Implement new Function.prototype.toString and fix CreateDynamicFunction parsing

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 13343 matching lines @@
     return isolate->factory()->NewSubString(
         script_source, Handle<Smi>::cast(class_start_position)->value(),
         Handle<Smi>::cast(class_end_position)->value());
   }
 
   // Check if we have source code for the {function}.
   if (!shared_info->HasSourceCode()) {
     return NativeCodeFunctionSourceString(shared_info);
   }
 
+  if (FLAG_harmony_function_tostring) {
+    return Handle<String>::cast(shared_info->GetSourceCodeHarmony());
+  }
+
   IncrementalStringBuilder builder(isolate);
   FunctionKind kind = shared_info->kind();
   if (!IsArrowFunction(kind)) {
     if (IsConciseMethod(kind)) {
       if (IsGeneratorFunction(kind)) {
         builder.AppendCharacter('*');
       } else if (IsAsyncFunction(kind)) {
         builder.AppendCString("async ");
       }
     } else {
@@ skipping 418 matching lines @@
 }
 
 
 Handle<Object> SharedFunctionInfo::GetSourceCode() {
   if (!HasSourceCode()) return GetIsolate()->factory()->undefined_value();
   Handle<String> source(String::cast(Script::cast(script())->source()));
   return GetIsolate()->factory()->NewSubString(
       source, start_position(), end_position());
 }
 
+Handle<Object> SharedFunctionInfo::GetSourceCodeHarmony() {
+  Isolate* isolate = GetIsolate();
+  if (!HasSourceCode()) return isolate->factory()->undefined_value();
+  Handle<String> script_source(String::cast(Script::cast(script())->source()));
+  int start_pos = function_token_position();
+  if (start_pos == kNoSourcePosition) start_pos = start_position();
+  return isolate->factory()->NewSubString(script_source, start_pos,
+                                          end_position());
+}
 
 bool SharedFunctionInfo::IsInlineable() {
   // Check that the function has a script associated with it.
   if (!script()->IsScript()) return false;
   return !optimization_disabled();
 }
 
 
 int SharedFunctionInfo::SourceSize() {
   return end_position() - start_position();
@@ skipping 6704 matching lines @@
       // depend on this.
       return DICTIONARY_ELEMENTS;
     }
     DCHECK_LE(kind, LAST_ELEMENTS_KIND);
     return kind;
   }
 }
 
 }  // namespace internal
 }  // namespace v8