| /* |
| ** $Id: lparser.c,v 1.190 2002/07/04 18:23:42 roberto Exp $ |
| ** Lua Parser |
| ** See Copyright Notice in lua.h |
| */ |
| |
| |
| #include <string.h> |
| |
| #include "lua.h" |
| |
| #include "lcode.h" |
| #include "ldebug.h" |
| #include "lfunc.h" |
| #include "llex.h" |
| #include "lmem.h" |
| #include "lobject.h" |
| #include "lopcodes.h" |
| #include "lparser.h" |
| #include "lstate.h" |
| #include "lstring.h" |
| |
| |
| |
| |
| #define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]]) |
| |
| |
| |
| /* |
| ** nodes for block list (list of active blocks) |
| */ |
| typedef struct BlockCnt { |
| struct BlockCnt *previous; /* chain */ |
| int breaklist; /* list of jumps out of this loop */ |
| int nactvar; /* # active local variables outside the breakable structure */ |
| int upval; /* true if some variable in the block is an upvalue */ |
| int isbreakable; /* true if `block' is a loop */ |
| } BlockCnt; |
| |
| |
| |
| /* |
| ** prototypes for recursive non-terminal functions |
| */ |
| static void body (LexState *ls, expdesc *v, int needself, int line); |
| static void chunk (LexState *ls); |
| static void constructor (LexState *ls, expdesc *v); |
| static void expr (LexState *ls, expdesc *v); |
| |
| |
| |
| static void next (LexState *ls) { |
| ls->lastline = ls->linenumber; |
| if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ |
| ls->t = ls->lookahead; /* use this one */ |
| ls->lookahead.token = TK_EOS; /* and discharge it */ |
| } |
| else |
| ls->t.token = luaX_lex(ls, &ls->t.seminfo); /* read next token */ |
| } |
| |
| |
| static void lookahead (LexState *ls) { |
| lua_assert(ls->lookahead.token == TK_EOS); |
| ls->lookahead.token = luaX_lex(ls, &ls->lookahead.seminfo); |
| } |
| |
| |
| static void error_expected (LexState *ls, int token) { |
| luaX_syntaxerror(ls, |
| luaO_pushfstring(ls->L, "`%s' expected", luaX_token2str(ls, token))); |
| } |
| |
| |
| static int testnext (LexState *ls, int c) { |
| if (ls->t.token == c) { |
| next(ls); |
| return 1; |
| } |
| else return 0; |
| } |
| |
| |
| static void check (LexState *ls, int c) { |
| if (!testnext(ls, c)) |
| error_expected(ls, c); |
| } |
| |
| |
| #define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } |
| |
| |
| |
| static void check_match (LexState *ls, int what, int who, int where) { |
| if (!testnext(ls, what)) { |
| if (where == ls->linenumber) |
| error_expected(ls, what); |
| else { |
| luaX_syntaxerror(ls, luaO_pushfstring(ls->L, |
| "`%s' expected (to close `%s' at line %d)", |
| luaX_token2str(ls, what), luaX_token2str(ls, who), where)); |
| } |
| } |
| } |
| |
| |
| static TString *str_checkname (LexState *ls) { |
| TString *ts; |
| check_condition(ls, (ls->t.token == TK_NAME), "<name> expected"); |
| ts = ls->t.seminfo.ts; |
| next(ls); |
| return ts; |
| } |
| |
| |
| static void init_exp (expdesc *e, expkind k, int i) { |
| e->f = e->t = NO_JUMP; |
| e->k = k; |
| e->info = i; |
| } |
| |
| |
| static void codestring (LexState *ls, expdesc *e, TString *s) { |
| init_exp(e, VK, luaK_stringK(ls->fs, s)); |
| } |
| |
| |
| static void checkname(LexState *ls, expdesc *e) { |
| codestring(ls, e, str_checkname(ls)); |
| } |
| |
| |
| static int luaI_registerlocalvar (LexState *ls, TString *varname) { |
| FuncState *fs = ls->fs; |
| Proto *f = fs->f; |
| luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, |
| LocVar, MAX_INT, ""); |
| f->locvars[fs->nlocvars].varname = varname; |
| return fs->nlocvars++; |
| } |
| |
| |
| static void new_localvar (LexState *ls, TString *name, int n) { |
| FuncState *fs = ls->fs; |
| luaX_checklimit(ls, fs->nactvar+n+1, MAXVARS, "local variables"); |
| fs->actvar[fs->nactvar+n] = luaI_registerlocalvar(ls, name); |
| } |
| |
| |
| static void adjustlocalvars (LexState *ls, int nvars) { |
| FuncState *fs = ls->fs; |
| fs->nactvar += nvars; |
| for (; nvars; nvars--) { |
| getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc; |
| } |
| } |
| |
| |
| static void removevars (LexState *ls, int tolevel) { |
| FuncState *fs = ls->fs; |
| while (fs->nactvar > tolevel) |
| getlocvar(fs, --fs->nactvar).endpc = fs->pc; |
| } |
| |
| |
| static void new_localvarstr (LexState *ls, const char *name, int n) { |
| new_localvar(ls, luaS_new(ls->L, name), n); |
| } |
| |
| |
| static void create_local (LexState *ls, const char *name) { |
| new_localvarstr(ls, name, 0); |
| adjustlocalvars(ls, 1); |
| } |
| |
| |
| static int indexupvalue (FuncState *fs, expdesc *v) { |
| int i; |
| for (i=0; i<fs->f->nupvalues; i++) { |
| if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->info) |
| return i; |
| } |
| /* new one */ |
| luaX_checklimit(fs->ls, fs->f->nupvalues+1, MAXUPVALUES, "upvalues"); |
| fs->upvalues[fs->f->nupvalues] = *v; |
| return fs->f->nupvalues++; |
| } |
| |
| |
| static int searchvar (FuncState *fs, TString *n) { |
| int i; |
| for (i=fs->nactvar-1; i >= 0; i--) { |
| if (n == getlocvar(fs, i).varname) |
| return i; |
| } |
| return -1; /* not found */ |
| } |
| |
| |
| static void markupval (FuncState *fs, int level) { |
| BlockCnt *bl = fs->bl; |
| while (bl && bl->nactvar > level) bl = bl->previous; |
| if (bl) bl->upval = 1; |
| } |
| |
| |
| static void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { |
| if (fs == NULL) /* no more levels? */ |
| init_exp(var, VGLOBAL, NO_REG); /* default is global variable */ |
| else { |
| int v = searchvar(fs, n); /* look up at current level */ |
| if (v >= 0) { |
| init_exp(var, VLOCAL, v); |
| if (!base) |
| markupval(fs, v); /* local will be used as an upval */ |
| } |
| else { /* not found at current level; try upper one */ |
| singlevaraux(fs->prev, n, var, 0); |
| if (var->k == VGLOBAL) { |
| if (base) |
| var->info = luaK_stringK(fs, n); /* info points to global name */ |
| } |
| else { /* LOCAL or UPVAL */ |
| var->info = indexupvalue(fs, var); |
| var->k = VUPVAL; /* upvalue in this level */ |
| } |
| } |
| } |
| } |
| |
| |
| static void singlevar (LexState *ls, expdesc *var, int base) { |
| singlevaraux(ls->fs, str_checkname(ls), var, base); |
| } |
| |
| |
| static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { |
| FuncState *fs = ls->fs; |
| int extra = nvars - nexps; |
| if (e->k == VCALL) { |
| extra++; /* includes call itself */ |
| if (extra <= 0) extra = 0; |
| else luaK_reserveregs(fs, extra-1); |
| luaK_setcallreturns(fs, e, extra); /* call provides the difference */ |
| } |
| else { |
| if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ |
| if (extra > 0) { |
| int reg = fs->freereg; |
| luaK_reserveregs(fs, extra); |
| luaK_nil(fs, reg, extra); |
| } |
| } |
| } |
| |
| |
| static void code_params (LexState *ls, int nparams, int dots) { |
| FuncState *fs = ls->fs; |
| adjustlocalvars(ls, nparams); |
| luaX_checklimit(ls, fs->nactvar, MAXPARAMS, "parameters"); |
| fs->f->numparams = cast(lu_byte, fs->nactvar); |
| fs->f->is_vararg = cast(lu_byte, dots); |
| if (dots) |
| create_local(ls, "arg"); |
| luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ |
| } |
| |
| |
| static void enterblock (FuncState *fs, BlockCnt *bl, int isbreakable) { |
| bl->breaklist = NO_JUMP; |
| bl->isbreakable = isbreakable; |
| bl->nactvar = fs->nactvar; |
| bl->upval = 0; |
| bl->previous = fs->bl; |
| fs->bl = bl; |
| lua_assert(fs->freereg == fs->nactvar); |
| } |
| |
| |
| static void leaveblock (FuncState *fs) { |
| BlockCnt *bl = fs->bl; |
| fs->bl = bl->previous; |
| removevars(fs->ls, bl->nactvar); |
| if (bl->upval) |
| luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); |
| lua_assert(bl->nactvar == fs->nactvar); |
| fs->freereg = fs->nactvar; /* free registers */ |
| luaK_patchtohere(fs, bl->breaklist); |
| } |
| |
| |
| static void pushclosure (LexState *ls, FuncState *func, expdesc *v) { |
| FuncState *fs = ls->fs; |
| Proto *f = fs->f; |
| int i; |
| luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *, |
| MAXARG_Bx, "constant table overflow"); |
| f->p[fs->np++] = func->f; |
| init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1)); |
| for (i=0; i<func->f->nupvalues; i++) { |
| luaK_exp2nextreg(fs, &func->upvalues[i]); |
| fs->freereg--; /* CLOSURE will use these values */ |
| } |
| } |
| |
| |
| static void open_func (LexState *ls, FuncState *fs) { |
| Proto *f = luaF_newproto(ls->L); |
| fs->f = f; |
| fs->prev = ls->fs; /* linked list of funcstates */ |
| fs->ls = ls; |
| fs->L = ls->L; |
| ls->fs = fs; |
| fs->pc = 0; |
| fs->lasttarget = 0; |
| fs->jpc = NO_JUMP; |
| fs->freereg = 0; |
| fs->nk = 0; |
| fs->h = luaH_new(ls->L, 0, 0); |
| fs->np = 0; |
| fs->nlocvars = 0; |
| fs->nactvar = 0; |
| fs->bl = NULL; |
| f->code = NULL; |
| f->source = ls->source; |
| f->maxstacksize = 1; /* register 0 is always valid */ |
| f->numparams = 0; /* default for main chunk */ |
| f->is_vararg = 0; /* default for main chunk */ |
| } |
| |
| |
| static void close_func (LexState *ls) { |
| lua_State *L = ls->L; |
| FuncState *fs = ls->fs; |
| Proto *f = fs->f; |
| removevars(ls, 0); |
| luaK_codeABC(fs, OP_RETURN, 0, 1, 0); /* final return */ |
| lua_assert(G(L)->roottable == fs->h); |
| G(L)->roottable = fs->h->next; |
| luaH_free(L, fs->h); |
| luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); |
| luaM_reallocvector(L, f->lineinfo, f->sizecode, fs->pc, int); |
| f->sizecode = fs->pc; |
| luaM_reallocvector(L, f->k, f->sizek, fs->nk, TObject); |
| f->sizek = fs->nk; |
| luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); |
| f->sizep = fs->np; |
| luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); |
| f->sizelocvars = fs->nlocvars; |
| lua_assert(luaG_checkcode(f)); |
| lua_assert(fs->bl == NULL); |
| ls->fs = fs->prev; |
| } |
| |
| |
| Proto *luaY_parser (lua_State *L, ZIO *z) { |
| struct LexState lexstate; |
| struct FuncState funcstate; |
| luaX_setinput(L, &lexstate, z, luaS_new(L, zname(z))); |
| open_func(&lexstate, &funcstate); |
| next(&lexstate); /* read first token */ |
| chunk(&lexstate); |
| check_condition(&lexstate, (lexstate.t.token == TK_EOS), "<eof> expected"); |
| close_func(&lexstate); |
| lua_assert(funcstate.prev == NULL); |
| lua_assert(funcstate.f->nupvalues == 0); |
| return funcstate.f; |
| } |
| |
| |
| |
| /*============================================================*/ |
| /* GRAMMAR RULES */ |
| /*============================================================*/ |
| |
| |
| static void luaY_field (LexState *ls, expdesc *v) { |
| /* field -> ['.' | ':'] NAME */ |
| FuncState *fs = ls->fs; |
| expdesc key; |
| luaK_exp2anyreg(fs, v); |
| next(ls); /* skip the dot or colon */ |
| checkname(ls, &key); |
| luaK_indexed(fs, v, &key); |
| } |
| |
| |
| static void luaY_index (LexState *ls, expdesc *v) { |
| /* index -> '[' expr ']' */ |
| next(ls); /* skip the '[' */ |
| expr(ls, v); |
| luaK_exp2val(ls->fs, v); |
| check(ls, ']'); |
| } |
| |
| |
| static int explist1 (LexState *ls, expdesc *v) { |
| /* explist1 -> expr { `,' expr } */ |
| int n = 1; /* at least one expression */ |
| expr(ls, v); |
| while (testnext(ls, ',')) { |
| luaK_exp2nextreg(ls->fs, v); |
| expr(ls, v); |
| n++; |
| } |
| return n; |
| } |
| |
| |
| static void funcargs (LexState *ls, expdesc *f) { |
| FuncState *fs = ls->fs; |
| expdesc args; |
| int base, nparams; |
| int line = ls->linenumber; |
| switch (ls->t.token) { |
| case '(': { /* funcargs -> `(' [ explist1 ] `)' */ |
| if (line != ls->lastline) |
| luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)"); |
| next(ls); |
| if (ls->t.token == ')') /* arg list is empty? */ |
| args.k = VVOID; |
| else { |
| explist1(ls, &args); |
| luaK_setcallreturns(fs, &args, LUA_MULTRET); |
| } |
| check_match(ls, ')', '(', line); |
| break; |
| } |
| case '{': { /* funcargs -> constructor */ |
| constructor(ls, &args); |
| break; |
| } |
| case TK_STRING: { /* funcargs -> STRING */ |
| codestring(ls, &args, ls->t.seminfo.ts); |
| next(ls); /* must use `seminfo' before `next' */ |
| break; |
| } |
| default: { |
| luaX_syntaxerror(ls, "function arguments expected"); |
| return; |
| } |
| } |
| lua_assert(f->k == VNONRELOC); |
| base = f->info; /* base register for call */ |
| if (args.k == VCALL) |
| nparams = LUA_MULTRET; /* open call */ |
| else { |
| if (args.k != VVOID) |
| luaK_exp2nextreg(fs, &args); /* close last argument */ |
| nparams = fs->freereg - (base+1); |
| } |
| init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); |
| fs->f->lineinfo[f->info] = line; |
| fs->freereg = base+1; /* call remove function and arguments and leaves |
| (unless changed) one result */ |
| } |
| |
| |
| |
| /* |
| ** {====================================================================== |
| ** Rules for Constructors |
| ** ======================================================================= |
| */ |
| |
| |
| struct ConsControl { |
| expdesc v; /* last list item read */ |
| expdesc *t; /* table descriptor */ |
| int nh; /* total number of `record' elements */ |
| int na; /* total number of array elements */ |
| int tostore; /* number of array elements pending to be stored */ |
| }; |
| |
| |
| static void recfield (LexState *ls, struct ConsControl *cc) { |
| /* recfield -> (NAME | `['exp1`]') = exp1 */ |
| FuncState *fs = ls->fs; |
| int reg = ls->fs->freereg; |
| expdesc key, val; |
| if (ls->t.token == TK_NAME) { |
| luaX_checklimit(ls, cc->nh, MAX_INT, "items in a constructor"); |
| cc->nh++; |
| checkname(ls, &key); |
| } |
| else /* ls->t.token == '[' */ |
| luaY_index(ls, &key); |
| check(ls, '='); |
| luaK_exp2RK(fs, &key); |
| expr(ls, &val); |
| luaK_exp2anyreg(fs, &val); |
| luaK_codeABC(fs, OP_SETTABLE, val.info, cc->t->info, luaK_exp2RK(fs, &key)); |
| fs->freereg = reg; /* free registers */ |
| } |
| |
| |
| static void closelistfield (FuncState *fs, struct ConsControl *cc) { |
| if (cc->v.k == VVOID) return; /* there is no list item */ |
| luaK_exp2nextreg(fs, &cc->v); |
| cc->v.k = VVOID; |
| if (cc->tostore == LFIELDS_PER_FLUSH) { |
| luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1); /* flush */ |
| cc->tostore = 0; /* no more items pending */ |
| fs->freereg = cc->t->info + 1; /* free registers */ |
| } |
| } |
| |
| |
| static void lastlistfield (FuncState *fs, struct ConsControl *cc) { |
| if (cc->tostore == 0) return; |
| if (cc->v.k == VCALL) { |
| luaK_setcallreturns(fs, &cc->v, LUA_MULTRET); |
| luaK_codeABx(fs, OP_SETLISTO, cc->t->info, cc->na-1); |
| } |
| else { |
| if (cc->v.k != VVOID) |
| luaK_exp2nextreg(fs, &cc->v); |
| luaK_codeABx(fs, OP_SETLIST, cc->t->info, cc->na-1); |
| } |
| fs->freereg = cc->t->info + 1; /* free registers */ |
| } |
| |
| |
| static void listfield (LexState *ls, struct ConsControl *cc) { |
| expr(ls, &cc->v); |
| luaX_checklimit(ls, cc->na, MAXARG_Bx, "items in a constructor"); |
| cc->na++; |
| cc->tostore++; |
| } |
| |
| |
| static void constructor (LexState *ls, expdesc *t) { |
| /* constructor -> ?? */ |
| FuncState *fs = ls->fs; |
| int line = ls->linenumber; |
| int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); |
| struct ConsControl cc; |
| cc.na = cc.nh = cc.tostore = 0; |
| cc.t = t; |
| init_exp(t, VRELOCABLE, pc); |
| init_exp(&cc.v, VVOID, 0); /* no value (yet) */ |
| luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */ |
| check(ls, '{'); |
| do { |
| lua_assert(cc.v.k == VVOID || cc.tostore > 0); |
| testnext(ls, ';'); /* compatibility only */ |
| if (ls->t.token == '}') break; |
| closelistfield(fs, &cc); |
| switch(ls->t.token) { |
| case TK_NAME: { /* may be listfields or recfields */ |
| lookahead(ls); |
| if (ls->lookahead.token != '=') /* expression? */ |
| listfield(ls, &cc); |
| else |
| recfield(ls, &cc); |
| break; |
| } |
| case '[': { /* constructor_item -> recfield */ |
| recfield(ls, &cc); |
| break; |
| } |
| default: { /* constructor_part -> listfield */ |
| listfield(ls, &cc); |
| break; |
| } |
| } |
| } while (testnext(ls, ',') || testnext(ls, ';')); |
| check_match(ls, '}', '{', line); |
| lastlistfield(fs, &cc); |
| if (cc.na > 0) |
| SETARG_B(fs->f->code[pc], luaO_log2(cc.na-1)+2); /* set initial table size */ |
| SETARG_C(fs->f->code[pc], luaO_log2(cc.nh)+1); /* set initial table size */ |
| } |
| |
| |
| /* }====================================================================== */ |
| |
| |
| |
| |
| /* |
| ** {====================================================================== |
| ** Expression parsing |
| ** ======================================================================= |
| */ |
| |
| |
| static void prefixexp (LexState *ls, expdesc *v) { |
| /* prefixexp -> NAME | '(' expr ')' */ |
| switch (ls->t.token) { |
| case '(': { |
| int line = ls->linenumber; |
| next(ls); |
| expr(ls, v); |
| check_match(ls, ')', '(', line); |
| luaK_dischargevars(ls->fs, v); |
| return; |
| } |
| case TK_NAME: { |
| singlevar(ls, v, 1); |
| return; |
| } |
| case '%': { /* for compatibility only */ |
| next(ls); /* skip `%' */ |
| singlevar(ls, v, 1); |
| check_condition(ls, v->k == VUPVAL, "global upvalues are obsolete"); |
| return; |
| } |
| default: { |
| luaX_syntaxerror(ls, "unexpected symbol"); |
| return; |
| } |
| } |
| } |
| |
| |
| static void primaryexp (LexState *ls, expdesc *v) { |
| /* primaryexp -> |
| prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */ |
| FuncState *fs = ls->fs; |
| prefixexp(ls, v); |
| for (;;) { |
| switch (ls->t.token) { |
| case '.': { /* field */ |
| luaY_field(ls, v); |
| break; |
| } |
| case '[': { /* `[' exp1 `]' */ |
| expdesc key; |
| luaK_exp2anyreg(fs, v); |
| luaY_index(ls, &key); |
| luaK_indexed(fs, v, &key); |
| break; |
| } |
| case ':': { /* `:' NAME funcargs */ |
| expdesc key; |
| next(ls); |
| checkname(ls, &key); |
| luaK_self(fs, v, &key); |
| funcargs(ls, v); |
| break; |
| } |
| case '(': case TK_STRING: case '{': { /* funcargs */ |
| luaK_exp2nextreg(fs, v); |
| funcargs(ls, v); |
| break; |
| } |
| default: return; |
| } |
| } |
| } |
| |
| |
| static void simpleexp (LexState *ls, expdesc *v) { |
| /* simpleexp -> NUMBER | STRING | NIL | constructor | FUNCTION body |
| | primaryexp */ |
| switch (ls->t.token) { |
| case TK_NUMBER: { |
| init_exp(v, VK, luaK_numberK(ls->fs, ls->t.seminfo.r)); |
| next(ls); /* must use `seminfo' before `next' */ |
| break; |
| } |
| case TK_STRING: { |
| codestring(ls, v, ls->t.seminfo.ts); |
| next(ls); /* must use `seminfo' before `next' */ |
| break; |
| } |
| case TK_NIL: { |
| init_exp(v, VNIL, 0); |
| next(ls); |
| break; |
| } |
| case TK_TRUE: { |
| init_exp(v, VTRUE, 0); |
| next(ls); |
| break; |
| } |
| case TK_FALSE: { |
| init_exp(v, VFALSE, 0); |
| next(ls); |
| break; |
| } |
| case '{': { /* constructor */ |
| constructor(ls, v); |
| break; |
| } |
| case TK_FUNCTION: { |
| next(ls); |
| body(ls, v, 0, ls->linenumber); |
| break; |
| } |
| default: { |
| primaryexp(ls, v); |
| break; |
| } |
| } |
| } |
| |
| |
| |
| |
| static UnOpr getunopr (int op) { |
| switch (op) { |
| case TK_NOT: return OPR_NOT; |
| case '-': return OPR_MINUS; |
| default: return OPR_NOUNOPR; |
| } |
| } |
| |
| |
| static BinOpr getbinopr (int op) { |
| switch (op) { |
| case '+': return OPR_ADD; |
| case '-': return OPR_SUB; |
| case '*': return OPR_MULT; |
| case '/': return OPR_DIV; |
| case '^': return OPR_POW; |
| case TK_CONCAT: return OPR_CONCAT; |
| case TK_NE: return OPR_NE; |
| case TK_EQ: return OPR_EQ; |
| case '<': return OPR_LT; |
| case TK_LE: return OPR_LE; |
| case '>': return OPR_GT; |
| case TK_GE: return OPR_GE; |
| case TK_AND: return OPR_AND; |
| case TK_OR: return OPR_OR; |
| default: return OPR_NOBINOPR; |
| } |
| } |
| |
| |
| static const struct { |
| lu_byte left; /* left priority for each binary operator */ |
| lu_byte right; /* right priority */ |
| } priority[] = { /* ORDER OPR */ |
| {6, 6}, {6, 6}, {7, 7}, {7, 7}, /* arithmetic */ |
| {10, 9}, {5, 4}, /* power and concat (right associative) */ |
| {3, 3}, {3, 3}, /* equality */ |
| {3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */ |
| {2, 2}, {1, 1} /* logical (and/or) */ |
| }; |
| |
| #define UNARY_PRIORITY 8 /* priority for unary operators */ |
| |
| |
| /* |
| ** subexpr -> (simplexep | unop subexpr) { binop subexpr } |
| ** where `binop' is any binary operator with a priority higher than `limit' |
| */ |
| static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { |
| BinOpr op; |
| UnOpr uop = getunopr(ls->t.token); |
| if (uop != OPR_NOUNOPR) { |
| next(ls); |
| subexpr(ls, v, UNARY_PRIORITY); |
| luaK_prefix(ls->fs, uop, v); |
| } |
| else simpleexp(ls, v); |
| /* expand while operators have priorities higher than `limit' */ |
| op = getbinopr(ls->t.token); |
| while (op != OPR_NOBINOPR && cast(int, priority[op].left) > limit) { |
| expdesc v2; |
| BinOpr nextop; |
| next(ls); |
| luaK_infix(ls->fs, op, v); |
| /* read sub-expression with higher priority */ |
| nextop = subexpr(ls, &v2, cast(int, priority[op].right)); |
| luaK_posfix(ls->fs, op, v, &v2); |
| op = nextop; |
| } |
| return op; /* return first untreated operator */ |
| } |
| |
| |
| static void expr (LexState *ls, expdesc *v) { |
| subexpr(ls, v, -1); |
| } |
| |
| /* }==================================================================== */ |
| |
| |
| /* |
| ** {====================================================================== |
| ** Rules for Statements |
| ** ======================================================================= |
| */ |
| |
| |
| static int block_follow (int token) { |
| switch (token) { |
| case TK_ELSE: case TK_ELSEIF: case TK_END: |
| case TK_UNTIL: case TK_EOS: |
| return 1; |
| default: return 0; |
| } |
| } |
| |
| |
| static void block (LexState *ls) { |
| /* block -> chunk */ |
| FuncState *fs = ls->fs; |
| BlockCnt bl; |
| enterblock(fs, &bl, 0); |
| chunk(ls); |
| lua_assert(bl.breaklist == NO_JUMP); |
| leaveblock(fs); |
| } |
| |
| |
| /* |
| ** structure to chain all variables in the left-hand side of an |
| ** assignment |
| */ |
| struct LHS_assign { |
| struct LHS_assign *prev; |
| expdesc v; /* variable (global, local, upvalue, or indexed) */ |
| }; |
| |
| |
| /* |
| ** check whether, in an assignment to a local variable, the local variable |
| ** is needed in a previous assignment (to a table). If so, save original |
| ** local value in a safe place and use this safe copy in the previous |
| ** assignment. |
| */ |
| static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { |
| FuncState *fs = ls->fs; |
| int extra = fs->freereg; /* eventual position to save local variable */ |
| int conflict = 0; |
| for (; lh; lh = lh->prev) { |
| if (lh->v.k == VINDEXED) { |
| if (lh->v.info == v->info) { /* conflict? */ |
| conflict = 1; |
| lh->v.info = extra; /* previous assignment will use safe copy */ |
| } |
| if (lh->v.aux == v->info) { /* conflict? */ |
| conflict = 1; |
| lh->v.aux = extra; /* previous assignment will use safe copy */ |
| } |
| } |
| } |
| if (conflict) { |
| luaK_codeABC(fs, OP_MOVE, fs->freereg, v->info, 0); /* make copy */ |
| luaK_reserveregs(fs, 1); |
| } |
| } |
| |
| |
| static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { |
| expdesc e; |
| check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED, |
| "syntax error"); |
| if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */ |
| struct LHS_assign nv; |
| nv.prev = lh; |
| primaryexp(ls, &nv.v); |
| if (nv.v.k == VLOCAL) |
| check_conflict(ls, lh, &nv.v); |
| assignment(ls, &nv, nvars+1); |
| } |
| else { /* assignment -> `=' explist1 */ |
| int nexps; |
| check(ls, '='); |
| nexps = explist1(ls, &e); |
| if (nexps != nvars) { |
| adjust_assign(ls, nvars, nexps, &e); |
| if (nexps > nvars) |
| ls->fs->freereg -= nexps - nvars; /* remove extra values */ |
| } |
| else { |
| luaK_setcallreturns(ls->fs, &e, 1); /* close last expression */ |
| luaK_storevar(ls->fs, &lh->v, &e); |
| return; /* avoid default */ |
| } |
| } |
| init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ |
| luaK_storevar(ls->fs, &lh->v, &e); |
| } |
| |
| |
| static void cond (LexState *ls, expdesc *v) { |
| /* cond -> exp */ |
| expr(ls, v); /* read condition */ |
| if (v->k == VNIL) v->k = VFALSE; /* `falses' are all equal here */ |
| luaK_goiftrue(ls->fs, v); |
| luaK_patchtohere(ls->fs, v->t); |
| } |
| |
| |
| /* |
| ** The while statement optimizes its code by coding the condition |
| ** after its body (and thus avoiding one jump in the loop). |
| */ |
| |
| /* |
| ** maximum size of expressions for optimizing `while' code |
| */ |
| #ifndef MAXEXPWHILE |
| #define MAXEXPWHILE 100 |
| #endif |
| |
| /* |
| ** the call `luaK_goiffalse' may grow the size of an expression by |
| ** at most this: |
| */ |
| #define EXTRAEXP 5 |
| |
| static void whilestat (LexState *ls, int line) { |
| /* whilestat -> WHILE cond DO block END */ |
| Instruction codeexp[MAXEXPWHILE + EXTRAEXP]; |
| int lineexp = 0; |
| int i; |
| int sizeexp; |
| FuncState *fs = ls->fs; |
| int whileinit, blockinit, expinit; |
| expdesc v; |
| BlockCnt bl; |
| next(ls); /* skip WHILE */ |
| whileinit = luaK_jump(fs); /* jump to condition (which will be moved) */ |
| expinit = luaK_getlabel(fs); |
| expr(ls, &v); /* parse condition */ |
| if (v.k == VK) v.k = VTRUE; /* `trues' are all equal here */ |
| lineexp = ls->linenumber; |
| luaK_goiffalse(fs, &v); |
| luaK_concat(fs, &v.f, fs->jpc); |
| fs->jpc = NO_JUMP; |
| sizeexp = fs->pc - expinit; /* size of expression code */ |
| if (sizeexp > MAXEXPWHILE) |
| luaX_syntaxerror(ls, "`while' condition too complex"); |
| for (i = 0; i < sizeexp; i++) /* save `exp' code */ |
| codeexp[i] = fs->f->code[expinit + i]; |
| fs->pc = expinit; /* remove `exp' code */ |
| enterblock(fs, &bl, 1); |
| check(ls, TK_DO); |
| blockinit = luaK_getlabel(fs); |
| block(ls); |
| luaK_patchtohere(fs, whileinit); /* initial jump jumps to here */ |
| /* move `exp' back to code */ |
| if (v.t != NO_JUMP) v.t += fs->pc - expinit; |
| if (v.f != NO_JUMP) v.f += fs->pc - expinit; |
| for (i=0; i<sizeexp; i++) |
| luaK_code(fs, codeexp[i], lineexp); |
| check_match(ls, TK_END, TK_WHILE, line); |
| leaveblock(fs); |
| luaK_patchlist(fs, v.t, blockinit); /* true conditions go back to loop */ |
| luaK_patchtohere(fs, v.f); /* false conditions finish the loop */ |
| } |
| |
| |
| static void repeatstat (LexState *ls, int line) { |
| /* repeatstat -> REPEAT block UNTIL cond */ |
| FuncState *fs = ls->fs; |
| int repeat_init = luaK_getlabel(fs); |
| expdesc v; |
| BlockCnt bl; |
| enterblock(fs, &bl, 1); |
| next(ls); |
| block(ls); |
| check_match(ls, TK_UNTIL, TK_REPEAT, line); |
| cond(ls, &v); |
| luaK_patchlist(fs, v.f, repeat_init); |
| leaveblock(fs); |
| } |
| |
| |
| static int exp1 (LexState *ls) { |
| expdesc e; |
| int k; |
| expr(ls, &e); |
| k = e.k; |
| luaK_exp2nextreg(ls->fs, &e); |
| return k; |
| } |
| |
| |
| static void fornum (LexState *ls, TString *varname, int line) { |
| /* fornum -> NAME = exp1,exp1[,exp1] DO body */ |
| FuncState *fs = ls->fs; |
| int prep, endfor; |
| int base = fs->freereg; |
| new_localvar(ls, varname, 0); |
| new_localvarstr(ls, "(for limit)", 1); |
| new_localvarstr(ls, "(for step)", 2); |
| check(ls, '='); |
| exp1(ls); /* initial value */ |
| check(ls, ','); |
| exp1(ls); /* limit */ |
| if (testnext(ls, ',')) |
| exp1(ls); /* optional step */ |
| else { /* default step = 1 */ |
| luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1)); |
| luaK_reserveregs(fs, 1); |
| } |
| adjustlocalvars(ls, 3); /* scope for control variables */ |
| luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1); |
| luaK_jump(fs); |
| prep = luaK_getlabel(fs); |
| check(ls, TK_DO); |
| block(ls); |
| luaK_patchtohere(fs, prep-1); |
| endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP); |
| luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */ |
| luaK_patchlist(fs, endfor, prep); |
| } |
| |
| |
| static void forlist (LexState *ls, TString *indexname) { |
| /* forlist -> NAME {,NAME} IN explist1 DO body */ |
| FuncState *fs = ls->fs; |
| expdesc e; |
| int line; |
| int nvars = 0; |
| int prep; |
| int base = fs->freereg; |
| new_localvarstr(ls, "(for generator)", nvars++); |
| new_localvarstr(ls, "(for state)", nvars++); |
| new_localvar(ls, indexname, nvars++); |
| while (testnext(ls, ',')) |
| new_localvar(ls, str_checkname(ls), nvars++); |
| check(ls, TK_IN); |
| line = ls->linenumber; |
| adjust_assign(ls, 3, explist1(ls, &e), &e); |
| luaK_reserveregs(fs, nvars - 3); /* registers for other variables */ |
| luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP); |
| adjustlocalvars(ls, nvars); /* scope for all variables */ |
| check(ls, TK_DO); |
| prep = luaK_getlabel(fs); |
| block(ls); |
| luaK_patchtohere(fs, prep-1); |
| removevars(fs->ls, fs->nactvar - nvars); /* deactivate locals for next op. */ |
| luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3); |
| luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */ |
| luaK_patchlist(fs, luaK_jump(fs), prep); |
| } |
| |
| |
| static void forstat (LexState *ls, int line) { |
| /* forstat -> fornum | forlist */ |
| FuncState *fs = ls->fs; |
| TString *varname; |
| BlockCnt bl; |
| enterblock(fs, &bl, 1); |
| next(ls); /* skip `for' */ |
| varname = str_checkname(ls); /* first variable name */ |
| switch (ls->t.token) { |
| case '=': fornum(ls, varname, line); break; |
| case ',': case TK_IN: forlist(ls, varname); break; |
| default: luaX_syntaxerror(ls, "`=' or `in' expected"); |
| } |
| check_match(ls, TK_END, TK_FOR, line); |
| leaveblock(fs); |
| } |
| |
| |
| static void test_then_block (LexState *ls, expdesc *v) { |
| /* test_then_block -> [IF | ELSEIF] cond THEN block */ |
| next(ls); /* skip IF or ELSEIF */ |
| cond(ls, v); |
| check(ls, TK_THEN); |
| block(ls); /* `then' part */ |
| } |
| |
| |
| static void ifstat (LexState *ls, int line) { |
| /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ |
| FuncState *fs = ls->fs; |
| expdesc v; |
| int escapelist = NO_JUMP; |
| test_then_block(ls, &v); /* IF cond THEN block */ |
| while (ls->t.token == TK_ELSEIF) { |
| luaK_concat(fs, &escapelist, luaK_jump(fs)); |
| luaK_patchtohere(fs, v.f); |
| test_then_block(ls, &v); /* ELSEIF cond THEN block */ |
| } |
| if (ls->t.token == TK_ELSE) { |
| luaK_concat(fs, &escapelist, luaK_jump(fs)); |
| luaK_patchtohere(fs, v.f); |
| next(ls); /* skip ELSE (after patch, for correct line info) */ |
| block(ls); /* `else' part */ |
| } |
| else |
| luaK_concat(fs, &escapelist, v.f); |
| luaK_patchtohere(fs, escapelist); |
| check_match(ls, TK_END, TK_IF, line); |
| } |
| |
| |
| static void localfunc (LexState *ls) { |
| expdesc v, b; |
| new_localvar(ls, str_checkname(ls), 0); |
| init_exp(&v, VLOCAL, ls->fs->freereg++); |
| adjustlocalvars(ls, 1); |
| body(ls, &b, 0, ls->linenumber); |
| luaK_storevar(ls->fs, &v, &b); |
| } |
| |
| |
| static void localstat (LexState *ls) { |
| /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */ |
| int nvars = 0; |
| int nexps; |
| expdesc e; |
| do { |
| new_localvar(ls, str_checkname(ls), nvars++); |
| } while (testnext(ls, ',')); |
| if (testnext(ls, '=')) |
| nexps = explist1(ls, &e); |
| else { |
| e.k = VVOID; |
| nexps = 0; |
| } |
| adjust_assign(ls, nvars, nexps, &e); |
| adjustlocalvars(ls, nvars); |
| } |
| |
| |
| static int funcname (LexState *ls, expdesc *v) { |
| /* funcname -> NAME {field} [`:' NAME] */ |
| int needself = 0; |
| singlevar(ls, v, 1); |
| while (ls->t.token == '.') |
| luaY_field(ls, v); |
| if (ls->t.token == ':') { |
| needself = 1; |
| luaY_field(ls, v); |
| } |
| return needself; |
| } |
| |
| |
| static void funcstat (LexState *ls, int line) { |
| /* funcstat -> FUNCTION funcname body */ |
| int needself; |
| expdesc v, b; |
| next(ls); /* skip FUNCTION */ |
| needself = funcname(ls, &v); |
| body(ls, &b, needself, line); |
| luaK_storevar(ls->fs, &v, &b); |
| } |
| |
| |
| static void exprstat (LexState *ls) { |
| /* stat -> func | assignment */ |
| FuncState *fs = ls->fs; |
| struct LHS_assign v; |
| primaryexp(ls, &v.v); |
| if (v.v.k == VCALL) { /* stat -> func */ |
| luaK_setcallreturns(fs, &v.v, 0); /* call statement uses no results */ |
| } |
| else { /* stat -> assignment */ |
| v.prev = NULL; |
| assignment(ls, &v, 1); |
| } |
| } |
| |
| |
| static void retstat (LexState *ls) { |
| /* stat -> RETURN explist */ |
| FuncState *fs = ls->fs; |
| expdesc e; |
| int first, nret; /* registers with returned values */ |
| next(ls); /* skip RETURN */ |
| if (block_follow(ls->t.token) || ls->t.token == ';') |
| first = nret = 0; /* return no values */ |
| else { |
| nret = explist1(ls, &e); /* optional return values */ |
| if (e.k == VCALL) { |
| luaK_setcallreturns(fs, &e, LUA_MULTRET); |
| if (nret == 1) { /* tail call? */ |
| SET_OPCODE(getcode(fs,&e), OP_TAILCALL); |
| lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); |
| } |
| first = fs->nactvar; |
| nret = LUA_MULTRET; /* return all values */ |
| } |
| else { |
| if (nret == 1) /* only one single value? */ |
| first = luaK_exp2anyreg(fs, &e); |
| else { |
| luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ |
| first = fs->nactvar; /* return all `active' values */ |
| lua_assert(nret == fs->freereg - first); |
| } |
| } |
| } |
| luaK_codeABC(fs, OP_RETURN, first, nret+1, 0); |
| } |
| |
| |
| static void breakstat (LexState *ls) { |
| /* stat -> BREAK [NAME] */ |
| FuncState *fs = ls->fs; |
| BlockCnt *bl = fs->bl; |
| int upval = 0; |
| next(ls); /* skip BREAK */ |
| while (bl && !bl->isbreakable) { |
| upval |= bl->upval; |
| bl = bl->previous; |
| } |
| if (!bl) |
| luaX_syntaxerror(ls, "no loop to break"); |
| if (upval) |
| luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0); |
| luaK_concat(fs, &bl->breaklist, luaK_jump(fs)); |
| } |
| |
| |
| static int statement (LexState *ls) { |
| int line = ls->linenumber; /* may be needed for error messages */ |
| switch (ls->t.token) { |
| case TK_IF: { /* stat -> ifstat */ |
| ifstat(ls, line); |
| return 0; |
| } |
| case TK_WHILE: { /* stat -> whilestat */ |
| whilestat(ls, line); |
| return 0; |
| } |
| case TK_DO: { /* stat -> DO block END */ |
| next(ls); /* skip DO */ |
| block(ls); |
| check_match(ls, TK_END, TK_DO, line); |
| return 0; |
| } |
| case TK_FOR: { /* stat -> forstat */ |
| forstat(ls, line); |
| return 0; |
| } |
| case TK_REPEAT: { /* stat -> repeatstat */ |
| repeatstat(ls, line); |
| return 0; |
| } |
| case TK_FUNCTION: { |
| funcstat(ls, line); /* stat -> funcstat */ |
| return 0; |
| } |
| case TK_LOCAL: { /* stat -> localstat */ |
| next(ls); /* skip LOCAL */ |
| if (testnext(ls, TK_FUNCTION)) /* local function? */ |
| localfunc(ls); |
| else |
| localstat(ls); |
| return 0; |
| } |
| case TK_RETURN: { /* stat -> retstat */ |
| retstat(ls); |
| return 1; /* must be last statement */ |
| } |
| case TK_BREAK: { /* stat -> breakstat */ |
| breakstat(ls); |
| return 1; /* must be last statement */ |
| } |
| default: { |
| exprstat(ls); |
| return 0; /* to avoid warnings */ |
| } |
| } |
| } |
| |
| |
| static void parlist (LexState *ls) { |
| /* parlist -> [ param { `,' param } ] */ |
| int nparams = 0; |
| int dots = 0; |
| if (ls->t.token != ')') { /* is `parlist' not empty? */ |
| do { |
| switch (ls->t.token) { |
| case TK_DOTS: dots = 1; next(ls); break; |
| case TK_NAME: new_localvar(ls, str_checkname(ls), nparams++); break; |
| default: luaX_syntaxerror(ls, "<name> or `...' expected"); |
| } |
| } while (!dots && testnext(ls, ',')); |
| } |
| code_params(ls, nparams, dots); |
| } |
| |
| |
| static void body (LexState *ls, expdesc *e, int needself, int line) { |
| /* body -> `(' parlist `)' chunk END */ |
| FuncState new_fs; |
| open_func(ls, &new_fs); |
| new_fs.f->lineDefined = line; |
| check(ls, '('); |
| if (needself) |
| create_local(ls, "self"); |
| parlist(ls); |
| check(ls, ')'); |
| chunk(ls); |
| check_match(ls, TK_END, TK_FUNCTION, line); |
| close_func(ls); |
| pushclosure(ls, &new_fs, e); |
| } |
| |
| |
| /* }====================================================================== */ |
| |
| |
| static void chunk (LexState *ls) { |
| /* chunk -> { stat [`;'] } */ |
| int islast = 0; |
| while (!islast && !block_follow(ls->t.token)) { |
| islast = statement(ls); |
| testnext(ls, ';'); |
| lua_assert(ls->fs->freereg >= ls->fs->nactvar); |
| ls->fs->freereg = ls->fs->nactvar; /* free registers */ |
| } |
| } |
| |