[Bug c++/107864] New: Internal Compiler Error (Large Project, C++20)

[Bug c++/107864] New: Internal Compiler Error (Large Project, C++20)

[ian at geometrian dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

            Bug ID: 107864
           Summary: Internal Compiler Error (Large Project, C++20)
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ian at geometrian dot com
  Target Milestone: ---

Created attachment 53962
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53962&action=edit
".zip" file containing "main.cpp", the repro

Using g++ built from source yesterday, getting internal compiler error
(segfault) on a large C++20 project. A preprocessed file (lightly edited and
zipped for file size limit) reproducing the error is attached.

Compiled with:

    g++ main.cpp -std=c++20 -mavx2

The output begins with:

    In file included from
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/../../_stdafx/matr.hpp:7,
                     from
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/../../_stdafx.hpp:254,
                     from
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/tuples.hpp:3,
                     from
/path/to/mycodedistr/include/mycode/grfx/_cpu/framebuffer.hpp:3,
                     from
/path/to/mycodedistr/src/mycode/grfx/_cpu/framebuffer.cpp:1:
   
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/../../_stdafx/_math.hpp:
In instantiation of ‘T BR::Math::round(const T&) requires 
is_floating_point_v<T> [with T = float]’:
    /path/to/mycodedistr/include/mycode/grfx/color/convert.hpp:132:29:  
required from here
   
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/../../_stdafx/_math.hpp:111:23:
internal compiler error: Segmentation fault
    0x7f3e5c1be51f ???
        ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
    0x7f3e5c1a5d8f __libc_start_call_main
        ../sysdeps/nptl/libc_start_call_main.h:58
    0x7f3e5c1a5e3f __libc_start_main_impl
        ../csu/libc-start.c:392
    Please submit a full bug report

"gcc -v" includes:

    Target: x86_64-pc-linux-gnu
    Configured with: ../gcc-src/configure --enable-languages=c,c++
--enable-multiarch --program-suffix=-trunk
    gcc version 13.0.0 20221124 (experimental) (GCC)

[Bug c++/107864] Internal Compiler Error (Large Project, C++20)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
/path/to/mycodedistr/include/mycode/grfx/_cpu/../color/../../_stdafx/_math.hpp:111:23:
internal compiler error: Segmentation fault
0x120e72f crash_signal
        /home/apinski/src/upstream-gcc/gcc/gcc/toplev.cc:314
0xc5c9b2 check_return_expr(tree_node*, bool*)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/typeck.cc:11062
0xc07eee finish_return_stmt(tree_node*)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/semantics.cc:1229
0xbca0db tsubst_expr(tree_node*, tree_node*, int, tree_node*)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:18580
0xbc9931 tsubst_expr(tree_node*, tree_node*, int, tree_node*)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:18932
0xbd4295 tsubst_expr(tree_node*, tree_node*, int, tree_node*)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:18556
0xbd4295 instantiate_body
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26484
0xbd52ba instantiate_decl(tree_node*, bool, bool)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26774
0xbf2b2b instantiate_pending_templates(int)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26852
0xaaa7fb c_parse_final_cleanups()
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/decl2.cc:4940
0xcd38b0 c_common_parse_file()
        /home/apinski/src/upstream-gcc/gcc/gcc/c-family/c-opts.cc:1266
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

Let me try to reduce it.

[Bug c++/107864] Internal Compiler Error (Large Project, C++20)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Hmm, I don't know if I reduced it too much but this might be __bfloat16_t
related ...

[Bug c++/107864] Internal Compiler Error (Large Project, C++20)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> Hmm, I don't know if I reduced it too much but this might be __bfloat16_t
> related ...

It is not, I changed 0.0bf16 to just 0.0f and it fails. still reducing it.

[Bug c++/107864] Internal Compiler Error (Large Project, C++20)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2022-11-24

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced testcase:
template<class T>
T j( T const& val ) requires true
{
  return val;
}
template<> int j( int const& val ) { return 0; }
int t = j(1);

[Bug c++/107864] [10/11/12/13 Regression] ICE (seg fault) in check_return_expr with concepts and specialized version

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |10.1.0, 11.1.0
      Known to work|                            |9.5.0
   Target Milestone|---                         |10.5
            Summary|ICE (seg fault) in          |[10/11/12/13 Regression]
                   |check_return_expr with      |ICE (seg fault) in
                   |concepts and specialized    |check_return_expr with
                   |version                     |concepts and specialized
                   |                            |version

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Works in GCC 9.5.0 with -std=c++2a -fconcepts.

[Bug c++/107864] [10/11/12/13 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[10/11/12/13 Regression]    |[10/11/12/13 Regression]
                   |ICE (seg fault) in          |ICE (seg fault) in
                   |check_return_expr with      |check_return_expr or
                   |concepts and specialized    |instantiate_body with
                   |version                     |concepts and specialized
                   |                            |version

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note without the concept there, GCC does not ICE.

Note changing it slightly (remove the if return type):
template<class T>
void j( T const& val ) requires true {}
template<> void j( int const& val ) { }
void g() {
  j(1);
}
--- CUT ---
Gives a different ICE:
t.cc: In instantiation of ‘void j(const T&) requires  true [with T = int]’:
t.cc:5:4:   required from here
t.cc:2:39: internal compiler error: Segmentation fault
    2 | void j( T const& val ) requires true {}
      |                                       ^
0x120e72f crash_signal
        /home/apinski/src/upstream-gcc/gcc/gcc/toplev.cc:314
0xbd42d1 instantiate_body
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26494
0xbd52ba instantiate_decl(tree_node*, bool, bool)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26774
0xbf2b2b instantiate_pending_templates(int)
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/pt.cc:26852
0xaaa7fb c_parse_final_cleanups()
        /home/apinski/src/upstream-gcc/gcc/gcc/cp/decl2.cc:4940
0xcd38b0 c_common_parse_file()
        /home/apinski/src/upstream-gcc/gcc/gcc/c-family/c-opts.cc:1266
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug c++/107864] [10/11/12/13 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

Jonathan Wakely <redi at gcc dot gnu.org> changed:

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

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Regression started with r10-3735-gcb57504a550158 "Update the concepts
implementation to conform to C++20."

[Bug c++/107864] [10/11/12/13 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
             Status|NEW                         |ASSIGNED
                 CC|                            |ppalka at gcc dot gnu.org

[Bug c++/107864] [10/11/12/13 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:36cabc257dfb7dd4f7625896891f6c5b195a0241

commit r13-4390-g36cabc257dfb7dd4f7625896891f6c5b195a0241
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Nov 29 09:55:21 2022 -0500

    c++: explicit specialization and trailing requirements [PR107864]

    Here we're crashing when using the explicit specialization of the
    function template g with trailing requirements ultimately because
    earlier decls_match (called indirectly from register_specialization) for
    for the explicit specialization returned false since the template has
    trailing requirements whereas the specialization doesn't.

    In r12-2230-gddd25bd1a7c8f4, we fixed a similar issue concerning template
    requirements instead of trailing requirements.  We could extend that fix
    to ignore trailing requirement mismatches for explicit specializations
    as well, but it seems cleaner to just propagate constraints from the
    specialized template to the specialization when declaring an explicit
    specialization so that decls_match will naturally return true in this
    case.  And it looks like determine_specialization already does this,
    albeit inconsistently (only when specializing a non-template member
    function of a class template as in cpp2a/concepts-explicit-spec4.C).

    So this patch makes determine_specialization consistently propagate
    constraints from the specialized template to the specialization, which
    in turn lets us get rid of the function_requirements_equivalent_p special
    case added by r12-2230.

            PR c++/107864

    gcc/cp/ChangeLog:

            * decl.cc (function_requirements_equivalent_p): Don't check
            DECL_TEMPLATE_SPECIALIZATION.
            * pt.cc (determine_specialization): Propagate constraints when
            specializing a function template too.  Simplify by using
            add_outermost_template_args.

    gcc/testsuite/ChangeLog:

            * g++.dg/concepts/explicit-spec1a.C: New test.

[Bug c++/107864] [10/11/12 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[10/11/12/13 Regression]    |[10/11/12 Regression] ICE
                   |ICE (seg fault) in          |(seg fault) in
                   |check_return_expr or        |check_return_expr or
                   |instantiate_body with       |instantiate_body with
                   |concepts and specialized    |concepts and specialized
                   |version                     |version

--- Comment #9 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed on trunk so far.

[Bug c++/107864] [10/11/12 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:18bd59990196462cde8011458e2518118b1b6681

commit r12-9228-g18bd59990196462cde8011458e2518118b1b6681
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Nov 29 09:55:21 2022 -0500

    c++: explicit specialization and trailing requirements [PR107864]

    Here we're crashing when using the explicit specialization of the
    function template g with trailing requirements ultimately because
    earlier decls_match (called indirectly from register_specialization) for
    for the explicit specialization returned false since the template has
    trailing requirements whereas the specialization doesn't.

    In r12-2230-gddd25bd1a7c8f4, we fixed a similar issue concerning template
    requirements instead of trailing requirements.  We could extend that fix
    to ignore trailing requirement mismatches for explicit specializations
    as well, but it seems cleaner to just propagate constraints from the
    specialized template to the specialization when declaring an explicit
    specialization so that decls_match will naturally return true in this
    case.  And it looks like determine_specialization already does this,
    albeit inconsistently (only when specializing a non-template member
    function of a class template as in cpp2a/concepts-explicit-spec4.C).

    So this patch makes determine_specialization consistently propagate
    constraints from the specialized template to the specialization, which
    in turn lets us get rid of the function_requirements_equivalent_p special
    case added by r12-2230.

            PR c++/107864

    gcc/cp/ChangeLog:

            * decl.cc (function_requirements_equivalent_p): Don't check
            DECL_TEMPLATE_SPECIALIZATION.
            * pt.cc (determine_specialization): Propagate constraints when
            specializing a function template too.  Simplify by using
            add_outermost_template_args.

    gcc/testsuite/ChangeLog:

            * g++.dg/concepts/explicit-spec1a.C: New test.

    (cherry picked from commit 36cabc257dfb7dd4f7625896891f6c5b195a0241)

[Bug c++/107864] [10/11 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

--- Comment #11 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:17e3edd6a25e47eed56678f25f6f8ab29b0ac5fc

commit r11-10803-g17e3edd6a25e47eed56678f25f6f8ab29b0ac5fc
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Nov 29 09:55:21 2022 -0500

    c++: explicit specialization and trailing requirements [PR107864]

    Here we're crashing when using the explicit specialization of the
    function template g with trailing requirements ultimately because
    earlier decls_match (called indirectly from register_specialization) for
    for the explicit specialization returned false since the template has
    trailing requirements whereas the specialization doesn't.

    In r12-2230-gddd25bd1a7c8f4, we fixed a similar issue concerning template
    requirements instead of trailing requirements.  We could extend that fix
    to ignore trailing requirement mismatches for explicit specializations
    as well, but it seems cleaner to just propagate constraints from the
    specialized template to the specialization when declaring an explicit
    specialization so that decls_match will naturally return true in this
    case.  And it looks like determine_specialization already does this,
    albeit inconsistently (only when specializing a non-template member
    function of a class template as in cpp2a/concepts-explicit-spec4.C).

    So this patch makes determine_specialization consistently propagate
    constraints from the specialized template to the specialization, which
    in turn lets us get rid of the function_requirements_equivalent_p special
    case added by r12-2230.

            PR c++/107864

    gcc/cp/ChangeLog:

            * decl.c (function_requirements_equivalent_p): Don't check
            DECL_TEMPLATE_SPECIALIZATION.
            * pt.c (determine_specialization): Propagate constraints when
            specializing a function template too.  Simplify by using
            add_outermost_template_args.

    gcc/testsuite/ChangeLog:

            * g++.dg/concepts/explicit-spec1a.C: New test.

    (cherry picked from commit 36cabc257dfb7dd4f7625896891f6c5b195a0241)

[Bug c++/107864] [10 Regression] ICE (seg fault) in check_return_expr or instantiate_body with concepts and specialized version

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107864

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|10.5                        |11.4
             Status|ASSIGNED                    |RESOLVED
      Known to work|                            |11.4.0, 12.3.0, 13.1.0
      Known to fail|                            |10.5.0, 11.3.0

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.