[Emacs-diffs] /srv/bzr/emacs/trunk r104708: Merge: Use gnulib's dup2 module instead of rolling our own.

[Paul Eggert]

------------------------------------------------------------
revno: 104708 [merge]
committer: Paul Eggert <address@hidden>
branch nick: trunk
timestamp: Sat 2011-06-25 11:39:15 -0700
message:
  Merge: Use gnulib's dup2 module instead of rolling our own.
added:
  lib/dup2.c
  m4/dup2.m4
modified:
  ChangeLog
  Makefile.in
  configure.in
  lib/gnulib.mk
  m4/gl-comp.m4
  src/ChangeLog
  src/sysdep.c

=== modified file 'ChangeLog'
--- a/ChangeLog 2011-06-23 08:10:57 +0000
+++ b/ChangeLog 2011-06-25 08:40:38 +0000
@@ -1,3 +1,10 @@
+2011-06-25  Paul Eggert  <address@hidden>
+
+       Use gnulib's dup2 module instead of rolling our own.
+       * Makefile.in (GNULIB_MODULES): Add dup2.
+       * configure.in: Do not check for dup2; gnulib does that now.
+       * lib/dup2.c, m4/dup2.m4: New files, from gnulib.
+
 2011-06-23  Paul Eggert  <address@hidden>
 
        * lib/getopt.c, lib/stat.c, m4/gl-comp.m4: Merge from gnulib.

=== modified file 'Makefile.in'
--- a/Makefile.in       2011-06-21 16:15:07 +0000
+++ b/Makefile.in       2011-06-25 08:40:38 +0000
@@ -334,6 +334,7 @@
 GNULIB_MODULES = \
   alloca-opt \
   careadlinkat crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr \
+  dup2 \
   filemode getloadavg getopt-gnu ignore-value intprops lstat mktime readlink \
   socklen stdarg stdio strftime strtoumax symlink sys_stat
 GNULIB_TOOL_FLAGS = \

=== modified file 'configure.in'
--- a/configure.in      2011-06-21 17:10:10 +0000
+++ b/configure.in      2011-06-25 08:40:38 +0000
@@ -2645,7 +2645,7 @@
 AC_SUBST(BLESSMAIL_TARGET)
 
 
-AC_CHECK_FUNCS(gethostname getdomainname dup2 \
+AC_CHECK_FUNCS(gethostname getdomainname \
 rename closedir mkdir rmdir sysinfo getrusage get_current_dir_name \
 random lrand48 logb frexp fmod rint cbrt ftime setsid \
 strerror fpathconf select euidaccess getpagesize tzset setlocale \

=== added file 'lib/dup2.c'
--- a/lib/dup2.c        1970-01-01 00:00:00 +0000
+++ b/lib/dup2.c        2011-06-25 08:40:38 +0000
@@ -0,0 +1,132 @@
+/* Duplicate an open file descriptor to a specified file descriptor.
+
+   Copyright (C) 1999, 2004-2007, 2009-2011 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 Paul Eggert */
+
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
+
+#include <errno.h>
+#include <fcntl.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Get declarations of the Win32 API functions.  */
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#if HAVE_DUP2
+
+# undef dup2
+
+int
+rpl_dup2 (int fd, int desired_fd)
+{
+  int result;
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  /* If fd is closed, mingw hangs on dup2 (fd, fd).  If fd is open,
+     dup2 (fd, fd) returns 0, but all further attempts to use fd in
+     future dup2 calls will hang.  */
+  if (fd == desired_fd)
+    {
+      if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE)
+        {
+          errno = EBADF;
+          return -1;
+        }
+      return fd;
+    }
+  /* Wine 1.0.1 return 0 when desired_fd is negative but not -1:
+     http://bugs.winehq.org/show_bug.cgi?id=21289 */
+  if (desired_fd < 0)
+    {
+      errno = EBADF;
+      return -1;
+    }
+# elif !defined __linux__
+  /* On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC.  */
+  if (fd == desired_fd)
+    return fcntl (fd, F_GETFL) == -1 ? -1 : fd;
+# endif
+  result = dup2 (fd, desired_fd);
+# ifdef __linux__
+  /* Correct a Linux return value.
+     
<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.30.y.git;a=commitdiff;h=2b79bc4f7ebbd5af3c8b867968f9f15602d5f802>
+   */
+  if (fd == desired_fd && result == (unsigned int) -EBADF)
+    {
+      errno = EBADF;
+      result = -1;
+    }
+# endif
+  if (result == 0)
+    result = desired_fd;
+  /* Correct a cygwin 1.5.x errno value.  */
+  else if (result == -1 && errno == EMFILE)
+    errno = EBADF;
+# if REPLACE_FCHDIR
+  if (fd != desired_fd && result != -1)
+    result = _gl_register_dup (fd, result);
+# endif
+  return result;
+}
+
+#else /* !HAVE_DUP2 */
+
+/* On older platforms, dup2 did not exist.  */
+
+# ifndef F_DUPFD
+static int
+dupfd (int fd, int desired_fd)
+{
+  int duplicated_fd = dup (fd);
+  if (duplicated_fd < 0 || duplicated_fd == desired_fd)
+    return duplicated_fd;
+  else
+    {
+      int r = dupfd (fd, desired_fd);
+      int e = errno;
+      close (duplicated_fd);
+      errno = e;
+      return r;
+    }
+}
+# endif
+
+int
+dup2 (int fd, int desired_fd)
+{
+  int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd;
+  if (result == -1 || fd == desired_fd)
+    return result;
+  close (desired_fd);
+# ifdef F_DUPFD
+  result = fcntl (fd, F_DUPFD, desired_fd);
+#  if REPLACE_FCHDIR
+  if (0 <= result)
+    result = _gl_register_dup (fd, result);
+#  endif
+# else
+  result = dupfd (fd, desired_fd);
+# endif
+  if (result == -1 && (errno == EMFILE || errno == EINVAL))
+    errno = EBADF;
+  return result;
+}
+#endif /* !HAVE_DUP2 */

=== modified file 'lib/gnulib.mk'
--- a/lib/gnulib.mk     2011-06-21 16:15:07 +0000
+++ b/lib/gnulib.mk     2011-06-25 08:40:38 +0000
@@ -9,7 +9,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib 
--m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. 
--makefile-name=gnulib.mk --conditional-dependencies --no-libtool 
--macro-prefix=gl --no-vc-files alloca-opt careadlinkat crypto/md5 crypto/sha1 
crypto/sha256 crypto/sha512 dtoastr filemode getloadavg getopt-gnu ignore-value 
intprops lstat mktime readlink socklen stdarg stdio strftime strtoumax symlink 
sys_stat
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib 
--m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. 
--makefile-name=gnulib.mk --conditional-dependencies --no-libtool 
--macro-prefix=gl --no-vc-files alloca-opt careadlinkat crypto/md5 crypto/sha1 
crypto/sha256 crypto/sha512 dtoastr dup2 filemode getloadavg getopt-gnu 
ignore-value intprops lstat mktime readlink socklen stdarg stdio strftime 
strtoumax symlink sys_stat
 
 
 MOSTLYCLEANFILES += core *.stackdump
@@ -159,6 +159,15 @@
 
 ## end   gnulib module dtoastr
 
+## begin gnulib module dup2
+
+
+EXTRA_DIST += dup2.c
+
+EXTRA_libgnu_a_SOURCES += dup2.c
+
+## end   gnulib module dup2
+
 ## begin gnulib module filemode
 
 libgnu_a_SOURCES += filemode.c

=== added file 'm4/dup2.m4'
--- a/m4/dup2.m4        1970-01-01 00:00:00 +0000
+++ b/m4/dup2.m4        2011-06-25 08:40:38 +0000
@@ -0,0 +1,76 @@
+#serial 13
+dnl Copyright (C) 2002, 2005, 2007, 2009-2011 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_DUP2],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  m4_ifdef([gl_FUNC_DUP2_OBSOLETE], [
+    AC_CHECK_FUNCS_ONCE([dup2])
+    if test $ac_cv_func_dup2 = no; then
+      HAVE_DUP2=0
+      AC_LIBOBJ([dup2])
+    fi
+  ], [
+    AC_DEFINE([HAVE_DUP2], [1], [Define to 1 if you have the 'dup2' function.])
+  ])
+  if test $HAVE_DUP2 = 1; then
+    AC_CACHE_CHECK([whether dup2 works], [gl_cv_func_dup2_works],
+      [AC_RUN_IFELSE([
+         AC_LANG_PROGRAM([[#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>]],
+           [int result = 0;
+#ifdef FD_CLOEXEC
+            if (fcntl (1, F_SETFD, FD_CLOEXEC) == -1)
+              result |= 1;
+#endif
+            if (dup2 (1, 1) == 0)
+              result |= 2;
+#ifdef FD_CLOEXEC
+            if (fcntl (1, F_GETFD) != FD_CLOEXEC)
+              result |= 4;
+#endif
+            close (0);
+            if (dup2 (0, 0) != -1)
+              result |= 8;
+            /* Many gnulib modules require POSIX conformance of EBADF.  */
+            if (dup2 (2, 1000000) == -1 && errno != EBADF)
+              result |= 16;
+            return result;
+           ])
+        ],
+        [gl_cv_func_dup2_works=yes], [gl_cv_func_dup2_works=no],
+        [case "$host_os" in
+           mingw*) # on this platform, dup2 always returns 0 for success
+             gl_cv_func_dup2_works=no;;
+           cygwin*) # on cygwin 1.5.x, dup2(1,1) returns 0
+             gl_cv_func_dup2_works=no;;
+           linux*) # On linux between 2008-07-27 and 2009-05-11, dup2 of a
+                   # closed fd may yield -EBADF instead of -1 / errno=EBADF.
+             gl_cv_func_dup2_works=no;;
+           freebsd*) # on FreeBSD 6.1, dup2(1,1000000) gives EMFILE, not EBADF.
+             gl_cv_func_dup2_works=no;;
+           haiku*) # on Haiku alpha 2, dup2(1, 1) resets FD_CLOEXEC.
+             gl_cv_func_dup2_works=no;;
+           *) gl_cv_func_dup2_works=yes;;
+         esac])
+      ])
+    if test "$gl_cv_func_dup2_works" = no; then
+      gl_REPLACE_DUP2
+    fi
+  fi
+])
+
+AC_DEFUN([gl_REPLACE_DUP2],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([dup2])
+  if test $ac_cv_func_dup2 = yes; then
+    REPLACE_DUP2=1
+  fi
+  AC_LIBOBJ([dup2])
+])

=== modified file 'm4/gl-comp.m4'
--- a/m4/gl-comp.m4     2011-06-23 08:10:57 +0000
+++ b/m4/gl-comp.m4     2011-06-25 08:40:38 +0000
@@ -37,6 +37,7 @@
   # Code from module crypto/sha512:
   # Code from module dosname:
   # Code from module dtoastr:
+  # Code from module dup2:
   # Code from module extensions:
   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
   # Code from module filemode:
@@ -102,6 +103,8 @@
 gl_SHA256
 gl_SHA512
 AC_REQUIRE([gl_C99_STRTOLD])
+gl_FUNC_DUP2
+gl_UNISTD_MODULE_INDICATOR([dup2])
 gl_FILEMODE
 gl_GETLOADAVG
 if test $HAVE_GETLOADAVG = 0; then
@@ -404,6 +407,7 @@
   lib/careadlinkat.h
   lib/dosname.h
   lib/dtoastr.c
+  lib/dup2.c
   lib/filemode.c
   lib/filemode.h
   lib/ftoastr.c
@@ -453,6 +457,7 @@
   m4/00gnulib.m4
   m4/alloca.m4
   m4/c-strtod.m4
+  m4/dup2.m4
   m4/extensions.m4
   m4/filemode.m4
   m4/getloadavg.m4

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2011-06-25 18:21:00 +0000
+++ b/src/ChangeLog     2011-06-25 18:31:36 +0000
@@ -1,3 +1,8 @@
+2011-06-25  Paul Eggert  <address@hidden>
+
+       Use gnulib's dup2 module instead of rolling our own.
+       * sysdep.c (dup2) [!HAVE_DUP2]: Remove; gnulib now does this.
+
 2011-06-25  YAMAMOTO Mitsuharu  <address@hidden>
 
        * dispnew.c (scrolling_window): Before scrolling, turn off a

=== modified file 'src/sysdep.c'
--- a/src/sysdep.c      2011-05-03 05:47:50 +0000
+++ b/src/sysdep.c      2011-06-25 08:40:38 +0000
@@ -2012,37 +2012,6 @@
 }
 #endif /* HPUX and not HAVE_PERROR */
 
-#ifndef HAVE_DUP2
-
-/*
- *     Emulate BSD dup2.  First close newd if it already exists.
- *     Then, attempt to dup oldd.  If not successful, call dup2 recursively
- *     until we are, then close the unsuccessful ones.
- */
-
-int
-dup2 (int oldd, int newd)
-{
-  register int fd, ret;
-
-  emacs_close (newd);
-
-#ifdef F_DUPFD
-  return fcntl (oldd, F_DUPFD, newd);
-#else
-  fd = dup (old);
-  if (fd == -1)
-    return -1;
-  if (fd == new)
-    return new;
-  ret = dup2 (old,new);
-  emacs_close (fd);
-  return ret;
-#endif
-}
-
-#endif /* not HAVE_DUP2 */
-
 /*
  *     Gettimeofday.  Simulate as much as possible.  Only accurate
  *     to nearest second.  Emacs doesn't use tzp so ignore it for now.