PeekStatementAST.py revision 10963:51f40b101a56 
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.StatementAST import StatementAST
29from slicc.symbols import Var
30
31class PeekStatementAST(StatementAST):
32    def __init__(self, slicc, queue_name, type_ast, pairs, statements, method):
33        super(PeekStatementAST, self).__init__(slicc, pairs)
34
35        self.queue_name = queue_name
36        self.type_ast = type_ast
37        self.statements = statements
38        self.method = method
39
40    def __repr__(self):
41        return "[PeekStatementAST: %r queue_name: %r type: %r %r]" % \
42               (self.method, self.queue_name, self.type_ast, self.statements)
43
44    def generate(self, code, return_type):
45        self.symtab.pushFrame()
46
47        msg_type = self.type_ast.type
48
49        # Add new local var to symbol table
50        var = Var(self.symtab, "in_msg", self.location, msg_type, "(*in_msg_ptr)",
51                  self.pairs)
52        self.symtab.newSymbol(var)
53
54        # Check the queue type
55        self.queue_name.assertType("InPort")
56
57        # Declare the new "in_msg_ptr" variable
58        mtid = msg_type.ident
59        qcode = self.queue_name.var.code
60        code('''
61{
62    // Declare message
63    const $mtid* in_msg_ptr M5_VAR_USED;
64    in_msg_ptr = dynamic_cast<const $mtid *>(($qcode).${{self.method}}());
65    if (in_msg_ptr == NULL) {
66        // If the cast fails, this is the wrong inport (wrong message type).
67        // Throw an exception, and the caller will decide to either try a
68        // different inport or punt.
69        throw RejectException();
70    }
71''')
72
73        if self.pairs.has_key("block_on"):
74            address_field = self.pairs['block_on']
75            code('''
76    if (m_is_blocking &&
77        (m_block_map.count(in_msg_ptr->m_$address_field) == 1) &&
78        (m_block_map[in_msg_ptr->m_$address_field] != &$qcode)) {
79            $qcode.delayHead();
80            continue;
81    }
82            ''')
83
84        if self.pairs.has_key("wake_up"):
85            address_field = self.pairs['wake_up']
86            code('''
87    if (m_waiting_buffers.count(in_msg_ptr->m_$address_field) > 0) {
88        wakeUpBuffers(in_msg_ptr->m_$address_field);
89    }
90            ''')
91
92        # The other statements
93        self.statements.generate(code, return_type)
94        self.symtab.popFrame()
95        code("}")
96
97    def findResources(self, resources):
98        self.statements.findResources(resources)
99