[PATCH 5/7] Makefile: add 'check-sort' target

[Denton Liu <liu.denton@gmail.com>]

In the previous few commits, we sorted many lists into ASCII-order. In
order to ensure that they remain that way, add the 'check-sort' target.

The check-sort.perl program ensures that consecutive lines that match
the same regex are sorted in ASCII-order. The 'check-sort' target runs
the check-sort.perl program on some files which are known to contain
sorted lists.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---

Notes:
    Full disclaimer: this is the first time I've written anything in Perl.
    Please let me know if I'm doing anything unconventional :)

 Makefile        | 25 +++++++++++++++++++++++++
 check-sort.perl | 31 +++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100755 check-sort.perl

diff --git a/Makefile b/Makefile
index 5832aa33da..b23dff384d 100644
--- a/Makefile
+++ b/Makefile
@@ -3240,6 +3240,31 @@ check-docs::
 check-builtins::
 	./check-builtins.sh
 
+.PHONY: check-sort
+check-sort::
+	./check-sort.perl \
+		'ALL_COMMANDS \+=' \
+		'ALL_COMMANDS_TO_INSTALL \+=' \
+		'BINDIR_PROGRAMS_NEED_X \+=' \
+		'BINDIR_PROGRAMS_NO_X \+=' \
+		'BUILTIN_OBJS \+=' \
+		'BUILT_INS \+=' \
+		'FUZZ_OBJS \+=' \
+		'GENERATED_H \+=' \
+		'LIB_OBJS \+=' \
+		'SCRIPT_LIB \+=' \
+		'SCRIPT_PERL \+=' \
+		'SCRIPT_PYTHON \+=' \
+		'SCRIPT_SH \+=' \
+		'TEST_BUILTINS_OBJS \+=' \
+		'TEST_PROGRAMS_NEED_X \+=' \
+		'THIRD_PARTY_SOURCES \+=' \
+		'XDIFF_OBJS \+=' \
+		<Makefile
+	./check-sort.perl 'int cmd_[^(]*\(' <builtin.h
+	./check-sort.perl 'int cmd__[^(]*\(' <t/helper/test-tool.h
+	./check-sort.perl '\t\{ "[^"]*",' <git.c
+
 ### Test suite coverage testing
 #
 .PHONY: coverage coverage-clean coverage-compile coverage-test coverage-report
diff --git a/check-sort.perl b/check-sort.perl
new file mode 100755
index 0000000000..cd723db14d
--- /dev/null
+++ b/check-sort.perl
@@ -0,0 +1,31 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+my @regexes = map { qr/^$_/ } @ARGV;
+my $last_regex = 0;
+my $last_line = '';
+
+while (<STDIN>) {
+	my $matched = 0;
+	chomp;
+
+	for my $regex (@regexes) {
+		next unless $_ =~ $regex;
+
+		if ($last_regex == $regex) {
+			die "duplicate lines: '$_'\n" unless $last_line ne $_;
+			die "unsorted lines: '$last_line' before '$_'\n" unless $last_line lt $_;
+		}
+
+		$matched = 1;
+		$last_regex = $regex;
+		$last_line = $_;
+	}
+
+	unless ($matched) {
+		$last_regex = 0;
+		$last_line = '';
+	}
+}
-- 
2.31.0.rc2.261.g7f71774620