Qualified friends

[Martin v. Loewis]

egcs currently rejects globally-scoped friend declarations; this was
reported for 1.1.1. It turned out there is an ambiguity in C++. The
examples below show this ambiguity and how it was resolved.

Unfortunately, the grammar change led to a new set of reduce/reduce
conflicts. bison isn't sure whether a certain construct is a
declarator or a primary, it will chose declarator in these cases. As a
result, this patch breaks g++.jason/parse4.C. It currently reads

    B( ::g() ).f();  // no syntax error 
    B( g() ).f();    // gets bogus error - treated as decl XFAIL *-*-*

g++ already treats the second line as a declaration. Now that a
declarator can start with a SCOPE, the first line runs into the same
error.

We desperately need Mark's new grammar.

Regards,
Martin

1999-02-20  Martin von Löwis  <loewis@informatik.hu-berlin.de>

	* parse.y (complex_direct_notype_declarator): Support global_scope.
	* Makefile: Adjust conflict count.

//Build don't link:
void foo();
class R{
  int i;
  friend void ::foo();
};

void ::foo()
{
  R r;
  r.i=4;
}

//Build don't link:
struct A{
  struct B{};
};

A::B C();

namespace B{
  A C();
}

class Test{
  friend A (::B::C)();  // Ok
  friend A::B (::C)();  // Ok
  friend A::B::C();     // ERROR: no A::B::C
};


Index: Makefile.in
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/Makefile.in,v
retrieving revision 1.46
diff -u -p -r1.46 Makefile.in
--- Makefile.in	1999/01/27 01:43:13	1.46
+++ Makefile.in	1999/02/20 20:52:47
@@ -1,5 +1,5 @@
 # Makefile for GNU C++ compiler.
-#   Copyright (C) 1987, 88, 90-4, 1995, 1998 Free Software Foundation, Inc.
+#   Copyright (C) 1987, 88, 90-95, 1998, 1999 Free Software Foundation, Inc.
 
 #This file is part of GNU CC.
 
@@ -225,7 +225,7 @@ parse.o : $(PARSE_C) $(CONFIG_H) $(CXX_T
 	$(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $(BIG_SWITCHFLAG) \
   `echo $(PARSE_C) | sed 's,^\./,,'`
 
-CONFLICTS = expect 36 shift/reduce conflicts and 42 reduce/reduce conflicts.
+CONFLICTS = expect 37 shift/reduce conflicts and 58 reduce/reduce conflicts.
 $(PARSE_H) : $(PARSE_C)
 $(PARSE_C) : $(srcdir)/parse.y
 	@echo $(CONFLICTS)
Index: parse.y
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/parse.y,v
retrieving revision 1.107
diff -u -p -r1.107 parse.y
--- parse.y	1998/12/16 21:16:01	1.107
+++ parse.y	1999/02/20 20:52:51
@@ -1,5 +1,5 @@
 /* YACC parser for C++ syntax.
-   Copyright (C) 1988, 89, 93-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1988, 89, 93-98, 1999 Free Software Foundation, Inc.
    Hacked by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GNU CC.
@@ -2851,6 +2851,12 @@ complex_direct_notype_declarator:
 		{ $$ = build_parse_node (ARRAY_REF, $$, NULL_TREE); }
 	| notype_qualified_id
                 { enter_scope_of ($1); }
+	| global_scope notype_qualified_id
+                { enter_scope_of ($2); $$ = $2;}
+	| global_scope notype_unqualified_id
+                { $$ = build_parse_node (SCOPE_REF, global_namespace, $2);
+		  enter_scope_of ($$); 
+		}
         | nested_name_specifier notype_template_declarator
                 { got_scope = NULL_TREE;
 		  $$ = build_parse_node (SCOPE_REF, $1, $2);