Add experimental support for tracing the state of the VM heap to a file

src/d8.cc

 // Copyright 2011 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 94 matching lines @@
 
 i::SmartArrayPointer<char> DumbLineEditor::Prompt(const char* prompt) {
   static const int kBufferSize = 256;
   char buffer[kBufferSize];
   printf("%s", prompt);
   char* str = fgets(buffer, kBufferSize, stdin);
   return i::SmartArrayPointer<char>(str ? i::StrDup(str) : str);
 }
 
 
+class FileHeapVisualizer : public v8::HeapVisualizer {
+ public:
+  explicit FileHeapVisualizer(const char* path) {
+    file_ = i::OS::FOpen(path, "w");
+  }
+
+  ~FileHeapVisualizer() {
+    if (file_ != NULL) fclose(file_);
+  }
+
+  void Write(const char* buf, int len) {
+    fwrite(reinterpret_cast<const void*>(buf), 1, len, file_);
+  }
+
+  bool open_succeeded() { return file_ != NULL; }
+
+ private:
+  FILE* file_;
+};
+
+
 CounterMap* Shell::counter_map_;
 i::OS::MemoryMappedFile* Shell::counters_file_ = NULL;
 CounterCollection Shell::local_counters_;
 CounterCollection* Shell::counters_ = &local_counters_;
 i::Mutex* Shell::context_mutex_(i::OS::CreateMutex());
 Persistent<Context> Shell::utility_context_;
 LineEditor* Shell::console = NULL;
 #endif  // V8_SHARED
 
 Persistent<Context> Shell::evaluation_context_;
@@ skipping 503 matching lines @@
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Start the in-process debugger if requested.
   if (i::FLAG_debugger && !i::FLAG_debugger_agent) {
     v8::Debug::SetDebugEventListener(HandleDebugEvent);
   }
 #endif  // ENABLE_DEBUGGER_SUPPORT
 }
 #endif  // V8_SHARED
 
-
 #ifdef COMPRESS_STARTUP_DATA_BZ2
 class BZip2Decompressor : public v8::StartupDataDecompressor {
  public:
   virtual ~BZip2Decompressor() { }
 
  protected:
   virtual int DecompressData(char* raw_data,
                              int* raw_data_size,
                              const char* compressed_data,
                              int compressed_data_size) {
@@ skipping 608 matching lines @@
       // Keep using the same context in the interactive shell.
       evaluation_context_ = context;
 #ifndef V8_SHARED
       // If the interactive debugger is enabled make sure to activate
       // it before running the files passed on the command line.
       if (i::FLAG_debugger) {
         InstallUtilityScript();
       }
 #endif  // V8_SHARED
     }
+
+    if (i::FLAG_trace_heap) {
+      FileHeapVisualizer* visualizer =
+          new FileHeapVisualizer(i::FLAG_trace_heap_file);
+      if (visualizer->open_succeeded()) {
+        RegisterHeapVisualizer(visualizer);
+      } else {
+        delete visualizer;
+      }
+    }
+
     {
       Context::Scope cscope(context);
       options.isolate_sources[0].Execute();
     }
     if (!options.last_run) {
       context.Dispose();
     }
 
 #ifndef V8_SHARED
     // Start preemption if threads have been created and preemption is enabled.
@@ skipping 80 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif