use vm->callLevel to count recursive calls to VM_Call

Throw an error if vm->callLevel is set and VM_Free is called.

code/qcommon/vm.c

@@ -608,6 +608,15 @@ VM_Free
 */
 void VM_Free( vm_t *vm ) {
 
+	if(!vm) {
+		return;
+	}
+
+	if(vm->callLevel) {
+		Com_Error( ERR_FATAL, "VM_Free(%s) on running vm", vm->name );
+		return;
+	}
+
 	if(vm->destroy)
 		vm->destroy(vm);
 
@@ -635,13 +644,8 @@ void VM_Free( vm_t *vm ) {
 void VM_Clear(void) {
 	int i;
 	for (i=0;i<MAX_VM; i++) {
-		if ( vmTable[i].dllHandle ) {
-			Sys_UnloadDll( vmTable[i].dllHandle );
-		}
-		Com_Memset( &vmTable[i], 0, sizeof( vm_t ) );
+		VM_Free(&vmTable[i]);
 	}
-	currentVM = NULL;
-	lastVM = NULL;
 }
 
 void *VM_ArgPtr( intptr_t intValue ) {
@@ -722,6 +726,7 @@ intptr_t	QDECL VM_Call( vm_t *vm, int callnum, ... ) {
 	  Com_Printf( "VM_Call( %d )\n", callnum );
 	}
 
+	++vm->callLevel;
 	// if we have a dll loaded, call it directly
 	if ( vm->entryPoint ) {
 		//rcg010207 -  see dissertation at top of VM_DllSyscall() in this file.
@@ -765,6 +770,7 @@ intptr_t	QDECL VM_Call( vm_t *vm, int callnum, ... ) {
 			r = VM_CallInterpreted( vm, &a.callnum );
 #endif
 	}
+	--vm->callLevel;
 
 	if ( oldVM != NULL )
 	  currentVM = oldVM;

code/qcommon/vm_interpreted.c

@@ -376,8 +376,6 @@ int	VM_CallInterpreted( vm_t *vm, int *args ) {
 	*(int *)&image[ programStack + 4 ] = 0;	// return stack
 	*(int *)&image[ programStack ] = -1;	// will terminate the loop on return
 
-	vm->callLevel = 0;
-	
 	VM_Debug(0);
 
 //	vm_debugLevel=2;
@@ -516,7 +514,7 @@ nextInstruction2:
 			if ( programCounter < 0 ) {
 				// system call
 				int		r;
-				int		temp;
+//				int		temp;
 #ifdef DEBUG_VM
 				int		stomped;
 
@@ -525,7 +523,7 @@ nextInstruction2:
 				}
 #endif
 				// save the stack to allow recursive VM entry
-				temp = vm->callLevel;
+//				temp = vm->callLevel;
 				vm->programStack = programStack - 4;
 #ifdef DEBUG_VM
 				stomped = *(int *)&image[ programStack + 4 ];
@@ -558,7 +556,7 @@ nextInstruction2:
 				opStack++;
 				*opStack = r;
 				programCounter = *(int *)&image[ programStack ];
-				vm->callLevel = temp;
+//				vm->callLevel = temp;
 #ifdef DEBUG_VM
 				if ( vm_debugLevel ) {
 					Com_Printf( "%s<--- %s\n", DEBUGSTR, VM_ValueToSymbol( vm, programCounter ) );
@@ -599,7 +597,7 @@ nextInstruction2:
 //					vm_debugLevel = 2;
 //					VM_StackTrace( vm, programCounter, programStack );
 				}
-				vm->callLevel++;
+//				vm->callLevel++;
 			}
 #endif
 			goto nextInstruction;
@@ -614,7 +612,7 @@ nextInstruction2:
 #ifdef DEBUG_VM
 			profileSymbol = VM_ValueToFunctionSymbol( vm, programCounter );
 			if ( vm_debugLevel ) {
-				vm->callLevel--;
+//				vm->callLevel--;
 				Com_Printf( "%s<--- %s\n", DEBUGSTR, VM_ValueToSymbol( vm, programCounter ) );
 			}
 #endif

code/qcommon/vm_local.h

@@ -156,7 +156,7 @@ struct vm_s {
 	int			numSymbols;
 	struct vmSymbol_s	*symbols;
 
-	int			callLevel;			// for debug indenting
+	int			callLevel;		// counts recursive VM_Call
 	int			breakFunction;		// increment breakCount on function entry to this
 	int			breakCount;
 

code/qcommon/vm_x86_64.c

@@ -1069,7 +1069,6 @@ int	VM_CallCompiled( vm_t *vm, int *args ) {
 
 	currentVM = vm;
 
-	++vm->callLevel;
 //	Com_Printf("entering %s level %d, call %d, arg1 = 0x%x\n", vm->name, vm->callLevel, args[0], args[1]);
 
 	// interpret the code
@@ -1131,7 +1130,6 @@ int	VM_CallCompiled( vm_t *vm, int *args ) {
 	}
 
 //	Com_Printf("exiting %s level %d\n", vm->name, vm->callLevel);
-	--vm->callLevel;
 	vm->programStack = stackOnEntry;
 
 	return *(int *)opStack;