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

[Aditya Srivastava <yashsri421@xxxxxxxxx>]

There are files in kernel, which use 'typedef struct' syntax for defining
struct. For eg, include/linux/zstd.h, drivers/scsi/megaraid/mega_common.h,
etc.
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!"

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;
+    }
 
+    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