I have two native modules to be build as shared library. Both the modules have dependecy on some other common modules.
I am giving the dependecy in Android.mk file using "PREBUILT_SHARED_LIBRARY", but the problem is the libraries specified with "PREBUILT_SHARED_LIBRARY" will get copied to libs/armeabi folder too.. :(
When I include their respective .jars in the main application it throws an eror saying duplicate copy of libraries..
I have to solve this problem by linking the common libraries in ndk build without using "PREBUILT_SHARED_LIBRARY" so that it will not copy the all dependent libraries to libs/areabi.
Can anybody please tell me how can I resolve this problem ? I have googled about this, but everywhere I see the answer use "PREBUILT_SHARED_LIBRARY" to link with already built shared libraries.
Your prebuilt's Android.mk is probably wrong, if you do something like this
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := mygreatlibrary-prebuilt
MY_LIBRARY_NAME := myGreatLibrary
### export include path
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
### path to library
LOCAL_SRC_FILES := libs/$(TARGET_ARCH_ABI)/lib$(MY_LIBRARY_NAME).so
### export dependency on the library
LOCAL_EXPORT_LDLIBS := -L$(LOCAL_PATH)/libs/$(TARGET_ARCH_ABI)/
LOCAL_EXPORT_LDLIBS += -l$(MY_LIBRARY_NAME)
include $(PREBUILT_SHARED_LIBRARY)
Then the correct library will be copied to the correct place
Related
I am getting a compile error:
undefined reference to 'TangoService_getConfig' (MoreTeapotsNativeActivity.cpp)
ld returned 1 exit status (collect2.exe)
I am working with the tango sdk TangoSDK_Ikariotikos_C.zip in Visual Studio 2015 using VisualGDB. I have also replicated the error in Android Studio so it isn't IDE specific.
I have started with an NDK sample project to test a native activity deploys correctly and reduce complexity whilst troubleshooting. I have used VisualGDB MoreTeaPotsNativeActivity but any will do. The app compiles and runs on our ASUS Zenfone AR. Once I include tango_client_api.h and add the following code, I get the compile error:
TangoCoordinateFramePair* Tango_FramePair;
Tango_FramePair = new TangoCoordinateFramePair();
Tango_FramePair->base = TANGO_COORDINATE_FRAME_START_OF_SERVICE;
Tango_FramePair->target = TANGO_COORDINATE_FRAME_DEVICE;
TangoErrorType retval;
// Connect to tango service.
TangoConfig tango_config;
tango_config = TangoService_getConfig(TANGO_CONFIG_DEFAULT);
The Tango header file has an extern "C" wrapper for the C functions and the .o shows them demangled so I can't see why it is failing.
If I comment out...
//tango_config = TangoService_getConfig(TANGO_CONFIG_DEFAULT);
...it compiles and the enums show as locals in the debug so it seems to be a problem with functions: see image of locals here
I may be missing something glaringly obvious because android is fairly new to me. Perhaps someone can test the tangoSDK library with the same code block and spot the issue. It is frustrating that I cannot even link a library. I may be missing something simple but to me it is not obvious.
Any help will be greatly appreciated.
I contacted Sysprogs Support who gave me a link:
PREBUILT_SHARED_LIBRARY syntax
I hadn't realised the library wasn't being copied even though intellisense was reading the header. I needed to include a reference in the make file (android.mk) to copy the library (I copied Tango include and lib folders to the project jni folder):
include $(CLEAR_VARS)
LOCAL_MODULE := tango_client_api
LOCAL_SRC_FILES := ../jni/lib/$(TARGET_ARCH_ABI)/libtango_client_api.so
include $(PREBUILT_SHARED_LIBRARY)
I did the same with an additional block for the support library:
include $(CLEAR_VARS)
LOCAL_MODULE := tango_support_api
LOCAL_SRC_FILES := ../jni/lib/$(TARGET_ARCH_ABI)/libtango_support_api.so
include $(PREBUILT_SHARED_LIBRARY)
The main module just needs this:
LOCAL_SHARED_LIBRARIES := tango_client_api
The whole file looks like this:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := tango_client_api
LOCAL_SRC_FILES := ../jni/lib/$(TARGET_ARCH_ABI)/libtango_client_api.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := tango_support_api
LOCAL_SRC_FILES := ../jni/lib/$(TARGET_ARCH_ABI)/libtango_support_api.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := MoreTeapotsNativeActivity
#VisualGDBAndroid: AutoUpdateSourcesInNextLine
LOCAL_SRC_FILES := gdbserver_launcher.c MoreTeapotsNativeActivity.cpp MoreTeapotsRenderer.cpp
LOCAL_C_INCLUDES := jni/include
LOCAL_LDLIBS := -llog -landroid -lEGL -lGLESv2
LOCAL_STATIC_LIBRARIES := cpufeatures android_native_app_glue ndk_helper
LOCAL_SHARED_LIBRARIES := tango_client_api
include $(BUILD_SHARED_LIBRARY)
$(call import-module,android/ndk_helper)
$(call import-module,android/native_app_glue)
$(call import-module,android/cpufeatures)
I didn't get this to work straight away when following the NDK examples but Sysprogs gave me feedback on my mistake which I will include.
I tried to include:
LOCAL_MODULE_FILENAME := tango_client_api
I left off the lib and .so as seemed to be convention. The .so was not necessary but taking lib off was changing the file name which caused a link error. That said, that line was unnecessary in the first place to I removed it. Then it removed the error relating to this. I have yet to see if the library works at runtime because I now get this error:
java.lang.UnsatisfiedLinkError: Unable to load native library "/data/app/com.sample.moreteapots-2/lib/arm64/libMoreTeapotsNativeActivity.so": dlopen failed: library "libbinder.so" not found
But this seems to relate to a problem with Android 7.0 platform 24 and higher where
the system prevents apps from dynamically linking against non-NDK libraries
from /Android/android-sdk/docs/about/versions/nougat/android-7.0-changes.html
I am trying to write an JNI file and it includes JNIHelp.h, however I met some error:
jni/JNIMPEG4Writer.cpp:4:21: fatal error: JNIHelp.h: No such file or directory
compilation terminated.
I guess I should add something to the Android.mk file, but I am not sure what should I add. This is my Android.mk file:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := JNIMPEG4Writer
LOCAL_STATIC_LIBRARIES := MPEG4Writer
#LOCAL_LDLIBS := -llog
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib –llog
LOCAL_SRC_FILES := JNIMPEG4Writer.cpp
include $(BUILD_SHARED_LIBRARY)
Does anyone have any ideas? Thanks!
JNIHelp.h is not part of NDK. You inherited some code from the Android platform. You will find other dependencies on non-public modules, most likely libcutils and libutils.
You have three options: build your code as a module of the platform, rewrite the code to only use public headers and libraries, or download parts of the platform, e.g. https://android.googlesource.com/platform/libnativehelper/, and arrange the include paths accordingly.
To satisfy the linker in the latter scenario, you can use adb pull /system/lib to acquire the versions of libnativehelper.so, libcutils.so, and other referenced non-public libraries. Note that ndk-build will complain about linking against these libraries.
I have read many posts on how to share prebuilt libraries using the Android.mk system. The solutions boil down to two steps:
A directory with the already-built library uses *include $(PREBUILT_SHARED_LIBRARY)*
The project consuming the library uses *LOCAL_SHARED_LIBRARIES*
(you can substitute "STATIC" for "SHARED" to build and use a .a instead of a .so)
What I am trying to do is add a step 0: build the library from sources. If I change a source file that contributes to the library I want the Android.mk system to execute steps 0, 1, and 2 in order.
I have two projects in Eclipse/ADT:
MyApp - uses MyLibrary
MyLibrary - contains the source files for the library
The question I'm asking here focuses on MyLibrary project. Here is the Android.mk for MyLibrary:
LOCAL_PATH := $(call my-dir)
# step 0: build my library
include $(CLEAR_VARS)
LOCAL_MODULE := mylibrary
LOCAL_LDLIBS := -llog
LOCAL_SRC_FILES := libsrc1.c libsrc2.c
include $(BUILD_SHARED_LIBRARY)
# step 1: export my library (PREBUILT_SHARED_LIBRARY):
include $(CLEAR_VARS)
LOCAL_MODULE := mylibrary-prebuilt
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/libmylibrary.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
include $(PREBUILT_SHARED_LIBRARY)
If I do a project->clean... and then a project->build project in this project I get the error:
ERROR:jni/Android.mk:mylibrary-prebuilt: LOCAL_SRC_FILES points to a missing file.
The clean removes the .so and I'm guessing PREBUILT_SHARED_LIBRARY detects the missing .so before BUILD_SHARED_LIBRARY rebuilds the library and copies it (even though the steps are in the correct order).
If I comment out step 1 and build, libmylibrary.so is correctly built and copied to libs/armeabi/libmylibrary.so. If I then uncomment step 2 and do a project->build project, that is without doing a clean first, I get these warnings and error:
warning: overriding commands for target `obj/local/armeabi/libmylibrary.so'
warning: ignoring old commands for target `obj/local/armeabi/libmylibrary.so'
warning: overriding commands for target `libs/armeabi/libmylibrary.so'
warning: ignoring old commands for target `libs/armeabi/libmylibrary.so'
make: *** No rule to make target `jni/../libs/armeabi/libmylibrary.so', needed by `obj/local/armeabi/libmylibrary.so'. Stop.
I think I understand these errors, but I do not see a way to accomplish what I want.
What am I missing?
You can simply avoid step 1 entirely and just rebuild the library from sources. I'm not sure I understand the benefits of having the three steps your describe. Feel free to clarify.
In all cases, your analysis of ndk-build's behaviour is spot on, and all of this is completely intentional.
The NDK itself provides several prebuilt libraries and allows you to rebuild them from sources if you want. For example, if you look at sources/cxx-stl/stlport/Android.mk, you will see that a variable (STLPORT_FORCE_REBUILD) is used to control whether to use the prebuilt binaries, or rebuild them from sources.
Maybe using a similar method for your project would work.
I want to build a static library link to a third_part static library. And then provide the static library which I built to other people to use. But when others use my library, they found an error "undefined reference to 'Func1()'", "Func1()" is a function defined in the third_part static library. Does anyone have an idea how to fix it?
Here's my Android.mk:
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := ThirdLib_Rebuild
LOCAL_SRC_FILES := libThird.a
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := MyLib
LOCAL_STATIC_LIBRARIES := ThirdLib_Rebuild
LOCAL_SRC_FILES := MyLib.c
include $(BUILD_STATIC_LIBRARY)
ndk-build supports transitive dependencies, i.e. if you define a shared library or executable that depends on your MyLib module, then both libMyLib.a and libThird.a will be linked into it (if not, this is a bug, which NDK are you using exactly?).
However, you're not very clear about what you're doing when distributing your libraries to other people. For the record, you need to distribute both libraries to your users, because libMyLib.a does not include the code from libThird.a, the use of LOCAL_STATIC_LIBRARIES in the MyLib module definition only serves to record a dependency between the two libs, unlike what happens when you use it for a shared library or executable.
I'm working on some code cuz I was asked to devlep c++ code about core part of a program.
But, it's my first time to use ndk so, I had some troubles and resolved that.
However, too difficult problem is coming to me. I had building my c++ code w/ ndk but,
it said,
.h:3:20: error: string: No such file or directory
.h:5: error: 'std::string' has not been declared
and any other errors about that.
Below is my 'Android.mk' file I wrote:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := clibs
LOCAL_SRC_FILES := sqlite3.c
LOCAL_LDLIBS := -llog
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_DEFAULT_CPP_EXTENSION := cpp
LOCAL_MODULE := mytweetlib
LOCAL_STATIC_LIBRARIES := clibs
LOCAL_SRC_FILES := Friend.cpp SQLiteDB.cpp Cursor.cpp DB4Friends.cpp ResultParser.cpp MyTweet.cpp Stub.cpp
include $(BUILD_SHARED_LIBRARY)
I tried to link the .c file(sqlite3.c) Making static library file w/ the other file(to be built to shared library).
Is there anyone knows about this? Even if it's just very little clue, plz give me that.
(I haven't been resolving this problem)
It looks like the NDK isn't being told to use stl port.
Try adding an Application.mk file containing APP_STL. This adds the stlport headers to the include path, and links against the libraries.
APP_STL := stlport_static
I would like to add further to Piklor answer.
Do not confuse with "Android.mk" file with "Application.mk" , in your jni folder.
Also your include should include string not string.h