glx/apple: locate dispatch table functions to wrap by name

Avoid reaching into the dispatch table internals (and thus having to deal
with the complexities of remap etc.) by identifying functions to wrap by
name.

See:
https://lists.freedesktop.org/archives/mesa-dev/2015-June/086721.html et seq.
https://bugs.freedesktop.org/show_bug.cgi?id=90311

Signed-off-by: Jon Turney <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>

2 files changed, 17 insertions, 0 deletions

diff --git a/src/mapi/glapi/gen/gl_gentable.py b/src/mapi/glapi/gen/gl_gentable.py
index 2f54d1d5792..50153bbabd5 100644
--- a/src/mapi/glapi/gen/gl_gentable.py
+++ b/src/mapi/glapi/gen/gl_gentable.py
@@ -56,6 +56,7 @@ header = """/* GLXEXT is the define used in the xserver when the GLX extension i
 #endif
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 #include "main/glheader.h"
 
@@ -144,6 +145,19 @@ _glapi_create_table_from_handle(void *handle, const char *symbol_prefix) {
 
     return disp;
 }
+
+void
+ _glapi_table_patch(struct _glapi_table *table, const char *name, void *wrapper)
+{
+   for (int func_index = 0; func_index < GLAPI_TABLE_COUNT; ++func_index) {
+      if (!strcmp(_glapi_table_func_names[func_index], name)) {
+            ((void **)table)[func_index] = wrapper;
+            return;
+         }
+   }
+   fprintf(stderr, "could not patch %s in dispatch table\\n", name);
+}
+
 """
 
 
diff --git a/src/mapi/glapi/glapi.h b/src/mapi/glapi/glapi.h
index f1ad4c1b5e8..d5d4e0a03a6 100644
--- a/src/mapi/glapi/glapi.h
+++ b/src/mapi/glapi/glapi.h
@@ -161,6 +161,9 @@ _glapi_get_proc_name(unsigned int offset);
 #if defined(GLX_USE_APPLEGL) || defined(GLX_USE_WINDOWSGL)
 _GLAPI_EXPORT struct _glapi_table *
 _glapi_create_table_from_handle(void *handle, const char *symbol_prefix);
+
+_GLAPI_EXPORT void
+_glapi_table_patch(struct _glapi_table *, const char *name, void *wrapper);
 #endif