1 files changed, 578 insertions, 0 deletions

diff --git a/src/lua/llex.c b/src/lua/llex.c
new file mode 100644
index 0000000..90a7951
--- /dev/null
+++ b/src/lua/llex.c
@@ -0,0 +1,578 @@
+/*
+** $Id: llex.c $
+** Lexical Analyzer
+** See Copyright Notice in lua.h
+*/
+
+#define llex_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <locale.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "lctype.h"
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.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 */
+static const char *const luaX_tokens [] = {
+    "and", "break", "do", "else", "elseif",
+    "end", "false", "for", "function", "goto", "if",
+    "in", "local", "nil", "not", "or", "repeat",
+    "return", "then", "true", "until", "while",
+    "//", "..", "...", "==", ">=", "<=", "~=",
+    "<<", ">>", "::", "<eof>",
+    "<number>", "<integer>", "<name>", "<string>"
+};
+
+
+#define save_and_next(ls) (save(ls, ls->current), next(ls))
+
+
+static l_noret lexerror (LexState *ls, const char *msg, int token);
+
+
+static void save (LexState *ls, int c) {
+  Mbuffer *b = ls->buff;
+  if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) {
+    size_t newsize;
+    if (luaZ_sizebuffer(b) >= MAX_SIZE/2)
+      lexerror(ls, "lexical element too long", 0);
+    newsize = luaZ_sizebuffer(b) * 2;
+    luaZ_resizebuffer(ls->L, b, newsize);
+  }
+  b->buffer[luaZ_bufflen(b)++] = cast_char(c);
+}
+
+
+void luaX_init (lua_State *L) {
+  int i;
+  TString *e = luaS_newliteral(L, LUA_ENV);  /* create env name */
+  luaC_fix(L, obj2gco(e));  /* never collect this name */
+  for (i=0; i<NUM_RESERVED; i++) {
+    TString *ts = luaS_new(L, luaX_tokens[i]);
+    luaC_fix(L, obj2gco(ts));  /* reserved words are never collected */
+    ts->extra = cast_byte(i+1);  /* reserved word */
+  }
+}
+
+
+const char *luaX_token2str (LexState *ls, int token) {
+  if (token < FIRST_RESERVED) {  /* single-byte symbols? */
+    lua_assert(token == cast_uchar(token));
+    if (lisprint(token))
+      return luaO_pushfstring(ls->L, "'%c'", token);
+    else  /* control character */
+      return luaO_pushfstring(ls->L, "'<\\%d>'", token);
+  }
+  else {
+    const char *s = luaX_tokens[token - FIRST_RESERVED];
+    if (token < TK_EOS)  /* fixed format (symbols and reserved words)? */
+      return luaO_pushfstring(ls->L, "'%s'", s);
+    else  /* names, strings, and numerals */
+      return s;
+  }
+}
+
+
+static const char *txtToken (LexState *ls, int token) {
+  switch (token) {
+    case TK_NAME: case TK_STRING:
+    case TK_FLT: case TK_INT:
+      save(ls, '\0');
+      return luaO_pushfstring(ls->L, "'%s'", luaZ_buffer(ls->buff));
+    default:
+      return luaX_token2str(ls, token);
+  }
+}
+
+
+static l_noret lexerror (LexState *ls, const char *msg, int token) {
+  msg = luaG_addinfo(ls->L, msg, ls->source, ls->linenumber);
+  if (token)
+    luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token));
+  luaD_throw(ls->L, LUA_ERRSYNTAX);
+}
+
+
+l_noret luaX_syntaxerror (LexState *ls, const char *msg) {
+  lexerror(ls, msg, ls->t.token);
+}
+
+
+/*
+** creates a new string and anchors it in scanner's table so that
+** it will not be collected until the end of the compilation
+** (by that time it should be anchored somewhere)
+*/
+TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
+  lua_State *L = ls->L;
+  TValue *o;  /* entry for 'str' */
+  TString *ts = luaS_newlstr(L, str, l);  /* create new string */
+  setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
+  o = luaH_set(L, ls->h, s2v(L->top - 1));
+  if (isempty(o)) {  /* not in use yet? */
+    /* boolean value does not need GC barrier;
+       table is not a metatable, so it does not need to invalidate cache */
+    setbtvalue(o);  /* t[string] = true */
+    luaC_checkGC(L);
+  }
+  else {  /* string already present */
+    ts = keystrval(nodefromval(o));  /* re-use value previously stored */
+  }
+  L->top--;  /* remove string from stack */
+  return ts;
+}
+
+
+/*
+** increment line number and skips newline sequence (any of
+** \n, \r, \n\r, or \r\n)
+*/
+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)
+    lexerror(ls, "chunk has too many lines", 0);
+}
+
+
+void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source,
+                    int firstchar) {
+  ls->t.token = 0;
+  ls->L = L;
+  ls->current = firstchar;
+  ls->lookahead.token = TK_EOS;  /* no look-ahead token */
+  ls->z = z;
+  ls->fs = NULL;
+  ls->linenumber = 1;
+  ls->lastline = 1;
+  ls->source = source;
+  ls->envn = luaS_newliteral(L, LUA_ENV);  /* get env name */
+  luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER);  /* initialize buffer */
+}
+
+
+
+/*
+** =======================================================
+** LEXICAL ANALYZER
+** =======================================================
+*/
+
+
+static int check_next1 (LexState *ls, int c) {
+  if (ls->current == c) {
+    next(ls);
+    return 1;
+  }
+  else return 0;
+}
+
+
+/*
+** Check whether current char is in set 'set' (with two chars) and
+** saves it
+*/
+static int check_next2 (LexState *ls, const char *set) {
+  lua_assert(set[2] == '\0');
+  if (ls->current == set[0] || ls->current == set[1]) {
+    save_and_next(ls);
+    return 1;
+  }
+  else return 0;
+}
+
+
+/* LUA_NUMBER */
+/*
+** This function is quite liberal in what it accepts, as 'luaO_str2num'
+** will reject ill-formed numerals. Roughly, it accepts the following
+** pattern:
+**
+**   %d(%x|%.|([Ee][+-]?))* | 0[Xx](%x|%.|([Pp][+-]?))*
+**
+** The only tricky part is to accept [+-] only after a valid exponent
+** mark, to avoid reading '3-4' or '0xe+1' as a single number.
+**
+** The caller might have already read an initial dot.
+*/
+static int read_numeral (LexState *ls, SemInfo *seminfo) {
+  TValue obj;
+  const char *expo = "Ee";
+  int first = ls->current;
+  lua_assert(lisdigit(ls->current));
+  save_and_next(ls);
+  if (first == '0' && check_next2(ls, "xX"))  /* hexadecimal? */
+    expo = "Pp";
+  for (;;) {
+    if (check_next2(ls, expo))  /* exponent mark? */
+      check_next2(ls, "-+");  /* optional exponent sign */
+    else if (lisxdigit(ls->current) || ls->current == '.')  /* '%x|%.' */
+      save_and_next(ls);
+    else break;
+  }
+  if (lislalpha(ls->current))  /* is numeral touching a letter? */
+    save_and_next(ls);  /* force an error */
+  save(ls, '\0');
+  if (luaO_str2num(luaZ_buffer(ls->buff), &obj) == 0)  /* format error? */
+    lexerror(ls, "malformed number", TK_FLT);
+  if (ttisinteger(&obj)) {
+    seminfo->i = ivalue(&obj);
+    return TK_INT;
+  }
+  else {
+    lua_assert(ttisfloat(&obj));
+    seminfo->r = fltvalue(&obj);
+    return TK_FLT;
+  }
+}
+
+
+/*
+** reads a sequence '[=*[' or ']=*]', leaving the last bracket.
+** If sequence is well formed, return its number of '='s + 2; otherwise,
+** return 1 if there is no '='s or 0 otherwise (an unfinished '[==...').
+*/
+static size_t skip_sep (LexState *ls) {
+  size_t 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 + 2
+         : (count == 0) ? 1
+         : 0;
+}
+
+
+static void read_long_string (LexState *ls, SemInfo *seminfo, size_t sep) {
+  int line = ls->linenumber;  /* initial line (for error message) */
+  save_and_next(ls);  /* skip 2nd '[' */
+  if (currIsNewline(ls))  /* string starts with a newline? */
+    inclinenumber(ls);  /* skip it */
+  for (;;) {
+    switch (ls->current) {
+      case EOZ: {  /* error */
+        const char *what = (seminfo ? "string" : "comment");
+        const char *msg = luaO_pushfstring(ls->L,
+                     "unfinished long %s (starting at line %d)", what, line);
+        lexerror(ls, msg, TK_EOS);
+        break;  /* to avoid warnings */
+      }
+      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 (!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) + sep,
+                                     luaZ_bufflen(ls->buff) - 2 * sep);
+}
+
+
+static void esccheck (LexState *ls, int c, const char *msg) {
+  if (!c) {
+    if (ls->current != EOZ)
+      save_and_next(ls);  /* add current to buffer for error message */
+    lexerror(ls, msg, TK_STRING);
+  }
+}
+
+
+static int gethexa (LexState *ls) {
+  save_and_next(ls);
+  esccheck (ls, lisxdigit(ls->current), "hexadecimal digit expected");
+  return luaO_hexavalue(ls->current);
+}
+
+
+static int readhexaesc (LexState *ls) {
+  int r = gethexa(ls);
+  r = (r << 4) + gethexa(ls);
+  luaZ_buffremove(ls->buff, 2);  /* remove saved chars from buffer */
+  return r;
+}
+
+
+static unsigned long readutf8esc (LexState *ls) {
+  unsigned long r;
+  int i = 4;  /* chars to be removed: '\', 'u', '{', and first digit */
+  save_and_next(ls);  /* skip 'u' */
+  esccheck(ls, ls->current == '{', "missing '{'");
+  r = gethexa(ls);  /* must have at least one digit */
+  while (cast_void(save_and_next(ls)), lisxdigit(ls->current)) {
+    i++;
+    esccheck(ls, r <= (0x7FFFFFFFu >> 4), "UTF-8 value too large");
+    r = (r << 4) + luaO_hexavalue(ls->current);
+  }
+  esccheck(ls, ls->current == '}', "missing '}'");
+  next(ls);  /* skip '}' */
+  luaZ_buffremove(ls->buff, i);  /* remove saved chars from buffer */
+  return r;
+}
+
+
+static void utf8esc (LexState *ls) {
+  char buff[UTF8BUFFSZ];
+  int n = luaO_utf8esc(buff, readutf8esc(ls));
+  for (; n > 0; n--)  /* add 'buff' to string */
+    save(ls, buff[UTF8BUFFSZ - n]);
+}
+
+
+static int readdecesc (LexState *ls) {
+  int i;
+  int r = 0;  /* result accumulator */
+  for (i = 0; i < 3 && lisdigit(ls->current); i++) {  /* read up to 3 digits */
+    r = 10*r + ls->current - '0';
+    save_and_next(ls);
+  }
+  esccheck(ls, r <= UCHAR_MAX, "decimal escape too large");
+  luaZ_buffremove(ls->buff, i);  /* remove read digits from buffer */
+  return r;
+}
+
+
+static void read_string (LexState *ls, int del, SemInfo *seminfo) {
+  save_and_next(ls);  /* keep delimiter (for error messages) */
+  while (ls->current != del) {
+    switch (ls->current) {
+      case EOZ:
+        lexerror(ls, "unfinished string", TK_EOS);
+        break;  /* to avoid warnings */
+      case '\n':
+      case '\r':
+        lexerror(ls, "unfinished string", TK_STRING);
+        break;  /* to avoid warnings */
+      case '\\': {  /* escape sequences */
+        int c;  /* final character to be saved */
+        save_and_next(ls);  /* keep '\\' for error messages */
+        switch (ls->current) {
+          case 'a': c = '\a'; goto read_save;
+          case 'b': c = '\b'; goto read_save;
+          case 'f': c = '\f'; goto read_save;
+          case 'n': c = '\n'; goto read_save;
+          case 'r': c = '\r'; goto read_save;
+          case 't': c = '\t'; goto read_save;
+          case 'v': c = '\v'; goto read_save;
+          case 'x': c = readhexaesc(ls); goto read_save;
+          case 'u': utf8esc(ls);  goto no_save;
+          case '\n': case '\r':
+            inclinenumber(ls); c = '\n'; goto only_save;
+          case '\\': case '\"': case '\'':
+            c = ls->current; goto read_save;
+          case EOZ: goto no_save;  /* will raise an error next loop */
+          case 'z': {  /* zap following span of spaces */
+            luaZ_buffremove(ls->buff, 1);  /* remove '\\' */
+            next(ls);  /* skip the 'z' */
+            while (lisspace(ls->current)) {
+              if (currIsNewline(ls)) inclinenumber(ls);
+              else next(ls);
+            }
+            goto no_save;
+          }
+          default: {
+            esccheck(ls, lisdigit(ls->current), "invalid escape sequence");
+            c = readdecesc(ls);  /* digital escape '\ddd' */
+            goto only_save;
+          }
+        }
+       read_save:
+         next(ls);
+         /* go through */
+       only_save:
+         luaZ_buffremove(ls->buff, 1);  /* remove '\\' */
+         save(ls, c);
+         /* go through */
+       no_save: break;
+      }
+      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': {  /* line breaks */
+        inclinenumber(ls);
+        break;
+      }
+      case ' ': case '\f': case '\t': case '\v': {  /* spaces */
+        next(ls);
+        break;
+      }
+      case '-': {  /* '-' or '--' (comment) */
+        next(ls);
+        if (ls->current != '-') return '-';
+        /* else is a comment */
+        next(ls);
+        if (ls->current == '[') {  /* long comment? */
+          size_t sep = skip_sep(ls);
+          luaZ_resetbuffer(ls->buff);  /* 'skip_sep' may dirty the buffer */
+          if (sep >= 2) {
+            read_long_string(ls, NULL, sep);  /* skip long comment */
+            luaZ_resetbuffer(ls->buff);  /* previous call may dirty the buff. */
+            break;
+          }
+        }
+        /* else short comment */
+        while (!currIsNewline(ls) && ls->current != EOZ)
+          next(ls);  /* skip until end of line (or end of file) */
+        break;
+      }
+      case '[': {  /* long string or simply '[' */
+        size_t sep = skip_sep(ls);
+        if (sep >= 2) {
+          read_long_string(ls, seminfo, sep);
+          return TK_STRING;
+        }
+        else if (sep == 0)  /* '[=...' missing second bracket? */
+          lexerror(ls, "invalid long string delimiter", TK_STRING);
+        return '[';
+      }
+      case '=': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_EQ;
+        else return '=';
+      }
+      case '<': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_LE;
+        else if (check_next1(ls, '<')) return TK_SHL;
+        else return '<';
+      }
+      case '>': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_GE;
+        else if (check_next1(ls, '>')) return TK_SHR;
+        else return '>';
+      }
+      case '/': {
+        next(ls);
+        if (check_next1(ls, '/')) return TK_IDIV;
+        else return '/';
+      }
+      case '~': {
+        next(ls);
+        if (check_next1(ls, '=')) return TK_NE;
+        else return '~';
+      }
+      case ':': {
+        next(ls);
+        if (check_next1(ls, ':')) return TK_DBCOLON;
+        else return ':';
+      }
+      case '"': case '\'': {  /* short literal strings */
+        read_string(ls, ls->current, seminfo);
+        return TK_STRING;
+      }
+      case '.': {  /* '.', '..', '...', or number */
+        save_and_next(ls);
+        if (check_next1(ls, '.')) {
+          if (check_next1(ls, '.'))
+            return TK_DOTS;   /* '...' */
+          else return TK_CONCAT;   /* '..' */
+        }
+        else if (!lisdigit(ls->current)) return '.';
+        else return read_numeral(ls, seminfo);
+      }
+      case '0': case '1': case '2': case '3': case '4':
+      case '5': case '6': case '7': case '8': case '9': {
+        return read_numeral(ls, seminfo);
+      }
+      case EOZ: {
+        return TK_EOS;
+      }
+      default: {
+        if (lislalpha(ls->current)) {  /* identifier or reserved word? */
+          TString *ts;
+          do {
+            save_and_next(ls);
+          } while (lislalnum(ls->current));
+          ts = luaX_newstring(ls, luaZ_buffer(ls->buff),
+                                  luaZ_bufflen(ls->buff));
+          seminfo->ts = ts;
+          if (isreserved(ts))  /* reserved word? */
+            return ts->extra - 1 + FIRST_RESERVED;
+          else {
+            return TK_NAME;
+          }
+        }
+        else {  /* single-char tokens (+ - / ...) */
+          int c = ls->current;
+          next(ls);
+          return c;
+        }
+      }
+    }
+  }
+}
+
+
+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 */
+}
+
+
+int luaX_lookahead (LexState *ls) {
+  lua_assert(ls->lookahead.token == TK_EOS);
+  ls->lookahead.token = llex(ls, &ls->lookahead.seminfo);
+  return ls->lookahead.token;
+}
+