VarExprAST.py revision 6657:ef5fae93a3b2 
1# Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
2# Copyright (c) 2009 The Hewlett-Packard Development Company
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
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26# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28from slicc.ast.ExprAST import ExprAST
29from slicc.symbols import Type, Var
30
31class VarExprAST(ExprAST):
32    def __init__(self, slicc, var):
33        super(VarExprAST, self).__init__(slicc)
34        self._var = var
35
36    def __repr__(self):
37        return "[VarExprAST: %r]" % self._var
38
39    @property
40    def name(self):
41        return str(self._var)
42
43    @property
44    def var(self):
45        var = self.symtab.find(self._var, Var)
46        if not var:
47            self.error("Unrecognized variable: %s", self._var)
48        return var
49
50    def assertType(self, type_ident):
51        expected_type = self.symtab.find(type_ident, Type)
52
53        if not expected_type:
54            self.error("There must be a type '%s' declared in this scope",
55                       type_ident)
56
57        if self.var.type != expected_type:
58            self.error("Incorrect type: " + \
59                       "'%s' is expected to be type '%s' not '%s'",
60                       self.var.ident, expected_type, self.var.type)
61
62    def generate(self, code):
63        fix = code.nofix()
64        code("${{self.var.code}}")
65        code.fix(fix)
66        return self.var.type
67