1 files changed, 166 insertions, 0 deletions
diff --git a/tests/test-errno-h.c b/tests/test-errno-h.c
new file mode 100644
index 00000000..cb20635b
--- /dev/null
+++ b/tests/test-errno-h.c
@@ -0,0 +1,166 @@
+/* Test of <errno.h> substitute.
+   Copyright (C) 2008-2025 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/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2008.  */
+
+#include <config.h>
+
+#include <errno.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Check all POSIX-defined errno values, using M (v) to check value v.  */
+#define CHECK_POSIX_ERRNOS(m) \
+  m (E2BIG) \
+  m (EACCES) \
+  m (EADDRINUSE) \
+  m (EADDRNOTAVAIL) \
+  m (EAFNOSUPPORT) \
+  m (EAGAIN) \
+  m (EALREADY) \
+  m (EBADF) \
+  m (EBADMSG) \
+  m (EBUSY) \
+  m (ECANCELED) \
+  m (ECHILD) \
+  m (ECONNABORTED) \
+  m (ECONNREFUSED) \
+  m (ECONNRESET) \
+  m (EDEADLK) \
+  m (EDESTADDRREQ) \
+  m (EDOM) \
+  m (EDQUOT) \
+  m (EEXIST) \
+  m (EFAULT) \
+  m (EFBIG) \
+  m (EHOSTUNREACH) \
+  m (EIDRM) \
+  m (EILSEQ) \
+  m (EINPROGRESS) \
+  m (EINTR) \
+  m (EINVAL) \
+  m (EIO) \
+  m (EISCONN) \
+  m (EISDIR) \
+  m (ELOOP) \
+  m (EMFILE) \
+  m (EMLINK) \
+  m (EMSGSIZE) \
+  m (EMULTIHOP) \
+  m (ENAMETOOLONG) \
+  m (ENETDOWN) \
+  m (ENETRESET) \
+  m (ENETUNREACH) \
+  m (ENFILE) \
+  m (ENOBUFS) \
+  m (ENODEV) \
+  m (ENOENT) \
+  m (ENOEXEC) \
+  m (ENOLCK) \
+  m (ENOLINK) \
+  m (ENOMEM) \
+  m (ENOMSG) \
+  m (ENOPROTOOPT) \
+  m (ENOSPC) \
+  m (ENOSYS) \
+  m (ENOTCONN) \
+  m (ENOTDIR) \
+  m (ENOTEMPTY) \
+  m (ENOTRECOVERABLE) \
+  m (ENOTSOCK) \
+  m (ENOTSUP) \
+  m (ENOTTY) \
+  m (ENXIO) \
+  m (EOPNOTSUPP) \
+  m (EOVERFLOW) \
+  m (EOWNERDEAD) \
+  m (EPERM) \
+  m (EPIPE) \
+  m (EPROTO) \
+  m (EPROTONOSUPPORT) \
+  m (EPROTOTYPE) \
+  m (ERANGE) \
+  m (EROFS) \
+  m (ESOCKTNOSUPPORT) \
+  m (ESPIPE) \
+  m (ESRCH) \
+  m (ESTALE) \
+  m (ETIMEDOUT) \
+  m (ETXTBSY) \
+  m (EWOULDBLOCK) \
+  m (EXDEV) \
+  /* end of CHECK_POSIX_ERRNOS */
+
+/* Verify that the POSIX mandated errno values can be used as integer
+   constant expressions and are all positive (except on Haiku).  */
+#if defined __HAIKU__
+# define NONZERO_INTEGER_CONSTANT_EXPRESSION(e) static_assert (0 != (e) << 0);
+CHECK_POSIX_ERRNOS (NONZERO_INTEGER_CONSTANT_EXPRESSION)
+#else
+# define POSITIVE_INTEGER_CONSTANT_EXPRESSION(e) static_assert (0 < (e) << 0);
+CHECK_POSIX_ERRNOS (POSITIVE_INTEGER_CONSTANT_EXPRESSION)
+#endif
+
+/* Verify that errno values can all be used in #if.  */
+#define USABLE_IN_IF(e) ^ e
+#if 0 CHECK_POSIX_ERRNOS (USABLE_IN_IF)
+#endif
+
+/* Check that errno values all differ, except possibly for
+   EWOULDBLOCK == EAGAIN and ENOTSUP == EOPNOTSUPP.  */
+#define ERRTAB(e) { #e, e },
+static struct nameval { char const *name; int value; }
+  errtab[] = { CHECK_POSIX_ERRNOS (ERRTAB) };
+
+static int
+errtab_cmp (void const *va, void const *vb)
+{
+  struct nameval const *a = va, *b = vb;
+
+  /* Sort by value first, then by name (to simplify later tests).
+     Subtraction cannot overflow as both are positive.  */
+  int diff = a->value - b->value;
+  return diff ? diff : strcmp (a->name, b->name);
+}
+
+int
+main ()
+{
+  int test_exit_status = EXIT_SUCCESS;
+
+  /* Verify that errno can be assigned.  */
+  errno = EOVERFLOW;
+
+  /* Check that errno values all differ, except possibly for
+     EAGAIN == EWOULDBLOCK and ENOTSUP == EOPNOTSUPP.  */
+  int nerrtab = sizeof errtab / sizeof *errtab;
+  qsort (errtab, nerrtab, sizeof *errtab, errtab_cmp);
+  for (int i = 1; i < nerrtab; i++)
+    if (errtab[i - 1].value == errtab[i].value)
+      {
+        fprintf (stderr, "%s == %s == %d\n",
+                 errtab[i - 1].name, errtab[i].name, errtab[i].value);
+        if (! ((strcmp ("EAGAIN", errtab[i - 1].name) == 0
+                && strcmp ("EWOULDBLOCK", errtab[i].name) == 0)
+               || (strcmp ("ENOTSUP", errtab[i - 1].name) == 0
+                   && strcmp ("EOPNOTSUPP", errtab[i].name) == 0)))
+          test_exit_status = EXIT_FAILURE;
+      }
+
+  return test_exit_status;
+}