Remove libsnark from depends system and integrate it into build system.

configure.ac

@@ -757,28 +757,12 @@ AC_CHECK_LIB([gmp],[[__gmpn_sub_n]],GMP_LIBS=-lgmp, [AC_MSG_ERROR(libgmp missing
 AC_CHECK_HEADER([gmpxx.h],,AC_MSG_ERROR(libgmpxx headers missing))
 AC_CHECK_LIB([gmpxx],[main],GMPXX_LIBS=-lgmpxx, [AC_MSG_ERROR(libgmpxx missing)])
 
-# libsnark header layout is broken unless cpp's -I is passed with the
-# libsnark directory, so for now we use this hideous workaround:
-echo 'Hunting for libsnark include directory...'
-[LIBSNARK_INCDIR="$(echo "$CPPFLAGS" | sed 's,^.*-I\([^ ]*/include\).*$,\1/libsnark,')"]
-if test -d "$LIBSNARK_INCDIR"; then
-   echo "Found libsnark include directory: $LIBSNARK_INCDIR"
-else
-    AC_MSG_ERROR(libsnark include directory not found)
-fi
-
-CPPFLAGS="-I$LIBSNARK_INCDIR $CPPFLAGS"
-
-# Now check for libsnark compilability using traditional autoconf tests:
-AC_CHECK_HEADER([libsnark/gadgetlib1/gadget.hpp],,AC_MSG_ERROR(libsnark headers missing))
-AC_CHECK_LIB([snark],[main],LIBSNARK_LIBS=-lsnark, [AC_MSG_ERROR(libsnark missing)], [-lgmpxx])
-
 RUST_LIBS=""
 if test x$enable_rust != xno; then
   RUST_LIBS="-lrustzcash"
 fi
 
-LIBZCASH_LIBS="-lsnark -lgmp -lgmpxx -lboost_system-mt -lcrypto -lsodium -fopenmp $RUST_LIBS"
+LIBZCASH_LIBS="-lgmp -lgmpxx -lboost_system-mt -lcrypto -lsodium -fopenmp $RUST_LIBS"
 
 CXXFLAGS_TEMP="$CXXFLAGS"
 LIBS_TEMP="$LIBS"
@@ -944,7 +928,7 @@ unset PKG_CONFIG_LIBDIR
 PKG_CONFIG_LIBDIR="$PKGCONFIG_LIBDIR_TEMP"
 
 ac_configure_args="${ac_configure_args} --disable-shared --with-pic --with-bignum=no --enable-module-recovery"
-AC_CONFIG_SUBDIRS([src/secp256k1 src/univalue])
+AC_CONFIG_SUBDIRS([src/secp256k1 src/snark src/univalue])
 
 AC_OUTPUT