No gcc, please don't optimize away the stack overflow check.

No gcc, please don't optimize away the stack overflow check.

Fixes language/issue22159_test for release + noopt.

BUG=http://dartbug.com/24659
R=regis@google.com

Committed: https://github.com/dart-lang/sdk/commit/1481dde8624043fa0e230bcd1d9cd6fcef2c95bc

[rmacnak, 2015-12-12 00:47:25]

rmacnak@google.com changed reviewers:
+ regis@google.com

[rmacnak, 2015-12-12 00:47:26]

Strangely adding volatile to the local in GetCurrentStackPointer does not fix
things, which I would expected to work because the undefined behavior here is
comparing the address of the local. I guess gcc only interprets that use of
volatile to prevent the local from being removed, still tracks that comparing
its value is undefined behavior, so marking the variable that is compared is
necessary.

[regis, 2015-12-12 00:58:50]

lgtm, although somewhat brittle. Using inline assembly would be more robust.

[rmacnak, 2015-12-14 17:20:13]

Description was changed from

==========
No gcc, please don't optimize away the stack overflow check.

Fixes language/issue22159_test for release + noopt.

BUG=http://dartbug.com/24659
==========

to

==========
No gcc, please don't optimize away the stack overflow check.

Fixes language/issue22159_test for release + noopt.

BUG=http://dartbug.com/24659
R=regis@google.com

Committed:
https://github.com/dart-lang/sdk/commit/1481dde8624043fa0e230bcd1d9cd6fcef2c95bc
==========

[rmacnak, 2015-12-14 17:20:14]

Committed patchset #1 (id:1) manually as
1481dde8624043fa0e230bcd1d9cd6fcef2c95bc (presubmit successful).