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>

12 files changed, 317 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index fbfa1e4838..8965456c00 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,21 @@
 2009-11-11  Eric Blake  <ebb9@byu.net>
 
+	mkfifo: new module
+	* 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.
+
 	readlink: detect FreeBSD bug
 	* m4/readlink.m4 (gl_FUNC_READLINK): Also detect FreeBSD bug with
 	slash on symlink.
diff --git a/MODULES.html.sh b/MODULES.html.sh
index 717e1ae0a9..a1e3acea0c 100755
--- a/MODULES.html.sh
+++ b/MODULES.html.sh
@@ -2287,6 +2287,7 @@ func_all_modules ()
   func_module mbsnrtowcs
   func_module mkdir
   func_module mkdtemp
+  func_module mkfifo
   func_module mkstemp
   func_module netdb
   func_module netinet_in
diff --git a/doc/posix-functions/mkfifo.texi b/doc/posix-functions/mkfifo.texi
index 926f57d700..ea872b1b37 100644
--- a/doc/posix-functions/mkfifo.texi
+++ b/doc/posix-functions/mkfifo.texi
@@ -4,15 +4,19 @@
 
 POSIX specification: @url{http://www.opengroup.org/onlinepubs/9699919799/functions/mkfifo.html}
 
-Gnulib module: ---
+Gnulib module: mkfifo
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function mishandles trailing slash on some platforms:
+FreeBSD 7.2, Solaris 9.
+@item
+This function is missing on some platforms; however, the replacement
+always fails with @code{ENOSYS}:
+mingw.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on some platforms:
-mingw.
 @end itemize
diff --git a/lib/mkfifo.c b/lib/mkfifo.c
new file mode 100644
index 0000000000..3c29e8f6b6
--- /dev/null
+++ b/lib/mkfifo.c
@@ -0,0 +1,58 @@
+/* Create a named fifo.
+   Copyright (C) 2009 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 <http://www.gnu.org/licenses/>.  */
+
+/* written by Eric Blake */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <string.h>
+
+#if !HAVE_MKFIFO
+/* Mingw lacks mkfifo; always fail with ENOSYS.  */
+
+int
+mkfifo (char const *name _UNUSED_PARAMETER_, mode_t mode _UNUSED_PARAMETER_)
+{
+  errno = ENOSYS;
+  return -1;
+}
+
+#else /* HAVE_MKFIFO */
+
+# undef mkfifo
+
+/* Create a named fifo FILE, with access permissions in MODE.  Work
+around trailing slash bugs.  */
+
+int
+rpl_mkfifo (char const *name, mode_t mode)
+{
+# if MKFIFO_TRAILING_SLASH_BUG
+  size_t len = strlen (name);
+  if (len && name[len - 1] == '/')
+    {
+      struct stat st;
+      if (stat (name, &st) == 0)
+        errno = EEXIST;
+      return -1;
+    }
+# endif
+  return mkfifo (name, mode);
+}
+#endif /* HAVE_MKFIFO */
diff --git a/lib/sys_stat.in.h b/lib/sys_stat.in.h
index 1e46da82a3..4ff2ff6cbc 100644
--- a/lib/sys_stat.in.h
+++ b/lib/sys_stat.in.h
@@ -424,6 +424,23 @@ extern int mkdirat (int fd, char const *file, mode_t mode);
 #endif
 
 
+#if @GNULIB_MKFIFO@
+# if @REPLACE_MKFIFO@
+#  undef mkfifo
+#  define mkfifo rpl_mkfifo
+# endif
+# if !@HAVE_MKFIFO@ || @REPLACE_MKFIFO@
+int mkfifo (char const *file, mode_t mode);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef mkfifo
+# define mkfifo(n,m)                                                    \
+    (GL_LINK_WARNING ("mkfifo is not portable - "                       \
+                      "use gnulib module mkfifo for portability"),      \
+     mkfifo (n, m))
+#endif
+
+
 #if @GNULIB_MKFIFOAT@
 # if !@HAVE_MKFIFOAT@
 int mkfifoat (int fd, char const *file, mode_t mode);
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
+])
diff --git a/m4/sys_stat_h.m4 b/m4/sys_stat_h.m4
index 1edf54834c..e864866458 100644
--- a/m4/sys_stat_h.m4
+++ b/m4/sys_stat_h.m4
@@ -1,4 +1,4 @@
-# sys_stat_h.m4 serial 19   -*- Autoconf -*-
+# sys_stat_h.m4 serial 20   -*- Autoconf -*-
 dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -45,6 +45,7 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   GNULIB_LCHMOD=0;      AC_SUBST([GNULIB_LCHMOD])
   GNULIB_LSTAT=0;       AC_SUBST([GNULIB_LSTAT])
   GNULIB_MKDIRAT=0;     AC_SUBST([GNULIB_MKDIRAT])
+  GNULIB_MKFIFO=0;      AC_SUBST([GNULIB_MKFIFO])
   GNULIB_MKFIFOAT=0;    AC_SUBST([GNULIB_MKFIFOAT])
   GNULIB_MKNODAT=0;     AC_SUBST([GNULIB_MKNODAT])
   GNULIB_STAT=0;        AC_SUBST([GNULIB_STAT])
@@ -56,6 +57,7 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   HAVE_LCHMOD=1;        AC_SUBST([HAVE_LCHMOD])
   HAVE_LSTAT=1;         AC_SUBST([HAVE_LSTAT])
   HAVE_MKDIRAT=1;       AC_SUBST([HAVE_MKDIRAT])
+  HAVE_MKFIFO=1;        AC_SUBST([HAVE_MKFIFO])
   HAVE_MKFIFOAT=1;      AC_SUBST([HAVE_MKFIFOAT])
   HAVE_MKNODAT=1;       AC_SUBST([HAVE_MKNODAT])
   HAVE_UTIMENSAT=1;     AC_SUBST([HAVE_UTIMENSAT])
@@ -64,6 +66,7 @@ AC_DEFUN([gl_SYS_STAT_H_DEFAULTS],
   REPLACE_FUTIMENS=0;   AC_SUBST([REPLACE_FUTIMENS])
   REPLACE_LSTAT=0;      AC_SUBST([REPLACE_LSTAT])
   REPLACE_MKDIR=0;      AC_SUBST([REPLACE_MKDIR])
+  REPLACE_MKFIFO=0;     AC_SUBST([REPLACE_MKFIFO])
   REPLACE_STAT=0;       AC_SUBST([REPLACE_STAT])
   REPLACE_UTIMENSAT=0;  AC_SUBST([REPLACE_UTIMENSAT])
 ])
diff --git a/modules/mkfifo b/modules/mkfifo
new file mode 100644
index 0000000000..ce7af63c8a
--- /dev/null
+++ b/modules/mkfifo
@@ -0,0 +1,25 @@
+Description:
+mkfifo(): create named FIFO
+
+Files:
+lib/mkfifo.c
+m4/mkfifo.m4
+
+Depends-on:
+stat
+sys_stat
+
+configure.ac:
+gl_FUNC_MKFIFO
+gl_UNISTD_MODULE_INDICATOR([mkfifo])
+
+Makefile.am:
+
+Include:
+<sys/stat.h>
+
+License:
+LGPL
+
+Maintainer:
+Eric Blake
diff --git a/modules/mkfifo-tests b/modules/mkfifo-tests
new file mode 100644
index 0000000000..87d6ce204a
--- /dev/null
+++ b/modules/mkfifo-tests
@@ -0,0 +1,13 @@
+Files:
+tests/test-mkfifo.h
+tests/test-mkfifo.c
+
+Depends-on:
+stdbool
+symlink
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-mkfifo
+check_PROGRAMS += test-mkfifo
diff --git a/modules/sys_stat b/modules/sys_stat
index 246011f31e..d51078ebcc 100644
--- a/modules/sys_stat
+++ b/modules/sys_stat
@@ -33,6 +33,7 @@ sys/stat.h: sys_stat.in.h
 	      -e 's|@''GNULIB_LCHMOD''@|$(GNULIB_LCHMOD)|g' \
 	      -e 's|@''GNULIB_LSTAT''@|$(GNULIB_LSTAT)|g' \
 	      -e 's|@''GNULIB_MKDIRAT''@|$(GNULIB_MKDIRAT)|g' \
+	      -e 's|@''GNULIB_MKFIFO''@|$(GNULIB_MKFIFO)|g' \
 	      -e 's|@''GNULIB_MKFIFOAT''@|$(GNULIB_MKFIFOAT)|g' \
 	      -e 's|@''GNULIB_MKNODAT''@|$(GNULIB_MKNODAT)|g' \
 	      -e 's|@''GNULIB_STAT''@|$(GNULIB_STAT)|g' \
@@ -43,6 +44,7 @@ sys/stat.h: sys_stat.in.h
 	      -e 's|@''HAVE_LCHMOD''@|$(HAVE_LCHMOD)|g' \
 	      -e 's|@''HAVE_LSTAT''@|$(HAVE_LSTAT)|g' \
 	      -e 's|@''HAVE_MKDIRAT''@|$(HAVE_MKDIRAT)|g' \
+	      -e 's|@''HAVE_MKFIFO''@|$(HAVE_MKFIFO)|g' \
 	      -e 's|@''HAVE_MKFIFOAT''@|$(HAVE_MKFIFOAT)|g' \
 	      -e 's|@''HAVE_MKNODAT''@|$(HAVE_MKNODAT)|g' \
 	      -e 's|@''HAVE_UTIMENSAT''@|$(HAVE_UTIMENSAT)|g' \
@@ -51,6 +53,7 @@ sys/stat.h: sys_stat.in.h
 	      -e 's|@''REPLACE_FUTIMENS''@|$(REPLACE_FUTIMENS)|g' \
 	      -e 's|@''REPLACE_LSTAT''@|$(REPLACE_LSTAT)|g' \
 	      -e 's|@''REPLACE_MKDIR''@|$(REPLACE_MKDIR)|g' \
+	      -e 's|@''REPLACE_MKFIFO''@|$(REPLACE_MKFIFO)|g' \
 	      -e 's|@''REPLACE_STAT''@|$(REPLACE_STAT)|g' \
 	      -e 's|@''REPLACE_UTIMENSAT''@|$(REPLACE_UTIMENSAT)|g' \
 	      -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
diff --git a/tests/test-mkfifo.c b/tests/test-mkfifo.c
new file mode 100644
index 0000000000..3a0336c330
--- /dev/null
+++ b/tests/test-mkfifo.c
@@ -0,0 +1,53 @@
+/* Tests of mkfifo.
+   Copyright (C) 2009 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 <http://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009.  */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <fcntl.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define ASSERT(expr) \
+  do                                                                         \
+    {                                                                        \
+      if (!(expr))                                                           \
+        {                                                                    \
+          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__);  \
+          fflush (stderr);                                                   \
+          abort ();                                                          \
+        }                                                                    \
+    }                                                                        \
+  while (0)
+
+#define BASE "test-mkfifo.t"
+
+#include "test-mkfifo.h"
+
+int
+main (void)
+{
+  /* Remove any leftovers from a previous partial run.  */
+  ASSERT (system ("rm -rf " BASE "*") == 0);
+
+  return test_mkfifo (mkfifo, true);
+}
diff --git a/tests/test-mkfifo.h b/tests/test-mkfifo.h
new file mode 100644
index 0000000000..7ced3ce8dc
--- /dev/null
+++ b/tests/test-mkfifo.h
@@ -0,0 +1,74 @@
+/* Tests of mkfifo and friends.
+   Copyright (C) 2009 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 <http://www.gnu.org/licenses/>.  */
+
+/* Written by Eric Blake <ebb9@byu.net>, 2009.  */
+
+/* This file is designed to test mkfifo(n,m), mknod(n,m|S_IFIFO,0),
+   mkfifoat(AT_FDCWD,n,m), and mknodat(AT_FDCWD,n,m|S_IFIFO,0).  FUNC
+   is the function to test.  Assumes that BASE and ASSERT are already
+   defined, and that appropriate headers are already included.  If
+   PRINT, warn before skipping symlink tests with status 77.  */
+
+static int
+test_mkfifo (int (*func) (char const *, mode_t), bool print)
+{
+  int result = func (BASE "fifo", 0600);
+  struct stat st;
+  if (result == -1 && errno == ENOSYS)
+    {
+      if (print)
+        fputs ("skipping test: no support for named fifos\n", stderr);
+      return 77;
+    }
+  ASSERT (result == 0);
+  ASSERT (stat (BASE "fifo", &st) == 0);
+  ASSERT (S_ISFIFO (st.st_mode));
+
+  /* Sanity checks of failures.  */
+  errno = 0;
+  ASSERT (func ("", S_IRUSR | S_IWUSR) == -1);
+  ASSERT (errno == ENOENT);
+  errno = 0;
+  ASSERT (func (".", 0600) == -1);
+  ASSERT (errno == EEXIST || errno == EINVAL);
+  errno = 0;
+  ASSERT (func (BASE "fifo", 0600) == -1);
+  ASSERT (errno == EEXIST);
+  ASSERT (unlink (BASE "fifo") == 0);
+  errno = 0;
+  ASSERT (func (BASE "fifo/", 0600) == -1);
+  ASSERT (errno == ENOENT || errno == ENOTDIR);
+
+  /* Test trailing slash behavior.  */
+  if (symlink (BASE "fifo", BASE "link"))
+    {
+      if (print)
+        fputs ("skipping test: symlinks not supported on this file system\n",
+               stderr);
+      return 77;
+    }
+  errno = 0;
+  ASSERT (func (BASE "link", 0600) == -1);
+  ASSERT (errno == EEXIST);
+  errno = 0;
+  ASSERT (func (BASE "link/", 0600) == -1);
+  ASSERT (errno == EEXIST || errno == ENOENT || errno == ENOTDIR);
+  errno = 0;
+  ASSERT (unlink (BASE "fifo") == -1);
+  ASSERT (errno == ENOENT);
+  ASSERT (unlink (BASE "link") == 0);
+  return 0;
+}