1、'ndk-build' OverviewI. Usage:The Android NDK r4 introduced a new tiny shell script, named 'ndk-build', to simplify building machine code.The script is located at the top-level directory of the NDK, and shall be invoked from the command-line when in your application project directory, or any of its sub-directories. For example:cd $PROJECT$NDK/ndk-buildWhere $NDK points to your NDK installation path. You can also create an alias or add $NDK to your PATH to avoid typing it every time.II. Options:All parameters to 'ndk-build' are passed directly to the underlying GNU Make command that runs the NDK build scripts. Notable uses include:ndk-build–> rebuild required machine code.ndk-build clean–> clean all generated binaries.ndk-build NDK_DEBUG=1–> generate debuggable native code.ndk-build V=1–> launch build, displaying build commands.ndk-build -B–> force a complete rebuild.ndk-build -B V=1–> force a complete rebuild and display buildcommands.ndk-build NDK_LOG=1–> display internal NDK log messages(used for debugging the NDK itself).ndk-build NDK_DEBUG=1–> force a debuggable build (see below)ndk-build NDK_DEBUG=0–> force a release build (see below)ndk-build NDK_HOST_32BIT=1 –> Always use toolchain in 32-bit (see below)ndk-build NDK_APPLICATION_MK=<file>–> rebuild, using a specific Application.mk pointed to bythe NDK_APPLICATION_MK command-line variable.ndk-build -C <project>–> build the native code for the projectpath located at <project>. Useful if youdon't want to 'cd' to it in your terminal.
(摘自NDK说明文档NDK-BUILD.html)
2、
我们看到上面ndk-build有很多可选参数，那在cocos2dx中，这些参数使用的呢？我们都知道在2.X版本中，我们都是通过build_native.sh脚本，编译cocos2dx项目，那么我们怎么通过build_native.sh脚本使用上面的参数呢？下面是从build_native.sh脚本中摘出来的：
if [[ "$buildexternalsfromsource" ]]; thenecho "Building external dependencies from source""$NDK_ROOT"/ndk-build -C "$APP_ANDROID_ROOT" $* \&;NDK_MODULE_PATH=${COCOS2DX_ROOT}:${COCOS2DXTALKINGDATA_ROOT}:${COCOS2DX_ROOT}/cocos2dx/platform/third_party/android/source"elseecho "Using prebuilt externals""$NDK_ROOT"/ndk-build -C "$APP_ANDROID_ROOT" $* \&;NDK_MODULE_PATH=${COCOS2DX_ROOT}:${COCOS2DXTALKINGDATA_ROOT}:${COCOS2DX_ROOT}/cocos2dx/platform/third_party/android/prebuilt"fi看下这部分：
"$NDK_ROOT"/ndk-build -C "$APP_ANDROID_ROOT" $* \&;NDK_MODULE_PATH=${COCOS2DX_ROOT}:${COCOS2DXTALKINGDATA_ROOT}:${COCOS2DX_ROOT}/cocos2dx/platform/third_party/android/prebuilt"
解释：$NDK_ROOT — NDK工具的根目录，在这里有ndk-build执行程序-C "$APP_ANDROID_ROOT" — 编译的工程，参看第一部分$* — shell脚本，传递给脚本或函数的所有参数。总结：所以如果我们需要使用上面ndk-build命令的可选参数，直接在执行build_native.sh脚本时，，添加在后面即可。例子：$ ./build_native.sh clean
会让你的心态更平和更坦然，也会让你心无旁骛，更会让你的心灵得到解脱和抚慰。
