Android Build Cookbook

Build Cookbook

In this document

The Android Build Cookbook offers code snippets to help you quickly implement some common build tasks. For additional instruction, please see the other build documents in this section.

Building a simple APK LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# Build all java files in the java subdirectory
LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
# Name of the APK to build
LOCAL_PACKAGE_NAME := LocalPackage
 
# Tell it to build an APK
include $(BUILD_PACKAGE)
Building a APK that depends on a static .jar file LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# List of static libraries to include in the package
LOCAL_STATIC_JAVA_LIBRARIES := static-library
 
# Build all java files in the java subdirectory
LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
# Name of the APK to build
LOCAL_PACKAGE_NAME := LocalPackage
 
# Tell it to build an APK
include $(BUILD_PACKAGE)
Building a APK that should be signed with the platform key LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# Build all java files in the java subdirectory
LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
# Name of the APK to build
LOCAL_PACKAGE_NAME := LocalPackage
 
LOCAL_CERTIFICATE := platform
 
# Tell it to build an APK
include $(BUILD_PACKAGE)
Building a APK that should be signed with a specific vendor key LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# Build all java files in the java subdirectory
LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
# Name of the APK to build
LOCAL_PACKAGE_NAME := LocalPackage
 
LOCAL_CERTIFICATE := vendor/example/certs/app
 
# Tell it to build an APK
include $(BUILD_PACKAGE)
Adding a prebuilt APK LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# Module name should match apk name to be installed.
LOCAL_MODULE := LocalModuleName
LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
 
include $(BUILD_PREBUILT)
Adding a Static Java Library LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
 
# Build all java files in the java subdirectory
LOCAL_SRC_FILES := $(call all-subdir-java-files)
 
# Any libraries that this library depends on
LOCAL_JAVA_LIBRARIES := android.test.runner
 
# The name of the jar file to create
LOCAL_MODULE := sample
 
# Build a static jar file.
include $(BUILD_STATIC_JAVA_LIBRARY)
Android.mk Variables

These are the variables that you'll commonly see in Android.mk files, listed alphabetically. First, a note on the variable naming:

• LOCAL_ - These variables are set per-module. They are cleared by the de>include $(CLEAR_VARS)de> line, so you can rely on them being empty after including that file. Most of the variables you'll use in most modules are LOCAL_ variables.
• PRIVATE_ - These variables are make-target-specific variables. That means they're only usable within the commands for that module. It also means that they're unlikely to change behind your back from modules that are included after yours. This link to the make documentation describes more about target-specific variables.
• HOST_ and TARGET_ - These contain the directories and definitions that are specific to either the host or the target builds. Do not set variables that start with HOST_ or TARGET_ in your makefiles.
• BUILD_ and CLEAR_VARS - These contain the names of well-defined template makefiles to include. Some examples are CLEAR_VARS and BUILD_HOST_PACKAGE.
• Any other name is fair-game for you to use in your Android.mk. However, remember that this is a non-recursive build system, so it is possible that your variable will be changed by another Android.mk included later, and be different when the commands for your rule / module are executed.

Parameter	Description
LOCAL_AAPT_FLAGS
LOCAL_ACP_UNAVAILABLE
LOCAL_ADDITIONAL_JAVA_DIR
LOCAL_AIDL_INCLUDES
LOCAL_ALLOW_UNDEFINED_SYMBOLS
LOCAL_ARM_MODE
LOCAL_ASFLAGS
LOCAL_ASSET_DIR
LOCAL_ASSET_FILES	In Android.mk files that include $(BUILD_PACKAGE) set this to the set of files you want built into your app. Usually: LOCAL_ASSET_FILES += $(call find-subdir-assets)
LOCAL_BUILT_MODULE_STEM
LOCAL_C_INCLUDES	Additional directories to instruct the C/C++ compilers to look for header files in. These paths are rooted at the top of the tree. Use LOCAL_PATH if you have subdirectories of your own that you want in the include paths. For example: LOCAL_C_INCLUDES += extlibs/zlib-1.2.3 LOCAL_C_INCLUDES += $(LOCAL_PATH)/src You should not add subdirectories of include to LOCAL_C_INCLUDES, instead you should reference those files in the #include statement with their subdirectories. For example: #include not #include
LOCAL_CC	If you want to use a different C compiler for this module, set LOCAL_CC to the path to the compiler. If LOCAL_CC is blank, the appropriate default compiler is used.
LOCAL_CERTIFICATE
LOCAL_CFLAGS	If you have additional flags to pass into the C or C++ compiler, add them here. For example: LOCAL_CFLAGS += -DLIBUTILS_NATIVE=1
LOCAL_CLASSPATH
LOCAL_COMPRESS_MODULE_SYMBOLS
LOCAL_COPY_HEADERS	The set of files to copy to the install include tree. You must also supply LOCAL_COPY_HEADERS_TO. This is going away because copying headers messes up the error messages, and may lead to people editing those headers instead of the correct ones. It also makes it easier to do bad layering in the system, which we want to avoid. We also aren't doing a C/C++ SDK, so there is no ultimate requirement to copy any headers.
LOCAL_COPY_HEADERS_TO	The directory within "include" to copy the headers listed in LOCAL_COPY_HEADERS to. This is going away because copying headers messes up the error messages, and may lead to people editing those headers instead of the correct ones. It also makes it easier to do bad layering in the system, which we want to avoid. We also aren't doing a C/C++ SDK, so there is no ultimate requirement to copy any headers.
LOCAL_CPP_EXTENSION	If your C++ files end in something other than ".cpp", you can specify the custom extension here. For example: LOCAL_CPP_EXTENSION := .cc Note that all C++ files for a given module must have the same extension; it is not currently possible to mix different extensions.
LOCAL_CPPFLAGS	If you have additional flags to pass into only the C++ compiler, add them here. For example: LOCAL_CPPFLAGS += -ffriend-injection LOCAL_CPPFLAGS is guaranteed to be after LOCAL_CFLAGS on the compile line, so you can use it to override flags listed in LOCAL_CFLAGS
LOCAL_CXX	If you want to use a different C++ compiler for this module, set LOCAL_CXX to the path to the compiler. If LOCAL_CXX is blank, the appropriate default compiler is used.
LOCAL_DX_FLAGS
LOCAL_EXPORT_PACKAGE_RESOURCES
LOCAL_FORCE_STATIC_EXECUTABLE	If your executable should be linked statically, set LOCAL_FORCE_STATIC_EXECUTABLE:=true. There is a very short list of libraries that we have in static form (currently only libc). This is really only used for executables in /sbin on the root filesystem.
LOCAL_GENERATED_SOURCES	Files that you add to LOCAL_GENERATED_SOURCES will be automatically generated and then linked in when your module is built. See the Custom Tools template makefile for an example.
LOCAL_INSTRUMENTATION_FOR
LOCAL_INSTRUMENTATION_FOR_PACKAGE_NAME
LOCAL_INTERMEDIATE_SOURCES
LOCAL_INTERMEDIATE_TARGETS
LOCAL_IS_HOST_MODULE
LOCAL_JAR_MANIFEST
LOCAL_JARJAR_RULES
LOCAL_JAVA_LIBRARIES	When linking Java apps and libraries, LOCAL_JAVA_LIBRARIES specifies which sets of java classes to include. Currently there are two of these: core and framework. In most cases, it will look like this: LOCAL_JAVA_LIBRARIES := core framework Note that setting LOCAL_JAVA_LIBRARIES is not necessary (and is not allowed) when building an APK with "include $(BUILD_PACKAGE)". The appropriate libraries will be included automatically.
LOCAL_JAVA_RESOURCE_DIRS
LOCAL_JAVA_RESOURCE_FILES
LOCAL_JNI_SHARED_LIBRARIES
LOCAL_LDFLAGS	You can pass additional flags to the linker by setting LOCAL_LDFLAGS. Keep in mind that the order of parameters is very important to ld, so test whatever you do on all platforms.
LOCAL_LDLIBS	LOCAL_LDLIBS allows you to specify additional libraries that are not part of the build for your executable or library. Specify the libraries you want in -lxxx format; they're passed directly to the link line. However, keep in mind that there will be no dependency generated for these libraries. It's most useful in simulator builds where you want to use a library preinstalled on the host. The linker (ld) is a particularly fussy beast, so it's sometimes necessary to pass other flags here if you're doing something sneaky. Some examples: LOCAL_LDLIBS += -lcurses -lpthread LOCAL_LDLIBS += -Wl,-z,origin
LOCAL_MODULE	LOCAL_MODULE is the name of what's supposed to be generated from your Android.mk. For exmample, for libkjs, the LOCAL_MODULE is "libkjs" (the build system adds the appropriate suffix -- .so .dylib .dll). For app modules, use LOCAL_PACKAGE_NAME instead of LOCAL_MODULE.
LOCAL_MODULE_PATH	Instructs the build system to put the module somewhere other than what's normal for its type. If you override this, make sure you also set LOCAL_UNSTRIPPED_PATH if it's an executable or a shared library so the unstripped binary has somewhere to go. An error will occur if you forget to. See for more.
LOCAL_MODULE_STEM
LOCAL_MODULE_TAGS	Set LOCAL_MODULE_TAGS to any number of whitespace-separated tags. This variable controls what build flavors the package gets included in. For example: user: include this in user/userdebug builds eng: include this in eng builds tests: the target is a testing target and makes it available for tests optional: don't include this
LOCAL_NO_DEFAULT_COMPILER_FLAGS
LOCAL_NO_EMMA_COMPILE
LOCAL_NO_EMMA_INSTRUMENT
LOCAL_NO_STANDARD_LIBRARIES
LOCAL_OVERRIDES_PACKAGES
LOCAL_PACKAGE_NAME	LOCAL_PACKAGE_NAME is the name of an app. For example, Dialer, Contacts, etc.
LOCAL_POST_PROCESS_COMMAND	For host executables, you can specify a command to run on the module after it's been linked. You might have to go through some contortions to get variables right because of early or late variable evaluation: module := $(HOST_OUT_EXECUTABLES)/$(LOCAL_MODULE) LOCAL_POST_PROCESS_COMMAND := /Developer/Tools/Rez -d __DARWIN__ -t APPL\        -d __WXMAC__ -o $(module) Carbon.r
LOCAL_PREBUILT_EXECUTABLES	When including $(BUILD_PREBUILT) or $(BUILD_HOST_PREBUILT), set these to executables that you want copied. They're located automatically into the right bin directory.
LOCAL_PREBUILT_JAVA_LIBRARIES
LOCAL_PREBUILT_LIBS	When including $(BUILD_PREBUILT) or $(BUILD_HOST_PREBUILT), set these to libraries that you want copied. They're located automatically into the right lib directory.
LOCAL_PREBUILT_OBJ_FILES
LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES
LOCAL_PRELINK_MODULE
LOCAL_REQUIRED_MODULES	Set LOCAL_REQUIRED_MODULES to any number of whitespace-separated module names, like "libblah" or "Email". If this module is installed, all of the modules that it requires will be installed as well. This can be used to, e.g., ensure that necessary shared libraries or providers are installed when a given app is installed.
LOCAL_RESOURCE_DIR
LOCAL_SDK_VERSION
LOCAL_SHARED_LIBRARIES	These are the libraries you directly link against. You don't need to pass transitively included libraries. Specify the name without the suffix: LOCAL_SHARED_LIBRARIES := \     libutils \     libui \     libaudio \     libexpat \     libsgl
LOCAL_SRC_FILES	The build system looks at LOCAL_SRC_FILES to know what source files to compile -- .cpp .c .y .l .java. For lex and yacc files, it knows how to correctly do the intermediate .h and .c/.cpp files automatically. If the files are in a subdirectory of the one containing the Android.mk, prefix them with the directory name: LOCAL_SRC_FILES := \     file1.cpp \     dir/file2.cpp
LOCAL_STATIC_JAVA_LIBRARIES
LOCAL_STATIC_LIBRARIES	These are the static libraries that you want to include in your module. Mostly, we use shared libraries, but there are a couple of places, like executables in sbin and host executables where we use static libraries instead. LOCAL_STATIC_LIBRARIES := \     libutils \     libtinyxml
LOCAL_UNINSTALLABLE_MODULE
LOCAL_UNSTRIPPED_PATH	Instructs the build system to put the unstripped version of the module somewhere other than what's normal for its type. Usually, you override this because you overrode LOCAL_MODULE_PATH for an executable or a shared library. If you overrode LOCAL_MODULE_PATH, but not LOCAL_UNSTRIPPED_PATH, an error will occur. See for more.
LOCAL_WHOLE_STATIC_LIBRARIES	These are the static libraries that you want to include in your module without allowing the linker to remove dead code from them. This is mostly useful if you want to add a static library to a shared library and have the static library's content exposed from the shared library. LOCAL_WHOLE_STATIC_LIBRARIES := \     libsqlite3_android
LOCAL_YACCFLAGS	Any flags to pass to invocations of yacc for your module. A known limitation here is that the flags will be the same for all invocations of YACC for your module. This can be fixed. If you ever need it to be, just ask. LOCAL_YACCFLAGS := -p kjsyy
OVERRIDE_BUILT_MODULE_PATH