gallium,st/mesa: allow reporting compile failures from create_vs/fs/.._state

This adds a proper interface for reporting shader compile failures.
They are propagated to the GLSL linker.

Reporting errors from finalize_nir will be deprecated.

Fixes: dae57e184a
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33341>
(cherry picked from commit dc1b719e1f)

.pick_status.json

@@ -84,7 +84,7 @@
         "description": "gallium,st/mesa: allow reporting compile failures from create_vs/fs/.._state",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "dae57e184aafdd7da562cb3120d530504a2426fc",
         "notes": null

src/gallium/auxiliary/util/u_live_shader_cache.c

@@ -139,6 +139,9 @@ util_live_shader_cache_get(struct pipe_context *ctx,
     * invocations to run simultaneously.
     */
    shader = (struct util_live_shader*)cache->create_shader(ctx, state);
+   if (!shader)
+      return NULL;
+
    pipe_reference_init(&shader->reference, 1);
    memcpy(shader->sha1, sha1, sizeof(sha1));
 

src/gallium/include/pipe/p_state.h

@@ -306,6 +306,14 @@ struct pipe_shader_state
       struct nir_shader *nir;
    } ir;
    struct pipe_stream_output_info stream_output;
+
+   /* If the caller sets report_compile_error=true, the driver can fail
+    * compilation and should allocate a string with the error message and
+    * store it in the pointer below. The caller is responsible for reading
+    * and freeing the error message.
+    */
+   bool report_compile_error;
+   char *error_message;
 };
 
 static inline void

src/mesa/state_tracker/st_atom_shader.c

@@ -183,7 +183,7 @@ st_update_fp( struct st_context *st )
       update_gl_clamp(st, st->ctx->FragmentProgram._Current, key.gl_clamp);
 
       simple_mtx_lock(&st->ctx->Shared->Mutex);
-      shader = st_get_fp_variant(st, fp, &key)->base.driver_shader;
+      shader = st_get_fp_variant(st, fp, &key, false, NULL)->base.driver_shader;
       simple_mtx_unlock(&st->ctx->Shared->Mutex);
    }
 
@@ -248,7 +248,7 @@ st_update_vp( struct st_context *st )
       update_gl_clamp(st, st->ctx->VertexProgram._Current, key.gl_clamp);
 
       simple_mtx_lock(&st->ctx->Shared->Mutex);
-      st->vp_variant = st_get_common_variant(st, vp, &key);
+      st->vp_variant = st_get_common_variant(st, vp, &key, false, NULL);
       simple_mtx_unlock(&st->ctx->Shared->Mutex);
    }
 
@@ -302,7 +302,7 @@ st_update_common_program(struct st_context *st, struct gl_program *prog,
    update_gl_clamp(st, prog, key.gl_clamp);
 
    simple_mtx_lock(&st->ctx->Shared->Mutex);
-   void *result = st_get_common_variant(st, prog, &key)->base.driver_shader;
+   void *result = st_get_common_variant(st, prog, &key, false, NULL)->base.driver_shader;
    simple_mtx_unlock(&st->ctx->Shared->Mutex);
 
    return result;

src/mesa/state_tracker/st_cb_bitmap.c

@@ -187,7 +187,7 @@ setup_render_state(struct gl_context *ctx,
                      clamp_frag_color;
    key.lower_alpha_func = COMPARE_FUNC_ALWAYS;
 
-   fpv = st_get_fp_variant(st, fp, &key);
+   fpv = st_get_fp_variant(st, fp, &key, false, NULL);
 
    /* As an optimization, Mesa's fragment programs will sometimes get the
     * primary color from a statevar/constant rather than a varying variable.

src/mesa/state_tracker/st_cb_drawpixels.c

@@ -1127,7 +1127,7 @@ get_color_fp_variant(struct st_context *st)
                      ctx->Color._ClampFragmentColor;
    key.lower_alpha_func = COMPARE_FUNC_ALWAYS;
 
-   fpv = st_get_fp_variant(st, ctx->FragmentProgram._Current, &key);
+   fpv = st_get_fp_variant(st, ctx->FragmentProgram._Current, &key, false, NULL);
 
    return fpv;
 }
@@ -1157,7 +1157,7 @@ get_color_index_fp_variant(struct st_context *st)
                      ctx->Color._ClampFragmentColor;
    key.lower_alpha_func = COMPARE_FUNC_ALWAYS;
 
-   fpv = st_get_fp_variant(st, ctx->FragmentProgram._Current, &key);
+   fpv = st_get_fp_variant(st, ctx->FragmentProgram._Current, &key, false, NULL);
 
    return fpv;
 }

src/mesa/state_tracker/st_draw_feedback.c

@@ -122,7 +122,7 @@ st_feedback_draw_vbo(struct gl_context *ctx,
       .is_draw_shader = true
    };
    vp = (struct gl_vertex_program *)ctx->VertexProgram._Current;
-   vp_variant = st_get_common_variant(st, &vp->Base, &key);
+   vp_variant = st_get_common_variant(st, &vp->Base, &key, false, NULL);
 
    /*
     * Set up the draw module's state.

src/mesa/state_tracker/st_glsl_to_nir.cpp

@@ -589,7 +589,13 @@ st_link_glsl_to_nir(struct gl_context *ctx,
       st_store_nir_in_disk_cache(st, prog);
 
       st_release_variants(st, prog);
-      st_finalize_program(st, prog);
+      char *error = st_finalize_program(st, prog, true);
+
+      if (error) {
+         linker_error(shader_program, error);
+         free(error);
+         return false;
+      }
    }
 
    struct pipe_context *pctx = st_context(ctx)->pipe;

src/mesa/state_tracker/st_program.c

@@ -762,7 +762,8 @@ get_stream_output_info_from_nir(nir_shader *nir,
 static struct st_common_variant *
 st_create_common_variant(struct st_context *st,
                          struct gl_program *prog,
-                         const struct st_common_variant_key *key)
+                         const struct st_common_variant_key *key,
+                         bool report_compile_error, char **error)
 {
    MESA_TRACE_FUNC();
 
@@ -879,6 +880,13 @@ st_create_common_variant(struct st_context *st,
    else
       v->base.driver_shader = st_create_nir_shader(st, &state);
 
+   if (report_compile_error && state.error_message) {
+      *error = state.error_message;
+      return NULL;
+   }
+
+   if (error)
+      *error = NULL;
    return v;
 }
 
@@ -904,7 +912,8 @@ st_add_variant(struct st_variant **list, struct st_variant *v)
 struct st_common_variant *
 st_get_common_variant(struct st_context *st,
                       struct gl_program *prog,
-                      const struct st_common_variant_key *key)
+                      const struct st_common_variant_key *key,
+                      bool report_compile_error, char **error)
 {
    struct st_common_variant *v;
 
@@ -930,7 +939,7 @@ st_get_common_variant(struct st_context *st,
       }
 
       /* create now */
-      v = st_create_common_variant(st, prog, key);
+      v = st_create_common_variant(st, prog, key, report_compile_error, error);
       if (v) {
          v->base.st = key->st;
 
@@ -1013,7 +1022,8 @@ st_translate_fragment_program(struct st_context *st,
 static struct st_fp_variant *
 st_create_fp_variant(struct st_context *st,
                      struct gl_program *fp,
-                     const struct st_fp_variant_key *key)
+                     const struct st_fp_variant_key *key,
+                     bool report_compile_error, char **error)
 {
    struct st_fp_variant *variant = CALLOC_STRUCT(st_fp_variant);
    struct pipe_shader_state state = {0};
@@ -1037,6 +1047,7 @@ st_create_fp_variant(struct st_context *st,
     */
    state.ir.nir = get_nir_shader(st, fp, false);
    state.type = PIPE_SHADER_IR_NIR;
+   state.report_compile_error = report_compile_error;
 
    bool finalize = false;
 
@@ -1233,8 +1244,14 @@ st_create_fp_variant(struct st_context *st,
    }
 
    variant->base.driver_shader = st_create_nir_shader(st, &state);
-   variant->key = *key;
+   if (report_compile_error && state.error_message) {
+      *error = state.error_message;
+      return NULL;
+   }
 
+   variant->key = *key;
+   if (error)
+      *error = NULL;
    return variant;
 }
 
@@ -1244,7 +1261,8 @@ st_create_fp_variant(struct st_context *st,
 struct st_fp_variant *
 st_get_fp_variant(struct st_context *st,
                   struct gl_program *fp,
-                  const struct st_fp_variant_key *key)
+                  const struct st_fp_variant_key *key,
+                  bool report_compile_error, char **error)
 {
    struct st_fp_variant *fpv;
 
@@ -1278,7 +1296,7 @@ st_get_fp_variant(struct st_context *st,
                           "depth_textures=", key->depth_textures);
       }
 
-      fpv = st_create_fp_variant(st, fp, key);
+      fpv = st_create_fp_variant(st, fp, key, report_compile_error, error);
       if (fpv) {
          fpv->base.st = key->st;
 
@@ -1397,10 +1415,13 @@ st_destroy_program_variants(struct st_context *st)
 /**
  * Compile one shader variant.
  */
-static void
+static char *
 st_precompile_shader_variant(struct st_context *st,
-                             struct gl_program *prog)
+                             struct gl_program *prog,
+                             bool report_compile_error)
 {
+   char *error = NULL;
+
    switch (prog->Target) {
    case GL_VERTEX_PROGRAM_ARB:
    case GL_TESS_CONTROL_PROGRAM_NV:
@@ -1421,8 +1442,8 @@ st_precompile_shader_variant(struct st_context *st,
       }
 
       key.st = st->has_shareable_shaders ? NULL : st;
-      st_get_common_variant(st, prog, &key);
-      break;
+      st_get_common_variant(st, prog, &key, report_compile_error, &error);
+      return error;
    }
 
    case GL_FRAGMENT_PROGRAM_ARB: {
@@ -1443,12 +1464,12 @@ st_precompile_shader_variant(struct st_context *st,
       if (!prog->shader_program)
          key.depth_textures = prog->ShadowSamplers;
 
-      st_get_fp_variant(st, prog, &key);
-      break;
+      st_get_fp_variant(st, prog, &key, report_compile_error, &error);
+      return error;
    }
 
    default:
-      assert(0);
+      unreachable("invalid shader stage");
    }
 }
 
@@ -1480,8 +1501,9 @@ st_serialize_base_nir(struct gl_program *prog, nir_shader *nir)
    }
 }
 
-void
-st_finalize_program(struct st_context *st, struct gl_program *prog)
+char *
+st_finalize_program(struct st_context *st, struct gl_program *prog,
+                    bool report_compile_error)
 {
    struct gl_context *ctx = st->ctx;
    bool is_bound = false;
@@ -1522,7 +1544,7 @@ st_finalize_program(struct st_context *st, struct gl_program *prog)
    }
 
    /* Always create the default variant of the program. */
-   st_precompile_shader_variant(st, prog);
+   return st_precompile_shader_variant(st, prog, report_compile_error);
 }
 
 /**
@@ -1555,6 +1577,6 @@ st_program_string_notify( struct gl_context *ctx,
       }
    }
 
-   st_finalize_program(st, prog);
+   st_finalize_program(st, prog, false);
    return GL_TRUE;
 }

src/mesa/state_tracker/st_program.h

@@ -343,12 +343,14 @@ st_set_prog_affected_state_flags(struct gl_program *prog);
 extern struct st_fp_variant *
 st_get_fp_variant(struct st_context *st,
                   struct gl_program *stfp,
-                  const struct st_fp_variant_key *key);
+                  const struct st_fp_variant_key *key,
+                  bool report_compile_error, char **error);
 
 extern struct st_common_variant *
 st_get_common_variant(struct st_context *st,
                       struct gl_program *p,
-                      const struct st_common_variant_key *key);
+                      const struct st_common_variant_key *key,
+                      bool report_compile_error, char **error);
 
 extern void
 st_release_variants(struct st_context *st, struct gl_program *p);
@@ -370,8 +372,9 @@ st_serialize_nir(struct gl_program *stp);
 void
 st_serialize_base_nir(struct gl_program *prog, struct nir_shader *nir);
 
-extern void
-st_finalize_program(struct st_context *st, struct gl_program *prog);
+extern char *
+st_finalize_program(struct st_context *st, struct gl_program *prog,
+                    bool report_compile_error);
 
 void *
 st_create_nir_shader(struct st_context *st, struct pipe_shader_state *state);

src/mesa/state_tracker/st_shader_cache.c

@@ -197,7 +197,7 @@ st_deserialise_nir_program(struct gl_context *ctx,
       }
    }
 
-   st_finalize_program(st, prog);
+   st_finalize_program(st, prog, false);
 }
 
 bool