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 <ntdef.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 */ 149