VEX/priv/ir_match.c

   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) 2004-2017 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, see <http://www.gnu.org/licenses/>.
  25
  26    The GNU General Public License is contained in the file COPYING.
  27
  28    Neither the names of the U.S. Department of Energy nor the
  29    University of California nor the names of its contributors may be
  30    used to endorse or promote products derived from this software
  31    without prior written permission.
  32 */
  33
  34 /* Provides a facility for doing IR tree matching. */
  35
  36 #include "main_util.h"
  37 #include "ir_match.h"
  38
  39
  40 /* Assign a value to a binder.  Checks for obvious stupidities. */
  41
  42 static
  43 void setBindee ( MatchInfo* mi, Int n, const IRExpr* bindee )
  44 {
  45    if (n < 0 || n >= N_IRMATCH_BINDERS)
  46       vpanic("setBindee: out of range index");
  47    if (mi->bindee[n] != NULL)
  48       vpanic("setBindee: bindee already set");
  49    mi->bindee[n] = bindee;
  50 }
  51
  52
  53 /* This is the actual matching function, recursing over the pattern
  54    and expression trees in the obvious way, and dumping any matches
  55    found into 'mi'. */
  56
  57 static
  58 Bool matchWrk ( MatchInfo* mi, const IRExpr* p/*attern*/,
  59                 const IRExpr* e/*xpr*/ )
  60 {
  61    switch (p->tag) {
  62       case Iex_Binder: /* aha, what we were looking for. */
  63          setBindee(mi, p->Iex.Binder.binder, e);
  64          return True;
  65       case Iex_Unop:
  66          if (e->tag != Iex_Unop) return False;
  67          if (p->Iex.Unop.op != e->Iex.Unop.op) return False;
  68          if (!matchWrk(mi, p->Iex.Unop.arg, e->Iex.Unop.arg))
  69             return False;
  70          return True;
  71       case Iex_Binop:
  72          if (e->tag != Iex_Binop) return False;
  73          if (p->Iex.Binop.op != e->Iex.Binop.op) return False;
  74          if (!matchWrk(mi, p->Iex.Binop.arg1, e->Iex.Binop.arg1))
  75             return False;
  76          if (!matchWrk(mi, p->Iex.Binop.arg2, e->Iex.Binop.arg2))
  77             return False;
  78          return True;
  79       case Iex_Load:
  80          if (e->tag != Iex_Load) return False;
  81          if (p->Iex.Load.end != e->Iex.Load.end) return False;
  82          if (p->Iex.Load.ty != e->Iex.Load.ty) return False;
  83          if (!matchWrk(mi, p->Iex.Load.addr, e->Iex.Load.addr))
  84             return False;
  85          return True;
  86       case Iex_Const:
  87          if (e->tag != Iex_Const) return False;
  88          return eqIRConst(p->Iex.Const.con, e->Iex.Const.con);
  89       default:
  90          ppIRExpr(p);
  91          vpanic("match");
  92    }
  93 }
  94
  95
  96 /* Top level entry point to the matcher. */
  97
  98 Bool matchIRExpr ( MatchInfo* mi, const IRExpr* p/*attern*/,
  99                    const 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 /*---------------------------------------------------------------*/