Re: [PATCH net-next v2 4/6] tools: ynl: Add struct attr decoding to ynl
From: Jakub Kicinski <kuba@kernel.org>
Date: 2023-03-22 18:38:17
On Wed, 22 Mar 2023 11:48:12 +0000 Donald Hunter wrote:
quoted
On Sun, 19 Mar 2023 19:38:01 +0000 Donald Hunter wrote:quoted
enum: [ unused, pad, flag, binary, u8, u16, u32, u64, s32, s64, - string, nest, array-nest, nest-type-value ] + string, nest, array-nest, nest-type-value, struct ]I wonder if we should also only allow struct as a subtype of binary? Structs can technically grow with newer kernels (i.e. new members can be added at the end). So I think for languages like C we will still need to expose to the user the original length of the attribute. And binary comes with a length so codgen reuse fits nicely. Either way - docs need to be updated.Yep, as I was replying to your previous comment, I started to think about making struct a subtype of binary. That would make a struct attr something like: - name: stats type: binary sub-type: struct struct: vport-stats
LGTM!
I originally chose 'struct' as the attr name, following the pattern that 'enum' is used for enum names but I'm not sure it's clear enough. Maybe 'sub-type-name' would be better?
Agreed, using the sub-type's value as name of another attr
is mixing keys and values.
But sub-type-name would then also be used for enums (I mean in
normal type: u32 enums, not binary arrays)?
enums don't have a sub-type so there we'd have sub-type-name
and no sub-type.
Plus for binary arrays of enums we'd have:
-
name: stats
type: binary
sub-type: u32
sub-type-name: vport-stats
Doesn't say enum anywhere :S We'd need to assume if sub-type is
a scalar the sub-type-name is an enum?
Maybe to avoid saying struct twice we should go the enum way and
actually ditch the sub-type for structs? Presence of struct: abc
implies it's a struct, only use sub-type for scalar types?
-
name: stats
type: binary
struct: vport-stats
-
name: another
type: binary
sub-type: u32
enum: enums-name