Messages in this thread Patch in this message | | | Subject | [PATCH] checkpatch: Warn on self-assignments | From | Joe Perches <> | Date | Sat, 05 Sep 2020 10:58:29 -0700 |
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The uninitialized_var() macro was removed recently via commit 63a0895d960a ("compiler: Remove uninitialized_var() macro") as it's not a particularly useful warning and its use can "paper over real bugs".
Add a checkpatch test to warn on self-assignments as a means to avoid compiler warnings and as a back-door mechanism to reproduce the old uninitialized_var macro behavior.
Signed-off-by: Joe Perches <joe@perches.com> --- scripts/checkpatch.pl | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 149518d2a6a7..300b2659aab3 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -3901,6 +3901,17 @@ sub process { #ignore lines not being added next if ($line =~ /^[^\+]/); +# check for self assigments used to avoid compiler warnings +# e.g.: int foo = foo, *bar = NULL; +# struct foo bar = *(&(bar)); + if ($line =~ /^\+\s*(?:$Declare)?([A-Za-z_][A-Za-z\d_]*)\s*=/) { + my $var = $1; + if ($line =~ /^\+\s*(?:$Declare)?$var\s*=\s*(?:$var|\*\s*\(?\s*&\s*\(?\s*$var\s*\)?\s*\)?)\s*[;,]/) { + WARN("SELF_ASSIGNMENT", + "Do not use self-assignments to avoid compiler warnings\n" . $herecurr); + } + } + # check for dereferences that span multiple lines if ($prevline =~ /^\+.*$Lval\s*(?:\.|->)\s*$/ && $line =~ /^\+\s*(?!\#\s*(?!define\s+|if))\s*$Lval/) {
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