C++ NamedDecl::getDeclContext方法代码示例

static Cl::Kinds ClassifyMemberExpr(ASTContext &Ctx, const MemberExpr *E) {
  if (E->getType() == Ctx.UnknownAnyTy)
    return (isa<FunctionDecl>(E->getMemberDecl())
              ? Cl::CL_PRValue : Cl::CL_LValue);

  // Handle C first, it's easier.
  if (!Ctx.getLangOpts().CPlusPlus) {
    // C99 6.5.2.3p3
    // For dot access, the expression is an lvalue if the first part is. For
    // arrow access, it always is an lvalue.
    if (E->isArrow())
      return Cl::CL_LValue;
    // ObjC property accesses are not lvalues, but get special treatment.
    Expr *Base = E->getBase()->IgnoreParens();
    if (isa<ObjCPropertyRefExpr>(Base))
      return Cl::CL_SubObjCPropertySetting;
    return ClassifyInternal(Ctx, Base);
  }

  NamedDecl *Member = E->getMemberDecl();
  // C++ [expr.ref]p3: E1->E2 is converted to the equivalent form (*(E1)).E2.
  // C++ [expr.ref]p4: If E2 is declared to have type "reference to T", then
  //   E1.E2 is an lvalue.
  if (ValueDecl *Value = dyn_cast<ValueDecl>(Member))
    if (Value->getType()->isReferenceType())
      return Cl::CL_LValue;

  //   Otherwise, one of the following rules applies.
  //   -- If E2 is a static member [...] then E1.E2 is an lvalue.
  if (isa<VarDecl>(Member) && Member->getDeclContext()->isRecord())
    return Cl::CL_LValue;

  //   -- If E2 is a non-static data member [...]. If E1 is an lvalue, then
  //      E1.E2 is an lvalue; if E1 is an xvalue, then E1.E2 is an xvalue;
  //      otherwise, it is a prvalue.
  if (isa<FieldDecl>(Member)) {
    // *E1 is an lvalue
    if (E->isArrow())
      return Cl::CL_LValue;
    Expr *Base = E->getBase()->IgnoreParenImpCasts();
    if (isa<ObjCPropertyRefExpr>(Base))
      return Cl::CL_SubObjCPropertySetting;
    return ClassifyInternal(Ctx, E->getBase());
  }

  //   -- If E2 is a [...] member function, [...]
  //      -- If it refers to a static member function [...], then E1.E2 is an
  //         lvalue; [...]
  //      -- Otherwise [...] E1.E2 is a prvalue.
  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member))
    return Method->isStatic() ? Cl::CL_LValue : Cl::CL_MemberFunction;

  //   -- If E2 is a member enumerator [...], the expression E1.E2 is a prvalue.
  // So is everything else we haven't handled yet.
  return Cl::CL_PRValue;
}

bool IdentifierResolver::tryAddTopLevelDecl(NamedDecl *D, DeclarationName Name){
  if (IdentifierInfo *II = Name.getAsIdentifierInfo())
    readingIdentifier(*II);
  
  void *Ptr = Name.getFETokenInfo<void>();
    
  if (!Ptr) {
    Name.setFETokenInfo(D);
    return true;
  }
  
  IdDeclInfo *IDI;
  
  if (isDeclPtr(Ptr)) {
    NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
    
    switch (compareDeclarations(PrevD, D)) {
    case DMK_Different:
      break;
      
    case DMK_Ignore:
      return false;
      
    case DMK_Replace:
      Name.setFETokenInfo(D);
      return true;
    }

    Name.setFETokenInfo(nullptr);
    IDI = &(*IdDeclInfos)[Name];
    
    // If the existing declaration is not visible in translation unit scope,
    // then add the new top-level declaration first.
    if (!PrevD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
      IDI->AddDecl(D);
      IDI->AddDecl(PrevD);
    } else {
      IDI->AddDecl(PrevD);
      IDI->AddDecl(D);
    }
    return true;
  } 
  
  IDI = toIdDeclInfo(Ptr);

  // See whether this declaration is identical to any existing declarations.
  // If not, find the right place to insert it.
  for (IdDeclInfo::DeclsTy::iterator I = IDI->decls_begin(), 
                                  IEnd = IDI->decls_end();
       I != IEnd; ++I) {
    
    switch (compareDeclarations(*I, D)) {
    case DMK_Different:
      break;
      
    case DMK_Ignore:
      return false;
      
    case DMK_Replace:
      *I = D;
      return true;
    }
    
    if (!(*I)->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
      // We've found a declaration that is not visible from the translation
      // unit (it's in an inner scope). Insert our declaration here.
      IDI->InsertDecl(I, D);
      return true;
    }
  }
  
  // Add the declaration to the end.
  IDI->AddDecl(D);
  return true;
}

  bool DeclExtractor::ExtractDecl(FunctionDecl* FD) {
    llvm::SmallVector<NamedDecl*, 4> TouchedDecls;
    CompoundStmt* CS = dyn_cast<CompoundStmt>(FD->getBody());
    assert(CS && "Function body not a CompoundStmt?");
    DeclContext* DC = FD->getTranslationUnitDecl();
    Scope* TUScope = m_Sema->TUScope;
    assert(TUScope == m_Sema->getScopeForContext(DC) && "TU scope from DC?");
    llvm::SmallVector<Stmt*, 4> Stmts;

    for (CompoundStmt::body_iterator I = CS->body_begin(), EI = CS->body_end();
         I != EI; ++I) {
      DeclStmt* DS = dyn_cast<DeclStmt>(*I);
      if (!DS) {
        Stmts.push_back(*I);
        continue;
      }
      
      for (DeclStmt::decl_iterator J = DS->decl_begin();
           J != DS->decl_end(); ++J) {
        NamedDecl* ND = dyn_cast<NamedDecl>(*J);
        if (isa<UsingDirectiveDecl>(*J))
          continue; // FIXME: Here we should be more elegant.
        if (ND) {
          if (Stmts.size()) {
            // We need to emit a new custom wrapper wrapping the stmts
            EnforceInitOrder(Stmts);
            assert(!Stmts.size() && "Stmt list must be flushed.");
          }

          // We know the transaction is closed, but it is safe.
          getTransaction()->forceAppend(ND);

          DeclContext* OldDC = ND->getDeclContext();

          // Make sure the decl is not found at its old possition
          ND->getLexicalDeclContext()->removeDecl(ND);
          if (Scope* S = m_Sema->getScopeForContext(OldDC)) {
            S->RemoveDecl(ND);
            if (utils::Analyze::isOnScopeChains(ND, *m_Sema))
              m_Sema->IdResolver.RemoveDecl(ND);
          }

          // For variable definitions causing var/function ambiguity such as:
          // MyClass my();, C++ standard says it shall be resolved as a function
          //
          // In the particular context this definition is inside a function
          // already, but clang thinks it as a lambda, so we need to ignore the
          // check decl context vs lexical decl context.
          if (ND->getDeclContext() == ND->getLexicalDeclContext()
              || isa<FunctionDecl>(ND))
            ND->setLexicalDeclContext(DC);
          else 
            assert(0 && "Not implemented: Decl with different lexical context");
          ND->setDeclContext(DC);

          if (VarDecl* VD = dyn_cast<VarDecl>(ND)) {
            VD->setStorageClass(SC_None);
          }

          clearLinkage(ND);

          TouchedDecls.push_back(ND);
        }
      }
    }
    bool hasNoErrors = !CheckForClashingNames(TouchedDecls, DC, TUScope);
    if (hasNoErrors) {
      for (size_t i = 0; i < TouchedDecls.size(); ++i) {
        // We should skip the checks for annonymous decls and we should not
        // register them in the lookup.
        if (!TouchedDecls[i]->getDeclName())
          continue;

        m_Sema->PushOnScopeChains(TouchedDecls[i],
                                  m_Sema->getScopeForContext(DC),
                    /*AddCurContext*/!isa<UsingDirectiveDecl>(TouchedDecls[i]));

        // The transparent DeclContexts (eg. scopeless enum) doesn't have 
        // scopes. While extracting their contents we need to update the
        // lookup tables and telling them to pick up the new possitions
        // in the AST.
        if (DeclContext* InnerDC = dyn_cast<DeclContext>(TouchedDecls[i])) {
          if (InnerDC->isTransparentContext()) {
            // We can't PushDeclContext, because we don't have scope.
            Sema::ContextRAII pushedDC(*m_Sema, InnerDC);

            for(DeclContext::decl_iterator DI = InnerDC->decls_begin(), 
                  DE = InnerDC->decls_end(); DI != DE ; ++DI) {
              if (NamedDecl* ND = dyn_cast<NamedDecl>(*DI))
                InnerDC->makeDeclVisibleInContext(ND);
            }
          }
        }
      }
    }

    CS->setStmts(*m_Context, Stmts.data(), Stmts.size());

    // The order matters, because when we extract decls from the wrapper we
    // append them to the transaction. If the transaction gets unloaded it will
//.........这里部分代码省略.........

//.........这里部分代码省略.........
    //     // Name lookup did not find anything. However, if the
    //     // nested-name-specifier refers to the current instantiation,
    //     // and that current instantiation has any dependent base
    //     // classes, we might find something at instantiation time: treat
    //     // this as a dependent elaborated-type-specifier.
    //     // But this only makes any sense for reference-like lookups.
    //     if (Previous.wasNotFoundInCurrentInstantiation() &&
    //         (TUK == TUK_Reference || TUK == TUK_Friend)) {
    //       IsDependent = true;
    //       return 0;
    //     }

    //     // A tag 'foo::bar' must already exist.
    //     Diag(NameLoc, diag::err_not_tag_in_scope)
    //       << Kind << Name << DC << SS.getRange();
    //     Name = 0;
    //     Invalid = true;
    //   goto CreateNewDecl;
    // }
    //} else
    if (Name) {
      // If this is a named struct, check to see if there was a previous forward
      // declaration or definition.
      // FIXME: We're looking into outer scopes here, even when we
      // shouldn't be. Doing so can result in ambiguities that we
      // shouldn't be diagnosing.

      //LookupName(Previous, S);

      if (Previous.isAmbiguous()) {
        LookupResult::Filter F = Previous.makeFilter();
        while (F.hasNext()) {
          NamedDecl *ND = F.next();
          if (ND->getDeclContext()->getRedeclContext() != SearchDC)
            F.erase();
        }
        F.done();
      }

      // Note:  there used to be some attempt at recovery here.
      if (Previous.isAmbiguous()) {
        return false;
      }

      if (!m_Sema->getLangOpts().CPlusPlus) {
        // FIXME: This makes sure that we ignore the contexts associated
        // with C structs, unions, and enums when looking for a matching
        // tag declaration or definition. See the similar lookup tweak
        // in Sema::LookupName; is there a better way to deal with this?
        while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC))
          SearchDC = SearchDC->getParent();
      }
    } else if (m_Sema->getScopeForContext(m_Sema->CurContext)
               ->isFunctionPrototypeScope()) {
      // If this is an enum declaration in function prototype scope, set its
      // initial context to the translation unit.
      SearchDC = m_Context->getTranslationUnitDecl();
    }

    if (Previous.isSingleResult() &&
        Previous.getFoundDecl()->isTemplateParameter()) {
      // Maybe we will complain about the shadowed template parameter.
      m_Sema->DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl());
      // Just pretend that we didn't see the previous declaration.
      Previous.clear();
    }

  bool DeclExtractor::ExtractDecl(Decl* D) {
    FunctionDecl* FD = dyn_cast<FunctionDecl>(D);

    if (FD) {
      if (FD->getNameAsString().find("__cling_Un1Qu3"))
        return true;

      llvm::SmallVector<NamedDecl*, 4> TouchedDecls;
      CompoundStmt* CS = dyn_cast<CompoundStmt>(FD->getBody());
      assert(CS && "Function body not a CompoundStmt?");
      DeclContext* DC = FD->getTranslationUnitDecl();
      Scope* TUScope = m_Sema->TUScope;
      assert(TUScope == m_Sema->getScopeForContext(DC) && "TU scope from DC?");
      llvm::SmallVector<Stmt*, 4> Stmts;

      for (CompoundStmt::body_iterator I = CS->body_begin(), EI = CS->body_end();
           I != EI; ++I) {
        DeclStmt* DS = dyn_cast<DeclStmt>(*I);
        if (!DS) {
          Stmts.push_back(*I);
          continue;
        }

        for (DeclStmt::decl_iterator J = DS->decl_begin();
             J != DS->decl_end(); ++J) {
          NamedDecl* ND = dyn_cast<NamedDecl>(*J);
          if (ND) {
            DeclContext* OldDC = ND->getDeclContext();

            // Make sure the decl is not found at its old possition
            OldDC->removeDecl(ND);
            if (Scope* S = m_Sema->getScopeForContext(OldDC)) {
              S->RemoveDecl(ND);
              m_Sema->IdResolver.RemoveDecl(ND);
            }

            if (ND->getDeclContext() == ND->getLexicalDeclContext())
              ND->setLexicalDeclContext(DC);
            else 
              assert("Not implemented: Decl with different lexical context");
            ND->setDeclContext(DC);

            if (VarDecl* VD = dyn_cast<VarDecl>(ND)) {
              VD->setStorageClass(SC_None);
              VD->setStorageClassAsWritten(SC_None);

              // if we want to print the result of the initializer of int i = 5
              // or the default initializer int i
              if (I+1 == EI || !isa<NullStmt>(*(I+1))) {
                QualType VDTy = VD->getType().getNonReferenceType();
                Expr* DRE = m_Sema->BuildDeclRefExpr(VD, VDTy,VK_LValue,
                                                     SourceLocation()
                                                     ).take();
                Stmts.push_back(DRE);
              }
            }
            // force recalc of the linkage (to external)
            ND->ClearLinkageCache();

            TouchedDecls.push_back(ND);
          }
        }
      }
      bool hasNoErrors = !CheckForClashingNames(TouchedDecls, DC, TUScope);
      if (hasNoErrors) {
        for (size_t i = 0; i < TouchedDecls.size(); ++i) {
          m_Sema->PushOnScopeChains(TouchedDecls[i],
                                    m_Sema->getScopeForContext(DC),
                    /*AddCurContext*/!isa<UsingDirectiveDecl>(TouchedDecls[i]));

          // The transparent DeclContexts (eg. scopeless enum) doesn't have 
          // scopes. While extracting their contents we need to update the
          // lookup tables and telling them to pick up the new possitions
          //  in the AST.
          if (DeclContext* InnerDC = dyn_cast<DeclContext>(TouchedDecls[i])) {
            if (InnerDC->isTransparentContext()) {
              // We can't PushDeclContext, because we don't have scope.
              Sema::ContextRAII pushedDC(*m_Sema, InnerDC);

              for(DeclContext::decl_iterator DI = InnerDC->decls_begin(), 
                    DE = InnerDC->decls_end(); DI != DE ; ++DI) {
                if (NamedDecl* ND = dyn_cast<NamedDecl>(*DI))
                  InnerDC->makeDeclVisibleInContext(ND);
              }
            }
          }

          // Append the new top level decl to the current transaction.
          getTransaction()->appendUnique(DeclGroupRef(TouchedDecls[i]));
        }
      }

      CS->setStmts(*m_Context, Stmts.data(), Stmts.size());

      // Put the wrapper after its declarations. (Nice when AST dumping)
      DC->removeDecl(FD);
      DC->addDecl(FD);

      return hasNoErrors;
    }
//.........这里部分代码省略.........