shared-glapi: implement _glapi_get_proc_name().

Previously this function was only implemented for non-shared-glapi
builds.  Since the function is only intended for debugging purposes we
use a simple O(n) algorithm.

Acked-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/mapi/mapi/mapi_glapi.c

@@ -219,8 +219,8 @@ _glapi_get_proc_address(const char *funcName)
 const char *
 _glapi_get_proc_name(unsigned int offset)
 {
-   /* not implemented */
-   return NULL;
+   const struct mapi_stub *stub = stub_find_by_slot(offset);
+   return stub ? stub_get_name(stub) : NULL;
 }
 
 unsigned long

src/mapi/mapi/stub.c

@@ -153,6 +153,28 @@ stub_find_dynamic(const char *name, int generate)
    return stub;
 }
 
+static const struct mapi_stub *
+search_table_by_slot(const struct mapi_stub *table, size_t num_entries,
+                     int slot)
+{
+   size_t i;
+   for (i = 0; i < num_entries; ++i) {
+      if (table[i].slot == slot)
+         return &table[i];
+   }
+   return NULL;
+}
+
+const struct mapi_stub *
+stub_find_by_slot(int slot)
+{
+   const struct mapi_stub *stub =
+      search_table_by_slot(public_stubs, ARRAY_SIZE(public_stubs), slot);
+   if (stub)
+      return stub;
+   return search_table_by_slot(dynamic_stubs, num_dynamic_stubs, slot);
+}
+
 void
 stub_fix_dynamic(struct mapi_stub *stub, const struct mapi_stub *alias)
 {

src/mapi/mapi/stub.h

@@ -42,6 +42,9 @@ stub_find_public(const char *name);
 struct mapi_stub *
 stub_find_dynamic(const char *name, int generate);
 
+const struct mapi_stub *
+stub_find_by_slot(int slot);
+
 void
 stub_fix_dynamic(struct mapi_stub *stub, const struct mapi_stub *alias);