一个简单的执行程序的GNU automake自动生成Makefile的方法及案例

在GNU的世界里，存在Automake这样的工具进行自动生成Makefile文件，automake是由Perl语言编写的，必须与GNU autoconf一并使用，具体的生成过程请参看GNU automake的wikipedia中的右下角的图，地址如下：http://en.wikipedia.org/wiki/Automake，由此图可看到使用自动生成Makefile的工具使用的流程，步骤主要如下：

1. autoscan
2. 修改生成的configure.scan为configure.in
3. aclocal
4. autoheader
5. autoconf
6. 创建Makefile.am并进行具体内容的写入
7. automake
8. automake
9. ./configure生成Makefile
10. make得到可执行程序

光空说太抽象了，那么来一个简单的例子吧，

0. 创建一个printf("Hello world!\n")的小程序，创建目录hello后创建hello.c，

ufo@ufo:~/hello$ ls
hello.c

那么下一步即可开始automake的工作了，

1、使用autoscan生成configure.scan

ufo@ufo:~/hello$ autoscan 
ufo@ufo:~/hello$ ls
autoscan.log  configure.scan  hello.c
ufo@ufo:~/hello$ aclocal
aclocal: `configure.ac‘ or `configure.in‘ is required

2、在上一步中直接执行aclocal时出现以上的提示，那么就要将生成的configure.scan修改为configure.ac或configure.in再进行aclocal的执行；

ufo@ufo:~/hello$ mv configure.scan configure.in 
ufo@ufo:~/hello$ ls
autoscan.log  configure.in  hello.c

3、执行aclocal

ufo@ufo:~/hello$ aclocal
ufo@ufo:~/hello$ ls
autom4te.cache  autoscan.log  configure.in  hello.c

4、执行autoheader

ufo@ufo:~/hello$ ls
autom4te.cache  autoscan.log  config.h.in  configure.in  hello.c

5、执行autoconf

ufo@ufo:~/hello$ autoconf 
ufo@ufo:~/hello$ ls
autom4te.cache  autoscan.log  config.h.in  configure  configure.in  hello.c

6、创建Makefile.am

ufo@ufo:~/hello$ vim Makefile.am 
ufo@ufo:~/hello$ cat Makefile.am 
bin_PROGRAMS=hello
hello_SOURCES=hello.c

关于Makefile.am中的具体内容的意思是说生成的可执行文件的名称为hello,对应的源代码为hello.c。

7、执行automake

ufo@ufo:~/hello$ automake
configure.in: no proper invocation of AM_INIT_AUTOMAKE was found.
configure.in: You should verify that configure.in invokes AM_INIT_AUTOMAKE,
configure.in: that aclocal.m4 is present in the top-level directory,
configure.in: and that aclocal.m4 was recently regenerated (using aclocal).
automake: no `Makefile.am‘ found for any configure output
automake: Did you forget AC_CONFIG_FILES([Makefile]) in configure.in?

这时出错了，是说configure.in文件中的AM_INIT_AUTOMAKE没有找到，只有修改configure.in
文件后再从第三步进行重新执行，configure.in中的AC_INIT行下添加
AM_INIT_AUTOMAKE(hello,1.0)，格式为AM_INIT_AUTOMAKE(package,version)，再修改AC_OUTPUT为AC_OUTPUT(Makefile)；

修改完configure.in文件后，再次执行2～7;

8、执行automake

ufo@ufo:~/hello$ automake
configure.in:6: required file `./install-sh‘ not found
configure.in:6:   `automake --add-missing‘ can install `install-sh‘
configure.in:6: required file `./missing‘ not found
configure.in:6:   `automake --add-missing‘ can install `missing‘
Makefile.am: required file `./INSTALL‘ not found
Makefile.am:   `automake --add-missing‘ can install `INSTALL‘
Makefile.am: required file `./NEWS‘ not found
Makefile.am: required file `./README‘ not found
Makefile.am: required file `./AUTHORS‘ not found
Makefile.am: required file `./ChangeLog‘ not found
Makefile.am: required file `./COPYING‘ not found
Makefile.am:   `automake --add-missing‘ can install `COPYING‘
Makefile.am: required file `./depcomp‘ not found
Makefile.am:   `automake --add-missing‘ can install `depcomp‘

按照提示创建缺少的文件,

ufo@ufo:~/hello$ touch NEWS README AUTHORS ChangeLog

再执行:

ufo@ufo:~/hello$ automake --add-missing

没有出错的情况下再次执行automake;

ufo@ufo:~/hello$ ls
aclocal.m4      ChangeLog     configure.in  INSTALL      missing
AUTHORS         config.h.in   COPYING       install-sh   NEWS
autom4te.cache  config.h.in~  depcomp       Makefile.am  README
autoscan.log    configure     hello.c       Makefile.in

此时已经生成了生成Makefile文件的cinfigure脚本；

9、./configure生成Makefile

ufo@ufo:~/hello$ ls Makefile
Makefile

10、make得到可执行程序

ufo@ufo:~/hello$ make
make  all-am
make[1]: 正在进入目录 `/home/ufo/hello‘
gcc -DHAVE_CONFIG_H -I.     -g -O2 -MT hello.o -MD -MP -MF .deps/hello.Tpo -c -o hello.o hello.c
mv -f .deps/hello.Tpo .deps/hello.Po
gcc  -g -O2   -o hello hello.o  
make[1]:正在离开目录 `/home/ufo/hello‘
ufo@ufo:~/hello$ ls
aclocal.m4      config.h       configure     hello.c     Makefile.am  stamp-h1
AUTHORS         config.h.in    configure.in  hello.o     Makefile.in
autom4te.cache  config.h.in~   COPYING       INSTALL     missing
autoscan.log    config.log     depcomp       install-sh  NEWS
ChangeLog       config.status  hello         Makefile    README
ufo@ufo:~/hello$ ./hello 
Hello World!

这就是牛X的automake的例子；关于其中的细节日后有空再表了 ;-)

Ref:

http://en.wikipedia.org/wiki/Automake
http://www.gnu.org/software/automake/manual/
http://socgsa.cs.clemson.edu/seminar/tools06/resources/08_autotools/automake.htm