gnulib/import/m4/limits-h.m4

   1 dnl Check whether limits.h has needed features.
   2
   3 dnl Copyright 2016-2019 Free Software Foundation, Inc.
   4 dnl This file is free software; the Free Software Foundation
   5 dnl gives unlimited permission to copy and/or distribute it,
   6 dnl with or without modifications, as long as this notice is preserved.
   7
   8 dnl From Paul Eggert.
   9
  10 AC_DEFUN_ONCE([gl_LIMITS_H],
  11 [
  12   gl_CHECK_NEXT_HEADERS([limits.h])
  13
  14   AC_CACHE_CHECK([whether limits.h has LLONG_MAX, WORD_BIT, ULLONG_WIDTH etc.],
  15     [gl_cv_header_limits_width],
  16     [AC_COMPILE_IFELSE(
  17        [AC_LANG_PROGRAM(
  18           [[#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
  19              #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
  20             #endif
  21             #include <limits.h>
  22             long long llm = LLONG_MAX;
  23             int wb = WORD_BIT;
  24             int ullw = ULLONG_WIDTH;
  25           ]])],
  26        [gl_cv_header_limits_width=yes],
  27        [gl_cv_header_limits_width=no])])
  28   if test "$gl_cv_header_limits_width" = yes; then
  29     LIMITS_H=
  30   else
  31     LIMITS_H=limits.h
  32   fi
  33   AC_SUBST([LIMITS_H])
  34   AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
  35 ])
  36
  37 dnl Unconditionally enables the replacement of <limits.h>.
  38 AC_DEFUN([gl_REPLACE_LIMITS_H],
  39 [
  40   AC_REQUIRE([gl_LIMITS_H])
  41   LIMITS_H='limits.h'
  42   AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
  43 ])