/*
 * 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.
 *
 * $FreeBSD: src/sys/ddb/db_sym.c,v 1.32 1999/08/28 00:41:10 peter Exp $
 */

/*
 *      Author: David B. Golub, Carnegie Mellon University
 *      Date:   7/90
 */
#include <sys/param.h>
#include <sys/systm.h>

#include <ddb/ddb.h>
#include <ddb/db_output.h>
#include <ddb/db_sym.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(char *start, char *end, char *name, char *ref)
{
        if (db_nsymtab >= MAXNOSYMTABS) {
                kprintf ("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(c_db_sym_t sym, char *symtabname)
{
        const char      *symname;
        static char     tmp[256];

        db_symbol_values(sym, &symname, 0);
        ksnprintf(tmp, sizeof(tmp), "%s:%s", symtabname, symname);
        return tmp;
}


boolean_t
db_eqname(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(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(const char *symstr)
{
        c_db_sym_t sp;
        int i;
        int symtab_start = 0;
        int symtab_end = db_nsymtab;
        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(c_db_sym_t sym)
{
        const char      *sym_name;
        int     i;
        
        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(db_addr_t val, db_strategy_t strategy, db_expr_t *offp)
{
        
        unsigned int    diff;
        size_t          newdiff;
        int     i;
        c_db_sym_t      ret = C_DB_SYM_NULL, sym;

        newdiff = diff = ~0;
        db_last_symtab = NULL;
        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(c_db_sym_t sym, const char **namep, db_expr_t *valuep)
{
        db_expr_t       value;

        if (sym == DB_SYM_NULL) {
                *namep = NULL;
                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 = 0x100000;

void
db_printsym(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;
        char            tbuf[24];

        cursym = db_search_symbol(off, strategy, &d);
        db_symbol_values(cursym, &name, &value);
        if (name == NULL)
                value = off;
        if (value >= DB_SMALL_VALUE_MIN && value <= DB_SMALL_VALUE_MAX) {
                db_format_radix(tbuf, 24, (long)off, TRUE);
                db_printf("%s", tbuf);
                return;
        }
        if (name == NULL || d >= (unsigned long)db_maxoff) {
                db_format_radix(tbuf, 24, (unsigned long)off, TRUE);
                db_printf("%s", tbuf);
                return;
        }
        db_printf("%s", name);
        if (d) {
                db_format_radix(tbuf, 24, (long)d, TRUE);
                db_printf("+%s", tbuf);
        }
        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(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(c_db_sym_t sym, int *nargp, char **argnames)
{
        return X_db_sym_numargs(db_last_symtab, sym, nargp, argnames);
}