On Fri, 2018-05-18 at 07:09 -0700, Matthew Wilcox wrote: > Hi Joe, > > A nice checkpatch addition would be to look for seq_puts(x, "s") > and recommend the author use seq_putc(x, 's') instead. The primary > offender is seq_puts(x, "\n") (a hundred or so, scattered throughout > the kernel), but seq_puts(x, " ") has its adherents too.
Firstly, has Markus Elfring left the building? Here's a grep to find the existing uses: $ git grep -P '\b(?:seq_puts|seq_printf)\s*\(\s*[^,]+,\s*"(?:\\.|.)"\s*\)\s*;' | \ wc -l 326 and a trivial script to convert them all treewide $ git grep -P --name-only '\b(?:seq_puts|seq_printf)\s*\(\s*[^,]+,\s*"(?:\\.|.)"\s*\)\s*;' | \ xargs perl -i -e 'local $/; while (<>) { s/\b(?:seq_puts|seq_printf)\s*\(\s*([^,]+),\s*"(\\.|.)"\s*\)\s*;/seq_putc(\1, '"'\2'"')/g; print;}' Anyway, I still like a variant of Steven Rostedt's trace_puts macro silliness hack that avoids all this by allowing seq_printf without format arguments to call the appropriate seq_puts/seq_putc invisibly. https://groups.google.com/forum/#!topic/linux.kernel/YGZhTD-n4UA It's relatively easy to expand this for seq_putc, but here's an expanded checkpatch rule anyway that seems to work. --- diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index baddac9379f0..62b36d7bb3af 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -5791,11 +5791,23 @@ sub process { "struct spinlock should be spinlock_t\n" . $herecurr); } -# check for seq_printf uses that could be seq_puts - if ($sline =~ /\bseq_printf\s*\(.*"\s*\)\s*;\s*$/) { +# check for seq_printf/seq_puts uses that could be seq_puts or seq_putc + if ($sline =~ /\b(seq_(?:printf|puts))\s*\(.*"\s*\)\s*;\s*$/) { + my $call = $1; my $fmt = get_quoted_string($line, $rawline); + my $fmt_nq = substr($fmt, 1, length($fmt) - 2); #strip outer quotes $fmt =~ s/%%//g; - if ($fmt !~ /%/) { + + if (length($fmt_nq) == 1 || + (length($fmt_nq) == 2 && ($fmt_nq =~ /^\\/ || $fmt_nq =~ /\%\%/))) { + my $fmt_sub = $fmt_nq; + $fmt_sub =~ s/\%\%/%/; + if (WARN("PREFER_SEQ_PUTC", + "Prefer seq_putc to $call\n" . $herecurr) && + $fix) { + $fixed[$fixlinenr] =~ s/\b$call\s*\(\s*($FuncArg)\s*,\s*"\Q$fmt_nq\E"\s*\)/seq_putc($1, '$fmt_sub')/x; + } + } elsif ($fmt !~ /%/) { if (WARN("PREFER_SEQ_PUTS", "Prefer seq_puts to seq_printf\n" . $herecurr) && $fix) {