Re: Patch ping

[Jakub Jelinek <jakub at redhat dot com>]

On Mon, Apr 10, 2017 at 08:41:28AM -0400, Nathan Sidwell wrote:
> On 04/10/2017 08:18 AM, Jakub Jelinek wrote:
> > Hi!
> > 
> > I'd like to ping 2 patches:
> > 
> > P2 PR c++/80176
> >    http://gcc.gnu.org/ml/gcc-patches/2017-04/msg00027.html
> >    reference binding to static member function
> 
> This smells fishy.  There's no reason one cannot have an overload set
> containing both static and non-static functions, in any order.  So it'll be
> 'random' as to which member of the set OVL_CURRENT looks at.

I actually don't know if I need the OVL_CURRENT thing, maybe not.
On the testcase there is an overloaded static member function and I don't
get an error on that, just on the non-overloaded one.
I've tried:
struct X { static void foo(); static void baz(int); static int baz(double); void m(int); void n(int); int n(float); } x;
void X::foo() {}
static void bar() {}
void (&r1)() = x.foo;
void (&r2)() = X::foo;
void (&r3)() = bar;
void (&r4)(int) = x.baz;
int (&r5)(double) = x.baz;
void (&r6)(int) = X::baz;
int (&r7)(double) = X::baz;
void (&r8)(int) = x.m;
void (&r9)(int) = x.n;
int (&r10)(float) = x.n;
and there I see COMPONENT_REF with BASELINK second operand with
BASELINK_FUNCTIONS being an overload only for the methods.
And even if I try overload with mixed methods and static member functions,
lvalue_kind with that is only called when seeing the invalid binding
to method:
struct X { void o(unsigned char); static void o(int); void o(double); } x;
void (&r12)(int) = x.o;
void (&r13)(double) = x.o;

Thus, would it be acceptable to omit the OVL_CURRENT as in (tested so far
just on the updated ref23.C with additional test from the above r12 snippet,
of course would perform full bootstrap/regtest with that)?

2017-04-08  Jakub Jelinek  <jakub@redhat.com>

	PR c++/80176
	* tree.c (lvalue_kind): For COMPONENT_REF with BASELINK second
	operand, if it is a static member function, recurse on the
	BASELINK.

	* g++.dg/init/ref23.C: New test.

--- gcc/cp/tree.c.jj	2017-04-07 21:17:57.078208891 +0200
+++ gcc/cp/tree.c	2017-04-10 15:18:57.941508441 +0200
@@ -105,6 +105,14 @@ lvalue_kind (const_tree ref)
       return op1_lvalue_kind;
 
     case COMPONENT_REF:
+      if (BASELINK_P (TREE_OPERAND (ref, 1)))
+	{
+	  tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (ref, 1));
+
+	  /* For static member function recurse on the BASELINK.  */
+	  if (TREE_CODE (fn) == FUNCTION_DECL && DECL_STATIC_FUNCTION_P (fn))
+	    return lvalue_kind (TREE_OPERAND (ref, 1));
+	}
       op1_lvalue_kind = lvalue_kind (TREE_OPERAND (ref, 0));
       /* Look at the member designator.  */
       if (!op1_lvalue_kind)
--- gcc/testsuite/g++.dg/init/ref23.C.jj	2017-04-10 15:17:04.823911276 +0200
+++ gcc/testsuite/g++.dg/init/ref23.C	2017-04-10 15:18:07.504133944 +0200
@@ -0,0 +1,15 @@
+// PR c++/80176
+// { dg-do compile }
+
+struct X { static void foo(); static void baz(int); static int baz(double); } x;
+struct Y { void o(unsigned char); static void o(int); void o(double); } y;
+void X::foo() {}
+static void bar() {}
+void (&r1)() = x.foo;
+void (&r2)() = X::foo;
+void (&r3)() = bar;
+void (&r4)(int) = x.baz;
+int (&r5)(double) = x.baz;
+void (&r6)(int) = X::baz;
+int (&r7)(double) = X::baz;
+void (&r8)(int) = y.o;

	Jakub