[Qemu-devel] [PATCH] scripts: let checkpatch.pl process an entire GIT branch

["Daniel P. Berrange" <berrange@redhat.com>]

Currently before submitting a series, devs should run checkpatch.pl
across each patch to be submitted. This can be automated using a
command such as:

  git rebase -i master -x 'git show | ./scripts/checkpatch.pl -'

This is rather long winded to type, so this patch introduces a new
flag '--branch' to checkpatch.pl which instructs it to check every
patch on the current GIT branch.

For example:

    $ ./scripts/checkpatch.pl --branch
    total: 0 errors, 0 warnings, 297 lines checked

    b886d352a2bf58f0996471fb3991a138373a2957 has no obvious style problems and is ready for submission.
    total: 0 errors, 0 warnings, 182 lines checked

    2a731f9a9ce145e0e0df6d42dd2a3ce4dfc543fa has no obvious style problems and is ready for submission.
    total: 0 errors, 0 warnings, 102 lines checked

    11844169bcc0c8ed4449eb3744a69877ed329dd7 has no obvious style problems and is ready for submission.

By default it checks every patch identified by 'master..', however,
an alternative origin can be given if desired, if the current branch
is rebased to another non-master branch:

    $ ./scripts/checkpatch.pl --branch somebranch..

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 scripts/checkpatch.pl | 97 +++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 71 insertions(+), 26 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index fa478074b8..f8d080441f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -19,6 +19,8 @@ my $quiet = 0;
 my $tree = 1;
 my $chk_signoff = 1;
 my $chk_patch = 1;
+my $chk_branch = 0;
+my $revlist = "master..";
 my $tst_only;
 my $emacs = 0;
 my $terse = 0;
@@ -43,6 +45,7 @@ Options:
   --no-tree                  run without a kernel tree
   --no-signoff               do not check for 'Signed-off-by' line
   --patch                    treat FILE as patchfile (default)
+  --branch                   check all patches on branch since master
   --emacs                    emacs compile window format
   --terse                    one line per report
   -f, --file                 treat FILE as regular source file
@@ -69,6 +72,7 @@ GetOptions(
 	'tree!'		=> \$tree,
 	'signoff!'	=> \$chk_signoff,
 	'patch!'	=> \$chk_patch,
+	'branch'	=> \$chk_branch,
 	'emacs!'	=> \$emacs,
 	'terse!'	=> \$terse,
 	'f|file!'	=> \$file,
@@ -88,9 +92,19 @@ help(0) if ($help);
 
 my $exit = 0;
 
-if ($#ARGV < 0) {
-	print "$P: no input files\n";
-	exit(1);
+if ($chk_branch) {
+	if ($#ARGV > 0) {
+		print "$P: expected zero or one origni revisions\n";
+		exit(1);
+	}
+	if ($#ARGV == 0) {
+		$revlist = shift @ARGV;
+	}
+} else {
+	if ($#ARGV < 0) {
+		print "$P: no input files\n";
+		exit(1);
+	}
 }
 
 my $dbg_values = 0;
@@ -251,32 +265,63 @@ $chk_signoff = 0 if ($file);
 my @rawlines = ();
 my @lines = ();
 my $vname;
-for my $filename (@ARGV) {
-	my $FILE;
-	if ($file) {
-		open($FILE, '-|', "diff -u /dev/null $filename") ||
-			die "$P: $filename: diff failed - $!\n";
-	} elsif ($filename eq '-') {
-		open($FILE, '<&STDIN');
-	} else {
-		open($FILE, '<', "$filename") ||
-			die "$P: $filename: open failed - $!\n";
-	}
-	if ($filename eq '-') {
-		$vname = 'Your patch';
-	} else {
-		$vname = $filename;
-	}
-	while (<$FILE>) {
+if ($chk_branch) {
+	my @patches;
+	my $HASH;
+	open($HASH, "-|", "git", "log", "--format=%H", $revlist) ||
+		die "$P: git log --format=%H $revlist failed - $!\n";
+
+	while (<$HASH>) {
 		chomp;
-		push(@rawlines, $_);
+		push @patches, $_;
 	}
-	close($FILE);
-	if (!process($filename)) {
-		$exit = 1;
+
+	close $HASH;
+
+	for my $hash (@patches) {
+		my $FILE;
+		open($FILE, '-|', "git", "show", $hash) ||
+			die "$P: git show $hash - $!\n";
+		$vname = $hash;
+		while (<$FILE>) {
+			chomp;
+			push(@rawlines, $_);
+		}
+		close($FILE);
+		if (!process($hash)) {
+			$exit = 1;
+		}
+		@rawlines = ();
+		@lines = ();
+	}
+} else {
+	for my $filename (@ARGV) {
+		my $FILE;
+		if ($file) {
+			open($FILE, '-|', "diff -u /dev/null $filename") ||
+				die "$P: $filename: diff failed - $!\n";
+		} elsif ($filename eq '-') {
+			open($FILE, '<&STDIN');
+		} else {
+			open($FILE, '<', "$filename") ||
+				die "$P: $filename: open failed - $!\n";
+		}
+		if ($filename eq '-') {
+			$vname = 'Your patch';
+		} else {
+			$vname = $filename;
+		}
+		while (<$FILE>) {
+			chomp;
+			push(@rawlines, $_);
+		}
+		close($FILE);
+		if (!process($filename)) {
+			$exit = 1;
+		}
+		@rawlines = ();
+		@lines = ();
 	}
-	@rawlines = ();
-	@lines = ();
 }
 
 exit($exit);
-- 
2.13.5