xref: /freebsd/sys/ddb/db_sym.c (revision 380a989b3223d455375b4fae70fd0b9bdd43bafb)
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  *	$Id: db_sym.c,v 1.26 1998/07/08 10:53:51 bde Exp $
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 db_sym_t		db_lookup __P(( char *symstr));
52 static char		*db_qualify __P((db_sym_t sym, char *symtabname));
53 static boolean_t	db_symbol_is_ambiguous __P((db_sym_t sym));
54 static boolean_t	db_line_at_pc __P((db_sym_t, char **, int *,
55 				db_expr_t));
56 
57 /*
58  * Add symbol table, with given name, to list of symbol tables.
59  */
60 void
61 db_add_symbol_table(start, end, name, ref)
62 	char *start;
63 	char *end;
64 	char *name;
65 	char *ref;
66 {
67 	if (db_nsymtab >= MAXNOSYMTABS) {
68 		printf ("No slots left for %s symbol table", name);
69 		panic ("db_sym.c: db_add_symbol_table");
70 	}
71 
72 	db_symtabs[db_nsymtab].start = start;
73 	db_symtabs[db_nsymtab].end = end;
74 	db_symtabs[db_nsymtab].name = name;
75 	db_symtabs[db_nsymtab].private = ref;
76 	db_nsymtab++;
77 }
78 
79 /*
80  *  db_qualify("vm_map", "ux") returns "unix:vm_map".
81  *
82  *  Note: return value points to static data whose content is
83  *  overwritten by each call... but in practice this seems okay.
84  */
85 static char *
86 db_qualify(sym, symtabname)
87 	db_sym_t	sym;
88 	register char	*symtabname;
89 {
90 	char		*symname;
91 	static char     tmp[256];
92 
93 	db_symbol_values(sym, &symname, 0);
94 	snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
95 	return tmp;
96 }
97 
98 
99 boolean_t
100 db_eqname(src, dst, c)
101 	char *src;
102 	char *dst;
103 	int c;
104 {
105 	if (!strcmp(src, dst))
106 	    return (TRUE);
107 	if (src[0] == c)
108 	    return (!strcmp(src+1,dst));
109 	return (FALSE);
110 }
111 
112 boolean_t
113 db_value_of_name(name, valuep)
114 	char		*name;
115 	db_expr_t	*valuep;
116 {
117 	db_sym_t	sym;
118 
119 	sym = db_lookup(name);
120 	if (sym == DB_SYM_NULL)
121 	    return (FALSE);
122 	db_symbol_values(sym, &name, valuep);
123 	return (TRUE);
124 }
125 
126 
127 /*
128  * Lookup a symbol.
129  * If the symbol has a qualifier (e.g., ux:vm_map),
130  * then only the specified symbol table will be searched;
131  * otherwise, all symbol tables will be searched.
132  */
133 static db_sym_t
134 db_lookup(symstr)
135 	char *symstr;
136 {
137 	db_sym_t sp;
138 	register int i;
139 	int symtab_start = 0;
140 	int symtab_end = db_nsymtab;
141 	register char *cp;
142 
143 	/*
144 	 * Look for, remove, and remember any symbol table specifier.
145 	 */
146 	for (cp = symstr; *cp; cp++) {
147 		if (*cp == ':') {
148 			*cp = '\0';
149 			for (i = 0; i < db_nsymtab; i++) {
150 				if (! strcmp(symstr, db_symtabs[i].name)) {
151 					symtab_start = i;
152 					symtab_end = i + 1;
153 					break;
154 				}
155 			}
156 			*cp = ':';
157 			if (i == db_nsymtab) {
158 				db_error("invalid symbol table name");
159 			}
160 			symstr = cp+1;
161 		}
162 	}
163 
164 	/*
165 	 * Look in the specified set of symbol tables.
166 	 * Return on first match.
167 	 */
168 	for (i = symtab_start; i < symtab_end; i++) {
169 		sp = X_db_lookup(&db_symtabs[i], symstr);
170 		if (sp) {
171 			db_last_symtab = &db_symtabs[i];
172 			return sp;
173 		}
174 	}
175 	return 0;
176 }
177 
178 /*
179  * If TRUE, check across symbol tables for multiple occurrences
180  * of a name.  Might slow things down quite a bit.
181  */
182 static volatile boolean_t db_qualify_ambiguous_names = FALSE;
183 
184 /*
185  * Does this symbol name appear in more than one symbol table?
186  * Used by db_symbol_values to decide whether to qualify a symbol.
187  */
188 static boolean_t
189 db_symbol_is_ambiguous(sym)
190 	db_sym_t	sym;
191 {
192 	char		*sym_name;
193 	register int	i;
194 	register
195 	boolean_t	found_once = FALSE;
196 
197 	if (!db_qualify_ambiguous_names)
198 		return FALSE;
199 
200 	db_symbol_values(sym, &sym_name, 0);
201 	for (i = 0; i < db_nsymtab; i++) {
202 		if (X_db_lookup(&db_symtabs[i], sym_name)) {
203 			if (found_once)
204 				return TRUE;
205 			found_once = TRUE;
206 		}
207 	}
208 	return FALSE;
209 }
210 
211 /*
212  * Find the closest symbol to val, and return its name
213  * and the difference between val and the symbol found.
214  */
215 db_sym_t
216 db_search_symbol( val, strategy, offp)
217 	register db_addr_t	val;
218 	db_strategy_t		strategy;
219 	db_expr_t		*offp;
220 {
221 	register
222 	unsigned int	diff;
223 	size_t		newdiff;
224 	register int	i;
225 	db_sym_t	ret = DB_SYM_NULL, sym;
226 
227 	newdiff = diff = ~0;
228 	db_last_symtab = 0;
229 	for (i = 0; i < db_nsymtab; i++) {
230 	    sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
231 	    if (newdiff < diff) {
232 		db_last_symtab = &db_symtabs[i];
233 		diff = newdiff;
234 		ret = sym;
235 	    }
236 	}
237 	*offp = diff;
238 	return ret;
239 }
240 
241 /*
242  * Return name and value of a symbol
243  */
244 void
245 db_symbol_values(sym, namep, valuep)
246 	db_sym_t	sym;
247 	char		**namep;
248 	db_expr_t	*valuep;
249 {
250 	db_expr_t	value;
251 
252 	if (sym == DB_SYM_NULL) {
253 		*namep = 0;
254 		return;
255 	}
256 
257 	X_db_symbol_values(db_last_symtab, sym, namep, &value);
258 
259 	if (db_symbol_is_ambiguous(sym))
260 		*namep = db_qualify(sym, db_last_symtab->name);
261 	if (valuep)
262 		*valuep = value;
263 }
264 
265 
266 /*
267  * Print a the closest symbol to value
268  *
269  * After matching the symbol according to the given strategy
270  * we print it in the name+offset format, provided the symbol's
271  * value is close enough (eg smaller than db_maxoff).
272  * We also attempt to print [filename:linenum] when applicable
273  * (eg for procedure names).
274  *
275  * If we could not find a reasonable name+offset representation,
276  * then we just print the value in hex.  Small values might get
277  * bogus symbol associations, e.g. 3 might get some absolute
278  * value like _INCLUDE_VERSION or something, therefore we do
279  * not accept symbols whose value is "small" (and use plain hex).
280  */
281 
282 db_expr_t	db_maxoff = 0x10000;
283 
284 void
285 db_printsym(off, strategy)
286 	db_expr_t	off;
287 	db_strategy_t	strategy;
288 {
289 	db_expr_t	d;
290 	char 		*filename;
291 	char		*name;
292 	db_expr_t	value;
293 	int 		linenum;
294 	db_sym_t	cursym;
295 
296 	cursym = db_search_symbol(off, strategy, &d);
297 	db_symbol_values(cursym, &name, &value);
298 	if (name == 0)
299 		value = off;
300 	if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
301 		db_printf("%+#lr", (long)off);
302 		return;
303 	}
304 	if (name == 0 || d >= (unsigned long)db_maxoff) {
305 		db_printf("%#lr", (unsigned long)off);
306 		return;
307 	}
308 	db_printf("%s", name);
309 	if (d)
310 		db_printf("+%+#r", d);
311 	if (strategy == DB_STGY_PROC) {
312 		if (db_line_at_pc(cursym, &filename, &linenum, off))
313 			db_printf(" [%s:%d]", filename, linenum);
314 	}
315 }
316 
317 static boolean_t
318 db_line_at_pc( sym, filename, linenum, pc)
319 	db_sym_t	sym;
320 	char		**filename;
321 	int		*linenum;
322 	db_expr_t	pc;
323 {
324 	return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
325 }
326 
327 int
328 db_sym_numargs(sym, nargp, argnames)
329 	db_sym_t	sym;
330 	int		*nargp;
331 	char		**argnames;
332 {
333 	return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
334 }
335