mkfifo: new module

Solaris 9 mkfifo("name/",mode) mistakenly creates "name".
FreeBSD 7.2 mkfifo("dangling/",mode) mistakenly creates a fifo
at the target of "dangling".  Mingw lacks named pipes altogether,
but this at least avoids link failures.

* modules/mkfifo: New file.
* m4/mkfifo.m4 (gl_FUNC_MKFIFO): Likewise.
* lib/mkfifo.c (mkfifo): Likewise.
* m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Set witness
defaults.
* modules/sys_stat (Makefile.am): Substitute them.
* lib/sys_stat.in.h (mkfifo): Declare replacement.
* MODULES.html.sh (Support for systems lacking POSIX:2008):
Document it.
* doc/posix-functions/mkfifo.texi (mkfifo): Likewise.
* modules/mkfifo-tests: New test.
* tests/test-mkfifo.h (test_mkfifo): New file, borrowed in part
from test-mkfifoat.c.
* tests/test-mkfifo.c: New file.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 45 insertions, 0 deletions

diff --git a/m4/mkfifo.m4 b/m4/mkfifo.m4
new file mode 100644
index 0000000000..fc8044ea39
--- /dev/null
+++ b/m4/mkfifo.m4
@@ -0,0 +1,45 @@
+# serial 1
+# See if we need to provide mkfifo replacement.
+
+dnl Copyright (C) 2009 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_MKFIFO],
+[
+  AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([mkfifo])
+  if test $ac_cv_func_mkfifo = no; then
+    HAVE_MKFIFO=0
+    AC_LIBOBJ([mkfifo])
+  else
+    dnl Check for Solaris 9 and FreeBSD bug with trailing slash.
+    AC_CHECK_FUNCS_ONCE([lstat])
+    AC_CACHE_CHECK([whether mkfifo rejects trailing slashes],
+      [gl_cv_func_mkfifo_works],
+      [# Assume that if we have lstat, we can also check symlinks.
+       if test $ac_cv_func_lstat = yes; then
+         ln -s conftest.tmp conftest.lnk
+       fi
+       AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM(
+           [[#include <sys/stat.h>
+]], [[if (!mkfifo ("conftest.tmp/", 0600)) return 1;
+#if HAVE_LSTAT
+      if (!mkfifo ("conftest.lnk/", 0600)) return 2;
+#endif
+           ]])],
+         [gl_cv_func_mkfifo_works=yes], [gl_cv_func_mkfifo_works=no],
+         [gl_cv_func_mkfifo_works="guessing no"])
+       rm -f conftest.tmp conftest.lnk])
+    if test "$gl_cv_func_mkfifo_works" != yes; then
+      AC_DEFINE([MKFIFO_TRAILING_SLASH_BUG], [1], [Define to 1 if mkfifo
+        does not reject trailing slash])
+      REPLACE_MKFIFO=1
+      AC_LIBOBJ([mkfifo])
+    fi
+  fi
+])