From b8b15d0b9961ce6e773bd973e3412b32b5e9acc6 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Sun, 16 Jul 2017 10:39:05 -0600
Subject: [PATCH] Replace message-less exceptions with ones that say what's
 happening.

---
 include/deal.II/dofs/dof_accessor.templates.h |  8 ++++++--
 include/deal.II/dofs/dof_handler.h            |  4 +++-
 include/deal.II/dofs/dof_renumbering.h        | 14 ++++++++++++++
 include/deal.II/hp/dof_handler.h              |  3 +++
 source/dofs/dof_renumbering.cc                | 12 ++++++------
 5 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/include/deal.II/dofs/dof_accessor.templates.h b/include/deal.II/dofs/dof_accessor.templates.h
index b127266e5a..77de465c2b 100644
--- a/include/deal.II/dofs/dof_accessor.templates.h
+++ b/include/deal.II/dofs/dof_accessor.templates.h
@@ -2047,9 +2047,13 @@ DoFAccessor<structdim,DoFHandlerType,level_dof_access>::get_dof_indices
 (std::vector<types::global_dof_index> &dof_indices,
  const unsigned int                    fe_index) const
 {
-  Assert (this->dof_handler != nullptr, ExcNotInitialized());
+  Assert (this->dof_handler != nullptr,
+          ExcMessage("This accessor object has not been associated "
+                     "with any DoFHandler object."));
   Assert (static_cast<unsigned int>(this->level()) < this->dof_handler->levels.size(),
-          ExcMessage ("DoFHandler not initialized"));
+          ExcMessage ("The DoFHandler to which this accessor points has not "
+                      "been initialized, i.e., it doesn't appear that DoF indices "
+                      "have been distributed on it."));
 
   switch (structdim)
     {
diff --git a/include/deal.II/dofs/dof_handler.h b/include/deal.II/dofs/dof_handler.h
index 515b9f613f..8cce7cbdfb 100644
--- a/include/deal.II/dofs/dof_handler.h
+++ b/include/deal.II/dofs/dof_handler.h
@@ -1227,7 +1227,9 @@ inline
 const Triangulation<dim,spacedim> &
 DoFHandler<dim,spacedim>::get_triangulation () const
 {
-  Assert(tria != nullptr, ExcNotInitialized());
+  Assert(tria != nullptr,
+         ExcMessage("This DoFHandler object has not been associated "
+                    "with a triangulation."));
   return *tria;
 }
 
diff --git a/include/deal.II/dofs/dof_renumbering.h b/include/deal.II/dofs/dof_renumbering.h
index 9c61467a33..43212cb374 100644
--- a/include/deal.II/dofs/dof_renumbering.h
+++ b/include/deal.II/dofs/dof_renumbering.h
@@ -1072,18 +1072,32 @@ namespace DoFRenumbering
    * @}
    */
 
+
+
+  /**
+   * Exception
+   *
+   * @ingroup Exceptions
+   */
+  DeclExceptionMsg (ExcDoFHandlerNotInitialized,
+                    "The DoFHandler on which this function should work has not "
+                    "been initialized, i.e., it doesn't appear that DoF indices "
+                    "have been distributed on it.");
+
   /**
    * Exception
    *
    * @ingroup Exceptions
    */
   DeclException0 (ExcRenumberingIncomplete);
+
   /**
    * Exception
    *
    * @ingroup Exceptions
    */
   DeclException0 (ExcInvalidComponentOrder);
+
   /**
    * The function is only implemented for Discontinuous Galerkin Finite
    * elements.
diff --git a/include/deal.II/hp/dof_handler.h b/include/deal.II/hp/dof_handler.h
index 81c0e3f40f..f315534172 100644
--- a/include/deal.II/hp/dof_handler.h
+++ b/include/deal.II/hp/dof_handler.h
@@ -1054,6 +1054,9 @@ namespace hp
   const Triangulation<dim,spacedim> &
   DoFHandler<dim,spacedim>::get_triangulation () const
   {
+    Assert(tria != nullptr,
+           ExcMessage("This DoFHandler object has not been associated "
+                      "with a triangulation."));
     return *tria;
   }
 
diff --git a/source/dofs/dof_renumbering.cc b/source/dofs/dof_renumbering.cc
index 652efdf5e4..81200c8fa5 100644
--- a/source/dofs/dof_renumbering.cc
+++ b/source/dofs/dof_renumbering.cc
@@ -474,7 +474,7 @@ namespace DoFRenumbering
                       const std::vector<types::global_dof_index> &starting_indices)
   {
     Assert(dof_handler.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     // make the connection graph
     DynamicSparsityPattern dsp (dof_handler.n_dofs(level),
@@ -541,7 +541,7 @@ namespace DoFRenumbering
                   const std::vector<unsigned int> &component_order_arg)
   {
     Assert(dof_handler.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     std::vector<types::global_dof_index> renumbering (dof_handler.n_dofs(level),
                                                       numbers::invalid_dof_index);
@@ -874,7 +874,7 @@ namespace DoFRenumbering
   block_wise (DoFHandler<dim,spacedim> &dof_handler, const unsigned int level)
   {
     Assert(dof_handler.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     std::vector<types::global_dof_index> renumbering (dof_handler.n_dofs(level),
                                                       numbers::invalid_dof_index);
@@ -1238,7 +1238,7 @@ namespace DoFRenumbering
                            const unsigned int       level)
   {
     Assert(dof_handler.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     std::vector<types::global_dof_index> renumbering(dof_handler.n_dofs(level),
                                                      numbers::invalid_dof_index);
@@ -1295,7 +1295,7 @@ namespace DoFRenumbering
                                    const unsigned int                    level)
   {
     Assert(dof_handler.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     const unsigned int n_dofs = dof_handler.n_dofs(level);
     Assert (selected_dofs.size() == n_dofs,
@@ -1419,7 +1419,7 @@ namespace DoFRenumbering
    const typename std::vector<typename DoFHandlerType::level_cell_iterator> &cells)
   {
     Assert(dof.n_dofs(level) != numbers::invalid_dof_index,
-           ExcNotInitialized());
+           ExcDoFHandlerNotInitialized());
 
     std::vector<types::global_dof_index> renumbering(dof.n_dofs(level));
     std::vector<types::global_dof_index> reverse(dof.n_dofs(level));
-- 
2.39.5