spot: Add Picosat to Spot library & Update satsolver class

* Makefile.am: Add picosat to subdirs.
* configure.ac: Add picosat/Makefile to AC_CONFIG_FILES.
* README: Add picosat/ in the list of directories.
* debian/copyright: Add picosat licence and details.
* picosat/Makefile.am: Implement Makefile.am in picosat directory.
* spot/Makefile.am: Tell the compiler to add libpico.la into libspot.la.
* picosat/LICENSE: Add picosat licence.
* picosat/NEWS: Add picosat NEWS.
* picosat/VERSION: Add picosat VERSION.
* picosat/picosat.c: Add picosat c file.
* picosat/picosat.h: Add picosat header file.
* spot/misc/satsolver.cc: Update functions.
* spot/misc/satsolver.hh: Add documentation, clean code, change
some functions visibility and separate templates functions.
* spot/twaalgos/dtbasat.cc: Update dtba_to_sat function.
* spot/twaalgos/dtwasat.cc: Update dtwa_to_sat function.

Makefile.am

@@ -32,7 +32,8 @@ if USE_PYTHON
   PYTHON_SUBDIR = python
 endif
 
-SUBDIRS = buddy lib ltdl spot bin tests $(PYTHON_SUBDIR) doc $(NEVER_SUBDIRS)
+SUBDIRS = picosat buddy lib ltdl spot bin tests $(PYTHON_SUBDIR) doc \
+					$(NEVER_SUBDIRS)
 
 UTF8 = utf8/doc/ReleaseNotes utf8/doc/utf8cpp.html utf8/utf8.h	\
   utf8/utf8/checked.h utf8/utf8/core.h utf8/utf8/unchecked.h

README

@@ -218,6 +218,7 @@ ltdl/             Libtool's portable dlopen() wrapper library.
 lib/              Gnulib's portability modules.
 utf8/             Nemanja Trifunovic's utf-8 routines.
 elisp/		  Related emacs modes, used for building the documentation.
+picosat/          A distribution of PicoSAT 965 (a satsolver library).
 
 Build-system stuff
 ------------------

configure.ac

@@ -261,6 +261,7 @@ AC_CONFIG_FILES([
   doc/org/init.el
   elisp/Makefile
   lib/Makefile
+  picosat/Makefile
   spot/graph/Makefile
   spot/kripke/Makefile
   spot/ltsmin/Makefile

debian/copyright

@@ -162,3 +162,24 @@ License: GPL-3+
  .
  On Debian systems, the complete text of the GNU General
  Public License version 3 can be found in "/usr/share/common-licenses/GPL-3".
+
+Files: picosat/*
+Copyright: 2006 - 2015, Armin Biere, Johannes Kepler University.
+License: MIT style
+ 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.

picosat/LICENSE

+Copyright (c) 2006 - 2014, Armin Biere, Johannes Kepler University.
+
+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.
+

picosat/Makefile.am

+noinst_LTLIBRARIES = libpico.la
+
+libpico_la_SOURCES = picosat.c picosat.h
+
+# Force -DNDEBUG regardless of the Spot settings
+libpico_la_CPPFLAGS = -DNDEBUG -DNGETRUSAGE
+EXTRA_DIST = LICENSE NEWS VERSION

picosat/NEWS

+news for release 965 since 959
+------------------------------
+
+* ADC code works again (spotted by Himanshu Jain)
+* include into R projects (with Christoph Muessel) (--rcode)
+* fixed 'undefined' + 'ptrdiff_' issues (thanks to Christoph Muessel)
+* added 'picosat_set_interrupt' and '-a <alarm>' command line option
+* fixed various issues pointed out by Stefan Hengelein:
+  - fixed incremental usage of 'picosat_adjust'
+  - added CPP fixes (STATS, NO_BINARY_CLAUSE versus TRACE mix-ups)
+  - removed redundant explicit set to zero on reset
+* fixed various usage bugs with 'picomus' (thanks to Stefan Hengelein)
+* removed '-fno-strict-aliasing' (thanks to Jerry James)
+
+news for release 959 since 953
+------------------------------
+
+* fixed header comments
+
+* fixed minor compilation issues
+
+* fixed unitialized memory access problem for 'picosat_deref_partial'
+  and another issue with partial models
+
+* added 'picosat_add_arg' and 'picosat_add_lits'
+
+* '--plain' and 'picosat_set_plain' to disable failed literal probing
+
+* new '#define PICOSAT_REENTRANT_API' in 'picosat.h'
+
+* added manager so no more global variables
+  (allows multiple instances, requires manager object)
+
+news for release 951 since 941
+------------------------------
+
+* cleaned up code (based on comments by Donald Knuth)
+
+* lreduce=O(conflicts^.5)
+
+* added 'picosat_visits' and 'picosat_decisions'
+
+* added '--partial' command line option
+
+* added 'picosat_deref_partial' and 'picosat_save_original_clauses'
+
+* added 'picomcs' as example for MSS computation
+
+news for release 941 since 936
+------------------------------
+
+* added 'picogcnf'
+
+* added All-SAT mode ('--all' command line option)
+
+* statistics include time spent in failed literal preprocessing (probing)
+
+* 'picosat_failed_context' for 'push & pop'
+   (and tested failed assumptions for 'push & pop')
+
+* 'picosat_simplify' for forced garbage collection
+
+* undefined NFL, defined NADC (= failed literals on, ADC's off)
+
+* 'picosat_push' and 'picosat_pop' (beta version)
+
+* fixed some issues related to binary clause handling and 
+  generating list of failed assumptions
+
+news for release 936 since 935
+------------------------------
+
+* simple minimal unsatisfiable core (MUS) extractor 'picomus'
+  (example for using 'picosat_mus_assumptions' and 'picosat_coreclause')
+
+* added 'picosat_mus_assumptions'
+
+* added 'picosat_{set_}propagations'
+
+* new 'int' return value for 'picosat_enable_trace_generation' to
+  check for trace code being compiled
+
+news for release 935 since 926
+------------------------------
+
+* added 'picosat_failed_assumptions' (plural)
+
+* new '-A <failedlits>' command line option
+
+* fixed failed assumption issues
+
+* added 'picosat_remove_learned'
+
+* added 'picosat_reset_{phases,scores}'
+
+* added 'picosat_set_less_important_lit'
+
+* added 'picosat_res'
+
+news for release 926 since 846
+------------------------------
+
+* random initial phase (API of 'picosat_set_default_phase' changed)
+
+* fixed accumulative failed assumption (multiple times)
+
+* fixed missing original clause in core generation with assumptions
+
+* fixed debugging code for memory allocation
+
+* shared library in addition to static library
+
+* removed potential UNKNOWN result without decision limit
+
+* added picosat_set_more_important_lit
+
+* added picosat_coreclause
+
+* propagation of binary clauses until completion
+
+* fixed API usage 'assume;sat;sat'
+
+* literals move to front (LMTF) during traversal of visited clauses
+
+* switched from inner/outer to Luby style restart scheduling
+
+* less agressive reduce schedule
+
+* replaced watched literals with head and tail pointers
+
+* add 'picosat_failed_assumption', which allows to avoid tracing and core
+  generation, if one is only interested in assumptions in the core
+
+* fixed a BUG in the generic iterator code of clauses
+  (should rarely happen unless you use a very sophisticated malloc lib)
+
+news for release 846 since 632
+------------------------------
+
+* cleaned up assumption handling (actually removed buggy optimization)
+
+* incremental core generation 
+
+* experimental 'all different constraint' handling as in our FMCAD'08 paper
+
+* new API calls: 
+
+  - picosat_add_ado_lit       (add all different object literal)
+  - picosat_deref_top_level   (deref top level assignment)
+  - picosat_changed           (check whether extension was possible)
+  - picosat_measure_all_calls (per default do not measure adding time)
+  - picosat_set_prefix        (set prefix for messages)
+
+* 64 bit port (and compilation options)
+
+* optional NVSIDS visualization code
+
+* resource controlled failed literal implementation
+
+* disconnect long clauses satisfied at lower decision level
+
+* controlling restarts

picosat/VERSION

+965

spot/Makefile.am

@@ -42,7 +42,8 @@ libspot_la_LIBADD =  \
   tl/libtl.la \
   twaalgos/libtwaalgos.la \
   twa/libtwa.la \
-  ../lib/libgnu.la
+  ../lib/libgnu.la \
+  ../picosat/libpico.la
 
 # Dummy C++ source to cause C++ linking.
 nodist_EXTRA_libspot_la_SOURCES = _.cc

spot/misc/satsolver.cc

@@ -23,66 +23,13 @@
 #include <sstream>
 #include <stdexcept>
 #include <spot/misc/satsolver.hh>
+#include <picosat/picosat.h>
 #include <fstream>
 #include <limits>
 #include <sys/wait.h>
 
 namespace spot
 {
-  namespace
-  {
-    struct satsolver_command: formater
-    {
-      const char* satsolver;
-
-      satsolver_command()
-      {
-        satsolver = getenv("SPOT_SATSOLVER");
-        if (!satsolver)
-          {
-            satsolver = "glucose -verb=0 -model %I >%O";
-            return;
-          }
-        prime(satsolver);
-        if (!has('I'))
-          throw std::runtime_error("SPOT_SATSOLVER should contain %I to "
-                                   "indicate how to use the input filename.");
-        if (!has('O'))
-          throw std::runtime_error("SPOT_SATSOLVER should contain %O to "
-                                   "indicate how to use the output filename.");
-      }
-
-      int
-      run(printable* in, printable* out)
-      {
-        declare('I', in);
-        declare('O', out);
-        std::ostringstream s;
-        format(s, satsolver);
-        int res = system(s.str().c_str());
-        if (res < 0 || (WIFEXITED(res) && WEXITSTATUS(res) == 127))
-          {
-            s << ": failed to execute";
-            throw std::runtime_error(s.str());
-          }
-        // For POSIX shells, "The exit status of a command that
-        // terminated because it received a signal shall be reported
-        // as greater than 128."
-        if (WIFEXITED(res) && WEXITSTATUS(res) >= 128)
-          {
-            s << ": terminated by signal";
-            throw std::runtime_error(s.str());
-          }
-        if (WIFSIGNALED(res))
-          {
-            s << ": terminated by signal " << WTERMSIG(res);
-            throw std::runtime_error(s.str());
-          }
-        return res;
-      }
-    };
-  }
-
   satsolver::solution
   satsolver_get_solution(const char* filename)
   {
@@ -122,17 +69,35 @@ namespace spot
     return sol;
   }
 
+  // In other functions, command_given() won't be called anymore as it is more
+  // easy to check if psat_ was initialized or not.
   satsolver::satsolver()
-    : cnf_tmp_(nullptr), cnf_stream_(nullptr)
+    : cnf_tmp_(nullptr), cnf_stream_(nullptr), nclauses_(0), nvars_(0),
+      psat_(nullptr)
   {
-    start();
+    if (cmd_.command_given())
+    {
+      start();
+    }
+    else
+    {
+      psat_ = picosat_init();
+      picosat_set_seed(psat_, 0);
+    }
   }
 
   satsolver::~satsolver()
   {
-    delete cnf_tmp_;
-    delete cnf_stream_;
-    delete nclauses_;
+    if (psat_)
+    {
+      picosat_reset(psat_);
+      psat_ = nullptr;
+    }
+    else
+    {
+      delete cnf_tmp_;
+      delete cnf_stream_;
+    }
   }
 
   void satsolver::start()
@@ -140,70 +105,192 @@ namespace spot
     cnf_tmp_ = create_tmpfile("sat-", ".cnf");
     cnf_stream_ = new std::ofstream(cnf_tmp_->name(), std::ios_base::trunc);
     cnf_stream_->exceptions(std::ofstream::failbit | std::ofstream::badbit);
-    nclauses_ = new clause_counter();
 
     // Add empty line for the header
     *cnf_stream_ << "                                                 \n";
   }
 
+  // Must be called only when SPOT_SATSOLVER is given
   void satsolver::end_clause()
   {
     *cnf_stream_ << '\n';
-    *nclauses_ += 1;
+    nclauses_ += 1;
+    if (nclauses_ < 0)
+      throw std::runtime_error("too many SAT clauses (more than INT_MAX)");
+  }
+
+  void satsolver::adjust_nvars(int nvars)
+  {
+    if (nvars < 0)
+      throw std::runtime_error("variable number must be at least 0");
+
+    if (psat_)
+    {
+      picosat_adjust(psat_, nvars);
+    }
+    else
+    {
+      if (nvars < nvars_)
+      {
+        throw std::runtime_error(
+            "wrong number of variables, a bigger one was already added");
+      }
+      nvars_ = nvars;
+    }
   }
 
   void satsolver::add(std::initializer_list<int> values)
   {
     for (auto& v : values)
     {
-      *cnf_stream_ << v << ' ';
-      if (!v) // ..., 0)
-        end_clause();
+      if (psat_)
+      {
+        picosat_add(psat_, v);
+      }
+      else
+      {
+        *cnf_stream_ << v << ' ';
+        if (!v) // ..., 0)
+          end_clause();
+
+        if (nvars_ < v)
+          nvars_ = v;
+      }
     }
   }
 
   void satsolver::add(int v)
   {
-    *cnf_stream_ << v << ' ';
-    if (!v) // 0
-      end_clause();
+    if (psat_)
+    {
+      picosat_add(psat_, v);
+    }
+    else
+    {
+      *cnf_stream_ << v << ' ';
+      if (!v) // 0
+        end_clause();
+
+      if (v && nvars_ < v)
+        nvars_ = v;
+    }
   }
 
   int satsolver::get_nb_clauses() const
   {
-    return nclauses_->nb_clauses();
+    if (psat_)
+      return picosat_added_original_clauses(psat_);
+    return nclauses_;
   }
 
-  std::pair<int, int> satsolver::stats(int nvars)
+  int satsolver::get_nb_vars() const
   {
-    int nclaus = nclauses_->nb_clauses();
-    cnf_stream_->seekp(0);
-    *cnf_stream_ << "p cnf " << nvars << ' ' << nclaus;
-    return std::make_pair(nvars, nclaus);
+    if (psat_)
+      return picosat_variables(psat_);
+    return nvars_;
   }
 
   std::pair<int, int> satsolver::stats()
   {
-    *cnf_stream_ << "p cnf 1 2\n-1 0\n1 0\n";
-    return std::make_pair(1, 2);
+    return std::make_pair(get_nb_vars(), get_nb_clauses());
+  }
+
+  satsolver::solution
+  satsolver::picosat_get_solution(int res)
+  {
+    satsolver::solution sol;
+    if (res == PICOSAT_SATISFIABLE)
+    {
+      int nvars = get_nb_vars();
+      for (int lit = 1; lit <= nvars; ++lit)
+      {
+        if (picosat_deref(psat_, lit) > 0)
+          sol.push_back(lit);
+        else
+          sol.push_back(-lit);
+      }
+    }
+    return sol;
   }
 
   satsolver::solution_pair
   satsolver::get_solution()
   {
-    delete cnf_stream_;                // Close the file.
-    cnf_stream_ = nullptr;
-
-    temporary_file* output = create_tmpfile("sat-", ".out");
     solution_pair p;
+    if (psat_)
+    {
+      p.first = 0; // A subprocess was not executed so nothing failed.
+      int res = picosat_sat(psat_, -1); // -1: no limit (number of decisions).
+      p.second = picosat_get_solution(res);
+    }
+    else
+    {
+      // Update header
+      cnf_stream_->seekp(0);
+      *cnf_stream_ << "p cnf " << get_nb_vars() << ' ' << get_nb_clauses();
+      cnf_stream_->seekp(0, std::ios_base::end);
+      if (!*cnf_stream_)
+        throw std::runtime_error("Failed to update cnf header");
 
-    // Make this static, so the SPOT_SATSOLVER lookup is done only on
-    // the first call to run_sat().
-    static satsolver_command cmd;
-
-    p.first = cmd.run(cnf_tmp_, output);
-    p.second = satsolver_get_solution(output->name());
-    delete output;
+      temporary_file* output = create_tmpfile("sat-", ".out");
+      p.first = cmd_.run(cnf_tmp_, output);
+      p.second = satsolver_get_solution(output->name());
+      delete output;
+    }
     return p;
   }
+
+  satsolver_command::satsolver_command() : satsolver(nullptr)
+  {
+    satsolver = getenv("SPOT_SATSOLVER");
+    if (!satsolver)
+      return;
+
+    prime(satsolver);
+    if (!has('I'))
+      throw std::runtime_error("SPOT_SATSOLVER should contain %I to "
+          "indicate how to use the input filename.");
+    if (!has('O'))
+      throw std::runtime_error("SPOT_SATSOLVER should contain %O to "
+          "indicate how to use the output filename.");
+  }
+
+  bool
+  satsolver_command::command_given()
+  {
+    return satsolver != nullptr;
+  }
+
+  int
+  satsolver_command::run(printable* in, printable* out)
+  {
+    declare('I', in);
+    declare('O', out);
+    std::ostringstream s;
+    format(s, satsolver);
+
+    int res = system(s.str().c_str());
+    if (res < 0 || (WIFEXITED(res) && WEXITSTATUS(res) == 127))
+    {
+      s << ": failed to execute";
+      throw std::runtime_error(s.str());
+    }
+
+    // For POSIX shells, "The exit status of a command that
+    // terminated because it received a signal shall be reported
+    // as greater than 128."
+    if (WIFEXITED(res) && WEXITSTATUS(res) >= 128)
+    {
+      s << ": terminated by signal";
+      throw std::runtime_error(s.str());
+    }
+
+    if (WIFSIGNALED(res))
+    {
+      s << ": terminated by signal " << WTERMSIG(res);
+      throw std::runtime_error(s.str());
+    }
+
+    return res;
+  }
 }

spot/misc/satsolver.hh

@@ -26,68 +26,58 @@
 #include <iosfwd>
 #include <initializer_list>
 
+struct PicoSAT; // forward
+
 namespace spot
 {
   class printable;
 
-  class clause_counter
+  /// \brief Interface with a given sat solver.
+  ///
+  /// When created, it checks if SPOT_SATSOLVER env var is set. If so,
+  /// its value is parsed and saved internally. The env variable musb be set
+  /// like this: "<satsolver> [its_options] %I > %O"
+  /// where %I and %O are replaced by input and output files.
+  ///
+  /// The run method permits of course to run the given sat solver.
+  class satsolver_command: formater
   {
   private:
-    int count_;
+    const char* satsolver;
 
   public:
-    clause_counter()
-      : count_(0)
-    {
-    }
-
-    void check() const
-    {
-      if (count_ < 0)
-        throw std::runtime_error("too many SAT clauses (more than INT_MAX)");
-    }
+    satsolver_command();
 
-    clause_counter& operator++()
-    {