[PATCH RFC] checkpatch: extend attributes check to handle more patterns

From: Dwaipayan Ray
Date: Thu Oct 22 2020 - 10:53:05 EST

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It is generally preferred that the macros from
include/linux/compiler_attributes.h are used, unless there
is a reason not to.

Checkpatch currently checks __attribute__ for each of
packed, aligned, printf, scanf, and weak. Other declarations
in compiler_attributes.h are not handled.

Add more definitions to the attribute check.
The following patterns are added:

__alias__(#symbol)
__always_inline__
__assume_aligned__(a, ## __VA_ARGS__)
__cold__
__const__
__copy__(symbol)
__designated_init__
__externally_visible__
__gnu_inline__
__malloc__
__mode__(x)
__no_caller_saved_registers__
__noclone__
__fallthrough__
__noinline__
__nonstring__
__noreturn__
__pure__
__unused__
__used__

Link: https://lore.kernel.org/linux-kernel-mentees/3ec15b41754b01666d94b76ce51b9832c2dd577a.camel@xxxxxxxxxxx/
Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx>
---
scripts/checkpatch.pl | 199 ++++++++++++++++++++++++++++++++++--------
1 file changed, 163 insertions(+), 36 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 7e505688257a..968adcb15793 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6155,50 +6155,177 @@ sub process {
}
}

-# Check for __attribute__ packed, prefer __packed
+# Check for compiler attributes
if ($realfile !~ m@\binclude/uapi/@ &&
- $line =~ /\b__attribute__\s*$\s*\(.*\bpacked\b/) {
- WARN("PREFER_PACKED",
- "__packed is preferred over __attribute__((packed))\n" . $herecurr);
- }
+ $line =~ /\b__attribute__\s*\(\s*\((.*)$\s*\)/) {
+ my $attr = trim($1);

-# Check for __attribute__ aligned, prefer __aligned
- if ($realfile !~ m@\binclude/uapi/@ &&
- $line =~ /\b__attribute__\s*$\s*\(.*aligned/) {
- WARN("PREFER_ALIGNED",
- "__aligned(size) is preferred over __attribute__((aligned(size)))\n" . $herecurr);
- }
+ # Check for __attribute__ alias, prefer __alias
+ if ($attr =~/^_*alias_*/) {
+ WARN("PREFER_ALIAS",
+ "__alias(symbol) is preferred over __attribute__((alias(#symbol)))\n" . $herecurr);
+ }

-# Check for __attribute__ section, prefer __section
- if ($realfile !~ m@\binclude/uapi/@ &&
- $line =~ /\b__attribute__\s*\(\s*\(.*_*section_*\s*\(\s*("[^"]*")/) {
- my $old = substr($rawline, $-[1], $+[1] - $-[1]);
- my $new = substr($old, 1, -1);
- if (WARN("PREFER_SECTION",
- "__section($new) is preferred over __attribute__((section($old)))\n" . $herecurr) &&
- $fix) {
- $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*_*section_*\s*\(\s*\Q$old\E\s*$\s*\)\s*\)/__section($new)/;
+ # Check for __attribute__ aligned(size), prefer __aligned(size)
+ if ($attr =~/^_*aligned_*$/) {
+ WARN("PREFER_ALIGNED",
+ "__aligned(size) is preferred over __attribute__((__aligned__(size)))\n" . $herecurr);
}
- }

-# Check for __attribute__ format(printf, prefer __printf
- if ($realfile !~ m@\binclude/uapi/@ &&
- $line =~ /\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf/) {
- if (WARN("PREFER_PRINTF",
- "__printf(string-index, first-to-check) is preferred over __attribute__((format(printf, string-index, first-to-check)))\n" . $herecurr) &&
- $fix) {
- $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.*)$\s*\)\s*\)/"__printf(" . trim($1) . ")"/ex;
+ # Check for __attribute__ aligned, prefer __aligned_largest
+ if ($attr =~/^_*aligned_*$/) {
+ WARN("PREFER_ALIGNED_LARGEST",
+ "__aligned_largest is preferred over __attribute__((__aligned__))\n" . $herecurr);
+ }

+ # Check for __attribute__ always_inline, prefer __always_inline
+ if ($attr =~/^_*always_inline_*/) {
+ WARN("PREFER_ALWAYS_INLINE",
+ "__always_inline is preferred over __attribute__((__always_inline__))\n" . $herecurr);
}
- }

-# Check for __attribute__ format(scanf, prefer __scanf
- if ($realfile !~ m@\binclude/uapi/@ &&
- $line =~ /\b__attribute__\s*$\s*\(\s*format\s*\(\s*scanf\b/) {
- if (WARN("PREFER_SCANF",
- "__scanf(string-index, first-to-check) is preferred over __attribute__((format(scanf, string-index, first-to-check)))\n" . $herecurr) &&
- $fix) {
- $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*scanf\s*,\s*(.*)$\s*\)\s*\)/"__scanf(" . trim($1) . ")"/ex;
+ # Check for __attribute__ assume_aligned, prefer __assume_aligned
+ if ($attr =~/^_*assume_aligned_*/) {
+ WARN("PREFER_ASSUME_ALIGNED",
+ "__asume_aligned(a, ...) is preferred over __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ cold, prefer __cold
+ if ($attr =~ /^_*cold_*/) {
+ WARN("PREFER_COLD",
+ "__cold is preferred over __attribute__((__cold__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ const, prefer __attribute_const
+ if ($attr =~ /^_*const_*/) {
+ WARN("PREFER_CONST",
+ "__attribute_const is preferred over __attribute__((__const__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ copy, prefer __copy
+ if ($attr =~ /^_*copy_*/) {
+ WARN("PREFER_COPY",
+ "__copy(symbol) is preferred over __attribute__((__copy__(symbol)))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ desginated_init, prefer __designated_init
+ if ($attr =~ /^_*designated_init_*/) {
+ WARN("PREFER_DESIGNATED_INIT",
+ "__designated_init is preferred over __attribute__((__designated_init__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ externally_visible, prefer __visible
+ if ($attr =~ /^_*externally_visible_*/) {
+ WARN("PREFER_VISIBLE",
+ "__visible is preferred over __attribute__((__externally_visible__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ format(printf, prefer __printf
+ if ($attr =~ /^_*format_*\s*$\s*printf/) {
+ if (WARN("PREFER_PRINTF",
+ "__printf(string-index, first-to-check) is preferred over __attribute__((format(printf, string-index, first-to-check)))\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.*)$\s*\)\s*\)/"__printf(" . trim($1) . ")"/ex;
+
+ }
+ }
+
+ # Check for __attribute__ format(scanf, prefer __scanf
+ if ($attr =~ /^_*format_*\s*$\s*scanf\b/) {
+ if (WARN("PREFER_SCANF",
+ "__scanf(string-index, first-to-check) is preferred over __attribute__((format(scanf, string-index, first-to-check)))\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*scanf\s*,\s*(.*)$\s*\)\s*\)/"__scanf(" . trim($1) . ")"/ex;
+ }
+ }
+
+ # Check for __attribute__ gnu_inline, prefer __gnu_inline
+ if ($attr =~ /^_*gnu_inline_*/) {
+ WARN("PREFER_GNU_INLINE",
+ "__gnu_inline is preferred over __attribute__((__gnu_inline__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ malloc, prefer __malloc
+ if ($attr =~ /^_*malloc_*/) {
+ WARN("PREFER_MALLOC",
+ "__malloc is preferred over __attribute__((__malloc__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ mode, prefer __mode
+ if ($attr =~ /^_*mode_*/) {
+ WARN("PREFER_MODE",
+ "__mode(x) is preferred over __attribute__((__mode__(x)))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ no_caller_saved_registers, prefer __no_caller_saved_registers
+ if ($attr =~ /^_*no_caller_saved_registers_*/) {
+ WARN("PREFER_NO_CALLER_SAVED_REGISTERS",
+ "__no_caller_saved_registers is preferred over __attribute__((__no_caller_saved_registers__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ noclone, prefer __noclone
+ if ($attr =~ /^_*noclone_*/) {
+ WARN("PREFER_NOCLONE",
+ "__noclone is preferred over __attribute__((__noclone__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ fallthrough, prefer fallthrough
+ if ($attr =~ /^_*fallthrough_*/) {
+ WARN("PREFER_FALLTHROUGH",
+ "fallthrough is preferred over __attribute__((__fallthrough__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ noinline, prefer noinline
+ if ($attr =~ /^_*noinline_*/) {
+ WARN("PREFER_NOINLINE",
+ "noinline is preferred over __attribute__((__noinline__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ nonstring, prefer __nonstring
+ if ($attr =~ /^_*nonstring_*/) {
+ WARN("PREFER_NONSTRING",
+ "__nonstring is preferred over __attribute__((__nonstring__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ noreturn, prefer __noreturn
+ if ($attr =~ /^_*noreturn_*/) {
+ WARN("PREFER_NORETURN",
+ "__noreturn is preferred over __attribute__((__noreturn__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ packed, prefer __packed
+ if ($attr =~ /^_*packed_*/) {
+ WARN("PREFER_PACKED",
+ "__packed is preferred over __attribute__((__packed__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ pure, prefer __pure
+ if ($attr =~ /^_*pure_*/) {
+ WARN("PREFER_PURE",
+ "__pure is preferred over __attribute__((__pure__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ section, prefer __section
+ if ($attr =~ /^_*section_*\s*$\s*("[^"]*")/) {
+ my $old = substr($rawline, $-[1], $+[1] - $-[1]);
+ my $new = substr($old, 1, -1);
+ if (WARN("PREFER_SECTION",
+ "__section($new) is preferred over __attribute__((section($old)))\n" . $herecurr) &&
+ $fix) {
+ $fixed[$fixlinenr] =~ s/\b__attribute__\s*\(\s*\(\s*_*section_*\s*\(\s*\Q$old\E\s*$\s*\)\s*\)/__section($new)/;
+ }
+ }
+
+ # Check for __attribute__ unused, prefer __always_unused or __maybe_unused
+ if ($attr =~ /^_*unused_*/) {
+ WARN("PREFER_UNUSED",
+ "__always_unused or __maybe_unused is preferred over __attribute__((__unused__))\n" . $herecurr);
+ }
+
+ # Check for __attribute__ used, prefer __used
+ if ($attr =~ /^_*used_*/) {
+ WARN("PREFER_USED",
+ "__used is preferred over __attribute__((__used__))\n" . $herecurr);
}
}

--
2.27.0

Next message: Mel Gorman: "Re: default cpufreq gov, was: [PATCH] sched/fair: check for idle core"
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