Merge JSON fix to 1.2 branch.

src/compiler.cc

 // Copyright 2009 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 67 matching lines @@
     return Handle<Code>::null();
   }
 
   // Generate code and return it.
   Handle<Code> result = CodeGenerator::MakeCode(literal, script, is_eval);
   return result;
 }
 
 
 static bool IsValidJSON(FunctionLiteral* lit) {
-  if (!lit->body()->length() == 1)
+  if (lit->body()->length() != 1)
     return false;
   Statement* stmt = lit->body()->at(0);
   if (stmt->AsExpressionStatement() == NULL)
     return false;
   Expression* expr = stmt->AsExpressionStatement()->expression();
   return expr->IsValidJSON();
 }
 
 
 static Handle<JSFunction> MakeFunction(bool is_global,
                                        bool is_eval,
-                                       bool is_json,
+                                       Compiler::ValidationState validate,
                                        Handle<Script> script,
                                        Handle<Context> context,
                                        v8::Extension* extension,
                                        ScriptDataImpl* pre_data) {
   CompilationZoneScope zone_scope(DELETE_ON_EXIT);
 
   // Make sure we have an initial stack limit.
   StackGuard guard;
   PostponeInterruptsScope postpone;
 
   ASSERT(!i::Top::global_context().is_null());
   script->set_context_data((*i::Top::global_context())->data());
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
+  bool is_json = (validate == Compiler::VALIDATE_JSON);
   if (is_eval || is_json) {
     script->set_compilation_type(
         is_json ? Smi::FromInt(Script::COMPILATION_TYPE_JSON) :
                                Smi::FromInt(Script::COMPILATION_TYPE_EVAL));
     // For eval scripts add information on the function from which eval was
     // called.
     if (is_eval) {
       JavaScriptFrameIterator it;
       script->set_eval_from_function(it.frame()->function());
       int offset = it.frame()->pc() - it.frame()->code()->instruction_start();
@@ skipping 13 matching lines @@
 
   // Check for parse errors.
   if (lit == NULL) {
     ASSERT(Top::has_pending_exception());
     return Handle<JSFunction>::null();
   }
 
   // When parsing JSON we do an ordinary parse and then afterwards
   // check the AST to ensure it was well-formed.  If not we give a
   // syntax error.
-  if (is_json && !IsValidJSON(lit)) {
+  if (validate == Compiler::VALIDATE_JSON && !IsValidJSON(lit)) {
     HandleScope scope;
     Handle<JSArray> args = Factory::NewJSArray(1);
     Handle<Object> source(script->source());
     SetElement(args, 0, source);
     Handle<Object> result = Factory::NewSyntaxError("invalid_json", args);
     Top::Throw(*result, NULL);
     return Handle<JSFunction>::null();
   }
 
   // Measure how long it takes to do the compilation; only take the
@@ skipping 99 matching lines @@
     Handle<Script> script = Factory::NewScript(source);
     if (!script_name.is_null()) {
       script->set_name(*script_name);
       script->set_line_offset(Smi::FromInt(line_offset));
       script->set_column_offset(Smi::FromInt(column_offset));
     }
 
     // Compile the function and add it to the cache.
     result = MakeFunction(true,
                           false,
-                          false,
+                          DONT_VALIDATE_JSON,
                           script,
                           Handle<Context>::null(),
                           extension,
                           pre_data);
     if (extension == NULL && !result.is_null()) {
       CompilationCache::PutScript(source, result);
     }
 
     // Get rid of the pre-parsing data (if necessary).
     if (input_pre_data == NULL && pre_data != NULL) {
       delete pre_data;
     }
   }
 
   if (result.is_null()) Top::ReportPendingMessages();
   return result;
 }
 
 
 Handle<JSFunction> Compiler::CompileEval(Handle<String> source,
                                          Handle<Context> context,
                                          bool is_global,
-                                         bool is_json) {
+                                         ValidationState validate) {
+  // Note that if validation is required then no path through this
+  // function is allowed to return a value without validating that
+  // the input is legal json.
+
   int source_length = source->length();
   Counters::total_eval_size.Increment(source_length);
   Counters::total_compile_size.Increment(source_length);
 
   // The VM is in the COMPILER state until exiting this function.
   VMState state(COMPILER);
 
   // Do a lookup in the compilation cache; if the entry is not there,
-  // invoke the compiler and add the result to the cache.
-  Handle<JSFunction> result =
-      CompilationCache::LookupEval(source, context, is_global);
+  // invoke the compiler and add the result to the cache.  If we're
+  // evaluating json we bypass the cache since we can't be sure a
+  // potential value in the cache has been validated.
+  Handle<JSFunction> result;
+  if (validate == DONT_VALIDATE_JSON)
+    result = CompilationCache::LookupEval(source, context, is_global);
+
   if (result.is_null()) {
     // Create a script object describing the script to be compiled.
     Handle<Script> script = Factory::NewScript(source);
     result = MakeFunction(is_global,
                           true,
-                          is_json,
+                          validate,
                           script,
                           context,
                           NULL,
                           NULL);
-    if (!result.is_null()) {
+    if (!result.is_null() && validate != VALIDATE_JSON) {
+      // For json it's unlikely that we'll ever see exactly the same
+      // string again so we don't use the compilation cache.
       CompilationCache::PutEval(source, context, is_global, result);
     }
   }
 
   return result;
 }
 
 
 bool Compiler::CompileLazy(Handle<SharedFunctionInfo> shared,
                            int loop_nesting) {
@@ skipping 76 matching lines @@
   // Set the expected number of properties for instances.
   SetExpectedNofPropertiesFromEstimate(shared, lit->expected_property_count());
 
   // Check the function has compiled code.
   ASSERT(shared->is_compiled());
   return true;
 }
 
 
 } }  // namespace v8::internal