From 60cc473bcfce079d1525fcffcfdfbeb66e35afa2 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Tue, 16 Sep 1997 16:25:59 -0300 Subject: Lexical Analizer --- lex.c | 466 ------------------------------------------------------------------ 1 file changed, 466 deletions(-) delete mode 100644 lex.c (limited to 'lex.c') diff --git a/lex.c b/lex.c deleted file mode 100644 index 59588d19..00000000 --- a/lex.c +++ /dev/null @@ -1,466 +0,0 @@ -char *rcs_lex = "$Id: lex.c,v 3.8 1997/07/30 22:00:50 roberto Exp roberto $"; - - -#include -#include - -#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 = ""; - 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; imarked = 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; - } - } - } -} - -- cgit v1.2.3-55-g6feb