tree c1ef8086e588509590e556b0156f354c6d9a5935
parent 262f24cdb80752b7a50452dc7f0ea941acdaf0f6
author John Stiles <johnstiles@google.com> 1613233551 -0500
committer John Stiles <johnstiles@google.com> 1613485729 +0000

Add test to demonstrate out-param semantics violation.

GLSL ES2 documentation on out parameters: "Evaluation of an out
parameter results in an l-value that is used to copy out a value when
the function returns."

The inliner does not do any alias checking when inlining an `out` param.
That is, passing the same variable to two separate `out` parameters
would not generate two distinct lvalues in the inlined code; it reuses
the same variable for each out-params in the inlined code.

(Amusingly, our CFG can fully optimize away this test code so it just
returns "red".)

Change-Id: Ib781d2cfdac54f01b6abe159af0c84ff24ff6976
Bug: skia:11326
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370256
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>