diff --git a/Modules/CheckCSourceCompiles.cmake b/Modules/CheckCSourceCompiles.cmake
index a1fb631b6..46f860593 100644
--- a/Modules/CheckCSourceCompiles.cmake
+++ b/Modules/CheckCSourceCompiles.cmake
@@ -13,7 +13,7 @@
 #  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
 
 MACRO(CHECK_C_SOURCE_COMPILES SOURCE VAR)
-  IF("${VAR}" MATCHES "^${VAR}$" OR "${VAR}" MATCHES "UNKNOWN")
+  IF("${VAR}" MATCHES "^${VAR}$")
     SET(MACRO_CHECK_FUNCTION_DEFINITIONS
       "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
     IF(CMAKE_REQUIRED_LIBRARIES)
@@ -28,20 +28,9 @@ MACRO(CHECK_C_SOURCE_COMPILES SOURCE VAR)
     ELSE(CMAKE_REQUIRED_INCLUDES)
       SET(CHECK_C_SOURCE_COMPILES_ADD_INCLUDES)
     ENDIF(CMAKE_REQUIRED_INCLUDES)
-    SET(src "")
-    FOREACH(def ${EXTRA_DEFINES})
-      SET(src "${src}#define ${def} 1\n")
-    ENDFOREACH(def)
-    FOREACH(inc ${HEADER_INCLUDES})
-      SET(src "${src}#include <${inc}>\n")
-    ENDFOREACH(inc)
+    FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c"
+      "${SOURCE}\n")
 
-    SET(src "${src}\nint main() { ${SOURCE} ; return 0; }")
-    FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src2.c"
-      "${src}\n")
-    EXEC_PROGRAM("${CMAKE_COMMAND}" 
-      "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp"
-      ARGS -E copy src2.c src.c)
     MESSAGE(STATUS "Performing Test ${VAR}")
     TRY_COMPILE(${VAR}
       ${CMAKE_BINARY_DIR}
@@ -57,14 +46,15 @@ MACRO(CHECK_C_SOURCE_COMPILES SOURCE VAR)
       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
         "Performing C SOURCE FILE Test ${VAR} succeded with the following output:\n"
         "${OUTPUT}\n"
-        "Source file was:\n${src}\n")
+        "Source file was:\n${SOURCE}\n")
     ELSE(${VAR})
       MESSAGE(STATUS "Performing Test ${VAR} - Failed")
       SET(${VAR} "" CACHE INTERNAL "Test ${VAR}")
       FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
         "Performing C SOURCE FILE Test ${VAR} failed with the following output:\n"
         "${OUTPUT}\n"
-        "Source file was:\n${src}\n")
+        "Source file was:\n${SOURCE}\n")
     ENDIF(${VAR})
-  ENDIF("${VAR}" MATCHES "^${VAR}$" OR "${VAR}" MATCHES "UNKNOWN")
+  ENDIF("${VAR}" MATCHES "^${VAR}$")
 ENDMACRO(CHECK_C_SOURCE_COMPILES)
+
diff --git a/Modules/CheckCSourceRuns.cmake b/Modules/CheckCSourceRuns.cmake
index 35d2cefdc..d843e9a8a 100644
--- a/Modules/CheckCSourceRuns.cmake
+++ b/Modules/CheckCSourceRuns.cmake
@@ -13,7 +13,7 @@
 #  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
 
 MACRO(CHECK_C_SOURCE_RUNS SOURCE VAR)
-  IF("${VAR}" MATCHES "^${VAR}$" OR "${VAR}" MATCHES "UNKNOWN")
+  IF("${VAR}" MATCHES "^${VAR}$")
     SET(MACRO_CHECK_FUNCTION_DEFINITIONS 
       "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
     IF(CMAKE_REQUIRED_LIBRARIES)
@@ -28,20 +28,9 @@ MACRO(CHECK_C_SOURCE_RUNS SOURCE VAR)
     ELSE(CMAKE_REQUIRED_INCLUDES)
       SET(CHECK_C_SOURCE_COMPILES_ADD_INCLUDES)
     ENDIF(CMAKE_REQUIRED_INCLUDES)
-    SET(src "")
-    FOREACH(def ${EXTRA_DEFINES})
-      SET(src "${src}#define ${def} 1\n")
-    ENDFOREACH(def)
-    FOREACH(inc ${HEADER_INCLUDES})
-      SET(src "${src}#include <${inc}>\n")
-    ENDFOREACH(inc)
+    FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.c"
+      "${SOURCE}\n")
 
-    SET(src "${src}\nint main() { ${SOURCE} ; return 0; }")
-    FILE(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src2.c"
-      "${src}\n")
-    EXEC_PROGRAM("${CMAKE_COMMAND}" 
-      "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp"
-      ARGS -E copy src2.c src.c)
     MESSAGE(STATUS "Performing Test ${VAR}")
     TRY_RUN(${VAR} ${VAR}_COMPILED
       ${CMAKE_BINARY_DIR}
@@ -60,19 +49,20 @@ MACRO(CHECK_C_SOURCE_RUNS SOURCE VAR)
     IF("${result_var}" EQUAL 0)
       SET(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
       MESSAGE(STATUS "Performing Test ${VAR} - Success")
-      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log 
         "Performing C SOURCE FILE Test ${VAR} succeded with the following output:\n"
         "${OUTPUT}\n"
         "Return value: ${${VAR}}\n"
-        "Source file was:\n${src}\n")
+        "Source file was:\n${SOURCE}\n")
     ELSE("${result_var}" EQUAL 0)
       MESSAGE(STATUS "Performing Test ${VAR} - Failed")
       SET(${VAR} "" CACHE INTERNAL "Test ${VAR}")
-      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+      FILE(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log 
         "Performing C SOURCE FILE Test ${VAR} failed with the following output:\n"
         "${OUTPUT}\n"
         "Return value: ${result_var}\n"
-        "Source file was:\n${src}\n")
+        "Source file was:\n${SOURCE}\n")
     ENDIF("${result_var}" EQUAL 0)
-  ENDIF("${VAR}" MATCHES "^${VAR}$" OR "${VAR}" MATCHES "UNKNOWN")
+  ENDIF("${VAR}" MATCHES "^${VAR}$")
 ENDMACRO(CHECK_C_SOURCE_RUNS)
+