[Python-Dev] -C in Setup files (original) (raw)

Guido van Rossum guido@python.org
Fri, 22 Mar 2002 21:37:53 -0500

Pete Shinners reported that Distutils doesn't treat the -C option in a Setup file the same as the makesetup script. He's right, but I don't think the -C option is useful in makesetup at all!

The relevant bit of code in makesetup is: case $arg in -framework) libs="$libs $arg"; skip=libs; ;; -[IDUCfF]*) cpps="$cpps $arg";; -Xlinker) libs="$libs $arg"; skip=libs;; '-Cfoo' in a Setup file therefore causes -Cfoo to be added to the list of compiler flags, but at least in GCC, that doesn't mean anything; -C indicates that the preprocessor shouldn't strip comments, and it doesn't take an argument. (Anyone know what -C does in other compilers?)

I believe that "don't skip comments" is the traditional meaning. The makesetup script is technically doing the right thing here -- $arg will contain the string "-C" if -C is used correctly, so it will add "-C" to the list of preprocessor options (which are later passed to the C compiler).

If you want to be strict and disallow -Cfoo, you could change it to

                    -[IDUfF]*)      cpps="$cpps $arg";;
                    -C)             cpps="$cpps $arg";;

but I'm not sure I see the point.

Because of this, I think -C in makesetup has been useless since revision 1.1 of makesetup (which is 1994 -- Python 1.0.0), so I doubt anyone has ever used it. Distutils should do something useful with it, and IMHO that would be to make '-C cpparg' add 'cpparg' to the compiler's arguments. Thoughts? Should makesetup be fixed to match?

I agree that there's little use for -C, but I don't think makesetup is incorrect.

I don't understand what you want it to do in Distutils: above, you say that "-C" doesn't take an argument, so why would you want "-C cpparg" to add "cpparg" to the compiler arguments? Is that because you need a way to transparently pass compiler arguments, and the C in -C can stand for compiler???

--Guido van Rossum (home page: http://www.python.org/~guido/)