1 files changed, 89 insertions, 0 deletions
diff --git a/tests/test-realloc-posix.c b/tests/test-realloc-posix.c
new file mode 100644
index 00000000..d50f8603
--- /dev/null
+++ b/tests/test-realloc-posix.c
@@ -0,0 +1,89 @@
+/* Test of realloc function.
+   Copyright (C) 2010-2025 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <stdlib.h>
+
+#include <errno.h>
+#include <stdint.h>
+
+#include "macros.h"
+
+/* Work around clang bug
+   <https://github.com/llvm/llvm-project/issues/114772>.  */
+void *(*volatile my_realloc) (void *, size_t) = realloc;
+#undef realloc
+#define realloc my_realloc
+
+int
+main (int argc, _GL_UNUSED char **argv)
+{
+  void *p;
+
+  /* Check that realloc (NULL, 0) is not a NULL pointer.  */
+  p = realloc (NULL, 0);
+  ASSERT (p != NULL);
+#ifdef NOT_YET
+  free (p);
+
+  /* Check that realloc (p, 0) for non-NULL p is not a NULL pointer.  */
+  p = malloc (200);
+  p = realloc (p, 0);
+  ASSERT (p != NULL);
+  free (p);
+
+  /* Check that realloc (p, 0) for non-NULL p is not a NULL pointer.  */
+  p = malloc (2 * 1024 * 1024);
+  p = realloc (p, 0);
+  ASSERT (p != NULL);
+#endif
+
+  /* Check that realloc (p, n) fails when p is non-null and n exceeds
+     PTRDIFF_MAX.  */
+  if (PTRDIFF_MAX < SIZE_MAX)
+    {
+      size_t one = argc != 12345;
+      void *r = realloc (p, PTRDIFF_MAX + one);
+      ASSERT (r == NULL);
+      /* Avoid a test failure due to glibc bug
+         <https://sourceware.org/PR27870>.  */
+      if (!getenv ("MALLOC_CHECK_"))
+        ASSERT (errno == ENOMEM);
+    }
+
+  /* Check that realloc sets errno when it fails.
+     Do this only in 64-bit processes, because there are many bi-arch systems
+     nowadays where a 32-bit process can actually allocate 2 GiB of RAM.  */
+  if (sizeof (size_t) >= 8)
+    {
+      void *r;
+
+      errno = 0;
+      r = realloc (p, SIZE_MAX / 10);
+      ASSERT (r == NULL);
+      ASSERT (errno == ENOMEM);
+
+      errno = 0;
+      r = realloc (p, SIZE_MAX / 3);
+      ASSERT (r == NULL);
+      ASSERT (errno == ENOMEM);
+    }
+
+  free (p);
+  return test_exit_status;
+}