src/mem/slicc/ast/IsValidPtrExprAST.py

   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
  29 from slicc.ast.ExprAST import ExprAST
  30 from slicc.symbols import Type
  31
  32 class 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