docs/NDK-BUILD.html - platform/ndk - Git at Google

 <html><body><pre>'ndk-build' Overview

 I. 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-build

 Where $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                  --&gt; rebuild required machine code.
   ndk-build clean            --&gt; clean all generated binaries.

   ndk-build NDK_DEBUG=1      --&gt; generate debuggable native code.

   ndk-build V=1              --&gt; launch build, displaying build commands.

   ndk-build -B               --&gt; force a complete rebuild.

   ndk-build -B V=1           --&gt; force a complete rebuild and display build
                                  commands.

   ndk-build NDK_LOG=1        --&gt; display internal NDK log messages
                                  (used for debugging the NDK itself).

   ndk-build NDK_DEBUG=1      --&gt; force a debuggable build (see below)
   ndk-build NDK_DEBUG=0      --&gt; force a release build (see below)

   ndk-build NDK_HOST_32BIT=1 --&gt; Always use toolchain in 32-bit (see below)

   ndk-build NDK_APPLICATION_MK=&lt;file&gt;
     --&gt; rebuild, using a specific Application.mk pointed to by
         the NDK_APPLICATION_MK command-line variable.

   ndk-build -C &lt;project&gt;     --&gt; build the native code for the project
                                  path located at &lt;project&gt;. Useful if you
                                  don't want to 'cd' to it in your terminal.


 III. Debuggable versus Release builds:
 --------------------------------------

 In NDK r5, ndk-build has been modified to make it easier to switch between
 release and debug builds. This is done by using the NDK_DEBUG variable.
 For example:

   $NDK/ndk-build NDK_DEBUG=1  =&gt; forces the generation of debug binaries
   $NDK/ndk-build NDK_DEBUG=0  =&gt; forces the generation of release binaries

 If you don't specify NDK_DEBUG, ndk-build will keep its default behaviour,
 which is to inspect the AndroidManifest.xml, if any, and see if its
 &lt;application&gt; element has android:debuggable="true".

 IMPORTANT: If you use the build tools of SDK r8 (or higher), you
            won't need to touch your AndroidManifest.xml file at all!

            That's because if you build a debug package (e.g. with
            "ant debug" or the corresponding option of the ADT plugin),
            the tool will  automatically pick the native debug files
            generated with NDK_DEBUG=1.

 Also, as a convenience, the release and debug object files generated by the
 NDK are now stored in different directories (e.g. obj/local/&lt;abi&gt;/objs and
 obj/local/&lt;abi&gt;/objs-debug). This avoids having to recompile all your sources
 when you switch between these two modes (even when you only modified one or
 two source files).


 IV. 64-bit and 32-bit toolchains:
 ---------------------------------

 Some toolchains come with both 64-bit and 32-bit versions.  For example,
 directories $NDK/toolchain/&lt;name&gt;/prebuilt and $NDK/prebuilt may contains both
 "linux-x86" and "linux-x86_64" folders for Linux tools in 32-bit and 64-bit modes,
 respectively.  The ndk-build script automatically chooses a 64-bit version of the
 toolchain if the host OS supports it.  You can force the use of a 32-bit toolchain by
 using NDK_HOST_32BIT=1 either in your envorinment or on the ndk-build command-line.

 Note that 64-bit tools utilize host resources better (faster, handle larger
 programs, etc) and they should function identically to their 32-bit counterparts.
 Ie. 64-bit toolchains still generate 32-bit binaries for Android.


 V. Requirements:
 ----------------

 You need GNU Make 3.81 or later to use 'ndk-build' or the NDK in general.
 The build scripts will detect that you're using a non-compliant Make tool
 and will complain with an error message.

 If you have GNU Make 3.81 installed, but that it is not launched by the
 default 'make' command, define GNUMAKE in your environment to point to it
 before launching 'ndk-build'. For example:

     GNUMAKE=/usr/local/bin/gmake ndk-build

 Or to make the change more permanent:

     export GNUMAKE=/usr/local/bin/gmake
     ndk-build

 Adapt to your shell and GNU Make 3.81 installation location.

 You may override other host prebuilt tools in $NDK/prebuilt/&lt;OS&gt;/bin
 with the following environment variables

     NDK_HOST_AWK=&lt;path-to-awk&gt;

     NDK_HOST_ECHO=&lt;path-to-echo&gt;

     NDK_HOST_CMP=&lt;path-to-cmp&gt;


 VI. Internals:
 --------------

 'ndk-build' itself is a tiny wrapper around GNU Make, its purpose is simply
 to invoke the right NDK build script, it is equivalent to;

     $GNUMAKE -f $NDK/build/core/build-local.mk [parameters]

 Where '$GNUMAKE' points to GNU Make 3.81 or later, and $NDK points to your
 NDK installation directory.

 Use this knowledge if you want to invoke the NDK build script from other
 shell scripts (or even your own Makefiles).
 </pre></body></html>
	<html><body><pre>'ndk-build' Overview

	I. 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-build

	Where $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 build
	commands.

	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 by
	the NDK_APPLICATION_MK command-line variable.

	ndk-build -C <project> --> build the native code for the project
	path located at <project>. Useful if you
	don't want to 'cd' to it in your terminal.


	III. Debuggable versus Release builds:
	--------------------------------------

	In NDK r5, ndk-build has been modified to make it easier to switch between
	release and debug builds. This is done by using the NDK_DEBUG variable.
	For example:

	$NDK/ndk-build NDK_DEBUG=1 => forces the generation of debug binaries
	$NDK/ndk-build NDK_DEBUG=0 => forces the generation of release binaries

	If you don't specify NDK_DEBUG, ndk-build will keep its default behaviour,
	which is to inspect the AndroidManifest.xml, if any, and see if its
	<application> element has android:debuggable="true".

	IMPORTANT: If you use the build tools of SDK r8 (or higher), you
	won't need to touch your AndroidManifest.xml file at all!

	That's because if you build a debug package (e.g. with
	"ant debug" or the corresponding option of the ADT plugin),
	the tool will automatically pick the native debug files
	generated with NDK_DEBUG=1.

	Also, as a convenience, the release and debug object files generated by the
	NDK are now stored in different directories (e.g. obj/local/<abi>/objs and
	obj/local/<abi>/objs-debug). This avoids having to recompile all your sources
	when you switch between these two modes (even when you only modified one or
	two source files).


	IV. 64-bit and 32-bit toolchains:
	---------------------------------

	Some toolchains come with both 64-bit and 32-bit versions. For example,
	directories $NDK/toolchain/<name>/prebuilt and $NDK/prebuilt may contains both
	"linux-x86" and "linux-x86_64" folders for Linux tools in 32-bit and 64-bit modes,
	respectively. The ndk-build script automatically chooses a 64-bit version of the
	toolchain if the host OS supports it. You can force the use of a 32-bit toolchain by
	using NDK_HOST_32BIT=1 either in your envorinment or on the ndk-build command-line.

	Note that 64-bit tools utilize host resources better (faster, handle larger
	programs, etc) and they should function identically to their 32-bit counterparts.
	Ie. 64-bit toolchains still generate 32-bit binaries for Android.


	V. Requirements:
	----------------

	You need GNU Make 3.81 or later to use 'ndk-build' or the NDK in general.
	The build scripts will detect that you're using a non-compliant Make tool
	and will complain with an error message.

	If you have GNU Make 3.81 installed, but that it is not launched by the
	default 'make' command, define GNUMAKE in your environment to point to it
	before launching 'ndk-build'. For example:

	GNUMAKE=/usr/local/bin/gmake ndk-build

	Or to make the change more permanent:

	export GNUMAKE=/usr/local/bin/gmake
	ndk-build

	Adapt to your shell and GNU Make 3.81 installation location.

	You may override other host prebuilt tools in $NDK/prebuilt/<OS>/bin
	with the following environment variables

	NDK_HOST_AWK=<path-to-awk>

	NDK_HOST_ECHO=<path-to-echo>

	NDK_HOST_CMP=<path-to-cmp>


	VI. Internals:
	--------------

	'ndk-build' itself is a tiny wrapper around GNU Make, its purpose is simply
	to invoke the right NDK build script, it is equivalent to;

	$GNUMAKE -f $NDK/build/core/build-local.mk [parameters]

	Where '$GNUMAKE' points to GNU Make 3.81 or later, and $NDK points to your
	NDK installation directory.

	Use this knowledge if you want to invoke the NDK build script from other
	shell scripts (or even your own Makefiles).
	</pre></body></html>