From 475533d3b92495973b048ff22251d85c330e77aa Mon Sep 17 00:00:00 2001
From: Heinz Riener <heinz.riener@gmail.com>
Date: Thu, 10 Dec 2020 16:24:59 +0100
Subject: [PATCH 1/2] Network fuzz tester.

---
 .../algorithms/network_fuzz_tester.hpp        | 135 ++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 include/mockturtle/algorithms/network_fuzz_tester.hpp

diff --git a/include/mockturtle/algorithms/network_fuzz_tester.hpp b/include/mockturtle/algorithms/network_fuzz_tester.hpp
new file mode 100644
index 000000000..3a0635d7a
--- /dev/null
+++ b/include/mockturtle/algorithms/network_fuzz_tester.hpp
@@ -0,0 +1,135 @@
+/* mockturtle: C++ logic network library
+ * Copyright (C) 2018-2020  EPFL
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*!
+  \file network_fuzz_tester.hpp
+  \brief Network fuzz tester
+
+  \author Heinz Riener
+*/
+
+#include <mockturtle/io/write_verilog.hpp>
+#include <mockturtle/io/verilog_reader.hpp>
+#include <lorina/lorina.hpp>
+#include <fmt/format.h>
+#include <optional>
+
+namespace mockturtle
+{
+
+struct fuzz_tester_params
+{
+  uint64_t num_pis{4u};
+  uint64_t num_gates{10u};
+  std::string filename{"fuzz_test.v"};
+
+  /* number of networks to test: nullopt means infinity */
+  std::optional<uint64_t> num_iterations{std::nullopt};
+}; /* fuzz_tester_params */
+
+/*! \brief Network fuzz tester
+ *
+ * Runs an algorithm on many small ramdon logic networks.  Fuzz
+ * testing is often useful to detect potential segmentation faults in
+ * new implementations.  The generated benchmarks are saved first in a
+ * file.  If a segmentation fault occurs, the file can be used to
+ * reproduce and debug the problem.
+ *
+ * Usage:
+ *  #include <mockturtle/algorithms/aig_resub.hpp>
+ *  #include <mockturtle/algorithms/cleanup.hpp>
+ *  #include <mockturtle/algorithms/network_fuzz_tester.hpp>
+ *  #include <mockturtle/algorithms/resubstitution.hpp>
+ *  #include <mockturtle/generators/random_logic_generator.hpp>
+ *
+ *  auto opt = [&]( aig_network aig ) -> bool {
+ *    resubstitution_params ps;
+ *    resubstitution_stats st;
+ *    aig_resubstitution( aig, ps, &st );
+ *    aig = cleanup_dangling( aig );
+ *    return true;
+ *  };
+ *
+ *  fuzz_tester_params ps;
+ *  ps.num_iterations = 100;
+ *  auto gen = default_random_aig_generator();
+ *  network_fuzz_tester fuzzer( gen, ps );
+ *  fuzzer.run( opt );
+*/
+template<class NetworkGenerator>
+class network_fuzz_tester
+{
+public:
+  explicit network_fuzz_tester( NetworkGenerator& gen, fuzz_tester_params const ps = {} )
+    : gen( gen )
+    , ps( ps )
+  {}
+
+  template<typename Fn>
+  void run( Fn&& fn )
+  {
+    uint64_t counter{0};
+    while ( !ps.num_iterations || counter < ps.num_iterations )
+    {
+      auto ntk = gen.generate( ps.num_pis, ps.num_gates, std::random_device{}() );
+      fmt::print( "[i] create network #{}: I/O = {}/{} gates = {} nodes = {}\n",
+                  counter++, ntk.num_pis(), ntk.num_pos(), ntk.num_gates(), ntk.size() );
+
+      fmt::print( "[i] write network `{}`\n", ps.filename );
+      write_verilog( ntk, ps.filename );
+
+      /* run optimization algorithm */
+      if ( !fn( ntk ) )
+      {
+        return;
+      }
+    }
+  }
+
+  template<typename Fn, typename Ntk>
+  void rerun_on_benchmark( Fn&& fn )
+  {
+    /* read benchmark from a file */
+    Ntk ntk;
+    fmt::print( "[i] read network `{}`\n", ps.filename );
+    if ( lorina::read_verilog( ps.filename, verilog_reader( ntk ) ) != lorina::return_code::success )
+    {
+      fmt::print( "[e] could not read benchmark `{}`\n", ps.filename );
+      return;
+    }
+
+    fmt::print( "[i] network: I/O = {}/{} gates = {} nodes = {}\n",
+                ntk.num_pis(), ntk.num_pos(), ntk.num_gates(), ntk.size() );
+
+    /* run optimization algorithm */
+    fn( ntk );
+  }
+
+private:
+  NetworkGenerator& gen;
+  fuzz_tester_params const ps;
+}; /* network_fuzz_tester */
+
+} /* namespace mockturtle */

From c273d9cf5c3833d2bbbd3ac612f77f73448efddb Mon Sep 17 00:00:00 2001
From: Heinz Riener <heinz.riener@gmail.com>
Date: Thu, 10 Dec 2020 16:28:28 +0100
Subject: [PATCH 2/2] changelog.

---
 docs/changelog.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 872c62eb9..37a75cf4e 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -32,6 +32,7 @@ v0.2 (not yet released)
     - Check functional equivalence (`circuit_validator`) `#346 <https://github.com/lsils/mockturtle/pull/346>`_
     - Restructured resubstitution framework (`resubstitution`), simulation-guided resubstitution (`sim_resub`) `#373 <https://github.com/lsils/mockturtle/pull/373>`_
     - Functional reduction (`functional_reduction`) `#380 <https://github.com/lsils/mockturtle/pull/380>`_
+    - Network fuzz testing (`network_fuzz_tester`) `#408 <https://github.com/lsils/mockturtle/pull/408>`_
 * Views:
     - Assign names to signals and outputs (`names_view`) `#181 <https://github.com/lsils/mockturtle/pull/181>`_ `#184 <https://github.com/lsils/mockturtle/pull/184>`_
     - Creates a CNF while creating a network (`cnf_view`) `#274 <https://github.com/lsils/mockturtle/pull/274>`_