On Tue, 4 Mar 2025, Patrick Palka wrote:
> On Sun, 2 Mar 2025, Da Xie wrote:
>
> > Add check for constrained auto type specifier in function declaration or
> > function type declaration with trailing return type. Issue error if such
> > usage is detected.
> >
> > Test file renamed, and added a new test for type declaration.
> >
> > Successfully bootstrapped and regretested on x86_64-pc-linux-gnu:
> > Added 6 passed and 4 unsupported tests.
> >
> > PR c++/100589
> >
> > gcc/cp/ChangeLog:
> >
> > * decl.cc (grokdeclarator): Issue an error for a declarator with
> > constrained auto type specifier and trailing return types. Include
> > function names if available.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/cpp2a/concepts-pr100589.C: New test.
>
> LGTM, thanks! Jason, shall I push this to trunk?
Pushed as r15-7834-g7439febd94368f.
>
> >
> > Signed-off-by: Da Xie <xxie...@163.com>
> > ---
> > gcc/cp/decl.cc | 13 +++++++++++++
> > gcc/testsuite/g++.dg/cpp2a/concepts-pr100589.C | 9 +++++++++
> > 2 files changed, 22 insertions(+)
> > create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr100589.C
> >
> > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> > index 9ca8c6c4481..337ee65752e 100644
> > --- a/gcc/cp/decl.cc
> > +++ b/gcc/cp/decl.cc
> > @@ -14037,6 +14037,19 @@ grokdeclarator (const cp_declarator *declarator,
> > "invalid use of %<decltype(auto)%>");
> > return error_mark_node;
> > }
> > + else if (is_constrained_auto (type))
> > + {
> > + if (funcdecl_p)
> > + error_at (typespec_loc,
> > + "%qs function with trailing return type "
> > + "has constrained %<auto%> type specifier "
> > + "rather than plain %<auto%>",
> > + name);
> > + else
> > + error_at (typespec_loc,
> > + "invalid use of constrained %<auto%> type");
> > + return error_mark_node;
> > + }
> > tree tmpl = CLASS_PLACEHOLDER_TEMPLATE (auto_node);
> > if (!tmpl)
> > if (tree late_auto = type_uses_auto (late_return_type))
> > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr100589.C
> > b/gcc/testsuite/g++.dg/cpp2a/concepts-pr100589.C
> > new file mode 100644
> > index 00000000000..0c60d31f29b
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr100589.C
> > @@ -0,0 +1,9 @@
> > +// PR c++/100589
> > +// { dg-do compile { target c++20 } }
> > +
> > +template<class T>
> > +concept false_concept = false;
> > +
> > +false_concept auto f() -> int; // { dg-error "'f' .* trailing return
> > type.* constrained 'auto'" }
>
> I can replace the use of .* with \[^\r\n\]* before pushing.
>
> > +
> > +using type = false_concept auto() -> int; // { dg-error "invalid use of
> > constrained 'auto' type"}
N.B. I added a missing space between the " and } that caused this
dircetive to get ignored.
> > --
> > 2.34.1
> >
> >
>
