mesa/st: remove redundant has_shareable_shaders from st_context

has_shareable_shaders is a direct copy of screen->caps.shareable_shaders.
Read the cap from the screen directly at each call site.

Fix st_format_test which was missing st_context.screen initialization,
exposed by this change.

Reviewed-by: Marek Olšák <maraeo@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41184>

src/mesa/state_tracker/st_atom_shader.c

@@ -133,7 +133,7 @@ st_update_fp( struct st_context *st )
       /* use memset, not an initializer to be sure all memory is zeroed */
       memset(&key, 0, sizeof(key));
 
-      key.st = st->has_shareable_shaders ? NULL : st;
+      key.st = st->screen->caps.shareable_shaders ? NULL : st;
 
       key.lower_flatshade = st->lower_flatshade &&
                             st->ctx->Light.ShadeModel == GL_FLAT;
@@ -219,7 +219,7 @@ st_update_vp( struct st_context *st )
 
       memset(&key, 0, sizeof(key));
 
-      key.st = st->has_shareable_shaders ? NULL : st;
+      key.st = st->screen->caps.shareable_shaders ? NULL : st;
 
       /* When this is true, we will add an extra input to the vertex
        * shader translation (for edgeflags), an extra output with
@@ -280,7 +280,7 @@ st_update_common_program(struct st_context *st, struct gl_program *prog,
    /* use memset, not an initializer to be sure all memory is zeroed */
    memset(&key, 0, sizeof(key));
 
-   key.st = st->has_shareable_shaders ? NULL : st;
+   key.st = st->screen->caps.shareable_shaders ? NULL : st;
 
    if (pipe_shader == MESA_SHADER_GEOMETRY ||
        pipe_shader == MESA_SHADER_TESS_EVAL) {

src/mesa/state_tracker/st_cb_bitmap.c

@@ -181,7 +181,7 @@ setup_render_state(struct gl_context *ctx,
    struct st_fp_variant_key key;
 
    memset(&key, 0, sizeof(key));
-   key.st = st->has_shareable_shaders ? NULL : st;
+   key.st = st->screen->caps.shareable_shaders ? NULL : st;
    key.bitmap = GL_TRUE;
    key.clamp_color = st->clamp_frag_color_in_shader &&
                      clamp_frag_color;

src/mesa/state_tracker/st_cb_drawpixels.c

@@ -1124,7 +1124,7 @@ get_color_fp_variant(struct st_context *st)
 
    memset(&key, 0, sizeof(key));
 
-   key.st = st->has_shareable_shaders ? NULL : st;
+   key.st = st->screen->caps.shareable_shaders ? NULL : st;
    key.drawpixels = 1;
    key.scaleAndBias = (ctx->Pixel.RedBias != 0.0 ||
                        ctx->Pixel.RedScale != 1.0 ||
@@ -1157,7 +1157,7 @@ get_color_index_fp_variant(struct st_context *st)
 
    memset(&key, 0, sizeof(key));
 
-   key.st = st->has_shareable_shaders ? NULL : st;
+   key.st = st->screen->caps.shareable_shaders ? NULL : st;
    key.drawpixels = 1;
    /* Since GL is always in RGBA mode MapColorFlag does not
     * affect GL_COLOR_INDEX format.

src/mesa/state_tracker/st_context.c

@@ -218,7 +218,7 @@ st_save_zombie_shader(struct st_context *st,
    struct st_zombie_shader_node *entry;
 
    /* we shouldn't be here if the driver supports shareable shaders */
-   assert(!st->has_shareable_shaders);
+   assert(!st->screen->caps.shareable_shaders);
 
    entry = MALLOC_STRUCT(st_zombie_shader_node);
    if (!entry)
@@ -571,7 +571,6 @@ st_create_context_priv(struct gl_context *ctx, struct pipe_context *pipe,
    st->force_persample_in_shader =
       screen->caps.sample_shading &&
       !screen->caps.force_persample_interp;
-   st->has_shareable_shaders = screen->caps.shareable_shaders;
    st->needs_texcoord_semantic =
       screen->caps.tgsi_texcoord;
    st->apply_texture_swizzle_to_border_color =
@@ -699,32 +698,32 @@ st_create_context_priv(struct gl_context *ctx, struct pipe_context *pipe,
 
    /* Set which shader types can be compiled at link time. */
    st->shader_has_one_variant[MESA_SHADER_VERTEX] =
-         st->has_shareable_shaders &&
+         st->screen->caps.shareable_shaders &&
          !st->clamp_vert_color_in_shader &&
          !st->lower_point_size &&
          (is_gles2 || !st->lower_ucp);
 
    st->shader_has_one_variant[MESA_SHADER_FRAGMENT] =
-         st->has_shareable_shaders &&
+         st->screen->caps.shareable_shaders &&
          !st->lower_flatshade &&
          (is_gles2 || !st->lower_alpha_test) &&
          !st->clamp_frag_color_in_shader &&
          !st->force_persample_in_shader &&
          (is_gles2 || !st->lower_two_sided_color);
 
-   st->shader_has_one_variant[MESA_SHADER_TESS_CTRL] = st->has_shareable_shaders;
+   st->shader_has_one_variant[MESA_SHADER_TESS_CTRL] = st->screen->caps.shareable_shaders;
    st->shader_has_one_variant[MESA_SHADER_TESS_EVAL] =
-         st->has_shareable_shaders &&
+         st->screen->caps.shareable_shaders &&
          !st->clamp_vert_color_in_shader &&
          !st->lower_point_size &&
          (is_gles2 || !st->lower_ucp);
 
    st->shader_has_one_variant[MESA_SHADER_GEOMETRY] =
-         st->has_shareable_shaders &&
+         st->screen->caps.shareable_shaders &&
          !st->clamp_vert_color_in_shader &&
          !st->lower_point_size &&
          (is_gles2 || !st->lower_ucp);
-   st->shader_has_one_variant[MESA_SHADER_COMPUTE] = st->has_shareable_shaders;
+   st->shader_has_one_variant[MESA_SHADER_COMPUTE] = st->screen->caps.shareable_shaders;
 
    if (!st->pipe->set_context_param || !util_thread_scheduler_enabled())
       st->thread_scheduler_disabled = true;

src/mesa/state_tracker/st_context.h

@@ -160,7 +160,6 @@ struct st_context
    bool force_compute_based_texture_transfer;
    bool force_specialized_compute_transfer;
    bool force_persample_in_shader;
-   bool has_shareable_shaders;
    bool has_multi_draw_indirect;
    bool has_indirect_partial_stride;
    bool has_occlusion_query;

src/mesa/state_tracker/st_program.c

@@ -237,7 +237,7 @@ delete_variant(struct st_context *st, struct st_variant *v, unsigned stage)
           ((struct st_common_variant*)v)->key.is_draw_shader) {
          /* Draw shader. */
          draw_delete_vertex_shader(st->draw, v->driver_shader);
-      } else if (st->has_shareable_shaders || v->st == st) {
+      } else if (st->screen->caps.shareable_shaders || v->st == st) {
          /* The shader's context matches the calling context, or we
           * don't care.
           */
@@ -1424,7 +1424,7 @@ st_destroy_program_variants(struct st_context *st)
    /* If shaders can be shared with other contexts, the last context will
     * call DeleteProgram on all shaders, releasing everything.
     */
-   if (st->has_shareable_shaders)
+   if (st->screen->caps.shareable_shaders)
       return;
 
    /* ARB vert/frag program */
@@ -1467,7 +1467,7 @@ st_precompile_shader_variant(struct st_context *st,
          key.clamp_color = true;
       }
 
-      key.st = st->has_shareable_shaders ? NULL : st;
+      key.st = st->screen->caps.shareable_shaders ? NULL : st;
       st_get_common_variant(st, prog, &key, report_compile_error, &error);
       return error;
    }
@@ -1477,7 +1477,7 @@ st_precompile_shader_variant(struct st_context *st,
 
       memset(&key, 0, sizeof(key));
 
-      key.st = st->has_shareable_shaders ? NULL : st;
+      key.st = st->screen->caps.shareable_shaders ? NULL : st;
       key.lower_alpha_func = COMPARE_FUNC_ALWAYS;
       if (prog->ati_fs) {
          for (int i = 0; i < ARRAY_SIZE(key.texture_index); i++)

src/mesa/state_tracker/tests/st_format.c

@@ -56,6 +56,7 @@ int main(int argc, char **argv)
    };
    struct st_context local_st = {
       .pipe = &pctx,
+      .screen = &screen,
       .has_etc1 = true,
       .has_etc2 = true,
       .has_astc_2d_ldr = true,