/*** $Id: llex.c,v 2.20.1.1 2007/12/27 13:02:25 roberto Exp $** Lexical Analyzer** See Copyright Notice in lua.h*/#include <ctype.h>#include <locale.h>#include <string.h>#define llex_c#define LUA_CORE#include "lua.h"#include "ldo.h"#include "llex.h"#include "lobject.h"#include "lparser.h"#include "lstate.h"#include "lstring.h"#include "ltable.h"#include "lzio.h"#define next(ls) (ls->current = zgetc(ls->z))#define currIsNewline(ls)	(ls->current == '\n' || ls->current == '\r')/* ORDER RESERVED */const char *const luaX_tokens [] = {    "and", "break", "do", "else", "elseif",    "end", "false", "for", "function", "if",    "in", "local", "nil", "not", "or", "repeat",    "return", "then", "true", "until", "while",    "..", "...", "==", ">=", "<=", "~=",    "<number>", "<name>", "<string>", "<eof>",    NULL};#define save_and_next(ls) (save(ls, ls->current), next(ls))static void save (LexState *ls, int c) {  Mbuffer *b = ls->buff;  if (b->n + 1 > b->buffsize) {    size_t newsize;    if (b->buffsize >= MAX_SIZET/2)      luaX_lexerror(ls, "lexical element too long", 0);    newsize = b->buffsize * 2;    luaZ_resizebuffer(ls->L, b, newsize);  }  b->buffer[b->n++] = cast(char, c);}void luaX_init (lua_State *L) {  int i;  for (i=0; i<NUM_RESERVED; i++) {    TString *ts = luaS_new(L, luaX_tokens[i]);    luaS_fix(ts);  /* reserved words are never collected */    lua_assert(strlen(luaX_tokens[i])+1 <= TOKEN_LEN);    ts->tsv.reserved = cast_byte(i+1);  /* reserved word */  }}#define MAXSRC          80const char *luaX_token2str (LexState *ls, int token) {  if (token < FIRST_RESERVED) {    lua_assert(token == cast(unsigned char, token));    return (iscntrl(token)) ? luaO_pushfstring(ls->L, "char(%d)", token) :                              luaO_pushfstring(ls->L, "%c", token);  }  else    return luaX_tokens[token-FIRST_RESERVED];}static const char *txtToken (LexState *ls, int token) {  switch (token) {    case TK_NAME:    case TK_STRING:    case TK_NUMBER:      save(ls, '\0');      return luaZ_buffer(ls->buff);    default:      return luaX_token2str(ls, token);  }}void luaX_lexerror (LexState *ls, const char *msg, int token) {  char buff[MAXSRC];  luaO_chunkid(buff, getstr(ls->source), MAXSRC);  msg = luaO_pushfstring(ls->L, "%s:%d: %s", buff, ls->linenumber, msg);  if (token)    luaO_pushfstring(ls->L, "%s near " LUA_QS, msg, txtToken(ls, token));  luaD_throw(ls->L, LUA_ERRSYNTAX);}void luaX_syntaxerror (LexState *ls, const char *msg) {  luaX_lexerror(ls, msg, ls->t.token);}TString *luaX_newstring (LexState *ls, const char *str, size_t l) {  lua_State *L = ls->L;  TString *ts = luaS_newlstr(L, str, l);  TValue *o = luaH_setstr(L, ls->fs->h, ts);  /* entry for `str' */  if (ttisnil(o))    setbvalue(o, 1);  /* make sure `str' will not be collected */  return ts;}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 >= MAX_INT)    luaX_syntaxerror(ls, "chunk has too many lines");}void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source) {  ls->decpoint = '.';  ls->L = L;  ls->lookahead.token = TK_EOS;  /* no look-ahead token */  ls->z = z;  ls->fs = NULL;  ls->linenumber = 1;  ls->lastline = 1;  ls->source = source;  luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER);  /* initialize buffer */  next(ls);  /* read first char */}/*** =======================================================** LEXICAL ANALYZER** =======================================================*/static int check_next (LexState *ls, const char *set) {  if (!strchr(set, ls->current))    return 0;  save_and_next(ls);  return 1;}static void buffreplace (LexState *ls, char from, char to) {  size_t n = luaZ_bufflen(ls->buff);  char *p = luaZ_buffer(ls->buff);  while (n--)    if (p[n] == from) p[n] = to;}static void trydecpoint (LexState *ls, SemInfo *seminfo) {  /* format error: try to update decimal point separator */  struct lconv *cv = localeconv();  char old = ls->decpoint;  ls->decpoint = (cv ? cv->decimal_point[0] : '.');  buffreplace(ls, old, ls->decpoint);  /* try updated decimal separator */  if (!luaO_str2d(luaZ_buffer(ls->buff), &seminfo->r)) {    /* format error with correct decimal point: no more options */    buffreplace(ls, ls->decpoint, '.');  /* undo change (for error message) */    luaX_lexerror(ls, "malformed number", TK_NUMBER);  }}/* LUA_NUMBER */static void read_numeral (LexState *ls, SemInfo *seminfo) {  lua_assert(isdigit(ls->current));  do {    save_and_next(ls);  } while (isdigit(ls->current) || ls->current == '.');  if (check_next(ls, "Ee"))  /* `E'? */    check_next(ls, "+-");  /* optional exponent sign */  while (isalnum(ls->current) || ls->current == '_')    save_and_next(ls);  save(ls, '\0');  buffreplace(ls, '.', ls->decpoint);  /* follow locale for decimal point */  if (!luaO_str2d(luaZ_buffer(ls->buff), &seminfo->r))  /* format error? */    trydecpoint(ls, seminfo); /* try to update decimal point separator */}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, SemInfo *seminfo, int sep) {  int cont = 0;  (void)(cont);  /* avoid warnings when `cont' is not used */  save_and_next(ls);  /* skip 2nd `[' */  if (currIsNewline(ls))  /* string starts with a newline? */    inclinenumber(ls);  /* skip it */  for (;;) {    switch (ls->current) {      case EOZ:        luaX_lexerror(ls, (seminfo) ? "unfinished long string" :                                   "unfinished long comment", TK_EOS);        break;  /* to avoid warnings */#if defined(LUA_COMPAT_LSTR)      case '[': {        if (skip_sep(ls) == sep) {          save_and_next(ls);  /* skip 2nd `[' */          cont++;#if LUA_COMPAT_LSTR == 1          if (sep == 0)            luaX_lexerror(ls, "nesting of [[...]] is deprecated", '[');#endif        }        break;      }#endif      case ']': {        if (skip_sep(ls) == sep) {          save_and_next(ls);  /* skip 2nd `]' */#if defined(LUA_COMPAT_LSTR) && LUA_COMPAT_LSTR == 2          cont--;          if (sep == 0 && cont >= 0) break;#endif          goto endloop;        }        break;      }      case '\n':      case '\r': {        save(ls, '\n');        inclinenumber(ls);        if (!seminfo) luaZ_resetbuffer(ls->buff);  /* avoid wasting space */        break;      }      default: {        if (seminfo) save_and_next(ls);        else next(ls);      }    }  } endloop:  if (seminfo)    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),                                     luaZ_bufflen(ls->buff) - 2*(2 + sep));}static void read_string (LexState *ls, int del, SemInfo *seminfo) {  save_and_next(ls);  while (ls->current != del) {    switch (ls->current) {      case EOZ:        luaX_lexerror(ls, "unfinished string", TK_EOS);        continue;  /* to avoid warnings */      case '\n':      case '\r':        luaX_lexerror(ls, "unfinished string", TK_STRING);        continue;  /* to avoid warnings */      case '\\': {        int c;        next(ls);  /* do not save the `\' */        switch (ls->current) {          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 '\n':  /* go through */          case '\r': save(ls, '\n'); inclinenumber(ls); continue;          case EOZ: continue;  /* will raise an error next loop */          default: {            if (!isdigit(ls->current))              save_and_next(ls);  /* handles \\, \", \', and \? */            else {  /* \xxx */              int i = 0;              c = 0;              do {                c = 10*c + (ls->current-'0');                next(ls);              } while (++i<3 && isdigit(ls->current));              if (c > UCHAR_MAX)                luaX_lexerror(ls, "escape sequence too large", TK_STRING);              save(ls, c);            }            continue;          }        }        save(ls, c);        next(ls);        continue;      }      default:        save_and_next(ls);    }  }  save_and_next(ls);  /* skip delimiter */  seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1,                                   luaZ_bufflen(ls->buff) - 2);}static int llex (LexState *ls, SemInfo *seminfo) {  luaZ_resetbuffer(ls->buff);  for (;;) {    switch (ls->current) {      case '\n':      case '\r': {        inclinenumber(ls);        continue;      }      case '-': {        next(ls);        if (ls->current != '-') return '-';        /* else is a comment */        next(ls);        if (ls->current == '[') {          int sep = skip_sep(ls);          luaZ_resetbuffer(ls->buff);  /* `skip_sep' may dirty the buffer */          if (sep >= 0) {            read_long_string(ls, NULL, sep);  /* long comment */            luaZ_resetbuffer(ls->buff);            continue;          }        }        /* else short comment */        while (!currIsNewline(ls) && ls->current != EOZ)          next(ls);        continue;      }      case '[': {        int sep = skip_sep(ls);        if (sep >= 0) {          read_long_string(ls, seminfo, sep);          return TK_STRING;        }        else if (sep == -1) return '[';        else luaX_lexerror(ls, "invalid long string delimiter", TK_STRING);      }      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 '"':      case '\'': {        read_string(ls, ls->current, seminfo);        return TK_STRING;      }      case '.': {        save_and_next(ls);        if (check_next(ls, ".")) {          if (check_next(ls, "."))            return TK_DOTS;   /* ... */          else return TK_CONCAT;   /* .. */        }        else if (!isdigit(ls->current)) return '.';        else {          read_numeral(ls, seminfo);          return TK_NUMBER;        }      }      case EOZ: {        return TK_EOS;      }      default: {        if (isspace(ls->current)) {          lua_assert(!currIsNewline(ls));          next(ls);          continue;        }        else if (isdigit(ls->current)) {          read_numeral(ls, seminfo);          return TK_NUMBER;        }        else if (isalpha(ls->current) || ls->current == '_') {          /* identifier or reserved word */          TString *ts;          do {            save_and_next(ls);          } while (isalnum(ls->current) || ls->current == '_');          ts = luaX_newstring(ls, luaZ_buffer(ls->buff),                                  luaZ_bufflen(ls->buff));          if (ts->tsv.reserved > 0)  /* reserved word? */            return ts->tsv.reserved - 1 + FIRST_RESERVED;          else {            seminfo->ts = ts;            return TK_NAME;          }        }        else {          int c = ls->current;          next(ls);          return c;  /* single-char tokens (+ - / ...) */        }      }    }  }}void luaX_next (LexState *ls) {  ls->lastline = ls->linenumber;  if (ls->lookahead.token != TK_EOS) {  /* is there a look-ahead token? */    ls->t = ls->lookahead;  /* use this one */    ls->lookahead.token = TK_EOS;  /* and discharge it */  }  else    ls->t.token = llex(ls, &ls->t.seminfo);  /* read next token */}void luaX_lookahead (LexState *ls) {  lua_assert(ls->lookahead.token == TK_EOS);  ls->lookahead.token = llex(ls, &ls->lookahead.seminfo);}