compiler warning cleanup: is_signed_type: compare -1 to 1

Comparing -1 to 0 triggers compiler warnings (gcc -Wtype-limits and
-Wbool-compare) and Coverity warning "Macro compares unsigned to 0".

Comparing -1 to 1 instead takes care of silencing those warnings while
keeping the same behavior.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: Id4aebce6eed214f0ccba2c0289fb3b034808cb64

diff --git a/src/common/macros.h b/src/common/macros.h
index cce09a6cbb66b0474d25dabcf34a43e3728f71ef..70de2875e1007278019b5460b80cc453ad5a70ea 100644 (file)
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -77,7 +77,7 @@ void *zmalloc(size_t len)
 #define LTTNG_PACKED __attribute__((__packed__))
 #endif
 
-#define is_signed(type) (((type) (-1)) < 0)
+#define is_signed(type) (((type) -1) < (type) 1)
 
 /*
  * Align value to the next multiple of align. Returns val if it already is a