skia2/tests/sksl/errors/CommasAsConstantExpressions.glsl
John Stiles 353e2c65c9 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>
2022-05-11 22:52:24 +00:00

13 lines
278 B
GLSL

### Compilation failed:
error: 1: array size must be an integer
int a[1, 2];
^^^^
error: 2: array size must be an integer
int b[(3, 4)];
^^^^^^
error: 3: 'const' variable initializer must be a constant expression
const int d = (5, 6);
^^^^^^
3 errors