%{ /* ** $Id: $ ** Syntax analizer and code generator ** See Copyright Notice in lua.h */ #include #include "lauxlib.h" #include "ldo.h" #include "lfunc.h" #include "lglobal.h" #include "llex.h" #include "lmem.h" #include "lopcodes.h" #include "lparser.h" #include "lstring.h" #include "lua.h" #include "luadebug.h" #include "lzio.h" /* to avoid warnings generated by yacc */ int luaY_parse (void); #define malloc luaM_malloc #define realloc luaM_realloc #define free luaM_free /* maximum number of local variables */ #define MAXLOCALS 32 /* maximum number of variables in a multiple assignment */ #define MAXVAR 32 /* maximum number of nested functions */ #define MAXSTATES 6 /* maximum number of upvalues */ #define MAXUPVALUES 8 /* ** Variable descriptor: if n>0, represents global variable indexed ** by (n-1); if n<0, represents local variable index (-n)-1; ** if n==0, represents an indexed variable (table and index on top of stack) ** Must be long to store negative Word values. */ typedef long vardesc; /* state needed to generate code for a given function */ static struct State { TProtoFunc *f; /* current function header */ int pc; /* next position to code */ TaggedString *localvar[MAXLOCALS]; /* store local variable names */ int stacksize; /* number of values on activation register */ int maxstacksize; /* maximum number of values on activation register */ int nlocalvar; /* number of active local variables */ int nvars; /* number of entries in f->locvars */ int maxcode; /* size of f->code */ int maxvars; /* size of f->locvars (-1 if no debug information) */ int maxconsts; /* size of f->consts */ vardesc varbuffer[MAXVAR]; /* variables in an assignment list */ vardesc upvalues[MAXUPVALUES]; /* upvalues */ } *mainState, *currState; void luaY_syntaxerror (char *s, char *token) { if (token[0] == 0) token = ""; luaL_verror("%.100s;\n> last token read: \"%.50s\" at line %d in file %.50s", s, token, luaX_linenumber, mainState->f->fileName->str); } void luaY_error (char *s) { luaY_syntaxerror(s, luaX_lasttoken()); } static void code_byte (Byte c) { if (currState->pc >= currState->maxcode) currState->maxcode = luaM_growvector(&currState->f->code, currState->maxcode, Byte, codeEM, MAX_INT); currState->f->code[currState->pc++] = c; } static void deltastack (int delta) { currState->stacksize += delta; if (currState->stacksize > currState->maxstacksize) { if (currState->stacksize > 255) luaY_error("expression too complex"); currState->maxstacksize = currState->stacksize; } } static void code_opcode (OpCode op, int delta) { code_byte(op); deltastack(delta); } static void code_word_at (int pc, int n) { Word w = n; if (w != n) luaY_error("block too big"); currState->f->code[pc] = n&0xFF; currState->f->code[pc+1] = n>>8; } static void code_word (int n) { code_byte(n&0xFF); code_byte(n>>8); } static void code_constant (int c) { if (c <= 255) { code_opcode(PUSHCONSTANTB, 1); code_byte(c); } else { code_opcode(PUSHCONSTANT, 1); code_word(c); } } static int next_constant (void) { TProtoFunc *f = currState->f; if (f->nconsts >= currState->maxconsts) { currState->maxconsts = luaM_growvector(&f->consts, currState->maxconsts, TObject, constantEM, MAX_WORD); } return f->nconsts++; } static int string_constant (TaggedString *s) { TProtoFunc *f = currState->f; int c = s->u.s.constindex; if (!(0 <= c && c < f->nconsts && ttype(&f->consts[c]) == LUA_T_STRING && tsvalue(&f->consts[c]) == s)) { c = next_constant(); ttype(&f->consts[c]) = LUA_T_STRING; tsvalue(&f->consts[c]) = s; s->u.s.constindex = c; /* hint for next time */ } return c; } static void code_string (TaggedString *s) { code_constant(string_constant(s)); } #define LIM 13 static int real_constant (real r) { /* check whether 'r' has appeared within the last LIM entries */ TObject *cnt = currState->f->consts; int c = currState->f->nconsts; int lim = c < LIM ? 0 : c-LIM; while (--c >= lim) { if (ttype(&cnt[c]) == LUA_T_NUMBER && nvalue(&cnt[c]) == r) return c; } /* not found; create a luaM_new entry */ c = next_constant(); cnt = currState->f->consts; /* 'next_constant' may reallocate this vector */ ttype(&cnt[c]) = LUA_T_NUMBER; nvalue(&cnt[c]) = r; return c; } static void code_number (real f) { Word i; if (f >= 0 && f <= (real)MAX_WORD && (real)(i=(Word)f) == f) { /* f has an (short) integer value */ if (i <= 2) code_opcode(PUSH0 + i, 1); else if (i <= 255) { code_opcode(PUSHBYTE, 1); code_byte(i); } else { code_opcode(PUSHWORD, 1); code_word(i); } } else code_constant(real_constant(f)); } static void flush_record (int n) { if (n == 0) return; code_opcode(SETMAP, -2*n); code_byte(n); } static void flush_list (int m, int n) { if (n == 0) return; if (m == 0) code_opcode(SETLIST0, -n); else if (m < 255) { code_opcode(SETLIST, -n); code_byte(m); } else luaY_error("list constructor too long"); code_byte(n); } static void luaI_registerlocalvar (TaggedString *varname, int line) { if (currState->maxvars != -1) { /* debug information? */ if (currState->nvars >= currState->maxvars) currState->maxvars = luaM_growvector(&currState->f->locvars, currState->maxvars, LocVar, "", MAX_WORD); currState->f->locvars[currState->nvars].varname = varname; currState->f->locvars[currState->nvars].line = line; currState->nvars++; } } static void luaI_unregisterlocalvar (int line) { luaI_registerlocalvar(NULL, line); } static void store_localvar (TaggedString *name, int n) { if (currState->nlocalvar+n < MAXLOCALS) currState->localvar[currState->nlocalvar+n] = name; else luaY_error("too many local variables"); luaI_registerlocalvar(name, luaX_linenumber); } static void add_localvar (TaggedString *name) { store_localvar(name, 0); currState->nlocalvar++; } static void add_varbuffer (vardesc var, int n) { if (n >= MAXVAR) luaY_error("variable buffer overflow"); currState->varbuffer[n] = var; } static int aux_localname (TaggedString *n, struct State *st) { int i; for (i=st->nlocalvar-1; i >= 0; i--) if (n == st->localvar[i]) return i; /* local var index */ return -1; /* not found */ } static vardesc singlevar (TaggedString *n, struct State *st) { int i = aux_localname(n, st); if (i == -1) { /* check shadowing */ int l; for (l=1; l<=(st-mainState); l++) if (aux_localname(n, st-l) >= 0) luaY_syntaxerror("cannot access a variable in outer scope", n->str); return luaG_findsymbol(n)+1; /* positive value */ } else return -(i+1); /* negative value */ } static int indexupvalue (TaggedString *n) { vardesc v = singlevar(n, currState-1); int i; for (i=0; if->nupvalues; i++) { if (currState->upvalues[i] == v) return i; } /* new one */ if (++currState->f->nupvalues > MAXUPVALUES) luaY_error("too many upvalues in a single function"); currState->upvalues[i] = v; /* i = currState->f->nupvalues - 1 */ return i; } static void pushupvalue (TaggedString *n) { int i; if (currState == mainState) luaY_error("cannot access upvalue in main"); if (aux_localname(n, currState) >= 0) luaY_syntaxerror("cannot access an upvalue in current scope", n->str); i = indexupvalue(n); if (i == 0) code_opcode(PUSHUPVALUE0, 1); else { code_opcode(PUSHUPVALUE, 1); code_byte(i); } } void luaY_codedebugline (int line) { static int lastline = 0; if (lua_debug && line != lastline) { code_opcode(SETLINE, 0); code_word(line); lastline = line; } } static void adjuststack (int n) { if (n > 0) { code_opcode(POPS, -n); code_byte(n); } else if (n < 0) { if (n == -1) code_opcode(PUSHNIL, 1); else { code_opcode(PUSHNILS, -n); code_byte(-n); } } } static long adjust_functioncall (long exp, int i) { if (exp <= 0) return -exp; /* exp is -list length */ else { int temp = currState->f->code[exp]; currState->f->code[exp] = i; if (i != MULT_RET) deltastack(i); return temp+i; } } static void adjust_mult_assign (int vars, long exps) { if (exps > 0) { /* must correct function call */ int diff = currState->f->code[exps] - vars; if (diff < 0) adjust_functioncall(exps, -diff); else { adjust_functioncall(exps, 0); adjuststack(diff); } } else adjuststack((-exps)-vars); } static void code_args (int dots) { if (!dots) { code_opcode(ARGS, currState->nlocalvar); code_byte(currState->nlocalvar); } else { code_opcode(VARARGS, currState->nlocalvar+1); code_byte(currState->nlocalvar); add_localvar(luaS_new("arg")); } } static void lua_pushvar (vardesc number) { if (number > 0) { /* global var */ code_opcode(PUSHGLOBAL, 1); code_word(number-1); } else if (number < 0) { /* local var */ number = (-number) - 1; if (number < 10) code_opcode(PUSHLOCAL0 + number, 1); else { code_opcode(PUSHLOCAL, 1); code_byte(number); } } else { code_opcode(PUSHTABLE, -1); } } static void storevar (vardesc number) { if (number == 0) /* indexed var */ code_opcode(SETTABLE0, -3); else if (number > 0) { /* global var */ code_opcode(SETGLOBAL, -1); code_word(number-1); } else { /* number < 0 - local var */ number = (-number) - 1; if (number < 10) code_opcode(SETLOCAL0 + number, -1); else { code_opcode(SETLOCAL, -1); code_byte(number); } } } /* returns how many elements are left as 'garbage' on the stack */ static int lua_codestore (int i, int left) { if (currState->varbuffer[i] != 0 || /* global or local var or */ left+i == 0) { /* indexed var without values in between */ storevar(currState->varbuffer[i]); return left; } else { /* indexed var with values in between*/ code_opcode(SETTABLE, -1); code_byte(left+i); /* number of elements between table/index and value */ return left+2; /* table/index are not poped, since they are not on top */ } } static void codeIf (int thenAdd, int elseAdd) { int elseinit = elseAdd+sizeof(Word)+1; if (currState->pc == elseinit) { /* no else part */ currState->pc -= sizeof(Word)+1; elseinit = currState->pc; } else { currState->f->code[elseAdd] = JMP; code_word_at(elseAdd+1, currState->pc-elseinit); } currState->f->code[thenAdd] = IFFJMP; code_word_at(thenAdd+1, elseinit-(thenAdd+sizeof(Word)+1)); } static void code_shortcircuit (int pc, Byte jmp) { currState->f->code[pc] = jmp; code_word_at(pc+1, currState->pc - (pc + sizeof(Word)+1)); } static void codereturn (void) { code_opcode(RETCODE, 0); code_byte(currState->nlocalvar); currState->stacksize = currState->nlocalvar; } static void func_onstack (TProtoFunc *f) { int i; int nupvalues = (currState+1)->f->nupvalues; int c = next_constant(); ttype(&currState->f->consts[c]) = LUA_T_PROTO; currState->f->consts[c].value.tf = (currState+1)->f; for (i=0; iupvalues[i]); code_constant(c); code_opcode(CLOSURE, -nupvalues); } static void init_state (TaggedString *filename) { TProtoFunc *f = luaF_newproto(); currState->stacksize = 0; currState->maxstacksize = 0; currState->nlocalvar = 0; currState->f = f; f->fileName = filename; currState->pc = 0; currState->maxcode = 0; f->code = NULL; currState->maxconsts = 0; if (lua_debug) { currState->nvars = 0; currState->maxvars = 0; } else currState->maxvars = -1; /* flag no debug information */ code_byte(0); /* to be filled with stacksize */ } static void init_func (void) { if (currState-mainState >= MAXSTATES-1) luaY_error("too many nested functions"); currState++; init_state(mainState->f->fileName); luaY_codedebugline(luaX_linenumber); currState->f->lineDefined = luaX_linenumber; } static TProtoFunc *close_func (void) { TProtoFunc *f = currState->f; code_opcode(ENDCODE, 0); f->code[0] = currState->maxstacksize; f->code = luaM_reallocvector(f->code, currState->pc, Byte); f->consts = luaM_reallocvector(f->consts, f->nconsts, TObject); if (currState->maxvars != -1) { /* debug information? */ luaI_registerlocalvar(NULL, -1); /* flag end of vector */ f->locvars = luaM_reallocvector(f->locvars, currState->nvars, LocVar); } currState--; return f; } /* ** Parse LUA code. */ TProtoFunc *luaY_parser (ZIO *z, char *chunkname) { struct State state[MAXSTATES]; currState = mainState = &state[0]; luaX_setinput(z); init_state(luaS_new(chunkname)); if (luaY_parse ()) lua_error("parse error"); return close_func(); } %} %union { int vInt; real vReal; char *pChar; long vLong; TaggedString *pTStr; TProtoFunc *pFunc; } %start chunk %token WRONGTOKEN %token NIL %token IF THEN ELSE ELSEIF WHILE DO REPEAT UNTIL END %token RETURN %token LOCAL %token FUNCTION %token DOTS %token NUMBER %token NAME STRING %type PrepJump, PrepJumpPop %type exprlist, exprlist1 /* if > 0, points to function return counter (which has list length); if <= 0, -list lenght */ %type functioncall, expr /* if != 0, points to function return counter */ %type varlist1, funcParams, funcvalue %type fieldlist, localdeclist, decinit %type ffieldlist, ffieldlist1, semicolonpart %type lfieldlist, lfieldlist1 %type parlist1, par %type var, singlevar, funcname /* vardesc */ %type body %left AND OR %left EQ NE '>' '<' LE GE %left CONC %left '+' '-' %left '*' '/' %left UNARY NOT %right '^' %% /* beginning of rules section */ chunk : statlist ret ; statlist : /* empty */ | statlist stat sc { if (currState->stacksize != currState->nlocalvar) { luaY_error("contagem"); exit(1); }} ; sc : /* empty */ | ';' ; stat : IF expr1 THEN PrepJumpPop block PrepJump elsepart END { codeIf($4, $6); } | WHILE {$$=currState->pc;} expr1 DO PrepJumpPop block PrepJump END { currState->f->code[$5] = IFFJMP; code_word_at($5+1, currState->pc - ($5+sizeof(Word)+1)); currState->f->code[$7] = UPJMP; code_word_at($7+1, currState->pc - ($2)); } | REPEAT {$$=currState->pc;} block UNTIL expr1 PrepJumpPop { currState->f->code[$6] = IFFUPJMP; code_word_at($6+1, currState->pc - ($2)); } | varlist1 '=' exprlist1 {{ int i; int left = 0; adjust_mult_assign($1, $3); for (i=$1-1; i>=0; i--) left = lua_codestore(i, left); adjuststack(left); /* remove eventual 'garbage' left on stack */ }} | functioncall | LOCAL localdeclist decinit { currState->nlocalvar += $2; adjust_mult_assign($2, $3); } | FUNCTION funcname body { func_onstack($3); storevar($2); } ; block : {$$ = currState->nlocalvar;} chunk { adjuststack(currState->nlocalvar - $1); for (; currState->nlocalvar > $1; currState->nlocalvar--) luaI_unregisterlocalvar(luaX_linenumber); } ; funcname : var { init_func(); $$ = $1; } | varexp ':' NAME { code_string($3); $$ = 0; /* indexed variable */ init_func(); add_localvar(luaS_new("self")); } ; body : '(' parlist ')' chunk END { $$ = close_func(); } ; elsepart : /* empty */ | ELSE block | ELSEIF expr1 THEN PrepJumpPop block PrepJump elsepart { codeIf($4, $6); } ; ret : /* empty */ | RETURN exprlist sc { adjust_functioncall($2, MULT_RET); codereturn(); } ; PrepJump : /* empty */ { $$ = currState->pc; code_opcode(0, 0); /* open space */ code_word(0); } ; PrepJumpPop : PrepJump { $$ = $1; deltastack(-1); /* pop condition */ } ; expr1 : expr { adjust_functioncall($1, 1); } ; expr : '(' expr ')' { $$ = $2; } | expr1 EQ expr1 { code_opcode(EQOP, -1); $$ = 0; } | expr1 '<' expr1 { code_opcode(LTOP, -1); $$ = 0; } | expr1 '>' expr1 { code_opcode(GTOP, -1); $$ = 0; } | expr1 NE expr1 { code_opcode(NEQOP, -1); $$ = 0; } | expr1 LE expr1 { code_opcode(LEOP, -1); $$ = 0; } | expr1 GE expr1 { code_opcode(GEOP, -1); $$ = 0; } | expr1 '+' expr1 { code_opcode(ADDOP, -1); $$ = 0; } | expr1 '-' expr1 { code_opcode(SUBOP, -1); $$ = 0; } | expr1 '*' expr1 { code_opcode(MULTOP, -1); $$ = 0; } | expr1 '/' expr1 { code_opcode(DIVOP, -1); $$ = 0; } | expr1 '^' expr1 { code_opcode(POWOP, -1); $$ = 0; } | expr1 CONC expr1 { code_opcode(CONCOP, -1); $$ = 0; } | '-' expr1 %prec UNARY { code_opcode(MINUSOP, 0); $$ = 0;} | table { $$ = 0; } | varexp { $$ = 0;} | NUMBER { code_number($1); $$ = 0; } | STRING { code_string($1); $$ = 0; } | NIL {code_opcode(PUSHNIL, 1); $$ = 0; } | functioncall { $$ = $1; } | NOT expr1 { code_opcode(NOTOP, 0); $$ = 0;} | expr1 AND PrepJumpPop expr1 { code_shortcircuit($3, ONFJMP); $$ = 0; } | expr1 OR PrepJumpPop expr1 { code_shortcircuit($3, ONTJMP); $$ = 0; } | FUNCTION { init_func(); } body { func_onstack($3); $$ = 0; } ; table : { code_opcode(CREATEARRAY, 1); $$ = currState->pc; code_word(0); } '{' fieldlist '}' { code_word_at($1, $3); } ; functioncall : funcvalue funcParams { code_opcode(CALLFUNC, -($1+$2+1)); /* ajdust counts results */ code_byte($1+$2); $$ = currState->pc; code_byte(0); /* may be adjusted by other rules */ } ; funcvalue : varexp { $$ = 0; } | varexp ':' NAME { code_opcode(PUSHSELF, 1); code_word(string_constant($3)); $$ = 1; } ; funcParams : '(' exprlist ')' { $$ = adjust_functioncall($2, 1); } | table { $$ = 1; } ; exprlist : /* empty */ { $$ = 0; } | exprlist1 { $$ = $1; } ; exprlist1 : expr { if ($1 != 0) $$ = $1; else $$ = -1; } | exprlist1 ',' { $$ = adjust_functioncall($1, 1); } expr { if ($4 == 0) $$ = -($3 + 1); /* -length */ else { currState->f->code[$4] = $3; /* store list length */ $$ = $4; } } ; parlist : /* empty */ { code_args(0); } | parlist1 { code_args($1); } ; parlist1 : par { $$ = $1; } | parlist1 ',' par { if ($1) luaY_error("invalid parameter list"); $$ = $3; } ; par : NAME { add_localvar($1); $$ = 0; } | DOTS { $$ = 1; } ; fieldlist : lfieldlist { flush_list($1/LFIELDS_PER_FLUSH, $1%LFIELDS_PER_FLUSH); } semicolonpart { $$ = $1+$3; } | ffieldlist1 lastcomma { $$ = $1; flush_record($1%RFIELDS_PER_FLUSH); } ; semicolonpart : /* empty */ { $$ = 0; } | ';' ffieldlist { $$ = $2; flush_record($2%RFIELDS_PER_FLUSH); } ; lastcomma : /* empty */ | ',' ; ffieldlist : /* empty */ { $$ = 0; } | ffieldlist1 lastcomma { $$ = $1; } ; ffieldlist1 : ffield {$$=1;} | ffieldlist1 ',' ffield { $$=$1+1; if ($$%RFIELDS_PER_FLUSH == 0) flush_record(RFIELDS_PER_FLUSH); } ; ffield : ffieldkey '=' expr1 ; ffieldkey : '[' expr1 ']' | NAME { code_string($1); } ; lfieldlist : /* empty */ { $$ = 0; } | lfieldlist1 lastcomma { $$ = $1; } ; lfieldlist1 : expr1 {$$=1;} | lfieldlist1 ',' expr1 { $$=$1+1; if ($$%LFIELDS_PER_FLUSH == 0) flush_list($$/LFIELDS_PER_FLUSH - 1, LFIELDS_PER_FLUSH); } ; varlist1 : var { $$ = 1; add_varbuffer($1, 0); } | varlist1 ',' var { add_varbuffer($3, $1); $$ = $1+1; } ; var : singlevar { $$ = $1; } | varexp '[' expr1 ']' { $$ = 0; /* indexed variable */ } | varexp '.' NAME { code_string($3); $$ = 0; /* indexed variable */ } ; singlevar : NAME { $$ = singlevar($1, currState); } ; varexp : var { lua_pushvar($1); } | '%' NAME { pushupvalue($2); } ; localdeclist : NAME {store_localvar($1, 0); $$ = 1;} | localdeclist ',' NAME { store_localvar($3, $1); $$ = $1+1; } ; decinit : /* empty */ { $$ = 0; } | '=' exprlist1 { $$ = $2; } ; %%