Strict mode - allow function only in SourceElements.

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 1088 matching lines @@
   InitializationBlockFinder block_finder;
   ThisNamedPropertyAssigmentFinder this_property_assignment_finder;
   bool directive_prologue = true;     // Parsing directive prologue.
 
   while (peek() != end_token) {
     if (directive_prologue && peek() != Token::STRING) {
       directive_prologue = false;
     }
 
     Scanner::Location token_loc = scanner().peek_location();
-    Statement* stat = ParseStatement(NULL, CHECK_OK);
+
+    Statement* stat;
+    if (peek() == Token::FUNCTION) {
+      // FunctionDeclaration is only allowed in the context of SourceElements
+      // (Ecma 262 5th Edition, clause 14):
+      // SourceElement:
+      //    Statement
+      //    FunctionDeclaration
+      // Common language extension is to allow function declaration in place
+      // of any statement. This language extension is disabled in strict mode.
+      stat = ParseFunctionDeclaration(CHECK_OK);
+    } else {
+      stat = ParseStatement(NULL, CHECK_OK);
+    }
 
     if (stat == NULL || stat->IsEmpty()) {
       directive_prologue = false;   // End of directive prologue.
       continue;
     }
 
     if (directive_prologue) {
       // A shot at a directive.
       ExpressionStatement *e_stat;
       Literal *literal;
@@ skipping 136 matching lines @@
       Block* result = new Block(labels, 1, false);
       Target target(&this->target_stack_, result);
       TryStatement* statement = ParseTryStatement(CHECK_OK);
       if (statement) {
         statement->set_statement_pos(statement_pos);
       }
       if (result) result->AddStatement(statement);
       return result;
     }
 
-    case Token::FUNCTION:
+    case Token::FUNCTION: {
+      // In strict mode, FunctionDeclaration is only allowed in the context
+      // of SourceElements.
+      if (temp_scope_->StrictMode()) {
+        ReportMessageAt(scanner().peek_location(), "strict_function",
+                        Vector<const char*>::empty());
+        *ok = false;
+        return NULL;
+      }
       return ParseFunctionDeclaration(ok);
+    }
 
     case Token::NATIVE:
       return ParseNativeDeclaration(ok);
 
     case Token::DEBUGGER:
       stmt = ParseDebuggerStatement(ok);
       break;
 
     default:
       stmt = ParseExpressionOrLabelledStatement(labels, ok);
@@ skipping 3836 matching lines @@
                                    info->is_global(),
                                    info->StrictMode());
     }
   }
 
   info->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal