Re: [PATCH v2] gdbsupport: add path_join function

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 20 Apr 2022 12:11:20 -0400
> Cc: pedro@palves.net, gdb-patches@sourceware.org, simon.marchi@efficios.com
> From: Simon Marchi <simon.marchi@polymtl.ca>
> 
> >>>   path_join ("d:/foo/bar", "d:quux");
> >>
> >> What does d:quux mean?  Should the "d:" be considered as a drive letter
> >> here or not?
> > 
> > Yes, of course.  It always does in Windows file names.
> 
> Then what does it mean?  How is it different from d:/quux?

It means 'quux' relative to the current directory on drive D:.  On
Windows, a process can have a separate directory on each drive, which
you get to if you type "D:" (or "C:" or "X:") at the cmd prompt.  By
contrast, "d:/quux" means 'quux' relative to the root of drive D:, no
matter what is the current directory there.

> > I just wonder how we will be able to document what this function does
> > and what it doesn't, because it seems like we are stopping halfway
> > between a simple concatenation that just avoids multiple consecutive
> > slashes and a much more heavy-weight functionality.  We need to
> > document our functionality well enough so that people know what to
> > expect and what not to expect when they call this function.
> 
> Since the problem is about absolute paths on the right hand side, maybe
> we can just forbid passing absolute paths except for the first (left
> hand side) operand.  I don't really need that feature for my DWARF
> fixes.

Yes, I think we should limit "tricky" processing to the minimum, then
it will be easier to document the behavior clearly and unequivocally.