Merge bitcoin/bitcoin#29876: build: add `-Wundef`

e3dc64f4990a15df3fd6147831f66fc2a31c71ad build: add -Wundef (fanquake)
82b43955f7948b225bebd08851a616d17f70a926 refactor: use #ifdef HAVE_SOCKADDR_UN (fanquake)
40cd7585a042938937b5964c9c264e2bf4a80742 randomenv: use ifdef over if (fanquake)
7839503b309c107e8229475a8fbf66601b0e7e8e zmq: use #ifdef ENABLE_ZMQ (fanquake)
79e197b17536b52647599ad9b3f09d2556f14385 build: Suppress warnings from boost and capnproto in multiprocess code (Ryan Ofsky)

Pull request description:

  Turn on `-Wundef`.

  [> Warn if an undefined identifier is evaluated in an #if directive. Such identifiers are replaced with zero.](https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wundef).

  Note that this is still beneficial with CMake, and may even be nice to have enabled prior, to catch any change in behaviour.

  If we end up with this enabled, it should probably be enough to fix #16419.

ACKs for top commit:
  hebasto:
    ACK e3dc64f4990a15df3fd6147831f66fc2a31c71ad, I have reviewed the code and it looks OK.

Tree-SHA512: 73436ead07f3a09ba0d30f7105df50d9b2ec8452f11e866bc1c7ebc10c005772ee77fedaa125f444175663c04dfc472f98c2699c63711da356089b66a8cc3e0a

5 files changed, 24 insertions, 20 deletions

diff --git a/configure.ac b/configure.ac
index ab369cc98a..23b8870d43 100644
--- a/configure.ac
+++ b/configure.ac
@@ -405,6 +405,7 @@ AX_CHECK_COMPILE_FLAG([-Wimplicit-fallthrough], [WARN_CXXFLAGS="$WARN_CXXFLAGS -
 AX_CHECK_COMPILE_FLAG([-Wunreachable-code], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wunreachable-code"], [], [$CXXFLAG_WERROR])
 AX_CHECK_COMPILE_FLAG([-Wdocumentation], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wdocumentation"], [], [$CXXFLAG_WERROR])
 AX_CHECK_COMPILE_FLAG([-Wself-assign], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wself-assign"], [], [$CXXFLAG_WERROR])
+AX_CHECK_COMPILE_FLAG([-Wundef], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wundef"], [], [$CXXFLAG_WERROR])
 
 dnl Some compilers (gcc) ignore unknown -Wno-* options, but warn about all
 dnl unknown options if any other warning is produced. Test the -Wfoo case, and
@@ -1392,6 +1393,9 @@ if test "$with_libmultiprocess" = "yes" || test "$with_libmultiprocess" = "auto"
   PKG_CHECK_MODULES([LIBMULTIPROCESS], [libmultiprocess], [
      libmultiprocess_found=yes;
      libmultiprocess_prefix=`$PKG_CONFIG --variable=prefix libmultiprocess`;
+     if test "$suppress_external_warnings" != "no" ; then
+       LIBMULTIPROCESS_CFLAGS=SUPPRESS_WARNINGS($LIBMULTIPROCESS_CFLAGS)
+     fi
   ], [true])
 elif test "$with_libmultiprocess" != "no"; then
   AC_MSG_ERROR([--with-libmultiprocess=$with_libmultiprocess value is not yes, auto, or no])
diff --git a/src/Makefile.am b/src/Makefile.am
index 4a1973aa87..fa1612b5b8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1088,7 +1088,7 @@ libbitcoin_ipc_a_SOURCES = \
   ipc/process.cpp \
   ipc/process.h \
   ipc/protocol.h
-libbitcoin_ipc_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+libbitcoin_ipc_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(BOOST_CPPFLAGS)
 libbitcoin_ipc_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS) $(LIBMULTIPROCESS_CFLAGS)
 
 include $(MPGEN_PREFIX)/include/mpgen.mk
diff --git a/src/init.cpp b/src/init.cpp
index 5bb82dc320..16cfa296cc 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -109,7 +109,7 @@
 
 #include <boost/signals2/signal.hpp>
 
-#if ENABLE_ZMQ
+#ifdef ENABLE_ZMQ
 #include <zmq/zmqabstractnotifier.h>
 #include <zmq/zmqnotificationinterface.h>
 #include <zmq/zmqrpc.h>
@@ -364,7 +364,7 @@ void Shutdown(NodeContext& node)
         client->stop();
     }
 
-#if ENABLE_ZMQ
+#ifdef ENABLE_ZMQ
     if (g_zmq_notification_interface) {
         if (node.validation_signals) node.validation_signals->UnregisterValidationInterface(g_zmq_notification_interface.get());
         g_zmq_notification_interface.reset();
@@ -531,7 +531,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-maxreceivebuffer=<n>", strprintf("Maximum per-connection receive buffer, <n>*1000 bytes (default: %u)", DEFAULT_MAXRECEIVEBUFFER), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-maxsendbuffer=<n>", strprintf("Maximum per-connection memory usage for the send buffer, <n>*1000 bytes (default: %u)", DEFAULT_MAXSENDBUFFER), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-maxuploadtarget=<n>", strprintf("Tries to keep outbound traffic under the given target per 24h. Limit does not apply to peers with 'download' permission or blocks created within past week. 0 = no limit (default: %s). Optional suffix units [k|K|m|M|g|G|t|T] (default: M). Lowercase is 1000 base while uppercase is 1024 base", DEFAULT_MAX_UPLOAD_TARGET), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
     argsman.AddArg("-onion=<ip:port|path>", "Use separate SOCKS5 proxy to reach peers via Tor onion services, set -noonion to disable (default: -proxy). May be a local file path prefixed with 'unix:'.", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
 #else
     argsman.AddArg("-onion=<ip:port>", "Use separate SOCKS5 proxy to reach peers via Tor onion services, set -noonion to disable (default: -proxy)", ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
@@ -544,7 +544,7 @@ void SetupServerArgs(ArgsManager& argsman)
     argsman.AddArg("-peerblockfilters", strprintf("Serve compact block filters to peers per BIP 157 (default: %u)", DEFAULT_PEERBLOCKFILTERS), ArgsManager::ALLOW_ANY, OptionsCategory::CONNECTION);
     argsman.AddArg("-txreconciliation", strprintf("Enable transaction reconciliations per BIP 330 (default: %d)", DEFAULT_TXRECONCILIATION_ENABLE), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::CONNECTION);
     argsman.AddArg("-port=<port>", strprintf("Listen for connections on <port> (default: %u, testnet: %u, signet: %u, regtest: %u). Not relevant for I2P (see doc/i2p.md).", defaultChainParams->GetDefaultPort(), testnetChainParams->GetDefaultPort(), signetChainParams->GetDefaultPort(), regtestChainParams->GetDefaultPort()), ArgsManager::ALLOW_ANY | ArgsManager::NETWORK_ONLY, OptionsCategory::CONNECTION);
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
     argsman.AddArg("-proxy=<ip:port|path>", "Connect through SOCKS5 proxy, set -noproxy to disable (default: disabled). May be a local file path prefixed with 'unix:' if the proxy supports it.", ArgsManager::ALLOW_ANY | ArgsManager::DISALLOW_ELISION, OptionsCategory::CONNECTION);
 #else
     argsman.AddArg("-proxy=<ip:port>", "Connect through SOCKS5 proxy, set -noproxy to disable (default: disabled)", ArgsManager::ALLOW_ANY | ArgsManager::DISALLOW_ELISION, OptionsCategory::CONNECTION);
@@ -578,7 +578,7 @@ void SetupServerArgs(ArgsManager& argsman)
 
     g_wallet_init_interface.AddWalletOptions(argsman);
 
-#if ENABLE_ZMQ
+#ifdef ENABLE_ZMQ
     argsman.AddArg("-zmqpubhashblock=<address>", "Enable publish hash block in <address>", ArgsManager::ALLOW_ANY, OptionsCategory::ZMQ);
     argsman.AddArg("-zmqpubhashtx=<address>", "Enable publish hash transaction in <address>", ArgsManager::ALLOW_ANY, OptionsCategory::ZMQ);
     argsman.AddArg("-zmqpubrawblock=<address>", "Enable publish raw block in <address>", ArgsManager::ALLOW_ANY, OptionsCategory::ZMQ);
@@ -1200,7 +1200,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     for (const auto& client : node.chain_clients) {
         client->registerRpcs();
     }
-#if ENABLE_ZMQ
+#ifdef ENABLE_ZMQ
     RegisterZMQRPCCommands(tableRPC);
 #endif
 
@@ -1325,7 +1325,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             std::string host_out;
             uint16_t port_out{0};
             if (!SplitHostPort(socket_addr, port_out, host_out)) {
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
                 // Allow unix domain sockets for some options e.g. unix:/some/file/path
                 if (!unix || socket_addr.find(ADDR_PREFIX_UNIX) != 0) {
                     return InitError(InvalidPortErrMsg(arg, socket_addr));
@@ -1472,7 +1472,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
             return InitError(ResolveErrMsg("externalip", strAddr));
     }
 
-#if ENABLE_ZMQ
+#ifdef ENABLE_ZMQ
     g_zmq_notification_interface = CZMQNotificationInterface::Create(
         [&chainman = node.chainman](std::vector<uint8_t>& block, const CBlockIndex& index) {
             assert(chainman);
diff --git a/src/netbase.cpp b/src/netbase.cpp
index fcbdb43e2a..f5f0997ba6 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -23,7 +23,7 @@
 #include <limits>
 #include <memory>
 
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
 #include <sys/un.h>
 #endif
 
@@ -218,7 +218,7 @@ CService LookupNumeric(const std::string& name, uint16_t portDefault, DNSLookupF
 
 bool IsUnixSocketPath(const std::string& name)
 {
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
     if (name.find(ADDR_PREFIX_UNIX) != 0) return false;
 
     // Split off "unix:" prefix
@@ -527,7 +527,7 @@ std::unique_ptr<Sock> CreateSockOS(int domain, int type, int protocol)
         return nullptr;
     }
 
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
     if (domain == AF_UNIX) return sock;
 #endif
 
@@ -638,7 +638,7 @@ std::unique_ptr<Sock> Proxy::Connect() const
 
     if (!m_is_unix_socket) return ConnectDirectly(proxy, /*manual_connection=*/true);
 
-#if HAVE_SOCKADDR_UN
+#ifdef HAVE_SOCKADDR_UN
     auto sock = CreateSock(AF_UNIX, SOCK_STREAM, 0);
     if (!sock) {
         LogPrintLevel(BCLog::NET, BCLog::Level::Error, "Cannot create a socket for connecting to %s\n", m_unix_socket_path);
diff --git a/src/randomenv.cpp b/src/randomenv.cpp
index aeec959c28..49033deef2 100644
--- a/src/randomenv.cpp
+++ b/src/randomenv.cpp
@@ -42,15 +42,15 @@
 #if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
 #include <ifaddrs.h>
 #endif
-#if HAVE_SYSCTL
+#ifdef HAVE_SYSCTL
 #include <sys/sysctl.h>
-#if HAVE_VM_VM_PARAM_H
+#ifdef HAVE_VM_VM_PARAM_H
 #include <vm/vm_param.h>
 #endif
-#if HAVE_SYS_RESOURCES_H
+#ifdef HAVE_SYS_RESOURCES_H
 #include <sys/resources.h>
 #endif
-#if HAVE_SYS_VMMETER_H
+#ifdef HAVE_SYS_VMMETER_H
 #include <sys/vmmeter.h>
 #endif
 #endif
@@ -162,7 +162,7 @@ void AddPath(CSHA512& hasher, const char *path)
 }
 #endif
 
-#if HAVE_SYSCTL
+#ifdef HAVE_SYSCTL
 template<int... S>
 void AddSysctl(CSHA512& hasher)
 {
@@ -274,7 +274,7 @@ void RandAddDynamicEnv(CSHA512& hasher)
     AddFile(hasher, "/proc/self/status");
 #endif
 
-#if HAVE_SYSCTL
+#ifdef HAVE_SYSCTL
 #  ifdef CTL_KERN
 #    if defined(KERN_PROC) && defined(KERN_PROC_ALL)
     AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
@@ -419,7 +419,7 @@ void RandAddStaticEnv(CSHA512& hasher)
 
     // For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
     // will exist on every system.
-#if HAVE_SYSCTL
+#ifdef HAVE_SYSCTL
 #  ifdef CTL_HW
 #    ifdef HW_MACHINE
     AddSysctl<CTL_HW, HW_MACHINE>(hasher);