1.autoscan (autoconf): 扫描源代码以搜寻普通的可移植性问题,比如检查编译器,库,头文件等,生成文件configure.scan,它是configure.ac的一个雏形。
your source files --> [autoscan*] --> [configure.scan] --> configure.ac
2.aclocal (automake):根据已经安装的宏,用户定义宏和acinclude.m4文件中的宏将configure.ac文件所需要的宏集中定义到文件 aclocal.m4中。aclocal是一个perl 脚本程序,它的定义是:“aclocal - create aclocal.m4 by scanning configure.ac”
user input files optional input process output files ================ ============== ======= ============ acinclude.m4 - - - - -. V .-------, configure.ac ------------------------>|aclocal| {user macro files} ->| |------> aclocal.m4 `-------' 3.autoheader(autoconf): 根据configure.ac中的某些宏,比如cpp宏定义,运行m4,声称config.h.in user input files optional input process output files ================ ============== ======= ============ aclocal.m4 - - - - - - - . | V .----------, configure.ac ----------------------->|autoheader|----> autoconfig.h.in `----------'
4.automake: automake将Makefile.am中定义的结构建立Makefile.in,然后configure脚本将生成的Makefile.in文件转换 为Makefile。如果在configure.ac中定义了一些特殊的宏,比如AC_PROG_LIBTOOL,它会调用libtoolize,否则它 会自己产生config.guess和config.sub
user input files optional input processes output files ================ ============== ========= ============ .--------, | | - - -> COPYING | | - - -> INSTALL | |------> install-sh | |------> missing |automake|------> mkinstalldirs configure.ac ----------------------->| | Makefile.am ----------------------->| |------> Makefile.in | |------> stamp-h.in .---+ | - - -> config.guess | | | - - -> config.sub | `------+-' | | - - - -> config.guess |libtoolize| - - - -> config.sub | |--------> ltmain.sh | |--------> ltconfig `----------'
5.autoconf:将configure.ac中的宏展开,生成 configure脚本。这个过程可能要用到aclocal.m4中定义的宏。
user input files optional input processes output files ================ ============== ========= ============ aclocal.m4 ,autoconfig.h.in - - - - - - -. V .--------, configure.ac ----------------------->|autoconf|------> configure
6. ./configure的过程
.-------------> [config.cache] configure* --------------------------+-------------> config.log | [config.h.in] -. v .--> [autoconfig.h] +-------> config.status* -+ Makefile.in ---' `--> Makefile
7. make过程
[autoconfig.h] -. +--> make* ---> 程序 Makefile ---'
.---------, config.site - - ->| | config.cache - - ->|<strong><span>configure</span> </strong> | - - -> config.cache | +-, `-+-------' | | |----> config.status config.h.in ------->|config- |----> config.h Makefile.in ------->| .status|----> Makefile | |----> stamp-h | +--, .-+ | | | `------+--' | ltmain.sh ------->|ltconfig|-------> libtool | | | `-+------' | |config.guess| | config.sub | `------------'
.--------, Makefile ------>| | config.h ------>| make | {project sources} ---------------->| |--------> {project targets} .-+ +--, | `--------' | | libtool | | missing | | install-sh | |mkinstalldirs| `-------------'
实例 :
在/hello/目录下创建一个hello.c文件,并编译运行它:
#cd /hello/
(1) 编写源文件hello.c:
#include<stdio.h>
int main(int argc, char** argv)
{
printf("Hello, GNU!n");
return 0;
}
[litao@vm0000131 hello]$ ll
total 4
-rw-rw-r-- 1 litao litao 68 Aug 12 12:02 hello.c
一、autoscan
[litao@vm0000131 hello]$ autoscan
autom4te: configure.ac: no such file or directory
autoscan: /usr/bin/autom4te failed with exit status: 1
[litao@vm0000131 hello]$ ll
total 8
-rw-rw-r-- 1 litao litao 0 Aug 12 12:03 autoscan.log
-rw-rw-r-- 1 litao litao 457 Aug 12 12:03 configure.scan
-rw-rw-r-- 1 litao litao 68 Aug 12 12:02 hello.c
已经生成了configure.scan,autoscan.log文件
将configure.scan 修改为 configure .in, 最后修改的内容如下:
[litao@vm0000131 hello]$ mv configure.scan configure.in
[litao@vm0000131 hello]$ vim configure.in
# -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.
AC_PREREQ(2.59)
AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)
AC_CONFIG_SRCDIR([hello.c])
#AC_CONFIG_HEADER([config.h])
AM_INIT_AUTOMAKE(hello, 1.0)
# Checks for programs.
AC_PROG_CC
# Checks for libraries.
# Checks for header files.
# Checks for typedefs, structures, and compiler characteristics.
# Checks for library functions.
AC_OUTPUT(Makefile)
二、acloacl
[litao@vm0000131 hello]$ aclocal
生成 aclocal.m4 和 autom4te.cache (生成aclocal.m4的过程中涉及到configure.in)
[litao@vm0000131 hello]$ ll
total 44
-rw-rw-r-- 1 litao litao 31120 Aug 12 12:08 aclocal.m4
drwxr-xr-x 2 litao litao 4096 Aug 12 12:08 autom4te.cache
-rw-rw-r-- 1 litao litao 0 Aug 12 12:03 autoscan.log
-rw-rw-r-- 1 litao litao 496 Aug 12 12:08 configure.in
-rw-rw-r-- 1 litao litao 68 Aug 12 12:02 hello.c
三、antoconf
[litao@vm0000131 hello]$ autoconf
生成 configure (根据 configure .in, 和 aclocal.m4)
[litao@vm0000131 hello]$ ll
total 168
-rw-rw-r-- 1 litao litao 31120 Aug 12 12:08 aclocal.m4
drwxr-xr-x 2 litao litao 4096 Aug 12 12:11 autom4te.cache
-rw-rw-r-- 1 litao litao 0 Aug 12 12:03 autoscan.log
-rwxrwxr-x 1 litao litao 122297 Aug 12 12:11 configure
-rw-rw-r-- 1 litao litao 496 Aug 12 12:08 configure.in
-rw-rw-r-- 1 litao litao 68 Aug 12 12:02 hello.c
四、编写Makefile.am:
AUTOMAKE_OPTIONS= foreign
bin_PROGRAMS= hello
hello_SOURCES= hello.c
五、automake
生成 Makefile.in, depcomp, install-sh, 和 missing (根据 Makefile.am, 和 aclocal.m4)
[litao@vm0000131 hello]$ automake
configure.in: required file `./install-sh' not found
configure.in: required file `./missing' not found
Makefile.am: required file `./depcomp' not found
[litao@vm0000131 hello]$ automake --add-missing
configure.in: installing `./install-sh'
configure.in: installing `./missing'
Makefile.am: installing `./depcomp'
[litao@vm0000131 hello]$ ll
total 192
-rw-rw-r-- 1 litao litao 31120 Aug 12 12:08 aclocal.m4
drwxr-xr-x 2 litao litao 4096 Aug 12 12:14 autom4te.cache
-rw-rw-r-- 1 litao litao 0 Aug 12 12:03 autoscan.log
-rwxrwxr-x 1 litao litao 122297 Aug 12 12:11 configure
-rw-rw-r-- 1 litao litao 496 Aug 12 12:08 configure.in
lrwxrwxrwx 1 litao litao 31 Aug 12 12:16 depcomp -> /usr/share/automake-1.9/depcomp
-rw-rw-r-- 1 litao litao 68 Aug 12 12:02 hello.c
lrwxrwxrwx 1 litao litao 34 Aug 12 12:16 install-sh -> /usr/share/automake-1.9/install-sh
-rw-rw-r-- 1 litao litao 69 Aug 12 12:15 Makefile.am
-rw-rw-r-- 1 litao litao 16561 Aug 12 12:16 Makefile.in
lrwxrwxrwx 1 litao litao 31 Aug 12 12:16 missing -> /usr/share/automake-1.9/missing
六、configure
生成 Makefile, config.log, 和 config.status
Summarize:
如果拿到的工程文件中,没有Makefile文件,而只有configure.in和Makefile.am文件,我们是不能够直接进行编译的,必须根据configure.in和Makefile.am文件生成编译所需的Makefile文件。具体操作步骤如下:
1、执行aclocal,产生aclocal.m4文件
aclocal是一个perl 脚本程序,它的定义是:“aclocal - create aclocal.m4 by scanning configure.ac”。aclocal根据configure.in文件的内容,自动生成aclocal.m4文件。而aclocal.m4文件中,包含了生成configure文件所必须的宏。
2、执行autoconf,生成configure文件
autoconf会根据configure.in和aclocal.m4文件,生成configure文件。其实,autoconf就是把configure.in和aclocal.m4文件中定义的内容,变成检查系统特性、环境变量、软件必须的参数的shell脚本。
3、执行automake命令,产生Makefile.in
具体命令为:automake --add-missing
automake会根据Makefile.am文件产生一些文件,包含最重要的Makefile.in。前面所生成的configure,会根据Makefile.in文件,来生成最终的Makefile文件。
4、执行configure命令,生成Makefile文件
这样,就产生了编译所需要的Makefile文件。运行make,即可编译。