Remove the PreCompile API and ScriptData.

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 206 matching lines @@
     result = scanner()->AllocateInternalizedString(isolate_);
     ASSERT(!result.is_null());
     symbol_cache_.at(symbol_id) = result;
     return result;
   }
   isolate()->counters()->total_preparse_symbols_skipped()->Increment();
   return result;
 }
 
 
+ScriptDataImpl::ScriptDataImpl(const char* data, int length)
+    : owns_store_(false) {
+  // The length is obviously invalid.
+  if (length % sizeof(unsigned) != 0) {

[Sven Panne, 2014/04/07 12:44:44]

Why do we silently return here? Wouldn't an ASSERT be better?

[marja, 2014/04/09 12:53:55]

This data is coming in via the API, maybe the original author (this func used to
be ScriptData::New) didn't want to use ASSERT to validate user input?

Nothing bad will happen if the user passes data which is obviously invalid; we
will (silently) ignore it and parsing will be slower.

Would you rather have an ASSERT here? What's the V8 policy wrt asserting if
input is invalid?

[Sven Panne, 2014/04/11 08:18:22]

I think that silently (not) doing something is quite bad and will bite us sooner
or later. The corresponding API function has a way to communicate failure by
returning an empty handle, so this is what should happen somehow. The question
is how to communicate this through the layers, failing in the constructor
without having exceptions is ugly, so one could e.g. use a factory method
instead, but I'll leave the details up to you. :-)

+    return;
+  }
+
+  // Copy the data to ensure it is properly aligned.

[Sven Panne, 2014/04/07 12:44:44]

This comment doesn't really belong here.

[marja, 2014/04/09 12:53:55]

Done.

+  int deserialized_data_length = length / sizeof(unsigned);
+  // If aligned, don't create a copy of the data.
+  if (reinterpret_cast<intptr_t>(data) % sizeof(unsigned) == 0) {

[Sven Panne, 2014/04/07 12:44:44]

I think restructuring this function makes things clearer, something along the
lines of:

    owns_store_ = reinterpret_cast<intptr_t>(data) % sizeof(unsigned) != 0;
    if (owns_store_) {
       <make an aligned copy and assign the start of it to data>
    }
    <wrap data/length into a vector>

[marja, 2014/04/09 12:53:55]

Done.

+    store_ =
+        Vector<unsigned>(reinterpret_cast<unsigned*>(const_cast<char*>(data)),
+                         length / static_cast<int>(sizeof(unsigned)));
+    return;
+  }
+
+  // Copy the data to align it.
+  unsigned* deserialized_data = i::NewArray<unsigned>(deserialized_data_length);
+  i::CopyBytes(reinterpret_cast<char*>(deserialized_data),
+               data, static_cast<size_t>(length));
+
+  // ScriptDataImpl will own the buffer.
+  store_ = i::Vector<unsigned>(deserialized_data, deserialized_data_length);
+  owns_store_ = true;
+}
+
+
 FunctionEntry ScriptDataImpl::GetFunctionEntry(int start) {
   // The current pre-data entry must be a FunctionEntry with the given
   // start position.
   if ((function_index_ + FunctionEntry::kSize <= store_.length())
       && (static_cast<int>(store_[function_index_]) == start)) {
     int index = function_index_;
     function_index_ += FunctionEntry::kSize;
     return FunctionEntry(store_.SubVector(index,
                                           index + FunctionEntry::kSize));
   }
@@ skipping 4356 matching lines @@
     if (data >= symbol_data_end_) return -1;
     input = *data;
     result = (result << 7) | (input & 0x7f);
     data++;
   }
   *source = data;
   return result;
 }
 
 
-// Create a Scanner for the preparser to use as input, and preparse the source.
-ScriptDataImpl* PreParserApi::PreParse(Isolate* isolate,
-                                       Utf16CharacterStream* source) {
-  CompleteParserRecorder recorder;
-  HistogramTimerScope timer(isolate->counters()->pre_parse());
-  Scanner scanner(isolate->unicode_cache());
-  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.Initialize(source);
-  PreParser::PreParseResult result = preparser.PreParseProgram();
-  if (result == PreParser::kPreParseStackOverflow) {
-    isolate->StackOverflow();
-    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();
-  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();
   if (parser.failed()) {
     ASSERT(tree == NULL);
     ASSERT(!result->error.is_null());
@@ skipping 38 matching lines @@
       ASSERT(info()->isolate()->has_pending_exception());
     } else {
       result = ParseProgram();
     }
   }
   info()->SetFunction(result);
   return (result != NULL);
 }
 
 } }  // namespace v8::internal