Debugger: Improve variable tooltips.

VariablesView:
- Tooltips now indicate if there was a problem resolving either the location
  or the actual value of a given variable, as well as whether or not the
  variable is editable in its current location.

src/apps/debugger/user_interface/gui/team_window/VariablesView.cpp

@@ -1509,29 +1509,41 @@ VariablesView::VariableTableModel::GetToolTipForTablePath(
 	if (node == NULL)
 		return false;
 
-	if (node->NodeChild()->LocationResolutionState() != B_OK)
-		return false;
-
 	BString tipData;
+	ValueNodeChild* child = node->NodeChild();
+	status_t error = child->LocationResolutionState();
+	if (error != B_OK)
+		tipData.SetToFormat("Unable to resolve location: %s", strerror(error));
+	else {
+		ValueNode* valueNode = child->Node();
+		if (valueNode == NULL)
+			return false;
+		error = valueNode->LocationAndValueResolutionState();
+		if (error != B_OK) {
+			tipData.SetToFormat("Unable to resolve value: %s\n\n",
+				strerror(error));
+		}
+
 		switch (columnIndex) {
 			case 0:
 			{
-			ValueLocation* location = node->NodeChild()->Location();
+				ValueLocation* location = child->Location();
 				for (int32 i = 0; i < location->CountPieces(); i++) {
 					ValuePieceLocation piece = location->PieceAt(i);
 					BString pieceData;
 					switch (piece.type) {
 						case VALUE_PIECE_LOCATION_MEMORY:
-						pieceData.SetToFormat("(%" B_PRId32 "): Address: %#"
+							pieceData.SetToFormat("(%" B_PRId32 "): Address: "
-							B_PRIx64 ", Size: %" B_PRId64 " bytes", i,
+								"%#" B_PRIx64 ", Size: %" B_PRId64 " bytes\n",
-							piece.address, piece.size);
+								i, piece.address, piece.size);
 							break;
 						case VALUE_PIECE_LOCATION_REGISTER:
 						{
 							Architecture* architecture = fThread->GetTeam()
 								->GetArchitecture();
-						pieceData.SetToFormat("(%" B_PRId32 "): Register (%s)",
+							pieceData.SetToFormat("(%" B_PRId32 "): Register "
-							i, architecture->Registers()[piece.reg].Name());
+								"(%s)\n", i,
+								architecture->Registers()[piece.reg].Name());
 							break;
 						}
 						default:
@@ -1539,9 +1551,10 @@ VariablesView::VariableTableModel::GetToolTipForTablePath(
 					}
 
 					tipData	+= pieceData;
-				if (i < location->CountPieces() - 1)
-					tipData += "\n";
 				}
+				tipData += "Editable: ";
+				tipData += error == B_OK && location->IsEditable()
+					? "Yes" : "No";
 				break;
 			}
 			case 1:
@@ -1555,6 +1568,7 @@ VariablesView::VariableTableModel::GetToolTipForTablePath(
 			default:
 				break;
 		}
+	}
 
 	if (tipData.IsEmpty())
 		return false;