Re: GNAT exception traceback

[Spam Hater <no.such.user@no.such.com>]

> __builtin_frame_address() does not take variables (I played with it to
> find this out :-).  And, on the Sparc, having the frame address does
> not give you the return address.

Oh.  Well, there you have it (or don't have it).

> > Someone gave me SPARC assembler that allegedly works reliably
> > when linked into a Verdix Ada program.  I am not at liberty to
> > release it, though, unless the originator reads this and says it's OK.
> 
> I assume you mean a SPARC traceback facility :-).  Yes, there is a
> system call you can make under Solaris and SunOS to get this
> information; that is what I would expect it would use.  If on a
> real-time platform, you can lock out interrupts and do the trace
> yourself.  I have code for both of these, but they are both extremely
> slow.

No system call or any other call.  40 lines of assembler, 
consisting of a little setup and a loopof nine instructions.  
The originator also claims it's fast.  I didn't think to ask 
whether it is Verdix specific.

> > With HPUX on PA RISC boxes, some C code I received from yet another
> > kind soul has worked reliably for me when linked into Alsys programs.
> 
> It may be that the Alsys compiler only uses one type of return
> mechanism and it can be traced by reliably.  I worked and worked and
> finally asked HP; they told me (and pointed me to the place in the
> manual with the information) about the difficulty when using their C
> compiler.  GCC seems to do the same thing.

I should have said that I had also tested it in a _few_ C programs.
Perhaps I should try more.
 
> > Pentium with SCO Unix is one I haven't done, but would like to.
> > Note that I am not claiming any expertise, just stating what has
> > worked for me and others and making some wild guesses from that
> > (in hopes that folks like Corey will keep on pointing out the bugs
> > in the idea).
> 
> SCO on Pentium should be easy, just the same as Linux on Pentium, the
> original code you posted will work.

Except that we may not always use gcc.  (Plus they've decided to drop
SCO and go to Windoze NT. Ugh!)

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