fixing the issue of ifConditional (could be methodInv, arrayAccess or fieldAccess)

AST.py

@@ -17,6 +17,8 @@ class ASTNode():
         # reachability: None = not set, True = maybe, False = no
         self.outMaybe = None # either None or True/False
 
+    def getConstant(self):
+        return None
 
     # Do certains actions on every node of the AST tree
     #   call the same method in each class and its children recursively

CodeGenUtils.py

@@ -96,6 +96,7 @@ def genMethodInvoke(method):
 
 # generates shorter code for constant value conditionals and comparison conditionals
 # cond is either literalNode or ExprNode or NameNode
+# cond could also be methodInvNode, arrayAccessNode or fieldAccessNode
 def iffalse(cond, label):
     result = ""
     if cond.__class__.__name__ == "NameNode":

ExprPrimaryNodes.py

@@ -163,6 +163,10 @@ class ArrayAccessNode(ASTNode):
         if not self.index.myType.isNum():
             raise Exception("ERROR: Array index must be a number.")
         self.myType = TypeStruct(self.array.myType.name, self.array.myType.typePointer)
+    
+    def getIfFalse(self, label):
+        self.codeGen()
+        return self.code + p("cmp", "eax", "[G__Zero]") + p("je", label)
 
     def addr(self):
         result = "; Start of calculating address for array access\n" + \
@@ -872,6 +876,10 @@ class FieldAccessNode(ASTNode):
                 checkProtected(self.ID.prefixLink, self)
         except: # where there are no mods
             return
+    
+    def getIfFalse(self, label):
+        self.codeGen()
+        return self.code + p("cmp", "eax", "[G__Zero]") + p("je", label)
 
     # generates code that evaluates the address of field access
     # result stored in eax (address)
@@ -1005,6 +1013,10 @@ class MethodInvNode(ASTNode):
                 self.args.codeGen()
             self.code += self.args.code
 
+    def getIfFalse(self, label):
+        self.codeGen()
+        return self.code + p("cmp", "eax", "[G__Zero]") + p("je", label)
+
     def codeGen(self):
         if hasattr(self, "code"):
             return