Re: [PATCH] C++ ice with overloaded functions [Second try]

[Theodore Papadopoulo <Theodore dot Papadopoulo at sophia dot inria dot fr>]

[Oups. I forgot to remove some crap in my previous mail that could be 
misleading]

Mark Mitchell <mark@codesourcery.com> wrote:
> Thanks for your patch.  I think a different approach is in order,
> though.  We shouldn't be calling arg_assoc_type for uninstantiated
> function templates -- only for ordinary functions, or for
> instantiations/specializations of function tempaltes.  The
> arg_assoc_type function is used to do Koenig lookup, and I don't think
> that should be hapenning yet.  Does that make sense?

Well I think I finally got the meaning of it...
I hope this new version is better.

The testcase given below (I'm not sure I named it correctly) fails with the
current version of gcc (actually 2000-08-01).

mururoa->g++ koenig9.C 
koenig9.C: In function `void bar ()':
koenig9.C:12: Internal compiler error 390.
koenig9.C:12: Please submit a full bug report.
koenig9.C:12: See <URL:http://www.gnu.org/software/gcc/bugs.html> for
instructions.

The problem is that the function arg_assoc in cp/decl2.c calls the function
arg_assoc_type for uninstantiated function templates which is wrong (as pointed
out by Mark). While I was there, I also cleaned a little the function add_function
in a way slightly more logical.

With the patch provided here (I hope this time I fixed the problem at the right place), it gives:

jamaique->/net/home/robotvis/gnu/egcs/bin/g++ koenig9.C 
koenig9.C: In function `void bar ()':
koenig9.C:12: address of overloaded function with no contextual type information

I have bootstrapped the compiler. Unfortunately, the current (unpatched) compiler gives me 
so many regressions that claiming that this patch introduces no regressions would be meaningless.
I have to investigate what is going wrong.

New file:

    gcc/testsuite/g++.old-deja/g++.ns/koenig9.C


// Build don't link:

// Copyright (C) 2000 Free Software Foundation, Inc.
// Contributed by Theodore.Papadopoulo 23 Jun 2000 <Theodore.Papadopoulo@sophia.inria.fr>

#include <algorithm>

void foo(const char*,...);

inline void
bar() {
  foo("",count);    //  ERROR - multiple overloaded count functions
}

ChangeLog for gcc/cp:

2000-08-04 Theodore Papadopoulo <Theodore.Papadopoulo@sophia.inria.fr>

    * decl2.c (add_function): Reorganize.
      (arg_assoc): Do not consider function template decls.


Index: gcc/cp/decl2.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/decl2.c,v
retrieving revision 1.380
diff -r1.380 decl2.c
4777,4793c4777
<   if (k->functions && is_overloaded_fn (k->functions)
<       && is_overloaded_fn (fn))
<     k->functions = build_overload (fn, k->functions);
<   else if (k->functions)
<     {
<       tree f1 = OVL_CURRENT (k->functions);
<       tree f2 = fn;
<       if (is_overloaded_fn (f1))
< 	{
< 	  fn = f1; f1 = f2; f2 = fn;
< 	}
<       cp_error_at ("`%D' is not a function,", f1);
<       cp_error_at ("  conflict with `%D'", f2);
<       cp_error ("  in call to `%D'", k->name);
<       return 1;
<     }
<   else
---
>   if (!k->functions) 
4794a4779,4795
>   else
>     if (is_overloaded_fn (k->functions) && is_overloaded_fn (fn))
>       k->functions = build_overload (fn, k->functions);
>     else
>       {
>         tree f1 = OVL_CURRENT (k->functions);
>         tree f2 = fn;
>         if (is_overloaded_fn (f1))
> 	  {
> 	    fn = f1; f1 = f2; f2 = fn;
> 	  }
>         cp_error_at ("`%D' is not a function,", f1);
>         cp_error_at ("  conflict with `%D'", f2);
>         cp_error ("  in call to `%D'", k->name);
>         return 1;
>       }
> 
5049,5051c5050,5058
<       for (; n; n = OVL_CHAIN (n))
< 	if (arg_assoc_type (k, TREE_TYPE (OVL_FUNCTION (n))))
< 	  return 1;
---
>       for (; n; n = OVL_CHAIN (n)) 
>         {
>           /* Do not consider function template decls during Koenig lookup.  */
> 
>           tree fn = OVL_FUNCTION (n);
> 	  if (!DECL_FUNCTION_TEMPLATE_P (fn)
>               && arg_assoc_type (k, TREE_TYPE (fn)))
> 	    return 1;
>         }


--------------------------------------------------------------------
Theodore Papadopoulo
Email: Theodore.Papadopoulo@sophia.inria.fr Tel: (33) 04 92 38 76 01
 --------------------------------------------------------------------