Add option to assume the best, not the worst, when cross-compiling.

Suggested by Jonas Termansen <sortie@maxsi.org>.

* m4/gnulib-common.m4 (gl_COMMON_BODY): Add --enable-cross-guesses=...
option. Set gl_cross_guess_normal and gl_cross_guess_inverted.
* m4/argz.m4 (gl_FUNC_ARGZ): Obey --enable-cross-guesses for
lt_cv_sys_argz_works.
* m4/calloc.m4 (_AC_FUNC_CALLOC_IF): Obey --enable-cross-guesses for
ac_cv_func_calloc_0_nonnull.
* m4/canonicalize.m4 (gl_FUNC_REALPATH_WORKS): Obey
--enable-cross-guesses for gl_cv_func_realpath_works.
* m4/cbrtl.m4 (gl_FUNC_CBRTL): Obey --enable-cross-guesses for
gl_cv_func_cbrtl_ieee.
* m4/ceil.m4 (gl_FUNC_CEIL): Obey --enable-cross-guesses for
gl_cv_func_ceil_ieee.
* m4/ceilf.m4 (gl_FUNC_CEILF): Obey --enable-cross-guesses for
gl_cv_func_ceilf_ieee.
* m4/ceill.m4 (gl_FUNC_CEILL): Obey --enable-cross-guesses for
gl_cv_func_ceill_ieee.
* m4/chown.m4 (AC_FUNC_CHOWN): Obey --enable-cross-guesses for
ac_cv_func_chown_works.
(gl_FUNC_CHOWN): Obey --enable-cross-guesses for
gl_cv_func_chown_slash_works, gl_cv_func_chown_ctime_works.
* m4/d-ino.m4 (gl_CHECK_TYPE_STRUCT_DIRENT_D_INO): Obey
--enable-cross-guesses for gl_cv_struct_dirent_d_ino.
* m4/exp2l.m4 (gl_FUNC_EXP2L): Obey --enable-cross-guesses for
gl_cv_func_exp2l_works, gl_cv_func_exp2l_ieee.
* m4/expl.m4 (gl_FUNC_EXPL): Obey --enable-cross-guesses for
gl_cv_func_expl_works.
* m4/expm1.m4 (gl_FUNC_EXPM1): Obey --enable-cross-guesses for
gl_cv_func_expm1_ieee.
* m4/expm1l.m4 (gl_FUNC_EXPM1L): Obey --enable-cross-guesses for
gl_cv_func_expm1l_works.
* m4/fchdir.m4 (gl_FUNC_FCHDIR): Obey --enable-cross-guesses for
gl_cv_func_open_directory_works.
* m4/fchownat.m4 (gl_FUNC_FCHOWNAT_DEREF_BUG): Obey
--enable-cross-guesses for gl_cv_func_fchownat_nofollow_works.
(gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG): Obey --enable-cross-guesses for
gl_cv_func_fchownat_empty_filename_works.
* m4/fdopendir.m4 (gl_FUNC_FDOPENDIR): Obey --enable-cross-guesses for
gl_cv_func_fdopendir_works.
* m4/floor.m4 (gl_FUNC_FLOOR): Obey --enable-cross-guesses for
gl_cv_func_floor_ieee.
* m4/floorf.m4 (gl_FUNC_FLOORF): Obey --enable-cross-guesses for
gl_cv_func_floorf_ieee.
* m4/fma.m4 (gl_FUNC_FMA_WORKS): Obey --enable-cross-guesses for
gl_cv_func_fma_works.
* m4/fmaf.m4 (gl_FUNC_FMAF_WORKS): Obey --enable-cross-guesses for
gl_cv_func_fmaf_works.
* m4/fmal.m4 (gl_FUNC_FMAL_WORKS): Obey --enable-cross-guesses for
gl_cv_func_fmal_works.
* m4/fmod.m4 (gl_FUNC_FMOD): Obey --enable-cross-guesses for
gl_cv_func_fmod_ieee.
* m4/fmodf.m4 (gl_FUNC_FMODF): Obey --enable-cross-guesses for
gl_cv_func_fmodf_ieee.
* m4/fmodl.m4 (gl_FUNC_FMODL): Obey --enable-cross-guesses for
gl_cv_func_fmodl_ieee.
* m4/fpurge.m4 (gl_FUNC_FPURGE): Obey --enable-cross-guesses for
gl_cv_func_fpurge_works.
* m4/getcwd-path-max.m4 (gl_FUNC_GETCWD_PATH_MAX): Obey
--enable-cross-guesses for gl_cv_func_getcwd_path_max.
* m4/getcwd.m4 (gl_FUNC_GETCWD_NULL): Obey --enable-cross-guesses for
gl_cv_func_getcwd_null.
(gl_FUNC_GETCWD): Update for getcwd-path-max.m4 change.
* m4/getdelim.m4 (gl_FUNC_GETDELIM): Obey --enable-cross-guesses for
gl_cv_func_working_getdelim.
* m4/getgroups.m4 (AC_FUNC_GETGROUPS): Obey --enable-cross-guesses for
ac_cv_func_getgroups_works. Keep this macro also in Autoconf >= 2.70.
(gl_FUNC_GETGROUPS): Obey --enable-cross-guesses for
gl_cv_func_getgroups_works.
* m4/getline.m4 (gl_FUNC_GETLINE): Obey --enable-cross-guesses for
am_cv_func_working_getline.
* m4/getopt.m4 (gl_GETOPT_CHECK_HEADERS): Obey --enable-cross-guesses
for gl_cv_func_getopt_gnu.
* m4/gettimeofday.m4 (gl_FUNC_GETTIMEOFDAY_CLOBBER): Obey
--enable-cross-guesses for gl_cv_func_gettimeofday_clobber.
* m4/hypot.m4 (gl_FUNC_HYPOT): Obey --enable-cross-guesses for
gl_cv_func_hypot_ieee.
* m4/hypotf.m4 (gl_FUNC_HYPOTF): Obey --enable-cross-guesses for
gl_cv_func_hypotf_ieee.
* m4/hypotl.m4 (gl_FUNC_HYPOTL): Obey --enable-cross-guesses for
gl_cv_func_hypotl_ieee.
* m4/iconv_open-utf.m4 (gl_FUNC_ICONV_OPEN_UTF_SUPPORT): Obey
--enable-cross-guesses for gl_cv_func_iconv_supports_utf.
* m4/link.m4 (gl_FUNC_LINK): Obey --enable-cross-guesses for
gl_cv_func_link_works.
* m4/linkat.m4 (gl_FUNC_LINKAT): Obey --enable-cross-guesses for
gl_cv_func_linkat_slash.
* m4/log.m4 (gl_FUNC_LOG): Obey --enable-cross-guesses for
gl_cv_func_log_ieee.
* m4/logf.m4 (gl_FUNC_LOGF): Obey --enable-cross-guesses for
gl_cv_func_logf_ieee.
* m4/logl.m4 (gl_FUNC_LOGL_WORKS): Obey --enable-cross-guesses for
gl_cv_func_logl_works.
* m4/log10.m4 (gl_FUNC_LOG10): Obey --enable-cross-guesses for
gl_cv_func_log10_ieee.
* m4/log10f.m4 (gl_FUNC_LOG10F): Obey --enable-cross-guesses for
gl_cv_func_log10f_ieee.
* m4/log10l.m4 (gl_FUNC_LOG10L_WORKS): Obey --enable-cross-guesses for
gl_cv_func_log10l_works.
* m4/log1p.m4 (gl_FUNC_LOG1P): Obey --enable-cross-guesses for
gl_cv_func_log1p_ieee.
* m4/log1pf.m4 (gl_FUNC_LOG1PF): Obey --enable-cross-guesses for
gl_cv_func_log1pf_ieee.
* m4/log1pl.m4 (gl_FUNC_LOG1PL): Obey --enable-cross-guesses for
gl_cv_func_log1pl_ieee.
* m4/log2.m4 (gl_FUNC_LOG2): Obey --enable-cross-guesses for
gl_cv_func_log2_ieee.
* m4/log2f.m4 (gl_FUNC_LOG2F): Obey --enable-cross-guesses for
gl_cv_func_log2f_ieee.
* m4/lstat.m4 (gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK): Obey
--enable-cross-guesses for
gl_cv_func_lstat_dereferences_slashed_symlink.
* m4/malloc.m4 (_AC_FUNC_MALLOC_IF): Obey --enable-cross-guesses for
ac_cv_func_malloc_0_nonnull. Keep this macro also in Autoconf >= 2.70.
* m4/mbrtowc.m4 (gl_MBRTOWC_C_LOCALE): Obey --enable-cross-guesses for
gl_cv_C_locale_sans_EILSEQ.
* m4/memchr.m4 (gl_FUNC_MEMCHR): Obey --enable-cross-guesses for
gl_cv_func_memchr_works.
* m4/memmem.m4 (gl_FUNC_MEMMEM_SIMPLE): Obey --enable-cross-guesses for
gl_cv_func_memmem_works_always.
(gl_FUNC_MEMMEM): Obey --enable-cross-guesses for
gl_cv_func_memmem_works_fast.
* m4/mkdir.m4 (gl_FUNC_MKDIR): Obey --enable-cross-guesses for
gl_cv_func_mkdir_trailing_slash_works,
gl_cv_func_mkdir_trailing_dot_works.
* m4/mkfifo.m4 (gl_FUNC_MKFIFO): Obey --enable-cross-guesses for
gl_cv_func_mkfifo_works.
* m4/mknod.m4 (gl_FUNC_MKNOD): Obey --enable-cross-guesses for
gl_cv_func_mknod_works.
* m4/mkstemp.m4 (gl_FUNC_MKSTEMP): Obey --enable-cross-guesses for
gl_cv_func_working_mkstemp.
* m4/mktime.m4 (gl_FUNC_MKTIME_WORKS): Obey --enable-cross-guesses for
gl_cv_func_working_mktime.
* m4/modf.m4 (gl_FUNC_MODF): Obey --enable-cross-guesses for
gl_cv_func_modf_ieee.
* m4/modff.m4 (gl_FUNC_MODFF): Obey --enable-cross-guesses for
gl_cv_func_modff_ieee.
* m4/modfl.m4 (gl_FUNC_MODFL): Obey --enable-cross-guesses for
gl_cv_func_modfl_ieee.
* m4/nanosleep.m4 (gl_FUNC_NANOSLEEP): Obey --enable-cross-guesses for
gl_cv_func_nanosleep.
* m4/perror.m4 (gl_FUNC_PERROR): Obey --enable-cross-guesses for
gl_cv_func_perror_works.
* m4/printf.m4 (gl_PRINTF_SIZES_C99): Obey --enable-cross-guesses for
gl_cv_func_printf_sizes_c99.
(gl_PRINTF_INFINITE): Obey --enable-cross-guesses for
gl_cv_func_printf_infinite.
(gl_PRINTF_INFINITE_LONG_DOUBLE): Obey --enable-cross-guesses for
gl_cv_func_printf_infinite_long_double.
(gl_PRINTF_DIRECTIVE_A): Obey --enable-cross-guesses for
gl_cv_func_printf_directive_a.
(gl_PRINTF_DIRECTIVE_F): Obey --enable-cross-guesses for
gl_cv_func_printf_directive_f.
(gl_PRINTF_FLAG_ZERO): Obey --enable-cross-guesses for
gl_cv_func_printf_flag_zero.
(gl_PRINTF_ENOMEM): Obey --enable-cross-guesses for
gl_cv_func_printf_enomem.
(gl_SNPRINTF_TRUNCATION_C99): Obey --enable-cross-guesses for
gl_cv_func_snprintf_truncation_c99.
(gl_SNPRINTF_RETVAL_C99): Obey --enable-cross-guesses for
gl_cv_func_snprintf_retval_c99.
(gl_SNPRINTF_DIRECTIVE_N): Obey --enable-cross-guesses for
gl_cv_func_snprintf_directive_n.
(gl_VSNPRINTF_ZEROSIZE_C99): Obey --enable-cross-guesses for
gl_cv_func_vsnprintf_zerosize_c99.
* m4/pselect.m4 (gl_FUNC_PSELECT): Obey --enable-cross-guesses for
gl_cv_func_pselect_detects_ebadf.
* m4/pthread_rwlock_rdlock.m4 (gl_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER):
Obey --enable-cross-guesses for
gl_cv_pthread_rwlock_rdlock_prefer_writer.
* m4/ptsname.m4 (gl_FUNC_PTSNAME): Obey --enable-cross-guesses for
gl_cv_func_ptsname_sets_errno.
* m4/putenv.m4 (gl_FUNC_PUTENV): Obey --enable-cross-guesses for
gl_cv_func_svid_putenv.
* m4/readlink.m4 (gl_FUNC_READLINK): Obey --enable-cross-guesses for
gl_cv_func_readlink_works.
* m4/realloc.m4 (_AC_FUNC_REALLOC_IF): Obey --enable-cross-guesses for
ac_cv_func_realloc_0_nonnull. Keep this macro also in Autoconf >= 2.70.
* m4/regex.m4 (gl_REGEX): Obey --enable-cross-guesses for
gl_cv_func_re_compile_pattern_working.
* m4/remainder.m4 (gl_FUNC_REMAINDER): Obey --enable-cross-guesses for
gl_cv_func_remainder_ieee.
* m4/remainderf.m4 (gl_FUNC_REMAINDERF): Obey --enable-cross-guesses for
gl_cv_func_remainderf_ieee.
* m4/remainderl.m4 (gl_FUNC_REMAINDERL): Obey --enable-cross-guesses for
gl_cv_func_remainderl_ieee.
* m4/rintl.m4 (gl_FUNC_RINTL): Obey --enable-cross-guesses for
gl_cv_func_rintl_works.
* m4/rmdir.m4 (gl_FUNC_RMDIR): Obey --enable-cross-guesses for
gl_cv_func_rmdir_works.
* m4/round.m4 (gl_FUNC_ROUND): Obey --enable-cross-guesses for
gl_cv_func_round_ieee.
* m4/roundf.m4 (gl_FUNC_ROUNDF): Obey --enable-cross-guesses for
gl_cv_func_roundf_ieee.
* m4/roundl.m4 (gl_FUNC_ROUNDL): Obey --enable-cross-guesses for
gl_cv_func_roundl_ieee.
* m4/select.m4 (gl_FUNC_SELECT): Obey --enable-cross-guesses for
gl_cv_func_select_detects_ebadf.
* m4/setenv.m4 (gl_FUNC_SETENV): Obey --enable-cross-guesses for
gl_cv_func_setenv_works.
(gl_FUNC_UNSETENV): Obey --enable-cross-guesses for
gl_cv_func_unsetenv_works.
* m4/signbit.m4 (gl_SIGNBIT): Obey --enable-cross-guesses for
gl_cv_func_signbit, gl_cv_func_signbit_gcc.
* m4/sleep.m4 (gl_FUNC_SLEEP): Obey --enable-cross-guesses for
gl_cv_func_sleep_works.
* m4/stat.m4 (gl_FUNC_STAT): Obey --enable-cross-guesses for
gl_cv_func_stat_file_slash.
* m4/stpncpy.m4 (gl_FUNC_STPNCPY): Obey --enable-cross-guesses for
gl_cv_func_stpncpy.
* m4/strcasestr.m4 (gl_FUNC_STRCASESTR_SIMPLE): Obey
--enable-cross-guesses for gl_cv_func_strcasestr_works_always.
(gl_FUNC_STRCASESTR): Obey --enable-cross-guesses for
gl_cv_func_strcasestr_linear.
* m4/strerror.m4 (gl_FUNC_STRERROR): Obey --enable-cross-guesses for
gl_cv_func_working_strerror.
(gl_FUNC_STRERROR_0): Obey --enable-cross-guesses for
gl_cv_func_strerror_0_works.
* m4/strerror_r.m4 (gl_FUNC_STRERROR_R_WORKS): Obey
--enable-cross-guesses for gl_cv_func_strerror_r_works.
* m4/strstr.m4 (gl_FUNC_STRSTR_SIMPLE): Obey --enable-cross-guesses for
gl_cv_func_strstr_works_always.
(gl_FUNC_STRSTR): Obey --enable-cross-guesses for
gl_cv_func_strstr_linear.
* m4/strtod.m4 (gl_FUNC_STRTOD): Obey --enable-cross-guesses for
gl_cv_func_strtod_works.
* m4/strtold.m4 (gl_FUNC_STRTOLD): Obey --enable-cross-guesses for
gl_cv_func_strtold_works.
* m4/symlink.m4 (gl_FUNC_SYMLINK): Obey --enable-cross-guesses for
gl_cv_func_symlink_works.
* m4/symlinkat.m4 (gl_FUNC_SYMLINKAT): Obey --enable-cross-guesses for
gl_cv_func_symlinkat_works.
* m4/trunc.m4 (gl_FUNC_TRUNC): Obey --enable-cross-guesses for
gl_cv_func_trunc_ieee.
* m4/truncf.m4 (gl_FUNC_TRUNCF): Obey --enable-cross-guesses for
gl_cv_func_truncf_ieee.
* m4/truncl.m4 (gl_FUNC_TRUNCL): Obey --enable-cross-guesses for
gl_cv_func_truncl_ieee.
* m4/tzset.m4 (gl_FUNC_TZSET_CLOBBER): Obey --enable-cross-guesses for
gl_cv_func_tzset_clobber.
* m4/ungetc.m4 (gl_FUNC_UNGETC_WORKS): Obey --enable-cross-guesses for
gl_cv_func_ungetc_works.
* m4/unlink.m4 (gl_FUNC_UNLINK): Obey --enable-cross-guesses for
gl_cv_func_unlink_honors_slashes, gl_cv_func_unlink_parent_fails.
* m4/usleep.m4 (gl_FUNC_USLEEP): Obey --enable-cross-guesses for
gl_cv_func_usleep_works.
* m4/utimens.m4 (gl_UTIMENS): Obey --enable-cross-guesses for
gl_cv_func_futimesat_works.
* m4/utimes.m4 (gl_FUNC_UTIMES): Obey --enable-cross-guesses for
gl_cv_func_working_utimes.
* m4/wcwidth.m4 (gl_FUNC_WCWIDTH): Obey --enable-cross-guesses for
gl_cv_func_wcwidth_works.
* m4/glob.m4 (gl_GLOB): When cross-compiling, don't create symlinks for
testing. Obey --enable-cross-guesses for gl_cv_glob_lists_symlinks.
* m4/rename.m4 (gl_FUNC_RENAME): When cross-compiling, don't create
links for testing. Obey --enable-cross-guesses for
gl_cv_func_rename_slash_dst_works, gl_cv_func_rename_slash_src_works,
gl_cv_func_rename_link_works, gl_cv_func_rename_dest_works.

1 files changed, 3 insertions, 3 deletions

diff --git a/m4/memchr.m4 b/m4/memchr.m4
index 0be394db4f..c12d20ac76 100644
--- a/m4/memchr.m4
+++ b/m4/memchr.m4
@@ -1,4 +1,4 @@
-# memchr.m4 serial 14
+# memchr.m4 serial 15
 dnl Copyright (C) 2002-2004, 2009-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -94,8 +94,8 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR],
             linux*-android*) gl_cv_func_memchr_works="guessing no" ;;
                              # Guess yes on native Windows.
             mingw*)          gl_cv_func_memchr_works="guessing yes" ;;
-                             # Be pessimistic for now.
-            *)               gl_cv_func_memchr_works="guessing no" ;;
+                             # If we don't know, obey --enable-cross-guesses.
+            *)               gl_cv_func_memchr_works="$gl_cross_guess_normal" ;;
           esac
          ])
       ])