1page.title=ndk-build 2@jd:body 3 4<div id="qv-wrapper"> 5 <div id="qv"> 6 <h2>On this page</h2> 7 8 <ol> 9 <li><a href="#int">Internals</a></li> 10 <li><a href="#ifc">Invoking from the Command Line</a></li> 11 <li><a href="#ife">Invoking from Eclipse</a></li> 12 <li><a href="#6432">64-Bit and 32-Bit Toolchains</a></li> 13 <li><a href="#req">Requirements</a></li> 14 </ol> 15 </li> 16 </ol> 17 </div> 18 </div> 19 20<p>The {@code ndk-build} file is a shell script introduced in Android NDK r4. Its purpose 21is to invoke the right NDK build script. 22 23<h2 id="int">Internals</h2> 24 25<p>Running the {@code ndk-build} script is equivalent to running the following command:</p> 26 27<pre class="no-pretty-print"> 28$GNUMAKE -f <ndk>/build/core/build-local.mk 29<parameters> 30</pre> 31 32<p><code>$GNUMAKE</code> points to GNU Make 3.81 or later, and 33<code><ndk></code> points to your NDK installation directory. You can use 34this information to invoke ndk-build from other shell scripts, or even your own 35make files.</p> 36 37<h2 id="ifc">Invoking from the Command Line</h2> 38<p>The {@code ndk-build} file lives in the top level the NDK installation directory. To run it 39from the command line, invoke it while in or under your application project directory. 40For example: </p> 41 42<pre class="no-pretty-print"> 43cd <project> 44$ <ndk>/ndk-build 45</pre> 46 47<p>In this example, <code><project></code> points to your 48project’s root directory, and <code><ndk></code> is the directory where 49you installed the NDK.</p> 50 51<p><a class="anchor" id="options"></a> </p> 52<h3>Options</h3> 53<p>All parameters to ndk-build are passed directly to the underlying GNU {@code make} 54command that runs the NDK build scripts. Combine <code>ndk-build</code> and 55options in the form <code>ndk-build <option></code>. For example: </p> 56 57<pre class="no-pretty-print"> 58$ ndk-build clean 59</pre> 60 61<p>The following options are available:</p> 62<dl> 63 <dt>{@code clean}</dt> 64 <dd>Remove any previously generated binaries.</dd> 65 <dt>{@code V=1}</dt> 66 <dd>Launch build, and display build commands.<dd> 67 <dt>{@code -B}</dt> 68 <dd>Force a complete rebuild.</dd> 69 <dt>{@code -B V=1}</dt> 70 <dd>Force a complete rebuild, and display build commands.</dd> 71 <dt>{@code NDK_LOG=1}</dd> 72 <dd>Display internal NDK log messages (used for debugging the NDK itself).</dd> 73 <dt>{@code NDK_DEBUG=1}</dt> 74 <dd>Force a debuggable build (see <a href="#dvr">Table 1</a>).</dd> 75 <dt>{@code NDK_DEBUG=0}</dt> 76 <dd>Force a release build (see <a href="#dvr">Table 1</a>).</dd> 77 <dt>{@code NDK_HOST_32BIT=1}</dt> 78 <dd>Always use the toolchain in 32-bit mode (see <a href="#6432">64-bit and 32-bit 79 Toolchains</a>).</dd> 80 <dt>{@code NDK_APPLICATION_MK=<file>}</dt> 81 <dd>Build, using a specific <code>Application.mk</code> file pointed to by the 82 {@code NDK_APPLICATION_MK} variable.</dd> 83 <dt>{@code -C <project>}</dt> 84 <dd>Build the native code for the project path located at {@code <project>}. Useful if you 85 don't want to {@code cd} to it in your terminal.</dd> 86</dl> 87 88<h2 id="ife">Invoking from Eclipse</h2> 89<p>To build from Eclipse, make sure that you have configured it as described in 90<a href="{@docRoot}ndk/guides/setup.html#configure">Setup</a>. If you 91wish to build using the default <code>ndk-build</code> command, with no 92options, you can just build your project just as you would any Android project. 93To get Eclipse to add any of the options described above, follow these steps:</p> 94<ol type="1"> 95<li>In the <em>Project Explorer</em> pane, right-click your project name.</li> 96<li>Select <strong>Properties</strong>.</li> 97<li>Click <strong>C/C++ Build</strong>.</li> 98<li>Under the <em>Builder Settings</em> tab, uncheck <strong>Use default build command</strong>.</li> 99<li>In the <em>Build command</em> field, enter the entire build string as if you were typing it on 100the command line.</li> 101<li>Click <strong>OK</strong>.</li> 102</ol> 103Figure 1 shows an example of an entered string.<br> 104<br> 105<img src="./images/NDK_build_string.png" 106 srcset="./images/NDK_build_string@2x.png 2x" 107 alt="enter the build string next to 'Build command'" 108 height="152" width="501"> 109<p style="clear:both"><b>Figure 1.</b> Specifying a debug build from within 110Eclipse</p> 111<p><a class="anchor" id="dvr"></a> </p> 112<h3>Debuggable versus Release builds</h3> 113<p>Use the <code>NDK_DEBUG</code> option and, in certain cases, 114{@code AndroidManifest.xml} to specify debug or release build, 115optimization-related behavior, and inclusion of symbols. Table 1 shows the 116results of each possible combination of settings.</p> 117<p><em>Table 1.</em> Results of <code>NDK_DEBUG</code> (command line) and 118<code>android:debuggable</code> (manifest) combinations.</p> 119<table> 120<tr> 121<th></th><th>NDK_DEBUG=0 </th><th>NDK_DEBUG=1</th><th>NDK_DEBUG not specified 122</th></tr> 123<tr> 124<td>android:debuggble="true" </td><td>Debug; Symbols; Optimized*1 125</td><td>Debug; Symbols; Not optimized*2 </td><td>(same as NDK_DEBUG=1) 126</td></tr> 127<tr> 128<td>android:debuggable="false"</td><td>Release; Symbols; Optimized 129</td><td>Release; Symbols; Not optimized</td><td>Release; No symbols; 130Optimized*3 </td></tr> 131</table> 132*1: Useful for profiling.<br> 133*2: Default for running <a href="{@docRoot}ndk/guides/ndk-gdb.html">{@code ndk-gdb}</a>.<br> 134*3: Default mode.<br> 135<br> 136<p class="note"><strong>Note:</strong> {@code NDK_DEBUG=0} is the equivalent of 137{@code APP_OPTIM=release}, and complies with the GCC {@code -O2} option. {@code NDK_DEBUG=1} is the 138equivalent of {@code APP_OPTIM=debug} in {@code Application.mk}, and complies with the GCC 139{@code -O0} option. For more information about {@code APP_OPTIM}, see 140<a href="{@docRoot}ndk/guides/application_mk.html">Application.mk</a>.</p> 141<p>The syntax on the command line is, for example: </p> 142 143<pre class="no-pretty-print"> 144$ ndk-build NDK_DEBUG=1 145</pre> 146 147<p>If you are using build tools from prior to SDK r8, you must also modify your 148{@code AndroidManifest.xml} file to specify debug mode. The syntax for doing so resembles the 149following:</p> 150 151<pre class="no-pretty-print"><application android:label="@string/app_name" 152android:debuggable="true"> 153</pre> 154 155From SDK r8 onward, you do not need to touch {@code AndroidManifest.xml}. Building a debug package 156(e.g. with ant debug or the corresponding option of the ADT plugin) causes the tool automatically to 157pick the native debug files generated with {@code NDK_DEBUG=1}. 158 159 160<h2 id="6432">64-Bit and 32-Bit Toolchains</h2> 161<p>Some toolchains come with both 64-bit and 32-bit versions. For example, 162directories {@code <ndk>/toolchain/<name>/prebuilt/} and 163{@code <ndk>/prebuilt/} may contain both {@code linux-x86} and 164{@code linux-x86_64} folders for Linux tools in 32-bit and 64-bit modes, 165respectively. The ndk-build script automatically chooses a 64-bit version of 166the toolchain if the host OS supports it. You can force the use of a 32-bit 167toolchain by using {@code NDK_HOST_32BIT=1} either in your environment or 168on the ndk-build command line.</p> 169<p>Note that 64-bit tools utilize host resources better (for instance, they are faster, and handle 170larger programs), and they can still generate 32-bit binaries for Android.</p> 171 172<h2 id="req">Requirements</h2> 173<p>You need GNU Make 3.81 or later to use ndk-build or the NDK in general. 174The build scripts will detect a non-compliant Make tool, and generate an error 175message.</p> 176<p>If you have GNU Make 3.81 installed, but the default <code>make</code> 177command doesn’t launch it, define {@code GNUMAKE} in your environment to point to it 178before launching ndk-build. For example: </p> 179 180<pre class="no-pretty-print"> 181$ export GNUMAKE=/usr/local/bin/gmake 182$ ndk-build 183</pre> 184 185<p>You can override other host prebuilt tools in {@code $NDK/prebuilt/<OS>/bin/} 186with the following environment variables: </p> 187 188<pre class="no-pretty-print"> 189$ export NDK_HOST_AWK=<path-to-awk> 190$ export NDK_HOST_ECHO=<path-to-echo> 191$ export NDK_HOST_CMP=<path-to-cmp> 192</pre> 193
