add specialized exception type for bad graphs

src/App/Application.cpp

@@ -1463,6 +1463,7 @@ void Application::initTypes(void)
     new ExceptionProducer<Base::IndexError>;
     new ExceptionProducer<Base::AttributeError>;
     new ExceptionProducer<Base::RuntimeError>;
+    new ExceptionProducer<Base::BadGraphError>;
     new ExceptionProducer<Base::NotImplementedError>;
     new ExceptionProducer<Base::DivisionByZeroError>;
     new ExceptionProducer<Base::ReferencesError>;

src/App/Document.cpp

@@ -2040,7 +2040,7 @@ Document::getDependencyList(const std::vector<App::DocumentObject*>& objs) const
         std::stringstream ss;
         ss << "Gathering all dependencies failed, probably due to circular dependencies. Error: ";
         ss << e.what();
-        throw Base::RuntimeError(ss.str().c_str());
+        throw Base::BadGraphError(ss.str().c_str());
     }
 
     std::set<Vertex> out;

src/App/DocumentObject.cpp

@@ -304,7 +304,7 @@ void _getInListRecursive(std::set<DocumentObject*>& objSet,
     for (const auto objIt : obj->getInList()) {
         // if the check object is in the recursive inList we have a cycle!
         if (objIt == checkObj || depth <= 0) {
-            throw Base::RuntimeError("DocumentObject::getInListRecursive(): cyclic dependency detected!");
+            throw Base::BadGraphError("DocumentObject::getInListRecursive(): cyclic dependency detected!");
         }
 
         // if the element was already in the set then there is no need to process it again
@@ -335,7 +335,7 @@ void _getOutListRecursive(std::set<DocumentObject*>& objSet,
     for (const auto objIt : obj->getOutList()) {
         // if the check object is in the recursive inList we have a cycle!
         if (objIt == checkObj || depth <= 0) {
-            throw Base::RuntimeError("DocumentObject::getOutListRecursive(): cyclic dependency detected!");
+            throw Base::BadGraphError("DocumentObject::getOutListRecursive(): cyclic dependency detected!");
         }
 
         // if the element was already in the set then there is no need to process it again
@@ -369,7 +369,7 @@ bool _isInInListRecursive(const DocumentObject* act,
             return true;
         // if we reach the depth limit we have a cycle!
         if (depth <= 0) {
-            throw Base::RuntimeError("DocumentObject::isInInListRecursive(): cyclic dependency detected!");
+            throw Base::BadGraphError("DocumentObject::isInInListRecursive(): cyclic dependency detected!");
         }
 
         if (_isInInListRecursive(obj, checkObj, depth - 1))
@@ -413,7 +413,7 @@ bool _isInOutListRecursive(const DocumentObject* act,
             return true;
         // if we reach the depth limit we have a cycle!
         if (depth <= 0) {
-            throw Base::RuntimeError("DocumentObject::isInOutListRecursive(): cyclic dependency detected!");
+            throw Base::BadGraphError("DocumentObject::isInOutListRecursive(): cyclic dependency detected!");
         }
 
         if (_isInOutListRecursive(obj, checkObj, depth - 1))

src/Base/Exception.cpp

@@ -634,6 +634,28 @@ RuntimeError::RuntimeError(const RuntimeError &inst)
 
 // ---------------------------------------------------------
 
+BadGraphError::BadGraphError()
+  : RuntimeError("The graph must be a DAG.")
+{
+}
+
+BadGraphError::BadGraphError(const char * sMessage)
+  : RuntimeError(sMessage)
+{
+}
+
+BadGraphError::BadGraphError(const std::string& sMessage)
+  : RuntimeError(sMessage)
+{
+}
+
+BadGraphError::BadGraphError(const BadGraphError &inst)
+  : RuntimeError(inst)
+{
+}
+
+// ---------------------------------------------------------
+
 NotImplementedError::NotImplementedError()
   : Exception()
 {

src/Base/Exception.h

@@ -468,6 +468,23 @@ public:
   virtual ~RuntimeError() throw() {}
 };
 
+/**
+ * The BadGraphError can be used to indicate that a graph is e.g. not a DAG.
+ * @author Werner Mayer
+ */
+class BaseExport BadGraphError : public RuntimeError
+{
+public:
+  /// Construction
+  BadGraphError();
+  BadGraphError(const char * sMessage);
+  BadGraphError(const std::string& sMessage);
+  /// Construction
+  BadGraphError(const BadGraphError &inst);
+  /// Destruction
+  virtual ~BadGraphError() throw() {}
+};
+
 /**
  * The NotImplementedError can be used to indicate that an invoked function is not implemented.
  * @author Werner Mayer