diff options
Diffstat (limited to 'lib/lua/src/ldo.c')
-rw-r--r-- | lib/lua/src/ldo.c | 930 |
1 files changed, 465 insertions, 465 deletions
diff --git a/lib/lua/src/ldo.c b/lib/lua/src/ldo.c index 44bba83..8c64852 100644 --- a/lib/lua/src/ldo.c +++ b/lib/lua/src/ldo.c @@ -1,465 +1,465 @@ -/* -** $Id: ldo.c,v 1.3 2004-07-23 13:08:23 pixel 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 - -#include "lua.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 (based on long jumps) -** ======================================================= -*/ - - -/* chain list of long jump buffers */ -struct lua_longjmp { - struct lua_longjmp *previous; - jmp_buf b; - volatile int status; /* error code */ -}; - - -static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { - switch (errcode) { - case LUA_ERRMEM: { - setsvalue2s(oldtop, luaS_new(L, MEMERRMSG)); - break; - } - case LUA_ERRERR: { - setsvalue2s(oldtop, luaS_new(L, "error in error handling")); - break; - } - case LUA_ERRSYNTAX: - case LUA_ERRRUN: { - setobjs2s(oldtop, L->top - 1); /* error message on current top */ - break; - } - } - L->top = oldtop + 1; -} - - -void luaD_throw (lua_State *L, int errcode) { - if (L->errorJmp) { - L->errorJmp->status = errcode; - longjmp(L->errorJmp->b, 1); - } - else { - G(L)->panic(L); - exit(EXIT_FAILURE); - } -} - - -int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { - struct lua_longjmp lj; - lj.status = 0; - lj.previous = L->errorJmp; /* chain new error handler */ - L->errorJmp = &lj; - if (setjmp(lj.b) == 0) - (*f)(L, ud); - L->errorJmp = lj.previous; /* restore old error handler */ - return lj.status; -} - - -static void restore_stack_limit (lua_State *L) { - L->stack_last = L->stack+L->stacksize-1; - if (L->size_ci > LUA_MAXCALLS) { /* there was an overflow? */ - int inuse = (L->ci - L->base_ci); - if (inuse + 1 < LUA_MAXCALLS) /* can `undo' overflow? */ - luaD_reallocCI(L, LUA_MAXCALLS); - } -} - -/* }====================================================== */ - - -static void correctstack (lua_State *L, TObject *oldstack) { - CallInfo *ci; - GCObject *up; - L->top = (L->top - oldstack) + L->stack; - for (up = L->openupval; up != NULL; up = up->gch.next) - gcotouv(up)->v = (gcotouv(up)->v - oldstack) + L->stack; - for (ci = L->base_ci; ci <= L->ci; ci++) { - ci->top = (ci->top - oldstack) + L->stack; - ci->base = (ci->base - oldstack) + L->stack; - } - L->base = L->ci->base; -} - - -void luaD_reallocstack (lua_State *L, int newsize) { - TObject *oldstack = L->stack; - luaM_reallocvector(L, L->stack, L->stacksize, newsize, TObject); - L->stacksize = newsize; - L->stack_last = L->stack+newsize-1-EXTRA_STACK; - correctstack(L, oldstack); -} - - -void luaD_reallocCI (lua_State *L, int newsize) { - CallInfo *oldci = L->base_ci; - luaM_reallocvector(L, L->base_ci, L->size_ci, newsize, CallInfo); - L->size_ci = cast(unsigned short, newsize); - L->ci = (L->ci - oldci) + L->base_ci; - L->end_ci = L->base_ci + L->size_ci; -} - - -void luaD_growstack (lua_State *L, int n) { - if (n <= L->stacksize) /* double size is enough? */ - luaD_reallocstack(L, 2*L->stacksize); - else - luaD_reallocstack(L, L->stacksize + n + EXTRA_STACK); -} - - -static void luaD_growCI (lua_State *L) { - if (L->size_ci > LUA_MAXCALLS) /* overflow while handling overflow? */ - luaD_throw(L, LUA_ERRERR); - else { - luaD_reallocCI(L, 2*L->size_ci); - if (L->size_ci > LUA_MAXCALLS) - luaG_runerror(L, "stack overflow"); - } -} - - -void luaD_callhook (lua_State *L, int event, int line) { - lua_Hook hook = L->hook; - if (hook && L->allowhook) { - ptrdiff_t top = savestack(L, L->top); - ptrdiff_t ci_top = savestack(L, L->ci->top); - lua_Debug ar; - ar.event = event; - ar.currentline = line; - if (event == LUA_HOOKTAILRET) - ar.i_ci = 0; /* tail call; no debug information about it */ - else - ar.i_ci = L->ci - L->base_ci; - luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ - L->ci->top = L->top + LUA_MINSTACK; - L->allowhook = 0; /* cannot call hooks inside a hook */ - lua_unlock(L); - (*hook)(L, &ar); - lua_lock(L); - lua_assert(!L->allowhook); - L->allowhook = 1; - L->ci->top = restorestack(L, ci_top); - L->top = restorestack(L, top); - } -} - - -static void adjust_varargs (lua_State *L, int nfixargs, StkId base) { - int i; - Table *htab; - TObject nname; - int actual = L->top - base; /* actual number of arguments */ - if (actual < nfixargs) { - luaD_checkstack(L, nfixargs - actual); - for (; actual < nfixargs; ++actual) - setnilvalue(L->top++); - } - actual -= nfixargs; /* number of extra arguments */ - htab = luaH_new(L, actual, 1); /* create `arg' table */ - for (i=0; i<actual; i++) /* put extra arguments into `arg' table */ - setobj2n(luaH_setnum(L, htab, i+1), L->top - actual + i); - /* store counter in field `n' */ - setsvalue(&nname, luaS_newliteral(L, "n")); - setnvalue(luaH_set(L, htab, &nname), cast(lua_Number, actual)); - L->top -= actual; /* remove extra elements from the stack */ - sethvalue(L->top, htab); - incr_top(L); -} - - -static StkId tryfuncTM (lua_State *L, StkId func) { - const TObject *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(p, p-1); - incr_top(L); - func = restorestack(L, funcr); /* previous call may change stack */ - setobj2s(func, tm); /* tag method is the new function to be called */ - return func; -} - - -StkId luaD_precall (lua_State *L, StkId func) { - LClosure *cl; - ptrdiff_t funcr = savestack(L, func); - if (!ttisfunction(func)) /* `func' is not a function? */ - func = tryfuncTM(L, func); /* check the `function' tag method */ - if (L->ci + 1 == L->end_ci) luaD_growCI(L); - else condhardstacktests(luaD_reallocCI(L, L->size_ci)); - cl = &clvalue(func)->l; - if (!cl->isC) { /* Lua function? prepare its call */ - CallInfo *ci; - Proto *p = cl->p; - if (p->is_vararg) /* varargs? */ - adjust_varargs(L, p->numparams, func+1); - luaD_checkstack(L, p->maxstacksize); - ci = ++L->ci; /* now `enter' new function */ - L->base = L->ci->base = restorestack(L, funcr) + 1; - ci->top = L->base + p->maxstacksize; - ci->u.l.savedpc = p->code; /* starting point */ - ci->u.l.tailcalls = 0; - ci->state = CI_SAVEDPC; - while (L->top < ci->top) - setnilvalue(L->top++); - L->top = ci->top; - return NULL; - } - else { /* if is a C function, call it */ - CallInfo *ci; - int n; - luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ - ci = ++L->ci; /* now `enter' new function */ - L->base = L->ci->base = restorestack(L, funcr) + 1; - ci->top = L->top + LUA_MINSTACK; - ci->state = CI_C; /* a C function */ - if (L->hookmask & LUA_MASKCALL) - luaD_callhook(L, LUA_HOOKCALL, -1); - lua_unlock(L); -#ifdef LUA_COMPATUPVALUES - lua_pushupvalues(L); -#endif - n = (*clvalue(L->base - 1)->c.f)(L); /* do the actual call */ - lua_lock(L); - return L->top - n; - } -} - - -static StkId callrethooks (lua_State *L, StkId firstResult) { - ptrdiff_t fr = savestack(L, firstResult); /* next call may change stack */ - luaD_callhook(L, LUA_HOOKRET, -1); - if (!(L->ci->state & CI_C)) { /* Lua function? */ - while (L->ci->u.l.tailcalls--) /* call hook for eventual tail calls */ - luaD_callhook(L, LUA_HOOKTAILRET, -1); - } - return restorestack(L, fr); -} - - -void luaD_poscall (lua_State *L, int wanted, StkId firstResult) { - StkId res; - if (L->hookmask & LUA_MASKRET) - firstResult = callrethooks(L, firstResult); - res = L->base - 1; /* res == final position of 1st result */ - L->ci--; - L->base = L->ci->base; /* restore base */ - /* move results to correct place */ - while (wanted != 0 && firstResult < L->top) { - setobjs2s(res++, firstResult++); - wanted--; - } - while (wanted-- > 0) - setnilvalue(res++); - L->top = res; -} - - -/* -** 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) { - StkId firstResult; - lua_assert(!(L->ci->state & CI_CALLING)); - if (++L->nCcalls >= LUA_MAXCCALLS) { - if (L->nCcalls == LUA_MAXCCALLS) - luaG_runerror(L, "C stack overflow"); - else if (L->nCcalls >= (LUA_MAXCCALLS + (LUA_MAXCCALLS>>3))) - luaD_throw(L, LUA_ERRERR); /* error while handing stack error */ - } - firstResult = luaD_precall(L, func); - if (firstResult == NULL) /* is a Lua function? */ - firstResult = luaV_execute(L); /* call it */ - luaD_poscall(L, nResults, firstResult); - L->nCcalls--; - luaC_checkGC(L); -} - - -static void resume (lua_State *L, void *ud) { - StkId firstResult; - int nargs = *cast(int *, ud); - CallInfo *ci = L->ci; - if (ci == L->base_ci) { /* no activation record? */ - if (nargs >= L->top - L->base) - luaG_runerror(L, "cannot resume dead coroutine"); - luaD_precall(L, L->top - (nargs + 1)); /* start coroutine */ - } - else if (ci->state & CI_YIELD) { /* inside a yield? */ - if (ci->state & CI_C) { /* `common' yield? */ - /* finish interrupted execution of `OP_CALL' */ - int nresults; - lua_assert((ci-1)->state & CI_SAVEDPC); - lua_assert(GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_CALL || - GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_TAILCALL); - nresults = GETARG_C(*((ci-1)->u.l.savedpc - 1)) - 1; - luaD_poscall(L, nresults, L->top - nargs); /* complete it */ - if (nresults >= 0) L->top = L->ci->top; - } - else { /* yielded inside a hook: just continue its execution */ - ci->state &= ~CI_YIELD; - } - } - else - luaG_runerror(L, "cannot resume non-suspended coroutine"); - firstResult = luaV_execute(L); - if (firstResult != NULL) /* return? */ - luaD_poscall(L, LUA_MULTRET, firstResult); /* finalize this coroutine */ -} - - -LUA_API int lua_resume (lua_State *L, int nargs) { - int status; - lu_byte old_allowhooks; - lua_lock(L); - old_allowhooks = L->allowhook; - lua_assert(L->errfunc == 0 && L->nCcalls == 0); - status = luaD_rawrunprotected(L, resume, &nargs); - if (status != 0) { /* error? */ - L->ci = L->base_ci; /* go back to initial level */ - L->base = L->ci->base; - L->nCcalls = 0; - luaF_close(L, L->base); /* close eventual pending closures */ - seterrorobj(L, status, L->base); - L->allowhook = old_allowhooks; - restore_stack_limit(L); - } - lua_unlock(L); - return status; -} - - -LUA_API int lua_yield (lua_State *L, int nresults) { - CallInfo *ci; - lua_lock(L); - ci = L->ci; - if (L->nCcalls > 0) - luaG_runerror(L, "attempt to yield across metamethod/C-call boundary"); - if (ci->state & CI_C) { /* usual yield */ - if ((ci-1)->state & CI_C) - luaG_runerror(L, "cannot yield a C function"); - if (L->top - nresults > L->base) { /* is there garbage in the stack? */ - int i; - for (i=0; i<nresults; i++) /* move down results */ - setobjs2s(L->base + i, L->top - nresults + i); - L->top = L->base + nresults; - } - } /* else it's an yield inside a hook: nothing to do */ - ci->state |= CI_YIELD; - lua_unlock(L); - return -1; -} - -LUA_API void lua_break (lua_State *L) { - CallInfo * ci; - lua_lock(L); - ci = L->ci; - ci->state |= CI_BREAK; - lua_unlock(L); -} - -int luaD_pcall (lua_State *L, Pfunc func, void *u, - ptrdiff_t old_top, ptrdiff_t ef) { - int status; - unsigned short oldnCcalls = L->nCcalls; - ptrdiff_t old_ci = saveci(L, L->ci); - lu_byte old_allowhooks = L->allowhook; - ptrdiff_t old_errfunc = L->errfunc; - L->errfunc = ef; - status = luaD_rawrunprotected(L, func, u); - if (status != 0) { /* an error occurred? */ - StkId oldtop = restorestack(L, old_top); - luaF_close(L, oldtop); /* close eventual pending closures */ - seterrorobj(L, status, oldtop); - L->nCcalls = oldnCcalls; - L->ci = restoreci(L, old_ci); - L->base = L->ci->base; - L->allowhook = old_allowhooks; - restore_stack_limit(L); - } - L->errfunc = old_errfunc; - return status; -} - - - -/* -** Execute a protected parser. -*/ -struct SParser { /* data to `f_parser' */ - ZIO *z; - Mbuffer buff; /* buffer to be used by the scanner */ - int bin; -}; - -static void f_parser (lua_State *L, void *ud) { - struct SParser *p; - Proto *tf; - Closure *cl; - luaC_checkGC(L); - p = cast(struct SParser *, ud); - tf = p->bin ? luaU_undump(L, p->z, &p->buff) : luaY_parser(L, p->z, &p->buff); - cl = luaF_newLclosure(L, 0, gt(L)); - cl->l.p = tf; - setclvalue(L->top, cl); - incr_top(L); -} - - -int luaD_protectedparser (lua_State *L, ZIO *z, int bin) { - struct SParser p; - int status; - ptrdiff_t oldtopr = savestack(L, L->top); /* save current top */ - p.z = z; p.bin = bin; - luaZ_initbuffer(L, &p.buff); - status = luaD_rawrunprotected(L, f_parser, &p); - luaZ_freebuffer(L, &p.buff); - if (status != 0) { /* error? */ - StkId oldtop = restorestack(L, oldtopr); - seterrorobj(L, status, oldtop); - } - return status; -} - - +/*
+** $Id: ldo.c,v 1.4 2004-11-27 21:35:20 pixel 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
+
+#include "lua.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 (based on long jumps)
+** =======================================================
+*/
+
+
+/* chain list of long jump buffers */
+struct lua_longjmp {
+ struct lua_longjmp *previous;
+ jmp_buf b;
+ volatile int status; /* error code */
+};
+
+
+static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+ switch (errcode) {
+ case LUA_ERRMEM: {
+ setsvalue2s(oldtop, luaS_new(L, MEMERRMSG));
+ break;
+ }
+ case LUA_ERRERR: {
+ setsvalue2s(oldtop, luaS_new(L, "error in error handling"));
+ break;
+ }
+ case LUA_ERRSYNTAX:
+ case LUA_ERRRUN: {
+ setobjs2s(oldtop, L->top - 1); /* error message on current top */
+ break;
+ }
+ }
+ L->top = oldtop + 1;
+}
+
+
+void luaD_throw (lua_State *L, int errcode) {
+ if (L->errorJmp) {
+ L->errorJmp->status = errcode;
+ longjmp(L->errorJmp->b, 1);
+ }
+ else {
+ G(L)->panic(L);
+ exit(EXIT_FAILURE);
+ }
+}
+
+
+int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
+ struct lua_longjmp lj;
+ lj.status = 0;
+ lj.previous = L->errorJmp; /* chain new error handler */
+ L->errorJmp = &lj;
+ if (setjmp(lj.b) == 0)
+ (*f)(L, ud);
+ L->errorJmp = lj.previous; /* restore old error handler */
+ return lj.status;
+}
+
+
+static void restore_stack_limit (lua_State *L) {
+ L->stack_last = L->stack+L->stacksize-1;
+ if (L->size_ci > LUA_MAXCALLS) { /* there was an overflow? */
+ int inuse = (L->ci - L->base_ci);
+ if (inuse + 1 < LUA_MAXCALLS) /* can `undo' overflow? */
+ luaD_reallocCI(L, LUA_MAXCALLS);
+ }
+}
+
+/* }====================================================== */
+
+
+static void correctstack (lua_State *L, TObject *oldstack) {
+ CallInfo *ci;
+ GCObject *up;
+ L->top = (L->top - oldstack) + L->stack;
+ for (up = L->openupval; up != NULL; up = up->gch.next)
+ gcotouv(up)->v = (gcotouv(up)->v - oldstack) + L->stack;
+ for (ci = L->base_ci; ci <= L->ci; ci++) {
+ ci->top = (ci->top - oldstack) + L->stack;
+ ci->base = (ci->base - oldstack) + L->stack;
+ }
+ L->base = L->ci->base;
+}
+
+
+void luaD_reallocstack (lua_State *L, int newsize) {
+ TObject *oldstack = L->stack;
+ luaM_reallocvector(L, L->stack, L->stacksize, newsize, TObject);
+ L->stacksize = newsize;
+ L->stack_last = L->stack+newsize-1-EXTRA_STACK;
+ correctstack(L, oldstack);
+}
+
+
+void luaD_reallocCI (lua_State *L, int newsize) {
+ CallInfo *oldci = L->base_ci;
+ luaM_reallocvector(L, L->base_ci, L->size_ci, newsize, CallInfo);
+ L->size_ci = cast(unsigned short, newsize);
+ L->ci = (L->ci - oldci) + L->base_ci;
+ L->end_ci = L->base_ci + L->size_ci;
+}
+
+
+void luaD_growstack (lua_State *L, int n) {
+ if (n <= L->stacksize) /* double size is enough? */
+ luaD_reallocstack(L, 2*L->stacksize);
+ else
+ luaD_reallocstack(L, L->stacksize + n + EXTRA_STACK);
+}
+
+
+static void luaD_growCI (lua_State *L) {
+ if (L->size_ci > LUA_MAXCALLS) /* overflow while handling overflow? */
+ luaD_throw(L, LUA_ERRERR);
+ else {
+ luaD_reallocCI(L, 2*L->size_ci);
+ if (L->size_ci > LUA_MAXCALLS)
+ luaG_runerror(L, "stack overflow");
+ }
+}
+
+
+void luaD_callhook (lua_State *L, int event, int line) {
+ lua_Hook hook = L->hook;
+ if (hook && L->allowhook) {
+ ptrdiff_t top = savestack(L, L->top);
+ ptrdiff_t ci_top = savestack(L, L->ci->top);
+ lua_Debug ar;
+ ar.event = event;
+ ar.currentline = line;
+ if (event == LUA_HOOKTAILRET)
+ ar.i_ci = 0; /* tail call; no debug information about it */
+ else
+ ar.i_ci = L->ci - L->base_ci;
+ luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
+ L->ci->top = L->top + LUA_MINSTACK;
+ L->allowhook = 0; /* cannot call hooks inside a hook */
+ lua_unlock(L);
+ (*hook)(L, &ar);
+ lua_lock(L);
+ lua_assert(!L->allowhook);
+ L->allowhook = 1;
+ L->ci->top = restorestack(L, ci_top);
+ L->top = restorestack(L, top);
+ }
+}
+
+
+static void adjust_varargs (lua_State *L, int nfixargs, StkId base) {
+ int i;
+ Table *htab;
+ TObject nname;
+ int actual = L->top - base; /* actual number of arguments */
+ if (actual < nfixargs) {
+ luaD_checkstack(L, nfixargs - actual);
+ for (; actual < nfixargs; ++actual)
+ setnilvalue(L->top++);
+ }
+ actual -= nfixargs; /* number of extra arguments */
+ htab = luaH_new(L, actual, 1); /* create `arg' table */
+ for (i=0; i<actual; i++) /* put extra arguments into `arg' table */
+ setobj2n(luaH_setnum(L, htab, i+1), L->top - actual + i);
+ /* store counter in field `n' */
+ setsvalue(&nname, luaS_newliteral(L, "n"));
+ setnvalue(luaH_set(L, htab, &nname), cast(lua_Number, actual));
+ L->top -= actual; /* remove extra elements from the stack */
+ sethvalue(L->top, htab);
+ incr_top(L);
+}
+
+
+static StkId tryfuncTM (lua_State *L, StkId func) {
+ const TObject *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(p, p-1);
+ incr_top(L);
+ func = restorestack(L, funcr); /* previous call may change stack */
+ setobj2s(func, tm); /* tag method is the new function to be called */
+ return func;
+}
+
+
+StkId luaD_precall (lua_State *L, StkId func) {
+ LClosure *cl;
+ ptrdiff_t funcr = savestack(L, func);
+ if (!ttisfunction(func)) /* `func' is not a function? */
+ func = tryfuncTM(L, func); /* check the `function' tag method */
+ if (L->ci + 1 == L->end_ci) luaD_growCI(L);
+ else condhardstacktests(luaD_reallocCI(L, L->size_ci));
+ cl = &clvalue(func)->l;
+ if (!cl->isC) { /* Lua function? prepare its call */
+ CallInfo *ci;
+ Proto *p = cl->p;
+ if (p->is_vararg) /* varargs? */
+ adjust_varargs(L, p->numparams, func+1);
+ luaD_checkstack(L, p->maxstacksize);
+ ci = ++L->ci; /* now `enter' new function */
+ L->base = L->ci->base = restorestack(L, funcr) + 1;
+ ci->top = L->base + p->maxstacksize;
+ ci->u.l.savedpc = p->code; /* starting point */
+ ci->u.l.tailcalls = 0;
+ ci->state = CI_SAVEDPC;
+ while (L->top < ci->top)
+ setnilvalue(L->top++);
+ L->top = ci->top;
+ return NULL;
+ }
+ else { /* if is a C function, call it */
+ CallInfo *ci;
+ int n;
+ luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
+ ci = ++L->ci; /* now `enter' new function */
+ L->base = L->ci->base = restorestack(L, funcr) + 1;
+ ci->top = L->top + LUA_MINSTACK;
+ ci->state = CI_C; /* a C function */
+ if (L->hookmask & LUA_MASKCALL)
+ luaD_callhook(L, LUA_HOOKCALL, -1);
+ lua_unlock(L);
+#ifdef LUA_COMPATUPVALUES
+ lua_pushupvalues(L);
+#endif
+ n = (*clvalue(L->base - 1)->c.f)(L); /* do the actual call */
+ lua_lock(L);
+ return L->top - n;
+ }
+}
+
+
+static StkId callrethooks (lua_State *L, StkId firstResult) {
+ ptrdiff_t fr = savestack(L, firstResult); /* next call may change stack */
+ luaD_callhook(L, LUA_HOOKRET, -1);
+ if (!(L->ci->state & CI_C)) { /* Lua function? */
+ while (L->ci->u.l.tailcalls--) /* call hook for eventual tail calls */
+ luaD_callhook(L, LUA_HOOKTAILRET, -1);
+ }
+ return restorestack(L, fr);
+}
+
+
+void luaD_poscall (lua_State *L, int wanted, StkId firstResult) {
+ StkId res;
+ if (L->hookmask & LUA_MASKRET)
+ firstResult = callrethooks(L, firstResult);
+ res = L->base - 1; /* res == final position of 1st result */
+ L->ci--;
+ L->base = L->ci->base; /* restore base */
+ /* move results to correct place */
+ while (wanted != 0 && firstResult < L->top) {
+ setobjs2s(res++, firstResult++);
+ wanted--;
+ }
+ while (wanted-- > 0)
+ setnilvalue(res++);
+ L->top = res;
+}
+
+
+/*
+** 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) {
+ StkId firstResult;
+ lua_assert(!(L->ci->state & CI_CALLING));
+ if (++L->nCcalls >= LUA_MAXCCALLS) {
+ if (L->nCcalls == LUA_MAXCCALLS)
+ luaG_runerror(L, "C stack overflow");
+ else if (L->nCcalls >= (LUA_MAXCCALLS + (LUA_MAXCCALLS>>3)))
+ luaD_throw(L, LUA_ERRERR); /* error while handing stack error */
+ }
+ firstResult = luaD_precall(L, func);
+ if (firstResult == NULL) /* is a Lua function? */
+ firstResult = luaV_execute(L); /* call it */
+ luaD_poscall(L, nResults, firstResult);
+ L->nCcalls--;
+ luaC_checkGC(L);
+}
+
+
+static void resume (lua_State *L, void *ud) {
+ StkId firstResult;
+ int nargs = *cast(int *, ud);
+ CallInfo *ci = L->ci;
+ if (ci == L->base_ci) { /* no activation record? */
+ if (nargs >= L->top - L->base)
+ luaG_runerror(L, "cannot resume dead coroutine");
+ luaD_precall(L, L->top - (nargs + 1)); /* start coroutine */
+ }
+ else if (ci->state & CI_YIELD) { /* inside a yield? */
+ if (ci->state & CI_C) { /* `common' yield? */
+ /* finish interrupted execution of `OP_CALL' */
+ int nresults;
+ lua_assert((ci-1)->state & CI_SAVEDPC);
+ lua_assert(GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_CALL ||
+ GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_TAILCALL);
+ nresults = GETARG_C(*((ci-1)->u.l.savedpc - 1)) - 1;
+ luaD_poscall(L, nresults, L->top - nargs); /* complete it */
+ if (nresults >= 0) L->top = L->ci->top;
+ }
+ else { /* yielded inside a hook: just continue its execution */
+ ci->state &= ~CI_YIELD;
+ }
+ }
+ else
+ luaG_runerror(L, "cannot resume non-suspended coroutine");
+ firstResult = luaV_execute(L);
+ if (firstResult != NULL) /* return? */
+ luaD_poscall(L, LUA_MULTRET, firstResult); /* finalize this coroutine */
+}
+
+
+LUA_API int lua_resume (lua_State *L, int nargs) {
+ int status;
+ lu_byte old_allowhooks;
+ lua_lock(L);
+ old_allowhooks = L->allowhook;
+ lua_assert(L->errfunc == 0 && L->nCcalls == 0);
+ status = luaD_rawrunprotected(L, resume, &nargs);
+ if (status != 0) { /* error? */
+ L->ci = L->base_ci; /* go back to initial level */
+ L->base = L->ci->base;
+ L->nCcalls = 0;
+ luaF_close(L, L->base); /* close eventual pending closures */
+ seterrorobj(L, status, L->base);
+ L->allowhook = old_allowhooks;
+ restore_stack_limit(L);
+ }
+ lua_unlock(L);
+ return status;
+}
+
+
+LUA_API int lua_yield (lua_State *L, int nresults) {
+ CallInfo *ci;
+ lua_lock(L);
+ ci = L->ci;
+ if (L->nCcalls > 0)
+ luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
+ if (ci->state & CI_C) { /* usual yield */
+ if ((ci-1)->state & CI_C)
+ luaG_runerror(L, "cannot yield a C function");
+ if (L->top - nresults > L->base) { /* is there garbage in the stack? */
+ int i;
+ for (i=0; i<nresults; i++) /* move down results */
+ setobjs2s(L->base + i, L->top - nresults + i);
+ L->top = L->base + nresults;
+ }
+ } /* else it's an yield inside a hook: nothing to do */
+ ci->state |= CI_YIELD;
+ lua_unlock(L);
+ return -1;
+}
+
+LUA_API void lua_break (lua_State *L) {
+ CallInfo * ci;
+ lua_lock(L);
+ ci = L->ci;
+ ci->state |= CI_BREAK;
+ lua_unlock(L);
+}
+
+int luaD_pcall (lua_State *L, Pfunc func, void *u,
+ ptrdiff_t old_top, ptrdiff_t ef) {
+ int status;
+ unsigned short oldnCcalls = L->nCcalls;
+ ptrdiff_t old_ci = saveci(L, L->ci);
+ lu_byte old_allowhooks = L->allowhook;
+ ptrdiff_t old_errfunc = L->errfunc;
+ L->errfunc = ef;
+ status = luaD_rawrunprotected(L, func, u);
+ if (status != 0) { /* an error occurred? */
+ StkId oldtop = restorestack(L, old_top);
+ luaF_close(L, oldtop); /* close eventual pending closures */
+ seterrorobj(L, status, oldtop);
+ L->nCcalls = oldnCcalls;
+ L->ci = restoreci(L, old_ci);
+ L->base = L->ci->base;
+ L->allowhook = old_allowhooks;
+ restore_stack_limit(L);
+ }
+ L->errfunc = old_errfunc;
+ return status;
+}
+
+
+
+/*
+** Execute a protected parser.
+*/
+struct SParser { /* data to `f_parser' */
+ ZIO *z;
+ Mbuffer buff; /* buffer to be used by the scanner */
+ int bin;
+};
+
+static void f_parser (lua_State *L, void *ud) {
+ struct SParser *p;
+ Proto *tf;
+ Closure *cl;
+ luaC_checkGC(L);
+ p = cast(struct SParser *, ud);
+ tf = p->bin ? luaU_undump(L, p->z, &p->buff) : luaY_parser(L, p->z, &p->buff);
+ cl = luaF_newLclosure(L, 0, gt(L));
+ cl->l.p = tf;
+ setclvalue(L->top, cl);
+ incr_top(L);
+}
+
+
+int luaD_protectedparser (lua_State *L, ZIO *z, int bin) {
+ struct SParser p;
+ int status;
+ ptrdiff_t oldtopr = savestack(L, L->top); /* save current top */
+ p.z = z; p.bin = bin;
+ luaZ_initbuffer(L, &p.buff);
+ status = luaD_rawrunprotected(L, f_parser, &p);
+ luaZ_freebuffer(L, &p.buff);
+ if (status != 0) { /* error? */
+ StkId oldtop = restorestack(L, oldtopr);
+ seterrorobj(L, status, oldtop);
+ }
+ return status;
+}
+
+
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