Allow Rust-language related assets to be disabled with `--disable-rust`.

configure.ac

@@ -88,6 +88,12 @@ AC_ARG_ENABLE([mining],
   [enable_mining=$enableval],
   [enable_mining=yes])
 
+AC_ARG_ENABLE([rust],
+  [AS_HELP_STRING([--enable-rust],
+  [enable rust (default is yes)])],
+  [enable_rust=$enableval],
+  [enable_rust=yes])
+
 AC_ARG_WITH([miniupnpc],
   [AS_HELP_STRING([--with-miniupnpc],
   [enable UPNP (default is yes if libminiupnpc is found)])],
@@ -751,7 +757,12 @@ CPPFLAGS="-I$LIBSNARK_INCDIR $CPPFLAGS"
 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])
 
-LIBZCASH_LIBS="-lrustzcash -lsnark -lgmp -lgmpxx -lboost_system-mt -lcrypto -lsodium -fopenmp"
+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"
 
 CXXFLAGS_TEMP="$CXXFLAGS"
 LIBS_TEMP="$LIBS"
@@ -819,6 +830,16 @@ else
   AC_MSG_RESULT(no)
 fi
 
+dnl enable rust
+AC_MSG_CHECKING([if rust should be enabled])
+if test x$enable_rust != xno; then
+  AC_MSG_RESULT(yes)
+  AC_DEFINE(ENABLE_RUST, 1, [Define to 1 to enable Rust language dependent functions])
+
+else
+  AC_MSG_RESULT(no)
+fi
+
 dnl enable upnp support
 AC_MSG_CHECKING([whether to build with support for UPnP])
 if test x$have_miniupnpc = xno; then
@@ -873,6 +894,7 @@ AM_CONDITIONAL([BUILD_DARWIN], [test x$BUILD_OS = xdarwin])
 AM_CONDITIONAL([TARGET_WINDOWS], [test x$TARGET_OS = xwindows])
 AM_CONDITIONAL([ENABLE_WALLET],[test x$enable_wallet = xyes])
 AM_CONDITIONAL([ENABLE_MINING],[test x$enable_mining = xyes])
+AM_CONDITIONAL([ENABLE_RUST],[test x$enable_rust = xyes])
 AM_CONDITIONAL([ENABLE_TESTS],[test x$BUILD_TEST = xyes])
 AM_CONDITIONAL([USE_LCOV],[test x$use_lcov = xyes])
 AM_CONDITIONAL([USE_COMPARISON_TOOL],[test x$use_comparison_tool != xno])

depends/Makefile

@@ -72,10 +72,11 @@ include builders/$(build_os).mk
 include builders/default.mk
 include packages/packages.mk
 
+rust_packages_$(NO_RUST) = $(rust_packages)
 wallet_packages_$(NO_WALLET) = $(wallet_packages)
 upnp_packages_$(NO_UPNP) = $(upnp_packages)
 
-packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(wallet_packages_) $(upnp_packages_)
+packages += $($(host_arch)_$(host_os)_packages) $($(host_os)_packages) $(rust_packages_) $(wallet_packages_) $(upnp_packages_)
 native_packages += $($(host_arch)_$(host_os)_native_packages) $($(host_os)_native_packages)
 all_packages = $(packages) $(native_packages)
 

depends/packages/packages.mk

@@ -1,4 +1,5 @@
-zcash_packages := libsnark libgmp libsodium rust librustzcash
+rust_packages := rust librustzcash
+zcash_packages := libsnark libgmp libsodium
 packages := boost openssl zeromq $(zcash_packages) googletest googlemock
 native_packages := native_ccache
 

src/pow.cpp

@@ -5,8 +5,6 @@
 
 #include "pow.h"
 
-#include "librustzcash.h"
-
 #include "arith_uint256.h"
 #include "chain.h"
 #include "chainparams.h"
@@ -18,6 +16,10 @@
 
 #include "sodium.h"
 
+#ifdef ENABLE_RUST
+#include "librustzcash.h"
+#endif // ENABLE_RUST
+
 unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
 {
     unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
@@ -98,11 +100,13 @@ bool CheckEquihashSolution(const CBlockHeader *pblock, const CChainParams& param
     // H(I||V||...
     crypto_generichash_blake2b_update(&state, (unsigned char*)&ss[0], ss.size());
 
+    #ifdef ENABLE_RUST
     // Ensure that our Rust interactions are working in production builds. This is
     // temporary and should be removed.
     {
         assert(librustzcash_xor(0x0f0f0f0f0f0f0f0f, 0x1111111111111111) == 0x1e1e1e1e1e1e1e1e);
     }
+    #endif // ENABLE_RUST
 
     bool isValid;
     EhIsValidSolution(n, k, state, pblock->nSolution, isValid);

zcutil/build.sh

@@ -33,7 +33,7 @@ Usage:
 $0 --help
   Show this help message and exit.
 
-$0 [ --enable-lcov || --disable-tests ] [ --disable-mining ] [ MAKEARGS... ]
+$0 [ --enable-lcov || --disable-tests ] [ --disable-mining ] [ --disable-rust ] [ MAKEARGS... ]
   Build Zcash and most of its transitive dependencies from
   source. MAKEARGS are applied to both dependencies and Zcash itself.
 
@@ -43,6 +43,9 @@ $0 [ --enable-lcov || --disable-tests ] [ --disable-mining ] [ MAKEARGS... ]
 
   If --disable-mining is passed, Zcash is configured to not build any mining
   code. It must be passed after the test arguments, if present.
+
+  If --disable-rust is passed, Zcash is configured to not build any Rust language
+  assets. It must be passed after mining/test arguments, if present.
 EOF
     exit 0
 fi
@@ -73,9 +76,17 @@ then
     shift
 fi
 
+# If --disable-rust is the next argument, disable Rust code:
+RUST_ARG=''
+if [ "x${1:-}" = 'x--disable-rust' ]
+then
+    RUST_ARG='--enable-rust=no'
+    shift
+fi
+
 PREFIX="$(pwd)/depends/$BUILD/"
 
-HOST="$HOST" BUILD="$BUILD" "$MAKE" "$@" -C ./depends/ V=1
+HOST="$HOST" BUILD="$BUILD" NO_RUST="$RUST_ARG" "$MAKE" "$@" -C ./depends/ V=1
 ./autogen.sh
-CC="$CC" CXX="$CXX" ./configure --prefix="${PREFIX}" --host="$HOST" --build="$BUILD" "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" CXXFLAGS='-fwrapv -fno-strict-aliasing -Werror -g'
+CC="$CC" CXX="$CXX" ./configure --prefix="${PREFIX}" --host="$HOST" --build="$BUILD" "$RUST_ARG" "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" CXXFLAGS='-fwrapv -fno-strict-aliasing -Werror -g'
 "$MAKE" "$@" V=1