Simplification in the parameters of 'luaD_precall'
The parameters 'nresults' and 'delta1', in 'luaD_precall', were never
meaningful simultaneously. So, they were combined in a single parameter
'retdel'.
diff --git a/ldo.c b/ldo.c
index 3854056..93fcbb1 100644
--- a/ldo.c
+++ b/ldo.c
@@ -486,20 +486,19 @@
}
-static CallInfo *prepCallInfo (lua_State *L, StkId func, int nresults,
- int delta1, int mask) {
+static CallInfo *prepCallInfo (lua_State *L, StkId func, int retdel,
+ int mask) {
CallInfo *ci;
- if (delta1) { /* tail call? */
+ if (isdelta(retdel)) { /* tail call? */
ci = L->ci; /* reuse stack frame */
- ci->func -= delta1 - 1; /* correct 'func' */
-
+ ci->func -= retdel2delta(retdel); /* correct 'func' */
ci->callstatus |= mask | CIST_TAIL;
moveparams(L, ci->func, func);
}
else { /* regular call */
ci = L->ci = next_ci(L); /* new frame */
ci->func = func;
- ci->nresults = nresults;
+ ci->nresults = retdel;
ci->callstatus = mask;
}
return ci;
@@ -518,7 +517,7 @@
** cannot be zero. Like 'moveparams', this correction can only be done
** when no more errors can occur in the call.
*/
-CallInfo *luaD_precall (lua_State *L, StkId func, int nresults, int delta1) {
+CallInfo *luaD_precall (lua_State *L, StkId func, int retdel) {
lua_CFunction f;
retry:
switch (ttypetag(s2v(func))) {
@@ -531,7 +530,7 @@
int n; /* number of returns */
CallInfo *ci;
checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
- ci = prepCallInfo(L, func, nresults, delta1, CIST_C);
+ ci = prepCallInfo(L, func, retdel, CIST_C);
ci->top = L->top + LUA_MINSTACK;
lua_assert(ci->top <= L->stack_last);
if (l_unlikely(L->hookmask & LUA_MASKCALL)) {
@@ -552,7 +551,7 @@
int nfixparams = p->numparams;
int fsize = p->maxstacksize; /* frame size */
checkstackGCp(L, fsize, func);
- ci = prepCallInfo(L, func, nresults, delta1, 0);
+ ci = prepCallInfo(L, func, retdel, 0);
ci->u.l.savedpc = p->code; /* starting point */
ci->top = func + 1 + fsize;
for (; narg < nfixparams; narg++)
@@ -579,7 +578,7 @@
L->nCcalls += inc;
if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS))
luaE_checkcstack(L);
- if ((ci = luaD_precall(L, func, nResults, 0)) != NULL) { /* Lua function? */
+ if ((ci = luaD_precall(L, func, nResults)) != NULL) { /* Lua function? */
ci->callstatus = CIST_FRESH; /* mark that it is a "fresh" execute */
luaV_execute(L, ci); /* call it */
}
diff --git a/ldo.h b/ldo.h
index 6edc445..49fbb49 100644
--- a/ldo.h
+++ b/ldo.h
@@ -49,6 +49,18 @@
luaD_checkstackaux(L, (fsize), luaC_checkGC(L), (void)0)
+/*
+** 'luaD_precall' is used for regular calls, when it needs the
+** number of results, and in tail calls, when it needs the 'delta'
+** (correction of base for vararg functions). The argument 'retdel'
+** codes these two options. A number of results is represented by
+** itself, while a delta is represented by 'delta2retdel(delta)'
+*/
+#define delta2retdel(d) (-(d) + LUA_MULTRET - 1)
+#define retdel2delta(d) (-(d) + LUA_MULTRET - 1)
+#define isdelta(rd) ((rd) < LUA_MULTRET)
+
+
/* type of protected functions, to be ran by 'runprotected' */
typedef void (*Pfunc) (lua_State *L, void *ud);
@@ -58,8 +70,7 @@
LUAI_FUNC void luaD_hook (lua_State *L, int event, int line,
int fTransfer, int nTransfer);
LUAI_FUNC void luaD_hookcall (lua_State *L, CallInfo *ci);
-LUAI_FUNC CallInfo *luaD_precall (lua_State *L, StkId func, int nresults,
- int delta1);
+LUAI_FUNC CallInfo *luaD_precall (lua_State *L, StkId func, int retdel);
LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
LUAI_FUNC void luaD_tryfuncTM (lua_State *L, StkId func);
diff --git a/lvm.c b/lvm.c
index 62ff70d..ec83f41 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1632,7 +1632,7 @@
L->top = ra + b; /* top signals number of arguments */
/* else previous instruction set top */
savepc(L); /* in case of errors */
- if ((newci = luaD_precall(L, ra, nresults, 0)) == NULL)
+ if ((newci = luaD_precall(L, ra, nresults)) == NULL)
updatetrap(ci); /* C call; nothing else to be done */
else { /* Lua call: run function in this same C frame */
ci = newci;
@@ -1654,7 +1654,7 @@
lua_assert(L->tbclist < base); /* no pending tbc variables */
lua_assert(base == ci->func + 1);
}
- if (luaD_precall(L, ra, LUA_MULTRET, delta + 1)) /* Lua function? */
+ if (luaD_precall(L, ra, delta2retdel(delta))) /* Lua function? */
goto startfunc; /* execute the callee */
else { /* C function */
updatetrap(ci);
