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.
 */
/*
 * HISTORY
 * $Log: db_sym.c,v $
 * Revision 1.1  1992/03/25  21:45:27  pace
 * Initial revision
 *
 * Revision 2.5  91/02/05  17:07:07  mrt
 *      Changed to new Mach copyright
 *      [91/01/31  16:19:17  mrt]
 *
 * Revision 2.4  90/10/25  14:44:05  rwd
 *      Changed db_printsym to print unsigned.
 *      [90/10/19            rpd]
 *
 * Revision 2.3  90/09/09  23:19:56  rpd
 *      Avoid totally incorrect guesses of symbol names for small values.
 *      [90/08/30  17:39:48  af]
 *
 * Revision 2.2  90/08/27  21:52:18  dbg
 *      Removed nlist.h.  Fixed some type declarations.
 *      Qualifier character is ':'.
 *      [90/08/20            dbg]
 *      Modularized symtab info into a new db_symtab_t type.
 *      Modified db_add_symbol_table  and others accordingly.
 *      Defined db_sym_t, a new (opaque) type used to represent
 *      symbols.  This should support all sort of future symtable
 *      formats. Functions like db_qualify take a db_sym_t now.
 *      New db_symbol_values() function to explode the content
 *      of a db_sym_t.
 *      db_search_symbol() replaces db_find_sym_and_offset(), which is
 *      now a macro defined in our (new) header file.  This new
 *      function accepts more restrictive searches, which are
 *      entirely delegated to the symtab-specific code.
 *      Accordingly, db_printsym() accepts a strategy parameter.
 *      New db_line_at_pc() function.
 *      Renamed misleading db_eqsym into db_eqname.
 *      [90/08/20  10:47:06  af]
 *
 *      Created.
 *      [90/07/25            dbg]
 *
 * Revision 2.1  90/07/26  16:43:52  dbg
 * Created.
 *
 */
/*
 *      Author: David B. Golub, Carnegie Mellon University
 *      Date:   7/90
 */
#include "param.h"
#include "proc.h"
#include <machine/db_machdep.h>
#include <ddb/db_sym.h>

/*
 * We import from the symbol-table dependent routines:
 */
extern db_sym_t X_db_lookup();
extern db_sym_t X_db_search_symbol();
extern boolean_t X_db_line_at_pc();
extern void     X_db_symbol_values();

/*
 * Multiple symbol tables
 */
#define MAXNOSYMTABS    3       /* mach, ux, emulator */

db_symtab_t     db_symtabs[MAXNOSYMTABS] = {{0,},};
int db_nsymtab = 0;

db_symtab_t     *db_last_symtab;

db_sym_t        db_lookup();    /* forward */

/*
 * 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)
        db_sym_t        sym;
        register char   *symtabname;
{
        char            *symname;
        static char     tmp[256];
        register char   *s;

        db_symbol_values(sym, &symname, 0);
        s = tmp;
        while (*s++ = *symtabname++) {
        }
        s[-1] = ':';
        while (*s++ = *symname++) {
        }
        return tmp;
}


boolean_t
db_eqname(src, dst, c)
        char *src;
        char *dst;
        char 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)
        char            *name;
        db_expr_t       *valuep;
{
        db_sym_t        sym;

        sym = db_lookup(name);
        if (sym == 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.
 */
db_sym_t
db_lookup(symstr)
        char *symstr;
{
        db_sym_t sp;
        register int i;
        int symtab_start = 0;
        int symtab_end = db_nsymtab;
        register char *cp;

        /*
         * Look for, remove, and remember any symbol table specifier.
         */
        for (cp = symstr; *cp; cp++) {
                if (*cp == ':') {
                        *cp = '\0';
                        for (i = 0; i < db_nsymtab; i++) {
                                if (! strcmp(symstr, db_symtabs[i].name)) {
                                        symtab_start = i;
                                        symtab_end = i + 1;
                                        break;
                                }
                        }
                        *cp = ':';
                        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++) {
                if (sp = X_db_lookup(&db_symtabs[i], symstr)) {
                        db_last_symtab = &db_symtabs[i];
                        return sp;
                }
        }
        return 0;
}

/*
 * Does this symbol name appear in more than one symbol table?
 * Used by db_symbol_values to decide whether to qualify a symbol.
 */
boolean_t db_qualify_ambiguous_names = FALSE;

boolean_t
db_symbol_is_ambiguous(sym)
        db_sym_t        sym;
{
        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.
 */
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;
        unsigned int    newdiff;
        register int    i;
        db_sym_t        ret = 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)
        db_sym_t        sym;
        char            **namep;
        db_expr_t       *valuep;
{
        db_expr_t       value;

        if (sym == DB_SYM_NULL) {
                *namep = 0;
                return;
        }

        X_db_symbol_values(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 zero (and use plain hex).
 */

unsigned int    db_maxoff = 0x10000000;

void
db_printsym(off, strategy)
        db_expr_t       off;
        db_strategy_t   strategy;
{
        db_expr_t       d;
        char            *filename;
        char            *name;
        db_expr_t       value;
        int             linenum;
        db_sym_t        cursym;

        cursym = db_search_symbol(off, strategy, &d);
        db_symbol_values(cursym, &name, &value);
        if (name == 0 || d >= db_maxoff || value == 0) {
                db_printf("%#n", off);
                return;
        }
        db_printf("%s", name);
        if (d)
                db_printf("+%#r", d);
        if (strategy == DB_STGY_PROC) {
                if (db_line_at_pc(cursym, &filename, &linenum, off))
                        db_printf(" [%s:%d]", filename, linenum);
        }
}


boolean_t
db_line_at_pc( sym, filename, linenum, pc)
{
        return X_db_line_at_pc( db_last_symtab, sym, filename, linenum, pc);
}