Cleanly handle excessively long JS source strings.

Source/bindings/core/v8/V8ScriptRunner.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 337 matching lines @@
 PassOwnPtr<CompileFn> selectCompileFunction(ScriptResource* resource, ScriptStreamer* streamer)
 {
     // We don't stream scripts which don't have a Resource.
     ASSERT(resource);
     // Failed resources should never get this far.
     ASSERT(!resource->errorOccurred());
     ASSERT(streamer->isFinished());
     ASSERT(!streamer->streamingSuppressed());
     return WTF::bind<v8::Isolate*, v8::Handle<v8::String>, v8::ScriptOrigin>(postStreamCompile, resource->cacheHandler(), streamer);
 }
+
+void throwSourceTooLargeException(const v8::FunctionCallbackInfo<v8::Value>& info)
+{
+    V8ThrowException::throwGeneralError(info.GetIsolate(), "Source file too large.");
+}
+
 } // namespace
 
 v8::Local<v8::Script> V8ScriptRunner::compileScript(const ScriptSourceCode& source, v8::Isolate* isolate, AccessControlStatus corsStatus, V8CacheOptions cacheOptions)
 {
-    return compileScript(v8String(isolate, source.source()), source.url(), source.sourceMapUrl(), source.startPosition(), isolate, source.resource(), source.streamer(), source.resource() ? source.resource()->cacheHandler() : nullptr, corsStatus, cacheOptions);
+    v8::Handle<v8::String> sourceAsV8String(v8String(isolate, source.source()));
+    if (sourceAsV8String.IsEmpty()) {
+        // String conversion fails when the source size exceeds the V8 string
+        // length of (currently) 256MB.
+        V8RecursionScope scope(isolate);
+        v8::Function::New(isolate, throwSourceTooLargeException)->Call(v8::Undefined(isolate), 0, 0);

[haraken, 2015/03/09 23:21:56]

Can we use a (already existing) helper function in V8ThrowException.h? We want
to centralize code that throws exceptions into V8ThrowException.h.

+        return v8::Local<v8::Script>();
+    }
+
+    return compileScript(sourceAsV8String, source.url(), source.sourceMapUrl(), source.startPosition(), isolate, source.resource(), source.streamer(), source.resource() ? source.resource()->cacheHandler() : nullptr, corsStatus, cacheOptions);
 }
 
 v8::Local<v8::Script> V8ScriptRunner::compileScript(v8::Handle<v8::String> code, const String& fileName, const String& sourceMapUrl, const TextPosition& scriptStartPosition, v8::Isolate* isolate, ScriptResource* resource, ScriptStreamer* streamer, CachedMetadataHandler* cacheHandler, AccessControlStatus corsStatus, V8CacheOptions cacheOptions, bool isInternalScript)
 {
     TRACE_EVENT1("v8", "v8.compile", "fileName", fileName.utf8());
     TRACE_EVENT_SCOPED_SAMPLING_STATE("v8", "V8Compile");
 
     ASSERT(!streamer || resource);
     ASSERT(!resource || resource->cacheHandler() == cacheHandler);
 
@@ skipping 133 matching lines @@
 {
     return cacheTag(CacheTagParser, cacheHandler);
 }
 
 unsigned V8ScriptRunner::tagForCodeCache(CachedMetadataHandler* cacheHandler)
 {
     return cacheTag(CacheTagCode, cacheHandler);
 }
 
 } // namespace blink