C++ ASTContext类代码示例

uint32_t ExternalASTSource::incrementGeneration(ASTContext &C) {
  uint32_t OldGeneration = CurrentGeneration;

  // Make sure the generation of the topmost external source for the context is
  // incremented. That might not be us.
  auto *P = C.getExternalSource();
  if (P && P != this)
    CurrentGeneration = P->incrementGeneration(C);
  else {
    // FIXME: Only bump the generation counter if the current generation number
    // has been observed?
    if (!++CurrentGeneration)
      llvm::report_fatal_error("generation counter overflowed", false);
  }

  return OldGeneration;
}

void ObjCInterfaceDecl::mergeClassExtensionProtocolList(
                              ObjCProtocolDecl *const* ExtList, unsigned ExtNum,
                              ASTContext &C)
{
  if (ExternallyCompleted)
    LoadExternalDefinition();

  if (AllReferencedProtocols.empty() && ReferencedProtocols.empty()) {
    AllReferencedProtocols.set(ExtList, ExtNum, C);
    return;
  }
  
  // Check for duplicate protocol in class's protocol list.
  // This is O(n*m). But it is extremely rare and number of protocols in
  // class or its extension are very few.
  llvm::SmallVector<ObjCProtocolDecl*, 8> ProtocolRefs;
  for (unsigned i = 0; i < ExtNum; i++) {
    bool protocolExists = false;
    ObjCProtocolDecl *ProtoInExtension = ExtList[i];
    for (all_protocol_iterator
          p = all_referenced_protocol_begin(),
          e = all_referenced_protocol_end(); p != e; ++p) {
      ObjCProtocolDecl *Proto = (*p);
      if (C.ProtocolCompatibleWithProtocol(ProtoInExtension, Proto)) {
        protocolExists = true;
        break;
      }      
    }
    // Do we want to warn on a protocol in extension class which
    // already exist in the class? Probably not.
    if (!protocolExists)
      ProtocolRefs.push_back(ProtoInExtension);
  }

  if (ProtocolRefs.empty())
    return;

  // Merge ProtocolRefs into class's protocol list;
  for (all_protocol_iterator p = all_referenced_protocol_begin(), 
        e = all_referenced_protocol_end(); p != e; ++p) {
    ProtocolRefs.push_back(*p);
  }

  AllReferencedProtocols.set(ProtocolRefs.data(), ProtocolRefs.size(), C);
}

    void HandleTranslationUnit(ASTContext &C) override {
      {
        PrettyStackTraceString CrashInfo("Per-file LLVM IR generation");
        if (llvm::TimePassesIsEnabled)
          LLVMIRGeneration.startTimer();

        Gen->HandleTranslationUnit(C);

        if (llvm::TimePassesIsEnabled)
          LLVMIRGeneration.stopTimer();
      }

      // Silently ignore if we weren't initialized for some reason.
      if (!getModule())
        return;

      // Install an inline asm handler so that diagnostics get printed through
      // our diagnostics hooks.
      LLVMContext &Ctx = getModule()->getContext();
      LLVMContext::InlineAsmDiagHandlerTy OldHandler =
        Ctx.getInlineAsmDiagnosticHandler();
      void *OldContext = Ctx.getInlineAsmDiagnosticContext();
      Ctx.setInlineAsmDiagnosticHandler(InlineAsmDiagHandler, this);

      LLVMContext::DiagnosticHandlerTy OldDiagnosticHandler =
          Ctx.getDiagnosticHandler();
      void *OldDiagnosticContext = Ctx.getDiagnosticContext();
      Ctx.setDiagnosticHandler(DiagnosticHandler, this);

      // Link LinkModule into this module if present, preserving its validity.
      for (auto &I : LinkModules) {
        unsigned LinkFlags = I.first;
        CurLinkModule = I.second.get();
        if (Linker::linkModules(*getModule(), std::move(I.second), LinkFlags))
          return;
      }

      EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts,
                        C.getTargetInfo().getDataLayoutString(),
                        getModule(), Action, AsmOutStream);

      Ctx.setInlineAsmDiagnosticHandler(OldHandler, OldContext);

      Ctx.setDiagnosticHandler(OldDiagnosticHandler, OldDiagnosticContext);
    }

// Checks if 'typedef' keyword can be removed - we do it only if
// it is the only declaration in a declaration chain.
static bool CheckRemoval(SourceManager &SM, SourceLocation StartLoc,
                         ASTContext &Context) {
  assert(StartLoc.isFileID() && "StartLoc must not be in a macro");
  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(StartLoc);
  StringRef File = SM.getBufferData(LocInfo.first);
  const char *TokenBegin = File.data() + LocInfo.second;
  Lexer DeclLexer(SM.getLocForStartOfFile(LocInfo.first), Context.getLangOpts(),
                  File.begin(), TokenBegin, File.end());

  Token Tok;
  int ParenLevel = 0;
  bool FoundTypedef = false;

  while (!DeclLexer.LexFromRawLexer(Tok) && !Tok.is(tok::semi)) {
    switch (Tok.getKind()) {
    case tok::l_brace:
    case tok::r_brace:
      // This might be the `typedef struct {...} T;` case.
      return false;
    case tok::l_paren:
      ParenLevel++;
      break;
    case tok::r_paren:
      ParenLevel--;
      break;
    case tok::comma:
      if (ParenLevel == 0) {
        // If there is comma and we are not between open parenthesis then it is
        // two or more declarations in this chain.
        return false;
      }
      break;
    case tok::raw_identifier:
      if (Tok.getRawIdentifier() == "typedef") {
        FoundTypedef = true;
      }
      break;
    default:
      break;
    }
  }

  // Sanity check against weird macro cases.
  return FoundTypedef;
}

// Constructor for C++ records.
ASTRecordLayout::ASTRecordLayout(const ASTContext &Ctx,
                                 CharUnits size, CharUnits alignment,
                                 bool hasOwnVFPtr, CharUnits vbptroffset,
                                 CharUnits datasize,
                                 const uint64_t *fieldoffsets,
                                 unsigned fieldcount,
                                 CharUnits nonvirtualsize,
                                 CharUnits nonvirtualalign,
                                 CharUnits SizeOfLargestEmptySubobject,
                                 const CXXRecordDecl *PrimaryBase,
                                 bool IsPrimaryBaseVirtual,
                                 const BaseOffsetsMapTy& BaseOffsets,
                                 const VBaseOffsetsMapTy& VBaseOffsets)
  : Size(size), DataSize(datasize), Alignment(alignment), FieldOffsets(0),
    FieldCount(fieldcount), CXXInfo(new (Ctx) CXXRecordLayoutInfo)
{
  if (FieldCount > 0)  {
    FieldOffsets = new (Ctx) uint64_t[FieldCount];
    memcpy(FieldOffsets, fieldoffsets, FieldCount * sizeof(*FieldOffsets));
  }

  CXXInfo->PrimaryBase.setPointer(PrimaryBase);
  CXXInfo->PrimaryBase.setInt(IsPrimaryBaseVirtual);
  CXXInfo->NonVirtualSize = nonvirtualsize;
  CXXInfo->NonVirtualAlign = nonvirtualalign;
  CXXInfo->SizeOfLargestEmptySubobject = SizeOfLargestEmptySubobject;
  CXXInfo->BaseOffsets = BaseOffsets;
  CXXInfo->VBaseOffsets = VBaseOffsets;
  CXXInfo->HasOwnVFPtr = hasOwnVFPtr;
  CXXInfo->VBPtrOffset = vbptroffset;

#ifndef NDEBUG
    if (const CXXRecordDecl *PrimaryBase = getPrimaryBase()) {
      if (isPrimaryBaseVirtual()) {
        if (Ctx.getTargetInfo().getCXXABI().hasPrimaryVBases()) {
          assert(getVBaseClassOffset(PrimaryBase).isZero() &&
                 "Primary virtual base must be at offset 0!");
        }
      } else {
        assert(getBaseClassOffset(PrimaryBase).isZero() &&
               "Primary base must be at offset 0!");
      }
    }
#endif        
}

void ScriptDefn::setCaptures(ASTContext &Context,
                            const Capture *begin,
                            const Capture *end) {
  if (begin == end) {
    NumCaptures = 0;
    Captures = 0;
    return;
  }

  NumCaptures = end - begin;

  // Avoid new Capture[] because we don't want to provide a default
  // constructor.
  size_t allocationSize = NumCaptures * sizeof(Capture);
  void *buffer = Context.Allocate(allocationSize, /*alignment*/sizeof(void*));
  memcpy(buffer, begin, allocationSize);
  Captures = static_cast<Capture*>(buffer);
}

void ObjCMigrateASTConsumer::HandleTranslationUnit(ASTContext &Ctx) {
  
  TranslationUnitDecl *TU = Ctx.getTranslationUnitDecl();
  if (MigrateProperty)
    for (DeclContext::decl_iterator D = TU->decls_begin(), DEnd = TU->decls_end();
         D != DEnd; ++D) {
      if (ObjCInterfaceDecl *CDecl = dyn_cast<ObjCInterfaceDecl>(*D))
        migrateObjCInterfaceDecl(Ctx, CDecl);
      else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(*D))
        ObjCProtocolDecls.insert(PDecl);
      else if (const ObjCImplementationDecl *ImpDecl =
               dyn_cast<ObjCImplementationDecl>(*D))
        migrateProtocolConformance(Ctx, ImpDecl);
      else if (const EnumDecl *ED = dyn_cast<EnumDecl>(*D)) {
        DeclContext::decl_iterator N = D;
        ++N;
        if (N != DEnd)
          if (const TypedefDecl *TD = dyn_cast<TypedefDecl>(*N))
            migrateNSEnumDecl(Ctx, ED, TD);
      }
      // migrate methods which can have instancetype as their result type.
      if (ObjCContainerDecl *CDecl = dyn_cast<ObjCContainerDecl>(*D))
        migrateInstanceType(Ctx, CDecl);
    }
  
  Rewriter rewriter(Ctx.getSourceManager(), Ctx.getLangOpts());
  RewritesReceiver Rec(rewriter);
  Editor->applyRewrites(Rec);

  for (Rewriter::buffer_iterator
        I = rewriter.buffer_begin(), E = rewriter.buffer_end(); I != E; ++I) {
    FileID FID = I->first;
    RewriteBuffer &buf = I->second;
    const FileEntry *file = Ctx.getSourceManager().getFileEntryForID(FID);
    assert(file);
    SmallString<512> newText;
    llvm::raw_svector_ostream vecOS(newText);
    buf.write(vecOS);
    vecOS.flush();
    llvm::MemoryBuffer *memBuf = llvm::MemoryBuffer::getMemBufferCopy(
                   StringRef(newText.data(), newText.size()), file->getName());
    SmallString<64> filePath(file->getName());
    FileMgr.FixupRelativePath(filePath);
    Remapper.remap(filePath.str(), memBuf);
  }

  if (IsOutputFile) {
    Remapper.flushToFile(MigrateDir, Ctx.getDiagnostics());
  } else {
    Remapper.flushToDisk(MigrateDir, Ctx.getDiagnostics());
  }
}

/// Get the returned ObjCObjectPointerType by a method based on the tracked type
/// information, or null pointer when the returned type is not an
/// ObjCObjectPointerType.
static QualType getReturnTypeForMethod(
    const ObjCMethodDecl *Method, ArrayRef<QualType> TypeArgs,
    const ObjCObjectPointerType *SelfType, ASTContext &C) {
  QualType StaticResultType = Method->getReturnType();

  // Is the return type declared as instance type?
  if (StaticResultType == C.getObjCInstanceType())
    return QualType(SelfType, 0);

  // Check whether the result type depends on a type parameter.
  if (!isObjCTypeParamDependent(StaticResultType))
    return QualType();

  QualType ResultType = StaticResultType.substObjCTypeArgs(
      C, TypeArgs, ObjCSubstitutionContext::Result);

  return ResultType;
}

TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
                                   QualType Type) {
  Integer.Kind = Integral;
  // Copy the APSInt value into our decomposed form.
  Integer.BitWidth = Value.getBitWidth();
  Integer.IsUnsigned = Value.isUnsigned();
  // If the value is large, we have to get additional memory from the ASTContext
  unsigned NumWords = Value.getNumWords();
  if (NumWords > 1) {
    void *Mem = Ctx.Allocate(NumWords * sizeof(uint64_t));
    std::memcpy(Mem, Value.getRawData(), NumWords * sizeof(uint64_t));
    Integer.pVal = static_cast<uint64_t *>(Mem);
  } else {
    Integer.VAL = Value.getZExtValue();
  }

  Integer.Type = Type.getAsOpaquePtr();
}

void TemplateArgument::Profile(llvm::FoldingSetNodeID &ID,
                               ASTContext &Context) const {
  ID.AddInteger(Kind);
  switch (Kind) {
  case Null:
    break;

  case Type:
    getAsType().Profile(ID);
    break;

  case Declaration:
    ID.AddPointer(getAsDecl()? getAsDecl()->getCanonicalDecl() : 0);
    break;

  case Template:
    if (TemplateTemplateParmDecl *TTP
          = dyn_cast_or_null<TemplateTemplateParmDecl>(
                                       getAsTemplate().getAsTemplateDecl())) {
      ID.AddBoolean(true);
      ID.AddInteger(TTP->getDepth());
      ID.AddInteger(TTP->getPosition());
    } else {
      ID.AddBoolean(false);
      ID.AddPointer(Context.getCanonicalTemplateName(getAsTemplate())
                      .getAsVoidPointer());
    }
    break;
      
  case Integral:
    getAsIntegral()->Profile(ID);
    getIntegralType().Profile(ID);
    break;

  case Expression:
    getAsExpr()->Profile(ID, Context, true);
    break;

  case Pack:
    ID.AddInteger(Args.NumArgs);
    for (unsigned I = 0; I != Args.NumArgs; ++I)
      Args.Args[I].Profile(ID, Context);
  }
}

/// Classify the given Clang enumeration to describe how to import it.
void EnumInfo::classifyEnum(ASTContext &ctx, const clang::EnumDecl *decl,
                            clang::Preprocessor &pp) {
  // Anonymous enumerations simply get mapped to constants of the
  // underlying type of the enum, because there is no way to conjure up a
  // name for the Swift type.
  if (!decl->hasNameForLinkage()) {
    kind = EnumKind::Constants;
    return;
  }

  // First, check for attributes that denote the classification
  if (auto domainAttr = decl->getAttr<clang::NSErrorDomainAttr>()) {
    kind = EnumKind::Enum;
    nsErrorDomain = ctx.AllocateCopy(domainAttr->getErrorDomain()->getName());
    return;
  }

  // Was the enum declared using *_ENUM or *_OPTIONS?
  // FIXME: Use Clang attributes instead of groveling the macro expansion loc.
  auto loc = decl->getLocStart();
  if (loc.isMacroID()) {
    StringRef MacroName = pp.getImmediateMacroName(loc);
    if (MacroName == "CF_ENUM" || MacroName == "__CF_NAMED_ENUM" ||
        MacroName == "OBJC_ENUM" || MacroName == "SWIFT_ENUM" ||
        MacroName == "SWIFT_ENUM_NAMED") {
      kind = EnumKind::Enum;
      return;
    }
    if (MacroName == "CF_OPTIONS" || MacroName == "OBJC_OPTIONS" ||
        MacroName == "SWIFT_OPTIONS") {
      kind = EnumKind::Options;
      return;
    }
  }

  // Hardcode a particular annoying case in the OS X headers.
  if (decl->getName() == "DYLD_BOOL") {
    kind = EnumKind::Enum;
    return;
  }

  // Fall back to the 'Unknown' path.
  kind = EnumKind::Unknown;
}

bool FunctionDecl::isExternC(ASTContext &Context) const {
  // In C, any non-static, non-overloadable function has external
  // linkage.
  if (!Context.getLangOptions().CPlusPlus)
    return getStorageClass() != Static && !getAttr<OverloadableAttr>();

  for (const DeclContext *DC = getDeclContext(); !DC->isTranslationUnit(); 
       DC = DC->getParent()) {
    if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC))  {
      if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
        return getStorageClass() != Static && 
               !getAttr<OverloadableAttr>();

      break;
    }
  }

  return false;
}

void TemplateSpecializationTypeLoc::initializeArgLocs(ASTContext &Context, 
                                                      unsigned NumArgs,
                                                  const TemplateArgument *Args,
                                              TemplateArgumentLocInfo *ArgInfos,
                                                      SourceLocation Loc) {
  for (unsigned i = 0, e = NumArgs; i != e; ++i) {
    switch (Args[i].getKind()) {
    case TemplateArgument::Null: 
    case TemplateArgument::Declaration:
    case TemplateArgument::Integral:
    case TemplateArgument::Pack:
    case TemplateArgument::Expression:
      // FIXME: Can we do better for declarations and integral values?
      ArgInfos[i] = TemplateArgumentLocInfo();
      break;
      
    case TemplateArgument::Type:
      ArgInfos[i] = TemplateArgumentLocInfo(
                          Context.getTrivialTypeSourceInfo(Args[i].getAsType(), 
                                                           Loc));
      break;
        
    case TemplateArgument::Template:
    case TemplateArgument::TemplateExpansion: {
      NestedNameSpecifierLocBuilder Builder;
      TemplateName Template = Args[i].getAsTemplate();
      if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
        Builder.MakeTrivial(Context, DTN->getQualifier(), Loc);
      else if (QualifiedTemplateName *QTN = Template.getAsQualifiedTemplateName())
        Builder.MakeTrivial(Context, QTN->getQualifier(), Loc);
      
      ArgInfos[i] = TemplateArgumentLocInfo(
                                           Builder.getWithLocInContext(Context),
                                            Loc, 
                                Args[i].getKind() == TemplateArgument::Template
                                            ? SourceLocation()
                                            : Loc);
      break;
    }        
    }
  }
}

static Cl::Kinds ClassifyConditional(ASTContext &Ctx, const Expr *True,
                                     const Expr *False) {
  assert(Ctx.getLangOptions().CPlusPlus &&
         "This is only relevant for C++.");

  // C++ [expr.cond]p2
  //   If either the second or the third operand has type (cv) void, [...]
  //   the result [...] is a prvalue.
  if (True->getType()->isVoidType() || False->getType()->isVoidType())
    return Cl::CL_PRValue;

  // Note that at this point, we have already performed all conversions
  // according to [expr.cond]p3.
  // C++ [expr.cond]p4: If the second and third operands are glvalues of the
  //   same value category [...], the result is of that [...] value category.
  // C++ [expr.cond]p5: Otherwise, the result is a prvalue.
  Cl::Kinds LCl = ClassifyInternal(Ctx, True),
            RCl = ClassifyInternal(Ctx, False);
  return LCl == RCl ? LCl : Cl::CL_PRValue;
}

void RewriterASTConsumer::HandleTranslationUnit(ASTContext& Context)
{
    TranslationUnitDecl* D = Context.getTranslationUnitDecl();
    TraverseDecl(D);

    const RewriteBuffer& RewriteBufG =
            TheGpuRewriter.getEditBuffer(TheGpuRewriter.getSourceMgr().getMainFileID());
    RewritenGpuSource = std::string(RewriteBufG.begin(), RewriteBufG.end());

    const RewriteBuffer& RewriteBufC =
            TheCpuRewriter.getEditBuffer(TheCpuRewriter.getSourceMgr().getMainFileID());
    RewritenCpuSource = std::string(RewriteBufC.begin(), RewriteBufC.end());

#ifdef Out
    llvm::errs() << "______________________________ CPU _____________________ \n";
    llvm::errs() << std::string(RewriteBufC.begin(), RewriteBufC.end());
    llvm::errs() << "\n\n______________________________ GPU _____________________ \n";
    llvm::errs() << std::string(RewriteBufG.begin(), RewriteBufG.end());
#endif
}