xref: /freebsd/sys/ddb/db_sym.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
1 /*
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie the
24  * rights to redistribute these changes.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * 	Author: David B. Golub, Carnegie Mellon University
31  *	Date:	7/90
32  */
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 
36 #include <ddb/ddb.h>
37 #include <ddb/db_sym.h>
38 
39 /*
40  * Multiple symbol tables
41  */
42 #ifndef MAXNOSYMTABS
43 #define	MAXNOSYMTABS	3	/* mach, ux, emulator */
44 #endif
45 
46 static db_symtab_t	db_symtabs[MAXNOSYMTABS] = {{0,},};
47 static int db_nsymtab = 0;
48 
49 static db_symtab_t	*db_last_symtab; /* where last symbol was found */
50 
51 static c_db_sym_t	db_lookup( const char *symstr);
52 static char		*db_qualify(c_db_sym_t sym, char *symtabname);
53 static boolean_t	db_symbol_is_ambiguous(c_db_sym_t sym);
54 static boolean_t	db_line_at_pc(c_db_sym_t, char **, int *, db_expr_t);
55 
56 /*
57  * Add symbol table, with given name, to list of symbol tables.
58  */
59 void
60 db_add_symbol_table(start, end, name, ref)
61 	char *start;
62 	char *end;
63 	char *name;
64 	char *ref;
65 {
66 	if (db_nsymtab >= MAXNOSYMTABS) {
67 		printf ("No slots left for %s symbol table", name);
68 		panic ("db_sym.c: db_add_symbol_table");
69 	}
70 
71 	db_symtabs[db_nsymtab].start = start;
72 	db_symtabs[db_nsymtab].end = end;
73 	db_symtabs[db_nsymtab].name = name;
74 	db_symtabs[db_nsymtab].private = ref;
75 	db_nsymtab++;
76 }
77 
78 /*
79  *  db_qualify("vm_map", "ux") returns "unix:vm_map".
80  *
81  *  Note: return value points to static data whose content is
82  *  overwritten by each call... but in practice this seems okay.
83  */
84 static char *
85 db_qualify(sym, symtabname)
86 	c_db_sym_t	sym;
87 	register char	*symtabname;
88 {
89 	const char	*symname;
90 	static char     tmp[256];
91 
92 	db_symbol_values(sym, &symname, 0);
93 	snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
94 	return tmp;
95 }
96 
97 
98 boolean_t
99 db_eqname(src, dst, c)
100 	const char *src;
101 	const char *dst;
102 	int c;
103 {
104 	if (!strcmp(src, dst))
105 	    return (TRUE);
106 	if (src[0] == c)
107 	    return (!strcmp(src+1,dst));
108 	return (FALSE);
109 }
110 
111 boolean_t
112 db_value_of_name(name, valuep)
113 	const char	*name;
114 	db_expr_t	*valuep;
115 {
116 	c_db_sym_t	sym;
117 
118 	sym = db_lookup(name);
119 	if (sym == C_DB_SYM_NULL)
120 	    return (FALSE);
121 	db_symbol_values(sym, &name, valuep);
122 	return (TRUE);
123 }
124 
125 
126 /*
127  * Lookup a symbol.
128  * If the symbol has a qualifier (e.g., ux:vm_map),
129  * then only the specified symbol table will be searched;
130  * otherwise, all symbol tables will be searched.
131  */
132 static c_db_sym_t
133 db_lookup(symstr)
134 	const char *symstr;
135 {
136 	c_db_sym_t sp;
137 	register int i;
138 	int symtab_start = 0;
139 	int symtab_end = db_nsymtab;
140 	register const char *cp;
141 
142 	/*
143 	 * Look for, remove, and remember any symbol table specifier.
144 	 */
145 	for (cp = symstr; *cp; cp++) {
146 		if (*cp == ':') {
147 			for (i = 0; i < db_nsymtab; i++) {
148 				int n = strlen(db_symtabs[i].name);
149 
150 				if (
151 				    n == (cp - symstr) &&
152 				    strncmp(symstr, db_symtabs[i].name, n) == 0
153 				) {
154 					symtab_start = i;
155 					symtab_end = i + 1;
156 					break;
157 				}
158 			}
159 			if (i == db_nsymtab) {
160 				db_error("invalid symbol table name");
161 			}
162 			symstr = cp+1;
163 		}
164 	}
165 
166 	/*
167 	 * Look in the specified set of symbol tables.
168 	 * Return on first match.
169 	 */
170 	for (i = symtab_start; i < symtab_end; i++) {
171 		sp = X_db_lookup(&db_symtabs[i], symstr);
172 		if (sp) {
173 			db_last_symtab = &db_symtabs[i];
174 			return sp;
175 		}
176 	}
177 	return 0;
178 }
179 
180 /*
181  * If TRUE, check across symbol tables for multiple occurrences
182  * of a name.  Might slow things down quite a bit.
183  */
184 static volatile boolean_t db_qualify_ambiguous_names = FALSE;
185 
186 /*
187  * Does this symbol name appear in more than one symbol table?
188  * Used by db_symbol_values to decide whether to qualify a symbol.
189  */
190 static boolean_t
191 db_symbol_is_ambiguous(sym)
192 	c_db_sym_t	sym;
193 {
194 	const char	*sym_name;
195 	register int	i;
196 	register
197 	boolean_t	found_once = FALSE;
198 
199 	if (!db_qualify_ambiguous_names)
200 		return FALSE;
201 
202 	db_symbol_values(sym, &sym_name, 0);
203 	for (i = 0; i < db_nsymtab; i++) {
204 		if (X_db_lookup(&db_symtabs[i], sym_name)) {
205 			if (found_once)
206 				return TRUE;
207 			found_once = TRUE;
208 		}
209 	}
210 	return FALSE;
211 }
212 
213 /*
214  * Find the closest symbol to val, and return its name
215  * and the difference between val and the symbol found.
216  */
217 c_db_sym_t
218 db_search_symbol( val, strategy, offp)
219 	register db_addr_t	val;
220 	db_strategy_t		strategy;
221 	db_expr_t		*offp;
222 {
223 	register
224 	unsigned int	diff;
225 	size_t		newdiff;
226 	register int	i;
227 	c_db_sym_t	ret = C_DB_SYM_NULL, sym;
228 
229 	newdiff = diff = ~0;
230 	db_last_symtab = 0;
231 	for (i = 0; i < db_nsymtab; i++) {
232 	    sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
233 	    if (newdiff < diff) {
234 		db_last_symtab = &db_symtabs[i];
235 		diff = newdiff;
236 		ret = sym;
237 	    }
238 	}
239 	*offp = diff;
240 	return ret;
241 }
242 
243 /*
244  * Return name and value of a symbol
245  */
246 void
247 db_symbol_values(sym, namep, valuep)
248 	c_db_sym_t	sym;
249 	const char	**namep;
250 	db_expr_t	*valuep;
251 {
252 	db_expr_t	value;
253 
254 	if (sym == DB_SYM_NULL) {
255 		*namep = 0;
256 		return;
257 	}
258 
259 	X_db_symbol_values(db_last_symtab, sym, namep, &value);
260 
261 	if (db_symbol_is_ambiguous(sym))
262 		*namep = db_qualify(sym, db_last_symtab->name);
263 	if (valuep)
264 		*valuep = value;
265 }
266 
267 
268 /*
269  * Print a the closest symbol to value
270  *
271  * After matching the symbol according to the given strategy
272  * we print it in the name+offset format, provided the symbol's
273  * value is close enough (eg smaller than db_maxoff).
274  * We also attempt to print [filename:linenum] when applicable
275  * (eg for procedure names).
276  *
277  * If we could not find a reasonable name+offset representation,
278  * then we just print the value in hex.  Small values might get
279  * bogus symbol associations, e.g. 3 might get some absolute
280  * value like _INCLUDE_VERSION or something, therefore we do
281  * not accept symbols whose value is "small" (and use plain hex).
282  */
283 
284 db_expr_t	db_maxoff = 0x10000;
285 
286 void
287 db_printsym(off, strategy)
288 	db_expr_t	off;
289 	db_strategy_t	strategy;
290 {
291 	db_expr_t	d;
292 	char 		*filename;
293 	const char	*name;
294 	db_expr_t	value;
295 	int 		linenum;
296 	c_db_sym_t	cursym;
297 
298 	cursym = db_search_symbol(off, strategy, &d);
299 	db_symbol_values(cursym, &name, &value);
300 	if (name == 0)
301 		value = off;
302 	if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
303 		db_printf("%+#lr", (long)off);
304 		return;
305 	}
306 	if (name == 0 || d >= (unsigned long)db_maxoff) {
307 		db_printf("%#lr", (unsigned long)off);
308 		return;
309 	}
310 	db_printf("%s", name);
311 	if (d)
312 		db_printf("+%+#lr", (long)d);
313 	if (strategy == DB_STGY_PROC) {
314 		if (db_line_at_pc(cursym, &filename, &linenum, off))
315 			db_printf(" [%s:%d]", filename, linenum);
316 	}
317 }
318 
319 static boolean_t
320 db_line_at_pc( sym, filename, linenum, pc)
321 	c_db_sym_t	sym;
322 	char		**filename;
323 	int		*linenum;
324 	db_expr_t	pc;
325 {
326 	return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
327 }
328 
329 int
330 db_sym_numargs(sym, nargp, argnames)
331 	c_db_sym_t	sym;
332 	int		*nargp;
333 	char		**argnames;
334 {
335 	return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
336 }
337