[waffle] [PATCH 1/2] tests/gl_basic: Make GL symbol queries more robust

[Chad Versace]

Emil, this patch fixes the regressions caused by your patch (still
uncommitted):

  [PATCH 07/13] wegl: untangle dl_can_open() and support_api()

On Tue 14 Jun 2016, Chad Versace wrote:
> The rules that dictate how to properly query a GL symbol are complex.
> The rules depend on the OS, on the winsys API, and even on the
> particular driver being used. The rules differ between EGL 1.4 and EGL
> 1.5; differ between Linux, Windows, and Mac; and differ between Mesa and
> Mali.
> 
> gl_basic_test didn't try very hard when querying a GL symbol. It tried
> only dlsym. If dlsym failed, then the test failed.
> 
> Make gl_basic_test more robust by falling back to
> waffle_get_proc_address() whenever dlsym fails.
> 
> Suggested-by: Emil Velikov <emil.l.velikov at collabora.co.uk>
> Signed-off-by: Chad Versace <chad.versace at intel.com>
> ---
>  tests/functional/gl_basic_test.c | 55 +++++++++++++++++++++++++---------------
>  1 file changed, 34 insertions(+), 21 deletions(-)
> 
> diff --git a/tests/functional/gl_basic_test.c b/tests/functional/gl_basic_test.c
> index 7af2229..4a90dfd 100644
> --- a/tests/functional/gl_basic_test.c
> +++ b/tests/functional/gl_basic_test.c
> @@ -169,19 +169,36 @@ teardown(void **state)
>      return 0;
>  }
>  
> -static int32_t
> -libgl_from_context_api(int32_t waffle_context_api)
> +// The rules that dictate how to properly query a GL symbol are complex. The
> +// rules depend on the OS, on the winsys API, and even on the particular driver
> +// being used. The rules differ between EGL 1.4 and EGL 1.5; differ between
> +// Linux, Windows, and Mac; and differ between Mesa and Mali.
> +//
> +// This function hides that complexity with a naive heuristic: try, then try
> +// again.
> +static void *
> +get_gl_symbol(enum waffle_enum context_api, const char *name)
>  {
> -    switch (waffle_context_api) {
> -        case WAFFLE_CONTEXT_OPENGL:     return WAFFLE_DL_OPENGL;
> -        case WAFFLE_CONTEXT_OPENGL_ES1: return WAFFLE_DL_OPENGL_ES1;
> -        case WAFFLE_CONTEXT_OPENGL_ES2: return WAFFLE_DL_OPENGL_ES2;
> -        case WAFFLE_CONTEXT_OPENGL_ES3: return WAFFLE_DL_OPENGL_ES3;
> -
> -        default:
> -            assert_true(0);
> -            return 0;
> +    void *sym = NULL;
> +    enum waffle_enum dl = 0;
> +
> +    switch (context_api) {
> +        case WAFFLE_CONTEXT_OPENGL: dl = WAFFLE_DL_OPENGL; break;
> +        case WAFFLE_CONTEXT_OPENGL_ES1: dl = WAFFLE_DL_OPENGL_ES1; break;
> +        case WAFFLE_CONTEXT_OPENGL_ES2: dl = WAFFLE_DL_OPENGL_ES2; break;
> +        case WAFFLE_CONTEXT_OPENGL_ES3: dl = WAFFLE_DL_OPENGL_ES3; break;
> +        default: assert_true(0); break;
> +    }
> +
> +    if (waffle_dl_can_open(dl)) {
> +        sym = waffle_dl_sym(dl, name);
>      }
> +
> +    if (!sym) {
> +        sym = waffle_get_proc_address(name);
> +    }
> +
> +    return sym;
>  }
>  
>  static int
> @@ -270,8 +287,6 @@ gl_basic_draw__(void **state, struct gl_basic_draw_args__ args)
>      bool context_debug = args.debug;
>      bool alpha = args.alpha;
>  
> -    int32_t libgl;
> -
>      int32_t config_attrib_list[64];
>      int i;
>  
> @@ -281,8 +296,6 @@ gl_basic_draw__(void **state, struct gl_basic_draw_args__ args)
>          0,
>      };
>  
> -    libgl = libgl_from_context_api(waffle_context_api);
> -
>      i = 0;
>      config_attrib_list[i++] = WAFFLE_CONTEXT_API;
>      config_attrib_list[i++] = waffle_context_api;
> @@ -353,12 +366,12 @@ gl_basic_draw__(void **state, struct gl_basic_draw_args__ args)
>      }
>  
>      // Get OpenGL functions.
> -    assert_true(glClear         = waffle_dl_sym(libgl, "glClear"));
> -    assert_true(glClearColor    = waffle_dl_sym(libgl, "glClearColor"));
> -    assert_true(glGetError      = waffle_dl_sym(libgl, "glGetError"));
> -    assert_true(glGetIntegerv   = waffle_dl_sym(libgl, "glGetIntegerv"));
> -    assert_true(glReadPixels    = waffle_dl_sym(libgl, "glReadPixels"));
> -    assert_true(glGetString     = waffle_dl_sym(libgl, "glGetString"));
> +    assert_true(glClear         = get_gl_symbol(waffle_context_api, "glClear"));
> +    assert_true(glClearColor    = get_gl_symbol(waffle_context_api, "glClearColor"));
> +    assert_true(glGetError      = get_gl_symbol(waffle_context_api, "glGetError"));
> +    assert_true(glGetIntegerv   = get_gl_symbol(waffle_context_api, "glGetIntegerv"));
> +    assert_true(glReadPixels    = get_gl_symbol(waffle_context_api, "glReadPixels"));
> +    assert_true(glGetString     = get_gl_symbol(waffle_context_api, "glGetString"));
>  
>      assert_true(waffle_make_current(ts->dpy, ts->window, ts->ctx));
>  
> -- 
> 2.9.0.rc2
>