diff options
Diffstat (limited to 'libs/liblua/src/ldo.c')
| -rw-r--r-- | libs/liblua/src/ldo.c | 506 |
1 files changed, 263 insertions, 243 deletions
diff --git a/libs/liblua/src/ldo.c b/libs/liblua/src/ldo.c index 316e45c8fe..c563b1d9b3 100644 --- a/libs/liblua/src/ldo.c +++ b/libs/liblua/src/ldo.c @@ -1,5 +1,5 @@ /* -** $Id: ldo.c,v 2.157.1.1 2017/04/19 17:20:42 roberto Exp $ +** $Id: ldo.c $ ** Stack and Call structure of Lua ** See Copyright Notice in lua.h */ @@ -88,7 +88,7 @@ struct lua_longjmp { }; -static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { +void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) { switch (errcode) { case LUA_ERRMEM: { /* memory error? */ setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ @@ -98,6 +98,10 @@ static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); break; } + case CLOSEPROTECT: { + setnilvalue(s2v(oldtop)); /* no error message */ + break; + } default: { setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ break; @@ -114,6 +118,7 @@ l_noret luaD_throw (lua_State *L, int errcode) { } else { /* thread has no error handler */ global_State *g = G(L); + errcode = luaF_close(L, L->stack, errcode); /* close all upvalues */ L->status = cast_byte(errcode); /* mark it as dead */ if (g->mainthread->errorJmp) { /* main thread has a handler? */ setobjs2s(L, g->mainthread->top++, L->top - 1); /* copy error obj. */ @@ -121,7 +126,7 @@ l_noret luaD_throw (lua_State *L, int errcode) { } else { /* no handler at all; abort */ if (g->panic) { /* panic function? */ - seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */ + luaD_seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */ if (L->ci->top < L->top) L->ci->top = L->top; /* pushing msg. can break this invariant */ lua_unlock(L); @@ -134,7 +139,8 @@ l_noret luaD_throw (lua_State *L, int errcode) { int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { - unsigned short oldnCcalls = L->nCcalls; + global_State *g = G(L); + l_uint32 oldnCcalls = g->Cstacklimit - (L->nCcalls + L->nci); struct lua_longjmp lj; lj.status = LUA_OK; lj.previous = L->errorJmp; /* chain new error handler */ @@ -143,7 +149,7 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { (*f)(L, ud); ); L->errorJmp = lj.previous; /* restore old error handler */ - L->nCcalls = oldnCcalls; + L->nCcalls = g->Cstacklimit - oldnCcalls - L->nci; return lj.status; } @@ -155,17 +161,19 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { ** Stack reallocation ** =================================================================== */ -static void correctstack (lua_State *L, TValue *oldstack) { +static void correctstack (lua_State *L, StkId oldstack, StkId newstack) { CallInfo *ci; UpVal *up; - L->top = (L->top - oldstack) + L->stack; + if (oldstack == newstack) + return; /* stack address did not change */ + L->top = (L->top - oldstack) + newstack; for (up = L->openupval; up != NULL; up = up->u.open.next) - up->v = (up->v - oldstack) + L->stack; + up->v = s2v((uplevel(up) - oldstack) + newstack); for (ci = L->ci; ci != NULL; ci = ci->previous) { - ci->top = (ci->top - oldstack) + L->stack; - ci->func = (ci->func - oldstack) + L->stack; + ci->top = (ci->top - oldstack) + newstack; + ci->func = (ci->func - oldstack) + newstack; if (isLua(ci)) - ci->u.l.base = (ci->u.l.base - oldstack) + L->stack; + ci->u.l.trap = 1; /* signal to update 'trap' in 'luaV_execute' */ } } @@ -174,36 +182,53 @@ static void correctstack (lua_State *L, TValue *oldstack) { #define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) -void luaD_reallocstack (lua_State *L, int newsize) { - TValue *oldstack = L->stack; +int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) { int lim = L->stacksize; + StkId newstack = luaM_reallocvector(L, L->stack, lim, newsize, StackValue); lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK); - luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue); + if (unlikely(newstack == NULL)) { /* reallocation failed? */ + if (raiseerror) + luaM_error(L); + else return 0; /* do not raise an error */ + } for (; lim < newsize; lim++) - setnilvalue(L->stack + lim); /* erase new segment */ + setnilvalue(s2v(newstack + lim)); /* erase new segment */ + correctstack(L, L->stack, newstack); + L->stack = newstack; L->stacksize = newsize; L->stack_last = L->stack + newsize - EXTRA_STACK; - correctstack(L, oldstack); + return 1; } -void luaD_growstack (lua_State *L, int n) { +/* +** Try to grow the stack by at least 'n' elements. when 'raiseerror' +** is true, raises any error; otherwise, return 0 in case of errors. +*/ +int luaD_growstack (lua_State *L, int n, int raiseerror) { int size = L->stacksize; - if (size > LUAI_MAXSTACK) /* error after extra size? */ - luaD_throw(L, LUA_ERRERR); + int newsize = 2 * size; /* tentative new size */ + if (unlikely(size > LUAI_MAXSTACK)) { /* need more space after extra size? */ + if (raiseerror) + luaD_throw(L, LUA_ERRERR); /* error inside message handler */ + else return 0; + } else { int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK; - int newsize = 2 * size; - if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK; - if (newsize < needed) newsize = needed; - if (newsize > LUAI_MAXSTACK) { /* stack overflow? */ - luaD_reallocstack(L, ERRORSTACKSIZE); - luaG_runerror(L, "stack overflow"); + if (newsize > LUAI_MAXSTACK) /* cannot cross the limit */ + newsize = LUAI_MAXSTACK; + if (newsize < needed) /* but must respect what was asked for */ + newsize = needed; + if (unlikely(newsize > LUAI_MAXSTACK)) { /* stack overflow? */ + /* add extra size to be able to handle the error message */ + luaD_reallocstack(L, ERRORSTACKSIZE, raiseerror); + if (raiseerror) + luaG_runerror(L, "stack overflow"); + else return 0; } - else - luaD_reallocstack(L, newsize); - } + } /* else no errors */ + return luaD_reallocstack(L, newsize, raiseerror); } @@ -223,17 +248,14 @@ void luaD_shrinkstack (lua_State *L) { int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK; 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 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); + luaD_reallocstack(L, goodsize, 0); /* ok if that fails */ else /* don't change stack */ condmovestack(L,{},{}); /* (change only for debugging) */ + luaE_shrinkCI(L); /* shrink CI list */ } @@ -247,12 +269,14 @@ void luaD_inctop (lua_State *L) { /* ** Call a hook for the given event. Make sure there is a hook to be -** called. (Both 'L->hook' and 'L->hookmask', which triggers this +** called. (Both 'L->hook' and 'L->hookmask', which trigger this ** function, can be changed asynchronously by signals.) */ -void luaD_hook (lua_State *L, int event, int line) { +void luaD_hook (lua_State *L, int event, int line, + int ftransfer, int ntransfer) { lua_Hook hook = L->hook; if (hook && L->allowhook) { /* make sure there is a hook */ + int mask = CIST_HOOKED; CallInfo *ci = L->ci; ptrdiff_t top = savestack(L, L->top); ptrdiff_t ci_top = savestack(L, ci->top); @@ -260,11 +284,16 @@ void luaD_hook (lua_State *L, int event, int line) { ar.event = event; ar.currentline = line; ar.i_ci = ci; + if (ntransfer != 0) { + mask |= CIST_TRAN; /* 'ci' has transfer information */ + ci->u2.transferinfo.ftransfer = ftransfer; + ci->u2.transferinfo.ntransfer = ntransfer; + } luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ - ci->top = L->top + LUA_MINSTACK; - lua_assert(ci->top <= L->stack_last); + if (L->top + LUA_MINSTACK > ci->top) + ci->top = L->top + LUA_MINSTACK; L->allowhook = 0; /* cannot call hooks inside a hook */ - ci->callstatus |= CIST_HOOKED; + ci->callstatus |= mask; lua_unlock(L); (*hook)(L, &ar); lua_lock(L); @@ -272,56 +301,66 @@ void luaD_hook (lua_State *L, int event, int line) { L->allowhook = 1; ci->top = restorestack(L, ci_top); L->top = restorestack(L, top); - ci->callstatus &= ~CIST_HOOKED; + ci->callstatus &= ~mask; } } -static void callhook (lua_State *L, CallInfo *ci) { - int hook = LUA_HOOKCALL; +/* +** Executes a call hook for Lua functions. This function is called +** whenever 'hookmask' is not zero, so it checks whether call hooks are +** active. +*/ +void luaD_hookcall (lua_State *L, CallInfo *ci) { + int hook = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL : LUA_HOOKCALL; + Proto *p; + if (!(L->hookmask & LUA_MASKCALL)) /* some other hook? */ + return; /* don't call hook */ + p = clLvalue(s2v(ci->func))->p; + L->top = ci->top; /* prepare top */ ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ - if (isLua(ci->previous) && - GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) { - ci->callstatus |= CIST_TAIL; - hook = LUA_HOOKTAILCALL; - } - luaD_hook(L, hook, -1); + luaD_hook(L, hook, -1, 1, p->numparams); ci->u.l.savedpc--; /* correct 'pc' */ } -static StkId adjust_varargs (lua_State *L, Proto *p, int actual) { - int i; - int nfixargs = p->numparams; - StkId base, fixed; - /* move fixed parameters to final position */ - fixed = L->top - actual; /* first fixed argument */ - base = L->top; /* final position of first argument */ - for (i = 0; i < nfixargs && i < actual; i++) { - setobjs2s(L, L->top++, fixed + i); - setnilvalue(fixed + i); /* erase original copy (for GC) */ +static StkId rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) { + ptrdiff_t oldtop = savestack(L, L->top); /* hook may change top */ + int delta = 0; + if (isLuacode(ci)) { + Proto *p = clLvalue(s2v(ci->func))->p; + if (p->is_vararg) + delta = ci->u.l.nextraargs + p->numparams + 1; + if (L->top < ci->top) + L->top = ci->top; /* correct top to run hook */ } - for (; i < nfixargs; i++) - setnilvalue(L->top++); /* complete missing arguments */ - return base; + if (L->hookmask & LUA_MASKRET) { /* is return hook on? */ + int ftransfer; + ci->func += delta; /* if vararg, back to virtual 'func' */ + ftransfer = cast(unsigned short, firstres - ci->func); + luaD_hook(L, LUA_HOOKRET, -1, ftransfer, nres); /* call it */ + ci->func -= delta; + } + if (isLua(ci->previous)) + L->oldpc = ci->previous->u.l.savedpc; /* update 'oldpc' */ + return restorestack(L, oldtop); } /* -** Check whether __call metafield of 'func' is a function. If so, put -** it in stack below original 'func' so that 'luaD_precall' can call -** it. Raise an error if __call metafield is not a function. +** Check whether 'func' has a '__call' metafield. If so, put it in the +** stack, below original 'func', so that 'luaD_call' can call it. Raise +** an error if there is no '__call' metafield. */ -static void tryfuncTM (lua_State *L, StkId func) { - const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL); +void luaD_tryfuncTM (lua_State *L, StkId func) { + const TValue *tm = luaT_gettmbyobj(L, s2v(func), TM_CALL); StkId p; - if (!ttisfunction(tm)) - luaG_typeerror(L, func, "call"); - /* Open a hole inside the stack at 'func' */ - for (p = L->top; p > func; p--) + if (unlikely(ttisnil(tm))) + luaG_typeerror(L, s2v(func), "call"); /* nothing to call */ + for (p = L->top; p > func; p--) /* open space for metamethod */ setobjs2s(L, p, p-1); - L->top++; /* slot ensured by caller */ - setobj2s(L, func, tm); /* tag method is the new function to be called */ + L->top++; /* stack space pre-allocated by the caller */ + setobj2s(L, func, tm); /* metamethod is the new function to be called */ } @@ -331,183 +370,161 @@ static void tryfuncTM (lua_State *L, StkId func) { ** expressions, multiple results for tail calls/single parameters) ** separated. */ -static int moveresults (lua_State *L, const TValue *firstResult, StkId res, - int nres, int wanted) { +static void moveresults (lua_State *L, StkId res, int nres, int wanted) { + StkId firstresult; + int i; switch (wanted) { /* handle typical cases separately */ - case 0: break; /* nothing to move */ - case 1: { /* one result needed */ + case 0: /* no values needed */ + L->top = res; + return; + case 1: /* one value needed */ if (nres == 0) /* no results? */ - firstResult = luaO_nilobject; /* adjust with nil */ - setobjs2s(L, res, firstResult); /* move it to proper place */ + setnilvalue(s2v(res)); /* adjust with nil */ + else + setobjs2s(L, res, L->top - nres); /* move it to proper place */ + L->top = res + 1; + return; + case LUA_MULTRET: + wanted = nres; /* we want all results */ 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); + default: /* multiple results (or to-be-closed variables) */ + if (hastocloseCfunc(wanted)) { /* to-be-closed variables? */ + ptrdiff_t savedres = savestack(L, res); + luaF_close(L, res, LUA_OK); /* may change the stack */ + res = restorestack(L, savedres); + wanted = codeNresults(wanted); /* correct value */ + if (wanted == LUA_MULTRET) + wanted = nres; } break; - } } + firstresult = L->top - nres; /* index of first result */ + /* move all results to correct place */ + for (i = 0; i < nres && i < wanted; i++) + setobjs2s(L, res + i, firstresult + i); + for (; i < wanted; i++) /* complete wanted number of results */ + setnilvalue(s2v(res + i)); 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. +** moves current number of results to proper place. */ -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 */ +void luaD_poscall (lua_State *L, CallInfo *ci, int nres) { + if (L->hookmask) + L->top = rethook(L, ci, L->top - nres, nres); L->ci = ci->previous; /* back to caller */ /* move results to proper place */ - return moveresults(L, firstResult, res, nres, wanted); + moveresults(L, ci->func, nres, ci->nresults); } -#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L))) +#define next_ci(L) (L->ci->next ? L->ci->next : luaE_extendCI(L)) -/* macro to check stack size, preserving 'p' */ -#define checkstackp(L,n,p) \ - luaD_checkstackaux(L, n, \ - ptrdiff_t t__ = savestack(L, p); /* save 'p' */ \ - luaC_checkGC(L), /* stack grow uses memory */ \ - p = restorestack(L, t__)) /* 'pos' part: restore 'p' */ +/* +** Prepare a function for a tail call, building its call info on top +** of the current call info. 'narg1' is the number of arguments plus 1 +** (so that it includes the function itself). +*/ +void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int narg1) { + Proto *p = clLvalue(s2v(func))->p; + int fsize = p->maxstacksize; /* frame size */ + int nfixparams = p->numparams; + int i; + for (i = 0; i < narg1; i++) /* move down function and arguments */ + setobjs2s(L, ci->func + i, func + i); + checkstackGC(L, fsize); + func = ci->func; /* moved-down function */ + for (; narg1 <= nfixparams; narg1++) + setnilvalue(s2v(func + narg1)); /* complete missing arguments */ + ci->top = func + 1 + fsize; /* top for new function */ + lua_assert(ci->top <= L->stack_last); + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus |= CIST_TAIL; + L->top = func + narg1; /* set top */ +} /* -** Prepares a function call: checks the stack, creates a new CallInfo -** entry, fills in the relevant information, calls hook if needed. -** If function is a C function, does the call, too. (Otherwise, leave -** the execution ('luaV_execute') to the caller, to allow stackless -** calls.) Returns true iff function has been executed (C function). +** Call a function (C or Lua). The function to be called is at *func. +** The arguments are on the stack, right after the function. +** When returns, all the results are on the stack, starting at the original +** function position. */ -int luaD_precall (lua_State *L, StkId func, int nresults) { +void luaD_call (lua_State *L, StkId func, int nresults) { lua_CFunction f; - CallInfo *ci; - switch (ttype(func)) { - case LUA_TCCL: /* C closure */ - f = clCvalue(func)->f; + retry: + switch (ttypetag(s2v(func))) { + case LUA_VCCL: /* C closure */ + f = clCvalue(s2v(func))->f; goto Cfunc; - case LUA_TLCF: /* light C function */ - f = fvalue(func); + case LUA_VLCF: /* light C function */ + f = fvalue(s2v(func)); Cfunc: { int n; /* number of returns */ + CallInfo *ci = next_ci(L); checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ - ci = next_ci(L); /* now 'enter' new function */ ci->nresults = nresults; - ci->func = func; + ci->callstatus = CIST_C; ci->top = L->top + LUA_MINSTACK; + ci->func = func; + L->ci = ci; lua_assert(ci->top <= L->stack_last); - ci->callstatus = 0; - if (L->hookmask & LUA_MASKCALL) - luaD_hook(L, LUA_HOOKCALL, -1); + if (L->hookmask & LUA_MASKCALL) { + int narg = cast_int(L->top - func) - 1; + luaD_hook(L, LUA_HOOKCALL, -1, 1, narg); + } lua_unlock(L); n = (*f)(L); /* do the actual call */ lua_lock(L); api_checknelems(L, n); - luaD_poscall(L, ci, L->top - n, n); - return 1; + luaD_poscall(L, ci, n); + break; } - case LUA_TLCL: { /* Lua function: prepare its call */ - StkId base; - Proto *p = clLvalue(func)->p; - int n = cast_int(L->top - func) - 1; /* number of real arguments */ + case LUA_VLCL: { /* Lua function */ + CallInfo *ci = next_ci(L); + Proto *p = clLvalue(s2v(func))->p; + int narg = cast_int(L->top - func) - 1; /* number of real arguments */ + int nfixparams = p->numparams; int fsize = p->maxstacksize; /* frame size */ checkstackp(L, fsize, func); - 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; - } - ci = next_ci(L); /* now 'enter' new function */ ci->nresults = nresults; + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus = 0; + ci->top = func + 1 + fsize; ci->func = func; - ci->u.l.base = base; - L->top = ci->top = base + fsize; + L->ci = ci; + for (; narg < nfixparams; narg++) + setnilvalue(s2v(L->top++)); /* complete missing arguments */ lua_assert(ci->top <= L->stack_last); - ci->u.l.savedpc = p->code; /* starting point */ - ci->callstatus = CIST_LUA; - if (L->hookmask & LUA_MASKCALL) - callhook(L, ci); - return 0; + luaV_execute(L, ci); /* run the function */ + break; } default: { /* not a function */ - checkstackp(L, 1, func); /* ensure space for metamethod */ - tryfuncTM(L, func); /* try to get '__call' metamethod */ - return luaD_precall(L, func, nresults); /* now it must be a function */ + checkstackp(L, 1, func); /* space for metamethod */ + luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ + goto retry; /* try again with metamethod */ } } } /* -** 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 -** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to -** allow overflow handling to work) -*/ -static void stackerror (lua_State *L) { - if (L->nCcalls == LUAI_MAXCCALLS) - luaG_runerror(L, "C stack overflow"); - else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3))) - luaD_throw(L, LUA_ERRERR); /* error while handing stack error */ -} - - -/* -** Call a function (C or Lua). The function to be called is at *func. -** The arguments are on the stack, right after the function. -** When returns, all the results are on the stack, starting at the original -** function position. -*/ -void luaD_call (lua_State *L, StkId func, int nResults) { - if (++L->nCcalls >= LUAI_MAXCCALLS) - stackerror(L); - if (!luaD_precall(L, func, nResults)) /* is a Lua function? */ - luaV_execute(L); /* call it */ - L->nCcalls--; -} - - -/* -** Similar to 'luaD_call', but does not allow yields during the call +** Similar to 'luaD_call', but does not allow yields during the call. +** If there is a stack overflow, freeing all CI structures will +** force the subsequent call to invoke 'luaE_extendCI', which then +** will raise any errors. */ void luaD_callnoyield (lua_State *L, StkId func, int nResults) { - L->nny++; + incXCcalls(L); + if (getCcalls(L) <= CSTACKERR) /* possible stack overflow? */ + luaE_freeCI(L); luaD_call(L, func, nResults); - L->nny--; + decXCcalls(L); } @@ -519,7 +536,7 @@ static void finishCcall (lua_State *L, int status) { CallInfo *ci = L->ci; int n; /* must have a continuation and must be able to call it */ - lua_assert(ci->u.c.k != NULL && L->nny == 0); + lua_assert(ci->u.c.k != NULL && yieldable(L)); /* 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? */ @@ -533,7 +550,7 @@ static void finishCcall (lua_State *L, int status) { n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation function */ lua_lock(L); api_checknelems(L, n); - luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_precall' */ + luaD_poscall(L, ci, n); /* finish 'luaD_call' */ } @@ -546,14 +563,15 @@ static void finishCcall (lua_State *L, int status) { ** status is LUA_YIELD). */ static void unroll (lua_State *L, void *ud) { + CallInfo *ci; if (ud != NULL) /* error status? */ finishCcall(L, *(int *)ud); /* finish 'lua_pcallk' callee */ - while (L->ci != &L->base_ci) { /* something in the stack */ - if (!isLua(L->ci)) /* C function? */ + while ((ci = L->ci) != &L->base_ci) { /* something in the stack */ + if (!isLua(ci)) /* C function? */ finishCcall(L, LUA_YIELD); /* complete its execution */ else { /* Lua function */ luaV_finishOp(L); /* finish interrupted instruction */ - luaV_execute(L); /* execute down to higher C 'boundary' */ + luaV_execute(L, ci); /* execute down to higher C 'boundary' */ } } } @@ -583,12 +601,12 @@ static int recover (lua_State *L, int status) { CallInfo *ci = findpcall(L); if (ci == NULL) return 0; /* no recovery point */ /* "finish" luaD_pcall */ - oldtop = restorestack(L, ci->extra); - luaF_close(L, oldtop); - seterrorobj(L, status, oldtop); + oldtop = restorestack(L, ci->u2.funcidx); + luaF_close(L, oldtop, status); /* may change the stack */ + oldtop = restorestack(L, ci->u2.funcidx); + luaD_seterrorobj(L, status, oldtop); L->ci = ci; L->allowhook = getoah(ci->callstatus); /* restore original 'allowhook' */ - L->nny = 0; /* should be zero to be yieldable */ luaD_shrinkstack(L); L->errfunc = ci->u.c.old_errfunc; return 1; /* continue running the coroutine */ @@ -621,71 +639,68 @@ static void resume (lua_State *L, void *ud) { StkId firstArg = L->top - n; /* first argument */ CallInfo *ci = L->ci; if (L->status == LUA_OK) { /* starting a coroutine? */ - if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */ - luaV_execute(L); /* call it */ + luaD_call(L, firstArg - 1, LUA_MULTRET); } 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? */ - luaV_execute(L); /* just continue running Lua code */ + luaV_execute(L, ci); /* just continue running Lua code */ else { /* 'common' yield */ if (ci->u.c.k != NULL) { /* does it have a continuation function? */ lua_unlock(L); n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */ lua_lock(L); api_checknelems(L, n); - firstArg = L->top - n; /* yield results come from continuation */ } - luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_precall' */ + luaD_poscall(L, ci, n); /* finish 'luaD_call' */ } unroll(L, NULL); /* run continuation */ } } - -LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) { +LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs, + int *nresults) { int status; - unsigned short oldnny = L->nny; /* save "number of non-yieldable" calls */ lua_lock(L); 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->top - (L->ci->func + 1) == nargs) /* no function? */ + return resume_error(L, "cannot resume dead coroutine", nargs); } - else if (L->status != LUA_YIELD) + else if (L->status != LUA_YIELD) /* ended with errors? */ return resume_error(L, "cannot resume dead coroutine", nargs); - L->nCcalls = (from) ? from->nCcalls + 1 : 1; - if (L->nCcalls >= LUAI_MAXCCALLS) + if (from == NULL) + L->nCcalls = CSTACKTHREAD; + else /* correct 'nCcalls' for this thread */ + L->nCcalls = getCcalls(from) + from->nci - L->nci - CSTACKCF; + if (L->nCcalls <= CSTACKERR) 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); - if (status == -1) /* error calling 'lua_resume'? */ - status = LUA_ERRRUN; - else { /* continue running after recoverable errors */ - while (errorstatus(status) && recover(L, status)) { - /* unroll continuation */ - status = luaD_rawrunprotected(L, unroll, &status); - } - if (errorstatus(status)) { /* unrecoverable error? */ - L->status = cast_byte(status); /* mark thread as 'dead' */ - seterrorobj(L, status, L->top); /* push error message */ - L->ci->top = L->top; - } - else lua_assert(status == L->status); /* normal end or yield */ + /* continue running after recoverable errors */ + while (errorstatus(status) && recover(L, status)) { + /* unroll continuation */ + status = luaD_rawrunprotected(L, unroll, &status); + } + if (likely(!errorstatus(status))) + lua_assert(status == L->status); /* normal end or yield */ + else { /* unrecoverable error */ + L->status = cast_byte(status); /* mark thread as 'dead' */ + luaD_seterrorobj(L, status, L->top); /* push error message */ + L->ci->top = L->top; } - L->nny = oldnny; /* restore 'nny' */ - L->nCcalls--; - lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0)); + *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield + : cast_int(L->top - (L->ci->func + 1)); lua_unlock(L); return status; } LUA_API int lua_isyieldable (lua_State *L) { - return (L->nny == 0); + return yieldable(L); } @@ -695,21 +710,22 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, luai_userstateyield(L, nresults); lua_lock(L); api_checknelems(L, nresults); - if (L->nny > 0) { + if (unlikely(!yieldable(L))) { if (L != G(L)->mainthread) luaG_runerror(L, "attempt to yield across a C-call boundary"); else luaG_runerror(L, "attempt to yield from outside a coroutine"); } L->status = LUA_YIELD; - ci->extra = savestack(L, ci->func); /* save current 'func' */ if (isLua(ci)) { /* inside a hook? */ + lua_assert(!isLuacode(ci)); api_check(L, k == NULL, "hooks cannot continue after yielding"); + ci->u2.nyield = 0; /* no results */ } else { if ((ci->u.c.k = k) != NULL) /* is there a continuation? */ ci->u.c.ctx = ctx; /* save context */ - ci->func = L->top - nresults - 1; /* protect stack below results */ + ci->u2.nyield = nresults; /* save number of results */ luaD_throw(L, LUA_YIELD); } lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ @@ -718,22 +734,26 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, } +/* +** Call the C function 'func' in protected mode, restoring basic +** thread information ('allowhook', etc.) and in particular +** its stack level in case of errors. +*/ int luaD_pcall (lua_State *L, Pfunc func, void *u, ptrdiff_t old_top, ptrdiff_t ef) { int status; CallInfo *old_ci = L->ci; lu_byte old_allowhooks = L->allowhook; - unsigned short old_nny = L->nny; ptrdiff_t old_errfunc = L->errfunc; L->errfunc = ef; status = luaD_rawrunprotected(L, func, u); - if (status != LUA_OK) { /* an error occurred? */ + if (unlikely(status != LUA_OK)) { /* an error occurred? */ StkId oldtop = restorestack(L, old_top); - luaF_close(L, oldtop); /* close possible pending closures */ - seterrorobj(L, status, oldtop); L->ci = old_ci; L->allowhook = old_allowhooks; - L->nny = old_nny; + status = luaF_close(L, oldtop, status); + oldtop = restorestack(L, old_top); /* previous call may change stack */ + luaD_seterrorobj(L, status, oldtop); luaD_shrinkstack(L); } L->errfunc = old_errfunc; @@ -784,7 +804,7 @@ int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, const char *mode) { struct SParser p; int status; - L->nny++; /* cannot yield during parsing */ + incnny(L); /* cannot yield during parsing */ p.z = z; p.name = name; p.mode = mode; p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0; p.dyd.gt.arr = NULL; p.dyd.gt.size = 0; @@ -795,7 +815,7 @@ int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size); luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size); luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size); - L->nny--; + decnny(L); return status; } |