Code comparing unsigned variables with zero using operators < or >= does not make sense. It is always false or true, respectively. However, its presence often indicates bugs in the code. gcc can detect it also using -Wtype-limits switch, but it warns also in correct cases, making too much noise. Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Acked-by: Julia Lawall <julia.lawall@xxxxxxx> --- v3: added bool type v2: added --all-includes option --- .../tests/unsigned_lesser_than_zero.cocci | 37 ++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci diff --git a/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci b/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci new file mode 100644 index 0000000..70e71c8 --- /dev/null +++ b/scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci @@ -0,0 +1,37 @@ +/// Unsigned variables cannot be lesser than zero. Presence of such checks +/// can indicate incorrect variable type or just unnecessary code. +/// +// Confidence: High +// Copyright: (C) 2015 Andrzej Hajda, Samsung Electronics Co., Ltd. GPLv2. +// URL: http://coccinelle.lip6.fr/ +// Options: --include-headers --all-includes + +virtual context +virtual org +virtual report + +@r depends on context || org || report@ +position p; +typedef bool, u8, u16, u32, u64; +{unsigned char, unsigned short int, unsigned int, unsigned long, unsigned long long, size_t, bool, u8, u16, u32, u64} v; +@@ + +( +*v@p < 0 +| +*v@p >= 0 +) + +@script:python depends on org@ +p << r.p; +@@ + +msg = "WARNING: Unsigned value cannot be lesser than zero" +coccilib.org.print_todo(p[0], msg) + +@script:python depends on report@ +p << r.p; +@@ + +msg = "WARNING: Unsigned value cannot be lesser than zero" +coccilib.report.print_report(p[0], msg) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
