ENH: only allow matching fortran a c compilers to be used

Tests/Fortran/CMakeLists.txt

@@ -1,5 +1,6 @@
 cmake_minimum_required (VERSION 2.6)
 PROJECT(testf C Fortran)
+message("CTEST_FULL_OUTPUT ")
 SET(CMAKE_VERBOSE_MAKEFILE 1)
 MESSAGE("ENV_FLAGS = $ENV{FFLAGS}")
 MESSAGE("CMAKE_Fortran_COMPILER_INIT = ${CMAKE_Fortran_COMPILER_INIT}")
@@ -29,9 +30,17 @@ set(FORTRAN_FUNCTIONS ${FORTRAN_FUNCTIONS} my_sub mysub )
 set(srcs ${srcs} mysub.f foo.c)
 create_fortran_c_interface("F_" FORTRAN_FUNCTIONS "${testf_BINARY_DIR}/foo.h")
 include_directories("${testf_BINARY_DIR}")
-add_executable(foo ${srcs})
+
+if("${CMAKE_Fortran_COMPILER_ID}" MATCHES "${CMAKE_C_COMPILER_ID}" )
+  message("Fortran = ${CMAKE_Fortran_COMPILER_ID}")
+  message("C = ${CMAKE_C_COMPILER_ID}")
+  add_executable(foo ${srcs})
+else()
+  message("Fortran does not match c compiler")
+  message("Fortran = ${CMAKE_Fortran_COMPILER_ID}")
+  message("C = ${CMAKE_C_COMPILER_ID}")
+endif()
 # print out some stuff to help debug on machines via cdash
-message("CTEST_FULL_OUTPUT ")
 file(READ "${testf_BINARY_DIR}/foo.h" fooh)
 message("foo.h contents:\n${fooh}")