pgindent: more ways to find files to indent

A new --commit option will add all the files in a commit to the file
list. The option can be specified more than once.

Also, if a directory is given on the command line, all the files in that
directory tree will be added to the file list.

Per suggestions from Robert Haas

Reviewed by Jelte Fennema

Discussion: https://postgr.es/m/CA+TgmoY59Ksso81RNLArNxj0a7xaqV_F_u7gSMHbgdc2kG5Vpw@mail.gmail.com

src/tools/pgindent/pgindent

@@ -23,12 +23,14 @@ my $devnull = File::Spec->devnull;
 
 my ($typedefs_file, $typedef_str, $code_base,
 	@excludes,      $indent,      $build,
-	$show_diff,     $silent_diff, $help);
+	$show_diff,     $silent_diff, $help,
+	@commits,);
 
 $help = 0;
 
 my %options = (
 	"help"               => \$help,
+	"commit=s"           => \@commits,
 	"typedefs=s"         => \$typedefs_file,
 	"list-of-typedefs=s" => \$typedef_str,
 	"code-base=s"        => \$code_base,
@@ -44,6 +46,9 @@ usage() if $help;
 usage("Cannot have both --silent-diff and --show-diff")
   if $silent_diff && $show_diff;
 
+usage("Cannot use --commit with --code-base or command line file list")
+  if (@commits && ($code_base || @ARGV));
+
 run_build($code_base) if ($build);
 
 # command line option wins, then environment (which is how --build sets it) ,
@@ -53,8 +58,9 @@ $typedefs_file ||= $ENV{PGTYPEDEFS};
 # build mode sets PGINDENT
 $indent ||= $ENV{PGINDENT} || $ENV{INDENT} || "pg_bsd_indent";
 
-# no non-option arguments given. so do everything in the current directory
-$code_base ||= '.' unless @ARGV;
+# if no non-option arguments or commits are given, default to looking in the
+# current directory
+$code_base ||= '.' unless (@ARGV || @commits);
 
 my $sourcedir = locate_sourcedir();
 
@@ -388,6 +394,7 @@ Usage:
 pgindent [OPTION]... [FILE]...
 Options:
 	--help                  show this message and quit
+    --commit=gitref         use files modified by the named commit
 	--typedefs=FILE         file containing a list of typedefs
 	--list-of-typedefs=STR  string containing typedefs, space separated
 	--code-base=DIR         path to the base of PostgreSQL source code
@@ -396,7 +403,7 @@ Options:
 	--build                 build the pg_bsd_indent program
 	--show-diff             show the changes that would be made
 	--silent-diff           exit with status 2 if any changes would be made
-The --excludes option can be given more than once.
+The --excludes and --commit options can be given more than once.
 EOF
 	if ($help)
 	{
@@ -412,27 +419,38 @@ EOF
 
 # main
 
-# get the list of files under code base, if it's set
-File::Find::find(
-	{
-		wanted => sub {
-			my ($dev, $ino, $mode, $nlink, $uid, $gid);
-			(($dev, $ino, $mode, $nlink, $uid, $gid) = lstat($_))
-			  && -f _
-			  && /^.*\.[ch]\z/s
-			  && push(@files, $File::Find::name);
-		}
-	},
-	$code_base) if $code_base;
-
 $filtered_typedefs_fh = load_typedefs();
 
 check_indent();
 
-# any non-option arguments are files to be processed
-push(@files, @ARGV);
+build_clean($code_base) if $build;
 
-# the exclude list applies to command line arguments as well as found files
+my $wanted = sub
+{
+	my ($dev, $ino, $mode, $nlink, $uid, $gid);
+	(($dev, $ino, $mode, $nlink, $uid, $gid) = lstat($_))
+	  && -f _
+	  && /^.*\.[ch]\z/s
+	  && push(@files, $File::Find::name);
+};
+
+# get the list of files under code base, if it's set
+File::Find::find({wanted => $wanted }, $code_base) if $code_base;
+
+# any non-option arguments are files or directories to be processed
+File::Find::find({wanted => $wanted}, @ARGV) if @ARGV;
+
+# process named commits by comparing each with their immediate ancestor
+foreach my $commit (@commits)
+{
+	my $prev="$commit~";
+	my @affected=`git diff-tree --no-commit-id --name-only -r $commit $prev`;
+	die "git error" if $?;
+	chomp(@affected);
+	push(@files,@affected);
+}
+
+# remove excluded files from the file list
 process_exclude();
 
 foreach my $source_filename (@files)
@@ -481,6 +499,4 @@ foreach my $source_filename (@files)
 	}
 }
 
-build_clean($code_base) if $build;
-
 exit 0;