ref: d7a8adfd00c4d92615387463382ba1e000c3b61c
dir: /lex.c/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "cc1.h"
#include "sizes.h"
static FILE *yyin;
const char *filename;
unsigned linenum;
uint8_t yytoken, yyntoken;;
union yystype yylval;
char yytext[IDENTSIZ + 1];
static union yystype yynlval;
static char yybuf[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(yybuf, NULL, base);
if (tp == inttype)
sym->u.i = v;
yynlval.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 = yybuf ; bp < &yybuf[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 == &yybuf[IDENTSIZ])
error("identifier too long %s", yybuf);
*bp = '\0';
ungetc(ch, yyin);
return integer(yybuf, 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;
yynlval.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, NULL, 0);
yynlval.sym = sym;
return STRING;
}
void
init_keywords(void)
{
static struct {
char *str;
uint8_t token, value;
} *bp, buff[] = {
{"auto", SCLASS, AUTO},
{"break", BREAK, BREAK},
{"_Bool", TYPE, BOOL},
{"case", CASE, CASE},
{"char", TYPE, CHAR},
{"const", TQUALIFIER, CONST},
{"continue", CONTINUE, CONTINUE},
{"default", DEFAULT, DEFAULT},
{"do", DO, DO},
{"double", TYPE, DOUBLE},
{"else", ELSE, ELSE},
{"enum", TYPE, ENUM},
{"extern", SCLASS, EXTERN},
{"float", TYPE, FLOAT},
{"for", FOR, FOR},
{"goto", GOTO, GOTO},
{"if", IF, IF},
{"int", TYPE, INT},
{"long", TYPE, LONG},
{"register", SCLASS, REGISTER},
{"restrict", TQUALIFIER, RESTRICT},
{"return", RETURN, RETURN},
{"short", TYPE, SHORT},
{"signed", TYPE, SIGNED},
{"sizeof", SIZEOF, SIZEOF},
{"static", SCLASS, STATIC},
{"struct", TYPE, STRUCT},
{"switch", SWITCH, SWITCH},
{"typedef", SCLASS, TYPEDEF},
{"union", TYPE, UNION},
{"unsigned", TYPE, UNSIGNED},
{"void", TYPE, VOID},
{"volatile", TQUALIFIER, VOLATILE},
{"while", WHILE, WHILE},
{NULL, 0, 0},
};
register Symbol *sym;
extern short symid;
for (bp = buff; bp->str; ++bp) {
sym = install(bp->str, NS_IDEN);
sym->token = bp->token;
sym->u.token = bp->value;
}
symid = 0;
}
static uint8_t
iden(void)
{
register char *bp;
register int c;
Symbol *sym;
for (bp = yybuf; bp < &yybuf[IDENTSIZ]; *bp++ = c) {
if (!isalnum(c = getc(yyin)) && c != '_')
break;
}
if (bp == &yybuf[IDENTSIZ])
error("identifier too long %s", yybuf);
*bp = '\0';
ungetc(c, yyin);
sym = lookup(yybuf, NS_IDEN);
if (!sym || sym->token == IDEN) {
yynlval.sym = sym;
return IDEN;
}
yynlval.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) {
yybuf[1] = c;
yybuf[2] = 0;
return ifyes;
}
ungetc(c, yyin);
return ifno;
}
static uint8_t
minus(void)
{
register int c = getc(yyin);
yybuf[1] = c;
yybuf[2] = '\0';
switch (c) {
case '-': return DEC;
case '>': return INDIR;
case '=': return SUB_EQ;
default:
yybuf[1] = '\0';
ungetc(c, yyin);
return '-';
}
}
static uint8_t
plus(void)
{
register int c = getc(yyin);
yybuf[1] = c;
yybuf[2] = '\0';
switch (c) {
case '+': return INC;
case '=': return ADD_EQ;
default:
yybuf[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);
yybuf[1] = c;
yybuf[2] = '\0';
if (c == '=')
return equal;
if (c == op)
return follow('=', assig, shift);
ungetc(c, yyin);
yybuf[1] = '\0';
return op;
}
static uint8_t
logic(uint8_t op, uint8_t equal, uint8_t logic)
{
register int c = getc(yyin);
yybuf[1] = c;
yybuf[2] = '\0';
if (c == '=')
return equal;
if (c == op)
return logic;
ungetc(c, yyin);
yybuf[1] = '\0';
return op;
}
static uint8_t
operator(void)
{
register uint8_t c = getc(yyin);
yybuf[0] = c;
yybuf[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();
default: return c;
}
}
uint8_t
next(void)
{
static int c;
extern int8_t forbid_eof;
strcpy(yytext, yybuf);
yylval = yynlval;
if ((yytoken = yyntoken) == EOFTOK) {
if (forbid_eof)
error("Find EOF while parsing");
goto ret;
}
while (isspace(c = getc(yyin))) {
if (c == '\n')
++linenum;
}
if (c == EOF) {
yyntoken = EOFTOK;
goto ret;
}
ungetc(c, yyin);
if (isalpha(c) || c == '_')
yyntoken = iden();
else if (isdigit(c))
yyntoken = number();
else if (c == '"')
yyntoken = string();
else if (c == '\'')
yyntoken = character();
else
yyntoken = operator();
ret: return yytoken;
}
void
expect(register uint8_t 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)";
} else {
if ((yyin = fopen(file, "r")) == NULL)
die("file '%s' not found", file);
filename = file;
}
linenum = 1;
next(); /* prefetch first token */
}