Fix VM crash when parsing what looks like a closure call during metadata evaluation.

Fix VM crash when parsing what looks like a closure call during metadata evaluation.

BUG=http://dartbug.com/17141
R=gbracha@google.com, hausner@google.com

Committed: https://code.google.com/p/dart/source/detail?r=33141

[gbracha, 2014-02-27 18:51:40]

test lgtm

[hausner, 2014-02-27 18:53:21]

Someone will scratch their head some time down the road if you don't add a
comment to your code. I am certainly doing so now.

https://codereview.chromium.org/180313003/diff/20001/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/180313003/diff/20001/runtime/vm/parser.cc#new...
runtime/vm/parser.cc:7667: return;
Can you please explain in a comment why it is necessary to return here when
parsing metadata, any why that is ok? Why do we not need to save the current
context?

[rmacnak, 2014-02-27 19:11:26]

https://codereview.chromium.org/180313003/diff/20001/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/180313003/diff/20001/runtime/vm/parser.cc#new...
runtime/vm/parser.cc:7667: return;
On 2014/02/27 18:53:22, hausner wrote:
> Can you please explain in a comment why it is necessary to return here when
> parsing metadata, any why that is ok? Why do we not need to save the current
> context?

Hm, actually this is dubious because it relies on the expression being noticed
as non-const later on. Hoisted the check to ParseSelectors so it fails early
with a more intention-revealing error message.

[hausner, 2014-02-27 22:50:25]

LGTM w/comment.

https://codereview.chromium.org/180313003/diff/60001/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/180313003/diff/60001/runtime/vm/parser.cc#new...
runtime/vm/parser.cc:8573: if (parsing_metadata_) {
It would still be good to have an explanation here why we need the special case
for parsing metadata.

[rmacnak, 2014-02-27 23:23:30]

https://codereview.chromium.org/180313003/diff/60001/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/180313003/diff/60001/runtime/vm/parser.cc#new...
runtime/vm/parser.cc:8573: if (parsing_metadata_) {
On 2014/02/27 22:50:25, hausner wrote:
> It would still be good to have an explanation here why we need the special
case
> for parsing metadata.

Done.

[rmacnak, 2014-02-27 23:24:16]

Committed patchset #5 manually as r33141 (presubmit successful).