ref: ed927690e4c089521410d92c9d3b06dbc33b95bd
dir: /lex.c/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "cc.h"
#include "tokens.h"
#include "symbol.h"
#include "sizes.h"
#define NR_KEYW_HASH 16
unsigned char yytoken;
char yytext[IDENTSIZ + 1];
unsigned linenum;
unsigned columnum;
const char *filename;
struct keyword {
char *str;
unsigned char tok;
struct keyword *next;
};
static FILE *yyin;
static struct keyword *ktab[NR_KEYW_HASH];
struct symbol *yyval;
struct symbol *
integer(char *s, char base)
{
static struct ctype *tp;
register struct symbol *sym;
static long long v;
static char ch;
tp = initctype(xmalloc(sizeof(*tp)));
type: switch (ch = toupper(getc(yyin))) {
case 'L':
tp = ctype(tp, LONG);
goto type;
case 'U':
tp = ctype(tp, UNSIGNED);
goto type;
default:
ungetc(ch, yyin);
}
v = strtoll(s, NULL, base);
sym = lookup(NULL, NS_IDEN);
sym->ctype = tp;
switch (sym->ctype->type) {
case INT:
sym->i = v;
break;
case SHORT:
sym->s = v;
break;
case LONG:
sym->l = xmalloc(sizeof(long));
*sym->l = v;
break;
case LLONG:
sym->ll = xmalloc(sizeof(long long));
*sym->ll = v;
break;
}
return sym;
}
static char
number(void)
{
register char *bp, ch;
static char base, type, sign;
if ((ch = getc(yyin)) == '0') {
if (toupper(ch = getc(yyin)) == 'X') {
base = 16;
} else {
base = 8;
ungetc(ch, yyin);
}
} else {
base = 10;
ungetc(ch, yyin);
}
for (bp = yytext; bp < yytext + IDENTSIZ; *bp++ = ch) {
ch = getc(yyin);
switch (base) {
case 8:
if (ch >= '7')
goto end;
/* passthru */
case 10:
if (!isdigit(ch))
goto end;
break;
case 16:
if (!isxdigit(ch))
goto end;
break;
}
}
end: if (bp == yytext + IDENTSIZ)
error("identifier too long %s", yytext);
*bp = '\0';
ungetc(ch, yyin);
yyval = integer(yytext, base);
return CONSTANT;
}
void
init_keywords(void)
{
static struct keyword buff[] = {
{"auto", AUTO, NULL},
{"break", BREAK, NULL},
{"_Bool", CHAR, NULL},
{"_Complex", COMPLEX, NULL},
{"case", CASE, NULL},
{"char", CHAR, NULL},
{"const", CONST, NULL},
{"continue", CONTINUE, NULL},
{"default", DEFAULT, NULL},
{"do", DO, NULL},
{"double", DOUBLE, NULL},
{"else", ELSE, NULL},
{"enum", ENUM, NULL},
{"extern", EXTERN, NULL},
{"float", FLOAT, NULL},
{"for", FOR, NULL},
{"goto", GOTO, NULL},
{"if", IF, NULL},
{"int", INT, NULL},
{"_Imaginary", IMAGINARY, NULL},
{"long", LONG, NULL},
{"register", REGISTER, NULL},
{"restricted", RESTRICT, NULL},
{"return", RETURN, NULL},
{"short", SHORT, NULL},
{"signed", SIGNED, NULL},
{"sizeof", SIZEOF, NULL},
{"static", STATIC, NULL},
{"struct", STRUCT, NULL},
{"switch", SWITCH, NULL},
{"typedef", TYPEDEF, NULL},
{"union", UNION, NULL},
{"unsigned", UNSIGNED, NULL},
{"void", VOID, NULL},
{"volatile", VOLATILE, NULL},
{"while", WHILE, NULL},
{NULL, 0, NULL},
};
register struct keyword *bp;
for (bp = buff; bp->str; ++bp) {
register unsigned char h = hash(bp->str) & NR_KEYW_HASH-1;
bp->next = ktab[h];
ktab[h] = bp;
}
}
static unsigned char
keyword(char *s)
{
register struct keyword *bp;
for (bp = ktab[hash(s) & NR_KEYW_HASH-1]; bp; bp = bp->next) {
if (!strcmp(bp->str, s))
return bp->tok;
}
return 0;
}
static unsigned char
iden(void)
{
register char ch, *bp;
register struct symbol *sym;
static unsigned char tok;
for (bp = yytext; bp < yytext + IDENTSIZ; *bp++ = ch) {
if (!isalnum(ch = getc(yyin)) && ch != '_')
break;
}
if (bp == yytext + IDENTSIZ)
error("identifier too long %s", yytext);
*bp = '\0';
ungetc(ch, yyin);
return (tok = keyword(yytext)) ? tok : IDEN;
}
static unsigned char
skip(void)
{
register int c;
extern char parser_out_home;
while (isspace(c = getc(yyin))) {
switch (c) {
case '\n': ++linenum, columnum = 1; break;
case '\t': columnum += 8; break;
default: ++columnum; break;
}
}
if (c == EOF) {
if (parser_out_home)
error("Find EOF while parsing");
return 0;
}
ungetc(c, yyin);
return 1;
}
static unsigned char
follow(unsigned char op, unsigned char eq, unsigned char rep)
{
register char c = getc(yyin);
yytext[1] = c;
yytext[2] = '\0';
if (c == '=')
return eq;
else if (c == op && rep)
return rep;
yytext[1] = '\0';
ungetc(c, yyin);
return op;
}
static unsigned char
rel_shift(unsigned char op)
{
static char tokens[2][3] = {
{GE, SHL, SHL_EQ},
{LE, SHR, SHR_EQ}};
register char c = getc(yyin);
register char *tp = tokens[op == '>'];
yytext[1] = c;
yytext[2] = '\0';
if (c == '=') {
return tp[0];
} else if (c == op) {
if ((c = getc(yyin)) == '=') {
yytext[2] = c;
yytext[3] = '\0';
return tp[2];
}
op = tp[1];
} else {
yytext[1] = '\0';
}
ungetc(c, yyin);
return op;
}
static unsigned char
minus(void)
{
register int c = getc(yyin);
yytext[1] = c;
switch (c) {
case '-': return DEC;
case '>': return INDIR;
case '=': return SUB_EQ;
default:
yytext[1] = '\0';
ungetc(c, yyin);
return '-';
}
}
static unsigned char
operator(void)
{
register unsigned char c = getc(yyin);
yytext[0] = c;
yytext[1] = '\0';
switch (c) {
case '=': return follow('=', EQ, 0);
case '^': return follow('^', XOR_EQ, 0);
case '*': return follow('*', MUL_EQ, 0);
case '!': return follow('!', NE, 0);
case '+': return follow('+', ADD_EQ, INC);
case '&': return follow('&', AND_EQ, AND);
case '|': return follow('|', OR_EQ, OR);
case '<': return rel_shift('<');
case '>': return rel_shift('>');
case '-': return minus();
default: return c;
}
}
void
next(void)
{
register unsigned char c;
if (!skip()) {
yytoken = EOFTOK;
} else {
ungetc(c = getc(yyin), yyin);
if (isalpha(c) || c == '_')
yytoken = iden();
else if (isdigit(c))
yytoken = number();
else
yytoken = operator();
}
}
unsigned char
ahead(void)
{
register char c;
if (!skip())
return EOFTOK;
ungetc(c = getc(yyin), yyin);
return c;
}
char
accept(register unsigned char tok)
{
if (yytoken == tok) {
next();
return 1;
}
return 0;
}
void
expect(register unsigned char tok)
{
if (yytoken != tok)
error("unexpected %s", yytext);
next();
}
void
open_file(register const char *file)
{
if (yyin != NULL)
fclose(yyin);
if (file == NULL) {
yyin = stdin;
filename = "(stdin)";
return;
}
if ((yyin = fopen(file, "r")) == NULL)
die("file '%s' not found", file);
filename = file;
columnum = linenum = 1;
}