tree ecef96556fce37b766d5dcc47a5e58908e9ded9a
parent 3fabfc0bd1920c5685890f7d0f534b7706987385
author John Stiles <johnstiles@google.com> 1601059244 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1601069200 +0000

Disallow assignment to unfoldable ternaries in SkSL.

GLSL does not support assigning to ternaries, and will fail to compile
and/or generate non-functional shaders if we pass in a shader that tries
to assign into a ternary expression.

If SkSL is able to completely eliminate the ternary (e.g. if it boils
down to a simple `true ? x : y` or `false ? x : y`), SkSL can strip out
the ternary entirely and generate valid GLSL. This case is harmless and
so it is still allowed.

Change-Id: I960f119fb9934f998697634e6c4e519cd77d3780
Bug: skia:10767
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319679
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>