[Bug c++/99008] New: [11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[Bug c++/99008] New: [11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

            Bug ID: 99008
           Summary: [11 Regression] ICE in set_constraints, at
                    cp/constraint.cc:1256
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Changed between 20200621 and 20200628 :
(maybe related to pr93297)


$ cat z1.cc
template <class> struct A;
template <class, class B> using C = A<B>;
void *f { C(); }


$ g++-11-20210207 -c z1.cc
z1.cc:3:13: internal compiler error: in set_constraints, at
cp/constraint.cc:1256
    3 | void *f { C(); }
      |             ^
0x6a757e set_constraints(tree_node*, tree_node*)
        ../../gcc/cp/constraint.cc:1256
0x7b1bd2 alias_ctad_tweaks
        ../../gcc/cp/pt.c:29025
0x7b1bd2 deduction_guides_for
        ../../gcc/cp/pt.c:29140
0x7b2042 do_class_deduction
        ../../gcc/cp/pt.c:29250
0x7b2042 do_auto_deduction(tree_node*, tree_node*, tree_node*, int,
auto_deduction_context, tree_node*, int)
        ../../gcc/cp/pt.c:29420
0x81c535 build_functional_cast_1
        ../../gcc/cp/typeck2.c:2208
0x81c535 build_functional_cast(unsigned int, tree_node*, tree_node*, int)
        ../../gcc/cp/typeck2.c:2308
0x772977 cp_parser_functional_cast
        ../../gcc/cp/parser.c:30553
0x783bd2 cp_parser_postfix_expression
        ../../gcc/cp/parser.c:7427
0x793d35 cp_parser_unary_expression
        ../../gcc/cp/parser.c:8818
0x76d96f cp_parser_cast_expression
        ../../gcc/cp/parser.c:9722
0x76e1a2 cp_parser_binary_expression
        ../../gcc/cp/parser.c:9824
0x76e900 cp_parser_assignment_expression
        ../../gcc/cp/parser.c:10128
0x76fddd cp_parser_constant_expression
        ../../gcc/cp/parser.c:10424
0x76fe41 cp_parser_initializer_clause
        ../../gcc/cp/parser.c:24145
0x76ffe4 cp_parser_initializer_list
        ../../gcc/cp/parser.c:24424
0x76ffe4 cp_parser_braced_list
        ../../gcc/cp/parser.c:24186
0x772b82 cp_parser_initializer
        ../../gcc/cp/parser.c:24103
0x79c6b7 cp_parser_init_declarator
        ../../gcc/cp/parser.c:21745
0x77cf3a cp_parser_simple_declaration
        ../../gcc/cp/parser.c:14381

[Bug c++/99008] [10/11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
   Last reconfirmed|                            |2021-02-08
            Summary|[11 Regression] ICE in      |[10/11 Regression] ICE in
                   |set_constraints, at         |set_constraints, at
                   |cp/constraint.cc:1256       |cp/constraint.cc:1256
     Ever confirmed|0                           |1

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
With -std=c++17, it started with r10-5020-g1a291106384cabc7.

[Bug c++/99008] [10/11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
   Target Milestone|---                         |10.3

[Bug c++/99008] [10/11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.3                        |10.4

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10.3 is being released, retargeting bugs to GCC 10.4.

[Bug c++/99008] [10/11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

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

[Bug c++/99008] [10/11 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

--- Comment #3 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:8913b2c2bcded39427ff27e6dfc276ae8555f6b8

commit r11-8155-g8913b2c2bcded39427ff27e6dfc276ae8555f6b8
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Apr 13 12:35:33 2021 -0400

    c++: Reject alias CTAD in C++17 [PR99008]

    Here, in C++17 mode, we only pedwarn about the use of alias CTAD and
    then later ICE from alias_ctad_tweaks when attempting to constrain
    the guides.  Since the construction of the guides of an alias template
    effectively relies on concepts, we shouldn't be permissive about alias
    CTAD in C++17 mode, so this patch turns the pertinent pedwarn in
    do_class_deduction into an error.

    In order to get a consistent diagnostic for B() vs the other forms in
    the added testcase, I had to remove the special handling of CTAD with
    empty initializer in build_functional_cast_1 so that we always pass
    'complain' to do_auto_deduction.

    gcc/cp/ChangeLog:

            PR c++/99008
            * pt.c (do_class_deduction): Reject alias CTAD in C++17 mode
            rather than issuing a pedwarn.
            * typeck2.c (build_functional_cast_1): Handle CTAD uniformly
            for consistent diagnostics.

    gcc/testsuite/ChangeLog:

            PR c++/99008
            * g++.dg/parse/template2.C: Adjust expected diagnostic.
            * g++.dg/template/error8.C: Likewise.
            * g++.dg/cpp1z/class-deduction84.C: New test.

[Bug c++/99008] [10 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[10/11 Regression] ICE in   |[10 Regression] ICE in
                   |set_constraints, at         |set_constraints, at
                   |cp/constraint.cc:1256       |cp/constraint.cc:1256

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 11 so far.

[Bug c++/99008] [10 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

--- Comment #5 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:96d73645c77e7784ebd12527322d52b6b7eedb06

commit r11-8160-g96d73645c77e7784ebd12527322d52b6b7eedb06
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Apr 13 15:40:08 2021 -0400

    c++: Adjust expected diagnostics for old-deja tests [PR99008]

    I missed adjusting these tests in the recently committed r11-8155.

    gcc/testsuite/ChangeLog:

            PR c++/99008
            * g++.old-deja/g++.ns/crash3.C: Adjust expected diagnostic.
            * g++.old-deja/g++.ns/template7.C: Likewise.
            * g++.old-deja/g++.pt/crash8.C: Likewise.

[Bug c++/99008] [10 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

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

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
*** Bug 97112 has been marked as a duplicate of this bug. ***

[Bug c++/99008] [10 Regression] ICE in set_constraints, at cp/constraint.cc:1256

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99008

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
   Target Milestone|10.4                        |11.0

--- Comment #7 from Patrick Palka <ppalka at gcc dot gnu.org> ---
I suppose this isn't worth backporting to the 10 branch.