On Sun, Jun 23, 2019 at 02:51:06PM +0100, Richard Sandiford wrote:
> What do you think? Is it worth pursuing this further?
Wouldn't it be more useful to just force all automatic variables to be
used at the end of their corresponding scope? That is IMHO the main issue
with -Og debugging, VTA is a best effort, if we can express a variable with
some expression, nice, but if there is no expression nor memory nor register
that holds the value, we are out of luck. Could be some magic stmt like
gimple_clobber or ifn or something similar, which would make sure that at
least until expansion to RTL we force those vars to be live in either a
register or memory.
I'm afraid having different modes, one in which debug stmts can't and one
where they can affect code generation might be a maintainance nightmare.
Jakub
