将 cmake 用于 googletest 时对“pthread_getspecific”的未定义引用答案

【问题标题】：undefined reference to `pthread_getspecific' when using cmake for googletest将 cmake 用于 googletest 时对“pthread_getspecific”的未定义引用
【发布时间】：2018-06-16 16:20:05
【问题描述】：

我正在关注这个book。

我安装了 GoogleTest 并构建了库：

kuyu@ub16:~/Downloads/googletest-master$ find . -name *.a
./mybuild/googlemock/libgmock_main.a
./mybuild/googlemock/gtest/libgtest_main.a
./mybuild/googlemock/gtest/libgtest.a
./mybuild/googlemock/libgmock.a

我有一个 CMakeLists.txt 文件：

kuyu@ub16:~/Downloads/lotdd-code/c2/2$ echo $GMOCK_HOME 
/home/kuyu/Downloads/googletest-master
kuyu@ub16:~/Downloads/lotdd-code/c2/2$ cat CMakeLists.txt
project(chapterFirstExample)
cmake_minimum_required(VERSION 2.6)

include_directories($ENV{GMOCK_HOME}/googlemock/include $ENV{GMOCK_HOME}/googletest/include)
link_directories($ENV{GMOCK_HOME}/mybuild/googlemock $ENV{GMOCK_HOME}/mybuild/googlemock/gtest)
add_definitions(-std=c++0x)
set(CMAKE_CXX_FLAGS "${CMAXE_CXX_FLAGS} -Wall")

set(sources 
   main.cpp 
   SoundexTest.cpp)
add_executable(test ${sources})
target_link_libraries(test pthread)
target_link_libraries(test gmock)
target_link_libraries(test gtest)

然后我尝试构建我的源文件：

kuyu@ub16:~/Downloads/lotdd-code/c2/2$ mkdir build && cd build
kuyu@ub16:~/Downloads/lotdd-code/c2/2/build$ cmake ..
# output omitted for brevity...
kuyu@ub16:~/Downloads/lotdd-code/c2/2/build$ make
Scanning dependencies of target test
[ 33%] Building CXX object CMakeFiles/test.dir/main.cpp.o
[ 66%] Building CXX object CMakeFiles/test.dir/SoundexTest.cpp.o
/home/kuyu/Downloads/lotdd-code/c2/2/SoundexTest.cpp: In member function ‘virtual void SoundexEncoding_RetainsSoleLetterOfOneLetterWord_Test::TestBody()’:
/home/kuyu/Downloads/lotdd-code/c2/2/SoundexTest.cpp:7:12: warning: unused variable ‘soundex’ [-Wunused-variable]
    Soundex soundex;
            ^
[100%] Linking CXX executable test
/home/kuyu/Downloads/googletest-master/mybuild/googlemock/libgmock.a(gtest-all.cc.o): In function `testing::internal::ThreadLocal<testing::TestPartResultReporterInterface*>::~ThreadLocal()':
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED2Ev[_ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED5Ev]+0x25): undefined reference to `pthread_getspecific'
gtest-all.cc:(.text._ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED2Ev[_ZN7testing8internal11ThreadLocalIPNS_31TestPartResultReporterInterfaceEED5Ev]+0x3a): undefined reference to `pthread_key_delete'
# output omitted for brevity...

我从here 读到我必须使用静态库而不是动态库。因此，我可以使用手动构建成功构建：

g++ SoundexTest.cpp main.cpp -I/home/kuyu/Downloads/googletest-master/googletest/include -I/home/kuyu/Downloads/googletest-master/googlemock/include /home/kuyu/Downloads/googletest-master/mybuild/googlemock/libgmock.a /home/kuyu/Downloads/googletest-master/mybuild/googlemock/gtest/libgtest.a -pthread

我的问题是，如何更正 CMakeLists.txt 以便构建成功？也就是说，使用 libgtest.a 代替 libgtest.so

【问题讨论】：

标签： c++ cmake googletest

【解决方案1】：

链接时出现问题。

这只是一个假设：你尝试过吗？

target_link_libraries(test gmock gtest pthread)

而不是您的版本：

target_link_libraries(test pthread)
target_link_libraries(test gmock)
target_link_libraries(test gtest)

【讨论】：

@Tsyvarev 好的，感谢您的反馈，我认为图书馆订单可能不是一个好的。 gtest 需要 pthread 并且链接器抱怨某些 pthread 符号未定义，我想确定“gtest，然后是 pthread”的顺序。
@picaud-vincent，更改图书馆顺序对我有用。非常感谢您的帮助。