Autoconf

Table of Contents

TODOs:

1 References

1.1 A tutorial

https://www.sourceware.org/autobook/download.html This book is a tutorial. Those I didn't study carefully in this book:

  • Dynamic load library
  • portable bash script
  • m4
  • what makes a GNU project
  • cross compilation

1.6 Other reference discovered by this reading

https://www.gnu.org/prep/standards/

2 Introduction

This article talks about the GNU build system:

  • autoconf
  • automake
  • libtool: portably create and maintani dynamic linked library

3 Some random staff

Autoconf is a tool for producing shell scripts that automatically configure software source code packages to adapt to many kinds of Posix-like systems. The configuration scripts produced by Autoconf are independent of Autoconf when they are run, so their users do not need to have Autoconf.

4 interaction

There're two files provided by developer: Makefile.am and configure.in.

  1. Makefile.am is taken by automake to generate Makefile.in.
  2. Makefile.in + configure.in with help of autoconf, generate configure
  3. Then, use this configure script, generates:
    • config.cache
    • config.log
    • config.status
    • config.h
    • Makefile

4.1 configuration name

config.guess can determines the configuration name for the system it is run on, e.g.

  • i586-pc-linux-gnu
  • i386-pc-cygwin
  • sparc-sun-solaris2.7

All configuration names used to have three parts, and in some documentation they are still called configuration triplets. A three part configuration name is cpu-manufacturer-operatingsystem.

5 A typical workflow

Makefile.am 

## Makefile.am -- Process this file with automake to produce Makefile.in
bin_PROGRAMS = foo
foo_SOURCES = a.c

configure.ac 

dnl Process this file with autoconf to produce a configure script.

AC_PREREQ(2.59)

AC_INIT([foo], [2.0], [[email protected]])

AM_INIT_AUTOMAKE([1.9 foreign])

AC_PROG_CC
AM_PROG_LEX
AC_PROG_YACC

AC_CONFIG_FILES([Makefile])
AC_OUTPUT

a.c 

#include <stdio.h>

int main() {
  printf("Hello Automake\n");
}

Then run 

aclocal # generate aclocal.m4
autoconf # generate configure
automake --add-missing # generate Makefile.in, and symbol link depcomp, compile, install-sh, missing
./configure # generate config.status, config.log, Makefile
make all # generate a.o, foo

5.1 bootstrap

From the empty project, how to reach a configure && make && make install ready status?

Create a bootstrap shell script: 

#! /bin/sh

aclocal \
&& automake --gnu --add-missing \
&& autoconf

The autoreconf does the same thing. Try it.