  NotUnknownSpecialization = !Record->hasAnyDependentBases();
3905 
3906  if (!NotUnknownSpecialization) {
3907  // When the scope specifier can refer to a member of an unknown
3908  // specialization, we take it as a type name.
3909  BaseType = CheckTypenameType(ETK_None, SourceLocation(),
3910  SS.getWithLocInContext(Context),
3911  *MemberOrBase, IdLoc);
3912  if (BaseType.isNull())
3913  return true;
3914 
3915  TInfo = Context.CreateTypeSourceInfo(BaseType);
3918  if (!TL.isNull()) {
3919  TL.setNameLoc(IdLoc);
3921  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3922  }
3923 
3924  R.clear();
3925  R.setLookupName(MemberOrBase);
3926  }
3927  }
3928 
3929  // If no results were found, try to correct typos.
3930  TypoCorrection Corr;
3931  MemInitializerValidatorCCC CCC(ClassDecl);
3932  if (R.empty() && BaseType.isNull() &&
3933  (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
3934  CCC, CTK_ErrorRecovery, ClassDecl))) {
3935  if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
3936  // We have found a non-static data member with a similar
3937  // name to what was typed; complain and initialize that
3938  // member.
3939  diagnoseTypo(Corr,
3940  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3941  << MemberOrBase << true);
3942  return BuildMemberInitializer(Member, Init, IdLoc);
3943  } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
3944  const CXXBaseSpecifier *DirectBaseSpec;
3945  const CXXBaseSpecifier *VirtualBaseSpec;
3946  if (FindBaseInitializer(*this, ClassDecl,
3947  Context.getTypeDeclType(Type),
3948  DirectBaseSpec, VirtualBaseSpec)) {
3949  // We have found a direct or virtual base class with a
3950  // similar name to what was typed; complain and initialize
3951  // that base class.
3952  diagnoseTypo(Corr,
3953  PDiag(diag::err_mem_init_not_member_or_class_suggest)
3954  << MemberOrBase << false,
3955  PDiag() /*Suppress note, we provide our own.*/);
3956 
3957  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
3958  : VirtualBaseSpec;
3959  Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
3960  << BaseSpec->getType() << BaseSpec->getSourceRange();
3961 
3962  TyD = Type;
3963  }
3964  }
3965  }
3966 
3967  if (!TyD && BaseType.isNull()) {
3968  Diag(IdLoc, diag::err_mem_init_not_member_or_class)
3969  << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
3970  return true;
3971  }
3972  }
3973 
3974  if (BaseType.isNull()) {
3975  BaseType = Context.getTypeDeclType(TyD);
3976  MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
3977  if (SS.isSet()) {
3978  BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
3979  BaseType);
3980  TInfo = Context.CreateTypeSourceInfo(BaseType);
3982  TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
3984  TL.setQualifierLoc(SS.getWithLocInContext(Context));
3985  }
3986  }
3987  }
3988 
3989  if (!TInfo)
3990  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
3991 
3992  return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
3993 }
3994 
3997  SourceLocation IdLoc) {
3998  FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
3999  IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4000  assert((DirectMember || IndirectMember) &&
4001  "Member must be a FieldDecl or IndirectFieldDecl");
4002 
4003  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4004  return true;
4005 
4006  if (Member->isInvalidDecl())
4007  return true;
4008 
4009  MultiExprArg Args;
4010  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4011  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4012  } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4013  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4014  } else {
4015  // Template instantiation doesn't reconstruct ParenListExprs for us.
4016  Args = Init;
4017  }
4018 
4019  SourceRange InitRange = Init->getSourceRange();
4020 
4021  if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4022  // Can't check initialization for a member of dependent type or when
4023  // any of the arguments are type-dependent expressions.
4024  DiscardCleanupsInEvaluationContext();
4025  } else {
4026  bool InitList = false;
4027  if (isa<InitListExpr>(Init)) {
4028  InitList = true;
4029  Args = Init;
4030  }
4031 
4032  // Initialize the member.
4033  InitializedEntity MemberEntity =
4034  DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4035  : InitializedEntity::InitializeMember(IndirectMember,
4036  nullptr);
4039  IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4040  : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4041  InitRange.getEnd());
4042 
4043  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4044  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4045  nullptr);
4046  if (MemberInit.isInvalid())
4047  return true;
4048 
4049  // C++11 [class.base.init]p7:
4050  // The initialization of each base and member constitutes a
4051  // full-expression.
4052  MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4053  /*DiscardedValue*/ false);
4054  if (MemberInit.isInvalid())
4055  return true;
4056 
4057  Init = MemberInit.get();
4058  }
4059 
4060  if (DirectMember) {
4061  return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4062  InitRange.getBegin(), Init,
4063  InitRange.getEnd());
4064  } else {
4065  return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4066  InitRange.getBegin(), Init,
4067  InitRange.getEnd());
4068  }
4069 }
4070 
4073  CXXRecordDecl *ClassDecl) {
4074  SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4075  if (!LangOpts.CPlusPlus11)
4076  return Diag(NameLoc, diag::err_delegating_ctor)
4077  << TInfo->getTypeLoc().getLocalSourceRange();
4078  Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4079 
4080  bool InitList = true;
4081  MultiExprArg Args = Init;
4082  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4083  InitList = false;
4084  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4085  }
4086 
4087  SourceRange InitRange = Init->getSourceRange();
4088  // Initialize the object.
4090  QualType(ClassDecl->getTypeForDecl(), 0));
4093  NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4094  : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4095  InitRange.getEnd());
4096  InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4097  ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4098  Args, nullptr);
4099  if (DelegationInit.isInvalid())
4100  return true;
4101 
4102  assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4103  "Delegating constructor with no target?");
4104 
4105  // C++11 [class.base.init]p7:
4106  // The initialization of each base and member constitutes a
4107  // full-expression.
4108  DelegationInit = ActOnFinishFullExpr(
4109  DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4110  if (DelegationInit.isInvalid())
4111  return true;
4112 
4113  // If we are in a dependent context, template instantiation will
4114  // perform this type-checking again. Just save the arguments that we
4115  // received in a ParenListExpr.
4116  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4117  // of the information that we have about the base
4118  // initializer. However, deconstructing the ASTs is a dicey process,
4119  // and this approach is far more likely to get the corner cases right.
4120  if (CurContext->isDependentContext())
4121  DelegationInit = Init;
4122 
4123  return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4124  DelegationInit.getAs<Expr>(),
4125  InitRange.getEnd());
4126 }
4127 
4130  Expr *Init, CXXRecordDecl *ClassDecl,
4131  SourceLocation EllipsisLoc) {
4132  SourceLocation BaseLoc
4133  = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4134 
4135  if (!BaseType->isDependentType() && !BaseType->isRecordType())
4136  return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4137  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4138 
4139  // C++ [class.base.init]p2:
4140  // [...] Unless the mem-initializer-id names a nonstatic data
4141  // member of the constructor's class or a direct or virtual base
4142  // of that class, the mem-initializer is ill-formed. A
4143  // mem-initializer-list can initialize a base class using any
4144  // name that denotes that base class type.
4145  bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4146 
4147  SourceRange InitRange = Init->getSourceRange();
4148  if (EllipsisLoc.isValid()) {
4149  // This is a pack expansion.
4150  if (!BaseType->containsUnexpandedParameterPack()) {
4151  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4152  << SourceRange(BaseLoc, InitRange.getEnd());
4153 
4154  EllipsisLoc = SourceLocation();
4155  }
4156  } else {
4157  // Check for any unexpanded parameter packs.
4158  if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4159  return true;
4160 
4161  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4162  return true;
4163  }
4164 
4165  // Check for direct and virtual base classes.
4166  const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4167  const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4168  if (!Dependent) {
4169  if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4170  BaseType))
4171  return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4172 
4173  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4174  VirtualBaseSpec);
4175 
4176  // C++ [base.class.init]p2:
4177  // Unless the mem-initializer-id names a nonstatic data member of the
4178  // constructor's class or a direct or virtual base of that class, the
4179  // mem-initializer is ill-formed.
4180  if (!DirectBaseSpec && !VirtualBaseSpec) {
4181  // If the class has any dependent bases, then it's possible that
4182  // one of those types will resolve to the same type as
4183  // BaseType. Therefore, just treat this as a dependent base
4184  // class initialization. FIXME: Should we try to check the
4185  // initialization anyway? It seems odd.
4186  if (ClassDecl->hasAnyDependentBases())
4187  Dependent = true;
4188  else
4189  return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4190  << BaseType << Context.getTypeDeclType(ClassDecl)
4191  << BaseTInfo->getTypeLoc().getLocalSourceRange();
4192  }
4193  }
4194 
4195  if (Dependent) {
4196  DiscardCleanupsInEvaluationContext();
4197 
4198  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4199  /*IsVirtual=*/false,
4200  InitRange.getBegin(), Init,
4201  InitRange.getEnd(), EllipsisLoc);
4202  }
4203 
4204  // C++ [base.class.init]p2:
4205  // If a mem-initializer-id is ambiguous because it designates both
4206  // a direct non-virtual base class and an inherited virtual base
4207  // class, the mem-initializer is ill-formed.
4208  if (DirectBaseSpec && VirtualBaseSpec)
4209  return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4210  << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4211 
4212  const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4213  if (!BaseSpec)
4214  BaseSpec = VirtualBaseSpec;
4215 
4216  // Initialize the base.
4217  bool InitList = true;
4218  MultiExprArg Args = Init;
4219  if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4220  InitList = false;
4221  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4222  }
4223 
4224  InitializedEntity BaseEntity =
4225  InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4227  InitList ? InitializationKind::CreateDirectList(BaseLoc)
4228  : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4229  InitRange.getEnd());
4230  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4231  ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4232  if (BaseInit.isInvalid())
4233  return true;
4234 
4235  // C++11 [class.base.init]p7:
4236  // The initialization of each base and member constitutes a
4237  // full-expression.
4238  BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4239  /*DiscardedValue*/ false);
4240  if (BaseInit.isInvalid())
4241  return true;
4242 
4243  // If we are in a dependent context, template instantiation will
4244  // perform this type-checking again. Just save the arguments that we
4245  // received in a ParenListExpr.
4246  // FIXME: This isn't quite ideal, since our ASTs don't capture all
4247  // of the information that we have about the base
4248  // initializer. However, deconstructing the ASTs is a dicey process,
4249  // and this approach is far more likely to get the corner cases right.
4250  if (CurContext->isDependentContext())
4251  BaseInit = Init;
4252 
4253  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4254  BaseSpec->isVirtual(),
4255  InitRange.getBegin(),
4256  BaseInit.getAs<Expr>(),
4257  InitRange.getEnd(), EllipsisLoc);
4258 }
4259 
4260 // Create a static_cast<T&&>(expr).
4261 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4262  if (T.isNull()) T = E->getType();
4263  QualType TargetType = SemaRef.BuildReferenceType(
4264  T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4265  SourceLocation ExprLoc = E->getBeginLoc();
4266  TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4267  TargetType, ExprLoc);
4268 
4269  return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4270  SourceRange(ExprLoc, ExprLoc),
4271  E->getSourceRange()).get();
4272 }
4273 
4274 /// ImplicitInitializerKind - How an implicit base or member initializer should
4275 /// initialize its base or member.
4281 };
4282 
4283 static bool
4285  ImplicitInitializerKind ImplicitInitKind,
4286  CXXBaseSpecifier *BaseSpec,
4287  bool IsInheritedVirtualBase,
4288  CXXCtorInitializer *&CXXBaseInit) {
4289  InitializedEntity InitEntity
4290  = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4291  IsInheritedVirtualBase);
4292 
4293  ExprResult BaseInit;
4294 
4295  switch (ImplicitInitKind) {
4296  case IIK_Inherit:
4297  case IIK_Default: {
4298  InitializationKind InitKind
4300  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4301  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4302  break;
4303  }
4304 
4305  case IIK_Move:
4306  case IIK_Copy: {
4307  bool Moving = ImplicitInitKind == IIK_Move;
4308  ParmVarDecl *Param = Constructor->getParamDecl(0);
4309  QualType ParamType = Param->getType().getNonReferenceType();
4310 
4311  Expr *CopyCtorArg =
4313  SourceLocation(), Param, false,
4314  Constructor->getLocation(), ParamType,
4315  VK_LValue, nullptr);
4316 
4317  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4318 
4319  // Cast to the base class to avoid ambiguities.
4320  QualType ArgTy =
4321  SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4322  ParamType.getQualifiers());
4323 
4324  if (Moving) {
4325  CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4326  }
4327 
4328  CXXCastPath BasePath;
4329  BasePath.push_back(BaseSpec);
4330  CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4331  CK_UncheckedDerivedToBase,
4332  Moving ? VK_XValue : VK_LValue,
4333  &BasePath).get();
4334 
4335  InitializationKind InitKind
4338  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4339  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4340  break;
4341  }
4342  }
4343 
4344  BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4345  if (BaseInit.isInvalid())
4346  return true;
4347 
4348  CXXBaseInit =
4349  new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4350  SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4351  SourceLocation()),
4352  BaseSpec->isVirtual(),
4353  SourceLocation(),
4354  BaseInit.getAs<Expr>(),
4355  SourceLocation(),
4356  SourceLocation());
4357 
4358  return false;
4359 }
4360 
4361 static bool RefersToRValueRef(Expr *MemRef) {
4362  ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4363  return Referenced->getType()->isRValueReferenceType();
4364 }
4365 
4366 static bool
4368  ImplicitInitializerKind ImplicitInitKind,
4369  FieldDecl *Field, IndirectFieldDecl *Indirect,
4370  CXXCtorInitializer *&CXXMemberInit) {
4371  if (Field->isInvalidDecl())
4372  return true;
4373 
4374  SourceLocation Loc = Constructor->getLocation();
4375 
4376  if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4377  bool Moving = ImplicitInitKind == IIK_Move;
4378  ParmVarDecl *Param = Constructor->getParamDecl(0);
4379  QualType ParamType = Param->getType().getNonReferenceType();
4380 
4381  // Suppress copying zero-width bitfields.
4382  if (Field->isZeroLengthBitField(SemaRef.Context))
4383  return false;
4384 
4385  Expr *MemberExprBase =
4387  SourceLocation(), Param, false,
4388  Loc, ParamType, VK_LValue, nullptr);
4389 
4390  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4391 
4392  if (Moving) {
4393  MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4394  }
4395 
4396  // Build a reference to this field within the parameter.
4397  CXXScopeSpec SS;
4398  LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4400  MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4401  : cast<ValueDecl>(Field), AS_public);
4402  MemberLookup.resolveKind();
4403  ExprResult CtorArg
4404  = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4405  ParamType, Loc,
4406  /*IsArrow=*/false,
4407  SS,
4408  /*TemplateKWLoc=*/SourceLocation(),
4409  /*FirstQualifierInScope=*/nullptr,
4410  MemberLookup,
4411  /*TemplateArgs=*/nullptr,
4412  /*S*/nullptr);
4413  if (CtorArg.isInvalid())
4414  return true;
4415 
4416  // C++11 [class.copy]p15:
4417  // - if a member m has rvalue reference type T&&, it is direct-initialized
4418  // with static_cast<T&&>(x.m);
4419  if (RefersToRValueRef(CtorArg.get())) {
4420  CtorArg = CastForMoving(SemaRef, CtorArg.get());
4421  }
4422 
4423  InitializedEntity Entity =
4424  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4425  /*Implicit*/ true)
4426  : InitializedEntity::InitializeMember(Field, nullptr,
4427  /*Implicit*/ true);
4428 
4429  // Direct-initialize to use the copy constructor.
4430  InitializationKind InitKind =
4432 
4433  Expr *CtorArgE = CtorArg.getAs<Expr>();
4434  InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4435  ExprResult MemberInit =
4436  InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4437  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4438  if (MemberInit.isInvalid())
4439  return true;
4440 
4441  if (Indirect)
4442  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4443  SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4444  else
4445  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4446  SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4447  return false;
4448  }
4449 
4450  assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4451  "Unhandled implicit init kind!");
4452 
4453  QualType FieldBaseElementType =
4454  SemaRef.Context.getBaseElementType(Field->getType());
4455 
4456  if (FieldBaseElementType->isRecordType()) {
4457  InitializedEntity InitEntity =
4458  Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4459  /*Implicit*/ true)
4460  : InitializedEntity::InitializeMember(Field, nullptr,
4461  /*Implicit*/ true);
4462  InitializationKind InitKind =
4464 
4465  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4466  ExprResult MemberInit =
4467  InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4468 
4469  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4470  if (MemberInit.isInvalid())
4471  return true;
4472 
4473  if (Indirect)
4474  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4475  Indirect, Loc,
4476  Loc,
4477  MemberInit.get(),
4478  Loc);
4479  else
4480  CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4481  Field, Loc, Loc,
4482  MemberInit.get(),
4483  Loc);
4484  return false;
4485  }
4486 
4487  if (!Field->getParent()->isUnion()) {
4488  if (FieldBaseElementType->isReferenceType()) {
4489  SemaRef.Diag(Constructor->getLocation(),
4490  diag::err_uninitialized_member_in_ctor)
4491  << (int)Constructor->isImplicit()
4492  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4493  << 0 << Field->getDeclName();
4494  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4495  return true;
4496  }
4497 
4498  if (FieldBaseElementType.isConstQualified()) {
4499  SemaRef.Diag(Constructor->getLocation(),
4500  diag::err_uninitialized_member_in_ctor)
4501  << (int)Constructor->isImplicit()
4502  << SemaRef.Context.getTagDeclType(Constructor->getParent())
4503  << 1 << Field->getDeclName();
4504  SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4505  return true;
4506  }
4507  }
4508 
4509  if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4510  // ARC and Weak:
4511  // Default-initialize Objective-C pointers to NULL.
4512  CXXMemberInit
4513  = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4514  Loc, Loc,
4515  new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4516  Loc);
4517  return false;
4518  }
4519 
4520  // Nothing to initialize.
4521  CXXMemberInit = nullptr;
4522  return false;
4523 }
4524 
4525 namespace {
4526 struct BaseAndFieldInfo {
4527  Sema &S;
4528  CXXConstructorDecl *Ctor;
4529  bool AnyErrorsInInits;
4531  llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4533  llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4534 
4535  BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4536  : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4537  bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4538  if (Ctor->getInheritedConstructor())
4539  IIK = IIK_Inherit;
4540  else if (Generated && Ctor->isCopyConstructor())
4541  IIK = IIK_Copy;
4542  else if (Generated && Ctor->isMoveConstructor())
4543  IIK = IIK_Move;
4544  else
4545  IIK = IIK_Default;
4546  }
4547 
4548  bool isImplicitCopyOrMove() const {
4549  switch (IIK) {
4550  case IIK_Copy:
4551  case IIK_Move:
4552  return true;
4553 
4554  case IIK_Default:
4555  case IIK_Inherit:
4556  return false;
4557  }
4558 
4559  llvm_unreachable("Invalid ImplicitInitializerKind!");
4560  }
4561 
4562  bool addFieldInitializer(CXXCtorInitializer *Init) {
4563  AllToInit.push_back(Init);
4564 
4565  // Check whether this initializer makes the field "used".
4566  if (Init->getInit()->HasSideEffects(S.Context))
4567  S.UnusedPrivateFields.remove(Init->getAnyMember());
4568 
4569  return false;
4570  }
4571 
4572  bool isInactiveUnionMember(FieldDecl *Field) {
4573  RecordDecl *Record = Field->getParent();
4574  if (!Record->isUnion())
4575  return false;
4576 
4577  if (FieldDecl *Active =
4578  ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4579  return Active != Field->getCanonicalDecl();
4580 
4581  // In an implicit copy or move constructor, ignore any in-class initializer.
4582  if (isImplicitCopyOrMove())
4583  return true;
4584 
4585  // If there's no explicit initialization, the field is active only if it
4586  // has an in-class initializer...
4587  if (Field->hasInClassInitializer())
4588  return false;
4589  // ... or it's an anonymous struct or union whose class has an in-class
4590  // initializer.
4591  if (!Field->isAnonymousStructOrUnion())
4592  return true;
4593  CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4594  return !FieldRD->hasInClassInitializer();
4595  }
4596 
4597  /// Determine whether the given field is, or is within, a union member
4598  /// that is inactive (because there was an initializer given for a different
4599  /// member of the union, or because the union was not initialized at all).
4600  bool isWithinInactiveUnionMember(FieldDecl *Field,
4601  IndirectFieldDecl *Indirect) {
4602  if (!Indirect)
4603  return isInactiveUnionMember(Field);
4604 
4605  for (auto *C : Indirect->chain()) {
4606  FieldDecl *Field = dyn_cast<FieldDecl>(C);
4607  if (Field && isInactiveUnionMember(Field))
4608  return true;
4609  }
4610  return false;
4611  }
4612 };
4613 }
4614 
4615 /// Determine whether the given type is an incomplete or zero-lenfgth
4616 /// array type.
4618  if (T->isIncompleteArrayType())
4619  return true;
4620 
4621  while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4622  if (!ArrayT->getSize())
4623  return true;
4624 
4625  T = ArrayT->getElementType();
4626  }
4627 
4628  return false;
4629 }
4630 
4631 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4632  FieldDecl *Field,
4633  IndirectFieldDecl *Indirect = nullptr) {
4634  if (Field->isInvalidDecl())
4635  return false;
4636 
4637  // Overwhelmingly common case: we have a direct initializer for this field.
4638  if (CXXCtorInitializer *Init =
4639  Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4640  return Info.addFieldInitializer(Init);
4641 
4642  // C++11 [class.base.init]p8:
4643  // if the entity is a non-static data member that has a
4644  // brace-or-equal-initializer and either
4645  // -- the constructor's class is a union and no other variant member of that
4646  // union is designated by a mem-initializer-id or
4647  // -- the constructor's class is not a union, and, if the entity is a member
4648  // of an anonymous union, no other member of that union is designated by
4649  // a mem-initializer-id,
4650  // the entity is initialized as specified in [dcl.init].
4651  //
4652  // We also apply the same rules to handle anonymous structs within anonymous
4653  // unions.
4654  if (Info.isWithinInactiveUnionMember(Field, Indirect))
4655  return false;
4656 
4657  if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4658  ExprResult DIE =
4659  SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4660  if (DIE.isInvalid())
4661  return true;
4662 
4663  auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4664  SemaRef.checkInitializerLifetime(Entity, DIE.get());
4665 
4666  CXXCtorInitializer *Init;
4667  if (Indirect)
4668  Init = new (SemaRef.Context)
4669  CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4670  SourceLocation(), DIE.get(), SourceLocation());
4671  else
4672  Init = new (SemaRef.Context)
4673  CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4674  SourceLocation(), DIE.get(), SourceLocation());
4675  return Info.addFieldInitializer(Init);
4676  }
4677 
4678  // Don't initialize incomplete or zero-length arrays.
4679  if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4680  return false;
4681 
4682  // Don't try to build an implicit initializer if there were semantic
4683  // errors in any of the initializers (and therefore we might be
4684  // missing some that the user actually wrote).
4685  if (Info.AnyErrorsInInits)
4686  return false;
4687 
4688  CXXCtorInitializer *Init = nullptr;
4689  if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4690  Indirect, Init))
4691  return true;
4692 
4693  if (!Init)
4694  return false;
4695 
4696  return Info.addFieldInitializer(Init);
4697 }
4698 
4699 bool
4701  CXXCtorInitializer *Initializer) {
4702  assert(Initializer->isDelegatingInitializer());
4703  Constructor->setNumCtorInitializers(1);
4704  CXXCtorInitializer **initializer =
4705  new (Context) CXXCtorInitializer*[1];
4706  memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4707  Constructor->setCtorInitializers(initializer);
4708 
4709  if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4710  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4711  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4712  }
4713 
4714  DelegatingCtorDecls.push_back(Constructor);
4715 
4716  DiagnoseUninitializedFields(*this, Constructor);
4717 
4718  return false;
4719 }
4720 
4721 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4722  ArrayRef<CXXCtorInitializer *> Initializers) {
4723  if (Constructor->isDependentContext()) {
4724  // Just store the initializers as written, they will be checked during
4725  // instantiation.
4726  if (!Initializers.empty()) {
4727  Constructor->setNumCtorInitializers(Initializers.size());
4728  CXXCtorInitializer **baseOrMemberInitializers =
4729  new (Context) CXXCtorInitializer*[Initializers.size()];
4730  memcpy(baseOrMemberInitializers, Initializers.data(),
4731  Initializers.size() * sizeof(CXXCtorInitializer*));
4732  Constructor->setCtorInitializers(baseOrMemberInitializers);
4733  }
4734 
4735  // Let template instantiation know whether we had errors.
4736  if (AnyErrors)
4737  Constructor->setInvalidDecl();
4738 
4739  return false;
4740  }
4741 
4742  BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4743 
4744  // We need to build the initializer AST according to order of construction
4745  // and not what user specified in the Initializers list.
4746  CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4747  if (!ClassDecl)
4748  return true;
4749 
4750  bool HadError = false;
4751 
4752  for (unsigned i = 0; i < Initializers.size(); i++) {
4753  CXXCtorInitializer *Member = Initializers[i];
4754 
4755  if (Member->isBaseInitializer())
4756  Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
4757  else {
4758  Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
4759 
4760  if (IndirectFieldDecl *F = Member->getIndirectMember()) {
4761  for (auto *C : F->chain()) {
4762  FieldDecl *FD = dyn_cast<FieldDecl>(C);
4763  if (FD && FD->getParent()->isUnion())
4764  Info.ActiveUnionMember.insert(std::make_pair(
4765  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4766  }
4767  } else if (FieldDecl *FD = Member->getMember()) {
4768  if (FD->getParent()->isUnion())
4769  Info.ActiveUnionMember.insert(std::make_pair(
4770  FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4771  }
4772  }
4773  }
4774 
4775  // Keep track of the direct virtual bases.
4776  llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
4777  for (auto &I : ClassDecl->bases()) {
4778  if (I.isVirtual())
4779  DirectVBases.insert(&I);
4780  }
4781 
4782  // Push virtual bases before others.
4783  for (auto &VBase : ClassDecl->vbases()) {
4785  = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
4786  // [class.base.init]p7, per DR257:
4787  // A mem-initializer where the mem-initializer-id names a virtual base
4788  // class is ignored during execution of a constructor of any class that
4789  // is not the most derived class.
4790  if (ClassDecl->isAbstract()) {
4791  // FIXME: Provide a fixit to remove the base specifier. This requires
4792  // tracking the location of the associated comma for a base specifier.
4793  Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
4794  << VBase.getType() << ClassDecl;
4795  DiagnoseAbstractType(ClassDecl);
4796  }
4797 
4798  Info.AllToInit.push_back(Value);
4799  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
4800  // [class.base.init]p8, per DR257:
4801  // If a given [...] base class is not named by a mem-initializer-id
4802  // [...] and the entity is not a virtual base class of an abstract
4803  // class, then [...] the entity is default-initialized.
4804  bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
4805  CXXCtorInitializer *CXXBaseInit;
4806  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4807  &VBase, IsInheritedVirtualBase,
4808  CXXBaseInit)) {
4809  HadError = true;
4810  continue;
4811  }
4812 
4813  Info.AllToInit.push_back(CXXBaseInit);
4814  }
4815  }
4816 
4817  // Non-virtual bases.
4818  for (auto &Base : ClassDecl->bases()) {
4819  // Virtuals are in the virtual base list and already constructed.
4820  if (Base.isVirtual())
4821  continue;
4822 
4824  = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
4825  Info.AllToInit.push_back(Value);
4826  } else if (!AnyErrors) {
4827  CXXCtorInitializer *CXXBaseInit;
4828  if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
4829  &Base, /*IsInheritedVirtualBase=*/false,
4830  CXXBaseInit)) {
4831  HadError = true;
4832  continue;
4833  }
4834 
4835  Info.AllToInit.push_back(CXXBaseInit);
4836  }
4837  }
4838 
4839  // Fields.
4840  for (auto *Mem : ClassDecl->decls()) {
4841  if (auto *F = dyn_cast<FieldDecl>(Mem)) {
4842  // C++ [class.bit]p2:
4843  // A declaration for a bit-field that omits the identifier declares an
4844  // unnamed bit-field. Unnamed bit-fields are not members and cannot be
4845  // initialized.
4846  if (F->isUnnamedBitfield())
4847  continue;
4848 
4849  // If we're not generating the implicit copy/move constructor, then we'll
4850  // handle anonymous struct/union fields based on their individual
4851  // indirect fields.
4852  if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
4853  continue;
4854 
4855  if (CollectFieldInitializer(*this, Info, F))
4856  HadError = true;
4857  continue;
4858  }
4859 
4860  // Beyond this point, we only consider default initialization.
4861  if (Info.isImplicitCopyOrMove())
4862  continue;
4863 
4864  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
4865  if (F->getType()->isIncompleteArrayType()) {
4866  assert(ClassDecl->hasFlexibleArrayMember() &&
4867  "Incomplete array type is not valid");
4868  continue;
4869  }
4870 
4871  // Initialize each field of an anonymous struct individually.
4872  if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
4873  HadError = true;
4874 
4875  continue;
4876  }
4877  }
4878 
4879  unsigned NumInitializers = Info.AllToInit.size();
4880  if (NumInitializers > 0) {
4881  Constructor->setNumCtorInitializers(NumInitializers);
4882  CXXCtorInitializer **baseOrMemberInitializers =
4883  new (Context) CXXCtorInitializer*[NumInitializers];
4884  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
4885  NumInitializers * sizeof(CXXCtorInitializer*));
4886  Constructor->setCtorInitializers(baseOrMemberInitializers);
4887 
4888  // Constructors implicitly reference the base and member
4889  // destructors.
4890  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
4891  Constructor->getParent());
4892  }
4893 
4894  return HadError;
4895 }
4896 
4898  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
4899  const RecordDecl *RD = RT->getDecl();
4900  if (RD->isAnonymousStructOrUnion()) {
4901  for (auto *Field : RD->fields())
4902  PopulateKeysForFields(Field, IdealInits);
4903  return;
4904  }
4905  }
4906  IdealInits.push_back(Field->getCanonicalDecl());
4907 }
4908 
4909 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
4910  return Context.getCanonicalType(BaseType).getTypePtr();
4911 }
4912 
4913 static const void *GetKeyForMember(ASTContext &Context,
4914  CXXCtorInitializer *Member) {
4915  if (!Member->isAnyMemberInitializer())
4916  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
4917 
4918  return Member->getAnyMember()->getCanonicalDecl();
4919 }
4920 
4922  Sema &SemaRef, const CXXConstructorDecl *Constructor,
4924  if (Constructor->getDeclContext()->isDependentContext())
4925  return;
4926 
4927  // Don't check initializers order unless the warning is enabled at the
4928  // location of at least one initializer.
4929  bool ShouldCheckOrder = false;
4930  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4931  CXXCtorInitializer *Init = Inits[InitIndex];
4932  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
4933  Init->getSourceLocation())) {
4934  ShouldCheckOrder = true;
4935  break;
4936  }
4937  }
4938  if (!ShouldCheckOrder)
4939  return;
4940 
4941  // Build the list of bases and members in the order that they'll
4942  // actually be initialized. The explicit initializers should be in
4943  // this same order but may be missing things.
4944  SmallVector<const void*, 32> IdealInitKeys;
4945 
4946  const CXXRecordDecl *ClassDecl = Constructor->getParent();
4947 
4948  // 1. Virtual bases.
4949  for (const auto &VBase : ClassDecl->vbases())
4950  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
4951 
4952  // 2. Non-virtual bases.
4953  for (const auto &Base : ClassDecl->bases()) {
4954  if (Base.isVirtual())
4955  continue;
4956  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
4957  }
4958 
4959  // 3. Direct fields.
4960  for (auto *Field : ClassDecl->fields()) {
4961  if (Field->isUnnamedBitfield())
4962  continue;
4963 
4964  PopulateKeysForFields(Field, IdealInitKeys);
4965  }
4966 
4967  unsigned NumIdealInits = IdealInitKeys.size();
4968  unsigned IdealIndex = 0;
4969 
4970  CXXCtorInitializer *PrevInit = nullptr;
4971  for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
4972  CXXCtorInitializer *Init = Inits[InitIndex];
4973  const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
4974 
4975  // Scan forward to try to find this initializer in the idealized
4976  // initializers list.
4977  for (; IdealIndex != NumIdealInits; ++IdealIndex)
4978  if (InitKey == IdealInitKeys[IdealIndex])
4979  break;
4980 
4981  // If we didn't find this initializer, it must be because we
4982  // scanned past it on a previous iteration. That can only
4983  // happen if we're out of order; emit a warning.
4984  if (IdealIndex == NumIdealInits && PrevInit) {
4986  SemaRef.Diag(PrevInit->getSourceLocation(),
4987  diag::warn_initializer_out_of_order);
4988 
4989  if (PrevInit->isAnyMemberInitializer())
4990  D << 0 << PrevInit->getAnyMember()->getDeclName();
4991  else
4992  D << 1 << PrevInit->getTypeSourceInfo()->getType();
4993 
4994  if (Init->isAnyMemberInitializer())
4995  D << 0 << Init->getAnyMember()->getDeclName();
4996  else
4997  D << 1 << Init->getTypeSourceInfo()->getType();
4998 
4999  // Move back to the initializer's location in the ideal list.
5000  for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5001  if (InitKey == IdealInitKeys[IdealIndex])
5002  break;
5003 
5004  assert(IdealIndex < NumIdealInits &&
5005  "initializer not found in initializer list");
5006  }
5007 
5008  PrevInit = Init;
5009  }
5010 }
5011 
5012 namespace {
5013 bool CheckRedundantInit(Sema &S,
5014  CXXCtorInitializer *Init,
5015  CXXCtorInitializer *&PrevInit) {
5016  if (!PrevInit) {
5017  PrevInit = Init;
5018  return false;
5019  }
5020 
5021  if (FieldDecl *Field = Init->getAnyMember())
5022  S.Diag(Init->getSourceLocation(),
5023  diag::err_multiple_mem_initialization)
5024  << Field->getDeclName()
5025  << Init->getSourceRange();
5026  else {
5027  const Type *BaseClass = Init->getBaseClass();
5028  assert(BaseClass && "neither field nor base");
5029  S.Diag(Init->getSourceLocation(),
5030  diag::err_multiple_base_initialization)
5031  << QualType(BaseClass, 0)
5032  << Init->getSourceRange();
5033  }
5034  S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5035  << 0 << PrevInit->getSourceRange();
5036 
5037  return true;
5038 }
5039 
5040 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5041 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5042 
5043 bool CheckRedundantUnionInit(Sema &S,
5044  CXXCtorInitializer *Init,
5045  RedundantUnionMap &Unions) {
5046  FieldDecl *Field = Init->getAnyMember();
5047  RecordDecl *Parent = Field->getParent();
5048  NamedDecl *Child = Field;
5049 
5050  while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5051  if (Parent->isUnion()) {
5052  UnionEntry &En = Unions[Parent];
5053  if (En.first && En.first != Child) {
5054  S.Diag(Init->getSourceLocation(),
5055  diag::err_multiple_mem_union_initialization)
5056  << Field->getDeclName()
5057  << Init->getSourceRange();
5058  S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5059  << 0 << En.second->getSourceRange();
5060  return true;
5061  }
5062  if (!En.first) {
5063  En.first = Child;
5064  En.second = Init;
5065  }
5066  if (!Parent->isAnonymousStructOrUnion())
5067  return false;
5068  }
5069 
5070  Child = Parent;
5071  Parent = cast<RecordDecl>(Parent->getDeclContext());
5072  }
5073 
5074  return false;
5075 }
5076 }
5077 
5078 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5079 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5082  bool AnyErrors) {
5083  if (!ConstructorDecl)
5084  return;
5085 
5086  AdjustDeclIfTemplate(ConstructorDecl);
5087 
5088  CXXConstructorDecl *Constructor
5089  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5090 
5091  if (!Constructor) {
5092  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5093  return;
5094  }
5095 
5096  // Mapping for the duplicate initializers check.
5097  // For member initializers, this is keyed with a FieldDecl*.
5098  // For base initializers, this is keyed with a Type*.
5099  llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5100 
5101  // Mapping for the inconsistent anonymous-union initializers check.
5102  RedundantUnionMap MemberUnions;
5103 
5104  bool HadError = false;
5105  for (unsigned i = 0; i < MemInits.size(); i++) {
5106  CXXCtorInitializer *Init = MemInits[i];
5107 
5108  // Set the source order index.
5109  Init->setSourceOrder(i);
5110 
5111  if (Init->isAnyMemberInitializer()) {
5112  const void *Key = GetKeyForMember(Context, Init);
5113  if (CheckRedundantInit(*this, Init, Members[Key]) ||
5114  CheckRedundantUnionInit(*this, Init, MemberUnions))
5115  HadError = true;
5116  } else if (Init->isBaseInitializer()) {
5117  const void *Key = GetKeyForMember(Context, Init);
5118  if (CheckRedundantInit(*this, Init, Members[Key]))
5119  HadError = true;
5120  } else {
5121  assert(Init->isDelegatingInitializer());
5122  // This must be the only initializer
5123  if (MemInits.size() != 1) {
5124  Diag(Init->getSourceLocation(),
5125  diag::err_delegating_initializer_alone)
5126  << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5127  // We will treat this as being the only initializer.
5128  }
5129  SetDelegatingInitializer(Constructor, MemInits[i]);
5130  // Return immediately as the initializer is set.
5131  return;
5132  }
5133  }
5134 
5135  if (HadError)
5136  return;
5137 
5138  DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5139 
5140  SetCtorInitializers(Constructor, AnyErrors, MemInits);
5141 
5142  DiagnoseUninitializedFields(*this, Constructor);
5143 }
5144 
5145 void
5147  CXXRecordDecl *ClassDecl) {
5148  // Ignore dependent contexts. Also ignore unions, since their members never
5149  // have destructors implicitly called.
5150  if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5151  return;
5152 
5153  // FIXME: all the access-control diagnostics are positioned on the
5154  // field/base declaration. That's probably good; that said, the
5155  // user might reasonably want to know why the destructor is being
5156  // emitted, and we currently don't say.
5157 
5158  // Non-static data members.
5159  for (auto *Field : ClassDecl->fields()) {
5160  if (Field->isInvalidDecl())
5161  continue;
5162 
5163  // Don't destroy incomplete or zero-length arrays.
5164  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5165  continue;
5166 
5167  QualType FieldType = Context.getBaseElementType(Field->getType());
5168 
5169  const RecordType* RT = FieldType->getAs<RecordType>();
5170  if (!RT)
5171  continue;
5172 
5173  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5174  if (FieldClassDecl->isInvalidDecl())
5175  continue;
5176  if (FieldClassDecl->hasIrrelevantDestructor())
5177  continue;
5178  // The destructor for an implicit anonymous union member is never invoked.
5179  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5180  continue;
5181 
5182  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5183  assert(Dtor && "No dtor found for FieldClassDecl!");
5184  CheckDestructorAccess(Field->getLocation(), Dtor,
5185  PDiag(diag::err_access_dtor_field)
5186  << Field->getDeclName()
5187  << FieldType);
5188 
5189  MarkFunctionReferenced(Location, Dtor);
5190  DiagnoseUseOfDecl(Dtor, Location);
5191  }
5192 
5193  // We only potentially invoke the destructors of potentially constructed
5194  // subobjects.
5195  bool VisitVirtualBases = !ClassDecl->isAbstract();
5196 
5197  llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5198 
5199  // Bases.
5200  for (const auto &Base : ClassDecl->bases()) {
5201  // Bases are always records in a well-formed non-dependent class.
5202  const RecordType *RT = Base.getType()->getAs<RecordType>();
5203 
5204  // Remember direct virtual bases.
5205  if (Base.isVirtual()) {
5206  if (!VisitVirtualBases)
5207  continue;
5208  DirectVirtualBases.insert(RT);
5209  }
5210 
5211  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5212  // If our base class is invalid, we probably can't get its dtor anyway.
5213  if (BaseClassDecl->isInvalidDecl())
5214  continue;
5215  if (BaseClassDecl->hasIrrelevantDestructor())
5216  continue;
5217 
5218  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5219  assert(Dtor && "No dtor found for BaseClassDecl!");
5220 
5221  // FIXME: caret should be on the start of the class name
5222  CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5223  PDiag(diag::err_access_dtor_base)
5224  << Base.getType() << Base.getSourceRange(),
5225  Context.getTypeDeclType(ClassDecl));
5226 
5227  MarkFunctionReferenced(Location, Dtor);
5228  DiagnoseUseOfDecl(Dtor, Location);
5229  }
5230 
5231  if (!VisitVirtualBases)
5232  return;
5233 
5234  // Virtual bases.
5235  for (const auto &VBase : ClassDecl->vbases()) {
5236  // Bases are always records in a well-formed non-dependent class.
5237  const RecordType *RT = VBase.getType()->castAs<RecordType>();
5238 
5239  // Ignore direct virtual bases.
5240  if (DirectVirtualBases.count(RT))
5241  continue;
5242 
5243  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5244  // If our base class is invalid, we probably can't get its dtor anyway.
5245  if (BaseClassDecl->isInvalidDecl())
5246  continue;
5247  if (BaseClassDecl->hasIrrelevantDestructor())
5248  continue;
5249 
5250  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5251  assert(Dtor && "No dtor found for BaseClassDecl!");
5252  if (CheckDestructorAccess(
5253  ClassDecl->getLocation(), Dtor,
5254  PDiag(diag::err_access_dtor_vbase)
5255  << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5256  Context.getTypeDeclType(ClassDecl)) ==
5257  AR_accessible) {
5258  CheckDerivedToBaseConversion(
5259  Context.getTypeDeclType(ClassDecl), VBase.getType(),
5260  diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5261  SourceRange(), DeclarationName(), nullptr);
5262  }
5263 
5264  MarkFunctionReferenced(Location, Dtor);
5265  DiagnoseUseOfDecl(Dtor, Location);
5266  }
5267 }
5268 
5269 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5270  if (!CDtorDecl)
5271  return;
5272 
5273  if (CXXConstructorDecl *Constructor
5274  = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5275  SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5276  DiagnoseUninitializedFields(*this, Constructor);
5277  }
5278 }
5279 
5281  if (!getLangOpts().CPlusPlus)
5282  return false;
5283 
5284  const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5285  if (!RD)
5286  return false;
5287 
5288  // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5289  // class template specialization here, but doing so breaks a lot of code.
5290 
5291  // We can't answer whether something is abstract until it has a
5292  // definition. If it's currently being defined, we'll walk back
5293  // over all the declarations when we have a full definition.
5294  const CXXRecordDecl *Def = RD->getDefinition();
5295  if (!Def || Def->isBeingDefined())
5296  return false;
5297 
5298  return RD->isAbstract();
5299 }
5300 
5302  TypeDiagnoser &Diagnoser) {
5303  if (!isAbstractType(Loc, T))
5304  return false;
5305 
5306  T = Context.getBaseElementType(T);
5307  Diagnoser.diagnose(*this, Loc, T);
5308  DiagnoseAbstractType(T->getAsCXXRecordDecl());
5309  return true;
5310 }
5311 
5313  // Check if we've already emitted the list of pure virtual functions
5314  // for this class.
5315  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5316  return;
5317 
5318  // If the diagnostic is suppressed, don't emit the notes. We're only
5319  // going to emit them once, so try to attach them to a diagnostic we're
5320  // actually going to show.
5321  if (Diags.isLastDiagnosticIgnored())
5322  return;
5323 
5324  CXXFinalOverriderMap FinalOverriders;
5325  RD->getFinalOverriders(FinalOverriders);
5326 
5327  // Keep a set of seen pure methods so we won't diagnose the same method
5328  // more than once.
5329  llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5330 
5331  for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5332  MEnd = FinalOverriders.end();
5333  M != MEnd;
5334  ++M) {
5335  for (OverridingMethods::iterator SO = M->second.begin(),
5336  SOEnd = M->second.end();
5337  SO != SOEnd; ++SO) {
5338  // C++ [class.abstract]p4:
5339  // A class is abstract if it contains or inherits at least one
5340  // pure virtual function for which the final overrider is pure
5341  // virtual.
5342 
5343  //
5344  if (SO->second.size() != 1)
5345  continue;
5346 
5347  if (!SO->second.front().Method->isPure())
5348  continue;
5349 
5350  if (!SeenPureMethods.insert(SO->second.front().Method).second)
5351  continue;
5352 
5353  Diag(SO->second.front().Method->getLocation(),
5354  diag::note_pure_virtual_function)
5355  << SO->second.front().Method->getDeclName() << RD->getDeclName();
5356  }
5357  }
5358 
5359  if (!PureVirtualClassDiagSet)
5360  PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5361  PureVirtualClassDiagSet->insert(RD);
5362 }
5363 
5364 namespace {
5365 struct AbstractUsageInfo {
5366  Sema &S;
5367  CXXRecordDecl *Record;
5368  CanQualType AbstractType;
5369  bool Invalid;
5370 
5371  AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5372  : S(S), Record(Record),
5373  AbstractType(S.Context.getCanonicalType(
5374  S.Context.getTypeDeclType(Record))),
5375  Invalid(false) {}
5376 
5377  void DiagnoseAbstractType() {
5378  if (Invalid) return;
5379  S.DiagnoseAbstractType(Record);
5380  Invalid = true;
5381  }
5382 
5383  void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5384 };
5385 
5386 struct CheckAbstractUsage {
5387  AbstractUsageInfo &Info;
5388  const NamedDecl *Ctx;
5389 
5390  CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5391  : Info(Info), Ctx(Ctx) {}
5392 
5393  void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5394  switch (TL.getTypeLocClass()) {
5395 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5396 #define TYPELOC(CLASS, PARENT) \
5397  case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5398 #include "clang/AST/TypeLocNodes.def"
5399  }
5400  }
5401 
5402  void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5404  for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5405  if (!TL.getParam(I))
5406  continue;
5407 
5408  TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5409  if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5410  }
5411  }
5412 
5413  void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5415  }
5416 
5418  // Visit the type parameters from a permissive context.
5419  for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5420  TemplateArgumentLoc TAL = TL.getArgLoc(I);
5422  if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5423  Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5424  // TODO: other template argument types?
5425  }
5426  }
5427 
5428  // Visit pointee types from a permissive context.
5429 #define CheckPolymorphic(Type) \
5430  void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5431  Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5432  }
5438 
5439  /// Handle all the types we haven't given a more specific
5440  /// implementation for above.
5441  void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5442  // Every other kind of type that we haven't called out already
5443  // that has an inner type is either (1) sugar or (2) contains that
5444  // inner type in some way as a subobject.
5445  if (TypeLoc Next = TL.getNextTypeLoc())
5446  return Visit(Next, Sel);
5447 
5448  // If there's no inner type and we're in a permissive context,
5449  // don't diagnose.
5450  if (Sel == Sema::AbstractNone) return;
5451 
5452  // Check whether the type matches the abstract type.
5453  QualType T = TL.getType();
5454  if (T->isArrayType()) {
5456  T = Info.S.Context.getBaseElementType(T);
5457  }
5459  if (CT != Info.AbstractType) return;
5460 
5461  // It matched; do some magic.
5462  if (Sel == Sema::AbstractArrayType) {
5463  Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5464  << T << TL.getSourceRange();
5465  } else {
5466  Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5467  << Sel << T << TL.getSourceRange();
5468  }
5469  Info.DiagnoseAbstractType();
5470  }
5471 };
5472 
5473 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5475  CheckAbstractUsage(*this, D).Visit(TL, Sel);
5476 }
5477 
5478 }
5479 
5480 /// Check for invalid uses of an abstract type in a method declaration.
5481 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5482  CXXMethodDecl *MD) {
5483  // No need to do the check on definitions, which require that
5484  // the return/param types be complete.
5485  if (MD->doesThisDeclarationHaveABody())
5486  return;
5487 
5488  // For safety's sake, just ignore it if we don't have type source
5489  // information. This should never happen for non-implicit methods,
5490  // but...
5491  if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5492  Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5493 }
5494 
5495 /// Check for invalid uses of an abstract type within a class definition.
5496 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5497  CXXRecordDecl *RD) {
5498  for (auto *D : RD->decls()) {
5499  if (D->isImplicit()) continue;
5500 
5501  // Methods and method templates.
5502  if (isa<CXXMethodDecl>(D)) {
5503  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5504  } else if (isa<FunctionTemplateDecl>(D)) {
5505  FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5506  CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5507 
5508  // Fields and static variables.
5509  } else if (isa<FieldDecl>(D)) {
5510  FieldDecl *FD = cast<FieldDecl>(D);
5511  if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5512  Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5513  } else if (isa<VarDecl>(D)) {
5514  VarDecl *VD = cast<VarDecl>(D);
5515  if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5516  Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5517 
5518  // Nested classes and class templates.
5519  } else if (isa<CXXRecordDecl>(D)) {
5520  CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5521  } else if (isa<ClassTemplateDecl>(D)) {
5523  cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5524  }
5525  }
5526 }
5527 
5529  Attr *ClassAttr = getDLLAttr(Class);
5530  if (!ClassAttr)
5531  return;
5532 
5533  assert(ClassAttr->getKind() == attr::DLLExport);
5534 
5536 
5538  // Don't go any further if this is just an explicit instantiation
5539  // declaration.
5540  return;
5541 
5542  if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
5543  S.MarkVTableUsed(Class->getLocation(), Class, true);
5544 
5545  for (Decl *Member : Class->decls()) {
5546  // Defined static variables that are members of an exported base
5547  // class must be marked export too.
5548  auto *VD = dyn_cast<VarDecl>(Member);
5549  if (VD && Member->getAttr<DLLExportAttr>() &&
5550  VD->getStorageClass() == SC_Static &&
5552  S.MarkVariableReferenced(VD->getLocation(), VD);
5553 
5554  auto *MD = dyn_cast<CXXMethodDecl>(Member);
5555  if (!MD)
5556  continue;
5557 
5558  if (Member->getAttr<DLLExportAttr>()) {
5559  if (MD->isUserProvided()) {
5560  // Instantiate non-default class member functions ...
5561 
5562  // .. except for certain kinds of template specializations.
5563  if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5564  continue;
5565 
5566  S.MarkFunctionReferenced(Class->getLocation(), MD);
5567 
5568  // The function will be passed to the consumer when its definition is
5569  // encountered.
5570  } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5571  MD->isCopyAssignmentOperator() ||
5572  MD->isMoveAssignmentOperator()) {
5573  // Synthesize and instantiate non-trivial implicit methods, explicitly
5574  // defaulted methods, and the copy and move assignment operators. The
5575  // latter are exported even if they are trivial, because the address of
5576  // an operator can be taken and should compare equal across libraries.
5577  DiagnosticErrorTrap Trap(S.Diags);
5578  S.MarkFunctionReferenced(Class->getLocation(), MD);
5579  if (Trap.hasErrorOccurred()) {
5580  S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5581  << Class << !S.getLangOpts().CPlusPlus11;
5582  break;
5583  }
5584 
5585  // There is no later point when we will see the definition of this
5586  // function, so pass it to the consumer now.
5588  }
5589  }
5590  }
5591 }
5592 
5594  CXXRecordDecl *Class) {
5595  // Only the MS ABI has default constructor closures, so we don't need to do
5596  // this semantic checking anywhere else.
5598  return;
5599 
5600  CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5601  for (Decl *Member : Class->decls()) {
5602  // Look for exported default constructors.
5603  auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5604  if (!CD || !CD->isDefaultConstructor())
5605  continue;
5606  auto *Attr = CD->getAttr<DLLExportAttr>();
5607  if (!Attr)
5608  continue;
5609 
5610  // If the class is non-dependent, mark the default arguments as ODR-used so
5611  // that we can properly codegen the constructor closure.
5612  if (!Class->isDependentContext()) {
5613  for (ParmVarDecl *PD : CD->parameters()) {
5614  (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5616  }
5617  }
5618 
5619  if (LastExportedDefaultCtor) {
5620  S.Diag(LastExportedDefaultCtor->getLocation(),
5621  diag::err_attribute_dll_ambiguous_default_ctor)
5622  << Class;
5623  S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5624  << CD->getDeclName();
5625  return;
5626  }
5627  LastExportedDefaultCtor = CD;
5628  }
5629 }
5630 
5632  // Mark any compiler-generated routines with the implicit code_seg attribute.
5633  for (auto *Method : Class->methods()) {
5634  if (Method->isUserProvided())
5635  continue;
5636  if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
5637  Method->addAttr(A);
5638  }
5639 }
5640 
5641 /// Check class-level dllimport/dllexport attribute.
5643  Attr *ClassAttr = getDLLAttr(Class);
5644 
5645  // MSVC inherits DLL attributes to partial class template specializations.
5646  if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5647  if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5648  if (Attr *TemplateAttr =
5649  getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5650  auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5651  A->setInherited(true);
5652  ClassAttr = A;
5653  }
5654  }
5655  }
5656 
5657  if (!ClassAttr)
5658  return;
5659 
5660  if (!Class->isExternallyVisible()) {
5661  Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5662  << Class << ClassAttr;
5663  return;
5664  }
5665 
5666  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5667  !ClassAttr->isInherited()) {
5668  // Diagnose dll attributes on members of class with dll attribute.
5669  for (Decl *Member : Class->decls()) {
5670  if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5671  continue;
5672  InheritableAttr *MemberAttr = getDLLAttr(Member);
5673  if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5674  continue;
5675 
5676  Diag(MemberAttr->getLocation(),
5677  diag::err_attribute_dll_member_of_dll_class)
5678  << MemberAttr << ClassAttr;
5679  Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5680  Member->setInvalidDecl();
5681  }
5682  }
5683 
5684  if (Class->getDescribedClassTemplate())
5685  // Don't inherit dll attribute until the template is instantiated.
5686  return;
5687 
5688  // The class is either imported or exported.
5689  const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5690 
5691  // Check if this was a dllimport attribute propagated from a derived class to
5692  // a base class template specialization. We don't apply these attributes to
5693  // static data members.
5694  const bool PropagatedImport =
5695  !ClassExported &&
5696  cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
5697 
5699 
5700  // Ignore explicit dllexport on explicit class template instantiation declarations.
5701  if (ClassExported && !ClassAttr->isInherited() &&
5703  Class->dropAttr<DLLExportAttr>();
5704  return;
5705  }
5706 
5707