使用automake一步步生成makefile
上一篇文章我们把ffmpeg库成功在windows平台下编译成dll了，ffmpeg的编译方案是跨平台的，直接使用它的现成的configure文件用于生成makefile,但是ijkplayer的另外两个库ijkplayer和ijksdl只支持android和IOS平台，因此在windows平台的编译需要自己实现，我们打算使用automake，先熟悉一下，从网络搜罗了两个例子，在自己的环境里面一步步成功生成了makefile，其中有些坑，现在将这些步骤记录下来。
准备环境
平台 windows mingw
autoconf 版本：2.68
automake版本：1.11.1
一个简单例子
创建文件夹hello，进入文件夹后编辑一个简单的hello.c文件
#include <stdio.h>
int main(int argc, char** argv)
{
printf("Hello, automake!\n");
return 0;
}
手动创建Makefile.am，內容如下:
AUTOMAKE_OPTIONS= foreign
bin_PROGRAMS= hello
hello_SOURCES= hello.c 执行autoscan，目录变化如下：
$ ls -l
total 2
drwxr-xr-x 2 zexu Administrators 0 Oct 20 12:14 autom4te.cache
-rw-r--r-- 1 zexu Administrators 0 Oct 20 12:14 autoscan-2.68.log
-rw-r--r-- 1 zexu Administrators 495 Oct 20 12:14 configure.scan
-rw-r--r-- 1 zexu Administrators 100 Oct 18 07:46 hello.c
看一下configure.scan的内容：
# -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.
AC_PREREQ([2.68])
AC_INIT([FULL-PACKAGE-NAME], [VERSION], [BUG-REPORT-ADDRESS])
AC_CONFIG_SRCDIR([hello.c])
AC_CONFIG_HEADERS([config.h])
# 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_CONFIG_FILES([Makefile])
AC_OUTPUT
将此文件重命名为configure.in，执行autolocal,autoconf，生成configure：
$ ls -lh
total 111K
drwxr-xr-x 2 zexu Administrators 0 Oct 20 12:29 autom4te.cache
-rw-r--r-- 1 zexu Administrators 0 Oct 20 12:14 autoscan-2.68.log
-rwxr-xr-x 1 zexu Administrators 109K Oct 20 12:29 configure
-rw-r--r-- 1 zexu Administrators 495 Oct 20 12:14 configure.in
-rw-r--r-- 1 zexu Administrators 100 Oct 18 07:46 hello.c
执行如下automake命令:
$ automake --add-missing
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).
configure.in:7: required file `config.h.in' not found
Makefile.am: installing `./depcomp'
/mingw/share/automake-1.11/am/depend2.am: am__fastdepCC does not appear in AM_CONDITIONAL
/mingw/share/automake-1.11/am/depend2.am: The usual way to define `am__fastdepCC' is to add `AC_PROG_CC'
/mingw/share/automake-1.11/am/depend2.am: to `configure.in' and run `aclocal' and `autoconf' again.
/mingw/share/automake-1.11/am/depend2.am: AMDEP does not appear in AM_CONDITIONAL
/mingw/share/automake-1.11/am/depend2.am: The usual way to define `AMDEP' is to add one of the compiler tests
/mingw/share/automake-1.11/am/depend2.am: AC_PROG_CC, AC_PROG_CXX, AC_PROG_CXX, AC_PROG_OBJC,
/mingw/share/automake-1.11/am/depend2.am: AM_PROG_AS, AM_PROG_GCJ, AM_PROG_UPC
/mingw/share/automake-1.11/am/depend2.am: to `configure.in' and run `aclocal' and `autoconf' again.
看到出错了，在configure.in中添加如下信息：
AM_INIT_AUTOMAKE([-Wall -Werror foreign]) 再次执行aclocal,autoconf和automake
zexu@DESKTOP-R4T030U ~/devel/hello
$ aclocal
zexu@DESKTOP-R4T030U ~/devel/hello
$ autoconf
$ automake --add-missing
configure.in:9: installing `./install-sh'
configure.in:9: installing `./missing'
configure.in:7: required file `config.h.in' not found
执行autoheader，生成头文件后再次automake，最后成功，可见没有任何无误提示。
zexu@DESKTOP-R4T030U ~/devel/hello
$ automake --add-missing
最后执行configure，生成Makefile文件:
zexu@DESKTOP-R4T030U ~/devel/hello
$ ./configure
执行make，生成hello.exe:
zexu@DESKTOP-R4T030U ~/devel/hello
$ make
make all-am
make[1]: Entering directory `/home/zexu/devel/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.exe hello.o
make[1]: Leaving directory `/home/zexu/devel/hello'
zexu@DESKTOP-R4T030U ~/devel/hello
$ ls
Makefile aclocal.m4 config.h config.status depcomp hello.o stamp-h1
Makefile.am autom4te.cache config.h.in configure hello.c install-sh
Makefile.in autoscan-2.68.log config.log configure.in hello.exe missing
一个复杂一些的例子
这个例子使用了libtool，我把代码提交到了github，先把其clone下来：
git clone https://github.com/harlanc/automake_examples.git
进入example_2,先看一下目录结构：
$ ls -R
.:
Makefile.am configure.in error.c error.h lib main.c replace
./lib:
Makefile.am source.c source.h
./replace:
Makefile.am basename.c dummy.c
执行下面的命令：
zexu@DESKTOP-R4T030U ~/automake_examples/example_2
$ aclocal
zexu@DESKTOP-R4T030U ~/automake_examples/example_2
$ autoheader
zexu@DESKTOP-R4T030U ~/automake_examples/example_2
$ automake --add-missing --copy
configure.in:11: installing `./config.guess'
configure.in:11: installing `./config.sub'
configure.in:8: installing `./install-sh'
configure.in:11: required file `./ltmain.sh' not found
configure.in:8: installing `./missing'
lib/Makefile.am: installing `./depcomp'
看到有一个错误，执行下面的语句：
$libtoolize --automake --copy --debug --force 在此执行automake:
$ automake --add-missing --copy
最后成功，执行autoconf和configure：
zexu@DESKTOP-R4T030U ~/automake_examples/example_2
$ autoconf
zexu@DESKTOP-R4T030U ~/automake_examples/example_2
$ ./configure
最后生成Makefile文件，执行make，生成可执行文件：
$ make
最后成功。
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