commit c5363a1b58573162ef13ba4a345bd48ad3c355d9
parent 332a06bbd1a8835c810e52bbf68014d6956b50b8
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 2 Nov 2015 12:05:35 -0200
in 'luaD_precall', in vararg functions, complete missing parameters
only after moving them to final place (avoids checking the stack
again)
Diffstat:
M | ldo.c | | | 28 | +++++++++++++--------------- |
M | lvm.c | | | 18 | ++++++++---------- |
2 files changed, 21 insertions(+), 25 deletions(-)
diff --git a/ldo.c b/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.144 2015/10/28 17:28:40 roberto Exp roberto $
+** $Id: ldo.c,v 2.145 2015/11/02 11:48:59 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -273,15 +273,15 @@ static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
int i;
int nfixargs = p->numparams;
StkId base, fixed;
- lua_assert(actual >= nfixargs);
/* move fixed parameters to final position */
- luaD_checkstack(L, p->maxstacksize); /* check again for new 'base' */
fixed = L->top - actual; /* first fixed argument */
base = L->top; /* final position of first argument */
- for (i=0; i<nfixargs; i++) {
+ for (i = 0; i < nfixargs && i < actual; i++) {
setobjs2s(L, L->top++, fixed + i);
- setnilvalue(fixed + i);
+ setnilvalue(fixed + i); /* erase original copy (for GC) */
}
+ for (; i < nfixargs; i++)
+ setnilvalue(L->top++); /* complete missing arguments */
return base;
}
@@ -354,25 +354,23 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
StkId base;
Proto *p = clLvalue(func)->p;
int n = cast_int(L->top - func) - 1; /* number of real arguments */
- checkstackp(L, p->maxstacksize, func);
- for (; n < p->numparams; n++)
- setnilvalue(L->top++); /* complete missing arguments */
- if (p->is_vararg != 1) /* do not use vararg? */
+ int fsize = p->maxstacksize; /* frame size */
+ checkstackp(L, fsize, func);
+ if (p->is_vararg != 1) { /* do not use vararg? */
+ for (; n < p->numparams; n++)
+ setnilvalue(L->top++); /* complete missing arguments */
base = func + 1;
- else {
- ptrdiff_t funcr = savestack(L, func);
- base = adjust_varargs(L, p, n);
- func = restorestack(L, funcr); /* previous call can change stack */
}
+ else
+ base = adjust_varargs(L, p, n);
ci = next_ci(L); /* now 'enter' new function */
ci->nresults = nresults;
ci->func = func;
ci->u.l.base = base;
- ci->top = base + p->maxstacksize;
+ L->top = ci->top = base + fsize;
lua_assert(ci->top <= L->stack_last);
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = CIST_LUA;
- L->top = ci->top;
if (L->hookmask & LUA_MASKCALL)
callhook(L, ci);
return 0;
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.257 2015/10/28 14:50:09 roberto Exp roberto $
+** $Id: lvm.c,v 2.258 2015/11/02 11:43:17 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -1274,23 +1274,21 @@ void luaV_execute (lua_State *L) {
vmbreak;
}
vmcase(OP_VARARG) {
- int b = GETARG_B(i) - 1;
+ int b = GETARG_B(i) - 1; /* required results */
int j;
int n = cast_int(base - ci->func) - cl->p->numparams - 1;
+ if (n < 0) /* less arguments than parameters? */
+ n = 0; /* no vararg arguments */
if (b < 0) { /* B == 0? */
b = n; /* get all var. arguments */
Protect(luaD_checkstack(L, n));
ra = RA(i); /* previous call may change the stack */
L->top = ra + n;
}
- for (j = 0; j < b; j++) {
- if (j < n) {
- setobjs2s(L, ra + j, base - n + j);
- }
- else {
- setnilvalue(ra + j);
- }
- }
+ for (j = 0; j < b && j < n; j++)
+ setobjs2s(L, ra + j, base - n + j);
+ for (; j < b; j++) /* complete required results with nil */
+ setnilvalue(ra + j);
vmbreak;
}
vmcase(OP_EXTRAARG) {