为什么我在使用 cygwin 时遇到错误？

Question

static jboolean libinit(JNIEnv *env, jobject obj, jint sdk) {
/*
#include <sys/system_properties.h>
   int sdk;
   char c[PROP_VALUE_MAX];
if(__system_property_get("ro.build.version.sdk",c) > 0) sscanf(c,"%d",&sdk);
else sdk = 8;
*/
     __android_log_print(ANDROID_LOG_INFO,"liblossless","libinit: sdk=%d",sdk);
    if(!libhandle) {
        if(sdk < 8) libhandle = dlopen("/data/data/net.avs234/lib/libatrack8.so",     RTLD_NOW);
        else libhandle = dlopen("/data/data/net.avs234/lib/libatrack9.so", RTLD_NOW);
    if(libhandle) {
        libmedia_pause = (typeof(libmedia_pause))     dlsym(libhandle,"libmedia_pause");
    libmedia_resume = (typeof(libmedia_resume)) dlsym(libhandle,"libmedia_resume");
    libmedia_start = (typeof(libmedia_start)) dlsym(libhandle,"libmedia_start");
    libmedia_stop = (typeof(libmedia_stop)) dlsym(libhandle,"libmedia_stop");
    libmedia_write = (typeof(libmedia_write)) dlsym(libhandle,"libmedia_write");
    libmediacb_start = (typeof(libmediacb_start)) dlsym(libhandle,"libmediacb_start");
    libmediacb_stop = (typeof(libmediacb_stop)) dlsym(libhandle,"libmediacb_stop");
        libmediacb_write = (typeof(libmediacb_write)) dlsym(libhandle,"libmediacb_write");
                libmediacb_wait_done = (typeof(libmediacb_wait_done))         dlsym(libhandle,"libmediacb_wait_done");
        }
    }
    __android_log_print(ANDROID_LOG_INFO,"liblossless","libinit: handle=%p",libhandle);
    return libhandle != 0;
}

static jboolean libexit(JNIEnv *env, jobject obj) {
   int ret = 0;
     __android_log_print(ANDROID_LOG_INFO,"liblossless","libexit");
    if(libhandle) {
        ret = dlclose(libhandle) ? 0 : 1;
        libhandle = 0;
    }
    return ret;
}

用cygwin编译给我一个错误：

    /cygdrive/C/androidndk4/apps/lossless/project/bin/ndk/local/armeabi/objs/lossles

s/main.o：在函数

libexit':
        /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:247: undefined referenc
e to

dlclose' 中 /cygdrive/C/androidndk4/apps/lossless/project/bin/ndk/local/armeabi/objs/lossles s/main.o：在函数

libinit':
        /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:226: undefined referenc
e to

dlopen' 中 /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:228：未定义的引用 e 至

dlsym'
        /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:229: undefined referenc
e to

dlsym' /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:230：未定义的引用 e 至

dlsym'
        /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:231: undefined referenc
e to

dlsym' /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:232：未定义的引用 e 到

dlsym'
        /cygdrive/C/androidndk4/apps/lossless/project/bin/ndk/local/armeabi/objs/lossles
s/main.o:/cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:233: more unde
fined references to

dlsym' 遵循 /cygdrive/C/androidndk4/apps/lossless/project/bin/ndk/local/armeabi/objs/lossles s/main.o：在函数

libinit':
        /cygdrive/C/androidndk4/apps/lossless/project/jni/main.c:225: undefined referenc
e to

dlopen' 中 Collect2: ld 返回 1 退出状态 制作：* [/cygdrive/C/androidndk4/apps/lossless/project/bin/ndk/local/armeabi/l iblossless.so]错误1

Answer 1

您的错误提到了“未定义的引用”。这意味着您正在使用的函数（dlopen、dlclose、dlsym 等）未定义。检查您是否包含正确的头文件，并检查您是否正确链接所需的库（如果这些函数来自共享库）。