ubsan: Add __ubsan_handle_vla_bound_not_positive

Another missing ubsan handler from gcc.

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard

newlib/libc/ubsan/CMakeLists.txt

@@ -63,6 +63,7 @@ picolibc_sources(
   ubsan_handle_sub_overflow.c
   ubsan_handle_type_mismatch.c
   ubsan_handle_type_mismatch_v1.c
+  ubsan_handle_vla_bound_not_positive.c
   ubsan_message.c
   ubsan_type_check_to_string.c
   ubsan_val_to_imax.c

newlib/libc/ubsan/meson.build

@@ -63,6 +63,7 @@ srcs_ubsan = [
   'ubsan_handle_sub_overflow.c',
   'ubsan_handle_type_mismatch.c',
   'ubsan_handle_type_mismatch_v1.c',
+  'ubsan_handle_vla_bound_not_positive.c',
   'ubsan_message.c',
   'ubsan_type_check_to_string.c',
   'ubsan_val_to_imax.c',

newlib/libc/ubsan/ubsan.h

@@ -224,7 +224,7 @@ struct cfi_check_fail_data {
     struct type_descriptor *type;
 };
 
-struct vla_bound_not_positive_data {
+struct vla_bound_data {
     struct source_location location;
     struct type_descriptor *type;
 };

newlib/libc/ubsan/ubsan_handle_vla_bound_not_positive.c

@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright © 2025 Keith Packard
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions and the following
+ *    disclaimer in the documentation and/or other materials provided
+ *    with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "ubsan.h"
+
+void
+__ubsan_handle_vla_bound_not_positive(void *_data,
+                                      void *ptr)
+{
+    struct vla_bound_data *data = _data;
+    __ubsan_error(&data->location, "vla_bound_not_positive", "(%s) %p\n",
+                  data->type->type_name, ptr);
+}