ref: c405c48a66cc5a7eeb192db81d42c08da2b19d73
dir: /cc1/lex.c/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sizes.h>
#include <cc.h>
#include "cc1.h"
static FILE *yyin;
uint8_t lex_ns = NS_IDEN;
const char *filename;
unsigned linenum;
uint8_t yytoken;
struct yystype yylval;
char yytext[IDENTSIZ + 1];
static uint8_t
integer(char *s, char base)
{
static Type *tp;
static Symbol *sym;
static char ch, size, sign;
static long v;
size = sign = 0;
type:
switch (ch = toupper(getc(yyin))) {
case 'L':
if (size == LONG + LONG)
goto wrong_type;
size += LONG;
goto type;
case 'U':
if (sign == UNSIGNED)
goto wrong_type;
goto type;
default:
ungetc(ch, yyin);
tp = ctype(INT, sign, size);
break;
wrong_type:
error("invalid suffix in integer constant");
}
sym = install("", NS_IDEN);
sym->type = tp;
v = strtol(yytext, NULL, base);
if (tp == inttype)
sym->u.i = v;
yylval.sym = sym;
return CONSTANT;
}
static uint8_t
number(void)
{
register char ch, *bp;
static char base;
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);
return integer(yytext, base);
}
static char *
escape(char *s)
{
char c;
repeat:
switch (getc(yyin)) {
case '\\': c = '\''; break;
case 'a': c = '\a'; break;
case 'f': c = '\f'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 't': c = '\t'; break;
case 'v': c = '\v'; break;
case '\'': c = '\\'; break;
case '"': c ='"'; break;
case '?': c = '?'; break;
case 'x': /* TODO: */
case '0': /* TODO: */
case 'u': /* TODO: */
case '\n':
++linenum;
if ((c = getc(yyin)) == '\\')
goto repeat;
break;
default:
warn(1, "unknown escape sequence");
return s;
}
*s = c;
return ++s;
}
static uint8_t
character(void)
{
static char c;
register Symbol *sym;
getc(yyin); /* discard the initial ' */
c = getc(yyin);
if (c == '\\')
escape(&c);
if (getc(yyin) != '\'')
error("invalid character constant");
sym = install("", NS_IDEN);
sym->u.i = c;
sym->type = inttype;
yylval.sym = sym;
return CONSTANT;
}
static uint8_t
string(void)
{
static char buf[STRINGSIZ+1];
register char *bp;
register int c;
static Symbol *sym;
getc(yyin); /* discard the initial " */
for (bp = buf; bp < &buf[STRINGSIZ]; ) {
switch (c = getc(yyin)) {
case EOF:
error("found EOF while parsing");
case '"':
goto end_string;
case '\\':
bp = escape(bp);
break;
default:
*bp++ = c;
}
}
end_string:
if (bp == &buf[IDENTSIZ])
error("string too long");
*bp = '\0';
sym = install("", NS_IDEN);
sym->u.s = xstrdup(buf);
sym->type = mktype(chartype, PTR, 0, NULL);
yylval.sym = sym;
return STRING;
}
static uint8_t
iden(void)
{
register char *bp;
register int c;
register Symbol *sym;
for (bp = yytext; bp < &yytext[IDENTSIZ]; *bp++ = c) {
if (!isalnum(c = getc(yyin)) && c != '_')
break;
}
if (bp == &yytext[IDENTSIZ])
error("identifier too long %s", yytext);
*bp = '\0';
ungetc(c, yyin);
sym = yylval.sym = lookup(yytext, lex_ns);
if (!sym || sym->token == IDEN)
return IDEN;
yylval.token = sym->u.token;
return sym->token;
}
static uint8_t
follow(int expect, int ifyes, int ifno)
{
register int c = getc(yyin);
if (c == expect) {
yytext[1] = c;
yytext[2] = 0;
return ifyes;
}
ungetc(c, yyin);
return ifno;
}
static uint8_t
minus(void)
{
register int c = getc(yyin);
yytext[1] = c;
yytext[2] = '\0';
switch (c) {
case '-': return DEC;
case '>': return INDIR;
case '=': return SUB_EQ;
default:
yytext[1] = '\0';
ungetc(c, yyin);
return '-';
}
}
static uint8_t
plus(void)
{
register int c = getc(yyin);
yytext[1] = c;
yytext[2] = '\0';
switch (c) {
case '+': return INC;
case '=': return ADD_EQ;
default:
yytext[1] = '\0';
ungetc(c, yyin);
return '+';
}
}
static uint8_t
relational(uint8_t op, uint8_t equal, uint8_t shift, uint8_t assig)
{
register int c = getc(yyin);
yytext[1] = c;
yytext[2] = '\0';
if (c == '=')
return equal;
if (c == op)
return follow('=', assig, shift);
ungetc(c, yyin);
yytext[1] = '\0';
return op;
}
static uint8_t
logic(uint8_t op, uint8_t equal, uint8_t logic)
{
register int c = getc(yyin);
yytext[1] = c;
yytext[2] = '\0';
if (c == '=')
return equal;
if (c == op)
return logic;
ungetc(c, yyin);
yytext[1] = '\0';
return op;
}
static uint8_t
dot(void)
{
int c;
if ((c = getc(yyin)) != '.') {
ungetc(c, yyin);
return '.';
} else if ((c = getc(yyin)) != '.') {
error("incorrect token '%s'", yytext);
} else {
yytext[2] = yytext[1] = '.';
yytext[3] = '\0';
return ELLIPSIS;
}
}
static uint8_t
operator(void)
{
register uint8_t c = getc(yyin);
yytext[0] = c;
yytext[1] = '\0';
switch (c) {
case '<': return relational('<', LE, SHL, SHL_EQ);
case '>': return relational('>', GE, SHR, SHR_EQ);
case '&': return logic('&', AND_EQ, AND);
case '|': return logic('|', OR_EQ, OR);
case '=': return follow('=', EQ, '=');
case '^': return follow('=', XOR_EQ, '^');
case '*': return follow('=', MUL_EQ, '*');
case '/': return follow('=', DIV_EQ, '/');
case '!': return follow('=', NE, '!');
case '-': return minus();
case '+': return plus();
case '.': return dot();
default: return c;
}
}
static int
skipspaces(void)
{
register int c;
while (isspace(c = getc(yyin))) {
if (c == '\n')
++linenum;
}
return c;
}
uint8_t
next(void)
{
register int c;
ungetc(c = skipspaces(), yyin);
if (isalpha(c) || c == '_') {
yytoken = iden();
} else if (isdigit(c)) {
yytoken = number();
} else if (c == '"') {
yytoken = string();
} else if (c == '\'') {
yytoken = character();
} else if (c == EOF) {
strcpy(yytext, "EOF");
yytoken = EOFTOK;
} else {
yytoken = operator();
}
return yytoken;
}
void
expect(register uint8_t tok)
{
if (yytoken != tok)
unexpected();
next();
}
uint8_t
ahead(void)
{
register int c;
ungetc(c = skipspaces(), yyin);
return c;
}
void
open_file(register const char *file)
{
if (yyin != NULL)
fclose(yyin);
if (file == NULL) {
yyin = stdin;
filename = "(stdin)";
} else {
if ((yyin = fopen(file, "r")) == NULL)
die("file '%s' not found", file);
filename = file;
}
linenum = 1;
}