Beispiel #1
0
  void DeclExtractor::EnforceInitOrder(llvm::SmallVectorImpl<Stmt*>& Stmts){
    Scope* TUScope = m_Sema->TUScope;
    DeclContext* TUDC = static_cast<DeclContext*>(TUScope->getEntity());
    // We can't PushDeclContext, because we don't have scope.
    Sema::ContextRAII pushedDC(*m_Sema, TUDC);

    std::string FunctionName = "__fd";
    createUniqueName(FunctionName);
    IdentifierInfo& IIFD = m_Context->Idents.get(FunctionName);
    SourceLocation Loc;
    NamedDecl* ND = m_Sema->ImplicitlyDefineFunction(Loc, IIFD, TUScope);
    if (FunctionDecl* FD = dyn_cast_or_null<FunctionDecl>(ND)) {
      FD->setImplicit(false); // Better for debugging

      // Add a return statement if it doesn't exist
      if (!isa<ReturnStmt>(Stmts.back())) {
        Sema::ContextRAII pushedDC(*m_Sema, FD);
        // Generate the return statement:
        // First a literal 0, then the return taking that literal.
        // One bit is enough:
        llvm::APInt ZeroInt(m_Context->getIntWidth(m_Context->IntTy), 0,
                            /*isSigned=*/true);
        IntegerLiteral* ZeroLit
          = IntegerLiteral::Create(*m_Context, ZeroInt, m_Context->IntTy,
                                   SourceLocation());
        Stmts.push_back(m_Sema->ActOnReturnStmt(ZeroLit->getExprLoc(), 
                                                ZeroLit).take());
      }

      // Wrap Stmts into a function body.
      llvm::ArrayRef<Stmt*> StmtsRef(Stmts.data(), Stmts.size());
      CompoundStmt* CS = new (*m_Context)CompoundStmt(*m_Context, StmtsRef,
                                                      Loc, Loc);
      FD->setBody(CS);
      // We know the transaction is closed, but it is safe.
      getTransaction()->forceAppend(FD);

      // Create the VarDecl with the init      
      std::string VarName = "__vd";
      createUniqueName(VarName);
      IdentifierInfo& IIVD = m_Context->Idents.get(VarName);
      VarDecl* VD = VarDecl::Create(*m_Context, TUDC, Loc, Loc, &IIVD,
                                    FD->getReturnType(), (TypeSourceInfo*)0,
                                    SC_None);
      LookupResult R(*m_Sema, FD->getDeclName(), Loc, Sema::LookupMemberName);
      R.addDecl(FD);
      CXXScopeSpec CSS;
      Expr* UnresolvedLookup
        = m_Sema->BuildDeclarationNameExpr(CSS, R, /*ADL*/ false).take();
      Expr* TheCall = m_Sema->ActOnCallExpr(TUScope, UnresolvedLookup, Loc, 
                                            MultiExprArg(), Loc).take();
      assert(VD && TheCall && "Missing VD or its init!");
      VD->setInit(TheCall);

      // We know the transaction is closed, but it is safe.
      getTransaction()->forceAppend(VD); // Add it to the transaction for codegenning
      TUDC->addHiddenDecl(VD);
      Stmts.clear();
      return;
    }
    llvm_unreachable("Must be able to enforce init order.");
  }