Adding upstream version 1.21.3.upstream/1.21.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/m4/link.m4 b/m4/link.m4
new file mode 100644
index 0000000..154b9d0
--- /dev/null
+++ b/m4/link.m4
@@ -0,0 +1,58 @@
+# link.m4 serial 11
+dnl Copyright (C) 2009-2022 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_LINK],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CHECK_FUNCS_ONCE([link])
+  if test $ac_cv_func_link = no; then
+    HAVE_LINK=0
+  else
+    AC_CACHE_CHECK([whether link obeys POSIX],
+      [gl_cv_func_link_works],
+      [touch conftest.a
+       # Assume that if we have lstat, we can also check symlinks.
+       if test $ac_cv_func_lstat = yes; then
+         ln -s conftest.a conftest.lnk
+       fi
+       AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+           [[#include <unistd.h>
+             #include <stdio.h>
+           ]],
+           [[int result = 0;
+             if (!link ("conftest.a", "conftest.b/"))
+               result |= 1;
+#if HAVE_LSTAT
+             if (!link ("conftest.lnk/", "conftest.b"))
+               result |= 2;
+             if (rename ("conftest.a", "conftest.b"))
+               result |= 4;
+             if (!link ("conftest.b", "conftest.lnk"))
+               result |= 8;
+#endif
+             return result;
+           ]])],
+         [gl_cv_func_link_works=yes], [gl_cv_func_link_works=no],
+         [case "$host_os" in
+                             # Guess yes on Linux systems.
+            linux-* | linux) gl_cv_func_link_works="guessing yes" ;;
+                             # Guess yes on glibc systems.
+            *-gnu* | gnu*)   gl_cv_func_link_works="guessing yes" ;;
+                             # If we don't know, obey --enable-cross-guesses.
+            *)               gl_cv_func_link_works="$gl_cross_guess_normal" ;;
+          esac
+         ])
+       rm -f conftest.a conftest.b conftest.lnk])
+    case "$gl_cv_func_link_works" in
+      *yes) ;;
+      *)
+        REPLACE_LINK=1
+        ;;
+    esac
+  fi
+])