From 839ae22b1fbbb0c0b3cb8dc30fbf110efd4923c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Villemot?= <sebastien@dynare.org>
Date: Fri, 29 Nov 2013 16:03:15 +0100
Subject: [PATCH] Add a warning when some exogenous are not used in the model

---
 preprocessor/DynamicModel.cc | 13 +++++++++++++
 preprocessor/DynamicModel.hh |  2 ++
 preprocessor/ModFile.cc      | 15 +++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/preprocessor/DynamicModel.cc b/preprocessor/DynamicModel.cc
index aa682d19e..ecd0881b6 100644
--- a/preprocessor/DynamicModel.cc
+++ b/preprocessor/DynamicModel.cc
@@ -3585,6 +3585,19 @@ DynamicModel::findUnusedEndogenous()
   return unusedEndo;
 }
 
+set<int>
+DynamicModel::findUnusedExogenous()
+{
+  set<int> usedExo, unusedExo;
+  for (int i = 0; i < (int) equations.size(); i++)
+    equations[i]->collectVariables(eExogenous, usedExo);
+  set<int> allExo = symbol_table.getExogenous();
+  set_difference(allExo.begin(), allExo.end(),
+                 usedExo.begin(), usedExo.end(),
+                 inserter(unusedExo, unusedExo.begin()));
+  return unusedExo;
+}
+
 void
 DynamicModel::computeDerivIDs()
 {
diff --git a/preprocessor/DynamicModel.hh b/preprocessor/DynamicModel.hh
index c02d11303..5f32ed11f 100644
--- a/preprocessor/DynamicModel.hh
+++ b/preprocessor/DynamicModel.hh
@@ -224,6 +224,8 @@ public:
 
   //! Find endogenous variables not used in model
   set<int> findUnusedEndogenous();
+  //! Find exogenous variables not used in model
+  set<int> findUnusedExogenous();
 
   //! Copies a dynamic model (only the equations)
   /*! It assumes that the dynamic model given in argument has just been allocated */
diff --git a/preprocessor/ModFile.cc b/preprocessor/ModFile.cc
index 56c5fb30d..6d6af32bb 100644
--- a/preprocessor/ModFile.cc
+++ b/preprocessor/ModFile.cc
@@ -286,6 +286,21 @@ ModFile::checkPass()
       cerr << ") also appear in the expressions defining the variance/covariance matrix of shocks; this is not allowed." << endl;
       exit(EXIT_FAILURE);
     }
+
+  // Check if some exogenous is not used in the model block
+  set<int> unusedExo = dynamic_model.findUnusedExogenous();
+  if (unusedExo.size() > 1)
+    {
+      warnings << "WARNING: some exogenous (";
+      for (set<int>::const_iterator it = unusedExo.begin();
+           it != unusedExo.end(); )
+        {
+          warnings << symbol_table.getName(*it);
+          if (++it != unusedExo.end())
+            warnings << ", ";
+        }
+      warnings << ") are declared but not used in the model. This may lead to crashes or unexpected behaviour." << endl;
+    }
 }
 
 void