[RFC] scripts: kernel-doc: improve parsing for kernel-doc comments syntax

[Aditya Srivastava]

On 15/4/21 12:55 am, Aditya Srivastava wrote:
> Currently kernel-doc does not identify some cases of probable kernel
> doc comments, for e.g. pointer used as declaration type for identifier,
> space separated identifier, etc.
> 
> Some example of these cases in files can be:
> i)" *  journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure"
> in fs/jbd2/journal.c
> 
> ii) "*      dget, dget_dlock -      get a reference to a dentry" in
> include/linux/dcache.h
> 
> iii) "  * DEFINE_SEQLOCK(sl) - Define a statically allocated seqlock_t"
> in include/linux/seqlock.h
> 
> Also improve identification for non-kerneldoc comments. For e.g.,
> 
> i) " *	The following functions allow us to read data using a swap map"
> in kernel/power/swap.c does follow the kernel-doc like syntax, but the
> content inside does not adheres to the expected format.
> 
> Improve parsing by adding support for these probable attempts to write
> kernel-doc comment.
> 
> Suggested-by: Jonathan Corbet <corbet at lwn.net>
> Link: https://lore.kernel.org/lkml/87mtujktl2.fsf@meer.lwn.net
> Signed-off-by: Aditya Srivastava <yashsri421 at gmail.com>
> ---
>  scripts/kernel-doc | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/scripts/kernel-doc b/scripts/kernel-doc
> index 888913528185..37665aa41e6b 100755
> --- a/scripts/kernel-doc
> +++ b/scripts/kernel-doc
> @@ -2110,17 +2110,25 @@ sub process_name($$) {
>      } elsif (/$doc_decl/o) {
>  	$identifier = $1;
>  	my $is_kernel_comment = 0;
> -	if (/^\s*\*\s*([\w\s]+?)(\(\))?\s*([-:].*)?$/) {
> +	my $decl_start = qr{\s*\*};
> +	my $fn_type = qr{\w+\s*\*\s*}; # i.e. pointer declaration type, foo * bar() - desc
> +	my $parenthesis = qr{\(\w*\)};
> +	my $decl_end = qr{[-:].*};
> +	if (/^$decl_start\s*([\w\s]+?)$parenthesis?\s*$decl_end?$/) {
>  	    $identifier = $1;
> -	    $decl_type = 'function';
> -	    $identifier =~ s/^define\s+//;
> -	    $is_kernel_comment = 1;
>  	}
>  	if ($identifier =~ m/^(struct|union|enum|typedef)\b\s*(\S*)/) {
>  	    $decl_type = $1;
>  	    $identifier = $2;
>  	    $is_kernel_comment = 1;
>  	}
> +	elsif (/^$decl_start\s*$fn_type?(\w+)\s*$parenthesis?\s*$decl_end?$/ ||	# i.e. foo()
> +	    /^$decl_start\s*$fn_type?(\w+.*)$parenthesis?\s*$decl_end$/) {	# i.e. static void foo() - description; or misspelt identifier
> +	    $identifier = $1;
> +	    $decl_type = 'function';
> +	    $identifier =~ s/^define\s+//;
> +	    $is_kernel_comment = 1;
> +	}
>  	$identifier =~ s/\s+$//;
>  
>  	$state = STATE_BODY;
> 

Hi
I have generated a diff file for changes in kernel-doc warnings for
all the files in the kernel-tree, before and after this patch.
It can be found at:
https://github.com/AdityaSrivast/kernel-tasks/blob/master/random/kernel-doc/kernel_doc_comment_syntax_improvement_diff.txt

Thanks
Aditya