Using FFTW on Android undefined references - android

I'm trying to use FFTW in my Android application. I have followed this tutorial and was able to buid fftw with floating point precision using this build.sh, on OSX:
INSTALL_DIR="`pwd`/jni/fftw3"
SRC_DIR="`pwd`/../fftw-3.3.3"
NDK_ROOT="/Users/awesomeUserName/Desktop/android-ndk-r9"
cd $SRC_DIR
export
PATH="$NDK_ROOT/toolchains/arm-linux-androideabi-4.8/prebuilt/darwin-x86_64/bin/:$PATH"
export SYS_ROOT="$NDK_ROOT/platforms/android-14/arch-arm/"
export CC="arm-linux-androideabi-gcc --sysroot=$SYS_ROOT"
export LD="arm-linux-androideabi-ld"
export AR="arm-linux-androideabi-ar"
export RANLIB="arm-linux-androideabi-ranlib"
export STRIP="arm-linux-androideabi-strip"
mkdir -p $INSTALL_DIR
./configure --host=arm-eabi --build=i386-apple-darwin10.8.0 --prefix=$INSTALL_DIR LIBS="-lc -lgcc" --enable-float
make
make install
exit 0
This generates the fftw3/lib and fftw3/include directories correctly and everything seems fine.
I then want to compile this .cpp file:
#include "./fftw3/include/fftw3.h"
extern "C" {
int FooPluginFunction ()
{
fftwf_complex *in, *out;
fftwf_plan p;
in = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex) * 1024);
out = (fftwf_complex*) fftwf_malloc(sizeof(fftwf_complex) * 1024);
p = fftwf_plan_dft_1d(1024, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
fftwf_execute(p); /* repeat as needed */
fftwf_destroy_plan(p);
fftwf_free(in); fftwf_free(out);
return 42;
}
}
To generate a shared library, using the following Android.mk makefile:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := fftw3
LOCAL_SRC_FILES := fftw3/lib/libfftw3f.a
LOCAL_EXPORT_CPPFLAGS := fftw3/include
include $(PREBUILT_STATIC_LIBRARY)
# Here we give our module name and source file(s)
LOCAL_MODULE := FooPlugin
LOCAL_SRC_FILES := FooPlugin.cpp
LOCAL_SHARED_LIBRARIES := fftw3f
include $(BUILD_SHARED_LIBRARY)
When I run Android.mk, I get a few undefined reference errors like this one:
/Users/awesomeUsername/Desktop/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/FooPlugin/FooPlugin.o: in function FooPluginFunction:jni/FooPlugin.cpp:8: error: undefined reference to 'fftwf_malloc'
The structures fftwf_complex and fftwf_plan are fine because these are defined in fftw.h, but the functions fftwf_malloc, fftwf_free, fftwf_destroy, fftwf_plan_dft_1d, etc. are defined in fftw.f03, which doesn't seem to be found by the compiler.
How can I modify my makefile so that it finds and uses the .f03 files so that I can use fftw on Android?

I just removed the --build parameter and the error disapeared

Related

Building Android Command Line Executable with Prebuilt Shared Library

I'm trying to cross-compile an Android executable (command line) that calls a method inside a proprietary android prebuilt shared object (.so aarch64)
I'm using an Ubuntu 20.04 x86_64 and I want cross-compile an executable for Android 10 aarch64.
The method is defined from the relative JNI in the following way:
public static native int getScore();
I build a simple C program:
#include <stdio.h>
extern int getScore();
int main(){
getScore();
return(1);
}
Then I develop an Android.mk file like the following:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := mygame
LOCAL_SRC_FILES := libmygame.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := getscore
LOCAL_SRC_FILES := getscore.c
LOCAL_SHARED_LIBRARIES := mygame
include $(BUILD_EXECUTABLE)
Then I try to compile with:
ndk-build NDK_PROJECT_PATH=. APP_BUILD_SCRIPT=./Android.mk
But I get the follwoing error:
./obj/local/arm64-v8a/objs/getscore/getscore.o: In function `main':
/tmp/cross-compile-test/./getscore.c:24: undefined reference to `getScore'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [/home/mark01/Android/Sdk/ndk/21.3.6528147/build/core/build-binary.mk:738: obj/local/arm64-v8a/getscore] Error 1

"undefined reference to" (function) & "in archive is not an object" Android ndk-build

I'll expose my problem quickly. I am trying to port curl on Android and to use it within my app. I built the curl library with the ARM toolchain, configured and made (a couple times to make sure I didn't do nothing wrong the first time).
I then proceeded to put the newly created libcurl.a and my curljni.c into my jni folder, as long as the following Android.mk :
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE:= libcurl
LOCAL_SRC_FILES := libcurl.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include/curl
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := curljni
LOCAL_SRC_FILES := curljni.c
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include/curl
LOCAL_STATIC_LIBRARIES := libcurl
include $(BUILD_SHARED_LIBRARY)
I've been trying a lot of things and I'm pretty sure it looks good now, but whenever I try to build with the ndk-build tool I obtain the following :
Note : curljni.c makes calls to functions within the libcurl library and its easy.h and curl.h files. They are then included in top of the file.
I also tried to ask for the whole library to get loaded into my Android app, using LOCAL_WHOLE_STATIC_LIBRARIES instead of LOCAL_STATIC_LIBRARIES, but without much more success :
Previously :
Downloaded curl.7.28.0
Made a standalone toolchain for ARM 4.6
Fixed several files within curl whose linebreaks were DOS like and needed Unix like (bug in configure) - one of which was depcomp, linked to libcurl_la-file.lo
./configure --host=arm-linux-androidaebi --with-zlib --enable-ipv6
make/make install
Added the resulting libcurl.a from curl\lib.libs
Ok,
Your Problem is that your library libcurl.a is not builded with Android ndk gcc ..
You have done :
$ ./configure --host=arm-linux-androidaebi --with-zlib --enable-ipv6
$ make
$ make install
this will generate a library using your PC gcc ..NOt good .
What i do is to configure open source library l for android using line command (or like you have done):
./configure --build=x86_64-unknown-linux-gnu --host=arm-linux-androideabi --target=arm-linux-androideabi
But then you schould not call make and make install ! .
You have to create an android.mk whinch will compile all source file in your libcurl + your jni file ' curljni.c' and put all in one lib : here an example of Android.mk compiling SQLITE3
###################################################
# SQLITE3
###################################################
include $(CLEAR_VARS)
LOCAL_MODULE := Mysqlite3
MY_LOCAL_SQLITE_SRC := $(LOCAL_PATH)/sqlite/
LOCAL_CPPFLAGS := -g
LOCAL_CPPFLAGS += -I $(MY_LOCAL_SQLITE_SRC)
LOCAL_EXPORT_C_INCLUDES:=$(MY_LOCAL_SQLITE_SRC)
FILE_LIST :=$(wildcard $(MY_LOCAL_SQLITE_SRC)*.c*)
LOCAL_SRC_FILES += $(FILE_LIST:$(LOCAL_PATH)/%=%)
# My SQLITE3 JNI FILE
LOCAL_SRC_FILES +=mysqlite_jni.cpp
# include native NDK library liblog and libz
LOCAL_LDLIBS := -llog -lz
include $(BUILD_SHARED_LIBRARY)

creating shared library using prebuilt static library using Android.mk

I am trying to build a shared library using prebuilt static library, the respective Android.mk file is below.
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
#Include kerne headers in a proper way later on
#LOCAL_C_INCLUDES:= $(LOCAL_PATH)/../../../../kernel/include
LOCAL_MODULE := sensors.$(TARGET_BOARD_PLATFORM)
LOCAL_MODULE_TAGS := optional
LOCAL_PRELINK_MODULE := false
LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)/hw
LOCAL_STATIC_LIBRARIES := LibFusion_ARM_cpp
#LOCAL_LDFLAGS := $(LOCAL_PATH)/LibFusion_ARM_cpp.a
LOCAL_SHARED_LIBRARIES := liblog libcutils
#include any shared library dependencies
LOCAL_LDFLAGS := $(LOCAL_PATH)/libimu.a
LOCAL_PRELINK_MODULE := false
LOCAL_SRC_FILES := sensors_u8500.cpp
include $(BUILD_SHARED_LIBRARY)
The files present in the folder is
Android.mk , LibFusion_ARM_cpp.a , libimu.a , MEMSAlgLib_eCompass.h , sensors_u8500.cpp
The error what I am getting while building is below,
**make: *** No rule to make target `out/target/product/u8500/obj/STATIC_LIBRARIES/LibFusion_ARM_cpp_intermediates/LibFusion_ARM_cpp.a', needed by `out/target/product/u8500/obj/SHARED_LIBRARIES/sensors.montblanc_intermediates/LINKED/sensors.montblanc.so'. Stop.**
What is the issue here?
Unable to build the shared library. I mean unable to generate libsensor.so file. facing the above mentioned error. ** make: * No rule to make target
It seems that the build system cannot find LibFusion_ARM_cpp.a. AFAIK, you have to first specify a pre-built library module using PREBUILT_STATIC_LIBRARY with LibFusion_ARM_cpp.a set as LOCAL_SRC_FILES and LOCAL_MODULE as LibFusion_ARM_cpp. This will basically copy the specified static library to the default directory the build system searches through for all of the necessary modules.
I did two things to understand the case:
A. In the above shown make file, I added the below so as to ensure that this .a file gets copied into the build.
include $(CLEAR_VARS)
LOCAL_MODULE := LibFusion_ARM
LOCAL_SRC_FILES := LibFusion_ARM_cpp.a
include $(BUILD_STATIC_LIBRARY)
When I build it using mm -n, command I see this strange statement rm -f ... of the LibFusion_ARM.a. Of course the build fails saying it's not able to locate the STATIC LIB.
mkdir -p out/target/product/u8500/obj/STATIC_LIBRARIES/LibFusion_ARM_intermediates/
rm -f out/target/product/u8500/obj/STATIC_LIBRARIES/LibFusion_ARM_intermediates/LibFusion_ARM.a
echo "target StaticLib: LibFusion_ARM (out/target/product/u8500/obj/STATIC_LIBRARIES/LibFusion_ARM_intermediates/LibFusion_ARM.a)"
mkdir -p out/target/product/u8500/obj/SHARED_LIBRARIES/sensors.montblanc_intermediates/LINKED/
.
.
Why does this deletion happens? I am not sure. This is causing the problem. Please provide suggestions.
B. I added the below lines in the make file:
include $(CLEAR_VARS)
LOCAL_MODULE := LibFusion_ARM
LOCAL_SRC_FILES := LibFusion_ARM_cpp.a
include $(PREBUILT_STATIC_LIBRARY)
I see the below error:
make: *** No rule to make target `out/target/product/u8500/obj/STATIC_LIBRARIES/LibFusion_ARM_intermediates/LibFusion_ARM.a', needed by `out/target/product/u8500/obj/SHARED_LIBRARIES/sensors.montblanc_intermediates/LINKED/sensors.montblanc.so'.
Stop.
Clearly in the second case, the file LibFusion_ARM is not getting copied (even obj/STATIC_LIBRARIES/LibFusion_ARM_intermediates directory is not created).
Needless to emphasis, if I manually copy the file LibFusion_ARM_cpp.a as LibFusion_ARM.a then the build goes through.

Link shared library under Android NDK

I with success compile library LibXtract to shared object libxtract.so and want to use is in second project.
In mention project I try to compile it on simple function:
#include <com_androidnative1_NativeClass.h>
#include <android/log.h>
#include "libxtract.h"
JNIEXPORT void JNICALL Java_com_androidnative1_NativeClass_showText
(JNIEnv *env, jclass clazz)
{
float mean = 0, vector[] = {.1, .2, .3, .4, -.5, -.4, -.3, -.2, -.1}, spectrum[10];
int n, N = 9;
float argf[4];
argf[0] = 8000.f;
argf[1] = XTRACT_MAGNITUDE_SPECTRUM;
argf[2] = 0.f;
argf[3] = 0.f;
xtract[XTRACT_MEAN]((void *)&vector, N, 0, (void *)&mean);
__android_log_print(ANDROID_LOG_DEBUG, "LIbXtract", "Button pushe2");
}
I have flat structure:
jni/com_androidnative1_NativeClass.c
jni/com_androidnative1_NativeClass.hjni/libxtract.h
jni/other *.h files from libxtract interface
jni/Android.mk
jni/Applicatoin.mk
library libxtract.so I put in mainproject/lib folder
my Android.mk file looks like:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_SRC_FILES := com_androidnative1_NativeClass.c
LOCAL_MODULE := com_androidnative1_NativeClass
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/
LOCAL_LDLIBS += -llog
LOCAL_SHARE_LIBRARIES := libxtract
NDK_MODULE_PATH += $(LOCAL_PATH)/../lib/
include $(BUILD_SHARED_LIBRARY)
and I still got error:
Compile thumb : com_androidnative1_NativeClass <= com_androidnative1_NativeClass.c
SharedLibrary : libcom_androidnative1_NativeClass.so./obj/local/armeabi/objs/com_androidnative1_NativeClass/com_androidnative1_Nativ eClass.o: In function `Java_com_androidnative1_NativeClass_showText':
/home/jack/Projects/AndroidNative1/jni/com_androidnative1_NativeClass.c:20: undefined reference to `xtract'
collect2: ld returned 1 exit status
make: *** [obj/local/armeabi/libcom_androidnative1_NativeClass.so] Error 1
Code came form example of LibXtract and under C++ compile without problems, any ideas?
Your Android make file should be ...
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LIB_PATH := $(LOCAL_PATH)/../lib
LOCAL_SRC_FILES := com_androidnative1_NativeClass.c
LOCAL_MODULE := com_androidnative1_NativeClass
LOCAL_LDLIBS += -llog
LOCAL_LDLIBS += $(LIB_PATH) -lxtract
LOCAL_SHARE_LIBRARIES := libxtract
include $(BUILD_SHARED_LIBRARY)
Try this make file in your second project, and you can successfully build your code without having any error.
In the above answer all is right but exept one.
When we want to link lib we must add -L before LOCAL_LDLIBS dir as below.
LIB_PATH := $(LOCAL_PATH)/../lib
LOCAL_LDLIBS += **-L**$(LIB_PATH) -lxtract
Else it will give error as below
cannot open XXX/../lib: Permission denied
You need to tell Android NDK build scripts about your shared library. Check ${NDK}/doc/PREBUILTS.html for instructions how this can be done. They advise to add Android.mk in the same directory where you have your libXtract.so:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libXtract
LOCAL_SRC_FILES := libXtract.so
include $(PREBUILT_SHARED_LIBRARY)
Debugging tip: I guess you are using ndk-build to build your "second project". Try running ndk-build with V=99 (try V=99 ndk-build or ndk-build V=99 - my memory failing). This will show you the the exact failing linking command. You should likely have options -lXtract and -L/path/to/libXtract/library. (Sometimes it is convenient to just copy and paste the linking command to run it manually to find the right options for successful linking, before actually fixing the build settings.)
Update: I now see #codetiger's comment seems to point to a same sort of answer (without mentioning the NDK document which is good reading - so I am not deleting this answer).

using pre-built static libraries for Android NDK development

I am trying to build an android application that uses static libraries from some existing c++ code. However I cannot seem to get things building, here are the steps I have taken so far..
I have ndk-r5b and have built the standalone toolchain as per ndk/docs/STANDALINE-TOOLCHAIN.html. I have then used the standalone toolchain compiler (arm-linux-androideabi-g++) instead of g++ for the CXX flag in the Makefile that compiles the static libraries I need. This compiles without errors and there are 3 static libraries produced.
Here is a code snippet of some of the flags used to build the prebuilt libraries:
CXX = arm-linux-androideabi-g++
SYSTEM_LIBS = -lstdc++ -lm
INCLUDE_PATH += ${NDK_PATH}/platforms/android-8/arch-arm/usr/include/
Here is a sample line that is produced from the makefile when compiling:
arm-linux-androideabi-g++ -c -DTIME_SIM -I./include -I/home/greg/dev/Android/android-ndk-r5b/platforms/android-8/arch-arm/usr/include/ -fpic -ggdb3 -SimTime.C -o SimTime.o
Next I build the app using ndk-build using the following for Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := engine
LOCAL_SRC_FILES := ../libs/libEngine.a
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := shmem
LOCAL_SRC_FILES := ../libs/libShMem.a
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := util
LOCAL_SRC_FILES := ../libs/libUtil.a
include $(PREBUILT_STATIC_LIBRARY)
# build server as a shared library
include $(CLEAR_VARS)
LOCAL_MODULE := libServer
LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../include
LOCAL_SRC_FILES := \
Server.C \
Router.C \
RouterMsgs.C \
Federation.C \
cripName.C \
ver.C \
JNIWrapper.cpp
LOCAL_STATIC_LIBRARIES := engine shmem util
include $(BUILD_SHARED_LIBRARY)
The prebuilt libraries compile fine using the standalone toolchain compiler given in the android ndk. However there are many unresolved references to ostream when linking the shared library to the prebuilt libraries using ndk-build. For exampe:
/home/android/obj/local/armeabi/libShMem.a(SubscriptionItem.o): In function `SUBSCRIPTION_ITEM::Print(std::basic_ostream<char, std::char_traits<char> >&)':/home/src/comm/SubscriptionItem.C:97: undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
I assume I am missing some important flags or not doing something correct when I am compiling using the standalone compiler but any help or insight on this issue would be greatly appreciated as I cant seem to find this answer on google or in any of the android ndk docs. Thanks!
Well, you can actually fix that with creating a Application.mk file inside the same folder as the Android.mk file is, containing:
APP_STL := stlport_static
for using the static stlport that is located inside the Android NDK.
I had the same issue and resolved it by adding a module for the standard C++ library. The library linked by the ndk-build system is from the wrong location (platforms/android-9/arch-arm/usr/lib in my case).
include $(CLEAR_VARS)
LOCAL_MODULE := rightstdc
LOCAL_SRC_FILES := <path to the correct libstdc++.a>
include $(PREBUILT_STATIC_LIBRARY)
Add the module tag to the list of static libraries:
LOCAL_STATIC_LIBRARIES := engine shmem util rightstdc
The build/core/build-binary.mk prepends -L$(SYSROOT)/usr/lib if any libraries are specified in LOCAL_LDLIBS but in my case that is the wrong path.
I don't know if there is a missing step that should copy the correct libstdc++ to that location but the approach above will work.

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