1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-12 09:28:24 +00:00
emacs/m4/minmax.m4
2024-01-02 09:47:10 +08:00

45 lines
1.3 KiB
Plaintext

# minmax.m4 serial 4
dnl Copyright (C) 2005, 2009-2024 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_PREREQ([2.53])
AC_DEFUN([gl_MINMAX],
[
AC_REQUIRE([gl_PREREQ_MINMAX])
])
# Prerequisites of lib/minmax.h.
AC_DEFUN([gl_PREREQ_MINMAX],
[
gl_MINMAX_IN_HEADER([limits.h])
gl_MINMAX_IN_HEADER([sys/param.h])
])
dnl gl_MINMAX_IN_HEADER(HEADER)
dnl The parameter has to be a literal header name; it cannot be macro,
dnl nor a shell variable. (Because autoheader collects only AC_DEFINE
dnl invocations with a literal macro name.)
AC_DEFUN([gl_MINMAX_IN_HEADER],
[
m4_pushdef([header], AS_TR_SH([$1]))
m4_pushdef([HEADER], AS_TR_CPP([$1]))
AC_CACHE_CHECK([whether <$1> defines MIN and MAX],
[gl_cv_minmax_in_]header,
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <$1>
int x = MIN (42, 17);]],
[[]])],
[gl_cv_minmax_in_]header[=yes],
[gl_cv_minmax_in_]header[=no])])
if test $gl_cv_minmax_in_[]header = yes; then
AC_DEFINE([HAVE_MINMAX_IN_]HEADER, 1,
[Define to 1 if <$1> defines the MIN and MAX macros.])
fi
m4_popdef([HEADER])
m4_popdef([header])
])