#
# Copyright (c) 2011 Mark D. Hill and David A. Wood
# All rights reserved.
#
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# modification, are permitted provided that the following conditions are
# met: redistributions of source code must retain the above copyright
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# redistributions in binary form must reproduce the above copyright
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# neither the name of the copyright holders nor the names of its
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# this software without specific prior written permission.
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from slicc.ast.ExprAST import ExprAST
from slicc.symbols import Type

class IsValidPtrExprAST(ExprAST):
    def __init__(self, slicc, variable, flag):
        super(IsValidPtrExprAST, self).__init__(slicc)
        self.variable = variable
        self.flag = flag

    def __repr__(self):
        return "[IsValidPtrExprAST: %r]" % self.variable

    def generate(self, code, **kwargs):
        # Make sure the variable is valid
        fix = code.nofix()
        code("(")
        var_type, var_code = self.variable.inline(True);
        if self.flag:
            code("${var_code} != NULL)")
        else:
            code("${var_code} == NULL)")
        code.fix(fix)
        type = self.symtab.find("bool", Type)
        return type
