ref: 49aed5a4c73098ed769563a1013cea334c7c6209
dir: /src/cmd/cc/cc1/lex.c/
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <setjmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <scc/cstd.h>
#include <scc/scc.h>
#include "cc1.h"
int yytoken;
struct yystype yylval;
char yytext[STRINGSIZ+3];
unsigned short yylen;
int lexmode = CCMODE;
unsigned lineno;
char filenam[FILENAME_MAX];
int namespace = NS_IDEN;
static int safe;
Input *input;
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);
}
void
setloc(char *fname, unsigned line)
{
size_t len;
if ((len = strlen(fname)) >= FILENAME_MAX)
die("cc1: %s: file name too long", fname);
memmove(filenam, fname, len);
filenam[len] = '\0';
free(input->filenam);
input->filenam = xstrdup(fname);
lineno = input->lineno = line;
}
int
addinput(char *fname, Symbol *hide, char *buffer, int fail)
{
FILE *fp;
char *extp;
unsigned flags;
int infileln;
Input *newip, *curip = input;
if (hide) {
/* this is a macro expansion */
fp = NULL;
if (hide->hide == UCHAR_MAX)
die("cc1: too many macro expansions");
++hide->hide;
flags = IMACRO;
} else if (fname) {
/* a new file */
if ((fp = fopen(fname, "r")) == NULL) {
if (!fail)
return 0;
die("cc1: %s: %s", fname, strerror(errno));
}
flags = IFILE;
if (curip && onlyheader) {
infileln = strlen(infile);
if (extp = strrchr(infile, '.'))
infileln -= strlen(extp);
printf("%.*s.o: %s %s\n",
infileln, infile, infile, fname);
}
} else {
/* reading from stdin */
fp = stdin;
fname = "<stdin>";
flags = ISTDIN;
}
newip = xmalloc(sizeof(*newip));
if (!buffer) {
buffer = xmalloc(INPUTSIZ);
buffer[0] = '\0';
}
if (curip)
curip->lineno = lineno;
newip->p = newip->begin = newip->line = buffer;
newip->filenam = NULL;
newip->lineno = 0;
newip->next = curip;
newip->fp = fp;
newip->hide = hide;
newip->flags = flags;
input = newip;
setloc(fname, (curip) ? curip->lineno : newip->lineno);
return 1;
}
void
delinput(void)
{
Input *ip = input;
Symbol *hide = ip->hide;
switch (ip->flags & ITYPE) {
case IFILE:
if (fclose(ip->fp))
die("cc1: %s: %s", ip->filenam, strerror(errno));
break;
case IMACRO:
assert(hide->hide == 1);
--hide->hide;
break;
}
input = ip->next;
free(ip->filenam);
free(ip->line);
if (input) {
lineno = input->lineno;
strcpy(filenam, input->filenam);
}
}
static void
newline(void)
{
if (++lineno == 0)
die("cc1: %s: file too long", filenam);
}
/*
* Read the next character from the input file, counting number of lines
* and joining lines escaped with \
*/
static int
readchar(void)
{
FILE *fp = input->fp;
int c;
repeat:
switch (c = getc(fp)) {
case '\\':
if ((c = getc(fp)) == '\n') {
newline();
goto repeat;
}
ungetc(c, fp);
c = '\\';
break;
case '\n':
newline();
break;
default:
if (!isprint(c) && !ispunct(c) && !isspace(c))
warn("invalid input character. The shame of UB is yours");
break;
}
return c;
}
/*
* discard a C comment. This function is only called from readline
* because it is impossible to have a comment in a macro, because
* comments are always discarded before processing any cpp directive
*/
static void
comment(int type)
{
int c;
repeat:
while ((c = readchar()) != EOF && c != type)
;
if (c == EOF) {
errorp("unterminated comment");
return;
}
if (type == '*' && (c = readchar()) != '/')
goto repeat;
}
/*
* readline is used to read a full logic line from a file.
* It discards comments and check that the line fits in
* the input buffer
*/
static int
readline(void)
{
char *bp, *lim;
int c, peekc = 0;
if (feof(input->fp)) {
input->flags |= IEOF;
return 0;
}
*input->line = '\0';
lim = &input->line[INPUTSIZ-1];
for (bp = input->line; bp < lim-1; *bp++ = c) {
c = (peekc) ? peekc : readchar();
peekc = 0;
if (c == '\n' || c == EOF)
break;
if (c != '/')
continue;
/* check for /* or // */
peekc = readchar();
if (peekc != '*' && peekc != '/')
continue;
comment((peekc == '/') ? '\n' : '*');
peekc = 0;
c = ' ';
}
input->begin = input->p = input->line;
if (bp == lim-1) {
errorp("line too long");
--bp;
}
*bp++ = '\n';
*bp = '\0';
return 1;
}
/*
* moreinput gets more bytes to be passed to the lexer.
* It can take more bytes from macro expansions or
* directly reading from files. When a cpp directive
* is processed the line is discarded because it must not
* be passed to the lexer
*/
static int
moreinput(void)
{
int wasexpand = 0;
repeat:
if (!input)
return 0;
if (*input->p == '\0') {
if ((input->flags&ITYPE) == IMACRO) {
wasexpand = 1;
input->flags |= IEOF;
}
if (input->flags & IEOF) {
delinput();
goto repeat;
}
if (!readline() || cpp()) {
*input->p = '\0';
goto repeat;
}
}
if (onlycpp && !wasexpand)
ppragmaln();
return 1;
}
static void
tok2str(void)
{
if ((yylen = input->p - input->begin) > INTIDENTSIZ)
error("token too big");
memcpy(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 int
integer(char *s, int 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(int base)
{
char *p;
int c;
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 int
number(void)
{
int 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 int
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;
/* FIXME: We don't check that there is an actual number */
c = strtoul(input->p, &input->p, base);
if (errno || c > 255)
warn("character constant out of range");
--input->p;
return c;
}
static int
character(void)
{
int c;
Symbol *sym;
if ((c = *++input->p) == '\\')
c = escape();
else
c = *input->p;
++input->p;
if (*input->p != '\'')
errorp("invalid character constant");
else
++input->p;
sym = newsym(NS_IDEN, NULL);
sym->u.i = c;
sym->type = inttype;
yylval.sym = sym;
tok2str();
return CONSTANT;
}
/*
* string() parses a constant string, and convert all the
* escape sequences into single characters. This behaviour
* is correct except when we parse a #define, where we want
* to preserve the literal content of the string. In that
* case cpp.c:/^define( sets the variable disescape to
* disable converting escape sequences into characters.
*/
static int
string(void)
{
char *bp = yytext;
int c, esc;
*bp++ = '"';
esc = 0;
for (++input->p; ; ++input->p) {
c = *input->p;
if (c == '"' && !esc)
break;
if (c == '\0') {
errorp("missing terminating '\"' character");
break;
}
if (c == '\\' && !esc && disescape)
esc = 1;
else
esc = 0;
if (c == '\\' && !esc)
c = escape();
if (bp == &yytext[STRINGSIZ+1]) {
for (++input->p; *input->p != '"'; ++input->p) {
if (*input->p == '\\')
++input->p;
if (*input->p == '\0')
break;
}
--bp;
errorp("string too long");
break;
}
*bp++ = c;
}
input->begin = ++input->p;
*bp = '\0';
yylen = bp - yytext + 1;
yylval.sym = newstring(yytext+1, yylen-1);
*bp++ = '"';
*bp = '\0';
return STRING;
}
static int
iden(void)
{
Symbol *sym;
char *p, *begin;
begin = input->p;
for (p = begin; isalnum(*p) || *p == '_'; ++p)
;
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 int
follow(int expect, int ifyes, int ifno)
{
if (*input->p++ == expect)
return ifyes;
--input->p;
return ifno;
}
static int
minus(void)
{
switch (*input->p++) {
case '-':
return DEC;
case '>':
return INDIR;
case '=':
return SUB_EQ;
default:
--input->p;
return '-';
}
}
static int
plus(void)
{
switch (*input->p++) {
case '+':
return INC;
case '=':
return ADD_EQ;
default:
--input->p;
return '+';
}
}
static int
relational(int op, int equal, int shift, int assig)
{
int c;
if ((c = *input->p++) == '=')
return equal;
if (c == op)
return follow('=', assig, shift);
--input->p;
return op;
}
static int
logic(int op, int equal, int logic)
{
int c;
if ((c = *input->p++) == '=')
return equal;
if (c == op)
return logic;
--input->p;
return op;
}
static int
dot(void)
{
int c;
if ((c = *input->p) != '.')
return '.';
if ((c = *++input->p) != '.')
error("incorrect token '..'");
++input->p;
return ELLIPSIS;
}
static int
operator(void)
{
int 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 */
/*
* skip all the spaces until the next token. When we are in
* CPPMODE \n is not considered a whitespace
*/
static int
skipspaces(void)
{
int c;
for (;;) {
switch (c = *input->p) {
case '\n':
if (lexmode == CPPMODE)
goto return_byte;
++input->p;
case '\0':
if (!moreinput())
return EOF;
break;
case ' ':
case '\t':
case '\v':
case '\r':
case '\f':
++input->p;
break;
default:
goto return_byte;
}
}
return_byte:
input->begin = input->p;
return c;
}
int
next(void)
{
int c;
if ((c = skipspaces()) == EOF)
yytoken = EOFTOK;
else 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();
if (yytoken == EOF) {
strcpy(yytext, "<EOF>");
if (cppctx)
errorp("#endif expected");
}
DBG("TOKEN %s", yytext);
return yytoken;
}
void
expect(int tok)
{
if (yytoken != tok) {
if (isgraph(tok))
errorp("expected '%c' before '%s'", tok, yytext);
else
errorp("unexpected '%s'", yytext);
} else {
next();
}
}
int
ahead(void)
{
skipspaces();
return *input->begin;
}
void
setsafe(int type)
{
safe = type;
}
void
discard(void)
{
extern jmp_buf recover;
int 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;
exit(EXIT_FAILURE);
/*
* FIXME: We don't have a proper recover mechanism at this moment
* and we don't set the recover point ever, so executing this
* longjmp will generate surely a segmentation fault, so it does
* not make sense to do it. We just exit until we can find time
* to solve this problem.
*/
longjmp(recover, 1);
}