diff options
Diffstat (limited to '3rdparty/lua/src/ldo.c')
-rw-r--r-- | 3rdparty/lua/src/ldo.c | 823 |
1 files changed, 509 insertions, 314 deletions
diff --git a/3rdparty/lua/src/ldo.c b/3rdparty/lua/src/ldo.c index 90b695fb04c..a48e35f9dba 100644 --- a/3rdparty/lua/src/ldo.c +++ b/3rdparty/lua/src/ldo.c @@ -1,5 +1,5 @@ /* -** $Id: ldo.c,v 2.157 2016/12/13 15:52:21 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. */ @@ -98,7 +98,12 @@ static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); break; } + case LUA_OK: { /* special case only for closing upvalues */ + setnilvalue(s2v(oldtop)); /* no error message */ + break; + } default: { + lua_assert(errorstatus(errcode)); /* real error */ setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ break; } @@ -114,16 +119,13 @@ l_noret luaD_throw (lua_State *L, int errcode) { } else { /* thread has no error handler */ global_State *g = G(L); - L->status = cast_byte(errcode); /* mark it as dead */ + errcode = luaE_resetthread(L, errcode); /* close all upvalues */ if (g->mainthread->errorJmp) { /* main thread has a handler? */ setobjs2s(L, g->mainthread->top++, L->top - 1); /* copy error obj. */ luaD_throw(g->mainthread, errcode); /* re-throw in main thread */ } else { /* no handler at all; abort */ if (g->panic) { /* panic function? */ - 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); g->panic(L); /* call panic function (last chance to jump out) */ } @@ -134,7 +136,7 @@ l_noret luaD_throw (lua_State *L, int errcode) { int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { - unsigned short oldnCcalls = L->nCcalls; + l_uint32 oldnCcalls = L->nCcalls; struct lua_longjmp lj; lj.status = LUA_OK; lj.previous = L->errorJmp; /* chain new error handler */ @@ -155,17 +157,18 @@ 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; + L->top = (L->top - oldstack) + newstack; + L->tbclist = (L->tbclist - 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' */ } } @@ -174,66 +177,116 @@ 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 lim = L->stacksize; +/* +** Reallocate the stack to a new size, correcting all pointers into +** it. (There are pointers to a stack from its upvalues, from its list +** of call infos, plus a few individual pointers.) The reallocation is +** done in two steps (allocation + free) because the correction must be +** done while both addresses (the old stack and the new one) are valid. +** (In ISO C, any pointer use after the pointer has been deallocated is +** undefined behavior.) +** In case of allocation error, raise an error or return false according +** to 'raiseerror'. +*/ +int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) { + int oldsize = stacksize(L); + int i; + StkId newstack = luaM_reallocvector(L, NULL, 0, + newsize + EXTRA_STACK, 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); - for (; lim < newsize; lim++) - setnilvalue(L->stack + lim); /* erase new segment */ - L->stacksize = newsize; - L->stack_last = L->stack + newsize - EXTRA_STACK; - correctstack(L, oldstack); + if (l_unlikely(newstack == NULL)) { /* reallocation failed? */ + if (raiseerror) + luaM_error(L); + else return 0; /* do not raise an error */ + } + /* number of elements to be copied to the new stack */ + i = ((oldsize <= newsize) ? oldsize : newsize) + EXTRA_STACK; + memcpy(newstack, L->stack, i * sizeof(StackValue)); + for (; i < newsize + EXTRA_STACK; i++) + setnilvalue(s2v(newstack + i)); /* erase new segment */ + correctstack(L, L->stack, newstack); + luaM_freearray(L, L->stack, oldsize + EXTRA_STACK); + L->stack = newstack; + L->stack_last = L->stack + newsize; + return 1; } -void luaD_growstack (lua_State *L, int n) { - int size = L->stacksize; - if (size > LUAI_MAXSTACK) /* error after extra size? */ - luaD_throw(L, LUA_ERRERR); +/* +** 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 = stacksize(L); + if (l_unlikely(size > LUAI_MAXSTACK)) { + /* if stack is larger than maximum, thread is already using the + extra space reserved for errors, that is, thread is handling + a stack error; cannot grow further than that. */ + lua_assert(stacksize(L) == ERRORSTACKSIZE); + if (raiseerror) + luaD_throw(L, LUA_ERRERR); /* error inside message handler */ + return 0; /* if not 'raiseerror', just signal it */ + } 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"); + int newsize = 2 * size; /* tentative new size */ + int needed = cast_int(L->top - L->stack) + n; + if (newsize > LUAI_MAXSTACK) /* cannot cross the limit */ + newsize = LUAI_MAXSTACK; + if (newsize < needed) /* but must respect what was asked for */ + newsize = needed; + if (l_likely(newsize <= LUAI_MAXSTACK)) + return luaD_reallocstack(L, newsize, raiseerror); + else { /* 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"); + return 0; } - else - luaD_reallocstack(L, newsize); } } static int stackinuse (lua_State *L) { CallInfo *ci; + int res; StkId lim = L->top; for (ci = L->ci; ci != NULL; ci = ci->previous) { 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 */ + res = cast_int(lim - L->stack) + 1; /* part of stack in use */ + if (res < LUA_MINSTACK) + res = LUA_MINSTACK; /* ensure a minimum size */ + return res; } +/* +** If stack size is more than 3 times the current use, reduce that size +** to twice the current use. (So, the final stack size is at most 2/3 the +** previous size, and half of its entries are empty.) +** As a particular case, if stack was handling a stack overflow and now +** it is not, 'max' (limited by LUAI_MAXSTACK) will be smaller than +** stacksize (equal to ERRORSTACKSIZE in this case), and so the stack +** will be reduced to a "regular" size. +*/ 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; /* 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 */ + int nsize = inuse * 2; /* proposed new size */ + int max = inuse * 3; /* maximum "reasonable" size */ + if (max > LUAI_MAXSTACK) { + max = LUAI_MAXSTACK; /* respect stack limit */ + if (nsize > LUAI_MAXSTACK) + nsize = LUAI_MAXSTACK; + } /* 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); + size is larger than maximum "reasonable" size, shrink it */ + if (inuse <= LUAI_MAXSTACK && stacksize(L) > max) + luaD_reallocstack(L, nsize, 0); /* ok if that fails */ else /* don't change stack */ condmovestack(L,{},{}); /* (change only for debugging) */ + luaE_shrinkCI(L); /* shrink CI list */ } @@ -247,24 +300,33 @@ 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); + ptrdiff_t top = savestack(L, L->top); /* preserve original 'top' */ + ptrdiff_t ci_top = savestack(L, ci->top); /* idem for 'ci->top' */ lua_Debug ar; 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; + } + if (isLua(ci) && L->top < ci->top) + L->top = ci->top; /* protect entire activation register */ luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ - ci->top = L->top + LUA_MINSTACK; - lua_assert(ci->top <= L->stack_last); + if (ci->top < L->top + LUA_MINSTACK) + 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 +334,71 @@ 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; - 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; +/* +** 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) { + L->oldpc = 0; /* set 'oldpc' for new function */ + if (L->hookmask & LUA_MASKCALL) { /* is call hook on? */ + int event = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL + : LUA_HOOKCALL; + Proto *p = ci_func(ci)->p; + ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ + luaD_hook(L, event, -1, 1, p->numparams); + ci->u.l.savedpc--; /* correct 'pc' */ } - luaD_hook(L, hook, -1); - 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) */ +/* +** Executes a return hook for Lua and C functions and sets/corrects +** 'oldpc'. (Note that this correction is needed by the line hook, so it +** is done even when return hooks are off.) +*/ +static void rethook (lua_State *L, CallInfo *ci, int nres) { + if (L->hookmask & LUA_MASKRET) { /* is return hook on? */ + StkId firstres = L->top - nres; /* index of first result */ + int delta = 0; /* correction for vararg functions */ + int ftransfer; + if (isLua(ci)) { + Proto *p = ci_func(ci)->p; + if (p->is_vararg) + delta = ci->u.l.nextraargs + p->numparams + 1; + } + 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; } - for (; i < nfixargs; i++) - setnilvalue(L->top++); /* complete missing arguments */ - return base; + if (isLua(ci = ci->previous)) + L->oldpc = pcRel(ci->u.l.savedpc, ci_func(ci)->p); /* set 'oldpc' */ } /* -** 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_precall' 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); +StkId luaD_tryfuncTM (lua_State *L, StkId func) { + const TValue *tm; 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--) + checkstackGCp(L, 1, func); /* space for metamethod */ + tm = luaT_gettmbyobj(L, s2v(func), TM_CALL); /* (after previous GC) */ + if (l_unlikely(ttisnil(tm))) + luaG_callerror(L, s2v(func)); /* 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 */ + return func; } @@ -331,229 +408,313 @@ 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) { +l_sinline 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 /* at least one result */ + 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: /* two/more results and/or to-be-closed variables */ + if (hastocloseCfunc(wanted)) { /* to-be-closed variables? */ + ptrdiff_t savedres = savestack(L, res); + L->ci->callstatus |= CIST_CLSRET; /* in case of yields */ + L->ci->u2.nres = nres; + luaF_close(L, res, CLOSEKTOP, 1); + L->ci->callstatus &= ~CIST_CLSRET; + if (L->hookmask) /* if needed, call hook after '__close's */ + rethook(L, L->ci, nres); + res = restorestack(L, savedres); /* close and hook can move stack */ + wanted = decodeNresults(wanted); + if (wanted == LUA_MULTRET) + wanted = nres; /* we want all results */ } break; - } } + /* generic case */ + firstresult = L->top - 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 = 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. +** Finishes a function call: calls hook if necessary, moves current +** number of results to proper place, and returns to previous call +** info. If function has to close variables, hook must be called after +** that. */ -int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) { - StkId res; +void luaD_poscall (lua_State *L, CallInfo *ci, int nres) { 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 */ + if (l_unlikely(L->hookmask && !hastocloseCfunc(wanted))) + rethook(L, ci, nres); /* move results to proper place */ - return moveresults(L, firstResult, res, nres, wanted); + moveresults(L, ci->func, nres, wanted); + /* function cannot be in any of these cases when returning */ + lua_assert(!(ci->callstatus & + (CIST_HOOKED | CIST_YPCALL | CIST_FIN | CIST_TRAN | CIST_CLSRET))); + L->ci = ci->previous; /* back to caller (after closing variables) */ } -#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' */ +l_sinline CallInfo *prepCallInfo (lua_State *L, StkId func, int nret, + int mask, StkId top) { + CallInfo *ci = L->ci = next_ci(L); /* new frame */ + ci->func = func; + ci->nresults = nret; + ci->callstatus = mask; + ci->top = top; + return ci; +} /* -** 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). +** precall for C functions */ -int luaD_precall (lua_State *L, StkId func, int nresults) { - lua_CFunction f; +l_sinline int precallC (lua_State *L, StkId func, int nresults, + lua_CFunction f) { + int n; /* number of returns */ CallInfo *ci; - switch (ttype(func)) { - case LUA_TCCL: /* C closure */ - f = clCvalue(func)->f; - goto Cfunc; - case LUA_TLCF: /* light C function */ - f = fvalue(func); - Cfunc: { - int n; /* number of returns */ - checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ - ci = next_ci(L); /* now 'enter' new function */ - ci->nresults = nresults; - ci->func = func; - ci->top = L->top + LUA_MINSTACK; + checkstackGCp(L, LUA_MINSTACK, func); /* ensure minimum stack size */ + L->ci = ci = prepCallInfo(L, func, nresults, CIST_C, + L->top + LUA_MINSTACK); + lua_assert(ci->top <= L->stack_last); + if (l_unlikely(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, n); + return n; +} + + +/* +** 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). Return the number of +** results, if it was a C function, or -1 for a Lua function. +*/ +int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, + int narg1, int delta) { + retry: + switch (ttypetag(s2v(func))) { + case LUA_VCCL: /* C closure */ + return precallC(L, func, LUA_MULTRET, clCvalue(s2v(func))->f); + case LUA_VLCF: /* light C function */ + return precallC(L, func, LUA_MULTRET, fvalue(s2v(func))); + case LUA_VLCL: { /* Lua function */ + Proto *p = clLvalue(s2v(func))->p; + int fsize = p->maxstacksize; /* frame size */ + int nfixparams = p->numparams; + int i; + checkstackGCp(L, fsize - delta, func); + ci->func -= delta; /* restore 'func' (if vararg) */ + for (i = 0; i < narg1; i++) /* move down function and arguments */ + setobjs2s(L, ci->func + i, func + i); + 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->callstatus = 0; - if (L->hookmask & LUA_MASKCALL) - luaD_hook(L, LUA_HOOKCALL, -1); - 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; + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus |= CIST_TAIL; + L->top = func + narg1; /* set top */ + return -1; + } + default: { /* not a function */ + func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ + /* return luaD_pretailcall(L, ci, func, narg1 + 1, delta); */ + narg1++; + goto retry; /* try again */ } - 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 */ + } +} + + +/* +** Prepares the call to a function (C or Lua). For C functions, also do +** the call. The function to be called is at '*func'. The arguments +** are on the stack, right after the function. Returns the CallInfo +** to be executed, if it was a Lua function. Otherwise (a C function) +** returns NULL, with all the results on the stack, starting at the +** original function position. +*/ +CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) { + retry: + switch (ttypetag(s2v(func))) { + case LUA_VCCL: /* C closure */ + precallC(L, func, nresults, clCvalue(s2v(func))->f); + return NULL; + case LUA_VLCF: /* light C function */ + precallC(L, func, nresults, fvalue(s2v(func))); + return NULL; + case LUA_VLCL: { /* Lua function */ + CallInfo *ci; + 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->func = func; - ci->u.l.base = base; - L->top = ci->top = base + fsize; - lua_assert(ci->top <= L->stack_last); + checkstackGCp(L, fsize, func); + L->ci = ci = prepCallInfo(L, func, nresults, 0, func + 1 + fsize); ci->u.l.savedpc = p->code; /* starting point */ - ci->callstatus = CIST_LUA; - if (L->hookmask & LUA_MASKCALL) - callhook(L, ci); - return 0; + for (; narg < nfixparams; narg++) + setnilvalue(s2v(L->top++)); /* complete missing arguments */ + lua_assert(ci->top <= L->stack_last); + return ci; } 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 */ + func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */ + /* return luaD_precall(L, func, nresults); */ + 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) +** Call a function (C or Lua) through C. 'inc' can be 1 (increment +** number of recursive invocations in the C stack) or nyci (the same +** plus increment number of non-yieldable calls). */ -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 */ +l_sinline void ccall (lua_State *L, StkId func, int nResults, int inc) { + CallInfo *ci; + L->nCcalls += inc; + if (l_unlikely(getCcalls(L) >= LUAI_MAXCCALLS)) + luaE_checkcstack(L); + 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 */ + } + L->nCcalls -= inc; } /* -** 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. +** External interface for 'ccall' */ 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--; + ccall(L, func, nResults, 1); } /* -** Similar to 'luaD_call', but does not allow yields during the call +** Similar to 'luaD_call', but does not allow yields during the call. */ void luaD_callnoyield (lua_State *L, StkId func, int nResults) { - L->nny++; - luaD_call(L, func, nResults); - L->nny--; + ccall(L, func, nResults, nyci); } /* -** Completes the execution of an interrupted C function, calling its -** continuation function. +** Finish the job of 'lua_pcallk' after it was interrupted by an yield. +** (The caller, 'finishCcall', does the final call to 'adjustresults'.) +** The main job is to complete the 'luaD_pcall' called by 'lua_pcallk'. +** If a '__close' method yields here, eventually control will be back +** to 'finishCcall' (when that '__close' method finally returns) and +** 'finishpcallk' will run again and close any still pending '__close' +** methods. Similarly, if a '__close' method errs, 'precover' calls +** 'unroll' which calls ''finishCcall' and we are back here again, to +** close any pending '__close' methods. +** Note that, up to the call to 'luaF_close', the corresponding +** 'CallInfo' is not modified, so that this repeated run works like the +** first one (except that it has at least one less '__close' to do). In +** particular, field CIST_RECST preserves the error status across these +** multiple runs, changing only if there is a new error. */ -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); - /* 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; /* 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); - lua_unlock(L); - 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' */ +static int finishpcallk (lua_State *L, CallInfo *ci) { + int status = getcistrecst(ci); /* get original status */ + if (l_likely(status == LUA_OK)) /* no error? */ + status = LUA_YIELD; /* was interrupted by an yield */ + else { /* error */ + StkId func = restorestack(L, ci->u2.funcidx); + L->allowhook = getoah(ci->callstatus); /* restore 'allowhook' */ + luaF_close(L, func, status, 1); /* can yield or raise an error */ + func = restorestack(L, ci->u2.funcidx); /* stack may be moved */ + luaD_seterrorobj(L, status, func); + luaD_shrinkstack(L); /* restore stack size in case of overflow */ + setcistrecst(ci, LUA_OK); /* clear original status */ + } + ci->callstatus &= ~CIST_YPCALL; + L->errfunc = ci->u.c.old_errfunc; + /* if it is here, there were errors or yields; unlike 'lua_pcallk', + do not change status */ + return status; +} + + +/* +** Completes the execution of a C function interrupted by an yield. +** The interruption must have happened while the function was either +** closing its tbc variables in 'moveresults' or executing +** 'lua_callk'/'lua_pcallk'. In the first case, it just redoes +** 'luaD_poscall'. In the second case, the call to 'finishpcallk' +** finishes the interrupted execution of 'lua_pcallk'. After that, it +** calls the continuation of the interrupted function and finally it +** completes the job of the 'luaD_call' that called the function. In +** the call to 'adjustresults', we do not know the number of results +** of the function called by 'lua_callk'/'lua_pcallk', so we are +** conservative and use LUA_MULTRET (always adjust). +*/ +static void finishCcall (lua_State *L, CallInfo *ci) { + int n; /* actual number of results from C function */ + if (ci->callstatus & CIST_CLSRET) { /* was returning? */ + lua_assert(hastocloseCfunc(ci->nresults)); + n = ci->u2.nres; /* just redo 'luaD_poscall' */ + /* don't need to reset CIST_CLSRET, as it will be set again anyway */ + } + else { + int status = LUA_YIELD; /* default if there were no errors */ + /* must have a continuation and must be able to call it */ + lua_assert(ci->u.c.k != NULL && yieldable(L)); + if (ci->callstatus & CIST_YPCALL) /* was inside a 'lua_pcallk'? */ + status = finishpcallk(L, ci); /* finish it */ + adjustresults(L, LUA_MULTRET); /* finish 'lua_callk' */ + lua_unlock(L); + n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation */ + lua_lock(L); + api_checknelems(L, n); + } + luaD_poscall(L, ci, n); /* finish 'luaD_call' */ } /* ** Executes "full continuation" (everything in the stack) of a ** previously interrupted coroutine until the stack is empty (or another -** interruption long-jumps out of the loop). If the coroutine is -** recovering from an error, 'ud' points to the error status, which must -** be passed to the first continuation function (otherwise the default -** status is LUA_YIELD). +** interruption long-jumps out of the loop). */ static void unroll (lua_State *L, void *ud) { - 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? */ - finishCcall(L, LUA_YIELD); /* complete its execution */ + CallInfo *ci; + UNUSED(ud); + while ((ci = L->ci) != &L->base_ci) { /* something in the stack */ + if (!isLua(ci)) /* C function? */ + finishCcall(L, ci); /* 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' */ } } } @@ -574,28 +735,6 @@ static CallInfo *findpcall (lua_State *L) { /* -** Recovers from an error in a coroutine. Finds a recover point (if -** there is one) and completes the execution of the interrupted -** 'luaD_pcall'. If there is no recover point, returns zero. -*/ -static int recover (lua_State *L, int status) { - StkId oldtop; - 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); - 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 */ -} - - -/* ** 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.) @@ -620,96 +759,111 @@ static void resume (lua_State *L, void *ud) { int n = *(cast(int*, ud)); /* number of arguments */ 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 */ - } + if (L->status == LUA_OK) /* starting a coroutine? */ + ccall(L, firstArg - 1, LUA_MULTRET, 0); /* just call its body */ 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 */ + if (isLua(ci)) { /* yielded inside a hook? */ + L->top = firstArg; /* discard arguments */ + 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) { +/* +** Unrolls a coroutine in protected mode while there are recoverable +** errors, that is, errors inside a protected call. (Any error +** interrupts 'unroll', and this loop protects it again so it can +** continue.) Stops with a normal end (status == LUA_OK), an yield +** (status == LUA_YIELD), or an unprotected error ('findpcall' doesn't +** find a recover point). +*/ +static int precover (lua_State *L, int status) { + CallInfo *ci; + while (errorstatus(status) && (ci = findpcall(L)) != NULL) { + L->ci = ci; /* go down to recovery functions */ + setcistrecst(ci, status); /* status to finish 'pcall' */ + status = luaD_rawrunprotected(L, unroll, NULL); + } + return status; +} + + +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) + L->nCcalls = (from) ? getCcalls(from) : 0; + if (getCcalls(L) >= LUAI_MAXCCALLS) return resume_error(L, "C stack overflow", nargs); + L->nCcalls++; 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 */ + status = precover(L, status); + if (l_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); } LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, lua_KFunction k) { - CallInfo *ci = L->ci; + CallInfo *ci; luai_userstateyield(L, nresults); lua_lock(L); + ci = L->ci; api_checknelems(L, nresults); - if (L->nny > 0) { + if (l_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' */ + ci->u2.nyield = nresults; /* save number of results */ if (isLua(ci)) { /* inside a hook? */ + lua_assert(!isLuacode(ci)); + api_check(L, nresults == 0, "hooks cannot yield values"); api_check(L, k == NULL, "hooks cannot continue after yielding"); } 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 */ luaD_throw(L, LUA_YIELD); } lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ @@ -718,23 +872,64 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, } +/* +** Auxiliary structure to call 'luaF_close' in protected mode. +*/ +struct CloseP { + StkId level; + int status; +}; + + +/* +** Auxiliary function to call 'luaF_close' in protected mode. +*/ +static void closepaux (lua_State *L, void *ud) { + struct CloseP *pcl = cast(struct CloseP *, ud); + luaF_close(L, pcl->level, pcl->status, 0); +} + + +/* +** Calls 'luaF_close' in protected mode. Return the original status +** or, in case of errors, the new status. +*/ +int luaD_closeprotected (lua_State *L, ptrdiff_t level, int status) { + CallInfo *old_ci = L->ci; + lu_byte old_allowhooks = L->allowhook; + for (;;) { /* keep closing upvalues until no more errors */ + struct CloseP pcl; + pcl.level = restorestack(L, level); pcl.status = status; + status = luaD_rawrunprotected(L, &closepaux, &pcl); + if (l_likely(status == LUA_OK)) /* no more errors? */ + return pcl.status; + else { /* an error occurred; restore saved state and repeat */ + L->ci = old_ci; + L->allowhook = old_allowhooks; + } + } +} + + +/* +** 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? */ - StkId oldtop = restorestack(L, old_top); - luaF_close(L, oldtop); /* close possible pending closures */ - seterrorobj(L, status, oldtop); + if (l_unlikely(status != LUA_OK)) { /* an error occurred? */ L->ci = old_ci; L->allowhook = old_allowhooks; - L->nny = old_nny; - luaD_shrinkstack(L); + status = luaD_closeprotected(L, old_top, status); + luaD_seterrorobj(L, status, restorestack(L, old_top)); + luaD_shrinkstack(L); /* restore stack size in case of overflow */ } L->errfunc = old_errfunc; return status; @@ -784,7 +979,7 @@ 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 +990,7 @@ 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; } |