Re: [Qemu-devel] [PATCH v7 03/10] checkpatch.pl: Check .cpp files

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Tomoki Sekiyama (2013-07-15 11:20:37)
> Enable checkpatch.pl to apply the same checks as C source files for
> C++ files with .cpp extensions. It also adds some exceptions for C++
> sources to suppress errors for:
>   - <> used in C++ template arguments (e.g. template <class T>)
>   - :: used to represent namespaces   (e.g. SomeClass::method())
>   - : used in class declaration       (e.g. class T : public Super)
>   - ~ used in destructor method name  (e.g. T::~T())
>   - spacing around 'catch'            (e.g. catch (...))
> 
> Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>

One small nit below about documentation. Looks good otherwise.

> ---
>  scripts/checkpatch.pl |   37 +++++++++++++++++++++++++++++--------
>  1 file changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index ec0aa4c..0ef72b5 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -1363,7 +1363,7 @@ sub process {
>  # Check for incorrect file permissions
>                 if ($line =~ /^new (file )?mode.*[7531]\d{0,2}$/) {
>                         my $permhere = $here . "FILE: $realfile\n";
> -                       if ($realfile =~ /(Makefile|Kconfig|\.c|\.h|\.S|\.tmpl)$/) {
> +                       if ($realfile =~ /(Makefile|Kconfig|\.c|\.cpp|\.h|\.S|\.tmpl)$/) {
>                                 ERROR("do not set execute permissions for source files\n" . $permhere);
>                         }
>                 }
> @@ -1460,7 +1460,7 @@ sub process {
>                 }
> 
>  # check we are in a valid source file if not then ignore this hunk
> -               next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);
> +               next if ($realfile !~ /\.(h|c|cpp|s|S|pl|sh)$/);
> 
>  #80 column limit
>                 if ($line =~ /^\+/ && $prevrawline !~ /\/\*\*/ &&
> @@ -1495,7 +1495,7 @@ sub process {
>                 }
> 
>  # check we are in a valid source file C or perl if not then ignore this hunk
> -               next if ($realfile !~ /\.(h|c|pl)$/);
> +               next if ($realfile !~ /\.(h|c|cpp|pl)$/);
> 
>  # in QEMU, no tabs are allowed
>                 if ($rawline =~ /^\+.*    /) {
> @@ -1505,7 +1505,7 @@ sub process {
>                 }
> 
>  # check we are in a valid C source file if not then ignore this hunk
> -               next if ($realfile !~ /\.(h|c)$/);
> +               next if ($realfile !~ /\.(h|c|cpp)$/);
> 
>  # check for RCS/CVS revision markers
>                 if ($rawline =~ /^\+.*\$(Revision|Log|Id)(?:\$|)/) {
> @@ -1969,6 +1969,9 @@ sub process {
>                                 asm|__asm__)$/x)
>                         {
> 
> +                       # Ignore 'catch (...)' in C++
> +                       } elsif ($name =~ /^catch$/ && $realfile =~ /(\.cpp|\.h)$/) {
> +
>                         # cpp #define statements have non-optional spaces, ie
>                         # if there is a space between the name and the open
>                         # parenthesis it is simply not a parameter group.
> @@ -1992,7 +1995,7 @@ sub process {
>                                 \+=|-=|\*=|\/=|%=|\^=|\|=|&=|
>                                 =>|->|<<|>>|<|>|=|!|~|
>                                 &&|\|\||,|\^|\+\+|--|&|\||\+|-|\*|\/|%|
> -                               \?|:
> +                               \?|::|:
>                         }x;
>                         my @elements = split(/($ops|;)/, $opline);
>                         my $off = 0;
> @@ -2066,7 +2069,8 @@ sub process {
>                                 #   ->
>                                 #   :   when part of a bitfield
>                                 } elsif ($op eq '->' || $opv eq ':B') {
> -                                       if ($ctx =~ /Wx.|.xW/) {
> +                                       if ($ctx =~ /Wx.|.xW/ &&
> +                                               !($opv eq ':B' && $line =~ /class/)) {

Everything else seemed fairly obvious or was well commented, but I couldn't
figure out what this change was for. Could you insert a small comment to
explain?

>                                                 ERROR("spaces prohibited around that '$op' $at\n" . $hereptr);
>                                         }
> 
> @@ -2088,7 +2092,11 @@ sub process {
>                                 } elsif ($op eq '!' || $op eq '~' ||
>                                          $opv eq '*U' || $opv eq '-U' ||
>                                          $opv eq '&U' || $opv eq '&&U') {
> -                                       if ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
> +                                       if ($op eq '~' && $ca =~ /::$/ && $realfile =~ /(\.cpp|\.h)$/) {
> +                                               # '~' used as a name of Destructor
> +
> +                                       }
> +                                       elsif ($ctx !~ /[WEBC]x./ && $ca !~ /(?:\)|!|~|\*|-|\&|\||\+\+|\-\-|\{)$/) {
>                                                 ERROR("space required before that '$op' $at\n" . $hereptr);
>                                         }
>                                         if ($op eq '*' && $cc =~/\s*$Modifier\b/) {
> @@ -2126,8 +2134,9 @@ sub process {
> 
>                                 # A colon needs no spaces before when it is
>                                 # terminating a case value or a label.
> +                               # Ignored if it is used in class declaration in C++.
>                                 } elsif ($opv eq ':C' || $opv eq ':L') {
> -                                       if ($ctx =~ /Wx./) {
> +                                       if ($ctx =~ /Wx./ && $line !~ /class/) {
>                                                 ERROR("space prohibited before that '$op' $at\n" . $hereptr);
>                                         }
> 
> @@ -2135,6 +2144,18 @@ sub process {
>                                 } elsif ($ctx !~ /[EWC]x[CWE]/) {
>                                         my $ok = 0;
> 
> +                                       if ($realfile =~ /\.cpp|\.h$/) {
> +                                               # Ignore template arguments <...> in C++
> +                                               if (($op eq '<' || $op eq '>') && $line =~ /<.*>/) {
> +                                                       $ok = 1;
> +                                               }
> +
> +                                               # Ignore :: in C++
> +                                               if ($op eq '::') {
> +                                                       $ok = 1;
> +                                               }
> +                                       }
> +
>                                         # Ignore email addresses <foo@bar>
>                                         if (($op eq '<' &&
>                                              $cc =~ /^\S+\@\S+>/) ||