Unifying CMake's FIND_PACKAGE - cmake

Question

Do you know a trick to get a unified output terminology when getting include and library paths from CMake's FIND_PACKAGE?
Sometimes it's FOO_INCLUDE. Sometimes it's FOO_INCLUDE_PATH. Etc.
For example, I would like to find a way to ensure that FOO_INCLUDE and FOO_LIB be always defined when FOO_FOUND is set to TRUE after a call to FIND_PACKAGE.

Answer 1

Turning my comment into an answer
To avoid the need to know the include path, library, etc. dependencies and their variable notations modern find_package's implementation do provide IMPORTED targets like Foo::Foo. But this is - as #Tsyvarev has commented - far from unified through all of CMake's find modules.
So generalizing the CMake's Sample Find Module implementation you could unify your find_package() calls with an overwritten find_package() macro version like the following:
cmake_minimum_required(VERSION 3.2)
project(UnifiedFindPackage)
macro(unify_vars _result)
set(${_result} "")
foreach(_i IN ITEMS ${ARGN})
if (${_i})
list(APPEND ${_result} "${${_i}}")
endif()
endforeach()
endmacro()
macro(find_package _name)
_find_package(${_name} ${ARGN})
if (${_name}_FOUND AND NOT TARGET ${_name}::${_name})
add_library(${_name}::${_name} STATIC IMPORTED GLOBAL)
unify_vars(_var ${_name}_LIBRARY ${_name}_LIB)
if (_var)
set_target_properties(${_name}::${_name} PROPERTIES IMPORTED_LOCATION "${_var}")
endif()
if (${_name}_LIBRARY_RELEASE)
set_property(TARGET ${_name}::${_name} APPEND PROPERTY IMPORTED_CONFIGURATIONS RELEASE)
set_target_properties(${_name}::${_name} PROPERTIES IMPORTED_LOCATION_RELEASE "${${_name}_LIBRARY_RELEASE}")
endif()
if (${_name}_LIBRARY_DEBUG)
set_property(TARGET ${_name}::${_name} APPEND PROPERTY IMPORTED_CONFIGURATIONS DEBUG)
set_target_properties(${_name}::${_name} PROPERTIES IMPORTED_LOCATION_DEBUG "${${_name}_LIBRARY_DEBUG}")
endif()
if (${_name}_LIBRARIES)
set_property(TARGET ${_name}::${_name} APPEND PROPERTY INTERFACE_LINK_LIBRARIES "${${_name}_LIBRARIES}")
endif()
unify_vars(_var ${_name}_INCLUDE_DIRS ${_name}_INCLUDE_PATH)
if (_var)
set_property(TARGET ${_name}::${_name} APPEND PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${_var}")
endif()
unify_vars(_var ${_name}_COMPILE_FLAGS ${_name}_DEFINITIONS)
if (_var)
set_property(TARGET ${_name}::${_name} APPEND PROPERTY INTERFACE_COMPILE_OPTIONS "${_var}")
endif()
endif()
endmacro()
find_package(MPI REQUIRED)
add_executable(${PROJECT_NAME} main.c)
target_link_libraries(${PROJECT_NAME} MPI::MPI)
This should only demonstrate a possible unification and could be extended on a need-by basis.
Edit: Turning this into an community wiki answer. Please feel free to contribute.
The code was tested in this example with MPI find module results.