使用Android Studio NDK的“未定义引用”函数

Question

我有3个类，native-lib.cpp、tracker.cpp和tracker.hpp，但是，在构建过程中，如果我在navive-lib.cpp中使用tracker.cpp中的isTracking函数，我会得到一个错误。

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错误：任务“：app：ExternalNativeBuildDebug”执行失败。

生成命令失败。执行进程/home/user/android/sdk/cmake/3.6.4111459/bin/cmake时出错，带有参数{--build/home/user/androidstudioProjects/project/app/.externalnativeBuild/cmake/debug/x86-target tracker}[1/2]构建CXX对象cmakefiles/tracker.dir/src/main/cpp/native-lib.cpp.o[2/2]链接CXX共享库linux-x86_64/bin/clang++--target=i686-none-linux-android=/home/user/android/sdk/ndk-bundle/toolchains/x86-4.9/prebuilt/linux-x86_64--sysroot=/home/user/android/sdk/ndk-bundle/sysroot-fpic-isystem/home/user/android/sdk/ndk-bundle/sysroot/usr/include/i686-linux-android-d__android-api_=-tables-fstack-protector-strong-no-canonical-prefixes-mstackrealign-wa,--noexecstack-wformat-werror=format-security-o0-fno-limit-debug-info-wl,--exclude-libs,libgcc.a,--sysroot/home/user/android/sdk/ndk-bundle/platforms/android-23/arch-x86-wl，--build-id-wl，--warn-shared-textrel-wl，--fatal-warnings-wl，--no-undefined-wl，-z，noexecstack-qunused-arguments-wl，-z，noexecstack-qunused-arguments-wl，-z，relro-wl，-z，no-shared-wl，-soname，libtracker.so-o.../.../.../.../main/cpp/native-lib.cpp.o/home/user/android/sdk/ndk-bundle/platforms/android-23/arch-x86/usr/lib/liblog.so................................./src/main/jnilibs/x86/libopencv_java3.so-lm“/home/”Tracker::Istracking()“Clang++:

set (pathToOpenCv /home/user/OpenCV-android-sdk3.2) set (pathToProject /home/user/AndroidStudioProjects/project)

cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_VERBOSE_MAKEFILE on)

include_directories(${pathToOpenCv}/sdk/native/jni/include)

FILE(GLOB_RECURSE cppfiles "/home/user/AndroidStudioProjects/project/app/src/main/cpp/*.cpp")

add_library(lib_opencv SHARED IMPORTED)

add_library(tracker SHARED ${cppfiles})

set_target_properties(lib_opencv PROPERTIES IMPORTED_LOCATION ${pathToProject}/app/src/main/jniLibs/${ANDROID_ABI}/libopencv_java3.so)

find_library( log-lib

              log ) target_link_libraries(
                       tracker

                       ${log-lib}

                       lib_opencv
                       )

这是我的母语-lib.cpp

#include <jni.h>
#include <string>
#include "tracker.hpp"

using namespace cv;

Tracker tracker;

extern "C"
JNIEXPORT jboolean JNICALL
Java_com_example_user_project_Tracker_isTrackingC(JNIEnv *env, jboolean boolean) {
    boolean = tracker.isTracking();
    return boolean;
}

为什么CMake不能从原生库中的tracker.cpp中找到我的函数？我想我是通过使用cmakelists中的add_library（跟踪器共享${cppfiles}）和target_link_libraries将所有的cpp链接在一起的。

Answer 1

“链接CXX共享库../../../../////build/intermediates/cmake/debug/obj/x86/libtracker.so failed”这是关键点。“--target=i686-none-linux-Android”也许您的项目编译工具链应该使用32bit