On Nov 14, 2005, at 7:31 AM, Jonathan Worthington wrote:
"Will Coleda" <[EMAIL PROTECTED]> wrote:
Storing the information is very good: how do we extract it, again?
we have {get,set}{file,line} opcodes, but if we're going to store
more generic information, we need a more generic way to extract it.
My current thinking on this is that a HLL will define a sub that
knows how to print errors for that HLL. That sub would be passed
an array PMC, with element 0 representing the current sub, element
1 representing it's caller, etc, so you can produce a backtrace.
Each entry in the array would be a hash containing the HLL debug
info. So a very simple handler could maybe look like:-
.sub err_handler
.param pmc bt
.local pmc entry
.local int i, elems
elems = elements bt
i = 0
LOOP:
if i >= elems goto END
entry = bt[i]
print "Error at line "
print entry["line"]
print " column "
print entry["column"]
print " of file "
print entry["file"]
print "\n"
inc i
goto LOOP
END:
.end
But there is also an issue relating to what if some of the BT is
from another HLL's code, so it may not be able to be quite as
simple as I suggest there. Also, the exception that was thrown
should probably be a parameter to that sub too.
I would imagine that whatever .HLL is in effect wins.
As one of the first "here's something extra I need", I need not
only line numbers for files, but line numbers of user defined
subroutines and eval blocks. (that is, the line *of the sub def*
that the error occurs on, in addition to each line as we go.)
Unless I'm missing something, that's fine with what I proposed; you
can emit a ".hll_debug line 42" or similar without having to
specify a filename. The line number means whatever you'd like it
to mean - it doesn't have to be line number in a file.
Right, the hard bit here was that I needed to specify something other
than "file". Just agreeing that we need something other than just
"file/line".
user generated error
while executing
"error "user generated error""
Am I right in thinking that:
error "user generated error"
Comes from the source text of the tcl program?
Yes. [error "user generated error"]
