src/mem/slicc/ast/InfixOperatorExprAST.py

# Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
# Copyright (c) 2009 The Hewlett-Packard Development Company
# All rights reserved.
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from m5.util import code_formatter

from slicc.ast.ExprAST import ExprAST
from slicc.symbols import Type

class InfixOperatorExprAST(ExprAST):
    def __init__(self, slicc, left, op, right):
        super(InfixOperatorExprAST, self).__init__(slicc)

        self.left = left
        self.op = op
        self.right = right

    def __repr__(self):
        return "[InfixExpr: %r %s %r]" % (self.left, self.op, self.right)

    def generate(self, code):
        lcode = code_formatter()
        rcode = code_formatter()

        ltype = self.left.generate(lcode)
        rtype = self.right.generate(rcode)

        # Figure out what the input and output types should be
        if self.op in ("==", "!="):
            output = "bool"
            if (ltype != rtype):
                self.error("Type mismatch: left and right operands of " +
                           "operator '%s' must be the same type. " +
                           "left: '%s', right: '%s'",
                           self.op, ltype, rtype)
        else:
            if self.op in ("&&", "||"):
                # boolean inputs and output
                inputs = "bool"
                output = "bool"
            elif self.op in ("==", "!=", ">=", "<=", ">", "<"):
                # Integer inputs, boolean output
                inputs = "int"
                output = "bool"
            else:
                # integer inputs and output
                inputs = "int"
                output = "int"

            inputs_type = self.symtab.find(inputs, Type)

            if inputs_type != ltype:
                self.left.error("Type mismatch: left operand of operator " +
                                "'%s' expects type '%s', actual was '%s'",
                                self.op, inputs, ltype)

            if inputs_type != rtype:
                self.right.error("Type mismatch: right operand of operator " +
                                 "'%s' expects type '%s', actual was '%s'",
                                 self.op, inputs, rtype)

        # All is well
        fix = code.nofix()
        code("($lcode ${{self.op}} $rcode)")
        code.fix(fix)
        return self.symtab.find(output, Type)