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'nresults' moved into 'callstatus'
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That gives us more free bits in 'callstatus', for future use.
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@roberto-ieru
roberto-ieru committed Jul 21, 2024
1 parent f407b3c commit 15231d4
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Showing 6 changed files with 79 additions and 62 deletions.
4 changes: 1 addition & 3 deletions lapi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1103,7 +1103,7 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
ci->u2.funcidx = cast_int(savestack(L, c.func));
ci->u.c.old_errfunc = L->errfunc;
L->errfunc = func;
setoah(ci->callstatus, L->allowhook); /* save value of 'allowhook' */
setoah(ci, L->allowhook); /* save value of 'allowhook' */
ci->callstatus |= CIST_YPCALL; /* function can do error recovery */
luaD_call(L, c.func, nresults); /* do the call */
ci->callstatus &= ~CIST_YPCALL;
Expand Down Expand Up @@ -1280,11 +1280,9 @@ LUA_API int lua_next (lua_State *L, int idx) {


LUA_API void lua_toclose (lua_State *L, int idx) {
int nresults;
StkId o;
lua_lock(L);
o = index2stack(L, idx);
nresults = L->ci->nresults;
api_check(L, L->tbclist.p < o, "given index below or equal a marked one");
luaF_newtbcupval(L, o); /* create new to-be-closed upvalue */
L->ci->callstatus |= CIST_CLSRET; /* mark that function has TBC slots */
Expand Down
4 changes: 2 additions & 2 deletions ldebug.c
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Original file line number Diff line number Diff line change
Expand Up @@ -346,13 +346,13 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
ar->nparams = 0;
}
else {
ar->isvararg = f->l.p->flag & PF_ISVARARG;
ar->isvararg = (f->l.p->flag & PF_ISVARARG) ? 1 : 0;
ar->nparams = f->l.p->numparams;
}
break;
}
case 't': {
ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
ar->istailcall = (ci != NULL && (ci->callstatus & CIST_TAIL));
break;
}
case 'n': {
Expand Down
72 changes: 38 additions & 34 deletions ldo.c
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Original file line number Diff line number Diff line change
Expand Up @@ -452,16 +452,31 @@ static StkId tryfuncTM (lua_State *L, StkId func) {
}


/* Generic case for 'moveresult */
l_sinline void genmoveresults (lua_State *L, StkId res, int nres,
int wanted) {
StkId firstresult = L->top.p - nres; /* index of first result */
int i;
if (nres > wanted) /* extra results? */
nres = wanted; /* don't need them */
for (i = 0; i < nres; i++) /* move all results to correct place */
setobjs2s(L, res + i, firstresult + i);
for (; i < wanted; i++) /* complete wanted number of results */
setnilvalue(s2v(res + i));
L->top.p = res + wanted; /* top points after the last result */
}


/*
** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'.
** Handle most typical cases (zero results for commands, one result for
** expressions, multiple results for tail calls/single parameters)
** separated.
** Given 'nres' results at 'firstResult', move 'fwanted-1' of them
** to 'res'. Handle most typical cases (zero results for commands,
** one result for expressions, multiple results for tail calls/single
** parameters) separated. The flag CIST_CLSRET in 'fwanted', if set,
** forces the swicth to go to the default case.
*/
l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
StkId firstresult;
int i;
switch (wanted) { /* handle typical cases separately */
l_sinline void moveresults (lua_State *L, StkId res, int nres,
l_uint32 fwanted) {
switch (fwanted) { /* handle typical cases separately */
case 0 + 1: /* no values needed */
L->top.p = res;
return;
Expand All @@ -473,12 +488,11 @@ l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
L->top.p = res + 1;
return;
case LUA_MULTRET + 1:
wanted = nres; /* we want all results */
genmoveresults(L, res, nres, nres); /* we want all results */
break;
default: /* two/more results and/or to-be-closed variables */
if (!(wanted & CIST_CLSRET))
wanted--;
else { /* to-be-closed variables? */
default: { /* two/more results and/or to-be-closed variables */
int wanted = get_nresults(fwanted);
if (fwanted & CIST_CLSRET) { /* to-be-closed variables? */
L->ci->u2.nres = nres;
res = luaF_close(L, res, CLOSEKTOP, 1);
L->ci->callstatus &= ~CIST_CLSRET;
Expand All @@ -487,21 +501,13 @@ l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
rethook(L, L->ci, nres);
res = restorestack(L, savedres); /* hook can move stack */
}
wanted = (wanted & ~CIST_CLSRET) - 1;
if (wanted == LUA_MULTRET)
wanted = nres; /* we want all results */
}
genmoveresults(L, res, nres, wanted);
break;
}
}
/* generic case */
firstresult = L->top.p - nres; /* index of first result */
if (nres > wanted) /* extra results? */
nres = wanted; /* don't need them */
for (i = 0; i < nres; i++) /* move all results to correct place */
setobjs2s(L, res + i, firstresult + i);
for (; i < wanted; i++) /* complete wanted number of results */
setnilvalue(s2v(res + i));
L->top.p = res + wanted; /* top points after the last result */
}


Expand All @@ -512,13 +518,11 @@ l_sinline void moveresults (lua_State *L, StkId res, int nres, int wanted) {
** that.
*/
void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
int wanted = ci->nresults + 1;
if (ci->callstatus & CIST_CLSRET)
wanted |= CIST_CLSRET; /* don't check hook in this case */
else if (l_unlikely(L->hookmask))
l_uint32 fwanted = ci->callstatus & (CIST_CLSRET | CIST_NRESULTS);
if (l_unlikely(L->hookmask) && !(fwanted & CIST_CLSRET))
rethook(L, ci, nres);
/* move results to proper place */
moveresults(L, ci->func.p, nres, wanted);
moveresults(L, ci->func.p, nres, fwanted);
/* function cannot be in any of these cases when returning */
lua_assert(!(ci->callstatus &
(CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET)));
Expand All @@ -530,12 +534,12 @@ void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
#define next_ci(L) (L->ci->next ? L->ci->next : luaE_extendCI(L))


l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nret,
int mask, StkId top) {
l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nresults,
l_uint32 mask, StkId top) {
CallInfo *ci = L->ci = next_ci(L); /* new frame */
ci->func.p = func;
ci->nresults = nret;
ci->callstatus = mask;
lua_assert(((nresults + 1) & ~CIST_NRESULTS) == 0);
ci->callstatus = mask | cast(l_uint32, nresults + 1);
ci->top.p = top;
return ci;
}
Expand Down Expand Up @@ -664,7 +668,7 @@ l_sinline void ccall (lua_State *L, StkId func, int nResults, l_uint32 inc) {
luaE_checkcstack(L);
}
if ((ci = luaD_precall(L, func, nResults)) != NULL) { /* Lua function? */
ci->callstatus = CIST_FRESH; /* mark that it is a "fresh" execute */
ci->callstatus |= CIST_FRESH; /* mark that it is a "fresh" execute */
luaV_execute(L, ci); /* call it */
}
L->nCcalls -= inc;
Expand Down Expand Up @@ -709,7 +713,7 @@ static int finishpcallk (lua_State *L, CallInfo *ci) {
status = LUA_YIELD; /* was interrupted by an yield */
else { /* error */
StkId func = restorestack(L, ci->u2.funcidx);
L->allowhook = getoah(ci->callstatus); /* restore 'allowhook' */
L->allowhook = getoah(ci); /* restore 'allowhook' */
func = luaF_close(L, func, status, 1); /* can yield or raise an error */
luaD_seterrorobj(L, status, func);
luaD_shrinkstack(L); /* restore stack size in case of overflow */
Expand Down
1 change: 0 additions & 1 deletion lstate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,6 @@ static void stack_init (lua_State *L1, lua_State *L) {
ci->callstatus = CIST_C;
ci->func.p = L1->top.p;
ci->u.c.k = NULL;
ci->nresults = 0;
setnilvalue(s2v(L1->top.p)); /* 'function' entry for this 'ci' */
L1->top.p++;
ci->top.p = L1->top.p + LUA_MINSTACK;
Expand Down
54 changes: 35 additions & 19 deletions lstate.h
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Original file line number Diff line number Diff line change
Expand Up @@ -211,31 +211,45 @@ struct CallInfo {
int ntransfer; /* number of values transferred */
} transferinfo;
} u2;
short nresults; /* expected number of results from this function */
unsigned short callstatus;
l_uint32 callstatus;
};


/*
** Bits in CallInfo status
*/
#define CIST_OAH (1<<0) /* original value of 'allowhook' */
#define CIST_C (1<<1) /* call is running a C function */
#define CIST_FRESH (1<<2) /* call is on a fresh "luaV_execute" frame */
#define CIST_HOOKED (1<<3) /* call is running a debug hook */
#define CIST_YPCALL (1<<4) /* doing a yieldable protected call */
#define CIST_TAIL (1<<5) /* call was tail called */
#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */
#define CIST_FIN (1<<7) /* function "called" a finalizer */
#define CIST_TRAN (1<<8) /* 'ci' has transfer information */
#define CIST_CLSRET (1<<9) /* function is closing tbc variables */
/* Bits 10-12 are used for CIST_RECST (see below) */
#define CIST_RECST 10
/* bits 0-7 are the expected number of results from this function + 1 */
#define CIST_NRESULTS 0xff
/* original value of 'allowhook' */
#define CIST_OAH (cast(l_uint32, 1) << 8)
/* call is running a C function */
#define CIST_C (cast(l_uint32, 1) << 9)
/* call is on a fresh "luaV_execute" frame */
#define CIST_FRESH (cast(l_uint32, 1) << 10)
/* call is running a debug hook */
#define CIST_HOOKED (cast(l_uint32, 1) << 11)
/* doing a yieldable protected call */
#define CIST_YPCALL (cast(l_uint32, 1) << 12)
/* call was tail called */
#define CIST_TAIL (cast(l_uint32, 1) << 13)
/* last hook called yielded */
#define CIST_HOOKYIELD (cast(l_uint32, 1) << 14)
/* function "called" a finalizer */
#define CIST_FIN (cast(l_uint32, 1) << 15)
/* 'ci' has transfer information */
#define CIST_TRAN (cast(l_uint32, 1) << 16)
/* function is closing tbc variables */
#define CIST_CLSRET (cast(l_uint32, 1) << 17)
/* Bits 18-20 are used for CIST_RECST (see below) */
#define CIST_RECST 18 /* the offset, not the mask */
#if defined(LUA_COMPAT_LT_LE)
#define CIST_LEQ (1<<13) /* using __lt for __le */
/* using __lt for __le */
#define CIST_LEQ (cast(l_uint32, 1) << 21)
#endif


#define get_nresults(cs) (cast_int((cs) & CIST_NRESULTS) - 1)

/*
** Field CIST_RECST stores the "recover status", used to keep the error
** status while closing to-be-closed variables in coroutines, so that
Expand All @@ -246,7 +260,7 @@ struct CallInfo {
#define setcistrecst(ci,st) \
check_exp(((st) & 7) == (st), /* status must fit in three bits */ \
((ci)->callstatus = ((ci)->callstatus & ~(7 << CIST_RECST)) \
| ((st) << CIST_RECST)))
| (cast(l_uint32, st) << CIST_RECST)))


/* active function is a Lua function */
Expand All @@ -255,9 +269,11 @@ struct CallInfo {
/* call is running Lua code (not a hook) */
#define isLuacode(ci) (!((ci)->callstatus & (CIST_C | CIST_HOOKED)))

/* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
#define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v))
#define getoah(st) ((st) & CIST_OAH)

#define setoah(ci,v) \
((ci)->callstatus = ((v) ? (ci)->callstatus | CIST_OAH \
: (ci)->callstatus & ~CIST_OAH))
#define getoah(ci) (((ci)->callstatus & CIST_OAH) ? 1 : 0)


/*
Expand Down
6 changes: 3 additions & 3 deletions lvm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1742,10 +1742,10 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
trap = 1;
}
else { /* do the 'poscall' here */
int nres;
int nres = get_nresults(ci->callstatus);
L->ci = ci->previous; /* back to caller */
L->top.p = base - 1;
for (nres = ci->nresults; l_unlikely(nres > 0); nres--)
for (; l_unlikely(nres > 0); nres--)
setnilvalue(s2v(L->top.p++)); /* all results are nil */
}
goto ret;
Expand All @@ -1759,7 +1759,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
trap = 1;
}
else { /* do the 'poscall' here */
int nres = ci->nresults;
int nres = get_nresults(ci->callstatus);
L->ci = ci->previous; /* back to caller */
if (nres == 0)
L->top.p = base - 1; /* asked for no results */
Expand Down

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