update lua 5.5.1

3rd/lua/ldo.c

@@ -221,13 +221,21 @@ l_noret luaD_errerr (lua_State *L) {
 
 
 /*
-** Check whether stack has enough space to run a simple function (such
-** as a finalizer): At least BASIC_STACK_SIZE in the Lua stack and
-** 2 slots in the C stack.
+** Check whether stacks have enough space to run a simple function (such
+** as a finalizer): At least BASIC_STACK_SIZE in the Lua stack, two
+** available CallInfos, and two "slots" in the C stack.
 */
 int luaD_checkminstack (lua_State *L) {
-  return ((stacksize(L) < MAXSTACK - BASIC_STACK_SIZE) &&
-          (getCcalls(L) < LUAI_MAXCCALLS - 2));
+  if (getCcalls(L) >= LUAI_MAXCCALLS - 2)
+    return 0;  /* not enough C-stack slots */
+  if (L->ci->next == NULL && luaE_extendCI(L, 0) == NULL)
+    return 0;  /* unable to allocate first ci */
+  if (L->ci->next->next == NULL && luaE_extendCI(L, 0) == NULL)
+    return 0;  /* unable to allocate second ci */
+  if (L->stack_last.p - L->top.p >= BASIC_STACK_SIZE)
+    return 1;  /* enough (BASIC_STACK_SIZE) free slots in the Lua stack */
+  else  /* try to grow stack to a size with enough free slots */
+    return luaD_growstack(L, BASIC_STACK_SIZE, 0);
 }
 
 
@@ -341,7 +349,7 @@ int luaD_reallocstack (lua_State *L, int newsize, int raiseerror) {
   correctstack(L, oldstack);  /* change offsets back to pointers */
   L->stack_last.p = L->stack.p + newsize;
   for (i = oldsize + EXTRA_STACK; i < newsize + EXTRA_STACK; i++)
-    setnilvalue(s2v(newstack + i)); /* erase new segment */
+    setnilvalue2s(newstack + i); /* erase new segment */
   return 1;
 }
 
@@ -422,12 +430,6 @@ void luaD_shrinkstack (lua_State *L) {
   luaE_shrinkCI(L);  /* shrink CI list */
 }
 
-
-void luaD_inctop (lua_State *L) {
-  L->top.p++;
-  luaD_checkstack(L, 1);
-}
-
 /* }================================================================== */
 
 
@@ -546,7 +548,7 @@ l_sinline void genmoveresults (lua_State *L, StkId res, int nres,
   for (i = 0; i < nres; i++)  /* move all results to correct place */
     setobjs2s(L, res + i, firstresult + i);
   for (; i < wanted; i++)  /* complete wanted number of results */
-    setnilvalue(s2v(res + i));
+    setnilvalue2s(res + i);
   L->top.p = res + wanted;  /* top points after the last result */
 }
 
@@ -566,7 +568,7 @@ l_sinline void moveresults (lua_State *L, StkId res, int nres,
       return;
     case 1 + 1:  /* one value needed */
       if (nres == 0)   /* no results? */
-        setnilvalue(s2v(res));  /* adjust with nil */
+        setnilvalue2s(res);  /* adjust with nil */
       else  /* at least one result */
         setobjs2s(L, res, L->top.p - nres);  /* move it to proper place */
       L->top.p = res + 1;
@@ -616,7 +618,7 @@ void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
 
 
 
-#define next_ci(L)  (L->ci->next ? L->ci->next : luaE_extendCI(L))
+#define next_ci(L)  (L->ci->next ? L->ci->next : luaE_extendCI(L, 1))
 
 
 /*
@@ -686,7 +688,7 @@ int luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func,
         setobjs2s(L, ci->func.p + i, func + i);
       func = ci->func.p;  /* moved-down function */
       for (; narg1 <= nfixparams; narg1++)
-        setnilvalue(s2v(func + narg1));  /* complete missing arguments */
+        setnilvalue2s(func + narg1);  /* complete missing arguments */
       ci->top.p = func + 1 + fsize;  /* top for new function */
       lua_assert(ci->top.p <= L->stack_last.p);
       ci->u.l.savedpc = p->code;  /* starting point */
@@ -733,7 +735,7 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) {
       L->ci = ci = prepCallInfo(L, func, status, func + 1 + fsize);
       ci->u.l.savedpc = p->code;  /* starting point */
       for (; narg < nfixparams; narg++)
-        setnilvalue(s2v(L->top.p++));  /* complete missing arguments */
+        setnilvalue2s(L->top.p++);  /* complete missing arguments */
       lua_assert(ci->top.p <= L->stack_last.p);
       return ci;
     }
@@ -1120,28 +1122,54 @@ static void checkmode (lua_State *L, const char *mode, const char *x) {
 }
 
 
+/*
+** Before the first call to the reader function, Lua reserves a slot
+** with a table for anchoring stuff.
+*/
 static void f_parser (lua_State *L, void *ud) {
   LClosure *cl;
   struct SParser *p = cast(struct SParser *, ud);
   const char *mode = p->mode ? p->mode : "bt";
-  int c = zgetc(p->z);  /* read first character */
+  int c;
+  Table *anchor;
+  ptrdiff_t otop = savestack(L, L->top.p);  /* original top */
+  luaD_checkstack(L, 2);
+  anchor = luaH_new(L);  /* create the anchor table */
+  sethvalue2s(L, L->top.p++, anchor);  /* anchor the anchor table */
+  c = zgetc(p->z);  /* read first character */
   if (c == LUA_SIGNATURE[0]) {
     int fixed = 0;
     if (strchr(mode, 'B') != NULL)
       fixed = 1;
     else
       checkmode(L, mode, "binary");
-    cl = luaU_undump(L, p->z, p->name, fixed);
+    cl = luaU_undump(L, p->z, anchor, p->name, fixed);
   }
   else {
     checkmode(L, mode, "text");
-    cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
+    cl = luaY_parser(L, p->z, anchor, &p->buff, &p->dyd, p->name, c);
   }
+  L->top.p = restorestack(L, otop);  /* restore stack */
+  setclLvalue2s(L, L->top.p++, cl);  /* push closure */
   lua_assert(cl->nupvalues == cl->p->sizeupvalues);
   luaF_initupvals(L, cl);
 }
 
 
+/*
+** Anchor an object in a table in the stack.  First, anchor the object
+** temporarily in the stack, as luaH_set may call an emergency GC.
+** Then, add it in the table with itself as its key.
+*/
+void luaD_anchorobj (lua_State *L, Table *anchor, GCObject *obj) {
+  setgcovalue(L, s2v(L->top.p++), obj);  /* temporary anchor in the stack */
+  luaH_set(L, anchor, s2v(L->top.p - 1), s2v(L->top.p - 1));
+  /* Because this is a new key, luaH_set will call the GC barrier, so
+     we don't need to call the barrier again here */
+  L->top.p--;
+}
+
+
 TStatus luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                             const char *mode) {
   struct SParser p;