1#
2# Copyright (c) 2011 Mark D. Hill and David A. Wood
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions are
7# met: redistributions of source code must retain the above copyright
8# notice, this list of conditions and the following disclaimer;
9# redistributions in binary form must reproduce the above copyright
10# notice, this list of conditions and the following disclaimer in the
11# documentation and/or other materials provided with the distribution;
12# neither the name of the copyright holders nor the names of its
13# contributors may be used to endorse or promote products derived from
14# this software without specific prior written permission.
15#
16# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27#
28
29from slicc.ast.ExprAST import ExprAST
30from slicc.symbols import Type
31
32class IsValidPtrExprAST(ExprAST):
33    def __init__(self, slicc, variable, flag):
34        super(IsValidPtrExprAST, self).__init__(slicc)
35        self.variable = variable
36        self.flag = flag
37
38    def __repr__(self):
39        return "[IsValidPtrExprAST: %r]" % self.variable
40
41    def generate(self, code):
42        # Make sure the variable is valid
43        fix = code.nofix()
44        code("(")
45        var_type, var_code = self.variable.inline(True);
46        if self.flag:
47            code("${var_code} != NULL)")
48        else:
49            code("${var_code} == NULL)")
50        code.fix(fix)
51        type = self.symtab.find("bool", Type)
52        return type
53