xref: /illumos-gate/usr/src/cmd/dis/dis_util.c (revision dc0093f44ee4fac928e006850f8ed53f68277af5)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <dlfcn.h>
30 #include <stdarg.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <demangle.h>
34 
35 #include "dis_util.h"
36 
37 int g_error;	/* global process exit status, set when warn() is called */
38 
39 /*
40  * Fatal error.  Print out the error with a leading "dis: ", and then exit the
41  * program.
42  */
43 void
44 die(const char *fmt, ...)
45 {
46 	va_list ap;
47 
48 	(void) fprintf(stderr, "dis: fatal: ");
49 
50 	va_start(ap, fmt);
51 	(void) vfprintf(stderr, fmt, ap);
52 	va_end(ap);
53 
54 	(void) fprintf(stderr, "\n");
55 
56 	exit(1);
57 }
58 
59 /*
60  * Non-fatal error.  Print out the error with a leading "dis: ", set the global
61  * error flag, and return.
62  */
63 void
64 warn(const char *fmt, ...)
65 {
66 	va_list ap;
67 
68 	(void) fprintf(stderr, "dis: warning: ");
69 
70 	va_start(ap, fmt);
71 	(void) vfprintf(stderr, fmt, ap);
72 	va_end(ap);
73 
74 	(void) fprintf(stderr, "\n");
75 
76 	g_error = 1;
77 }
78 
79 /*
80  * Convenience wrapper around malloc() to cleanly exit if any allocation fails.
81  */
82 void *
83 safe_malloc(size_t size)
84 {
85 	void *ret;
86 
87 	if ((ret = calloc(1, size)) == NULL)
88 		die("Out of memory");
89 
90 	return (ret);
91 }
92 
93 
94 /*
95  * Generic interface to demangle C++ names.  Calls cplus_demangle to do the
96  * necessary translation.  If the translation fails, the argument is returned
97  * unchanged.  The memory returned is only valid until the next call to
98  * demangle().
99  *
100  * We dlopen() libdemangle.so rather than linking directly against it in case it
101  * is not installed on the system.
102  */
103 const char *
104 dis_demangle(const char *name)
105 {
106 	static char *demangled_name;
107 	static int (*demangle_func)() = NULL;
108 	static int size = BUFSIZE;
109 	static int first_flag = 0;
110 	int ret;
111 
112 	/*
113 	 * If this is the first call, allocate storage
114 	 * for the buffer.
115 	 */
116 	if (first_flag == 0) {
117 		void *demangle_hand;
118 
119 		demangle_hand = dlopen("libdemangle.so.1", RTLD_LAZY);
120 		if (demangle_hand != NULL)
121 			demangle_func = (int (*)(int))dlsym(
122 				demangle_hand, "cplus_demangle");
123 
124 		demangled_name = safe_malloc(size);
125 		first_flag = 1;
126 	}
127 
128 	/*
129 	 * If libdemangle is not present, pass through unchanged.
130 	 */
131 	if (demangle_func == NULL)
132 		return (name);
133 
134 	/*
135 	 * The function returns -1 when the buffer size is not sufficient.
136 	 */
137 	while ((ret = (*demangle_func)(name, demangled_name, size)) == -1) {
138 		free(demangled_name);
139 		size = size + BUFSIZE;
140 		demangled_name = safe_malloc(size);
141 	}
142 
143 	if (ret != 0)
144 		return (name);
145 
146 	return (demangled_name);
147 }
148