Commit f59b64bf authored by Joe Perches's avatar Joe Perches Committed by Linus Torvalds

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@perches.comSigned-off-by: default avatarJoe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent af207524
......@@ -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
......
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