Line data    Source code

       1             : // Copyright 2015 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #include "src/parsing/expression-scope-reparenter.h"
       6             : 
       7             : #include "src/ast/ast-traversal-visitor.h"
       8             : #include "src/ast/ast.h"
       9             : #include "src/ast/scopes.h"
      10             : #include "src/objects-inl.h"
      11             : 
      12             : namespace v8 {
      13             : namespace internal {
      14             : 
      15             : namespace {
      16             : 
      17             : class Reparenter final : public AstTraversalVisitor<Reparenter> {
      18             :  public:
      19             :   Reparenter(uintptr_t stack_limit, Expression* initializer, Scope* scope)
      20        1688 :       : AstTraversalVisitor(stack_limit, initializer), scope_(scope) {}
      21             : 
      22             :  private:
      23             :   // This is required so that the overriden Visit* methods can be
      24             :   // called by the base class (template).
      25             :   friend class AstTraversalVisitor<Reparenter>;
      26             : 
      27             :   void VisitFunctionLiteral(FunctionLiteral* expr);
      28             :   void VisitClassLiteral(ClassLiteral* expr);
      29             :   void VisitVariableProxy(VariableProxy* expr);
      30             : 
      31             :   void VisitBlock(Block* stmt);
      32             :   void VisitTryCatchStatement(TryCatchStatement* stmt);
      33             :   void VisitWithStatement(WithStatement* stmt);
      34             : 
      35             :   Scope* scope_;
      36             : };
      37             : 
      38         152 : void Reparenter::VisitFunctionLiteral(FunctionLiteral* function_literal) {
      39         152 :   function_literal->scope()->ReplaceOuterScope(scope_);
      40             : }
      41             : 
      42           0 : void Reparenter::VisitClassLiteral(ClassLiteral* class_literal) {
      43           0 :   class_literal->scope()->ReplaceOuterScope(scope_);
      44             :   // No need to visit the constructor since it will have the class
      45             :   // scope on its scope chain.
      46             :   DCHECK_EQ(class_literal->constructor()->scope()->outer_scope(),
      47             :             class_literal->scope());
      48             : #if DEBUG
      49             :   // The same goes for the rest of the class, but we do some
      50             :   // sanity checking in debug mode.
      51             :   ZoneList<ClassLiteralProperty*>* props = class_literal->properties();
      52             :   for (int i = 0; i < props->length(); ++i) {
      53             :     ClassLiteralProperty* prop = props->at(i);
      54             :     // No need to visit the values, since all values are functions with
      55             :     // the class scope on their scope chain.
      56             :     DCHECK(prop->value()->IsFunctionLiteral());
      57             :     DCHECK_EQ(prop->value()->AsFunctionLiteral()->scope()->outer_scope(),
      58             :               class_literal->scope());
      59             :   }
      60             : #endif
      61             : }
      62             : 
      63        3827 : void Reparenter::VisitVariableProxy(VariableProxy* proxy) {
      64        3827 :   if (!proxy->is_resolved()) {
      65        1259 :     if (scope_->outer_scope()->RemoveUnresolved(proxy)) {
      66        1259 :       scope_->AddUnresolved(proxy);
      67             :     }
      68             :   } else {
      69             :     // Ensure that temporaries we find are already in the correct scope.
      70             :     DCHECK(proxy->var()->mode() != TEMPORARY ||
      71             :            proxy->var()->scope() == scope_->GetClosureScope());
      72             :   }
      73        3827 : }
      74             : 
      75         210 : void Reparenter::VisitBlock(Block* stmt) {
      76         210 :   if (stmt->scope() != nullptr)
      77          30 :     stmt->scope()->ReplaceOuterScope(scope_);
      78             :   else
      79         180 :     VisitStatements(stmt->statements());
      80         210 : }
      81             : 
      82          80 : void Reparenter::VisitTryCatchStatement(TryCatchStatement* stmt) {
      83          40 :   Visit(stmt->try_block());
      84          80 :   stmt->scope()->ReplaceOuterScope(scope_);
      85          40 : }
      86             : 
      87          20 : void Reparenter::VisitWithStatement(WithStatement* stmt) {
      88          10 :   Visit(stmt->expression());
      89          20 :   stmt->scope()->ReplaceOuterScope(scope_);
      90          10 : }
      91             : 
      92             : }  // anonymous namespace
      93             : 
      94        1688 : void ReparentExpressionScope(uintptr_t stack_limit, Expression* expr,
      95             :                              Scope* scope) {
      96             :   // The only case that uses this code is block scopes for parameters containing
      97             :   // sloppy eval.
      98             :   DCHECK(scope->is_block_scope());
      99             :   DCHECK(scope->is_declaration_scope());
     100             :   DCHECK(scope->AsDeclarationScope()->calls_sloppy_eval());
     101             :   DCHECK(scope->outer_scope()->is_function_scope());
     102             : 
     103             :   Reparenter r(stack_limit, expr, scope);
     104             :   r.Run();
     105        1688 : }
     106             : 
     107             : }  // namespace internal
     108             : }  // namespace v8