mirror of
https://github.com/lua/lua.git
synced 2024-11-24 02:33:48 +08:00
391 lines
9.8 KiB
C
391 lines
9.8 KiB
C
/*
|
|
** $Id: llex.c,v 1.1 2001/11/29 22:14:34 rieru Exp rieru $
|
|
** Lexical Analyzer
|
|
** See Copyright Notice in lua.h
|
|
*/
|
|
|
|
|
|
#include <ctype.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#include "lua.h"
|
|
|
|
#include "llex.h"
|
|
#include "lobject.h"
|
|
#include "lparser.h"
|
|
#include "lstate.h"
|
|
#include "lstring.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", "false", "for", "function", "global", "if",
|
|
"in", "local", "nil", "not", "or", "repeat",
|
|
"return", "then", "true", "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]);
|
|
lua_assert(strlen(token2string[i])+1 <= TOKEN_LEN);
|
|
ts->tsv.marked = cast(unsigned short, RESERVEDMARK+i); /* reserved word */
|
|
}
|
|
}
|
|
|
|
|
|
#define MAXSRC 80
|
|
|
|
|
|
void luaX_checklimit (LexState *ls, int val, int limit, const char *msg) {
|
|
if (val > limit) {
|
|
char buff[90];
|
|
sprintf(buff, "too many %.40s (limit=%d)", msg, limit);
|
|
luaX_error(ls, buff, ls->t.token);
|
|
}
|
|
}
|
|
|
|
|
|
static void luaX_syntaxerror (LexState *ls, const char *s,
|
|
const char *token) {
|
|
char buff[MAXSRC];
|
|
luaO_chunkid(buff, getstr(ls->source), MAXSRC);
|
|
luaO_verror(ls->L,
|
|
"%.99s;\n last token read: `%.30s' at line %d in %.80s",
|
|
s, token, ls->linenumber, buff);
|
|
}
|
|
|
|
|
|
void luaX_token2str (int token, char *s) {
|
|
if (token < FIRST_RESERVED) {
|
|
lua_assert(token == (char)token);
|
|
s[0] = (char)token;
|
|
s[1] = '\0';
|
|
}
|
|
else
|
|
strcpy(s, token2string[token-FIRST_RESERVED]);
|
|
}
|
|
|
|
|
|
static char *token2str_all (LexState *ls, int token, char *s) {
|
|
luaX_token2str(token, s);
|
|
if (s[0] == '\0')
|
|
return cast(char *, G(ls->L)->Mbuffer);
|
|
else
|
|
return s;
|
|
}
|
|
|
|
|
|
void luaX_error (LexState *ls, const char *s, int token) {
|
|
char buff[TOKEN_LEN];
|
|
luaX_syntaxerror(ls, s, token2str_all(ls, token, buff));
|
|
}
|
|
|
|
|
|
static void luaX_invalidchar (LexState *ls, int c) {
|
|
char buff[8];
|
|
sprintf(buff, "0x%02X", (unsigned char)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))*sizeof(char) > G(L)->Mbuffsize) \
|
|
luaO_openspace(L, (len)+(n)+EXTRABUFF, char)
|
|
|
|
#define save(L, c, l) (cast(char *, G(L)->Mbuffer)[l++] = (char)c)
|
|
#define save_and_next(L, LS, l) (save(L, LS->current, l), next(LS))
|
|
|
|
|
|
static size_t 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-1;
|
|
}
|
|
|
|
|
|
/* 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(cast(char *, G(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 `[' */
|
|
if (LS->current == '\n') /* string starts with a newline? */
|
|
inclinenumber(LS); /* skip it */
|
|
for (;;) {
|
|
checkbuffer(L, 10, l);
|
|
switch (LS->current) {
|
|
case EOZ:
|
|
save(L, '\0', l);
|
|
luaX_error(LS, "unfinished long string", TK_EOS);
|
|
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, cast(char *, G(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;
|
|
default: {
|
|
if (!isdigit(LS->current))
|
|
save_and_next(L, LS, l); /* handles \\, \", \', and \? */
|
|
else { /* \xxx */
|
|
int c = 0;
|
|
int i = 0;
|
|
do {
|
|
c = 10*c + (LS->current-'0');
|
|
next(LS);
|
|
} while (++i<3 && isdigit(LS->current));
|
|
if (c > UCHAR_MAX) {
|
|
save(L, '\0', l);
|
|
luaX_error(LS, "escape sequence too large", TK_STRING);
|
|
}
|
|
save(L, c, 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, cast(char *, G(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 '-':
|
|
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 EOZ:
|
|
return TK_EOS;
|
|
|
|
default: {
|
|
if (isdigit(LS->current)) {
|
|
read_number(LS, 0, seminfo);
|
|
return TK_NUMBER;
|
|
}
|
|
else if (isalpha(LS->current) || LS->current == '_') {
|
|
/* identifier or reserved word */
|
|
size_t l = readname(LS);
|
|
TString *ts = luaS_newlstr(LS->L, cast(char *, G(LS->L)->Mbuffer), l);
|
|
if (ts->tsv.marked >= RESERVEDMARK) /* reserved word? */
|
|
return ts->tsv.marked-RESERVEDMARK+FIRST_RESERVED;
|
|
seminfo->ts = ts;
|
|
return TK_NAME;
|
|
}
|
|
else {
|
|
int c = LS->current;
|
|
if (iscntrl(c))
|
|
luaX_invalidchar(LS, c);
|
|
next(LS);
|
|
return c; /* single-char tokens (+ - / ...) */
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|