[DTrace-devel] [PATCH] test: ensure casting does not affect value

[Eugene Loh]

What is the point of this test?  If we do not know the type of the 
kernel variable, then what does "kernel_read_neg_small_scalar" mean?

On 7/31/24 15:01, Kris Van Hees wrote:
> On systems without CTF, we do not know the type of kernel variables.
> By doing an explicit cast to int64_t a negative int is converted into a
> large positive integer.  The proper cast is 'int' of course.
>
> Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
> ---
>   test/unittest/codegen/tst.kernel_read_neg_small_scalar.d | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/test/unittest/codegen/tst.kernel_read_neg_small_scalar.d b/test/unittest/codegen/tst.kernel_read_neg_small_scalar.d
> index 7c585d1b..cda6649b 100644
> --- a/test/unittest/codegen/tst.kernel_read_neg_small_scalar.d
> +++ b/test/unittest/codegen/tst.kernel_read_neg_small_scalar.d
> @@ -1,6 +1,6 @@
>   /*
>    * Oracle Linux DTrace.
> - * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
> + * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
>    * Licensed under the Universal Permissive License v 1.0 as shown at
>    * http://oss.oracle.com/licenses/upl.
>    */
> @@ -11,10 +11,10 @@ BEGIN
>   {
>   	/*
>   	 * Unless we are actually crashing, the `crashing_cpu int will be -1.
> -	 * We cast it to int64_t to ensure that the value read from the kernel
> +	 * We cast it to int to ensure that the value read from the kernel
>   	 * is sign-extended.
>   	 */
> -	trace((int64_t)`crashing_cpu);
> +	trace((int)`crashing_cpu);
>   	exit(0);
>   }
>