xref: /illumos-gate/usr/src/cmd/sgs/libelf/misc/demangle.c (revision d1aea6f139360e9e7f1504facb24f8521047b15c)
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  *	Copyright (c) 1988 AT&T
24  *	  All Rights Reserved
25  *
26  *
27  *	Copyright (c) 1998 by Sun Microsystems, Inc.
28  *	All rights reserved.
29  */
30 
31 #include <ctype.h>
32 #include <setjmp.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <thread.h>
36 #include <note.h>
37 #include "elf_dem.h"
38 #include "String.h"
39 #include "msg.h"
40 
41 /*
42  * The variable "hold" contains the pointer to the array initially
43  * handed to demangle.  It is returned if it is not possible to
44  * demangle the string.  NULL is returned if a memory allocation
45  * problem is encountered.  Thus one can do the following:
46  *
47  * char *mn = "Some mangled name";
48  * char *dm = mangle(mn);
49  * if (dm == NULL)
50  *	printf("allocation error\n");
51  * else if (dm == mn)
52  * 	printf("name could not be demangled\n");
53  * else
54  *	printf("demangled name is: %s\n",dm);
55  */
56 static char *hold;
57 
58 /*
59  * this String is the working buffer for the demangle
60  * routine.  A pointer into this String is returned
61  * from demangle when it is possible to demangle the
62  * String.  For this reason, the pointer should not
63  * be saved between calls of demangle(), nor freed.
64  */
65 static String *s = 0;
66 
67 static int
68 getint(char **c)
69 {
70 	return (strtol(*c, c, 10));
71 }
72 
73 /*
74  * If a mangled name has a __
75  * that is not at the very beginning
76  * of the string, then this routine
77  * is called to demangle that part
78  * of the name.  All overloaded functions,
79  * and class members fall into this category.
80  *
81  * c should start with two underscores followed by a non-zero digit or an F.
82  */
83 static char *
84 second(char *c)
85 {
86 	int n;
87 	if (strncmp(c, MSG_ORIG(MSG_STR_DBLUNDBAR), 2))
88 		return (hold);
89 	c += 2;
90 
91 	if (!(isdigit(*c) || *c == 'F'))
92 		return (hold);
93 
94 	if (isdigit(*c)) {
95 		/* a member */
96 		n = getint(&c);
97 		if (n == 0 || (int)strlen(c) < n)
98 			return (hold);
99 		s = prep_String(MSG_ORIG(MSG_STR_DBLCOL), s);
100 		s = nprep_String(c, s, n);
101 		c += n;
102 	}
103 	if (*c == 'F') {
104 		/* an overloaded function */
105 		switch (*++c) {
106 		case '\0':
107 			return (hold);
108 		case 'v':
109 			s = app_String(s, MSG_ORIG(MSG_STR_OPENCLOSEPAR));
110 			break;
111 		default:
112 			if (demangle_doargs(&s, c) < 0)
113 				return (hold);
114 		}
115 	}
116 	return (PTR(s));
117 }
118 
119 char *
120 demangle(char *c)
121 {
122 	volatile int i = 0;
123 	extern jmp_buf jbuf;
124 	static mutex_t	mlock = DEFAULTMUTEX;
125 
126 	NOTE(MUTEX_PROTECTS_DATA(mlock, String))
127 	(void) mutex_lock(&mlock);
128 
129 	if (setjmp(jbuf)) {
130 		(void) mutex_unlock(&mlock);
131 		return (0);
132 	}
133 
134 	hold = c;
135 	s = mk_String(s);
136 	s = set_String(s, MSG_ORIG(MSG_STR_EMPTY));
137 
138 	if (c == 0 || *c == 0) {
139 		c = hold;
140 		(void) mutex_unlock(&mlock);
141 		return (c);
142 	}
143 
144 	if (strncmp(c, MSG_ORIG(MSG_STR_DBLUNDBAR), 2) != 0) {
145 		/*
146 		 * If a name does not begin with a __
147 		 * but it does contain one, it is either
148 		 * a member or an overloaded function.
149 		 */
150 		while (c[i] && strncmp(c+i, MSG_ORIG(MSG_STR_DBLUNDBAR), 2))
151 			i++;
152 		if (c[i]) {
153 			/* Advance to first non-underscore */
154 			while (c[i+2] == '_')
155 				i++;
156 		}
157 		if (strncmp(c+i, MSG_ORIG(MSG_STR_DBLUNDBAR), 2) == 0) {
158 			/* Copy the simple name */
159 			s = napp_String(s, c, i);
160 			/* Process the signature */
161 			c = second(c+i);
162 			(void) mutex_unlock(&mlock);
163 			return (c);
164 		} else {
165 			c = hold;
166 			(void) mutex_unlock(&mlock);
167 			return (c);
168 		}
169 	} else {
170 		const char	*x;
171 		int		oplen;
172 
173 		c += 2;
174 
175 		/*
176 		 * For automatic variables, or internal static
177 		 * variables, a __(number) is prepended to the
178 		 * name.  If this is encountered, strip this off
179 		 * and return.
180 		 */
181 		if (isdigit(*c)) {
182 			while (isdigit(*c))
183 				c++;
184 			(void) mutex_unlock(&mlock);
185 			return (c);
186 		}
187 
188 		/*
189 		 * Handle operator functions -- this
190 		 * automatically calls second, since
191 		 * all operator functions are overloaded.
192 		 */
193 		if (x = findop(c, &oplen)) {
194 			s = app_String(s, MSG_ORIG(MSG_STR_OPERATOR_1));
195 			s = app_String(s, x);
196 			c += oplen;
197 			c = second(c);
198 			(void) mutex_unlock(&mlock);
199 			return (c);
200 		}
201 
202 		/*
203 		 * Operator cast does not fit the mould
204 		 * of the other operators.  Its type name
205 		 * is encoded.  The cast function must
206 		 * take a void as an argument.
207 		 */
208 		if (strncmp(c, MSG_ORIG(MSG_STR_OP), 2) == 0) {
209 			int r;
210 			s = app_String(s, MSG_ORIG(MSG_STR_OPERATOR_2));
211 			c += 2;
212 			r = demangle_doarg(&s, c);
213 			if (r < 0) {
214 				c = hold;
215 				(void) mutex_unlock(&mlock);
216 				return (c);
217 			}
218 			c += r;
219 			c = second(c);
220 			(void) mutex_unlock(&mlock);
221 			return (c);
222 		}
223 
224 		/*
225 		 * Constructors and Destructors are also
226 		 * a special case of operator name.  Note
227 		 * that the destructor, while overloaded,
228 		 * must always take the same arguments --
229 		 * none.
230 		 */
231 		if ((*c == 'c' || *c == 'd') &&
232 		    strncmp(c+1, MSG_ORIG(MSG_STR_TDBLUNDBAR), 3) == 0) {
233 			int n;
234 			char *c2 = c+2;
235 			char cx = c[0];
236 			c += 4;
237 			n = getint(&c);
238 			if (n == 0) {
239 				c = hold;
240 				(void) mutex_unlock(&mlock);
241 				return (c);
242 			}
243 			s = napp_String(s, c, n);
244 			if (cx == 'd')
245 				s = prep_String(MSG_ORIG(MSG_STR_TILDE), s);
246 			c = second(c2);
247 			(void) mutex_unlock(&mlock);
248 			return (c);
249 		}
250 		c = hold;
251 		(void) mutex_unlock(&mlock);
252 		return (c);
253 	}
254 }
255