LibFindMacros.cmake

# Copyright Raimar Sandner 2012–2014. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE.txt)

#! \file
#! \ingroup Helpers
#! \brief Improved versions of %CMake's `find_package`

#! \ingroup Helpers
#! \brief Works the same as `find_package`, but forwards the "REQUIRED" and "QUIET" arguments
#!   used for the current package.
#!
#! For this to work, the first parameter must be the prefix of the current package, then the
#! prefix of the new package etc, which are passed to `find_package`.
macro (libfind_package PREFIX)
  set (LIBFIND_PACKAGE_ARGS ${ARGN})
  if (${PREFIX}_FIND_QUIETLY)
    set (LIBFIND_PACKAGE_ARGS ${LIBFIND_PACKAGE_ARGS} QUIET)
  endif (${PREFIX}_FIND_QUIETLY)
  if (${PREFIX}_FIND_REQUIRED)
    set (LIBFIND_PACKAGE_ARGS ${LIBFIND_PACKAGE_ARGS} REQUIRED)
  endif (${PREFIX}_FIND_REQUIRED)
  find_package(${LIBFIND_PACKAGE_ARGS})
endmacro (libfind_package)


#! \ingroup Helpers
#! \brief Do the final processing once the paths have been detected.
#!
#! If include dirs are needed, `${PREFIX}_PROCESS_INCLUDES` should be set to contain
#! all the variables, each of which contain one include directory.
#! Ditto for `${PREFIX}_PROCESS_LIBS` and library files.
#! Will set `${PREFIX}_FOUND`, `${PREFIX}_INCLUDE_DIRS` and `${PREFIX}_LIBRARIES`.
#! Also handles errors in case library detection was required, etc.
macro (libfind_process PREFIX)
  # Skip processing if already processed during this run
  if (NOT ${PREFIX}_FOUND)
    # Start with the assumption that the library was found
    set (${PREFIX}_FOUND TRUE)

    # Process all includes and set _FOUND to false if any are missing
    foreach (i ${${PREFIX}_PROCESS_INCLUDES})
      if (${i})
        set (${PREFIX}_INCLUDE_DIRS ${${PREFIX}_INCLUDE_DIRS} ${${i}})
        mark_as_advanced(${i})
      else (${i})
        set (${PREFIX}_FOUND FALSE)
      endif (${i})
    endforeach (i)

    # Process all libraries and set _FOUND to false if any are missing
    foreach (i ${${PREFIX}_PROCESS_LIBS})
      if (${i})
        set (${PREFIX}_LIBRARIES ${${PREFIX}_LIBRARIES} ${${i}})
        mark_as_advanced(${i})
      else (${i})
        set (${PREFIX}_FOUND FALSE)
      endif (${i})
    endforeach (i)

    # Print message and/or exit on fatal error
    if (${PREFIX}_FOUND)
      if (NOT ${PREFIX}_FIND_QUIETLY)
        message (STATUS "Found ${PREFIX} ${${PREFIX}_VERSION}")
      endif (NOT ${PREFIX}_FIND_QUIETLY)
    else (${PREFIX}_FOUND)
      if (${PREFIX}_FIND_REQUIRED)
        foreach (i ${${PREFIX}_PROCESS_INCLUDES} ${${PREFIX}_PROCESS_LIBS})
          message("${i}=${${i}}")
        endforeach (i)
        message (FATAL_ERROR "Required library ${PREFIX} NOT FOUND.\nInstall the library (dev version) and try again. If the library is already installed, use ccmake to set the missing variables manually.")
      endif (${PREFIX}_FIND_REQUIRED)
    endif (${PREFIX}_FOUND)
  endif (NOT ${PREFIX}_FOUND)
endmacro (libfind_process)