This is my personal CMake FindPackage script template - it handles having multiple versions installed and it doesn't require any modification for my purposes other than changing the filename.
You can use it for your purposes too!
Simply change the filename to Find<name of your package>.cmake and make sure your install script puts things in the right places.
You need to use a versioned directory structure for your installation, with a package config file stored at a location like MyPackage/3.14.159/cmake/MyPackage.cmake.
Components are also supported, just put their package config files at a location like MyPackage/3.14.159/cmake/MyPackage/Component.cmake.
MyPackage_ROOT can be set before calling find_package to help with finding the desired location, otherwise it will be found automatically if it is in a standard location.
Within the MyPackage_ROOT directory, there should be a directory named MyPackage, and within that directory should be directories named after the versions they contain (e.g. 3.14.159).
Within each version directory is a typical installation tree with directories such as cmake, include, lib, bin, etc.
There is support for rich version matching - for example, find(MyPackage 2 EXACT) will find the highest version with a major version of 2, whereas find(MyPackage 3.14) will find the highest available version where the major version number is at least 3 and, if the major version equals 3, the minor version number is at least 14.
All CMake-style versions are supported - that is, versions in the format major[.minor[.patch[.tweak]]].
Although you can have different depths for each version, I recommend that you use the same depth for all versions to avoid confusion.
When requesting optional components, only the version(s) with the most requested optional components are considered (so a lower version may be selected if it has more of the desired optional components).
Obviously, versions that are missing requsted required components are not considered at all.
That's great! You can have a slash in your package name and the 'friendly name' will replace the slashes with double colons.
For example, for my library LB::events, I create a directory named FindLB and within it place this file named as events.cmake.
Then users can use find_package(LB/events) and it will work, whilst the package name displayed in the output is LB::events.
And yes, CMake variable names can contain slashes - ${LB/events_FOUND} will indicate whether my package is found.
The script will find and include my package config file at a path like LB/events/3.14.159/cmake/LB/events.cmake and it is expected that this will introduce an imported target named LB::events.
Rmemeber: CMake variable names are case sensitive.
If your package is named CamelCasePackage, then you will need to listen for ${CamelCasePackage_FOUND} with the same case.
All input variables are optional.
<package>_ROOT- the directory containing the start of the directory tree (should contain a folder named<package>)<package>_PREFER_HIGHEST- instead of selecting a lower version with more of the requested optional components, prefer selecting the highest version even if it has fewer requested optional components
<package>_FOUND- 1 if found, unset otherwise.<package>_<component>_FOUND- 1 if the requested component was found, unset otherwise.<package>_NOT_FOUND_MESSAGE- the error message if the package was not found<package>_ROOT- the directory containing the start of the directory tree (contains a folder named<package>)<package>_ROOT_DIR- path to the selected installation (contains the version number in the path)<package>_VERSIONS_DIRECTORY- path to the directory containing the version directories<package>_VERSIONS- ;-list of all versions that were considered<package>_VERSION- the selected version<package>_VERSION_STRING- same as<package>_VERSION<package>_VERSION_MAJOR<package>_VERSION_MINOR<package>_VERSION_PATCH<package>_VERSION_TWEAK
- LB::events - typical library with dependencies
- LB::optional - header only library w/o dependencies
- LB::tuples - header only library w/o dependencies
- LB::cloning - header only library w/o dependencies