C++ 对“pthread_key_create”的未定义引用（链接器错误）
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/21116622/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
undefined reference to `pthread_key_create' (linker error)
提问by user3165964
I have downloaded gtest 1.7.0 sources from here:
我已经从这里下载了 gtest 1.7.0 源代码：
https://code.google.com/p/googletest/downloads/list
https://code.google.com/p/googletest/downloads/list
and build the gtest .a files (lib files) on ubuntu 13.10:
并在 ubuntu 13.10 上构建 gtest .a 文件（lib 文件）：
Linux ubuntu 3.11.0-15-generic #23-Ubuntu SMP Mon Dec 9 18:17:04 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
and the resulting lib is called: libgtest.a. In my main.cpp file Have:
生成的库被称为：libgtest.a。在我的 main.cpp 文件中有：
#include <iostream>
#include "gtest/gtest.h"
int main(){
std::cout << "Test \n";
int argc = 2;
char* cp01;
char* cp02;
char* argv[] = {cp01, cp02};
testing::InitGoogleTest(&argc, argv);
return 0;
}
From a terminal I build with:
从我构建的终端：
g++ main.cpp -I/home/user/gtest-1.7.0/include -L/home/user/gtest-1.7.0/lib/.libs -lpthread -lgtest
which gives the following errors:
这给出了以下错误：
/home/user/gtest-1.7.0/lib/.libs/libgtest.so: undefined reference to `pthread_key_create'
/home/user/gtest-1.7.0/lib/.libs/libgtest.so: undefined reference to `pthread_getspecific'
/home/user/gtest-1.7.0/lib/.libs/libgtest.so: undefined reference to `pthread_key_delete'
/home/user/gtest-1.7.0/lib/.libs/libgtest.so: undefined reference to `pthread_setspecific'
collect2: error: ld returned 1 exit status
Based on this: error during making GTest
基于此： 制作 GTest 时出错
I have also tried -pthreadinstead of -lpthreadbut gives same error:
我也试过-pthread代替-lpthread但给出了同样的错误：
g++ main.cpp -I/home/user/gtest-1.7.0/include -L/home/user/gtest-1.7.0/lib/.libs -pthread -lgtest
EDIT: I have also tried to specifying -pthreadas the last argument:
编辑：我也尝试指定-pthread为最后一个参数：
g++ main.cpp -I/home/user/gtest-1.7.0/include -L/home/user/gtest-1.7.0/lib/.libs -lgtest -pthread
same error What am I doing wrong?
同样的错误我做错了什么？
采纳答案by Mike Kinghan
The option -lgtestis attempting to link the dynamic library libgtest.so. You
wish to link the static library /home/user/gtest-1.7.0/lib/.libs/libgtest.a.
该选项-lgtest正在尝试链接动态库libgtest.so。您希望链接静态库/home/user/gtest-1.7.0/lib/.libs/libgtest.a。
Instead of:
代替：
g++ main.cpp -I/home/user/gtest-1.7.0/include -L/home/user/gtest-1.7.0/lib/.libs -lgtest -pthread
use:
用：
g++ main.cpp -I/home/user/gtest-1.7.0/include /home/user/gtest-1.7.0/lib/.libs/libgtest.a -pthread
Note that your commandline supplies no name for the resulting executable, which will default
to a.out. If you want it called, e.g. mytest, then do:
请注意，您的命令行没有为生成的可执行文件提供名称，默认为a.out. 如果你想调用它，例如mytest，然后执行：
g++ -o mytest main.cpp -I/home/user/gtest-1.7.0/include /home/user/gtest-1.7.0/lib/.libs/libgtest.a -pthread
回答by Mike Seymour
You need to specify -pthreadafter -lgtest. The linker takes libraries in order, and only takes as much as it needs to resolve references which are undefined at that point.
您需要在-pthread之后指定-lgtest。链接器按顺序获取库，并且只需要解析当时未定义的引用。
回答by jimi
Nope, the problem is with Gtest's build.
不，问题出在 Gtest 的构建上。
If you build it using the standard configureapproach, it isn't supplying the -lpthreadcorrectly to create libgtest.so. Hence, when you try building a final shared library that actually uses the pthread capability it fails.
如果您使用标准配置方法构建它，它不会-lpthread正确提供创建libgtest.so. 因此，当您尝试构建实际使用 pthread 功能的最终共享库时，它会失败。
Instead, use the Cmake approach:
相反，使用 Cmake 方法：
cd gtest-1.7.0
mkdir build
cd build
cmake -DBUILD_SHARED_LIBS=ON ..
make
And then manually install these into /usr/lib/
然后手动安装这些到 /usr/lib/
This version correctly links in libpthread into libgtest.
此版本将 libpthread 中的正确链接到 libgtest。
回答by parasrish
Use -pthreadinstead of -lpthread(for linking with pthread-library), while you using gtest in your executable.
当您在可执行文件中使用 gtest 时，使用-pthread代替-lpthread（用于与 pthread-library 链接）。
OR
或者
Move the -lpthreadafter libgtest.a(sequence matters).
移动-lpthread之后libgtest.a（顺序很重要）。
回答by Lambage
To answer we probably need more information, are you on a 64 bit machine and downloaded a 32 bit library?
要回答我们可能需要更多信息，您是否在 64 位机器上并下载了 32 位库？
