# use bison for .yy files

# search for bison
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)
    ENDIF(NOT BISON_EXECUTABLE)
ENDMACRO(FIND_BISON)

MACRO(ADD_BISON_FILES _sources )
    FIND_BISON()

    FOREACH (_current_FILE ${ARGN})
      GET_FILENAME_COMPONENT(_in ${_current_FILE} ABSOLUTE)
      GET_FILENAME_COMPONENT(_basename ${_current_FILE} NAME_WE)

      SET(_out ${CMAKE_CURRENT_BINARY_DIR}/${_basename}.cpp)


		# bison options:
		# -t add debugging facilities
		# -d produce additional header file (used in parser.l)
		# -v produce additional *.output file with parser states

      ADD_CUSTOM_COMMAND(
         OUTPUT ${_out}
         COMMAND ${BISON_EXECUTABLE}
         ARGS
         -o${_out} -d -v -t
         ${_in}
         DEPENDS ${_in}
      )

      SET(${_sources} ${${_sources}} ${_out} )
   ENDFOREACH (_current_FILE)
ENDMACRO(ADD_BISON_FILES)