diff options
Diffstat (limited to 'src/front/ast.py')
| -rw-r--r-- | src/front/ast.py | 121 |
1 files changed, 78 insertions, 43 deletions
diff --git a/src/front/ast.py b/src/front/ast.py index f221440..99ccbee 100644 --- a/src/front/ast.py +++ b/src/front/ast.py @@ -1,4 +1,5 @@ from back.tac import * +from back.generator import Register import sys class Node(object): @@ -9,12 +10,14 @@ class Node(object): return Node.labels def emitlabel(self, i): - sys.stdout.write("L" + str(i) + ":") - sys.stdout.flush() + TACList().add(Label("L%d" % i)) - def emit(self, s): - sys.stdout.write("\t" + s + "\n") - sys.stdout.flush() + def emitfunction(self, name): + TACList().add(FunctionLabel(name)) + + def emit(self, op, arg1=None, arg2=None): + self.debug("emit(): op = %s, arg = %s, arg2 = %s" % (op, arg1, arg2)) + TACList().add(TAC(op, arg1, arg2)) def debug(self, msg): #sys.stdout.write("DEBUG: " + msg + "\n") @@ -43,13 +46,13 @@ class Function(Node): def generate(self): self.debug("Function.generate(): name = %s, params = %s, statement = %s" % (self.name, self.params, self.statement)) - print "%s:" % self.name + self.emitfunction(self.name) begin = self.newlabel() after = self.newlabel() self.emitlabel(begin) self.statement.generate(begin, after) self.emitlabel(after) - print + self.emit(Op.RETURN, 0) def __repr__(self): return "<Function: %s(%s) at line %d: %s>" % (self.name, str(self.params), self.lineno, str(self.statement)) @@ -93,15 +96,15 @@ class IfStatement(Statement): if self.false_statement: true_label = self.newlabel() false_label = self.newlabel() - self.emit("iffalse %s goto L%d" % (x, false_label)) + self.emit(Op.BEQ, x, "L%d" % false_label) self.emitlabel(true_label) self.true_statement.generate(true_label, after) - self.emit("goto L%d" % after) + self.emit(Op.JMP, "L%d" % after) self.emitlabel(false_label) self.false_statement.generate(false_label, after) else: true_label = self.newlabel() - self.emit("iffalse %s goto L%d" % (x, after)) + self.emit(Op.BEQ, x, "L%d" % after) self.emitlabel(true_label) self.true_statement.generate(true_label, after) @@ -116,19 +119,15 @@ class WhileStatement(Statement): def generate(self, before, after): self.debug("WhileStatement.generate(before = %d, after = %d): expression = %s, statement = %s" % (before, after, self.expression, self.statement)) - x = self.expression.reduce() - self.emit("iffalse %s goto L%d" % (x, after)) + self.emit(Op.BEQ, self.expression.reduce(), "L%d" % after) label = self.newlabel() self.emitlabel(label) self.statement.generate(label, before) - self.emit("goto L%d" % before) + self.emit(Op.JMP, "L%d" % before) def __repr__(self): return "<WhileStatement at line %d>" % self.lineno - def eval(self,tacarray): - return tacarray.append(te) - class ReturnStatement(Statement): def __init__(self, expression, lineno = -1): self.expression = expression @@ -136,7 +135,7 @@ class ReturnStatement(Statement): def generate(self, before, after): self.debug("ReturnStatement.generate(before = %d, after = %d): expression = %s" % (before, after, self.expression)) - self.emit("return %s" % self.expression.reduce()) + self.emit(Op.RETURN, self.expression.reduce()) def __repr__(self): return "<ReturnStatement at line %d>" % self.lineno @@ -149,7 +148,7 @@ class AssignStatement(Statement): def generate(self, before, after): self.debug("AssignStatement.generate(before = %d, after = %d): ident = %s, expression = %s" % (before, after, self.ident, self.expression)) - self.emit("%s = %s" % (self.ident, self.expression.reduce())) + self.emit(Op.STORE, self.ident, self.expression.reduce()) def __repr__(self): return "<AssignStatement for %s at line %d>" % (self.ident, self.lineno) @@ -162,13 +161,17 @@ class FunctionCall(Statement): def generate(self): self.debug("FunctionCall.generate(): ident = %s, arguments = %s" % (self.ident, self.arguments)) - self.emit("call %s" % self.ident) + for argument in self.arguments: + self.emit(Op.PARAM, argument.reduce()) + self.emit(Op.CALL, self.ident, len(self.arguments)) def reduce(self): self.debug("FunctionCall.reduce(): %s" % self) - t = Temporary() - self.emit("%s = call %s%s" % (t, self.ident, self.arguments)) - return t + for argument in self.arguments: + self.emit(Op.PARAM, argument.reduce()) + r = Register().new() + self.emit(Op.CALL, self.ident, r) + return r def __repr__(self): return "<FunctionCall for %s at line %d>" % (self.ident, self.lineno) @@ -178,12 +181,6 @@ class Expression(Node): self.op = op self.lineno = -1 - def generate(self): - return self - - def reduce(self): - return self - def __str__(self): return str(self.op) @@ -194,13 +191,6 @@ class Operation(Expression): def __init__(self, op, lineno = -1): super(Operation, self).__init__(op, lineno) - def reduce(self): - self.debug("Operation.reduce(): %s" % self) - x = self.generate() - t = Temporary() - self.emit("%s = %s" % (t, x)) - return t - def __repr__(self): return "<Operation at line %d>" % self.lineno @@ -210,9 +200,15 @@ class UnaryExpression(Operation): super(UnaryExpression, self).__init__(op, lineno) self.right = right - def generate(self): + def reduce(self): self.debug("UnaryExpression.generate(): op = %s, right = %s" % (self.op, self.right)) - return UnaryExpression(self.op, self.right.reduce()) + op = { + "!": Op.NOT, + "-": Op.MINUS, + }[self.op] + r = self.right.reduce() + self.emit(op, r) + return r def __str__(self): return "%s %s" % (str(self.op), str(self.right)) @@ -227,9 +223,36 @@ class BinaryExpression(Operation): self.left = left self.right = right - def generate(self): - self.debug("BinaryExpression.generate(): left = %s, op = %s, right = %s" % (self.left, self.op, self.right)) - return BinaryExpression(self.left.reduce(), self.op, self.right.reduce()) + def reduce(self): + self.debug("BinaryExpression.reduce(): left = %s, op = %s, right = %s" % (self.left, self.op, self.right)) + arith_op = { + "+": Op.ADD, + "-": Op.SUB, + "*": Op.MUL, + "/": Op.DIV, + "%": Op.MOD, + } + + logic_op = { + "==": Op.EQ, + "!=": Op.NE, + "<": Op.LT, + "<=": Op.LE, + ">=": Op.GE, + ">": Op.GT, + } + + try: + op = arith_op[self.op] + r = self.left.reduce() + self.emit(op, r, self.right.reduce()) + except KeyError: + op = logic_op[self.op] + r = Register().new() + self.emit(Op.CMP, self.left.reduce(), self.right.reduce()) + self.emit(op, r) + + return r def __str__(self): return "%s %s %s" % (str(self.left), str(self.op), str(self.right)) @@ -241,6 +264,12 @@ class Variable(Expression): def __init__(self, name, lineno = -1): super(Variable, self).__init__(name, lineno) + def reduce(self): + self.debug("Variable.reduce(): name = %s" % self.op) + r = Register().new() + self.emit(Op.LOAD, self.op, r) + return r + def __repr__(self): return "<Variable: %s at line %d>" %(self.op, self.lineno) @@ -250,9 +279,15 @@ class Constant(Expression): def jumping(self, true_label, false_label): if self.op and true_label != 0: - self.emit("goto L%d" % true_label) + self.emit(Op.JMP, "L%d" % true_label) elif not self.op and false_label != 0: - self.emit("goto L%d" % false_label) + self.emit(Op.JMP, "L%d" % false_label) + + def reduce(self): + self.debug("Constant.reduce(): value = %s" % self.op) + r = Register().new() + self.emit(Op.MOV, r, self.op) + return r def __repr__(self): return "<Constant: %d at line %d>" %(self.op, self.lineno) @@ -265,4 +300,4 @@ class Temporary(Expression): Temporary.count += 1 def __str__(self): - return "t%d" % self.number + return "r%d" % self.number |