Basic implementation of liveedit feature

Review URL: http://codereview.chromium.org/652027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4045 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/SConscript

@@ -249,6 +249,7 @@ math.js
 messages.js
 apinatives.js
 debug-delay.js
+liveedit-delay.js
 mirror-delay.js
 date-delay.js
 regexp-delay.js

src/compiler.cc

@@ -117,6 +117,14 @@ static Handle<Code> MakeCode(Handle<Context> context, CompilationInfo* info) {
 }
 
 
+#ifdef ENABLE_DEBUGGER_SUPPORT
+Handle<Code> MakeCodeForLiveEdit(CompilationInfo* info) {
+  Handle<Context> context = Handle<Context>::null();
+  return MakeCode(context, info);
+}
+#endif
+
+
 static Handle<JSFunction> MakeFunction(bool is_global,
                                        bool is_eval,
                                        Compiler::ValidationState validate,
@@ -224,7 +232,7 @@ static Handle<JSFunction> MakeFunction(bool is_global,
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // Notify debugger
-  Debugger::OnAfterCompile(script, fun);
+  Debugger::OnAfterCompile(script, Debugger::NO_AFTER_COMPILE_FLAGS);
 #endif
 
   return fun;

src/compiler.h

@@ -276,6 +276,13 @@ class Compiler : public AllStatic {
 };
 
 
+#ifdef ENABLE_DEBUGGER_SUPPORT
+
+Handle<Code> MakeCodeForLiveEdit(CompilationInfo* info);
+
+#endif
+
+
 // During compilation we need a global list of handles to constants
 // for frame elements.  When the zone gets deleted, we make sure to
 // clear this list of handles as well.

src/debug-delay.js

@@ -1251,7 +1251,9 @@ DebugCommandProcessor.prototype.processDebugJSONRequest = function(json_request)
       } else if (request.command == 'version') {
         this.versionRequest_(request, response);
       } else if (request.command == 'profile') {
-        this.profileRequest_(request, response);
+          this.profileRequest_(request, response);
+      } else if (request.command == 'changelive') {
+          this.changeLiveRequest_(request, response);
       } else {
         throw new Error('Unknown command "' + request.command + '" in request');
       }
@@ -1954,6 +1956,43 @@ DebugCommandProcessor.prototype.profileRequest_ = function(request, response) {
 };
 
 
+DebugCommandProcessor.prototype.changeLiveRequest_ = function(request, response) {
+  if (!Debug.LiveEditChangeScript) {
+    return response.failed('LiveEdit feature is not supported');
+  }
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+  var script_id = request.arguments.script_id;
+  var change_pos = parseInt(request.arguments.change_pos);
+  var change_len = parseInt(request.arguments.change_len);
+  var new_string = request.arguments.new_string;
+  if (!IS_STRING(new_string)) {
+    response.failed('Argument "new_string" is not a string value');
+    return;
+  }
+  
+  var scripts = %DebugGetLoadedScripts();
+
+  var the_script = null;
+  for (var i = 0; i < scripts.length; i++) {
+    if (scripts[i].id == script_id) {
+      the_script = scripts[i];
+    }
+  }
+  if (!the_script) {
+    response.failed('Script not found');
+    return;
+  }
+  
+  var change_log = new Array();
+  Debug.LiveEditChangeScript(the_script, change_pos, change_len, new_string,
+                             change_log);
+      
+  response.body = {change_log: change_log};
+};
+
+
 // Check whether the previously processed command caused the VM to become
 // running.
 DebugCommandProcessor.prototype.isRunning = function() {

src/debug.cc

@@ -757,6 +757,12 @@ bool Debug::Load() {
   bool caught_exception =
       !CompileDebuggerScript(Natives::GetIndex("mirror")) ||
       !CompileDebuggerScript(Natives::GetIndex("debug"));
+
+  if (FLAG_enable_liveedit) {
+    caught_exception = caught_exception ||
+        !CompileDebuggerScript(Natives::GetIndex("liveedit"));
+  }
+
   Debugger::set_compiling_natives(false);
 
   // Make sure we mark the debugger as not loading before we might
@@ -1963,7 +1969,8 @@ void Debugger::OnBeforeCompile(Handle<Script> script) {
 
 
 // Handle debugger actions when a new script is compiled.
-void Debugger::OnAfterCompile(Handle<Script> script, Handle<JSFunction> fun) {
+void Debugger::OnAfterCompile(Handle<Script> script,
+                              AfterCompileFlags after_compile_flags) {
   HandleScope scope;
 
   // Add the newly compiled script to the script cache.
@@ -2010,7 +2017,7 @@ void Debugger::OnAfterCompile(Handle<Script> script, Handle<JSFunction> fun) {
     return;
   }
   // Bail out based on state or if there is no listener for this event
-  if (in_debugger) return;
+  if (in_debugger && (after_compile_flags & SEND_WHEN_DEBUGGING) == 0) return;
   if (!Debugger::EventActive(v8::AfterCompile)) return;
 
   // Create the compile state object.

src/debug.h

@@ -604,8 +604,13 @@ class Debugger {
   static void OnDebugBreak(Handle<Object> break_points_hit, bool auto_continue);
   static void OnException(Handle<Object> exception, bool uncaught);
   static void OnBeforeCompile(Handle<Script> script);
+
+  enum AfterCompileFlags {
+    NO_AFTER_COMPILE_FLAGS,
+    SEND_WHEN_DEBUGGING
+  };
   static void OnAfterCompile(Handle<Script> script,
-                           Handle<JSFunction> fun);
+                             AfterCompileFlags after_compile_flags);
   static void OnNewFunction(Handle<JSFunction> fun);
   static void OnScriptCollected(int id);
   static void ProcessDebugEvent(v8::DebugEvent event,

src/flag-definitions.h

@@ -163,6 +163,7 @@ DEFINE_bool(trace_debug_json, false, "trace debugging JSON request/response")
 DEFINE_bool(debugger_auto_break, true,
             "automatically set the debug break flag when debugger commands are "
             "in the queue")
+DEFINE_bool(enable_liveedit, true, "enable liveedit experimental feature")
 
 // frames.cc
 DEFINE_int(max_stack_trace_source_length, 300,

src/liveedit.h

@@ -73,6 +73,28 @@ class LiveEditFunctionTracker {
   static bool IsActive();
 };
 
+#ifdef ENABLE_DEBUGGER_SUPPORT
+
+class LiveEdit : AllStatic {
+ public:
+  static JSArray* GatherCompileInfo(Handle<Script> script,
+                                    Handle<String> source);
+
+  static void WrapSharedFunctionInfos(Handle<JSArray> array);
+
+  static void ReplaceFunctionCode(Handle<JSArray> new_compile_info_array,
+                                  Handle<JSArray> shared_info_array);
+
+  static void RelinkFunctionToScript(Handle<JSArray> shared_info_array,
+                                     Handle<Script> script_handle);
+
+  static void PatchFunctionPositions(Handle<JSArray> shared_info_array,
+                                     Handle<JSArray> position_change_array);
+};
+
+#endif  // ENABLE_DEBUGGER_SUPPORT
+
+
 } }  // namespace v8::internal
 
 #endif /* V*_LIVEEDIT_H_ */

src/runtime.cc

@@ -38,6 +38,7 @@
 #include "debug.h"
 #include "execution.h"
 #include "jsregexp.h"
+#include "liveedit.h"
 #include "parser.h"
 #include "platform.h"
 #include "runtime.h"
@@ -8291,6 +8292,157 @@ static Object* Runtime_FunctionGetInferredName(Arguments args) {
   return f->shared()->inferred_name();
 }
 
+
+static int FindSharedFunctionInfosForScript(Script* script,
+                                     FixedArray* buffer) {
+  AssertNoAllocation no_allocations;
+
+  int counter = 0;
+  int buffer_size = buffer->length();
+  HeapIterator iterator;
+  for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
+    ASSERT(obj != NULL);
+    if (!obj->IsSharedFunctionInfo()) {
+      continue;
+    }
+    SharedFunctionInfo* shared = SharedFunctionInfo::cast(obj);
+    if (shared->script() != script) {
+      continue;
+    }
+    if (counter < buffer_size) {
+      buffer->set(counter, shared);
+    }
+    counter++;
+  }
+  return counter;
+}
+
+// For a script finds all SharedFunctionInfo's in the heap that points
+// to this script. Returns JSArray of SharedFunctionInfo wrapped
+// in OpaqueReferences.
+static Object* Runtime_LiveEditFindSharedFunctionInfosForScript(
+    Arguments args) {
+  ASSERT(args.length() == 1);
+  HandleScope scope;
+  CONVERT_CHECKED(JSValue, script_value, args[0]);
+
+  Handle<Script> script = Handle<Script>(Script::cast(script_value->value()));
+
+  const int kBufferSize = 32;
+
+  Handle<FixedArray> array;
+  array = Factory::NewFixedArray(kBufferSize);
+  int number = FindSharedFunctionInfosForScript(*script, *array);
+  if (number > kBufferSize) {
+    array = Factory::NewFixedArray(number);
+    FindSharedFunctionInfosForScript(*script, *array);
+  }
+
+  Handle<JSArray> result = Factory::NewJSArrayWithElements(array);
+  result->set_length(Smi::FromInt(number));
+
+  LiveEdit::WrapSharedFunctionInfos(result);
+
+  return *result;
+}
+
+// For a script calculates compilation information about all its functions.
+// The script source is explicitly specified by the second argument.
+// The source of the actual script is not used, however it is important that
+// all generated code keeps references to this particular instance of script.
+// Returns a JSArray of compilation infos. The array is ordered so that
+// each function with all its descendant is always stored in a continues range
+// with the function itself going first. The root function is a script function.
+static Object* Runtime_LiveEditGatherCompileInfo(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_CHECKED(JSValue, script, args[0]);
+  CONVERT_ARG_CHECKED(String, source, 1);
+  Handle<Script> script_handle = Handle<Script>(Script::cast(script->value()));
+
+  JSArray* result =  LiveEdit::GatherCompileInfo(script_handle, source);
+
+  if (Top::has_pending_exception()) {
+    return Failure::Exception();
+  }
+
+  return result;
+}
+
+// Changes the source of the script to a new_source and creates a new
+// script representing the old version of the script source.
+static Object* Runtime_LiveEditReplaceScript(Arguments args) {
+  ASSERT(args.length() == 3);
+  HandleScope scope;
+  CONVERT_CHECKED(JSValue, original_script_value, args[0]);
+  CONVERT_ARG_CHECKED(String, new_source, 1);
+  CONVERT_ARG_CHECKED(String, old_script_name, 2);
+  Handle<Script> original_script =
+      Handle<Script>(Script::cast(original_script_value->value()));
+
+  Handle<String> original_source(String::cast(original_script->source()));
+
+  original_script->set_source(*new_source);
+  Handle<Script> old_script = Factory::NewScript(original_source);
+  old_script->set_name(*old_script_name);
+  old_script->set_line_offset(original_script->line_offset());
+  old_script->set_column_offset(original_script->column_offset());
+  old_script->set_data(original_script->data());
+  old_script->set_type(original_script->type());
+  old_script->set_context_data(original_script->context_data());
+  old_script->set_compilation_type(original_script->compilation_type());
+  old_script->set_eval_from_shared(original_script->eval_from_shared());
+  old_script->set_eval_from_instructions_offset(
+      original_script->eval_from_instructions_offset());
+
+
+  Debugger::OnAfterCompile(old_script, Debugger::SEND_WHEN_DEBUGGING);
+
+  return *(GetScriptWrapper(old_script));
+}
+
+// Replaces code of SharedFunctionInfo with a new one.
+static Object* Runtime_LiveEditReplaceFunctionCode(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSArray, new_compile_info, 0);
+  CONVERT_ARG_CHECKED(JSArray, shared_info, 1);
+
+  LiveEdit::ReplaceFunctionCode(new_compile_info, shared_info);
+
+  return Heap::undefined_value();
+}
+
+// Connects SharedFunctionInfo to another script.
+static Object* Runtime_LiveEditRelinkFunctionToScript(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSArray, shared_info_array, 0);
+  CONVERT_ARG_CHECKED(JSValue, script_value, 1);
+  Handle<Script> script = Handle<Script>(Script::cast(script_value->value()));
+
+  LiveEdit::RelinkFunctionToScript(shared_info_array, script);
+
+  return Heap::undefined_value();
+}
+
+// Updates positions of a shared function info (first parameter) according
+// to script source change. Text change is described in second parameter as
+// array of groups of 3 numbers:
+// (change_begin, change_end, change_end_new_position).
+// Each group describes a change in text; groups are sorted by change_begin.
+static Object* Runtime_LiveEditPatchFunctionPositions(Arguments args) {
+  ASSERT(args.length() == 2);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
+  CONVERT_ARG_CHECKED(JSArray, position_change_array, 1);
+
+  LiveEdit::PatchFunctionPositions(shared_array, position_change_array);
+
+  return Heap::undefined_value();
+}
+
+
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #ifdef ENABLE_LOGGING_AND_PROFILING

src/runtime.h

@@ -325,7 +325,13 @@ namespace internal {
   F(SystemBreak, 0, 1) \
   F(DebugDisassembleFunction, 1, 1) \
   F(DebugDisassembleConstructor, 1, 1) \
-  F(FunctionGetInferredName, 1, 1)
+  F(FunctionGetInferredName, 1, 1) \
+  F(LiveEditFindSharedFunctionInfosForScript, 1, 1) \
+  F(LiveEditGatherCompileInfo, 2, 1) \
+  F(LiveEditReplaceScript, 3, 1) \
+  F(LiveEditReplaceFunctionCode, 2, 1) \
+  F(LiveEditRelinkFunctionToScript, 2, 1) \
+  F(LiveEditPatchFunctionPositions, 2, 1)
 #else
 #define RUNTIME_FUNCTION_LIST_DEBUGGER_SUPPORT(F)
 #endif

test/mjsunit/debug-liveedit-1.js

+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --expose-debug-as debug
+// Get the Debug object exposed from the debug context global object.
+
+Debug = debug.Debug
+
+eval("var something1 = 25; "
+     + " function ChooseAnimal() { return          'Cat';          } "
+     + " ChooseAnimal.Helper = function() { return 'Help!'; }");
+
+assertEquals("Cat", ChooseAnimal());
+
+var script = Debug.findScript(ChooseAnimal);
+
+var orig_animal = "Cat";
+var patch_pos = script.source.indexOf(orig_animal);
+var new_animal_patch = "Cap' + 'y' + 'bara";
+
+var change_log = new Array();
+Debug.LiveEditChangeScript(script, patch_pos, orig_animal.length, new_animal_patch, change_log);
+
+assertEquals("Capybara", ChooseAnimal());

test/mjsunit/debug-liveedit-2.js

+// Copyright 2010 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --expose-debug-as debug
+// Get the Debug object exposed from the debug context global object.
+
+
+Debug = debug.Debug
+
+
+eval(
+    "function ChooseAnimal(p) {\n " +
+    "  if (p == 7) {\n" + // Use p
+    "    return;\n" +
+    "  }\n" +
+    "  return function Chooser() {\n" +
+    "    return 'Cat';\n" +
+    "  };\n" +
+    "}\n"
+);
+
+var old_closure = ChooseAnimal(19);
+
+assertEquals("Cat", old_closure());
+
+var script = Debug.findScript(ChooseAnimal);
+
+var orig_animal = "'Cat'";
+var patch_pos = script.source.indexOf(orig_animal);
+var new_animal_patch = "'Capybara' + p";
+
+// We patch innermost function "Chooser".
+// However, this does not actually patch existing "Chooser" instances,
+// because old value of parameter "p" was not saved.
+// Instead it patches ChooseAnimal.
+var change_log = new Array();
+Debug.LiveEditChangeScript(script, patch_pos, orig_animal.length, new_animal_patch, change_log);
+print("Change log: " + JSON.stringify(change_log) + "\n");
+
+var new_closure = ChooseAnimal(19);
+// New instance of closure is patched.
+assertEquals("Capybara19", new_closure());
+
+// Old instance of closure is not patched.
+assertEquals("Cat", old_closure());
+

test/mjsunit/debug-script.js

@@ -52,7 +52,7 @@ for (i = 0; i < scripts.length; i++) {
 }
 
 // This has to be updated if the number of native scripts change.
-assertEquals(12, named_native_count);
+assertEquals(13, named_native_count);
 // If no snapshot is used, only the 'gc' extension is loaded.
 // If snapshot is used, all extensions are cached in the snapshot.
 assertTrue(extension_count == 1 || extension_count == 5);

tools/gyp/v8.gyp

@@ -562,6 +562,7 @@
           '../../src/messages.js',
           '../../src/apinatives.js',
           '../../src/debug-delay.js',
+          '../../src/liveedit-delay.js',
           '../../src/mirror-delay.js',
           '../../src/date-delay.js',
           '../../src/json-delay.js',

tools/visual_studio/js2c.cmd

@@ -3,4 +3,4 @@ set SOURCE_DIR=%1
 set TARGET_DIR=%2
 set PYTHON="..\..\..\third_party\python_24\python.exe"
 if not exist %PYTHON% set PYTHON=python.exe
-%PYTHON% ..\js2c.py %TARGET_DIR%\natives.cc %TARGET_DIR%\natives-empty.cc CORE %SOURCE_DIR%\macros.py %SOURCE_DIR%\runtime.js %SOURCE_DIR%\v8natives.js %SOURCE_DIR%\array.js %SOURCE_DIR%\string.js %SOURCE_DIR%\uri.js %SOURCE_DIR%\math.js %SOURCE_DIR%\messages.js %SOURCE_DIR%\apinatives.js %SOURCE_DIR%\debug-delay.js %SOURCE_DIR%\mirror-delay.js %SOURCE_DIR%\date-delay.js %SOURCE_DIR%\regexp-delay.js %SOURCE_DIR%\json-delay.js
+%PYTHON% ..\js2c.py %TARGET_DIR%\natives.cc %TARGET_DIR%\natives-empty.cc CORE %SOURCE_DIR%\macros.py %SOURCE_DIR%\runtime.js %SOURCE_DIR%\v8natives.js %SOURCE_DIR%\array.js %SOURCE_DIR%\string.js %SOURCE_DIR%\uri.js %SOURCE_DIR%\math.js %SOURCE_DIR%\messages.js %SOURCE_DIR%\apinatives.js %SOURCE_DIR%\debug-delay.js %SOURCE_DIR%\liveedit-delay.js %SOURCE_DIR%\mirror-delay.js %SOURCE_DIR%\date-delay.js %SOURCE_DIR%\regexp-delay.js %SOURCE_DIR%\json-delay.js

tools/visual_studio/v8.vcproj

@@ -142,6 +142,10 @@
 				RelativePath="..\..\src\debug-delay.js"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\liveedit-delay.js"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\macros.py"
 				>

tools/visual_studio/v8_arm.vcproj

@@ -142,6 +142,10 @@
 				RelativePath="..\..\src\debug-delay.js"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\liveedit-delay.js"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\macros.py"
 				>

tools/visual_studio/v8_x64.vcproj

@@ -142,6 +142,10 @@
 				RelativePath="..\..\src\debug-delay.js"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\liveedit-delay.js"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\macros.py"
 				>