ref: e5c045851833cfd6b4a8a3326131caf5a406410b
dir: /cc1/lex.c/
/* See LICENSE file for copyright and license details. */
static char sccsid[] = "@(#) ./cc1/lex.c";
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <cstd.h>
#include "../inc/cc.h"
#include "cc1.h"
unsigned yytoken;
struct yystype yylval;
char yytext[STRINGSIZ+3];
unsigned short yylen;
int cppoff;
int lexmode = CCMODE;
int namespace = NS_IDEN;
static int safe, eof;
Input *input;
void
allocinput(char *fname, FILE *fp, char *line)
{
Input *ip = xmalloc(sizeof(Input));
if (!line) {
line = xmalloc(INPUTSIZ);
line[0] = '\0';
}
ip->p = ip->begin = ip->line = line;
ip->nline = 0;
ip->fname = xstrdup(fname);
ip->next = input;
ip->fp = fp;
input = ip;
}
void
ilex(void)
{
static struct keyword keys[] = {
{"auto", SCLASS, AUTO},
{"break", BREAK, BREAK},
{"_Bool", TYPE, BOOL},
{"__builtin_va_list", TYPE, VA_LIST},
{"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},
{"inline", TQUALIFIER, INLINE},
{"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},
};
keywords(keys, NS_KEYWORD);
}
int
addinput(char *fname, Symbol *hide)
{
FILE *fp;
unsigned nline = 0;
if (hide) {
/* this is a macro expansion */
fp = NULL;
fname = xstrdup(input->fname);
nline = input->nline;
if (hide->hide == UCHAR_MAX)
die("Too many macro expansions");
++hide->hide;
} else if (fname) {
/* a new file */
if ((fp = fopen(fname, "r")) == NULL)
return 0;
} else {
/* reading from stdin */
fp = stdin;
fname = "<stdin>";
}
allocinput(fname, fp, NULL);
input->hide = hide;
input->nline = nline;
return 1;
}
void
delinput(void)
{
Input *ip = input;
Symbol *hide = ip->hide;
if (ip->fp) {
if (fclose(ip->fp))
die("error: failed to read from input file '%s'",
ip->fname);
if (!ip->next)
eof = 1;
}
if (hide) {
--hide->hide;
/*
* If the symbol is not declared then it was
* an extension due to a #if directive with
* a non declared symbol (expanded to 0),
* thus we have to kill the symbol
*/
if ((hide->flags & SDECLARED) == 0)
killsym(hide);
}
if (eof)
return;
input = ip->next;
free(ip->fname);
free(ip->line);
}
static void
newline(void)
{
if (++input->nline == 0)
die("error: input file '%s' too long", input->fname);
}
static int
readchar(void)
{
FILE *fp = input->fp;
int c;
if (eof || !fp)
return 0;
repeat:
switch (c = getc(fp)) {
case EOF:
c = '\0';
break;
case '\\':
if ((c = getc(fp)) == '\n') {
newline();
goto repeat;
}
ungetc(c, fp);
c = '\\';
break;
case '\n':
newline();
break;
}
return c;
}
static void
comment(int type)
{
int c;
c = -1;
repeat:
do {
if (!c || eof) {
errorp("unterminated comment");
return;
}
} while ((c = readchar()) != type);
if (type == '*' && (c = readchar()) != '/')
goto repeat;
}
static int
readline(void)
{
char *bp, *lim;
char c, peekc = 0;
repeat_from_file:
input->begin = input->p = input->line;
*input->line = '\0';
repeat_from_expand:
if (eof)
return 0;
if (!input->fp) {
delinput();
goto repeat_from_expand;
}
if (feof(input->fp)) {
delinput();
goto repeat_from_file;
}
lim = &input->line[INPUTSIZ-1];
for (bp = input->line; bp < lim; *bp++ = c) {
c = (peekc) ? peekc : readchar();
peekc = 0;
if (c == '\n' || c == '\0')
break;
if (c != '/' || (peekc = readchar()) != '*' && peekc != '/')
continue;
comment((peekc == '/') ? '\n' : peekc);
peekc = 0;
c = ' ';
}
if (bp == lim)
error("line too long");
*bp = '\0';
return 1;
}
int
moreinput(void)
{
static char file[FILENAME_MAX];
static unsigned nline;
char *s;
int wasexpand;
repeat:
wasexpand = input->hide != NULL;
if (!readline())
return 0;
while (isspace(*input->p))
++input->p;
input->begin = input->p;
if (*input->p == '\0' || cpp() || cppoff) {
*input->begin = '\0';
goto repeat;
}
if (onlycpp && !wasexpand) {
putchar('\n');
if (strcmp(file, input->fname)) {
strcpy(file, input->fname);
s = "#line %u %s\n";
} else if (nline+1 != input->nline) {
s = "#line %u\n";
} else {
s = "";
}
nline = input->nline;
printf(s, nline, file);
}
input->begin = input->p;
return 1;
}
static void
tok2str(void)
{
if ((yylen = input->p - input->begin) > INTIDENTSIZ)
error("token too big");
strncpy(yytext, input->begin, yylen);
yytext[yylen] = '\0';
input->begin = input->p;
}
static Symbol *
readint(char *s, int base, int sign, Symbol *sym)
{
Type *tp = sym->type;
struct limits *lim;
TUINT u, val, max;
int c;
lim = getlimits(tp);
max = lim->max.i;
if (*s == '0')
++s;
if (toupper(*s) == 'X')
++s;
for (u = 0; isxdigit(c = *s++); u = u*base + val) {
static char letters[] = "0123456789ABCDEF";
val = strchr(letters, toupper(c)) - letters;
repeat:
if (u <= max/base && u*base <= max - val)
continue;
if (tp->prop & TSIGNED) {
if (tp == inttype)
tp = (base==10) ? longtype : uinttype;
else if (tp == longtype)
tp = (base==10) ? llongtype : ulongtype;
else
goto overflow;
} else {
if (tp == uinttype)
tp = (sign==UNSIGNED) ? ulongtype : longtype;
else if (tp == ulongtype)
tp = (sign==UNSIGNED) ? ullongtype : llongtype;
else
goto overflow;
}
sym->type = tp;
lim = getlimits(tp);
max = lim->max.i;
goto repeat;
}
if (tp->prop & TSIGNED)
sym->u.i = u;
else
sym->u.u = u;
return sym;
overflow:
errorp("overflow in integer constant");
return sym;
}
static unsigned
integer(char *s, char base)
{
Type *tp;
Symbol *sym;
unsigned size, sign;
for (size = sign = 0; ; ++input->p) {
switch (toupper(*input->p)) {
case 'L':
if (size == LLONG)
goto wrong_type;
size = (size == LONG) ? LLONG : LONG;
continue;
case 'U':
if (sign == UNSIGNED)
goto wrong_type;
sign = UNSIGNED;
continue;
default:
goto convert;
wrong_type:
error("invalid suffix in integer constant");
}
}
convert:
tp = ctype(INT, sign, size);
sym = newsym(NS_IDEN, NULL);
sym->type = tp;
sym->flags |= SCONSTANT;
yylval.sym = readint(s, base, sign, sym);
return CONSTANT;
}
static char *
digits(unsigned base)
{
char c, *p;
for (p = input->p; c = *p; ++p) {
switch (base) {
case 8:
if (!strchr("01234567", c))
goto end;
break;
case 10:
if (!isdigit(c))
goto end;
break;
case 16:
if (!isxdigit(c))
goto end;
break;
}
}
end:
input->p = p;
tok2str();
return yytext;
}
static unsigned
number(void)
{
char base;
if (*input->p != '0') {
base = 10;
} else {
if (toupper(*++input->p) == 'X') {
++input->p;
base = 16;
} else {
base = 8;
}
}
return integer(digits(base), base);
}
static char
escape(void)
{
int c, base;
switch (*++input->p) {
case 'a': return '\a';
case 'f': return '\f';
case 'n': return '\n';
case 'r': return '\r';
case 't': return '\t';
case 'v': return '\v';
case '"': return '"';
case '\'': return '\'';
case '\\': return '\\';
case '\?': return '\?';
case 'u':
/*
* FIXME: universal constants are not correctly handled
*/
if (!isdigit(*++input->p))
warn("incorrect digit for numerical character constant");
base = 10;
break;
case 'x':
if (!isxdigit(*++input->p))
warn("\\x used with no following hex digits");
base = 16;
break;
case '0':
if (!strchr("01234567", *++input->p))
warn("\\0 used with no following octal digits");
base = 8;
break;
default:
warn("unknown escape sequence");
return ' ';
}
errno = 0;
c = strtoul(input->p, &input->p, base);
if (errno || c > 255)
warn("character constant out of range");
--input->p;
return c;
}
static unsigned
character(void)
{
static char c;
Symbol *sym;
if ((c = *++input->p) == '\\')
c = escape();
else
c = *input->p;
++input->p;
if (*input->p != '\'')
error("invalid character constant");
else
++input->p;
sym = newsym(NS_IDEN, NULL);
sym->u.i = c;
sym->type = inttype;
yylval.sym = sym;
return CONSTANT;
}
static unsigned
string(void)
{
char *bp = yytext, c;
*bp++ = '"';
repeat:
for (++input->p; (c = *input->p) != '"'; ++input->p) {
if (c == '\0')
error("missing terminating '\"' character");
if (c == '\\')
c = escape();
if (bp == &yytext[STRINGSIZ+1])
error("string too long");
*bp++ = c;
}
input->begin = ++input->p;
if (ahead() == '"')
goto repeat;
*bp = '\0';
yylen = bp - yytext + 1;
yylval.sym = newstring(yytext+1, yylen-1);
*bp++ = '"';
*bp = '\0';
return STRING;
}
static unsigned
iden(void)
{
Symbol *sym;
char *p, *begin;
begin = input->p;
for (p = begin; isalnum(*p) || *p == '_'; ++p)
/* nothing */;
input->p = p;
tok2str();
if ((sym = lookup(NS_CPP, yytext, NOALLOC)) != NULL) {
if (!disexpand && !sym->hide && expand(begin, sym))
return next();
}
sym = lookup(namespace, yytext, ALLOC);
yylval.sym = sym;
if (sym->flags & SCONSTANT)
return CONSTANT;
if (sym->token != IDEN)
yylval.token = sym->u.token;
return sym->token;
}
static unsigned
follow(int expect, int ifyes, int ifno)
{
if (*input->p++ == expect)
return ifyes;
--input->p;
return ifno;
}
static unsigned
minus(void)
{
switch (*input->p++) {
case '-': return DEC;
case '>': return INDIR;
case '=': return SUB_EQ;
default: --input->p; return '-';
}
}
static unsigned
plus(void)
{
switch (*input->p++) {
case '+': return INC;
case '=': return ADD_EQ;
default: --input->p; return '+';
}
}
static unsigned
relational(int op, int equal, int shift, int assig)
{
char c;
if ((c = *input->p++) == '=')
return equal;
if (c == op)
return follow('=', assig, shift);
--input->p;
return op;
}
static unsigned
logic(int op, int equal, int logic)
{
char c;
if ((c = *input->p++) == '=')
return equal;
if (c == op)
return logic;
--input->p;
return op;
}
static unsigned
dot(void)
{
char c;
if ((c = *input->p) != '.')
return '.';
if ((c = *++input->p) != '.')
error("incorrect token '..'");
++input->p;
return ELLIPSIS;
}
static unsigned
operator(void)
{
unsigned t;
switch (t = *input->p++) {
case '<': t = relational('<', LE, SHL, SHL_EQ); break;
case '>': t = relational('>', GE, SHR, SHR_EQ); break;
case '&': t = logic('&', AND_EQ, AND); break;
case '|': t = logic('|', OR_EQ, OR); break;
case '=': t = follow('=', EQ, '='); break;
case '^': t = follow('=', XOR_EQ, '^'); break;
case '*': t = follow('=', MUL_EQ, '*'); break;
case '/': t = follow('=', DIV_EQ, '/'); break;
case '!': t = follow('=', NE, '!'); break;
case '#': t = follow('#', '$', '#'); break;
case '-': t = minus(); break;
case '+': t = plus(); break;
case '.': t = dot(); break;
}
tok2str();
return t;
}
/* TODO: Ensure that namespace is NS_IDEN after a recovery */
static void
skipspaces(void)
{
repeat:
while (isspace(*input->p))
++input->p;
if (*input->p == '\0' && lexmode != CPPMODE) {
if (!moreinput())
return;
goto repeat;
}
input->begin = input->p;
}
unsigned
next(void)
{
char c;
skipspaces();
c = *input->begin;
if ((eof || lexmode == CPPMODE) && c == '\0') {
strcpy(yytext, "<EOF>");
if (cppctx && eof)
error("#endif expected");
yytoken = EOFTOK;
goto exit;
}
if (isalpha(c) || c == '_')
yytoken = iden();
else if (isdigit(c))
yytoken = number();
else if (c == '"')
yytoken = string();
else if (c == '\'')
yytoken = character();
else
yytoken = operator();
exit:
DBG("TOKEN %s", yytext);
return yytoken;
}
void
expect(unsigned tok)
{
if (yytoken != tok) {
if (isgraph(tok))
errorp("expected '%c' before '%s'", tok, yytext);
else
errorp("unexpected '%s'", yytext);
} else {
next();
}
}
char
ahead(void)
{
skipspaces();
return *input->begin;
}
void
setsafe(int type)
{
safe = type;
}
void
discard(void)
{
extern jmp_buf recover;
char c;
input->begin = input->p;
for (c = yytoken; ; c = *input->begin++) {
switch (safe) {
case END_COMP:
if (c == '}')
goto jump;
goto semicolon;
case END_COND:
if (c == ')')
goto jump;
break;
case END_LDECL:
if (c == ',')
goto jump;
case END_DECL:
semicolon:
if (c == ';')
goto jump;
break;
}
if (c == '\0' && !moreinput())
exit(1);
}
jump:
yytoken = c;
longjmp(recover, 1);
}