sys/ddb/db_sym.c

   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: src/sys/ddb/db_sym.c,v 1.32 1999/08/28 00:41:10 peter Exp $
  27  * $DragonFly: src/sys/ddb/db_sym.c,v 1.4 2003/08/27 10:47:13 rob Exp $
  28  */
  29
  30 /*
  31  *      Author: David B. Golub, Carnegie Mellon University
  32  *      Date:   7/90
  33  */
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36
  37 #include <ddb/ddb.h>
  38 #include <ddb/db_sym.h>
  39
  40 /*
  41  * Multiple symbol tables
  42  */
  43 #ifndef MAXNOSYMTABS
  44 #define MAXNOSYMTABS    3       /* mach, ux, emulator */
  45 #endif
  46
  47 static db_symtab_t      db_symtabs[MAXNOSYMTABS] = {{0,},};
  48 static int db_nsymtab = 0;
  49
  50 static db_symtab_t      *db_last_symtab; /* where last symbol was found */
  51
  52 static c_db_sym_t       db_lookup ( const char *symstr);
  53 static char             *db_qualify (c_db_sym_t sym, char *symtabname);
  54 static boolean_t        db_symbol_is_ambiguous (c_db_sym_t sym);
  55 static boolean_t        db_line_at_pc (c_db_sym_t, char **, int *,
  56                                 db_expr_t);
  57
  58 /*
  59  * Add symbol table, with given name, to list of symbol tables.
  60  */
  61 void
  62 db_add_symbol_table(start, end, name, ref)
  63         char *start;
  64         char *end;
  65         char *name;
  66         char *ref;
  67 {
  68         if (db_nsymtab >= MAXNOSYMTABS) {
  69                 printf ("No slots left for %s symbol table", name);
  70                 panic ("db_sym.c: db_add_symbol_table");
  71         }
  72
  73         db_symtabs[db_nsymtab].start = start;
  74         db_symtabs[db_nsymtab].end = end;
  75         db_symtabs[db_nsymtab].name = name;
  76         db_symtabs[db_nsymtab].private = ref;
  77         db_nsymtab++;
  78 }
  79
  80 /*
  81  *  db_qualify("vm_map", "ux") returns "unix:vm_map".
  82  *
  83  *  Note: return value points to static data whose content is
  84  *  overwritten by each call... but in practice this seems okay.
  85  */
  86 static char *
  87 db_qualify(sym, symtabname)
  88         c_db_sym_t      sym;
  89         char    *symtabname;
  90 {
  91         const char      *symname;
  92         static char     tmp[256];
  93
  94         db_symbol_values(sym, &symname, 0);
  95         snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
  96         return tmp;
  97 }
  98
  99
 100 boolean_t
 101 db_eqname(src, dst, c)
 102         const char *src;
 103         const char *dst;
 104         int c;
 105 {
 106         if (!strcmp(src, dst))
 107             return (TRUE);
 108         if (src[0] == c)
 109             return (!strcmp(src+1,dst));
 110         return (FALSE);
 111 }
 112
 113 boolean_t
 114 db_value_of_name(name, valuep)
 115         const char      *name;
 116         db_expr_t       *valuep;
 117 {
 118         c_db_sym_t      sym;
 119
 120         sym = db_lookup(name);
 121         if (sym == C_DB_SYM_NULL)
 122             return (FALSE);
 123         db_symbol_values(sym, &name, valuep);
 124         return (TRUE);
 125 }
 126
 127
 128 /*
 129  * Lookup a symbol.
 130  * If the symbol has a qualifier (e.g., ux:vm_map),
 131  * then only the specified symbol table will be searched;
 132  * otherwise, all symbol tables will be searched.
 133  */
 134 static c_db_sym_t
 135 db_lookup(symstr)
 136         const char *symstr;
 137 {
 138         c_db_sym_t sp;
 139         int i;
 140         int symtab_start = 0;
 141         int symtab_end = db_nsymtab;
 142         const char *cp;
 143
 144         /*
 145          * Look for, remove, and remember any symbol table specifier.
 146          */
 147         for (cp = symstr; *cp; cp++) {
 148                 if (*cp == ':') {
 149                         for (i = 0; i < db_nsymtab; i++) {
 150                                 int n = strlen(db_symtabs[i].name);
 151
 152                                 if (
 153                                     n == (cp - symstr) &&
 154                                     strncmp(symstr, db_symtabs[i].name, n) == 0
 155                                 ) {
 156                                         symtab_start = i;
 157                                         symtab_end = i + 1;
 158                                         break;
 159                                 }
 160                         }
 161                         if (i == db_nsymtab) {
 162                                 db_error("invalid symbol table name");
 163                         }
 164                         symstr = cp+1;
 165                 }
 166         }
 167
 168         /*
 169          * Look in the specified set of symbol tables.
 170          * Return on first match.
 171          */
 172         for (i = symtab_start; i < symtab_end; i++) {
 173                 sp = X_db_lookup(&db_symtabs[i], symstr);
 174                 if (sp) {
 175                         db_last_symtab = &db_symtabs[i];
 176                         return sp;
 177                 }
 178         }
 179         return 0;
 180 }
 181
 182 /*
 183  * If TRUE, check across symbol tables for multiple occurrences
 184  * of a name.  Might slow things down quite a bit.
 185  */
 186 static volatile boolean_t db_qualify_ambiguous_names = FALSE;
 187
 188 /*
 189  * Does this symbol name appear in more than one symbol table?
 190  * Used by db_symbol_values to decide whether to qualify a symbol.
 191  */
 192 static boolean_t
 193 db_symbol_is_ambiguous(sym)
 194         c_db_sym_t      sym;
 195 {
 196         const char      *sym_name;
 197         int     i;
 198
 199         boolean_t       found_once = FALSE;
 200
 201         if (!db_qualify_ambiguous_names)
 202                 return FALSE;
 203
 204         db_symbol_values(sym, &sym_name, 0);
 205         for (i = 0; i < db_nsymtab; i++) {
 206                 if (X_db_lookup(&db_symtabs[i], sym_name)) {
 207                         if (found_once)
 208                                 return TRUE;
 209                         found_once = TRUE;
 210                 }
 211         }
 212         return FALSE;
 213 }
 214
 215 /*
 216  * Find the closest symbol to val, and return its name
 217  * and the difference between val and the symbol found.
 218  */
 219 c_db_sym_t
 220 db_search_symbol( val, strategy, offp)
 221         db_addr_t       val;
 222         db_strategy_t           strategy;
 223         db_expr_t               *offp;
 224 {
 225
 226         unsigned int    diff;
 227         size_t          newdiff;
 228         int     i;
 229         c_db_sym_t      ret = C_DB_SYM_NULL, sym;
 230
 231         newdiff = diff = ~0;
 232         db_last_symtab = 0;
 233         for (i = 0; i < db_nsymtab; i++) {
 234             sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
 235             if (newdiff < diff) {
 236                 db_last_symtab = &db_symtabs[i];
 237                 diff = newdiff;
 238                 ret = sym;
 239             }
 240         }
 241         *offp = diff;
 242         return ret;
 243 }
 244
 245 /*
 246  * Return name and value of a symbol
 247  */
 248 void
 249 db_symbol_values(sym, namep, valuep)
 250         c_db_sym_t      sym;
 251         const char      **namep;
 252         db_expr_t       *valuep;
 253 {
 254         db_expr_t       value;
 255
 256         if (sym == DB_SYM_NULL) {
 257                 *namep = 0;
 258                 return;
 259         }
 260
 261         X_db_symbol_values(db_last_symtab, sym, namep, &value);
 262
 263         if (db_symbol_is_ambiguous(sym))
 264                 *namep = db_qualify(sym, db_last_symtab->name);
 265         if (valuep)
 266                 *valuep = value;
 267 }
 268
 269
 270 /*
 271  * Print a the closest symbol to value
 272  *
 273  * After matching the symbol according to the given strategy
 274  * we print it in the name+offset format, provided the symbol's
 275  * value is close enough (eg smaller than db_maxoff).
 276  * We also attempt to print [filename:linenum] when applicable
 277  * (eg for procedure names).
 278  *
 279  * If we could not find a reasonable name+offset representation,
 280  * then we just print the value in hex.  Small values might get
 281  * bogus symbol associations, e.g. 3 might get some absolute
 282  * value like _INCLUDE_VERSION or something, therefore we do
 283  * not accept symbols whose value is "small" (and use plain hex).
 284  */
 285
 286 db_expr_t       db_maxoff = 0x10000;
 287
 288 void
 289 db_printsym(off, strategy)
 290         db_expr_t       off;
 291         db_strategy_t   strategy;
 292 {
 293         db_expr_t       d;
 294         char            *filename;
 295         const char      *name;
 296         db_expr_t       value;
 297         int             linenum;
 298         c_db_sym_t      cursym;
 299
 300         cursym = db_search_symbol(off, strategy, &d);
 301         db_symbol_values(cursym, &name, &value);
 302         if (name == 0)
 303                 value = off;
 304         if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
 305                 db_printf("%+#lr", (long)off);
 306                 return;
 307         }
 308         if (name == 0 || d >= (unsigned long)db_maxoff) {
 309                 db_printf("%#lr", (unsigned long)off);
 310                 return;
 311         }
 312         db_printf("%s", name);
 313         if (d)
 314                 db_printf("+%+#lr", (long)d);
 315         if (strategy == DB_STGY_PROC) {
 316                 if (db_line_at_pc(cursym, &filename, &linenum, off))
 317                         db_printf(" [%s:%d]", filename, linenum);
 318         }
 319 }
 320
 321 static boolean_t
 322 db_line_at_pc( sym, filename, linenum, pc)
 323         c_db_sym_t      sym;
 324         char            **filename;
 325         int             *linenum;
 326         db_expr_t       pc;
 327 {
 328         return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
 329 }
 330
 331 int
 332 db_sym_numargs(sym, nargp, argnames)
 333         c_db_sym_t      sym;
 334         int             *nargp;
 335         char            **argnames;
 336 {
 337         return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
 338 }