commit 196c87c9cecfacf978f37de4ec69eba0a5971256
parent 39f26b1480502cc2f75a5af6e06e5410e06634ba
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Thu, 23 Nov 2017 14:40:49 -0200
no more 'stackless' implementation; 'luaV_execute' calls itself
recursively to execute function calls. 'unroll' continues all
executions suspended by an yield (through a long jump)
Diffstat:
M | ldebug.c | | | 3 | ++- |
M | ldo.c | | | 66 | ++++++++++++++++++------------------------------------------------ |
M | ldo.h | | | 3 | +-- |
M | llimits.h | | | 7 | ++++--- |
M | lparser.c | | | 12 | ++++-------- |
M | lstate.c | | | 28 | ++++++++++++++++++++++++++-- |
M | lstate.h | | | 17 | ++++++++--------- |
M | ltests.h | | | 6 | +++++- |
M | lvm.c | | | 60 | ++++++++++++++++++++++-------------------------------------- |
9 files changed, 90 insertions(+), 112 deletions(-)
diff --git a/ldebug.c b/ldebug.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldebug.c,v 2.143 2017/11/13 12:20:51 roberto Exp roberto $
+** $Id: ldebug.c,v 2.144 2017/11/13 15:36:52 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@@ -724,6 +724,7 @@ l_noret luaG_errormsg (lua_State *L) {
setobjs2s(L, L->top, L->top - 1); /* move argument */
setobjs2s(L, L->top - 1, errfunc); /* push function */
L->top++; /* assume EXTRA_STACK */
+ luaE_incCcalls(L);
luaD_callnoyield(L, L->top - 2, 1); /* call it */
}
luaD_throw(L, LUA_ERRRUN);
diff --git a/ldo.c b/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.172 2017/11/13 15:36:52 roberto Exp roberto $
+** $Id: ldo.c,v 2.173 2017/11/21 14:17:35 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -135,7 +135,7 @@ l_noret luaD_throw (lua_State *L, int errcode) {
int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
- unsigned short oldnCcalls = L->nCcalls;
+ unsigned short oldnCcalls = L->nCcalls - L->nci;
struct lua_longjmp lj;
lj.status = LUA_OK;
lj.previous = L->errorJmp; /* chain new error handler */
@@ -144,7 +144,7 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
(*f)(L, ud);
);
L->errorJmp = lj.previous; /* restore old error handler */
- L->nCcalls = oldnCcalls;
+ L->nCcalls = oldnCcalls + L->nci;
return lj.status;
}
@@ -299,7 +299,7 @@ static void callhook (lua_State *L, CallInfo *ci, int istail) {
/*
** Check whether __call metafield of 'func' is a function. If so, put
-** it in stack below original 'func' so that 'luaD_precall' can call
+** it in stack below original 'func' so that 'luaD_call' can call
** it. Raise an error if __call metafield is not a function.
*/
StkId luaD_tryfuncTM (lua_State *L, StkId func) {
@@ -417,13 +417,12 @@ void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int n) {
/*
-** Prepares a function call: checks the stack, creates a new CallInfo
-** entry, fills in the relevant information, calls hook if needed.
-** If function is a C function, does the call, too. (Otherwise, leave
-** the execution ('luaV_execute') to the caller, to allow stackless
-** calls.) Returns true iff function has been executed (C function).
+** 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.
*/
-int luaD_precall (lua_State *L, StkId func, int nresults) {
+void luaD_call (lua_State *L, StkId func, int nresults) {
lua_CFunction f;
TValue *funcv = s2v(func);
CallInfo *ci;
@@ -449,7 +448,7 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
lua_lock(L);
api_checknelems(L, n);
luaD_poscall(L, ci, L->top - n, n);
- return 1;
+ break;
}
case LUA_TLCL: { /* Lua function: prepare its call */
Proto *p = clLvalue(funcv)->p;
@@ -469,47 +468,19 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
ci->callstatus = CIST_LUA;
if (L->hookmask)
callhook(L, ci, 0);
- return 0;
+ luaV_execute(L); /* run the function */
+ break;
}
default: { /* not a function */
func = luaD_tryfuncTM(L, func); /* try to get '__call' metamethod */
- return luaD_precall(L, func, nresults); /* now it must be a function */
+ luaD_call(L, func, nresults); /* now it must be a function */
+ break;
}
}
}
/*
-** Check appropriate error for stack overflow ("regular" overflow or
-** overflow while handling stack overflow). If 'nCalls' is larger than
-** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
-** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
-** allow overflow handling to work)
-*/
-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) {
@@ -541,7 +512,7 @@ static void finishCcall (lua_State *L, int status) {
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' */
+ luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_call' */
}
@@ -629,8 +600,7 @@ static void resume (lua_State *L, void *ud) {
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 */
+ luaD_call(L, firstArg - 1, LUA_MULTRET);
}
else { /* resuming from previous yield */
lua_assert(L->status == LUA_YIELD);
@@ -645,7 +615,7 @@ static void resume (lua_State *L, void *ud) {
api_checknelems(L, n);
firstArg = L->top - n; /* yield results come from continuation */
}
- luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_precall' */
+ luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_call' */
}
unroll(L, NULL); /* run continuation */
}
@@ -688,7 +658,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
: L->top - (L->ci->func + 1);
L->nny = oldnny; /* restore 'nny' */
L->nCcalls--;
- lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
+ // lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
lua_unlock(L);
return status;
}
diff --git a/ldo.h b/ldo.h
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.h,v 2.33 2017/11/07 13:25:26 roberto Exp roberto $
+** $Id: ldo.h,v 2.34 2017/11/21 14:18:03 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -47,7 +47,6 @@ typedef void (*Pfunc) (lua_State *L, void *ud);
LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
const char *mode);
LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
-LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
LUAI_FUNC void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int n);
LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
diff --git a/llimits.h b/llimits.h
@@ -1,5 +1,5 @@
/*
-** $Id: llimits.h,v 1.143 2017/06/01 19:16:34 roberto Exp roberto $
+** $Id: llimits.h,v 1.144 2017/06/27 11:35:01 roberto Exp roberto $
** Limits, basic types, and some other 'installation-dependent' definitions
** See Copyright Notice in lua.h
*/
@@ -140,10 +140,11 @@ typedef LUAI_UACINT l_uacInt;
/*
** maximum depth for nested C calls and syntactical nested non-terminals
-** in a program. (Value must fit in an unsigned short int.)
+** in a program. (Value must fit in an unsigned short int. It must also
+** be compatible with the size of the C stack.)
*/
#if !defined(LUAI_MAXCCALLS)
-#define LUAI_MAXCCALLS 200
+#define LUAI_MAXCCALLS 1000
#endif
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 2.166 2017/09/28 16:53:29 roberto Exp roberto $
+** $Id: lparser.c,v 2.167 2017/10/04 21:53:03 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -330,11 +330,7 @@ static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
}
-static void enterlevel (LexState *ls) {
- lua_State *L = ls->L;
- ++L->nCcalls;
- checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels");
-}
+#define enterlevel(ls) luaE_incCcalls((ls)->L)
#define leavelevel(ls) ((ls)->L->nCcalls--)
@@ -1188,9 +1184,9 @@ static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
suffixedexp(ls, &nv.v);
if (!vkisindexed(nv.v.k))
check_conflict(ls, lh, &nv.v);
- checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS,
- "C levels");
+ luaE_incCcalls(ls->L); /* control recursion depth */
assignment(ls, &nv, nvars+1);
+ ls->L->nCcalls--;
}
else { /* assignment -> '=' explist */
int nexps;
diff --git a/lstate.c b/lstate.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.c,v 2.146 2017/11/07 13:25:26 roberto Exp roberto $
+** $Id: lstate.c,v 2.147 2017/11/13 15:36:52 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -97,8 +97,28 @@ void luaE_setdebt (global_State *g, l_mem debt) {
}
+/*
+** Increment count of "C calls" and check for overflows. In case of
+** a stack overflow, check appropriate error ("regular" overflow or
+** overflow while handling stack overflow). If 'nCalls' is larger than
+** LUAI_MAXCCALLS (which means it is handling a "regular" overflow) but
+** smaller than 9/8 of LUAI_MAXCCALLS, does not report an error (to
+** allow overflow handling to work)
+*/
+void luaE_incCcalls (lua_State *L) {
+ 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 */
+ }
+}
+
+
CallInfo *luaE_extendCI (lua_State *L) {
- CallInfo *ci = luaM_new(L, CallInfo);
+ CallInfo *ci;
+ luaE_incCcalls(L);
+ ci = luaM_new(L, CallInfo);
lua_assert(L->ci->next == NULL);
L->ci->next = ci;
ci->previous = L->ci;
@@ -116,11 +136,13 @@ void luaE_freeCI (lua_State *L) {
CallInfo *ci = L->ci;
CallInfo *next = ci->next;
ci->next = NULL;
+ L->nCcalls -= L->nci; /* to subtract removed elements from 'nCcalls' */
while ((ci = next) != NULL) {
next = ci->next;
luaM_free(L, ci);
L->nci--;
}
+ L->nCcalls += L->nci; /* to subtract removed elements from 'nCcalls' */
}
@@ -130,6 +152,7 @@ void luaE_freeCI (lua_State *L) {
void luaE_shrinkCI (lua_State *L) {
CallInfo *ci = L->ci;
CallInfo *next2; /* next's next */
+ L->nCcalls -= L->nci; /* to subtract removed elements from 'nCcalls' */
/* while there are two nexts */
while (ci->next != NULL && (next2 = ci->next->next) != NULL) {
luaM_free(L, ci->next); /* free next */
@@ -138,6 +161,7 @@ void luaE_shrinkCI (lua_State *L) {
next2->previous = ci;
ci = next2; /* keep next's next */
}
+ L->nCcalls += L->nci; /* to subtract removed elements from 'nCcalls' */
}
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 2.150 2017/11/07 13:25:26 roberto Exp roberto $
+** $Id: lstate.h,v 2.151 2017/11/13 15:36:52 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -104,7 +104,7 @@ typedef struct CallInfo {
int nyield; /* number of values yielded */
} u2;
short nresults; /* expected number of results from this function */
- unsigned short callstatus;
+ lu_byte callstatus;
} CallInfo;
@@ -114,13 +114,11 @@ typedef struct CallInfo {
#define CIST_OAH (1<<0) /* original value of 'allowhook' */
#define CIST_LUA (1<<1) /* call is running a Lua function */
#define CIST_HOOKED (1<<2) /* call is running a debug hook */
-#define CIST_FRESH (1<<3) /* call is running on a fresh invocation
- of luaV_execute */
-#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */
-#define CIST_TAIL (1<<5) /* call was tail called */
-#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */
-#define CIST_LEQ (1<<7) /* using __lt for __le */
-#define CIST_FIN (1<<8) /* call is running a finalizer */
+#define CIST_YPCALL (1<<3) /* call is a yieldable protected call */
+#define CIST_TAIL (1<<4) /* call was tail called */
+#define CIST_HOOKYIELD (1<<5) /* last hook called yielded */
+#define CIST_LEQ (1<<6) /* using __lt for __le */
+#define CIST_FIN (1<<7) /* call is running a finalizer */
#define isLua(ci) ((ci)->callstatus & CIST_LUA)
@@ -256,6 +254,7 @@ LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
LUAI_FUNC void luaE_freeCI (lua_State *L);
LUAI_FUNC void luaE_shrinkCI (lua_State *L);
+LUAI_FUNC void luaE_incCcalls (lua_State *L);
#endif
diff --git a/ltests.h b/ltests.h
@@ -1,5 +1,5 @@
/*
-** $Id: ltests.h,v 2.51 2017/06/27 11:35:31 roberto Exp roberto $
+** $Id: ltests.h,v 2.52 2017/11/13 12:19:35 roberto Exp roberto $
** Internal Header for Debugging of the Lua Implementation
** See Copyright Notice in lua.h
*/
@@ -34,6 +34,10 @@
#define lua_assert(c) assert(c)
+/* compiled with -O0, Lua uses a lot of C stack space... */
+#undef LUAI_MAXCCALLS
+#define LUAI_MAXCCALLS 300
+
/* to avoid warnings, and to make sure value is really unused */
#define UNUSED(x) (x=0, (void)(x))
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,9 @@
/*
-** $Id: lvm.c,v 2.314 2017/11/22 18:41:20 roberto Exp roberto $
+<<<<<<< lvm.c
+** $Id: lvm.c,v 2.313 2017/11/21 14:17:35 roberto Exp roberto $
+=======
+** $Id: lvm.c,v 2.315 2017/11/22 19:15:44 roberto Exp $
+>>>>>>> 2.315
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -829,20 +833,12 @@ void luaV_finishOp (lua_State *L) {
void luaV_execute (lua_State *L) {
- CallInfo *ci = L->ci; /* local copy of 'L->ci' */
- LClosure *cl;
- TValue *k;
- StkId base; /* local copy of 'ci->func + 1' */
- int trap;
- const Instruction *pc; /* local copy of 'ci->u.l.savedpc' */
- ci->callstatus |= CIST_FRESH; /* fresh invocation of 'luaV_execute" */
- newframe: /* reentry point when frame changes (call/return) */
- lua_assert(ci == L->ci);
- cl = clLvalue(s2v(ci->func)); /* local reference to function's closure */
- k = cl->p->k; /* local reference to function's constant table */
- updatetrap(ci);
- updatebase(ci);
- pc = ci->u.l.savedpc;
+ CallInfo *ci = L->ci;
+ LClosure *cl = clLvalue(s2v(ci->func));
+ TValue *k = cl->p->k;
+ StkId base = ci->func + 1;
+ int trap = ci->u.l.trap;
+ const Instruction *pc = ci->u.l.savedpc;
/* main loop of interpreter */
for (;;) {
Instruction i;
@@ -1418,20 +1414,13 @@ void luaV_execute (lua_State *L) {
vmcase(OP_CALL) {
int b = GETARG_B(i);
int nresults = GETARG_C(i) - 1;
- int isC;
if (b != 0) /* fixed number of arguments? */
L->top = ra + b; /* top signals number of arguments */
/* else previous instruction set top */
- Protect(isC = luaD_precall(L, ra, nresults));
- if (isC) { /* C function? */
- if (nresults >= 0) /* fixed number of results? */
- L->top = ci->top; /* correct top */
- /* else leave top for next instruction */
- }
- else { /* Lua function */
- ci = L->ci;
- goto newframe; /* restart luaV_execute over new Lua function */
- }
+ Protect(luaD_call(L, ra, nresults));
+ if (nresults >= 0) /* fixed number of results? */
+ L->top = ci->top; /* correct top */
+ /* else leave top for next instruction */
vmbreak;
}
vmcase(OP_TAILCALL) {
@@ -1447,12 +1436,15 @@ void luaV_execute (lua_State *L) {
b++; /* there is now one extra argument */
}
if (!ttisLclosure(s2v(ra))) /* C function? */
- Protect(luaD_precall(L, ra, LUA_MULTRET)); /* call it */
+ Protect(luaD_call(L, ra, LUA_MULTRET)); /* call it */
else { /* tail call */
if (cl->p->sizep > 0) /* close upvalues from previous call */
luaF_close(L, ci->func + 1);
luaD_pretailcall(L, ci, ra, b); /* prepare call frame */
- goto newframe; /* restart luaV_execute over new Lua function */
+ cl = clLvalue(s2v(ci->func));
+ k = cl->p->k;
+ updatebase(ci);
+ pc = ci->u.l.savedpc;
}
vmbreak;
}
@@ -1461,16 +1453,8 @@ void luaV_execute (lua_State *L) {
if (cl->p->sizep > 0)
luaF_close(L, base);
savepc(L);
- b = luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
- if (ci->callstatus & CIST_FRESH) /* local 'ci' still from callee */
- return; /* external invocation: return */
- else { /* invocation via reentry: continue execution */
- ci = L->ci;
- if (b) L->top = ci->top;
- lua_assert(isLua(ci));
- lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
- goto newframe; /* restart luaV_execute over new Lua function */
- }
+ luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
+ return; /* external invocation: return */
}
vmcase(OP_FORLOOP) {
if (ttisinteger(s2v(ra))) { /* integer loop? */