[Piglit] [PATCH] es2_compat: run glReleaseShaderCompiler and use a builtin

[Timothy Arceri]

On Sat, 2016-02-06 at 15:35 -0500, Ilia Mirkin wrote:
> All that mesa does when releasing the shader compiler is clear its
> builtins list. So make sure to use a builtin, and release the
> compiler
> sooner, to trigger a bug in mesa.
> 
> This code sequence is hit by some core Android component.
> 
> Reported-by: Rob Herring <robh at kernel.org>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  .../arb_es2_compatibility-
> releaseshadercompiler.c                     | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/spec/arb_es2_compatibility/arb_es2_compatibility-
> releaseshadercompiler.c
> b/tests/spec/arb_es2_compatibility/arb_es2_compatibility-
> releaseshadercompiler.c
> index b5c476e..0abdb5d 100644
> --- a/tests/spec/arb_es2_compatibility/arb_es2_compatibility-
> releaseshadercompiler.c
> +++ b/tests/spec/arb_es2_compatibility/arb_es2_compatibility-
> releaseshadercompiler.c
> @@ -55,7 +55,7 @@ static const char fs_text[] =
>  	"#version 100\n"
>  	"uniform mediump vec4 color;\n"
>  	"void main () {\n"
> -	"    gl_FragColor = color;\n"
> +	"    gl_FragColor = clamp(color, vec4(0), vec4(1));\n"
>  	"}\n"
>  	;
>  
> @@ -67,6 +67,7 @@ draw(const float *color, float x_offset)
>  	GLint offset_location;
>  
>  	prog = piglit_build_simple_program(vs_text, fs_text);
> +	glReleaseShaderCompiler();
>  
>  	glBindAttribLocation(prog, 0, "vertex");
>  	glLinkProgram(prog);
> @@ -92,7 +93,6 @@ piglit_display(void)
>  	float blue[] = {0.0, 0.0, 1.0, 0.0};
>  
>  	draw(green, 0.0f);
> -	glReleaseShaderCompiler();
>  	draw(blue, 1.0f);
>  
>  	pass &= piglit_probe_pixel_rgba(piglit_width / 4,
> piglit_height / 2,


I really think this should be a new subtest rather then moving things
around in the existing test. It's not clear at all that you are testing
that builtins still work from just looking at the code after the
change.

Also it no longer checks for:

glReleaseShaderCompiler()
glCompileShader()

Its now only checking:

glReleaseShaderCompiler()
glLinkProgram()
glCompileShader()

Which seems could make a difference.