Develop Reference

Adding Cryptopp to Android.mk

I have tried building cryptopp library for android.I have used this part of the tutorial.
https://www.cryptopp.com/wiki/Android_(Command_Line)
$ cat build-all-android.sh
#!/bin/bash
for arch in armeabi armeabi-v7a armeabi-v7a-hard arm64-v8a mips mips64 x86 x86_64
do
. ./setenv-android.sh $arch stlport
if [ "$?" -eq "0" ]; then
make -f GNUmakefile-cross distclean
make -f GNUmakefile-cross static dynamic
sudo make -f GNUmakefile-cross install PREFIX=/usr/local/cryptopp/android-$arch
fi
done
I was able to make the libraries.
My problem is, I can't add it to my project.
It seems like I need to edit my Android.mk file but I can't seem to do it properly. I added this block to my Anroid.mk
#########################################################
# STLport library
include $(CLEAR_VARS)
STLPORT_INCL := /Applications/Cocos/Android/android-ndk-r10e/sources/cxx-stl/stlport
STLPORT_LIB := /Applications/Cocos/Android/android-ndk-r10e/sources/cxx-stl/stlport/libs/$(TARGET_ARCH_ABI)
LOCAL_MODULE := stlport_shared
LOCAL_SRC_FILES := $(STLPORT_LIB)/libstlport_shared.so
LOCAL_CPP_FEATURES += rtti exceptions
LOCAL_EXPORT_CPPFLAGS :=
LOCAL_EXPORT_C_INCLUDES := $(STLPORT_INCL)
include $(PREBUILT_SHARED_LIBRARY)
LOCAL_SHARED_LIBRARIES := stlport_shared
#########################################################
# Crypto++ library
include $(CLEAR_VARS)
CRYPTOPP_INCL := /usr/local/cryptopp/android-$(TARGET_ARCH_ABI)/include
CRYPTOPP_LIB := /usr/local/cryptopp/android-$(TARGET_ARCH_ABI)/lib
LOCAL_MODULE := cryptopp
LOCAL_SRC_FILES := $(CRYPTOPP_LIB)/libcryptopp.so
LOCAL_CPP_FEATURES := rtti exceptions
LOCAL_EXPORT_C_INCLUDES := $(CRYPTOPP_INCL) $(CRYPTOPP_INCL)/cryptopp
include $(PREBUILT_SHARED_LIBRARY)
LOCAL_SHARED_LIBRARIES := cryptopp
#########################################################
I based this on the Crypto++ wiki page Android Activity which referenced AndroidPRNG, which demonstrates using Crypto++ as a shared object on Android.
I'm stuck because I can't make it work. I'm very new to android so I don't exactly know what to do about it. I was able to make the ios version of it run. I followed the XCode tutorial. It's just this that's making me crazy. I would appreciate all the help I can get. Is there something wrong with how I build? After building, do I copy it to my project or just linking the installed verion is fine? How do I properly add/link it to my project? Sorry for asking so many questions.
PS: I'm using cocos2dx for my project. Maybe it's worth mentioning.

After reading and trying all sorts of combination for my Android.mk, I was able to compile cryptopp with cocos2dx.
Anyway, here's how i fixed the compiler error:
FIRST - Build the libraries
cat build-all-android.sh
#!/bin/bash
for arch in armeabi armeabi-v7a armeabi-v7a-hard arm64-v8a mips mips64 x86 x86_64
do
AOSP_PI="android-16" . ./setenv-android.sh $arch gnu-static
if [ "$?" -eq "0" ]; then
make -f GNUmakefile-cross distclean
make -f GNUmakefile-cross static dynamic
sudo make -f GNUmakefile-cross install PREFIX=/usr/local/cryptopp/android-$arch
fi
done
Notice that I used gnu-static -> this is because cocos2dx is using gnu-static.
SECOND - Update Android.mk
# Crypto++ library
include $(CLEAR_VARS)
CRYPTOPP_INCL := /usr/local/cryptopp/android-$(TARGET_ARCH_ABI)/include
CRYPTOPP_LIB := /usr/local/cryptopp/android-$(TARGET_ARCH_ABI)/lib
LOCAL_MODULE := cryptopp
LOCAL_SRC_FILES := $(CRYPTOPP_LIB)/libcryptopp.a
LOCAL_CPP_FEATURES := rtti exceptions
LOCAL_EXPORT_C_INCLUDES := $(CRYPTOPP_INCL) $(CRYPTOPP_INCL)/cryptopp
include $(PREBUILT_STATIC_LIBRARY)
LOCAL_SHARED_LIBRARIES := cryptopp
---------------------------------------- FOR WINDOWS ----------------------------------------
The answer above only works for mac. In Windows, I tried installing the cryptopp libraries but I wasn't successful. AOSP_TOOLCHAIN_PATH was invalid. I tried fixing it by updating the setenv-android.sh to include "windows-x86_64". I was able to fix that part but sadly I had a "make:not a command" error. I was told that I had to download it for my cygwin.
I'm currently downloading it. I will udpate this answer when I'm able to install the make and sudo commands to my Windows.
In the mean time, here's what I did to make my project using cryptopp compile in Windows assuming that you have successfully compiled it in mac:
1.) Copy the cryptopp android specific libraries and header files from /usr/local/cryptopp to your jni folder. It should look something like this:
Note: In /usr/local/cryptopp the include files are located in the specific android folder. In the example above, I placed the include file outside since they are all using the same header files. This way, we will avoid duplicated header files.
2.) After copying, update your Android.mk. Make it point to your new cryptopp directory instead. If you followed the hierarchy in step1, your Android.mk code for cryptopp will look something like this:
# Crypto++ library
include $(CLEAR_VARS)
CRYPTOPP_INCL := $(LOCAL_PATH)/Cryptopp/include
CRYPTOPP_LIB := Cryptopp/android-$(TARGET_ARCH_ABI)/lib
LOCAL_MODULE := cryptopp
LOCAL_SRC_FILES := $(CRYPTOPP_LIB)/libcryptopp.a
LOCAL_CPP_FEATURES := rtti exceptions
LOCAL_EXPORT_C_INCLUDES := $(CRYPTOPP_INCL) $(CRYPTOPP_INCL)/cryptopp
include $(PREBUILT_STATIC_LIBRARY)
LOCAL_SHARED_LIBRARIES := cryptopp
Note: Notice that we didn't use $(LOCAL_PATH) for the CRYPTOPP_LIB which was used by LOCAL_SRC_FILES. This is to avoid having a missing directory: jni/jni/Cryptopp/android-$(TARGET_ARCH_ABI)/lib/libcryptopp.a. Remember that LOCAL_SRC_FILES start searching in jni/.

ANDROID: How to properly link against static libraries while creating shared libraries with dependencies on the static ones

I have to use some c++ code in my android application. This code was used successfully in an iOS project.
The code depends on 2 external libraries: zero-mq and protocol buffers.
I compiled the zmq library as an static library like explained here. I added the static (.a) library and the .jar to my project.
I created the protobuf library with the following configurations:
./configure --host=arm-eabi --with-sysroot=x/android-ndk-r10d/platforms/android-21/arch-arm CC="x/android-ndk-r10d/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86/bin/arm-linux-androideabi-gcc --sysroot x/android-ndk-r10d/platforms/android-21/arch-arm" --enable-cross-compile --with-protoc=protoc LIBS=-lc
make
I changed the real directories to x to make them shorter.
In my Android Project(IDE: Android Studio) I prepared everything which is necessary. I created a JNI Folder and deactivated the auto-creation of the makefiles.
Application.mk:
APP_MODULE := proxy
APP_STL := gnustl_shared
APP_CPPFLAGS := -frtti -fexceptions --std=c++11
APP_ABI := armeabi-v7a ##all later
NDK_TOOLCHAIN_VERSION := 4.9
Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := zmq_static
LOCAL_SRC_FILES := zmq/libzmq.a
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static1
LOCAL_SRC_FILES := protobuf/libprotobuf.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static2
LOCAL_SRC_FILES := protobuf/libprotobuf-lite.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static3
LOCAL_SRC_FILES := protobuf/libprotoc.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := proxy
LOCAL_CFLAGS := -I/include -pthread -lpthread -D__GXX_EXPERIMENTAL_CXX0X__ - frtti
LOCAL_CPPFLAGS := -I/include -pthread -lpthread -D__GXX_EXPERIMENTAL_CXX0X__ -frtti
LOCAL_CPP_FEATURES += exceptions
LOCAL_LDLIBS := -llog
LOCAL_SRC_FILES := \
usersession.cpp\
## LOCAL_ALLOW_UNDEFINED_SYMBOLS := true will compile the code but shutdown on runtime
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\main\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\arm\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\debug\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\armDebug\jni
LOCAL_C_INCLUDES += \zmq
LOCAL_C_INCLUDES += \protobuf
LOCAL_STATIC_LIBRARIES := zmq_static protobuf_static1 protobuf_static2 protobuf_static3
LOCAL_WHOLE_STATIC_LIBRARIES := zmq_static protobuf_static1 protobuf_static2 protobuf_static3
include $(BUILD_SHARED_LIBRARY)
The zmq library is in the subdirectory zmq and the protobuf library is in the subfolder protobuf.
Now the linking of the Objects still does not work. The Error Output when I execute ndk-build:
C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\main\jni>ndk-build
[armeabi-v7a] SharedLibrary : libproxy.so
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/ext/new_allocator.h:127: error: undefined reference to 'ControlledInstance::ControlledInstan (std::shared_ptr<protogen::Application>, std:
:shared_ptr<protogen::Role>, std::shared_ptr<protogen::User>)'
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/bits/shared_ptr_base.h:511: error: undefined reference to 'protogen::User::User()'
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/bits/shared_ptr_base.h:914: error: undefined reference to 'google::protobuf::internal::empty tring_'
C:/Users/M/Dropbox/Workspace/ndk_swig_test/app/src/main//jni/controlledinstance.h :23: error: undefined reference to 'protogen::MetaGraph::~MetaGraph()'
collect2.exe: error: ld returned 1 exit status
make.exe: *** [C:/Users/M/Dropbox/Workspace/ndk_swig_test/app/src/main//obj/local/armeabi- v7a/libproxy.so] Error 1
I tried many versions of the Android.mk and recreated the library more than once with different options which I found all over the internet.
I also looked at dozens of threads on stackoverflow which did not help me.(I'm not allowed to link them because of low reputation)
Additionally i read most of the doc files from the ndk e.g. PREBUILTS.
I added some other directories to my JNI directory e.g. the directory with the original files and directories (compiler, io, stubs...). I think this directory should offer the export of the necessary methods if the prebuild library was successfully linked to my shared library - which is not the case.
I tried far more than I can explain in few minutes and I think it would be overkill if i added everything I've tried because nothing helped.
Because this is my first question I dont have the reputation to include more than 2 links. Sorry for that.

There may probably be other issues as well, but you at least have got a typo - it should be include $(PREBUILT_STATIC_LIBRARY), as in, BUILT, not BUILD.

Android native shared libraries installation path

I'm struggling to get a native Android application correctly link against a custom shared object built in the same AOSP tree.
I have a shared object built with
LOCAL_SRC_FILES += \
src/libscanengine.c
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_C_INCLUDES += $(LOCAL_PATH)/include/
LOCAL_C_INCLUDES += kernel/include/
#every module depending on us will
#automagically have this included
LOCAL_EXPORT_C_INCLUDES := \
$(LOCAL_PATH)/include
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE := libscanengine
LOCAL_PRELINK_MODULE := false
include $(BUILD_SHARED_LIBRARY)
It gets built and installed as the mm command invocation
build/core/dynamic_binary.mk:141: warning: overriding commands for target `.so'
build/core/dynamic_binary.mk:118: warning: ignoring old commands for target `.so'
build/core/shared_library.mk:54: warning: overriding commands for target `.so'
build/core/dynamic_binary.mk:141: warning: ignoring old commands for target `.so'
No private recovery resources for TARGET_DEVICE X
No recovery.fstab for TARGET_DEVICE X
make: Circular .so <- .so dependency dropped.
make: Circular .so <- out/target/product/X/symbols/system/lib/libscanengine dependency dropped.
make: Circular .so <- .so dependency dropped.
target Non-prelinked: libscanengine (out/target/product/X/symbols/system/lib/libscanengine)
target Strip: libscanengine (out/target/product/X/obj/lib/libscanengine)
Install: out/target/product/X/system/lib/libscanengine.so
Once I try to buil a native application linked against the newly created .so with the following Android.mk
LOCAL_SRC_FILES := \
src/mores.c
LOCAL_C_INCLUDES += \
$(LOCAL_PATH)
LOCAL_C_INCLUDES += \
$(LOCAL_PATH)/include/
#not working: commented out
#LOCAL_LDLIBS += \
-lscanengine
#LOCAL_C_FLAGS += \
-L../../out/target/product/X/system/lib/
LOCAL_SHARED_LIBRARIES := \
libscanengine
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE := mores
include $(BUILD_EXECUTABLE)
I get:
make: *** No rule to make target `out/target/product/X/obj/lib/libscanengine.so', needed by `out/target/product/X/obj/EXECUTABLES/mores_intermediates/LINKED/mores'. Stop.
I noticed two things: the shared library is installed under X/out/lib as libscanengine and not libscanenegine.so as it is required by the native application.
I have to manually copy the .so everytime, which is stupid since all of this should be handled in some way by the Android build system.
Furthermore, the LOCAL_EXPORT_C_INCLUDES directive does not work. Does it work only with PREBUILT_SHARED_OBJECTS?
Android version is 2.3, there is no Java involved, everything is built under AOSP.
Thank you
j

LOCAL_C_FLAGS += \
-L../../out/target/product/X/system/lib/
does not work because it should read
LOCAL_LDFLAGS += \
-Lout/target/product/X/system/lib
or
LOCAL_LDFLAGS += \
-L$(LOCAL_PATH)/out/target/product/X/system/lib
But this does not explain why LOCAL_SHARED_LIBRARIES is not working. What commands do you use to build?

Whilst not a good solution, if the libscanengine target can't be found implicitly via AOSP, then you can always include it manually, like so.
include $(AOSP_ROOT)/PATH/TO/libscanengine/Android.mk
Regarding why the shared object won't build correctly, a hacky solution is providing a static object directly after the shared one which references it, in the Android.mk. For instance, this I adapted from an existing jpeg port. What I wanted was a shared library I could work with in a separate compilation step, but it wouldn't be built unless it was required by something.
$(call my-dir)
include $(CLEAR_VARS)
LOCAL_ARM_MODE := arm
LOCAL_SRC_FILES := \
jcapimin.c jcapistd.c jccoefct.c jccolor.c jcdctmgr.c jchuff.c \
jcinit.c jcmainct.c jcmarker.c jcmaster.c jcomapi.c jcparam.c \
jcphuff.c jcprepct.c jcsample.c jctrans.c jdapimin.c jdapistd.c \
jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jddctmgr.c jdhuff.c \
jdinput.c jdmainct.c jdmarker.c jdmaster.c jdmerge.c jdphuff.c \
jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \
jfdctint.c jidctflt.c jidctred.c jquant1.c \
jquant2.c jutils.c jmemmgr.c \
jmem-android.c
# the assembler is only for the ARM version, don't break the Linux sim
ifneq ($(TARGET_ARCH),arm)
ANDROID_JPEG_NO_ASSEMBLER := true
endif
# temp fix until we understand why this broke cnn.com
#ANDROID_JPEG_NO_ASSEMBLER := true
ifeq ($(strip $(ANDROID_JPEG_NO_ASSEMBLER)),true)
LOCAL_SRC_FILES += jidctint.c jidctfst.c
else
LOCAL_SRC_FILES += jidctint.c jidctfst.S
endif
LOCAL_CFLAGS += -I"$(LOCAL_PATH)/./include" -DAVOID_TABLES
LOCAL_CFLAGS += -O3 -fstrict-aliasing -fprefetch-loop-arrays
#LOCAL_CFLAGS += -march=armv6j
LOCAL_MODULE:= jpeg
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := jpeg2
LOCAL_STATIC_LIBRARIES := jpeg
include $(BUILD_SHARED_LIBRARY)
Whilst neither of these are true solutions, as they don't address the underlying reason behind your problems, they may aid you, as they did me, in getting stuff working quickly and automatically.

Android NDK: How to get compiler architecture in Android.mk dynamically

I'm trying to configure Android.mk to cross compile native code to support different chipset namely armeabi, mips, and x86. I know I can configure Application.mk in the following way to compile the source code for different chip set:
APP_ABI := all
This will trigger Android-NDK's build script to compile the source code for all the chipsets. However, I want to dynamically tell Android.mk to look for different static library dependencies compiled with different chip set.
# Get the architecture info
ARCH := ????
include $(CLEAR_VARS)
LOCAL_MODULE:= mylib
LOCAL_SRC_FILES:= build/lib/libxxx_$(ARCH).a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
include $(PREBUILT_STATIC_LIBRARY)
Is this possible to do? If so, can anyone advice how to do so?
Update: I tried something like this in Application.mk:
APP_ABI := armeabi armeabi-v7a mips x64
with Android.mk:
# Get the architecture info
ARCH := $(APP_ABI)
include $(CLEAR_VARS)
LOCAL_MODULE:= mylib
LOCAL_SRC_FILES:= build/lib/libxxx_$(ARCH).a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
include $(PREBUILT_STATIC_LIBRARY)
but it errors with the following:
The LOCAL_SRC_FILES for a prebuilt static library should only contain one item
which makes sense. I want to pass APP_ABI := all in Application.mk and be able to
dynamically reference it. Any ideas?

Check TARGET_ARCH_ABI:
ifeq($(TARGET_ARCH_ABI), armeabi-v7a)
# v7a-specific stuff
endif

There is TARGET_ARCH variable that holds the value of the current ABI being built. You can use it the following way:
ifeq ($(TARGET_ARCH),x86)
LOCAL_CFLAGS := $(COMMON_FLAGS_LIST)
else
LOCAL_CFLAGS := -mfpu=vfp -mfloat-abi=softfp $(COMMON_FLAGS_LIST)
endif
If you specify APP_ABI := armeabi-v7a armeabi mips x86 or APP_ABI := all in your Application.mk you will get each and every separate ABI value.

Android NDK linking

I am trying to build an android application that calls into a C++ backend. This backend uses ZeroMQ for messaging. Per the android build page on the ZeroMQ guide, I have built a native toolchain of ndk version 6 and used that to (successfully) build ZeroMQ.
However, when I build my own .so with the JNI implementations, I can't seem to make everything load properly. Specifically, if I call System.LoadLibrary("zmq"), this completes successfully, but if I then call *System.LoadLibrary("my_lib")* I always get an UnsatisfiedLinkError complaining that:
Cannot load library reloc_library[1244]: 29 cannot locate zmq_msg_init'...
The libmy_lib.so has been generated several different ways, each with no success. After generating it, I always copies libmy_lib.so (as well as libzmq.so) to my android project's folder: libs/armeabi/.
# Compile all object files - this part was done for all options
/opt/android-toolchain/bin/arm-linux-androideabi-g++ -fpic -c Client_Events.cpp \
Client Wrapper.cpp jni.cpp -I /opt/android-root/include/ -I /my/project/specific/stuff
# Option 1 - Don't link the lib in at all
/opt/android-toolchain/bin/arm-linux-androideabi-g++ -shared \
-Wl,-soname,libmy_lib.so -o libmy_lib.so jni.o Client_Events.o Client_Wrapper.o
# Option 2 - Link ZeroMQ in statically
/opt/android-toolchain/bin/arm-linux-androideabi-g++ -shared \
-Wl,-soname,libmy_lib.so -o libmy_lib.so jni.o Client_Events.o Client_Wrapper.o \
libzmq.a libstdc++.a -Wl,--whole-archive
# Option 3 - Explicitly link ZeroMQ in dynamically
/opt/android-toolchain/bin/arm-linux-androideabi-g++ -shared \
-Wl,-soname,libmy_lib.so -o libmy_lib.so jni.o Client_Events.o Client_Wrapper.o \
-L /opt/android-root/lib/ -lzmq
With each of these options I tried both explicitly calling System.LoadLibrary("zmq") before loading my own library and not. Nothing varied the results. Using nm confirms that, at least in the case of option #2, the missing symbol *zmq_msg_init* is indeed present in libmy_lib.so.
Any ideas as to why it cannot find the ZeroMQ symbols that are linked in?

I just learnt how to compile a 2nd library and link it to my main library in android ndk. Let me see if I am of any use to you.
The following is how I create my 2nd library (In my case, I build bullet physics library and the irrlicht rendering engine as 2 separate libraries for my game).
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := HEADER FILES
LOCAL_MODULE := bullet
LOCAL_SRC_FILES := SRC FILES
LOCAL_ARM_MODE := arm
LOCAL_CFLAGS := $(LOCAL_C_INCLUDES:%=-I%) -O3 -DANDROID_NDK -DDISABLE_IMPORTGL
LOCAL_LDLIBS := -ldl -llog
include $(BUILD_SHARED_LIBRARY)
Then copy your libxxxx.so (In my case, libbullet.so and libirrlicht.so) to your jni folder. And in your main library .mk file add the following.
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := (includes for bullet)
LOCAL_MODULE := bullet
LOCAL_SRC_FILES := libbullet.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := (includes for irrlicht)
LOCAL_MODULE := irrlicht
LOCAL_SRC_FILES := libirrlicht.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := (includes for bullet + includes for irrlicht + includes for main code)
LOCAL_SRC_FILES := main code src files
LOCAL_MODULE := gamescript
LOCAL_ARM_MODE := arm
LOCAL_CFLAGS := $(LOCAL_C_INCLUDES:%=-I%) -O3 -DANDROID_NDK -DDISABLE_IMPORTGL
LOCAL_LDLIBS := -lOpenSLES -landroid -ldl -llog
LOCAL_SHARED_LIBRARIES := bullet irrlicht
include $(BUILD_SHARED_LIBRARY)
And now, add all the libraries to your java code in right order.
System.loadLibrary("bullet");
System.loadLibrary("irrlicht");
System.loadLibrary("gamescript");