[Bug c++/101209] New: ICE with trailing return type on a conversion operator

[Bug c++/101209] New: ICE with trailing return type on a conversion operator

[aaron at aaronballman dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101209

            Bug ID: 101209
           Summary: ICE with trailing return type on a conversion operator
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: aaron at aaronballman dot com
  Target Milestone: ---

I was curious what kind of diagnostics different compilers would give me for
some nonsense code, and found that the following code causes an ICE in GCC.

struct S {
  operator int() const -> double;
};

<source>:2:27: internal compiler error: in splice_late_return_type, at
cp/pt.c:29753
    2 |   operator int() const -> double;
      |                           ^~~~~~
0x1d48999 internal_error(char const*, ...)
        ???:0
0x724013 fancy_abort(char const*, int, char const*)
        ???:0
0x9847fc splice_late_return_type(tree_node*, tree_node*)
        ???:0
0x808c53 grokdeclarator(cp_declarator const*, cp_decl_specifier_seq*,
decl_context, int, tree_node**)
        ???:0
0x834403 grokfield(cp_declarator const*, cp_decl_specifier_seq*, tree_node*,
bool, tree_node*, tree_node*)
        ???:0
0x94cadd c_parse_file()
        ???:0
0xacfe82 c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1

This should likely give an error about using a trailing return type for a
function with a declared return type other than a placeholder type.

[Bug c++/101209] ICE with trailing return type on a conversion operator

[aaron at aaronballman dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101209

--- Comment #1 from Aaron Ballman <aaron at aaronballman dot com> ---
> This should likely give an error about using a trailing return type for a function with a declared return type other than a placeholder type.

Err, that would be bad now that I think about it
(http://eel.is/c++draft/class.conv.fct#6). So I'd amend this to: it should
probably give a reasonable diagnostic. :-)

[Bug c++/101209] [10/11/12 Regression] ICE with trailing return type on a conversion operator

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101209

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-08-07
   Target Milestone|---                         |9.5
            Summary|ICE with trailing return    |[10/11/12 Regression] ICE
                   |type on a conversion        |with trailing return type
                   |operator                    |on a conversion operator
      Known to work|                            |7.1.0, 9.1.0, 9.4.0
      Known to fail|                            |10.1.0

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed, a regression from 9.x.

[Bug c++/101209] [10/11/12 Regression] ICE with trailing return type on a conversion operator

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101209

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

[Bug c++/101209] [10/11/12 Regression] ICE with trailing return type on a conversion operator

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101209

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is a dup of bug 101051.

*** This bug has been marked as a duplicate of bug 101051 ***