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- /*
- ** $Id: llex.c,v 1.58 2000/05/08 19:32:53 roberto Exp roberto $
- ** Lexical Analyzer
- ** See Copyright Notice in lua.h
- */
- #include <ctype.h>
- #include <stdio.h>
- #include <string.h>
- #define LUA_REENTRANT
- #include "lauxlib.h"
- #include "llex.h"
- #include "lmem.h"
- #include "lobject.h"
- #include "lparser.h"
- #include "lstate.h"
- #include "lstring.h"
- #include "ltable.h"
- #include "luadebug.h"
- #include "lzio.h"
- #define next(LS) (LS->current = zgetc(LS->z))
- #define save(L, c) luaL_addchar(L, c)
- #define save_and_next(L, LS) (save(L, LS->current), next(LS))
- /* ORDER RESERVED */
- static const char *const token2string [] = {
- "and", "break", "do", "else", "elseif", "end", "for",
- "function", "if", "local", "nil", "not", "or", "repeat", "return", "then",
- "until", "while", "", "..", "...", "==", ">=", "<=", "~=", "", "", "<eof>"};
- void luaX_init (lua_State *L) {
- int i;
- for (i=0; i<NUM_RESERVED; i++) {
- TString *ts = luaS_new(L, token2string[i]);
- ts->marked = (unsigned char)(RESERVEDMARK+i); /* reserved word */
- }
- }
- #define MAXSRC 80
- void luaX_checklimit (LexState *ls, int val, int limit, const char *msg) {
- if (val > limit) {
- char buff[100];
- sprintf(buff, "too many %.50s (limit=%d)", msg, limit);
- luaX_error(ls, buff, ls->token);
- }
- }
- void luaX_syntaxerror (LexState *ls, const char *s, const char *token) {
- char buff[MAXSRC];
- luaL_chunkid(buff, zname(ls->z), sizeof(buff));
- luaL_verror(ls->L, "%.100s;\n last token read: `%.50s' at line %d in %.80s",
- s, token, ls->linenumber, buff);
- }
- void luaX_error (LexState *ls, const char *s, int token) {
- char buff[TOKEN_LEN];
- luaX_token2str(token, buff);
- if (buff[0] == '\0') {
- save(ls->L, '\0');
- luaX_syntaxerror(ls, s, luaL_buffer(ls->L));
- }
- else
- luaX_syntaxerror(ls, s, buff);
- }
- void luaX_token2str (int token, char *s) {
- if (token < 256) {
- s[0] = (char)token;
- s[1] = '\0';
- }
- else
- strcpy(s, token2string[token-FIRST_RESERVED]);
- }
- static void luaX_invalidchar (LexState *ls, int c) {
- char buff[8];
- sprintf(buff, "0x%02X", c);
- luaX_syntaxerror(ls, "invalid control char", buff);
- }
- static void firstline (LexState *LS)
- {
- int c = zgetc(LS->z);
- if (c == '#')
- while ((c=zgetc(LS->z)) != '\n' && c != EOZ) /* skip first line */;
- zungetc(LS->z);
- }
- void luaX_setinput (lua_State *L, LexState *LS, ZIO *z) {
- LS->L = L;
- LS->current = '\n';
- LS->linenumber = 0;
- LS->iflevel = 0;
- LS->ifstate[0].skip = 0;
- LS->ifstate[0].elsepart = 1; /* to avoid a free $else */
- LS->z = z;
- LS->fs = NULL;
- firstline(LS);
- luaL_resetbuffer(L);
- }
- /*
- ** =======================================================
- ** PRAGMAS
- ** =======================================================
- */
- static void skipspace (LexState *LS) {
- while (LS->current == ' ' || LS->current == '\t' || LS->current == '\r')
- next(LS);
- }
- static int globaldefined (lua_State *L, const char *name) {
- const TObject *value = luaH_getglobal(L, name);
- return ttype(value) != TAG_NIL;
- }
- static int checkcond (lua_State *L, LexState *LS, const char *buff) {
- static const char *const opts[] = {"nil", "1", NULL};
- int i = luaL_findstring(buff, opts);
- if (i >= 0) return i;
- else if (isalpha((unsigned char)buff[0]) || buff[0] == '_')
- return globaldefined(L, buff);
- else {
- luaX_syntaxerror(LS, "invalid $if condition", buff);
- return 0; /* to avoid warnings */
- }
- }
- static void readname (LexState *LS, char *buff) {
- int i = 0;
- skipspace(LS);
- while (isalnum(LS->current) || LS->current == '_') {
- if (i >= PRAGMASIZE) {
- buff[PRAGMASIZE] = 0;
- luaX_syntaxerror(LS, "pragma too long", buff);
- }
- buff[i++] = (char)LS->current;
- next(LS);
- }
- buff[i] = 0;
- }
- static void inclinenumber (lua_State *L, LexState *LS);
- static void ifskip (lua_State *L, LexState *LS) {
- while (LS->ifstate[LS->iflevel].skip) {
- if (LS->current == '\n')
- inclinenumber(L, LS);
- else if (LS->current == EOZ)
- luaX_error(LS, "input ends inside a $if", TK_EOS);
- else next(LS);
- }
- }
- static void inclinenumber (lua_State *L, LexState *LS) {
- static const char *const pragmas [] =
- {"debug", "nodebug", "endinput", "end", "ifnot", "if", "else", NULL};
- next(LS); /* skip '\n' */
- ++LS->linenumber;
- luaX_checklimit(LS, LS->linenumber, MAX_INT, "lines in a chunk");
- if (LS->current == '$') { /* is a pragma? */
- char buff[PRAGMASIZE+1];
- int ifnot = 0;
- int skip = LS->ifstate[LS->iflevel].skip;
- next(LS); /* skip $ */
- readname(LS, buff);
- switch (luaL_findstring(buff, pragmas)) {
- case 0: /* debug */
- if (!skip) L->debug = 1;
- break;
- case 1: /* nodebug */
- if (!skip) L->debug = 0;
- break;
- case 2: /* endinput */
- if (!skip) {
- LS->current = EOZ;
- LS->iflevel = 0; /* to allow $endinput inside a $if */
- }
- break;
- case 3: /* end */
- if (LS->iflevel-- == 0)
- luaX_syntaxerror(LS, "unmatched $end", "$end");
- break;
- case 4: /* ifnot */
- ifnot = 1;
- /* go through */
- case 5: /* if */
- if (LS->iflevel == MAX_IFS-1)
- luaX_syntaxerror(LS, "too many nested $ifs", "$if");
- readname(LS, buff);
- LS->iflevel++;
- LS->ifstate[LS->iflevel].elsepart = 0;
- LS->ifstate[LS->iflevel].condition = checkcond(L, LS, buff) ? !ifnot : ifnot;
- LS->ifstate[LS->iflevel].skip = skip || !LS->ifstate[LS->iflevel].condition;
- break;
- case 6: /* else */
- if (LS->ifstate[LS->iflevel].elsepart)
- luaX_syntaxerror(LS, "unmatched $else", "$else");
- LS->ifstate[LS->iflevel].elsepart = 1;
- LS->ifstate[LS->iflevel].skip = LS->ifstate[LS->iflevel-1].skip ||
- LS->ifstate[LS->iflevel].condition;
- break;
- default:
- luaX_syntaxerror(LS, "unknown pragma", buff);
- }
- skipspace(LS);
- if (LS->current == '\n') /* pragma must end with a '\n' ... */
- inclinenumber(L, LS);
- else if (LS->current != EOZ) /* or eof */
- luaX_syntaxerror(LS, "invalid pragma format", buff);
- ifskip(L, LS);
- }
- }
- /*
- ** =======================================================
- ** LEXICAL ANALYZER
- ** =======================================================
- */
- static void read_long_string (lua_State *L, LexState *LS) {
- int cont = 0;
- for (;;) {
- switch (LS->current) {
- case EOZ:
- luaX_error(LS, "unfinished long string", TK_STRING);
- break; /* to avoid warnings */
- case '[':
- save_and_next(L, LS);
- if (LS->current == '[') {
- cont++;
- save_and_next(L, LS);
- }
- continue;
- case ']':
- save_and_next(L, LS);
- if (LS->current == ']') {
- if (cont == 0) goto endloop;
- cont--;
- save_and_next(L, LS);
- }
- continue;
- case '\n':
- save(L, '\n');
- inclinenumber(L, LS);
- continue;
- default:
- save_and_next(L, LS);
- }
- } endloop:
- save_and_next(L, LS); /* skip the second ']' */
- LS->seminfo.ts = luaS_newlstr(L, L->Mbuffer+(L->Mbuffbase+2),
- L->Mbuffnext-L->Mbuffbase-4);
- }
- static void read_string (lua_State *L, LexState *LS, int del) {
- save_and_next(L, LS);
- while (LS->current != del) {
- switch (LS->current) {
- case EOZ: case '\n':
- luaX_error(LS, "unfinished string", TK_STRING);
- break; /* to avoid warnings */
- case '\\':
- next(LS); /* do not save the '\' */
- switch (LS->current) {
- case 'a': save(L, '\a'); next(LS); break;
- case 'b': save(L, '\b'); next(LS); break;
- case 'f': save(L, '\f'); next(LS); break;
- case 'n': save(L, '\n'); next(LS); break;
- case 'r': save(L, '\r'); next(LS); break;
- case 't': save(L, '\t'); next(LS); break;
- case 'v': save(L, '\v'); next(LS); break;
- case '\n': save(L, '\n'); inclinenumber(L, LS); break;
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9': {
- int c = 0;
- int i = 0;
- do {
- c = 10*c + (LS->current-'0');
- next(LS);
- } while (++i<3 && isdigit(LS->current));
- if (c != (unsigned char)c)
- luaX_error(LS, "escape sequence too large", TK_STRING);
- save(L, c);
- break;
- }
- default: /* handles \\, \", \', and \? */
- save(L, LS->current);
- next(LS);
- }
- break;
- default:
- save_and_next(L, LS);
- }
- }
- save_and_next(L, LS); /* skip delimiter */
- LS->seminfo.ts = luaS_newlstr(L, L->Mbuffer+(L->Mbuffbase+1),
- L->Mbuffnext-L->Mbuffbase-2);
- }
- int luaX_lex (LexState *LS) {
- lua_State *L = LS->L;
- for (;;) {
- switch (LS->current) {
- case ' ': case '\t': case '\r': /* `\r' to avoid problems with DOS */
- next(LS);
- continue;
- case '\n':
- inclinenumber(L, LS);
- continue;
- case '-':
- next(LS);
- if (LS->current != '-') return '-';
- do { next(LS); } while (LS->current != '\n' && LS->current != EOZ);
- continue;
- case '[':
- luaL_resetbuffer(L);
- save_and_next(L, LS);
- if (LS->current != '[') return '[';
- else {
- save_and_next(L, LS); /* pass the second '[' */
- read_long_string(L, LS);
- return 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 '\'':
- luaL_resetbuffer(L);
- read_string(L, LS, LS->current);
- return TK_STRING;
- case '.':
- luaL_resetbuffer(L);
- save_and_next(L, LS);
- if (LS->current == '.') {
- next(LS);
- if (LS->current == '.') {
- next(LS);
- return TK_DOTS; /* ... */
- }
- else return TK_CONCAT; /* .. */
- }
- else if (!isdigit(LS->current)) return '.';
- else goto fraction; /* LS->current is a digit */
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9':
- luaL_resetbuffer(L);
- do {
- save_and_next(L, LS);
- } while (isdigit(LS->current));
- if (LS->current == '.') {
- save_and_next(L, LS);
- if (LS->current == '.') {
- save(L, '.');
- luaX_error(LS, "ambiguous syntax"
- " (decimal point x string concatenation)", TK_NUMBER);
- }
- }
- fraction: /* LUA_NUMBER */
- while (isdigit(LS->current))
- save_and_next(L, LS);
- if (LS->current == 'e' || LS->current == 'E') {
- save_and_next(L, LS); /* read 'E' */
- if (LS->current == '+' || LS->current == '-')
- save_and_next(L, LS); /* optional exponent sign */
- while (isdigit(LS->current))
- save_and_next(L, LS);
- }
- save(L, '\0');
- if (!luaO_str2d(L->Mbuffer+L->Mbuffbase, &LS->seminfo.r))
- luaX_error(LS, "malformed number", TK_NUMBER);
- return TK_NUMBER;
- case EOZ:
- if (LS->iflevel > 0)
- luaX_error(LS, "input ends inside a $if", TK_EOS);
- return TK_EOS;
- case '_': goto tname;
- default:
- if (!isalpha(LS->current)) {
- int c = LS->current;
- if (iscntrl(c))
- luaX_invalidchar(LS, c);
- next(LS);
- return c;
- }
- tname: { /* identifier or reserved word */
- TString *ts;
- luaL_resetbuffer(L);
- do {
- save_and_next(L, LS);
- } while (isalnum(LS->current) || LS->current == '_');
- save(L, '\0');
- ts = luaS_new(L, L->Mbuffer+L->Mbuffbase);
- if (ts->marked >= RESERVEDMARK) /* reserved word? */
- return ts->marked-RESERVEDMARK+FIRST_RESERVED;
- LS->seminfo.ts = ts;
- return TK_NAME;
- }
- }
- }
- }
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