/*-
* SPDX-License-Identifier: MIT-CMU
*
* 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#include <ddb/db_access.h>
#include <ddb/db_command.h>
static bool db_add_expr(db_expr_t *valuep);
static bool db_mult_expr(db_expr_t *valuep);
static bool db_shift_expr(db_expr_t *valuep);
static bool db_term(db_expr_t *valuep);
static bool db_unary(db_expr_t *valuep);
static bool db_logical_or_expr(db_expr_t *valuep);
static bool db_logical_and_expr(db_expr_t *valuep);
static bool db_logical_relation_expr(db_expr_t *valuep);
static bool
db_term(db_expr_t *valuep)
{
int t;
t = db_read_token();
if (t == tIDENT) {
if (!db_value_of_name(db_tok_string, valuep) &&
!db_value_of_name_pcpu(db_tok_string, valuep) &&
!db_value_of_name_vnet(db_tok_string, valuep)) {
db_printf("Symbol '%s' not found\n", db_tok_string);
db_error(NULL);
/*NOTREACHED*/
}
return (true);
}
if (t == tNUMBER) {
*valuep = (db_expr_t)db_tok_number;
return (true);
}
if (t == tDOT) {
*valuep = (db_expr_t)db_dot;
return (true);
}
if (t == tDOTDOT) {
*valuep = (db_expr_t)db_prev;
return (true);
}
if (t == tPLUS) {
*valuep = (db_expr_t) db_next;
return (true);
}
if (t == tDITTO) {
*valuep = (db_expr_t)db_last_addr;
return (true);
}
if (t == tDOLLAR) {
if (!db_get_variable(valuep))
return (false);
return (true);
}
if (t == tLPAREN) {
if (!db_expression(valuep)) {
db_printf("Expression syntax error after '%c'\n", '(');
db_error(NULL);
/*NOTREACHED*/
}
t = db_read_token();
if (t != tRPAREN) {
db_printf("Expression syntax error -- expected '%c'\n", ')');
db_error(NULL);
/*NOTREACHED*/
}
return (true);
}
db_unread_token(t);
return (false);
}
static bool
db_unary(db_expr_t *valuep)
{
int t;
t = db_read_token();
if (t == tMINUS) {
if (!db_unary(valuep)) {
db_printf("Expression syntax error after '%c'\n", '-');
db_error(NULL);
/*NOTREACHED*/
}
*valuep = -*valuep;
return (true);
}
if (t == tEXCL) {
if (!db_unary(valuep)) {
db_printf("Expression syntax error after '%c'\n", '!');
db_error(NULL);
/* NOTREACHED */
}
*valuep = (!(*valuep));
return (true);
}
if (t == tBIT_NOT) {
if (!db_unary(valuep)) {
db_printf("Expression syntax error after '%c'\n", '~');
db_error(NULL);
/* NOTREACHED */
}
*valuep = (~(*valuep));
return (true);
}
if (t == tSTAR) {
/* indirection */
if (!db_unary(valuep)) {
db_printf("Expression syntax error after '%c'\n", '*');
db_error(NULL);
/*NOTREACHED*/
}
*valuep = db_get_value((db_addr_t)*valuep, sizeof(void *),
false);
return (true);
}
db_unread_token(t);
return (db_term(valuep));
}
static bool
db_mult_expr(db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_unary(&lhs))
return (false);
t = db_read_token();
while (t == tSTAR || t == tSLASH || t == tPCT || t == tHASH ||
t == tBIT_AND ) {
if (!db_term(&rhs)) {
db_printf("Expression syntax error after '%c'\n",
t == tSTAR ? '*' : t == tSLASH ? '/' : t == tPCT ? '%' :
t == tHASH ? '#' : '&');
db_error(NULL);
/*NOTREACHED*/
}
switch(t) {
case tSTAR:
lhs *= rhs;
break;
case tBIT_AND:
lhs &= rhs;
break;
default:
if (rhs == 0) {
db_error("Division by 0\n");
/*NOTREACHED*/
}
if (t == tSLASH)
lhs /= rhs;
else if (t == tPCT)
lhs %= rhs;
else
lhs = roundup(lhs, rhs);
}
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
static bool
db_add_expr(db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_mult_expr(&lhs))
return (false);
t = db_read_token();
while (t == tPLUS || t == tMINUS || t == tBIT_OR) {
if (!db_mult_expr(&rhs)) {
db_printf("Expression syntax error after '%c'\n",
t == tPLUS ? '+' : t == tMINUS ? '-' : '|');
db_error(NULL);
/*NOTREACHED*/
}
switch (t) {
case tPLUS:
lhs += rhs;
break;
case tMINUS:
lhs -= rhs;
break;
case tBIT_OR:
lhs |= rhs;
break;
default:
__assert_unreachable();
}
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
static bool
db_shift_expr(db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_add_expr(&lhs))
return (false);
t = db_read_token();
while (t == tSHIFT_L || t == tSHIFT_R) {
if (!db_add_expr(&rhs)) {
db_printf("Expression syntax error after '%s'\n",
t == tSHIFT_L ? "<<" : ">>");
db_error(NULL);
/*NOTREACHED*/
}
if (rhs < 0) {
db_printf("Negative shift amount %jd\n", (intmax_t)rhs);
db_error(NULL);
/*NOTREACHED*/
}
if (t == tSHIFT_L)
lhs <<= rhs;
else {
/* Shift right is unsigned */
lhs = (db_addr_t)lhs >> rhs;
}
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
static bool
db_logical_relation_expr(
db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_shift_expr(&lhs))
return (false);
t = db_read_token();
while (t == tLOG_EQ || t == tLOG_NOT_EQ || t == tGREATER ||
t == tGREATER_EQ || t == tLESS || t == tLESS_EQ) {
if (!db_shift_expr(&rhs)) {
db_printf("Expression syntax error after '%s'\n",
t == tLOG_EQ ? "==" : t == tLOG_NOT_EQ ? "!=" :
t == tGREATER ? ">" : t == tGREATER_EQ ? ">=" :
t == tLESS ? "<" : "<=");
db_error(NULL);
/*NOTREACHED*/
}
switch(t) {
case tLOG_EQ:
lhs = (lhs == rhs);
break;
case tLOG_NOT_EQ:
lhs = (lhs != rhs);
break;
case tGREATER:
lhs = (lhs > rhs);
break;
case tGREATER_EQ:
lhs = (lhs >= rhs);
break;
case tLESS:
lhs = (lhs < rhs);
break;
case tLESS_EQ:
lhs = (lhs <= rhs);
break;
default:
__assert_unreachable();
}
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
static bool
db_logical_and_expr(
db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_logical_relation_expr(&lhs))
return (false);
t = db_read_token();
while (t == tLOG_AND) {
if (!db_logical_relation_expr(&rhs)) {
db_printf("Expression syntax error after '%s'\n", "&&");
db_error(NULL);
/*NOTREACHED*/
}
lhs = (lhs && rhs);
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
static bool
db_logical_or_expr(
db_expr_t *valuep)
{
db_expr_t lhs, rhs;
int t;
if (!db_logical_and_expr(&lhs))
return(false);
t = db_read_token();
while (t == tLOG_OR) {
if (!db_logical_and_expr(&rhs)) {
db_printf("Expression syntax error after '%s'\n", "||");
db_error(NULL);
/*NOTREACHED*/
}
lhs = (lhs || rhs);
t = db_read_token();
}
db_unread_token(t);
*valuep = lhs;
return (true);
}
int
db_expression(db_expr_t *valuep)
{
return (db_logical_or_expr(valuep));
}
