Message-ID: <38d7d022d6e88d643c8037e26707a719cb55ff1d.camel@perches.com>
Subject: Re: [PATCH] riscv: Add header include guards to insn.h
From:   Joe Perches <joe@perches.com>
To:     "liaochang (A)" <liaochang1@huawei.com>,
        Conor Dooley <conor.dooley@microchip.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     paul.walmsley@sifive.com, palmer@dabbelt.com,
        aou@eecs.berkeley.edu, heiko.stuebner@vrull.eu,
        ajones@ventanamicro.com, prabhakar.mahadev-lad.rj@bp.renesas.com,
        jszhang@kernel.org, vincent.chen@sifive.com,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Date:   Wed, 01 Feb 2023 19:33:28 -0800
In-Reply-To: <f161df27-f2d7-0367-33a0-9ff5e4b880d9@huawei.com>
References: <20230129094242.282620-1-liaochang1@huawei.com>
         <Y9fZ2ZxdMmXgO5aB@wendy> <9a4f98a7-fa03-7960-29ce-0bff018c0ac9@huawei.com>
         <Y9o0Bv7VBM74ePHH@wendy> <f161df27-f2d7-0367-33a0-9ff5e4b880d9@huawei.com>
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On Thu, 2023-02-02 at 08:52 +0800, liaochang (A) wrote:
> 
> 在 2023/2/1 17:42, Conor Dooley 写道:
> > Hi,
> > 
> > On Wed, Feb 01, 2023 at 05:37:24PM +0800, liaochang (A) wrote:
> > > 在 2023/1/30 22:53, Conor Dooley 写道:
> > > > On Sun, Jan 29, 2023 at 05:42:42PM +0800, Liao Chang wrote:
> > > > > Add header include guards to insn.h to prevent repeating declaration of
> > > > > any identifiers in insn.h.
> > > > 
> > > > I'm curious, did you spot this "by hand" while doing other work, or do
> > > > you have a tool that found it for you?
> > > 
> > > I found this "by hand", inspired by scripts/checkdeclares.pl, i write a tiny tool
> > > to analyse the missing header guards in header file.
> > 
> > Ohh, cool! I'd love to add this one to the checks on patchwork so that
> > we do not end up adding any more of these. If this is based on
> > checkdeclares, is it GPLv2?
> 
> Definitely, it is GPLv2,i will appending licence identifier and copyright info later.
> 
> Hi，@Joe Perches, is it ok to integrate this tool to scripts?

Don't see why not.
Perhaps submit it as a real patch to Andrew Morton <akpm@linux-foundation.org>

Trivial notes below:

> > > #!/usr/bin/env perl
> > > use strict;
> > > 
> > > sub usage {
> > >         print "Usage: checkguards.pl file1.h ...\n";
> > >         print "Warn of missing header guards\n";
> > >         exit 1;
> > > }
> > > 
> > > if ($#ARGV < 0) {
> > >         usage();
> > > }
> > > 
> > > foreach my $file (@ARGV) {
> > >         open(my $f, '<', $file)
> > >             or die "Cannot open $file: $!.\n";
> > > 
> > >         my $scan_area = 1;
> > >         my $guards_warn = 0;
> > > 
> > >         # The lines of header file are divided into several areas as follows:
> > >         #
> > >         # ... area1 ...
> > >         # #ifndef _HEADER_GUARD
> > >         # ... area2 ...
> > >         # #define _HEADER_GUARD
> > >         # ... area3 ...
> > >         # #endif /* _HEADER_GUARD */
> > >         # ... area4 ...
> > >         # EOF
> > >         #
> > >         # If any statement is found in area1, area2, and area4, it
> > >         # throws a warning of illegal usage of header guard usage.

Not illegal, invalid

> > >         while (<$f>) {
> > >                 if (m/^(.*);\s*$/o) {
> > >                         if ($scan_area == 1 || $scan_area == 2 || $scan_area == 4) {
> > >                                 ++$guards_warn;
> > >                         }
> > >                 } elsif (m/^\s*(#ifndef\s+)[a-zA-Z0-9_]*_H[_]*\s*$/o) {
> > >                         ++$scan_area;
> > >                 } elsif (m/^\s*(#define\s+)[a-zA-Z0-9_]*_H[_]*\s*$/o) {
> > >                         ++$scan_area;
> > >                 } elsif (m/^\s*(#endif)\s*\/\*\s*[a-zA-Z0-9_]*_H[_]*\s*\*\/\s*$/o) {
> > >                         ++$scan_area;
> > >                 }
> > >         }
> > > 
> > >         close($f);
> > > 
> > >         if ($guards_warn) {
> > >                 print "Illegal usage of header guard found in $file.\n";

here too

There are also uses like #if !defined(FOO)
There can be spaces before and after the #

It might also be useful to have a check for missing header guards.