[RFC PATCH] ARM: Use generic BUG() handler
Russell King - ARM Linux
linux at arm.linux.org.uk
Tue Mar 1 05:03:06 EST 2011
On Tue, Mar 01, 2011 at 10:12:40AM +0100, Mikael Pettersson wrote:
> Russell King - ARM Linux writes:
> > On Tue, Mar 01, 2011 at 08:49:49AM +0000, Russell King - ARM Linux wrote:
> > > On Mon, Feb 28, 2011 at 04:27:43PM -0800, Simon Glass wrote:
> > > > + asm volatile("1:\t.word %c3\n" \
> > > > + ".pushsection __bug_table,\"a\"\n" \
> > > > + "2:\t.word 1b, %c0\n" \
> > > > + "\t.hword %c1, 0\n" \
> > > > + "\t.org 2b+%c2\n" \
> > >
> > > %c doesn't work on lots of versions of gcc, which is why we can't use
> > > the generic bug support. There's no way to reliably generate constants
> > > without many compiler versions spitting out a '#' before them.
> > gcc 4.3.2:
> > asm(".word %c0" : : "i" (0));
> > produces:
> > .word #0
> > which gas chokes on:
> > /tmp/cc2hGOHd.s:12: Error: bad expression
> > /tmp/cc2hGOHd.s:12: Error: junk at end of line, first unrecognized character is `0'
> > So what this means is that it's impossible to generate constants in
> > assembly with GCC targetting ARM without having them prefixed by '#',
> > which in turn makes it impossible to use the generic BUG support.
> > I reported this bug to gcc folk many years ago. I've no idea which
> > version it has been fixed in or if it's even been fixed.
> What's the gcc bugzilla bug number?
No idea off hand - I'll have to search for that.
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