[runtime] set AsyncFunctionNext/Throw to adapt arguments

src/frames.cc

 // Copyright 2012 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/frames.h"
 
 #include <sstream>
 
 #include "src/ast/ast.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 816 matching lines @@
 
 Code* JavaScriptFrame::unchecked_code() const {
   return function()->code();
 }
 
 
 int JavaScriptFrame::GetNumberOfIncomingArguments() const {
   DCHECK(can_access_heap_objects() &&
          isolate()->heap()->gc_state() == Heap::NOT_IN_GC);
 
-  return function()->shared()->internal_formal_parameter_count();
+  int param_count = function()->shared()->internal_formal_parameter_count();
+  if (param_count == SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
+    param_count = function()->shared()->length();
+  }
+  return param_count;

[Dan Ehrenberg, 2016/05/18 18:58:02]

Why is this change needed?

[caitp (gmail), 2016/05/18 19:03:43]

for anything with DontAdaptArguments() called on the shared function info, it
has this sentinel value (which is -1) --- so this breaks stuff.

AsyncFunctionNext/Throw don't (and shouldn't) need to adapt arguments, though.

An alternative fix would be to just make these functions adapt arguments (which
would add a few extra test/branches each time they're called --- not too worried
about that), but this is technically broken for every case that doesn't apply
arguments.

 }
 
 
 Address JavaScriptFrame::GetCallerStackPointer() const {
   return fp() + StandardFrameConstants::kCallerSPOffset;
 }
 
 
 void JavaScriptFrame::GetFunctions(List<JSFunction*>* functions) const {
   DCHECK(functions->length() == 0);
@@ skipping 944 matching lines @@
   for (StackFrameIterator it(isolate); !it.done(); it.Advance()) {
     StackFrame* frame = AllocateFrameCopy(it.frame(), zone);
     list.Add(frame, zone);
   }
   return list.ToVector();
 }
 
 
 }  // namespace internal
 }  // namespace v8