+++ /dev/null
-/*
-** $Id: lparser.c,v 2.130.1.1 2013/04/12 18:48:47 roberto Exp $
-** Lua Parser
-** See Copyright Notice in lua.h
-*/
-
-
-#include <string.h>
-
-#define lparser_c
-#define LUA_CORE
-
-#include "lua.h"
-
-#include "lcode.h"
-#include "ldebug.h"
-#include "ldo.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"
-#include "ltable.h"
-
-
-
-/* maximum number of local variables per function (must be smaller
- than 250, due to the bytecode format) */
-#define MAXVARS 200
-
-
-#define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
-
-
-
-/*
-** nodes for block list (list of active blocks)
-*/
-typedef struct BlockCnt {
- struct BlockCnt *previous; /* chain */
- short firstlabel; /* index of first label in this block */
- short firstgoto; /* index of first pending goto in this block */
- lu_byte nactvar; /* # active locals outside the block */
- lu_byte upval; /* true if some variable in the block is an upvalue */
- lu_byte isloop; /* true if `block' is a loop */
-} BlockCnt;
-
-
-
-/*
-** prototypes for recursive non-terminal functions
-*/
-static void statement (LexState *ls);
-static void expr (LexState *ls, expdesc *v);
-
-
-static void anchor_token (LexState *ls) {
- /* last token from outer function must be EOS */
- lua_assert(ls->fs != NULL || ls->t.token == TK_EOS);
- if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) {
- TString *ts = ls->t.seminfo.ts;
- luaX_newstring(ls, getstr(ts), ts->tsv.len);
- }
-}
-
-
-/* semantic error */
-static l_noret semerror (LexState *ls, const char *msg) {
- ls->t.token = 0; /* remove 'near to' from final message */
- luaX_syntaxerror(ls, msg);
-}
-
-
-static l_noret error_expected (LexState *ls, int token) {
- luaX_syntaxerror(ls,
- luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token)));
-}
-
-
-static l_noret errorlimit (FuncState *fs, int limit, const char *what) {
- lua_State *L = fs->ls->L;
- const char *msg;
- int line = fs->f->linedefined;
- const char *where = (line == 0)
- ? "main function"
- : luaO_pushfstring(L, "function at line %d", line);
- msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s",
- what, limit, where);
- luaX_syntaxerror(fs->ls, msg);
-}
-
-
-static void checklimit (FuncState *fs, int v, int l, const char *what) {
- if (v > l) errorlimit(fs, l, what);
-}
-
-
-static int testnext (LexState *ls, int c) {
- if (ls->t.token == c) {
- luaX_next(ls);
- return 1;
- }
- else return 0;
-}
-
-
-static void check (LexState *ls, int c) {
- if (ls->t.token != c)
- error_expected(ls, c);
-}
-
-
-static void checknext (LexState *ls, int c) {
- check(ls, c);
- luaX_next(ls);
-}
-
-
-#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(ls, TK_NAME);
- ts = ls->t.seminfo.ts;
- luaX_next(ls);
- return ts;
-}
-
-
-static void init_exp (expdesc *e, expkind k, int i) {
- e->f = e->t = NO_JUMP;
- e->k = k;
- e->u.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 registerlocalvar (LexState *ls, TString *varname) {
- FuncState *fs = ls->fs;
- Proto *f = fs->f;
- int oldsize = f->sizelocvars;
- luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
- LocVar, SHRT_MAX, "local variables");
- while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
- f->locvars[fs->nlocvars].varname = varname;
- luaC_objbarrier(ls->L, f, varname);
- return fs->nlocvars++;
-}
-
-
-static void new_localvar (LexState *ls, TString *name) {
- FuncState *fs = ls->fs;
- Dyndata *dyd = ls->dyd;
- int reg = registerlocalvar(ls, name);
- checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
- MAXVARS, "local variables");
- luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1,
- dyd->actvar.size, Vardesc, MAX_INT, "local variables");
- dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg);
-}
-
-
-static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) {
- new_localvar(ls, luaX_newstring(ls, name, sz));
-}
-
-#define new_localvarliteral(ls,v) \
- new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1)
-
-
-static LocVar *getlocvar (FuncState *fs, int i) {
- int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx;
- lua_assert(idx < fs->nlocvars);
- return &fs->f->locvars[idx];
-}
-
-
-static void adjustlocalvars (LexState *ls, int nvars) {
- FuncState *fs = ls->fs;
- fs->nactvar = cast_byte(fs->nactvar + nvars);
- for (; nvars; nvars--) {
- getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc;
- }
-}
-
-
-static void removevars (FuncState *fs, int tolevel) {
- fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel);
- while (fs->nactvar > tolevel)
- getlocvar(fs, --fs->nactvar)->endpc = fs->pc;
-}
-
-
-static int searchupvalue (FuncState *fs, TString *name) {
- int i;
- Upvaldesc *up = fs->f->upvalues;
- for (i = 0; i < fs->nups; i++) {
- if (luaS_eqstr(up[i].name, name)) return i;
- }
- return -1; /* not found */
-}
-
-
-static int newupvalue (FuncState *fs, TString *name, expdesc *v) {
- Proto *f = fs->f;
- int oldsize = f->sizeupvalues;
- checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues");
- luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues,
- Upvaldesc, MAXUPVAL, "upvalues");
- while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL;
- f->upvalues[fs->nups].instack = (v->k == VLOCAL);
- f->upvalues[fs->nups].idx = cast_byte(v->u.info);
- f->upvalues[fs->nups].name = name;
- luaC_objbarrier(fs->ls->L, f, name);
- return fs->nups++;
-}
-
-
-static int searchvar (FuncState *fs, TString *n) {
- int i;
- for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) {
- if (luaS_eqstr(n, getlocvar(fs, i)->varname))
- return i;
- }
- return -1; /* not found */
-}
-
-
-/*
- Mark block where variable at given level was defined
- (to emit close instructions later).
-*/
-static void markupval (FuncState *fs, int level) {
- BlockCnt *bl = fs->bl;
- while (bl->nactvar > level) bl = bl->previous;
- bl->upval = 1;
-}
-
-
-/*
- Find variable with given name 'n'. If it is an upvalue, add this
- upvalue into all intermediate functions.
-*/
-static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
- if (fs == NULL) /* no more levels? */
- return VVOID; /* default is global */
- else {
- int v = searchvar(fs, n); /* look up locals at current level */
- if (v >= 0) { /* found? */
- init_exp(var, VLOCAL, v); /* variable is local */
- if (!base)
- markupval(fs, v); /* local will be used as an upval */
- return VLOCAL;
- }
- else { /* not found as local at current level; try upvalues */
- int idx = searchupvalue(fs, n); /* try existing upvalues */
- if (idx < 0) { /* not found? */
- if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */
- return VVOID; /* not found; is a global */
- /* else was LOCAL or UPVAL */
- idx = newupvalue(fs, n, var); /* will be a new upvalue */
- }
- init_exp(var, VUPVAL, idx);
- return VUPVAL;
- }
- }
-}
-
-
-static void singlevar (LexState *ls, expdesc *var) {
- TString *varname = str_checkname(ls);
- FuncState *fs = ls->fs;
- if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */
- expdesc key;
- singlevaraux(fs, ls->envn, var, 1); /* get environment variable */
- lua_assert(var->k == VLOCAL || var->k == VUPVAL);
- codestring(ls, &key, varname); /* key is variable name */
- luaK_indexed(fs, var, &key); /* env[varname] */
- }
-}
-
-
-static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
- FuncState *fs = ls->fs;
- int extra = nvars - nexps;
- if (hasmultret(e->k)) {
- extra++; /* includes call itself */
- if (extra < 0) extra = 0;
- luaK_setreturns(fs, e, extra); /* last exp. provides the difference */
- if (extra > 1) luaK_reserveregs(fs, extra-1);
- }
- 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 enterlevel (LexState *ls) {
- lua_State *L = ls->L;
- ++L->nCcalls;
- checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
-}
-
-
-#define leavelevel(ls) ((ls)->L->nCcalls--)
-
-
-static void closegoto (LexState *ls, int g, Labeldesc *label) {
- int i;
- FuncState *fs = ls->fs;
- Labellist *gl = &ls->dyd->gt;
- Labeldesc *gt = &gl->arr[g];
- lua_assert(luaS_eqstr(gt->name, label->name));
- if (gt->nactvar < label->nactvar) {
- TString *vname = getlocvar(fs, gt->nactvar)->varname;
- const char *msg = luaO_pushfstring(ls->L,
- "<goto %s> at line %d jumps into the scope of local " LUA_QS,
- getstr(gt->name), gt->line, getstr(vname));
- semerror(ls, msg);
- }
- luaK_patchlist(fs, gt->pc, label->pc);
- /* remove goto from pending list */
- for (i = g; i < gl->n - 1; i++)
- gl->arr[i] = gl->arr[i + 1];
- gl->n--;
-}
-
-
-/*
-** try to close a goto with existing labels; this solves backward jumps
-*/
-static int findlabel (LexState *ls, int g) {
- int i;
- BlockCnt *bl = ls->fs->bl;
- Dyndata *dyd = ls->dyd;
- Labeldesc *gt = &dyd->gt.arr[g];
- /* check labels in current block for a match */
- for (i = bl->firstlabel; i < dyd->label.n; i++) {
- Labeldesc *lb = &dyd->label.arr[i];
- if (luaS_eqstr(lb->name, gt->name)) { /* correct label? */
- if (gt->nactvar > lb->nactvar &&
- (bl->upval || dyd->label.n > bl->firstlabel))
- luaK_patchclose(ls->fs, gt->pc, lb->nactvar);
- closegoto(ls, g, lb); /* close it */
- return 1;
- }
- }
- return 0; /* label not found; cannot close goto */
-}
-
-
-static int newlabelentry (LexState *ls, Labellist *l, TString *name,
- int line, int pc) {
- int n = l->n;
- luaM_growvector(ls->L, l->arr, n, l->size,
- Labeldesc, SHRT_MAX, "labels/gotos");
- l->arr[n].name = name;
- l->arr[n].line = line;
- l->arr[n].nactvar = ls->fs->nactvar;
- l->arr[n].pc = pc;
- l->n++;
- return n;
-}
-
-
-/*
-** check whether new label 'lb' matches any pending gotos in current
-** block; solves forward jumps
-*/
-static void findgotos (LexState *ls, Labeldesc *lb) {
- Labellist *gl = &ls->dyd->gt;
- int i = ls->fs->bl->firstgoto;
- while (i < gl->n) {
- if (luaS_eqstr(gl->arr[i].name, lb->name))
- closegoto(ls, i, lb);
- else
- i++;
- }
-}
-
-
-/*
-** "export" pending gotos to outer level, to check them against
-** outer labels; if the block being exited has upvalues, and
-** the goto exits the scope of any variable (which can be the
-** upvalue), close those variables being exited.
-*/
-static void movegotosout (FuncState *fs, BlockCnt *bl) {
- int i = bl->firstgoto;
- Labellist *gl = &fs->ls->dyd->gt;
- /* correct pending gotos to current block and try to close it
- with visible labels */
- while (i < gl->n) {
- Labeldesc *gt = &gl->arr[i];
- if (gt->nactvar > bl->nactvar) {
- if (bl->upval)
- luaK_patchclose(fs, gt->pc, bl->nactvar);
- gt->nactvar = bl->nactvar;
- }
- if (!findlabel(fs->ls, i))
- i++; /* move to next one */
- }
-}
-
-
-static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) {
- bl->isloop = isloop;
- bl->nactvar = fs->nactvar;
- bl->firstlabel = (short)fs->ls->dyd->label.n;
- bl->firstgoto = (short)fs->ls->dyd->gt.n;
- bl->upval = 0;
- bl->previous = fs->bl;
- fs->bl = bl;
- lua_assert(fs->freereg == fs->nactvar);
-}
-
-
-/*
-** create a label named "break" to resolve break statements
-*/
-static void breaklabel (LexState *ls) {
- TString *n = luaS_new(ls->L, "break");
- int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc);
- findgotos(ls, &ls->dyd->label.arr[l]);
-}
-
-/*
-** generates an error for an undefined 'goto'; choose appropriate
-** message when label name is a reserved word (which can only be 'break')
-*/
-static l_noret undefgoto (LexState *ls, Labeldesc *gt) {
- const char *msg = isreserved(gt->name)
- ? "<%s> at line %d not inside a loop"
- : "no visible label " LUA_QS " for <goto> at line %d";
- msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
- semerror(ls, msg);
-}
-
-
-static void leaveblock (FuncState *fs) {
- BlockCnt *bl = fs->bl;
- LexState *ls = fs->ls;
- if (bl->previous && bl->upval) {
- /* create a 'jump to here' to close upvalues */
- int j = luaK_jump(fs);
- luaK_patchclose(fs, j, bl->nactvar);
- luaK_patchtohere(fs, j);
- }
- if (bl->isloop)
- breaklabel(ls); /* close pending breaks */
- fs->bl = bl->previous;
- removevars(fs, bl->nactvar);
- lua_assert(bl->nactvar == fs->nactvar);
- fs->freereg = fs->nactvar; /* free registers */
- ls->dyd->label.n = bl->firstlabel; /* remove local labels */
- if (bl->previous) /* inner block? */
- movegotosout(fs, bl); /* update pending gotos to outer block */
- else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */
- undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */
-}
-
-
-/*
-** adds a new prototype into list of prototypes
-*/
-static Proto *addprototype (LexState *ls) {
- Proto *clp;
- lua_State *L = ls->L;
- FuncState *fs = ls->fs;
- Proto *f = fs->f; /* prototype of current function */
- if (fs->np >= f->sizep) {
- int oldsize = f->sizep;
- luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions");
- while (oldsize < f->sizep) f->p[oldsize++] = NULL;
- }
- f->p[fs->np++] = clp = luaF_newproto(L);
- luaC_objbarrier(L, f, clp);
- return clp;
-}
-
-
-/*
-** codes instruction to create new closure in parent function.
-** The OP_CLOSURE instruction must use the last available register,
-** so that, if it invokes the GC, the GC knows which registers
-** are in use at that time.
-*/
-static void codeclosure (LexState *ls, expdesc *v) {
- FuncState *fs = ls->fs->prev;
- init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1));
- luaK_exp2nextreg(fs, v); /* fix it at the last register */
-}
-
-
-static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
- lua_State *L = ls->L;
- Proto *f;
- fs->prev = ls->fs; /* linked list of funcstates */
- fs->ls = ls;
- ls->fs = fs;
- fs->pc = 0;
- fs->lasttarget = 0;
- fs->jpc = NO_JUMP;
- fs->freereg = 0;
- fs->nk = 0;
- fs->np = 0;
- fs->nups = 0;
- fs->nlocvars = 0;
- fs->nactvar = 0;
- fs->firstlocal = ls->dyd->actvar.n;
- fs->bl = NULL;
- f = fs->f;
- f->source = ls->source;
- f->maxstacksize = 2; /* registers 0/1 are always valid */
- fs->h = luaH_new(L);
- /* anchor table of constants (to avoid being collected) */
- sethvalue2s(L, L->top, fs->h);
- incr_top(L);
- enterblock(fs, bl, 0);
-}
-
-
-static void close_func (LexState *ls) {
- lua_State *L = ls->L;
- FuncState *fs = ls->fs;
- Proto *f = fs->f;
- luaK_ret(fs, 0, 0); /* final return */
- leaveblock(fs);
- 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, TValue);
- 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, fs->nups, Upvaldesc);
- f->sizeupvalues = fs->nups;
- lua_assert(fs->bl == NULL);
- ls->fs = fs->prev;
- /* last token read was anchored in defunct function; must re-anchor it */
- anchor_token(ls);
- L->top--; /* pop table of constants */
- luaC_checkGC(L);
-}
-
-
-
-/*============================================================*/
-/* GRAMMAR RULES */
-/*============================================================*/
-
-
-/*
-** check whether current token is in the follow set of a block.
-** 'until' closes syntactical blocks, but do not close scope,
-** so it handled in separate.
-*/
-static int block_follow (LexState *ls, int withuntil) {
- switch (ls->t.token) {
- case TK_ELSE: case TK_ELSEIF:
- case TK_END: case TK_EOS:
- return 1;
- case TK_UNTIL: return withuntil;
- default: return 0;
- }
-}
-
-
-static void statlist (LexState *ls) {
- /* statlist -> { stat [`;'] } */
- while (!block_follow(ls, 1)) {
- if (ls->t.token == TK_RETURN) {
- statement(ls);
- return; /* 'return' must be last statement */
- }
- statement(ls);
- }
-}
-
-
-static void fieldsel (LexState *ls, expdesc *v) {
- /* fieldsel -> ['.' | ':'] NAME */
- FuncState *fs = ls->fs;
- expdesc key;
- luaK_exp2anyregup(fs, v);
- luaX_next(ls); /* skip the dot or colon */
- checkname(ls, &key);
- luaK_indexed(fs, v, &key);
-}
-
-
-static void yindex (LexState *ls, expdesc *v) {
- /* index -> '[' expr ']' */
- luaX_next(ls); /* skip the '[' */
- expr(ls, v);
- luaK_exp2val(ls->fs, v);
- checknext(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;
- int rkkey;
- if (ls->t.token == TK_NAME) {
- checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
- checkname(ls, &key);
- }
- else /* ls->t.token == '[' */
- yindex(ls, &key);
- cc->nh++;
- checknext(ls, '=');
- rkkey = luaK_exp2RK(fs, &key);
- expr(ls, &val);
- luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val));
- fs->freereg = (lu_byte)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_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */
- cc->tostore = 0; /* no more items pending */
- }
-}
-
-
-static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
- if (cc->tostore == 0) return;
- if (hasmultret(cc->v.k)) {
- luaK_setmultret(fs, &cc->v);
- luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET);
- cc->na--; /* do not count last expression (unknown number of elements) */
- }
- else {
- if (cc->v.k != VVOID)
- luaK_exp2nextreg(fs, &cc->v);
- luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore);
- }
-}
-
-
-static void listfield (LexState *ls, struct ConsControl *cc) {
- /* listfield -> exp */
- expr(ls, &cc->v);
- checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
- cc->na++;
- cc->tostore++;
-}
-
-
-static void field (LexState *ls, struct ConsControl *cc) {
- /* field -> listfield | recfield */
- switch(ls->t.token) {
- case TK_NAME: { /* may be 'listfield' or 'recfield' */
- if (luaX_lookahead(ls) != '=') /* expression? */
- listfield(ls, cc);
- else
- recfield(ls, cc);
- break;
- }
- case '[': {
- recfield(ls, cc);
- break;
- }
- default: {
- listfield(ls, cc);
- break;
- }
- }
-}
-
-
-static void constructor (LexState *ls, expdesc *t) {
- /* constructor -> '{' [ field { sep field } [sep] ] '}'
- sep -> ',' | ';' */
- 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 */
- checknext(ls, '{');
- do {
- lua_assert(cc.v.k == VVOID || cc.tostore > 0);
- if (ls->t.token == '}') break;
- closelistfield(fs, &cc);
- field(ls, &cc);
- } 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_int2fb(cc.nh)); /* set initial table size */
-}
-
-/* }====================================================================== */
-
-
-
-static void parlist (LexState *ls) {
- /* parlist -> [ param { `,' param } ] */
- FuncState *fs = ls->fs;
- Proto *f = fs->f;
- int nparams = 0;
- f->is_vararg = 0;
- if (ls->t.token != ')') { /* is `parlist' not empty? */
- do {
- switch (ls->t.token) {
- case TK_NAME: { /* param -> NAME */
- new_localvar(ls, str_checkname(ls));
- nparams++;
- break;
- }
- case TK_DOTS: { /* param -> `...' */
- luaX_next(ls);
- f->is_vararg = 1;
- break;
- }
- default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected");
- }
- } while (!f->is_vararg && testnext(ls, ','));
- }
- adjustlocalvars(ls, nparams);
- f->numparams = cast_byte(fs->nactvar);
- luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
-}
-
-
-static void body (LexState *ls, expdesc *e, int ismethod, int line) {
- /* body -> `(' parlist `)' block END */
- FuncState new_fs;
- BlockCnt bl;
- new_fs.f = addprototype(ls);
- new_fs.f->linedefined = line;
- open_func(ls, &new_fs, &bl);
- checknext(ls, '(');
- if (ismethod) {
- new_localvarliteral(ls, "self"); /* create 'self' parameter */
- adjustlocalvars(ls, 1);
- }
- parlist(ls);
- checknext(ls, ')');
- statlist(ls);
- new_fs.f->lastlinedefined = ls->linenumber;
- check_match(ls, TK_END, TK_FUNCTION, line);
- codeclosure(ls, e);
- close_func(ls);
-}
-
-
-static int explist (LexState *ls, expdesc *v) {
- /* explist -> 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, int line) {
- FuncState *fs = ls->fs;
- expdesc args;
- int base, nparams;
- switch (ls->t.token) {
- case '(': { /* funcargs -> `(' [ explist ] `)' */
- luaX_next(ls);
- if (ls->t.token == ')') /* arg list is empty? */
- args.k = VVOID;
- else {
- explist(ls, &args);
- luaK_setmultret(fs, &args);
- }
- check_match(ls, ')', '(', line);
- break;
- }
- case '{': { /* funcargs -> constructor */
- constructor(ls, &args);
- break;
- }
- case TK_STRING: { /* funcargs -> STRING */
- codestring(ls, &args, ls->t.seminfo.ts);
- luaX_next(ls); /* must use `seminfo' before `next' */
- break;
- }
- default: {
- luaX_syntaxerror(ls, "function arguments expected");
- }
- }
- lua_assert(f->k == VNONRELOC);
- base = f->u.info; /* base register for call */
- if (hasmultret(args.k))
- 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 = (lu_byte)base + 1; /* call remove function and arguments and leaves
- (unless changed) one result */
-}
-
-
-
-
-/*
-** {======================================================================
-** Expression parsing
-** =======================================================================
-*/
-
-
-static void primaryexp (LexState *ls, expdesc *v) {
- /* primaryexp -> NAME | '(' expr ')' */
- switch (ls->t.token) {
- case '(': {
- int line = ls->linenumber;
- luaX_next(ls);
- expr(ls, v);
- check_match(ls, ')', '(', line);
- luaK_dischargevars(ls->fs, v);
- return;
- }
- case TK_NAME: {
- singlevar(ls, v);
- return;
- }
- default: {
- luaX_syntaxerror(ls, "unexpected symbol");
- }
- }
-}
-
-
-static void suffixedexp (LexState *ls, expdesc *v) {
- /* suffixedexp ->
- primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
- FuncState *fs = ls->fs;
- int line = ls->linenumber;
- primaryexp(ls, v);
- for (;;) {
- switch (ls->t.token) {
- case '.': { /* fieldsel */
- fieldsel(ls, v);
- break;
- }
- case '[': { /* `[' exp1 `]' */
- expdesc key;
- luaK_exp2anyregup(fs, v);
- yindex(ls, &key);
- luaK_indexed(fs, v, &key);
- break;
- }
- case ':': { /* `:' NAME funcargs */
- expdesc key;
- luaX_next(ls);
- checkname(ls, &key);
- luaK_self(fs, v, &key);
- funcargs(ls, v, line);
- break;
- }
- case '(': case TK_STRING: case '{': { /* funcargs */
- luaK_exp2nextreg(fs, v);
- funcargs(ls, v, line);
- break;
- }
- default: return;
- }
- }
-}
-
-
-static void simpleexp (LexState *ls, expdesc *v) {
- /* simpleexp -> NUMBER | STRING | NIL | TRUE | FALSE | ... |
- constructor | FUNCTION body | suffixedexp */
- switch (ls->t.token) {
- case TK_NUMBER: {
- init_exp(v, VKNUM, 0);
- v->u.nval = ls->t.seminfo.r;
- break;
- }
- case TK_STRING: {
- codestring(ls, v, ls->t.seminfo.ts);
- break;
- }
- case TK_NIL: {
- init_exp(v, VNIL, 0);
- break;
- }
- case TK_TRUE: {
- init_exp(v, VTRUE, 0);
- break;
- }
- case TK_FALSE: {
- init_exp(v, VFALSE, 0);
- break;
- }
- case TK_DOTS: { /* vararg */
- FuncState *fs = ls->fs;
- check_condition(ls, fs->f->is_vararg,
- "cannot use " LUA_QL("...") " outside a vararg function");
- init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
- break;
- }
- case '{': { /* constructor */
- constructor(ls, v);
- return;
- }
- case TK_FUNCTION: {
- luaX_next(ls);
- body(ls, v, 0, ls->linenumber);
- return;
- }
- default: {
- suffixedexp(ls, v);
- return;
- }
- }
- luaX_next(ls);
-}
-
-
-static UnOpr getunopr (int op) {
- switch (op) {
- case TK_NOT: return OPR_NOT;
- case '-': return OPR_MINUS;
- case '#': return OPR_LEN;
- default: return OPR_NOUNOPR;
- }
-}
-
-
-static BinOpr getbinopr (int op) {
- switch (op) {
- case '+': return OPR_ADD;
- case '-': return OPR_SUB;
- case '*': return OPR_MUL;
- case '/': return OPR_DIV;
- case '%': return OPR_MOD;
- 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}, {7, 7}, /* `+' `-' `*' `/' `%' */
- {10, 9}, {5, 4}, /* ^, .. (right associative) */
- {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */
- {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */
- {2, 2}, {1, 1} /* and, or */
-};
-
-#define UNARY_PRIORITY 8 /* priority for unary operators */
-
-
-/*
-** subexpr -> (simpleexp | 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) {
- int line = ls->linenumber;
- luaX_next(ls);
- subexpr(ls, v, UNARY_PRIORITY);
- luaK_prefix(ls->fs, uop, v, line);
- }
- else simpleexp(ls, v);
- /* expand while operators have priorities higher than `limit' */
- op = getbinopr(ls->t.token);
- while (op != OPR_NOBINOPR && priority[op].left > limit) {
- expdesc v2;
- BinOpr nextop;
- int line = ls->linenumber;
- luaX_next(ls);
- luaK_infix(ls->fs, op, v);
- /* read sub-expression with higher priority */
- nextop = subexpr(ls, &v2, priority[op].right);
- luaK_posfix(ls->fs, op, v, &v2, line);
- op = nextop;
- }
- leavelevel(ls);
- return op; /* return first untreated operator */
-}
-
-
-static void expr (LexState *ls, expdesc *v) {
- subexpr(ls, v, 0);
-}
-
-/* }==================================================================== */
-
-
-
-/*
-** {======================================================================
-** Rules for Statements
-** =======================================================================
-*/
-
-
-static void block (LexState *ls) {
- /* block -> statlist */
- FuncState *fs = ls->fs;
- BlockCnt bl;
- enterblock(fs, &bl, 0);
- statlist(ls);
- 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 an upvalue/local variable, the
-** upvalue/local variable is begin used in a previous assignment to a
-** table. If so, save original upvalue/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) { /* check all previous assignments */
- if (lh->v.k == VINDEXED) { /* assigning to a table? */
- /* table is the upvalue/local being assigned now? */
- if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) {
- conflict = 1;
- lh->v.u.ind.vt = VLOCAL;
- lh->v.u.ind.t = (lu_byte)extra; /* previous assignment will use safe copy */
- }
- /* index is the local being assigned? (index cannot be upvalue) */
- if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) {
- conflict = 1;
- lh->v.u.ind.idx = (short)extra; /* previous assignment will use safe copy */
- }
- }
- }
- if (conflict) {
- /* copy upvalue/local value to a temporary (in position 'extra') */
- OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
- luaK_codeABC(fs, op, extra, v->u.info, 0);
- luaK_reserveregs(fs, 1);
- }
-}
-
-
-static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
- expdesc e;
- check_condition(ls, vkisvar(lh->v.k), "syntax error");
- if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */
- struct LHS_assign nv;
- nv.prev = lh;
- suffixedexp(ls, &nv.v);
- if (nv.v.k != VINDEXED)
- check_conflict(ls, lh, &nv.v);
- checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
- "C levels");
- assignment(ls, &nv, nvars+1);
- }
- else { /* assignment -> `=' explist */
- int nexps;
- checknext(ls, '=');
- nexps = explist(ls, &e);
- if (nexps != nvars) {
- adjust_assign(ls, nvars, nexps, &e);
- if (nexps > nvars)
- ls->fs->freereg -= (lu_byte)(nexps - nvars); /* remove extra values */
- }
- else {
- luaK_setoneret(ls->fs, &e); /* 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 int cond (LexState *ls) {
- /* cond -> exp */
- expdesc v;
- expr(ls, &v); /* read condition */
- if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */
- luaK_goiftrue(ls->fs, &v);
- return v.f;
-}
-
-
-static void gotostat (LexState *ls, int pc) {
- int line = ls->linenumber;
- TString *label;
- int g;
- if (testnext(ls, TK_GOTO))
- label = str_checkname(ls);
- else {
- luaX_next(ls); /* skip break */
- label = luaS_new(ls->L, "break");
- }
- g = newlabelentry(ls, &ls->dyd->gt, label, line, pc);
- findlabel(ls, g); /* close it if label already defined */
-}
-
-
-/* check for repeated labels on the same block */
-static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) {
- int i;
- for (i = fs->bl->firstlabel; i < ll->n; i++) {
- if (luaS_eqstr(label, ll->arr[i].name)) {
- const char *msg = luaO_pushfstring(fs->ls->L,
- "label " LUA_QS " already defined on line %d",
- getstr(label), ll->arr[i].line);
- semerror(fs->ls, msg);
- }
- }
-}
-
-
-/* skip no-op statements */
-static void skipnoopstat (LexState *ls) {
- while (ls->t.token == ';' || ls->t.token == TK_DBCOLON)
- statement(ls);
-}
-
-
-static void labelstat (LexState *ls, TString *label, int line) {
- /* label -> '::' NAME '::' */
- FuncState *fs = ls->fs;
- Labellist *ll = &ls->dyd->label;
- int l; /* index of new label being created */
- checkrepeated(fs, ll, label); /* check for repeated labels */
- checknext(ls, TK_DBCOLON); /* skip double colon */
- /* create new entry for this label */
- l = newlabelentry(ls, ll, label, line, fs->pc);
- skipnoopstat(ls); /* skip other no-op statements */
- if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */
- /* assume that locals are already out of scope */
- ll->arr[l].nactvar = fs->bl->nactvar;
- }
- findgotos(ls, &ll->arr[l]);
-}
-
-
-static void whilestat (LexState *ls, int line) {
- /* whilestat -> WHILE cond DO block END */
- FuncState *fs = ls->fs;
- int whileinit;
- int condexit;
- BlockCnt bl;
- luaX_next(ls); /* skip WHILE */
- whileinit = luaK_getlabel(fs);
- condexit = cond(ls);
- enterblock(fs, &bl, 1);
- checknext(ls, TK_DO);
- block(ls);
- luaK_jumpto(fs, whileinit);
- check_match(ls, TK_END, TK_WHILE, line);
- leaveblock(fs);
- luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
-}
-
-
-static void repeatstat (LexState *ls, int line) {
- /* repeatstat -> REPEAT block UNTIL cond */
- int condexit;
- FuncState *fs = ls->fs;
- int repeat_init = luaK_getlabel(fs);
- BlockCnt bl1, bl2;
- enterblock(fs, &bl1, 1); /* loop block */
- enterblock(fs, &bl2, 0); /* scope block */
- luaX_next(ls); /* skip REPEAT */
- statlist(ls);
- check_match(ls, TK_UNTIL, TK_REPEAT, line);
- condexit = cond(ls); /* read condition (inside scope block) */
- if (bl2.upval) /* upvalues? */
- luaK_patchclose(fs, condexit, bl2.nactvar);
- leaveblock(fs); /* finish scope */
- luaK_patchlist(fs, condexit, repeat_init); /* close the loop */
- leaveblock(fs); /* finish loop */
-}
-
-
-static int exp1 (LexState *ls) {
- expdesc e;
- int reg;
- expr(ls, &e);
- luaK_exp2nextreg(ls->fs, &e);
- lua_assert(e.k == VNONRELOC);
- reg = e.u.info;
- return reg;
-}
-
-
-static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
- /* forbody -> DO block */
- BlockCnt bl;
- FuncState *fs = ls->fs;
- int prep, endfor;
- adjustlocalvars(ls, 3); /* control variables */
- checknext(ls, TK_DO);
- prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
- enterblock(fs, &bl, 0); /* scope for declared variables */
- adjustlocalvars(ls, nvars);
- luaK_reserveregs(fs, nvars);
- block(ls);
- leaveblock(fs); /* end of scope for declared variables */
- luaK_patchtohere(fs, prep);
- if (isnum) /* numeric for? */
- endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP);
- else { /* generic for */
- luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars);
- luaK_fixline(fs, line);
- endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP);
- }
- luaK_patchlist(fs, endfor, prep + 1);
- luaK_fixline(fs, line);
-}
-
-
-static void fornum (LexState *ls, TString *varname, int line) {
- /* fornum -> NAME = exp1,exp1[,exp1] forbody */
- FuncState *fs = ls->fs;
- int base = fs->freereg;
- new_localvarliteral(ls, "(for index)");
- new_localvarliteral(ls, "(for limit)");
- new_localvarliteral(ls, "(for step)");
- new_localvar(ls, varname);
- checknext(ls, '=');
- exp1(ls); /* initial value */
- checknext(ls, ',');
- exp1(ls); /* limit */
- if (testnext(ls, ','))
- exp1(ls); /* optional step */
- else { /* default step = 1 */
- luaK_codek(fs, fs->freereg, luaK_numberK(fs, 1));
- luaK_reserveregs(fs, 1);
- }
- forbody(ls, base, line, 1, 1);
-}
-
-
-static void forlist (LexState *ls, TString *indexname) {
- /* forlist -> NAME {,NAME} IN explist forbody */
- FuncState *fs = ls->fs;
- expdesc e;
- int nvars = 4; /* gen, state, control, plus at least one declared var */
- int line;
- int base = fs->freereg;
- /* create control variables */
- new_localvarliteral(ls, "(for generator)");
- new_localvarliteral(ls, "(for state)");
- new_localvarliteral(ls, "(for control)");
- /* create declared variables */
- new_localvar(ls, indexname);
- while (testnext(ls, ',')) {
- new_localvar(ls, str_checkname(ls));
- nvars++;
- }
- checknext(ls, TK_IN);
- line = ls->linenumber;
- adjust_assign(ls, 3, explist(ls, &e), &e);
- luaK_checkstack(fs, 3); /* extra space to call generator */
- forbody(ls, base, line, nvars - 3, 0);
-}
-
-
-static void forstat (LexState *ls, int line) {
- /* forstat -> FOR (fornum | forlist) END */
- FuncState *fs = ls->fs;
- TString *varname;
- BlockCnt bl;
- enterblock(fs, &bl, 1); /* scope for loop and control variables */
- luaX_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, LUA_QL("=") " or " LUA_QL("in") " expected");
- }
- check_match(ls, TK_END, TK_FOR, line);
- leaveblock(fs); /* loop scope (`break' jumps to this point) */
-}
-
-
-static void test_then_block (LexState *ls, int *escapelist) {
- /* test_then_block -> [IF | ELSEIF] cond THEN block */
- BlockCnt bl;
- FuncState *fs = ls->fs;
- expdesc v;
- int jf; /* instruction to skip 'then' code (if condition is false) */
- luaX_next(ls); /* skip IF or ELSEIF */
- expr(ls, &v); /* read condition */
- checknext(ls, TK_THEN);
- if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) {
- luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */
- enterblock(fs, &bl, 0); /* must enter block before 'goto' */
- gotostat(ls, v.t); /* handle goto/break */
- skipnoopstat(ls); /* skip other no-op statements */
- if (block_follow(ls, 0)) { /* 'goto' is the entire block? */
- leaveblock(fs);
- return; /* and that is it */
- }
- else /* must skip over 'then' part if condition is false */
- jf = luaK_jump(fs);
- }
- else { /* regular case (not goto/break) */
- luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */
- enterblock(fs, &bl, 0);
- jf = v.f;
- }
- statlist(ls); /* `then' part */
- leaveblock(fs);
- if (ls->t.token == TK_ELSE ||
- ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */
- luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */
- luaK_patchtohere(fs, jf);
-}
-
-
-static void ifstat (LexState *ls, int line) {
- /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
- FuncState *fs = ls->fs;
- int escapelist = NO_JUMP; /* exit list for finished parts */
- test_then_block(ls, &escapelist); /* IF cond THEN block */
- while (ls->t.token == TK_ELSEIF)
- test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */
- if (testnext(ls, TK_ELSE))
- block(ls); /* `else' part */
- check_match(ls, TK_END, TK_IF, line);
- luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */
-}
-
-
-static void localfunc (LexState *ls) {
- expdesc b;
- FuncState *fs = ls->fs;
- new_localvar(ls, str_checkname(ls)); /* new local variable */
- adjustlocalvars(ls, 1); /* enter its scope */
- body(ls, &b, 0, ls->linenumber); /* function created in next register */
- /* debug information will only see the variable after this point! */
- getlocvar(fs, b.u.info)->startpc = fs->pc;
-}
-
-
-static void localstat (LexState *ls) {
- /* stat -> LOCAL NAME {`,' NAME} [`=' explist] */
- int nvars = 0;
- int nexps;
- expdesc e;
- do {
- new_localvar(ls, str_checkname(ls));
- nvars++;
- } while (testnext(ls, ','));
- if (testnext(ls, '='))
- nexps = explist(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 {fieldsel} [`:' NAME] */
- int ismethod = 0;
- singlevar(ls, v);
- while (ls->t.token == '.')
- fieldsel(ls, v);
- if (ls->t.token == ':') {
- ismethod = 1;
- fieldsel(ls, v);
- }
- return ismethod;
-}
-
-
-static void funcstat (LexState *ls, int line) {
- /* funcstat -> FUNCTION funcname body */
- int ismethod;
- expdesc v, b;
- luaX_next(ls); /* skip FUNCTION */
- ismethod = funcname(ls, &v);
- body(ls, &b, ismethod, 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;
- suffixedexp(ls, &v.v);
- if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */
- v.prev = NULL;
- assignment(ls, &v, 1);
- }
- else { /* stat -> func */
- check_condition(ls, v.v.k == VCALL, "syntax error");
- SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
- }
-}
-
-
-static void retstat (LexState *ls) {
- /* stat -> RETURN [explist] [';'] */
- FuncState *fs = ls->fs;
- expdesc e;
- int first, nret; /* registers with returned values */
- if (block_follow(ls, 1) || ls->t.token == ';')
- first = nret = 0; /* return no values */
- else {
- nret = explist(ls, &e); /* optional return values */
- if (hasmultret(e.k)) {
- luaK_setmultret(fs, &e);
- if (e.k == VCALL && 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_ret(fs, first, nret);
- testnext(ls, ';'); /* skip optional semicolon */
-}
-
-
-static void statement (LexState *ls) {
- int line = ls->linenumber; /* may be needed for error messages */
- enterlevel(ls);
- switch (ls->t.token) {
- case ';': { /* stat -> ';' (empty statement) */
- luaX_next(ls); /* skip ';' */
- break;
- }
- case TK_IF: { /* stat -> ifstat */
- ifstat(ls, line);
- break;
- }
- case TK_WHILE: { /* stat -> whilestat */
- whilestat(ls, line);
- break;
- }
- case TK_DO: { /* stat -> DO block END */
- luaX_next(ls); /* skip DO */
- block(ls);
- check_match(ls, TK_END, TK_DO, line);
- break;
- }
- case TK_FOR: { /* stat -> forstat */
- forstat(ls, line);
- break;
- }
- case TK_REPEAT: { /* stat -> repeatstat */
- repeatstat(ls, line);
- break;
- }
- case TK_FUNCTION: { /* stat -> funcstat */
- funcstat(ls, line);
- break;
- }
- case TK_LOCAL: { /* stat -> localstat */
- luaX_next(ls); /* skip LOCAL */
- if (testnext(ls, TK_FUNCTION)) /* local function? */
- localfunc(ls);
- else
- localstat(ls);
- break;
- }
- case TK_DBCOLON: { /* stat -> label */
- luaX_next(ls); /* skip double colon */
- labelstat(ls, str_checkname(ls), line);
- break;
- }
- case TK_RETURN: { /* stat -> retstat */
- luaX_next(ls); /* skip RETURN */
- retstat(ls);
- break;
- }
- case TK_BREAK: /* stat -> breakstat */
- case TK_GOTO: { /* stat -> 'goto' NAME */
- gotostat(ls, luaK_jump(ls->fs));
- break;
- }
- default: { /* stat -> func | assignment */
- exprstat(ls);
- break;
- }
- }
- lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
- ls->fs->freereg >= ls->fs->nactvar);
- ls->fs->freereg = ls->fs->nactvar; /* free registers */
- leavelevel(ls);
-}
-
-/* }====================================================================== */
-
-
-/*
-** compiles the main function, which is a regular vararg function with an
-** upvalue named LUA_ENV
-*/
-static void mainfunc (LexState *ls, FuncState *fs) {
- BlockCnt bl;
- expdesc v;
- open_func(ls, fs, &bl);
- fs->f->is_vararg = 1; /* main function is always vararg */
- init_exp(&v, VLOCAL, 0); /* create and... */
- newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */
- luaX_next(ls); /* read first token */
- statlist(ls); /* parse main body */
- check(ls, TK_EOS);
- close_func(ls);
-}
-
-
-Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
- Dyndata *dyd, const char *name, int firstchar) {
- LexState lexstate;
- FuncState funcstate;
- Closure *cl = luaF_newLclosure(L, 1); /* create main closure */
- /* anchor closure (to avoid being collected) */
- setclLvalue(L, L->top, cl);
- incr_top(L);
- funcstate.f = cl->l.p = luaF_newproto(L);
- funcstate.f->source = luaS_new(L, name); /* create and anchor TString */
- lexstate.buff = buff;
- lexstate.dyd = dyd;
- dyd->actvar.n = dyd->gt.n = dyd->label.n = 0;
- luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar);
- mainfunc(&lexstate, &funcstate);
- lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs);
- /* all scopes should be correctly finished */
- lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0);
- return cl; /* it's on the stack too */
-}
-
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