[C++ PATCH] [PR13683] bogus warning about passing non-PODs through ellipsis in sizeof

[Giovanni Bajo]

Hi Jason,

as suggested by you, checking for skip_evaluation is enough to fix this PR.
Tested i686-pc-linux-gnu, OK for mainline? OK also for 3.4/3.3, assuming it
applies/works there as well?

Giovanni Bajo


cp/
2004-01-30  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

 PR c++/13683
 * call.c (convert_arg_to_ellipsis): Don't emit a warning if within
 a sizeof expression.block

testsuite/
2004-01-30  Giovanni Bajo  <giovannibajo@gcc.gnu.org>

 PR c++/13683
 * g++.dg/template/sizeof6.C: New test.


Index: call.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/call.c,v
retrieving revision 1.454
diff -c -3 -p -r1.454 call.c
*** call.c 21 Jan 2004 20:52:24 -0000 1.454
--- call.c 30 Jan 2004 13:18:50 -0000
*************** convert_arg_to_ellipsis (tree arg)
*** 4127,4140 ****

    arg = require_complete_type (arg);

!   if (arg != error_mark_node && ! pod_type_p (TREE_TYPE (arg)))
      {
        /* Undefined behavior [expr.call] 5.2.2/7.  We used to just warn
    here and do a bitwise copy, but now cp_expr_size will abort if we
!   try to do that.  */
!       warning ("cannot pass objects of non-POD type `%#T' through `...'; \
! call will abort at runtime",
!         TREE_TYPE (arg));
        arg = call_builtin_trap (TREE_TYPE (arg));
      }

--- 4127,4144 ----

    arg = require_complete_type (arg);

!   if (arg != error_mark_node
!       && !pod_type_p (TREE_TYPE (arg)))
      {
        /* Undefined behavior [expr.call] 5.2.2/7.  We used to just warn
    here and do a bitwise copy, but now cp_expr_size will abort if we
!   try to do that.
!   If the call appears in the context of a sizeof expression,
!   there is no need to emit a warning, since the expression won't be
!   evaluated. We keep the builtin_trap just as a safety check.  */
!       if (!skip_evaluation)
!  warning ("cannot pass objects of non-POD type `%#T' through `...'; "
!           "call will abort at runtime", TREE_TYPE (arg));
        arg = call_builtin_trap (TREE_TYPE (arg));
      }



// { dg-do compile }
// Contributed by Giovanni Bajo <giovannibajo at gcc dot gnu dot org>
// PR c++/13683: bogus warning about passing non-PODs through ellipsis

struct B {};
struct NonPOD : B {};

struct A
{
  static int check(...);
  static NonPOD GetNonPOD(void);
  enum { value = sizeof(A::check(A::GetNonPOD())) };
};