From 18afb90349fc1b698d179e29fdc014589c2e1145 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Thu, 20 Dec 2001 13:13:38 -0200
Subject: first version of stackless Lua
---
lvm.c | 87 +++++++++++++++++++++++++++++++++++++++++++------------------------
1 file changed, 56 insertions(+), 31 deletions(-)
(limited to 'lvm.c')
diff --git a/lvm.c b/lvm.c
index 85746e03..435229a0 100644
--- a/lvm.c
+++ b/lvm.c
@@ -97,14 +97,9 @@ static void callTM (lua_State *L, const TObject *f,
setobj(base+3, p3); /* 3th argument */
L->top++;
}
- luaD_call(L, base);
+ luaD_call(L, base, (result ? 1 : 0));
if (result) { /* need a result? */
- if (L->top == base) { /* are there valid results? */
- setnilvalue(result); /* function had no results */
- }
- else {
- setobj(result, base); /* get first result */
- }
+ setobj(result, base); /* get it */
}
L->top = base; /* restore top */
}
@@ -140,7 +135,7 @@ void luaV_gettable (lua_State *L, StkId t, TObject *key, StkId res) {
if (ttype(tm) == LUA_TFUNCTION)
callTM(L, tm, t, key, NULL, res);
else {
- t = tm;
+ t = (StkId)tm; /* ?? */
goto init; /* return luaV_gettable(L, tm, key, res); */
}
}
@@ -169,7 +164,7 @@ void luaV_settable (lua_State *L, StkId t, TObject *key, StkId val) {
if (ttype(tm) == LUA_TFUNCTION)
callTM(L, tm, t, key, val, NULL);
else {
- t = tm;
+ t = (StkId)tm; /* ?? */
goto init; /* luaV_settable(L, tm, key, val); */
}
}
@@ -311,15 +306,15 @@ static void powOp (lua_State *L, StkId ra, StkId rb, StkId rc) {
** some macros for common tasks in `luaV_execute'
*/
-#define runtime_check(L, c) { if (!(c)) return L->top; }
+#define runtime_check(L, c) { if (!(c)) return 0; }
#define RA(i) (base+GETARG_A(i))
#define RB(i) (base+GETARG_B(i))
#define RC(i) (base+GETARG_C(i))
#define RKC(i) ((GETARG_C(i) < MAXSTACK) ? \
base+GETARG_C(i) : \
- tf->k+GETARG_C(i)-MAXSTACK)
-#define KBc(i) (tf->k+GETARG_Bc(i))
+ cl->p->k+GETARG_C(i)-MAXSTACK)
+#define KBc(i) (cl->p->k+GETARG_Bc(i))
#define Arith(op, optm) { \
const TObject *b = RB(i); const TObject *c = RKC(i); \
@@ -332,6 +327,16 @@ static void powOp (lua_State *L, StkId ra, StkId rb, StkId rc) {
}
+#define luaV_poscall(L,c,f) \
+ if (c != NO_REG) { \
+ luaD_poscall(L, c, f); \
+ L->top = base + cl->p->maxstacksize; \
+ } \
+ else { \
+ luaD_poscall(L, LUA_MULTRET, f); \
+ }
+
+
#define dojump(pc, i) ((pc) += GETARG_sBc(i))
/*
@@ -339,17 +344,18 @@ static void powOp (lua_State *L, StkId ra, StkId rb, StkId rc) {
** Returns n such that the results are between [n,top).
*/
StkId luaV_execute (lua_State *L, const LClosure *cl, StkId base) {
- const Proto *const tf = cl->p;
const Instruction *pc;
lua_Hook linehook;
- if (tf->is_vararg) /* varargs? */
- adjust_varargs(L, base, tf->numparams);
- if (base > L->stack_last - tf->maxstacksize)
+ reinit:
+ lua_assert(L->ci->savedpc == NULL);
+ if (cl->p->is_vararg) /* varargs? */
+ adjust_varargs(L, base, cl->p->numparams);
+ if (base > L->stack_last - cl->p->maxstacksize)
luaD_stackerror(L);
- luaD_adjusttop(L, base + tf->maxstacksize);
- pc = tf->code;
+ luaD_adjusttop(L, base + cl->p->maxstacksize);
L->ci->pc = &pc;
- linehook = L->linehook;
+ linehook = L->ci->linehook = L->linehook;
+ pc = cl->p->code;
/* main loop of interpreter */
for (;;) {
const Instruction i = *pc++;
@@ -528,25 +534,44 @@ StkId luaV_execute (lua_State *L, const LClosure *cl, StkId base) {
break;
}
case OP_CALL: {
- int c;
+ StkId firstResult;
int b = GETARG_B(i);
- if (b != NO_REG)
- L->top = ra+b+1;
- luaD_call(L, ra);
- c = GETARG_C(i);
- if (c != NO_REG) {
- while (L->top < ra+c) setnilvalue(L->top++);
- L->top = base + tf->maxstacksize;
+ if (b != NO_REG) L->top = ra+b+1;
+ /* else previous instruction set top */
+ firstResult = luaD_precall(L, ra);
+ if (firstResult) {
+ /* it was a C function (`precall' called it); adjust results */
+ luaV_poscall(L, GETARG_C(i), firstResult);
+ }
+ else { /* it is a Lua function: `call' it */
+ CallInfo *ci = L->ci;
+ (ci-1)->savedpc = pc;
+ base = ci->base;
+ cl = &clvalue(base - 1)->l;
+ goto reinit;
}
break;
}
case OP_RETURN: {
+ CallInfo *ci;
int b;
luaF_close(L, base);
b = GETARG_B(i);
- if (b != NO_REG)
- L->top = ra+b;
- return ra;
+ if (b != NO_REG) L->top = ra+b;
+ ci = L->ci - 1;
+ if (ci->savedpc == NULL)
+ return ra;
+ else { /* previous function is Lua: continue its execution */
+ lua_assert(ttype(ci->base-1) == LUA_TFUNCTION);
+ base = ci->base; /* restore previous values */
+ linehook = ci->linehook;
+ cl = &clvalue(base - 1)->l;
+ pc = ci->savedpc;
+ ci->savedpc = NULL;
+ lua_assert(GET_OPCODE(*(pc-1)) == OP_CALL);
+ luaV_poscall(L, GETARG_C(*(pc-1)), ra);
+ }
+ break;
}
case OP_FORPREP: {
if (luaV_tonumber(ra, ra) == NULL)
@@ -623,7 +648,7 @@ StkId luaV_execute (lua_State *L, const LClosure *cl, StkId base) {
Closure *ncl;
int nup, j;
luaV_checkGC(L, L->top);
- p = tf->p[GETARG_Bc(i)];
+ p = cl->p->p[GETARG_Bc(i)];
nup = p->nupvalues;
ncl = luaF_newLclosure(L, nup);
ncl->l.p = p;
--
cgit v1.2.3-55-g6feb