view m4/wctype_h.m4 @ 15308:a3ba680ad389

strerror_r: fix OpenBSD behavior on 0 OpenBSD treats strerror_r(0,,) as a success, but with a message "Undefined error: 0"; while this is distinct from strerror_r(-1,,) returning "Unknown error: -1", it does not imply success. Meanwhile, if buf is short enough for ERANGE, then we can't use strstr to look for "Unknown" or "Undefined" in the resulting message, like we had been doing for strerror(). Fix this by shifting the burden - now the strerror-override code guarantees that 0 will have an override when needed. * lib/strerror-override.c (strerror_override): Also override 0 when needed. * lib/strerror-override.h (strerror_override): Likewise. * lib/strerror.c (strerror): Simplify, now that 0 override is done earlier. * lib/strerror_r.c (strerror_r): Likewise. * m4/strerror.m4 (gl_FUNC_STRERROR): Split detection of 0 behavior... (gl_FUNC_STRERROR_0): ...into new macro. * m4/strerror_r.m4 (gl_FUNC_STRERROR_R): Replace strerror_r if 0 is overridden. (gl_FUNC_STRERROR_R_WORKS): Avoid extra tests if 0 is broken. * modules/strerror-override (Files): Add strerror.m4. (configure.ac): Also provide override for 0 when needed. * doc/posix-functions/strerror.texi (strerror): Document this. * doc/posix-functions/perror.texi (perror): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Tue, 21 Jun 2011 08:50:51 -0600
parents 4d31d731ac62
children fe7627541c17
line wrap: on
line source

# wctype_h.m4 serial 14

dnl A placeholder for ISO C99 <wctype.h>, for platforms that lack it.

dnl Copyright (C) 2006-2011 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.

dnl Written by Paul Eggert.

AC_DEFUN([gl_WCTYPE_H],
[
  AC_REQUIRE([gl_WCTYPE_H_DEFAULTS])
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_CANONICAL_HOST])
  AC_CHECK_FUNCS_ONCE([iswcntrl])
  if test $ac_cv_func_iswcntrl = yes; then
    HAVE_ISWCNTRL=1
  else
    HAVE_ISWCNTRL=0
  fi
  AC_SUBST([HAVE_ISWCNTRL])

  AC_REQUIRE([AC_C_INLINE])

  AC_REQUIRE([gt_TYPE_WINT_T])
  if test $gt_cv_c_wint_t = yes; then
    HAVE_WINT_T=1
  else
    HAVE_WINT_T=0
  fi
  AC_SUBST([HAVE_WINT_T])

  gl_CHECK_NEXT_HEADERS([wctype.h])
  if test $ac_cv_header_wctype_h = yes; then
    if test $ac_cv_func_iswcntrl = yes; then
      dnl Linux libc5 has an iswprint function that returns 0 for all arguments.
      dnl The other functions are likely broken in the same way.
      AC_CACHE_CHECK([whether iswcntrl works], [gl_cv_func_iswcntrl_works],
        [
          AC_RUN_IFELSE(
            [AC_LANG_SOURCE([[
               /* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
                  included before <wchar.h>.
                  BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
                  must be included before <wchar.h>.  */
               #include <stddef.h>
               #include <stdio.h>
               #include <time.h>
               #include <wchar.h>
               #include <wctype.h>
               int main () { return iswprint ('x') == 0; }
            ]])],
            [gl_cv_func_iswcntrl_works=yes], [gl_cv_func_iswcntrl_works=no],
            [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
                          #if __GNU_LIBRARY__ == 1
                          Linux libc5 i18n is broken.
                          #endif]], [])],
              [gl_cv_func_iswcntrl_works=yes], [gl_cv_func_iswcntrl_works=no])
            ])
        ])
    fi
    HAVE_WCTYPE_H=1
  else
    HAVE_WCTYPE_H=0
  fi
  AC_SUBST([HAVE_WCTYPE_H])

  if test "$gl_cv_func_iswcntrl_works" = no; then
    REPLACE_ISWCNTRL=1
  else
    REPLACE_ISWCNTRL=0
  fi
  AC_SUBST([REPLACE_ISWCNTRL])

  if test $HAVE_ISWCNTRL = 0 || test $REPLACE_ISWCNTRL = 1; then
    dnl Redefine all of iswcntrl, ..., towupper in <wctype.h>.
    :
  fi

  dnl We assume that the wctype() and iswctype() functions exist if and only
  dnl if the type wctype_t is defined in <wchar.h> or in <wctype.h> if that
  dnl exists.
  dnl HP-UX 11.00 declares all these in <wchar.h> and lacks <wctype.h>.
  AC_CACHE_CHECK([for wctype_t], [gl_cv_type_wctype_t],
    [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
          [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
               included before <wchar.h>.
               BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
               must be included before <wchar.h>.  */
            #include <stddef.h>
            #include <stdio.h>
            #include <time.h>
            #include <wchar.h>
            #if HAVE_WCTYPE_H
            # include <wctype.h>
            #endif
            wctype_t a;
          ]],
          [[]])],
       [gl_cv_type_wctype_t=yes],
       [gl_cv_type_wctype_t=no])
    ])
  if test $gl_cv_type_wctype_t = no; then
    HAVE_WCTYPE_T=0
  fi

  dnl We assume that the wctrans() and towctrans() functions exist if and only
  dnl if the type wctrans_t is defined in <wctype.h>.
  AC_CACHE_CHECK([for wctrans_t], [gl_cv_type_wctrans_t],
    [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
          [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
               included before <wchar.h>.
               BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
               must be included before <wchar.h>.  */
            #include <stddef.h>
            #include <stdio.h>
            #include <time.h>
            #include <wchar.h>
            #include <wctype.h>
            wctrans_t a;
          ]],
          [[]])],
       [gl_cv_type_wctrans_t=yes],
       [gl_cv_type_wctrans_t=no])
    ])
  if test $gl_cv_type_wctrans_t = no; then
    HAVE_WCTRANS_T=0
  fi

  dnl Check for declarations of anything we want to poison if the
  dnl corresponding gnulib module is not in use.
  gl_WARN_ON_USE_PREPARE([[
/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
   <wchar.h>.
   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
   included before <wchar.h>.  */
#if !(defined __GLIBC__ && !defined __UCLIBC__)
# include <stddef.h>
# include <stdio.h>
# include <time.h>
# include <wchar.h>
#endif
#include <wctype.h>
    ]],
    [wctype iswctype wctrans towctrans
    ])
])

AC_DEFUN([gl_WCTYPE_MODULE_INDICATOR],
[
  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
  AC_REQUIRE([gl_WCTYPE_H_DEFAULTS])
  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
  dnl Define it also as a C macro, for the benefit of the unit tests.
  gl_MODULE_INDICATOR_FOR_TESTS([$1])
])

AC_DEFUN([gl_WCTYPE_H_DEFAULTS],
[
  GNULIB_ISWBLANK=0;    AC_SUBST([GNULIB_ISWBLANK])
  GNULIB_WCTYPE=0;      AC_SUBST([GNULIB_WCTYPE])
  GNULIB_ISWCTYPE=0;    AC_SUBST([GNULIB_ISWCTYPE])
  GNULIB_WCTRANS=0;     AC_SUBST([GNULIB_WCTRANS])
  GNULIB_TOWCTRANS=0;   AC_SUBST([GNULIB_TOWCTRANS])
  dnl Assume proper GNU behavior unless another module says otherwise.
  HAVE_ISWBLANK=1;      AC_SUBST([HAVE_ISWBLANK])
  HAVE_WCTYPE_T=1;      AC_SUBST([HAVE_WCTYPE_T])
  HAVE_WCTRANS_T=1;     AC_SUBST([HAVE_WCTRANS_T])
  REPLACE_ISWBLANK=0;   AC_SUBST([REPLACE_ISWBLANK])
])