[Android 开发]移植libcurl到Android4.4

感谢伟大的libcurl及互联网开放分享的精神，顺利的完成了这次移植。

1. 获取libcurl的源码，这个简单

2. 将源码释放到external/curl下面

3. 执行buildconf，生成configure

4. 执行以下命令，以便生成头文件

A=`realpath ../..` && PATH="$A/prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin:$PATH" ./configure --host=arm-linux CC=arm-eabi-gcc LIB="$A/prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/lib/gcc/arm-eabi/4.7/libgcc.a $A/prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/lib/gcc/arm-eabi/4.7/crtbegin.o $A/prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/lib/gcc/arm-eabi/4.7/crtend.o"

可以得到32位的curl版本，使用了linux-x86的配置，但是arm32位的手机还是可以用

5. 编写Android.mk

# Google Android makefile for curl and libcurl
#
# Place the curl source (including this makefile) into external/curl/ in the
# Android source tree.  Then build them with 'make curl' or just 'make libcurl'
# from the Android root. Tested with Android 1.5 and 2.1
#
# Note: you must first create a curl_config.h file by running configure in the
# Android environment. The only way I've found to do this is tricky. Perform a
# normal Android build with libcurl in the source tree, providing the target
# "showcommands" to make. The build will eventually fail (because curl_config.h
# doesn't exist yet), but the compiler commands used to build curl will be
# shown. Now, from the external/curl/ directory, run curl's normal configure
# command with flags that match what Android itself uses. This will mean
# putting the compiler directory into the PATH, putting the -I, -isystem and
# -D options into CPPFLAGS, putting the -W, -m, -f, -O and -nostdlib options
# into CFLAGS, and putting the -Wl, -L and -l options into LIBS, along with the
# path to the files libgcc.a, crtbegin_dynamic.o, and ccrtend_android.o.
# Remember that the paths must be absolute since you will not be running
# configure from the same directory as the Android make.  The normal
# cross-compiler options must also be set. Note that the -c, -o, -MD and
# similar flags must not be set.
#
# To see all the LIBS options, you'll need to do the "showcommands" trick on an
# executable that's already buildable and watch what flags Android uses to link
# it (dhcpcd is a good choice to watch). You'll also want to add -L options to
# LIBS that point to the out/.../obj/lib/ and out/.../obj/system/lib/
# directories so that additional libraries can be found and used by curl.
#
# The end result will be a configure command that looks something like this
# (the environment variable A is set to the Android root path which makes the
# command shorter):
#
#  A=`realpath ../..` && \
#  PATH="$A/prebuilt/linux-x86/toolchain/arm-eabi-X/bin:$PATH" \
#  ./configure --host=arm-linux CC=arm-eabi-gcc \
#  CPPFLAGS="-I $A/system/core/include ..." \
#  CFLAGS="-nostdlib -fno-exceptions -Wno-multichar ..." \
#  LIBS="$A/prebuilt/linux-x86/toolchain/arm-eabi-X/lib/gcc/arm-eabi/X\
#  /interwork/libgcc.a ..."
#
# Finally, copy the file COPYING to NOTICE so that the curl license gets put
# into the right place (but see the note about this below).
#
# Dan Fandrich
# August 2010

LOCAL_PATH:= $(call my-dir)

common_CFLAGS := -Wpointer-arith -Wwrite-strings -Wunused -Winline -Wnested-externs -Wmissing-declarations -Wmissing-prototypes -Wno-long-long -Wfloat-equal -Wno-multichar -Wsign-compare -Wno-format-nonliteral -Wendif-labels -Wstrict-prototypes -Wdeclaration-after-statement -Wno-system-headers -DHAVE_CONFIG_H

#########################
# Build the libcurl library

include $(CLEAR_VARS)
include $(LOCAL_PATH)/lib/Makefile.inc
CURL_HEADERS := \
	curlbuild.h \
	curl.h \
	curlrules.h \
	curlver.h \
	easy.h \
	mprintf.h \
	multi.h \
	stdcheaders.h \
	typecheck-gcc.h
#	types.h

LOCAL_SRC_FILES := $(addprefix lib/,$(CSOURCES))
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include/
LOCAL_C_INCLUDES += $(LOCAL_PATH)/lib/
LOCAL_C_INCLUDES += $(LOCAL_PATH)/../external/openssl/include/
LOCAL_CFLAGS += $(common_CFLAGS)

LOCAL_COPY_HEADERS_TO := libcurl/curl
LOCAL_COPY_HEADERS := $(addprefix include/curl/,$(CURL_HEADERS))
LOCAL_SHARED_LIBRARIES := libc libcutils libnetutils
LOCAL_MODULE:= libcurl

# Copy the licence to a place where Android will find it.
# Actually, this doesn't quite work because the build system searches
# for NOTICE files before it gets to this point, so it will only be seen
# on subsequent builds.
#ALL_PREBUILT += $(LOCAL_PATH)/NOTICE
#$(LOCAL_PATH)/NOTICE: $(LOCAL_PATH)/COPYING | $(ACP)
#	$(copy-file-to-target)

include $(BUILD_SHARED_LIBRARY)


#########################
# Build the curl binary

include $(CLEAR_VARS)
include $(LOCAL_PATH)/src/Makefile.inc
LOCAL_SRC_FILES := $(addprefix src/,$(CURL_CFILES))

LOCAL_MODULE := curl
LOCAL_STATIC_LIBRARIES := libcurl
LOCAL_SYSTEM_SHARED_LIBRARIES := libc libnetutils

LOCAL_C_INCLUDES += $(LOCAL_PATH)/include $(LOCAL_PATH)/lib

# This may also need to include $(CURLX_ONES) in order to correctly link
# if libcurl is changed to be built as a dynamic library
LOCAL_CFLAGS += $(common_CFLAGS)

include $(BUILD_EXECUTABLE)

6. 会发生ifaddrs.h找不到的错误，不过这个不要紧，从Android其他目录拷ifaddrs.h & ifaddrs.c到curl/lib/下面，顺便改下/src/Makefile.inc,把ifaddrs.c添加到里面参加编译

7.最后mm，即可得到libcurl.lib，然后尽情的享用你的劳动成果吧。