c++ - CMake 的导出如何知道目标是什么版本？

Question

我正在尝试制作一个图书馆。我的 CMakeLists.txt 看起来像这样:

add_library(Lib STATIC)
set_target_properties(Lib PROPERTIES
    VERSION 0.1)
export(TARGETS Lib
    FILE ${BIN_DIR}/LibConfig.cmake)

当外部项目使用这个库时，CMake 显示错误:

CMake Error at CMakeLists.txt:10 (find_package):
  Could not find a configuration file for package "Lib" that is
  compatible with requested version "0.1".

  The following configuration files were considered but not accepted:

some directory/Lib/bin/LibConfig.cmake, version: unknown

查看生成的LibConfig.cmake，除了没有携带版本信息外，没有任何问题。

Answer 1

要允许 CMake 确定您的库的版本，您需要创建一个 LibConfigVersion.cmake 文件。

可以在 CMake 文档中找到示例:generating package files

对于您的图书馆，这会产生如下结果:

add_library(Lib STATIC)
set_target_properties(Lib PROPERTIES VERSION 0.1)
export(TARGETS LibFILE ${BIN_DIR}/LibConfig.cmake)

include(CMakePackageConfigHelpers)
write_basic_package_version_file(${BIN_DIR}/LibConfigVersion.cmake
                                 VERSION 0.1
                                 COMPATIBILITY SameMajorVersion)

您可以在 project 命令中设置一次，而不是多次提供版本信息:

project(Lib VERSION 0.1)