backport macro STACK_ARRAY, needed for fix for CVE-226-40393

Origin: https://gitlab.freedesktop.org/mesa/mesa/-/blob/f43cff3728e58c377d1e03b13db62514217abfe1/src/util/stack_array.h
Forwarded: not-needed
Last-Update: 2026-05-25 <YYYY-MM-DD, last update of the meta-information, optional>

Last-Update: 2026-05-25 <YYYY-MM-DD, last update of the meta-information, optional>
Gbp-Pq: Name backport_STACK_ARRAY.patch

diff --git a/src/util/stack_array.h b/src/util/stack_array.h
new file mode 100644 (file)
index 0000000..e2133bd
--- /dev/null
+++ b/src/util/stack_array.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2025 Collabora, Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+
+#ifndef UTIL_STACK_ARRAY_H
+#define UTIL_STACK_ARRAY_H
+
+#define STACK_ARRAY_SIZE 8
+
+/* Sometimes gcc may claim -Wmaybe-uninitialized for the stack array in some
+ * places it can't verify that when size is 0 nobody down the call chain reads
+ * the array. Please don't try to fix it by zero-initializing the array here
+ * since it's used in a lot of different places. An "if (size == 0) return;"
+ * may work for you.
+ */
+#define STACK_ARRAY(type, name, size) \
+   type _stack_##name[STACK_ARRAY_SIZE]; \
+   type *const name = \
+     ((size) <= STACK_ARRAY_SIZE ? _stack_##name : (type *)malloc((size) * sizeof(type)))
+
+#define STACK_ARRAY_FINISH(name) \
+   if (name != _stack_##name) free(name)
+
+#endif /* UTIL_STACK_ARRAY_H */