[Bug tree-optimization/91355] [8/9/10/11 Regression] optimized code does not call destructor while unwinding after exception

[Bug tree-optimization/91355] [8/9/10/11 Regression] optimized code does not call destructor while unwinding after exception

[bill.torpey at ullink dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

Bill Torpey <bill.torpey at ullink dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bill.torpey at ullink dot com

--- Comment #12 from Bill Torpey <bill.torpey at ullink dot com> ---
According to this link (https://linux.oracle.com/errata/ELBA-2020-1683.html) it
appears that this bug was fixed in gcc 9.2.1-2 (?), but I'm curious if this
applies only to Oracle Linux, or whether this bug has been fixed anywhere in
mainline gcc.  

We're experiencing runtime issues with gcc 8 that *may* be related to this bug.
 The issues do not occur with gcc 6, but we'd like to know if the bug has been
fixed in *any* releases of gcc.

TIA for any information you can provide.

[Bug tree-optimization/91355] [9/10/11/12 Regression] optimized code does not call destructor while unwinding after exception

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug tree-optimization/91355] [9/10/11/12 Regression] optimized code does not call destructor while unwinding after exception

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #14 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug tree-optimization/91355] [10/11/12/13 Regression] optimized code does not call destructor while unwinding after exception

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #15 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug tree-optimization/91355] [10/11/12/13 Regression] optimized code does not call destructor while unwinding after exception

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug tree-optimization/91355] [10/11/12/13 Regression] optimized code does not call destructor while unwinding after exception

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |matz at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
   Last reconfirmed|2019-08-05 00:00:00         |2023-4-13

--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> ---
Re-confirmed.

The implicit IL contract with the following is incredibly fragile:

<bb 5> [count: 0]:
<L2>:
d.1_16 = d;
_17 = d.1_16 + 4294967295;
d = _17;
resx 4   // EDGE_EH fallthru

<bb 6> [count: 0]:
<L3>:
_20 = __builtin_eh_filter (1);

if we don't support any stmts inbetween the RESX and the landing pad then
we should prohibit splitting the edge.

I think the issue is that splitting the EH edge creates a new landing pad
(OK), but when we sink stmts into that empty block there's a fallthru
from that landing pad to another landing pad.  When ehcleanup then
elides the just RESX 4 containing forwarder via cleanup_empty_eh_merge_phis
that confuses it and the EH tree gets corrupt.

Into GIMPLE sink we get

Eh tree:
   1 allowed_exceptions land:{1,<L3>},{3,} filter :-1 types:int
     4 cleanup land:{2,<L2>}

which splitting two EH edges via split_edges_for_insertion turns into

Eh tree:
   1 allowed_exceptions land:{4,<L6>},{1,<L7>},{3,} filter :-1 types:int
     4 cleanup land:{2,<L2>}

remove_unreachable_handlers does

Eh tree:
   1 allowed_exceptions land:{4,<L6>},{1,<L7>} filter :-1 types:int
     4 cleanup land:{2,<L2>}

and cleanup_empty_eh

Eh tree:
   1 allowed_exceptions land:{4,<L3>},{1,<L7>} filter :-1 types:int
     4 cleanup

[Bug tree-optimization/91355] [11/12/13/14 Regression] optimized code does not call destructor while unwinding after exception

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91355

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.5

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.