Re: [PATCH v4 bpf-next] bpftool: introduce btf c dump sorting

[Quentin Monnet <qmo@kernel.org>]

2024-05-14 14:12 UTC+0100 ~ Mykyta Yatsenko mykyta.yatsenko5@gmail.com
> From: Mykyta Yatsenko <yatsenko@meta.com>
> 
> Sort bpftool c dump output; aiming to simplify vmlinux.h diffing and
> forcing more natural type definitions ordering.
> 
> Definitions are sorted first by their BTF kind ranks, then by their base
> type name and by their own name.
> 
> Type ranks
> 
> Assign ranks to btf kinds (defined in function btf_type_rank) to set
> next order:
> 1. Anonymous enums/enums64
> 2. Named enums/enums64
> 3. Trivial types typedefs (ints, then floats)
> 4. Structs/Unions
> 5. Function prototypes
> 6. Forward declarations
> 
> Type rank is set to maximum for unnamed reference types, structs and
> unions to avoid emitting those types early. They will be emitted as
> part of the type chain starting with named type.
> 
> Lexicographical ordering
> 
> Each type is assigned a sort_name and own_name.
> sort_name is the resolved name of the final base type for reference
> types (typedef, pointer, array etc). Sorting by sort_name allows to
> group typedefs of the same base type. sort_name for non-reference type
> is the same as own_name. own_name is a direct name of particular type,
> is used as final sorting step.
> 
> Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>


Please keep the tags from previous versions when the changes are trivial:

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>

Reviewed-by: Quentin Monnet <qmo@kernel.org>

Thanks a lot!