xref: /illumos-gate/usr/src/cmd/sgs/gprof/common/lookup.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 }
128