cmake_parse_arguments()
cmake_parse_arguments
cmake_parse_arguments
is intended to be used in macros or functions for parsing the arguments given to that macro or function. It processes the arguments and defines a set of variables which hold the values of the respective options.
cmake_parse_arguments(<prefix> <options> <one_value_keywords> <multi_value_keywords> args...) cmake_parse_arguments(PARSE_ARGV N <prefix> <options> <one_value_keywords> <multi_value_keywords>)
The first signature reads processes arguments passed in the args...
. This may be used in either a macro()
or a function()
.
The PARSE_ARGV
signature is only for use in a function()
body. In this case the arguments that are parsed come from the ARGV#
variables of the calling function. The parsing starts with the Nth argument, where N
is an unsigned integer. This allows for the values to have special characters like ;
in them.
The <options>
argument contains all options for the respective macro, i.e. keywords which can be used when calling the macro without any value following, like e.g. the OPTIONAL
keyword of the install()
command.
The <one_value_keywords>
argument contains all keywords for this macro which are followed by one value, like e.g. DESTINATION
keyword of the install()
command.
The <multi_value_keywords>
argument contains all keywords for this macro which can be followed by more than one value, like e.g. the TARGETS
or FILES
keywords of the install()
command.
Note
All keywords shall be unique. I.e. every keyword shall only be specified once in either <options>
, <one_value_keywords>
or <multi_value_keywords>
. A warning will be emitted if uniqueness is violated.
When done, cmake_parse_arguments
will have defined for each of the keywords listed in <options>
, <one_value_keywords>
and <multi_value_keywords>
a variable composed of the given <prefix>
followed by "_"
and the name of the respective keyword. These variables will then hold the respective value from the argument list. For the <options>
keywords this will be TRUE
or FALSE
.
All remaining arguments are collected in a variable <prefix>_UNPARSED_ARGUMENTS
, this can be checked afterwards to see whether your macro was called with unrecognized parameters.
As an example here a my_install()
macro, which takes similar arguments as the real install()
command:
function(MY_INSTALL) set(options OPTIONAL FAST) set(oneValueArgs DESTINATION RENAME) set(multiValueArgs TARGETS CONFIGURATIONS) cmake_parse_arguments(MY_INSTALL "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN} ) # ...
Assume my_install()
has been called like this:
my_install(TARGETS foo bar DESTINATION bin OPTIONAL blub)
After the cmake_parse_arguments
call the macro will have set the following variables:
MY_INSTALL_OPTIONAL = TRUE MY_INSTALL_FAST = FALSE (was not used in call to my_install) MY_INSTALL_DESTINATION = "bin" MY_INSTALL_RENAME = "" (was not used) MY_INSTALL_TARGETS = "foo;bar" MY_INSTALL_CONFIGURATIONS = "" (was not used) MY_INSTALL_UNPARSED_ARGUMENTS = "blub" (nothing expected after "OPTIONAL")
You can then continue and process these variables.
Keywords terminate lists of values, e.g. if directly after a one_value_keyword another recognized keyword follows, this is interpreted as the beginning of the new option. E.g. my_install(TARGETS foo DESTINATION OPTIONAL)
would result in MY_INSTALL_DESTINATION
set to "OPTIONAL"
, but as OPTIONAL
is a keyword itself MY_INSTALL_DESTINATION
will be empty and MY_INSTALL_OPTIONAL
will therefore be set to TRUE
.
© 2000–2017 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
https://cmake.org/cmake/help/v3.7/command/cmake_parse_arguments.html