Experimental scanner: support preparsing API.

src/parser.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 5590 matching lines @@
     data++;
   }
   *source = data;
   return result;
 }
 
 
 // Create a ScannerBase for the preparser to use as input, and preparse the
 // source.
 ScriptDataImpl* PreParserApi::PreParse(Isolate* isolate,
-                                       Utf16CharacterStream* source) {
-  // FIXME(experimental-scanner): implement
-  return NULL;
+                                       Handle<String> source) {
+  CompleteParserRecorder recorder;
+  HistogramTimerScope timer(isolate->counters()->pre_parse());
+  ScannerBase* scanner = NULL;
+  if (source->IsTwoByteRepresentation()) {
+    scanner = new ExperimentalScanner<uint16_t>(source, isolate);
+  } else {
+    scanner = new ExperimentalScanner<uint8_t>(source, isolate);
+  }
+  intptr_t stack_limit = isolate->stack_guard()->real_climit();
+  PreParser preparser(scanner, &recorder, stack_limit);
+  preparser.set_allow_lazy(true);
+  preparser.set_allow_generators(FLAG_harmony_generators);
+  preparser.set_allow_for_of(FLAG_harmony_iteration);
+  preparser.set_allow_harmony_scoping(FLAG_harmony_scoping);
+  preparser.set_allow_harmony_numeric_literals(FLAG_harmony_numeric_literals);
+  scanner->Init();
+  PreParser::PreParseResult result = preparser.PreParseProgram();
+  if (result == PreParser::kPreParseStackOverflow) {
+    isolate->StackOverflow();
+    delete scanner;
+    return NULL;
+  }
+
+  // Extract the accumulated data from the recorder as a single
+  // contiguous vector that we are responsible for disposing.
+  Vector<unsigned> store = recorder.ExtractData();
+  delete scanner;
+  return new ScriptDataImpl(store);
 }
 
 
 bool RegExpParser::ParseRegExp(FlatStringReader* input,
                                bool multiline,
                                RegExpCompileData* result,
                                Zone* zone) {
   ASSERT(result != NULL);
   RegExpParser parser(input, &result->error, multiline, zone);
   RegExpTree* tree = parser.ParsePattern();
@@ skipping 46 matching lines @@
 }
 
 
 void Parser::SetScannerFlags() {
   scanner_->SetHarmonyScoping(!info_->is_native() && FLAG_harmony_scoping);
   scanner_->SetHarmonyModules(!info_->is_native() && FLAG_harmony_modules);
   scanner_->SetHarmonyNumericLiterals(FLAG_harmony_numeric_literals);
 }
 
 } }  // namespace v8::internal