Re: [PATCH v2 2/2] selftests/bpf: add BTF dedup tests for recursive typedef definitions

[Eduard Zingerman <eddyz87@gmail.com>]

On Wed, 2025-11-12 at 15:11 +0100, Paul Houssel wrote:

Lgtm, one nit below:

> +{
> +	.descr = "dedup: recursive typedef",
> +	/*
> +	 * This test simulates a recursive typedef, which in GO is defined as such:
> +	 *
> +	 *   type Foo func() Foo
> +	 *
> +	 * In BTF terms, this is represented as a TYPEDEF referencing
> +	 * a FUNC_PROTO that returns the same TYPEDEF.
> +	 */
> +	.input = {
> +		.raw_types = {
> +			/*
> +			 * [1] typedef Foo -> func() Foo
> +			 * [2] func_proto() -> Foo
> +			 */
> +			BTF_TYPEDEF_ENC(NAME_NTH(1), 2),	/* [1] */
> +			BTF_FUNC_PROTO_ENC(1, 0),		/* [2] */

Nit:
Maybe repeat the above two types, just to make sure that deduplication happens?

> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0Foo"),
> +	},
> +	.expect = {
> +		.raw_types = {
> +			BTF_TYPEDEF_ENC(NAME_NTH(1), 2),	/* [1] */
> +			BTF_FUNC_PROTO_ENC(1, 0),		/* [2] */
> +			BTF_END_RAW,
> +		},
> +		BTF_STR_SEC("\0Foo"),
> +	},
> +},

[...]