/*
-** $Id: ldo.c,v 2.151 2015/12/16 16:40:07 roberto Exp $
+** $Id: ldo.c,v 2.157 2016/12/13 15:52:21 roberto Exp $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
CallInfo *ci;
StkId lim = L->top;
for (ci = L->ci; ci != NULL; ci = ci->previous) {
- lua_assert(ci->top <= L->stack_last);
if (lim < ci->top) lim = ci->top;
}
+ lua_assert(lim <= L->stack_last);
return cast_int(lim - L->stack) + 1; /* part of stack in use */
}
void luaD_shrinkstack (lua_State *L) {
int inuse = stackinuse(L);
int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
- if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK;
- if (L->stacksize > LUAI_MAXSTACK) /* was handling stack overflow? */
+ if (goodsize > LUAI_MAXSTACK)
+ goodsize = LUAI_MAXSTACK; /* respect stack limit */
+ if (L->stacksize > LUAI_MAXSTACK) /* had been handling stack overflow? */
luaE_freeCI(L); /* free all CIs (list grew because of an error) */
else
luaE_shrinkCI(L); /* shrink list */
- if (inuse <= LUAI_MAXSTACK && /* not handling stack overflow? */
- goodsize < L->stacksize) /* trying to shrink? */
- luaD_reallocstack(L, goodsize); /* shrink it */
- else
- condmovestack(L,,); /* don't change stack (change only for debugging) */
+ /* if thread is currently not handling a stack overflow and its
+ good size is smaller than current size, shrink its stack */
+ if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
+ goodsize < L->stacksize)
+ luaD_reallocstack(L, goodsize);
+ else /* don't change stack */
+ condmovestack(L,{},{}); /* (change only for debugging) */
}
}
+/*
+** 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.
+*/
+static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
+ int nres, int wanted) {
+ switch (wanted) { /* handle typical cases separately */
+ case 0: break; /* nothing to move */
+ case 1: { /* one result needed */
+ if (nres == 0) /* no results? */
+ firstResult = luaO_nilobject; /* adjust with nil */
+ setobjs2s(L, res, firstResult); /* move it to proper place */
+ break;
+ }
+ case LUA_MULTRET: {
+ int i;
+ for (i = 0; i < nres; i++) /* move all results to correct place */
+ setobjs2s(L, res + i, firstResult + i);
+ L->top = res + nres;
+ return 0; /* wanted == LUA_MULTRET */
+ }
+ default: {
+ int i;
+ if (wanted <= nres) { /* enough results? */
+ for (i = 0; i < wanted; i++) /* move wanted results to correct place */
+ setobjs2s(L, res + i, firstResult + i);
+ }
+ else { /* not enough results; use all of them plus nils */
+ 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(res + i);
+ }
+ break;
+ }
+ }
+ L->top = res + wanted; /* top points after the last result */
+ return 1;
+}
+
+
+/*
+** Finishes a function call: calls hook if necessary, removes CallInfo,
+** moves current number of results to proper place; returns 0 iff call
+** wanted multiple (variable number of) results.
+*/
+int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
+ StkId res;
+ int wanted = ci->nresults;
+ if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
+ if (L->hookmask & LUA_MASKRET) {
+ ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
+ luaD_hook(L, LUA_HOOKRET, -1);
+ firstResult = restorestack(L, fr);
+ }
+ L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
+ }
+ res = ci->func; /* res == final position of 1st result */
+ L->ci = ci->previous; /* back to caller */
+ /* move results to proper place */
+ return moveresults(L, firstResult, res, nres, wanted);
+}
+
+
#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
int n = cast_int(L->top - func) - 1; /* number of real arguments */
int fsize = p->maxstacksize; /* frame size */
checkstackp(L, fsize, func);
- if (p->is_vararg != 1) { /* do not use vararg? */
+ if (p->is_vararg)
+ base = adjust_varargs(L, p, n);
+ else { /* non vararg function */
for (; n < p->numparams; n++)
setnilvalue(L->top++); /* complete missing arguments */
base = func + 1;
}
- else
- base = adjust_varargs(L, p, n);
ci = next_ci(L); /* now 'enter' new function */
ci->nresults = nresults;
ci->func = func;
/*
-** 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.
-*/
-static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
- int nres, int wanted) {
- switch (wanted) { /* handle typical cases separately */
- case 0: break; /* nothing to move */
- case 1: { /* one result needed */
- if (nres == 0) /* no results? */
- firstResult = luaO_nilobject; /* adjust with nil */
- setobjs2s(L, res, firstResult); /* move it to proper place */
- break;
- }
- case LUA_MULTRET: {
- int i;
- for (i = 0; i < nres; i++) /* move all results to correct place */
- setobjs2s(L, res + i, firstResult + i);
- L->top = res + nres;
- return 0; /* wanted == LUA_MULTRET */
- }
- default: {
- int i;
- if (wanted <= nres) { /* enough results? */
- for (i = 0; i < wanted; i++) /* move wanted results to correct place */
- setobjs2s(L, res + i, firstResult + i);
- }
- else { /* not enough results; use all of them plus nils */
- 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(res + i);
- }
- break;
- }
- }
- L->top = res + wanted; /* top points after the last result */
- return 1;
-}
-
-
-/*
-** Finishes a function call: calls hook if necessary, removes CallInfo,
-** moves current number of results to proper place; returns 0 iff call
-** wanted multiple (variable number of) results.
-*/
-int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
- StkId res;
- int wanted = ci->nresults;
- if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
- if (L->hookmask & LUA_MASKRET) {
- ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
- luaD_hook(L, LUA_HOOKRET, -1);
- firstResult = restorestack(L, fr);
- }
- L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
- }
- res = ci->func; /* res == final position of 1st result */
- L->ci = ci->previous; /* back to caller */
- /* move results to proper place */
- return moveresults(L, firstResult, res, nres, wanted);
-}
-
-
-/*
** Check appropriate error for stack overflow ("regular" overflow or
** overflow while handling stack overflow). If 'nCalls' is larger than
** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
/* error status can only happen in a protected call */
lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */
- ci->callstatus &= ~CIST_YPCALL; /* finish 'lua_pcall' */
- L->errfunc = ci->u.c.old_errfunc;
+ ci->callstatus &= ~CIST_YPCALL; /* continuation is also inside it */
+ L->errfunc = ci->u.c.old_errfunc; /* with the same error function */
}
/* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
handled */
adjustresults(L, ci->nresults);
- /* call continuation function */
lua_unlock(L);
- n = (*ci->u.c.k)(L, status, ci->u.c.ctx);
+ n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation function */
lua_lock(L);
api_checknelems(L, n);
- /* finish 'luaD_precall' */
- luaD_poscall(L, ci, L->top - n, n);
+ luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_precall' */
}
/*
-** signal an error in the call to 'resume', not in the execution of the
-** coroutine itself. (Such errors should not be handled by any coroutine
-** error handler and should not kill the coroutine.)
+** Signal an error in the call to 'lua_resume', not in the execution
+** of the coroutine itself. (Such errors should not be handled by any
+** coroutine error handler and should not kill the coroutine.)
*/
-static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
- L->top = firstArg; /* remove args from the stack */
+static int resume_error (lua_State *L, const char *msg, int narg) {
+ L->top -= narg; /* remove args from the stack */
setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */
api_incr_top(L);
- luaD_throw(L, -1); /* jump back to 'lua_resume' */
+ lua_unlock(L);
+ return LUA_ERRRUN;
}
** coroutine.
*/
static void resume (lua_State *L, void *ud) {
- int nCcalls = L->nCcalls;
int n = *(cast(int*, ud)); /* number of arguments */
StkId firstArg = L->top - n; /* first argument */
CallInfo *ci = L->ci;
- if (nCcalls >= LUAI_MAXCCALLS)
- resume_error(L, "C stack overflow", firstArg);
- if (L->status == LUA_OK) { /* may be starting a coroutine */
- if (ci != &L->base_ci) /* not in base level? */
- resume_error(L, "cannot resume non-suspended coroutine", firstArg);
- /* coroutine is in base level; start running it */
+ if (L->status == LUA_OK) { /* starting a coroutine? */
if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */
luaV_execute(L); /* call it */
}
- else if (L->status != LUA_YIELD)
- resume_error(L, "cannot resume dead coroutine", firstArg);
else { /* resuming from previous yield */
+ lua_assert(L->status == LUA_YIELD);
L->status = LUA_OK; /* mark that it is running (again) */
ci->func = restorestack(L, ci->extra);
if (isLua(ci)) /* yielded inside a hook? */
}
unroll(L, NULL); /* run continuation */
}
- lua_assert(nCcalls == L->nCcalls);
}
int status;
unsigned short oldnny = L->nny; /* save "number of non-yieldable" calls */
lua_lock(L);
- luai_userstateresume(L, nargs);
+ if (L->status == LUA_OK) { /* may be starting a coroutine */
+ if (L->ci != &L->base_ci) /* not in base level? */
+ return resume_error(L, "cannot resume non-suspended coroutine", nargs);
+ }
+ else if (L->status != LUA_YIELD)
+ return resume_error(L, "cannot resume dead coroutine", nargs);
L->nCcalls = (from) ? from->nCcalls + 1 : 1;
+ if (L->nCcalls >= LUAI_MAXCCALLS)
+ return resume_error(L, "C stack overflow", nargs);
+ luai_userstateresume(L, nargs);
L->nny = 0; /* allow yields */
api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
status = luaD_rawrunprotected(L, resume, &nargs);
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