ShaderVariable: separate fields for staticUse and active Thus far the compiler has used the "staticUse" flag to mark variables that should have rather been marked "active", meaning that the code may actually execute in a way that accesses the variable. There's a clear definition for this use of the term "active" in the GLES 3.0.5 spec, section 2.12.6, and in GLES 3.1 section 7.3.1. Having separate fields for recording static use and "activeness" of a variable is the first step to fixing this. According to the spec, usually only active resources should be considered when checking use against max limits. Also, only active uniforms get assigned a location. libANGLE code now correctly checks the active flag rather than the static use flag in these cases. The static use field still mirrors the active field for now, since some code in Chromium also needs to be fixed to use the active field correctly before the two can diverge. After Chromium is fixed, we can fix ANGLE so that static use information is recorded earlier during compilation and will accurately reflect whether variables are statically used. Currently the compiler only records variables once some static use may already have been pruned from the AST. BUG=angleproject:2262 TEST=angle_unittests, angle_end2end_tests Change-Id: I025bb71361246ae00c911a1f8b66ec045f665f29 Reviewed-on: https://chromium-review.googlesource.com/970962 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>