Mercurial > hg > octave-kai > gnulib-hg
changeset 16822:9dc1117772ee
signbit: Avoid "guessing no" when cross-compiling to glibc systems.
* m4/signbit.m4 (gl_SIGNBIT): Require AC_CANONICAL_HOST. When cross-
compiling to a glibc system, set gl_cv_func_signbit and
gl_cv_func_signbit_gcc to "guessing yes".
| author | Bruno Haible <bruno@clisp.org> |
|---|---|
| date | Sat, 05 May 2012 11:42:54 +0200 |
| parents | d9b4f726faa7 |
| children | c663938a6408 |
| files | ChangeLog m4/signbit.m4 |
| diffstat | 2 files changed, 103 insertions(+), 77 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-05-05 Bruno Haible <bruno@clisp.org> + + signbit: Avoid "guessing no" when cross-compiling to glibc systems. + * m4/signbit.m4 (gl_SIGNBIT): Require AC_CANONICAL_HOST. When cross- + compiling to a glibc system, set gl_cv_func_signbit and + gl_cv_func_signbit_gcc to "guessing yes". + 2012-05-05 Bruno Haible <bruno@clisp.org> strerror: Avoid "guessing no" when cross-compiling to glibc systems.
--- a/m4/signbit.m4 +++ b/m4/signbit.m4 @@ -1,4 +1,4 @@ -# signbit.m4 serial 11 +# signbit.m4 serial 12 dnl Copyright (C) 2007-2012 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -7,6 +7,7 @@ AC_DEFUN([gl_SIGNBIT], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([for signbit macro], [gl_cv_func_signbit], [ AC_RUN_IFELSE( @@ -27,7 +28,13 @@ ])], [gl_cv_func_signbit=yes], [gl_cv_func_signbit=no], - [gl_cv_func_signbit="guessing no"]) + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu*) gl_cv_func_signbit="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_signbit="guessing no" ;; + esac + ]) ]) dnl GCC 4.0 and newer provides three built-ins for signbit. dnl They can be used without warnings, also in C++, regardless of <math.h>. @@ -50,87 +57,99 @@ ])], [gl_cv_func_signbit_gcc=yes], [gl_cv_func_signbit_gcc=no], - [gl_cv_func_signbit_gcc="guessing no"]) + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu*) gl_cv_func_signbit_gcc="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_signbit_gcc="guessing no" ;; + esac + ]) ]) dnl Use the compiler built-ins whenever possible, because they are more dnl efficient than the system library functions (if they exist). - if test "$gl_cv_func_signbit_gcc" = yes; then - REPLACE_SIGNBIT_USING_GCC=1 - else - if test "$gl_cv_func_signbit" != yes; then - dnl REPLACE_SIGNBIT=1 makes sure the signbit[fdl] functions get built. - REPLACE_SIGNBIT=1 - gl_FLOAT_SIGN_LOCATION - gl_DOUBLE_SIGN_LOCATION - gl_LONG_DOUBLE_SIGN_LOCATION - if test "$gl_cv_cc_float_signbit" = unknown; then - dnl Test whether copysignf() is declared. - AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]]) - if test "$ac_cv_have_decl_copysignf" = yes; then - dnl Test whether copysignf() can be used without libm. - AC_CACHE_CHECK([whether copysignf can be used without linking with libm], - [gl_cv_func_copysignf_no_libm], - [ - AC_LINK_IFELSE( - [AC_LANG_PROGRAM( - [[#include <math.h> - float x, y;]], - [[return copysignf (x, y) < 0;]])], - [gl_cv_func_copysignf_no_libm=yes], - [gl_cv_func_copysignf_no_libm=no]) - ]) - if test $gl_cv_func_copysignf_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1], - [Define if the copysignf function is declared in <math.h> and available in libc.]) + case "$gl_cv_func_signbit_gcc" in + *yes) + REPLACE_SIGNBIT_USING_GCC=1 + ;; + *) + case "$gl_cv_func_signbit" in + *yes) ;; + *) + dnl REPLACE_SIGNBIT=1 makes sure the signbit[fdl] functions get built. + REPLACE_SIGNBIT=1 + gl_FLOAT_SIGN_LOCATION + gl_DOUBLE_SIGN_LOCATION + gl_LONG_DOUBLE_SIGN_LOCATION + if test "$gl_cv_cc_float_signbit" = unknown; then + dnl Test whether copysignf() is declared. + AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysignf" = yes; then + dnl Test whether copysignf() can be used without libm. + AC_CACHE_CHECK([whether copysignf can be used without linking with libm], + [gl_cv_func_copysignf_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + float x, y;]], + [[return copysignf (x, y) < 0;]])], + [gl_cv_func_copysignf_no_libm=yes], + [gl_cv_func_copysignf_no_libm=no]) + ]) + if test $gl_cv_func_copysignf_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1], + [Define if the copysignf function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - if test "$gl_cv_cc_double_signbit" = unknown; then - dnl Test whether copysign() is declared. - AC_CHECK_DECLS([copysign], , , [[#include <math.h>]]) - if test "$ac_cv_have_decl_copysign" = yes; then - dnl Test whether copysign() can be used without libm. - AC_CACHE_CHECK([whether copysign can be used without linking with libm], - [gl_cv_func_copysign_no_libm], - [ - AC_LINK_IFELSE( - [AC_LANG_PROGRAM( - [[#include <math.h> - double x, y;]], - [[return copysign (x, y) < 0;]])], - [gl_cv_func_copysign_no_libm=yes], - [gl_cv_func_copysign_no_libm=no]) - ]) - if test $gl_cv_func_copysign_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1], - [Define if the copysign function is declared in <math.h> and available in libc.]) + if test "$gl_cv_cc_double_signbit" = unknown; then + dnl Test whether copysign() is declared. + AC_CHECK_DECLS([copysign], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysign" = yes; then + dnl Test whether copysign() can be used without libm. + AC_CACHE_CHECK([whether copysign can be used without linking with libm], + [gl_cv_func_copysign_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + double x, y;]], + [[return copysign (x, y) < 0;]])], + [gl_cv_func_copysign_no_libm=yes], + [gl_cv_func_copysign_no_libm=no]) + ]) + if test $gl_cv_func_copysign_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1], + [Define if the copysign function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - if test "$gl_cv_cc_long_double_signbit" = unknown; then - dnl Test whether copysignl() is declared. - AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]]) - if test "$ac_cv_have_decl_copysignl" = yes; then - dnl Test whether copysignl() can be used without libm. - AC_CACHE_CHECK([whether copysignl can be used without linking with libm], - [gl_cv_func_copysignl_no_libm], - [ - AC_LINK_IFELSE( - [AC_LANG_PROGRAM( - [[#include <math.h> - long double x, y;]], - [[return copysignl (x, y) < 0;]])], - [gl_cv_func_copysignl_no_libm=yes], - [gl_cv_func_copysignl_no_libm=no]) - ]) - if test $gl_cv_func_copysignl_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1], - [Define if the copysignl function is declared in <math.h> and available in libc.]) + if test "$gl_cv_cc_long_double_signbit" = unknown; then + dnl Test whether copysignl() is declared. + AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysignl" = yes; then + dnl Test whether copysignl() can be used without libm. + AC_CACHE_CHECK([whether copysignl can be used without linking with libm], + [gl_cv_func_copysignl_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + long double x, y;]], + [[return copysignl (x, y) < 0;]])], + [gl_cv_func_copysignl_no_libm=yes], + [gl_cv_func_copysignl_no_libm=no]) + ]) + if test $gl_cv_func_copysignl_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1], + [Define if the copysignl function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - fi - fi + ;; + esac + ;; + esac ]) AC_DEFUN([gl_SIGNBIT_TEST_PROGRAM], [[