From: Joe Perches <joe@xxxxxxxxxxx> Subject: checkpatch: add --strict test for macro argument reuse If a macro argument is used multiple times in the macro definition, the macro argument may have an unexpected side-effect. Add a test (MACRO_ARG_REUSE) for that condition which is only emitted with command-line option --strict. Link: http://lkml.kernel.org/r/b6d67a87cafcafd15499e91780dc63b15dec0aa0.1473744906.git.joe@xxxxxxxxxxx Signed-off-by: Joe Perches <joe@xxxxxxxxxxx> Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx> Cc: Julia Lawall <julia.lawall@xxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- scripts/checkpatch.pl | 43 ++++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 8 deletions(-) diff -puN scripts/checkpatch.pl~checkpatch-add-strict-test-for-macro-argument-reuse scripts/checkpatch.pl --- a/scripts/checkpatch.pl~checkpatch-add-strict-test-for-macro-argument-reuse +++ a/scripts/checkpatch.pl @@ -4753,7 +4753,17 @@ sub process { $has_flow_statement = 1 if ($ctx =~ /\b(goto|return)\b/); $has_arg_concat = 1 if ($ctx =~ /\#\#/ && $ctx !~ /\#\#\s*(?:__VA_ARGS__|args)\b/); - $dstat =~ s/^.\s*\#\s*define\s+$Ident(?:\([^\)]*\))?\s*//; + $dstat =~ s/^.\s*\#\s*define\s+$Ident(\([^\)]*\))?\s*//; + my $define_args = $1; + my $define_stmt = $dstat; + my @def_args = (); + + if (defined $define_args && $define_args ne "") { + $define_args = substr($define_args, 1, length($define_args) - 2); + $define_args =~ s/\s*//g; + @def_args = split(",", $define_args); + } + $dstat =~ s/$;//g; $dstat =~ s/\\\n.//g; $dstat =~ s/^\s*//s; @@ -4789,6 +4799,15 @@ sub process { ^\[ }x; #print "REST<$rest> dstat<$dstat> ctx<$ctx>\n"; + + $ctx =~ s/\n*$//; + my $herectx = $here . "\n"; + my $stmt_cnt = statement_rawlines($ctx); + + for (my $n = 0; $n < $stmt_cnt; $n++) { + $herectx .= raw_line($linenr, $n) . "\n"; + } + if ($dstat ne '' && $dstat !~ /^(?:$Ident|-?$Constant),$/ && # 10, // foo(), $dstat !~ /^(?:$Ident|-?$Constant);$/ && # foo(); @@ -4804,13 +4823,6 @@ sub process { $dstat !~ /^\(\{/ && # ({... $ctx !~ /^.\s*#\s*define\s+TRACE_(?:SYSTEM|INCLUDE_FILE|INCLUDE_PATH)\b/) { - $ctx =~ s/\n*$//; - my $herectx = $here . "\n"; - my $cnt = statement_rawlines($ctx); - - for (my $n = 0; $n < $cnt; $n++) { - $herectx .= raw_line($linenr, $n) . "\n"; - } if ($dstat =~ /;/) { ERROR("MULTISTATEMENT_MACRO_USE_DO_WHILE", @@ -4819,6 +4831,21 @@ sub process { ERROR("COMPLEX_MACRO", "Macros with complex values should be enclosed in parentheses\n" . "$herectx"); } + + } +# check if any macro arguments are reused (ignore '...' and 'type') + foreach my $arg (@def_args) { + next if ($arg =~ /\.\.\./); + next if ($arg =~ /^type$/); + my $tmp = $define_stmt; + $tmp =~ s/\b(typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b//g; + $tmp =~ s/\#\s*$arg\b//g; + $tmp =~ s/\b$arg\s*\#\#//g; + my $use_cnt = $tmp =~ s/\b$arg\b//g; + if ($use_cnt > 1) { + CHK("MACRO_ARG_REUSE", + "Macro argument reuse '$arg' - possible side-effects?\n" . "$herectx"); + } } # check for macros with flow control, but without ## concatenation _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
