[Makefile] add option to enable gcc sanitizer for UB and asan

Add option to enable gcc sanitizer option for undefined behavior.
The following changesets will make ubsan work.

Signed-off-by: Isaku Yamahata <isaku.yamahata@gmail.com>

LibOS/shim/src/Makefile

@@ -9,6 +9,7 @@ CFLAGS	= -Wall -fPIC -std=c11 -Winline -Wwrite-strings \
 	  -fmerge-all-constants -Wstrict-prototypes \
 	  -Werror=implicit-function-declaration \
 	  $(cc-option, -Wnull-dereference) \
+	  $(CFLAGS_SANITIZE) \
 	  -fno-stack-protector -fno-builtin -Wno-inline \
 	  -I../include -I../../../Pal/lib -I../../../Pal/include/pal
 

Makefile.configs

@@ -11,3 +11,13 @@ ifeq ($(origin LD),default)
 LD	= ld
 endif
 OBJCOPY ?= objcopy
+
+# CONFIG_ENABLE_UBSAN=y
+CONFIG_ENABLE_UBSAN=n
+
+#
+# variables depend on configrations
+#
+ifeq ($(CONFIG_ENABLE_UBSAN),y)
+	CFLAGS_SANITIZE += $(call cc-option,-fsanitize=undefined)
+endif

Pal/lib/Makefile

@@ -5,7 +5,8 @@ include ../src/Makefile.Host
 CFLAGS	= -Wall -fPIC -O2 -std=gnu99 -fgnu89-inline -U_FORTIFY_SOURCE \
 	  $(call cc-option,-Wnull-dereference) \
 	  -fno-omit-frame-pointer \
-	  -fno-stack-protector -fno-builtin
+	  -fno-stack-protector -fno-builtin \
+	  $(CFLAGS_SANITIZE)
 ARFLAGS	=
 
 include ../src/host/$(PAL_HOST)/Makefile.am

Pal/src/host/Linux-SGX/Makefile.am

@@ -2,6 +2,7 @@
 HOST_DIR = host/$(PAL_HOST)
 
 CFLAGS	= -Wall -fPIC -O2 -maes -std=c11 -U_FORTIFY_SOURCE \
+	  $(CFLAGS_SANITIZE) \
 	  -fno-omit-frame-pointer \
 	  -fno-stack-protector -fno-builtin
 

Pal/src/host/Linux/Makefile.am

@@ -3,7 +3,8 @@ HOST_DIR = host/$(PAL_HOST)
 SEC_DIR = security/$(PAL_HOST)
 
 CFLAGS	= -Wall -fPIC -O2 -std=c11 -U_FORTIFY_SOURCE \
-	  -fno-stack-protector -fno-builtin
+	  -fno-stack-protector -fno-builtin \
+	  $(CFLAGS_SANITIZE)
 
 EXTRAFLAGS = -Wextra $(call cc-option,-Wnull-dereference)