Re: Building world with clang

From: Daniel Nebdal <dnebdal_at_gmail.com>
Date: Tue, 17 Aug 2010 16:28:59 +0200
On Tue, Aug 17, 2010 at 3:47 PM, Dimitry Andric <dimitry_at_andric.com> wrote:
> On 2010-08-17 15:03, Daniel Nebdal wrote:
>>>> However, a disadvantage is that the built-in search paths of the
>>>> bootstrap compiler are not entirely disabled by using the -isysroot, -B
>>>> and -L flags,
> ...
>> For clarification, did you (Dimitry, that is) mean
>> a) The paths are still there so they could resurface if some Makefile
>> doesn't specify those flags , or
>> b) they sometimes come into play even when using the appropriate flags?
>
> Any sub-makefiles would not have to specify those flags explicitly,
> since they were added to ${CC} and ${CXX}.
>
> But what I meant is that even if you specify those flags, the compiler
> still searches for headers and libraries in the base system.  So if some
> header is removed from /usr/src, for example, but is still available in
> /usr/include, it can be erroneously picked up during buildworld.
>

Mmh, I just read through the in-detail description you gave in another
mail. It's a bit surprising that there isn't a simple and reliable way
to disable/replace all hardcoded paths, but I guess it doesn't come up
that often.

As a third possibility, hacking a real -drop-all-builtin-paths flag
into the local copies of both compilers could work (essentially being
a cleanup of your alternative 1), though there's still the issues with
-B. All in all, I agree that your alternative 2 sounds better.


-- 
Daniel Nebdal
Received on Tue Aug 17 2010 - 12:29:01 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:06 UTC