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From: jl%dac.triumf.cdn%ubc.CSNET@CSNET-RELAY.ARPA (John Lloyd)
Newsgroups: mod.computers.vax
Subject: Getting tracebacks without signalling
Message-ID: <41:jl@dac.triumf.cdn>
Date: Sun, 2-Feb-86 20:25:23 EST
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Posted: Sun Feb  2 20:25:23 1986
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Does anyone know how to do this?  We want to get a traceback at any place
in a program without having to signal anything (otherwise, of course,
you just signal a Success value to get the traceback on SYS$ERROR).  The
problem is that within a condition handler in which you want to call
SYS$UNWIND, there is no obvious way to get the traceback information
as well as unwind the stack.  Hence, in recovering (i.e. unwinding) you
lose the information about what went wrong and the important stuff 
like where it went wrong.  Any ideas?