Replace boolean indications of strict mode by an enum value.

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 634 matching lines @@
 
   Scope::Type type =
     in_global_context
       ? Scope::GLOBAL_SCOPE
       : Scope::EVAL_SCOPE;
   Handle<String> no_name = isolate()->factory()->empty_symbol();
 
   FunctionLiteral* result = NULL;
   { Scope* scope = NewScope(top_scope_, type);
     LexicalScope lexical_scope(this, scope, isolate());
-    if (strict_mode == kStrictMode) {
-      top_scope_->EnableStrictMode();
-    }
+    top_scope_->SetStrictModeFlag(strict_mode);

[Yang, 2011/10/20 14:18:59]

Here again. This only works if you assume the previous state to be not in strict
mode.

[Steven, 2011/10/21 13:59:00]

Because we start with a GLOBAL or EVAL scope the previous scope is null and
therefore no the created scope won't be in strict mode.
On 2011/10/20 14:18:59, Yang wrote:

     ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(16);
     bool ok = true;
     int beg_loc = scanner().location().beg_pos;
     ParseSourceElements(body, Token::EOS, &ok);
     if (ok && top_scope_->is_strict_mode()) {
       CheckOctalLiteral(beg_loc, scanner().location().end_pos, &ok);
     }
 
     if (ok && harmony_scoping_) {
       CheckConflictingVarDeclarations(scope, &ok);
@@ skipping 66 matching lines @@
   fni_->PushEnclosingName(name);
 
   mode_ = PARSE_EAGERLY;
 
   // Place holder for the result.
   FunctionLiteral* result = NULL;
 
   {
     // Parse the function literal.
     Scope* scope = NewScope(top_scope_, Scope::GLOBAL_SCOPE);
+    scope->SetStrictModeFlag(shared_info->strict_mode_flag());

[Yang, 2011/10/20 14:18:59]

Ditto.

[Steven, 2011/10/21 13:59:00]

The move before the if was not correct. I added a test case which catches this.
Always setting the StrictModeFlag here is a non-issue, however for non-trivial
reasons. Added ASSERTS to verify this. As far as I can see these are the
possible cases
* the SharedFunctionInfo has the correct value: this  function is non-strict or
outer scope is strict or the function was preparsed
* the outer scope is non-strict and the non-preparsed  strict function is being
parsed for the first time. In this case ParseFunctionLiteral will determine the
correct mode and Compiler::CompileLazy updates the SharedFunctionInfo to the
correct value.

On 2011/10/20 14:18:59, Yang wrote:

     if (!info->closure().is_null()) {
       scope = Scope::DeserializeScopeChain(info, scope);
     }
     LexicalScope lexical_scope(this, scope, isolate());
-
-    if (shared_info->strict_mode()) {
-      top_scope_->EnableStrictMode();
-    }
-
     FunctionLiteral::Type type = shared_info->is_expression()
         ? (shared_info->is_anonymous()
               ? FunctionLiteral::ANONYMOUS_EXPRESSION
               : FunctionLiteral::NAMED_EXPRESSION)
         : FunctionLiteral::DECLARATION;
     bool ok = true;
     result = ParseFunctionLiteral(name,
                                   false,  // Strict mode name already checked.
                                   RelocInfo::kNoPosition,
                                   type,
@@ skipping 426 matching lines @@
       if ((e_stat = stat->AsExpressionStatement()) != NULL &&
           (literal = e_stat->expression()->AsLiteral()) != NULL &&
           literal->handle()->IsString()) {
         Handle<String> directive = Handle<String>::cast(literal->handle());
 
         // Check "use strict" directive (ES5 14.1).
         if (!top_scope_->is_strict_mode() &&
             directive->Equals(isolate()->heap()->use_strict()) &&
             token_loc.end_pos - token_loc.beg_pos ==
               isolate()->heap()->use_strict()->length() + 2) {
-          top_scope_->EnableStrictMode();
+          top_scope_->SetStrictModeFlag(kStrictMode);
           // "use strict" is the only directive for now.
           directive_prologue = false;
         }
       } else {
         // End of the directive prologue.
         directive_prologue = false;
       }
     }
 
     block_finder.Update(stat);
@@ skipping 379 matching lines @@
 
 Block* Parser::ParseScopedBlock(ZoneStringList* labels, bool* ok) {
   // The harmony mode uses source elements instead of statements.
   //
   // Block ::
   //   '{' SourceElement* '}'
 
   // Construct block expecting 16 statements.
   Block* body = new(zone()) Block(isolate(), labels, 16, false);
   Scope* block_scope = NewScope(top_scope_, Scope::BLOCK_SCOPE);
-  if (top_scope_->is_strict_mode()) {
-    block_scope->EnableStrictMode();
-  }
 
   // Parse the statements and collect escaping labels.
   Expect(Token::LBRACE, CHECK_OK);
   { SaveScope save_scope(this, block_scope);
     TargetCollector collector;
     Target target(&this->target_stack_, &collector);
     Target target_body(&this->target_stack_, body);
     InitializationBlockFinder block_finder(top_scope_, target_stack_);
 
     while (peek() != Token::RBRACE) {
@@ skipping 225 matching lines @@
         // the number of arguments (1 or 2).
         initialize =
             new(zone()) CallRuntime(
                 isolate(),
                 isolate()->factory()->InitializeConstGlobal_symbol(),
                 Runtime::FunctionForId(Runtime::kInitializeConstGlobal),
                 arguments);
       } else {
         // Add strict mode.
         // We may want to pass singleton to avoid Literal allocations.
-        StrictModeFlag flag = initialization_scope->is_strict_mode()
-            ? kStrictMode
-            : kNonStrictMode;
+        StrictModeFlag flag = initialization_scope->strict_mode_flag();
         arguments->Add(NewNumberLiteral(flag));
 
         // Be careful not to assign a value to the global variable if
         // we're in a with. The initialization value should not
         // necessarily be stored in the global object in that case,
         // which is why we need to generate a separate assignment node.
         if (value != NULL && !inside_with()) {
           arguments->Add(value);
           value = NULL;  // zap the value to avoid the unnecessary assignment
         }
@@ skipping 389 matching lines @@
       ReportMessage("strict_catch_variable", Vector<const char*>::empty());
       *ok = false;
       return NULL;
     }
 
     Expect(Token::RPAREN, CHECK_OK);
 
     if (peek() == Token::LBRACE) {
       Target target(&this->target_stack_, &catch_collector);
       catch_scope = NewScope(top_scope_, Scope::CATCH_SCOPE);
-      if (top_scope_->is_strict_mode()) {
-        catch_scope->EnableStrictMode();
-      }
       VariableMode mode = harmony_scoping_ ? LET : VAR;
       catch_variable = catch_scope->DeclareLocal(name, mode);
 
       SaveScope save_scope(this, catch_scope);
       catch_block = ParseBlock(NULL, CHECK_OK);
     } else {
       Expect(Token::LBRACE, CHECK_OK);
     }
 
     tok = peek();
@@ skipping 97 matching lines @@
 
 Statement* Parser::ParseForStatement(ZoneStringList* labels, bool* ok) {
   // ForStatement ::
   //   'for' '(' Expression? ';' Expression? ';' Expression? ')' Statement
 
   Statement* init = NULL;
 
   // Create an in-between scope for let-bound iteration variables.
   Scope* saved_scope = top_scope_;
   Scope* for_scope = NewScope(top_scope_, Scope::BLOCK_SCOPE);
-  if (top_scope_->is_strict_mode()) {
-    for_scope->EnableStrictMode();
-  }
   top_scope_ = for_scope;
 
   Expect(Token::FOR, CHECK_OK);
   Expect(Token::LPAREN, CHECK_OK);
   if (peek() != Token::SEMICOLON) {
     if (peek() == Token::VAR || peek() == Token::CONST) {
       Handle<String> name;
       Block* variable_statement =
           ParseVariableDeclarations(kForStatement, NULL, &name, CHECK_OK);
 
@@ skipping 1576 matching lines @@
         if (end_pos <= function_block_pos) {
           // End position greater than end of stream is safe, and hard to check.
           ReportInvalidPreparseData(function_name, CHECK_OK);
         }
         isolate()->counters()->total_preparse_skipped()->Increment(
             end_pos - function_block_pos);
         // Seek to position just before terminal '}'.
         scanner().SeekForward(end_pos - 1);
         materialized_literal_count = entry.literal_count();
         expected_property_count = entry.property_count();
-        if (entry.strict_mode()) top_scope_->EnableStrictMode();
+        if (entry.strict_mode()) top_scope_->SetStrictModeFlag(kStrictMode);
         only_simple_this_property_assignments = false;
         this_property_assignments = isolate()->factory()->empty_fixed_array();
         Expect(Token::RBRACE, CHECK_OK);
       }
     }
 
     if (!is_lazily_compiled) {
       ParseSourceElements(body, Token::RBRACE, CHECK_OK);
 
       materialized_literal_count = lexical_scope.materialized_literal_count();
@@ skipping 1389 matching lines @@
       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->strict_mode_flag());
     }
   }
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal