ref: 8c7f4dc57396e542b1e24a849f95561739a88887
dir: /jslex.c/
#include "js.h"
#include "jslex.h"
#include "jsstate.h"
#include "jsutf.h"
#define nelem(a) (sizeof (a) / sizeof (a)[0])
static const char *tokenstring[] = {
"(end-of-file)",
"'\\x01'", "'\\x02'", "'\\x03'", "'\\x04'", "'\\x05'", "'\\x06'", "'\\x07'",
"'\\x08'", "'\\x09'", "'\\x0A'", "'\\x0B'", "'\\x0C'", "'\\x0D'", "'\\x0E'", "'\\x0F'",
"'\\x10'", "'\\x11'", "'\\x12'", "'\\x13'", "'\\x14'", "'\\x15'", "'\\x16'", "'\\x17'",
"'\\x18'", "'\\x19'", "'\\x1A'", "'\\x1B'", "'\\x1C'", "'\\x1D'", "'\\x1E'", "'\\x1F'",
"' '", "'!'", "'\"'", "'#'", "'$'", "'%'", "'&'", "'\\''",
"'('", "')'", "'*'", "'+'", "','", "'-'", "'.'", "'/'",
"'0'", "'1'", "'2'", "'3'", "'4'", "'5'", "'6'", "'7'",
"'8'", "'9'", "':'", "';'", "'<'", "'='", "'>'", "'?'",
"'@'", "'A'", "'B'", "'C'", "'D'", "'E'", "'F'", "'G'",
"'H'", "'I'", "'J'", "'K'", "'L'", "'M'", "'N'", "'O'",
"'P'", "'Q'", "'R'", "'S'", "'T'", "'U'", "'V'", "'W'",
"'X'", "'Y'", "'Z'", "'['", "'\'", "']'", "'^'", "'_'",
"'`'", "'a'", "'b'", "'c'", "'d'", "'e'", "'f'", "'g'",
"'h'", "'i'", "'j'", "'k'", "'l'", "'m'", "'n'", "'o'",
"'p'", "'q'", "'r'", "'s'", "'t'", "'u'", "'v'", "'w'",
"'x'", "'y'", "'z'", "'{'", "'|'", "'}'", "'~'", "'\\x7F'",
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0,
"(identifier)", "(number)", "(string)", "(regexp)",
"'<='", "'>='", "'=='", "'!='", "'==='", "'!=='",
"'<<'", "'>>'", "'>>>'", "'&&'", "'||'",
"'+='", "'-='", "'*='", "'/='", "'%='",
"'<<='", "'>>='", "'>>>='", "'&='", "'|='", "'^='",
"'++'", "'--'",
"'break'", "'case'", "'catch'", "'continue'", "'debugger'",
"'default'", "'delete'", "'do'", "'else'", "'false'", "'finally'", "'for'",
"'function'", "'if'", "'in'", "'instanceof'", "'new'", "'null'", "'return'",
"'switch'", "'this'", "'throw'", "'true'", "'try'", "'typeof'", "'var'",
"'void'", "'while'", "'with'",
};
const char *jsP_tokenstring(int token)
{
if (token >= 0 && token < nelem(tokenstring))
if (tokenstring[token])
return tokenstring[token];
return "<unknown>";
}
static const char *keywords[] = {
"break", "case", "catch", "continue", "debugger", "default", "delete",
"do", "else", "false", "finally", "for", "function", "if", "in",
"instanceof", "new", "null", "return", "switch", "this", "throw",
"true", "try", "typeof", "var", "void", "while", "with",
};
static inline int findword(const char *s, const char **list, int num)
{
int l = 0;
int r = num - 1;
while (l <= r) {
int m = (l + r) >> 1;
int c = strcmp(s, list[m]);
if (c < 0)
r = m - 1;
else if (c > 0)
l = m + 1;
else
return m;
}
return -1;
}
static inline int findkeyword(js_State *J, const char *s)
{
int i = findword(s, keywords, nelem(keywords));
if (i >= 0) {
J->text = keywords[i];
return TK_BREAK + i; /* first keyword + i */
}
J->text = js_intern(J, s);
return TK_IDENTIFIER;
}
static inline int iswhite(int c)
{
return c == 0x9 || c == 0xB || c == 0xC || c == 0x20 || c == 0xA0 || c == 0xFEFF;
}
static inline int isnewline(c)
{
return c == 0xA || c == 0xD || c == 0x2028 || c == 0x2029;
}
static inline int isidentifierstart(int c)
{
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '$' || c == '_' || isalpharune(c);
}
static inline int isidentifierpart(int c)
{
return (c >= '0' && c <= '9') || isidentifierstart(c);
}
static inline int isdec(int c)
{
return (c >= '0' && c <= '9');
}
static inline int ishex(int c)
{
return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
}
static inline int tohex(int c)
{
if (c >= '0' && c <= '9')
return c - '0';
if (c >= 'a' && c <= 'f')
return c - 'a' + 0xA;
if (c >= 'A' && c <= 'F')
return c - 'A' + 0xA;
return 0;
}
#define PEEK (J->lexchar)
#define NEXT() next(J, sp)
#define NEXTPEEK (NEXT(), PEEK)
#define ACCEPT(x) (PEEK == x ? (NEXT(), 1) : 0)
#define EXPECT(x) (ACCEPT(x) || (jsP_error(J, "expected '%c'", x), 0))
static void next(js_State *J, const char **sp)
{
Rune c;
(*sp) += chartorune(&c, *sp);
/* consume CR LF as one unit */
if (c == '\r' && PEEK == '\n')
(*sp)++;
if (isnewline(c)) {
J->line++;
c = '\n';
}
J->lexchar = c;
}
static void unescape(js_State *J, const char **sp)
{
if (ACCEPT('\\')) {
if (ACCEPT('u')) {
int x = 0;
if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 12; NEXT();
if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 8; NEXT();
if (!ishex(PEEK)) goto error; x |= tohex(PEEK) << 4; NEXT();
if (!ishex(PEEK)) goto error; x |= tohex(PEEK);
J->lexchar = x;
return;
}
error:
jsP_error(J, "unexpected escape sequence");
}
}
static void textinit(js_State *J)
{
if (!J->buf.text) {
J->buf.cap = 4096;
J->buf.text = malloc(J->buf.cap);
}
J->buf.len = 0;
}
static inline void textpush(js_State *J, Rune c)
{
int n = runelen(c);
if (J->buf.len + n > J->buf.cap) {
J->buf.cap = J->buf.cap * 2;
J->buf.text = realloc(J->buf.text, J->buf.cap);
}
J->buf.len += runetochar(J->buf.text + J->buf.len, &c);
}
static inline char *textend(js_State *J)
{
textpush(J, 0);
return J->buf.text;
}
static inline void lexlinecomment(js_State *J, const char **sp)
{
while (PEEK && !isnewline(PEEK))
NEXT();
}
static inline int lexcomment(js_State *J, const char **sp)
{
/* already consumed initial '/' '*' sequence */
while (PEEK != 0) {
if (ACCEPT('*')) {
while (ACCEPT('*'))
NEXT();
if (ACCEPT('/'))
return 0;
}
NEXT();
}
return -1;
}
static inline double lexhex(js_State *J, const char **sp)
{
double n = 0;
if (!ishex(PEEK))
return jsP_error(J, "malformed hexadecimal number");
while (ishex(PEEK)) {
n = n * 16 + tohex(PEEK);
NEXT();
}
return n;
}
static inline double lexinteger(js_State *J, const char **sp)
{
double n = 0;
if (!isdec(PEEK))
return jsP_error(J, "malformed number");
while (isdec(PEEK)) {
n = n * 10 + (PEEK - '0');
NEXT();
}
return n;
}
static inline double lexfraction(js_State *J, const char **sp)
{
double n = 0;
double d = 1;
while (isdec(PEEK)) {
n = n * 10 + (PEEK - '0');
d = d * 10;
NEXT();
}
return n / d;
}
static inline double lexexponent(js_State *J, const char **sp)
{
double sign;
if (ACCEPT('e') || ACCEPT('E')) {
if (ACCEPT('-')) sign = -1;
else if (ACCEPT('+')) sign = 1;
else sign = 1;
return sign * lexinteger(J, sp);
}
return 0;
}
static inline int lexnumber(js_State *J, const char **sp)
{
double n;
if (ACCEPT('0')) {
if (ACCEPT('x') || ACCEPT('X')) {
J->number = lexhex(J, sp);
return TK_NUMBER;
}
if (isdec(PEEK))
return jsP_error(J, "number with leading zero");
n = 0;
if (ACCEPT('.'))
n += lexfraction(J, sp);
n *= pow(10, lexexponent(J, sp));
} else if (ACCEPT('.')) {
if (!isdec(PEEK))
return '.';
n = lexfraction(J, sp);
n *= pow(10, lexexponent(J, sp));
} else {
n = lexinteger(J, sp);
if (ACCEPT('.'))
n += lexfraction(J, sp);
n *= pow(10, lexexponent(J, sp));
}
if (isidentifierstart(PEEK))
return jsP_error(J, "number with letter suffix");
J->number = n;
return TK_NUMBER;
}
static inline int lexescape(js_State *J, const char **sp)
{
int x = 0;
/* already consumed '\' */
if (isnewline(PEEK)) {
NEXT();
return 0;
}
switch (PEEK) {
case 'u':
NEXT();
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 12; NEXT(); }
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 8; NEXT(); }
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 4; NEXT(); }
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK); NEXT(); }
textpush(J, x);
break;
case 'x':
NEXT();
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK) << 4; NEXT(); }
if (!ishex(PEEK)) return 1; else { x |= tohex(PEEK); NEXT(); }
textpush(J, x);
break;
case '0': textpush(J, 0); NEXT(); break;
case '\\': textpush(J, '\\'); NEXT(); break;
case '\'': textpush(J, '\''); NEXT(); break;
case '"': textpush(J, '"'); NEXT(); break;
case 'b': textpush(J, '\b'); NEXT(); break;
case 'f': textpush(J, '\f'); NEXT(); break;
case 'n': textpush(J, '\n'); NEXT(); break;
case 'r': textpush(J, '\r'); NEXT(); break;
case 't': textpush(J, '\t'); NEXT(); break;
case 'v': textpush(J, '\v'); NEXT(); break;
default: textpush(J, PEEK); NEXT(); break;
}
return 0;
}
static inline int lexstring(js_State *J, const char **sp)
{
const char *s;
int q = PEEK;
NEXT();
textinit(J);
while (PEEK != q) {
if (PEEK == 0 || isnewline(PEEK))
return jsP_error(J, "string not terminated");
if (ACCEPT('\\')) {
if (lexescape(J, sp))
return jsP_error(J, "malformed escape sequence");
} else {
textpush(J, PEEK);
NEXT();
}
}
EXPECT(q);
s = textend(J);
J->text = js_intern(J, s);
return TK_STRING;
}
/* the ugliest language wart ever... */
static int isregexpcontext(int last)
{
switch (last) {
case ']':
case ')':
case '}':
case TK_IDENTIFIER:
case TK_NUMBER:
case TK_STRING:
case TK_FALSE:
case TK_NULL:
case TK_THIS:
case TK_TRUE:
return 0;
default:
return 1;
}
}
static int lexregexp(js_State *J, const char **sp)
{
const char *s;
int g, m, i;
int c;
/* already consumed initial '/' */
textinit(J);
/* regexp body */
while (PEEK != '/') {
if (PEEK == 0 || isnewline(PEEK)) {
return jsP_error(J, "regular expression not terminated");
} else if (ACCEPT('\\')) {
textpush(J, '\\');
if (PEEK == 0 || isnewline(PEEK))
return jsP_error(J, "regular expression not terminated");
textpush(J, PEEK);
NEXT();
} else {
textpush(J, PEEK);
NEXT();
}
}
EXPECT('/');
s = textend(J);
/* regexp flags */
g = i = m = 0;
c = PEEK;
while (isidentifierpart(PEEK)) {
if (ACCEPT('g')) ++g;
else if (ACCEPT('i')) ++i;
else if (ACCEPT('m')) ++m;
else return jsP_error(J, "illegal flag in regular expression: %c", PEEK);
}
if (g > 1 || i > 1 || m > 1)
return jsP_error(J, "duplicated flag in regular expression");
J->text = js_intern(J, s);
J->number = 0;
if (g) J->number += JS_REGEXP_G;
if (i) J->number += JS_REGEXP_I;
if (m) J->number += JS_REGEXP_M;
return TK_REGEXP;
}
/* simple "return [no Line Terminator here] ..." contexts */
static inline int isnlthcontext(int last)
{
switch (last) {
case TK_BREAK:
case TK_CONTINUE:
case TK_RETURN:
case TK_THROW:
return 1;
default:
return 0;
}
}
static int lex(js_State *J, const char **sp)
{
J->newline = 0;
while (1) {
J->lexline = J->line; /* save location of beginning of token */
while (iswhite(PEEK))
NEXT();
if (isnewline(PEEK)) {
NEXT();
J->newline = 1;
if (isnlthcontext(J->lasttoken))
return ';';
continue;
}
if (ACCEPT('/')) {
if (ACCEPT('/')) {
lexlinecomment(J, sp);
continue;
} else if (ACCEPT('*')) {
if (lexcomment(J, sp))
return jsP_error(J, "multi-line comment not terminated");
continue;
} else if (isregexpcontext(J->lasttoken)) {
return lexregexp(J, sp);
} else if (ACCEPT('=')) {
return TK_DIV_ASS;
} else {
return '/';
}
}
if (PEEK >= '0' && PEEK <= '9') {
return lexnumber(J, sp);
}
switch (PEEK) {
case '(': NEXT(); return '(';
case ')': NEXT(); return ')';
case ',': NEXT(); return ',';
case ':': NEXT(); return ':';
case ';': NEXT(); return ';';
case '?': NEXT(); return '?';
case '[': NEXT(); return '[';
case ']': NEXT(); return ']';
case '{': NEXT(); return '{';
case '}': NEXT(); return '}';
case '~': NEXT(); return '~';
case '\'':
case '"':
return lexstring(J, sp);
case '.':
return lexnumber(J, sp);
case '<':
NEXT();
if (ACCEPT('<')) {
if (ACCEPT('='))
return TK_SHL_ASS;
return TK_SHL;
}
if (ACCEPT('='))
return TK_LE;
return '<';
case '>':
NEXT();
if (ACCEPT('>')) {
if (ACCEPT('>')) {
if (ACCEPT('='))
return TK_USHR_ASS;
return TK_USHR;
}
if (ACCEPT('='))
return TK_SHR_ASS;
return TK_SHR;
}
if (ACCEPT('='))
return TK_GE;
return '>';
case '=':
NEXT();
if (ACCEPT('=')) {
if (ACCEPT('='))
return TK_STRICTEQ;
return TK_EQ;
}
return '=';
case '!':
NEXT();
if (ACCEPT('=')) {
if (ACCEPT('='))
return TK_STRICTNE;
return TK_NE;
}
return '!';
case '+':
NEXT();
if (ACCEPT('+'))
return TK_INC;
if (ACCEPT('='))
return TK_ADD_ASS;
return '+';
case '-':
NEXT();
if (ACCEPT('-'))
return TK_DEC;
if (ACCEPT('='))
return TK_SUB_ASS;
return '-';
case '*':
NEXT();
if (ACCEPT('='))
return TK_MUL_ASS;
return '*';
case '%':
NEXT();
if (ACCEPT('='))
return TK_MOD_ASS;
return '%';
case '&':
NEXT();
if (ACCEPT('&'))
return TK_AND;
if (ACCEPT('='))
return TK_AND_ASS;
return '&';
case '|':
NEXT();
if (ACCEPT('|'))
return TK_OR;
if (ACCEPT('='))
return TK_OR_ASS;
return '|';
case '^':
NEXT();
if (ACCEPT('='))
return TK_XOR_ASS;
return '^';
case 0:
return 0; /* EOF */
}
/* Handle \uXXXX escapes in identifiers */
unescape(J, sp);
if (isidentifierstart(PEEK)) {
textinit(J);
textpush(J, PEEK);
NEXT();
unescape(J, sp);
while (isidentifierpart(PEEK)) {
textpush(J, PEEK);
NEXT();
unescape(J, sp);
}
textend(J);
return findkeyword(J, J->buf.text);
}
if (PEEK >= 0x20 && PEEK <= 0x7E)
return jsP_error(J, "unexpected character: '%c'", PEEK);
return jsP_error(J, "unexpected character: \\u%04X", PEEK);
}
}
void jsP_initlex(js_State *J, const char *filename, const char *source)
{
J->filename = filename;
J->source = source;
J->line = 1;
J->lasttoken = 0;
next(J, &J->source); /* load first lookahead character */
}
int jsP_lex(js_State *J)
{
return J->lasttoken = lex(J, &J->source);
}