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. Reported-by: Thomas Huth <th...@redhat.com> Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- This comment check is unique to QEMU checkpatch so the bug doesn't exist in the Linux version. --- scripts/checkpatch.pl | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index d10dddf1be4..5f1ec537d21 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); } -- 2.20.1