Proof of concept: API for doing only one parsing pass instead of first preparsing and then parsing.

src/compiler.cc

 // Copyright 2012 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 97 matching lines @@
 
 
 void CompilationInfo::Initialize(Isolate* isolate,
                                  Mode mode,
                                  Zone* zone) {
   isolate_ = isolate;
   function_ = NULL;
   scope_ = NULL;
   global_scope_ = NULL;
   extension_ = NULL;
-  pre_parse_data_ = NULL;
+  cached_data_ = NULL;
   zone_ = zone;
   deferred_handles_ = NULL;
   code_stub_ = NULL;
   prologue_offset_ = Code::kPrologueOffsetNotSet;
   opt_count_ = shared_info().is_null() ? 0 : shared_info()->opt_count();
   no_frame_ranges_ = isolate->cpu_profiler()->is_profiling()
                    ? new List<OffsetRange>(2) : NULL;
   for (int i = 0; i < DependentCode::kGroupCount; i++) {
     dependencies_[i] = NULL;
   }
@@ skipping 671 matching lines @@
   FixedArray* array = isolate->native_context()->embedder_data();
   script->set_context_data(array->get(0));
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   isolate->debugger()->OnBeforeCompile(script);
 #endif
 
   ASSERT(info->is_eval() || info->is_global());
 
   bool parse_allow_lazy =
-      (info->pre_parse_data() != NULL ||
+      (info->cached_data() != NULL ||
        String::cast(script->source())->length() > FLAG_min_preparse_length) &&
       !DebuggerWantsEagerCompilation(info);
 
-  if (!parse_allow_lazy && info->pre_parse_data() != NULL) {
-    // We are going to parse eagerly, but we have preparse data produced by lazy
-    // preparsing. We cannot use it, since it won't contain all the symbols we
-    // need for eager parsing.
-    info->SetPreParseData(NULL);
+  if (!parse_allow_lazy && info->cached_data() != NULL) {
+    // We are going to parse eagerly, but we either 1) have cached data produced
+    // by lazy parsing or 2) are asked to generate cached data. We cannot use
+    // the existing data, since it won't contain all the symbols we need for
+    // eager parsing. In addition, it doesn't make sense to generate the data
+    // when parsing eagerly. That data would contain all symbols, but no
+    // functions, so it couldn't be used to aid lazy parsing later.
+    info->SetCachedData(NULL);
   }
 
   Handle<SharedFunctionInfo> result;
 
   { VMState<COMPILER> state(info->isolate());
     if (!Parser::Parse(info, parse_allow_lazy)) {
       return Handle<SharedFunctionInfo>::null();
     }
 
     FunctionLiteral* lit = info->function();
@@ skipping 107 matching lines @@
 }
 
 
 Handle<SharedFunctionInfo> Compiler::CompileScript(Handle<String> source,
                                                    Handle<Object> script_name,
                                                    int line_offset,
                                                    int column_offset,
                                                    bool is_shared_cross_origin,
                                                    Handle<Context> context,
                                                    v8::Extension* extension,
-                                                   ScriptDataImpl* pre_data,
+                                                   ScriptDataImpl** cached_data,
                                                    NativesFlag natives) {
   Isolate* isolate = source->GetIsolate();
   int source_length = source->length();
   isolate->counters()->total_load_size()->Increment(source_length);
   isolate->counters()->total_compile_size()->Increment(source_length);
 
   CompilationCache* compilation_cache = isolate->compilation_cache();
 
   // Do a lookup in the compilation cache but not for extensions.
   Handle<SharedFunctionInfo> result;
@@ skipping 25 matching lines @@
       script->set_name(*script_name);
       script->set_line_offset(Smi::FromInt(line_offset));
       script->set_column_offset(Smi::FromInt(column_offset));
     }
     script->set_is_shared_cross_origin(is_shared_cross_origin);
 
     // Compile the function and add it to the cache.
     CompilationInfoWithZone info(script);
     info.MarkAsGlobal();
     info.SetExtension(extension);
-    info.SetPreParseData(pre_data);
+    info.SetCachedData(cached_data);
     info.SetContext(context);
     if (FLAG_use_strict) info.SetStrictMode(STRICT);
     result = CompileToplevel(&info);
     if (extension == NULL && !result.is_null() && !result->dont_cache()) {
       compilation_cache->PutScript(source, context, result);
     }
   } else if (result->ic_age() != isolate->heap()->global_ic_age()) {
       result->ResetForNewContext(isolate->heap()->global_ic_age());
   }
 
@@ skipping 316 matching lines @@
   AllowHandleDereference allow_deref;
   bool tracing_on = info()->IsStub()
       ? FLAG_trace_hydrogen_stubs
       : (FLAG_trace_hydrogen &&
          info()->closure()->PassesFilter(FLAG_trace_hydrogen_filter));
   return (tracing_on &&
       OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL);
 }
 
 } }  // namespace v8::internal