Fix cflags in scan-build stack escape checking

Author: Craig Ringer

c/clang_return_stack_checks/Makefile

@@ -2,17 +2,21 @@ ifeq ($(origin CC),default)
 CC = scan-build clang
 endif
 
-ifeq ($(origin CFLAGS),default)
-CFLAGS = -Wall -Wextra
+ifeq ($(origin CFLAGS),undefined)
+CFLAGS = -Wall -Wextra -Og -ggdb3
 endif
 
 all: return_stack_escape
 
 guard.so: guard.c guard.h
-	$(CC) -shared -fPIC $< -o $@
+	$(CC) $(CFLAGS) -shared -fPIC $< -o $@
 
 return_stack_escape: return_stack_escape.c guard.so
-	$(CC) $< ./guard.so -o $@
+	$(CC) $(CFLAGS) $< ./guard.so -o $@
 
 clean:
 	rm -f guard.so return_stack_escape
+
+run:
+	./return_stack_escape 0
+	if ./return_stack_escape; then exit 1; fi