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-rw-r--r--m4/symlinkat.m456
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diff --git a/m4/symlinkat.m4 b/m4/symlinkat.m4
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+# serial 10
+# See if we need to provide symlinkat replacement.
+
+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.
+
+# Written by Eric Blake.
+
+AC_DEFUN([gl_FUNC_SYMLINKAT],
+[
+ AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+ AC_REQUIRE([gl_FUNC_OPENAT])
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CHECK_FUNCS_ONCE([symlinkat])
+ if test $ac_cv_func_symlinkat = no; then
+ HAVE_SYMLINKAT=0
+ else
+ AC_CACHE_CHECK([whether symlinkat handles trailing slash correctly],
+ [gl_cv_func_symlinkat_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <fcntl.h>
+ #include <unistd.h>
+ ]],
+ [[int result = 0;
+ if (!symlinkat ("a", AT_FDCWD, "conftest.link/"))
+ result |= 1;
+ if (symlinkat ("conftest.f", AT_FDCWD, "conftest.lnk2"))
+ result |= 2;
+ else if (!symlinkat ("a", AT_FDCWD, "conftest.lnk2/"))
+ result |= 4;
+ return result;
+ ]])],
+ [gl_cv_func_symlinkat_works=yes],
+ [gl_cv_func_symlinkat_works=no],
+ [case "$host_os" in
+ # Guess yes on Linux systems.
+ linux-* | linux) gl_cv_func_symlinkat_works="guessing yes" ;;
+ # Guess yes on glibc systems.
+ *-gnu* | gnu*) gl_cv_func_symlinkat_works="guessing yes" ;;
+ # If we don't know, obey --enable-cross-guesses.
+ *) gl_cv_func_symlinkat_works="$gl_cross_guess_normal" ;;
+ esac
+ ])
+ rm -f conftest.f conftest.link conftest.lnk2])
+ case "$gl_cv_func_symlinkat_works" in
+ *yes) ;;
+ *)
+ REPLACE_SYMLINKAT=1
+ ;;
+ esac
+ fi
+])