Re: [RFC] scripts: kernel-doc: fix attribute capture in function parsing

On Fri, Mar 5, 2021 at 8:38 PM Aditya [off-list ref] wrote:

On 6/3/21 12:13 am, Matthew Wilcox wrote:

quoted

On Fri, Mar 05, 2021 at 11:50:00PM +0530, Aditya Srivastava wrote:

quoted

Provide a simple fix by adding "__attribute_const__" in the corresponding
regex expression.

A quick evaluation by running 'kernel-doc -none' on kernel-tree reveals
that no additional warning or error has been added or removed by the fix.

I'm no perlmonger, but why isn't this simply:

+++ b/scripts/kernel-doc

@@ -1753,6 +1753,7 @@ sub dump_function($$) {
     $prototype =~ s/^__inline +//;
     $prototype =~ s/^__always_inline +//;
     $prototype =~ s/^noinline +//;
+    $prototype =~ s/__attribute_const__ +//;
     $prototype =~ s/__init +//;
     $prototype =~ s/__init_or_module +//;
     $prototype =~ s/__meminit +//;

(completely untested)

quoted

+++ b/scripts/kernel-doc

@@ -1753,6 +1753,7 @@ sub dump_function($$) {
     my $prototype = shift;
     my $file = shift;
     my $noret = 0;
+    my $attribute_const = qr{__attribute_const__};

     print_lineno($new_start_line);

@@ -1808,7 +1809,7 @@ sub dump_function($$) {
     $prototype =~ m/^(\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
     $prototype =~ m/^(\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
     $prototype =~ m/^(\w+\s+\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
-    $prototype =~ m/^(\w+\s+\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
+    $prototype =~ m/^(\w+\s+\w+\s*\*+$attribute_const?)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
     $prototype =~ m/^(\w+\s+\w+\s+\w+)\s+([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
     $prototype =~ m/^(\w+\s+\w+\s+\w+\s*\*+)\s*([a-zA-Z0-9_~:]+)\s*\(([^\(]*)\)/ ||
     $prototype =~ m/^()([a-zA-Z0-9_~:]+)\s*\(([^\{]*)\)/ ||

Hi Matthew
You are correct, it should be placed there. I was considering it as a
return type instead.
I'll send a modified v2 with the changes.

Aditya, I also ran:

git ls-files | xargs ./scripts/kernel-doc -none 2>&1 | tee kernel-doc-output

cat kernel-doc-output | grep "cannot understand function prototype:" |
sed 's/[^:].*:[0-9]*: \(.*\)$/\1/' | sort

and I found another instance of failed parsing function prototypes in
mm/percpu.c:2671:

struct pcpu_alloc_info * __flatten pcpu_build_alloc_info(size_t
reserved_size, size_t dyn_size, size_t atom_size,
pcpu_fc_cpu_distance_fn_t cpu_distance_fn)

Could you address that one in your patch as well?

Lukas