blob: 9ddb117e0bd1d010b7e6bc88542b90d2934711a6 [file] [log] [blame]
/*
** $Id: llex.c,v 1.71 2000/09/27 17:41:58 roberto Exp roberto $
** Lexical Analyzer
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include "lua.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))
/* 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->t.token);
}
}
void luaX_syntaxerror (LexState *ls, const char *s, const char *token) {
char buff[MAXSRC];
luaO_chunkid(buff, ls->source->str, sizeof(buff));
luaO_verror(ls->L, "%.99s;\n last token read: `%.30s' 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')
luaX_syntaxerror(ls, s, ls->L->Mbuffer);
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 inclinenumber (LexState *LS) {
next(LS); /* skip '\n' */
++LS->linenumber;
luaX_checklimit(LS, LS->linenumber, MAX_INT, "lines in a chunk");
}
void luaX_setinput (lua_State *L, LexState *LS, ZIO *z, TString *source) {
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;
next(LS); /* read first char */
if (LS->current == '#') {
do { /* skip first line */
next(LS);
} while (LS->current != '\n' && LS->current != EOZ);
}
}
/*
** =======================================================
** LEXICAL ANALYZER
** =======================================================
*/
/* use Mbuffer to store names, literal strings and numbers */
#define EXTRABUFF 128
#define checkbuffer(L, n, len) if ((len)+(n) > L->Mbuffsize) \
luaO_openspace(L, (len)+(n)+EXTRABUFF)
#define save(L, c, l) (L->Mbuffer[l++] = (char)c)
#define save_and_next(L, LS, l) (save(L, LS->current, l), next(LS))
static const char *readname (LexState *LS) {
lua_State *L = LS->L;
size_t l = 0;
checkbuffer(L, 10, l);
do {
checkbuffer(L, 10, l);
save_and_next(L, LS, l);
} while (isalnum(LS->current) || LS->current == '_');
save(L, '\0', l);
return L->Mbuffer;
}
/* LUA_NUMBER */
static void read_number (LexState *LS, int comma, SemInfo *seminfo) {
lua_State *L = LS->L;
size_t l = 0;
checkbuffer(L, 10, l);
if (comma) save(L, '.', l);
while (isdigit(LS->current)) {
checkbuffer(L, 10, l);
save_and_next(L, LS, l);
}
if (LS->current == '.') {
save_and_next(L, LS, l);
if (LS->current == '.') {
save_and_next(L, LS, l);
save(L, '\0', l);
luaX_error(LS, "ambiguous syntax"
" (decimal point x string concatenation)", TK_NUMBER);
}
}
while (isdigit(LS->current)) {
checkbuffer(L, 10, l);
save_and_next(L, LS, l);
}
if (LS->current == 'e' || LS->current == 'E') {
save_and_next(L, LS, l); /* read 'E' */
if (LS->current == '+' || LS->current == '-')
save_and_next(L, LS, l); /* optional exponent sign */
while (isdigit(LS->current)) {
checkbuffer(L, 10, l);
save_and_next(L, LS, l);
}
}
save(L, '\0', l);
if (!luaO_str2d(L->Mbuffer, &seminfo->r))
luaX_error(LS, "malformed number", TK_NUMBER);
}
static void read_long_string (LexState *LS, SemInfo *seminfo) {
lua_State *L = LS->L;
int cont = 0;
size_t l = 0;
checkbuffer(L, 10, l);
save(L, '[', l); /* save first '[' */
save_and_next(L, LS, l); /* pass the second '[' */
for (;;) {
checkbuffer(L, 10, l);
switch (LS->current) {
case EOZ:
save(L, '\0', l);
luaX_error(LS, "unfinished long string", TK_STRING);
break; /* to avoid warnings */
case '[':
save_and_next(L, LS, l);
if (LS->current == '[') {
cont++;
save_and_next(L, LS, l);
}
continue;
case ']':
save_and_next(L, LS, l);
if (LS->current == ']') {
if (cont == 0) goto endloop;
cont--;
save_and_next(L, LS, l);
}
continue;
case '\n':
save(L, '\n', l);
inclinenumber(LS);
continue;
default:
save_and_next(L, LS, l);
}
} endloop:
save_and_next(L, LS, l); /* skip the second ']' */
save(L, '\0', l);
seminfo->ts = luaS_newlstr(L, L->Mbuffer+2, l-5);
}
static void read_string (LexState *LS, int del, SemInfo *seminfo) {
lua_State *L = LS->L;
size_t l = 0;
checkbuffer(L, 10, l);
save_and_next(L, LS, l);
while (LS->current != del) {
checkbuffer(L, 10, l);
switch (LS->current) {
case EOZ: case '\n':
save(L, '\0', l);
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', l); next(LS); break;
case 'b': save(L, '\b', l); next(LS); break;
case 'f': save(L, '\f', l); next(LS); break;
case 'n': save(L, '\n', l); next(LS); break;
case 'r': save(L, '\r', l); next(LS); break;
case 't': save(L, '\t', l); next(LS); break;
case 'v': save(L, '\v', l); next(LS); break;
case '\n': save(L, '\n', l); inclinenumber(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) {
save(L, '\0', l);
luaX_error(LS, "escape sequence too large", TK_STRING);
}
save(L, c, l);
break;
}
default: /* handles \\, \", \', and \? */
save_and_next(L, LS, l);
}
break;
default:
save_and_next(L, LS, l);
}
}
save_and_next(L, LS, l); /* skip delimiter */
save(L, '\0', l);
seminfo->ts = luaS_newlstr(L, L->Mbuffer+1, l-3);
}
int luaX_lex (LexState *LS, SemInfo *seminfo) {
for (;;) {
switch (LS->current) {
case ' ': case '\t': case '\r': /* `\r' to avoid problems with DOS */
next(LS);
continue;
case '\n':
inclinenumber(LS);
continue;
case '$':
luaX_error(LS, "unexpected `$' (pragmas are no longer supported)", '$');
break;
case '-':
next(LS);
if (LS->current != '-') return '-';
do { next(LS); } while (LS->current != '\n' && LS->current != EOZ);
continue;
case '[':
next(LS);
if (LS->current != '[') return '[';
else {
read_long_string(LS, seminfo);
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 '\'':
read_string(LS, LS->current, seminfo);
return TK_STRING;
case '.':
next(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 {
read_number(LS, 1, seminfo);
return TK_NUMBER;
}
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
read_number(LS, 0, seminfo);
return TK_NUMBER;
case EOZ:
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 = luaS_new(LS->L, readname(LS));
if (ts->marked >= RESERVEDMARK) /* reserved word? */
return ts->marked-RESERVEDMARK+FIRST_RESERVED;
seminfo->ts = ts;
return TK_NAME;
}
}
}
}