Do not use guarded cid on externalizable cid-s (one and two byte strings).

Do not use guarded cid on externalizable cid-s (one and two byte strings). An externalizable object can change its type on the fly and therefore we cannot rely on the information obntained while storing into the field.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=25893

[Vyacheslav Egorov (Google), 2013-08-07 17:56:09]

LGTM! Nice catch.

https://codereview.chromium.org/22314017/diff/6001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/22314017/diff/6001/runtime/vm/object.h#newcod...
runtime/vm/object.h:1964: intptr_t guarded_cid() const {
Please add assertion in the place where we infer CompileType for LoadField.

[srdjan, 2013-08-07 18:27:48]

PTAL

https://codereview.chromium.org/22314017/diff/6001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/22314017/diff/6001/runtime/vm/object.h#newcod...
runtime/vm/object.h:1964: intptr_t guarded_cid() const {
On 2013/08/07 17:56:09, Vyacheslav Egorov (Google) wrote:
> Please add assertion in the place where we infer CompileType for LoadField.

Done.

[Vyacheslav Egorov (Google), 2013-08-07 18:31:03]

still lgtm

https://codereview.chromium.org/22314017/diff/13001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/22314017/diff/13001/runtime/vm/object.h#newco...
runtime/vm/object.h:6002: return
*(reinterpret_cast<intptr_t*>(native_fields->ptr()->data_) + index);
nit: you can use array syntax for this

reinterpret_cast<intptr_t*>(native_fields->ptr()->data_)[index]

(though I don't see how it is related to this CL).

[srdjan, 2013-08-07 18:38:16]

https://codereview.chromium.org/22314017/diff/13001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/22314017/diff/13001/runtime/vm/object.h#newco...
runtime/vm/object.h:6002: return
*(reinterpret_cast<intptr_t*>(native_fields->ptr()->data_) + index);
On 2013/08/07 18:31:03, Vyacheslav Egorov (Google) wrote:
> nit: you can use array syntax for this
> 
> reinterpret_cast<intptr_t*>(native_fields->ptr()->data_)[index]
> 
> (though I don't see how it is related to this CL).

Forwarded your comment to the CL that changed that line.

[srdjan, 2013-08-07 18:56:52]

Committed patchset #3 manually as r25893 (presubmit successful).