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-rw-r--r--lua-5.3.5/lparser.c1650
1 files changed, 1650 insertions, 0 deletions
diff --git a/lua-5.3.5/lparser.c b/lua-5.3.5/lparser.c
new file mode 100644
index 0000000..cc54de4
--- /dev/null
+++ b/lua-5.3.5/lparser.c
@@ -0,0 +1,1650 @@
+/*
+** $Id: lparser.c,v 2.155.1.2 2017/04/29 18:11:40 roberto Exp $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+#define lparser_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+#include <string.h>
+
+#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)
+
+
+/* because all strings are unified by the scanner, the parser
+ can use pointer equality for string equality */
+#define eqstr(a,b) ((a) == (b))
+
+
+/*
+** nodes for block list (list of active blocks)
+*/
+typedef struct BlockCnt {
+ struct BlockCnt *previous; /* chain */
+ int firstlabel; /* index of first label in this block */
+ int 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);
+
+
+/* semantic error */
+static l_noret semerror (LexState *ls, const char *msg) {
+ ls->t.token = 0; /* remove "near <token>" 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 (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 (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 void singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
+ if (fs == NULL) /* no more levels? */
+ init_exp(var, VVOID, 0); /* 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 */
+ }
+ else { /* not found as local at current level; try upvalues */
+ int idx = searchupvalue(fs, n); /* try existing upvalues */
+ if (idx < 0) { /* not found? */
+ singlevaraux(fs->prev, n, var, 0); /* try upper levels */
+ if (var->k == VVOID) /* not found? */
+ return; /* it is a global */
+ /* else was LOCAL or UPVAL */
+ idx = newupvalue(fs, n, var); /* will be a new upvalue */
+ }
+ init_exp(var, VUPVAL, idx); /* new or old upvalue */
+ }
+ }
+}
+
+
+static void singlevar (LexState *ls, expdesc *var) {
+ TString *varname = str_checkname(ls);
+ FuncState *fs = ls->fs;
+ singlevaraux(fs, varname, var, 1);
+ if (var->k == VVOID) { /* global name? */
+ expdesc key;
+ singlevaraux(fs, ls->envn, var, 1); /* get environment variable */
+ lua_assert(var->k != VVOID); /* this one must exist */
+ 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);
+ }
+ }
+ if (nexps > nvars)
+ ls->fs->freereg -= nexps - nvars; /* remove extra values */
+}
+
+
+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(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 '%s'",
+ 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 (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 = n + 1;
+ 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 (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 = fs->ls->dyd->label.n;
+ bl->firstgoto = 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 '%s' 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) {
+ 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 */
+ 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;
+ 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 is 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 = 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; /* declared vararg */
+ break;
+ }
+ default: luaX_syntaxerror(ls, "<name> or '...' 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 = 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 -> FLT | INT | STRING | NIL | TRUE | FALSE | ... |
+ constructor | FUNCTION body | suffixedexp */
+ switch (ls->t.token) {
+ case TK_FLT: {
+ init_exp(v, VKFLT, 0);
+ v->u.nval = ls->t.seminfo.r;
+ break;
+ }
+ case TK_INT: {
+ init_exp(v, VKINT, 0);
+ v->u.ival = ls->t.seminfo.i;
+ 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 '...' 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_BNOT;
+ 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_MOD;
+ case '^': return OPR_POW;
+ case '/': return OPR_DIV;
+ case TK_IDIV: return OPR_IDIV;
+ case '&': return OPR_BAND;
+ case '|': return OPR_BOR;
+ case '~': return OPR_BXOR;
+ case TK_SHL: return OPR_SHL;
+ case TK_SHR: return OPR_SHR;
+ 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 */
+ {10, 10}, {10, 10}, /* '+' '-' */
+ {11, 11}, {11, 11}, /* '*' '%' */
+ {14, 13}, /* '^' (right associative) */
+ {11, 11}, {11, 11}, /* '/' '//' */
+ {6, 6}, {4, 4}, {5, 5}, /* '&' '|' '~' */
+ {7, 7}, {7, 7}, /* '<<' '>>' */
+ {9, 8}, /* '..' (right associative) */
+ {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */
+ {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */
+ {2, 2}, {1, 1} /* and, or */
+};
+
+#define UNARY_PRIORITY 12 /* 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 = 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 = 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);
+ 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 (eqstr(label, ll->arr[i].name)) {
+ const char *msg = luaO_pushfstring(fs->ls->L,
+ "label '%s' 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, luaK_getlabel(fs));
+ 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_intK(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, "'=' or '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 */
+ while (testnext(ls, ';')) {} /* skip colons */
+ 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(getinstruction(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(getinstruction(fs,&e), OP_TAILCALL);
+ lua_assert(GETARG_A(getinstruction(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 declared 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);
+}
+
+
+LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
+ Dyndata *dyd, const char *name, int firstchar) {
+ LexState lexstate;
+ FuncState funcstate;
+ LClosure *cl = luaF_newLclosure(L, 1); /* create main closure */
+ setclLvalue(L, L->top, cl); /* anchor it (to avoid being collected) */
+ luaD_inctop(L);
+ lexstate.h = luaH_new(L); /* create table for scanner */
+ sethvalue(L, L->top, lexstate.h); /* anchor it */
+ luaD_inctop(L);
+ funcstate.f = cl->p = luaF_newproto(L);
+ funcstate.f->source = luaS_new(L, name); /* create and anchor TString */
+ lua_assert(iswhite(funcstate.f)); /* do not need barrier here */
+ 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);
+ L->top--; /* remove scanner's table */
+ return cl; /* closure is on the stack, too */
+}
+