[PATCH] checkpatch: Add ability to --fix (coalesce) string fragments on multiple lines

Joe Perches
2014-11-20T19:16:56Z

Add --fix option to coalesce string fragments.

This does not coalesce string fragments that have
newline terminations or are otherwise exempted.

Other miscellanea:

o move all the string tests together.
o fix get_quoted_string function for tab characters
o fix concatination typo

Signed-off-by: Joe Perches <joe@perches.com>
---
scripts/checkpatch.pl | 112 +++++++++++++++++++++++++++++---------------------
1 file changed, 66 insertions(+), 46 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 6d85c7b..5a6c2dc 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -946,7 +946,7 @@ sub sanitise_line {
sub get_quoted_string {
my ($line, $rawline) = @_;

- return "" if ($line !~ m/(\"[X]+\")/g);
+ return "" if ($line !~ m/(\"[X\t]+\")/g);
return substr($rawline, $-[0], $+[0] - $-[0]);
}

@@ -2413,33 +2413,6 @@ sub process {
"line over $max_line_length characters\n" . $herecurr);
}

-# Check for user-visible strings broken across lines, which breaks the ability
-# to grep for the string. Make exceptions when the previous string ends in a
-# newline (multiple lines in one string constant) or '\t', '\r', ';', or '{'
-# (common in inline assembly) or is a octal \123 or hexadecimal \xaf value
- if ($line =~ /^\+\s*"/ &&
- $prevline =~ /"\s*$/ &&
- $prevrawline !~ /(?:\\(?:[ntr]|[0-7]{1,3}|x[0-9a-fA-F]{1,2})|;\s*|\{\s*)"\s*$/) {
- WARN("SPLIT_STRING",
- "quoted string split across lines\n" . $hereprev);
- }
-
-# check for missing a space in a string concatination
- if ($prevrawline =~ /[^\\]\w"$/ && $rawline =~ /^\+[\t ]+"\w/) {
- WARN('MISSING_SPACE',
- "break quoted strings at a space character\n" . $hereprev);
- }
-
-# check for spaces before a quoted newline
- if ($rawline =~ /^.*\".*\s\\n/) {
- if (WARN("QUOTED_WHITESPACE_BEFORE_NEWLINE",
- "unnecessary whitespace before a quoted newline\n" . $herecurr) &&
- $fix) {
- $fixed[$fixlinenr] =~ s/^(\+.*\".*)\s+\\n/$1\\n/;
- }
-
- }
-
# check for adding lines without a newline.
if ($line =~ /^\+/ && defined $lines[$linenr] && $lines[$linenr] =~ /^\\ No newline at end of file/) {
WARN("MISSING_EOF_NEWLINE",
@@ -4458,6 +4431,53 @@ sub process {
"Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt\n" . $herecurr);
}

+# Check for user-visible strings broken across lines, which breaks the ability
+# to grep for the string. Make exceptions when the previous string ends in a
+# newline (multiple lines in one string constant) or '\t', '\r', ';', or '{'
+# (common in inline assembly) or is a octal \123 or hexadecimal \xaf value
+ if ($line =~ /^\+\s*"[X\t]*"/ &&
+ $prevline =~ /"\s*$/ &&
+ $prevrawline !~ /(?:\\(?:[ntr]|[0-7]{1,3}|x[0-9a-fA-F]{1,2})|;\s*|\{\s*)"\s*$/) {
+ if (WARN("SPLIT_STRING",
+ "quoted string split across lines\n" . $hereprev) &&
+ $fix &&
+ $prevrawline =~ /^\+.*"\s*$/) {
+ my $extracted_string = get_quoted_string($line, $rawline);
+ my $comma_close = "";
+ if ($rawline =~ /\Q$extracted_string\E(\s*\)\s*;\s*$|\s*,\s*)/) {
+ $comma_close = $1;
+ }
+
+ fix_delete_line($fixlinenr - 1, $prevrawline);
+ fix_delete_line($fixlinenr, $rawline);
+ my $fixedline = $prevrawline;
+ $fixedline =~ s/"\s*$//;
+ $fixedline .= substr($extracted_string, 1) . trim($comma_close);
+ fix_insert_line($fixlinenr - 1, $fixedline);
+ $fixedline = $rawline;
+ $fixedline =~ s/\Q$extracted_string\E\Q$comma_close\E//;
+ if ($fixedline !~ /\+\s*$/) {
+ fix_insert_line($fixlinenr, $fixedline);
+ }
+ }
+ }
+
+# check for missing a space in a string concatenation
+ if ($prevrawline =~ /[^\\]\w"$/ && $rawline =~ /^\+[\t ]+"\w/) {
+ WARN('MISSING_SPACE',
+ "break quoted strings at a space character\n" . $hereprev);
+ }
+
+# check for spaces before a quoted newline
+ if ($rawline =~ /^.*\".*\s\\n/) {
+ if (WARN("QUOTED_WHITESPACE_BEFORE_NEWLINE",
+ "unnecessary whitespace before a quoted newline\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/^(\+.*\".*)\s+\\n/$1\\n/;
+ }
+
+ }
+
# concatenated string without spaces between elements
if ($line =~ /"X+"[A-Z_]+/ || $line =~ /[A-Z_]+"X+"/) {
CHK("CONCATENATED_STRING",
@@ -4470,6 +4490,24 @@ sub process {
"Consecutive strings are generally better as a single string\n" . $herecurr);
}

+# check for %L{u,d,i} in strings
+ my $string;
+ while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {
+ $string = substr($rawline, $-[1], $+[1] - $-[1]);
+ $string =~ s/%%/__/g;
+ if ($string =~ /(?<!%)%L[udi]/) {
+ WARN("PRINTF_L",
+ "\%Ld/%Lu are not-standard C, use %lld/%llu\n" . $herecurr);
+ last;
+ }
+ }
+
+# check for line continuations in quoted strings with odd counts of "
+ if ($rawline =~ /\\$/ && $rawline =~ tr/"/"/ % 2) {
+ WARN("LINE_CONTINUATIONS",
+ "Avoid line continuations in quoted strings\n" . $herecurr);
+ }
+
# warn about #if 0
if ($line =~ /^.\s*\#\s*if\s+0\b/) {
CHK("REDUNDANT_CODE",
@@ -4754,12 +4792,6 @@ sub process {
}
}

-# check for line continuations in quoted strings with odd counts of "
- if ($rawline =~ /\\$/ && $rawline =~ tr/"/"/ % 2) {
- WARN("LINE_CONTINUATIONS",
- "Avoid line continuations in quoted strings\n" . $herecurr);
- }
-
# check for struct spinlock declarations
if ($line =~ /^.\s*\bstruct\s+spinlock\s+\w+\s*;/) {
WARN("USE_SPINLOCK_T",
@@ -5169,18 +5201,6 @@ sub process {
"#define of '$1' is wrong - use Kconfig variables or standard guards instead\n" . $herecurr);
}

-# check for %L{u,d,i} in strings
- my $string;
- while ($line =~ /(?:^|")([X\t]*)(?:"|$)/g) {
- $string = substr($rawline, $-[1], $+[1] - $-[1]);
- $string =~ s/%%/__/g;
- if ($string =~ /(?<!%)%L[udi]/) {
- WARN("PRINTF_L",
- "\%Ld/%Lu are not-standard C, use %lld/%llu\n" . $herecurr);
- last;
- }
- }
-
# whine mightly about in_atomic
if ($line =~ /\bin_atomic\s*\(/) {
if ($realfile =~ m@^drivers/@) {