1//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the actions class which performs semantic analysis and
11// builds an AST out of a parse stream.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Sema/SemaInternal.h"
16#include "TargetAttributesSema.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/ASTDiagnostic.h"
19#include "clang/AST/DeclCXX.h"
20#include "clang/AST/DeclFriend.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/Expr.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/StmtCXX.h"
25#include "clang/Basic/FileManager.h"
26#include "clang/Basic/PartialDiagnostic.h"
27#include "clang/Basic/TargetInfo.h"
28#include "clang/Lex/HeaderSearch.h"
29#include "clang/Lex/Preprocessor.h"
30#include "clang/Sema/CXXFieldCollector.h"
31#include "clang/Sema/DelayedDiagnostic.h"
32#include "clang/Sema/ExternalSemaSource.h"
33#include "clang/Sema/MultiplexExternalSemaSource.h"
34#include "clang/Sema/ObjCMethodList.h"
35#include "clang/Sema/PrettyDeclStackTrace.h"
36#include "clang/Sema/Scope.h"
37#include "clang/Sema/ScopeInfo.h"
38#include "clang/Sema/SemaConsumer.h"
39#include "clang/Sema/TemplateDeduction.h"
40#include "llvm/ADT/APFloat.h"
41#include "llvm/ADT/DenseMap.h"
42#include "llvm/ADT/SmallSet.h"
43#include "llvm/Support/CrashRecoveryContext.h"
44using namespace clang;
45using namespace sema;
46
47PrintingPolicy Sema::getPrintingPolicy(const ASTContext &Context,
48                                       const Preprocessor &PP) {
49  PrintingPolicy Policy = Context.getPrintingPolicy();
50  Policy.Bool = Context.getLangOpts().Bool;
51  if (!Policy.Bool) {
52    if (const MacroInfo *
53          BoolMacro = PP.getMacroInfo(&Context.Idents.get("bool"))) {
54      Policy.Bool = BoolMacro->isObjectLike() &&
55        BoolMacro->getNumTokens() == 1 &&
56        BoolMacro->getReplacementToken(0).is(tok::kw__Bool);
57    }
58  }
59
60  return Policy;
61}
62
63void Sema::ActOnTranslationUnitScope(Scope *S) {
64  TUScope = S;
65  PushDeclContext(S, Context.getTranslationUnitDecl());
66
67  VAListTagName = PP.getIdentifierInfo("__va_list_tag");
68}
69
70Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
71           TranslationUnitKind TUKind,
72           CodeCompleteConsumer *CodeCompleter)
73  : TheTargetAttributesSema(0), ExternalSource(0),
74    isMultiplexExternalSource(false), FPFeatures(pp.getLangOpts()),
75    LangOpts(pp.getLangOpts()), PP(pp), Context(ctxt), Consumer(consumer),
76    Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
77    CollectStats(false), CodeCompleter(CodeCompleter),
78    CurContext(0), OriginalLexicalContext(0),
79    PackContext(0), MSStructPragmaOn(false), VisContext(0),
80    IsBuildingRecoveryCallExpr(false),
81    ExprNeedsCleanups(false), LateTemplateParser(0), OpaqueParser(0),
82    IdResolver(pp), StdInitializerList(0), CXXTypeInfoDecl(0), MSVCGuidDecl(0),
83    NSNumberDecl(0),
84    NSStringDecl(0), StringWithUTF8StringMethod(0),
85    NSArrayDecl(0), ArrayWithObjectsMethod(0),
86    NSDictionaryDecl(0), DictionaryWithObjectsMethod(0),
87    GlobalNewDeleteDeclared(false),
88    TUKind(TUKind),
89    NumSFINAEErrors(0), InFunctionDeclarator(0),
90    AccessCheckingSFINAE(false), InNonInstantiationSFINAEContext(false),
91    NonInstantiationEntries(0), ArgumentPackSubstitutionIndex(-1),
92    CurrentInstantiationScope(0), DisableTypoCorrection(false),
93    TyposCorrected(0), AnalysisWarnings(*this),
94    VarDataSharingAttributesStack(0), CurScope(0),
95    Ident_super(0), Ident___float128(0)
96{
97  TUScope = 0;
98
99  LoadedExternalKnownNamespaces = false;
100  for (unsigned I = 0; I != NSAPI::NumNSNumberLiteralMethods; ++I)
101    NSNumberLiteralMethods[I] = 0;
102
103  if (getLangOpts().ObjC1)
104    NSAPIObj.reset(new NSAPI(Context));
105
106  if (getLangOpts().CPlusPlus)
107    FieldCollector.reset(new CXXFieldCollector());
108
109  // Tell diagnostics how to render things from the AST library.
110  PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
111                                       &Context);
112
113  ExprEvalContexts.push_back(
114        ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0,
115                                          false, 0, false));
116
117  FunctionScopes.push_back(new FunctionScopeInfo(Diags));
118
119  // Initilization of data sharing attributes stack for OpenMP
120  InitDataSharingAttributesStack();
121}
122
123void Sema::Initialize() {
124  // Tell the AST consumer about this Sema object.
125  Consumer.Initialize(Context);
126
127  // FIXME: Isn't this redundant with the initialization above?
128  if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
129    SC->InitializeSema(*this);
130
131  // Tell the external Sema source about this Sema object.
132  if (ExternalSemaSource *ExternalSema
133      = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
134    ExternalSema->InitializeSema(*this);
135
136  // Initialize predefined 128-bit integer types, if needed.
137  if (PP.getTargetInfo().hasInt128Type()) {
138    // If either of the 128-bit integer types are unavailable to name lookup,
139    // define them now.
140    DeclarationName Int128 = &Context.Idents.get("__int128_t");
141    if (IdResolver.begin(Int128) == IdResolver.end())
142      PushOnScopeChains(Context.getInt128Decl(), TUScope);
143
144    DeclarationName UInt128 = &Context.Idents.get("__uint128_t");
145    if (IdResolver.begin(UInt128) == IdResolver.end())
146      PushOnScopeChains(Context.getUInt128Decl(), TUScope);
147  }
148
149
150  // Initialize predefined Objective-C types:
151  if (PP.getLangOpts().ObjC1) {
152    // If 'SEL' does not yet refer to any declarations, make it refer to the
153    // predefined 'SEL'.
154    DeclarationName SEL = &Context.Idents.get("SEL");
155    if (IdResolver.begin(SEL) == IdResolver.end())
156      PushOnScopeChains(Context.getObjCSelDecl(), TUScope);
157
158    // If 'id' does not yet refer to any declarations, make it refer to the
159    // predefined 'id'.
160    DeclarationName Id = &Context.Idents.get("id");
161    if (IdResolver.begin(Id) == IdResolver.end())
162      PushOnScopeChains(Context.getObjCIdDecl(), TUScope);
163
164    // Create the built-in typedef for 'Class'.
165    DeclarationName Class = &Context.Idents.get("Class");
166    if (IdResolver.begin(Class) == IdResolver.end())
167      PushOnScopeChains(Context.getObjCClassDecl(), TUScope);
168
169    // Create the built-in forward declaratino for 'Protocol'.
170    DeclarationName Protocol = &Context.Idents.get("Protocol");
171    if (IdResolver.begin(Protocol) == IdResolver.end())
172      PushOnScopeChains(Context.getObjCProtocolDecl(), TUScope);
173  }
174
175  DeclarationName BuiltinVaList = &Context.Idents.get("__builtin_va_list");
176  if (IdResolver.begin(BuiltinVaList) == IdResolver.end())
177    PushOnScopeChains(Context.getBuiltinVaListDecl(), TUScope);
178}
179
180Sema::~Sema() {
181  for (LateParsedTemplateMapT::iterator I = LateParsedTemplateMap.begin(),
182                                        E = LateParsedTemplateMap.end();
183       I != E; ++I)
184    delete I->second;
185  if (PackContext) FreePackedContext();
186  if (VisContext) FreeVisContext();
187  delete TheTargetAttributesSema;
188  MSStructPragmaOn = false;
189  // Kill all the active scopes.
190  for (unsigned I = 1, E = FunctionScopes.size(); I != E; ++I)
191    delete FunctionScopes[I];
192  if (FunctionScopes.size() == 1)
193    delete FunctionScopes[0];
194
195  // Tell the SemaConsumer to forget about us; we're going out of scope.
196  if (SemaConsumer *SC = dyn_cast<SemaConsumer>(&Consumer))
197    SC->ForgetSema();
198
199  // Detach from the external Sema source.
200  if (ExternalSemaSource *ExternalSema
201        = dyn_cast_or_null<ExternalSemaSource>(Context.getExternalSource()))
202    ExternalSema->ForgetSema();
203
204  // If Sema's ExternalSource is the multiplexer - we own it.
205  if (isMultiplexExternalSource)
206    delete ExternalSource;
207
208  // Destroys data sharing attributes stack for OpenMP
209  DestroyDataSharingAttributesStack();
210}
211
212/// makeUnavailableInSystemHeader - There is an error in the current
213/// context.  If we're still in a system header, and we can plausibly
214/// make the relevant declaration unavailable instead of erroring, do
215/// so and return true.
216bool Sema::makeUnavailableInSystemHeader(SourceLocation loc,
217                                         StringRef msg) {
218  // If we're not in a function, it's an error.
219  FunctionDecl *fn = dyn_cast<FunctionDecl>(CurContext);
220  if (!fn) return false;
221
222  // If we're in template instantiation, it's an error.
223  if (!ActiveTemplateInstantiations.empty())
224    return false;
225
226  // If that function's not in a system header, it's an error.
227  if (!Context.getSourceManager().isInSystemHeader(loc))
228    return false;
229
230  // If the function is already unavailable, it's not an error.
231  if (fn->hasAttr<UnavailableAttr>()) return true;
232
233  fn->addAttr(new (Context) UnavailableAttr(loc, Context, msg));
234  return true;
235}
236
237ASTMutationListener *Sema::getASTMutationListener() const {
238  return getASTConsumer().GetASTMutationListener();
239}
240
241///\brief Registers an external source. If an external source already exists,
242/// creates a multiplex external source and appends to it.
243///
244///\param[in] E - A non-null external sema source.
245///
246void Sema::addExternalSource(ExternalSemaSource *E) {
247  assert(E && "Cannot use with NULL ptr");
248
249  if (!ExternalSource) {
250    ExternalSource = E;
251    return;
252  }
253
254  if (isMultiplexExternalSource)
255    static_cast<MultiplexExternalSemaSource*>(ExternalSource)->addSource(*E);
256  else {
257    ExternalSource = new MultiplexExternalSemaSource(*ExternalSource, *E);
258    isMultiplexExternalSource = true;
259  }
260}
261
262/// \brief Print out statistics about the semantic analysis.
263void Sema::PrintStats() const {
264  llvm::errs() << "\n*** Semantic Analysis Stats:\n";
265  llvm::errs() << NumSFINAEErrors << " SFINAE diagnostics trapped.\n";
266
267  BumpAlloc.PrintStats();
268  AnalysisWarnings.PrintStats();
269}
270
271/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
272/// If there is already an implicit cast, merge into the existing one.
273/// The result is of the given category.
274ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
275                                   CastKind Kind, ExprValueKind VK,
276                                   const CXXCastPath *BasePath,
277                                   CheckedConversionKind CCK) {
278#ifndef NDEBUG
279  if (VK == VK_RValue && !E->isRValue()) {
280    switch (Kind) {
281    default:
282      assert(0 && "can't implicitly cast lvalue to rvalue with this cast kind");
283    case CK_LValueToRValue:
284    case CK_ArrayToPointerDecay:
285    case CK_FunctionToPointerDecay:
286    case CK_ToVoid:
287      break;
288    }
289  }
290  assert((VK == VK_RValue || !E->isRValue()) && "can't cast rvalue to lvalue");
291#endif
292
293  QualType ExprTy = Context.getCanonicalType(E->getType());
294  QualType TypeTy = Context.getCanonicalType(Ty);
295
296  if (ExprTy == TypeTy)
297    return Owned(E);
298
299  // If this is a derived-to-base cast to a through a virtual base, we
300  // need a vtable.
301  if (Kind == CK_DerivedToBase &&
302      BasePathInvolvesVirtualBase(*BasePath)) {
303    QualType T = E->getType();
304    if (const PointerType *Pointer = T->getAs<PointerType>())
305      T = Pointer->getPointeeType();
306    if (const RecordType *RecordTy = T->getAs<RecordType>())
307      MarkVTableUsed(E->getLocStart(),
308                     cast<CXXRecordDecl>(RecordTy->getDecl()));
309  }
310
311  if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(E)) {
312    if (ImpCast->getCastKind() == Kind && (!BasePath || BasePath->empty())) {
313      ImpCast->setType(Ty);
314      ImpCast->setValueKind(VK);
315      return Owned(E);
316    }
317  }
318
319  return Owned(ImplicitCastExpr::Create(Context, Ty, Kind, E, BasePath, VK));
320}
321
322/// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
323/// to the conversion from scalar type ScalarTy to the Boolean type.
324CastKind Sema::ScalarTypeToBooleanCastKind(QualType ScalarTy) {
325  switch (ScalarTy->getScalarTypeKind()) {
326  case Type::STK_Bool: return CK_NoOp;
327  case Type::STK_CPointer: return CK_PointerToBoolean;
328  case Type::STK_BlockPointer: return CK_PointerToBoolean;
329  case Type::STK_ObjCObjectPointer: return CK_PointerToBoolean;
330  case Type::STK_MemberPointer: return CK_MemberPointerToBoolean;
331  case Type::STK_Integral: return CK_IntegralToBoolean;
332  case Type::STK_Floating: return CK_FloatingToBoolean;
333  case Type::STK_IntegralComplex: return CK_IntegralComplexToBoolean;
334  case Type::STK_FloatingComplex: return CK_FloatingComplexToBoolean;
335  }
336  return CK_Invalid;
337}
338
339/// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
340static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
341  if (D->getMostRecentDecl()->isUsed())
342    return true;
343
344  if (D->isExternallyVisible())
345    return true;
346
347  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
348    // UnusedFileScopedDecls stores the first declaration.
349    // The declaration may have become definition so check again.
350    const FunctionDecl *DeclToCheck;
351    if (FD->hasBody(DeclToCheck))
352      return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
353
354    // Later redecls may add new information resulting in not having to warn,
355    // so check again.
356    DeclToCheck = FD->getMostRecentDecl();
357    if (DeclToCheck != FD)
358      return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
359  }
360
361  if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
362    // If a variable usable in constant expressions is referenced,
363    // don't warn if it isn't used: if the value of a variable is required
364    // for the computation of a constant expression, it doesn't make sense to
365    // warn even if the variable isn't odr-used.  (isReferenced doesn't
366    // precisely reflect that, but it's a decent approximation.)
367    if (VD->isReferenced() &&
368        VD->isUsableInConstantExpressions(SemaRef->Context))
369      return true;
370
371    // UnusedFileScopedDecls stores the first declaration.
372    // The declaration may have become definition so check again.
373    const VarDecl *DeclToCheck = VD->getDefinition();
374    if (DeclToCheck)
375      return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
376
377    // Later redecls may add new information resulting in not having to warn,
378    // so check again.
379    DeclToCheck = VD->getMostRecentDecl();
380    if (DeclToCheck != VD)
381      return !SemaRef->ShouldWarnIfUnusedFileScopedDecl(DeclToCheck);
382  }
383
384  return false;
385}
386
387namespace {
388  struct SortUndefinedButUsed {
389    const SourceManager &SM;
390    explicit SortUndefinedButUsed(SourceManager &SM) : SM(SM) {}
391
392    bool operator()(const std::pair<NamedDecl *, SourceLocation> &l,
393                    const std::pair<NamedDecl *, SourceLocation> &r) const {
394      if (l.second.isValid() && !r.second.isValid())
395        return true;
396      if (!l.second.isValid() && r.second.isValid())
397        return false;
398      if (l.second != r.second)
399        return SM.isBeforeInTranslationUnit(l.second, r.second);
400      return SM.isBeforeInTranslationUnit(l.first->getLocation(),
401                                          r.first->getLocation());
402    }
403  };
404}
405
406/// Obtains a sorted list of functions that are undefined but ODR-used.
407void Sema::getUndefinedButUsed(
408    SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined) {
409  for (llvm::DenseMap<NamedDecl *, SourceLocation>::iterator
410         I = UndefinedButUsed.begin(), E = UndefinedButUsed.end();
411       I != E; ++I) {
412    NamedDecl *ND = I->first;
413
414    // Ignore attributes that have become invalid.
415    if (ND->isInvalidDecl()) continue;
416
417    // __attribute__((weakref)) is basically a definition.
418    if (ND->hasAttr<WeakRefAttr>()) continue;
419
420    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
421      if (FD->isDefined())
422        continue;
423      if (FD->isExternallyVisible() &&
424          !FD->getMostRecentDecl()->isInlined())
425        continue;
426    } else {
427      if (cast<VarDecl>(ND)->hasDefinition() != VarDecl::DeclarationOnly)
428        continue;
429      if (ND->isExternallyVisible())
430        continue;
431    }
432
433    Undefined.push_back(std::make_pair(ND, I->second));
434  }
435
436  // Sort (in order of use site) so that we're not dependent on the iteration
437  // order through an llvm::DenseMap.
438  std::sort(Undefined.begin(), Undefined.end(),
439            SortUndefinedButUsed(Context.getSourceManager()));
440}
441
442/// checkUndefinedButUsed - Check for undefined objects with internal linkage
443/// or that are inline.
444static void checkUndefinedButUsed(Sema &S) {
445  if (S.UndefinedButUsed.empty()) return;
446
447  // Collect all the still-undefined entities with internal linkage.
448  SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
449  S.getUndefinedButUsed(Undefined);
450  if (Undefined.empty()) return;
451
452  for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator
453         I = Undefined.begin(), E = Undefined.end(); I != E; ++I) {
454    NamedDecl *ND = I->first;
455
456    if (!ND->isExternallyVisible()) {
457      S.Diag(ND->getLocation(), diag::warn_undefined_internal)
458        << isa<VarDecl>(ND) << ND;
459    } else {
460      assert(cast<FunctionDecl>(ND)->getMostRecentDecl()->isInlined() &&
461             "used object requires definition but isn't inline or internal?");
462      S.Diag(ND->getLocation(), diag::warn_undefined_inline) << ND;
463    }
464    if (I->second.isValid())
465      S.Diag(I->second, diag::note_used_here);
466  }
467}
468
469void Sema::LoadExternalWeakUndeclaredIdentifiers() {
470  if (!ExternalSource)
471    return;
472
473  SmallVector<std::pair<IdentifierInfo *, WeakInfo>, 4> WeakIDs;
474  ExternalSource->ReadWeakUndeclaredIdentifiers(WeakIDs);
475  for (unsigned I = 0, N = WeakIDs.size(); I != N; ++I) {
476    llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator Pos
477      = WeakUndeclaredIdentifiers.find(WeakIDs[I].first);
478    if (Pos != WeakUndeclaredIdentifiers.end())
479      continue;
480
481    WeakUndeclaredIdentifiers.insert(WeakIDs[I]);
482  }
483}
484
485
486typedef llvm::DenseMap<const CXXRecordDecl*, bool> RecordCompleteMap;
487
488/// \brief Returns true, if all methods and nested classes of the given
489/// CXXRecordDecl are defined in this translation unit.
490///
491/// Should only be called from ActOnEndOfTranslationUnit so that all
492/// definitions are actually read.
493static bool MethodsAndNestedClassesComplete(const CXXRecordDecl *RD,
494                                            RecordCompleteMap &MNCComplete) {
495  RecordCompleteMap::iterator Cache = MNCComplete.find(RD);
496  if (Cache != MNCComplete.end())
497    return Cache->second;
498  if (!RD->isCompleteDefinition())
499    return false;
500  bool Complete = true;
501  for (DeclContext::decl_iterator I = RD->decls_begin(),
502                                  E = RD->decls_end();
503       I != E && Complete; ++I) {
504    if (const CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(*I))
505      Complete = M->isDefined() || (M->isPure() && !isa<CXXDestructorDecl>(M));
506    else if (const FunctionTemplateDecl *F = dyn_cast<FunctionTemplateDecl>(*I))
507      Complete = F->getTemplatedDecl()->isDefined();
508    else if (const CXXRecordDecl *R = dyn_cast<CXXRecordDecl>(*I)) {
509      if (R->isInjectedClassName())
510        continue;
511      if (R->hasDefinition())
512        Complete = MethodsAndNestedClassesComplete(R->getDefinition(),
513                                                   MNCComplete);
514      else
515        Complete = false;
516    }
517  }
518  MNCComplete[RD] = Complete;
519  return Complete;
520}
521
522/// \brief Returns true, if the given CXXRecordDecl is fully defined in this
523/// translation unit, i.e. all methods are defined or pure virtual and all
524/// friends, friend functions and nested classes are fully defined in this
525/// translation unit.
526///
527/// Should only be called from ActOnEndOfTranslationUnit so that all
528/// definitions are actually read.
529static bool IsRecordFullyDefined(const CXXRecordDecl *RD,
530                                 RecordCompleteMap &RecordsComplete,
531                                 RecordCompleteMap &MNCComplete) {
532  RecordCompleteMap::iterator Cache = RecordsComplete.find(RD);
533  if (Cache != RecordsComplete.end())
534    return Cache->second;
535  bool Complete = MethodsAndNestedClassesComplete(RD, MNCComplete);
536  for (CXXRecordDecl::friend_iterator I = RD->friend_begin(),
537                                      E = RD->friend_end();
538       I != E && Complete; ++I) {
539    // Check if friend classes and methods are complete.
540    if (TypeSourceInfo *TSI = (*I)->getFriendType()) {
541      // Friend classes are available as the TypeSourceInfo of the FriendDecl.
542      if (CXXRecordDecl *FriendD = TSI->getType()->getAsCXXRecordDecl())
543        Complete = MethodsAndNestedClassesComplete(FriendD, MNCComplete);
544      else
545        Complete = false;
546    } else {
547      // Friend functions are available through the NamedDecl of FriendDecl.
548      if (const FunctionDecl *FD =
549          dyn_cast<FunctionDecl>((*I)->getFriendDecl()))
550        Complete = FD->isDefined();
551      else
552        // This is a template friend, give up.
553        Complete = false;
554    }
555  }
556  RecordsComplete[RD] = Complete;
557  return Complete;
558}
559
560/// ActOnEndOfTranslationUnit - This is called at the very end of the
561/// translation unit when EOF is reached and all but the top-level scope is
562/// popped.
563void Sema::ActOnEndOfTranslationUnit() {
564  assert(DelayedDiagnostics.getCurrentPool() == NULL
565         && "reached end of translation unit with a pool attached?");
566
567  // If code completion is enabled, don't perform any end-of-translation-unit
568  // work.
569  if (PP.isCodeCompletionEnabled())
570    return;
571
572  // Complete translation units and modules define vtables and perform implicit
573  // instantiations. PCH files do not.
574  if (TUKind != TU_Prefix) {
575    DiagnoseUseOfUnimplementedSelectors();
576
577    // If any dynamic classes have their key function defined within
578    // this translation unit, then those vtables are considered "used" and must
579    // be emitted.
580    for (DynamicClassesType::iterator I = DynamicClasses.begin(ExternalSource),
581                                      E = DynamicClasses.end();
582         I != E; ++I) {
583      assert(!(*I)->isDependentType() &&
584             "Should not see dependent types here!");
585      if (const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(*I)) {
586        const FunctionDecl *Definition = 0;
587        if (KeyFunction->hasBody(Definition))
588          MarkVTableUsed(Definition->getLocation(), *I, true);
589      }
590    }
591
592    // If DefinedUsedVTables ends up marking any virtual member functions it
593    // might lead to more pending template instantiations, which we then need
594    // to instantiate.
595    DefineUsedVTables();
596
597    // C++: Perform implicit template instantiations.
598    //
599    // FIXME: When we perform these implicit instantiations, we do not
600    // carefully keep track of the point of instantiation (C++ [temp.point]).
601    // This means that name lookup that occurs within the template
602    // instantiation will always happen at the end of the translation unit,
603    // so it will find some names that are not required to be found. This is
604    // valid, but we could do better by diagnosing if an instantiation uses a
605    // name that was not visible at its first point of instantiation.
606    PerformPendingInstantiations();
607    CheckDelayedMemberExceptionSpecs();
608  }
609
610  // All delayed member exception specs should be checked or we end up accepting
611  // incompatible declarations.
612  assert(DelayedDefaultedMemberExceptionSpecs.empty());
613  assert(DelayedDestructorExceptionSpecChecks.empty());
614
615  // Remove file scoped decls that turned out to be used.
616  UnusedFileScopedDecls.erase(
617      std::remove_if(UnusedFileScopedDecls.begin(0, true),
618                     UnusedFileScopedDecls.end(),
619                     std::bind1st(std::ptr_fun(ShouldRemoveFromUnused), this)),
620      UnusedFileScopedDecls.end());
621
622  if (TUKind == TU_Prefix) {
623    // Translation unit prefixes don't need any of the checking below.
624    TUScope = 0;
625    return;
626  }
627
628  // Check for #pragma weak identifiers that were never declared
629  // FIXME: This will cause diagnostics to be emitted in a non-determinstic
630  // order!  Iterating over a densemap like this is bad.
631  LoadExternalWeakUndeclaredIdentifiers();
632  for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
633       I = WeakUndeclaredIdentifiers.begin(),
634       E = WeakUndeclaredIdentifiers.end(); I != E; ++I) {
635    if (I->second.getUsed()) continue;
636
637    Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared)
638      << I->first;
639  }
640
641  if (LangOpts.CPlusPlus11 &&
642      Diags.getDiagnosticLevel(diag::warn_delegating_ctor_cycle,
643                               SourceLocation())
644        != DiagnosticsEngine::Ignored)
645    CheckDelegatingCtorCycles();
646
647  if (TUKind == TU_Module) {
648    // If we are building a module, resolve all of the exported declarations
649    // now.
650    if (Module *CurrentModule = PP.getCurrentModule()) {
651      ModuleMap &ModMap = PP.getHeaderSearchInfo().getModuleMap();
652
653      SmallVector<Module *, 2> Stack;
654      Stack.push_back(CurrentModule);
655      while (!Stack.empty()) {
656        Module *Mod = Stack.pop_back_val();
657
658        // Resolve the exported declarations and conflicts.
659        // FIXME: Actually complain, once we figure out how to teach the
660        // diagnostic client to deal with complaints in the module map at this
661        // point.
662        ModMap.resolveExports(Mod, /*Complain=*/false);
663        ModMap.resolveUses(Mod, /*Complain=*/false);
664        ModMap.resolveConflicts(Mod, /*Complain=*/false);
665
666        // Queue the submodules, so their exports will also be resolved.
667        for (Module::submodule_iterator Sub = Mod->submodule_begin(),
668                                     SubEnd = Mod->submodule_end();
669             Sub != SubEnd; ++Sub) {
670          Stack.push_back(*Sub);
671        }
672      }
673    }
674
675    // Modules don't need any of the checking below.
676    TUScope = 0;
677    return;
678  }
679
680  // C99 6.9.2p2:
681  //   A declaration of an identifier for an object that has file
682  //   scope without an initializer, and without a storage-class
683  //   specifier or with the storage-class specifier static,
684  //   constitutes a tentative definition. If a translation unit
685  //   contains one or more tentative definitions for an identifier,
686  //   and the translation unit contains no external definition for
687  //   that identifier, then the behavior is exactly as if the
688  //   translation unit contains a file scope declaration of that
689  //   identifier, with the composite type as of the end of the
690  //   translation unit, with an initializer equal to 0.
691  llvm::SmallSet<VarDecl *, 32> Seen;
692  for (TentativeDefinitionsType::iterator
693            T = TentativeDefinitions.begin(ExternalSource),
694         TEnd = TentativeDefinitions.end();
695       T != TEnd; ++T)
696  {
697    VarDecl *VD = (*T)->getActingDefinition();
698
699    // If the tentative definition was completed, getActingDefinition() returns
700    // null. If we've already seen this variable before, insert()'s second
701    // return value is false.
702    if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD))
703      continue;
704
705    if (const IncompleteArrayType *ArrayT
706        = Context.getAsIncompleteArrayType(VD->getType())) {
707      // Set the length of the array to 1 (C99 6.9.2p5).
708      Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
709      llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true);
710      QualType T = Context.getConstantArrayType(ArrayT->getElementType(),
711                                                One, ArrayType::Normal, 0);
712      VD->setType(T);
713    } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
714                                   diag::err_tentative_def_incomplete_type))
715      VD->setInvalidDecl();
716
717    CheckCompleteVariableDeclaration(VD);
718
719    // Notify the consumer that we've completed a tentative definition.
720    if (!VD->isInvalidDecl())
721      Consumer.CompleteTentativeDefinition(VD);
722
723  }
724
725  // If there were errors, disable 'unused' warnings since they will mostly be
726  // noise.
727  if (!Diags.hasErrorOccurred()) {
728    // Output warning for unused file scoped decls.
729    for (UnusedFileScopedDeclsType::iterator
730           I = UnusedFileScopedDecls.begin(ExternalSource),
731           E = UnusedFileScopedDecls.end(); I != E; ++I) {
732      if (ShouldRemoveFromUnused(this, *I))
733        continue;
734
735      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
736        const FunctionDecl *DiagD;
737        if (!FD->hasBody(DiagD))
738          DiagD = FD;
739        if (DiagD->isDeleted())
740          continue; // Deleted functions are supposed to be unused.
741        if (DiagD->isReferenced()) {
742          if (isa<CXXMethodDecl>(DiagD))
743            Diag(DiagD->getLocation(), diag::warn_unneeded_member_function)
744                  << DiagD->getDeclName();
745          else {
746            if (FD->getStorageClass() == SC_Static &&
747                !FD->isInlineSpecified() &&
748                !SourceMgr.isInMainFile(
749                   SourceMgr.getExpansionLoc(FD->getLocation())))
750              Diag(DiagD->getLocation(), diag::warn_unneeded_static_internal_decl)
751                << DiagD->getDeclName();
752            else
753              Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
754                   << /*function*/0 << DiagD->getDeclName();
755          }
756        } else {
757          Diag(DiagD->getLocation(),
758               isa<CXXMethodDecl>(DiagD) ? diag::warn_unused_member_function
759                                         : diag::warn_unused_function)
760                << DiagD->getDeclName();
761        }
762      } else {
763        const VarDecl *DiagD = cast<VarDecl>(*I)->getDefinition();
764        if (!DiagD)
765          DiagD = cast<VarDecl>(*I);
766        if (DiagD->isReferenced()) {
767          Diag(DiagD->getLocation(), diag::warn_unneeded_internal_decl)
768                << /*variable*/1 << DiagD->getDeclName();
769        } else if (DiagD->getType().isConstQualified()) {
770          Diag(DiagD->getLocation(), diag::warn_unused_const_variable)
771              << DiagD->getDeclName();
772        } else {
773          Diag(DiagD->getLocation(), diag::warn_unused_variable)
774              << DiagD->getDeclName();
775        }
776      }
777    }
778
779    if (ExternalSource)
780      ExternalSource->ReadUndefinedButUsed(UndefinedButUsed);
781    checkUndefinedButUsed(*this);
782  }
783
784  if (Diags.getDiagnosticLevel(diag::warn_unused_private_field,
785                               SourceLocation())
786        != DiagnosticsEngine::Ignored) {
787    RecordCompleteMap RecordsComplete;
788    RecordCompleteMap MNCComplete;
789    for (NamedDeclSetType::iterator I = UnusedPrivateFields.begin(),
790         E = UnusedPrivateFields.end(); I != E; ++I) {
791      const NamedDecl *D = *I;
792      const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
793      if (RD && !RD->isUnion() &&
794          IsRecordFullyDefined(RD, RecordsComplete, MNCComplete)) {
795        Diag(D->getLocation(), diag::warn_unused_private_field)
796              << D->getDeclName();
797      }
798    }
799  }
800
801  // Check we've noticed that we're no longer parsing the initializer for every
802  // variable. If we miss cases, then at best we have a performance issue and
803  // at worst a rejects-valid bug.
804  assert(ParsingInitForAutoVars.empty() &&
805         "Didn't unmark var as having its initializer parsed");
806
807  TUScope = 0;
808}
809
810
811//===----------------------------------------------------------------------===//
812// Helper functions.
813//===----------------------------------------------------------------------===//
814
815DeclContext *Sema::getFunctionLevelDeclContext() {
816  DeclContext *DC = CurContext;
817
818  while (true) {
819    if (isa<BlockDecl>(DC) || isa<EnumDecl>(DC) || isa<CapturedDecl>(DC)) {
820      DC = DC->getParent();
821    } else if (isa<CXXMethodDecl>(DC) &&
822               cast<CXXMethodDecl>(DC)->getOverloadedOperator() == OO_Call &&
823               cast<CXXRecordDecl>(DC->getParent())->isLambda()) {
824      DC = DC->getParent()->getParent();
825    }
826    else break;
827  }
828
829  return DC;
830}
831
832/// getCurFunctionDecl - If inside of a function body, this returns a pointer
833/// to the function decl for the function being parsed.  If we're currently
834/// in a 'block', this returns the containing context.
835FunctionDecl *Sema::getCurFunctionDecl() {
836  DeclContext *DC = getFunctionLevelDeclContext();
837  return dyn_cast<FunctionDecl>(DC);
838}
839
840ObjCMethodDecl *Sema::getCurMethodDecl() {
841  DeclContext *DC = getFunctionLevelDeclContext();
842  while (isa<RecordDecl>(DC))
843    DC = DC->getParent();
844  return dyn_cast<ObjCMethodDecl>(DC);
845}
846
847NamedDecl *Sema::getCurFunctionOrMethodDecl() {
848  DeclContext *DC = getFunctionLevelDeclContext();
849  if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
850    return cast<NamedDecl>(DC);
851  return 0;
852}
853
854void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
855  // FIXME: It doesn't make sense to me that DiagID is an incoming argument here
856  // and yet we also use the current diag ID on the DiagnosticsEngine. This has
857  // been made more painfully obvious by the refactor that introduced this
858  // function, but it is possible that the incoming argument can be
859  // eliminnated. If it truly cannot be (for example, there is some reentrancy
860  // issue I am not seeing yet), then there should at least be a clarifying
861  // comment somewhere.
862  if (Optional<TemplateDeductionInfo*> Info = isSFINAEContext()) {
863    switch (DiagnosticIDs::getDiagnosticSFINAEResponse(
864              Diags.getCurrentDiagID())) {
865    case DiagnosticIDs::SFINAE_Report:
866      // We'll report the diagnostic below.
867      break;
868
869    case DiagnosticIDs::SFINAE_SubstitutionFailure:
870      // Count this failure so that we know that template argument deduction
871      // has failed.
872      ++NumSFINAEErrors;
873
874      // Make a copy of this suppressed diagnostic and store it with the
875      // template-deduction information.
876      if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
877        Diagnostic DiagInfo(&Diags);
878        (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
879                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
880      }
881
882      Diags.setLastDiagnosticIgnored();
883      Diags.Clear();
884      return;
885
886    case DiagnosticIDs::SFINAE_AccessControl: {
887      // Per C++ Core Issue 1170, access control is part of SFINAE.
888      // Additionally, the AccessCheckingSFINAE flag can be used to temporarily
889      // make access control a part of SFINAE for the purposes of checking
890      // type traits.
891      if (!AccessCheckingSFINAE && !getLangOpts().CPlusPlus11)
892        break;
893
894      SourceLocation Loc = Diags.getCurrentDiagLoc();
895
896      // Suppress this diagnostic.
897      ++NumSFINAEErrors;
898
899      // Make a copy of this suppressed diagnostic and store it with the
900      // template-deduction information.
901      if (*Info && !(*Info)->hasSFINAEDiagnostic()) {
902        Diagnostic DiagInfo(&Diags);
903        (*Info)->addSFINAEDiagnostic(DiagInfo.getLocation(),
904                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
905      }
906
907      Diags.setLastDiagnosticIgnored();
908      Diags.Clear();
909
910      // Now the diagnostic state is clear, produce a C++98 compatibility
911      // warning.
912      Diag(Loc, diag::warn_cxx98_compat_sfinae_access_control);
913
914      // The last diagnostic which Sema produced was ignored. Suppress any
915      // notes attached to it.
916      Diags.setLastDiagnosticIgnored();
917      return;
918    }
919
920    case DiagnosticIDs::SFINAE_Suppress:
921      // Make a copy of this suppressed diagnostic and store it with the
922      // template-deduction information;
923      if (*Info) {
924        Diagnostic DiagInfo(&Diags);
925        (*Info)->addSuppressedDiagnostic(DiagInfo.getLocation(),
926                       PartialDiagnostic(DiagInfo, Context.getDiagAllocator()));
927      }
928
929      // Suppress this diagnostic.
930      Diags.setLastDiagnosticIgnored();
931      Diags.Clear();
932      return;
933    }
934  }
935
936  // Set up the context's printing policy based on our current state.
937  Context.setPrintingPolicy(getPrintingPolicy());
938
939  // Emit the diagnostic.
940  if (!Diags.EmitCurrentDiagnostic())
941    return;
942
943  // If this is not a note, and we're in a template instantiation
944  // that is different from the last template instantiation where
945  // we emitted an error, print a template instantiation
946  // backtrace.
947  if (!DiagnosticIDs::isBuiltinNote(DiagID) &&
948      !ActiveTemplateInstantiations.empty() &&
949      ActiveTemplateInstantiations.back()
950        != LastTemplateInstantiationErrorContext) {
951    PrintInstantiationStack();
952    LastTemplateInstantiationErrorContext = ActiveTemplateInstantiations.back();
953  }
954}
955
956Sema::SemaDiagnosticBuilder
957Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
958  SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID()));
959  PD.Emit(Builder);
960
961  return Builder;
962}
963
964/// \brief Looks through the macro-expansion chain for the given
965/// location, looking for a macro expansion with the given name.
966/// If one is found, returns true and sets the location to that
967/// expansion loc.
968bool Sema::findMacroSpelling(SourceLocation &locref, StringRef name) {
969  SourceLocation loc = locref;
970  if (!loc.isMacroID()) return false;
971
972  // There's no good way right now to look at the intermediate
973  // expansions, so just jump to the expansion location.
974  loc = getSourceManager().getExpansionLoc(loc);
975
976  // If that's written with the name, stop here.
977  SmallVector<char, 16> buffer;
978  if (getPreprocessor().getSpelling(loc, buffer) == name) {
979    locref = loc;
980    return true;
981  }
982  return false;
983}
984
985/// \brief Determines the active Scope associated with the given declaration
986/// context.
987///
988/// This routine maps a declaration context to the active Scope object that
989/// represents that declaration context in the parser. It is typically used
990/// from "scope-less" code (e.g., template instantiation, lazy creation of
991/// declarations) that injects a name for name-lookup purposes and, therefore,
992/// must update the Scope.
993///
994/// \returns The scope corresponding to the given declaraion context, or NULL
995/// if no such scope is open.
996Scope *Sema::getScopeForContext(DeclContext *Ctx) {
997
998  if (!Ctx)
999    return 0;
1000
1001  Ctx = Ctx->getPrimaryContext();
1002  for (Scope *S = getCurScope(); S; S = S->getParent()) {
1003    // Ignore scopes that cannot have declarations. This is important for
1004    // out-of-line definitions of static class members.
1005    if (S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope))
1006      if (DeclContext *Entity = S->getEntity())
1007        if (Ctx == Entity->getPrimaryContext())
1008          return S;
1009  }
1010
1011  return 0;
1012}
1013
1014/// \brief Enter a new function scope
1015void Sema::PushFunctionScope() {
1016  if (FunctionScopes.size() == 1) {
1017    // Use the "top" function scope rather than having to allocate
1018    // memory for a new scope.
1019    FunctionScopes.back()->Clear();
1020    FunctionScopes.push_back(FunctionScopes.back());
1021    return;
1022  }
1023
1024  FunctionScopes.push_back(new FunctionScopeInfo(getDiagnostics()));
1025}
1026
1027void Sema::PushBlockScope(Scope *BlockScope, BlockDecl *Block) {
1028  FunctionScopes.push_back(new BlockScopeInfo(getDiagnostics(),
1029                                              BlockScope, Block));
1030}
1031
1032LambdaScopeInfo *Sema::PushLambdaScope() {
1033  LambdaScopeInfo *const LSI = new LambdaScopeInfo(getDiagnostics());
1034  FunctionScopes.push_back(LSI);
1035  return LSI;
1036}
1037
1038void Sema::RecordParsingTemplateParameterDepth(unsigned Depth) {
1039  if (LambdaScopeInfo *const LSI = getCurLambda()) {
1040    LSI->AutoTemplateParameterDepth = Depth;
1041    return;
1042  }
1043  llvm_unreachable(
1044      "Remove assertion if intentionally called in a non-lambda context.");
1045}
1046
1047void Sema::PopFunctionScopeInfo(const AnalysisBasedWarnings::Policy *WP,
1048                                const Decl *D, const BlockExpr *blkExpr) {
1049  FunctionScopeInfo *Scope = FunctionScopes.pop_back_val();
1050  assert(!FunctionScopes.empty() && "mismatched push/pop!");
1051
1052  // Issue any analysis-based warnings.
1053  if (WP && D)
1054    AnalysisWarnings.IssueWarnings(*WP, Scope, D, blkExpr);
1055  else {
1056    for (SmallVectorImpl<sema::PossiblyUnreachableDiag>::iterator
1057         i = Scope->PossiblyUnreachableDiags.begin(),
1058         e = Scope->PossiblyUnreachableDiags.end();
1059         i != e; ++i) {
1060      const sema::PossiblyUnreachableDiag &D = *i;
1061      Diag(D.Loc, D.PD);
1062    }
1063  }
1064
1065  if (FunctionScopes.back() != Scope) {
1066    delete Scope;
1067  }
1068}
1069
1070void Sema::PushCompoundScope() {
1071  getCurFunction()->CompoundScopes.push_back(CompoundScopeInfo());
1072}
1073
1074void Sema::PopCompoundScope() {
1075  FunctionScopeInfo *CurFunction = getCurFunction();
1076  assert(!CurFunction->CompoundScopes.empty() && "mismatched push/pop");
1077
1078  CurFunction->CompoundScopes.pop_back();
1079}
1080
1081/// \brief Determine whether any errors occurred within this function/method/
1082/// block.
1083bool Sema::hasAnyUnrecoverableErrorsInThisFunction() const {
1084  return getCurFunction()->ErrorTrap.hasUnrecoverableErrorOccurred();
1085}
1086
1087BlockScopeInfo *Sema::getCurBlock() {
1088  if (FunctionScopes.empty())
1089    return 0;
1090
1091  return dyn_cast<BlockScopeInfo>(FunctionScopes.back());
1092}
1093
1094LambdaScopeInfo *Sema::getCurLambda() {
1095  if (FunctionScopes.empty())
1096    return 0;
1097
1098  return dyn_cast<LambdaScopeInfo>(FunctionScopes.back());
1099}
1100// We have a generic lambda if we parsed auto parameters, or we have
1101// an associated template parameter list.
1102LambdaScopeInfo *Sema::getCurGenericLambda() {
1103  if (LambdaScopeInfo *LSI =  getCurLambda()) {
1104    return (LSI->AutoTemplateParams.size() ||
1105                    LSI->GLTemplateParameterList) ? LSI : 0;
1106  }
1107  return 0;
1108}
1109
1110
1111void Sema::ActOnComment(SourceRange Comment) {
1112  if (!LangOpts.RetainCommentsFromSystemHeaders &&
1113      SourceMgr.isInSystemHeader(Comment.getBegin()))
1114    return;
1115  RawComment RC(SourceMgr, Comment, false,
1116                LangOpts.CommentOpts.ParseAllComments);
1117  if (RC.isAlmostTrailingComment()) {
1118    SourceRange MagicMarkerRange(Comment.getBegin(),
1119                                 Comment.getBegin().getLocWithOffset(3));
1120    StringRef MagicMarkerText;
1121    switch (RC.getKind()) {
1122    case RawComment::RCK_OrdinaryBCPL:
1123      MagicMarkerText = "///<";
1124      break;
1125    case RawComment::RCK_OrdinaryC:
1126      MagicMarkerText = "/**<";
1127      break;
1128    default:
1129      llvm_unreachable("if this is an almost Doxygen comment, "
1130                       "it should be ordinary");
1131    }
1132    Diag(Comment.getBegin(), diag::warn_not_a_doxygen_trailing_member_comment) <<
1133      FixItHint::CreateReplacement(MagicMarkerRange, MagicMarkerText);
1134  }
1135  Context.addComment(RC);
1136}
1137
1138// Pin this vtable to this file.
1139ExternalSemaSource::~ExternalSemaSource() {}
1140
1141void ExternalSemaSource::ReadMethodPool(Selector Sel) { }
1142
1143void ExternalSemaSource::ReadKnownNamespaces(
1144                           SmallVectorImpl<NamespaceDecl *> &Namespaces) {
1145}
1146
1147void ExternalSemaSource::ReadUndefinedButUsed(
1148                       llvm::DenseMap<NamedDecl *, SourceLocation> &Undefined) {
1149}
1150
1151void PrettyDeclStackTraceEntry::print(raw_ostream &OS) const {
1152  SourceLocation Loc = this->Loc;
1153  if (!Loc.isValid() && TheDecl) Loc = TheDecl->getLocation();
1154  if (Loc.isValid()) {
1155    Loc.print(OS, S.getSourceManager());
1156    OS << ": ";
1157  }
1158  OS << Message;
1159
1160  if (TheDecl && isa<NamedDecl>(TheDecl)) {
1161    std::string Name = cast<NamedDecl>(TheDecl)->getNameAsString();
1162    if (!Name.empty())
1163      OS << " '" << Name << '\'';
1164  }
1165
1166  OS << '\n';
1167}
1168
1169/// \brief Figure out if an expression could be turned into a call.
1170///
1171/// Use this when trying to recover from an error where the programmer may have
1172/// written just the name of a function instead of actually calling it.
1173///
1174/// \param E - The expression to examine.
1175/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
1176///  with no arguments, this parameter is set to the type returned by such a
1177///  call; otherwise, it is set to an empty QualType.
1178/// \param OverloadSet - If the expression is an overloaded function
1179///  name, this parameter is populated with the decls of the various overloads.
1180bool Sema::tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
1181                         UnresolvedSetImpl &OverloadSet) {
1182  ZeroArgCallReturnTy = QualType();
1183  OverloadSet.clear();
1184
1185  const OverloadExpr *Overloads = NULL;
1186  bool IsMemExpr = false;
1187  if (E.getType() == Context.OverloadTy) {
1188    OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
1189
1190    // Ignore overloads that are pointer-to-member constants.
1191    if (FR.HasFormOfMemberPointer)
1192      return false;
1193
1194    Overloads = FR.Expression;
1195  } else if (E.getType() == Context.BoundMemberTy) {
1196    Overloads = dyn_cast<UnresolvedMemberExpr>(E.IgnoreParens());
1197    IsMemExpr = true;
1198  }
1199
1200  bool Ambiguous = false;
1201
1202  if (Overloads) {
1203    for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
1204         DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
1205      OverloadSet.addDecl(*it);
1206
1207      // Check whether the function is a non-template, non-member which takes no
1208      // arguments.
1209      if (IsMemExpr)
1210        continue;
1211      if (const FunctionDecl *OverloadDecl
1212            = dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
1213        if (OverloadDecl->getMinRequiredArguments() == 0) {
1214          if (!ZeroArgCallReturnTy.isNull() && !Ambiguous) {
1215            ZeroArgCallReturnTy = QualType();
1216            Ambiguous = true;
1217          } else
1218            ZeroArgCallReturnTy = OverloadDecl->getResultType();
1219        }
1220      }
1221    }
1222
1223    // If it's not a member, use better machinery to try to resolve the call
1224    if (!IsMemExpr)
1225      return !ZeroArgCallReturnTy.isNull();
1226  }
1227
1228  // Attempt to call the member with no arguments - this will correctly handle
1229  // member templates with defaults/deduction of template arguments, overloads
1230  // with default arguments, etc.
1231  if (IsMemExpr && !E.isTypeDependent()) {
1232    bool Suppress = getDiagnostics().getSuppressAllDiagnostics();
1233    getDiagnostics().setSuppressAllDiagnostics(true);
1234    ExprResult R = BuildCallToMemberFunction(NULL, &E, SourceLocation(), None,
1235                                             SourceLocation());
1236    getDiagnostics().setSuppressAllDiagnostics(Suppress);
1237    if (R.isUsable()) {
1238      ZeroArgCallReturnTy = R.get()->getType();
1239      return true;
1240    }
1241    return false;
1242  }
1243
1244  if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
1245    if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
1246      if (Fun->getMinRequiredArguments() == 0)
1247        ZeroArgCallReturnTy = Fun->getResultType();
1248      return true;
1249    }
1250  }
1251
1252  // We don't have an expression that's convenient to get a FunctionDecl from,
1253  // but we can at least check if the type is "function of 0 arguments".
1254  QualType ExprTy = E.getType();
1255  const FunctionType *FunTy = NULL;
1256  QualType PointeeTy = ExprTy->getPointeeType();
1257  if (!PointeeTy.isNull())
1258    FunTy = PointeeTy->getAs<FunctionType>();
1259  if (!FunTy)
1260    FunTy = ExprTy->getAs<FunctionType>();
1261
1262  if (const FunctionProtoType *FPT =
1263      dyn_cast_or_null<FunctionProtoType>(FunTy)) {
1264    if (FPT->getNumArgs() == 0)
1265      ZeroArgCallReturnTy = FunTy->getResultType();
1266    return true;
1267  }
1268  return false;
1269}
1270
1271/// \brief Give notes for a set of overloads.
1272///
1273/// A companion to tryExprAsCall. In cases when the name that the programmer
1274/// wrote was an overloaded function, we may be able to make some guesses about
1275/// plausible overloads based on their return types; such guesses can be handed
1276/// off to this method to be emitted as notes.
1277///
1278/// \param Overloads - The overloads to note.
1279/// \param FinalNoteLoc - If we've suppressed printing some overloads due to
1280///  -fshow-overloads=best, this is the location to attach to the note about too
1281///  many candidates. Typically this will be the location of the original
1282///  ill-formed expression.
1283static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
1284                          const SourceLocation FinalNoteLoc) {
1285  int ShownOverloads = 0;
1286  int SuppressedOverloads = 0;
1287  for (UnresolvedSetImpl::iterator It = Overloads.begin(),
1288       DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1289    // FIXME: Magic number for max shown overloads stolen from
1290    // OverloadCandidateSet::NoteCandidates.
1291    if (ShownOverloads >= 4 && S.Diags.getShowOverloads() == Ovl_Best) {
1292      ++SuppressedOverloads;
1293      continue;
1294    }
1295
1296    NamedDecl *Fn = (*It)->getUnderlyingDecl();
1297    S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
1298    ++ShownOverloads;
1299  }
1300
1301  if (SuppressedOverloads)
1302    S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
1303      << SuppressedOverloads;
1304}
1305
1306static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
1307                                   const UnresolvedSetImpl &Overloads,
1308                                   bool (*IsPlausibleResult)(QualType)) {
1309  if (!IsPlausibleResult)
1310    return noteOverloads(S, Overloads, Loc);
1311
1312  UnresolvedSet<2> PlausibleOverloads;
1313  for (OverloadExpr::decls_iterator It = Overloads.begin(),
1314         DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
1315    const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
1316    QualType OverloadResultTy = OverloadDecl->getResultType();
1317    if (IsPlausibleResult(OverloadResultTy))
1318      PlausibleOverloads.addDecl(It.getDecl());
1319  }
1320  noteOverloads(S, PlausibleOverloads, Loc);
1321}
1322
1323/// Determine whether the given expression can be called by just
1324/// putting parentheses after it.  Notably, expressions with unary
1325/// operators can't be because the unary operator will start parsing
1326/// outside the call.
1327static bool IsCallableWithAppend(Expr *E) {
1328  E = E->IgnoreImplicit();
1329  return (!isa<CStyleCastExpr>(E) &&
1330          !isa<UnaryOperator>(E) &&
1331          !isa<BinaryOperator>(E) &&
1332          !isa<CXXOperatorCallExpr>(E));
1333}
1334
1335bool Sema::tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
1336                                bool ForceComplain,
1337                                bool (*IsPlausibleResult)(QualType)) {
1338  SourceLocation Loc = E.get()->getExprLoc();
1339  SourceRange Range = E.get()->getSourceRange();
1340
1341  QualType ZeroArgCallTy;
1342  UnresolvedSet<4> Overloads;
1343  if (tryExprAsCall(*E.get(), ZeroArgCallTy, Overloads) &&
1344      !ZeroArgCallTy.isNull() &&
1345      (!IsPlausibleResult || IsPlausibleResult(ZeroArgCallTy))) {
1346    // At this point, we know E is potentially callable with 0
1347    // arguments and that it returns something of a reasonable type,
1348    // so we can emit a fixit and carry on pretending that E was
1349    // actually a CallExpr.
1350    SourceLocation ParenInsertionLoc = PP.getLocForEndOfToken(Range.getEnd());
1351    Diag(Loc, PD)
1352      << /*zero-arg*/ 1 << Range
1353      << (IsCallableWithAppend(E.get())
1354          ? FixItHint::CreateInsertion(ParenInsertionLoc, "()")
1355          : FixItHint());
1356    notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
1357
1358    // FIXME: Try this before emitting the fixit, and suppress diagnostics
1359    // while doing so.
1360    E = ActOnCallExpr(0, E.take(), Range.getEnd(), None,
1361                      Range.getEnd().getLocWithOffset(1));
1362    return true;
1363  }
1364
1365  if (!ForceComplain) return false;
1366
1367  Diag(Loc, PD) << /*not zero-arg*/ 0 << Range;
1368  notePlausibleOverloads(*this, Loc, Overloads, IsPlausibleResult);
1369  E = ExprError();
1370  return true;
1371}
1372
1373IdentifierInfo *Sema::getSuperIdentifier() const {
1374  if (!Ident_super)
1375    Ident_super = &Context.Idents.get("super");
1376  return Ident_super;
1377}
1378
1379IdentifierInfo *Sema::getFloat128Identifier() const {
1380  if (!Ident___float128)
1381    Ident___float128 = &Context.Idents.get("__float128");
1382  return Ident___float128;
1383}
1384
1385void Sema::PushCapturedRegionScope(Scope *S, CapturedDecl *CD, RecordDecl *RD,
1386                                   CapturedRegionKind K) {
1387  CapturingScopeInfo *CSI = new CapturedRegionScopeInfo(getDiagnostics(), S, CD, RD,
1388                                                        CD->getContextParam(), K);
1389  CSI->ReturnType = Context.VoidTy;
1390  FunctionScopes.push_back(CSI);
1391}
1392
1393CapturedRegionScopeInfo *Sema::getCurCapturedRegion() {
1394  if (FunctionScopes.empty())
1395    return 0;
1396
1397  return dyn_cast<CapturedRegionScopeInfo>(FunctionScopes.back());
1398}
1399