diff options
Diffstat (limited to 'Build/source/libs/lua52/lua-5.2.1/src/ldo.c')
| -rw-r--r-- | Build/source/libs/lua52/lua-5.2.1/src/ldo.c | 668 |
1 files changed, 668 insertions, 0 deletions
diff --git a/Build/source/libs/lua52/lua-5.2.1/src/ldo.c b/Build/source/libs/lua52/lua-5.2.1/src/ldo.c new file mode 100644 index 00000000000..d18e33cd418 --- /dev/null +++ b/Build/source/libs/lua52/lua-5.2.1/src/ldo.c @@ -0,0 +1,668 @@ +/* +** $Id: ldo.c,v 2.105 2012/06/08 15:14:04 roberto Exp $ +** Stack and Call structure of Lua +** See Copyright Notice in lua.h +*/ + + +#include <setjmp.h> +#include <stdlib.h> +#include <string.h> + +#define ldo_c +#define LUA_CORE + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lundump.h" +#include "lvm.h" +#include "lzio.h" + + + + +/* +** {====================================================== +** Error-recovery functions +** ======================================================= +*/ + +/* +** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By +** default, Lua handles errors with exceptions when compiling as +** C++ code, with _longjmp/_setjmp when asked to use them, and with +** longjmp/setjmp otherwise. +*/ +#if !defined(LUAI_THROW) + +#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) +/* C++ exceptions */ +#define LUAI_THROW(L,c) throw(c) +#define LUAI_TRY(L,c,a) \ + try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; } +#define luai_jmpbuf int /* dummy variable */ + +#elif defined(LUA_USE_ULONGJMP) +/* in Unix, try _longjmp/_setjmp (more efficient) */ +#define LUAI_THROW(L,c) _longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#else +/* default handling with long jumps */ +#define LUAI_THROW(L,c) longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#endif + +#endif + + + +/* chain list of long jump buffers */ +struct lua_longjmp { + struct lua_longjmp *previous; + luai_jmpbuf b; + volatile int status; /* error code */ +}; + + +static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { + switch (errcode) { + case LUA_ERRMEM: { /* memory error? */ + setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ + break; + } + case LUA_ERRERR: { + setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); + break; + } + default: { + setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ + break; + } + } + L->top = oldtop + 1; +} + + +l_noret luaD_throw (lua_State *L, int errcode) { + if (L->errorJmp) { /* thread has an error handler? */ + L->errorJmp->status = errcode; /* set status */ + LUAI_THROW(L, L->errorJmp); /* jump to it */ + } + else { /* thread has no error handler */ + L->status = cast_byte(errcode); /* mark it as dead */ + if (G(L)->mainthread->errorJmp) { /* main thread has a handler? */ + setobjs2s(L, G(L)->mainthread->top++, L->top - 1); /* copy error obj. */ + luaD_throw(G(L)->mainthread, errcode); /* re-throw in main thread */ + } + else { /* no handler at all; abort */ + if (G(L)->panic) { /* panic function? */ + lua_unlock(L); + G(L)->panic(L); /* call it (last chance to jump out) */ + } + abort(); + } + } +} + + +int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { + unsigned short oldnCcalls = L->nCcalls; + struct lua_longjmp lj; + lj.status = LUA_OK; + lj.previous = L->errorJmp; /* chain new error handler */ + L->errorJmp = &lj; + LUAI_TRY(L, &lj, + (*f)(L, ud); + ); + L->errorJmp = lj.previous; /* restore old error handler */ + L->nCcalls = oldnCcalls; + return lj.status; +} + +/* }====================================================== */ + + +static void correctstack (lua_State *L, TValue *oldstack) { + CallInfo *ci; + GCObject *up; + L->top = (L->top - oldstack) + L->stack; + for (up = L->openupval; up != NULL; up = up->gch.next) + gco2uv(up)->v = (gco2uv(up)->v - oldstack) + L->stack; + for (ci = L->ci; ci != NULL; ci = ci->previous) { + ci->top = (ci->top - oldstack) + L->stack; + ci->func = (ci->func - oldstack) + L->stack; + if (isLua(ci)) + ci->u.l.base = (ci->u.l.base - oldstack) + L->stack; + } +} + + +/* some space for error handling */ +#define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) + + +void luaD_reallocstack (lua_State *L, int newsize) { + TValue *oldstack = L->stack; + int lim = L->stacksize; + 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); +} + + +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); + 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"); + } + else + luaD_reallocstack(L, newsize); + } +} + + +static int stackinuse (lua_State *L) { + 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; + } + 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 (inuse > LUAI_MAXSTACK || /* handling stack overflow? */ + goodsize >= L->stacksize) /* would grow instead of shrink? */ + condmovestack(L); /* don't change stack (change only for debugging) */ + else + luaD_reallocstack(L, goodsize); /* shrink it */ +} + + +void luaD_hook (lua_State *L, int event, int line) { + lua_Hook hook = L->hook; + if (hook && L->allowhook) { + CallInfo *ci = L->ci; + ptrdiff_t top = savestack(L, L->top); + ptrdiff_t ci_top = savestack(L, ci->top); + lua_Debug ar; + ar.event = event; + ar.currentline = line; + ar.i_ci = ci; + luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ + ci->top = L->top + LUA_MINSTACK; + lua_assert(ci->top <= L->stack_last); + L->allowhook = 0; /* cannot call hooks inside a hook */ + ci->callstatus |= CIST_HOOKED; + lua_unlock(L); + (*hook)(L, &ar); + lua_lock(L); + lua_assert(!L->allowhook); + L->allowhook = 1; + ci->top = restorestack(L, ci_top); + L->top = restorestack(L, top); + ci->callstatus &= ~CIST_HOOKED; + } +} + + +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; + } + 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; + lua_assert(actual >= nfixargs); + /* 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++) { + setobjs2s(L, L->top++, fixed + i); + setnilvalue(fixed + i); + } + return base; +} + + +static StkId tryfuncTM (lua_State *L, StkId func) { + const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL); + StkId p; + ptrdiff_t funcr = savestack(L, func); + if (!ttisfunction(tm)) + luaG_typeerror(L, func, "call"); + /* Open a hole inside the stack at `func' */ + for (p = L->top; p > func; p--) setobjs2s(L, p, p-1); + incr_top(L); + func = restorestack(L, funcr); /* previous call may change stack */ + setobj2s(L, func, tm); /* tag method is the new function to be called */ + return func; +} + + + +#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L))) + + +/* +** returns true if function has been executed (C function) +*/ +int luaD_precall (lua_State *L, StkId func, int nresults) { + lua_CFunction f; + CallInfo *ci; + int n; /* number of arguments (Lua) or returns (C) */ + ptrdiff_t funcr = savestack(L, func); + switch (ttype(func)) { + case LUA_TLCF: /* light C function */ + f = fvalue(func); + goto Cfunc; + case LUA_TCCL: { /* C closure */ + f = clCvalue(func)->f; + Cfunc: + luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ + ci = next_ci(L); /* now 'enter' new function */ + ci->nresults = nresults; + ci->func = restorestack(L, funcr); + ci->top = L->top + LUA_MINSTACK; + 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, L->top - n); + return 1; + } + case LUA_TLCL: { /* Lua function: prepare its call */ + StkId base; + Proto *p = clLvalue(func)->p; + luaD_checkstack(L, p->maxstacksize); + func = restorestack(L, funcr); + n = cast_int(L->top - func) - 1; /* number of real arguments */ + for (; n < p->numparams; n++) + setnilvalue(L->top++); /* complete missing arguments */ + base = (!p->is_vararg) ? func + 1 : adjust_varargs(L, p, n); + ci = next_ci(L); /* now 'enter' new function */ + ci->nresults = nresults; + ci->func = func; + ci->u.l.base = base; + ci->top = base + p->maxstacksize; + lua_assert(ci->top <= L->stack_last); + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus = CIST_LUA; + L->top = ci->top; + if (L->hookmask & LUA_MASKCALL) + callhook(L, ci); + return 0; + } + default: { /* not a function */ + func = tryfuncTM(L, func); /* retry with 'function' tag method */ + return luaD_precall(L, func, nresults); /* now it must be a function */ + } + } +} + + +int luaD_poscall (lua_State *L, StkId firstResult) { + StkId res; + int wanted, i; + CallInfo *ci = L->ci; + 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 */ + wanted = ci->nresults; + L->ci = ci = ci->previous; /* back to caller */ + /* move results to correct place */ + for (i = wanted; i != 0 && firstResult < L->top; i--) + setobjs2s(L, res++, firstResult++); + while (i-- > 0) + setnilvalue(res++); + L->top = res; + return (wanted - LUA_MULTRET); /* 0 iff wanted == LUA_MULTRET */ +} + + +/* +** 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, int allowyield) { + if (++L->nCcalls >= LUAI_MAXCCALLS) { + 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 */ + } + if (!allowyield) L->nny++; + if (!luaD_precall(L, func, nResults)) /* is a Lua function? */ + luaV_execute(L); /* call it */ + if (!allowyield) L->nny--; + L->nCcalls--; + luaC_checkGC(L); +} + + +static void finishCcall (lua_State *L) { + CallInfo *ci = L->ci; + int n; + lua_assert(ci->u.c.k != NULL); /* must have a continuation */ + lua_assert(L->nny == 0); + /* finish 'lua_callk' */ + adjustresults(L, ci->nresults); + /* call continuation function */ + if (!(ci->callstatus & CIST_STAT)) /* no call status? */ + ci->u.c.status = LUA_YIELD; /* 'default' status */ + lua_assert(ci->u.c.status != LUA_OK); + ci->callstatus = (ci->callstatus & ~(CIST_YPCALL | CIST_STAT)) | CIST_YIELDED; + lua_unlock(L); + n = (*ci->u.c.k)(L); + lua_lock(L); + api_checknelems(L, n); + /* finish 'luaD_precall' */ + luaD_poscall(L, L->top - n); +} + + +static void unroll (lua_State *L, void *ud) { + UNUSED(ud); + for (;;) { + if (L->ci == &L->base_ci) /* stack is empty? */ + return; /* coroutine finished normally */ + if (!isLua(L->ci)) /* C function? */ + finishCcall(L); + else { /* Lua function */ + luaV_finishOp(L); /* finish interrupted instruction */ + luaV_execute(L); /* execute down to higher C 'boundary' */ + } + } +} + + +/* +** check whether thread has a suspended protected call +*/ +static CallInfo *findpcall (lua_State *L) { + CallInfo *ci; + for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */ + if (ci->callstatus & CIST_YPCALL) + return ci; + } + return NULL; /* no pending pcall */ +} + + +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 = ci->u.c.old_allowhook; + L->nny = 0; /* should be zero to be yieldable */ + luaD_shrinkstack(L); + L->errfunc = ci->u.c.old_errfunc; + ci->callstatus |= CIST_STAT; /* call has error status */ + ci->u.c.status = status; /* (here it is) */ + return 1; /* continue running the coroutine */ +} + + +/* +** 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.) +*/ +static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) { + L->top = firstArg; /* remove args from the stack */ + setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */ + incr_top(L); + luaD_throw(L, -1); /* jump back to 'lua_resume' */ +} + + +/* +** do the work for 'lua_resume' in protected mode +*/ +static void resume (lua_State *L, void *ud) { + int nCcalls = L->nCcalls; + StkId firstArg = cast(StkId, ud); + 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 (!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 */ + L->status = LUA_OK; + ci->func = restorestack(L, ci->extra); + if (isLua(ci)) /* yielded inside a hook? */ + luaV_execute(L); /* just continue running Lua code */ + else { /* 'common' yield */ + if (ci->u.c.k != NULL) { /* does it have a continuation? */ + int n; + ci->u.c.status = LUA_YIELD; /* 'default' status */ + ci->callstatus |= CIST_YIELDED; + lua_unlock(L); + n = (*ci->u.c.k)(L); /* call continuation */ + lua_lock(L); + api_checknelems(L, n); + firstArg = L->top - n; /* yield results come from continuation */ + } + luaD_poscall(L, firstArg); /* finish 'luaD_precall' */ + } + unroll(L, NULL); + } + lua_assert(nCcalls == L->nCcalls); +} + + +LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) { + int status; + lua_lock(L); + luai_userstateresume(L, nargs); + L->nCcalls = (from) ? from->nCcalls + 1 : 1; + L->nny = 0; /* allow yields */ + api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); + status = luaD_rawrunprotected(L, resume, L->top - nargs); + if (status == -1) /* error calling 'lua_resume'? */ + status = LUA_ERRRUN; + else { /* yield or regular error */ + while (status != LUA_OK && status != LUA_YIELD) { /* error? */ + if (recover(L, status)) /* recover point? */ + status = luaD_rawrunprotected(L, unroll, NULL); /* run continuation */ + else { /* unrecoverable error */ + L->status = cast_byte(status); /* mark thread as `dead' */ + seterrorobj(L, status, L->top); + L->ci->top = L->top; + break; + } + } + lua_assert(status == L->status); + } + L->nny = 1; /* do not allow yields */ + L->nCcalls--; + lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0)); + lua_unlock(L); + return status; +} + + +LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) { + CallInfo *ci = L->ci; + luai_userstateyield(L, nresults); + lua_lock(L); + api_checknelems(L, nresults); + if (L->nny > 0) { + if (L != G(L)->mainthread) + luaG_runerror(L, "attempt to yield across metamethod/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? */ + 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 */ + lua_unlock(L); + return 0; /* return to 'luaD_hook' */ +} + + +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); + L->ci = old_ci; + L->allowhook = old_allowhooks; + L->nny = old_nny; + luaD_shrinkstack(L); + } + L->errfunc = old_errfunc; + return status; +} + + + +/* +** Execute a protected parser. +*/ +struct SParser { /* data to `f_parser' */ + ZIO *z; + Mbuffer buff; /* dynamic structure used by the scanner */ + Dyndata dyd; /* dynamic structures used by the parser */ + const char *mode; + const char *name; +}; + + +static void checkmode (lua_State *L, const char *mode, const char *x) { + if (mode && strchr(mode, x[0]) == NULL) { + luaO_pushfstring(L, + "attempt to load a %s chunk (mode is " LUA_QS ")", x, mode); + luaD_throw(L, LUA_ERRSYNTAX); + } +} + + +static void f_parser (lua_State *L, void *ud) { + int i; + Closure *cl; + struct SParser *p = cast(struct SParser *, ud); + int c = zgetc(p->z); /* read first character */ + if (c == LUA_SIGNATURE[0]) { + checkmode(L, p->mode, "binary"); + cl = luaU_undump(L, p->z, &p->buff, p->name); + } + else { + checkmode(L, p->mode, "text"); + cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c); + } + lua_assert(cl->l.nupvalues == cl->l.p->sizeupvalues); + for (i = 0; i < cl->l.nupvalues; i++) { /* initialize upvalues */ + UpVal *up = luaF_newupval(L); + cl->l.upvals[i] = up; + luaC_objbarrier(L, cl, up); + } +} + + +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 */ + 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; + p.dyd.label.arr = NULL; p.dyd.label.size = 0; + luaZ_initbuffer(L, &p.buff); + status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc); + luaZ_freebuffer(L, &p.buff); + 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--; + return status; +} + + |