reactos/lib/rossym/find.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            lib/rossym/find.c
   5  * PURPOSE:         Find symbol info for an address
   6  *
   7  * PROGRAMMERS:     Ge van Geldorp (gvg@reactos.com)
   8  */
   9 /*
  10  * Parts of this file based on work Copyright (c) 1990, 1993
  11  *      The Regents of the University of California.  All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  */
  37
  38 #include <ntddk.h>
  39 #include <reactos/rossym.h>
  40 #include "rossympriv.h"
  41
  42 #define NDEBUG
  43 #include <debug.h>
  44
  45 static PROSSYM_ENTRY
  46 FindEntry(IN PROSSYM_INFO RosSymInfo, IN ULONG_PTR RelativeAddress)
  47 {
  48   /*
  49    * Perform a binary search.
  50    *
  51    * The code below is a bit sneaky.  After a comparison fails, we
  52    * divide the work in half by moving either left or right. If lim
  53    * is odd, moving left simply involves halving lim: e.g., when lim
  54    * is 5 we look at item 2, so we change lim to 2 so that we will
  55    * look at items 0 & 1.  If lim is even, the same applies.  If lim
  56    * is odd, moving right again involes halving lim, this time moving
  57    * the base up one item past p: e.g., when lim is 5 we change base
  58    * to item 3 and make lim 2 so that we will look at items 3 and 4.
  59    * If lim is even, however, we have to shrink it by one before
  60    * halving: e.g., when lim is 4, we still looked at item 2, so we
  61    * have to make lim 3, then halve, obtaining 1, so that we will only
  62    * look at item 3.
  63    */
  64   PROSSYM_ENTRY Base = RosSymInfo->Symbols;
  65   ULONG Lim;
  66   PROSSYM_ENTRY Mid, Low;
  67
  68   if (RelativeAddress < Base->Address)
  69     {
  70       return NULL;
  71     }
  72
  73   Low = Base;
  74   for (Lim = RosSymInfo->SymbolsCount; Lim != 0; Lim >>= 1)
  75     {
  76       Mid = Base + (Lim >> 1);
  77       if (RelativeAddress == Mid->Address)
  78         {
  79           return Mid;
  80         }
  81       if (Mid->Address < RelativeAddress)  /* key > mid: move right */
  82         {
  83           Low = Mid;
  84           Base = Mid + 1;
  85           Lim--;
  86         }               /* else move left */
  87     }
  88
  89   return Low;
  90 }
  91
  92
  93 BOOLEAN
  94 RosSymGetAddressInformation(PROSSYM_INFO RosSymInfo,
  95                             ULONG_PTR RelativeAddress,
  96                             ULONG *LineNumber,
  97                             char *FileName,
  98                             char *FunctionName)
  99 {
 100   PROSSYM_ENTRY RosSymEntry;
 101
 102   DPRINT("RelativeAddress = 0x%08x\n", RelativeAddress);
 103
 104   if (RosSymInfo->Symbols == NULL || RosSymInfo->SymbolsCount == 0 ||
 105       RosSymInfo->Strings == NULL || RosSymInfo->StringsLength == 0)
 106     {
 107       DPRINT1("Uninitialized RosSymInfo\n");
 108       return FALSE;
 109     }
 110
 111   ASSERT(LineNumber || FileName || FunctionName);
 112
 113   /* find symbol entry for function */
 114   RosSymEntry = FindEntry(RosSymInfo, RelativeAddress);
 115
 116   if (NULL == RosSymEntry)
 117     {
 118       DPRINT("None of the requested information was found!\n");
 119       return FALSE;
 120     }
 121
 122   if (LineNumber != NULL)
 123     {
 124       *LineNumber = RosSymEntry->SourceLine;
 125     }
 126   if (FileName != NULL)
 127     {
 128       PCSTR Name = "";
 129       if (RosSymEntry->FileOffset != 0)
 130         {
 131           Name = (PCHAR) RosSymInfo->Strings + RosSymEntry->FileOffset;
 132         }
 133       strcpy(FileName, Name);
 134     }
 135   if (FunctionName != NULL)
 136     {
 137       PCSTR Name = "";
 138       if (RosSymEntry->FunctionOffset != 0)
 139         {
 140           Name = (PCHAR) RosSymInfo->Strings + RosSymEntry->FunctionOffset;
 141         }
 142       strcpy(FunctionName, Name);
 143     }
 144
 145   return TRUE;
 146 }
 147
 148 /* EOF */