Script streaming: don't produce (empty) cached data when debugger forces eagerness.

src/background-parsing-task.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/background-parsing-task.h"
 
 namespace v8 {
 namespace internal {
 
 BackgroundParsingTask::BackgroundParsingTask(
     StreamedSource* source, ScriptCompiler::CompileOptions options,
     int stack_size, Isolate* isolate)
     : source_(source), options_(options), stack_size_(stack_size) {
   // Prepare the data for the internalization phase and compilation phase, which
   // will happen in the main thread after parsing.
   source->info.Reset(new i::CompilationInfoWithZone(source->source_stream.get(),
                                                     source->encoding, isolate));
   source->info->MarkAsGlobal();
 
   // We don't set the context to the CompilationInfo yet, because the background
   // thread cannot do anything with it anyway. We set it just before compilation
   // on the foreground thread.
   DCHECK(options == ScriptCompiler::kProduceParserCache ||
          options == ScriptCompiler::kProduceCodeCache ||
          options == ScriptCompiler::kNoCompileOptions);
   source->allow_lazy =
       !i::Compiler::DebuggerWantsEagerCompilation(source->info.get());
+
+  if (!source->allow_lazy && options_ == ScriptCompiler::kProduceParserCache) {
+    // Producing cached data while parsing eagerly is not supported.
+    options_ = ScriptCompiler::kNoCompileOptions;
+  }
   source->hash_seed = isolate->heap()->HashSeed();
 }
 
 
 void BackgroundParsingTask::Run() {
   DisallowHeapAllocation no_allocation;
   DisallowHandleAllocation no_handles;
   DisallowHandleDereference no_deref;
 
   ScriptData* script_data = NULL;
@@ skipping 15 matching lines @@
   if (script_data != NULL) {
     source_->cached_data.Reset(new ScriptCompiler::CachedData(
         script_data->data(), script_data->length(),
         ScriptCompiler::CachedData::BufferOwned));
     script_data->ReleaseDataOwnership();
     delete script_data;
   }
 }
 }
 }  // namespace v8::internal