Re: 2G tmpfile of sort

[Paul Eggert]

Eric Blake <address@hidden> writes:

> Thanks for the report.  Which platform, which compiler, and which version
> of coreutils was this?  If it is still present in coreutils 6.2, we would
> like to get it fixed before 6.3.

Yes, likewise.

Looking at the implementation, it seems like there are some obvious
checks to add, e.g., that one can seek to a 4 GiB boundary in a
mkstemp file.  Also, there are some naming problems, since some
stdlib.h have "#define mkstemp ..." in some situations, and this runs
afoul of config.h's "#define mkstmep rpl_mkstemp".

I don't know whether the following patch will fix his problem (we need
more info for that) but I don't see how it could hurt, so I installed
it into gnulib.

2006-09-20  Paul Eggert  <address@hidden>

        * modules/mkstemp (Depends-on): Add extensions, so that
        mkstemp is visible on some platforms.
        (Makefile.am): Add mkstemp.h to EXTRA_DIST.
        (Include): Change to "mkstemp.h" from <stdlib.h>.
        * lib/mkstemp.h: New file, since some standard headers
        #define mkstemp.
        * lib/mkstemp.c: Revamp to put the !_LIBC code together.
        Include "mkstemp.h".
        Make the _LIBC code resemble glibc original more,
        e.g., use K&R style.
        * lib/stdlib--.h: Include mkstemp.h.
        * m4/mkstemp.m4 (gl_FUNC_MKSTEMP): Require AC_SYS_LARGEFILE.
        Check that large offsets work.  Modernize Autoconf usages.
        Prefer "yes" to mean a good thing rather than a bad.
        Don't put "#define mkstemp" in config.h, as this might interfere
        with standard system headers that "#define mkstemp mkstemp64".

Index: modules/mkstemp
===================================================================
RCS file: /cvsroot/gnulib/gnulib/modules/mkstemp,v
retrieving revision 1.8
diff -p -u -r1.8 mkstemp
--- modules/mkstemp     21 Aug 2006 06:11:26 -0000      1.8
+++ modules/mkstemp     20 Sep 2006 18:47:22 -0000
@@ -7,6 +7,7 @@ lib/tempname.c
 m4/mkstemp.m4
 
 Depends-on:
+extensions
 stat-macros
 stdint
 sys_stat
@@ -15,9 +16,10 @@ configure.ac:
 gl_FUNC_MKSTEMP
 
 Makefile.am:
+EXTRA_DIST += mkstemp.h
 
 Include:
-<stdlib.h>
+"mkstemp.h"
 
 License:
 GPL
Index: lib/mkstemp.h
===================================================================
RCS file: lib/mkstemp.h
diff -N lib/mkstemp.h
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ lib/mkstemp.h       20 Sep 2006 18:43:20 -0000
@@ -0,0 +1,30 @@
+/* Create a unique temporary file.
+
+   Copyright (C) 2006 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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* written by Jim Meyering */
+
+#include <stdlib.h>
+
+#ifdef __MKSTEMP_PREFIX
+# define _GL_CONCAT(x, y) x ## y
+# define _GL_XCONCAT(x, y) _GL_CONCAT (x, y)
+# define __MKSTEMP_ID(y) _GL_XCONCAT (__MKSTEMP_PREFIX, y)
+# undef mkstemp
+# define mkstemp __MKSTEMP_ID (mkstemp)
+int mkstemp (char *);
+#endif
Index: lib/mkstemp.c
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/mkstemp.c,v
retrieving revision 1.7
diff -u -r1.7 mkstemp.c
--- lib/mkstemp.c       13 Sep 2006 22:38:14 -0000      1.7
+++ lib/mkstemp.c       20 Sep 2006 18:43:20 -0000
@@ -15,12 +15,11 @@
    with this program; if not, write to the Free Software Foundation,
    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

-#include <config.h>
-
-/* Disable the definition of mkstemp to rpl_mkstemp (from config.h) in this
-   file.  Otherwise, we'd get conflicting prototypes for rpl_mkstemp on
-   most systems.  */
-#undef mkstemp
+#if !_LIBC
+# include <config.h>
+# include "mkstemp.h"
+int __gen_tempname ();
+#endif

 #include <stdio.h>
 #include <stdlib.h>
@@ -29,14 +28,13 @@
 # define __GT_FILE 0
 #endif

-int __gen_tempname ();
-
 /* Generate a unique temporary file name from TEMPLATE.
    The last six characters of TEMPLATE must be "XXXXXX";
    they are replaced with a string that makes the file name unique.
    Then open the file and return a fd. */
 int
-rpl_mkstemp (char *template)
+mkstemp (template)
+     char *template;
 {
   return __gen_tempname (template, __GT_FILE);
 }
Index: lib/stdlib--.h
===================================================================
RCS file: /cvsroot/gnulib/gnulib/lib/stdlib--.h,v
retrieving revision 1.1
diff -u -r1.1 stdlib--.h
--- lib/stdlib--.h      27 Aug 2005 20:12:02 -0000      1.1
+++ lib/stdlib--.h      20 Sep 2006 18:43:20 -0000
@@ -1,6 +1,6 @@
 /* Like stdlib.h, but redefine some names to avoid glitches.

-   Copyright (C) 2005 Free Software Foundation, Inc.
+   Copyright (C) 2005, 2006 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
@@ -21,5 +21,6 @@
 #include <stdlib.h>
 #include "stdlib-safer.h"

+#include "mkstemp.h"
 #undef mkstemp
 #define mkstemp mkstemp_safer
Index: m4/mkstemp.m4
===================================================================
RCS file: /cvsroot/gnulib/gnulib/m4/mkstemp.m4,v
retrieving revision 1.18
diff -u -r1.18 mkstemp.m4
--- m4/mkstemp.m4       21 Aug 2006 06:11:26 -0000      1.18
+++ m4/mkstemp.m4       20 Sep 2006 18:43:20 -0000
@@ -1,4 +1,4 @@
-#serial 13
+#serial 14

 # Copyright (C) 2001, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
@@ -12,46 +12,41 @@
 # only 32 files per process.
 # On systems like the above, arrange to use the replacement function.
 AC_DEFUN([gl_FUNC_MKSTEMP],
-[dnl
-  AC_REPLACE_FUNCS(mkstemp)
-  if test $ac_cv_func_mkstemp = no; then
-    gl_cv_func_mkstemp_limitations=yes
-  else
-    AC_CACHE_CHECK([for mkstemp limitations],
-      gl_cv_func_mkstemp_limitations,
-      [
-        mkdir conftest.mkstemp
-       AC_TRY_RUN([
-#           include <stdlib.h>
-#           include <unistd.h>
-           int main ()
-           {
-             int i;
-             for (i = 0; i < 70; i++)
-               {
-                 char template[] = "conftest.mkstemp/coXXXXXX";
-                 int fd = mkstemp (template);
-                 if (fd == -1)
-                   exit (1);
-                 close (fd);
-               }
-             exit (0);
-           }
-           ],
-         gl_cv_func_mkstemp_limitations=no,
-         gl_cv_func_mkstemp_limitations=yes,
-         gl_cv_func_mkstemp_limitations=yes
-         )
-        rm -rf conftest.mkstemp
-      ]
-    )
-  fi
+[
+  AC_REQUIRE([AC_SYS_LARGEFILE])
+
+  AC_CACHE_CHECK([for working mkstemp],
+    [gl_cv_func_working_mkstemp],
+    [
+      mkdir conftest.mkstemp
+      AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM(
+         [AC_INCLUDES_DEFAULT],
+         [[int i;
+           off_t large = (off_t) 4294967295u;
+           if (large < 0)
+             large = 2147483647;
+           for (i = 0; i < 70; i++)
+             {
+               char template[] = "conftest.mkstemp/coXXXXXX";
+               int (*mkstemp_function) (char *) = mkstemp;
+               int fd = mkstemp_function (template);
+               if (fd < 0 || lseek (fd, large, SEEK_SET) != large)
+                 return 1;
+               close (fd);
+             }
+           return 0;]])],
+       [gl_cv_func_working_mkstemp=yes],
+       [gl_cv_func_working_mkstemp=no],
+       [gl_cv_func_working_mkstemp=no])
+      rm -rf conftest.mkstemp
+    ])

-  if test $gl_cv_func_mkstemp_limitations = yes; then
+  if test $gl_cv_func_working_mkstemp != yes; then
+    AC_DEFINE([__MKSTEMP_PREFIX], [[rpl_]],
+      [Define to rpl_ if the mkstemp replacement function should be used.])
     AC_LIBOBJ(mkstemp)
     AC_LIBOBJ(tempname)
-    AC_DEFINE(mkstemp, rpl_mkstemp,
-      [Define to rpl_mkstemp if the replacement function should be used.])
     gl_PREREQ_MKSTEMP
     gl_PREREQ_TEMPNAME
   fi