[OLPC-devel] Re: linker garbage collection

[Marcelo Tosatti]

On Thu, Aug 31, 2006 at 02:48:47PM -0700, David Woodhouse wrote:
> On Thu, 2006-08-31 at 14:05 -0300, Marcelo Tosatti wrote:
> > On Thu, Aug 31, 2006 at 08:22:57AM -0700, David Woodhouse wrote:
> > > On Tue, 2006-08-29 at 23:54 -0300, Marcelo Tosatti wrote:
> > > > * Condition CONFIG_GC_SECTIONS on presence of a recent binutils  
> > > 
> > > Er, I missed something -- why does this need a recent binutils? We've
> > > been building kernels with --gc-sections for years, at least on some
> > > platforms.
> > 
> > First, I think its prudent to guarantee that a well behaved version of
> > binutils (wrt. garbage collection) is being used. No?
> 
> Are recent versions of binutils known to misbehave? It's not as if
> --gc-sections is a new thing.

Not that I know, just being (overly) safe.

> > Second reason is the newly added --print-gc-sections option, which:
> 
> ... needs to be a CONFIG option anyway so _that_ CONFIG option can
> require the new binutils.

Agreed.

> > 2) Its very useful for developers to
> > 
> > - Debug breakage caused by gc-section misbehaviour.
> > - Easily check what symbols are being swept.
> 
> Some people will care -- many won't, but might want to build with
> --gc-sections anyway. No reason not to let them do so, surely? Just
> require new binutils if you want the --print-gc-sections stuff.

Agreed.