Makefile: disable unaligned loads with UBSan

peff · gitster · commit 566cf0b3bd64 · 2017-07-10T10:02:31.000-07:00
The undefined behavior sanitizer complains about unaligned
loads, even if they're OK for a particular platform in
practice. It's possible that they _are_ a problem, of
course, but since it's a known tradeoff the UBSan errors are
just noise.

Let's quiet it automatically by building with
NO_UNALIGNED_LOADS when SANITIZE=undefined is in use.

Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Makefile b/Makefile
@@ -994,6 +994,9 @@ endif
 ifdef SANITIZE
 BASIC_CFLAGS += -fsanitize=$(SANITIZE) -fno-sanitize-recover=$(SANITIZE)
 BASIC_CFLAGS += -fno-omit-frame-pointer
+ifeq ($(SANITIZE),undefined)
+BASIC_CFLAGS += -DNO_UNALIGNED_LOADS
+endif
 endif
 
 ifndef sysconfdir
