cmake/modules/LLVMParseArguments.cmake

# Copied from http://www.itk.org/Wiki/CMakeMacroParseArguments under
# http://creativecommons.org/licenses/by/2.5/.
#
# The PARSE_ARGUMENTS macro will take the arguments of another macro and define
# several variables. The first argument to PARSE_ARGUMENTS is a prefix to put on
# all variables it creates. The second argument is a list of names, and the
# third argument is a list of options. Both of these lists should be quoted. The
# rest of PARSE_ARGUMENTS are arguments from another macro to be parsed.
#
# PARSE_ARGUMENTS(prefix arg_names options arg1 arg2...)
#
# For each item in options, PARSE_ARGUMENTS will create a variable with that
# name, prefixed with prefix_. So, for example, if prefix is MY_MACRO and
# options is OPTION1;OPTION2, then PARSE_ARGUMENTS will create the variables
# MY_MACRO_OPTION1 and MY_MACRO_OPTION2. These variables will be set to true if
# the option exists in the command line or false otherwise.
#
#For each item in arg_names, PARSE_ARGUMENTS will create a variable with that
#name, prefixed with prefix_. Each variable will be filled with the arguments
#that occur after the given arg_name is encountered up to the next arg_name or
#the end of the arguments. All options are removed from these
#lists. PARSE_ARGUMENTS also creates a prefix_DEFAULT_ARGS variable containing
#the list of all arguments up to the first arg_name encountered.
#
#Here is a simple, albeit impractical, example of using PARSE_ARGUMENTS that
#demonstrates its behavior.
#
# SET(arguments
#     hello OPTION3 world
#     LIST3 foo bar
#     OPTION2
#     LIST1 fuz baz
#     )
#
# PARSE_ARGUMENTS(ARG "LIST1;LIST2;LIST3" "OPTION1;OPTION2;OPTION3" ${arguments})
#
# PARSE_ARGUMENTS creates 7 variables and sets them as follows:
#   ARG_DEFAULT_ARGS: hello;world
#   ARG_LIST1: fuz;baz
#   ARG_LIST2:
#   ARG_LIST3: foo;bar
#   ARG_OPTION1: FALSE
#   ARG_OPTION2: TRUE
#   ARG_OPTION3: TRUE
#
# If you don't have any options, use an empty string in its place.
#   PARSE_ARGUMENTS(ARG "LIST1;LIST2;LIST3" "" ${arguments})
# Likewise if you have no lists.
#   PARSE_ARGUMENTS(ARG "" "OPTION1;OPTION2;OPTION3" ${arguments})

MACRO(PARSE_ARGUMENTS prefix arg_names option_names)
  SET(DEFAULT_ARGS)
  FOREACH(arg_name ${arg_names})
    SET(${prefix}_${arg_name})
  ENDFOREACH(arg_name)
  FOREACH(option ${option_names})
    SET(${prefix}_${option} FALSE)
  ENDFOREACH(option)

  SET(current_arg_name DEFAULT_ARGS)
  SET(current_arg_list)
  FOREACH(arg ${ARGN})
    SET(larg_names ${arg_names})
    LIST(FIND larg_names "${arg}" is_arg_name)
    IF (is_arg_name GREATER -1)
      SET(${prefix}_${current_arg_name} ${current_arg_list})
      SET(current_arg_name ${arg})
      SET(current_arg_list)
    ELSE (is_arg_name GREATER -1)
      SET(loption_names ${option_names})
      LIST(FIND loption_names "${arg}" is_option)
      IF (is_option GREATER -1)
        SET(${prefix}_${arg} TRUE)
      ELSE (is_option GREATER -1)
        SET(current_arg_list ${current_arg_list} ${arg})
      ENDIF (is_option GREATER -1)
    ENDIF (is_arg_name GREATER -1)
  ENDFOREACH(arg)
  SET(${prefix}_${current_arg_name} ${current_arg_list})
ENDMACRO(PARSE_ARGUMENTS)