Re: [PATCH 00/33] ABI: add it to the documentation build system

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Wed, 28 Oct 2020 15:39:37 +0100
Greg Kroah-Hartman <gregkh@linuxfoundation.org> escreveu:

> On Wed, Oct 28, 2020 at 03:22:58PM +0100, Mauro Carvalho Chehab wrote:
> > Hi Greg,
> > 
> > As requested, this is a rebased version on the top of v5.10-rc1
> > adding support for having the Linux ABI documentted inside
> > the Linux admin manual.
> > 
> > When compared with the version I sent years ago, this
> > version has:
> > 
> > - a logic to detect duplicated ABI symbols;
> > - it auto-generate cross-reference markups for ABI symbols,
> >   ABI files and .rst files;
> > - Other files from 5.10-rc1 required adjustments in order
> >   to be accepted by the script in rst-source mode;
> > - Some bug fixes.
> > 
> > PS.: I didn't try to merge it against linux-next yet. So,
> > I won't doubt that applying it could cause some conflicts.
> > 
> > Feel free to review it.  
> 
> After applying the first 10 patches, and running it, I see a bunch of
> these types of warnings:
> 
> Use of uninitialized value $kernelversion in substitution (s///) at ./scripts/get_abi.pl line 444.
> Use of uninitialized value $users in substitution (s///) at ./scripts/get_abi.pl line 446.
> Use of uninitialized value $users in substitution (s///) at ./scripts/get_abi.pl line 447.

Hmm.. I didn't test search after adding "use warnings".

The thing is that "use warnings" was added on one of get_abi.pl
patches, just to be sure that some ABI parsers were 100%.

That makes perl very pedantic, as it won't accept things like:

	my $foo;
	...
	my $bar = $foo;

Without "warnings", $bar will be undefined, and everything
works properly, but, when this used, the above will still
work properly, but will start producing warnings like the
one you're seeing.

I'm enclosing a diff addressing it for "search" mode.

It should be fold on this patch:

	scripts: get_abi.pl: cleanup ABI cross-reference logic

Which is the one that added "use warnings".

Feel free to fold it there. Otherwise, I'll fold it and
send you on a v2 of this series.

> 
> When doing something like:
> $ ./scripts/get_abi.pl search usb --dir Documentation/ABI/stable/
> 
> Is that expected?
> 
> thanks,
> 
> greg k-h


Thanks,
Mauro

diff --git a/scripts/get_abi.pl b/scripts/get_abi.pl
index bdef3e5c35c7..00b6ddec0ebb 100755
--- a/scripts/get_abi.pl
+++ b/scripts/get_abi.pl
@@ -442,17 +442,20 @@ sub search_symbols {
 
 		print "\n$what\n$bar\n\n";
 
-		my $kernelversion = $data{$what}->{kernelversion};
-		my $contact = $data{$what}->{contact};
-		my $users = $data{$what}->{users};
-		my $date = $data{$what}->{date};
-		my $desc = $data{$what}->{description};
-		$kernelversion =~ s/^\s+//;
-		$contact =~ s/^\s+//;
-		$users =~ s/^\s+//;
-		$users =~ s/\n//g;
-		$date =~ s/^\s+//;
-		$desc =~ s/^\s+//;
+		my $kernelversion = $data{$what}->{kernelversion} if (defined($data{$what}->{kernelversion}));
+		my $contact = $data{$what}->{contact} if (defined($data{$what}->{contact}));
+		my $users = $data{$what}->{users} if (defined($data{$what}->{users}));
+		my $date = $data{$what}->{date} if (defined($data{$what}->{date}));
+		my $desc = $data{$what}->{description} if (defined($data{$what}->{description}));
+
+		$kernelversion =~ s/^\s+// if ($kernelversion);
+		$contact =~ s/^\s+// if ($contact);
+		if ($users) {
+			$users =~ s/^\s+//;
+			$users =~ s/\n//g;
+		}
+		$date =~ s/^\s+// if ($date);
+		$desc =~ s/^\s+// if ($desc);
 
 		printf "Kernel version:\t\t%s\n", $kernelversion if ($kernelversion);
 		printf "Date:\t\t\t%s\n", $date if ($date);