[m-dev.] add goal path at external ports

[Fergus Henderson]

On 28-Jan-1999, Mark Anthony BROWN <dougl at cs.mu.OZ.AU> wrote:
> Fergus Henderson writes:
> > 
> > On 27-Jan-1999, Mark Anthony BROWN <dougl at cs.mu.OZ.AU> wrote:
> > > Does anybody have any comments on how source linking should
> > > be implemented?
> > 
> > The compiler should generate line numbers in the debug info
> > (specifically, in the MR_Stack_Layout_Entry_Struct).
> 
> Would that give us the line number that a call was made from, or
> will it just give us the line number of the called procedure?

For each event, it would give the current line number at the time of that
event.  For call events, for example, that would be the line number
of the called procedure.

However, the stack tracing code gives you the ability to find
out the MR_Stack_Layout_Entry_Struct for each of your ancestors.
That would give you the line number for the caller.

Current the LLDS optimizer will merge labels without checking if their
line number information is the same; you'd have to modify that code
to make things work properly.  (Simply turning off the LLDS optimizer
would lead to unacceptable inefficiency.)

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "Binaries may die
WWW: <http://www.cs.mu.oz.au/~fjh>  |   but source code lives forever"
PGP: finger fjh at 128.250.37.3        |     -- leaked Microsoft memo.