/* $NetBSD: db_lex.c,v 1.27 2022/08/30 22:37:03 riastradh Exp $ */
/*
* 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 "AS IS"
* 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
[email protected]
* 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
*/
/*
* Lexical analyzer.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: db_lex.c,v 1.27 2022/08/30 22:37:03 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/cpu.h>
#include <ddb/ddb.h>
db_expr_t db_tok_number;
char db_tok_string[TOK_STRING_SIZE];
static char db_line[DB_LINE_MAXLEN];
static const char *db_lp;
static const char *db_endlp;
static int db_look_char = 0;
static int db_look_token = 0;
static void db_flush_line(void);
static int db_read_char(void);
static void db_unread_char(int);
static int db_lex(void);
int
db_read_line(void)
{
int i;
#ifdef _KERNEL
/*
* crash(8) prints the prompt using libedit. That's why we used to
* print it in db_readline(). But now people are using db_read_line()
* for general purpose input, so..
*/
#ifdef MULTIPROCESSOR
db_printf("db{%ld}> ", (long)cpu_number());
#else
db_printf("db> ");
#endif
#endif
i = db_readline(db_line, sizeof(db_line));
if (i == 0)
return (0); /* EOI */
db_set_line(db_line, db_line + i);
return (i);
}
void
db_set_line(const char *sp, const char *ep)
{
db_lp = sp;
db_endlp = ep;
}
void
db_get_line(const char **psp, const char **pep)
{
if (psp != NULL)
*psp = db_lp;
if (pep != NULL)
*pep = db_endlp;
}
static void
db_flush_line(void)
{
db_lp = db_line;
db_endlp = db_line;
}
static int
db_read_char(void)
{
int c;
if (db_look_char != 0) {
c = db_look_char;
db_look_char = 0;
}
else if (db_lp >= db_endlp)
c = -1;
else
c = *db_lp++;
return (c);
}
static void
db_unread_char(int c)
{
db_look_char = c;
}
void
db_unread_token(int t)
{
db_look_token = t;
}
int
db_read_token(void)
{
int t;
if (db_look_token) {
t = db_look_token;
db_look_token = 0;
}
else
t = db_lex();
return (t);
}
int db_radix = 16;
/*
* Convert the number to a string in the current radix.
* This replaces the non-standard %n printf() format.
*/
char *
db_num_to_str(db_expr_t val)
{
/*
* 2 chars for "0x", 1 for a sign ("-")
* up to 21 chars for a 64-bit number:
* % echo 2^64 | bc | wc -c
* 21
* and 1 char for a terminal NUL
* 2+1+21+1 => 25
*/
static char buf[25];
db_num_to_strbuf(val, buf, sizeof(buf));
return (buf);
}
void
db_num_to_strbuf(db_expr_t val, char *buf, size_t len)
{
if (db_radix == 16)
snprintf(buf, len, "%" DDB_EXPR_FMT "x", val);
else if (db_radix == 8)
snprintf(buf, len, "%" DDB_EXPR_FMT "o", val);
else
snprintf(buf, len, "%" DDB_EXPR_FMT "u", val);
}
void
db_flush_lex(void)
{
db_flush_line();
db_look_char = 0;
db_look_token = 0;
}
static int
db_lex(void)
{
int c;
c = db_read_char();
while (c <= ' ' || c > '~') {
if (c == '\n' || c == -1)
return (tEOL);
c = db_read_char();
}
if (c >= '0' && c <= '9') {
/* number */
db_expr_t r, digit = 0;
if (c > '0')
r = db_radix;
else {
c = db_read_char();
if (c == 'O' || c == 'o')
r = 8;
else if (c == 'T' || c == 't')
r = 10;
else if (c == 'X' || c == 'x')
r = 16;
else {
r = db_radix;
db_unread_char(c);
}
c = db_read_char();
}
db_tok_number = 0;
for (;;) {
if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
digit = c - '0';
else if (r == 16) {
if (c >= 'A' && c <= 'F')
digit = c - 'A' + 10;
else if (c >= 'a' && c <= 'f')
digit = c - 'a' + 10;
else
break;
} else
break;
db_tok_number = db_tok_number * r + digit;
c = db_read_char();
}
if ((c >= '0' && c <= '9') ||
(c >= 'A' && c <= 'Z') ||
(c >= 'a' && c <= 'z') ||
(c == '_')) {
db_error("Bad character in number\n");
/*NOTREACHED*/
}
db_unread_char(c);
return (tNUMBER);
}
if ((c >= 'A' && c <= 'Z') ||
(c >= 'a' && c <= 'z') ||
c == '_' || c == '\\') {
/* string */
char *cp;
cp = db_tok_string;
if (c == '\\') {
c = db_read_char();
if (c == '\n' || c == -1) {
db_error("Bad escape\n");
/*NOTREACHED*/
}
}
*cp++ = c;
while (1) {
c = db_read_char();
if ((c >= 'A' && c <= 'Z') ||
(c >= 'a' && c <= 'z') ||
(c >= '0' && c <= '9') ||
c == '_' || c == '\\' || c == ':') {
if (c == '\\') {
c = db_read_char();
if (c == '\n' || c == -1) {
db_error("Bad escape\n");
/*NOTREACHED*/
}
}
*cp++ = c;
if (cp == db_tok_string+sizeof(db_tok_string)) {
db_error("String too long\n");
/*NOTREACHED*/
}
continue;
} else {
*cp = '\0';
break;
}
}
db_unread_char(c);
return (tIDENT);
}
switch (c) {
case '+':
return (tPLUS);
case '-':
return (tMINUS);
case '.':
c = db_read_char();
if (c == '.')
return (tDOTDOT);
db_unread_char(c);
return (tDOT);
case '*':
return (tSTAR);
case '/':
return (tSLASH);
case '=':
return (tEQ);
case '%':
return (tPCT);
case '#':
return (tHASH);
case '(':
return (tLPAREN);
case ')':
return (tRPAREN);
case ',':
return (tCOMMA);
case '"':
return (tDITTO);
case '$':
return (tDOLLAR);
case '!':
return (tEXCL);
case '<':
c = db_read_char();
if (c == '<')
return (tSHIFT_L);
db_unread_char(c);
break;
case '>':
c = db_read_char();
if (c == '>')
return (tSHIFT_R);
db_unread_char(c);
break;
case -1:
return (tEOF);
}
db_printf("Bad character\n");
db_flush_lex();
return (tEOF);
}
/*
* Utility routine - discard tokens through end-of-line.
*/
void
db_skip_to_eol(void)
{
int t;
do {
t = db_read_token();
} while (t != tEOL);
}
void
db_error(const char *s)
{
if (s)
db_printf("%s", s);
db_flush_lex();
longjmp(db_recover);
}
