xref: /libbtbb/cmake/modules/CMakeParseArguments.cmake (revision 0c4345b4af6f79de3a7ff3dc01692f6d597247eb)
1# CMAKE_PARSE_ARGUMENTS(<prefix> <options> <one_value_keywords> <multi_value_keywords> args...)
2#
3# CMAKE_PARSE_ARGUMENTS() is intended to be used in macros or functions for
4# parsing the arguments given to that macro or function.
5# It processes the arguments and defines a set of variables which hold the
6# values of the respective options.
7#
8# The <options> argument contains all options for the respective macro,
9# i.e. keywords which can be used when calling the macro without any value
10# following, like e.g. the OPTIONAL keyword of the install() command.
11#
12# The <one_value_keywords> argument contains all keywords for this macro
13# which are followed by one value, like e.g. DESTINATION keyword of the
14# install() command.
15#
16# The <multi_value_keywords> argument contains all keywords for this macro
17# which can be followed by more than one value, like e.g. the TARGETS or
18# FILES keywords of the install() command.
19#
20# When done, CMAKE_PARSE_ARGUMENTS() will have defined for each of the
21# keywords listed in <options>, <one_value_keywords> and
22# <multi_value_keywords> a variable composed of the given <prefix>
23# followed by "_" and the name of the respective keyword.
24# These variables will then hold the respective value from the argument list.
25# For the <options> keywords this will be TRUE or FALSE.
26#
27# All remaining arguments are collected in a variable
28# <prefix>_UNPARSED_ARGUMENTS, this can be checked afterwards to see whether
29# your macro was called with unrecognized parameters.
30#
31# As an example here a my_install() macro, which takes similar arguments as the
32# real install() command:
33#
34#   function(MY_INSTALL)
35#     set(options OPTIONAL FAST)
36#     set(oneValueArgs DESTINATION RENAME)
37#     set(multiValueArgs TARGETS CONFIGURATIONS)
38#     cmake_parse_arguments(MY_INSTALL "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN} )
39#     ...
40#
41# Assume my_install() has been called like this:
42#   my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub)
43#
44# After the cmake_parse_arguments() call the macro will have set the following
45# variables:
46#   MY_INSTALL_OPTIONAL = TRUE
47#   MY_INSTALL_FAST = FALSE (this option was not used when calling my_install()
48#   MY_INSTALL_DESTINATION = "bin"
49#   MY_INSTALL_RENAME = "" (was not used)
50#   MY_INSTALL_TARGETS = "foo;bar"
51#   MY_INSTALL_CONFIGURATIONS = "" (was not used)
52#   MY_INSTALL_UNPARSED_ARGUMENTS = "blub" (no value expected after "OPTIONAL"
53#
54# You can the continue and process these variables.
55#
56# Keywords terminate lists of values, e.g. if directly after a one_value_keyword
57# another recognized keyword follows, this is interpreted as the beginning of
58# the new option.
59# E.g. my_install(TARGETS foo DESTINATION OPTIONAL) would result in
60# MY_INSTALL_DESTINATION set to "OPTIONAL", but MY_INSTALL_DESTINATION would
61# be empty and MY_INSTALL_OPTIONAL would be set to TRUE therefor.
62
63#=============================================================================
64# Copyright 2010 Alexander Neundorf <[email protected]>
65#
66# Distributed under the OSI-approved BSD License (the "License");
67# see accompanying file Copyright.txt for details.
68#
69# This software is distributed WITHOUT ANY WARRANTY; without even the
70# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
71# See the License for more information.
72#=============================================================================
73# (To distribute this file outside of CMake, substitute the full
74#  License text for the above reference.)
75
76
77if(__CMAKE_PARSE_ARGUMENTS_INCLUDED)
78  return()
79endif()
80set(__CMAKE_PARSE_ARGUMENTS_INCLUDED TRUE)
81
82
83function(CMAKE_PARSE_ARGUMENTS prefix _optionNames _singleArgNames _multiArgNames)
84  # first set all result variables to empty/FALSE
85  foreach(arg_name ${_singleArgNames} ${_multiArgNames})
86    set(${prefix}_${arg_name})
87  endforeach()
88
89  foreach(option ${_optionNames})
90    set(${prefix}_${option} FALSE)
91  endforeach()
92
93  set(${prefix}_UNPARSED_ARGUMENTS)
94
95  set(insideValues FALSE)
96  set(currentArgName)
97
98  # now iterate over all arguments and fill the result variables
99  foreach(currentArg ${ARGN})
100    list(FIND _optionNames "${currentArg}" optionIndex)  # ... then this marks the end of the arguments belonging to this keyword
101    list(FIND _singleArgNames "${currentArg}" singleArgIndex)  # ... then this marks the end of the arguments belonging to this keyword
102    list(FIND _multiArgNames "${currentArg}" multiArgIndex)  # ... then this marks the end of the arguments belonging to this keyword
103
104    if(${optionIndex} EQUAL -1  AND  ${singleArgIndex} EQUAL -1  AND  ${multiArgIndex} EQUAL -1)
105      if(insideValues)
106        if("${insideValues}" STREQUAL "SINGLE")
107          set(${prefix}_${currentArgName} ${currentArg})
108          set(insideValues FALSE)
109        elseif("${insideValues}" STREQUAL "MULTI")
110          list(APPEND ${prefix}_${currentArgName} ${currentArg})
111        endif()
112      else()
113        list(APPEND ${prefix}_UNPARSED_ARGUMENTS ${currentArg})
114      endif()
115    else()
116      if(NOT ${optionIndex} EQUAL -1)
117        set(${prefix}_${currentArg} TRUE)
118        set(insideValues FALSE)
119      elseif(NOT ${singleArgIndex} EQUAL -1)
120        set(currentArgName ${currentArg})
121        set(${prefix}_${currentArgName})
122        set(insideValues "SINGLE")
123      elseif(NOT ${multiArgIndex} EQUAL -1)
124        set(currentArgName ${currentArg})
125        set(${prefix}_${currentArgName})
126        set(insideValues "MULTI")
127      endif()
128    endif()
129
130  endforeach()
131
132  # propagate the result variables to the caller:
133  foreach(arg_name ${_singleArgNames} ${_multiArgNames} ${_optionNames})
134    set(${prefix}_${arg_name}  ${${prefix}_${arg_name}} PARENT_SCOPE)
135  endforeach()
136  set(${prefix}_UNPARSED_ARGUMENTS ${${prefix}_UNPARSED_ARGUMENTS} PARENT_SCOPE)
137
138endfunction()
139