| 1 | # strerror.m4 serial 21 |
| 2 | dnl Copyright (C) 2002, 2007-2019 Free Software Foundation, Inc. |
| 3 | dnl This file is free software; the Free Software Foundation |
| 4 | dnl gives unlimited permission to copy and/or distribute it, |
| 5 | dnl with or without modifications, as long as this notice is preserved. |
| 6 | |
| 7 | AC_DEFUN([gl_FUNC_STRERROR], |
| 8 | [ |
| 9 | AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS]) |
| 10 | AC_REQUIRE([gl_HEADER_ERRNO_H]) |
| 11 | AC_REQUIRE([gl_FUNC_STRERROR_0]) |
| 12 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| 13 | m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [ |
| 14 | AC_REQUIRE([gl_FUNC_STRERROR_R_WORKS]) |
| 15 | ]) |
| 16 | if test "$ERRNO_H:$REPLACE_STRERROR_0" = :0; then |
| 17 | AC_CACHE_CHECK([for working strerror function], |
| 18 | [gl_cv_func_working_strerror], |
| 19 | [AC_RUN_IFELSE( |
| 20 | [AC_LANG_PROGRAM( |
| 21 | [[#include <string.h> |
| 22 | ]], |
| 23 | [[if (!*strerror (-2)) return 1;]])], |
| 24 | [gl_cv_func_working_strerror=yes], |
| 25 | [gl_cv_func_working_strerror=no], |
| 26 | [case "$host_os" in |
| 27 | # Guess yes on glibc systems. |
| 28 | *-gnu* | gnu*) gl_cv_func_working_strerror="guessing yes" ;; |
| 29 | # Guess yes on musl systems. |
| 30 | *-musl*) gl_cv_func_working_strerror="guessing yes" ;; |
| 31 | # If we don't know, obey --enable-cross-guesses. |
| 32 | *) gl_cv_func_working_strerror="$gl_cross_guess_normal" ;; |
| 33 | esac |
| 34 | ]) |
| 35 | ]) |
| 36 | case "$gl_cv_func_working_strerror" in |
| 37 | *yes) ;; |
| 38 | *) |
| 39 | dnl The system's strerror() fails to return a string for out-of-range |
| 40 | dnl integers. Replace it. |
| 41 | REPLACE_STRERROR=1 |
| 42 | ;; |
| 43 | esac |
| 44 | m4_ifdef([gl_FUNC_STRERROR_R_WORKS], [ |
| 45 | dnl If the system's strerror_r or __xpg_strerror_r clobbers strerror's |
| 46 | dnl buffer, we must replace strerror. |
| 47 | case "$gl_cv_func_strerror_r_works" in |
| 48 | *no) REPLACE_STRERROR=1 ;; |
| 49 | esac |
| 50 | ]) |
| 51 | else |
| 52 | dnl The system's strerror() cannot know about the new errno values we add |
| 53 | dnl to <errno.h>, or any fix for strerror(0). Replace it. |
| 54 | REPLACE_STRERROR=1 |
| 55 | fi |
| 56 | ]) |
| 57 | |
| 58 | dnl Detect if strerror(0) passes (that is, does not set errno, and does not |
| 59 | dnl return a string that matches strerror(-1)). |
| 60 | AC_DEFUN([gl_FUNC_STRERROR_0], |
| 61 | [ |
| 62 | AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles |
| 63 | REPLACE_STRERROR_0=0 |
| 64 | AC_CACHE_CHECK([whether strerror(0) succeeds], |
| 65 | [gl_cv_func_strerror_0_works], |
| 66 | [AC_RUN_IFELSE( |
| 67 | [AC_LANG_PROGRAM( |
| 68 | [[#include <string.h> |
| 69 | #include <errno.h> |
| 70 | ]], |
| 71 | [[int result = 0; |
| 72 | char *str; |
| 73 | errno = 0; |
| 74 | str = strerror (0); |
| 75 | if (!*str) result |= 1; |
| 76 | if (errno) result |= 2; |
| 77 | if (strstr (str, "nknown") || strstr (str, "ndefined")) |
| 78 | result |= 4; |
| 79 | return result;]])], |
| 80 | [gl_cv_func_strerror_0_works=yes], |
| 81 | [gl_cv_func_strerror_0_works=no], |
| 82 | [case "$host_os" in |
| 83 | # Guess yes on glibc systems. |
| 84 | *-gnu* | gnu*) gl_cv_func_strerror_0_works="guessing yes" ;; |
| 85 | # Guess yes on musl systems. |
| 86 | *-musl*) gl_cv_func_strerror_0_works="guessing yes" ;; |
| 87 | # Guess yes on native Windows. |
| 88 | mingw*) gl_cv_func_strerror_0_works="guessing yes" ;; |
| 89 | # If we don't know, obey --enable-cross-guesses. |
| 90 | *) gl_cv_func_strerror_0_works="$gl_cross_guess_normal" ;; |
| 91 | esac |
| 92 | ]) |
| 93 | ]) |
| 94 | case "$gl_cv_func_strerror_0_works" in |
| 95 | *yes) ;; |
| 96 | *) |
| 97 | REPLACE_STRERROR_0=1 |
| 98 | AC_DEFINE([REPLACE_STRERROR_0], [1], [Define to 1 if strerror(0) |
| 99 | does not return a message implying success.]) |
| 100 | ;; |
| 101 | esac |
| 102 | ]) |