[RFC PATCH v2 05/10] checkpatch: Propose tests to execute

[Nikolai Kondrashov <Nikolai.Kondrashov@redhat.com>]

Make scripts/checkpatch.pl output a 'CHECK' advertising any test suites
proposed for the changed subsystems, and prompting their execution.

Using 'CHECK', instead of 'WARNING', or 'ERROR', because test suite
commands executed for testing can generally be off by an option/argument
or two, depending on the situation, while still satisfying the
maintainer requirements, but failing the comparison with the V: entry
and raising alarm unnecessarily.

However, see the later patch adding the proposal strength to the V:
entry and allowing raising the severity of the message for those who'd
like that.

Signed-off-by: Nikolai Kondrashov <Nikolai.Kondrashov@redhat.com>
---
 scripts/checkpatch.pl | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index bea602c30df5d..1da617e1edb5f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1144,6 +1144,29 @@ sub is_maintained_obsolete {
 	return $maintained_status{$filename} =~ /obsolete/i;
 }
 
+# Test suites proposed per changed file
+our %files_proposed_tests = ();
+
+# Return a list of test suites proposed for execution for a particular file
+sub get_file_proposed_tests {
+	my ($filename) = @_;
+	my $file_proposed_tests;
+
+	return () if (!$tree || !(-e "$root/scripts/get_maintainer.pl"));
+
+	if (!exists($files_proposed_tests{$filename})) {
+		my $command = "perl $root/scripts/get_maintainer.pl --test --multiline --nogit --nogit-fallback -f $filename";
+		# Ignore warnings on stderr
+		my $output = `$command 2>/dev/null`;
+		# But regenerate stderr on failure
+		die "Failed retrieving tests proposed for changes to \"$filename\":\n" . `$command 2>&1 >/dev/null` if ($?);
+		$files_proposed_tests{$filename} = [grep { !/@/ } split("\n", $output)]
+	}
+
+	$file_proposed_tests = $files_proposed_tests{$filename};
+	return @$file_proposed_tests;
+}
+
 sub is_SPDX_License_valid {
 	my ($license) = @_;
 
@@ -2689,6 +2712,9 @@ sub process {
 	my @setup_docs = ();
 	my $setup_docs = 0;
 
+	# Test suites which should not be proposed for execution
+	my %dont_propose_tests = ();
+
 	my $camelcase_file_seeded = 0;
 
 	my $checklicenseline = 1;
@@ -2907,6 +2933,17 @@ sub process {
 				}
 			}
 
+			# Check if tests are proposed for changes to the file
+			foreach my $test (get_file_proposed_tests($realfile)) {
+				next if exists $dont_propose_tests{$test};
+				CHK("TEST_PROPOSAL",
+				    "Running the following test suite is proposed for changes to $realfile:\n" .
+				    "$test\n" .
+				    "Add the following to the tested commit's message, IF IT PASSES:\n" .
+				    "Tested-with: $test\n");
+				$dont_propose_tests{$test} = 1;
+			}
+
 			next;
 		}
 
@@ -3233,6 +3270,12 @@ sub process {
 			}
 		}
 
+# Check and accumulate executed test suites (stripping URLs off the end)
+		if (!$in_commit_log && $line =~ /^\s*Tested-with:\s*(.*?)\s*#.*$/i) {
+			# Do not propose this certified-passing test suite
+			$dont_propose_tests{$1} = 1;
+		}
+
 # Check email subject for common tools that don't need to be mentioned
 		if ($in_header_lines &&
 		    $line =~ /^Subject:.*\b(?:checkpatch|sparse|smatch)\b[^:]/i) {
-- 
2.42.0