axmol/scripting/lua/luajit/LuaJIT-2.0.1/src/lj_lex.c

482 lines
12 KiB
C

/*
** Lexical analyzer.
** Copyright (C) 2005-2013 Mike Pall. See Copyright Notice in luajit.h
**
** Major portions taken verbatim or adapted from the Lua interpreter.
** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
*/
#define lj_lex_c
#define LUA_CORE
#include "lj_obj.h"
#include "lj_gc.h"
#include "lj_err.h"
#include "lj_str.h"
#if LJ_HASFFI
#include "lj_tab.h"
#include "lj_ctype.h"
#include "lj_cdata.h"
#include "lualib.h"
#endif
#include "lj_state.h"
#include "lj_lex.h"
#include "lj_parse.h"
#include "lj_char.h"
#include "lj_strscan.h"
/* Lua lexer token names. */
static const char *const tokennames[] = {
#define TKSTR1(name) #name,
#define TKSTR2(name, sym) #sym,
TKDEF(TKSTR1, TKSTR2)
#undef TKSTR1
#undef TKSTR2
NULL
};
/* -- Buffer handling ----------------------------------------------------- */
#define char2int(c) ((int)(uint8_t)(c))
#define next(ls) \
(ls->current = (ls->n--) > 0 ? char2int(*ls->p++) : fillbuf(ls))
#define save_and_next(ls) (save(ls, ls->current), next(ls))
#define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r')
#define END_OF_STREAM (-1)
static int fillbuf(LexState *ls)
{
size_t sz;
const char *buf = ls->rfunc(ls->L, ls->rdata, &sz);
if (buf == NULL || sz == 0) return END_OF_STREAM;
ls->n = (MSize)sz - 1;
ls->p = buf;
return char2int(*(ls->p++));
}
static LJ_NOINLINE void save_grow(LexState *ls, int c)
{
MSize newsize;
if (ls->sb.sz >= LJ_MAX_STR/2)
lj_lex_error(ls, 0, LJ_ERR_XELEM);
newsize = ls->sb.sz * 2;
lj_str_resizebuf(ls->L, &ls->sb, newsize);
ls->sb.buf[ls->sb.n++] = (char)c;
}
static LJ_AINLINE void save(LexState *ls, int c)
{
if (LJ_UNLIKELY(ls->sb.n + 1 > ls->sb.sz))
save_grow(ls, c);
else
ls->sb.buf[ls->sb.n++] = (char)c;
}
static void inclinenumber(LexState *ls)
{
int old = ls->current;
lua_assert(currIsNewline(ls));
next(ls); /* skip `\n' or `\r' */
if (currIsNewline(ls) && ls->current != old)
next(ls); /* skip `\n\r' or `\r\n' */
if (++ls->linenumber >= LJ_MAX_LINE)
lj_lex_error(ls, ls->token, LJ_ERR_XLINES);
}
/* -- Scanner for terminals ----------------------------------------------- */
/* Parse a number literal. */
static void lex_number(LexState *ls, TValue *tv)
{
StrScanFmt fmt;
int c, xp = 'e';
lua_assert(lj_char_isdigit(ls->current));
if ((c = ls->current) == '0') {
save_and_next(ls);
if ((ls->current | 0x20) == 'x') xp = 'p';
}
while (lj_char_isident(ls->current) || ls->current == '.' ||
((ls->current == '-' || ls->current == '+') && (c | 0x20) == xp)) {
c = ls->current;
save_and_next(ls);
}
save(ls, '\0');
fmt = lj_strscan_scan((const uint8_t *)ls->sb.buf, tv,
(LJ_DUALNUM ? STRSCAN_OPT_TOINT : STRSCAN_OPT_TONUM) |
(LJ_HASFFI ? (STRSCAN_OPT_LL|STRSCAN_OPT_IMAG) : 0));
if (LJ_DUALNUM && fmt == STRSCAN_INT) {
setitype(tv, LJ_TISNUM);
} else if (fmt == STRSCAN_NUM) {
/* Already in correct format. */
#if LJ_HASFFI
} else if (fmt != STRSCAN_ERROR) {
lua_State *L = ls->L;
GCcdata *cd;
lua_assert(fmt == STRSCAN_I64 || fmt == STRSCAN_U64 || fmt == STRSCAN_IMAG);
if (!ctype_ctsG(G(L))) {
ptrdiff_t oldtop = savestack(L, L->top);
luaopen_ffi(L); /* Load FFI library on-demand. */
L->top = restorestack(L, oldtop);
}
if (fmt == STRSCAN_IMAG) {
cd = lj_cdata_new_(L, CTID_COMPLEX_DOUBLE, 2*sizeof(double));
((double *)cdataptr(cd))[0] = 0;
((double *)cdataptr(cd))[1] = numV(tv);
} else {
cd = lj_cdata_new_(L, fmt==STRSCAN_I64 ? CTID_INT64 : CTID_UINT64, 8);
*(uint64_t *)cdataptr(cd) = tv->u64;
}
lj_parse_keepcdata(ls, tv, cd);
#endif
} else {
lua_assert(fmt == STRSCAN_ERROR);
lj_lex_error(ls, TK_number, LJ_ERR_XNUMBER);
}
}
static int skip_sep(LexState *ls)
{
int count = 0;
int s = ls->current;
lua_assert(s == '[' || s == ']');
save_and_next(ls);
while (ls->current == '=') {
save_and_next(ls);
count++;
}
return (ls->current == s) ? count : (-count) - 1;
}
static void read_long_string(LexState *ls, TValue *tv, int sep)
{
save_and_next(ls); /* skip 2nd `[' */
if (currIsNewline(ls)) /* string starts with a newline? */
inclinenumber(ls); /* skip it */
for (;;) {
switch (ls->current) {
case END_OF_STREAM:
lj_lex_error(ls, TK_eof, tv ? LJ_ERR_XLSTR : LJ_ERR_XLCOM);
break;
case ']':
if (skip_sep(ls) == sep) {
save_and_next(ls); /* skip 2nd `]' */
goto endloop;
}
break;
case '\n':
case '\r':
save(ls, '\n');
inclinenumber(ls);
if (!tv) lj_str_resetbuf(&ls->sb); /* avoid wasting space */
break;
default:
if (tv) save_and_next(ls);
else next(ls);
break;
}
} endloop:
if (tv) {
GCstr *str = lj_parse_keepstr(ls, ls->sb.buf + (2 + (MSize)sep),
ls->sb.n - 2*(2 + (MSize)sep));
setstrV(ls->L, tv, str);
}
}
static void read_string(LexState *ls, int delim, TValue *tv)
{
save_and_next(ls);
while (ls->current != delim) {
switch (ls->current) {
case END_OF_STREAM:
lj_lex_error(ls, TK_eof, LJ_ERR_XSTR);
continue;
case '\n':
case '\r':
lj_lex_error(ls, TK_string, LJ_ERR_XSTR);
continue;
case '\\': {
int c = next(ls); /* Skip the '\\'. */
switch (c) {
case 'a': c = '\a'; break;
case 'b': c = '\b'; 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 'x': /* Hexadecimal escape '\xXX'. */
c = (next(ls) & 15u) << 4;
if (!lj_char_isdigit(ls->current)) {
if (!lj_char_isxdigit(ls->current)) goto err_xesc;
c += 9 << 4;
}
c += (next(ls) & 15u);
if (!lj_char_isdigit(ls->current)) {
if (!lj_char_isxdigit(ls->current)) goto err_xesc;
c += 9;
}
break;
case 'z': /* Skip whitespace. */
next(ls);
while (lj_char_isspace(ls->current))
if (currIsNewline(ls)) inclinenumber(ls); else next(ls);
continue;
case '\n': case '\r': save(ls, '\n'); inclinenumber(ls); continue;
case '\\': case '\"': case '\'': break;
case END_OF_STREAM: continue;
default:
if (!lj_char_isdigit(c))
goto err_xesc;
c -= '0'; /* Decimal escape '\ddd'. */
if (lj_char_isdigit(next(ls))) {
c = c*10 + (ls->current - '0');
if (lj_char_isdigit(next(ls))) {
c = c*10 + (ls->current - '0');
if (c > 255) {
err_xesc:
lj_lex_error(ls, TK_string, LJ_ERR_XESC);
}
next(ls);
}
}
save(ls, c);
continue;
}
save(ls, c);
next(ls);
continue;
}
default:
save_and_next(ls);
break;
}
}
save_and_next(ls); /* skip delimiter */
setstrV(ls->L, tv, lj_parse_keepstr(ls, ls->sb.buf + 1, ls->sb.n - 2));
}
/* -- Main lexical scanner ------------------------------------------------ */
static int llex(LexState *ls, TValue *tv)
{
lj_str_resetbuf(&ls->sb);
for (;;) {
if (lj_char_isident(ls->current)) {
GCstr *s;
if (lj_char_isdigit(ls->current)) { /* Numeric literal. */
lex_number(ls, tv);
return TK_number;
}
/* Identifier or reserved word. */
do {
save_and_next(ls);
} while (lj_char_isident(ls->current));
s = lj_parse_keepstr(ls, ls->sb.buf, ls->sb.n);
setstrV(ls->L, tv, s);
if (s->reserved > 0) /* Reserved word? */
return TK_OFS + s->reserved;
return TK_name;
}
switch (ls->current) {
case '\n':
case '\r':
inclinenumber(ls);
continue;
case ' ':
case '\t':
case '\v':
case '\f':
next(ls);
continue;
case '-':
next(ls);
if (ls->current != '-') return '-';
/* else is a comment */
next(ls);
if (ls->current == '[') {
int sep = skip_sep(ls);
lj_str_resetbuf(&ls->sb); /* `skip_sep' may dirty the buffer */
if (sep >= 0) {
read_long_string(ls, NULL, sep); /* long comment */
lj_str_resetbuf(&ls->sb);
continue;
}
}
/* else short comment */
while (!currIsNewline(ls) && ls->current != END_OF_STREAM)
next(ls);
continue;
case '[': {
int sep = skip_sep(ls);
if (sep >= 0) {
read_long_string(ls, tv, sep);
return TK_string;
} else if (sep == -1) {
return '[';
} else {
lj_lex_error(ls, TK_string, LJ_ERR_XLDELIM);
continue;
}
}
case '=':
next(ls);
if (ls->current != '=') return '='; else { next(ls); return TK_eq; }
case '<':
next(ls);
if (ls->current != '=') return '<'; else { next(ls); return TK_le; }
case '>':
next(ls);
if (ls->current != '=') return '>'; else { next(ls); return TK_ge; }
case '~':
next(ls);
if (ls->current != '=') return '~'; else { next(ls); return TK_ne; }
case ':':
next(ls);
if (ls->current != ':') return ':'; else { next(ls); return TK_label; }
case '"':
case '\'':
read_string(ls, ls->current, tv);
return TK_string;
case '.':
save_and_next(ls);
if (ls->current == '.') {
next(ls);
if (ls->current == '.') {
next(ls);
return TK_dots; /* ... */
}
return TK_concat; /* .. */
} else if (!lj_char_isdigit(ls->current)) {
return '.';
} else {
lex_number(ls, tv);
return TK_number;
}
case END_OF_STREAM:
return TK_eof;
default: {
int c = ls->current;
next(ls);
return c; /* Single-char tokens (+ - / ...). */
}
}
}
}
/* -- Lexer API ----------------------------------------------------------- */
/* Setup lexer state. */
int lj_lex_setup(lua_State *L, LexState *ls)
{
int header = 0;
ls->L = L;
ls->fs = NULL;
ls->n = 0;
ls->p = NULL;
ls->vstack = NULL;
ls->sizevstack = 0;
ls->vtop = 0;
ls->bcstack = NULL;
ls->sizebcstack = 0;
ls->lookahead = TK_eof; /* No look-ahead token. */
ls->linenumber = 1;
ls->lastline = 1;
lj_str_resizebuf(ls->L, &ls->sb, LJ_MIN_SBUF);
next(ls); /* Read-ahead first char. */
if (ls->current == 0xef && ls->n >= 2 && char2int(ls->p[0]) == 0xbb &&
char2int(ls->p[1]) == 0xbf) { /* Skip UTF-8 BOM (if buffered). */
ls->n -= 2;
ls->p += 2;
next(ls);
header = 1;
}
if (ls->current == '#') { /* Skip POSIX #! header line. */
do {
next(ls);
if (ls->current == END_OF_STREAM) return 0;
} while (!currIsNewline(ls));
inclinenumber(ls);
header = 1;
}
if (ls->current == LUA_SIGNATURE[0]) { /* Bytecode dump. */
if (header) {
/*
** Loading bytecode with an extra header is disabled for security
** reasons. This may circumvent the usual check for bytecode vs.
** Lua code by looking at the first char. Since this is a potential
** security violation no attempt is made to echo the chunkname either.
*/
setstrV(L, L->top++, lj_err_str(L, LJ_ERR_BCBAD));
lj_err_throw(L, LUA_ERRSYNTAX);
}
return 1;
}
return 0;
}
/* Cleanup lexer state. */
void lj_lex_cleanup(lua_State *L, LexState *ls)
{
global_State *g = G(L);
lj_mem_freevec(g, ls->bcstack, ls->sizebcstack, BCInsLine);
lj_mem_freevec(g, ls->vstack, ls->sizevstack, VarInfo);
lj_str_freebuf(g, &ls->sb);
}
void lj_lex_next(LexState *ls)
{
ls->lastline = ls->linenumber;
if (LJ_LIKELY(ls->lookahead == TK_eof)) { /* No lookahead token? */
ls->token = llex(ls, &ls->tokenval); /* Get next token. */
} else { /* Otherwise return lookahead token. */
ls->token = ls->lookahead;
ls->lookahead = TK_eof;
ls->tokenval = ls->lookaheadval;
}
}
LexToken lj_lex_lookahead(LexState *ls)
{
lua_assert(ls->lookahead == TK_eof);
ls->lookahead = llex(ls, &ls->lookaheadval);
return ls->lookahead;
}
const char *lj_lex_token2str(LexState *ls, LexToken token)
{
if (token > TK_OFS)
return tokennames[token-TK_OFS-1];
else if (!lj_char_iscntrl(token))
return lj_str_pushf(ls->L, "%c", token);
else
return lj_str_pushf(ls->L, "char(%d)", token);
}
void lj_lex_error(LexState *ls, LexToken token, ErrMsg em, ...)
{
const char *tok;
va_list argp;
if (token == 0) {
tok = NULL;
} else if (token == TK_name || token == TK_string || token == TK_number) {
save(ls, '\0');
tok = ls->sb.buf;
} else {
tok = lj_lex_token2str(ls, token);
}
va_start(argp, em);
lj_err_lex(ls->L, ls->chunkname, tok, ls->linenumber, em, argp);
va_end(argp);
}
void lj_lex_init(lua_State *L)
{
uint32_t i;
for (i = 0; i < TK_RESERVED; i++) {
GCstr *s = lj_str_newz(L, tokennames[i]);
fixstring(s); /* Reserved words are never collected. */
s->reserved = (uint8_t)(i+1);
}
}