drirc: add mesa_extension_override option

This allows specific per-application override.
The existing MESA_EXTENSION_OVERRIDE env variable is kept.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13364>

docs/envvars.rst

@@ -78,7 +78,8 @@ Core Mesa environment variables
 :envvar:`MESA_EXTENSION_OVERRIDE`
    can be used to enable/disable extensions. A value such as
    ``GL_EXT_foo -GL_EXT_bar`` will enable the ``GL_EXT_foo`` extension
-   and disable the ``GL_EXT_bar`` extension.
+   and disable the ``GL_EXT_bar`` extension. Note that this will override
+   extensions override configured using driconf.
 :envvar:`MESA_EXTENSION_MAX_YEAR`
    The ``GL_EXTENSIONS`` string returned by Mesa is sorted by extension
    year. If this variable is set to year X, only extensions defined on

src/gallium/auxiliary/pipe-loader/driinfo_gallium.h

@@ -41,6 +41,7 @@ DRI_CONF_SECTION_DEBUG
    DRI_CONF_FORCE_GL_RENDERER()
    DRI_CONF_OVERRIDE_VRAM_SIZE()
    DRI_CONF_GLX_EXTENSION_OVERRIDE()
+   DRI_CONF_MESA_EXTENSION_OVERRIDE()
    DRI_CONF_INDIRECT_GL_EXTENSION_OVERRIDE()
    DRI_CONF_DISABLE_PROTECTED_CONTENT_CHECK(false)
    DRI_CONF_IGNORE_MAP_UNSYNCHRONIZED(false)

src/gallium/auxiliary/util/u_driconf.c

@@ -66,6 +66,7 @@ u_driconf_fill_st_options(struct st_config_options *options,
    query_bool_option(transcode_astc);
    query_string_option(force_gl_vendor);
    query_string_option(force_gl_renderer);
+   query_string_option(mesa_extension_override);
 
    driComputeOptionsSha1(optionCache, options->config_options_sha1);
 }

src/gallium/frontends/dri/dri_screen.c

@@ -510,6 +510,7 @@ dri_destroy_screen(__DRIscreen * sPriv)
 
    free(screen->options.force_gl_vendor);
    free(screen->options.force_gl_renderer);
+   free(screen->options.mesa_extension_override);
 
    /* The caller in dri_util preserves the fd ownership */
    free(screen);

src/gallium/frontends/wgl/stw_device.c

@@ -231,6 +231,7 @@ stw_cleanup(void)
 
    free(stw_dev->st_options.force_gl_vendor);
    free(stw_dev->st_options.force_gl_renderer);
+   free(stw_dev->st_options.mesa_extension_override);
    driDestroyOptionCache(&stw_dev->option_cache);
    driDestroyOptionInfo(&stw_dev->option_info);
 

src/gallium/include/frontend/api.h

@@ -243,6 +243,7 @@ struct st_config_options
    bool transcode_astc;
    char *force_gl_vendor;
    char *force_gl_renderer;
+   char *mesa_extension_override;
    unsigned char config_options_sha1[20];
 };
 

src/mesa/main/context.c

@@ -268,7 +268,7 @@ one_time_fini(void)
  */
 
 static void
-one_time_init(void)
+one_time_init(const char *extensions_override)
 {
    GLuint i;
 
@@ -281,7 +281,16 @@ one_time_init(void)
 
    _mesa_locale_init();
 
-   _mesa_one_time_init_extension_overrides();
+   const char *env_const = os_get_option("MESA_EXTENSION_OVERRIDE");
+   if (env_const) {
+      if (extensions_override &&
+          strcmp(extensions_override, env_const)) {
+         printf("Warning: MESA_EXTENSION_OVERRIDE used instead of driconf setting\n");
+      }
+      extensions_override = env_const;
+   }
+
+   _mesa_one_time_init_extension_overrides(extensions_override);
 
    _mesa_get_cpu_features();
 
@@ -327,13 +336,13 @@ static void init_lock(void) {
  * defined.
  */
 void
-_mesa_initialize(void)
+_mesa_initialize(const char *extensions_override)
 {
    call_once(&init_once, init_lock);
 
    mtx_lock(&init_once_lock);
    if (!init_done) {
-      one_time_init();
+      one_time_init(extensions_override);
       init_done = true;
    }
    mtx_unlock(&init_once_lock);
@@ -1120,7 +1129,7 @@ _mesa_initialize_context(struct gl_context *ctx,
    _mesa_override_gl_version(ctx);
 
    /* misc one-time initializations */
-   _mesa_initialize();
+   _mesa_initialize(NULL);
 
    /* Plug in driver functions and context pointer here.
     * This is important because when we call alloc_shared_state() below

src/mesa/main/context.h

@@ -90,7 +90,7 @@ _mesa_initialize_visual( struct gl_config *v,
 /*@{*/
 
 extern void
-_mesa_initialize(void);
+_mesa_initialize(const char *extensions_override);
 
 extern GLboolean
 _mesa_initialize_context( struct gl_context *ctx,

src/mesa/main/extensions.c

@@ -223,11 +223,11 @@ free_unknown_extensions_strings(void)
 
 
 /**
- * \brief Initialize extension override tables based on \c MESA_EXTENSION_OVERRIDE
+ * \brief Initialize extension override tables based on \c override
  *
  * This should be called one time early during first context initialization.
 
- * \c MESA_EXTENSION_OVERRIDE is a space-separated list of extensions to
+ * \c override is a space-separated list of extensions to
  * enable or disable. The list is processed thus:
  *    - Enable recognized extension names that are prefixed with '+'.
  *    - Disable recognized extension names that are prefixed with '-'.
@@ -235,9 +235,8 @@ free_unknown_extensions_strings(void)
  *    - Collect unrecognized extension names in a new string.
  */
 void
-_mesa_one_time_init_extension_overrides(void)
+_mesa_one_time_init_extension_overrides(const char *override)
 {
-   const char *env_const = os_get_option("MESA_EXTENSION_OVERRIDE");
    char *env;
    char *ext;
    size_t offset;
@@ -246,12 +245,12 @@ _mesa_one_time_init_extension_overrides(void)
    memset(&_mesa_extension_override_enables, 0, sizeof(struct gl_extensions));
    memset(&_mesa_extension_override_disables, 0, sizeof(struct gl_extensions));
 
-   if (env_const == NULL) {
+   if (override == NULL || override[0] == '\0') {
       return;
    }
 
-   /* Copy env_const because strtok() is destructive. */
-   env = strdup(env_const);
+   /* Copy 'override' because strtok() is destructive. */
+   env = strdup(override);
 
    if (env == NULL)
       return;

src/mesa/main/extensions.h

@@ -47,7 +47,7 @@ struct gl_extensions;
 
 extern void _mesa_enable_sw_extensions(struct gl_context *ctx);
 
-extern void _mesa_one_time_init_extension_overrides(void);
+extern void _mesa_one_time_init_extension_overrides(const char *override);
 
 extern void _mesa_init_extensions(struct gl_extensions *extentions);
 

src/mesa/state_tracker/st_manager.c

@@ -903,7 +903,7 @@ st_api_create_context(struct st_api *stapi, struct st_manager *smapi,
       return NULL;
    }
 
-   _mesa_initialize();
+   _mesa_initialize(attribs->options.mesa_extension_override);
 
    /* Create a hash table for the framebuffer interface objects
     * if it has not been created for this st manager.

src/util/driconf.h

@@ -251,6 +251,10 @@
 #define DRI_CONF_TRANSCODE_ASTC(def) \
    DRI_CONF_OPT_B(transcode_astc, def, "Transcode ASTC formats to DXTC if unsupported")
 
+#define DRI_CONF_MESA_EXTENSION_OVERRIDE() \
+   DRI_CONF_OPT_S_NODEF(mesa_extension_override, \
+                  "Allow enabling/disabling a list of extensions")
+
 #define DRI_CONF_GLX_EXTENSION_OVERRIDE() \
    DRI_CONF_OPT_S_NODEF(glx_extension_override, \
                   "Allow enabling/disabling a list of GLX extensions")