xref: /illumos-gate/usr/src/cmd/sgs/libelf/misc/demangle.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  *	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 #pragma ident	"%Z%%M%	%I%	%E% SMI" 	/* SVr4.0 1.2	*/
31 
32 #include <ctype.h>
33 #include <setjmp.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <thread.h>
37 #include <note.h>
38 #include "elf_dem.h"
39 #include "String.h"
40 #include "msg.h"
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 /* this String is the working buffer for the demangle
59  * routine.  A pointer into this String is returned
60  * from demangle when it is possible to demangle the
61  * String.  For this reason, the pointer should not
62  * be saved between calls of demangle(), nor freed.
63  */
64 static String *s = 0;
65 
66 static int
67 getint(c)
68 char **c;
69 {
70 	return strtol(*c, c, 10);
71 }
72 
73 /* If a mangled name has a __
74  * that is not at the very beginning
75  * of the string, then this routine
76  * is called to demangle that part
77  * of the name.  All overloaded functions,
78  * and class members fall into this category.
79  *
80  * c should start with two underscores followed by a non-zero digit or an F.
81  */
82 static char *
83 second(c)
84 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(c)
121 char *c;
122 {
123 	register int i = 0;
124 	extern jmp_buf jbuf;
125 	static mutex_t	mlock = DEFAULTMUTEX;
126 
127 	NOTE(MUTEX_PROTECTS_DATA(mlock, String))
128 	(void) mutex_lock(&mlock);
129 
130 	if (setjmp(jbuf)) {
131 		(void) mutex_unlock(&mlock);
132 		return 0;
133 	}
134 
135 	hold = c;
136 	s = mk_String(s);
137 	s = set_String(s, MSG_ORIG(MSG_STR_EMPTY));
138 
139 	if(c == 0 || *c == 0) {
140 		c = hold;
141 		(void) mutex_unlock(&mlock);
142 		return c;
143 	}
144 
145 	if(strncmp(c, MSG_ORIG(MSG_STR_DBLUNDBAR), 2) != 0) {
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 		/* For automatic variables, or internal static
176 		 * variables, a __(number) is prepended to the
177 		 * name.  If this is encountered, strip this off
178 		 * and return.
179 		 */
180 		if(isdigit(*c)) {
181 			while(isdigit(*c))
182 				c++;
183 			(void) mutex_unlock(&mlock);
184 			return c;
185 		}
186 
187 		/* Handle operator functions -- this
188 		 * automatically calls second, since
189 		 * all operator functions are overloaded.
190 		 */
191 		if(x = findop(c, &oplen)) {
192 			s = app_String(s, MSG_ORIG(MSG_STR_OPERATOR_1));
193 			s = app_String(s,x);
194 			c += oplen;
195 			c = second(c);
196 			(void) mutex_unlock(&mlock);
197 			return c;
198 		}
199 
200 		/* Operator cast does not fit the mould
201 		 * of the other operators.  Its type name
202 		 * is encoded.  The cast function must
203 		 * take a void as an argument.
204 		 */
205 		if(strncmp(c, MSG_ORIG(MSG_STR_OP), 2) == 0) {
206 			int r;
207 			s = app_String(s, MSG_ORIG(MSG_STR_OPERATOR_2));
208 			c += 2;
209 			r = demangle_doarg(&s,c);
210 			if(r < 0) {
211 				c = hold;
212 				(void) mutex_unlock(&mlock);
213 				return c;
214 			}
215 			c += r;
216 			c = second(c);
217 			(void) mutex_unlock(&mlock);
218 			return c;
219 		}
220 
221 		/* Constructors and Destructors are also
222 		 * a special case of operator name.  Note
223 		 * that the destructor, while overloaded,
224 		 * must always take the same arguments --
225 		 * none.
226 		 */
227 		if ((*c == 'c' || *c == 'd') && strncmp(c+1,
228 		    MSG_ORIG(MSG_STR_TDBLUNDBAR), 3) == 0) {
229 			int n;
230 			char *c2 = c+2;
231 			char cx = c[0];
232 			c += 4;
233 			n = getint(&c);
234 			if(n == 0) {
235 				c = hold;
236 				(void) mutex_unlock(&mlock);
237 				return c;
238 			}
239 			s = napp_String(s,c,n);
240 			if(cx == 'd')
241 				s = prep_String(MSG_ORIG(MSG_STR_TILDE), s);
242 			c = second(c2);
243 			(void) mutex_unlock(&mlock);
244 			return c;
245 		}
246 		c = hold;
247 		(void) mutex_unlock(&mlock);
248 		return c;
249 	}
250 }
251