I have a shared library libfoo.so and need to use it in my android app.
My first try was to have in Android.mk:
include $(CLEAR_VARS)
LOCAL_MODULE := test
LOCAL_SRC_FILES := test.cpp
LOCAL_LDLIBS := -L$(PATH_TO_FOO) -lfoo
include $(BUILD_SHARED_LIBRARY)
in my activity, I have:
statis
{
System.loadLibrary("foo");
}
This builds correctly, however I noticed that created apk doesnt include libfoo.so (also I see it is not copied to libs/armeabi). I guess for that reason I have UnsatisfiedLinkError when executing my app.
I saw in some other posts that I need to add $(PREBUILD_SHARED_LIBRARY), so I add the following to my Android.mk:
include $(CLEAR_VARS)
LOCAL_MODULE:= foo
LOCAL_SRC_FILES := $(FOO_PATH)/libfoo.so
include $(PREBUILD_SHARED_LIBRARY)
But now I am getting the build error:
foo: LOCAL_SRC_FILES points to a missing file.
I am sure that the path is correct. Note that the libfoo.so was having origionally the version number at the end, though I had to remove it (and leave only .so) since ndk-build complained.
What am I doing wrong?
The include appears to be misspelt:
include $(PREBUILD_SHARED_LIBRARY)
should be
include $(PREBUILT_SHARED_LIBRARY)
Found the solution!! LOCAL_SRC_FILES can not have absolute or relative paths, just the filename. The path must be set in LOCAL_PATH.
So in my case, instead of:
LOCAL_SRC_FILES := $(FOO_PATH)/libfoo.so
I have now:
LOCAL_PATH := $(FOO_PATH)
LOCAL_SRC_FILES := libfoo.so
And this works ok.
In eclipse, i add a static library by copying the file in the path project/libs/armeabi/ and rebuild the project after cleaning it. This includes the .so in the apk.
Related
I'm having trouble getting the dependency module to build while building a static library in AOSP. Call this library A, it has a dependency on another static lib B.
A's Android.mk looks like this:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := A
LOCAL_SRC_FILES := <files...>
LOCAL_STATIC_LIBRARIES := B
include $(BUILD_STATIC_LIBRARY)
Individually B builds fine (mma).
Problem is when I build A, B is not being built. Instead I see this at output:
Export includes file: <...>/B/Android.mk -- out/<...>/STATIC_LIBRARIES/B_intermediates/export_includes
Can someone explain what does this line mean and, why is it not trying use B's Android.mk to properly build B?
I understand it's not ideal to package a static lib inside another, but here I'm more courious about why is it the build system not running through B's makefile, when it's clearly a dependency?
Thank you!
The build system ignores lots of irrelevant statements, LOCAL_STATIC_LIBRARIES being one of examples. They don't write every entry in LOCAL_STATIC_LIBRARIES as a dependency for libA.a. Instead, they interpret the Android.mk files to produce make rules for all targets, and if a dependency happens to show up, it will eventually get built, too.
Therefore, the easiest workaround for you would be to add a dummy shared library to your Android.mk, like
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := A
LOCAL_SRC_FILES := <files...>
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := dummyA
LOCAL_SRC_FILES := dummy.c
LOCAL_STATIC_LIBRARIES := B
include $(BUILD_SHARED_LIBRARY)
I am not sure if you can drop LOCAL_SRC_FILES completely. In terms of good old plain make files, the above is roughly equivalent to:
all: libA.a libdummyA.so
libdummyA.so: dummy.c libB.a
gcc -o $# dummy.c -lb
Alternatively, you can manually specify the dependency:
$(PRODUCT_OUT)/obj/STATIC_LIBRARIES/libA_intermediates/libA.a: $(PRODUCT_OUT)/obj/STATIC_LIBRARIES/libB_intermediates/libB.a
Re: export_includes message, it is the result of processing LOCAL_EXPORT_C_INCLUDES statement for libB.
So I've been scratching my head for quite some time with this: basically, I have two Android makefile, one in my jni folder, and one in another folder that contains my native c++ code.
Thing is, for the following makefile,
LOCAL_PATH := $(call my-dir)
GENERATED_PATH := $(LOCAL_PATH)/../../generated/release/api/Android
############################ Includes ############################
#------------------------------------------------------------------ Assimp
LOCAL_MODULE := Assimp
LOCAL_EXPORT_C_INCLUDES := $(GENERATED_PATH)/assimp/include
LOCAL_SRC_FILES := $(GENERATED_PATH)/assimp/lib/libassimp.a
include $(PREBUILT_STATIC_LIBRARY)
# More Libraries included....
#....
I get the following error:
Android NDK: ERROR:jni/../../../appCommon/Android.mk:Assimp: LOCAL_SRC_FILES points to a missing file
Android NDK: Check that jni/../../../appCommon/jni/../../../appCommon/../../generated/release/api/Android/assimp/lib/libassimp.a exists or that its path is correct
What bugs me is that there's twice the LOCAL_PATH in the path where the ndk searches for the library. I've already read about a few cases like this one (like using the notdir macro) but couldn't find a satisfying solution.
How can I specify correctly (and not manually) the correct directory ?
So it turns out that the problem stems from the PREBUILT_STATIC_LIBRARY script, which looks for the lib in the following path: $(LOCAL_PATH)/$(LOCAL_SRC_FILES)
Thus, a simple workaround that worked is to have separate variables for the directories, like that:
GENERATED_PATH := ../../generated/release/api/Android
GENERATED_INCLUDE_PATH := $(LOCAL_PATH)/$(GENERATED_PATH)
and then use them like that:
LOCAL_MODULE := Assimp
LOCAL_EXPORT_C_INCLUDES := $(GENERATED_INCLUDE_PATH)/assimp/include
LOCAL_SRC_FILES := $(GENERATED_PATH)/assimp/lib/libassimp.a
include $(PREBUILT_STATIC_LIBRARY)
Good Day everyone. Still trying to figure out what's wrong with adding xml library.(Previos thread Cannot find libxml2 in android ndk project)
In jni folder: i jave prebuild libxml.so, which i successfully builded, android.mk and start-spice.c. Start-spice.c needs libxml in order to work.
Android.mk:
include $(CLEAR_VARS)
LOCAL_MODULE := libxml
LOCAL_SRC_FILES :=libxml.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := start-spice
LOCAL_SRC_FILES := start-spice.c
LOCAL_LDLIBS := -lxml
LOCAL_SHARED_LIBRARIES= xml
include $(BUILD_SHARED_LIBRARY)
And still it says that cannot find libxml/parser.h
Maybe someone could tell me what's wrong?
The think is that in .ci use libxml methods from linux and here i downloaded libxml2 and builded it - is there any difference?
Are you remembering to add the .h directories of libxml to the list of include directories for the other modules? I don't see any -I flags or LOCAL_C_INCLUDES being set
I have recently started working with NDK and am stuck with a problem. I basically want to use an external static library (.so) into my application. Here's what I've tried till now.
Create a library
1) Add a method in the Java class with native keyword
public native static void FibNR ();
2) In the terminal navigate to the project folder and run the following command
mkdir jni
javah -jni -classpath bin/classes/ -d jni/ com.example.fibonaccinative.FibLib
3) Refresh project and add a C file corresponding to the generated H file.
4) Create a Android.mk file in the JNI folder and add the following code in it
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCV_LIB_TYPE :=STATIC
LOCAL_SRC_FILES := com_example_fibonaccinative_FibLib.c
LOCAL_MODULE := com_example_fibonaccinative_FibLib
include $(BUILD_SHARED_LIBRARY)
5) Build the code using the following command
/Developer/android-ndk-r9b/ndk-build all
The above steps execute successfully and I'm able to view the results of the c code also. Now I want to create a new application and use the generated .so file (com_example_fibonaccinative_FibLib.so) into it. For this I do the following
Use the library
follow steps 1, 2 and 3 from above for the new application
4) Create a Android.mk file in the JNI folder and add the following code in it
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCV_LIB_TYPE :=STATIC
LOCAL_SRC_FILES := com_example_usingstaticlibrary_LibraryTest.c
LOCAL_MODULE := com_example_usingstaticlibrary_LibraryTest
LOCAL_SHARED_LIBRARIES :=libcom_example_fibonaccinative_FibLib.so
LOCAL_LDLIBS := -L$(SYSROOT)/usr -llog
include $(BUILD_SHARED_LIBRARY)
5) Build the code using the following command
/Developer/android-ndk-r9b/ndk-build all
I'm not sure what to do next. What I think is I need to call the function of the library into com_example_usingstaticlibrary_LibraryTest.c. But doing so gives me an error saying
'com_example_fibonaccinative_FibLib' undeclared
EDIT 1:
1) In project 2 (where I want to use the Prebuilt Shared Library (.so)) I copied the library into the 'jni' folder
2) Changed the Android.mk file with the below text.
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libcom_example_fibonaccinative_FibLib
LOCAL_SRC_FILES := libcom_example_fibonaccinative_FibLib.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_usingstaticlibrary_LibraryTest
LOCAL_SHARED_LIBRARIES := libcom_example_fibonaccinative_FibLib
LOCAL_SRC_FILES := com_example_usingstaticlibrary_LibraryTest.c
include $(BUILD_SHARED_LIBRARY)
3) Added the .h file from the old project (com_example_fibonaccinative_FibLib.h) into the 'jni' folder
4) Changed the source of com_example_usingstaticlibrary_LibraryTest.c to
#include "com_example_usingstaticlibrary_LibraryTest.h"
#include "com_example_fibonaccinative_FibLib.h"
JNIEXPORT jlong JNICALL Java_com_example_usingstaticlibrary_LibraryTest_callLibraryFunction
(JNIEnv *env, jclass class) {
Java_com_example_fibonaccinative_FibLib_fibNR(env, class, 500l);
return -500l;
}
Clean/Build results into the following error
undefined reference to 'Java_com_example_fibonaccinative_FibLib_fibNR'
Edit 2:
With reference to this I've edited the Android.mk as follows
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_fibonaccinative_FibLib
LOCAL_SRC_FILES := libcom_example_fibonaccinative_FibLib.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_usingstaticlibrary_LibraryTest
LOCAL_SRC_FILES := com_example_usingstaticlibrary_LibraryTest.c
LOCAL_SHARED_LIBRARIES := com_example_fibonaccinative_FibLib
include $(BUILD_SHARED_LIBRARY)
The NDK build command compiles the code without error. When trying to load the library it gives the following error
Exception Ljava/lang/UnsatisfiedLinkError; thrown while initializing Lcom/example/usingstaticlibrary/LibraryTest
When I remove LOCAL_SHARED_LIBRARIES := com_example_fibonaccinative_FibLib it works fine but I cannot use any function of the Prebuilt shared library.
Edit 3:
I tried a few more things including the suggestion by #jcm but nothing worked. I'm now attaching the source code. It has both the projects (Cleaned version to reduce size).
FibonacciNative: Contains the first project.
UsingStaticLibrary: Contains the second project. I intend to use the Prebuilt Shared Library of the first project into the second one.
You say you want to include a precompiled static library .a, but the file you reference is a shared library .so. If you still want to include a static library, here comes the solution and explanation:
LOCAL_SHARED_LIBRARIES :=libcom_example_fibonaccinative_FibLib.so
You're trying to include the static library as a shared one, looks like an accidental slip from using the previous shared library entry as reference :).
Upon that, Android makefiles still requires you to actually make a module for the external library.
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_fibonaccinative_FibLib
LOCAL_SRC_FILES := com_example_fibonaccinative_FibLib.a
include $(PREBUILT_STATIC_LIBRARY)
Then you can simply add it as a dependency:
LOCAL_STATIC_LIBRARIES := com_example_fibonaccinative_FibLib
But if you're actually trying to include an external shared library. You would need to change the above to the following:
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_fibonaccinative_FibLib
LOCAL_SRC_FILES := com_example_fibonaccinative_FibLib.so
include $(PREBUILT_SHARED_LIBRARY)
and include it as a shared library.
LOCAL_SHARED_LIBRARIES := com_example_fibonaccinative_FibLib
Hope I helped!
Disclaimer: I have not actually tried to compile an example, simply referencing my knowledge and quick research.
References:
Android NDK: Static library used is different than precompiled library specified
As you're including libcom_example_fibonaccinative_FibLib.so as LibraryTest's shared library, in your java static method, you should load it before loading LibraryTest:
System.loadlibrary(com_example_fibonaccinative_FibLib);
System.loadLibrary(LibraryTest);
Update:
After checking your code, LibraryTest.java should look like:
package com.kochartech.usingstaticlibrary;
public class LibraryTest {
public native static long callLibraryFunction();
static {
System.loadLibrary("com_kochartech_fibonaccinative_FibLib");
System.loadLibrary("com_kochartech_usingstaticlibrary_LibraryTest");
}
}
I'm trying to link some .so that I generated using the NDK to a new .so I'm trying to create,
as the old .so contains definitions of functions that I want to use in the new .so.
I've tried this Android.mk :
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := prog_test
LOCAL_SRC_FILES := main.c
LOCAL_MODULE_TAGS := optional
LOCAL_SHARED_LIBRARIES += mylib
include $(BUILD_SHARED_LIBRARY)
$(call import-module,<tag>) # with and without
I've also tried this method I found in stackoverflow NDK - How to use a generated .so library in another project but still no succes as I get always :
prebuilt/linux-x86/toolchain/arm-linux-androideabi-4.4.x/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/ld: error: cannot find -lmylib.so
I really appreciate any help to solve this issue.
B.R
you have to use include $(PREBUILD_SHARED_LIBRARY) instead of include $(BUILD_SHARED_LIBRARY)