使用cmake时出现链接错误

Question

我正在使用cmake编译一些代码，遇到错误。这是我收到的消息：

[ 79%] Linking CXX executable ../release/report_intr_dim
/usr/bin/ld: ../release/libNonMetricSpaceLib.a(pivot_neighb_invindx.cc.o): undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
//lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
test/CMakeFiles/report_intr_dim.dir/build.make:99: recipe for target 'release/report_intr_dim' failed
make[2]: *** [release/report_intr_dim] Error 1
CMakeFiles/Makefile2:326: recipe for target 'test/CMakeFiles/report_intr_dim.dir/all' failed
make[1]: *** [test/CMakeFiles/report_intr_dim.dir/all] Error 2
Makefile:127: recipe for target 'all' failed
make: *** [all] Error 2

Makefile:127：

[126]all: cmake_check_build_system
[127]        $(CMAKE_COMMAND) -E cmake_progress_start /home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/CMakeFiles /home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/CMakeFiles/progress.marks
[128]        $(MAKE) -f CMakeFiles/Makefile2 all
[129]        $(CMAKE_COMMAND) -E cmake_progress_start /home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/CMakeFiles 0
[130].PHONY : all

CMakeFiles/Makefile2:326：

[323]# All Build rule for target.
[324]test/CMakeFiles/report_intr_dim.dir/all: lshkit/CMakeFiles/lshkit.dir/all
[325]test/CMakeFiles/report_intr_dim.dir/all: src/CMakeFiles/NonMetricSpaceLib.dir/all
[326]        $(MAKE) -f test/CMakeFiles/report_intr_dim.dir/build.make test/CMakeFiles/report_intr_dim.dir/depend
[327]        $(MAKE) -f test/CMakeFiles/report_intr_dim.dir/build.make test/CMakeFiles/report_intr_dim.dir/build
[328]        @$(CMAKE_COMMAND) -E cmake_echo_color --switch=$(COLOR) --progress-dir=/home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/CMakeFiles --progress-num=93,94 "Built target report_intr_dim"
[329].PHONY : test/CMakeFiles/report_intr_dim.dir/all
[330]
[331]# Include target in all.
[332]all: test/CMakeFiles/report_intr_dim.dir/all
[333]
[334].PHONY : all

test/CMakeFiles/report_intr_dim.dir/build.make:99：

[88]# External object files for target report_intr_dim
[89]report_intr_dim_EXTERNAL_OBJECTS =
[90]
[91]release/report_intr_dim: test/CMakeFiles/report_intr_dim.dir/report_intr_dim.cc.o
[92]release/report_intr_dim: test/CMakeFiles/report_intr_dim.dir/build.make
[93]release/report_intr_dim: release/libNonMetricSpaceLib.a
[94]release/report_intr_dim: release/liblshkit.a
[95]release/report_intr_dim: /usr/lib/x86_64-linux-gnu/libboost_system.so
[96]release/report_intr_dim: /usr/lib/x86_64-linux-gnu/libboost_filesystem.so
[97]release/report_intr_dim: /usr/lib/x86_64-linux-gnu/libboost_program_options.so
[98]release/report_intr_dim: test/CMakeFiles/report_intr_dim.dir/link.txt
[99]        @$(CMAKE_COMMAND) -E cmake_echo_color --switch=$(COLOR) --green --bold --progress-dir=/home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/CMakeFiles --progress-num=$(CMAKE_PROGRESS_2) "Linking CXX executable ../release/report_intr_dim"
[100]       cd /home/safarisoul/nns_benchmark-master/algorithms/NMSLIB/code/test && $(CMAKE_COMMAND) -E cmake_link_script CMakeFiles/report_intr_dim.dir/link.txt --verbose=$(VERBOSE)

我在谷歌上搜索了一下，发现我需要在某个地方添加'-pthread‘，而且我可能应该在CMakeLists.txt中修改一些东西。但这是我第一次使用cmake，而且我不熟悉c/c++。我不知道该怎么解决这个问题。请帮帮忙。

Answer 1

假设这真的是与缺少pthread的链接，这是当前在CMakeLists.txt中应该如何完成的方式：

find_package(Threads REQUIRED)
[..]
target_link_libraries(target [SCOPE] Threads::Threads)

Answer 2

使用CMake链接pthreads

find_package(Threads REQUIRED) target_link_libraries(NonMetricSpaceLib Threads::Threads)

如果您有多个线程库，可以尝试设置CMAKE_THREAD_PREFER_PTHREAD和THREADS_PREFER_PTHREAD_FLAG。

• https://cmake.org/cmake/help/latest/command/target_link_libraries.html
• https://cmake.org/cmake/help/latest/module/FindThreads.html