[Bug c++/102454] New: [12 Regression] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[Bug c++/102454] New: [12 Regression] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

            Bug ID: 102454
           Summary: [12 Regression] ICE in gimplify_var_or_parm_decl, at
                    gimplify.c:2958
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

g++-12.0.0-alpha20210919 snapshot (g:32731fa5b0abf092029b8e2be64319b978bda514)
ICEs when compiling the following testcase, reduced from
gcc/testsuite/g++.dg/coroutines/torture/co-yield-04-complex-local-state.C, w/
-fcoroutines -fno-exceptions:

#include <coroutine>
#include <string>

template <typename T>
struct looper {
  struct promise_type {
    auto get_return_object () { return handle_type::from_promise (*this); }
    auto initial_suspend () { return suspend_always_prt {}; }
    auto final_suspend () noexcept { return suspend_always_prt {}; }
    void return_value (T);
    void unhandled_exception ();
  };

  using handle_type = std::coroutine_handle<promise_type>;

  looper (handle_type);

  struct suspend_always_prt {
    bool await_ready () noexcept;
    void await_suspend (handle_type) noexcept;
    void await_resume () noexcept;
  };
};

template <typename T>
looper<T>
with_ctorable_state (T)
{
  co_return T ();
}

auto
foo ()
{
  return with_ctorable_state<std::string>;
}

% g++-12.0.0 -fcoroutines -fno-exceptions -c n7pshqai.C
n7pshqai.C: In function 'looper<T> with_ctorable_state(T) [with T =
std::__cxx11::basic_string<char>]':
n7pshqai.C:27:1: internal compiler error: in gimplify_var_or_parm_decl, at
gimplify.c:2958
   27 | with_ctorable_state (T)
      | ^~~~~~~~~~~~~~~~~~~
0x7984d0 gimplify_var_or_parm_decl
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:2958
0xe96100 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:15029
0xeaefd3 gimplify_modify_expr
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:5960
0xe960ed gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:14568
0xeb0f2b gimplify_cleanup_point_expr
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:7006
0xe964f1 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:14961
0xe999d6 gimplify_stmt(tree_node**, gimple**)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:7006
0xe9746b gimplify_statement_list
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:1997
0xe9746b gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:15013
0xe999d6 gimplify_stmt(tree_node**, gimple**)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:7006
0xe9a28f gimplify_bind_expr
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:1426
0xe967b4 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*),
int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:14769
0xeb04d6 gimplify_stmt(tree_node**, gimple**)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:7006
0xeb04d6 gimplify_body(tree_node*, bool)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:15814
0xeb094d gimplify_function_tree(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/gimplify.c:15968
0xcce107 cgraph_node::analyze()
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/cgraphunit.c:670
0xcd0d57 analyze_functions
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/cgraphunit.c:1234
0xcd1a3d symbol_table::finalize_compilation_unit()
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210919/work/gcc-12-20210919/gcc/cgraphunit.c:2508

[Bug c++/102454] [12 Regression] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0

[Bug c++/102454] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |iains at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-09-27
            Summary|[12 Regression] ICE in      |ICE in
                   |gimplify_var_or_parm_decl,  |gimplify_var_or_parm_decl,
                   |at gimplify.c:2958          |at gimplify.c:2958

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Confirmed. Started with the revision the coroutines were added.

[Bug c++/102454] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

Iain Sandoe <iains at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |iains at gcc dot gnu.org

--- Comment #2 from Iain Sandoe <iains at gcc dot gnu.org> ---
this is caused by an omitted "flag_exceptions" on the update to a frame
variable DTOR, that it "started with the rev coroutines was added" is somewhat
surprising - since the guard vars were only added with r11-7527-gfe55086547c.

patch under test.

[Bug c++/102454] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> ---
https://gcc.gnu.org/pipermail/gcc-patches/2021-September/580328.html

[Bug c++/102454] ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Iain D Sandoe <iains@gcc.gnu.org>:

https://gcc.gnu.org/g:fae627162d5f8cfb273b10349883eeb74baaa43f

commit r12-3932-gfae627162d5f8cfb273b10349883eeb74baaa43f
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Mon Sep 27 20:21:40 2021 +0100

    coroutines: Only set parm copy guard vars if we have exceptions [PR
102454].

    For coroutines, we make copies of the original function arguments into
    the coroutine frame.  Normally, these are destroyed on the proper exit
    from the coroutine when the frame is destroyed.

    However, if an exception is thrown before the first suspend point is
    reached, the cleanup has to happen in the ramp function.  These cleanups
    are guarded such that they are only applied to any param copies actually
    made.

    The ICE is caused by an attempt to set the guard variable when there are
    no exceptions enabled (the guard var is not created in this case).

    Fixed by checking for flag_exceptions in this case too.

    While touching this code paths, also clean up the synthetic names used
    when a function parm is unnamed.

    Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

            PR c++/102454

    gcc/cp/ChangeLog:

            * coroutines.cc (analyze_fn_parms): Clean up synthetic names for
            unnamed function params.
            (morph_fn_to_coro): Do not try to set a guard variable for param
            DTORs in the ramp, unless we have exceptions active.

    gcc/testsuite/ChangeLog:

            * g++.dg/coroutines/pr102454.C: New test.

[Bug c++/102454] coroutines: ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Iain D Sandoe
<iains@gcc.gnu.org>:

https://gcc.gnu.org/g:a1ef1020c424d8f3ca1486ce12408819f4746fd6

commit r11-9063-ga1ef1020c424d8f3ca1486ce12408819f4746fd6
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Mon Sep 27 20:21:40 2021 +0100

    coroutines: Only set parm copy guard vars if we have exceptions [PR
102454].

    For coroutines, we make copies of the original function arguments into
    the coroutine frame.  Normally, these are destroyed on the proper exit
    from the coroutine when the frame is destroyed.

    However, if an exception is thrown before the first suspend point is
    reached, the cleanup has to happen in the ramp function.  These cleanups
    are guarded such that they are only applied to any param copies actually
    made.

    The ICE is caused by an attempt to set the guard variable when there are
    no exceptions enabled (the guard var is not created in this case).

    Fixed by checking for flag_exceptions in this case too.

    While touching this code paths, also clean up the synthetic names used
    when a function parm is unnamed.

    Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

            PR c++/102454

    gcc/cp/ChangeLog:

            * coroutines.cc (analyze_fn_parms): Clean up synthetic names for
            unnamed function params.
            (morph_fn_to_coro): Do not try to set a guard variable for param
            DTORs in the ramp, unless we have exceptions active.

    gcc/testsuite/ChangeLog:

            * g++.dg/coroutines/pr102454.C: New test.

    (cherry picked from commit fae627162d5f8cfb273b10349883eeb74baaa43f)

[Bug c++/102454] coroutines: ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

--- Comment #6 from Arseny Solokha <asolokha at gmx dot com> ---
Should this PR be closed now?

[Bug c++/102454] coroutines: ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> ---
I was leaving it to check if we needed to back port to 10.x as well.

[Bug c++/102454] coroutines: ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|12.0                        |12.2

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 12.1 is being released, retargeting bugs to GCC 12.2.

[Bug c++/102454] coroutines: ICE in gimplify_var_or_parm_decl, at gimplify.c:2958

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102454

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|12.3                        |12.4

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 12.3 is being released, retargeting bugs to GCC 12.4.