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