Move LFSC checker out of the CVC repository. (#222)

LFSC now lives outside of the CVC4 repository and is not part of the CVC4 distribution
anymore. As a consequence, we

+ Add --with-lfsc and --with-lfsc-directory as configure options.
   In the case where CVC4 has not been built with integrated LFSC, all code that interacts with
   LFSC is disabled.

+ Disable proof checking if CVC4_USE_LFSC is not defined.
   Configuring the build with --check-proofs but without --with-lfsc results in an error.

+ Do not call LFSC's cleanup function (but we should in the future).
   LFSC checker segfaults during cleanup on regression testcase regress0/bv/core/bitvec7.smt.
   Disabled call to lfscc_cleanup until the problem in lfscc is fixed.

+ Disable building with LFSC for the distcheck travis build since it is not part of the distribution
   anymore. Further, make distcheck with LFSC would require to call contrib/get-lfsc-checker
   before calling make check on the temp build (the build of the unpacked distribution tar ball).

3 files changed, 13 insertions, 1 deletions

diff --git a/src/options/options_handler.cpp b/src/options/options_handler.cpp
index 5658b17b0..87dc1ecc1 100644
--- a/src/options/options_handler.cpp
+++ b/src/options/options_handler.cpp
@@ -1281,6 +1281,17 @@ void OptionsHandler::proofEnabledBuild(std::string option, bool value) throw(Opt
 #endif /* CVC4_PROOF */
 }
 
+void OptionsHandler::LFSCEnabledBuild(std::string option, bool value) {
+#ifndef CVC4_USE_LFSC
+  if (value) {
+    std::stringstream ss;
+    ss << "option `" << option << "' requires a build of CVC4 with integrated "
+                                  "LFSC; this binary was not built with LFSC";
+    throw OptionException(ss.str());
+  }
+#endif /* CVC4_USE_LFSC */
+}
+
 void OptionsHandler::notifyDumpToFile(std::string option) {
   d_options->d_dumpToFileListeners.notify();
 }
diff --git a/src/options/options_handler.h b/src/options/options_handler.h
index 16c77b166..923a87d3a 100644
--- a/src/options/options_handler.h
+++ b/src/options/options_handler.h
@@ -143,6 +143,7 @@ public:
   SimplificationMode stringToSimplificationMode(std::string option, std::string optarg) throw(OptionException);
   void setProduceAssertions(std::string option, bool value) throw();
   void proofEnabledBuild(std::string option, bool value) throw(OptionException);
+  void LFSCEnabledBuild(std::string option, bool value);
   void notifyDumpToFile(std::string option);
   void notifySetRegularOutputChannel(std::string option);
   void notifySetDiagnosticOutputChannel(std::string option);
diff --git a/src/options/smt_options b/src/options/smt_options
index 5f50ed202..00424e103 100644
--- a/src/options/smt_options
+++ b/src/options/smt_options
@@ -33,7 +33,7 @@ option omitDontCares --omit-dont-cares bool :default false
  When producing a model, omit variables whose value does not matter
 option proof produce-proofs --proof bool :default false :predicate proofEnabledBuild :notify notifyBeforeSearch
  turn on proof generation
-option checkProofs check-proofs --check-proofs bool :link --proof :link-smt produce-proofs :notify notifyBeforeSearch :read-write
+option checkProofs check-proofs --check-proofs bool :link --proof :link-smt produce-proofs :predicate LFSCEnabledBuild :notify notifyBeforeSearch :read-write
  after UNSAT/VALID, machine-check the generated proof
 option dumpProofs --dump-proofs bool :default false :link --proof :link-smt produce-proofs
  output proofs after every UNSAT/VALID response