| /* |
| ** $Id: llex.c,v 1.69 2000/09/11 17:38:42 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, "%.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') |
| 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) { |
| 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, &LS->t.seminfo.r)) |
| luaX_error(LS, "malformed number", TK_NUMBER); |
| } |
| |
| |
| static void read_long_string (LexState *LS) { |
| 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); |
| LS->t.seminfo.ts = luaS_newlstr(L, L->Mbuffer+2, l-5); |
| } |
| |
| |
| static void read_string (LexState *LS, int del) { |
| 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); |
| LS->t.seminfo.ts = luaS_newlstr(L, L->Mbuffer+1, l-3); |
| } |
| |
| |
| int luaX_lex (LexState *LS) { |
| 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); |
| 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); |
| 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); |
| 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); |
| 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; |
| LS->t.seminfo.ts = ts; |
| return TK_NAME; |
| } |
| } |
| } |
| } |
| |
