minix/commands/i386/asmconv/tokenize.c

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2005-04-21 16:53:53 +02:00
/* tokenize.c - split input into tokens Author: Kees J. Bot
* 13 Dec 1993
*/
#define nil 0
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "asmconv.h"
#include "token.h"
static FILE *tf;
static char *tfile;
static char *orig_tfile;
static int tcomment;
static int tc;
static long tline;
static token_t *tq;
static void readtc(void)
/* Read one character from the input file and put it in the global 'tc'. */
{
static int nl= 0;
if (nl) tline++;
if ((tc= getc(tf)) == EOF && ferror(tf)) fatal(orig_tfile);
nl= (tc == '\n');
}
void set_file(char *file, long line)
/* Set file name and line number, changed by a preprocessor trick. */
{
deallocate(tfile);
tfile= allocate(nil, (strlen(file) + 1) * sizeof(tfile[0]));
strcpy(tfile, file);
tline= line;
}
void get_file(char **file, long *line)
/* Get file name and line number. */
{
*file= tfile;
*line= tline;
}
void parse_err(int err, token_t *t, const char *fmt, ...)
/* Report a parsing error. */
{
va_list ap;
fprintf(stderr, "\"%s\", line %ld: ", tfile,
t == nil ? tline : t->line);
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
if (err) set_error();
}
void tok_init(char *file, int comment)
/* Open the file to tokenize and initialize the tokenizer. */
{
if (file == nil) {
file= "stdin";
tf= stdin;
} else {
if ((tf= fopen(file, "r")) == nil) fatal(file);
}
orig_tfile= file;
set_file(file, 1);
readtc();
tcomment= comment;
}
static int isspace(int c)
{
return between('\0', c, ' ') && c != '\n';
}
#define iscomment(c) ((c) == tcomment)
static int isidentchar(int c)
{
return between('a', c, 'z')
|| between('A', c, 'Z')
|| between('0', c, '9')
|| c == '.'
|| c == '_'
;
}
static token_t *new_token(void)
{
token_t *new;
new= allocate(nil, sizeof(*new));
new->next= nil;
new->line= tline;
new->name= nil;
new->symbol= -1;
return new;
}
static token_t *get_word(void)
/* Read one word, an identifier, a number, a label, or a mnemonic. */
{
token_t *w;
char *name;
size_t i, len;
i= 0;
len= 16;
name= allocate(nil, len * sizeof(name[0]));
while (isidentchar(tc)) {
name[i++]= tc;
readtc();
if (i == len) name= allocate(name, (len*= 2) * sizeof(name[0]));
}
name[i]= 0;
name= allocate(name, (i+1) * sizeof(name[0]));
w= new_token();
w->type= T_WORD;
w->name= name;
w->len= i;
return w;
}
static token_t *get_string(void)
/* Read a single or double quotes delimited string. */
{
token_t *s;
int quote;
char *str;
size_t i, len;
int n, j;
int seen;
quote= tc;
readtc();
i= 0;
len= 16;
str= allocate(nil, len * sizeof(str[0]));
while (tc != quote && tc != '\n' && tc != EOF) {
seen= -1;
if (tc == '\\') {
readtc();
if (tc == '\n' || tc == EOF) break;
switch (tc) {
case 'a': tc= '\a'; break;
case 'b': tc= '\b'; break;
case 'f': tc= '\f'; break;
case 'n': tc= '\n'; break;
case 'r': tc= '\r'; break;
case 't': tc= '\t'; break;
case 'v': tc= '\v'; break;
case 'x':
n= 0;
for (j= 0; j < 3; j++) {
readtc();
if (between('0', tc, '9'))
tc-= '0' + 0x0;
else
if (between('A', tc, 'A'))
tc-= 'A' + 0xA;
else
if (between('a', tc, 'a'))
tc-= 'a' + 0xa;
else {
seen= tc;
break;
}
n= n*0x10 + tc;
}
tc= n;
break;
default:
if (!between('0', tc, '9')) break;
n= 0;
for (j= 0; j < 3; j++) {
if (between('0', tc, '9'))
tc-= '0';
else {
seen= tc;
break;
}
n= n*010 + tc;
readtc();
}
tc= n;
}
}
str[i++]= tc;
if (i == len) str= allocate(str, (len*= 2) * sizeof(str[0]));
if (seen < 0) readtc(); else tc= seen;
}
if (tc == quote) {
readtc();
} else {
parse_err(1, nil, "string contains newline\n");
}
str[i]= 0;
str= allocate(str, (i+1) * sizeof(str[0]));
s= new_token();
s->type= T_STRING;
s->name= str;
s->len= i;
return s;
}
static int old_n= 0; /* To speed up n, n+1, n+2, ... accesses. */
static token_t **old_ptq= &tq;
token_t *get_token(int n)
/* Return the n-th token on the input queue. */
{
token_t *t, **ptq;
assert(n >= 0);
if (0 && n >= old_n) {
/* Go forward from the previous point. */
n-= old_n;
old_n+= n;
ptq= old_ptq;
} else {
/* Restart from the head of the queue. */
old_n= n;
ptq= &tq;
}
for (;;) {
if ((t= *ptq) == nil) {
/* Token queue doesn't have element <n>, read a
* new token from the input stream.
*/
while (isspace(tc) || iscomment(tc)) {
if (iscomment(tc)) {
while (tc != '\n' && tc != EOF)
readtc();
} else {
readtc();
}
}
if (tc == EOF) {
t= new_token();
t->type= T_EOF;
} else
if (isidentchar(tc)) {
t= get_word();
} else
if (tc == '\'' || tc == '"') {
t= get_string();
} else {
if (tc == '\n') tc= ';';
t= new_token();
t->type= T_CHAR;
t->symbol= tc;
readtc();
if (t->symbol == '<' && tc == '<') {
t->symbol= S_LEFTSHIFT;
readtc();
} else
if (t->symbol == '>' && tc == '>') {
t->symbol= S_RIGHTSHIFT;
readtc();
}
}
*ptq= t;
}
if (n == 0) break;
n--;
ptq= &t->next;
}
old_ptq= ptq;
return t;
}
void skip_token(int n)
/* Remove n tokens from the input queue. One is not allowed to skip unread
* tokens.
*/
{
token_t *junk;
assert(n >= 0);
while (n > 0) {
assert(tq != nil);
junk= tq;
tq= tq->next;
deallocate(junk->name);
deallocate(junk);
n--;
}
/* Reset the old reference. */
old_n= 0;
old_ptq= &tq;
}