+ case ${gl_cv_func_strerror_r_works-unset} in
+ unset|*yes)
+ AC_CACHE_CHECK([whether perror matches strerror],
+ [gl_cv_func_perror_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <errno.h>
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+ ]],
+ [[char *str = strerror (-1);
+ if (!getenv("CONFTEST_OUTPUT")) return 0;
+ if (!str) str = "";
+ puts (str);
+ errno = -1;
+ perror ("");
+ return 0;
+ ]])],
+ [if CONFTEST_OUTPUT=1 ./conftest$EXEEXT >conftest.txt1 2>conftest.txt2 \
+ && cmp conftest.txt1 conftest.txt2 >/dev/null; then
+ gl_cv_func_perror_works=yes
+ else
+ gl_cv_func_perror_works=no
+ fi
+ rm -rf conftest.txt1 conftest.txt2],
+ [gl_cv_func_perror_works=no],
+ [case "$host_os" in
+ # Guess yes on native Windows.
+ mingw*) gl_cv_func_perror_works="guessing yes" ;;
+ # Otherwise guess no.
+ *) gl_cv_func_perror_works="guessing no" ;;
+ esac
+ ])
+ ])
+ case "$gl_cv_func_perror_works" in
+ *yes) ;;
+ *) REPLACE_PERROR=1 ;;
+ esac
+ ;;
+ *)
+ dnl The system's perror() probably inherits the bugs in the
+ dnl system's strerror_r(). Replace it.
+ REPLACE_PERROR=1
+ ;;
+ esac