ir_match.c revision 2d3c75979dd0bbf2606bf1a8e11b72ae6220e5db 
1
2/*---------------------------------------------------------------*/
3/*--- begin                                        ir_match.c ---*/
4/*---------------------------------------------------------------*/
5
6/*
7   This file is part of Valgrind, a dynamic binary instrumentation
8   framework.
9
10   Copyright (C) 2004-2012 OpenWorks LLP
11      info@open-works.net
12
13   This program is free software; you can redistribute it and/or
14   modify it under the terms of the GNU General Public License as
15   published by the Free Software Foundation; either version 2 of the
16   License, or (at your option) any later version.
17
18   This program is distributed in the hope that it will be useful, but
19   WITHOUT ANY WARRANTY; without even the implied warranty of
20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21   General Public License for more details.
22
23   You should have received a copy of the GNU General Public License
24   along with this program; if not, write to the Free Software
25   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
26   02110-1301, USA.
27
28   The GNU General Public License is contained in the file COPYING.
29
30   Neither the names of the U.S. Department of Energy nor the
31   University of California nor the names of its contributors may be
32   used to endorse or promote products derived from this software
33   without prior written permission.
34*/
35
36/* Provides a facility for doing IR tree matching. */
37
38#include "main_util.h"
39#include "ir_match.h"
40
41
42/* Assign a value to a binder.  Checks for obvious stupidities. */
43
44static
45void setBindee ( MatchInfo* mi, Int n, IRExpr* bindee )
46{
47   if (n < 0 || n >= N_IRMATCH_BINDERS)
48      vpanic("setBindee: out of range index");
49   if (mi->bindee[n] != NULL)
50      vpanic("setBindee: bindee already set");
51   mi->bindee[n] = bindee;
52}
53
54
55/* This is the actual matching function, recursing over the pattern
56   and expression trees in the obvious way, and dumping any matches
57   found into 'mi'. */
58
59static
60Bool matchWrk ( MatchInfo* mi, IRExpr* p/*attern*/, IRExpr* e/*xpr*/ )
61{
62   switch (p->tag) {
63      case Iex_Binder: /* aha, what we were looking for. */
64         setBindee(mi, p->Iex.Binder.binder, e);
65         return True;
66      case Iex_Unop:
67         if (e->tag != Iex_Unop) return False;
68         if (p->Iex.Unop.op != e->Iex.Unop.op) return False;
69         if (!matchWrk(mi, p->Iex.Unop.arg, e->Iex.Unop.arg))
70            return False;
71         return True;
72      case Iex_Binop:
73         if (e->tag != Iex_Binop) return False;
74         if (p->Iex.Binop.op != e->Iex.Binop.op) return False;
75         if (!matchWrk(mi, p->Iex.Binop.arg1, e->Iex.Binop.arg1))
76            return False;
77         if (!matchWrk(mi, p->Iex.Binop.arg2, e->Iex.Binop.arg2))
78            return False;
79         return True;
80      case Iex_Load:
81         if (e->tag != Iex_Load) return False;
82         if (p->Iex.Load.end != e->Iex.Load.end) return False;
83         if (p->Iex.Load.ty != e->Iex.Load.ty) return False;
84         if (!matchWrk(mi, p->Iex.Load.addr, e->Iex.Load.addr))
85            return False;
86         return True;
87      case Iex_Const:
88         if (e->tag != Iex_Const) return False;
89         return eqIRConst(p->Iex.Const.con, e->Iex.Const.con);
90      default:
91         ppIRExpr(p);
92         vpanic("match");
93   }
94}
95
96
97/* Top level entry point to the matcher. */
98
99Bool matchIRExpr ( MatchInfo* mi, IRExpr* p/*attern*/, IRExpr* e/*xpr*/ )
100{
101   Int i;
102   for (i = 0; i < N_IRMATCH_BINDERS; i++)
103      mi->bindee[i] = NULL;
104   return matchWrk(mi, p, e);
105}
106
107
108
109/*---------------------------------------------------------------*/
110/*--- end                                          ir_match.c ---*/
111/*---------------------------------------------------------------*/
112