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 (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #include <stdio.h>
27 #include <demangle.h>
28 #include "_conv.h"
29 #include "demangle_msg.h"
30
31 /*
32 * Demangle C++ symbols.
33 *
34 * This routine acts as a generic routine for use by liblddbg (and hence tools
35 * like elfdump(1) and pvs(1)), ld(1) and ld.so.1(1).
36 *
37 * The C++ ABI-2 places no limits on symbol names, thus when demangling a name
38 * it's possible the buffer won't be big enough (DEMANGLE_ESPACE) so here we
39 * try to allocate bigger buffers. However, we place a limit on this buffer
40 * size for fear of a C++ error sending us into an infinit loop.
41 *
42 * NOTE. we create and use a common buffer for use by cplus_demangle(), thus
43 * each call to this routine will override the contents of any existing call.
44 * Normally this is sufficient for typical error diagnostics referencing one
45 * symbol. For those diagnostics using more than one symbol name, all but the
46 * last name must be copied to a temporary buffer (regardless of whether
47 * demangling occurred, as the process of attempting to demangle may damage the
48 * buffer). One model is:
49 *
50 * if ((_name1 = demangle(name1)) != name1) {
51 * char * __name1 = strdupa(_name1);
52 * name1 = (const char *)__name1;
53 * }
54 * name2 = demangle(name2);
55 * eprintf(format, name1, name2);
56 */
57 #define SYM_MAX 1000
58
59 const char *
60 conv_demangle_name(const char *name)
61 {
62 static char _str[SYM_MAX], *str = _str;
63 static size_t size = SYM_MAX;
64 static int again = 1;
65 static int (*fptr)() = 0;
66 int error;
67
68 if (str == 0)
69 return (name);
70
71 /*
72 * If we haven't located the demangler yet try now (we do this rather
73 * than maintain a static dependency on libdemangle as it's part of an
74 * optional package). Null the str element out to reject any other
75 * callers until this operation is complete - under ld.so.1 we can get
76 * into serious recursion without this.
77 */
78 if (fptr == 0) {
79 void *hdl;
80
81 str = 0;
82 if (!(hdl = dlopen(MSG_ORIG(MSG_DEM_LIB), RTLD_LAZY)) ||
83 !(fptr = (int (*)())dlsym(hdl, MSG_ORIG(MSG_DEM_SYM))))
84 return (name);
85 str = _str;
86 }
87
88 if ((error = (*fptr)(name, str, size)) == 0)
89 return ((const char *)str);
90
91 while ((error == DEMANGLE_ESPACE) && again) {
92 char *_str;
93 size_t _size = size;
94
95 /*
96 * If we haven't allocated our maximum try incrementing the
97 * present buffer size. Use malloc() rather than realloc() so
98 * that we at least have the old buffer on failure.
99 */
100 if (((_size += SYM_MAX) > (SYM_MAX * 4)) ||
101 ((_str = malloc(_size)) == 0)) {
102 again = 0;
103 break;
104 }
105 if (size != SYM_MAX) {
106 free(str);
107 }
108 str = _str;
109 size = _size;
110
111 if ((error = (*fptr)(name, str, size)) == 0)
112 return ((const char *)str);
113 }
114 return (name);
115 }