gbm: Promote dri_bind_extensions() to the loader util library.

It's better than EGL's copy of it by having optional ext support in the
match structs, and GLX wishes it had either of the two.

Reviewed-by: Adam Jackson <ajax@redhat.com>
Acked-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20069>

src/gbm/backends/dri/gbm_dri.c

@@ -286,13 +286,6 @@ static const __DRIextension *gbm_dri_screen_extensions[] = {
    NULL,
 };
 
-struct dri_extension_match {
-   const char *name;
-   int version;
-   int offset;
-   bool optional;
-};
-
 static struct dri_extension_match dri_core_extensions[] = {
    { __DRI2_FLUSH, 1, offsetof(struct gbm_dri_device, flush), false },
    { __DRI_IMAGE, 6, offsetof(struct gbm_dri_device, image), false },
@@ -310,36 +303,6 @@ static struct dri_extension_match gbm_swrast_device_extensions[] = {
    { __DRI_KOPPER, 1, offsetof(struct gbm_dri_device, kopper), true },
 };
 
-static bool
-dri_bind_extensions(struct gbm_dri_device *dri,
-                    struct dri_extension_match *matches, size_t num_matches,
-                    const __DRIextension **extensions)
-{
-   bool ret = true;
-   void *field;
-
-   for (size_t i = 0; extensions[i]; i++) {
-      for (size_t j = 0; j < num_matches; j++) {
-         if (strcmp(extensions[i]->name, matches[j].name) == 0 &&
-             extensions[i]->version >= matches[j].version) {
-            field = ((char *) dri + matches[j].offset);
-            *(const __DRIextension **) field = extensions[i];
-         }
-      }
-   }
-
-   for (size_t j = 0; j < num_matches; j++) {
-      field = ((char *) dri + matches[j].offset);
-      if ((*(const __DRIextension **) field == NULL) && !matches[j].optional) {
-         fprintf(stderr, "gbm: did not find extension %s version %d\n",
-                 matches[j].name, matches[j].version);
-         ret = false;
-      }
-   }
-
-   return ret;
-}
-
 static const __DRIextension **
 dri_open_driver(struct gbm_dri_device *dri)
 {
@@ -374,9 +337,9 @@ dri_load_driver(struct gbm_dri_device *dri)
    if (!extensions)
       return -1;
 
-   if (!dri_bind_extensions(dri, gbm_dri_device_extensions,
-                            ARRAY_SIZE(gbm_dri_device_extensions),
-                            extensions)) {
+   if (!loader_bind_extensions(dri, gbm_dri_device_extensions,
+                               ARRAY_SIZE(gbm_dri_device_extensions),
+                               extensions)) {
       dlclose(dri->driver);
       fprintf(stderr, "failed to bind extensions\n");
       return -1;
@@ -396,9 +359,9 @@ dri_load_driver_swrast(struct gbm_dri_device *dri)
    if (!extensions)
       return -1;
 
-   if (!dri_bind_extensions(dri, gbm_swrast_device_extensions,
-                            ARRAY_SIZE(gbm_swrast_device_extensions),
-                            extensions)) {
+   if (!loader_bind_extensions(dri, gbm_swrast_device_extensions,
+                               ARRAY_SIZE(gbm_swrast_device_extensions),
+                               extensions)) {
       dlclose(dri->driver);
       fprintf(stderr, "failed to bind extensions\n");
       return -1;
@@ -438,9 +401,9 @@ dri_screen_create_dri2(struct gbm_dri_device *dri, char *driver_name)
       return -1;
 
    extensions = dri->core->getExtensions(dri->screen);
-   if (!dri_bind_extensions(dri, dri_core_extensions,
-                            ARRAY_SIZE(dri_core_extensions),
-                            extensions)) {
+   if (!loader_bind_extensions(dri, dri_core_extensions,
+                               ARRAY_SIZE(dri_core_extensions),
+                               extensions)) {
       ret = -1;
       goto free_screen;
    }

src/loader/loader.c

@@ -603,6 +603,35 @@ loader_get_extensions_name(const char *driver_name)
    return name;
 }
 
+bool
+loader_bind_extensions(void *data,
+                       const struct dri_extension_match *matches, size_t num_matches,
+                       const __DRIextension **extensions)
+{
+   bool ret = true;
+   void *field;
+
+   for (size_t i = 0; extensions[i]; i++) {
+      for (size_t j = 0; j < num_matches; j++) {
+         if (strcmp(extensions[i]->name, matches[j].name) == 0 &&
+             extensions[i]->version >= matches[j].version) {
+            field = ((char *) data + matches[j].offset);
+            *(const __DRIextension **) field = extensions[i];
+         }
+      }
+   }
+
+   for (size_t j = 0; j < num_matches; j++) {
+      field = ((char *) data + matches[j].offset);
+      if ((*(const __DRIextension **) field == NULL) && !matches[j].optional) {
+         log_(_LOADER_FATAL, "did not find extension %s version %d\n",
+              matches[j].name, matches[j].version);
+         ret = false;
+      }
+   }
+
+   return ret;
+}
 /**
  * Opens a driver or backend using its name, returning the library handle.
  *

src/loader/loader.h

@@ -29,6 +29,8 @@
 
 #include <stdbool.h>
 #include <sys/stat.h>
+#include <stddef.h>
+#include "GL/internal/dri_interface.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -92,6 +94,23 @@ loader_set_logger(loader_logger *logger);
 char *
 loader_get_extensions_name(const char *driver_name);
 
+struct dri_extension_match {
+   /* __DRI_* extension name */
+   const char *name;
+
+   /* Required minimum version in the extension struct */
+   int version;
+
+   /* offset in the data arg at which to store a pointer to the extension */
+   int offset;
+
+   bool optional;
+};
+
+bool loader_bind_extensions(void *data,
+                            const struct dri_extension_match *matches, size_t num_matches,
+                            const __DRIextension **extensions);
+
 #ifdef __cplusplus
 }
 #endif