How do I correctly pass CMake list (semicolon-sep) of flags to set_target_properties?

Question

CMake lists are essentially just semicolon-separated strings, but if you pass such a variable to a command, it does get expanded into multiple arguments - for example,

set(FLAGS f1 f2 f3) # now FLAGS == 'f1;f2;f3' add_custom_command(   ...   COMMAND my_cmd ${FLAGS}   ... ) 

will correctly call my_cmd f1 f2 f3.

Now if I do this with

set_target_properties(   myTarget PROPERTIES   LINK_FLAGS  "${LD_FLAGS}" ) 

the expansion does not occur, and I end up with a single LD_FLAG that contains semicolons -- useless, instead of expanding it into a space-separated string.

Is there any way to make it so that when I pass a list to the LINK_FLAGS property (or any property that is), it gets expanded into multiple arguments rather than just one?

Thanks, Dan

Answer 1

I don't think set_target_properties can do the expansion automatically, but you can use string (REPLACE ...) to expand a list into a space separated string:

string (REPLACE ";" " " LD_FLAGS_STR "${LD_FLAGS}") set_target_properties(   myTarget PROPERTIES   LINK_FLAGS  "${LD_FLAGS_STR}" ) 

Answer 2

For using a cmake List as list, use

${LD_FLAG} 

For using a cmake list as string, (i.e. list items are separated with ';'), use

"${LD_FLAG}" 

So in your case, just remove "" should be sufficient.