Re: RFC: setjmp/longjmp (and friends) for a new port

[Matt Thomas <matt%3am-software.com@localhost>]

On Sep 1, 2009, at 1:11 PM, Christos Zoulas wrote:

> In article <20090901130545.GC3447%britannica.bec.de@localhost>,
> Joerg Sonnenberger  <joerg%britannica.bec.de@localhost> wrote:
> > On Tue, Sep 01, 2009 at 02:53:36PM +0200, Joerg Sonnenberger wrote:
> > > On Tue, Sep 01, 2009 at 12:54:14AM -0700, Matt Thomas wrote:
> > > > So I'm thinking that in MIPS64, setjmp/longjmp can just be  
> > > > versions of
> > > > getcontext/setcontext.
> > > > longjmp need to be able to set the return value, but that's a minor
> > > > variation.
> > > >
> > > > Can anyone think of valid reasons not do that?
> > >
> > > getcontext/setcontext modify the signal mask, setjmp/longjmp don't.
> >
> > OK, let me partially take that back. setjmp/longjmp may restore the
> > signal mask, SUS leaves that as undefined behavior. As such it is  
> > valid
> > to use getcontext/setcontext for that. Depending on the ABI  
> > patching the
> > output of getcontext should be good enough for longjmp, e.g. set  
> > the IP
> > to a ret and the return value register to the expected data.
>
> Well, you could clear the uc_flags for signal mask and fpu before  
> calling
> setcontext to implement this, no?

Exactly what I thinking.  (well, not FP).