c++ - CMake- 'target_link_options(.. -lgcov)' 和 'target_link_libraries(...gcov)' 之间有什么区别？

Question

我正在尝试构建一个启用代码覆盖率的库，如下所示:

    add_library(my_library my_lib.cpp)
    target_compile_options(my_library PRIVATE --coverage)
    target_link_options(my_library PRIVATE -lgcov)

然后我对库进行了一些测试:

    add_executable(my_test my_test.cpp)
    target_link_libraries(my_test my_library)

但是我在构建测试时遇到链接错误-

libmy_library.a(my_lib.cpp.o): In function `_GLOBAL__sub_I_00100_0__ZN7myClass10returnTrueEv':
my_lib.cpp:(.text+0x2f): undefined reference to `__gcov_init'
libmy_library.a(my_lib.cpp.o): In function `_GLOBAL__sub_D_00100_1__ZN7myClass10returnTrueEv':
my_lib.cpp:(.text+0x3a): undefined reference to `__gcov_exit'
libmy_library.a(my_lib.cpp.o):(.data.rel+0x20): undefined reference to `__gcov_merge_add'

如果我不使用 target_link_options 而使用 target_link_libraries -

    target_link_libraries(my_library PRIVATE gcov)

然后我就不会收到错误了。

行为差异的原因是什么？我认为 target_link_libraries(my_library PRIVATE gcov) 相当于 target_link_options(my_library PRIVATE -lgcov)。

Answer 1

答案就在那里，在 docs 中:

Note This command cannot be used to add options for static library targets, since they do not use a linker. To add archiver or MSVC librarian flags, see the STATIC_LIBRARY_OPTIONS target property.