xref: /illumos-gate/usr/src/cmd/sgs/gprof/common/lookup.c (revision 08855964b9970604433f7b19dcd71cf5af5e5f14)
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 #include "gprof.h"
29 
30 /*
31  * look up an address in a sorted-by-address namelist
32  * this deals with misses by mapping them to the next lower
33  * entry point.
34  */
35 static   int	searchmsg = 0; /* Emit the diagnostic only once */
36 
37 nltype *
38 nllookup(mod_info_t *module, pctype address, pctype *nxtsym)
39 {
40 	size_t	low = 0, middle, high = module->nname - 1;
41 	pctype	keyval;
42 	nltype	*mnl = module->nl;
43 
44 	/*
45 	 * If this is the program executable in which we are looking up
46 	 * a symbol, then the actual load address will be the same as the
47 	 * address specified in the ELF file. For shared objects, the
48 	 * load address may differ from what is specified in the file. In
49 	 * this case, we may need to look for a different value altogether.
50 	 */
51 	keyval = module->txt_origin + (address - module->load_base);
52 
53 	if (keyval < mnl[low].value) {
54 		if (nxtsym) {
55 			*nxtsym = module->load_base +
56 					(mnl[low].value - module->txt_origin);
57 		}
58 		return (NULL);
59 	}
60 
61 	if (keyval >= mnl[high].value) {
62 		if (nxtsym)
63 			*nxtsym = module->load_end;
64 		return (&mnl[high]);
65 	}
66 
67 	while (low != high) {
68 		middle = (high + low) >> 1;
69 
70 		if (mnl[middle].value <= keyval &&
71 					    mnl[middle + 1].value > keyval) {
72 			if (nxtsym) {
73 				*nxtsym = module->load_base +
74 						    (mnl[middle + 1].value -
75 						    module->txt_origin);
76 			}
77 			return (&mnl[middle]);
78 		}
79 
80 		if (mnl[middle].value > keyval) {
81 			high = middle;
82 		} else {
83 			low = middle + 1;
84 		}
85 	}
86 
87 	if (searchmsg++ == 0)
88 		(void) fprintf(stderr, "[nllookup] binary search fails???\n");
89 
90 	/* must never reach here! */
91 	return (0);
92 }
93 
94 arctype *
95 arclookup(nltype *parentp, nltype *childp)
96 {
97 	arctype	*arcp;
98 
99 	if (parentp == 0 || childp == 0) {
100 		(void) fprintf(stderr,
101 		    "[arclookup] parentp == 0 || childp == 0\n");
102 		return (0);
103 	}
104 #ifdef DEBUG
105 	if (debug & LOOKUPDEBUG) {
106 		(void) printf("[arclookup] parent %s child %s\n",
107 		    parentp->name, childp->name);
108 	}
109 #endif /* DEBUG */
110 
111 	for (arcp = parentp->children; arcp; arcp = arcp->arc_childlist) {
112 #ifdef DEBUG
113 		if (debug & LOOKUPDEBUG) {
114 			(void) printf(
115 			    "[arclookup]\t arc_parent %s arc_child %s\n",
116 			    arcp->arc_parentp->name,
117 			    arcp->arc_childp->name);
118 		}
119 #endif /* DEBUG */
120 		if (arcp->arc_childp == childp) {
121 			return (arcp);
122 		}
123 	}
124 	return (0);
125 }
126