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).

1 files changed, 51 insertions, 0 deletions

diff --git a/contrib/get-lfsc-checker b/contrib/get-lfsc-checker
new file mode 100755
index 000000000..495082387
--- /dev/null
+++ b/contrib/get-lfsc-checker
@@ -0,0 +1,51 @@
+#!/bin/bash
+#
+set -e
+
+lfscrepo="https://github.com/CVC4/LFSC.git"
+dirname="lfsc-checker"
+
+
+cd "$(dirname "$0")/.."
+
+if ! [ -e src/parser/cvc/Cvc.g ]; then
+  echo "$(basename $0): I expect to be in the contrib/ of a CVC4 source tree," >&2
+  echo "but apparently:" >&2
+  echo >&2
+  echo "  $(pwd)" >&2
+  echo >&2
+  echo "is not a CVC4 source tree ?!" >&2
+  exit 1
+fi
+
+function gitclone {
+  if which git &> /dev/null
+  then
+    git clone "$1" "$2"
+  else
+    echo "Need git to clone LFSC checker. Please install git." >&2
+    exit 1
+  fi
+}
+
+if [ -e lfsc-checker ]; then
+  echo 'error: file or directory "lfsc-checker" already exists!' >&2
+  exit 1
+fi
+
+mkdir $dirname
+cd $dirname
+
+LFSC_PATH=`pwd`
+
+gitclone $lfscrepo .
+mkdir install
+mkdir build
+cd build
+cmake -DCMAKE_INSTALL_PREFIX:PATH=$LFSC_PATH/install ..
+make install
+cd ..
+
+echo
+echo ===================== Now configure CVC4 with =====================
+echo ./configure --with-lfsc