Improve presentation.

stepper.py

@@ -22,6 +22,9 @@ def warn(msg):
 class Garbage(Enum):
     GARBAGE = '<<Unitialized memory>>'
 
+    def __repr__(self):
+        return '<<Garbage>>'
+
 
 def step(insns, terminator, blocks, stack_frames, ssa_env, global_env, heap,
          tdecs, fdecs, call_res):
@@ -347,6 +350,8 @@ def ty2base_ty(ty, tdecs, seen=[]):
     if isinstance(ty, ll.SimpleType):
         return ty
     elif isinstance(ty, ll.PointerType):
+        # TODO: Consider if types behind pointers should not be
+        # expanded. They might be allowed for cyclic types
         return ll.PointerType(ty2base_ty(ty.inner_ty, tdecs, seen))
     if isinstance(ty, ll.StructType):
         return ll.StructType([ty2base_ty(t, tdecs, seen)
@@ -424,8 +429,10 @@ define i64 @tigermain (i64 %U_mainSL_8, i64 %U_mainDummy_9) {
                                                        fdecs, call_res)
         step_cnt += 1
         if terminator is None:
-            print('Stepping done! Final ssa_env:\n{}'
+            print('Stepping done!\nFinal ssa_env: {}'
                   .format(ssa_env))
+            print('Final heap: {}'
+                  .format(heap))
             print('Program resulted in {}'.
                   format(insns[0][1].val))
             break