summaryrefslogtreecommitdiff
path: root/lib/lua/src/lparser.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/lua/src/lparser.c')
-rw-r--r--lib/lua/src/lparser.c2658
1 files changed, 1329 insertions, 1329 deletions
diff --git a/lib/lua/src/lparser.c b/lib/lua/src/lparser.c
index 2b557d4..a242338 100644
--- a/lib/lua/src/lparser.c
+++ b/lib/lua/src/lparser.c
@@ -1,1329 +1,1329 @@
-/*
-** $Id: lparser.c,v 1.3 2004-11-27 21:35:20 pixel Exp $
-** Lua Parser
-** See Copyright Notice in lua.h
-*/
-
-
-#include <string.h>
-
-#define lparser_c
-
-#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]])
-
-
-#define enterlevel(ls) if (++(ls)->nestlevel > LUA_MAXPARSERLEVEL) \
- luaX_syntaxerror(ls, "too many syntax levels");
-#define leavelevel(ls) ((ls)->nestlevel--)
-
-
-/*
-** 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 chunk (LexState *ls);
-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, TString *name, expdesc *v) {
- int i;
- Proto *f = fs->f;
- for (i=0; i<f->nups; i++) {
- if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->info) {
- lua_assert(fs->f->upvalues[i] == name);
- return i;
- }
- }
- /* new one */
- luaX_checklimit(fs->ls, f->nups + 1, MAXUPVALUES, "upvalues");
- luaM_growvector(fs->L, fs->f->upvalues, f->nups, fs->f->sizeupvalues,
- TString *, MAX_INT, "");
- fs->f->upvalues[f->nups] = name;
- fs->upvalues[f->nups] = *v;
- return f->nups++;
-}
-
-
-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, n, var);
- var->k = VUPVAL; /* upvalue in this level */
- }
- }
- }
-}
-
-
-static TString *singlevar (LexState *ls, expdesc *var, int base) {
- TString *varname = str_checkname(ls);
- singlevaraux(ls->fs, varname, var, base);
- return varname;
-}
-
-
-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->nups; i++) {
- OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
- luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
- }
-}
-
-
-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->source = ls->source;
- f->maxstacksize = 2; /* registers 0/1 are always valid */
-}
-
-
-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 */
- luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
- f->sizecode = fs->pc;
- luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
- f->sizelineinfo = 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->upvalues, f->sizeupvalues, f->nups, TString *);
- f->sizeupvalues = f->nups;
- lua_assert(luaG_checkcode(f));
- lua_assert(fs->bl == NULL);
- ls->fs = fs->prev;
-}
-
-
-Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff) {
- struct LexState lexstate;
- struct FuncState funcstate;
- lexstate.buff = buff;
- lexstate.nestlevel = 0;
- 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->nups == 0);
- lua_assert(lexstate.nestlevel == 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, ']');
-}
-
-
-/*
-** {======================================================================
-** 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_codeABC(fs, OP_SETTABLE, cc->t->info, luaK_exp2RK(fs, &key),
- luaK_exp2RK(fs, &val));
- 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);
- SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
- SETARG_C(fs->f->code[pc], luaO_log2(cc.nh)+1); /* set initial table size */
-}
-
-/* }====================================================================== */
-
-
-
-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 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));
- luaK_fixline(fs, line);
- fs->freereg = base+1; /* call remove function and arguments and leaves
- (unless changed) one result */
-}
-
-
-
-
-/*
-** {======================================================================
-** 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;
- }
-#ifdef LUA_COMPATUPSYNTAX
- case '%': { /* for compatibility only */
- TString *varname;
- int line = ls->linenumber;
- next(ls); /* skip `%' */
- varname = singlevar(ls, v, 1);
- if (v->k != VUPVAL)
- luaX_errorline(ls, "global upvalues are obsolete",
- getstr(varname), line);
- return;
- }
-#endif
- 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;
- enterlevel(ls);
- 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;
- }
- leavelevel(ls);
- 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;
- 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 forbody (LexState *ls, int base, int line, int nvars, int isnum) {
- BlockCnt bl;
- FuncState *fs = ls->fs;
- int prep, endfor;
- adjustlocalvars(ls, nvars); /* scope for all variables */
- check(ls, TK_DO);
- enterblock(fs, &bl, 1); /* loop block */
- prep = luaK_getlabel(fs);
- block(ls);
- luaK_patchtohere(fs, prep-1);
- endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
- luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
- luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
- luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep);
- leaveblock(fs);
-}
-
-
-static void fornum (LexState *ls, TString *varname, int line) {
- /* fornum -> NAME = exp1,exp1[,exp1] DO body */
- FuncState *fs = ls->fs;
- 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);
- }
- luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1);
- luaK_jump(fs);
- forbody(ls, base, line, 3, 1);
-}
-
-
-static void forlist (LexState *ls, TString *indexname) {
- /* forlist -> NAME {,NAME} IN explist1 DO body */
- FuncState *fs = ls->fs;
- expdesc e;
- int nvars = 0;
- int line;
- 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, nvars, explist1(ls, &e), &e);
- luaK_checkstack(fs, 3); /* extra space to call generator */
- luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP);
- forbody(ls, base, line, nvars, 0);
-}
-
-
-static void forstat (LexState *ls, int line) {
- /* forstat -> fornum | forlist */
- FuncState *fs = ls->fs;
- TString *varname;
- BlockCnt bl;
- enterblock(fs, &bl, 0); /* block to control variable scope */
- 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);
- luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
-}
-
-
-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 chunk (LexState *ls) {
- /* chunk -> { stat [`;'] } */
- int islast = 0;
- enterlevel(ls);
- 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 */
- }
- leavelevel(ls);
-}
-
-/* }====================================================================== */
+/*
+** $Id: lparser.c,v 1.4 2004-11-27 21:46:07 pixel Exp $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+
+#include <string.h>
+
+#define lparser_c
+
+#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]])
+
+
+#define enterlevel(ls) if (++(ls)->nestlevel > LUA_MAXPARSERLEVEL) \
+ luaX_syntaxerror(ls, "too many syntax levels");
+#define leavelevel(ls) ((ls)->nestlevel--)
+
+
+/*
+** 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 chunk (LexState *ls);
+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, TString *name, expdesc *v) {
+ int i;
+ Proto *f = fs->f;
+ for (i=0; i<f->nups; i++) {
+ if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->info) {
+ lua_assert(fs->f->upvalues[i] == name);
+ return i;
+ }
+ }
+ /* new one */
+ luaX_checklimit(fs->ls, f->nups + 1, MAXUPVALUES, "upvalues");
+ luaM_growvector(fs->L, fs->f->upvalues, f->nups, fs->f->sizeupvalues,
+ TString *, MAX_INT, "");
+ fs->f->upvalues[f->nups] = name;
+ fs->upvalues[f->nups] = *v;
+ return f->nups++;
+}
+
+
+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, n, var);
+ var->k = VUPVAL; /* upvalue in this level */
+ }
+ }
+ }
+}
+
+
+static TString *singlevar (LexState *ls, expdesc *var, int base) {
+ TString *varname = str_checkname(ls);
+ singlevaraux(ls->fs, varname, var, base);
+ return varname;
+}
+
+
+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->nups; i++) {
+ OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
+ luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
+ }
+}
+
+
+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->source = ls->source;
+ f->maxstacksize = 2; /* registers 0/1 are always valid */
+}
+
+
+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 */
+ luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
+ f->sizecode = fs->pc;
+ luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
+ f->sizelineinfo = 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->upvalues, f->sizeupvalues, f->nups, TString *);
+ f->sizeupvalues = f->nups;
+ lua_assert(luaG_checkcode(f));
+ lua_assert(fs->bl == NULL);
+ ls->fs = fs->prev;
+}
+
+
+Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff) {
+ struct LexState lexstate;
+ struct FuncState funcstate;
+ lexstate.buff = buff;
+ lexstate.nestlevel = 0;
+ 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->nups == 0);
+ lua_assert(lexstate.nestlevel == 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, ']');
+}
+
+
+/*
+** {======================================================================
+** 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_codeABC(fs, OP_SETTABLE, cc->t->info, luaK_exp2RK(fs, &key),
+ luaK_exp2RK(fs, &val));
+ 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);
+ SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
+ SETARG_C(fs->f->code[pc], luaO_log2(cc.nh)+1); /* set initial table size */
+}
+
+/* }====================================================================== */
+
+
+
+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 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));
+ luaK_fixline(fs, line);
+ fs->freereg = base+1; /* call remove function and arguments and leaves
+ (unless changed) one result */
+}
+
+
+
+
+/*
+** {======================================================================
+** 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;
+ }
+#ifdef LUA_COMPATUPSYNTAX
+ case '%': { /* for compatibility only */
+ TString *varname;
+ int line = ls->linenumber;
+ next(ls); /* skip `%' */
+ varname = singlevar(ls, v, 1);
+ if (v->k != VUPVAL)
+ luaX_errorline(ls, "global upvalues are obsolete",
+ getstr(varname), line);
+ return;
+ }
+#endif
+ 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;
+ enterlevel(ls);
+ 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;
+ }
+ leavelevel(ls);
+ 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;
+ 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 forbody (LexState *ls, int base, int line, int nvars, int isnum) {
+ BlockCnt bl;
+ FuncState *fs = ls->fs;
+ int prep, endfor;
+ adjustlocalvars(ls, nvars); /* scope for all variables */
+ check(ls, TK_DO);
+ enterblock(fs, &bl, 1); /* loop block */
+ prep = luaK_getlabel(fs);
+ block(ls);
+ luaK_patchtohere(fs, prep-1);
+ endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
+ luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
+ luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
+ luaK_patchlist(fs, (isnum) ? endfor : luaK_jump(fs), prep);
+ leaveblock(fs);
+}
+
+
+static void fornum (LexState *ls, TString *varname, int line) {
+ /* fornum -> NAME = exp1,exp1[,exp1] DO body */
+ FuncState *fs = ls->fs;
+ 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);
+ }
+ luaK_codeABC(fs, OP_SUB, fs->freereg - 3, fs->freereg - 3, fs->freereg - 1);
+ luaK_jump(fs);
+ forbody(ls, base, line, 3, 1);
+}
+
+
+static void forlist (LexState *ls, TString *indexname) {
+ /* forlist -> NAME {,NAME} IN explist1 DO body */
+ FuncState *fs = ls->fs;
+ expdesc e;
+ int nvars = 0;
+ int line;
+ 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, nvars, explist1(ls, &e), &e);
+ luaK_checkstack(fs, 3); /* extra space to call generator */
+ luaK_codeAsBx(fs, OP_TFORPREP, base, NO_JUMP);
+ forbody(ls, base, line, nvars, 0);
+}
+
+
+static void forstat (LexState *ls, int line) {
+ /* forstat -> fornum | forlist */
+ FuncState *fs = ls->fs;
+ TString *varname;
+ BlockCnt bl;
+ enterblock(fs, &bl, 0); /* block to control variable scope */
+ 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);
+ luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
+}
+
+
+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 chunk (LexState *ls) {
+ /* chunk -> { stat [`;'] } */
+ int islast = 0;
+ enterlevel(ls);
+ 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 */
+ }
+ leavelevel(ls);
+}
+
+/* }====================================================================== */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 20:33:31 +0000