Make SharedFunctionInfo::GetSourceCodeHarmony GC-safe.

R=mlippautz@chromium.org

Bug: chromium:795856
Change-Id: I2a631a94e4bc0c000842923a962e812e0370b837
Reviewed-on: https://chromium-review.googlesource.com/832454
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50190}

src/objects.cc

@@ -13163,7 +13163,8 @@ Handle<String> JSFunction::ToString(Handle<JSFunction> function) {
   }
 
   if (FLAG_harmony_function_tostring) {
-    return Handle<String>::cast(shared_info->GetSourceCodeHarmony());
+    return Handle<String>::cast(
+        SharedFunctionInfo::GetSourceCodeHarmony(shared_info));
   }
 
   IncrementalStringBuilder builder(isolate);
@@ -13205,7 +13206,8 @@ Handle<String> JSFunction::ToString(Handle<JSFunction> function) {
     }
     builder.AppendCString(") {\n");
   }
-  builder.AppendString(Handle<String>::cast(shared_info->GetSourceCode()));
+  builder.AppendString(
+      Handle<String>::cast(SharedFunctionInfo::GetSourceCode(shared_info)));
   if (shared_info->is_wrapped()) {
     builder.AppendCString("\n}");
   }
@@ -13687,27 +13689,32 @@ bool SharedFunctionInfo::HasSourceCode() const {
          !reinterpret_cast<Script*>(script())->source()->IsUndefined(isolate);
 }
 
-
-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());
+// static
+Handle<Object> SharedFunctionInfo::GetSourceCode(
+    Handle<SharedFunctionInfo> shared) {
+  Isolate* isolate = shared->GetIsolate();
+  if (!shared->HasSourceCode()) return isolate->factory()->undefined_value();
+  Handle<String> source(String::cast(Script::cast(shared->script())->source()));
+  return isolate->factory()->NewSubString(source, shared->start_position(),
+                                          shared->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();
+// static
+Handle<Object> SharedFunctionInfo::GetSourceCodeHarmony(
+    Handle<SharedFunctionInfo> shared) {
+  Isolate* isolate = shared->GetIsolate();
+  if (!shared->HasSourceCode()) return isolate->factory()->undefined_value();
+  Handle<String> script_source(
+      String::cast(Script::cast(shared->script())->source()));
+  int start_pos = shared->function_token_position();
+  if (start_pos == kNoSourcePosition) start_pos = shared->start_position();
   Handle<String> source = isolate->factory()->NewSubString(
-      script_source, start_pos, end_position());
-  if (!is_wrapped()) return source;
+      script_source, start_pos, shared->end_position());
+  if (!shared->is_wrapped()) return source;
 
   IncrementalStringBuilder builder(isolate);
   builder.AppendCString("function (");
-  Handle<FixedArray> args(Script::cast(script())->wrapped_arguments());
+  Handle<FixedArray> args(Script::cast(shared->script())->wrapped_arguments());
   int argc = args->length();
   for (int i = 0; i < argc; i++) {
     if (i > 0) builder.AppendCString(", ");

src/objects/shared-function-info.h

@@ -339,8 +339,8 @@ class SharedFunctionInfo : public HeapObject {
 
   // [source code]: Source code for the function.
   bool HasSourceCode() const;
-  Handle<Object> GetSourceCode();
-  Handle<Object> GetSourceCodeHarmony();
+  static Handle<Object> GetSourceCode(Handle<SharedFunctionInfo> shared);
+  static Handle<Object> GetSourceCodeHarmony(Handle<SharedFunctionInfo> shared);
 
   // Tells whether this function should be subject to debugging.
   inline bool IsSubjectToDebugging();

src/runtime/runtime-function.cc

@@ -63,7 +63,9 @@ RUNTIME_FUNCTION(Runtime_FunctionGetSourceCode) {
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, function, 0);
   if (function->IsJSFunction()) {
-    return *Handle<JSFunction>::cast(function)->shared()->GetSourceCode();
+    Handle<SharedFunctionInfo> shared(
+        Handle<JSFunction>::cast(function)->shared());
+    return *SharedFunctionInfo::GetSourceCode(shared);
   }
   return isolate->heap()->undefined_value();
 }