Re: Putting C++ code into gcc front end

[Geoff Keating <geoffk at geoffk dot org>]

> Cc: Phil Edwards <phil at jaj dot com>, Richard dot Earnshaw at arm dot com,
>    Olivier Galibert <galibert at pobox dot com>, Rupert Wood <me at rupey dot net>,
>    gcc at gcc dot gnu dot org
> From: Gabriel Dos Reis <gdr at integrable-solutions dot net>
> Organization: Integrable Solutions
> Date: 04 Mar 2003 21:54:38 +0100
> X-OriginalArrivalTime: 04 Mar 2003 20:57:15.0666 (UTC) FILETIME=[A2F0E720:01C2E290]
> 
> Geoff Keating <geoffk at geoffk dot org> writes:
> 
> | Phil Edwards <phil at jaj dot com> writes:
> | 
> | > On Tue, Mar 04, 2003 at 09:29:04AM -0800, Zack Weinberg wrote:
> | > > Ignoring Ada for the moment, what if we only built the C front end,
> | > > optimizers, and back end during all three stages of a bootstrap?  And
> | > > then came back to build the other front ends when we were done?
> | > 
> | > I've always been confused why the C++ frontend was rebuilt multiple times
> | > during a bootstrap; actually assumed that it was done for some kind of odd
> | > binutils compatability or hysterical raisins.  Please, if this is possible,
> | > let's do it.  Bootstrap times will go down as a nice side-effect.
> | 
> | It's a test of the C compiler.  It verifies that the un-optimised C
> | compiler generates the same code as the optimised C compiler.
> 
> Such a test is done when bootstrapping the C compiler proper.

This is a different test, because it tests different source code
inputs.

Mind, I wouldn't claim it's a very _useful_ test.  I don't remember
ever seeing a bootstrap miscomparison that only showed up in the C++
frontend.

> The point is: multiple builds of the C++ front-end is a waste of time
> when your interest is in C++ ;-)

Yes.  This test doesn't test the C++ compiler at all.  If you only
care about C++, you don't need to bootstrap.

-- 
- Geoffrey Keating <geoffk at geoffk dot org>