On Mon, May 13, 2013 at 03:25:11PM -0400, Jason Merrill wrote:
> In this testcase, since one of the overloads takes a pointer, we
> need to check whether the argument is a valid null pointer constant.
> In C++11 only an integer literal can be a null pointer constant of
> integral type, but in C++03 we need to handle other integer constant
> expressions. Here we were passing the call expression into
> value_dependent_expression_p, but in C++03 mode that function
> expects its argument to be a constant expression, and the expression
> wasn't filtered out by potential_constant_expression. The simplest
> solution is to just check TREE_SIDE_EFFECTS since in C++03 mode an
> expression with side-effects can't be a constant expression (unlike
> in C++11, where constexpr function substitution can produce a
> constant expression from one with TREE_SIDE_EFFECTS).
What about the 4 other
maybe_constant_value on fold_non_dependent_expr_sfinae (something, tf_none)
calls in typeck.c (two for -Wdiv-by-zero and two for shift diagnostics)?
Should that be if (cxx_dialect >= cxx0x || !TREE_SIDE_EFFECTS (t)) guarded
(or wrapped into some helper function that will do all of
tree some_good_name (tree t)
{
if (cxx_dialect < cxx0x && TREE_SIDE_EFFECTS (t))
return t;
t = fold_non_dependent_expr_sfinae (t, tf_none);
return maybe_constant_value (t);
}
Plus there is one guarded by ENABLE_CHECKING in pt.c.
Jakub
