[Bug middle-end/112087] gimple front end: Simple testcase with array fails to round trip

["rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112087

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-10-27
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
"Round-tripping" in the sense of

gcc -fdump-tree-X-gimple=- t.c -S | gcc -x c -fgimple -

was never the intention.

Yes, parsing of CLOBBERs isn't implemented, nor is parsing of
"gimple_has_volatile_ops", but since that's redundant info recomputed
at update_stmt time we can just scrap it at dump time (but then it's
a bit odd to not see it with -gimple ..).

It would be nice to have bugreports more specific that "cannot round-trip A or
B".

Two bugs for this.

Parsing of ={v}

Parsing of {CLOBBER} (and variants)

parsing of ={v} is a bit difficult since it would need to be tentative
(there's always a reason why seemingly "easy" things are not yet done).
Finding a better syntax for dumping the flags on a stmt might help.


Workaround for both: use -fstack-reuse=none