Re: RFC: case insensitive for #include

[David Daney <ddaney at caviumnetworks dot com>]

H.J. Lu wrote:
> On Wed, Jan 28, 2009 at 12:21 PM, Chris Lattner <clattner@apple.com> wrote:
> > On Jan 28, 2009, at 11:51 AM, H.J. Lu wrote:
> >
> > > Hi,
> > >
> > > I got a request to try "FOO.H" if foo.h doesn't exist when dealing
> > > with
> > >
> > > #include "foo.h"
> > >
> > > Any comments?
> > I strongly recommend against this, unless this is only a "last chance" fall
> > back.
> >
> > From a performance standpoint, if you have -Idir1 -Idir2 -Idir3, you don't
> > want to stat all variants of "foo.h" in dir1 before moving on to dir2.  If
> > you do a full search for foo.h in all appropriate search paths, and then
> > redo it only on failure, then the performance issue goes away.  However, in
> > that  case you get very difficult to explain behavior if you have multiple
> > files with spelling variants of foo.h in different search paths.
>
> I won't stat all variants of "foo.h". I think scandir will work here and
> this feature will be supported only if scandir is available.

And would you preemptivly scan all include directories and flatten all 
names found, or would you only do it on failure to find the name as 
written (i.e. could you address Chris' question)?

David Daney