On Thu, Apr 15, 2021 at 03:31:24PM -0400, Jason Merrill wrote:
> On 4/14/21 9:21 PM, Marek Polacek wrote:
> > Here we ICE when compiling this code in C++20, because we're trying to
> > slam a 'typename' after the ->. The cp_parser_template_id call just
> > before the spot I'm changing parsed A::template A<int> as a BASELINK
> > that contains a constructor, but make_typename_type crashes on that.
> >
> > My fix is the same as c++/88325, add an is_overloaded_fn check.
>
> Instead of handling this in various callers, maybe make_typename_type should
> handle the error, like it already does for e.g.
>
> struct A { template <class T> static T t; };
> A(unsigned) -> A:: template t<int>;
Okay, done.
> Incidentally, in the testcase for 88325:
>
> > A<T>::A<U> () // { dg-error "partial specialization" }
>
> this error is misleading; this isn't a partial specialization, it's
> redundant template arguments while trying to define the primary template. I
> wouldn't worry about fixing the compiler now, but let's not test for the
> wrong error.
Makes sense.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
-- >8 --
Here we ICE when compiling this code in C++20, because we're trying to
slam a 'typename' after the ->. The cp_parser_template_id call just
before the spot I'm changing parsed A::template A<int> as a BASELINK
that contains a constructor, but make_typename_type crashes on that.
This patch makes make_typename_type more robust instead of checking
for is_overloaded_fn prior calling it.
gcc/cp/ChangeLog:
PR c++/99803
* decl.c (make_typename_type): Give an error and return when
name is is_overloaded_fn.
* parser.c (cp_parser_class_name): Don't check is_overloaded_fn
before calling make_typename_type.
gcc/testsuite/ChangeLog:
PR c++/99803
* g++.dg/cpp2a/typename14.C: Don't expect particular error
messages.
* g++.dg/cpp2a/typename19.C: New test.
---
gcc/cp/decl.c | 8 +++++++-
gcc/cp/parser.c | 4 +---
gcc/testsuite/g++.dg/cpp2a/typename14.C | 4 ++--
gcc/testsuite/g++.dg/cpp2a/typename19.C | 5 +++++
4 files changed, 15 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/typename19.C
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 1cb47313923..6668a65acbf 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4055,6 +4055,12 @@ make_typename_type (tree context, tree name, enum
tag_types tag_type,
error ("%qD used without template arguments", name);
return error_mark_node;
}
+ else if (is_overloaded_fn (name))
+ {
+ if (complain & tf_error)
+ error ("%qD is a function, not a type", name);
+ return error_mark_node;
+ }
gcc_assert (identifier_p (name));
gcc_assert (TYPE_P (context));
@@ -4066,7 +4072,7 @@ make_typename_type (tree context, tree name, enum
tag_types tag_type,
error ("%q#T is not a class", context);
return error_mark_node;
}
-
+
/* When the CONTEXT is a dependent type, NAME could refer to a
dependent base class of CONTEXT. But look inside it anyway
if CONTEXT is a currently open scope, in case it refers to a
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 940751b5f05..3640ae51331 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -24730,9 +24730,7 @@ cp_parser_class_name (cp_parser *parser,
decl = cp_parser_maybe_treat_template_as_class (decl, class_head_p);
/* If this is a typename, create a TYPENAME_TYPE. */
- if (typename_p
- && decl != error_mark_node
- && !is_overloaded_fn (decl))
+ if (typename_p && decl != error_mark_node)
{
decl = make_typename_type (scope, decl, typename_type,
/*complain=*/tf_error);
diff --git a/gcc/testsuite/g++.dg/cpp2a/typename14.C
b/gcc/testsuite/g++.dg/cpp2a/typename14.C
index 8d82b6b8d34..ba7dad8245f 100644
--- a/gcc/testsuite/g++.dg/cpp2a/typename14.C
+++ b/gcc/testsuite/g++.dg/cpp2a/typename14.C
@@ -8,7 +8,7 @@ template<typename> struct A
template<typename T>
template<typename U>
-A<T>::A<U> () // { dg-error "partial specialization" }
+A<T>::A<U> () // { dg-error "" }
{
}
@@ -19,7 +19,7 @@ template<typename> struct B
template<typename T>
template<typename U>
-B<T>::foo<int>(int) // { dg-error "partial specialization|declaration" }
+B<T>::foo<int>(int) // { dg-error "" }
{
return 1;
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/typename19.C
b/gcc/testsuite/g++.dg/cpp2a/typename19.C
new file mode 100644
index 00000000000..320a14d6a0c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/typename19.C
@@ -0,0 +1,5 @@
+// PR c++/99803
+// { dg-do compile { target c++20 } }
+
+struct A { template<typename T> A(T); };
+auto A(unsigned) -> A::template A<int>; // { dg-error "not a type" }
base-commit: ee351f7fdbd82f8947fe9a0e74cea65d216a8549
--
2.30.2
