| char *rcs_lex = "$Id: lex.c,v 3.8 1997/07/30 22:00:50 roberto Exp roberto $"; |
| |
| |
| #include <ctype.h> |
| #include <string.h> |
| |
| #include "auxlib.h" |
| #include "luamem.h" |
| #include "tree.h" |
| #include "table.h" |
| #include "lex.h" |
| #include "inout.h" |
| #include "luadebug.h" |
| #include "parser.h" |
| |
| #define MINBUFF 250 |
| |
| static int current; /* look ahead character */ |
| static ZIO *lex_z; |
| |
| |
| #define next() (current = zgetc(lex_z)) |
| #define save(x) (yytext[tokensize++] = (x)) |
| #define save_and_next() (save(current), next()) |
| |
| |
| #define MAX_IFS 5 |
| |
| /* "ifstate" keeps the state of each nested $if the lexical is dealing with. */ |
| |
| static struct { |
| int elsepart; /* true if its in the $else part */ |
| int condition; /* true if $if condition is true */ |
| int skip; /* true if part must be skiped */ |
| } ifstate[MAX_IFS]; |
| |
| static int iflevel; /* level of nested $if's */ |
| |
| |
| |
| static void firstline (void) |
| { |
| int c = zgetc(lex_z); |
| if (c == '#') |
| while((c=zgetc(lex_z)) != '\n' && c != EOZ) /* skip first line */; |
| zungetc(lex_z); |
| } |
| |
| |
| void lua_setinput (ZIO *z) |
| { |
| current = '\n'; |
| lua_linenumber = 0; |
| iflevel = 0; |
| ifstate[0].skip = 0; |
| ifstate[0].elsepart = 1; /* to avoid a free $else */ |
| lex_z = z; |
| firstline(); |
| } |
| |
| |
| static void luaI_auxsyntaxerror (char *s) |
| { |
| luaL_verror("%s;\n> at line %d in file %s", |
| s, lua_linenumber, lua_parsedfile->str); |
| } |
| |
| static void luaI_auxsynterrbf (char *s, char *token) |
| { |
| if (token[0] == 0) |
| token = "<eof>"; |
| luaL_verror("%s;\n> last token read: \"%s\" at line %d in file %s", |
| s, token, lua_linenumber, lua_parsedfile->str); |
| } |
| |
| void luaI_syntaxerror (char *s) |
| { |
| luaI_auxsynterrbf(s, luaI_buffer(1)); |
| } |
| |
| |
| static struct |
| { |
| char *name; |
| int token; |
| } reserved [] = { |
| {"and", AND}, |
| {"do", DO}, |
| {"else", ELSE}, |
| {"elseif", ELSEIF}, |
| {"end", END}, |
| {"function", FUNCTION}, |
| {"if", IF}, |
| {"local", LOCAL}, |
| {"nil", NIL}, |
| {"not", NOT}, |
| {"or", OR}, |
| {"repeat", REPEAT}, |
| {"return", RETURN}, |
| {"then", THEN}, |
| {"until", UNTIL}, |
| {"while", WHILE} }; |
| |
| |
| #define RESERVEDSIZE (sizeof(reserved)/sizeof(reserved[0])) |
| |
| |
| void luaI_addReserved (void) |
| { |
| int i; |
| for (i=0; i<RESERVEDSIZE; i++) |
| { |
| TaggedString *ts = luaI_createstring(reserved[i].name); |
| ts->marked = reserved[i].token; /* reserved word (always > 255) */ |
| } |
| } |
| |
| |
| /* |
| ** Pragma handling |
| */ |
| |
| #define PRAGMASIZE 20 |
| |
| static void skipspace (void) |
| { |
| while (current == ' ' || current == '\t') next(); |
| } |
| |
| |
| static int checkcond (char *buff) |
| { |
| static char *opts[] = {"nil", "1"}; |
| int i = luaI_findstring(buff, opts); |
| if (i >= 0) return i; |
| else if (isalpha((unsigned char)buff[0]) || buff[0] == '_') |
| return luaI_globaldefined(buff); |
| else { |
| luaI_auxsynterrbf("invalid $if condition", buff); |
| return 0; /* to avoid warnings */ |
| } |
| } |
| |
| |
| static void readname (char *buff) |
| { |
| int i = 0; |
| skipspace(); |
| while (isalnum((unsigned char)current) || current == '_') { |
| if (i >= PRAGMASIZE) { |
| buff[PRAGMASIZE] = 0; |
| luaI_auxsynterrbf("pragma too long", buff); |
| } |
| buff[i++] = current; |
| next(); |
| } |
| buff[i] = 0; |
| } |
| |
| |
| static void inclinenumber (void); |
| |
| |
| static void ifskip (void) |
| { |
| while (ifstate[iflevel].skip) { |
| if (current == '\n') |
| inclinenumber(); |
| else if (current == EOZ) |
| luaI_auxsyntaxerror("input ends inside a $if"); |
| else next(); |
| } |
| } |
| |
| |
| static void inclinenumber (void) |
| { |
| static char *pragmas [] = |
| {"debug", "nodebug", "endinput", "end", "ifnot", "if", "else", NULL}; |
| next(); /* skip '\n' */ |
| ++lua_linenumber; |
| if (current == '$') { /* is a pragma? */ |
| char buff[PRAGMASIZE+1]; |
| int ifnot = 0; |
| int skip = ifstate[iflevel].skip; |
| next(); /* skip $ */ |
| readname(buff); |
| switch (luaI_findstring(buff, pragmas)) { |
| case 0: /* debug */ |
| if (!skip) lua_debug = 1; |
| break; |
| case 1: /* nodebug */ |
| if (!skip) lua_debug = 0; |
| break; |
| case 2: /* endinput */ |
| if (!skip) { |
| current = EOZ; |
| iflevel = 0; /* to allow $endinput inside a $if */ |
| } |
| break; |
| case 3: /* end */ |
| if (iflevel-- == 0) |
| luaI_auxsyntaxerror("unmatched $endif"); |
| break; |
| case 4: /* ifnot */ |
| ifnot = 1; |
| /* go through */ |
| case 5: /* if */ |
| if (iflevel == MAX_IFS-1) |
| luaI_auxsyntaxerror("too many nested `$ifs'"); |
| readname(buff); |
| iflevel++; |
| ifstate[iflevel].elsepart = 0; |
| ifstate[iflevel].condition = checkcond(buff) ? !ifnot : ifnot; |
| ifstate[iflevel].skip = skip || !ifstate[iflevel].condition; |
| break; |
| case 6: /* else */ |
| if (ifstate[iflevel].elsepart) |
| luaI_auxsyntaxerror("unmatched $else"); |
| ifstate[iflevel].elsepart = 1; |
| ifstate[iflevel].skip = |
| ifstate[iflevel-1].skip || ifstate[iflevel].condition; |
| break; |
| default: |
| luaI_auxsynterrbf("invalid pragma", buff); |
| } |
| skipspace(); |
| if (current == '\n') /* pragma must end with a '\n' ... */ |
| inclinenumber(); |
| else if (current != EOZ) /* or eof */ |
| luaI_auxsyntaxerror("invalid pragma format"); |
| ifskip(); |
| } |
| } |
| |
| static int read_long_string (char *yytext, int buffsize) |
| { |
| int cont = 0; |
| int tokensize = 2; /* '[[' already stored */ |
| while (1) |
| { |
| if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */ |
| yytext = luaI_buffer(buffsize *= 2); |
| switch (current) |
| { |
| case EOZ: |
| save(0); |
| return WRONGTOKEN; |
| case '[': |
| save_and_next(); |
| if (current == '[') |
| { |
| cont++; |
| save_and_next(); |
| } |
| continue; |
| case ']': |
| save_and_next(); |
| if (current == ']') |
| { |
| if (cont == 0) goto endloop; |
| cont--; |
| save_and_next(); |
| } |
| continue; |
| case '\n': |
| save('\n'); |
| inclinenumber(); |
| continue; |
| default: |
| save_and_next(); |
| } |
| } endloop: |
| save_and_next(); /* pass the second ']' */ |
| yytext[tokensize-2] = 0; /* erases ']]' */ |
| luaY_lval.pTStr = luaI_createtempstring(yytext+2); |
| yytext[tokensize-2] = ']'; /* restores ']]' */ |
| save(0); |
| return STRING; |
| } |
| |
| int luaY_lex (void) |
| { |
| static int linelasttoken = 0; |
| double a; |
| int buffsize = MINBUFF; |
| char *yytext = luaI_buffer(buffsize); |
| yytext[1] = yytext[2] = yytext[3] = 0; |
| if (lua_debug) |
| luaI_codedebugline(linelasttoken); |
| linelasttoken = lua_linenumber; |
| while (1) { |
| int tokensize = 0; |
| switch (current) { |
| case '\n': |
| inclinenumber(); |
| linelasttoken = lua_linenumber; |
| continue; |
| |
| case ' ': case '\t': case '\r': /* CR: to avoid problems with DOS */ |
| next(); |
| continue; |
| |
| case '-': |
| save_and_next(); |
| if (current != '-') return '-'; |
| do { next(); } while (current != '\n' && current != EOZ); |
| continue; |
| |
| case '[': |
| save_and_next(); |
| if (current != '[') return '['; |
| else |
| { |
| save_and_next(); /* pass the second '[' */ |
| return read_long_string(yytext, buffsize); |
| } |
| |
| case '=': |
| save_and_next(); |
| if (current != '=') return '='; |
| else { save_and_next(); return EQ; } |
| |
| case '<': |
| save_and_next(); |
| if (current != '=') return '<'; |
| else { save_and_next(); return LE; } |
| |
| case '>': |
| save_and_next(); |
| if (current != '=') return '>'; |
| else { save_and_next(); return GE; } |
| |
| case '~': |
| save_and_next(); |
| if (current != '=') return '~'; |
| else { save_and_next(); return NE; } |
| |
| case '"': |
| case '\'': |
| { |
| int del = current; |
| save_and_next(); |
| while (current != del) |
| { |
| if (buffsize-tokensize <= 2) /* may read more than 1 char in one cicle */ |
| yytext = luaI_buffer(buffsize *= 2); |
| switch (current) |
| { |
| case EOZ: |
| case '\n': |
| save(0); |
| return WRONGTOKEN; |
| case '\\': |
| next(); /* do not save the '\' */ |
| switch (current) |
| { |
| case 'n': save('\n'); next(); break; |
| case 't': save('\t'); next(); break; |
| case 'r': save('\r'); next(); break; |
| case '\n': save('\n'); inclinenumber(); break; |
| default : save_and_next(); break; |
| } |
| break; |
| default: |
| save_and_next(); |
| } |
| } |
| next(); /* skip delimiter */ |
| save(0); |
| luaY_lval.pTStr = luaI_createtempstring(yytext+1); |
| tokensize--; |
| save(del); save(0); /* restore delimiter */ |
| return STRING; |
| } |
| |
| case '.': |
| save_and_next(); |
| if (current == '.') |
| { |
| save_and_next(); |
| if (current == '.') |
| { |
| save_and_next(); |
| return DOTS; /* ... */ |
| } |
| else return CONC; /* .. */ |
| } |
| else if (!isdigit((unsigned char)current)) return '.'; |
| /* current is a digit: goes through to number */ |
| a=0.0; |
| goto fraction; |
| |
| case '0': case '1': case '2': case '3': case '4': |
| case '5': case '6': case '7': case '8': case '9': |
| a=0.0; |
| do { |
| a=10.0*a+(current-'0'); |
| save_and_next(); |
| } while (isdigit((unsigned char)current)); |
| if (current == '.') { |
| save_and_next(); |
| if (current == '.') |
| luaI_syntaxerror( |
| "ambiguous syntax (decimal point x string concatenation)"); |
| } |
| fraction: |
| { double da=0.1; |
| while (isdigit((unsigned char)current)) |
| { |
| a+=(current-'0')*da; |
| da/=10.0; |
| save_and_next(); |
| } |
| if (current == 'e' || current == 'E') |
| { |
| int e=0; |
| int neg; |
| double ea; |
| save_and_next(); |
| neg=(current=='-'); |
| if (current == '+' || current == '-') save_and_next(); |
| if (!isdigit((unsigned char)current)) { |
| save(0); return WRONGTOKEN; } |
| do { |
| e=10.0*e+(current-'0'); |
| save_and_next(); |
| } while (isdigit((unsigned char)current)); |
| for (ea=neg?0.1:10.0; e>0; e>>=1) |
| { |
| if (e & 1) a*=ea; |
| ea*=ea; |
| } |
| } |
| luaY_lval.vReal = a; |
| save(0); |
| return NUMBER; |
| } |
| |
| case EOZ: |
| save(0); |
| if (iflevel > 0) |
| luaI_syntaxerror("missing $endif"); |
| return 0; |
| |
| default: |
| if (current != '_' && !isalpha((unsigned char)current)) { |
| save_and_next(); |
| return yytext[0]; |
| } |
| else { /* identifier or reserved word */ |
| TaggedString *ts; |
| do { |
| save_and_next(); |
| } while (isalnum((unsigned char)current) || current == '_'); |
| save(0); |
| ts = luaI_createtempstring(yytext); |
| if (ts->marked > 255) |
| return ts->marked; /* reserved word */ |
| luaY_lval.pTStr = ts; |
| return NAME; |
| } |
| } |
| } |
| } |
| |