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-rw-r--r--lua/ldo.c652
1 files changed, 402 insertions, 250 deletions
diff --git a/lua/ldo.c b/lua/ldo.c
index 8de05f7..26f9a67 100644
--- a/lua/ldo.c
+++ b/lua/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.38.1.3 2008/01/18 22:31:22 roberto Exp $
+** $Id: ldo.c,v 2.102 2011/11/29 15:55:08 roberto Exp $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -14,6 +14,7 @@
#include "lua.h"
+#include "lapi.h"
#include "ldebug.h"
#include "ldo.h"
#include "lfunc.h"
@@ -39,6 +40,38 @@
** =======================================================
*/
+/*
+** 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 {
@@ -48,18 +81,17 @@ struct lua_longjmp {
};
-void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
+static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
switch (errcode) {
- case LUA_ERRMEM: {
- setsvalue2s(L, oldtop, luaS_newliteral(L, MEMERRMSG));
+ 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;
}
- case LUA_ERRSYNTAX:
- case LUA_ERRRUN: {
+ default: {
setobjs2s(L, oldtop, L->top - 1); /* error message on current top */
break;
}
@@ -68,55 +100,39 @@ void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
}
-static void restore_stack_limit (lua_State *L) {
- lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK - 1);
- if (L->size_ci > LUAI_MAXCALLS) { /* there was an overflow? */
- int inuse = cast_int(L->ci - L->base_ci);
- if (inuse + 1 < LUAI_MAXCALLS) /* can `undo' overflow? */
- luaD_reallocCI(L, LUAI_MAXCALLS);
+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 */
}
-}
-
-
-static void resetstack (lua_State *L, int status) {
- L->ci = L->base_ci;
- L->base = L->ci->base;
- luaF_close(L, L->base); /* close eventual pending closures */
- luaD_seterrorobj(L, status, L->base);
- L->nCcalls = L->baseCcalls;
- L->allowhook = 1;
- restore_stack_limit(L);
- L->errfunc = 0;
- L->errorJmp = NULL;
-}
-
-
-void luaD_throw (lua_State *L, int errcode) {
- if (L->errorJmp) {
- L->errorJmp->status = errcode;
- LUAI_THROW(L, L->errorJmp);
- }
- else {
- L->status = cast_byte(errcode);
- if (G(L)->panic) {
- resetstack(L, errcode);
- lua_unlock(L);
- G(L)->panic(L);
+ 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();
}
- exit(EXIT_FAILURE);
}
}
int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
+ unsigned short oldnCcalls = L->nCcalls;
struct lua_longjmp lj;
- lj.status = 0;
+ 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;
}
@@ -129,112 +145,126 @@ static void correctstack (lua_State *L, TValue *oldstack) {
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->base_ci; ci <= L->ci; ci++) {
+ for (ci = L->ci; ci != NULL; ci = ci->previous) {
ci->top = (ci->top - oldstack) + L->stack;
- ci->base = (ci->base - oldstack) + L->stack;
ci->func = (ci->func - oldstack) + L->stack;
+ if (isLua(ci))
+ ci->u.l.base = (ci->u.l.base - oldstack) + L->stack;
}
- L->base = (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 realsize = newsize + 1 + EXTRA_STACK;
- lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK - 1);
- luaM_reallocvector(L, L->stack, L->stacksize, realsize, TValue);
- L->stacksize = realsize;
- L->stack_last = L->stack+newsize;
+ 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_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 = newsize;
- L->ci = (L->ci - oldci) + L->base_ci;
- L->end_ci = L->base_ci + L->size_ci - 1;
+void luaD_growstack (lua_State *L, int n) {
+ int size = L->stacksize;
+ if (size > LUAI_MAXSTACK) /* error after extra size? */
+ luaD_throw(L, LUA_ERRERR);
+ 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);
+ }
}
-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);
+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 */
}
-static CallInfo *growCI (lua_State *L) {
- if (L->size_ci > LUAI_MAXCALLS) /* overflow while handling overflow? */
- luaD_throw(L, LUA_ERRERR);
- else {
- luaD_reallocCI(L, 2*L->size_ci);
- if (L->size_ci > LUAI_MAXCALLS)
- luaG_runerror(L, "stack overflow");
- }
- return ++L->ci;
+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_callhook (lua_State *L, int event, int line) {
+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, L->ci->top);
+ ptrdiff_t ci_top = savestack(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 = cast_int(L->ci - L->base_ci);
+ ar.i_ci = ci;
luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
- L->ci->top = L->top + LUA_MINSTACK;
- lua_assert(L->ci->top <= L->stack_last);
+ 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;
- L->ci->top = restorestack(L, ci_top);
+ 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;
- Table *htab = NULL;
StkId base, fixed;
- for (; actual < nfixargs; ++actual)
- setnilvalue(L->top++);
-#if defined(LUA_COMPAT_VARARG)
- if (p->is_vararg & VARARG_NEEDSARG) { /* compat. with old-style vararg? */
- int nvar = actual - nfixargs; /* number of extra arguments */
- lua_assert(p->is_vararg & VARARG_HASARG);
- luaC_checkGC(L);
- htab = luaH_new(L, nvar, 1); /* create `arg' table */
- for (i=0; i<nvar; i++) /* put extra arguments into `arg' table */
- setobj2n(L, luaH_setnum(L, htab, i+1), L->top - nvar + i);
- /* store counter in field `n' */
- setnvalue(luaH_setstr(L, htab, luaS_newliteral(L, "n")), cast_num(nvar));
- }
-#endif
+ 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);
- }
- /* add `arg' parameter */
- if (htab) {
- sethvalue(L, L->top++, htab);
- lua_assert(iswhite(obj2gco(htab)));
+ setobjs2s(L, L->top++, fixed + i);
+ setnilvalue(fixed + i);
}
return base;
}
@@ -256,100 +286,85 @@ static StkId tryfuncTM (lua_State *L, StkId func) {
-#define inc_ci(L) \
- ((L->ci == L->end_ci) ? growCI(L) : \
- (condhardstacktests(luaD_reallocCI(L, L->size_ci)), ++L->ci))
+#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) {
- LClosure *cl;
- ptrdiff_t funcr;
- if (!ttisfunction(func)) /* `func' is not a function? */
- func = tryfuncTM(L, func); /* check the `function' tag method */
- funcr = savestack(L, func);
- cl = &clvalue(func)->l;
- L->ci->savedpc = L->savedpc;
- if (!cl->isC) { /* Lua function? prepare its call */
- CallInfo *ci;
- StkId st, base;
- Proto *p = cl->p;
- luaD_checkstack(L, p->maxstacksize);
- func = restorestack(L, funcr);
- if (!p->is_vararg) { /* no varargs? */
- base = func + 1;
- if (L->top > base + p->numparams)
- L->top = base + p->numparams;
- }
- else { /* vararg function */
- int nargs = cast_int(L->top - func) - 1;
- base = adjust_varargs(L, p, nargs);
- func = restorestack(L, funcr); /* previous call may change the stack */
+ 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;
}
- ci = inc_ci(L); /* now `enter' new function */
- ci->func = func;
- L->base = ci->base = base;
- ci->top = L->base + p->maxstacksize;
- lua_assert(ci->top <= L->stack_last);
- L->savedpc = p->code; /* starting point */
- ci->tailcalls = 0;
- ci->nresults = nresults;
- for (st = L->top; st < ci->top; st++)
- setnilvalue(st);
- L->top = ci->top;
- if (L->hookmask & LUA_MASKCALL) {
- L->savedpc++; /* hooks assume 'pc' is already incremented */
- luaD_callhook(L, LUA_HOOKCALL, -1);
- L->savedpc--; /* correct 'pc' */
+ 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;
}
- return PCRLUA;
- }
- else { /* if is a C function, call it */
- CallInfo *ci;
- int n;
- luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
- ci = inc_ci(L); /* now `enter' new function */
- ci->func = restorestack(L, funcr);
- L->base = ci->base = ci->func + 1;
- ci->top = L->top + LUA_MINSTACK;
- lua_assert(ci->top <= L->stack_last);
- ci->nresults = nresults;
- if (L->hookmask & LUA_MASKCALL)
- luaD_callhook(L, LUA_HOOKCALL, -1);
- lua_unlock(L);
- n = (*curr_func(L)->c.f)(L); /* do the actual call */
- lua_lock(L);
- if (n < 0) /* yielding? */
- return PCRYIELD;
- else {
- luaD_poscall(L, L->top - n);
- return PCRC;
+ 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 */
}
}
}
-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 (f_isLua(L->ci)) { /* Lua function? */
- while ((L->hookmask & LUA_MASKRET) && L->ci->tailcalls--) /* tail calls */
- luaD_callhook(L, LUA_HOOKTAILRET, -1);
- }
- return restorestack(L, fr);
-}
-
-
int luaD_poscall (lua_State *L, StkId firstResult) {
StkId res;
int wanted, i;
- CallInfo *ci;
- if (L->hookmask & LUA_MASKRET)
- firstResult = callrethooks(L, firstResult);
- ci = L->ci--;
+ 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->base = (ci - 1)->base; /* restore base */
- L->savedpc = (ci - 1)->savedpc; /* restore savedpc */
+ 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++);
@@ -365,112 +380,223 @@ int luaD_poscall (lua_State *L, StkId firstResult) {
** 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) {
+*/
+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 (luaD_precall(L, func, nResults) == PCRLUA) /* is a Lua function? */
- luaV_execute(L, 1); /* call it */
+ 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 resume (lua_State *L, void *ud) {
- StkId firstArg = cast(StkId, ud);
+static void finishCcall (lua_State *L) {
CallInfo *ci = L->ci;
- if (L->status == 0) { /* start coroutine? */
- lua_assert(ci == L->base_ci && firstArg > L->base);
- if (luaD_precall(L, firstArg - 1, LUA_MULTRET) != PCRLUA)
- return;
- }
- else { /* resuming from previous yield */
- lua_assert(L->status == LUA_YIELD);
- L->status = 0;
- if (!f_isLua(ci)) { /* `common' yield? */
- /* finish interrupted execution of `OP_CALL' */
- lua_assert(GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_CALL ||
- GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_TAILCALL);
- if (luaD_poscall(L, firstArg)) /* complete it... */
- L->top = L->ci->top; /* and correct top if not multiple results */
+ int n;
+ lua_assert(ci->u.c.k != NULL); /* must have a continuation */
+ lua_assert(L->nny == 0);
+ /* finish 'luaD_call' */
+ L->nCcalls--;
+ /* 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' */
}
- else /* yielded inside a hook: just continue its execution */
- L->base = L->ci->base;
}
- luaV_execute(L, cast_int(L->ci - L->base_ci));
}
-static int resume_error (lua_State *L, const char *msg) {
- L->top = L->ci->base;
- setsvalue2s(L, L->top, luaS_new(L, msg));
+/*
+** 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->u.c.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);
- lua_unlock(L);
- return LUA_ERRRUN;
+ luaD_throw(L, -1); /* jump back to 'lua_resume' */
}
-LUA_API int lua_resume (lua_State *L, int nargs) {
+/*
+** do the work for 'lua_resume' in protected mode
+*/
+static void resume (lua_State *L, void *ud) {
+ StkId firstArg = cast(StkId, ud);
+ CallInfo *ci = L->ci;
+ if (L->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;
+ if (isLua(ci)) /* yielded inside a hook? */
+ luaV_execute(L); /* just continue running Lua code */
+ else { /* 'common' yield */
+ ci->func = restorestack(L, ci->u.c.extra);
+ 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 */
+ }
+ L->nCcalls--; /* finish 'luaD_call' */
+ luaD_poscall(L, firstArg); /* finish 'luaD_precall' */
+ }
+ unroll(L, NULL);
+ }
+}
+
+
+LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
int status;
lua_lock(L);
- if (L->status != LUA_YIELD && (L->status != 0 || L->ci != L->base_ci))
- return resume_error(L, "cannot resume non-suspended coroutine");
- if (L->nCcalls >= LUAI_MAXCCALLS)
- return resume_error(L, "C stack overflow");
luai_userstateresume(L, nargs);
- lua_assert(L->errfunc == 0);
- L->baseCcalls = ++L->nCcalls;
+ 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 != 0) { /* error? */
- L->status = cast_byte(status); /* mark thread as `dead' */
- luaD_seterrorobj(L, status, L->top);
- L->ci->top = L->top;
- }
- else {
- lua_assert(L->nCcalls == L->baseCcalls);
- status = L->status;
+ 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->nCcalls;
+ 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_yield (lua_State *L, int nresults) {
+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);
- if (L->nCcalls > L->baseCcalls)
- luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
- L->base = L->top - nresults; /* protect stack slots below */
+ 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;
+ 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->u.c.extra = savestack(L, ci->func); /* save current 'func' */
+ 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 -1;
+ 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;
- unsigned short oldnCcalls = L->nCcalls;
- ptrdiff_t old_ci = saveci(L, L->ci);
+ 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 != 0) { /* an error occurred? */
+ if (status != LUA_OK) { /* an error occurred? */
StkId oldtop = restorestack(L, old_top);
- luaF_close(L, oldtop); /* close eventual pending closures */
- luaD_seterrorobj(L, status, oldtop);
- L->nCcalls = oldnCcalls;
- L->ci = restoreci(L, old_ci);
- L->base = L->ci->base;
- L->savedpc = L->ci->savedpc;
+ luaF_close(L, oldtop); /* close possible pending closures */
+ seterrorobj(L, status, oldtop);
+ L->ci = old_ci;
L->allowhook = old_allowhooks;
- restore_stack_limit(L);
+ L->nny = old_nny;
+ luaD_shrinkstack(L);
}
L->errfunc = old_errfunc;
return status;
@@ -483,35 +609,61 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
*/
struct SParser { /* data to `f_parser' */
ZIO *z;
- Mbuffer buff; /* buffer to be used by the scanner */
+ 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;
Proto *tf;
Closure *cl;
struct SParser *p = cast(struct SParser *, ud);
- int c = luaZ_lookahead(p->z);
- luaC_checkGC(L);
- tf = ((c == LUA_SIGNATURE[0]) ? luaU_undump : luaY_parser)(L, p->z,
- &p->buff, p->name);
- cl = luaF_newLclosure(L, tf->nups, hvalue(gt(L)));
- cl->l.p = tf;
- for (i = 0; i < tf->nups; i++) /* initialize eventual upvalues */
- cl->l.upvals[i] = luaF_newupval(L);
- setclvalue(L, L->top, cl);
+ int c = zgetc(p->z); /* read first character */
+ if (c == LUA_SIGNATURE[0]) {
+ checkmode(L, p->mode, "binary");
+ tf = luaU_undump(L, p->z, &p->buff, p->name);
+ }
+ else {
+ checkmode(L, p->mode, "text");
+ tf = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
+ }
+ setptvalue2s(L, L->top, tf);
incr_top(L);
+ cl = luaF_newLclosure(L, tf);
+ setclLvalue(L, L->top - 1, cl);
+ for (i = 0; i < tf->sizeupvalues; i++) /* initialize upvalues */
+ cl->l.upvals[i] = luaF_newupval(L);
}
-int luaD_protectedparser (lua_State *L, ZIO *z, const char *name) {
+int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
+ const char *mode) {
struct SParser p;
int status;
- p.z = z; p.name = name;
+ 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;
}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-19 10:02:09 +0000