diff options
Diffstat (limited to 'lib/lua/src/lvm.c')
| -rw-r--r-- | lib/lua/src/lvm.c | 780 |
1 files changed, 780 insertions, 0 deletions
diff --git a/lib/lua/src/lvm.c b/lib/lua/src/lvm.c new file mode 100644 index 0000000..26abd38 --- /dev/null +++ b/lib/lua/src/lvm.c @@ -0,0 +1,780 @@ +/*
+** $Id: lvm.c,v 1.1 2003-11-06 11:56:07 pixel Exp $
+** Lua virtual machine
+** See Copyright Notice in lua.h
+*/
+
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* needed only when `lua_number2str' uses `sprintf' */
+#include <stdio.h>
+
+#define lvm_c
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lfunc.h"
+#include "lgc.h"
+#include "lobject.h"
+#include "lopcodes.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lvm.h"
+
+
+
+/* function to convert a lua_Number to a string */
+#ifndef lua_number2str
+#define lua_number2str(s,n) sprintf((s), LUA_NUMBER_FMT, (n))
+#endif
+
+
+/* limit for table tag-method chains (to avoid loops) */
+#define MAXTAGLOOP 100
+
+
+const TObject *luaV_tonumber (const TObject *obj, TObject *n) {
+ lua_Number num;
+ if (ttisnumber(obj)) return obj;
+ if (ttisstring(obj) && luaO_str2d(svalue(obj), &num)) {
+ setnvalue(n, num);
+ return n;
+ }
+ else
+ return NULL;
+}
+
+
+int luaV_tostring (lua_State *L, StkId obj) {
+ if (!ttisnumber(obj))
+ return 0;
+ else {
+ char s[32]; /* 16 digits, sign, point and \0 (+ some extra...) */
+ lua_number2str(s, nvalue(obj));
+ setsvalue2s(obj, luaS_new(L, s));
+ return 1;
+ }
+}
+
+
+static void traceexec (lua_State *L) {
+ lu_byte mask = L->hookmask;
+ if (mask > LUA_MASKLINE) { /* instruction-hook set? */
+ if (L->hookcount == 0) {
+ resethookcount(L);
+ luaD_callhook(L, LUA_HOOKCOUNT, -1);
+ return;
+ }
+ }
+ if (mask & LUA_MASKLINE) {
+ CallInfo *ci = L->ci;
+ Proto *p = ci_func(ci)->l.p;
+ int newline = getline(p, pcRel(*ci->u.l.pc, p));
+ if (!L->hookinit) {
+ luaG_inithooks(L);
+ return;
+ }
+ lua_assert(ci->state & CI_HASFRAME);
+ if (pcRel(*ci->u.l.pc, p) == 0) /* tracing may be starting now? */
+ ci->u.l.savedpc = *ci->u.l.pc; /* initialize `savedpc' */
+ /* calls linehook when enters a new line or jumps back (loop) */
+ if (*ci->u.l.pc <= ci->u.l.savedpc ||
+ newline != getline(p, pcRel(ci->u.l.savedpc, p))) {
+ luaD_callhook(L, LUA_HOOKLINE, newline);
+ ci = L->ci; /* previous call may reallocate `ci' */
+ }
+ ci->u.l.savedpc = *ci->u.l.pc;
+ }
+}
+
+
+static void callTMres (lua_State *L, const TObject *f,
+ const TObject *p1, const TObject *p2) {
+ setobj2s(L->top, f); /* push function */
+ setobj2s(L->top+1, p1); /* 1st argument */
+ setobj2s(L->top+2, p2); /* 2nd argument */
+ luaD_checkstack(L, 3); /* cannot check before (could invalidate p1, p2) */
+ L->top += 3;
+ luaD_call(L, L->top - 3, 1);
+ L->top--; /* result will be in L->top */
+}
+
+
+
+static void callTM (lua_State *L, const TObject *f,
+ const TObject *p1, const TObject *p2, const TObject *p3) {
+ setobj2s(L->top, f); /* push function */
+ setobj2s(L->top+1, p1); /* 1st argument */
+ setobj2s(L->top+2, p2); /* 2nd argument */
+ setobj2s(L->top+3, p3); /* 3th argument */
+ luaD_checkstack(L, 4); /* cannot check before (could invalidate p1...p3) */
+ L->top += 4;
+ luaD_call(L, L->top - 4, 0);
+}
+
+
+static const TObject *luaV_index (lua_State *L, const TObject *t,
+ TObject *key, int loop) {
+ const TObject *tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);
+ if (tm == NULL) return &luaO_nilobject; /* no TM */
+ if (ttisfunction(tm)) {
+ callTMres(L, tm, t, key);
+ return L->top;
+ }
+ else return luaV_gettable(L, tm, key, loop);
+}
+
+static const TObject *luaV_getnotable (lua_State *L, const TObject *t,
+ TObject *key, int loop) {
+ const TObject *tm = luaT_gettmbyobj(L, t, TM_INDEX);
+ if (ttisnil(tm))
+ luaG_typeerror(L, t, "index");
+ if (ttisfunction(tm)) {
+ callTMres(L, tm, t, key);
+ return L->top;
+ }
+ else return luaV_gettable(L, tm, key, loop);
+}
+
+
+/*
+** Function to index a table.
+** Receives the table at `t' and the key at `key'.
+** leaves the result at `res'.
+*/
+const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key,
+ int loop) {
+ if (loop > MAXTAGLOOP)
+ luaG_runerror(L, "loop in gettable");
+ if (ttistable(t)) { /* `t' is a table? */
+ Table *h = hvalue(t);
+ const TObject *v = luaH_get(h, key); /* do a primitive get */
+ if (!ttisnil(v)) return v;
+ else return luaV_index(L, t, key, loop+1);
+ }
+ else return luaV_getnotable(L, t, key, loop+1);
+}
+
+
+/*
+** Receives table at `t', key at `key' and value at `val'.
+*/
+void luaV_settable (lua_State *L, const TObject *t, TObject *key, StkId val) {
+ const TObject *tm;
+ int loop = 0;
+ do {
+ if (ttistable(t)) { /* `t' is a table? */
+ Table *h = hvalue(t);
+ TObject *oldval = luaH_set(L, h, key); /* do a primitive set */
+ if (!ttisnil(oldval) || /* result is no nil? */
+ (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
+ setobj2t(oldval, val); /* write barrier */
+ return;
+ }
+ /* else will try the tag method */
+ }
+ else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
+ luaG_typeerror(L, t, "index");
+ if (ttisfunction(tm)) {
+ callTM(L, tm, t, key, val);
+ return;
+ }
+ t = tm; /* else repeat with `tm' */
+ } while (++loop <= MAXTAGLOOP);
+ luaG_runerror(L, "loop in settable");
+}
+
+
+static int call_binTM (lua_State *L, const TObject *p1, const TObject *p2,
+ StkId res, TMS event) {
+ ptrdiff_t result = savestack(L, res);
+ const TObject *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */
+ if (ttisnil(tm))
+ tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
+ if (!ttisfunction(tm)) return 0;
+ callTMres(L, tm, p1, p2);
+ res = restorestack(L, result); /* previous call may change stack */
+ setobjs2s(res, L->top);
+ return 1;
+}
+
+
+static const TObject *get_compTM (lua_State *L, Table *mt1, Table *mt2,
+ TMS event) {
+ const TObject *tm1 = fasttm(L, mt1, event);
+ const TObject *tm2;
+ if (tm1 == NULL) return NULL; /* no metamethod */
+ if (mt1 == mt2) return tm1; /* same metatables => same metamethods */
+ tm2 = fasttm(L, mt2, event);
+ if (tm2 == NULL) return NULL; /* no metamethod */
+ if (luaO_rawequalObj(tm1, tm2)) /* same metamethods? */
+ return tm1;
+ return NULL;
+}
+
+
+static int call_orderTM (lua_State *L, const TObject *p1, const TObject *p2,
+ TMS event) {
+ const TObject *tm1 = luaT_gettmbyobj(L, p1, event);
+ const TObject *tm2;
+ if (ttisnil(tm1)) return -1; /* no metamethod? */
+ tm2 = luaT_gettmbyobj(L, p2, event);
+ if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
+ return -1;
+ callTMres(L, tm1, p1, p2);
+ return !l_isfalse(L->top);
+}
+
+
+static int luaV_strcmp (const TString *ls, const TString *rs) {
+ const char *l = getstr(ls);
+ size_t ll = ls->tsv.len;
+ const char *r = getstr(rs);
+ size_t lr = rs->tsv.len;
+ for (;;) {
+ int temp = strcoll(l, r);
+ if (temp != 0) return temp;
+ else { /* strings are equal up to a `\0' */
+ size_t len = strlen(l); /* index of first `\0' in both strings */
+ if (len == lr) /* r is finished? */
+ return (len == ll) ? 0 : 1;
+ else if (len == ll) /* l is finished? */
+ return -1; /* l is smaller than r (because r is not finished) */
+ /* both strings longer than `len'; go on comparing (after the `\0') */
+ len++;
+ l += len; ll -= len; r += len; lr -= len;
+ }
+ }
+}
+
+
+int luaV_lessthan (lua_State *L, const TObject *l, const TObject *r) {
+ int res;
+ if (ttype(l) != ttype(r))
+ return luaG_ordererror(L, l, r);
+ else if (ttisnumber(l))
+ return nvalue(l) < nvalue(r);
+ else if (ttisstring(l))
+ return luaV_strcmp(tsvalue(l), tsvalue(r)) < 0;
+ else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
+ return res;
+ return luaG_ordererror(L, l, r);
+}
+
+
+static int luaV_lessequal (lua_State *L, const TObject *l, const TObject *r) {
+ int res;
+ if (ttype(l) != ttype(r))
+ return luaG_ordererror(L, l, r);
+ else if (ttisnumber(l))
+ return nvalue(l) <= nvalue(r);
+ else if (ttisstring(l))
+ return luaV_strcmp(tsvalue(l), tsvalue(r)) <= 0;
+ else if ((res = call_orderTM(L, l, r, TM_LE)) != -1) /* first try `le' */
+ return res;
+ else if ((res = call_orderTM(L, r, l, TM_LT)) != -1) /* else try `lt' */
+ return !res;
+ return luaG_ordererror(L, l, r);
+}
+
+
+int luaV_equalval (lua_State *L, const TObject *t1, const TObject *t2) {
+ const TObject *tm;
+ lua_assert(ttype(t1) == ttype(t2));
+ switch (ttype(t1)) {
+ case LUA_TNIL: return 1;
+ case LUA_TNUMBER: return nvalue(t1) == nvalue(t2);
+ case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */
+ case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2);
+ case LUA_TUSERDATA: {
+ if (uvalue(t1) == uvalue(t2)) return 1;
+ tm = get_compTM(L, uvalue(t1)->uv.metatable, uvalue(t2)->uv.metatable,
+ TM_EQ);
+ break; /* will try TM */
+ }
+ case LUA_TTABLE: {
+ if (hvalue(t1) == hvalue(t2)) return 1;
+ tm = get_compTM(L, hvalue(t1)->metatable, hvalue(t2)->metatable, TM_EQ);
+ break; /* will try TM */
+ }
+ default: return gcvalue(t1) == gcvalue(t2);
+ }
+ if (tm == NULL) return 0; /* no TM? */
+ callTMres(L, tm, t1, t2); /* call TM */
+ return !l_isfalse(L->top);
+}
+
+
+void luaV_concat (lua_State *L, int total, int last) {
+ do {
+ StkId top = L->base + last + 1;
+ int n = 2; /* number of elements handled in this pass (at least 2) */
+ if (!tostring(L, top-2) || !tostring(L, top-1)) {
+ if (!call_binTM(L, top-2, top-1, top-2, TM_CONCAT))
+ luaG_concaterror(L, top-2, top-1);
+ } else if (tsvalue(top-1)->tsv.len > 0) { /* if len=0, do nothing */
+ /* at least two string values; get as many as possible */
+ lu_mem tl = cast(lu_mem, tsvalue(top-1)->tsv.len) +
+ cast(lu_mem, tsvalue(top-2)->tsv.len);
+ char *buffer;
+ int i;
+ while (n < total && tostring(L, top-n-1)) { /* collect total length */
+ tl += tsvalue(top-n-1)->tsv.len;
+ n++;
+ }
+ if (tl > MAX_SIZET) luaG_runerror(L, "string size overflow");
+ buffer = luaZ_openspace(L, &G(L)->buff, tl);
+ tl = 0;
+ for (i=n; i>0; i--) { /* concat all strings */
+ size_t l = tsvalue(top-i)->tsv.len;
+ memcpy(buffer+tl, svalue(top-i), l);
+ tl += l;
+ }
+ setsvalue2s(top-n, luaS_newlstr(L, buffer, tl));
+ }
+ total -= n-1; /* got `n' strings to create 1 new */
+ last -= n-1;
+ } while (total > 1); /* repeat until only 1 result left */
+}
+
+
+static void Arith (lua_State *L, StkId ra,
+ const TObject *rb, const TObject *rc, TMS op) {
+ TObject tempb, tempc;
+ const TObject *b, *c;
+ if ((b = luaV_tonumber(rb, &tempb)) != NULL &&
+ (c = luaV_tonumber(rc, &tempc)) != NULL) {
+ switch (op) {
+ case TM_ADD: setnvalue(ra, nvalue(b) + nvalue(c)); break;
+ case TM_SUB: setnvalue(ra, nvalue(b) - nvalue(c)); break;
+ case TM_MUL: setnvalue(ra, nvalue(b) * nvalue(c)); break;
+ case TM_DIV: setnvalue(ra, nvalue(b) / nvalue(c)); break;
+ case TM_POW: {
+ const TObject *f = luaH_getstr(hvalue(gt(L)), G(L)->tmname[TM_POW]);
+ ptrdiff_t res = savestack(L, ra);
+ if (!ttisfunction(f))
+ luaG_runerror(L, "`__pow' (`^' operator) is not a function");
+ callTMres(L, f, b, c);
+ ra = restorestack(L, res); /* previous call may change stack */
+ setobjs2s(ra, L->top);
+ break;
+ }
+ default: lua_assert(0); break;
+ }
+ }
+ else if (!call_binTM(L, rb, rc, ra, op))
+ luaG_aritherror(L, rb, rc);
+}
+
+
+
+/*
+** some macros for common tasks in `luaV_execute'
+*/
+
+#define runtime_check(L, c) { if (!(c)) return 0; }
+
+#define RA(i) (base+GETARG_A(i))
+/* to be used after possible stack reallocation */
+#define XRA(i) (L->base+GETARG_A(i))
+#define RB(i) (base+GETARG_B(i))
+#define RKB(i) ((GETARG_B(i) < MAXSTACK) ? RB(i) : k+GETARG_B(i)-MAXSTACK)
+#define RC(i) (base+GETARG_C(i))
+#define RKC(i) ((GETARG_C(i) < MAXSTACK) ? RC(i) : k+GETARG_C(i)-MAXSTACK)
+#define KBx(i) (k+GETARG_Bx(i))
+
+
+#define dojump(pc, i) ((pc) += (i))
+
+
+StkId luaV_execute (lua_State *L) {
+ LClosure *cl;
+ TObject *k;
+ const Instruction *pc;
+ callentry: /* entry point when calling new functions */
+ L->ci->u.l.pc = &pc;
+ if (L->hookmask & LUA_MASKCALL)
+ luaD_callhook(L, LUA_HOOKCALL, -1);
+ retentry: /* entry point when returning to old functions */
+ lua_assert(L->ci->state == CI_SAVEDPC ||
+ L->ci->state == (CI_SAVEDPC | CI_CALLING));
+ L->ci->state = CI_HASFRAME; /* activate frame */
+ pc = L->ci->u.l.savedpc;
+ cl = &clvalue(L->base - 1)->l;
+ k = cl->p->k;
+ /* main loop of interpreter */
+ for (;;) {
+ const Instruction i = *pc++;
+ StkId base, ra;
+ if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
+ (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
+ traceexec(L);
+ if (L->ci->state & CI_YIELD) { /* did hook yield? */
+ L->ci->u.l.savedpc = pc - 1;
+ L->ci->state = CI_YIELD | CI_SAVEDPC;
+ return NULL;
+ }
+ }
+ /* warning!! several calls may realloc the stack and invalidate `ra' */
+ base = L->base;
+ ra = RA(i);
+ lua_assert(L->ci->state & CI_HASFRAME);
+ lua_assert(base == L->ci->base);
+ lua_assert(L->top <= L->stack + L->stacksize && L->top >= base);
+ lua_assert(L->top == L->ci->top ||
+ GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL ||
+ GET_OPCODE(i) == OP_RETURN || GET_OPCODE(i) == OP_SETLISTO);
+ switch (GET_OPCODE(i)) {
+ case OP_MOVE: {
+ setobjs2s(ra, RB(i));
+ break;
+ }
+ case OP_LOADK: {
+ setobj2s(ra, KBx(i));
+ break;
+ }
+ case OP_LOADBOOL: {
+ setbvalue(ra, GETARG_B(i));
+ if (GETARG_C(i)) pc++; /* skip next instruction (if C) */
+ break;
+ }
+ case OP_LOADNIL: {
+ TObject *rb = RB(i);
+ do {
+ setnilvalue(rb--);
+ } while (rb >= ra);
+ break;
+ }
+ case OP_GETUPVAL: {
+ int b = GETARG_B(i);
+ setobj2s(ra, cl->upvals[b]->v);
+ break;
+ }
+ case OP_GETGLOBAL: {
+ TObject *rb = KBx(i);
+ const TObject *v;
+ lua_assert(ttisstring(rb) && ttistable(&cl->g));
+ v = luaH_getstr(hvalue(&cl->g), tsvalue(rb));
+ if (!ttisnil(v)) { setobj2s(ra, v); }
+ else
+ setobj2s(XRA(i), luaV_index(L, &cl->g, rb, 0));
+ break;
+ }
+ case OP_GETTABLE: {
+ StkId rb = RB(i);
+ TObject *rc = RKC(i);
+ if (ttistable(rb)) {
+ const TObject *v = luaH_get(hvalue(rb), rc);
+ if (!ttisnil(v)) { setobj2s(ra, v); }
+ else
+ setobj2s(XRA(i), luaV_index(L, rb, rc, 0));
+ }
+ else
+ setobj2s(XRA(i), luaV_getnotable(L, rb, rc, 0));
+ break;
+ }
+ case OP_SETGLOBAL: {
+ lua_assert(ttisstring(KBx(i)) && ttistable(&cl->g));
+ luaV_settable(L, &cl->g, KBx(i), ra);
+ break;
+ }
+ case OP_SETUPVAL: {
+ int b = GETARG_B(i);
+ setobj(cl->upvals[b]->v, ra); /* write barrier */
+ break;
+ }
+ case OP_SETTABLE: {
+ luaV_settable(L, ra, RKB(i), RKC(i));
+ break;
+ }
+ case OP_NEWTABLE: {
+ int b = GETARG_B(i);
+ b = fb2int(b);
+ sethvalue(ra, luaH_new(L, b, GETARG_C(i)));
+ luaC_checkGC(L);
+ break;
+ }
+ case OP_SELF: {
+ StkId rb = RB(i);
+ TObject *rc = RKC(i);
+ runtime_check(L, ttisstring(rc));
+ setobjs2s(ra+1, rb);
+ if (ttistable(rb)) {
+ const TObject *v = luaH_getstr(hvalue(rb), tsvalue(rc));
+ if (!ttisnil(v)) { setobj2s(ra, v); }
+ else
+ setobj2s(XRA(i), luaV_index(L, rb, rc, 0));
+ }
+ else
+ setobj2s(XRA(i), luaV_getnotable(L, rb, rc, 0));
+ break;
+ }
+ case OP_ADD: {
+ TObject *rb = RKB(i);
+ TObject *rc = RKC(i);
+ if (ttisnumber(rb) && ttisnumber(rc)) {
+ setnvalue(ra, nvalue(rb) + nvalue(rc));
+ }
+ else
+ Arith(L, ra, rb, rc, TM_ADD);
+ break;
+ }
+ case OP_SUB: {
+ TObject *rb = RKB(i);
+ TObject *rc = RKC(i);
+ if (ttisnumber(rb) && ttisnumber(rc)) {
+ setnvalue(ra, nvalue(rb) - nvalue(rc));
+ }
+ else
+ Arith(L, ra, rb, rc, TM_SUB);
+ break;
+ }
+ case OP_MUL: {
+ TObject *rb = RKB(i);
+ TObject *rc = RKC(i);
+ if (ttisnumber(rb) && ttisnumber(rc)) {
+ setnvalue(ra, nvalue(rb) * nvalue(rc));
+ }
+ else
+ Arith(L, ra, rb, rc, TM_MUL);
+ break;
+ }
+ case OP_DIV: {
+ TObject *rb = RKB(i);
+ TObject *rc = RKC(i);
+ if (ttisnumber(rb) && ttisnumber(rc)) {
+ setnvalue(ra, nvalue(rb) / nvalue(rc));
+ }
+ else
+ Arith(L, ra, rb, rc, TM_DIV);
+ break;
+ }
+ case OP_POW: {
+ Arith(L, ra, RKB(i), RKC(i), TM_POW);
+ break;
+ }
+ case OP_UNM: {
+ const TObject *rb = RB(i);
+ TObject temp;
+ if (tonumber(rb, &temp)) {
+ setnvalue(ra, -nvalue(rb));
+ }
+ else {
+ setnilvalue(&temp);
+ if (!call_binTM(L, RB(i), &temp, ra, TM_UNM))
+ luaG_aritherror(L, RB(i), &temp);
+ }
+ break;
+ }
+ case OP_NOT: {
+ int res = l_isfalse(RB(i)); /* next assignment may change this value */
+ setbvalue(ra, res);
+ break;
+ }
+ case OP_CONCAT: {
+ int b = GETARG_B(i);
+ int c = GETARG_C(i);
+ luaV_concat(L, c-b+1, c); /* may change `base' (and `ra') */
+ base = L->base;
+ setobjs2s(RA(i), base+b);
+ luaC_checkGC(L);
+ break;
+ }
+ case OP_JMP: {
+ dojump(pc, GETARG_sBx(i));
+ break;
+ }
+ case OP_EQ: {
+ if (equalobj(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+ else dojump(pc, GETARG_sBx(*pc) + 1);
+ break;
+ }
+ case OP_LT: {
+ if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+ else dojump(pc, GETARG_sBx(*pc) + 1);
+ break;
+ }
+ case OP_LE: {
+ if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++;
+ else dojump(pc, GETARG_sBx(*pc) + 1);
+ break;
+ }
+ case OP_TEST: {
+ TObject *rb = RB(i);
+ if (l_isfalse(rb) == GETARG_C(i)) pc++;
+ else {
+ setobjs2s(ra, rb);
+ dojump(pc, GETARG_sBx(*pc) + 1);
+ }
+ break;
+ }
+ case OP_CALL:
+ case OP_TAILCALL: {
+ StkId firstResult;
+ int b = GETARG_B(i);
+ int nresults;
+ if (b != 0) L->top = ra+b; /* else previous instruction set top */
+ nresults = GETARG_C(i) - 1;
+ firstResult = luaD_precall(L, ra);
+ if (firstResult) {
+ if (firstResult > L->top) { /* yield? */
+ lua_assert(L->ci->state == (CI_C | CI_YIELD));
+ (L->ci - 1)->u.l.savedpc = pc;
+ (L->ci - 1)->state = CI_SAVEDPC;
+ return NULL;
+ }
+ /* it was a C function (`precall' called it); adjust results */
+ luaD_poscall(L, nresults, firstResult);
+ if (nresults >= 0) L->top = L->ci->top;
+ }
+ else { /* it is a Lua function */
+ if (GET_OPCODE(i) == OP_CALL) { /* regular call? */
+ (L->ci-1)->u.l.savedpc = pc; /* save `pc' to return later */
+ (L->ci-1)->state = (CI_SAVEDPC | CI_CALLING);
+ }
+ else { /* tail call: put new frame in place of previous one */
+ int aux;
+ base = (L->ci - 1)->base; /* `luaD_precall' may change the stack */
+ ra = RA(i);
+ if (L->openupval) luaF_close(L, base);
+ for (aux = 0; ra+aux < L->top; aux++) /* move frame down */
+ setobjs2s(base+aux-1, ra+aux);
+ (L->ci - 1)->top = L->top = base+aux; /* correct top */
+ lua_assert(L->ci->state & CI_SAVEDPC);
+ (L->ci - 1)->u.l.savedpc = L->ci->u.l.savedpc;
+ (L->ci - 1)->u.l.tailcalls++; /* one more call lost */
+ (L->ci - 1)->state = CI_SAVEDPC;
+ L->ci--; /* remove new frame */
+ L->base = L->ci->base;
+ }
+ goto callentry;
+ }
+ break;
+ }
+ case OP_RETURN: {
+ CallInfo *ci = L->ci - 1; /* previous function frame */
+ int b = GETARG_B(i);
+ if (b != 0) L->top = ra+b-1;
+ lua_assert(L->ci->state & CI_HASFRAME);
+ if (L->openupval) luaF_close(L, base);
+ L->ci->state = CI_SAVEDPC; /* deactivate current function */
+ L->ci->u.l.savedpc = pc;
+ /* previous function was running `here'? */
+ if (!(ci->state & CI_CALLING)) {
+ lua_assert((ci->state & CI_C) || ci->u.l.pc != &pc);
+ return ra; /* no: return */
+ }
+ else { /* yes: continue its execution */
+ int nresults;
+ lua_assert(ci->u.l.pc == &pc &&
+ ttisfunction(ci->base - 1) &&
+ (ci->state & CI_SAVEDPC));
+ lua_assert(GET_OPCODE(*(ci->u.l.savedpc - 1)) == OP_CALL);
+ nresults = GETARG_C(*(ci->u.l.savedpc - 1)) - 1;
+ luaD_poscall(L, nresults, ra);
+ if (nresults >= 0) L->top = L->ci->top;
+ goto retentry;
+ }
+ }
+ case OP_FORLOOP: {
+ lua_Number step, idx, limit;
+ const TObject *plimit = ra+1;
+ const TObject *pstep = ra+2;
+ if (!ttisnumber(ra))
+ luaG_runerror(L, "`for' initial value must be a number");
+ if (!tonumber(plimit, ra+1))
+ luaG_runerror(L, "`for' limit must be a number");
+ if (!tonumber(pstep, ra+2))
+ luaG_runerror(L, "`for' step must be a number");
+ step = nvalue(pstep);
+ idx = nvalue(ra) + step; /* increment index */
+ limit = nvalue(plimit);
+ if (step > 0 ? idx <= limit : idx >= limit) {
+ dojump(pc, GETARG_sBx(i)); /* jump back */
+ chgnvalue(ra, idx); /* update index */
+ }
+ break;
+ }
+ case OP_TFORLOOP: {
+ int nvar = GETARG_C(i) + 1;
+ StkId cb = ra + nvar + 2; /* call base */
+ setobjs2s(cb, ra);
+ setobjs2s(cb+1, ra+1);
+ setobjs2s(cb+2, ra+2);
+ L->top = cb+3; /* func. + 2 args (state and index) */
+ luaD_call(L, cb, nvar);
+ L->top = L->ci->top;
+ ra = XRA(i) + 2; /* final position of first result */
+ cb = ra + nvar;
+ do { /* move results to proper positions */
+ nvar--;
+ setobjs2s(ra+nvar, cb+nvar);
+ } while (nvar > 0);
+ if (ttisnil(ra)) /* break loop? */
+ pc++; /* skip jump (break loop) */
+ else
+ dojump(pc, GETARG_sBx(*pc) + 1); /* jump back */
+ break;
+ }
+ case OP_TFORPREP: { /* for compatibility only */
+ if (ttistable(ra)) {
+ setobjs2s(ra+1, ra);
+ setobj2s(ra, luaH_getstr(hvalue(gt(L)), luaS_new(L, "next")));
+ }
+ dojump(pc, GETARG_sBx(i));
+ break;
+ }
+ case OP_SETLIST:
+ case OP_SETLISTO: {
+ int bc;
+ int n;
+ Table *h;
+ runtime_check(L, ttistable(ra));
+ h = hvalue(ra);
+ bc = GETARG_Bx(i);
+ if (GET_OPCODE(i) == OP_SETLIST)
+ n = (bc&(LFIELDS_PER_FLUSH-1)) + 1;
+ else {
+ n = L->top - ra - 1;
+ L->top = L->ci->top;
+ }
+ bc &= ~(LFIELDS_PER_FLUSH-1); /* bc = bc - bc%FPF */
+ for (; n > 0; n--)
+ setobj2t(luaH_setnum(L, h, bc+n), ra+n); /* write barrier */
+ break;
+ }
+ case OP_CLOSE: {
+ luaF_close(L, ra);
+ break;
+ }
+ case OP_CLOSURE: {
+ Proto *p;
+ Closure *ncl;
+ int nup, j;
+ p = cl->p->p[GETARG_Bx(i)];
+ nup = p->nups;
+ ncl = luaF_newLclosure(L, nup, &cl->g);
+ ncl->l.p = p;
+ for (j=0; j<nup; j++, pc++) {
+ if (GET_OPCODE(*pc) == OP_GETUPVAL)
+ ncl->l.upvals[j] = cl->upvals[GETARG_B(*pc)];
+ else {
+ lua_assert(GET_OPCODE(*pc) == OP_MOVE);
+ ncl->l.upvals[j] = luaF_findupval(L, base + GETARG_B(*pc));
+ }
+ }
+ setclvalue(ra, ncl);
+ luaC_checkGC(L);
+ break;
+ }
+ }
+ }
+}
+
|