Eclipse C/C++：外部库的交叉编译链接器错误：Ubuntu VM amd64 到 Ubuntu armhf (Raspberry Pi)答案

【问题标题】：Eclipse C/C++ : Cross compile Linker error for external libraries: Ubuntu VM amd64 to Ubuntu armhf ( Raspberry Pi)Eclipse C/C++：外部库的交叉编译链接器错误：Ubuntu VM amd64 到 Ubuntu armhf (Raspberry Pi)
【发布时间】：2016-06-22 11:00:12
【问题描述】：

设置：

主机：-- amd64 VM 托管安装了 Eclipse Mars x64 的 Ubuntu Mate 15.10。还安装了 Linaro x64 工具链

目标：-- armhf Ubuntu Mate 15.10 树莓派

问题

我正在尝试交叉编译 existing code I found on git 但是由于链接器错误，我无法这样做。该项目有一个编译的 lib mqtt3as.so，它查找 libcrypt 和 libssl。链接器找不到那些。我应该提到我尝试了以下步骤..

-- Git 代码在 Raspberry Pi 上构建良好

-- Host to Target 交叉编译器在 Hello_world 代码中运行良好。部署和调试工作

-- NFS 从 Raspi 挂载 /lib 和 /usr/lib 到 toolchainx64/lib 文件夹

但没有任何改变。我了解该问题与链接器无法找到库有关。我试图遵循我在谷歌上搜索的所有可能的建议。以下是主机上 eclipse 的日志。如果需要，我可以分享详细日志。

现在几乎没有想法了。我有unix经验..但那是几年前的事了，而且对eclipse来说还算新。如果有需要，我可以学习和探索。

日志

    18:18:50 **** Build of configuration Default for project prj_c ****
make all 
Building file: ../cJSON.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"cJSON.d" -MT"cJSON.o" -o "cJSON.o" "../cJSON.c"
Finished building: ../cJSON.c

Building file: ../cpustat.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"cpustat.d" -MT"cpustat.o" -o "cpustat.o" "../cpustat.c"
../cpustat.c: In function ‘GetCPULoad’:
../cpustat.c:68:10: warning: implicit declaration of function ‘sleep’ [-Wimplicit-function-declaration]
          sleep(1);
          ^
../cpustat.c:63:11: warning: unused variable ‘dump’ [-Wunused-variable]
      char dump[50];
           ^
Finished building: ../cpustat.c

Building file: ../iotmain.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"iotmain.d" -MT"iotmain.o" -o "iotmain.o" "../iotmain.c"
../iotmain.c: In function ‘main’:
../iotmain.c:75:6: warning: unused variable ‘lckStatus’ [-Wunused-variable]
  int lckStatus;
      ^
../iotmain.c: In function ‘trim’:
../iotmain.c:266:2: warning: implicit declaration of function ‘isspace’ [-Wimplicit-function-declaration]
  while (isspace(*(++frontp)))
  ^
../iotmain.c: In function ‘get_config’:
../iotmain.c:291:17: warning: unused variable ‘str2’ [-Wunused-variable]
  char str1[10], str2[10];
                 ^
../iotmain.c:291:7: warning: unused variable ‘str1’ [-Wunused-variable]
  char str1[10], str2[10];
       ^
Finished building: ../iotmain.c

Building file: ../jsonReader.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"jsonReader.d" -MT"jsonReader.o" -o "jsonReader.o" "../jsonReader.c"
Finished building: ../jsonReader.c

Building file: ../jsonator.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"jsonator.d" -MT"jsonator.o" -o "jsonator.o" "../jsonator.c"
Finished building: ../jsonator.c

Building file: ../mac.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"mac.d" -MT"mac.o" -o "mac.o" "../mac.c"
Finished building: ../mac.c

Building file: ../mqttPublisher.c
Invoking: Cross GCC Compiler
arm-linux-gnueabihf-gcc -I"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c" -O2 -g -Wall -c -fmessage-length=0 -MMD -MP -MF"mqttPublisher.d" -MT"mqttPublisher.o" -o "mqttPublisher.o" "../mqttPublisher.c"
../mqttPublisher.c: In function ‘subscribeMessage’:
../mqttPublisher.c:117:6: warning: unused variable ‘i’ [-Wunused-variable]
  int i;
      ^
../mqttPublisher.c:126:10: warning: ‘command’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   sprintf(command,"sudo /sbin/shutdown -r %d", time_delay);
          ^
Finished building: ../mqttPublisher.c

Building target: prj_c
Invoking: Cross G++ Linker
arm-linux-gnueabihf-g++ -L"/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib" -o "prj_c"  ./cJSON.o ./cpustat.o ./iotmain.o ./jsonReader.o ./jsonator.o ./mac.o ./mqttPublisher.o   -lpaho-mqtt3as
/home/k/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: warning: libcrypto.so.1.0.0, needed by /home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so, not found (try using -rpath or -rpath-link)
/home/k/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../lib/gcc/arm-linux-gnueabihf/4.8.3/../../../../arm-linux-gnueabihf/bin/ld: warning: libssl.so.1.0.0, needed by /home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so, not found (try using -rpath or -rpath-link)
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_get_error@OPENSSL_1.0.0'
makefile:44: recipe for target 'prj_c' failed
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_load_verify_locations@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_alert_desc_string_long@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_msg_callback@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_get1_session@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_write@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `CRYPTO_THREADID_set_numeric@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `ERR_get_error@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_alert_type_string_long@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_default_passwd_cb@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CIPHER_get_name@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_load_error_strings@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_default_passwd_cb_userdata@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_new@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `CRYPTO_set_locking_callback@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `OPENSSL_add_all_algorithms_noconf@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_use_PrivateKey_file@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_library_init@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_get_current_cipher@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_cipher_list@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_default_verify_paths@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_shutdown@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_connect@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_get_cipher_list@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSLv23_client_method@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_use_certificate_chain_file@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `ERR_print_errors_fp@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_info_callback@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_set_session@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_new@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `CRYPTO_THREADID_set_callback@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `CRYPTO_num_locks@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_free@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_read@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSLeay_version@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `ERR_load_crypto_strings@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_get_verify_result@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_free@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_ctrl@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_pending@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_CTX_set_verify@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_state_string_long@OPENSSL_1.0.0'
/home/k/dev/workspace/iot/iot-raspberrypi/samples/c/lib/libpaho-mqtt3as.so: undefined reference to `SSL_set_fd@OPENSSL_1.0.0'
collect2: error: ld returned 1 exit status
make: *** [prj_c] Error 1

18:18:52 Build Finished (took 1s.675ms)

【问题讨论】：

标签： c++ eclipse ubuntu raspberry-pi

【解决方案1】：

您的构建系统上缺少 2 个库：libcrypto.so.1.0.0 和 libssl.so.1.0.0。

开发人员在其存储库中添加了一个额外部分，描述了构建示例所需的内容：Note for users who want to change the code, compile and build the .deb file

他们声明的一件事是您需要安装libssl-dev，它将自动安装libssl1.0.0。这个包包含libcrypto.so.1.0.0和libssl.so.1.0.0。

所以运行sudo apt-get install libssl-dev 可能会解决您的问题。

但是：您不是直接在 arm 系统上构建代码，而是在 x86/64 系统上构建代码。我不确定链接是否会起作用。

【讨论】：

我确实在主机和目标上安装了 libssl-dev。该代码在 Raspberry pi 上构建良好。我 NFS 将 lib 文件夹挂载到主机上的工具链文件夹。我认为这应该可以解决问题，但事实并非如此。查看日志我应该如何解释找不到 libcrypto.so.1.0.0 的长路径。路径格式为 ../../../../../..//bin/ld
这只是ld 可执行文件的路径。您是否尝试将文件夹添加到库路径(link)？
arm..g++ -search-dirs 提供了许多文件夹，包括以下文件夹。 /home/k/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../arm-linux-gnueabihf/libc/lib/ ........ .................. /home/k/dev/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin/../arm -linux-gnueabihf/libc/usr/lib/ 我将 /lib 和 usr/lib 挂载到这些位置的子文件夹
@Manish 这看起来与您的问题非常相似：raspberrypi.org/forums/viewtopic.php?f=33&t=37658
在详细模式下找到这个 *********** GNU ld (crosstool-NG linaro-1.13.1) 支持的仿真： armelf_linux_eabi armelfb_linux_eabi 。使用内部链接器脚本： ====================== OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm") OUTPUT_ARCH(arm) ENTRY(_start) SEARCH_DIR("=/usr/local/lib/arm-linux-gnueabihf"); SEARCH_DIR("=/usr/local/lib"); SEARCH_DIR("=/lib/arm-linux-gnueabihf"); SEARCH_DIR("=/lib"); SEARCH_DIR("=/usr/lib/arm-linux-gnueabihf"); SEARCH_DIR("=/usr/lib"); ******** 这些是链接器的搜索目录吗？我认为 g++ --search-dirs 是搜索路径。

【解决方案2】：

我能够正确构建。从一开始就一直是链接器路径问题。然而，由于我缺乏 Eclipse 和 linux 方面的专业知识，我无法找到原因。将我的观察结果发布给其他人。

链接器正在寻找 libssl.so 和 libcrypto.so。而 Eclipse 控制台中的错误是查找 libcrypto.1.0.0。 谁能指导我为什么会出现这个命名问题？
我能够使用 本地库文件夹 以及 NFS 链接 到外部库进行构建。
库 -L 的链接应指向 .so 的最终文件夹，而不是父级或层次结构中的上层。
在使用 NFS 时，由于第 1 点中提到的问题，我登录到目标（Raspberry Pi）并通过文件资源管理器 > 右键单击 > 创建链接将 .so.1.0.0 链接到 .so。此链接在主机 nfs 挂载上显示已损坏。也许那是绝对的。很少有带有链接的标准库看起来不错。
为了从主机上的 eclipse 有效运行，如果遇到错误 - “加载共享库时出错”，则需要将这些库复制到目标上的 /lib 或 /usr/lib。

【讨论】：