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Diffstat (limited to 'src/lvm.c')
-rw-r--r--src/lvm.c217
1 files changed, 123 insertions, 94 deletions
diff --git a/src/lvm.c b/src/lvm.c
index a8cefc5..aba7ace 100644
--- a/src/lvm.c
+++ b/src/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.245 2015/06/09 15:53:35 roberto Exp $
+** $Id: lvm.c,v 2.265 2015/11/23 11:30:45 roberto Exp $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -153,30 +153,28 @@ static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
/*
-** Main function for table access (invoking metamethods if needed).
-** Compute 'val = t[key]'
+** Complete a table access: if 't' is a table, 'tm' has its metamethod;
+** otherwise, 'tm' is NULL.
*/
-void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
+void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
+ const TValue *tm) {
int loop; /* counter to avoid infinite loops */
+ lua_assert(tm != NULL || !ttistable(t));
for (loop = 0; loop < MAXTAGLOOP; loop++) {
- const TValue *tm;
- if (ttistable(t)) { /* 't' is a table? */
- Table *h = hvalue(t);
- const TValue *res = luaH_get(h, key); /* do a primitive get */
- if (!ttisnil(res) || /* result is not nil? */
- (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
- setobj2s(L, val, res); /* result is the raw get */
- return;
- }
- /* else will try metamethod */
+ if (tm == NULL) { /* no metamethod (from a table)? */
+ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
+ luaG_typeerror(L, t, "index"); /* no metamethod */
}
- else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
- luaG_typeerror(L, t, "index"); /* no metamethod */
if (ttisfunction(tm)) { /* metamethod is a function */
- luaT_callTM(L, tm, t, key, val, 1);
+ luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else repeat access over 'tm' */
+ if (luaV_fastget(L,t,key,tm,luaH_get)) { /* try fast track */
+ setobj2s(L, val, tm); /* done */
+ return;
+ }
+ /* else repeat */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
@@ -186,40 +184,41 @@ void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
** Main function for table assignment (invoking metamethods if needed).
** Compute 't[key] = val'
*/
-void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
+void luaV_finishset (lua_State *L, const TValue *t, TValue *key,
+ StkId val, const TValue *oldval) {
int loop; /* counter to avoid infinite loops */
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
- if (ttistable(t)) { /* 't' is a table? */
- Table *h = hvalue(t);
- TValue *oldval = cast(TValue *, luaH_get(h, key));
- /* if previous value is not nil, there must be a previous entry
- in the table; a metamethod has no relevance */
- if (!ttisnil(oldval) ||
- /* previous value is nil; must check the metamethod */
- ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
+ if (oldval != NULL) {
+ lua_assert(ttistable(t) && ttisnil(oldval));
+ /* must check the metamethod */
+ if ((tm = fasttm(L, hvalue(t)->metatable, TM_NEWINDEX)) == NULL &&
/* no metamethod; is there a previous entry in the table? */
(oldval != luaO_nilobject ||
/* no previous entry; must create one. (The next test is
always true; we only need the assignment.) */
- (oldval = luaH_newkey(L, h, key), 1)))) {
+ (oldval = luaH_newkey(L, hvalue(t), key), 1))) {
/* no metamethod and (now) there is an entry with given key */
- setobj2t(L, oldval, val); /* assign new value to that entry */
- invalidateTMcache(h);
- luaC_barrierback(L, h, val);
+ setobj2t(L, cast(TValue *, oldval), val);
+ invalidateTMcache(hvalue(t));
+ luaC_barrierback(L, hvalue(t), val);
return;
}
/* else will try the metamethod */
}
- else /* not a table; check metamethod */
+ else { /* not a table; check metamethod */
if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
+ }
/* try the metamethod */
if (ttisfunction(tm)) {
luaT_callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat assignment over 'tm' */
+ if (luaV_fastset(L, t, key, oldval, luaH_get, val))
+ return; /* done */
+ /* else loop */
}
luaG_runerror(L, "settable chain too long; possible loop");
}
@@ -443,6 +442,17 @@ int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) {
#define isemptystr(o) (ttisshrstring(o) && tsvalue(o)->shrlen == 0)
+/* copy strings in stack from top - n up to top - 1 to buffer */
+static void copy2buff (StkId top, int n, char *buff) {
+ size_t tl = 0; /* size already copied */
+ do {
+ size_t l = vslen(top - n); /* length of string being copied */
+ memcpy(buff + tl, svalue(top - n), l * sizeof(char));
+ tl += l;
+ } while (--n > 0);
+}
+
+
/*
** Main operation for concatenation: concat 'total' values in the stack,
** from 'L->top - total' up to 'L->top - 1'.
@@ -462,24 +472,24 @@ void luaV_concat (lua_State *L, int total) {
else {
/* at least two non-empty string values; get as many as possible */
size_t tl = vslen(top - 1);
- char *buffer;
- int i;
- /* collect total length */
- for (i = 1; i < total && tostring(L, top-i-1); i++) {
- size_t l = vslen(top - i - 1);
+ TString *ts;
+ /* collect total length and number of strings */
+ for (n = 1; n < total && tostring(L, top - n - 1); n++) {
+ size_t l = vslen(top - n - 1);
if (l >= (MAX_SIZE/sizeof(char)) - tl)
luaG_runerror(L, "string length overflow");
tl += l;
}
- buffer = luaZ_openspace(L, &G(L)->buff, tl);
- tl = 0;
- n = i;
- do { /* copy all strings to buffer */
- size_t l = vslen(top - i);
- memcpy(buffer+tl, svalue(top-i), l * sizeof(char));
- tl += l;
- } while (--i > 0);
- setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */
+ if (tl <= LUAI_MAXSHORTLEN) { /* is result a short string? */
+ char buff[LUAI_MAXSHORTLEN];
+ copy2buff(top, n, buff); /* copy strings to buffer */
+ ts = luaS_newlstr(L, buff, tl);
+ }
+ else { /* long string; copy strings directly to final result */
+ ts = luaS_createlngstrobj(L, tl);
+ copy2buff(top, n, getstr(ts));
+ }
+ setsvalue2s(L, top - n, ts); /* create result */
}
total -= n-1; /* got 'n' strings to create 1 new */
L->top -= n-1; /* popped 'n' strings and pushed one */
@@ -700,27 +710,20 @@ void luaV_finishOp (lua_State *L) {
** some macros for common tasks in 'luaV_execute'
*/
-#if !defined(luai_runtimecheck)
-#define luai_runtimecheck(L, c) /* void */
-#endif
-
#define RA(i) (base+GETARG_A(i))
-/* to be used after possible stack reallocation */
#define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i))
#define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i))
#define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \
ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i))
#define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \
ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i))
-#define KBx(i) \
- (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++)))
/* execute a jump instruction */
#define dojump(ci,i,e) \
{ int a = GETARG_A(i); \
- if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \
+ if (a != 0) luaF_close(L, ci->u.l.base + a - 1); \
ci->u.l.savedpc += GETARG_sBx(i) + e; }
/* for test instructions, execute the jump instruction that follows it */
@@ -730,34 +733,49 @@ void luaV_finishOp (lua_State *L) {
#define Protect(x) { {x;}; base = ci->u.l.base; }
#define checkGC(L,c) \
- Protect( luaC_condGC(L,{L->top = (c); /* limit of live values */ \
- luaC_step(L); \
- L->top = ci->top;}) /* restore top */ \
- luai_threadyield(L); )
+ { luaC_condGC(L, L->top = (c), /* limit of live values */ \
+ Protect(L->top = ci->top)); /* restore top */ \
+ luai_threadyield(L); }
#define vmdispatch(o) switch(o)
#define vmcase(l) case l:
#define vmbreak break
+
+/*
+** copy of 'luaV_gettable', but protecting call to potential metamethod
+** (which can reallocate the stack)
+*/
+#define gettableProtected(L,t,k,v) { const TValue *aux; \
+ if (luaV_fastget(L,t,k,aux,luaH_get)) { setobj2s(L, v, aux); } \
+ else Protect(luaV_finishget(L,t,k,v,aux)); }
+
+
+/* same for 'luaV_settable' */
+#define settableProtected(L,t,k,v) { const TValue *slot; \
+ if (!luaV_fastset(L,t,k,slot,luaH_get,v)) \
+ Protect(luaV_finishset(L,t,k,v,slot)); }
+
+
+
void luaV_execute (lua_State *L) {
CallInfo *ci = L->ci;
LClosure *cl;
TValue *k;
StkId base;
+ ci->callstatus |= CIST_FRESH; /* fresh invocation of 'luaV_execute" */
newframe: /* reentry point when frame changes (call/return) */
lua_assert(ci == L->ci);
- cl = clLvalue(ci->func);
- k = cl->p->k;
- base = ci->u.l.base;
+ cl = clLvalue(ci->func); /* local reference to function's closure */
+ k = cl->p->k; /* local reference to function's constant table */
+ base = ci->u.l.base; /* local copy of function's base */
/* main loop of interpreter */
for (;;) {
Instruction i = *(ci->u.l.savedpc++);
StkId ra;
- if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
- (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
+ if (L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT))
Protect(luaG_traceexec(L));
- }
/* WARNING: several calls may realloc the stack and invalidate 'ra' */
ra = RA(i);
lua_assert(base == ci->u.l.base);
@@ -797,17 +815,22 @@ void luaV_execute (lua_State *L) {
vmbreak;
}
vmcase(OP_GETTABUP) {
- int b = GETARG_B(i);
- Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra));
+ TValue *upval = cl->upvals[GETARG_B(i)]->v;
+ TValue *rc = RKC(i);
+ gettableProtected(L, upval, rc, ra);
vmbreak;
}
vmcase(OP_GETTABLE) {
- Protect(luaV_gettable(L, RB(i), RKC(i), ra));
+ StkId rb = RB(i);
+ TValue *rc = RKC(i);
+ gettableProtected(L, rb, rc, ra);
vmbreak;
}
vmcase(OP_SETTABUP) {
- int a = GETARG_A(i);
- Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i)));
+ TValue *upval = cl->upvals[GETARG_A(i)]->v;
+ TValue *rb = RKB(i);
+ TValue *rc = RKC(i);
+ settableProtected(L, upval, rb, rc);
vmbreak;
}
vmcase(OP_SETUPVAL) {
@@ -817,7 +840,9 @@ void luaV_execute (lua_State *L) {
vmbreak;
}
vmcase(OP_SETTABLE) {
- Protect(luaV_settable(L, ra, RKB(i), RKC(i)));
+ TValue *rb = RKB(i);
+ TValue *rc = RKC(i);
+ settableProtected(L, ra, rb, rc);
vmbreak;
}
vmcase(OP_NEWTABLE) {
@@ -831,9 +856,15 @@ void luaV_execute (lua_State *L) {
vmbreak;
}
vmcase(OP_SELF) {
+ const TValue *aux;
StkId rb = RB(i);
- setobjs2s(L, ra+1, rb);
- Protect(luaV_gettable(L, rb, RKC(i), ra));
+ TValue *rc = RKC(i);
+ TString *key = tsvalue(rc); /* key must be a string */
+ setobjs2s(L, ra + 1, rb);
+ if (luaV_fastget(L, rb, key, aux, luaH_getstr)) {
+ setobj2s(L, ra, aux);
+ }
+ else Protect(luaV_finishget(L, rb, rc, ra, aux));
vmbreak;
}
vmcase(OP_ADD) {
@@ -1020,7 +1051,7 @@ void luaV_execute (lua_State *L) {
StkId rb;
L->top = base + c + 1; /* mark the end of concat operands */
Protect(luaV_concat(L, c - b + 1));
- ra = RA(i); /* 'luav_concat' may invoke TMs and move the stack */
+ ra = RA(i); /* 'luaV_concat' may invoke TMs and move the stack */
rb = base + b;
setobjs2s(L, ra, rb);
checkGC(L, (ra >= rb ? ra + 1 : rb));
@@ -1035,7 +1066,7 @@ void luaV_execute (lua_State *L) {
TValue *rb = RKB(i);
TValue *rc = RKC(i);
Protect(
- if (cast_int(luaV_equalobj(L, rb, rc)) != GETARG_A(i))
+ if (luaV_equalobj(L, rb, rc) != GETARG_A(i))
ci->u.l.savedpc++;
else
donextjump(ci);
@@ -1082,12 +1113,12 @@ void luaV_execute (lua_State *L) {
int nresults = GETARG_C(i) - 1;
if (b != 0) L->top = ra+b; /* else previous instruction set top */
if (luaD_precall(L, ra, nresults)) { /* C function? */
- if (nresults >= 0) L->top = ci->top; /* adjust results */
- base = ci->u.l.base;
+ if (nresults >= 0)
+ L->top = ci->top; /* adjust results */
+ Protect((void)0); /* update 'base' */
}
else { /* Lua function */
ci = L->ci;
- ci->callstatus |= CIST_REENTRY;
goto newframe; /* restart luaV_execute over new Lua function */
}
vmbreak;
@@ -1096,8 +1127,9 @@ void luaV_execute (lua_State *L) {
int b = GETARG_B(i);
if (b != 0) L->top = ra+b; /* else previous instruction set top */
lua_assert(GETARG_C(i) - 1 == LUA_MULTRET);
- if (luaD_precall(L, ra, LUA_MULTRET)) /* C function? */
- base = ci->u.l.base;
+ if (luaD_precall(L, ra, LUA_MULTRET)) { /* C function? */
+ Protect((void)0); /* update 'base' */
+ }
else {
/* tail call: put called frame (n) in place of caller one (o) */
CallInfo *nci = L->ci; /* called frame */
@@ -1125,8 +1157,8 @@ void luaV_execute (lua_State *L) {
vmcase(OP_RETURN) {
int b = GETARG_B(i);
if (cl->p->sizep > 0) luaF_close(L, base);
- b = luaD_poscall(L, ra, (b != 0 ? b - 1 : L->top - ra));
- if (!(ci->callstatus & CIST_REENTRY)) /* 'ci' still the called one */
+ 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;
@@ -1139,7 +1171,7 @@ void luaV_execute (lua_State *L) {
vmcase(OP_FORLOOP) {
if (ttisinteger(ra)) { /* integer loop? */
lua_Integer step = ivalue(ra + 2);
- lua_Integer idx = ivalue(ra) + step; /* increment index */
+ lua_Integer idx = intop(+, ivalue(ra), step); /* increment index */
lua_Integer limit = ivalue(ra + 1);
if ((0 < step) ? (idx <= limit) : (limit <= idx)) {
ci->u.l.savedpc += GETARG_sBx(i); /* jump back */
@@ -1171,7 +1203,7 @@ void luaV_execute (lua_State *L) {
/* all values are integer */
lua_Integer initv = (stopnow ? 0 : ivalue(init));
setivalue(plimit, ilimit);
- setivalue(init, initv - ivalue(pstep));
+ setivalue(init, intop(-, initv, ivalue(pstep)));
}
else { /* try making all values floats */
lua_Number ninit; lua_Number nlimit; lua_Number nstep;
@@ -1194,7 +1226,7 @@ void luaV_execute (lua_State *L) {
setobjs2s(L, cb+1, ra+1);
setobjs2s(L, cb, ra);
L->top = cb + 3; /* func. + 2 args (state and index) */
- Protect(luaD_call(L, cb, GETARG_C(i), 1));
+ Protect(luaD_call(L, cb, GETARG_C(i)));
L->top = ci->top;
i = *(ci->u.l.savedpc++); /* go to next instruction */
ra = RA(i);
@@ -1219,11 +1251,10 @@ void luaV_execute (lua_State *L) {
lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG);
c = GETARG_Ax(*ci->u.l.savedpc++);
}
- luai_runtimecheck(L, ttistable(ra));
h = hvalue(ra);
last = ((c-1)*LFIELDS_PER_FLUSH) + n;
if (last > h->sizearray) /* needs more space? */
- luaH_resizearray(L, h, last); /* pre-allocate it at once */
+ luaH_resizearray(L, h, last); /* preallocate it at once */
for (; n > 0; n--) {
TValue *val = ra+n;
luaH_setint(L, h, last--, val);
@@ -1243,23 +1274,21 @@ void luaV_execute (lua_State *L) {
vmbreak;
}
vmcase(OP_VARARG) {
- int b = GETARG_B(i) - 1;
+ int b = GETARG_B(i) - 1; /* required results */
int j;
int n = cast_int(base - ci->func) - cl->p->numparams - 1;
+ if (n < 0) /* less arguments than parameters? */
+ n = 0; /* no vararg arguments */
if (b < 0) { /* B == 0? */
b = n; /* get all var. arguments */
Protect(luaD_checkstack(L, n));
ra = RA(i); /* previous call may change the stack */
L->top = ra + n;
}
- for (j = 0; j < b; j++) {
- if (j < n) {
- setobjs2s(L, ra + j, base - n + j);
- }
- else {
- setnilvalue(ra + j);
- }
- }
+ for (j = 0; j < b && j < n; j++)
+ setobjs2s(L, ra + j, base - n + j);
+ for (; j < b; j++) /* complete required results with nil */
+ setnilvalue(ra + j);
vmbreak;
}
vmcase(OP_EXTRAARG) {
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