function¶
Start recording a function for later invocation as a command:
function(<name> [arg1 [arg2 [arg3 ...]]])
COMMAND1(ARGS ...)
COMMAND2(ARGS ...)
...
endfunction(<name>)
Define a function named <name> that takes arguments named arg1,
arg2, arg3, (…).
Commands listed after function, but before the matching
endfunction(), are not invoked until the function is invoked.
When it is invoked, the commands recorded in the function are first
modified by replacing formal parameters (${arg1}) with the arguments
passed, and then invoked as normal commands.
In addition to referencing the formal parameters you can reference the
ARGC variable which will be set to the number of arguments passed
into the function as well as ARGV0, ARGV1, ARGV2, … which
will have the actual values of the arguments passed in.
This facilitates creating functions with optional arguments.
Additionally ARGV holds the list of all arguments given to the
function and ARGN holds the list of arguments past the last expected
argument.
Referencing to ARGV# arguments beyond ARGC have undefined
behavior. Checking that ARGC is greater than # is the only way
to ensure that ARGV# was passed to the function as an extra
argument.
A function opens a new scope: see set(var PARENT_SCOPE) for
details.
See the cmake_policy() command documentation for the behavior
of policies inside functions.