store the compiler in the cache

Modules/CMakeDetermineCCompiler.cmake

@@ -5,11 +5,15 @@
 # the cmake variable CMAKE_GENERATOR_CC which can be defined by a generator
 # as a default compiler
 
-FIND_PROGRAM(CMAKE_C_COMPILER_FULLPATH NAMES $ENV{CC} ${CMAKE_GENERATOR_CC} gcc cc cl bcc )
-GET_FILENAME_COMPONENT(CMAKE_C_COMPILER ${CMAKE_C_COMPILER_FULLPATH} NAME_WE)
-# set this to notfound right after so that it is searched for each time this
-# file is included
-SET(CMAKE_C_COMPILER_FULLPATH NOTFOUND CACHE INTERNAL "full path to c compiler" FORCE)
+IF(NOT CMAKE_C_COMPILER)
+  FIND_PROGRAM(CMAKE_C_COMPILER_FULLPATH NAMES $ENV{CC} ${CMAKE_GENERATOR_CC} gcc cc cl bcc )
+  GET_FILENAME_COMPONENT(CMAKE_C_COMPILER ${CMAKE_C_COMPILER_FULLPATH} NAME_WE)
+  # set this to notfound right after so that it is searched for each time this
+  # file is included
+  SET(CMAKE_C_COMPILER_FULLPATH NOTFOUND CACHE INTERNAL "full path to c compiler" FORCE) 
+  SET(CMAKE_C_COMPILER ${CMAKE_C_COMPILER} CACHE STRING "C++ compiler")
+ENDIF(NOT CMAKE_C_COMPILER)
+MARK_AS_ADVANCED(CMAKE_C_COMPILER)  
 FIND_PROGRAM(CMAKE_AR NAMES ar PATHS /bin /usr/bin /usr/local/bin)
 
 FIND_PROGRAM(CMAKE_RANLIB NAMES ranlib PATHS /bin /usr/bin /usr/local/bin)

Modules/CMakeDetermineCXXCompiler.cmake

@@ -5,8 +5,12 @@
 # the cmake variable CMAKE_GENERATOR_CXX which can be defined by a generator
 # as a default compiler
 
-FIND_PROGRAM(CMAKE_CXX_COMPILER_FULLPATH NAMES $ENV{CXX} ${CMAKE_GENERATOR_CXX} c++ g++ CC aCC cl bcc )
-GET_FILENAME_COMPONENT(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER_FULLPATH} NAME_WE)
+IF(NOT CMAKE_CXX_COMPILER)
+  FIND_PROGRAM(CMAKE_CXX_COMPILER_FULLPATH NAMES $ENV{CXX} ${CMAKE_GENERATOR_CXX} c++ g++ CC aCC cl bcc )
+  GET_FILENAME_COMPONENT(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER_FULLPATH} NAME_WE)
+  SET(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER} CACHE STRING "C++ compiler")
+ENDIF(NOT CMAKE_CXX_COMPILER)
+MARK_AS_ADVANCED(CMAKE_CXX_COMPILER)
 
 # set this to notfound right after so that it is searched for each time this
 # file is included