Develop Reference

NDK cannot locate symbol "_Znwj"

I've compiled a 3rd party library on Linux using a standalone toolchain, and I'm now trying to load that library in my app.
Problem is I'm getting java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol "_Znwj" referenced by "libmxnet_predict.so"
I've tried adding CFLAGS and LDFLAGS, both APP & LOCAL, but to no avail.
Before you ask, I'm developing with ADT because I have to.
This is my Application.mk:
APP_STL := gnustl_shared
APP_CFLAGS += -std=c++11
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi-v7a
APP_PLATFORM := android-19
My (simplified) Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCV_LIB_TYPE:=SHARED
OPENCV_CAMERA_MODULES:=off
OPENCV_INSTALL_MODULES:=on
NDK_TOOLCHAIN_VERSION=4.9
include $(CLEAR_VARS)
include $(PREBUILT_SHARED_LIBRARIES)
include C:/OpenCV-2.4.8-android-sdk/sdk/native/jni/OpenCV.mk
LOCAL_MODULE := FreshubML
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_SRC_FILES := Mldevlib.cpp \
Tablet.cpp \
Interface.cpp \
LOCAL_LDLIBS += -llog -ldl -landroid -lm -ljnigraphics -lstdc++
C:\KitchenVision\Workspaces\MLDevWorkspace\MLDev\assets\share
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libmxnet_predict
LOCAL_SRC_FILES := lib/armeabi-v7a/libmxnet_predict.so
include $(PREBUILT_SHARED_LIBRARY)
Searching the standalone toolchain I saw that the symbol was referenced in libgnust_shared.so which I added to my project via APP_STL and in libstdc++.so but still, same error.
How do I get this to work?

Android NDK module that is dependant on another module

I have an android project written using the Android NDK. Within the project, I am using two prebuilt shared libraries(GpkgSDK and spatialite) and building two more shared libraries(WFSHelpers and com_example_gpkgviewer_jni_WKTConverter). The only library that interacts with the Java level of the application is the com_example_gpkgviewer_jni_WKTConverter library.
The dependencies between the libraries are shown below:
WFSHelpers is dependent on GpkgSDK and spatialite
com_example_gpkgviewer_jni_WKTConverter is dependent on WFSHelpers
The issue that I am having is that when I try to run ndk-build, I am getting a lot of undefined references when attempting to build the com_example_gpkgviewer_jni_WKTConverter library. The other libraries are successfully built. The way I would normally resolve these undefined references is by including the following in my com_example_gpkgviewer_jni_WKTConverter module definition :
LOCAL_SHARED_LIBRARY := WFSHelpers
I am unsure as to whether I would also need to include the libraries that the WFSHelpers is dependent on like so:
LOCAL_SHARED_LIBRARY := WFSHelpers GpkgSDK spatialite
I have also tried them in a different order like so but it does not seem to resolve my issue:
LOCAL_SHARED_LIBRARY := GpkgSDK spatialite WFSHelpers
My Application.mk is included below:
NDK_TOOLCHAIN_VERSION := 4.8
# APP_STL := stlport_shared --> does not seem to contain C++11 features
APP_STL := gnustl_shared
# Enable c++11 extentions in source code
APP_CPPFLAGS += -std=c++11
APP_CPPFLAGS += -frtti
APP_CPPFLAGS += -fexceptions
APP_MODULES := GpkgSDK spatialite WFSHelpers com_example_gpkgviewer_jni_WKTConverter
APP_ABI := armeabi armeabi-v7a
My Android.mk is shown below:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := GpkgSDK
LOCAL_SRC_FILES := libMP.so
LOCAL_EXPORT_C_INCLUDES := \
$(LOCAL_PATH)/include \
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := spatialite
LOCAL_SRC_FILES := spatialamal/prebuilt/$(TARGET_ARCH_ABI)/libspatialite.so
LOCAL_EXPORT_C_INCLUDES := spatialamal/headers/spatialite \
spatialamal/headers
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := WFSHelpers
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
LOCAL_SRC_FILES := \
GPKGReader/Debug.h \
GPKGReader/DLLExport.h \
GPKGReader/DBQueryResult.cpp \
GPKGReader/GeoPackageDB.cpp \
GPKGReader/GPKGReader.cpp \
GPKGReader/order32.h \
GPKGReader/SpecDefinitions.h \
GPKGReader/WKBGenericGeometry.cpp \
GPKGReader/WKBLineString.cpp \
GPKGReader/WKBMultiLineString.cpp \
GPKGReader/WKBMultiPolygon.cpp \
GPKGReader/WKBPoint.cpp \
GPKGReader/WKBPolygon.cpp \
GPKGDataLayer/GPKGDataLayer.cpp
LOCAL_SHARED_LIBRARIES := GpkgSDK spatialite
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
LOCAL_MODULE := com_example_gpkgviewer_jni_WKTConverter
LOCAL_SRC_FILES := com_example_gpkgviewer_jni_WKTConverter.cpp
LOCAL_SHARED_LIBRARY := WFSHelpers GpkgSDK spatialite
include $(BUILD_SHARED_LIBRARY)
An example of the undefined reference errors that I am getting is shown below:
[armeabi] SharedLibrary : libcom_example_gpkgviewer_jni_WKTConverter.so
jni/com_example_gpkgviewer_jni_WKTConverter.cpp:59: error: undefined reference
o 'WKBGenericGeometry::readInt32(unsigned char, unsigned char*, unsigned int)'
collect2.exe: error: ld returned 1 exit status
make.exe: *** [obj/local/armeabi/libcom_example_gpkgviewer_jni_WKTConverter.so]
Error 1
The line of code within com_example_gpkgviewer_jni_WKTConverter.cpp that causes this error is shown below:
*id_arg = WKBGenericGeometry::readInt32(byte_order, &(bytes[4]), length - 4);
Any suggestions on how I can resolve the dependencies.

After attempting to get this to build for ages, I have finally been able to get it to work. Although, I am not quite sure what the differences are, so anyone who can shed a light on this is welcome to do so. My issue was that I had dependencies on other libraries. The documentation states the following:
LOCAL_SHARED_LIBRARIES
The list of shared libraries modules this
module depends on at runtime. This is necessary at link time and to
embed the corresponding information in the generated file.
LOCAL_LDLIBS
The list of additional linker flags to be used when building your shared library or executable. This is useful to pass the
name of specific system libraries with the '-l' prefix. For example,
the following will tell the linker to generate a module that links to
/system/lib/libz.so at load time:
LOCAL_LDLIBS := -lz
See STABLE-APIS for the list of exposed system libraries you can linked against with this NDK release.
NOTE: This is ignored for static libraries, and ndk-build will print a warning if
you define it in such a module.
Thus in my Android.mk file, I had to use LOCAL_LDLIBS instead of LOCAL_SHARED_LIBRARIES to indicate the dependencies.
My new Android.mk is as shown below:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := GpkgSDK
LOCAL_SRC_FILES := libMP.so
LOCAL_EXPORT_C_INCLUDES := \
$(LOCAL_PATH)/include \
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := spatialite
LOCAL_SRC_FILES := spatialamal/prebuilt/$(TARGET_ARCH_ABI)/libspatialite.so
LOCAL_EXPORT_C_INCLUDES := spatialamal/headers/spatialite \
spatialamal/headers
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := WFSHelpers
LOCAL_SRC_FILES := \
GPKGReader/Debug.h \
GPKGReader/DLLExport.h \
GPKGReader/DBQueryResult.cpp \
GPKGReader/GeoPackageDB.cpp \
GPKGReader/GPKGReader.cpp \
GPKGReader/order32.h \
GPKGReader/SpecDefinitions.h \
GPKGReader/WKBGenericGeometry.cpp \
GPKGReader/WKBLineString.cpp \
GPKGReader/WKBMultiLineString.cpp \
GPKGReader/WKBMultiPolygon.cpp \
GPKGReader/WKBPoint.cpp \
GPKGReader/WKBPolygon.cpp \
GPKGDataLayer/GPKGDataLayer.cpp
LOCAL_LDLIBS := libs/$(TARGET_ARCH_ABI)/libGpkgSDK.so
LOCAL_LDLIBS += libs/$(TARGET_ARCH_ABI)/libspatialite.so
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := com_example_gpkgviewer_jni_WKTConverter
LOCAL_SRC_FILES := com_example_gpkgviewer_jni_WKTConverter.cpp
LOCAL_LDLIBS := libs/$(TARGET_ARCH_ABI)/libWFSHelpers.so
LOCAL_LDLIBS += libs/$(TARGET_ARCH_ABI)/libGpkgSDK.so
include $(BUILD_SHARED_LIBRARY)
I shall leave this answer open for a while as I am not entirely sure what the difference between LOCAL_LDLIBS and LOCAL_SHARED_LIBRARIES is. If anyone can provide me with an explanation, please do. If not, I shall mark this answer as accepted after giving it some time. Thanks !

Android NDK:linking static library with shared library

Iam trying to compile my native code. Here is my android.mk file
//part1-static lib
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := irrlicht
IRRLICHT_LIB_NAME := lib$(LOCAL_MODULE).a
LOCAL_C_INCLUDES := include
LOCAL_SRC_FILES := \
CColorConverter.cpp \
CCSMLoader.cpp \
CCubeSceneNode.cpp \
CD3D8Driver.cpp \
include $(BUILD_STATIC_LIBRARY)
//part-2 shared lib
include $(CLEAR_VARS)
LOCAL_MODULE := irrlichttest
LOCAL_SRC_FILES := test-app.cpp test.cpp android-receiver.cpp
LOCAL_C_INCLUDES := include
LOCAL_CFLAGS := -O3 -DANDROID_NDK -DDISABLE_IMPORTGL -I$(LOCAL_PATH)/../include/ - I./include/
LOCAL_CPPFLAGS := -Wno-error=format-security
LOCAL_LDLIBS := -lGLESv1_CM -ldl -llog -lGLESv2
LOCAL_STATIC_LIBRARIES := irrlicht
include $(BUILD_SHARED_LIBRARY)
and here is my application.mk
APP_ABI := armeabi armeabi-v7a
APP_PLATFORM := android-10
APP_MODULE := irrlicht irrlichttest
i want to compile "irrlicht" module first and then "irrlichttest' module. The problem iam facing is my irrlichttest module compile first and it start looking for reference and give me undefined reference error.Right now If i compile part1(static lib) only it successfully generate libirrlicht.a, But with part2 it start giving me error. What am i doing wrong.

You have one extra \ at the end of your first LOCAL_SRC_FILES definition, this makes the 'include $(BUILD_STATIC_LIBRARY)' part go into LOCAL_SRC_FILES, and the line is never parsed / executed. In other words, due to this your module definition for the 'iirlicht' module is completely ignored by ndk-build, hence the problem you're seeing.
Remove the \ after CD3D8Driver.cpp, and that should fix it.

NDK will compile the irrlichttest sources, then irrlich sources, then create libirrlich.a, and only after that it will link libirrlichttest.so. It is very insightful to run
ndk-build clean all V=1
and see in the build log which commands are actually executed to build the project.

how to specify the use of g++ in Android.mk?

I have a c++ library that i've added to the android2.3.6 source code and i want to compile it and link using g++ instead of gcc and ld.
is it possible?
Also,i've added this line into my Android.mk file:
LOCAL_CXX=path/to/g++compiler
But the building still use gcc.
is there any solution?
Thanks in advance!
EDIT:
Full Android.mk
LOCAL_PATH := $(call my-dir)
libdash_src_files :=cppfiles
LOCAL_C_INCLUDES :=headers
include $(CLEAR_VARS)
LOCAL_C_INCLUDES += path_to/stlport
LOCAL_SRC_FILES := $(libdash_src_files)
include external/stlport/libstlport.mk
LOCAL_SHARED_LIBRARIES += libstlport libz LOCAL_SYSTEM_SHARED_LIBRARIES :=libdl libutils libc
LOCAL_LDLIBS := $(LOCAL_LDLIBS) -llog
LOCAL_LDFLAGS:= -lz -Wl -shared
LOCAL_CXX := $(CXX)
libdash_cppflags :=-g -fPIC -v -frtti -fexceptions
LOCAL_CPPFLAGS :=$(libdash_cppflags) -fpermissive -w
LOCAL_MODULE :=libdash
LOCAL_MODULE_TAGS :=optional
include $(BUILD_SHARED_LIBRARY)

i just followed jermaine indications and did a make clean
then build it again and it worked fine.
Thanks guys.

Android NDK, two Static Libraries and Linking

I started off creating libraries as shared libraries, but I considered it would be more efficient to create one shared libraries and the rest static. When it was all shared, it compiled and linked fine, but moving to static, I get on linking "undefined reference".
Edit: I build all the libraries in one Android.mk
Android.mk:
MY_LOCAL_PATH := $(call my-dir)
MY_LOCAL_CFLAGS := -DDEBUG
TARGET_PLATFORM := 'android-4'
LOCAL_PATH := $(MY_LOCAL_PATH)/../../Base
include $(CLEAR_VARS)
LOCAL_MODULE := Base
LOCAL_SRC_FILES := <Base src files>
include $(BUILD_STATIC_LIBRARY)
MY_LOCAL_STATIC_LIBRARIES := Base
MY_LOCAL_C_INCLUDES := $(MY_LOCAL_PATH)/../../Base
LOCAL_PATH := $(MY_LOCAL_PATH)/../../Framework
include $(CLEAR_VARS)
LOCAL_MODULE := Framework
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)
LOCAL_SRC_FILES := <Framework src files>
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
include $(BUILD_STATIC_LIBRARY)
MY_LOCAL_STATIC_LIBRARIES += Framework
MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/../../Framework
LOCAL_PATH := $(MY_LOCAL_PATH)/Graphics
include $(CLEAR_VARS)
LOCAL_MODULE := Graphics
LOCAL_SRC_FILES := <Graphics src files>
LOCAL_EXPORT_LDLIBS := -lGLESv1_CM
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)
include $(BUILD_STATIC_LIBRARY)
MY_LOCAL_STATIC_LIBRARIES += Graphics
MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/Graphics
LOCAL_PATH := $(MY_LOCAL_PATH)/Platform
include $(CLEAR_VARS)
LOCAL_MODULE := Platform
LOCAL_SRC_FILES := <Platform src files>
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)
include $(BUILD_STATIC_LIBRARY)
MY_LOCAL_STATIC_LIBRARIES += Platform
MY_LOCAL_C_INCLUDES += $(MY_LOCAL_PATH)/Platform
LOCAL_PATH := $(MY_LOCAL_PATH)
include $(CLEAR_VARS)
LOCAL_MODULE := Final
LOCAL_SRC_FILES := <Final src files>
LOCAL_STATIC_LIBRARIES := $(MY_LOCAL_STATIC_LIBRARIES)
LOCAL_LDLIBS := -llog
LOCAL_CFLAGS := $(MY_LOCAL_CFLAGS)
LOCAL_C_INCLUDES := $(MY_LOCAL_C_INCLUDES)
include $(BUILD_SHARED_LIBRARY)
Last line of ndk-build V=1 -B:
SharedLibrary : libFinal.so
/Users/robbie/Library/Frameworks/Android-NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/darwin-x86/bin/arm-linux-androideabi-g++ -Wl,-soname,libFinal.so -shared --sysroot=/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm <object files> /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libBase.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libFramework.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libGraphics.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libPlatform.a /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libstdc++.a /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libc.so /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libstdc++.so /Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib/libm.so -Wl,--no-undefined -Wl,-z,noexecstack -L/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib -llog -lGLESv1_CM -lstdc++ -Wl,-rpath-link=/Users/robbie/Library/Frameworks/Android-NDK/platforms/android-4/arch-arm/usr/lib -lsupc++ -o /Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libFinal.so
/Users/robbie/Documents/Apps/Revolution/Android/obj/local/armeabi/libPlatform.a(ATexture.o): In function `ATexture':
/Users/robbie/Documents/Apps/Revolution/Android/jni/SpinTap/ATexture.cpp:9: undefined reference to `TextureRenderer::TextureRenderer(unsigned int)'
/Users/robbie/Documents/Apps/Revolution/Android/jni/SpinTap/ATexture.cpp:9: undefined reference to `TextureRenderer::TextureRenderer(unsigned int)'
Edit2: TextureRenderer is in Graphics, which is included.
Does anyone have an idea why it may not be working and how to fix it?

This looks like an order-of-linking issue to me.
Your command line is:
arm-linux-androideabi-g++ -Wl,-soname,libFinal.so -shared \
libBase.a libFramework.a libGraphics.a libPlatform.a -o libFinal.so
and the error is
libPlatform.a(ATexture.o): In function `ATexture':
ATexture.cpp:9: undefined reference to `TextureRenderer'
ATexture.cpp:9: undefined reference to `TextureRenderer'
TextureRenderer is in Graphics. But libGraphics is before libPlatform on the command line. g++ will search each library on the command line in the order they are given, loading functions to resolve external references. It will read libGraphics once, load the functions that resolve external references and move on to libPlatform.
Try changing LOCAL_STATIC_LIBRARIES := $(MY_LOCAL_STATIC_LIBRARIES) to LOCAL_STATIC_LIBRARIES := Platform Graphics Framework Base and see how you get on.

In your Android.mk, make sure you are referencing the static library with the proper call:
LOCAL_STATIC_LIBRARIES := mystaticlibproj
before calling include $(BUILD_SHARED_LIBRARY).
Then, at the end of the file, place the call to import the static lib module
$(call import-module, mystaticlibproj)
If you're still having trouble, post the verbose build log (ndk-build V=1 -B) and your Android.mk