| /* |
| ** $Id: lparser.c,v 1.151 2001/06/28 14:57:17 roberto Exp roberto $ |
| ** LL(1) Parser and code generator for Lua |
| ** See Copyright Notice in lua.h |
| */ |
| |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #define LUA_PRIVATE |
| #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" |
| |
| |
| /* |
| ** Constructors descriptor: |
| ** `n' indicates number of elements, and `k' signals whether |
| ** it is a list constructor (k = 0) or a record constructor (k = 1) |
| ** or empty (k = `;' or `}') |
| */ |
| typedef struct Constdesc { |
| int n; |
| int k; |
| } Constdesc; |
| |
| |
| /* |
| ** nodes for break list (list of active breakable loops) |
| */ |
| typedef struct Breaklabel { |
| struct Breaklabel *previous; /* chain */ |
| int breaklist; /* list of jumps out of this loop */ |
| } Breaklabel; |
| |
| |
| |
| |
| /* |
| ** 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) { |
| l_char buff[30], t[TOKEN_LEN]; |
| luaX_token2str(token, t); |
| sprintf(buff, l_s("`%.10s' expected"), t); |
| luaK_error(ls, buff); |
| } |
| |
| |
| static void check (LexState *ls, int c) { |
| if (ls->t.token != c) |
| error_expected(ls, c); |
| next(ls); |
| } |
| |
| |
| static void check_condition (LexState *ls, int c, const l_char *msg) { |
| if (!c) luaK_error(ls, msg); |
| } |
| |
| |
| static int optional (LexState *ls, int c) { |
| if (ls->t.token == c) { |
| next(ls); |
| return 1; |
| } |
| else return 0; |
| } |
| |
| |
| static void check_match (LexState *ls, int what, int who, int where) { |
| if (ls->t.token != what) { |
| if (where == ls->linenumber) |
| error_expected(ls, what); |
| else { |
| l_char buff[70]; |
| l_char t_what[TOKEN_LEN], t_who[TOKEN_LEN]; |
| luaX_token2str(what, t_what); |
| luaX_token2str(who, t_who); |
| sprintf(buff, l_s("`%.10s' expected (to close `%.10s' at line %d)"), |
| t_what, t_who, where); |
| luaK_error(ls, buff); |
| } |
| } |
| next(ls); |
| } |
| |
| |
| static TString *str_checkname (LexState *ls) { |
| check_condition(ls, (ls->t.token == TK_NAME), l_s("<name> expected")); |
| return ls->t.seminfo.ts; |
| } |
| |
| |
| static void init_exp (expdesc *e, expkind k, int i) { |
| e->f = e->t = NO_JUMP; |
| e->k = k; |
| e->u.i.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)); |
| next(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, l_s("")); |
| 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->nactloc+n+1, MAXLOCALS, l_s("local variables")); |
| fs->actloc[fs->nactloc+n] = luaI_registerlocalvar(ls, name); |
| } |
| |
| |
| static void adjustlocalvars (LexState *ls, int nvars) { |
| FuncState *fs = ls->fs; |
| while (nvars--) |
| fs->f->locvars[fs->actloc[fs->nactloc++]].startpc = fs->pc; |
| } |
| |
| |
| static void removelocalvars (LexState *ls, int nvars) { |
| FuncState *fs = ls->fs; |
| while (nvars--) |
| fs->f->locvars[fs->actloc[--fs->nactloc]].endpc = fs->pc; |
| } |
| |
| |
| static void new_localvarstr (LexState *ls, const l_char *name, int n) { |
| new_localvar(ls, luaS_new(ls->L, name), n); |
| } |
| |
| |
| static int search_local (LexState *ls, TString *n, expdesc *var) { |
| FuncState *fs; |
| int level = 0; |
| for (fs=ls->fs; fs; fs=fs->prev) { |
| int i; |
| for (i=fs->nactloc-1; i >= 0; i--) { |
| if (n == fs->f->locvars[fs->actloc[i]].varname) { |
| init_exp(var, VLOCAL, i); |
| return level; |
| } |
| } |
| level++; /* `var' not found; check outer level */ |
| } |
| init_exp(var, VGLOBAL, 0); /* not found in any level; must be global */ |
| return -1; |
| } |
| |
| |
| static void singlevar (LexState *ls, TString *n, expdesc *var) { |
| int level = search_local(ls, n, var); |
| if (level >= 1) /* neither local (0) nor global (-1)? */ |
| luaX_syntaxerror(ls, l_s("cannot access a variable in outer function"), |
| getstr(n)); |
| else if (level == -1) /* global? */ |
| var->u.i.info = luaK_stringk(ls->fs, n); |
| } |
| |
| |
| static int indexupvalue (LexState *ls, expdesc *v) { |
| FuncState *fs = ls->fs; |
| int i; |
| for (i=0; i<fs->f->nupvalues; i++) { |
| if (fs->upvalues[i].k == v->k && fs->upvalues[i].u.i.info == v->u.i.info) |
| return i; |
| } |
| /* new one */ |
| luaX_checklimit(ls, fs->f->nupvalues+1, MAXUPVALUES, l_s("upvalues")); |
| fs->upvalues[fs->f->nupvalues] = *v; |
| return fs->f->nupvalues++; |
| } |
| |
| |
| static void codeupvalue (LexState *ls, expdesc *v, TString *n) { |
| FuncState *fs = ls->fs; |
| int level; |
| level = search_local(ls, n, v); |
| if (level == -1) { /* global? */ |
| if (fs->prev == NULL) |
| luaX_syntaxerror(ls, l_s("cannot access an upvalue at top level"), |
| getstr(n)); |
| v->u.i.info = luaK_stringk(fs->prev, n); |
| } |
| else if (level != 1) { |
| luaX_syntaxerror(ls, |
| l_s("upvalue must be global or local to immediately outer function"), |
| getstr(n)); |
| } |
| init_exp(v, VRELOCABLE, |
| luaK_codeABc(fs, OP_LOADUPVAL, 0, indexupvalue(ls, v))); |
| } |
| |
| |
| 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, short dots) { |
| FuncState *fs = ls->fs; |
| adjustlocalvars(ls, nparams); |
| luaX_checklimit(ls, fs->nactloc, MAXPARAMS, l_s("parameters")); |
| fs->f->numparams = (short)fs->nactloc; /* `self' could be there already */ |
| fs->f->is_vararg = dots; |
| if (dots) { |
| new_localvarstr(ls, l_s("arg"), 0); |
| adjustlocalvars(ls, 1); |
| } |
| luaK_reserveregs(fs, fs->nactloc); /* reserve register for parameters */ |
| } |
| |
| |
| static void enterbreak (FuncState *fs, Breaklabel *bl) { |
| bl->breaklist = NO_JUMP; |
| bl->previous = fs->bl; |
| fs->bl = bl; |
| } |
| |
| |
| static void leavebreak (FuncState *fs, Breaklabel *bl) { |
| fs->bl = bl->previous; |
| luaK_patchlist(fs, bl->breaklist, luaK_getlabel(fs)); |
| } |
| |
| |
| static void pushclosure (LexState *ls, FuncState *func, expdesc *v) { |
| FuncState *fs = ls->fs; |
| Proto *f = fs->f; |
| int i; |
| int reg = fs->freereg; |
| for (i=0; i<func->f->nupvalues; i++) |
| luaK_exp2nextreg(fs, &func->upvalues[i]); |
| luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *, |
| MAXARG_Bc, l_s("constant table overflow")); |
| f->p[fs->np++] = func->f; |
| fs->freereg = reg; /* CLOSURE will consume those values */ |
| init_exp(v, VNONRELOC, reg); |
| luaK_reserveregs(fs, 1); |
| luaK_codeABc(fs, OP_CLOSURE, v->u.i.info, fs->np-1); |
| } |
| |
| |
| 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->jlt = NO_JUMP; |
| fs->freereg = 0; |
| fs->nk = 0; |
| fs->np = 0; |
| fs->nlineinfo = 0; |
| fs->nlocvars = 0; |
| fs->nactloc = 0; |
| fs->lastline = 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; |
| luaK_codeABC(fs, OP_RETURN, 0, 0, 0); /* final return */ |
| luaK_getlabel(fs); /* close eventual list of pending jumps */ |
| removelocalvars(ls, fs->nactloc); |
| luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); |
| 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; |
| luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->nlineinfo+1, int); |
| f->lineinfo[fs->nlineinfo++] = MAX_INT; /* end flag */ |
| f->sizelineinfo = fs->nlineinfo; |
| 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), |
| l_s("<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, l_c(']')); |
| } |
| |
| |
| static int explist1 (LexState *ls, expdesc *v) { |
| /* explist1 -> expr { `,' expr } */ |
| int n = 1; /* at least one expression */ |
| expr(ls, v); |
| while (ls->t.token == l_c(',')) { |
| next(ls); /* skip comma */ |
| 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; |
| switch (ls->t.token) { |
| case l_c('('): { /* funcargs -> `(' [ explist1 ] `)' */ |
| int line = ls->linenumber; |
| next(ls); |
| if (ls->t.token == l_c(')')) /* arg list is empty? */ |
| args.k = VVOID; |
| else { |
| explist1(ls, &args); |
| luaK_setcallreturns(fs, &args, LUA_MULTRET); |
| } |
| check_match(ls, l_c(')'), l_c('('), line); |
| break; |
| } |
| case l_c('{'): { /* 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: { |
| luaK_error(ls, l_s("function arguments expected")); |
| break; |
| } |
| } |
| lua_assert(f->k == VNONRELOC); |
| base = f->u.i.info; /* base register for call */ |
| if (args.k == VCALL) |
| nparams = NO_REG; /* 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)); |
| fs->freereg = base+1; /* call remove function and arguments and leaves |
| (unless changed) one result */ |
| } |
| |
| |
| |
| /* |
| ** {====================================================================== |
| ** Rules for Constructors |
| ** ======================================================================= |
| */ |
| |
| |
| static void recfield (LexState *ls, expdesc *t) { |
| /* recfield -> (NAME | `['exp1`]') = exp1 */ |
| FuncState *fs = ls->fs; |
| int reg = ls->fs->freereg; |
| expdesc key, val; |
| switch (ls->t.token) { |
| case TK_NAME: { |
| checkname(ls, &key); |
| break; |
| } |
| case l_c('['): { |
| luaY_index(ls, &key); |
| break; |
| } |
| default: luaK_error(ls, l_s("<name> or `[' expected")); |
| } |
| check(ls, l_c('=')); |
| luaK_exp2RK(fs, &key); |
| expr(ls, &val); |
| luaK_exp2anyreg(fs, &val); |
| luaK_codeABC(fs, OP_SETTABLE, val.u.i.info, t->u.i.info, |
| luaK_exp2RK(fs, &key)); |
| fs->freereg = reg; /* free registers */ |
| } |
| |
| |
| static int anotherfield (LexState *ls) { |
| if (ls->t.token != l_c(',')) return 0; |
| next(ls); /* skip the comma */ |
| return (ls->t.token != l_c(';') && ls->t.token != l_c('}')); |
| } |
| |
| |
| static int recfields (LexState *ls, expdesc *t) { |
| /* recfields -> recfield { `,' recfield } [`,'] */ |
| int n = 0; |
| do { /* at least one element */ |
| recfield(ls, t); |
| n++; |
| } while (anotherfield(ls)); |
| return n; |
| } |
| |
| |
| static int listfields (LexState *ls, expdesc *t) { |
| /* listfields -> exp1 { `,' exp1 } [`,'] */ |
| expdesc v; |
| FuncState *fs = ls->fs; |
| int n = 1; /* at least one element */ |
| int reg; |
| reg = fs->freereg; |
| expr(ls, &v); |
| while (anotherfield(ls)) { |
| luaK_exp2nextreg(fs, &v); |
| luaX_checklimit(ls, n, MAXARG_Bc, |
| l_s("`item groups' in a list initializer")); |
| if (n%LFIELDS_PER_FLUSH == 0) { |
| luaK_codeABc(fs, OP_SETLIST, t->u.i.info, n-1); /* flush */ |
| fs->freereg = reg; /* free registers */ |
| } |
| expr(ls, &v); |
| n++; |
| } |
| if (v.k == VCALL) { |
| luaK_setcallreturns(fs, &v, LUA_MULTRET); |
| luaK_codeABc(fs, OP_SETLISTO, t->u.i.info, n-1); |
| } |
| else { |
| luaK_exp2nextreg(fs, &v); |
| luaK_codeABc(fs, OP_SETLIST, t->u.i.info, n-1); |
| } |
| fs->freereg = reg; /* free registers */ |
| return n; |
| } |
| |
| |
| static void constructor_part (LexState *ls, expdesc *t, Constdesc *cd) { |
| switch (ls->t.token) { |
| case l_c(';'): case l_c('}'): { /* constructor_part -> empty */ |
| cd->n = 0; |
| cd->k = ls->t.token; |
| break; |
| } |
| case TK_NAME: { /* may be listfields or recfields */ |
| lookahead(ls); |
| if (ls->lookahead.token != l_c('=')) /* expression? */ |
| goto case_default; |
| /* else go through to recfields */ |
| } |
| case l_c('['): { /* constructor_part -> recfields */ |
| cd->n = recfields(ls, t); |
| cd->k = 1; /* record */ |
| break; |
| } |
| default: { /* constructor_part -> listfields */ |
| case_default: |
| cd->n = listfields(ls, t); |
| cd->k = 0; /* list */ |
| break; |
| } |
| } |
| } |
| |
| |
| static void constructor (LexState *ls, expdesc *t) { |
| /* constructor -> `{' constructor_part [`;' constructor_part] `}' */ |
| FuncState *fs = ls->fs; |
| int line = ls->linenumber; |
| int n; |
| int pc; |
| Constdesc cd; |
| pc = luaK_codeABc(fs, OP_NEWTABLE, 0, 0); |
| init_exp(t, VRELOCABLE, pc); |
| luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */ |
| check(ls, l_c('{')); |
| constructor_part(ls, t, &cd); |
| n = cd.n; |
| if (optional(ls, l_c(';'))) { |
| Constdesc other_cd; |
| constructor_part(ls, t, &other_cd); |
| check_condition(ls, (cd.k != other_cd.k), l_s("invalid constructor syntax")); |
| n += other_cd.n; |
| } |
| check_match(ls, l_c('}'), l_c('{'), line); |
| luaX_checklimit(ls, n, MAXARG_Bc, l_s("elements in a table constructor")); |
| SETARG_Bc(fs->f->code[pc], n); /* set initial table size */ |
| } |
| |
| /* }====================================================================== */ |
| |
| |
| |
| |
| /* |
| ** {====================================================================== |
| ** Expression parsing |
| ** ======================================================================= |
| */ |
| |
| static void primaryexp (LexState *ls, expdesc *v) { |
| switch (ls->t.token) { |
| case TK_NUMBER: { |
| init_exp(v, VNUMBER, 0); |
| v->u.n = 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 l_c('{'): { /* constructor */ |
| constructor(ls, v); |
| break; |
| } |
| case TK_FUNCTION: { |
| next(ls); |
| body(ls, v, 0, ls->linenumber); |
| break; |
| } |
| case l_c('('): { |
| next(ls); |
| expr(ls, v); |
| check(ls, l_c(')')); |
| luaK_dischargevars(ls->fs, v); |
| return; |
| } |
| case TK_NAME: { |
| singlevar(ls, str_checkname(ls), v); |
| next(ls); |
| return; |
| } |
| case l_c('%'): { |
| next(ls); /* skip `%' */ |
| codeupvalue(ls, v, str_checkname(ls)); |
| next(ls); |
| break; |
| } |
| default: { |
| luaK_error(ls, l_s("unexpected symbol")); |
| return; |
| } |
| } |
| } |
| |
| |
| static void simpleexp (LexState *ls, expdesc *v) { |
| /* simpleexp -> |
| primaryexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */ |
| FuncState *fs = ls->fs; |
| primaryexp(ls, v); |
| for (;;) { |
| switch (ls->t.token) { |
| case l_c('.'): { /* field */ |
| luaY_field(ls, v); |
| break; |
| } |
| case l_c('['): { /* `[' exp1 `]' */ |
| expdesc key; |
| luaK_exp2anyreg(fs, v); |
| luaY_index(ls, &key); |
| luaK_indexed(fs, v, &key); |
| break; |
| } |
| case l_c(':'): { /* `:' NAME funcargs */ |
| expdesc key; |
| next(ls); |
| checkname(ls, &key); |
| luaK_self(fs, v, &key); |
| funcargs(ls, v); |
| break; |
| } |
| case l_c('('): case TK_STRING: case l_c('{'): { /* funcargs */ |
| luaK_exp2nextreg(fs, v); |
| funcargs(ls, v); |
| break; |
| } |
| default: return; /* should be follow... */ |
| } |
| } |
| } |
| |
| |
| static UnOpr getunopr (int op) { |
| switch (op) { |
| case TK_NOT: return OPR_NOT; |
| case l_c('-'): return OPR_MINUS; |
| default: return OPR_NOUNOPR; |
| } |
| } |
| |
| |
| static BinOpr getbinopr (int op) { |
| switch (op) { |
| case l_c('+'): return OPR_ADD; |
| case l_c('-'): return OPR_SUB; |
| case l_c('*'): return OPR_MULT; |
| case l_c('/'): return OPR_DIV; |
| case l_c('^'): return OPR_POW; |
| case TK_CONCAT: return OPR_CONCAT; |
| case TK_NE: return OPR_NE; |
| case TK_EQ: return OPR_EQ; |
| case l_c('<'): return OPR_LT; |
| case TK_LE: return OPR_LE; |
| case l_c('>'): 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 */ |
| {5, 5}, {5, 5}, {6, 6}, {6, 6}, /* arithmetic */ |
| {9, 8}, {4, 3}, /* power and concat (right associative) */ |
| {2, 2}, {2, 2}, /* equality */ |
| {2, 2}, {2, 2}, {2, 2}, {2, 2}, /* order */ |
| {1, 1}, {1, 1} /* logical */ |
| }; |
| |
| #define UNARY_PRIORITY 7 /* 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 && (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, (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; |
| int nactloc = fs->nactloc; |
| chunk(ls); |
| removelocalvars(ls, fs->nactloc - nactloc); |
| fs->freereg = nactloc; /* free registers used by locals */ |
| } |
| |
| |
| /* |
| ** 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, 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.u.i.info == v->u.i.info) { /* conflict? */ |
| conflict = 1; |
| lh->v.u.i.info = extra; /* previous assignment will use safe copy */ |
| } |
| if (lh->v.u.i.aux == v->u.i.info) { /* conflict? */ |
| conflict = 1; |
| lh->v.u.i.aux = extra; /* previous assignment will use safe copy */ |
| } |
| } |
| } |
| if (conflict) { |
| luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.i.info, 0); /* make copy */ |
| luaK_reserveregs(fs, 1); |
| } |
| } |
| |
| |
| static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { |
| expdesc e; |
| check_condition(ls, lh->v.k == VLOCAL || lh->v.k == VGLOBAL || |
| lh->v.k == VINDEXED, |
| l_s("syntax error")); |
| if (ls->t.token == l_c(',')) { /* assignment -> `,' simpleexp assignment */ |
| struct LHS_assign nv; |
| nv.prev = lh; |
| next(ls); |
| simpleexp(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, l_c('=')); |
| 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_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 */ |
| luaK_goiftrue(ls->fs, v); |
| } |
| |
| |
| static void whilestat (LexState *ls, int line) { |
| /* whilestat -> WHILE cond DO block END */ |
| FuncState *fs = ls->fs; |
| int while_init = luaK_getlabel(fs); |
| expdesc v; |
| Breaklabel bl; |
| enterbreak(fs, &bl); |
| next(ls); |
| cond(ls, &v); |
| check(ls, TK_DO); |
| block(ls); |
| luaK_patchlist(fs, luaK_jump(fs), while_init); |
| luaK_patchlist(fs, v.f, luaK_getlabel(fs)); |
| check_match(ls, TK_END, TK_WHILE, line); |
| leavebreak(fs, &bl); |
| } |
| |
| |
| static void repeatstat (LexState *ls, int line) { |
| /* repeatstat -> REPEAT block UNTIL cond */ |
| FuncState *fs = ls->fs; |
| int repeat_init = luaK_getlabel(fs); |
| expdesc v; |
| Breaklabel bl; |
| enterbreak(fs, &bl); |
| next(ls); |
| block(ls); |
| check_match(ls, TK_UNTIL, TK_REPEAT, line); |
| cond(ls, &v); |
| luaK_patchlist(fs, v.f, repeat_init); |
| leavebreak(fs, &bl); |
| } |
| |
| |
| static void exp1 (LexState *ls) { |
| expdesc e; |
| expr(ls, &e); |
| luaK_exp2nextreg(ls->fs, &e); |
| } |
| |
| |
| static void forbody (LexState *ls, int nvar, OpCode prepfor, OpCode loopfor) { |
| /* forbody -> DO block END */ |
| FuncState *fs = ls->fs; |
| int basereg = fs->freereg - nvar; |
| int prep = luaK_codeAsBc(fs, prepfor, basereg, NO_JUMP); |
| int blockinit = luaK_getlabel(fs); |
| check(ls, TK_DO); |
| adjustlocalvars(ls, nvar); /* scope for control variables */ |
| block(ls); |
| luaK_patchlist(fs, luaK_codeAsBc(fs, loopfor, basereg, NO_JUMP), blockinit); |
| luaK_fixfor(fs, prep, luaK_getlabel(fs)); |
| removelocalvars(ls, nvar); |
| } |
| |
| |
| static void fornum (LexState *ls, TString *varname) { |
| /* fornum -> NAME = exp1,exp1[,exp1] forbody */ |
| FuncState *fs = ls->fs; |
| check(ls, l_c('=')); |
| exp1(ls); /* initial value */ |
| check(ls, l_c(',')); |
| exp1(ls); /* limit */ |
| if (optional(ls, l_c(','))) |
| exp1(ls); /* optional step */ |
| else { |
| luaK_codeAsBc(fs, OP_LOADINT, fs->freereg, 1); /* default step */ |
| luaK_reserveregs(fs, 1); |
| } |
| new_localvar(ls, varname, 0); |
| new_localvarstr(ls, l_s("(limit)"), 1); |
| new_localvarstr(ls, l_s("(step)"), 2); |
| forbody(ls, 3, OP_FORPREP, OP_FORLOOP); |
| } |
| |
| |
| static void forlist (LexState *ls, TString *indexname) { |
| /* forlist -> NAME,NAME IN exp1 forbody */ |
| TString *valname; |
| check(ls, l_c(',')); |
| valname = str_checkname(ls); |
| next(ls); /* skip var name */ |
| check(ls, TK_IN); |
| exp1(ls); /* table */ |
| new_localvarstr(ls, l_s("(table)"), 0); |
| new_localvarstr(ls, l_s("(index)"), 1); |
| new_localvar(ls, indexname, 2); |
| new_localvar(ls, valname, 3); |
| luaK_reserveregs(ls->fs, 3); /* registers for control, index and val */ |
| forbody(ls, 4, OP_TFORPREP, OP_TFORLOOP); |
| } |
| |
| |
| static void forstat (LexState *ls, int line) { |
| /* forstat -> fornum | forlist */ |
| FuncState *fs = ls->fs; |
| TString *varname; |
| Breaklabel bl; |
| enterbreak(fs, &bl); |
| next(ls); /* skip `for' */ |
| varname = str_checkname(ls); /* first variable name */ |
| next(ls); /* skip var name */ |
| switch (ls->t.token) { |
| case l_c('='): fornum(ls, varname); break; |
| case l_c(','): forlist(ls, varname); break; |
| default: luaK_error(ls, l_s("`=' or `,' expected")); |
| } |
| check_match(ls, TK_END, TK_FOR, line); |
| leavebreak(fs, &bl); |
| } |
| |
| |
| 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_patchlist(fs, v.f, luaK_getlabel(fs)); |
| test_then_block(ls, &v); /* ELSEIF cond THEN block */ |
| } |
| if (ls->t.token == TK_ELSE) { |
| luaK_concat(fs, &escapelist, luaK_jump(fs)); |
| luaK_patchlist(fs, v.f, luaK_getlabel(fs)); |
| next(ls); /* skip ELSE */ |
| block(ls); /* `else' part */ |
| } |
| else |
| luaK_concat(fs, &escapelist, v.f); |
| luaK_patchlist(fs, escapelist, luaK_getlabel(fs)); |
| check_match(ls, TK_END, TK_IF, line); |
| } |
| |
| |
| static void localstat (LexState *ls) { |
| /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */ |
| int nvars = 0; |
| int nexps; |
| expdesc e; |
| do { |
| next(ls); /* skip LOCAL or `,' */ |
| new_localvar(ls, str_checkname(ls), nvars++); |
| next(ls); /* skip var name */ |
| } while (ls->t.token == l_c(',')); |
| if (optional(ls, l_c('='))) |
| 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, str_checkname(ls), v); |
| next(ls); /* skip var name */ |
| while (ls->t.token == l_c('.')) { |
| luaY_field(ls, v); |
| } |
| if (ls->t.token == l_c(':')) { |
| 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; |
| simpleexp(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 == l_c(';')) |
| first = nret = 0; /* return no values */ |
| else { |
| int n = explist1(ls, &e); /* optional return values */ |
| if (e.k == VCALL) { |
| luaK_setcallreturns(fs, &e, LUA_MULTRET); |
| first = fs->nactloc; |
| nret = NO_REG; /* return all values */ |
| } |
| else { |
| if (n == 1) { /* only one value? */ |
| luaK_exp2anyreg(fs, &e); |
| first = e.u.i.info; |
| nret = 1; /* return only this value */ |
| } |
| else { |
| luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */ |
| first = fs->nactloc; |
| nret = fs->freereg - first; /* return all `active' values */ |
| } |
| } |
| } |
| luaK_codeABC(fs, OP_RETURN, first, nret, 0); |
| fs->freereg = fs->nactloc; /* removes all temp values */ |
| } |
| |
| |
| static void breakstat (LexState *ls) { |
| /* stat -> BREAK [NAME] */ |
| FuncState *fs = ls->fs; |
| Breaklabel *bl = fs->bl; |
| if (!bl) |
| luaK_error(ls, l_s("no loop to break")); |
| next(ls); /* skip BREAK */ |
| luaK_concat(fs, &bl->breaklist, luaK_jump(fs)); |
| /* correct stack for compiler and symbolic execution */ |
| } |
| |
| |
| 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: { |
| lookahead(ls); |
| if (ls->lookahead.token == '(') |
| exprstat(ls); |
| else |
| funcstat(ls, line); /* stat -> funcstat */ |
| return 0; |
| } |
| case TK_LOCAL: { /* stat -> localstat */ |
| 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; |
| short dots = 0; |
| if (ls->t.token != l_c(')')) { /* is `parlist' not empty? */ |
| do { |
| switch (ls->t.token) { |
| case TK_DOTS: dots = 1; break; |
| case TK_NAME: new_localvar(ls, str_checkname(ls), nparams++); break; |
| default: luaK_error(ls, l_s("<name> or `...' expected")); |
| } |
| next(ls); |
| } while (!dots && optional(ls, l_c(','))); |
| } |
| 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, l_c('(')); |
| if (needself) { |
| new_localvarstr(ls, l_s("self"), 0); |
| adjustlocalvars(ls, 1); |
| } |
| parlist(ls); |
| check(ls, l_c(')')); |
| 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); |
| optional(ls, l_c(';')); |
| lua_assert(ls->fs->freereg >= ls->fs->nactloc); |
| ls->fs->freereg = ls->fs->nactloc; /* free registers */ |
| } |
| } |
| |