Collect statistics about normal form inferences (#4127)

This commit adds code to count the number of inferences made of each
inference type for normal form inferences. It extends the Inference
enum in `infer_info.h` and adds two new `sendInference()` methods in the
`InferenceManager` to send and count inferences that have a corresonding
entry in the `Inference` enum.

1 files changed, 37 insertions, 0 deletions

diff --git a/src/theory/strings/sequences_stats.cpp b/src/theory/strings/sequences_stats.cpp
new file mode 100644
index 000000000..0f1e93599
--- /dev/null
+++ b/src/theory/strings/sequences_stats.cpp
@@ -0,0 +1,37 @@
+/*********************                                                        */
+/*! \file sequences_stats.cpp
+ ** \verbatim
+ ** Top contributors (to current version):
+ **   Andres Noetzli
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2020 by the authors listed in the file AUTHORS
+ ** in the top-level source directory) and their institutional affiliations.
+ ** All rights reserved.  See the file COPYING in the top-level source
+ ** directory for licensing information.\endverbatim
+ **
+ ** \brief Statistics for the theory of strings/sequences
+ **/
+
+
+#include "theory/strings/sequences_stats.h"
+
+#include "smt/smt_statistics_registry.h"
+
+namespace CVC4 {
+namespace theory {
+namespace strings {
+
+SequencesStatistics::SequencesStatistics()
+    : d_inferences("theory::strings::inferences")
+{
+  smtStatisticsRegistry()->registerStat(&d_inferences);
+}
+
+SequencesStatistics::~SequencesStatistics()
+{
+  smtStatisticsRegistry()->unregisterStat(&d_inferences);
+}
+
+}
+}
+}