[CMake] Quick Question: add_custom_target( xxx ) add_custom_command( TARGET xxx ... )

[Matthew Woehlke]

On 2014-03-10 02:55, J Decker wrote:
> add_custom_target( xxx )
> add_custom_command( TARGET xxx
>     (PREBUILD? POSTBUILD? PRELINK?)
> COMMAND blah )

This doesn't make sense; a custom target doesn't have build/link/etc. steps.

The usual way to do this is:

add_custom_command(OUTPUT x.y ...)
add_custom_target(xxx DEPENDS x.y ...)

...which anyway more correctly expresses the individual file 
dependencies, e.g. foo -> foo.in, bar -> bar.in, etc.... so if only 
foo.in changes, only the step for foo needs to execute.

> EXECUTE( cmake copy_if_different )

Just so you know, this is much better done via configure_file :-). (Of 
course that won't be available when you switch to using custom commands, 
but...)

-- 
Matthew