Version 3.5.5.

src/parser.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 566 matching lines @@
       scanner_(isolate_->unicode_cache()),
       top_scope_(NULL),
       with_nesting_level_(0),
       lexical_scope_(NULL),
       target_stack_(NULL),
       allow_natives_syntax_(allow_natives_syntax),
       extension_(extension),
       pre_data_(pre_data),
       fni_(NULL),
       stack_overflow_(false),
-      parenthesized_function_(false) {
+      parenthesized_function_(false),
+      harmony_block_scoping_(false) {
   AstNode::ResetIds();
 }
 
 
 FunctionLiteral* Parser::ParseProgram(Handle<String> source,
                                       bool in_global_context,
                                       StrictModeFlag strict_mode) {
   ZoneScope zone_scope(isolate(), DONT_DELETE_ON_EXIT);
 
   HistogramTimerScope timer(isolate()->counters()->parse());
@@ skipping 204 matching lines @@
   Factory* factory = isolate()->factory();
   Handle<FixedArray> elements = factory->NewFixedArray(args.length());
   for (int i = 0; i < args.length(); i++) {
     elements->set(i, *args[i]);
   }
   Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
   Handle<Object> result = factory->NewSyntaxError(type, array);
   isolate()->Throw(*result, &location);
 }
 
+void Parser::SetHarmonyBlockScoping(bool block_scoping) {
+  harmony_block_scoping_ = block_scoping;
+}
 
 // Base class containing common code for the different finder classes used by
 // the parser.
 class ParserFinder {
  protected:
   ParserFinder() {}
   static Assignment* AsAssignment(Statement* stat) {
     if (stat == NULL) return NULL;
     ExpressionStatement* exp_stat = stat->AsExpressionStatement();
     if (exp_stat == NULL) return NULL;
@@ skipping 658 matching lines @@
                                               CHECK_OK);
   // Even if we're not at the top-level of the global or a function
   // scope, we treat is as such and introduce the function with it's
   // initial value upon entering the corresponding scope.
   Declare(name, Variable::VAR, fun, true, CHECK_OK);
   return EmptyStatement();
 }
 
 
 Block* Parser::ParseBlock(ZoneStringList* labels, bool* ok) {
+  if (harmony_block_scoping_) return ParseScopedBlock(labels, ok);
+
   // Block ::
   //   '{' Statement* '}'
 
   // Note that a Block does not introduce a new execution scope!
   // (ECMA-262, 3rd, 12.2)
   //
   // Construct block expecting 16 statements.
   Block* result = new(zone()) Block(isolate(), labels, 16, false);
   Target target(&this->target_stack_, result);
   Expect(Token::LBRACE, CHECK_OK);
   InitializationBlockFinder block_finder(top_scope_, target_stack_);
   while (peek() != Token::RBRACE) {
     Statement* stat = ParseStatement(NULL, CHECK_OK);
     if (stat && !stat->IsEmpty()) {
       result->AddStatement(stat);
       block_finder.Update(stat);
     }
   }
   Expect(Token::RBRACE, CHECK_OK);
   return result;
 }
 
 
+Block* Parser::ParseScopedBlock(ZoneStringList* labels, bool* ok) {
+  // Construct block expecting 16 statements.
+  Block* body = new(zone()) Block(isolate(), labels, 16, false);
+  Scope* saved_scope = top_scope_;
+  Scope* block_scope = NewScope(top_scope_,
+                                Scope::BLOCK_SCOPE,
+                                inside_with());
+  body->set_block_scope(block_scope);
+  block_scope->DeclareLocal(isolate()->factory()->block_scope_symbol(),
+                            Variable::VAR);
+  if (top_scope_->is_strict_mode()) {
+    block_scope->EnableStrictMode();
+  }
+  top_scope_ = block_scope;
+
+  // Parse the statements and collect escaping labels.
+  TargetCollector collector;
+  Target target(&this->target_stack_, &collector);
+  Expect(Token::LBRACE, CHECK_OK);
+  {
+    Target target_body(&this->target_stack_, body);
+    InitializationBlockFinder block_finder(top_scope_, target_stack_);
+
+    while (peek() != Token::RBRACE) {
+      Statement* stat = ParseStatement(NULL, CHECK_OK);
+      if (stat && !stat->IsEmpty()) {
+        body->AddStatement(stat);
+        block_finder.Update(stat);
+      }
+    }
+  }
+  Expect(Token::RBRACE, CHECK_OK);
+
+  // Create exit block.
+  Block* exit = new(zone()) Block(isolate(), NULL, 1, false);
+  exit->AddStatement(new(zone()) ExitContextStatement());
+
+  // Create a try-finally statement.
+  TryFinallyStatement* try_finally =
+      new(zone()) TryFinallyStatement(body, exit);
+  try_finally->set_escaping_targets(collector.targets());
+  top_scope_ = saved_scope;
+
+  // Create a result block.
+  Block* result = new(zone()) Block(isolate(), NULL, 1, false);
+  result->AddStatement(try_finally);
+  return result;
+}
+
+
 Block* Parser::ParseVariableStatement(bool* ok) {
   // VariableStatement ::
   //   VariableDeclarations ';'
 
   Handle<String> ignore;
   Block* result = ParseVariableDeclarations(true, &ignore, CHECK_OK);
   ExpectSemicolon(CHECK_OK);
   return result;
 }
 
@@ skipping 426 matching lines @@
     ExpectSemicolon(CHECK_OK);
     return new(zone()) ReturnStatement(GetLiteralUndefined());
   }
 
   Expression* expr = ParseExpression(true, CHECK_OK);
   ExpectSemicolon(CHECK_OK);
   return new(zone()) ReturnStatement(expr);
 }
 
 
-Block* Parser::WithHelper(Expression* obj, ZoneStringList* labels, bool* ok) {
-  // Parse the statement and collect escaping labels.
-  TargetCollector collector;
-  Statement* stat;
-  { Target target(&this->target_stack_, &collector);
-    with_nesting_level_++;
-    top_scope_->DeclarationScope()->RecordWithStatement();
-    stat = ParseStatement(labels, CHECK_OK);
-    with_nesting_level_--;
-  }
-  // Create resulting block with two statements.
-  // 1: Evaluate the with expression.
-  // 2: The try-finally block evaluating the body.
-  Block* result = new(zone()) Block(isolate(), NULL, 2, false);
-
-  if (result != NULL) {
-    result->AddStatement(new(zone()) EnterWithContextStatement(obj));
-
-    // Create body block.
-    Block* body = new(zone()) Block(isolate(), NULL, 1, false);
-    body->AddStatement(stat);
-
-    // Create exit block.
-    Block* exit = new(zone()) Block(isolate(), NULL, 1, false);
-    exit->AddStatement(new(zone()) ExitContextStatement());
-
-    // Return a try-finally statement.
-    TryFinallyStatement* wrapper = new(zone()) TryFinallyStatement(body, exit);
-    wrapper->set_escaping_targets(collector.targets());
-    result->AddStatement(wrapper);
-  }
-  return result;
-}
-
-
 Statement* Parser::ParseWithStatement(ZoneStringList* labels, bool* ok) {
   // WithStatement ::
   //   'with' '(' Expression ')' Statement
 
   Expect(Token::WITH, CHECK_OK);
 
   if (top_scope_->is_strict_mode()) {
     ReportMessage("strict_mode_with", Vector<const char*>::empty());
     *ok = false;
     return NULL;
   }
 
   Expect(Token::LPAREN, CHECK_OK);
   Expression* expr = ParseExpression(true, CHECK_OK);
   Expect(Token::RPAREN, CHECK_OK);
 
-  return WithHelper(expr, labels, CHECK_OK);
+  ++with_nesting_level_;
+  top_scope_->DeclarationScope()->RecordWithStatement();
+  Statement* stmt = ParseStatement(labels, CHECK_OK);
+  --with_nesting_level_;
+  return new(zone()) WithStatement(expr, stmt);
 }
 
 
 CaseClause* Parser::ParseCaseClause(bool* default_seen_ptr, bool* ok) {
   // CaseClause ::
   //   'case' Expression ':' Statement*
   //   'default' ':' Statement*
 
   Expression* label = NULL;  // NULL expression indicates default case
   if (peek() == Token::CASE) {
@@ skipping 114 matching lines @@
 
     if (top_scope_->is_strict_mode() && IsEvalOrArguments(name)) {
       ReportMessage("strict_catch_variable", Vector<const char*>::empty());
       *ok = false;
       return NULL;
     }
 
     Expect(Token::RPAREN, CHECK_OK);
 
     if (peek() == Token::LBRACE) {
-      // Rewrite the catch body B to a single statement block
-      // { try B finally { PopContext }}.
-      Block* inner_body;
-      // We need to collect escapes from the body for both the inner
-      // try/finally used to pop the catch context and any possible outer
-      // try/finally.
-      TargetCollector inner_collector;
-      { Target target(&this->target_stack_, &catch_collector);
-        { Target target(&this->target_stack_, &inner_collector);
-          catch_scope = NewScope(top_scope_, Scope::CATCH_SCOPE, inside_with());
-          if (top_scope_->is_strict_mode()) {
-            catch_scope->EnableStrictMode();
-          }
-          catch_variable = catch_scope->DeclareLocal(name, Variable::VAR);
+      // Rewrite the catch body { B } to a block:
+      // { { B } ExitContext; }.
+      Target target(&this->target_stack_, &catch_collector);
+      catch_scope = NewScope(top_scope_, Scope::CATCH_SCOPE, inside_with());
+      if (top_scope_->is_strict_mode()) {
+        catch_scope->EnableStrictMode();
+      }
+      catch_variable = catch_scope->DeclareLocal(name, Variable::VAR);
+      catch_block = new(zone()) Block(isolate(), NULL, 2, false);
 
-          Scope* saved_scope = top_scope_;
-          top_scope_ = catch_scope;
-          inner_body = ParseBlock(NULL, CHECK_OK);
-          top_scope_ = saved_scope;
-        }
-      }
-
-      // Create exit block.
-      Block* inner_finally = new(zone()) Block(isolate(), NULL, 1, false);
-      inner_finally->AddStatement(new(zone()) ExitContextStatement());
-
-      // Create a try/finally statement.
-      TryFinallyStatement* inner_try_finally =
-          new(zone()) TryFinallyStatement(inner_body, inner_finally);
-      inner_try_finally->set_escaping_targets(inner_collector.targets());
-
-      catch_block = new(zone()) Block(isolate(), NULL, 1, false);
-      catch_block->AddStatement(inner_try_finally);
+      Scope* saved_scope = top_scope_;
+      top_scope_ = catch_scope;
+      Block* catch_body = ParseBlock(NULL, CHECK_OK);
+      top_scope_ = saved_scope;
+      catch_block->AddStatement(catch_body);
+      catch_block->AddStatement(new(zone()) ExitContextStatement());
     } else {
       Expect(Token::LBRACE, CHECK_OK);
     }
 
     tok = peek();
   }
 
   Block* finally_block = NULL;
   if (tok == Token::FINALLY || catch_block == NULL) {
     Consume(Token::FINALLY);
@@ skipping 2910 matching lines @@
   return !parser.failed();
 }
 
 
 bool ParserApi::Parse(CompilationInfo* info) {
   ASSERT(info->function() == NULL);
   FunctionLiteral* result = NULL;
   Handle<Script> script = info->script();
   if (info->is_lazy()) {
     Parser parser(script, true, NULL, NULL);
+    parser.SetHarmonyBlockScoping(!info->is_native() &&
+                                  FLAG_harmony_block_scoping);
     result = parser.ParseLazy(info);
   } else {
     // Whether we allow %identifier(..) syntax.
     bool allow_natives_syntax =
         info->allows_natives_syntax() || FLAG_allow_natives_syntax;
     ScriptDataImpl* pre_data = info->pre_parse_data();
     Parser parser(script, allow_natives_syntax, info->extension(), pre_data);
+    parser.SetHarmonyBlockScoping(!info->is_native() &&
+                                  FLAG_harmony_block_scoping);
     if (pre_data != NULL && pre_data->has_error()) {
       Scanner::Location loc = pre_data->MessageLocation();
       const char* message = pre_data->BuildMessage();
       Vector<const char*> args = pre_data->BuildArgs();
       parser.ReportMessageAt(loc, message, args);
       DeleteArray(message);
       for (int i = 0; i < args.length(); i++) {
         DeleteArray(args[i]);
       }
       DeleteArray(args.start());
       ASSERT(info->isolate()->has_pending_exception());
     } else {
       Handle<String> source = Handle<String>(String::cast(script->source()));
       result = parser.ParseProgram(source,
                                    info->is_global(),
                                    info->StrictMode());
     }
   }
-
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal