util: Convert rb_tree_test to gtest

Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Acked-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13425>

src/util/meson.build

@@ -294,18 +294,6 @@ if with_tests
     )
   endif
 
-  test(
-    'rb_tree',
-    executable(
-      'rb_tree_test',
-      files('rb_tree_test.c'),
-      include_directories : [inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux],
-      dependencies : idep_mesautil,
-      c_args : [c_msvc_compat_args],
-    ),
-    suite : ['util'],
-  )
-
   test(
     'roundeven',
     executable(
@@ -322,6 +310,7 @@ if with_tests
   files_util_tests = files(
     'bitset_test.cpp',
     'blob_test.cpp',
+    'rb_tree_test.cpp',
     'register_allocate_test.cpp',
     'tests/dag_test.cpp',
     'tests/fast_idiv_by_const_test.cpp',

src/util/rb_tree.h

@@ -28,6 +28,10 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** A red-black tree node
  *
  * This struct represents a node in the red-black tree.  This struct should
@@ -311,4 +315,8 @@ struct rb_node *rb_node_prev(struct rb_node *node);
  */
 void rb_tree_validate(struct rb_tree *T);
 
+#ifdef __cplusplus
+} /* extern C */
+#endif
+
 #endif /* RB_TREE_H */

src/util/rb_tree_test.cpp

@@ -25,6 +25,7 @@
 #include "rb_tree.h"
 
 #include <assert.h>
+#include <gtest/gtest.h>
 #include <limits.h>
 
 /* A list of 100 random numbers from 1 to 100.  The number 30 is explicitly
@@ -204,8 +205,7 @@ validate_search(struct rb_tree *tree, int first_number,
     }
 }
 
-int
-main()
+TEST(RBTreeTest, InsertAndSearch)
 {
     struct rb_test_node nodes[ARRAY_SIZE(test_numbers)];
     struct rb_tree tree;