如我們要生成交叉編譯給ARM CPU使用的共享庫,這里假設我們要使用的編譯器為arm-none-linux-gnueabi-gcc，并且我們最終在ARM板上執行時，要把庫安裝到目標板的/usr/local/armrx2d目錄中去?？梢赃@樣配置:
#
#
# 利用libtool自動生成動態庫
#
1. autoscan命令在當前目錄生成configure.scan文件, 內容為:
# -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.
AC_PREREQ(2.57)
AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)
AC_CONFIG_SRCDIR([src/bot.h])
AC_CONFIG_HEADER([config.h])
# Checks for programs.
AC_PROG_CXX
AC_PROG_CC
# Checks for libraries.
# Checks for header files.
AC_HEADER_STDC
AC_CHECK_HEADERS([limits.h malloc.h stdlib.h string.h unistd.h])
# Checks for typedefs, structures, and compiler characteristics.
AC_HEADER_STDBOOL
AC_C_CONST
AC_C_INLINE
# Checks for library functions.
AC_FUNC_MALLOC
AC_FUNC_REALLOC
AC_CHECK_FUNCS([memset strcasecmp strchr strdup])
AC_OUTPUT
將其該名為configure.ac 然后修改:
configure.ac 文件是 autoconf 的輸入文件，經過 autoconf 處理，展開里面的 m4宏，
輸出的是 configure 腳本。
第 4 行聲明本文件要求的 autoconf 版本，因為本例使用了新版本 2.57，所以在此注明。
第 5 行 AC_INIT 宏用來定義軟件的名稱和版本等信息
AC_INIT([test], 1.0, [email]linhanzu@gmail.com[/email])
增加版本信息(為生成lib庫做準備)
lt_major=1
lt_age=1
lt_revision=12
dist_version=0.1.12
AM_INIT_AUTOMAKE(test, $dist_version) //自動生成Makefile文件
增加宏, 打開共享庫
AC_PROG_LIBTOOL
# Check for dl
DL_PRESENT=""
AC_CHECK_LIB( dl, dlopen, DL_PRESENT="yes",, $DL_LIBS -ldl )
if test "x$DL_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBDL, 1, [Define if DL lib is present])
DL_LIBS="-ldl"
AC_SUBST(DL_LIBS)
fi
# Check for libm
M_PRESENT=""
AC_CHECK_LIB( m, sin, M_PRESENT="yes",, $M_LIBS -lm )
if test "x$M_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBM, 1, [Define if libm is present])
M_LIBS="-lm"
AC_SUBST(M_LIBS)
fi
增加依賴庫，這里就僅僅列舉了pthread庫，生成的Makefile會自動加上-pthread
# Check for pthread
PTHREAD_PRESENT=""
AC_CHECK_LIB( pthread, pthread_create, PTHREAD_PRESENT="yes",, $PTHREAD_LIBS
-lpthread )
if test "x$PTHREAD_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBPTHREAD, 1, [Define if libpthread is present])
PTHREAD_LIBS="-lpthread"
AC_SUBST(PTHREAD_LIBS)
fi
要生成項目工程目錄和其它目錄下的Makefile 文件, 必需加入
AM_CONFIG_FILES的宏:
例如: AC_CONFIG_FILES([Makefile
src/Makefile
data/Makefile
docs/Makefile])
修改完后Makefile.ac如下:
# -*- Autoconf -*-
# Process this file with autoconf to produce a configure script.
AC_PREREQ(2.57)
AC_INIT([test],[1.0],[[email]arne_caspari@users.sourceforge.net[/email]])
AM_CONFIG_HEADER(config.h)
lt_major=1
lt_age=1
lt_revision=12
dist_version=0.1.12
AM_INIT_AUTOMAKE(test, $dist_version)
AC_SUBST(lt_major)
AC_SUBST(lt_revision)
AC_SUBST(lt_age)
# Checks for programs.
#AC_PROG_CC
#AC_PROG_INSTALL
#AC_PROG_LN_S
#AC_PROG_LIBTOOL
AM_PROG_LIBTOOL
# Checks for libraries.
pkg_modules="gtk+-2.0 >= 2.0.0"
PKG_CHECK_MODULES(GTK_PACKAGE, [$pkg_modules], HAVE_GTK2="yes", HAVE_GTK2="no" )
AC_SUBST(GTK_PACKAGE_CFLAGS)
AC_SUBST(GTK_PACKAGE_LIBS)
# Check for dl
DL_PRESENT=""
AC_CHECK_LIB( dl, dlopen, DL_PRESENT="yes",, $DL_LIBS -ldl )
if test "x$DL_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBDL, 1, [Define if DL lib is present])
DL_LIBS="-ldl"
AC_SUBST(DL_LIBS)
fi
# Check for libm
M_PRESENT=""
AC_CHECK_LIB( m, sin, M_PRESENT="yes",, $M_LIBS -lm )
if test "x$M_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBM, 1, [Define if libm is present])
M_LIBS="-lm"
AC_SUBST(M_LIBS)
fi
# Check for pthread
PTHREAD_PRESENT=""
AC_CHECK_LIB( pthread, pthread_create, PTHREAD_PRESENT="yes",, $PTHREAD_LIBS
-lpthread )
if test "x$PTHREAD_PRESENT" = "xyes"; then
AC_DEFINE(HAVE_LIBPTHREAD, 1, [Define if libpthread is present])
PTHREAD_LIBS="-lpthread"
AC_SUBST(PTHREAD_LIBS)
fi
# Checks for header files.
#AC_HEADER_DIRENT
#AC_HEADER_STDC
#AC_CHECK_HEADERS([fcntl.h stdlib.h string.h sys/time.h unistd.h])
# Checks for typedefs, structures, and compiler characteristics.
#AC_TYPE_PID_T
#AC_TYPE_SIZE_T
#AC_HEADER_TIME
# Checks for library functions.
#AC_FUNC_CLOSEDIR_VOID
#AC_FUNC_MALLOC
#AC_CHECK_FUNCS([memset strstr])
AC_CONFIG_FILES([Makefile
src/Makefile
data/Makefile
doc/Makefile])
AC_OUTPUT
2.生成各目錄下的Makefile.am文件
./Makefile.am //工程目錄下
SUBDIR = src data doc
../src/Makefile.am //源碼目錄下
MAINTAINERCLEANFILES = Makefile.in
INCLUDES = -I../include
CPPFLAGS=-DINSTALL_PREFIX="\"$(prefix)\""
lib_LTLIBRARIES = libtest.la
libtest_la_LDFLAGS = -version-info @lt_major@:@lt_revision@:@lt_age@
libtest_la_SOURCES = \
test.c \
test_private.h \
check_match.c \
check_match.h \
test_helpers.c \
test_helpers.h \
debug.h
libtest_la_LIBADD = \
@DL_LIBS@ \
@M_LIBS@
3. 生成autogen.sh腳本, 內容
#! /bin/sh
set -x
aclocal
autoheader
automake --foreign --add-missing --copy
autoconf
保存后修改權限 chmod a+x autogen.sh
3.運行腳本./autogen.sh, 生成configure腳本. 這里可能會遇到錯誤, 可以根據錯誤提示作相應修改.（注意：如果您修改了Makefile.am中的項，那么就得重新執行這一步）
4.運行./configure腳本.自動生成src目錄下的makefile文件
5. 切換到目錄src, 運行make 自動在當前目錄下建立.libs文件, 編程生成的庫文件就保存在該目錄下.
make install 安裝在默認目錄 /usr/local/lib/下.
6.如果要生成其它的安裝目錄，Makefile.am就要這樣寫
MAINTAINERCLEANFILES = Makefile.in
INCLUDES = -I../include
lib_LTLIBRARIES = libtt.la
libdir = $(prefix)/lib/test //這個就是安裝目錄
libtt_la_LDFLAGS = -version-info @lt_major@:@lt_revision@:@lt_age@
libtt_la_LIBADD = @PTHREAD_LIBS@
libtt_la_SOURCES = \
tt.c \
video.c \
video.h
當然，Makefile中的語法規則中還有很多宏定義，您可以在Makefile的官方網站找到說明。
下一篇就打算寫寫條件編譯的Makefile寫法。