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vararg back to '...' (but with another implementation)

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new implementation should have zero overhead for non-vararg functions
This commit is contained in:
Roberto Ierusalimschy
2018-02-09 13:16:06 -02:00
parent 4e0de3a43c
commit b1379936cf
11 changed files with 136 additions and 113 deletions
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61
ltm.c
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@@ -1,5 +1,5 @@
/*
** $Id: ltm.c,v 2.58 2018/01/28 13:39:52 roberto Exp roberto $
** $Id: ltm.c,v 2.59 2018/02/07 15:18:04 roberto Exp roberto $
** Tag methods
** See Copyright Notice in lua.h
*/
@@ -216,41 +216,32 @@ int luaT_callorderiTM (lua_State *L, const TValue *p1, int v2,
}
void luaT_adjustvarargs (lua_State *L, int nfixparams, StkId base) {
void luaT_adjustvarargs (lua_State *L, int nfixparams, CallInfo *ci) {
int i;
Table *vtab;
TValue nname;
int actual = cast_int(L->top - base); /* number of arguments */
int actual = cast_int(L->top - ci->func) - 1; /* number of arguments */
int nextra = actual - nfixparams; /* number of extra arguments */
vtab = luaH_new(L); /* create vararg table */
sethvalue2s(L, L->top, vtab); /* anchor it for resizing */
L->top++; /* space ensured by caller */
luaH_resize(L, vtab, nextra, 1);
for (i = 0; i < nextra; i++) /* put extra arguments into vararg table */
setobj2n(L, &vtab->array[i], s2v(L->top - nextra + i - 1));
setsvalue(L, &nname, G(L)->nfield); /* get field 'n' */
setivalue(luaH_set(L, vtab, &nname), nextra); /* store counter there */
L->top -= nextra; /* remove extra elements from the stack */
sethvalue2s(L, L->top - 1, vtab); /* move table to new top */
luaC_checkGC(L);
}
void luaT_getvarargs (lua_State *L, TValue *t, StkId where, int wanted) {
if (!ttistable(t))
luaG_runerror(L, "'vararg' parameter is not a table");
else {
int i;
Table *h = hvalue(t);
if (wanted < 0) { /* get all? */
const TValue *ns = luaH_getstr(h, G(L)->nfield);
int n = (ttisinteger(ns)) ? cast_int(ivalue(ns)) : 0;
wanted = n;
checkstackp(L, n, where);
L->top = where + n;
}
for (i = 0; i < wanted; i++) /* get what is available */
setobj2s(L, where + i, luaH_getint(h, i + 1));
return;
ci->u.l.nextraargs = nextra;
checkstackGC(L, nfixparams + 1);
/* copy function and fixed parameters to the top of the stack */
for (i = 0; i <= nfixparams; i++) {
setobjs2s(L, L->top++, ci->func + i);
setnilvalue(s2v(ci->func + i)); /* erase original copy (for GC) */
}
ci->func += actual + 1;
ci->top += actual + 1;
}
void luaT_getvarargs (lua_State *L, CallInfo *ci, StkId where, int wanted) {
int i;
int nextra = ci->u.l.nextraargs;
if (wanted < 0) {
wanted = nextra; /* get all extra arguments available */
checkstackp(L, nextra, where); /* ensure stack space */
L->top = where + nextra; /* next instruction will need top */
}
for (i = 0; i < wanted && i < nextra; i++)
setobjs2s(L, where + i, ci->func - nextra + i);
for (; i < wanted; i++) /* complete required results with nil */
setnilvalue(s2v(where + i));
}