According to the GLSL ES 3.20, GLSL 4.50, and GLSL 1.20 specs:
"To force all output variables to be invariant, use the pragma
#pragma STDGL invariant(all)
before all declarations in a shader."
Notably, this is only supposed to affect output variables. Furthermore,
"Only variables output from a shader can be candidates for invariance."
It looks like this has been wrong since we first supported the pragma in
2011 (commit 86b4398cd1).
Fixes dEQP-GLES2.functional.shaders.preprocessor.pragmas.pragma_fragment.
v2: Now that all cases are identical (other than compute shaders, which
have no output variables anyway), we can drop the switch statement
entirely. We also don't need the current_function == NULL check;
this was a hold over from when we had a single var_mode_out for both
function parameters and shader varyings, in the bad old days.
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
688d695868