ACX_DEBUG_CFLAGS usage

configure.ac

#                                               -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.
AC_PREREQ([2.69])

# our own version constants
m4_define([VERSION_MAJOR], [1])
m4_define([VERSION_MINOR], [0])
m4_define([VERSION_PATCH], [0])
m4_define([VERSION_STATE], [dev])

m4_define([VERSION_FULL],
        [VERSION_MAJOR.VERSION_MINOR.VERSION_PATCH-VERSION_STATE])

AC_INIT([gicht], m4_defn([VERSION_FULL]), [mike@php.net])

AC_CONFIG_AUX_DIR([.])
AC_CONFIG_SRCDIR([src/gichtd.c])
AC_CONFIG_MACRO_DIR([m4])

AM_INIT_AUTOMAKE([-Wall foreign check-news no-define])
AM_SILENT_RULES([yes])

AC_SUBST([GICHT_VERSION_MAJOR], [VERSION_MAJOR])
AC_SUBST([GICHT_VERSION_MINOR], [VERSION_MINOR])
AC_SUBST([GICHT_VERSION_PATCH], [VERSION_PATCH])
AC_SUBST([GICHT_VERSION_STATE], [VERSION_STATE])

# *** library versioning
# See: https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
# If the library source code has changed at all since the last update, 
# then increment revision (‘c:r:a’ becomes ‘c:r+1:a’).
# If any interfaces have been added, removed, or changed since the last update, 
# increment current, and set revision to 0.
# If any interfaces have been added since the last public release, then increment age.
# If any interfaces have been removed or changed since the last public release, 
# then set age to 0.
AC_SUBST([VERSION_INFO], [0:0:0])

ACX_DEBUG_CFLAGS