From e0251572d862e628d2265b5f0b04be9cfb703d9f Mon Sep 17 00:00:00 2001
From: Xun Yang <x299yang@uwaterloo.ca>
Date: Mon, 6 Apr 2020 14:27:57 -0400
Subject: [PATCH] ifNode and iffalse and boolean literals
---
CodeGenUtils.py | 27 +++++++++++++++++-
ExprPrimaryNodes.py | 57 ++++++++++++++++++++++++++++++--------
LineNodes.py | 34 ++++++++++++++++++++++-
Tests/A5/J1_01_ifelse.java | 20 +++++++++++++
UnitNodes.py | 5 ++++
5 files changed, 129 insertions(+), 14 deletions(-)
create mode 100644 Tests/A5/J1_01_ifelse.java
diff --git a/CodeGenUtils.py b/CodeGenUtils.py
index 03b3370..c461da7 100644
--- a/CodeGenUtils.py
+++ b/CodeGenUtils.py
@@ -15,9 +15,17 @@ def p(instruction, arg1, arg2="", comment=""):
# (local label are just for local running of the code)
used_labels = set()
local_labels = 0
+control_flow_label = 0
+
+def getCFlowLabel():
+ global control_flow_label
+ control_flow_label += 1
+ return str(control_flow_label)
def pLabel(name, type, comment=""):
- if type == "local":
+ global local_labels
+ global used_labels
+ if type == "local":
l = "_" + str(local_labels)
local_labels += 1
else:
@@ -70,6 +78,23 @@ def genMethodInvoke(method):
return (pro, epi)
+# generates shorter code for constant value conditionals and comparison conditionals
+# cond is either literalNode or ExprNode
+def iffalse(cond, label):
+ result = ""
+ val = cond.getConstant()
+ if val != None:
+ if val == True:
+ result = "" # no jump if true
+ elif val == False:
+ result += p("jmp", label)
+ # else val == Int shouldn't happen here, since we already done typeCheck
+ else:
+ result = cond.getIfFalse(label)
+
+ return result
+
+
####################################################
diff --git a/ExprPrimaryNodes.py b/ExprPrimaryNodes.py
index fa09ac1..d0474e3 100644
--- a/ExprPrimaryNodes.py
+++ b/ExprPrimaryNodes.py
@@ -247,7 +247,7 @@ class AssignNode(ASTNode):
def codeGen(self):
self.right.codeGen()
self.code = self.right.code
-
+
if self.left.__class__.__name__ == "NameNode":
if self.left.prefixLink.__class__.__name__ == "VarDclNode":
# move init result to var location
@@ -431,6 +431,9 @@ class ExprNode(ASTNode):
raise Exception("ERROR: Incompatible types. Left of {} type can't be used with right of {} type on operation {}".format(self.left.myType.name, self.right.myType.name, self.op))
def codeGen(self):
+ if hasattr(self, "code") and self.code != "":
+ return
+
self.code = ""
# Unary:
@@ -438,17 +441,7 @@ class ExprNode(ASTNode):
self.code = ""
return
- # get left output
- if not hasattr(self.left, "code"):
- self.left.codeGen()
- self.code += self.left.code
- self.code += p("push", "eax") # left result onto stack
-
- # get right output
- if not hasattr(self.right, "code"):
- self.right.codeGen()
- self.code += self.right.code
- self.code += p("pop", "ebx") # left output into ebx
+ self.code += self.codeGenLeftRight()
# now:
# ebx = left result
@@ -464,6 +457,46 @@ class ExprNode(ASTNode):
self.code += p(ops[self.op], "ebx", "eax", " " + ops[self.op] + " left and right")
self.code += p("mov", "eax", "ebx", " move result to eax")
+ # generate shorter code if self.op = comparison
+ def getIfFalse(self, label):
+ if self.op not in ['==', '!=', '<=', '>=', '>', '<']:
+ self.codeGen()
+ return self.code
+ else:
+ result = self.codeGenLeftRight()
+ result += p("cmp", "ebx", "eax", "left " + self.op + " right")
+ if self.op == '==':
+ result += p("jne", label) # jump if false (not equal)
+ elif self.op == '!=':
+ result += p("je", label) # jump if false (equal)
+ elif self.op == '>':
+ result += p("jle", label) # jump if false (le)
+ elif self.op == '<':
+ result += p("jge", label) # jump if false (ge)
+ elif self.op == '>=':
+ result += p("jl", label) # jump if false (lt)
+ elif self.op == '<=':
+ result += p("jg", label) # jump if false (gt)
+ return result
+
+
+ # helper for codeGen for getting code from left and right
+ def codeGenLeftRight(self):
+ result = ""
+ # get left output
+ if not hasattr(self.left, "code"):
+ self.left.codeGen()
+ result += self.left.code
+ result += p("push", "eax") # left result onto stack
+
+ # get right output
+ if not hasattr(self.right, "code"):
+ self.right.codeGen()
+ result += self.right.code
+ result += p("pop", "ebx") # left output into ebx
+
+ return result
+
# returns True, False, Int or None (for non-constant expr)
# children of exprNode is either exprNode or literalNode
def getConstant(self):
diff --git a/LineNodes.py b/LineNodes.py
index 422c307..9141c44 100644
--- a/LineNodes.py
+++ b/LineNodes.py
@@ -2,7 +2,7 @@ from AST import ASTNode, getParseTreeNodes, getASTNode
from Environment import Env
from ExprPrimaryNodes import makeNodeFromExpr, makeNodeFromAllPrimary, MethodInvNode, ClassCreateNode
from TheTypeNode import TypeNode, TypeStruct
-from CodeGenUtils import p
+from CodeGenUtils import p, getCFlowLabel, iffalse
# Contains:
# block
@@ -231,6 +231,38 @@ class IfNode(ASTNode):
# no need to check reachability for empty elseBody, since in[elseBody] = in[L]
self.outMaybe = self.ifBody.outMaybe
+ def codeGen(self):
+ if hasattr(self, "code") and self.code != "":
+ return
+
+ n = getCFlowLabel()
+ elseLabel = "_else" + n
+ endLabel = "_end" + n
+
+ self.code = "; start of if clause" + n + "\n"
+
+ if self.elseBody:
+ self.code += iffalse(self.ifConditional, elseLabel)
+ else:
+ self.code += iffalse(self.ifConditional, endLabel)
+
+ self.code += "; start of ifBody code for if clause" + n + "\n"
+
+ self.ifBody.codeGen()
+ self.code += self.ifBody.code
+
+ if self.elseBody:
+ self.code += "; start of elseBody code for if clause" + n + "\n"
+ self.code += p("jmp", endLabel)
+ self.code += elseLabel + ":\n"
+
+ self.elseBody.codeGen()
+ self.code += self.elseBody.code
+
+ self.code += endLabel + ":\n"
+ self.code += "; end of if clause" + n + "\n"
+
+
# whileStatement, whileStatementNoShortIf
# Rules:
diff --git a/Tests/A5/J1_01_ifelse.java b/Tests/A5/J1_01_ifelse.java
new file mode 100644
index 0000000..cd3fbe7
--- /dev/null
+++ b/Tests/A5/J1_01_ifelse.java
@@ -0,0 +1,20 @@
+public class J1_01_ifelse {
+
+ public J1_01_ifelse() {}
+
+ public static int test() {
+ return J1_01_ifelse.test2();
+ }
+
+ public static int test2(){
+ int i = 2;
+ if (1 == 2)
+ i = 4;
+ if (i >= 1+1) {
+ i = 6;
+ } else {
+ i = 8;
+ }
+ return i;
+ }
+}
diff --git a/UnitNodes.py b/UnitNodes.py
index b811b12..15b42cc 100644
--- a/UnitNodes.py
+++ b/UnitNodes.py
@@ -47,6 +47,11 @@ class LiteralNode(ASTNode):
# int
if self.name == 'int':
self.code += p("mov", "eax", str(self.getConstant()), " set to literal int")
+ if self.name == 'boolean':
+ if self.getConstant:
+ self.code = p("mov", "eax", "1", " set to literal true")
+ else:
+ self.code = p("mov", "eax", "0", " set to literal false")
def getConstant(self):
if self.name == 'int':
--
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