Re: [RFC] scripts: kernel-doc: fix typedef support for struct parsing

[Lukas Bulwahn]

On Mon, Feb 22, 2021 at 5:03 PM Aditya Srivastava <yashsri421@xxxxxxxxx> wrote:
>
> There are files in kernel, which use 'typedef struct' syntax for defining
stylistic:
s/in kernel/in the kernel tree/
s/defining struct/defining some struct/
> struct. For eg, include/linux/zstd.h, drivers/scsi/megaraid/mega_common.h,
> etc.

stylistic:
s/For eg/E.g./ or
s/For eg/For example/

semantically:
It makes much more sense to name how many occurrences of this pattern
exist in the kernel tree within how many files in order to get a good
impression on the use of that pattern within the kernel tree.


> However, kernel-doc still does not support it, causing a parsing error.
>
> For eg, running scripts/kernel-doc -none on include/linux/zstd.h emits:
> "error: Cannot parse struct or union!"
>

semantically:
Drop the example and turn the two sentences above into one.

> Add support for parsing it.
>
> Signed-off-by: Aditya Srivastava <yashsri421@xxxxxxxxx>
> ---
>  scripts/kernel-doc | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/kernel-doc b/scripts/kernel-doc
> index 8b5bc7bf4bb8..46e904dc3f87 100755
> --- a/scripts/kernel-doc
> +++ b/scripts/kernel-doc
> @@ -1201,12 +1201,20 @@ sub dump_union($$) {
>  sub dump_struct($$) {
>      my $x = shift;
>      my $file = shift;
> +    my $decl_type;
> +    my $members;
>
>      if ($x =~ /(struct|union)\s+(\w+)\s*\{(.*)\}(\s*(__packed|__aligned|____cacheline_aligned_in_smp|____cacheline_aligned|__attribute__\s*\(\([a-z0-9,_\s\(\)]*\)\)))*/) {
> -       my $decl_type = $1;
> +       $decl_type = $1;
>         $declaration_name = $2;
> -       my $members = $3;
> +       $members = $3;
> +    } elsif ($x =~ /typedef\s+(struct|union)\s*\{(.*)\}(?:\s*(?:__packed|__aligned|____cacheline_aligned_in_smp|____cacheline_aligned|__attribute__\s*\(\([a-z0-9,_\s\(\)]*\)\)))*\s*(\w*)\s*;/) {
> +       $decl_type = $1;
> +       $declaration_name = $3;
> +       $members = $2;
> +    }
>

Could you put the common expression parts into meaningful variables to
avoid repeating yourself in the two pattern matching expressions?

Other than that, it looks good to me.

Lukas

> +    if ($members) {
>         if ($identifier ne $declaration_name) {
>             print STDERR "${file}:$.: warning: expecting prototype for $decl_type $identifier. Prototype was for $decl_type $declaration_name instead\n";
>             return;
> --
> 2.17.1
>