Don't lazily compile functions that are immediately receded by '('.

src/parser.cc

 // Copyright 2010 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 582 matching lines @@
       script_(script),
       scanner_(),
       top_scope_(NULL),
       with_nesting_level_(0),
       temp_scope_(NULL),
       target_stack_(NULL),
       allow_natives_syntax_(allow_natives_syntax),
       extension_(extension),
       pre_data_(pre_data),
       fni_(NULL),
-      stack_overflow_(false) {
+      stack_overflow_(false),
+      parenthesized_function_(false) {
   AstNode::ResetIds();
 }
 
 
 FunctionLiteral* Parser::ParseProgram(Handle<String> source,
                                       bool in_global_context) {
   CompilationZoneScope zone_scope(DONT_DELETE_ON_EXIT);
 
   HistogramTimerScope timer(&Counters::parse);
   Counters::total_parse_size.Increment(source->length());
@@ skipping 1861 matching lines @@
 
       case Token::LPAREN: {
         int pos = scanner().location().beg_pos;
         ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
 
         // Keep track of eval() calls since they disable all local variable
         // optimizations.
         // The calls that need special treatment are the
         // direct (i.e. not aliased) eval calls. These calls are all of the
         // form eval(...) with no explicit receiver object where eval is not
-        // declared in the current scope chain. These calls are marked as
-        // potentially direct eval calls. Whether they are actually direct calls
-        // to eval is determined at run time.
+        // declared in the current scope chain.
+        // These calls are marked as potentially direct eval calls. Whether
+        // they are actually direct calls to eval is determined at run time.
+        // TODO(994): In ES5, it doesn't matter if the "eval" var is declared
+        // in the local scope chain. It only matters that it's called "eval",
+        // is called without a receiver and it refers to the original eval
+        // function.
         VariableProxy* callee = result->AsVariableProxy();
         if (callee != NULL && callee->IsVariable(Factory::eval_symbol())) {
           Handle<String> name = callee->name();
           Variable* var = top_scope_->Lookup(name);
           if (var == NULL) {
             top_scope_->RecordEvalCall();
           }
         }
         result = NewCall(result, args, pos);
         break;
@@ skipping 229 matching lines @@
     case Token::LBRACK:
       result = ParseArrayLiteral(CHECK_OK);
       break;
 
     case Token::LBRACE:
       result = ParseObjectLiteral(CHECK_OK);
       break;
 
     case Token::LPAREN:
       Consume(Token::LPAREN);
+      // Heuristically try to detect immediately called functions before
+      // seeing the call parentheses.
+      parenthesized_function_ = (peek() == Token::FUNCTION);
       result = ParseExpression(true, CHECK_OK);
       Expect(Token::RPAREN, CHECK_OK);
       break;
 
     case Token::MOD:
       if (allow_natives_syntax_ || extension_ != NULL) {
         result = ParseV8Intrinsic(CHECK_OK);
         break;
       }
       // If we're not allowing special syntax we fall-through to the
@@ skipping 471 matching lines @@
           top_scope_->NewUnresolved(function_name, inside_with());
       fproxy->BindTo(fvar);
       body->Add(new ExpressionStatement(
                     new Assignment(Token::INIT_CONST, fproxy,
                                    new ThisFunction(),
                                    RelocInfo::kNoPosition)));
     }
 
     // Determine if the function will be lazily compiled. The mode can
     // only be PARSE_LAZILY if the --lazy flag is true.
-    bool is_lazily_compiled =
-        mode() == PARSE_LAZILY && top_scope_->HasTrivialOuterContext();
+    bool is_lazily_compiled = (mode() == PARSE_LAZILY &&
+                               top_scope_->outer_scope()->is_global_scope() &&
+                               top_scope_->HasTrivialOuterContext() &&
+                               !parenthesized_function_);
+    parenthesized_function_ = false;  // The bit was set for this function only.
 
     int function_block_pos = scanner().location().beg_pos;
     int materialized_literal_count;
     int expected_property_count;
     int end_pos;
     bool only_simple_this_property_assignments;
     Handle<FixedArray> this_property_assignments;
     if (is_lazily_compiled && pre_data() != NULL) {
       FunctionEntry entry = pre_data()->GetFunctionEntry(function_block_pos);
       if (!entry.is_valid()) {
@@ skipping 1455 matching lines @@
       Handle<String> source = Handle<String>(String::cast(script->source()));
       result = parser.ParseProgram(source, info->is_global());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal