Re: an interesting idea, but...

[Zack Weinberg <zack@rabi.columbia.edu>]

On Sat, 26 Sep 1998 12:37:01 +1000, Geoff Keating wrote:
>> Date: Wed, 23 Sep 1998 09:00:04 -0400
>> From: Zack Weinberg <zack@rabi.columbia.edu>
>
>> It's worth a try, but I think the main performance penalty is from
>> scanning the -I list over and over again.  Cpplib wouldn't help that
>> much.
>
>Make a directory containing symlinks to all the used header files
>(perhaps only those in sysdep/ directories).  Then only one -I
>directory need be searched.

I've been thinking about this.  It's too much of a change for 2.1 though.

You can't use symlinks, because they aren't available everywhere.
Wrapper headers akin to the ones in include/ would work, but they have
to be generated at build time.  This proves to be nontrivial to do;
the biggest problem is knowing which subdirectories of any given
sysdep dir to look in for headers.  You want to search bits, sys, net,
netinet, etc. but not i386, fpu, bsd4.4, etc.

(Alpha hackers: the directory sysdeps/unix/sysv/linux/alpha/alpha
is the only case that can't be handled by a one-path-element selection
rule.  Is there any chance this dir could go away?)

zw