将CrystaX与Qt结合使用以构建android应用程序：java.lang.UnsatisfiedLinkError

Question

I am trying to build Qt application for android using Qt Creator . I use CrystaX NDK for android instead of goolge's one because I need to use boost libraries in my project, and, as CrystaX's official site says, it is comes with it.

I am using following versions of tools:

• Qt Creator 3.4.2
• Qt 5.5.0
• CrystaX NDK 10.2.1

At first, I had to manually add libraries and headers paths in my .pro file, because it hasn't been found automatically. There was compiler error: can't locate libcrystax , there was some errors in source files about including boost headers . I've added following lines in my project file:

android {
    INCLUDEPATH +=  $$NDK_ROOT/sources/crystax/include \
                    $$NDK_ROOT/sources/boost/1.58.0/include \
                    $$PWD/ssl
    LIBS += -L"$$PWD/ssl" -lssl -lcrypto
    LIBS += -L"$$NDK_ROOT/sources/crystax/libs/$$ANDROID_TARGET_ARCH"
    ANDROID_EXTRA_LIBS = $$NDK_ROOT/sources/crystax/libs/$$ANDROID_TARGET_ARCH/libcrystax.so
    ANDROID_PACKAGE_SOURCE_DIR = $$PWD/android
}

After rebuilding again, I've got an error ( runtime error ) that says libgnustl_shared requires libcrystax, but libcrystax is not loaded or something similar.

After searching the internet, I've found that it's happening because one library that requires another, is loading before it, and that second library, is not being searched for, at application directory, only in system paths.

I've found a workaround - to load required library manually. I copied default QtActivity.java into my project directory ( android/src/.../QtActivity.java ) to replace default one and added following code:

static {
    System.loadLibrary( "crystax" );
}

After that I am not getting that error, but now I'm stuck with another one:

java.lang.UnsatisfiedLinkError: Cannot load library: reloc_library[1285]: 37 cannot locate '__aeabi_ldiv0'...

Is it possible to use Qt + CrystaX NDK for build android app? Am I doing it wrong way? Please, explain how to do it properly, if I've mistaken or if I misunderstood whole concept. Any help is appreciated.

Answer 1

This happens because you haven't linked with libgcc.a . I don't know how exactly your build system works (well, Qt's one), but generally, adding libgcc.a to the list of additional libraries should help:

ANDROID_EXTRA_LIBS = $$NDK_ROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64/lib/gcc/arm-linux-androideabi/4.9/libgcc.a

This line specify arm variant of libgcc.a ; obviously, you should use proper one depending on ANDROID_TARGET_ARCH value.