Android.mk basic syntax and examples

Examples of this article are as follows:
https://github.com/hanyuhang-hz/android-demos
testExternal/test.zip

Android. The compilation of MK can be divided into:
(1)C/C++
It can be compiled into executable file, dynamic library or static library file.
(2)Java
It can be compiled into jar package or apk.

1 a simple Android MK example

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

test.c:

#include <stdio.h>

int main() {
    printf("hyh test! \n");
    return 0;
}

mmm external/test/1

...
[100% 3/3] Install: external/test/test

#### build completed successfully (19 seconds) ####

View the format of the generated executable file: file test

external/test/test: ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /system/bin/linker, BuildID[md5/uuid]=f2b0744bf9b392b2100f5dc43c9b112f, stripped

Let's analyze this simple Android mk:
(1)LOCAL_PATH:=$(call my-dir)
LOCAL_PATH refers to Android The directory where MK is located.
(2)include $(CLEAR_VARS)
CLEAR_VARS means to clear all environment variables except LOCAL_PATH.
Why should "include $(CLEAR_VARS)" be placed after "LOCAL_PATH: = $(call my DIR)"? Because if you put it before, clear_ vars. The path of MK will be treated as local_ PATH!!!
(3)LOCAL_MODULE:=test
Module name generated by compilation
(4)LOCAL_SRC_FILES:=test.c
Specify source file
(5)LOCAL_MODULE_PATH := $(LOCAL_PATH)
Specifies the directory where the target files are generated
(6)include $(BUILD_EXECUTABLE)
Set the format of the target file. Here is the executable file.

2 Android.mk basic grammar

2.1 multi source file compilation

(1) Add each file to Android In MK
Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c \
                   call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

call.c:

void call() {
    return ;
}

test.c:

#include <stdio.h>

// extern: it can be placed in front of variables or functions to indicate that the definitions of variables or functions are in other files
extern void call();

int main() {
    call();
    printf("hyh test! \n");
    return 0;
}

(2) Use the functions provided by the system
Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := test
#LOCAL_SRC_FILES := test.c \
                   call.c
LOCAL_ALL_C_FILES := $(call all-c-files-under)
LOCAL_SRC_FILES := $(LOCAL_ALL_C_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

Note: all-c-files-under is defined in build / core / definitions MK, my dir are also defined in this file

2.2 compiling multiple target files in one mk

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_ALL_C_FILES := $(call all-c-files-under)
LOCAL_SRC_FILES := $(LOCAL_ALL_C_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

include $(CLEAR_VARS)
LOCAL_MODULE := test1
LOCAL_ALL_C_FILES := $(call all-c-files-under)
LOCAL_SRC_FILES := $(LOCAL_ALL_C_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

test.c:

#include <stdio.h>

int main() {
    printf("hyh test! \n");
    return 0;
}

Note: update all files in the directory, touch externel/test/*

2.3 compiling dynamic library

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcall
LOCAL_ALL_C_FILES := $(call all-c-files-under)
LOCAL_SRC_FILES := $(LOCAL_ALL_C_FILES)
#LOCAL_SRC_FILES := call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_SHARED_LIBRARY)

The compilation type is BUILD_SHARED_LIBRARY
call.c:

void call() {
    return ;
}

2.4 compiling static library

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libtest
LOCAL_ALL_C_FILES := $(call all-c-files-under)
LOCAL_SRC_FILES := $(LOCAL_ALL_C_FILES)
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_STATIC_LIBRARY)

The compilation type is BUILD_STATIC_LIBRARY
call.c:

void call() {
    return ;
}

2.5 reference system library

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c
LOCAL_SHARED_LIBRARIES += liblog
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

LOCAL_SHARED_LIBRARIES += liblog
test.c:

#include <stdio.h>
#define LOG_TAG "HYH"
#include <utils/Log.h>

int main() {
    printf("hyh test! \n");
    ALOGE("test!");
    return 0;
}

2.6 reference to third-party libraries

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcall
LOCAL_SRC_FILES := call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c
LOCAL_SHARED_LIBRARIES += liblog
LOCAL_LDFLAGS := -L./ -lcall
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

LOCAL_LDFLAGS := -L/Path -lxxx
call.c:

void call() {
    return ;
}

test.c:

#include <stdio.h>
#define LOG_TAG "HYH"
#include <utils/Log.h>

// extern: it can be placed in front of variables or functions to indicate that the definitions of variables or functions are in other files
extern void call();

int main() {
    call();
    printf("hyh test! \n");
    ALOGE("test!");
    return 0;
}

2.7 reference to third party header documents

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcall
LOCAL_SRC_FILES := call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c
LOCAL_C_INCLUDES := $(LOCAL_PATH)/inc/
LOCAL_SHARED_LIBRARIES += liblog
LOCAL_LDFLAGS := -L./ -lcall
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

LOCAL_C_INCLUDES := $(LOCAL_PATH)/inc/
Note: LOCAL_C_INCLUDES requires an absolute path.
inc/call.h:

#ifndef CALL_H
#define CALL_H
extern void call();
#endif

call.c:

void call() {
    return ;
}

test.c:

#include <stdio.h>
#define LOG_TAG "HYH"
#include <utils/Log.h>
#include <call.h>

int main() {
    call();
    printf("hyh test! \n");
    ALOGE("test!");
    return 0;
}

2.8 reference static library

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcall
LOCAL_SRC_FILES := call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_STATIC_LIBRARY)

#include $(CLEAR_VARS)
#LOCAL_MODULE := test
#LOCAL_SRC_FILES := test.c
#LOCAL_C_INCLUDES := $(LOCAL_PATH)/inc/
#LOCAL_SHARED_LIBRARIES += liblog
#LOCAL_LDFLAGS := $(LOCAL_PATH)/lib/libcall.a
#LOCAL_MODULE_PATH := $(LOCAL_PATH)
#include $(BUILD_EXECUTABLE)

Note: the static library is generated in the following directory and needs to be manually copied to the current directory.

out/target/product/xxx/obj/STATIC_LIBRARIES/libcall_intermediates/libcall.a

call.c:

void call() {
    return ;
}

test.c:

#include <stdio.h>
#define LOG_TAG "HYH"
#include <utils/Log.h>
#include <call.h>

int main() {
    call();
    printf("hyh test! \n");
    ALOGE("test!");
    return 0;
}

call.h:

#ifndef CALL_H
#define CALL_H
extern void call();
#endif

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcall
LOCAL_SRC_FILES := call.c
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.c
LOCAL_C_INCLUDES := $(LOCAL_PATH)/inc/
LOCAL_SHARED_LIBRARIES += liblog
LOCAL_LDFLAGS := $(LOCAL_PATH)/libcall.a
LOCAL_MODULE_PATH := $(LOCAL_PATH)
include $(BUILD_EXECUTABLE)

Note: LOCAL_LDFLAGS requires an absolute path.

2.9 compiling apk

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_PACKAGE_NAME := TestPackage
include $(BUILD_PACKAGE)

BUILD_PACKAGE: indicates the apk generated by compilation
LOCAL_PACKAGE_NAME: indicates the apk name generated by compilation

2.10 compile and generate jar package

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_MODULE := com.test.jar
include $(BUILD_STATIC_JAVA_LIBRARY)
#include $(BUILD_JAVA_LIBRARY)

jar package classification:
(1) Static jar package:
include $(BUILD_STATIC_JAVA_LIBRARY)
Used at compile time The jar file packaged from the class file can run on any java virtual machine
(2) Dynamic jar package:
include $(BUILD_JAVA_LIBRARY)
When compiling, based on the static jar package, use The jar file packaged by dex can only run on android system

2.11 apk reference jar package

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_STATIC_JAVA_LIBRARIES := static-library
#LOCAL_JAVA_LIBRARIES := share-library
LOCAL_SRC_FILES := $(call all-subdir-java-files)
LOCAL_PACKAGE_NAME := TestPackage
include $(BUILD_PACKAGE)

2.12 precompiled jar package

Android.mk:

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE_CLASS := JAVA_LIBRARIES
LOCAL_MODULE := com.test.share
LOCAL_SRC_FILES := com.test.static
include $(BUILD_PREBUILT)

Precompile static jar packages into dynamic jar packages.
LOCAL_MODULE_CLASS: represents the precompiled file type
(1)JAVA_LIBRARIES: dynamic jar package
(2)APPS: apk
(3)SHARED_LIBRARIES: dynamic library file so
(4)EXECUTABLES: binary files

2.13 Android.mk judgment grammar

ifeq ($(VALUE, x))
    ...
else
    ...
endif

USED_SHARE := true
ifeq ($(USED_SHARE), true)
LOCAL_LDFLAGS := -L./ -ltest
else
LOCAL_LDFLAGS := $(LOCAL_PATH)/lib/libcall.a
endif

Added by tc48 on Sat, 12 Feb 2022 06:35:39 +0200

Programming VIP

Android.mk basic syntax and examples

1 a simple Android MK example

2 Android.mk basic grammar

2.1 multi source file compilation

2.2 compiling multiple target files in one mk

2.3 compiling dynamic library

2.4 compiling static library

2.5 reference system library

2.6 reference to third-party libraries

2.7 reference to third party header documents

2.8 reference static library

2.9 compiling apk

2.10 compile and generate jar package

2.11 apk reference jar package

2.12 precompiled jar package

2.13 Android.mk judgment grammar

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