Add helpful error messages if Irrlicht library / include dir are set incorrectly...

diff --git a/cmake/Modules/FindIrrlicht.cmake b/cmake/Modules/FindIrrlicht.cmake
index bb501b3b4a7f7f7b30f3592138134a8dd572f8fe..058e938782760ef68d36d127a383f02b6fe023e9 100644 (file)
--- a/cmake/Modules/FindIrrlicht.cmake
+++ b/cmake/Modules/FindIrrlicht.cmake
@@ -1,5 +1,5 @@
 
-mark_as_advanced(IRRLICHT_LIBRARY IRRLICHT_INCLUDE_DIR IRRLICHT_DLL)
+mark_as_advanced(IRRLICHT_DLL)
 
 # Find include directory and libraries
 
@@ -29,8 +29,22 @@ foreach(libname IN ITEMS IrrlichtMt Irrlicht)
        endif()
 endforeach()
 
-# Users will likely need to edit these
-mark_as_advanced(CLEAR IRRLICHT_LIBRARY IRRLICHT_INCLUDE_DIR)
+# Handholding for users
+if(IRRLICHT_INCLUDE_DIR AND (NOT IS_DIRECTORY "${IRRLICHT_INCLUDE_DIR}" OR
+       NOT EXISTS "${IRRLICHT_INCLUDE_DIR}/irrlicht.h"))
+       message(WARNING "IRRLICHT_INCLUDE_DIR was set to ${IRRLICHT_INCLUDE_DIR} "
+               "but irrlicht.h does not exist inside. The path will not be used.")
+       unset(IRRLICHT_INCLUDE_DIR CACHE)
+endif()
+if(WIN32 OR CMAKE_SYSTEM_NAME STREQUAL "Linux" OR APPLE)
+       # (only on systems where we're sure how a valid library looks like)
+       if(IRRLICHT_LIBRARY AND (IS_DIRECTORY "${IRRLICHT_LIBRARY}" OR
+               NOT IRRLICHT_LIBRARY MATCHES "\\.(a|so|dylib|lib)([.0-9]+)?$"))
+               message(WARNING "IRRLICHT_LIBRARY was set to ${IRRLICHT_LIBRARY} "
+                       "but is not a valid library file. The path will not be used.")
+               unset(IRRLICHT_LIBRARY CACHE)
+       endif()
+endif()
 
 # On Windows, find the DLL for installation
 if(WIN32)