On Thu, Mar 31, 2016 at 04:54:04PM -0400, Patrick Palka wrote:
> I think that covers all the vanilla C++ constructs that this warning has
> to consider. As for C++ extensions, we still fail to warn for
>
> if (a)
> #pragma GCC ivdep
> while (1)
> if (b)
> bar ();
> else
> baz ();
>
> and
>
> if (a)
> _Cilk_for (int i = 0; i < 10; i++)
> if (b)
> bar ();
> else
> baz ();
>
> and probably other constructs. I suppose support for this can be
> implemented in a subsequent patch if deemed appropriate at this stage.
> It would probably just involve more threading of the parameter IF_P.
>
> Is this OK to commit after bootstrap + regtesting?
If this makes it in, I can take care of OpenMP, perhaps Cilk+ too.
> --- a/gcc/cp/parser.c
> +++ b/gcc/cp/parser.c
> @@ -2104,7 +2104,7 @@ static tree cp_parser_selection_statement
> static tree cp_parser_condition
> (cp_parser *);
> static tree cp_parser_iteration_statement
> - (cp_parser *, bool);
> + (cp_parser *, bool *if_p, bool);
I wouldn't add a named argument where all others are unnamed in the
prototype.
> static bool cp_parser_for_init_statement
> (cp_parser *, tree *decl);
> static tree cp_parser_for
> @@ -2127,7 +2127,7 @@ static void cp_parser_declaration_statement
> static tree cp_parser_implicitly_scoped_statement
> (cp_parser *, bool *, const token_indent_info &, vec<tree> * = NULL);
> static void cp_parser_already_scoped_statement
> - (cp_parser *, const token_indent_info &);
> + (cp_parser *, bool *if_p, const token_indent_info &);
Likewise here.
> +void
> +foo (void)
> +{
> + if (a) /* { dg-warning "ambiguous" } */
> + for (;;)
> + if (b)
> + bar ();
> + else
> + baz ();
What about multiple nested for or while loops, like:
if (a)
for (i = 0; i < 10; i++)
for (j = 0; j < 10; j++)
if (b)
bar ();
else
baz ();
and similarly for multiple nested while loops?
I only see while (1) for (;;) in the test.
Otherwise, I'll defer to Jason.
Jakub
