This project was created to help answer Stackoverflow question 56135785. See https://stackoverflow.com/questions/56135785/correctly-set-the-location-of-imported-cmake-targets-for-an-installed-package

It improves the sample code originally submitted by user bruce-adams and provides some recommendations to better organize the associated CMake project.

• 2019-05-25
  • Create GitHub project to streamline reuse and adaptation. See https://github.com/jcfr/stackoverflow-56135785-answer
  • Rename project and source directory from foobar to FooBarLib, update Suggestions section accordingly
  • Improve build.sh
  • Updated suggestions (CPACK_PACKAGING_INSTALL_PREFIX should indeed be absolute to properly impact RPM layout)
  • RPM:
    • Be aware that setting CPACK_PACKAGING_INSTALL_PREFIX also impact the layout of the TGZ archive, this propably not what you want.
    • Update build.sh to display content of RPM package
    • CPACK_PACKAGING_INSTALL_PREFIX is set to /opt

• Two config files should be generated:
  • one for the build tree: this allow user of your project to directly build against your project and import targets
  • one for the install tree (which also end up being packaged)
• Do not force the value of CMAKE_INSTALL_PREFIX
• CPACK_PACKAGING_INSTALL_PREFIX should NOT be set to an absolute directory
• For sake of consistency, use foobarTargets instead of foobarLibTargets
• <projecname_uc> placeholder used below correspond to the name of the project upper-cased (ABC instead of abc)
• To allow configuring your project when vendorized along other one, prefer variable with <projecname_uc>_. This means <projecname_uc>_INSTALL_LIBRARY_DIR is better than LIBRARY_INSTALL_DIR.
• To allow user of the project to configure *_INSTALL_DIR variables, wrap them around if(DEFINED ...)
• Consistently use variables (e.g LIBRARY_INSTALL_DIR should always be used instead of lib)
• Prefer naming variable <projecname_uc>_INSTALL_*_DIR instead of <projecname_uc>_*_INSTALL_DIR, it make it easier to know the purpose of the variable when reading the code.
• Since version is already associated with the project, there is no need to set VERSION variable. Instead, you can use PROJECT_VERSION or FOOBAR_VERSION
• If starting a new project, prefer the most recent CMake version. CMake 3.13 instead of CMake 3.7
• Introduced variable <projecname_uc>_INSTALL_CONFIG_DIR
• <project_name>Targets.cmake should not be installed using install(FILES ...), it is already associated with an install rule
• conditionally set CMAKE_INSTALL_RPATH, it is valid only on Linux
• <project_name>Config.cmake.in:
  • there is no need to set FOOBAR_LIBRARY, this information is already associated with the exported foobar target
  • FOOBAR_LIBRARY_DIR is also not needed, this information is already associated with the exported foobar target
  • instead of setting FOOBAR_INCLUDE_DIR, the command target_include_directories should be used
  • remove setting of FOOBAR_VERSION, the generate version file already takes care of setting the version.
• always specify ARCHIVE, LIBRARY and RUNTIME when declaring install rules for target. It avoid issue when switching library type. One less thing to think about.
• always specify component with your install rule. It allows user of your project to selectively install part of it only development component or only runtime one, ...
• initializing CMAKE_BUILD_TYPE is also important, it ensures the generated Targets file are associated with a configuration (instead of having the suffix -noconfig.cmake)