From 69a84e4c2f794be6ac86fe2516065a8ed8b743d8 Mon Sep 17 00:00:00 2001
From: Xun Yang <x299yang@uwaterloo.ca>
Date: Fri, 6 Mar 2020 21:04:17 -0500
Subject: [PATCH] forward ref checks
---
MemberNodes.py | 44 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 4 deletions(-)
diff --git a/MemberNodes.py b/MemberNodes.py
index 4eeabd1..87caedc 100644
--- a/MemberNodes.py
+++ b/MemberNodes.py
@@ -37,6 +37,20 @@ class FieldNode(ASTNode):
def checkType(self):
self.variableDcl.checkType()
+ # check forward reference
+ if self.variableDcl.variableInit:
+ allNames = getForwardRefNames(self.variableDcl.variableInit)
+ from pprint import pprint
+
+ for n in allNames:
+ if n.prefixLink is self.variableDcl:
+ raise Exception("ERROR: Forward reference of field {} in itself is not allowed.".format(n.prefixLink.name))
+
+ if n.prefixLink.__class__.__name__ == 'FieldNode' \
+ and n.prefixLink.typeName == self.typeName \
+ and self.order <= n.prefixLink.order \
+ and "this" not in n.name:
+ raise Exception("ERROR: Forward reference of field {} is not allowed.".format(n.prefixLink.name))
###########################################################
@@ -106,6 +120,12 @@ class MethodNode(ASTNode):
self.env = env
return env
+ def disambigName(self):
+ if self.body:
+ self.body.disambigName()
+ for p in self.params:
+ p.disambigName()
+
def checkType(self):
if self.methodType: # constructor would be None
self.myType = self.methodType.myType
@@ -118,7 +138,7 @@ class MethodNode(ASTNode):
# No method body: do not check type as function isn't implemented
if not self.body:
return
-
+
# With method body
returnNodes = getASTNode(["ReturnNode"], self.body)
@@ -127,7 +147,7 @@ class MethodNode(ASTNode):
# Either a constructor or the function has type Void
if not self.methodType or self.myType.name == "void":
return
- raise Exception("ERROR: no return statement at function {}".format(self.name))
+ raise Exception("ERROR: no return statement at function {}".format(self.name))
# Checking for cases where there are return statements
for n in returnNodes:
@@ -135,9 +155,25 @@ class MethodNode(ASTNode):
# Only valid if either the function doesn't have a return statement(checked above), or the return statement is a semicolon (return;)
if self.myType.name == "void":
if n.myType:
- raise Exception("ERROR: return type of function {} doesn't match with return statement.".format(self.name))
+ raise Exception("ERROR: return type of function {} doesn't match with return statement.".format(self.name))
# Checking for non void cases
if not self.myType.assignable(n.myType):
raise Exception("ERROR: return type of function {} doesn't match with return statement.".format(self.name))
- return
\ No newline at end of file
+ return
+
+############# helper for forward ref checking ########
+# Input: AST Node
+# Output: A list of names to be check
+def getForwardRefNames(node):
+ if node.__class__.__name__ == 'NameNode':
+ return [node]
+
+ result = []
+ if node.__class__.__name__ == 'AssignNode':
+ result.extend(getForwardRefNames(node.right))
+ else:
+ for c in node.children:
+ result.extend(getForwardRefNames(c))
+
+ return result
--
GitLab