From 9cc6e92972329c939fc5a6945c7acf453b90281c Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Sat, 3 Sep 2016 21:36:53 +0200
Subject: [PATCH] btrfs-progs: build: add UBSAN to debugging features

usage: make D=ubsan

Signed-off-by: David Sterba <dsterba@suse.com>
---
 Makefile.in | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Makefile.in b/Makefile.in
index fd68b3ee..214b0428 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -18,6 +18,7 @@
 #                  abort   - call abort() on first error (dumps core)
 #                  all     - shortcut for all of the above
 #                  asan    - enable address sanitizer compiler feature
+#                  ubsan   - undefined behaviour sanitizer compiler feature
 #   W=123          build with warnings (default: off)
 #   DEBUG_CFLAGS   additional compiler flags for debugging build
 #   EXTRA_CFLAGS   additional compiler flags
@@ -150,6 +151,10 @@ ifneq (,$(findstring asan,$(D)))
   DEBUG_CFLAGS_INTERNAL += -fsanitize=address
 endif
 
+ifneq (,$(findstring ubsan,$(D)))
+  DEBUG_CFLAGS_INTERNAL += -fsanitize=undefined
+endif
+
 MAKEOPTS = --no-print-directory Q=$(Q)
 
 # build all by default