800 lines
25 KiB
C++
800 lines
25 KiB
C++
/*
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** $Id: ldo.c,v 2.157 2016/12/13 15:52:21 roberto Exp $
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** Stack and Call structure of Lua
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** See Copyright Notice in lua.h
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*/
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#define ldo_c
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#define LUA_CORE
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#include "ldo.h"
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#include "lprefix.h"
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#include <setjmp.h>
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#include <stdlib.h>
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#include <string.h>
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#include "lua.h"
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#include "lapi.h"
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#include "ldebug.h"
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#include "lfunc.h"
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#include "lgc.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lopcodes.h"
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#include "lparser.h"
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#include "lstate.h"
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#include "lstring.h"
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#include "ltable.h"
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#include "ltm.h"
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#include "lundump.h"
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#include "lvm.h"
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#include "lzio.h"
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#define errorstatus(s) ((s) > LUA_YIELD)
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/*
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** {======================================================
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** Error-recovery functions
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** =======================================================
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*/
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/*
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** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By
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** default, Lua handles errors with exceptions when compiling as
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** C++ code, with _longjmp/_setjmp when asked to use them, and with
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** longjmp/setjmp otherwise.
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*/
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#if !defined(LUAI_THROW) /* { */
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#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */
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/* C++ exceptions */
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#define LUAI_THROW(L,c) throw(c)
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#define LUAI_TRY(L,c,a) \
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try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; }
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#define luai_jmpbuf int /* dummy variable */
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#elif defined(LUA_USE_POSIX) /* }{ */
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/* in POSIX, try _longjmp/_setjmp (more efficient) */
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#define LUAI_THROW(L,c) _longjmp((c)->b, 1)
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#define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a }
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#define luai_jmpbuf jmp_buf
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#else /* }{ */
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/* ISO C handling with long jumps */
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#define LUAI_THROW(L,c) longjmp((c)->b, 1)
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#define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a }
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#define luai_jmpbuf jmp_buf
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#endif /* } */
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#endif /* } */
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namespace NS_SLUA {
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/* chain list of long jump buffers */
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struct lua_longjmp {
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struct lua_longjmp *previous;
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luai_jmpbuf b;
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volatile int status; /* error code */
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};
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static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
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switch (errcode) {
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case LUA_ERRMEM: { /* memory error? */
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setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */
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break;
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}
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case LUA_ERRERR: {
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setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
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break;
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}
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default: {
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setobjs2s(L, oldtop, L->top - 1); /* error message on current top */
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break;
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}
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}
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L->top = oldtop + 1;
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}
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l_noret luaD_throw (lua_State *L, int errcode) {
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if (L->errorJmp) { /* thread has an error handler? */
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L->errorJmp->status = errcode; /* set status */
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LUAI_THROW(L, L->errorJmp); /* jump to it */
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}
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else { /* thread has no error handler */
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global_State *g = G(L);
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L->status = cast_byte(errcode); /* mark it as dead */
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if (g->mainthread->errorJmp) { /* main thread has a handler? */
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setobjs2s(L, g->mainthread->top++, L->top - 1); /* copy error obj. */
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luaD_throw(g->mainthread, errcode); /* re-throw in main thread */
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}
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else { /* no handler at all; abort */
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if (g->panic) { /* panic function? */
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seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */
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if (L->ci->top < L->top)
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L->ci->top = L->top; /* pushing msg. can break this invariant */
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lua_unlock(L);
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g->panic(L); /* call panic function (last chance to jump out) */
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}
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abort();
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}
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}
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}
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int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
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unsigned short oldnCcalls = L->nCcalls;
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struct lua_longjmp lj;
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lj.status = LUA_OK;
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lj.previous = L->errorJmp; /* chain new error handler */
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L->errorJmp = &lj;
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LUAI_TRY(L, &lj,
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(*f)(L, ud);
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);
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L->errorJmp = lj.previous; /* restore old error handler */
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L->nCcalls = oldnCcalls;
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return lj.status;
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}
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/* }====================================================== */
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/*
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** {==================================================================
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** Stack reallocation
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** ===================================================================
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*/
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static void correctstack (lua_State *L, TValue *oldstack) {
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CallInfo *ci;
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UpVal *up;
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L->top = (L->top - oldstack) + L->stack;
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for (up = L->openupval; up != NULL; up = up->u.open.next)
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up->v = (up->v - oldstack) + L->stack;
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for (ci = L->ci; ci != NULL; ci = ci->previous) {
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ci->top = (ci->top - oldstack) + L->stack;
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ci->func = (ci->func - oldstack) + L->stack;
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if (isLua(ci))
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ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
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}
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}
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/* some space for error handling */
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#define ERRORSTACKSIZE (LUAI_MAXSTACK + 200)
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void luaD_reallocstack (lua_State *L, int newsize) {
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TValue *oldstack = L->stack;
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int lim = L->stacksize;
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lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE);
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lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK);
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luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue);
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for (; lim < newsize; lim++)
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setnilvalue(L->stack + lim); /* erase new segment */
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L->stacksize = newsize;
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L->stack_last = L->stack + newsize - EXTRA_STACK;
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correctstack(L, oldstack);
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}
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void luaD_growstack (lua_State *L, int n) {
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int size = L->stacksize;
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if (size > LUAI_MAXSTACK) /* error after extra size? */
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luaD_throw(L, LUA_ERRERR);
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else {
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int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK;
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int newsize = 2 * size;
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if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK;
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if (newsize < needed) newsize = needed;
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if (newsize > LUAI_MAXSTACK) { /* stack overflow? */
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luaD_reallocstack(L, ERRORSTACKSIZE);
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luaG_runerror(L, "stack overflow");
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}
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else
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luaD_reallocstack(L, newsize);
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}
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}
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static int stackinuse (lua_State *L) {
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CallInfo *ci;
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StkId lim = L->top;
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for (ci = L->ci; ci != NULL; ci = ci->previous) {
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if (lim < ci->top) lim = ci->top;
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}
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lua_assert(lim <= L->stack_last);
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return cast_int(lim - L->stack) + 1; /* part of stack in use */
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}
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void luaD_shrinkstack (lua_State *L) {
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int inuse = stackinuse(L);
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int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
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if (goodsize > LUAI_MAXSTACK)
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goodsize = LUAI_MAXSTACK; /* respect stack limit */
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if (L->stacksize > LUAI_MAXSTACK) /* had been handling stack overflow? */
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luaE_freeCI(L); /* free all CIs (list grew because of an error) */
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else
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luaE_shrinkCI(L); /* shrink list */
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/* if thread is currently not handling a stack overflow and its
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good size is smaller than current size, shrink its stack */
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if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
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goodsize < L->stacksize)
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luaD_reallocstack(L, goodsize);
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else /* don't change stack */
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condmovestack(L,{},{}); /* (change only for debugging) */
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}
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void luaD_inctop (lua_State *L) {
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luaD_checkstack(L, 1);
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L->top++;
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}
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/* }================================================================== */
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/*
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** Call a hook for the given event. Make sure there is a hook to be
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** called. (Both 'L->hook' and 'L->hookmask', which triggers this
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** function, can be changed asynchronously by signals.)
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*/
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void luaD_hook (lua_State *L, int event, int line) {
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lua_Hook hook = L->hook;
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if (hook && L->allowhook) { /* make sure there is a hook */
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CallInfo *ci = L->ci;
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ptrdiff_t top = savestack(L, L->top);
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ptrdiff_t ci_top = savestack(L, ci->top);
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lua_Debug ar;
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ar.event = event;
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ar.currentline = line;
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ar.i_ci = ci;
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luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
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ci->top = L->top + LUA_MINSTACK;
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lua_assert(ci->top <= L->stack_last);
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L->allowhook = 0; /* cannot call hooks inside a hook */
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ci->callstatus |= CIST_HOOKED;
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lua_unlock(L);
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(*hook)(L, &ar);
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lua_lock(L);
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lua_assert(!L->allowhook);
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L->allowhook = 1;
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ci->top = restorestack(L, ci_top);
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L->top = restorestack(L, top);
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ci->callstatus &= ~CIST_HOOKED;
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}
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}
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static void callhook (lua_State *L, CallInfo *ci) {
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int hook = LUA_HOOKCALL;
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ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
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if (isLua(ci->previous) &&
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GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
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ci->callstatus |= CIST_TAIL;
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hook = LUA_HOOKTAILCALL;
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}
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luaD_hook(L, hook, -1);
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ci->u.l.savedpc--; /* correct 'pc' */
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}
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static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
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int i;
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int nfixargs = p->numparams;
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StkId base, fixed;
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/* move fixed parameters to final position */
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fixed = L->top - actual; /* first fixed argument */
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base = L->top; /* final position of first argument */
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for (i = 0; i < nfixargs && i < actual; i++) {
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setobjs2s(L, L->top++, fixed + i);
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setnilvalue(fixed + i); /* erase original copy (for GC) */
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}
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for (; i < nfixargs; i++)
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setnilvalue(L->top++); /* complete missing arguments */
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return base;
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}
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/*
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** Check whether __call metafield of 'func' is a function. If so, put
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** it in stack below original 'func' so that 'luaD_precall' can call
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** it. Raise an error if __call metafield is not a function.
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*/
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static void tryfuncTM (lua_State *L, StkId func) {
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const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL);
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StkId p;
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if (!ttisfunction(tm))
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luaG_typeerror(L, func, "call");
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/* Open a hole inside the stack at 'func' */
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for (p = L->top; p > func; p--)
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setobjs2s(L, p, p-1);
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L->top++; /* slot ensured by caller */
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setobj2s(L, func, tm); /* tag method is the new function to be called */
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}
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/*
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** Given 'nres' results at 'firstResult', move 'wanted' of them to 'res'.
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** Handle most typical cases (zero results for commands, one result for
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** expressions, multiple results for tail calls/single parameters)
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** separated.
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*/
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static int moveresults (lua_State *L, const TValue *firstResult, StkId res,
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int nres, int wanted) {
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switch (wanted) { /* handle typical cases separately */
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case 0: break; /* nothing to move */
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case 1: { /* one result needed */
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if (nres == 0) /* no results? */
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firstResult = luaO_nilobject; /* adjust with nil */
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setobjs2s(L, res, firstResult); /* move it to proper place */
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break;
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}
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case LUA_MULTRET: {
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int i;
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for (i = 0; i < nres; i++) /* move all results to correct place */
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setobjs2s(L, res + i, firstResult + i);
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L->top = res + nres;
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return 0; /* wanted == LUA_MULTRET */
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}
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default: {
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int i;
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if (wanted <= nres) { /* enough results? */
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for (i = 0; i < wanted; i++) /* move wanted results to correct place */
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setobjs2s(L, res + i, firstResult + i);
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}
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else { /* not enough results; use all of them plus nils */
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for (i = 0; i < nres; i++) /* move all results to correct place */
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setobjs2s(L, res + i, firstResult + i);
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for (; i < wanted; i++) /* complete wanted number of results */
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setnilvalue(res + i);
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}
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break;
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}
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}
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L->top = res + wanted; /* top points after the last result */
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return 1;
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}
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/*
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** Finishes a function call: calls hook if necessary, removes CallInfo,
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** moves current number of results to proper place; returns 0 iff call
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** wanted multiple (variable number of) results.
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*/
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int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
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StkId res;
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int wanted = ci->nresults;
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if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
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if (L->hookmask & LUA_MASKRET) {
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ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
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luaD_hook(L, LUA_HOOKRET, -1);
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firstResult = restorestack(L, fr);
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}
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L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
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}
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res = ci->func; /* res == final position of 1st result */
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L->ci = ci->previous; /* back to caller */
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/* move results to proper place */
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return moveresults(L, firstResult, res, nres, wanted);
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}
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#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
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/* macro to check stack size, preserving 'p' */
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#define checkstackp(L,n,p) \
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luaD_checkstackaux(L, n, \
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ptrdiff_t t__ = savestack(L, p); /* save 'p' */ \
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luaC_checkGC(L), /* stack grow uses memory */ \
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p = restorestack(L, t__)) /* 'pos' part: restore 'p' */
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/*
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** Prepares a function call: checks the stack, creates a new CallInfo
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** entry, fills in the relevant information, calls hook if needed.
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** If function is a C function, does the call, too. (Otherwise, leave
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** the execution ('luaV_execute') to the caller, to allow stackless
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** calls.) Returns true iff function has been executed (C function).
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*/
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int luaD_precall (lua_State *L, StkId func, int nresults) {
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lua_CFunction f;
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CallInfo *ci;
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switch (ttype(func)) {
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case LUA_TCCL: /* C closure */
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f = clCvalue(func)->f;
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goto Cfunc;
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case LUA_TLCF: /* light C function */
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f = fvalue(func);
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Cfunc: {
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int n; /* number of returns */
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checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
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ci = next_ci(L); /* now 'enter' new function */
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ci->nresults = nresults;
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ci->func = func;
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ci->top = L->top + LUA_MINSTACK;
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lua_assert(ci->top <= L->stack_last);
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ci->callstatus = 0;
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if (L->hookmask & LUA_MASKCALL)
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luaD_hook(L, LUA_HOOKCALL, -1);
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lua_unlock(L);
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n = (*f)(L); /* do the actual call */
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lua_lock(L);
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api_checknelems(L, n);
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luaD_poscall(L, ci, L->top - n, n);
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return 1;
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}
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case LUA_TLCL: { /* Lua function: prepare its call */
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StkId base;
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Proto *p = clLvalue(func)->p;
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int n = cast_int(L->top - func) - 1; /* number of real arguments */
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int fsize = p->maxstacksize; /* frame size */
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checkstackp(L, fsize, func);
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if (p->is_vararg)
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base = adjust_varargs(L, p, n);
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else { /* non vararg function */
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for (; n < p->numparams; n++)
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setnilvalue(L->top++); /* complete missing arguments */
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base = func + 1;
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}
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ci = next_ci(L); /* now 'enter' new function */
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ci->nresults = nresults;
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ci->func = func;
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ci->u.l.base = base;
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L->top = ci->top = base + fsize;
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lua_assert(ci->top <= L->stack_last);
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ci->u.l.savedpc = p->code; /* starting point */
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ci->callstatus = CIST_LUA;
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if (L->hookmask & LUA_MASKCALL)
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callhook(L, ci);
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return 0;
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}
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default: { /* not a function */
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checkstackp(L, 1, func); /* ensure space for metamethod */
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tryfuncTM(L, func); /* try to get '__call' metamethod */
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return luaD_precall(L, func, nresults); /* now it must be a function */
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}
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}
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}
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/*
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** Check appropriate error for stack overflow ("regular" overflow or
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** overflow while handling stack overflow). If 'nCalls' is larger than
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** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
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** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
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** allow overflow handling to work)
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|
*/
|
|
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
|
|
*/
|
|
void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
|
|
L->nny++;
|
|
luaD_call(L, func, nResults);
|
|
L->nny--;
|
|
}
|
|
|
|
|
|
/*
|
|
** Completes the execution of an interrupted C function, calling its
|
|
** continuation function.
|
|
*/
|
|
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' */
|
|
}
|
|
|
|
|
|
/*
|
|
** 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).
|
|
*/
|
|
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 */
|
|
else { /* Lua function */
|
|
luaV_finishOp(L); /* finish interrupted instruction */
|
|
luaV_execute(L); /* execute down to higher C 'boundary' */
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
** Try to find a suspended protected call (a "recover point") for the
|
|
** given thread.
|
|
*/
|
|
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 */
|
|
}
|
|
|
|
|
|
/*
|
|
** 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.)
|
|
*/
|
|
static int resume_error (lua_State *L, const char *msg, int narg) {
|
|
L->top -= narg; /* remove args from the stack */
|
|
setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */
|
|
api_incr_top(L);
|
|
lua_unlock(L);
|
|
return LUA_ERRRUN;
|
|
}
|
|
|
|
|
|
/*
|
|
** Do the work for 'lua_resume' in protected mode. Most of the work
|
|
** depends on the status of the coroutine: initial state, suspended
|
|
** inside a hook, or regularly suspended (optionally with a continuation
|
|
** function), plus erroneous cases: non-suspended coroutine or dead
|
|
** coroutine.
|
|
*/
|
|
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 */
|
|
}
|
|
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 */
|
|
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' */
|
|
}
|
|
unroll(L, NULL); /* run continuation */
|
|
}
|
|
}
|
|
|
|
|
|
LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
|
|
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->status != LUA_YIELD)
|
|
return resume_error(L, "cannot resume dead coroutine", nargs);
|
|
L->nCcalls = (from) ? from->nCcalls + 1 : 1;
|
|
if (L->nCcalls >= LUAI_MAXCCALLS)
|
|
return resume_error(L, "C stack overflow", nargs);
|
|
luai_userstateresume(L, nargs);
|
|
L->nny = 0; /* allow yields */
|
|
api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
|
|
status = luaD_rawrunprotected(L, resume, &nargs);
|
|
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 */
|
|
}
|
|
L->nny = oldnny; /* restore 'nny' */
|
|
L->nCcalls--;
|
|
lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
|
|
lua_unlock(L);
|
|
return status;
|
|
}
|
|
|
|
|
|
LUA_API int lua_isyieldable (lua_State *L) {
|
|
return (L->nny == 0);
|
|
}
|
|
|
|
|
|
LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
|
|
lua_KFunction 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 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? */
|
|
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 '%s')", x, mode);
|
|
luaD_throw(L, LUA_ERRSYNTAX);
|
|
}
|
|
}
|
|
|
|
|
|
static void f_parser (lua_State *L, void *ud) {
|
|
LClosure *cl;
|
|
struct SParser *p = cast(struct SParser *, ud);
|
|
if (L->onlyluac == 0) {
|
|
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->name);
|
|
} else {
|
|
checkmode(L, p->mode, "text");
|
|
cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
|
|
}
|
|
} else {
|
|
checkmode(L, p->mode, "binary");
|
|
cl = luaU_undump(L, p->z, p->name);
|
|
}
|
|
lua_assert(cl->nupvalues == cl->p->sizeupvalues);
|
|
luaF_initupvals(L, cl);
|
|
}
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
} // end NS_SLUA
|