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 13240 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 395 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());
 }
 
+namespace {
+template <typename Char>
+Handle<Object> NormalizeLineTerminators(FlatStringReader* reader,
+                                        IncrementalStringBuilder* builder) {
+  for (int i = 0; i < reader->length(); i++) {
+    Char c = reader->Get<Char>(i);
+    if (c == '\r') {
+      // normalize CR or CRLF
+      builder->AppendCharacter('\n');
+      if (i + 1 < reader->length() && reader->Get<Char>(i + 1) == '\n') {
+        // also consume the LF in the CRLF
+        i++;
+      }
+    } else {
+      builder->Append<Char, Char>(c);
+    }
+  }
+  return builder->Finish().ToHandleChecked();
+}
+}  // namespace
+
+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();
+  Handle<String> function_source = isolate->factory()->NewSubString(
+      script_source, start_pos, end_position());
+  // normalize line terminators
+  FlatStringReader reader(isolate, function_source);
+  // TODO(jwolfe): we know the upper bound on the build is reader.length(). how
+  // to specify it?

[jwolfe, 2016/11/01 21:34:19]

this is an optional optimization we may want to do.

+  IncrementalStringBuilder builder(isolate);
+  if (function_source->IsOneByteRepresentationUnderneath()) {
+    return NormalizeLineTerminators<uint8_t>(&reader, &builder);
+  } else {
+    builder.ChangeEncoding();
+    return NormalizeLineTerminators<uc16>(&reader, &builder);
+  }
+}
 
 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 6532 matching lines @@
         ns, Accessors::ModuleNamespaceEntryInfo(isolate, name, attr))
         .Check();
   }
   JSObject::PreventExtensions(ns, THROW_ON_ERROR).ToChecked();
 
   return ns;
 }
 
 }  // namespace internal
 }  // namespace v8