typeck.c (get_delta_difference): If via a virtual base, return zero.

cp:
	* typeck.c (get_delta_difference): If via a virtual base,
	return zero.
	* cvt.c (cp_convert_to_pointer): If via a virtual base, do no
	adjustment.
testsuite:
	* g++.old-deja/g++.mike/pmf5.C: Remove test.

From-SVN: r38039

gcc/cp/ChangeLog

+2000-12-05  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* typeck.c (get_delta_difference): If via a virtual base,
+	return zero.
+	* cvt.c (cp_convert_to_pointer): If via a virtual base, do no
+	adjustment.
+
 2000-12-04  Richard Henderson  <rth@redhat.com>
 
 	* error.c (dump_tree): Use output_add_string not OB_PUTS.

gcc/cp/cvt.c

@@ -209,10 +209,9 @@ cp_convert_to_pointer (type, expr, force)
           if (virt_binfo)
 	    {
 	      if (force)
-	        cp_warning ("pointer to member cast via virtual base `%T' of `%T' will only work for objects of dynamic type `%T'",
+	        cp_warning ("pointer to member cast via virtual base `%T' of `%T'",
 	                    BINFO_TYPE (virt_binfo),
-                            BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)),
-                            code == MINUS_EXPR ? b2 : b1);
+                            BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
               else
                 {
 	          cp_error ("pointer to member cast via virtual base `%T' of `%T'",
@@ -220,13 +219,16 @@ cp_convert_to_pointer (type, expr, force)
                             BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
 	          return error_mark_node;
 	        }
+	      /* This is a reinterpret cast, whose result is unspecified.
+	         We choose to do nothing.  */
+	      return build1 (NOP_EXPR, type, expr);
 	    }
 	      
 	  if (TREE_CODE (expr) == PTRMEM_CST)
 	    expr = cplus_expand_constant (expr);
 
-	  if (binfo && ! TREE_VIA_VIRTUAL (binfo))
-	    expr = size_binop (code, convert (sizetype,expr),
+	  if (binfo)
+	    expr = size_binop (code, convert (sizetype, expr),
 			       BINFO_OFFSET (binfo));
 	}
       else if (TYPE_PTRMEMFUNC_P (type))

gcc/cp/typeck.c

@@ -5936,31 +5936,39 @@ get_delta_difference (from, to, force)
       virt_binfo = binfo_from_vbase (binfo);
       
       if (virt_binfo)
-        cp_warning ("pointer to member cast via virtual base `%T' of `%T' will only work for objects of dynamic type `%T'",
-	            BINFO_TYPE (virt_binfo),
-	            BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)), from);
+        {
+          /* This is a reinterpret cast, we choose to do nothing. */
+          cp_warning ("pointer to member cast via virtual base `%T' of `%T'",
+	              BINFO_TYPE (virt_binfo),
+	              BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
+          return delta;
+        }
       delta = BINFO_OFFSET (binfo);
       delta = cp_convert (ptrdiff_type_node, delta);
-      
-      return cp_build_binary_op (MINUS_EXPR,
+      delta = cp_build_binary_op (MINUS_EXPR,
 				 integer_zero_node,
 				 delta);
+
+      return delta;
     }
 
   virt_binfo = binfo_from_vbase (binfo);
   if (virt_binfo)
     {
+      /* This is a reinterpret cast, we choose to do nothing. */
       if (force)
-        cp_warning ("pointer to member cast via virtual base `%T' of `%T' will only work for objects of dynamic type `%T'",
+        cp_warning ("pointer to member cast via virtual base `%T' of `%T'",
                     BINFO_TYPE (virt_binfo),
-                    BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)), to);
+                    BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
       else
 	cp_error ("pointer to member conversion via virtual base `%T' of `%T'",
 		  BINFO_TYPE (virt_binfo),
                   BINFO_TYPE (BINFO_INHERITANCE_CHAIN (virt_binfo)));
+      return delta;
     }
+  delta = BINFO_OFFSET (binfo);
 
-  return BINFO_OFFSET (binfo);
+  return cp_convert (ptrdiff_type_node, delta);
 }
 
 /* Return a constructor for the pointer-to-member-function TYPE using

gcc/testsuite/ChangeLog

+2000-12-05  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* g++.old-deja/g++.mike/pmf5.C: Remove test.
+
 2000-12-05  Richard Henderson  <rth@redhat.com>
 
 	* gcc.c-torture/compile/20001205-1.c: New.

gcc/testsuite/g++.old-deja/g++.mike/pmf5.C

-// Special g++ Options: -w
-
-class A {
-  int j;
-};
-
-class Space {
-  int j;
-};
-
-typedef int (A::*pma)();
-
-class B : public Space, virtual public A {
-public:
-  int i;
-  int foo () {
-    return i!=42;
-  }
-  B() {
-    i = 42;
-  }
-};
-
-int call_base (A* ap, pma pmf) {
-  return (ap->*pmf)();
-}
-
-int main() {
-  B b;
-  return call_base ((A*)&b, (pma)&B::foo);
-}