Re: [PATCH] Fix ICE in build_function_type_skip_args (PR tree-optimization/40792)

[Richard Guenther <richard dot guenther at gmail dot com>]

On Mon, Jul 20, 2009 at 11:43 AM, Jakub Jelinek<jakub@redhat.com> wrote:
> Hi!
>
> On the following testcase build_function_type_skip_args is called with
> bitmask { 0, 1 } on a function with argument 0, 1 and ... after it.
> In this case new_reversed is obviously NULL (the two arguments are removed
> and ... is represented by NULL TREE_CHAIN rather than void_list_node).
> build_function_type_skip_args asserts that this is not the case, but I fail
> to see why, there is nothing wrong on NULL TYPE_ARG_TYPES, e.g. C++ FE
> happily creates it for void foo (...) { }. ?The problematic case could be if
> va_start with an argument that is going to be removed, but that would be
> already problematic even if removing just that last argument before ... and
> not other arguments. ?Except that those functions never hit here as they
> aren't considered inlinable, thus not suitable for versioning.
>
> Ok for trunk/4.4 if bootstrap/regtest passes (given that it just removes an
> assert that isn't triggered during bootstrap nor regtest and that this
> testcase on which it triggered compiles just fine that is quite pointless
> exercise, but I'll do it anyway)?

Ok.

Thanks,
Richard.

> 2009-07-20 ?Jakub Jelinek ?<jakub@redhat.com>
>
> ? ? ? ?PR tree-optimization/40792
> ? ? ? ?* tree.c (build_function_type_skip_args): Remove bogus assert.
>
> ? ? ? ?* gcc.dg/pr40792.c: New test.
>
> --- gcc/tree.c.jj ? ? ? 2009-07-07 14:24:59.000000000 +0200
> +++ gcc/tree.c ?2009-07-20 11:32:30.000000000 +0200
> @@ -5960,7 +5960,6 @@ build_function_type_skip_args (tree orig
> ? ? ? else
> ? ? ? ?new_reversed = void_list_node;
> ? ? }
> - ? ?gcc_assert (new_reversed);
>
> ? /* Use copy_node to preserve as much as possible from original type
> ? ? ?(debug info, attribute lists etc.)
> --- gcc/testsuite/gcc.dg/pr40792.c.jj ? 2009-07-20 11:33:05.000000000 +0200
> +++ gcc/testsuite/gcc.dg/pr40792.c ? ? ?2009-07-20 11:33:32.000000000 +0200
> @@ -0,0 +1,21 @@
> +/* PR tree-optimization/40792 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3" } */
> +
> +void foo (int, char *, int *);
> +
> +void
> +bar (int *a, int *b, ...)
> +{
> + ?int c;
> + ?char d[256];
> + ?foo (*b, d, &c);
> +}
> +
> +static int a, b;
> +
> +void
> +baz (int c)
> +{
> + ?bar (&a, &b);
> +}
>
> ? ? ? ?Jakub
>