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

2 files changed, 60 insertions, 41 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 #
diff --git a/src/Makefile.qt.include b/src/Makefile.qt.include
index cf09eee2cb..13bfea7646 100644
--- a/src/Makefile.qt.include
+++ b/src/Makefile.qt.include
@@ -3,6 +3,11 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 bin_PROGRAMS += qt/bitcoin-qt
+
+if BUILD_BITCOIN_GUI
+  bin_PROGRAMS += bitcoin-gui
+endif
+
 EXTRA_LIBRARIES += qt/libbitcoinqt.a
 
 # bitcoin qt core #
@@ -294,29 +299,43 @@ QT_FORMS_H=$(join $(dir $(QT_FORMS_UI)),$(addprefix ui_, $(notdir $(QT_FORMS_UI:
 # Most files will depend on the forms and moc files as includes. Generate them
 # before anything else.
 $(QT_MOC): $(QT_FORMS_H)
-$(qt_libbitcoinqt_a_OBJECTS) $(qt_bitcoin_qt_OBJECTS) : | $(QT_MOC)
+$(qt_libbitcoinqt_a_OBJECTS) $(qt_bitcoin_qt_OBJECTS) $(bitcoin_gui_OBJECTS) : | $(QT_MOC)
 
-# bitcoin-qt binary #
-qt_bitcoin_qt_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(BITCOIN_QT_INCLUDES) \
+# bitcoin-qt and bitcoin-gui binaries #
+bitcoin_qt_cppflags = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(BITCOIN_QT_INCLUDES) \
   $(QT_INCLUDES) $(QR_CFLAGS)
-qt_bitcoin_qt_CXXFLAGS = $(AM_CXXFLAGS) $(QT_PIE_FLAGS)
+bitcoin_qt_cxxflags = $(AM_CXXFLAGS) $(QT_PIE_FLAGS)
 
-qt_bitcoin_qt_SOURCES = qt/main.cpp
+bitcoin_qt_sources = qt/main.cpp
 if TARGET_WINDOWS
-  qt_bitcoin_qt_SOURCES += $(BITCOIN_RC)
+  bitcoin_qt_sources += $(BITCOIN_RC)
 endif
-qt_bitcoin_qt_LDADD = qt/libbitcoinqt.a $(LIBBITCOIN_SERVER)
+bitcoin_qt_ldadd = qt/libbitcoinqt.a $(LIBBITCOIN_SERVER)
 if ENABLE_WALLET
-qt_bitcoin_qt_LDADD += $(LIBBITCOIN_UTIL) $(LIBBITCOIN_WALLET)
+bitcoin_qt_ldadd += $(LIBBITCOIN_UTIL) $(LIBBITCOIN_WALLET)
 endif
 if ENABLE_ZMQ
-qt_bitcoin_qt_LDADD += $(LIBBITCOIN_ZMQ) $(ZMQ_LIBS)
+bitcoin_qt_ldadd += $(LIBBITCOIN_ZMQ) $(ZMQ_LIBS)
 endif
-qt_bitcoin_qt_LDADD += $(LIBBITCOIN_CLI) $(LIBBITCOIN_COMMON) $(LIBBITCOIN_UTIL) $(LIBBITCOIN_CONSENSUS) $(LIBBITCOIN_CRYPTO) $(LIBUNIVALUE) $(LIBLEVELDB) $(LIBLEVELDB_SSE42) $(LIBMEMENV) \
+bitcoin_qt_ldadd += $(LIBBITCOIN_CLI) $(LIBBITCOIN_COMMON) $(LIBBITCOIN_UTIL) $(LIBBITCOIN_CONSENSUS) $(LIBBITCOIN_CRYPTO) $(LIBUNIVALUE) $(LIBLEVELDB) $(LIBLEVELDB_SSE42) $(LIBMEMENV) \
   $(BOOST_LIBS) $(QT_LIBS) $(QT_DBUS_LIBS) $(QR_LIBS) $(BDB_LIBS) $(MINIUPNPC_LIBS) $(LIBSECP256K1) \
   $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS)
-qt_bitcoin_qt_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(QT_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
-qt_bitcoin_qt_LIBTOOLFLAGS = $(AM_LIBTOOLFLAGS) --tag CXX
+bitcoin_qt_ldflags = $(RELDFLAGS) $(AM_LDFLAGS) $(QT_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+bitcoin_qt_libtoolflags = $(AM_LIBTOOLFLAGS) --tag CXX
+
+qt_bitcoin_qt_CPPFLAGS = $(bitcoin_qt_cppflags)
+qt_bitcoin_qt_CXXFLAGS = $(bitcoin_qt_cxxflags)
+qt_bitcoin_qt_SOURCES = $(bitcoin_qt_sources)
+qt_bitcoin_qt_LDADD = $(bitcoin_qt_ldadd)
+qt_bitcoin_qt_LDFLAGS = $(bitcoin_qt_ldflags)
+qt_bitcoin_qt_LIBTOOLFLAGS = $(bitcoin_qt_libtoolflags)
+
+bitcoin_gui_CPPFLAGS = $(bitcoin_qt_cppflags)
+bitcoin_gui_CXXFLAGS = $(bitcoin_qt_cxxflags)
+bitcoin_gui_SOURCES = $(bitcoin_qt_sources)
+bitcoin_gui_LDADD = $(bitcoin_qt_ldadd)
+bitcoin_gui_LDFLAGS = $(bitcoin_qt_ldflags)
+bitcoin_gui_LIBTOOLFLAGS = $(bitcoin_qt_libtoolflags)
 
 #locale/foo.ts -> locale/foo.qm
 QT_QM=$(QT_TS:.ts=.qm)