Re: [RFA] Dependency output with -MMD/-MD and -o

["Zack Weinberg" <zackw at Stanford dot EDU>]

On Tue, Jan 09, 2001 at 02:29:39PM +0000, Neil Booth wrote:
> 
> Zack, do you want to give a rationale for your extra dependencies
> proposal in projects/cpplib.html?  Does it require an extra switch?
> If you give full details, and it's simple to do, I'll squeeze it in.

Are you talking about

#    I would also like to see a mode in which GCC suppresses system
#    headers from the dependency list based on where they're found,
#    not what sort of quotation marks were used when they were
#    included (as -MM currently does)

Last I looked, -MM excluded files included with <>, but would happily
stick in /usr/include/stdio.h if it were included with "".  What I
want is a mode where system headers never get listed and user headers
always do - using the existing definition of "system headers":
-isystem directory, or built in.  The idea is that you aren't going to
be changing /usr/include/stdio.h, and if you do it probably doesn't
affect the meaning of your program.  But if I include <splay-tree.h>
from libiberty with <>, I definitely do want it listed in the .d file.

I don't know off the top of my head how hard this is.  To avoid
breaking things, it does need a new switch (-MU?)

zw