Merge #18677: Multiprocess build support

e2bab2aa162ae38b2bf8195b577c982402fbee9d multiprocess: add multiprocess travis configuration (Russell Yanofsky)
603fd6a2e708c04ef6c9880f89d0a4cbaa6fc7c5 depends: add MULTIPROCESS depends option (Russell Yanofsky)
5d1377b52bfcd4edf8553aaf332bfeb92fc554cc build: multiprocess autotools changes (Russell Yanofsky)

Pull request description:

  This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).

  ---

  This PR consists of build changes only. It adds an `--enable-multiprocess` autoconf option (off by default and marked experimental), that builds new `bitcoin-node` and `bitcoin-gui` binaries. These currently function the same as existing `bitcoind` and `bitcoin-qt` binaries, but are extended in #10102 with IPC features to execute node, wallet, and gui functions in separate processes.

  In addition to adding the `--enable-multiprocess` config flag, it also adds a depends package and autoconf rules to build with the [libmultiprocess](https://github.com/chaincodelabs/libmultiprocess) library, and it adds new travis configuration to exercise the build code and run functional tests with the new binaries.

  The changes in this PR were originally part of #10102 but were moved into #16367 to be able to develop and review the multiprocess build changes independently of the code changes. #16367 was briefly merged and then reverted in #18588. Only change since #16367 has been dropping the `native_boost.mk` depends package which was pointed out to be no longer necessary in https://github.com/bitcoin/bitcoin/pull/16367#issuecomment-596484337 and https://github.com/bitcoin/bitcoin/pull/18588#pullrequestreview-391765649

ACKs for top commit:
  practicalswift:
    ACK e2bab2aa162ae38b2bf8195b577c982402fbee9d
  Sjors:
    tACK e2bab2aa162ae38b2bf8195b577c982402fbee9d on macOS 10.15.4
  hebasto:
    ACK e2bab2aa162ae38b2bf8195b577c982402fbee9d, tested on Linux Mint 19.3 (x86_64):

Tree-SHA512: b5a76eab5abf63d9d8b6d628cbdff4cc1888eef15cafa0a5d56369e2f9d02595fed623f4b74b2cf2830c42c05a774f0943e700f9c768a82d9d348cad199e135c

1 files changed, 29 insertions, 29 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 13812de0e7..c5cd1c1ea7 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -85,6 +85,10 @@ if BUILD_BITCOIND
   bin_PROGRAMS += bitcoind
 endif
 
+if BUILD_BITCOIN_NODE
+  bin_PROGRAMS += bitcoin-node
+endif
+
 if BUILD_BITCOIN_CLI
   bin_PROGRAMS += bitcoin-cli
 endif
@@ -546,22 +550,21 @@ libbitcoin_cli_a_SOURCES = \
 nodist_libbitcoin_util_a_SOURCES = $(srcdir)/obj/build.h
 #
 
-# bitcoind binary #
-bitcoind_SOURCES = bitcoind.cpp
-bitcoind_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
-bitcoind_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
-bitcoind_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+# bitcoind & bitcoin-node binaries #
+bitcoin_daemon_sources = bitcoind.cpp
+bitcoin_bin_cppflags = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+bitcoin_bin_cxxflags = $(AM_CXXFLAGS) $(PIE_FLAGS)
+bitcoin_bin_ldflags = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 
 if TARGET_WINDOWS
-bitcoind_SOURCES += bitcoind-res.rc
+bitcoin_daemon_sources += bitcoind-res.rc
 endif
 
-bitcoind_LDADD = \
-  $(LIBBITCOIN_SERVER) \
+bitcoin_bin_ldadd = \
   $(LIBBITCOIN_WALLET) \
   $(LIBBITCOIN_COMMON) \
-  $(LIBUNIVALUE) \
   $(LIBBITCOIN_UTIL) \
+  $(LIBUNIVALUE) \
   $(LIBBITCOIN_ZMQ) \
   $(LIBBITCOIN_CONSENSUS) \
   $(LIBBITCOIN_CRYPTO) \
@@ -570,7 +573,19 @@ bitcoind_LDADD = \
   $(LIBMEMENV) \
   $(LIBSECP256K1)
 
-bitcoind_LDADD += $(BOOST_LIBS) $(BDB_LIBS) $(MINIUPNPC_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(ZMQ_LIBS)
+bitcoin_bin_ldadd += $(BOOST_LIBS) $(BDB_LIBS) $(MINIUPNPC_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(ZMQ_LIBS)
+
+bitcoind_SOURCES = $(bitcoin_daemon_sources)
+bitcoind_CPPFLAGS = $(bitcoin_bin_cppflags)
+bitcoind_CXXFLAGS = $(bitcoin_bin_cxxflags)
+bitcoind_LDFLAGS = $(bitcoin_bin_ldflags)
+bitcoind_LDADD = $(LIBBITCOIN_SERVER) $(bitcoin_bin_ldadd)
+
+bitcoin_node_SOURCES = $(bitcoin_daemon_sources)
+bitcoin_node_CPPFLAGS = $(bitcoin_bin_cppflags)
+bitcoin_node_CXXFLAGS = $(bitcoin_bin_cxxflags)
+bitcoin_node_LDFLAGS = $(bitcoin_bin_ldflags)
+bitcoin_node_LDADD = $(LIBBITCOIN_SERVER) $(bitcoin_bin_ldadd)
 
 # bitcoin-cli binary #
 bitcoin_cli_SOURCES = bitcoin-cli.cpp
@@ -614,29 +629,14 @@ bitcoin_tx_LDADD += $(BOOST_LIBS)
 
 # bitcoin-wallet binary #
 bitcoin_wallet_SOURCES = bitcoin-wallet.cpp
-bitcoin_wallet_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
-bitcoin_wallet_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
-bitcoin_wallet_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+bitcoin_wallet_CPPFLAGS = $(bitcoin_bin_cppflags)
+bitcoin_wallet_CXXFLAGS = $(bitcoin_bin_cxxflags)
+bitcoin_wallet_LDFLAGS = $(bitcoin_bin_ldflags)
+bitcoin_wallet_LDADD = $(LIBBITCOIN_WALLET_TOOL) $(bitcoin_bin_ldadd)
 
 if TARGET_WINDOWS
 bitcoin_wallet_SOURCES += bitcoin-wallet-res.rc
 endif
-
-bitcoin_wallet_LDADD = \
-  $(LIBBITCOIN_WALLET_TOOL) \
-  $(LIBBITCOIN_WALLET) \
-  $(LIBBITCOIN_COMMON) \
-  $(LIBBITCOIN_CONSENSUS) \
-  $(LIBBITCOIN_UTIL) \
-  $(LIBBITCOIN_CRYPTO) \
-  $(LIBBITCOIN_ZMQ) \
-  $(LIBLEVELDB) \
-  $(LIBLEVELDB_SSE42) \
-  $(LIBMEMENV) \
-  $(LIBSECP256K1) \
-  $(LIBUNIVALUE)
-
-bitcoin_wallet_LDADD += $(BOOST_LIBS) $(BDB_LIBS) $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS) $(MINIUPNPC_LIBS) $(ZMQ_LIBS)
 #
 
 # bitcoinconsensus library #