CMake: added check to accept Bison 2.0 or higher

(it's known not to work correctly with 1.28)


git-svn-id: http://svn.osgeo.org/qgis/trunk@6524 c8812cc2-4d05-0410-92ff-de0c093fc19c

cmake/Bison.cmake

@@ -5,9 +5,24 @@ MACRO(FIND_BISON)
     IF(NOT BISON_EXECUTABLE)
         FIND_PROGRAM(BISON_EXECUTABLE bison)
         IF (NOT BISON_EXECUTABLE)
-          MESSAGE(FATAL_ERROR "Bison not found - aborting")
-        ENDIF (NOT BISON_EXECUTABLE)
+
+	  MESSAGE(FATAL_ERROR "Bison not found - aborting")
+
+	ELSE (NOT BISON_EXECUTABLE)
+
+          EXEC_PROGRAM(${BISON_EXECUTABLE} ARGS --version OUTPUT_VARIABLE BISON_VERSION_STR)
+          # get first line in case it's multiline
+          STRING(REGEX REPLACE "([^\n]+).*" "\\1" FIRST_LINE "${BISON_VERSION_STR}")
+          # get version information
+          STRING(REGEX REPLACE ".* ([0-9]+)\\.([0-9]+)" "\\1" BISON_VERSION_MAJOR "${FIRST_LINE}")
+          STRING(REGEX REPLACE ".* ([0-9]+)\\.([0-9]+)" "\\2" BISON_VERSION_MINOR "${FIRST_LINE}")
+          IF (BISON_VERSION_MAJOR LESS 2)
+            MESSAGE (FATAL_ERROR "Bison version is too old (${BISON_VERSION_MAJOR}.${BISON_VERSION_MINOR}). Use 2.0 or higher.")
+          ENDIF (BISON_VERSION_MAJOR LESS 2)
+
+      ENDIF (NOT BISON_EXECUTABLE)
     ENDIF(NOT BISON_EXECUTABLE)
+
 ENDMACRO(FIND_BISON)
 
 MACRO(ADD_BISON_FILES _sources )