add CHECK_UNINITIALIZED make option

Makefile

@@ -7,10 +7,20 @@ LIBDIR := ext/tangerine
 LIB := $(LIBDIR)/build/libTangerine.a
 
 CXX := g++
-# NOTE: have to set -O or -O1 here to get warnings for uninitialized variables
+# NOTE: due to a longstanding 'bug' in gcc, we can only check for unitialized
-CXXFLAGS := -std=c++11 -g -ggdb3 -O -Wall -Wuninitialized \
+# 	variables if an optimization pass is run. However, compiling without
-			-I$(LIBDIR)/include/ \
+# 	optimization is useful for debugging, so we can add some local variables
+# 	for easier inspection.
+# 	see) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=18501
+CHECK_UNITIALIZED := false
+ifeq ($(CHECK_UNITIALIZED), true)
+	CXXFLAGS := -std=c++11 -g -ggdb3 -O -Wall
+else
+	CXXFLAGS := -std=c++11 -g -ggdb3 -Wall
+endif
+CXXFLAGS += -I$(LIBDIR)/include/ \
 			$(shell sdl2-config --cflags)
+
 LDFLAGS := $(shell sdl2-config --libs) -lGLEW -lGL
 
 COMMON_SOURCES := $(SRCDIR)/orbits.cpp