[Bug c++/105098] New: ICE: endless recursion during auto deduction

[Bug c++/105098] New: ICE: endless recursion during auto deduction

[a3at.mail at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

            Bug ID: 105098
           Summary: ICE: endless recursion during auto deduction
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: a3at.mail at gmail dot com
  Target Milestone: ---

Created attachment 52711
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52711&action=edit
original cpp code

While switching to libcxx from llvm-14 (actually llvm-13 fails too), using
tuple w/o explicitly passing types leads to ICE with gcc-11.2 (gcc-12 works
fine).

Note, that you can reproduce this with simple usage of tuple from libcxx 13+,
i.e.:

    # /usr/include/c++/v1 - path to libcxx
    g++ -std=gnu++20 -c -o /dev/null -isystem /usr/include/c++/v1 -nostdinc++
libcxx-tuple.cpp

[Bug c++/105098] ICE: endless recursion during auto deduction

[a3at.mail at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

--- Comment #1 from Azat <a3at.mail at gmail dot com> ---
Created attachment 52712
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52712&action=edit
reduced

Here is reduced file, that had been created with the following test for
creduce:

    #!/usr/bin/env bash

    # NOTE: due to [1], you need to set CWD to the directory where you have
libcxx-tuple.ii
    # 
    #   [1]: https://github.com/csmith-project/creduce/issues/195

    # NOTE: that we need only first line to avoid some syntax errors and
similar things
    g++ -std=gnu++20 -c -o /dev/null -nostdinc++ libcxx-tuple.ii |& head -1 |
fgrep 'internal compiler error: Segmentation fault signal terminated program
cc1plus'

[Bug c++/105098] ICE: endless recursion during auto deduction

[a3at.mail at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

--- Comment #2 from Azat <a3at.mail at gmail dot com> ---
Created attachment 52713
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52713&action=edit
original file generated with -save-temps

And here is the original pre-processed temporary file.

[Bug c++/105098] ICE: endless recursion during auto deduction

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Seems to be fixed on trunk by r12-3906-g51018dd1395c72.

[Bug c++/105098] ICE: endless recursion during auto deduction

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
dup.

*** This bug has been marked as a duplicate of bug 102479 ***

[Bug c++/105098] ICE: endless recursion during auto deduction

[a3at.mail at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105098

--- Comment #5 from Azat <a3at.mail at gmail dot com> ---
>Seems to be fixed on trunk by r12-3906-g51018dd1395c72.

Indeed, thanks!

Will it be backported to gcc-11?