| /* |
| ** $Id: llex.c,v 1.88 2001/06/20 21:07:57 roberto Exp roberto $ |
| ** Lexical Analyzer |
| ** See Copyright Notice in lua.h |
| */ |
| |
| |
| #include <ctype.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #define LUA_PRIVATE |
| #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 l_char *const token2string [] = { |
| l_s("and"), l_s("break"), l_s("do"), l_s("else"), l_s("elseif"), |
| l_s("end"), l_s("for"), l_s("function"), l_s("global"), l_s("if"), |
| l_s("in"), l_s("local"), l_s("nil"), l_s("not"), l_s("or"), l_s("repeat"), |
| l_s("return"), l_s("then"), l_s("until"), l_s("while"), l_s(""), |
| l_s(".."), l_s("..."), l_s("=="), l_s(">="), l_s("<="), l_s("~="), |
| l_s(""), l_s(""), l_s("<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 = (unsigned short)(RESERVEDMARK+i); /* reserved word */ |
| } |
| } |
| |
| |
| #define MAXSRC 80 |
| |
| |
| void luaX_checklimit (LexState *ls, int val, int limit, const l_char *msg) { |
| if (val > limit) { |
| l_char buff[90]; |
| sprintf(buff, l_s("too many %.40s (limit=%d)"), msg, limit); |
| luaX_error(ls, buff, ls->t.token); |
| } |
| } |
| |
| |
| void luaX_syntaxerror (LexState *ls, const l_char *s, const l_char *token) { |
| l_char buff[MAXSRC]; |
| luaO_chunkid(buff, getstr(ls->source), MAXSRC); |
| luaO_verror(ls->L, |
| l_s("%.99s;\n last token read: `%.30s' at line %d in %.80s"), |
| s, token, ls->linenumber, buff); |
| } |
| |
| |
| void luaX_error (LexState *ls, const l_char *s, int token) { |
| l_char buff[TOKEN_LEN]; |
| luaX_token2str(token, buff); |
| if (buff[0] == l_c('\0')) |
| luaX_syntaxerror(ls, s, (l_char *)G(ls->L)->Mbuffer); |
| else |
| luaX_syntaxerror(ls, s, buff); |
| } |
| |
| |
| void luaX_token2str (int token, l_char *s) { |
| if (token < 256) { |
| s[0] = (l_char)token; |
| s[1] = l_c('\0'); |
| } |
| else |
| strcpy(s, token2string[token-FIRST_RESERVED]); |
| } |
| |
| |
| static void luaX_invalidchar (LexState *ls, int c) { |
| l_char buff[8]; |
| sprintf(buff, l_s("0x%02X"), uchar(c)); |
| luaX_syntaxerror(ls, l_s("invalid control char"), buff); |
| } |
| |
| |
| static void inclinenumber (LexState *LS) { |
| next(LS); /* skip `\n' */ |
| ++LS->linenumber; |
| luaX_checklimit(LS, LS->linenumber, MAX_INT, l_s("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 == l_c('#')) { |
| do { /* skip first line */ |
| next(LS); |
| } while (LS->current != l_c('\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(l_char) > G(L)->Mbuffsize) \ |
| luaO_openspace(L, (len)+(n)+EXTRABUFF, l_char) |
| |
| #define save(L, c, l) (((l_char *)G(L)->Mbuffer)[l++] = (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 == l_c('_')); |
| save(L, l_c('\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_c('.'), l); |
| while (isdigit(LS->current)) { |
| checkbuffer(L, 10, l); |
| save_and_next(L, LS, l); |
| } |
| if (LS->current == l_c('.')) { |
| save_and_next(L, LS, l); |
| if (LS->current == l_c('.')) { |
| save_and_next(L, LS, l); |
| save(L, l_c('\0'), l); |
| luaX_error(LS, |
| l_s("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 == l_c('e') || LS->current == l_c('E')) { |
| save_and_next(L, LS, l); /* read `E' */ |
| if (LS->current == l_c('+') || LS->current == l_c('-')) |
| 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, l_c('\0'), l); |
| if (!luaO_str2d((l_char *)G(L)->Mbuffer, &seminfo->r)) |
| luaX_error(LS, l_s("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_c('['), l); /* save first `[' */ |
| save_and_next(L, LS, l); /* pass the second `[' */ |
| if (LS->current == l_c('\n')) /* string starts with a newline? */ |
| inclinenumber(LS); /* skip it */ |
| for (;;) { |
| checkbuffer(L, 10, l); |
| switch (LS->current) { |
| case EOZ: |
| save(L, l_c('\0'), l); |
| luaX_error(LS, l_s("unfinished long string"), TK_STRING); |
| break; /* to avoid warnings */ |
| case l_c('['): |
| save_and_next(L, LS, l); |
| if (LS->current == l_c('[')) { |
| cont++; |
| save_and_next(L, LS, l); |
| } |
| continue; |
| case l_c(']'): |
| save_and_next(L, LS, l); |
| if (LS->current == l_c(']')) { |
| if (cont == 0) goto endloop; |
| cont--; |
| save_and_next(L, LS, l); |
| } |
| continue; |
| case l_c('\n'): |
| save(L, l_c('\n'), l); |
| inclinenumber(LS); |
| continue; |
| default: |
| save_and_next(L, LS, l); |
| } |
| } endloop: |
| save_and_next(L, LS, l); /* skip the second `]' */ |
| save(L, l_c('\0'), l); |
| seminfo->ts = luaS_newlstr(L, (l_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 l_c('\n'): |
| save(L, l_c('\0'), l); |
| luaX_error(LS, l_s("unfinished string"), TK_STRING); |
| break; /* to avoid warnings */ |
| case l_c('\\'): |
| next(LS); /* do not save the `\' */ |
| switch (LS->current) { |
| case l_c('a'): save(L, l_c('\a'), l); next(LS); break; |
| case l_c('b'): save(L, l_c('\b'), l); next(LS); break; |
| case l_c('f'): save(L, l_c('\f'), l); next(LS); break; |
| case l_c('n'): save(L, l_c('\n'), l); next(LS); break; |
| case l_c('r'): save(L, l_c('\r'), l); next(LS); break; |
| case l_c('t'): save(L, l_c('\t'), l); next(LS); break; |
| case l_c('v'): save(L, l_c('\v'), l); next(LS); break; |
| case l_c('\n'): save(L, l_c('\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-l_c('0')); |
| next(LS); |
| } while (++i<3 && isdigit(LS->current)); |
| if (c > UCHAR_MAX) { |
| save(L, l_c('\0'), l); |
| luaX_error(LS, l_s("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, l_c('\0'), l); |
| seminfo->ts = luaS_newlstr(L, (l_char *)G(L)->Mbuffer+1, l-3); |
| } |
| |
| |
| int luaX_lex (LexState *LS, SemInfo *seminfo) { |
| for (;;) { |
| switch (LS->current) { |
| |
| case l_c(' '): case l_c('\t'): case l_c('\r'): /* `\r' to avoid problems with DOS */ |
| next(LS); |
| continue; |
| |
| case l_c('\n'): |
| inclinenumber(LS); |
| continue; |
| |
| case l_c('$'): |
| luaX_error(LS, |
| l_s("unexpected `$' (pragmas are no longer supported)"), |
| LS->current); |
| break; |
| |
| case l_c('-'): |
| next(LS); |
| if (LS->current != l_c('-')) return l_c('-'); |
| do { next(LS); } while (LS->current != l_c('\n') && LS->current != EOZ); |
| continue; |
| |
| case l_c('['): |
| next(LS); |
| if (LS->current != l_c('[')) return l_c('['); |
| else { |
| read_long_string(LS, seminfo); |
| return TK_STRING; |
| } |
| |
| case l_c('='): |
| next(LS); |
| if (LS->current != l_c('=')) return l_c('='); |
| else { next(LS); return TK_EQ; } |
| |
| case l_c('<'): |
| next(LS); |
| if (LS->current != l_c('=')) return l_c('<'); |
| else { next(LS); return TK_LE; } |
| |
| case l_c('>'): |
| next(LS); |
| if (LS->current != l_c('=')) return l_c('>'); |
| else { next(LS); return TK_GE; } |
| |
| case l_c('~'): |
| next(LS); |
| if (LS->current != l_c('=')) return l_c('~'); |
| else { next(LS); return TK_NE; } |
| |
| case l_c('"'): |
| case l_c('\''): |
| read_string(LS, LS->current, seminfo); |
| return TK_STRING; |
| |
| case l_c('.'): |
| next(LS); |
| if (LS->current == l_c('.')) { |
| next(LS); |
| if (LS->current == l_c('.')) { |
| next(LS); |
| return TK_DOTS; /* ... */ |
| } |
| else return TK_CONCAT; /* .. */ |
| } |
| else if (!isdigit(LS->current)) return l_c('.'); |
| 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 == l_c('_')) { |
| /* identifier or reserved word */ |
| size_t l = readname(LS); |
| TString *ts = luaS_newlstr(LS->L, (l_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 { |
| l_charint c = LS->current; |
| if (iscntrl(c)) |
| luaX_invalidchar(LS, c); |
| next(LS); |
| return c; /* single-char tokens (+ - / ...) */ |
| } |
| } |
| } |
| } |
| } |
| |
