通过 find_package() 找不到 CMake 传递依赖

Question

我有静态库 Foo , 静态库 Bar这取决于 Foo和可执行 Baz这取决于 Bar .

相关栏目来自 Foo CMakeLists.txt :

# Specifying files to copy during "make install" command.
install(TARGETS Foo EXPORT FooConfig
    INCLUDES DESTINATION include
    LIBRARY DESTINATION lib
    ARCHIVE DESTINATION lib)

# Specifying config file that will be used to find a library using find_package().
install(EXPORT FooConfig
    FILE FooConfig.cmake
    NAMESPACE Foo::
    DESTINATION lib/cmake/Foo)
export(TARGETS Foo
    NAMESPACE Foo::
    FILE FooConfig.cmake)

相关栏目来自 Bar CMakeLists.txt :

# Specifying libraries that are required for build.
find_package(Foo REQUIRED)

# Specifying libraries to link to for the users of the library.
target_link_libraries(Bar PUBLIC Foo::Foo)

# Specifying files to copy during "make install" command.
install(TARGETS Bar EXPORT BarConfig
    INCLUDES DESTINATION include
    LIBRARY DESTINATION lib
    ARCHIVE DESTINATION lib)

# Specifying config file that will be used to find a library using find_package().
install(EXPORT BarConfig
    FILE BarConfig.cmake
    NAMESPACE Bar::
    DESTINATION lib/cmake/Bar)
export(TARGETS Bar
    NAMESPACE Bar::
    FILE BarConfig.cmake)

最后 Baz CmakeLists.txt :

find_package(Bar REQUIRED)

target_link_libraries(Baz PRIVATE Bar::Bar)

现在正在 build Baz我得到:

CMake Error at CMakeLists.txt:19 (add_executable):
  Target "Baz" links to target "Foo::Foo" but the
  target was not found.  Perhaps a find_package() call is missing for an
  IMPORTED target, or an ALIAS target is missing?

所以构建发现 Bar并正确确定它依赖于 Foo但找不到 Foo .我有另一个直接依赖于 Foo 的测试项目它构建得很好。如何解决这个问题？

Answer 1

不幸的是，BarConfig.cmake像这样生成的不处理查找依赖项，我不得不修改 Bar CMakeLists.txt对此:

# Specifying files to copy during "make install" command.
install(TARGETS Bar EXPORT BarTargets
    INCLUDES DESTINATION include
    LIBRARY DESTINATION lib
    ARCHIVE DESTINATION lib)
install(FILES CMake/BarConfig.cmake DESTINATION lib/cmake/Bar)

# Specifying config file that will be used to find a library using find_package().
install(EXPORT BarTargets
    FILE BarTargets.cmake
    NAMESPACE Bar::
    DESTINATION lib/cmake/Bar)
export(TARGETS Bar
    NAMESPACE Bar::
    FILE BarTargets.cmake)

然后我创建了一个文件 CMake/BarConfig.cmake有了这个:

include("${CMAKE_CURRENT_LIST_DIR}/BarTargets.cmake")

find_package(Foo REQUIRED)

现在这个 BarConfig.cmake在全局安装并调用 find_package找到 Foo .