From 101e58b8fe092d5c44cbca1fcfcd8413579f5118 Mon Sep 17 00:00:00 2001
From: Nicholas Robinson <nwrobins@edu.uwaterloo.ca>
Date: Wed, 11 Mar 2020 01:52:22 -0400
Subject: [PATCH] reachability basics
- change Test.py to run reachabilityChecking
- basic ASTNode reachCheck
- implemented reachability in: MethodNode, IfNode, WhileNode, ReturnNode
- tiny bit of cleanup (whitespace)
---
AST.py | 22 ++++++++++++++++++++++
AstBuilding.py | 13 ++++++++++---
LineNodes.py | 43 +++++++++++++++++++++++++++++++++++++++++++
MemberNodes.py | 14 ++++++++++++++
Test.py | 12 +++++++-----
TypeNodes.py | 1 -
6 files changed, 96 insertions(+), 9 deletions(-)
diff --git a/AST.py b/AST.py
index 5e8ed05..fbb2702 100644
--- a/AST.py
+++ b/AST.py
@@ -14,6 +14,10 @@ class ASTNode():
self.children = []
self.myType = "" # either empty string or a TypeStruct
+ # reachability: None = not set, True = maybe, False = no
+ self.inMaybe = None # either None or True/False
+ self.outMaybe = None # either None or True/False
+
# Do certains actions on every node of the AST tree
# call the same method in each class and its children recursively
# the methods that represent an action would return arguments to be used in
@@ -69,6 +73,24 @@ class ASTNode():
if c and hasattr(c, 'staticAnalysis'):
c.staticAnalysis()
+ # return outMaybe
+ def reachCheck(self, inMaybe = True):
+ if inMaybe == False:
+ # error if in[s] = no for any s
+ # I don't think it should get to here... but maybe?
+ raise Exception("in[s] = no for a certain {}".format(type(self)))
+
+ self.inMaybe = inMaybe
+ self.outMaybe = self.inMaybe
+ lastOut = self.inMaybe
+
+ for c in self.children:
+ if c and hasattr(c, 'reachCheck'):
+ lastOut = c.reachCheck(lastOut)
+ self.outMaybe = self.outMaybe and lastOut
+
+ return self.outMaybe
+
def printNodePretty(self, prefix=0):
pp = pprint.PrettyPrinter(indent=prefix)
pp.pprint(self.__class__.__name__)
diff --git a/AstBuilding.py b/AstBuilding.py
index 035a8f9..5563a7b 100644
--- a/AstBuilding.py
+++ b/AstBuilding.py
@@ -9,8 +9,6 @@ def astBuild(trees):
ASTs.append((n, CompNode(t)))
return ASTs
-
-
def buildEnvAndLink(ASTs):
# build env
globalEnv = GlobalEnv()
@@ -51,4 +49,13 @@ def disamiguateAndTypeChecking(ASTs):
for t in ASTs:
t[1].checkType()
- # resolving the rest of the name
\ No newline at end of file
+ # resolving the rest of the name
+
+#######################################################
+
+def reachabilityChecking(ASTs):
+ for t in ASTs:
+ t[1].reachCheck()
+
+ # for t in ASTs:
+ # t[1].staticAnalysis()
diff --git a/LineNodes.py b/LineNodes.py
index 8a0b2a4..30058be 100644
--- a/LineNodes.py
+++ b/LineNodes.py
@@ -164,6 +164,27 @@ class IfNode(ASTNode):
if self.elseBody:
self.elseBody.checkType()
+ def reachCheck(self, inMaybe = True):
+ if inMaybe == False:
+ # error if in[s] = no for any s
+ raise Exception("in[s] = no for IfNode in class {}".format(self.typeName))
+
+ self.inMaybe = inMaybe
+ s1 = self.ifBody.reachCheck(self.inMaybe)
+ if not self.elseBody:
+ # L : if (E) S
+ # in[S] = in[L]
+ # out[L] = in[L]
+ self.outMaybe = self.inMaybe
+ else:
+ # L : if (E) S1 else S2
+ # in[S1] = in[L]
+ # in[S2] = in[L]
+ # out[L] = out[S1] V out[S2]
+ s2 = self.elseBody.reachCheck(self.inMaybe)
+ self.outMaybe = s1 or s2
+ return self.outMaybe
+
# whileStatement, whileStatementNoShortIf
# Rules:
# 1. whileStatement WHILE LPAREN expr RPAREN statement
@@ -197,6 +218,17 @@ class WhileNode(ASTNode):
if con != None:
print(con, self.whileBound.typeName)
+ def reachCheck(self, inMaybe = True):
+ if inMaybe == False:
+ # error if in[s] = no for any s
+ raise Exception("in[s] = no for WhileNode in class {}".format(self.typeName))
+
+ # L : while (E) S
+ # in[S] = in[L]
+ # out[L] = in[L]
+ self.inMaybe = inMaybe
+ self.whileBound.reachCheck(self.inMaybe)
+ self.outMaybe = self.inMaybe
# returnStatement
# Rules:
@@ -226,6 +258,17 @@ class ReturnNode(ASTNode):
else:
self.myType = None # this is None as returning a value of type Void is invalid even in a function with type Void
+ def reachCheck(self, inMaybe = True):
+ if inMaybe == False:
+ # error if in[s] = no for any s
+ raise Exception("in[s] = no for ReturnNode in class {}".format(self.typeName))
+
+ # L : return, L : return E
+ # out[L] = no
+ self.inMaybe = inMaybe
+ self.outMaybe = False
+ return self.outMaybe
+
# forStatement and forStatementNoShortIf
# Rules:
# 1. forStatement FOR LPAREN forInit SEMICO forExpr SEMICO forInit RPAREN statement
diff --git a/MemberNodes.py b/MemberNodes.py
index 7a0bb3e..cfafa1a 100644
--- a/MemberNodes.py
+++ b/MemberNodes.py
@@ -169,6 +169,20 @@ class MethodNode(ASTNode):
raise Exception("ERROR: return type of function {} doesn't match with return statement.".format(self.name))
return
+ def reachCheck(self, inMaybe = True):
+ # self.inMaybe is always true for methods
+ self.inMaybe = True
+ self.outMaybe = False
+
+ if self.body:
+ self.outMaybe = self.body.reachCheck()
+
+ # error if out[(non-void) method body] = maybe
+ # self.methodType is an empty string if it's a constructor
+ if type(self.methodType) != str and self.methodType.myType.name != "void" and self.outMaybe == True:
+ raise Exception("Non-void method '{}' in class '{}' does not return".format(self.name, self.typeName))
+ return self.outMaybe
+
############# helper for forward ref checking ########
# Input: AST Node
# Output: A list of names to be check
diff --git a/Test.py b/Test.py
index de43b30..a08be2a 100644
--- a/Test.py
+++ b/Test.py
@@ -6,7 +6,7 @@ import traceback
from Scanning import scan
from Parsing import parse
-from AstBuilding import astBuild, buildEnvAndLink, disamiguateAndTypeChecking
+from AstBuilding import astBuild, buildEnvAndLink, disamiguateAndTypeChecking, reachabilityChecking
import Weeding
@@ -48,7 +48,7 @@ def a2Multiple():
for c in testCases:
# get all files from stdlib folder
- testFiles = [join(dp, f) for dp, dn, filenames in walk('stdlib/3.0/java/') for f in filenames]
+ testFiles = [join(dp, f) for dp, dn, filenames in walk('stdlib/4.0/java/') for f in filenames]
if '.java' in c:
# add this one file
@@ -155,9 +155,11 @@ def run(testFiles):
disamiguateAndTypeChecking(ASTs)
except Exception as e:
return "disamiguateAndTypeChecking: " + e.args[0]
-
- for t in ASTs:
- t[1].staticAnalysis()
+
+ try:
+ reachabilityChecking(ASTs)
+ except Exception as e:
+ return "reachabilityChecking: " + e.args[0]
return ""
diff --git a/TypeNodes.py b/TypeNodes.py
index 20cd7a5..87c79ad 100644
--- a/TypeNodes.py
+++ b/TypeNodes.py
@@ -261,7 +261,6 @@ class ClassNode(ClassInterNode):
raise Exception("ERROR: Constructor {0} doesn't have the same name as class {1}".format(constructor.name, self.name))
return
-
#####################################################################
# interface
class InterNode(ClassInterNode):
--
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