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ac_define_integer_bits

SYNOPSIS

AC_DEFINE_INTEGER_BITS (TYPE [, CANDIDATE-TYPE]...)

DESCRIPTION

Given a TYPE of the form "int##_t" or "uint##_t", see if the datatype TYPE is predefined. If not, then define TYPE -- both with AC_DEFINE and as a shell variable -- to the first datatype of exactly ## bits in a list of CANDIDATE-TYPEs. If none of the CANDIDATE-TYPEs contains exactly ## bits, then set the TYPE shell variable to "no".

For example, the following ensures that uint64_t is defined as a 64-bit datatype:

    AC_DEFINE_INTEGER_BITS(uint64_t, unsigned long long, unsigned __int64, long)
    if test "$uint64_t" = no; then
      AC_MSG_ERROR([unable to continue without a 64-bit datatype])
    fi

You should then put the following in your C code to ensure that all datatypes defined by AC_DEFINE_INTEGER_BITS are visible to your program:

    #include "config.h"

    #if HAVE_INTTYPES_H
    # include <inttypes.h>
    #else
    # if HAVE_STDINT_H
    #  include <stdint.h>
    # endif
    #endif

SOURCE CODE

http://autoconf-archive.cryp.to/ac_define_integer_bits.m4

LICENSE

Copyright © 2008 Scott Pakin <pakin@uiuc.edu>

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.