From mboxrd@z Thu Jan  1 00:00:00 1970
To: 9fans@cse.psu.edu
From: "Thomas Bushnell, BSG" <tb+usenet@becket.net>
Message-ID: <87ofi9h7zp.fsf@becket.becket.net>
Content-Type: text/plain; charset=us-ascii
References: <65cb447dbaf5f9da39d670e4f0596c79@plan9.bell-labs.com>
Subject: Re: [9fans] GUI toolkit for Plan 9
Date: Thu, 28 Feb 2002 16:55:28 +0000
Topicbox-Message-UUID: 5c1e5a76-eaca-11e9-9e20-41e7f4b1d025

presotto@plan9.bell-labs.com writes:

> I heard a rumor yesterday that I'ld like dispelled if
> possible.  It was that the Linux kernel had to be compiled
> with optimization turned on to work.  

That has been true for some versions; it's a programmer bug.

Specifically, there are certain kinds of inlining that happen only
when optimizing, and Linux required those to occur.  For example, in
GCC, if you define a function like:

extern inline foo (...) {...}

Then you get a function which will be inlined (but generally only if
optimization is turned on); if it's not inlined, then no code is
output at all for the function.  (You are supposed to link with a
regular static version too.)  Such "extern inline" declarations are
normally put in header files.

Linux had problems like these, where it was using such inlines, but
didn't provide the static version.  So when optimization is turned
off, the inline doesn't happen, and you get an unresolvable external
reference.

There may have been other problems too.  These are all in the category
of programmer errors.

Thomas