[rfa/6.0] Better handle unspecified CFI values

[Andrew Cagney]

> On Fri, Sep 05, 2003 at 08:57:57PM -0400, Andrew Cagney wrote:
> 

>> - delete the SP_REGNUM hack from the REG_UNDEFINED rule (it's no longer 
>> needed, I think)
> 
> 
> Leaving the hack in REG_UNSPECIFIED?  Yes, I'm pretty sure you're
> right.

Yes, leaving the hack in REG_UNSPECIFIED - I know that one's needed :-)

>> - add a check/complaint for the SP v CFA problem.
> 
> 
> Could you hold off on the complaint until there's a valid way to
> specify the SP in the unwind information?  Right now there isn't one,
> as I described on the dwarf2 list three weeks ago.

Arrrrgh.  So "sp" should be specified as the same value as the "cfa" 
register?

> Otherwise this looks good to me.

m'kay

>> @@ -611,7 +646,9 @@
>>  
>>    switch (cache->reg[regnum].how)
>>      {
>> -    case REG_UNSAVED:
>> +    case REG_UNDEFINED:
>> +      /* If CFI explicitly specified that the value isn't defined,
>> +	 mark it as optomized away - the value isn't available.  */
> 
> 
> "optimized"

Oops fixed (contrary to the patch I just posted).

Andrew