usr/src/cmd/sgs/gprof/common/lookup.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22
  23 /*
  24  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  25  * Use is subject to license terms.
  26  */
  27
  28 #pragma ident   "%Z%%M% %I%     %E% SMI"
  29
  30 #include "gprof.h"
  31
  32 /*
  33  * look up an address in a sorted-by-address namelist
  34  * this deals with misses by mapping them to the next lower
  35  * entry point.
  36  */
  37 static   int    searchmsg = 0; /* Emit the diagnostic only once */
  38
  39 nltype *
  40 nllookup(mod_info_t *module, pctype address, pctype *nxtsym)
  41 {
  42         size_t  low = 0, middle, high = module->nname - 1;
  43         pctype  keyval;
  44         nltype  *mnl = module->nl;
  45
  46         /*
  47          * If this is the program executable in which we are looking up
  48          * a symbol, then the actual load address will be the same as the
  49          * address specified in the ELF file. For shared objects, the
  50          * load address may differ from what is specified in the file. In
  51          * this case, we may need to look for a different value altogether.
  52          */
  53         keyval = module->txt_origin + (address - module->load_base);
  54
  55         if (keyval < mnl[low].value) {
  56                 if (nxtsym) {
  57                         *nxtsym = module->load_base +
  58                                         (mnl[low].value - module->txt_origin);
  59                 }
  60                 return (NULL);
  61         }
  62
  63         if (keyval >= mnl[high].value) {
  64                 if (nxtsym)
  65                         *nxtsym = module->load_end;
  66                 return (&mnl[high]);
  67         }
  68
  69         while (low != high) {
  70                 middle = (high + low) >> 1;
  71
  72                 if (mnl[middle].value <= keyval &&
  73                                             mnl[middle + 1].value > keyval) {
  74                         if (nxtsym) {
  75                                 *nxtsym = module->load_base +
  76                                                     (mnl[middle + 1].value -
  77                                                     module->txt_origin);
  78                         }
  79                         return (&mnl[middle]);
  80                 }
  81
  82                 if (mnl[middle].value > keyval) {
  83                         high = middle;
  84                 } else {
  85                         low = middle + 1;
  86                 }
  87         }
  88
  89         if (searchmsg++ == 0)
  90                 (void) fprintf(stderr, "[nllookup] binary search fails???\n");
  91
  92         /* must never reach here! */
  93         return (0);
  94 }
  95
  96 arctype *
  97 arclookup(nltype *parentp, nltype *childp)
  98 {
  99         arctype *arcp;
 100
 101         if (parentp == 0 || childp == 0) {
 102                 (void) fprintf(stderr,
 103                     "[arclookup] parentp == 0 || childp == 0\n");
 104                 return (0);
 105         }
 106 #ifdef DEBUG
 107         if (debug & LOOKUPDEBUG) {
 108                 (void) printf("[arclookup] parent %s child %s\n",
 109                     parentp->name, childp->name);
 110         }
 111 #endif /* DEBUG */
 112
 113         for (arcp = parentp->children; arcp; arcp = arcp->arc_childlist) {
 114 #ifdef DEBUG
 115                 if (debug & LOOKUPDEBUG) {
 116                         (void) printf(
 117                             "[arclookup]\t arc_parent %s arc_child %s\n",
 118                             arcp->arc_parentp->name,
 119                             arcp->arc_childp->name);
 120                 }
 121 #endif /* DEBUG */
 122                 if (arcp->arc_childp == childp) {
 123                         return (arcp);
 124                 }
 125         }
 126         return (0);
 127 }