[CMake] When is escaping of space characters in parameters really needed?

[SF Markus Elfring]

Hello,

I would like to construct a custom command for the tool "Latexmk".
http://www.cmake.org/cmake/help/v3.2/command/add_custom_command.html

The corresponding Perl script can handle a parameter like "pdflatex".

If I omit the parameter "VERBATIM", the current CMake software
will add backslashes before space characters.

Example:
… -pdf -pdflatex='/usr/bin/pdflatex\ -halt-on-error\ --shell-escape\ %O\ %S' …


Can such "an adjustment" of the really desired string value
be avoided anyhow?
Should the value work also without the shown escaping?

Regards,
Markus