[PATCH] c++: Fix ICE diagnosing incomplete type of overloaded function set [PR98356]

[PATCH] c++: Fix ICE diagnosing incomplete type of overloaded function set [PR98356]

[Nathaniel Shead]

Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk?

-- >8 --

In the linked PR the result of 'get_first_fn' is a USING_DECL against
the template parameter, to be filled in on instantiation. But we don't
actually need to get the first set of the member functions: it's enough
to know that we have a (possibly overloaded) member function at all.

	PR c++/98356

gcc/cp/ChangeLog:

	* typeck2.cc (cxx_incomplete_type_diagnostic): Don't assume
	'member' will be a FUNCTION_DECL (or something like it).

gcc/testsuite/ChangeLog:

	* g++.dg/pr98356.C: New test.

Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
---
 gcc/cp/typeck2.cc              | 11 +++++------
 gcc/testsuite/g++.dg/pr98356.C |  9 +++++++++
 2 files changed, 14 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/pr98356.C

diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc
index 9608bdccd8b..31198b2f9f5 100644
--- a/gcc/cp/typeck2.cc
+++ b/gcc/cp/typeck2.cc
@@ -350,16 +350,15 @@ cxx_incomplete_type_diagnostic (location_t loc, const_tree value,
     bad_member:
       {
 	tree member = TREE_OPERAND (value, 1);
-	if (is_overloaded_fn (member))
-	  member = get_first_fn (member);
-
-	if (DECL_FUNCTION_MEMBER_P (member)
-	    && ! flag_ms_extensions)
+	if (is_overloaded_fn (member) && !flag_ms_extensions)
 	  {
 	    gcc_rich_location richloc (loc);
 	    /* If "member" has no arguments (other than "this"), then
 	       add a fix-it hint.  */
-	    if (type_num_arguments (TREE_TYPE (member)) == 1)
+	    member = MAYBE_BASELINK_FUNCTIONS (member);
+	    if (TREE_CODE (member) == FUNCTION_DECL
+		&& DECL_OBJECT_MEMBER_FUNCTION_P (member)
+		&& type_num_arguments (TREE_TYPE (member)) == 1)
 	      richloc.add_fixit_insert_after ("()");
 	    complained = emit_diagnostic (diag_kind, &richloc, 0,
 			     "invalid use of member function %qD "
diff --git a/gcc/testsuite/g++.dg/pr98356.C b/gcc/testsuite/g++.dg/pr98356.C
new file mode 100644
index 00000000000..acea238593b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr98356.C
@@ -0,0 +1,9 @@
+// PR c++/98356
+// { dg-do compile { target c++11 } }
+
+template <template <typename> class T> struct S {
+  using A = T<int>;
+  using A::foo;
+  void foo ();
+  void bar () {foo.}  // { dg-error "invalid use of member function" }
+};
-- 
2.43.2

Re: [PATCH] c++: Fix ICE diagnosing incomplete type of overloaded function set [PR98356]

[Jason Merrill]

On 3/4/24 18:30, Nathaniel Shead wrote:
> Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk?

OK.

> -- >8 --
> 
> In the linked PR the result of 'get_first_fn' is a USING_DECL against
> the template parameter, to be filled in on instantiation. But we don't
> actually need to get the first set of the member functions: it's enough
> to know that we have a (possibly overloaded) member function at all.
> 
> 	PR c++/98356
> 
> gcc/cp/ChangeLog:
> 
> 	* typeck2.cc (cxx_incomplete_type_diagnostic): Don't assume
> 	'member' will be a FUNCTION_DECL (or something like it).
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/pr98356.C: New test.
> 
> Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
> ---
>   gcc/cp/typeck2.cc              | 11 +++++------
>   gcc/testsuite/g++.dg/pr98356.C |  9 +++++++++
>   2 files changed, 14 insertions(+), 6 deletions(-)
>   create mode 100644 gcc/testsuite/g++.dg/pr98356.C
> 
> diff --git a/gcc/cp/typeck2.cc b/gcc/cp/typeck2.cc
> index 9608bdccd8b..31198b2f9f5 100644
> --- a/gcc/cp/typeck2.cc
> +++ b/gcc/cp/typeck2.cc
> @@ -350,16 +350,15 @@ cxx_incomplete_type_diagnostic (location_t loc, const_tree value,
>       bad_member:
>         {
>   	tree member = TREE_OPERAND (value, 1);
> -	if (is_overloaded_fn (member))
> -	  member = get_first_fn (member);
> -
> -	if (DECL_FUNCTION_MEMBER_P (member)
> -	    && ! flag_ms_extensions)
> +	if (is_overloaded_fn (member) && !flag_ms_extensions)
>   	  {
>   	    gcc_rich_location richloc (loc);
>   	    /* If "member" has no arguments (other than "this"), then
>   	       add a fix-it hint.  */
> -	    if (type_num_arguments (TREE_TYPE (member)) == 1)
> +	    member = MAYBE_BASELINK_FUNCTIONS (member);
> +	    if (TREE_CODE (member) == FUNCTION_DECL
> +		&& DECL_OBJECT_MEMBER_FUNCTION_P (member)
> +		&& type_num_arguments (TREE_TYPE (member)) == 1)
>   	      richloc.add_fixit_insert_after ("()");
>   	    complained = emit_diagnostic (diag_kind, &richloc, 0,
>   			     "invalid use of member function %qD "
> diff --git a/gcc/testsuite/g++.dg/pr98356.C b/gcc/testsuite/g++.dg/pr98356.C
> new file mode 100644
> index 00000000000..acea238593b
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/pr98356.C
> @@ -0,0 +1,9 @@
> +// PR c++/98356
> +// { dg-do compile { target c++11 } }
> +
> +template <template <typename> class T> struct S {
> +  using A = T<int>;
> +  using A::foo;
> +  void foo ();
> +  void bar () {foo.}  // { dg-error "invalid use of member function" }
> +};