Android Native C 之 Helloworld的四种编译方式

一.编写helloworld.c Android.mk

[root@fontlose jni]# cat hello.c

#include <stdio.h>int main(){    printf("Hello World!\n");    return 0;}

[root@fontlose jni]# cat Android.mk

LOCAL_PATH:= $(call my-dir)include $(CLEAR_VARS)LOCAL_SRC_FILES:=hello.cLOCAL_MODULE := helloworldLOCAL_MODULE_TAGS := optionalinclude $(BUILD_EXECUTABLE)

二.编译

1) 使用NDK r5

目录结构 ─ hello
├── jni
├── Android.mk

└── hello.c

         [root@fontlose nativity]# cd hello         [root@fontlose hello]# export NDK_PROJECT_PATH=`pwd`         [root@fontlose hello]# ndk-build         Install        : helloworld => libs/armeabi/helloworld         [root@fontlose hello]# adb push libs/armeabi/helloworld  /data         44 KB/s (2176 bytes in 0.047s)                 [root@fontlose hello]# adb shell         / # cd  /data         /data # ls -l         -rwxrwxrwx root     root         2176 2011-08-07 03:01 helloworld        /data # ./helloworld         Hello World!

2) 使用通用toolchain

在hello.c目录下

      [root@fontlose jni]# arm-none-linux-gnueabi-gcc -static hello.c -o helloworld       [root@fontlose jni]# adb push helloworld  /data       1718 KB/s (581219 bytes in 0.330s)       [root@fontlose jni]# adb shell       / # cd /data       /data # ls -l      -rwxrwxrwx root     root       581219 2011-08-07 03:28 helloworld       /data # ./helloworld       Hello World!

Windows: http://www.codesourcery.com/gnu_toolchains/arm/portal/package3400/public/arm-none-linux-gnueabi/arm-2008q3-41-arm-none-linux-gnueabi.exe
Linux: http://www.codesourcery.com/gnu_toolchains/arm/portal/package3399/public/arm-none-linux-gnueabi/arm-2008q3-41-arm-none-linux-gnueabi.bin

3) 在源码环境中编译

1. 在源码development 目录下创建hello目录

 [root@fontlose Android-2.3]# mkdir $Android_Src/development/hello

2.将helloworld.c Android.mk拷贝至hello目录下
3. [root@fontlose Android-2.3]# . build/envsetup.sh

4. [root@fontlose Android-2.3]# mmm development/hello/

============================================PLATFORM_VERSION_CODENAME=RELPLATFORM_VERSION=2.3.2TARGET_PRODUCT=genericTARGET_BUILD_VARIANT=engTARGET_SIMULATOR=TARGET_BUILD_TYPE=releaseTARGET_BUILD_APPS=TARGET_ARCH=armHOST_ARCH=x86HOST_OS=linuxHOST_BUILD_TYPE=releaseBUILD_ID=GRH78C============================================make: 进入目录“/opt/FriendlyARM/mini6410/android/Android-2.3”target thumb C: helloworld <= development/hello/hello.ctarget Executable: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld)target Non-prelinked: helloworld (out/target/product/generic/symbols/system/bin/helloworld)target Strip: helloworld (out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld)Install: out/target/product/generic/system/bin/helloworldmake: 离开目录“/opt/FriendlyARM/mini6410/android/Android-2.3”

5.编译完成执行文件在out/target/product/generic/symbols/system/bin/helloworld
下载至设备

 [root@fontlose Android-2.3]# adb push out/target/product/generic/symbols/system/bin/helloworld  /data       135 KB/s (7608 bytes in 0.054s)       [root@fontlose Android-2.3]# adb shell       / # cd /data       /data # ls -l          -rwxrwxrwx root     root         7608 2011-08-07 03:49 helloworld         /data # ./helloworld       Hello World!

4) 使用源码自带Toolchain

在这之前要把上一步中的helloworld模块clean:

       [root@fontlose Android-2.3]# make clean-helloworld

使用showcommands选项重新编译helloworld，查看具体命令，从输出命令行可以看到，Android编译环境所用的交叉编译工具链是prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-gcc。

       [root@fontlose Android-2.3]# make  helloworld  showcommands

利用上面输出的编译命令，简化来手工编译helloworld程序，先手工删除上次编译得到的helloworld程序：

      [root@fontlose Android-2.3]#  rm out/target/product/generic/system/bin/helloworld

gcc编译，生成目标文件

 [root@fontlose Android-2.3]# prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-gcc  -I development/hello   -I out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates   -I dalvik/libnativehelper/include/nativehelper   -I system/core/include   -I hardware/libhardware/include   -I hardware/libhardware_legacy/include   -I hardware/ril/include   -I dalvik/libnativehelper/include   -I frameworks/base/include   -I frameworks/base/opengl/include   -I frameworks/base/native/include   -I external/skia/include   -I out/target/product/generic/obj/include   -I bionic/libc/arch-arm/include   -I bionic/libc/include   -I bionic/libstdc++/include   -I bionic/libc/kernel/common   -I bionic/libc/kernel/arch-arm   -I bionic/libm/include   -I bionic/libm/include/arch/arm   -I bionic/libthread_db/include  -c  -fno-exceptions -Wno-multichar -msoft-float -fpic -ffunction-sections -funwind-tables -fstack-protector -Wa,--noexecstack -Werror=format-security -fno-short-enums -march=armv5te -mtune=xscale -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ -include system/core/include/arch/linux-arm/AndroidConfig.h -I system/core/include/arch/linux-arm/ -Wno-psabi -mthumb-interwork -DANDROID -fmessage-length=0 -W -Wall -Wno-unused -Winit-self -Wpointer-arith -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -DNDEBUG -g -Wstrict-aliasing=2 -finline-functions -fno-inline-functions-called-once -fgcse-after-reload -frerun-cse-after-loop -frename-registers -DNDEBUG -UDEBUG -mthumb -Os -fomit-frame-pointer -fno-strict-aliasing -finline-limit=64       -MD -o out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o development/hello/hello.c

生成可执行文件：

       [root@fontlose Android-2.3]# prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/arm-eabi-g++ -nostdlib -Bdynamic -Wl,-T,build/core/armelf.x -Wl,-dynamic-linker,/system/bin/linker -Wl,--gc-sections -Wl,-z,nocopyreloc -o out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/LINKED/helloworld -Lout/target/product/generic/obj/lib -Wl,-rpath-link=out/target/product/generic/obj/lib -lc -lstdc++ -lm  out/target/product/generic/obj/lib/crtbegin_dynamic.o         out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/hello.o        -Wl,-z,noexecstack    -Wl,--no-undefined  prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin/../lib/gcc/arm-eabi/4.4.3/libgcc.a out/target/product/generic/obj/lib/crtend_android.o

使用了out/host/linux-x86/bin/soslim工具进行STRIP

       [root@fontlose Android-2.3]# out/host/linux-x86/bin/soslim --strip --shady --quiet out/target/product/generic/symbols/system/bin/helloworld --outfile out/target/product/generic/obj/EXECUTABLES/helloworld_intermediates/helloworld

[root@fontlose Android-2.3]# adb push out/target/product/generic/symbols/system/bin/helloworld  /data145 KB/s (7608 bytes in 0.051s)[root@fontlose Android-2.3]# adb shell/ # cd /data//data # ls -l-rwxrwxrwx root     root         7608 2011-08-07 04:14 helloworld/data # ./helloworldHello World!

Android并没有采用glibc作为C库，而是采用了Google自己开发的Bionic Libc，通用的Toolchain用来编译和移植Android 的Linux内核是可行的，因为内核并不需要C库，但是开发Android的应用程序时，其他Toolchain编译的应用程序只能采用静态编译的方式才能运行，使用静态方式编译出来的执行文件都比较大。