From b94e809d3e4dbfa986d7c19fd2072c313b9a3a36 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 29 Jan 2019 11:46:05 +0000 Subject: checkpatch: Don't emit spurious warnings about block comments In checkpatch we attempt to check for and warn about block comments which start with /* or /** followed by a non-blank. Unfortunately a bug in the regex meant that we would incorrectly warn about comments starting with "/**" with no following text: git show 9813dc6ac3954d58ba16b3920556f106f97e1c67|./scripts/checkpatch.pl - WARNING: Block comments use a leading /* on a separate line #34: FILE: tests/libqtest.h:233: +/** The sequence "/\*\*?" was intended to match either "/*" or "/**", but Perl's semantics for '?' allow it to backtrack and try the "matches 0 chars" option if the "matches 1 char" choice leads to a failure of the rest of the regex to match. Switch to "/\*\*?+" which uses what perlre(1) calls the "possessive" quantifier form: this means that if it matches the "/**" string it will not later backtrack to matching just the "/*" prefix. The other end of the regex is also wrong: it is attempting to check for "/* or /** followed by something that isn't just whitespace", but [ \t]*.+[ \t]* will match on pure whitespace. This is less significant but means that a line with just a comment-starter followed by trailing whitespace will generate an incorrect warning about block comment style as well as the correct error about trailing whitespace which a different checkpatch test emits. Fixes: 8c06fbdf36bf4d ("scripts/checkpatch.pl: Enforce multiline comment syntax") Reported-by: Thomas Huth Reported-by: Eric Blake Signed-off-by: Peter Maydell Reviewed-by: Eric Blake Message-id: 20190118165050.22270-1-peter.maydell@linaro.org --- scripts/checkpatch.pl | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index d10dddf..88682cb 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -1624,7 +1624,7 @@ sub process { # Block comments use /* on a line of its own if ($rawline !~ m@^\+.*/\*.*\*/[ \t]*$@ && #inline /*...*/ - $rawline =~ m@^\+.*/\*\*?[ \t]*.+[ \t]*$@) { # /* or /** non-blank + $rawline =~ m@^\+.*/\*\*?+[ \t]*[^ \t]@) { # /* or /** non-blank WARN("Block comments use a leading /* on a separate line\n" . $herecurr); } -- cgit v1.1