FreeBSD-5.3/sys/ddb/db_sym.c
/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/ddb/db_sym.c,v 1.35 2004/02/24 22:51:42 phk Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <ddb/ddb.h>
#include <ddb/db_sym.h>
#include <opt_ddb.h>
/*
* Multiple symbol tables
*/
#ifndef MAXNOSYMTABS
#define MAXNOSYMTABS 3 /* mach, ux, emulator */
#endif
static db_symtab_t db_symtabs[MAXNOSYMTABS] = {{0,},};
static int db_nsymtab = 0;
static db_symtab_t *db_last_symtab; /* where last symbol was found */
static c_db_sym_t db_lookup( const char *symstr);
static char *db_qualify(c_db_sym_t sym, char *symtabname);
static boolean_t db_symbol_is_ambiguous(c_db_sym_t sym);
static boolean_t db_line_at_pc(c_db_sym_t, char **, int *, db_expr_t);
/*
* Add symbol table, with given name, to list of symbol tables.
*/
void
db_add_symbol_table(start, end, name, ref)
char *start;
char *end;
char *name;
char *ref;
{
if (db_nsymtab >= MAXNOSYMTABS) {
printf ("No slots left for %s symbol table", name);
panic ("db_sym.c: db_add_symbol_table");
}
db_symtabs[db_nsymtab].start = start;
db_symtabs[db_nsymtab].end = end;
db_symtabs[db_nsymtab].name = name;
db_symtabs[db_nsymtab].private = ref;
db_nsymtab++;
}
/*
* db_qualify("vm_map", "ux") returns "unix:vm_map".
*
* Note: return value points to static data whose content is
* overwritten by each call... but in practice this seems okay.
*/
static char *
db_qualify(sym, symtabname)
c_db_sym_t sym;
register char *symtabname;
{
const char *symname;
static char tmp[256];
db_symbol_values(sym, &symname, 0);
snprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
return tmp;
}
boolean_t
db_eqname(src, dst, c)
const char *src;
const char *dst;
int c;
{
if (!strcmp(src, dst))
return (TRUE);
if (src[0] == c)
return (!strcmp(src+1,dst));
return (FALSE);
}
boolean_t
db_value_of_name(name, valuep)
const char *name;
db_expr_t *valuep;
{
c_db_sym_t sym;
sym = db_lookup(name);
if (sym == C_DB_SYM_NULL)
return (FALSE);
db_symbol_values(sym, &name, valuep);
return (TRUE);
}
/*
* Lookup a symbol.
* If the symbol has a qualifier (e.g., ux:vm_map),
* then only the specified symbol table will be searched;
* otherwise, all symbol tables will be searched.
*/
static c_db_sym_t
db_lookup(symstr)
const char *symstr;
{
c_db_sym_t sp;
register int i;
int symtab_start = 0;
int symtab_end = db_nsymtab;
register const char *cp;
/*
* Look for, remove, and remember any symbol table specifier.
*/
for (cp = symstr; *cp; cp++) {
if (*cp == ':') {
for (i = 0; i < db_nsymtab; i++) {
int n = strlen(db_symtabs[i].name);
if (
n == (cp - symstr) &&
strncmp(symstr, db_symtabs[i].name, n) == 0
) {
symtab_start = i;
symtab_end = i + 1;
break;
}
}
if (i == db_nsymtab) {
db_error("invalid symbol table name");
}
symstr = cp+1;
}
}
/*
* Look in the specified set of symbol tables.
* Return on first match.
*/
for (i = symtab_start; i < symtab_end; i++) {
sp = X_db_lookup(&db_symtabs[i], symstr);
if (sp) {
db_last_symtab = &db_symtabs[i];
return sp;
}
}
return 0;
}
/*
* If TRUE, check across symbol tables for multiple occurrences
* of a name. Might slow things down quite a bit.
*/
static volatile boolean_t db_qualify_ambiguous_names = FALSE;
/*
* Does this symbol name appear in more than one symbol table?
* Used by db_symbol_values to decide whether to qualify a symbol.
*/
static boolean_t
db_symbol_is_ambiguous(sym)
c_db_sym_t sym;
{
const char *sym_name;
register int i;
register
boolean_t found_once = FALSE;
if (!db_qualify_ambiguous_names)
return FALSE;
db_symbol_values(sym, &sym_name, 0);
for (i = 0; i < db_nsymtab; i++) {
if (X_db_lookup(&db_symtabs[i], sym_name)) {
if (found_once)
return TRUE;
found_once = TRUE;
}
}
return FALSE;
}
/*
* Find the closest symbol to val, and return its name
* and the difference between val and the symbol found.
*/
c_db_sym_t
db_search_symbol( val, strategy, offp)
register db_addr_t val;
db_strategy_t strategy;
db_expr_t *offp;
{
register
unsigned int diff;
size_t newdiff;
register int i;
c_db_sym_t ret = C_DB_SYM_NULL, sym;
newdiff = diff = ~0;
db_last_symtab = 0;
for (i = 0; i < db_nsymtab; i++) {
sym = X_db_search_symbol(&db_symtabs[i], val, strategy, &newdiff);
if (newdiff < diff) {
db_last_symtab = &db_symtabs[i];
diff = newdiff;
ret = sym;
}
}
*offp = diff;
return ret;
}
/*
* Return name and value of a symbol
*/
void
db_symbol_values(sym, namep, valuep)
c_db_sym_t sym;
const char **namep;
db_expr_t *valuep;
{
db_expr_t value;
if (sym == DB_SYM_NULL) {
*namep = 0;
return;
}
X_db_symbol_values(db_last_symtab, sym, namep, &value);
if (db_symbol_is_ambiguous(sym))
*namep = db_qualify(sym, db_last_symtab->name);
if (valuep)
*valuep = value;
}
/*
* Print a the closest symbol to value
*
* After matching the symbol according to the given strategy
* we print it in the name+offset format, provided the symbol's
* value is close enough (eg smaller than db_maxoff).
* We also attempt to print [filename:linenum] when applicable
* (eg for procedure names).
*
* If we could not find a reasonable name+offset representation,
* then we just print the value in hex. Small values might get
* bogus symbol associations, e.g. 3 might get some absolute
* value like _INCLUDE_VERSION or something, therefore we do
* not accept symbols whose value is "small" (and use plain hex).
*/
db_expr_t db_maxoff = 0x10000;
void
db_printsym(off, strategy)
db_expr_t off;
db_strategy_t strategy;
{
db_expr_t d;
char *filename;
const char *name;
db_expr_t value;
int linenum;
c_db_sym_t cursym;
cursym = db_search_symbol(off, strategy, &d);
db_symbol_values(cursym, &name, &value);
if (name == 0)
value = off;
if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
db_printf("%+#lr", (long)off);
return;
}
if (name == 0 || d >= (unsigned long)db_maxoff) {
db_printf("%#lr", (unsigned long)off);
return;
}
#ifdef DDB_NUMSYM
db_printf("%#lr = %s", (unsigned long)off, name);
#else
db_printf("%s", name);
#endif
if (d)
db_printf("+%+#lr", (long)d);
if (strategy == DB_STGY_PROC) {
if (db_line_at_pc(cursym, &filename, &linenum, off))
db_printf(" [%s:%d]", filename, linenum);
}
}
static boolean_t
db_line_at_pc( sym, filename, linenum, pc)
c_db_sym_t sym;
char **filename;
int *linenum;
db_expr_t pc;
{
return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
}
int
db_sym_numargs(sym, nargp, argnames)
c_db_sym_t sym;
int *nargp;
char **argnames;
{
return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
}