view m4/snprintf-posix.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 97fc9a21a8fb
children 8250f2777afc
line wrap: on
line source

# snprintf-posix.m4 serial 14
dnl Copyright (C) 2007-2011 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_SNPRINTF_POSIX],
[
  AC_REQUIRE([gl_PRINTF_SIZES_C99])
  AC_REQUIRE([gl_PRINTF_LONG_DOUBLE])
  AC_REQUIRE([gl_PRINTF_INFINITE])
  AC_REQUIRE([gl_PRINTF_INFINITE_LONG_DOUBLE])
  AC_REQUIRE([gl_PRINTF_DIRECTIVE_A])
  AC_REQUIRE([gl_PRINTF_DIRECTIVE_F])
  AC_REQUIRE([gl_PRINTF_DIRECTIVE_N])
  AC_REQUIRE([gl_PRINTF_DIRECTIVE_LS])
  AC_REQUIRE([gl_PRINTF_POSITIONS])
  AC_REQUIRE([gl_PRINTF_FLAG_GROUPING])
  AC_REQUIRE([gl_PRINTF_FLAG_LEFTADJUST])
  AC_REQUIRE([gl_PRINTF_FLAG_ZERO])
  AC_REQUIRE([gl_PRINTF_PRECISION])
  AC_REQUIRE([gl_PRINTF_ENOMEM])
  gl_cv_func_snprintf_posix=no
  AC_CHECK_FUNCS([snprintf])
  if test $ac_cv_func_snprintf = yes; then
    gl_SNPRINTF_TRUNCATION_C99
    gl_SNPRINTF_RETVAL_C99
    gl_SNPRINTF_DIRECTIVE_N
    gl_SNPRINTF_SIZE1
    gl_VSNPRINTF_ZEROSIZE_C99
    case "$gl_cv_func_printf_sizes_c99" in
      *yes)
        case "$gl_cv_func_printf_long_double" in
          *yes)
            case "$gl_cv_func_printf_infinite" in
              *yes)
                case "$gl_cv_func_printf_infinite_long_double" in
                  *yes)
                    case "$gl_cv_func_printf_directive_a" in
                      *yes)
                        case "$gl_cv_func_printf_directive_f" in
                          *yes)
                            case "$gl_cv_func_printf_directive_n" in
                              *yes)
                                case "$gl_cv_func_printf_directive_ls" in
                                  *yes)
                                    case "$gl_cv_func_printf_positions" in
                                      *yes)
                                        case "$gl_cv_func_printf_flag_grouping" in
                                          *yes)
                                            case "$gl_cv_func_printf_flag_leftadjust" in
                                              *yes)
                                                case "$gl_cv_func_printf_flag_zero" in
                                                  *yes)
                                                    case "$gl_cv_func_printf_precision" in
                                                      *yes)
                                                        case "$gl_cv_func_printf_enomem" in
                                                          *yes)
                                                            case "$gl_cv_func_snprintf_truncation_c99" in
                                                              *yes)
                                                                case "$gl_cv_func_snprintf_retval_c99" in
                                                                  *yes)
                                                                    case "$gl_cv_func_snprintf_directive_n" in
                                                                      *yes)
                                                                        case "$gl_cv_func_snprintf_size1" in
                                                                          *yes)
                                                                            case "$gl_cv_func_vsnprintf_zerosize_c99" in
                                                                              *yes)
                                                                                # snprintf exists and is
                                                                                # already POSIX compliant.
                                                                                gl_cv_func_snprintf_posix=yes
                                                                                ;;
                                                                            esac
                                                                            ;;
                                                                        esac
                                                                        ;;
                                                                    esac
                                                                    ;;
                                                                esac
                                                                ;;
                                                            esac
                                                            ;;
                                                        esac
                                                        ;;
                                                    esac
                                                    ;;
                                                esac
                                                ;;
                                            esac
                                            ;;
                                        esac
                                        ;;
                                    esac
                                    ;;
                                esac
                                ;;
                            esac
                            ;;
                        esac
                        ;;
                    esac
                    ;;
                esac
                ;;
            esac
            ;;
        esac
        ;;
    esac
  fi
  if test $gl_cv_func_snprintf_posix = no; then
    gl_PREREQ_VASNPRINTF_LONG_DOUBLE
    gl_PREREQ_VASNPRINTF_INFINITE_DOUBLE
    gl_PREREQ_VASNPRINTF_INFINITE_LONG_DOUBLE
    gl_PREREQ_VASNPRINTF_DIRECTIVE_A
    gl_PREREQ_VASNPRINTF_DIRECTIVE_F
    gl_PREREQ_VASNPRINTF_DIRECTIVE_LS
    gl_PREREQ_VASNPRINTF_FLAG_GROUPING
    gl_PREREQ_VASNPRINTF_FLAG_LEFTADJUST
    gl_PREREQ_VASNPRINTF_FLAG_ZERO
    gl_PREREQ_VASNPRINTF_PRECISION
    gl_PREREQ_VASNPRINTF_ENOMEM
    gl_REPLACE_VASNPRINTF
    gl_REPLACE_SNPRINTF
  fi
])