pt.c (convert_nontype_argument): Don't create things that aren't PTRMEM_CSTs when...

	* pt.c (convert_nontype_argument): Don't create things that aren't
	PTRMEM_CSTs when applying a qualification conversion to a
	PTRMEM_CST.

From-SVN: r25929

gcc/cp/ChangeLog

 1999-03-23  Mark Mitchell  <mark@codesourcery.com>
 
+	* pt.c (convert_nontype_argument): Don't create things that aren't
+	PTRMEM_CSTs when applying a qualification conversion to a
+	PTRMEM_CST.
+
+1999-03-23  Mark Mitchell  <mark@codesourcery.com>
+
 	* Makefile.in (OBJS): Don't mention hash.o.
 	(OBJDEPS): Likewise.
 

gcc/cp/pt.c

@@ -2703,10 +2703,28 @@ convert_nontype_argument (type, expr)
 	tree type_pointed_to = TREE_TYPE (type);
  
 	if (TYPE_PTRMEM_P (type))
-	  /* For a non-type template-parameter of type pointer to data
-	     member, qualification conversions (_conv.qual_) are
-	     applied.  */
-	  return perform_qualification_conversions (type, expr);
+	  {
+	    tree e;
+
+	    /* For a non-type template-parameter of type pointer to data
+	       member, qualification conversions (_conv.qual_) are
+	       applied.  */
+	    e = perform_qualification_conversions (type, expr);
+	    if (TREE_CODE (e) == NOP_EXPR)
+	      {
+		/* The call to perform_qualification_conversions will
+		   insert a NOP_EXPR over EXPR to do express
+		   conversion, if necessary.  But, that will confuse
+		   us if we use this (converted) template parameter to
+		   instantiate another template; then the thing will
+		   not look like a valid template argument.  So, just
+		   make a new constant, of the appropriate type.  */
+		e = make_node (PTRMEM_CST);
+		TREE_TYPE (e) = type;
+		PTRMEM_CST_MEMBER (e) = PTRMEM_CST_MEMBER (expr);
+	      }
+	    return e;
+	  }
 	else if (TREE_CODE (type_pointed_to) == FUNCTION_TYPE)
 	  { 
 	    /* For a non-type template-parameter of type pointer to

gcc/testsuite/g++.old-deja/g++.pt/ptrmem7.C

+// Build don't link:
+// Origin: Jason Merrill <jason@cygnus.com>
+
+struct A
+{
+  A() : x(123) { }
+  int x;
+};
+A a;
+
+template<const int A::*PX>
+struct B
+{
+  static int g() { return a.*PX; }
+};
+
+
+int main(int argc, char *argv[])
+{
+  int n = B<&A::x>::g();
+}