tree a67a595cf047c0ab6576a14aaa3171ddbaf6523f
parent e9ae96cdcd74e3ab62fd34b071dcbe1cba4a285e
author John Stiles <johnstiles@google.com> 1652307253 -0400
committer SkCQ <skcq-be@skia-corp.google.com.iam.gserviceaccount.com> 1652309544 +0000

Prevent comma operator constant-folding or constant-expression-usage.

OpenGL docs specifically insist that the sequence (comma) operator
should not be treated as a constant-expression so that attempts to
declare multidimensional arrays with a comma will fail:
http://screen/vJEpAe9yNmbzZTm

(See "12.43 Sequence operator and constant expressions" in the OpenGL
ES3 documentation or read skia:13311 for details.)

In practice, we don't get much benefit from optimizing away unused
comma-expressions; it improves some synthetic tests, but realistically
this will not help Skia in any real-world scenario. The constant folder
no longer attempts this optimization, and comma-expressions are now
rejected in a constant-expression context.

Change-Id: Ic5dea6ff90e36614b548c1ce89a444e81da944ae
Bug: skia:13311
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/539565
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Arman Uguray <armansito@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>