commit b0abc2ca03556a4483750c2c2389bd413710e36f
parent b320d37a80c6068cf6b7a91cdd8c8bc8bf71e06c
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 3 May 2005 16:00:55 -0300
better control of local variables in luaV_execute
Diffstat:
| M | lvm.c | | | 175 | +++++++++++++++++++++++++++++++++++++++++++------------------------------------ |
1 file changed, 96 insertions(+), 79 deletions(-)
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.38 2005/04/11 18:01:29 roberto Exp roberto $
+** $Id: lvm.c,v 2.39 2005/05/02 17:49:43 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -83,10 +83,10 @@ static void traceexec (lua_State *L, const Instruction *pc) {
static void callTMres (lua_State *L, StkId res, const TValue *f,
const TValue *p1, const TValue *p2) {
ptrdiff_t result = savestack(L, res);
- luaD_checkstack(L, 3);
setobj2s(L, L->top, f); /* push function */
setobj2s(L, L->top+1, p1); /* 1st argument */
setobj2s(L, L->top+2, p2); /* 2nd argument */
+ luaD_checkstack(L, 3);
L->top += 3;
luaD_call(L, L->top - 3, 1);
res = restorestack(L, result);
@@ -97,11 +97,11 @@ static void callTMres (lua_State *L, StkId res, const TValue *f,
static void callTM (lua_State *L, const TValue *f, const TValue *p1, const TValue *p2, const TValue *p3) {
- luaD_checkstack(L, 4);
setobj2s(L, L->top, f); /* push function */
setobj2s(L, L->top+1, p1); /* 1st argument */
setobj2s(L, L->top+2, p2); /* 2nd argument */
setobj2s(L, L->top+3, p3); /* 3th argument */
+ luaD_checkstack(L, 4);
L->top += 4;
luaD_call(L, L->top - 4, 0);
}
@@ -354,8 +354,12 @@ static StkId Arith (lua_State *L, StkId ra, const TValue *rb,
#define dojump(L,pc,i) {(pc) += (i); luai_threadyield(L);}
+#define Protect(x) { L->savedpc = pc; {x;}; base = L->base; }
+
+
StkId luaV_execute (lua_State *L, int nexeccalls) {
LClosure *cl;
+ StkId base;
TValue *k;
const Instruction *pc;
callentry: /* entry point when calling new functions */
@@ -364,25 +368,24 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
retentry: /* entry point when returning to old functions */
pc = L->savedpc;
cl = &clvalue(L->ci->func)->l;
+ base = L->base;
k = cl->p->k;
/* main loop of interpreter */
for (;;) {
- StkId base;
const Instruction i = *pc++;
StkId ra;
if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
- traceexec(L, pc); /***/
+ traceexec(L, pc);
if (L->status == LUA_YIELD) { /* did hook yield? */
L->savedpc = pc - 1;
return NULL;
}
+ base = L->base;
}
/* warning!! several calls may realloc the stack and invalidate `ra' */
- base = L->base;
ra = RA(i);
- L->savedpc = pc;
- lua_assert(base == L->ci->base);
+ lua_assert(base == L->base && L->base == L->ci->base);
lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
switch (GET_OPCODE(i)) {
@@ -416,18 +419,18 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
TValue *rb = KBx(i);
sethvalue(L, &g, cl->env);
lua_assert(ttisstring(rb));
- luaV_gettable(L, &g, rb, ra); /***/
+ Protect(luaV_gettable(L, &g, rb, ra));
continue;
}
case OP_GETTABLE: {
- luaV_gettable(L, RB(i), RKC(i), ra); /***/
+ Protect(luaV_gettable(L, RB(i), RKC(i), ra));
continue;
}
case OP_SETGLOBAL: {
TValue g;
sethvalue(L, &g, cl->env);
lua_assert(ttisstring(KBx(i)));
- luaV_settable(L, &g, KBx(i), ra); /***/
+ Protect(luaV_settable(L, &g, KBx(i), ra));
continue;
}
case OP_SETUPVAL: {
@@ -437,20 +440,20 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
continue;
}
case OP_SETTABLE: {
- luaV_settable(L, ra, RKB(i), RKC(i)); /***/
+ Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
continue;
}
case OP_NEWTABLE: {
int b = GETARG_B(i);
int c = GETARG_C(i);
sethvalue(L, ra, luaH_new(L, luaO_fb2int(b), luaO_fb2int(c)));
- luaC_checkGC(L); /***/
+ Protect(luaC_checkGC(L));
continue;
}
case OP_SELF: {
StkId rb = RB(i);
setobjs2s(L, ra+1, rb);
- luaV_gettable(L, rb, RKC(i), ra); /***/
+ Protect(luaV_gettable(L, rb, RKC(i), ra));
continue;
}
case OP_ADD: {
@@ -461,7 +464,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_numadd(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_ADD); /***/
+ Protect(Arith(L, ra, rb, rc, TM_ADD));
continue;
}
case OP_SUB: {
@@ -472,7 +475,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_numsub(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_SUB); /***/
+ Protect(Arith(L, ra, rb, rc, TM_SUB));
continue;
}
case OP_MUL: {
@@ -483,7 +486,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_nummul(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_MUL); /***/
+ Protect(Arith(L, ra, rb, rc, TM_MUL));
continue;
}
case OP_DIV: {
@@ -494,7 +497,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_numdiv(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_DIV); /***/
+ Protect(Arith(L, ra, rb, rc, TM_DIV));
continue;
}
case OP_MOD: {
@@ -505,7 +508,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_nummod(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_MOD); /***/
+ Protect(Arith(L, ra, rb, rc, TM_MOD));
continue;
}
case OP_POW: {
@@ -516,7 +519,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, luai_numpow(nb, nc));
}
else
- Arith(L, ra, rb, rc, TM_POW); /***/
+ Protect(Arith(L, ra, rb, rc, TM_POW));
continue;
}
case OP_UNM: {
@@ -528,8 +531,10 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
}
else {
rb = RB(i); /* `tonumber' erased `rb' */
- if (!call_binTM(L, rb, &luaO_nilobject, ra, TM_UNM)) /***/
- luaG_aritherror(L, rb, &luaO_nilobject);
+ Protect(
+ if (!call_binTM(L, rb, &luaO_nilobject, ra, TM_UNM))
+ luaG_aritherror(L, rb, &luaO_nilobject);
+ )
}
continue;
}
@@ -544,17 +549,17 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setnvalue(ra, cast(lua_Number, luaH_getn(hvalue(rb))));
}
else { /* try metamethod */
- if (!call_binTM(L, rb, &luaO_nilobject, ra, TM_SIZ)) /***/
- luaG_typeerror(L, rb, "get size of");
+ Protect(
+ if (!call_binTM(L, rb, &luaO_nilobject, ra, TM_SIZ))
+ luaG_typeerror(L, rb, "get size of");
+ )
}
continue;
}
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') */ /***/
- luaC_checkGC(L); /***/
- base = L->base;
+ Protect(luaV_concat(L, c-b+1, c); luaC_checkGC(L));
setobjs2s(L, RA(i), base+b);
continue;
}
@@ -563,18 +568,27 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
continue;
}
case OP_EQ: {
- if (equalobj(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++; /***/
- else dojump(L, pc, GETARG_sBx(*pc) + 1);
+ Protect(
+ if (equalobj(L, RKB(i), RKC(i)) == GETARG_A(i))
+ dojump(L, pc, GETARG_sBx(*pc));
+ )
+ pc++;
continue;
}
case OP_LT: {
- if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++; /***/
- else dojump(L, pc, GETARG_sBx(*pc) + 1);
+ Protect(
+ if (luaV_lessthan(L, RKB(i), RKC(i)) == GETARG_A(i))
+ dojump(L, pc, GETARG_sBx(*pc));
+ )
+ pc++;
continue;
}
case OP_LE: {
- if (lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) pc++; /***/
- else dojump(L, pc, GETARG_sBx(*pc) + 1);
+ Protect(
+ if (lessequal(L, RKB(i), RKC(i)) == GETARG_A(i))
+ dojump(L, pc, GETARG_sBx(*pc));
+ )
+ pc++;
continue;
}
case OP_TEST: {
@@ -586,62 +600,65 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
}
continue;
}
- case OP_CALL: { /***/
- int pcr;
+ case OP_CALL: {
int b = GETARG_B(i);
int nresults = GETARG_C(i) - 1;
if (b != 0) L->top = ra+b; /* else previous instruction set top */
- pcr = luaD_precall(L, ra, nresults);
- if (pcr == PCRLUA) {
- nexeccalls++;
- goto callentry; /* restart luaV_execute over new Lua function */
- }
- else if (pcr == PCRC) {
- /* it was a C function (`precall' called it); adjust results */
- if (nresults >= 0) L->top = L->ci->top;
- continue;
- }
- else {
- lua_assert(pcr == PCRYIELD);
- return NULL;
+ L->savedpc = pc;
+ switch (luaD_precall(L, ra, nresults)) {
+ case PCRLUA: {
+ nexeccalls++;
+ goto callentry; /* restart luaV_execute over new Lua function */
+ }
+ case PCRC: {
+ /* it was a C function (`precall' called it); adjust results */
+ if (nresults >= 0) L->top = L->ci->top;
+ base = L->base;
+ continue;
+ }
+ default: {
+ return NULL;
+ }
}
}
- case OP_TAILCALL: { /***/
- int pcr;
+ case OP_TAILCALL: {
int b = GETARG_B(i);
if (b != 0) L->top = ra+b; /* else previous instruction set top */
+ L->savedpc = pc;
lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
- pcr = luaD_precall(L, ra, LUA_MULTRET);
- if (pcr == PCRLUA) {
- /* tail call: put new frame in place of previous one */
- CallInfo *ci = L->ci - 1; /* previous frame */
- int aux;
- StkId func = ci->func;
- StkId pfunc = (ci+1)->func; /* previous function index */
- if (L->openupval) luaF_close(L, ci->base);
- L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
- for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
- setobjs2s(L, func+aux, pfunc+aux);
- ci->top = L->top = func+aux; /* correct top */
- lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
- ci->savedpc = L->savedpc;
- ci->tailcalls++; /* one more call lost */
- L->ci--; /* remove new frame */
- goto callentry;
- }
- else if (pcr == PCRC) {
- /* it was a C function (`precall' called it) */
- continue;
- }
- else {
- lua_assert(pcr == PCRYIELD);
- return NULL;
+ switch (luaD_precall(L, ra, LUA_MULTRET)) {
+ case PCRLUA: {
+ /* tail call: put new frame in place of previous one */
+ CallInfo *ci = L->ci - 1; /* previous frame */
+ int aux;
+ StkId func = ci->func;
+ StkId pfunc = (ci+1)->func; /* previous function index */
+ if (L->openupval) luaF_close(L, ci->base);
+ L->base = ci->base = ci->func + ((ci+1)->base - pfunc);
+ for (aux = 0; pfunc+aux < L->top; aux++) /* move frame down */
+ setobjs2s(L, func+aux, pfunc+aux);
+ ci->top = L->top = func+aux; /* correct top */
+ lua_assert(L->top == L->base + clvalue(func)->l.p->maxstacksize);
+ ci->savedpc = L->savedpc;
+ ci->tailcalls++; /* one more call lost */
+ L->ci--; /* remove new frame */
+ goto callentry;
+ }
+ case PCRC: {
+ /* it was a C function (`precall' called it) */
+ base = L->base;
+ continue;
+ }
+ default: {
+ return NULL;
+ }
}
}
case OP_RETURN: {
int b = GETARG_B(i);
if (b != 0) L->top = ra+b-1;
if (L->openupval) luaF_close(L, base);
+ L->savedpc = pc;
if (--nexeccalls == 0) /* was previous function running `here'? */
return ra; /* no: return */
else { /* yes: continue its execution */
@@ -664,10 +681,11 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
}
continue;
}
- case OP_FORPREP: { /***/
+ case OP_FORPREP: {
const TValue *init = ra;
const TValue *plimit = ra+1;
const TValue *pstep = ra+2;
+ L->savedpc = pc; /* next steps may throw errors */
if (!tonumber(init, ra))
luaG_runerror(L, "`for' initial value must be a number");
else if (!tonumber(plimit, ra+1))
@@ -684,9 +702,8 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
setobjs2s(L, cb+1, ra+1);
setobjs2s(L, cb, ra);
L->top = cb+3; /* func. + 2 args (state and index) */
- luaD_call(L, cb, GETARG_C(i)); /***/
+ Protect(luaD_call(L, cb, GETARG_C(i)));
L->top = L->ci->top;
- base = L->base;
cb = RA(i) + 3; /* previous call may change the stack */
if (ttisnil(cb)) /* break loop? */
pc++; /* skip jump (break loop) */
@@ -747,7 +764,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
}
}
setclvalue(L, ra, ncl);
- luaC_checkGC(L); /***/
+ Protect(luaC_checkGC(L));
continue;
}
case OP_VARARG: {
