AX_DEFINE_INTEGER_BITS (TYPE [, CANDIDATE-TYPE]...)
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:
AX_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 AX_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
Download the latest version of ax_define_integer_bits.m4 or browse the macro’s revision history.
Copyright © 2008 Scott Pakin pakin@uiuc.edu
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