Re: [PATCH] Fix a few incorrect accesses.

[Thomas Schwinge <thomas@codesourcery.com>]

Hi Andrew!

On 2022-12-02T09:12:23-0500, Andrew MacLeod via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> This consists of 3 changes which stronger type checking has indicated
> are non-compliant with the type field.

I'm curious what that "stronger type checking" is?


Grüße
 Thomas


> I doubt they are super important because there has not been a trap
> triggered by them, and they have been in the source base since sometime
> before 2017.  However, we should probably fix them.
>
> I also notice that those are all uses of VOID_TYPE_P, which
> coincidentally does not check if its a type node being checked:
>
>     /* Nonzero if this type is the (possibly qualified) void type.  */
>     #define VOID_TYPE_P(NODE) (TREE_CODE (NODE) == VOID_TYPE)
>
> So I guess it wouldn't trap anyway, just silently never trigger.
>
> Bootstraps on x86_64-pc-linux-gnu with no regressions.  OK for trunk?
>
> Andrew


> From d1003e853d1813105eef6e441578e5bea9de8d03 Mon Sep 17 00:00:00 2001
> From: Andrew MacLeod <amacleod@redhat.com>
> Date: Tue, 29 Nov 2022 13:07:28 -0500
> Subject: [PATCH] Fix a few incorrect accesses.
>
> This consists of 3 changes which stronger type checking has indicated
> are incorrect.
>
>       gcc/
>       * fold-const.cc (fold_unary_loc): Check TREE_TYPE of node.
>       (tree_invalid_nonnegative_warnv_p): Likewise.
>
>       gcc/c-family/
>       * c-attribs.cc (handle_deprecated_attribute): Use type when
>       using TYPE_NAME.
> ---
>  gcc/c-family/c-attribs.cc | 2 +-
>  gcc/fold-const.cc         | 6 +++---
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
> index 07bca68e9b9..b36dd97802b 100644
> --- a/gcc/c-family/c-attribs.cc
> +++ b/gcc/c-family/c-attribs.cc
> @@ -4240,7 +4240,7 @@ handle_deprecated_attribute (tree *node, tree name,
>        if (type && TYPE_NAME (type))
>       {
>         if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
> -         what = TYPE_NAME (*node);
> +         what = TYPE_NAME (type);
>         else if (TREE_CODE (TYPE_NAME (type)) == TYPE_DECL
>                  && DECL_NAME (TYPE_NAME (type)))
>           what = DECL_NAME (TYPE_NAME (type));
> diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
> index 114258fa182..e80be8049e1 100644
> --- a/gcc/fold-const.cc
> +++ b/gcc/fold-const.cc
> @@ -9369,8 +9369,8 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
>             && TREE_CODE (tem) == COND_EXPR
>             && TREE_CODE (TREE_OPERAND (tem, 1)) == code
>             && TREE_CODE (TREE_OPERAND (tem, 2)) == code
> -           && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
> -           && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
> +           && ! VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (tem, 1)))
> +           && ! VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (tem, 2)))
>             && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
>                 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
>             && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
> @@ -15002,7 +15002,7 @@ tree_invalid_nonnegative_warnv_p (tree t, bool *strict_overflow_p, int depth)
>
>       /* If the initializer is non-void, then it's a normal expression
>          that will be assigned to the slot.  */
> -     if (!VOID_TYPE_P (t))
> +     if (!VOID_TYPE_P (TREE_TYPE (t)))
>         return RECURSE (t);
>
>       /* Otherwise, the initializer sets the slot in some way.  One common
> --
> 2.38.1
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