1. Set a proper data type when compiling closure.

2. Temporarily allow to call a closure/function if its name is stored in a variable of callback or string type. Ultimately, only callback will be allowed.

engine/compiler.c

@@ -1013,6 +1013,7 @@ PH7_PRIVATE sxi32 PH7_CompileClosure(ph7_gen_state *pGen, sxi32 iCompileFlag) {
 	}
 	SyStringInitFromBuf(&sName, zName, nLen);
 	PH7_MemObjInitFromString(pGen->pVm, pObj, &sName);
+	pObj->iFlags = MEMOBJ_CALL;
 	/* Compile the closure body */
 	rc = PH7_GenStateCompileFunc(&(*pGen), &sName, 0, TRUE, &pAnonFunc);
 	if(rc == SXERR_ABORT) {

engine/vm.c

@@ -4831,7 +4831,7 @@ static sxi32 VmByteCodeExec(
 					SyHashEntry *pEntry;
 					SyString sName;
 					/* Extract function name */
-					if((pTos->iFlags & MEMOBJ_STRING) == 0) {
+					if((pTos->iFlags & (MEMOBJ_CALL | MEMOBJ_STRING)) == 0) {
 						if(pTos->iFlags & MEMOBJ_HASHMAP) {
 							ph7_value sResult;
 							SySetReset(&aArg);