view m4/mkstemp.m4 @ 17627:4d899884c95c

m4: fix gl_TIMER_TIME() detection of threads on uClibc The timer_time.m4 gl_TIMER_TIME function determines which libraries need to be linked to get access to the timer function, generally -lrt for Linux systems. On platforms where threads are used, librt typically uses thread functions from libpthread. However, the test to determine whether the platform has thread or not is incorrect: it assumes that if the C library is uClibc, then threads are not available. This is actually not true: uClibc has configurable thread support, and when thread support is available, librt calls libpthread functions. This is important when static linking is used, because otherwise only -lrt is used at link time, which fails because librt calls undefined thread functions. Both -lrt and -lpthread must be passed. This problem is fixed by making the uClibc thread detection a bit smarter, thanks to the usage of the __HAS_NO_THREADS__ macro defined in <bits/uClibc_config.h>, which itself is included by <features.h>. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Eric Blake <eblake@redhat.com>
author Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
date Sat, 22 Feb 2014 00:41:38 +0100
parents 344018b6e5d7
children
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#serial 23

# Copyright (C) 2001, 2003-2007, 2009-2014 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

# On some hosts (e.g., HP-UX 10.20, SunOS 4.1.4, Solaris 2.5.1), mkstemp has a
# silly limit that it can create no more than 26 files from a given template.
# Other systems lack mkstemp altogether.
# On OSF1/Tru64 V4.0F, the system-provided mkstemp function can create
# only 32 files per process.
# On some hosts, mkstemp creates files with mode 0666, which is a security
# problem and a violation of POSIX 2008.
# On systems like the above, arrange to use the replacement function.
AC_DEFUN([gl_FUNC_MKSTEMP],
[
  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

  AC_CHECK_FUNCS_ONCE([mkstemp])
  if test $ac_cv_func_mkstemp = yes; then
    AC_CACHE_CHECK([for working mkstemp],
      [gl_cv_func_working_mkstemp],
      [
        mkdir conftest.mkstemp
        AC_RUN_IFELSE(
          [AC_LANG_PROGRAM(
            [AC_INCLUDES_DEFAULT],
            [[int result = 0;
              int i;
              off_t large = (off_t) 4294967295u;
              if (large < 0)
                large = 2147483647;
              umask (0);
              for (i = 0; i < 70; i++)
                {
                  char templ[] = "conftest.mkstemp/coXXXXXX";
                  int (*mkstemp_function) (char *) = mkstemp;
                  int fd = mkstemp_function (templ);
                  if (fd < 0)
                    result |= 1;
                  else
                    {
                      struct stat st;
                      if (lseek (fd, large, SEEK_SET) != large)
                        result |= 2;
                      if (fstat (fd, &st) < 0)
                        result |= 4;
                      else if (st.st_mode & 0077)
                        result |= 8;
                      if (close (fd))
                        result |= 16;
                    }
                }
              return result;]])],
          [gl_cv_func_working_mkstemp=yes],
          [gl_cv_func_working_mkstemp=no],
          [case "$host_os" in
                     # Guess yes on glibc systems.
             *-gnu*) gl_cv_func_working_mkstemp="guessing yes" ;;
                     # If we don't know, assume the worst.
             *)      gl_cv_func_working_mkstemp="guessing no" ;;
           esac
          ])
        rm -rf conftest.mkstemp
      ])
    case "$gl_cv_func_working_mkstemp" in
      *yes) ;;
      *)
        REPLACE_MKSTEMP=1
        ;;
    esac
  else
    HAVE_MKSTEMP=0
  fi
])

# Prerequisites of lib/mkstemp.c.
AC_DEFUN([gl_PREREQ_MKSTEMP],
[
])