[PATCH] checkpatch: fix for stripping brackets from macros.

[PATCH] checkpatch: fix for stripping brackets from macros.

[Jeremy Sowden]

When checking macros, checkpatch.pl strips parentheses, square brackets
and braces.  However, the search-and-replace expression was not correct,
and instead of replacing the brackets and their contents with just the
contents, it was replacing them with literal 1's.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---
 scripts/checkpatch.pl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 168687ae24fa..3b67646df845 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4874,9 +4874,9 @@ sub process {
 			$dstat =~ s/\s*$//s;
 
 			# Flatten any parentheses and braces
-			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
-			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
-			       $dstat =~ s/.\[[^\[\]]*\]/1/)
+			while ($dstat =~ s/\(([^\(\)]*)\)/$1/ ||
+			       $dstat =~ s/\{([^\{\}]*)\}/$1/ ||
+			       $dstat =~ s/.\[([^\[\]]*)\]/$1/)
 			{
 			}
 

base-commit: 53600ecfb6004f355bd3551bee180caf4b42d7a7
-- 
2.15.1

Re: [PATCH] checkpatch: fix for stripping brackets from macros.

[Joe Perches]

On Mon, 2017-12-18 at 14:17 +0000, Jeremy Sowden wrote:
> When checking macros, checkpatch.pl strips parentheses, square brackets
> and braces.  However, the search-and-replace expression was not correct,
> and instead of replacing the brackets and their contents with just the
> contents, it was replacing them with literal 1's.

Jeremy:

What is the effect on the rest of the block that
uses this substituted
$dstat?  Why should this be
done?

Andy:

I believe this is intentional as it simplifies
the macro analysis and has no other effect on the
rest of the block.  Correct?

> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -4874,9 +4874,9 @@ sub process {
>  			$dstat =~ s/\s*$//s;
>  
>  			# Flatten any parentheses and braces
> -			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
> -			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
> -			       $dstat =~ s/.\[[^\[\]]*\]/1/)
> +			while ($dstat =~ s/\(([^\(\)]*)\)/$1/ ||
> +			       $dstat =~ s/\{([^\{\}]*)\}/$1/ ||
> +			       $dstat =~ s/.\[([^\[\]]*)\]/$1/)
>  			{
>  			}

Re: [PATCH] checkpatch: fix for stripping brackets from macros.

[Jeremy Sowden]

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On 2017-12-18, at 07:12:50 -0800, Joe Perches wrote:
> On Mon, 2017-12-18 at 14:17 +0000, Jeremy Sowden wrote:
> > When checking macros, checkpatch.pl strips parentheses, square
> > brackets and braces.  However, the search-and-replace expression was
> > not correct, and instead of replacing the brackets and their
> > contents with just the contents, it was replacing them with literal
> > 1's.
>
> Jeremy:
>
> What is the effect on the rest of the block that uses this substituted
> $dstat?  Why should this be done?

I had some macros which defined compound literals, e.g.:

  #define TEST (struct test) { .member = 1 }

and checkpatch.pl complained that macros with complex values should be
enclosed in parentheses.  When I had a look at the checkpatch.pl source
I noticed that there were a number of exceptions against which $dstat
was matched and that they included the struct and union keywords.  These
matches failed, however, 'cause the compound-literal had been turned
into:

 1 1

which didn't seem to make much sense.  Given that the while-loop was
immediately followed by another that did the more obvious thing:

  # Flatten any parentheses and braces
  while ($dstat =~ s/\([^\(\)]*\)/1/ ||
         $dstat =~ s/\{[^\{\}]*\}/1/ ||
         $dstat =~ s/.\[[^\[\]]*\]/1/)
  {
  }

  # Flatten any obvious string concatentation.
  while ($dstat =~ s/($String)\s*$Ident/$1/ ||
         $dstat =~ s/$Ident\s*($String)/$1/)
  {
  }

it occurred to me that this might be a bug.

> Andy:
>
> I believe this is intentional as it simplifies
> the macro analysis and has no other effect on the
> rest of the block.  Correct?
>
> > diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> []
> > @@ -4874,9 +4874,9 @@ sub process {
> >  			$dstat =~ s/\s*$//s;
> >
> >  			# Flatten any parentheses and braces
> > -			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
> > -			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
> > -			       $dstat =~ s/.\[[^\[\]]*\]/1/)
> > +			while ($dstat =~ s/\(([^\(\)]*)\)/$1/ ||
> > +			       $dstat =~ s/\{([^\{\}]*)\}/$1/ ||
> > +			       $dstat =~ s/.\[([^\[\]]*)\]/$1/)
> >  			{
> >  			}

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