[Bug middle-end/106421] New: ICE with computed goto from a nested functon

[Bug middle-end/106421] New: ICE with computed goto from a nested functon

[amonakov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

            Bug ID: 106421
           Summary: ICE with computed goto from a nested functon
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: amonakov at gcc dot gnu.org
  Target Milestone: ---

int main(int argc, char **argv)
{
        __label__ loop, end;
        void jmp(int c) { goto *(c ? &&loop : &&end); }
loop:
        jmp(argc < 0);
end:{}
}


makes gcc -O2 segfault in find_edge during RTL cprop.

The documentation might want to specify that goto from a nested function to a
containing function cannot be a 'computed goto' (must refer to the target label
directly by name).

[Bug middle-end/106421] ICE with computed goto from a nested functon

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
> The documentation might want to specify that goto from a nested function

It already does.
from
https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gcc/Labels-as-Values.html#Labels-as-Values
:
"You may not use this mechanism to jump to code in a different function."

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It is undefined but still valid.

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

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

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-07-25
                 CC|                            |marxin at gcc dot gnu.org
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu.org

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I think bypass_block has to be just resilent tho this case, guarding against
dest == NULL

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug rtl-optimization/106421] [10/11/12/13 Regression] ICE with computed goto from a nested functon

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Roger Sayle <sayle@gcc.gnu.org>:

https://gcc.gnu.org/g:851e1ba03f9de699a754dd8648fc151c3e26d697

commit r13-5091-g851e1ba03f9de699a754dd8648fc151c3e26d697
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Tue Jan 10 14:05:46 2023 +0000

    PR rtl-optimization/106421: ICE in bypass_block from non-local goto.

    This patch fixes PR rtl-optimization/106421, an ICE-on-valid (but
    undefined) regression.  The fix, as proposed by Richard Biener, is to
    defend against BLOCK_FOR_INSN returning NULL in cprop's bypass_block.

    2023-01-10  Roger Sayle  <roger@nextmovesoftware.com>

    gcc/ChangeLog
            PR rtl-optimization/106421
            * cprop.cc (bypass_block): Check that DEST is local to this
            function (non-NULL) before calling find_edge.

    gcc/testsuite/ChangeLog
            PR rtl-optimization/106421
            * gcc.dg/pr106421.c: New test case.

[Bug rtl-optimization/106421] [10/11/12 Regression] ICE with computed goto from a nested functon

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:0a5fb0ee337b824224a2c13b76fd682b62e6d314

commit r12-9480-g0a5fb0ee337b824224a2c13b76fd682b62e6d314
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Tue Jan 10 14:05:46 2023 +0000

    PR rtl-optimization/106421: ICE in bypass_block from non-local goto.

    This patch fixes PR rtl-optimization/106421, an ICE-on-valid (but
    undefined) regression.  The fix, as proposed by Richard Biener, is to
    defend against BLOCK_FOR_INSN returning NULL in cprop's bypass_block.

    2023-01-10  Roger Sayle  <roger@nextmovesoftware.com>

    gcc/ChangeLog
            PR rtl-optimization/106421
            * cprop.cc (bypass_block): Check that DEST is local to this
            function (non-NULL) before calling find_edge.

    gcc/testsuite/ChangeLog
            PR rtl-optimization/106421
            * gcc.dg/pr106421.c: New test case.

    (cherry picked from commit 851e1ba03f9de699a754dd8648fc151c3e26d697)

[Bug rtl-optimization/106421] [11 Regression] ICE with computed goto from a nested functon

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106421

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

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

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10 branch is being closed.