fuzz: move-only FillNode implementation to cpp file

This allows to modify the implementation without having to recompile all
fuzz targets.

Can be reviewed with --color-moved=dimmed-zebra

src/Makefile.test_fuzz.include

@@ -16,6 +16,7 @@ libtest_fuzz_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) $(MINIUPNPC_CPPFLAG
 libtest_fuzz_a_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 libtest_fuzz_a_SOURCES = \
   test/fuzz/fuzz.cpp \
+  test/fuzz/util.cpp \
   $(TEST_FUZZ_H)
 
 LIBTEST_FUZZ += $(LIBBITCOIN_SERVER)

src/test/fuzz/util.cpp

@@ -0,0 +1,22 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/fuzz/util.h>
+
+void FillNode(FuzzedDataProvider& fuzzed_data_provider, CNode& node, const std::optional<int32_t>& version_in) noexcept
+{
+    const ServiceFlags remote_services = ConsumeWeakEnum(fuzzed_data_provider, ALL_SERVICE_FLAGS);
+    const NetPermissionFlags permission_flags = ConsumeWeakEnum(fuzzed_data_provider, ALL_NET_PERMISSION_FLAGS);
+    const int32_t version = version_in.value_or(fuzzed_data_provider.ConsumeIntegral<int32_t>());
+    const bool filter_txs = fuzzed_data_provider.ConsumeBool();
+
+    node.nServices = remote_services;
+    node.m_permissionFlags = permission_flags;
+    node.nVersion = version;
+    node.SetCommonVersion(version);
+    if (node.m_tx_relay != nullptr) {
+        LOCK(node.m_tx_relay->cs_filter);
+        node.m_tx_relay->fRelayTxes = filter_txs;
+    }
+}

src/test/fuzz/util.h

@@ -322,22 +322,7 @@ auto ConsumeNode(FuzzedDataProvider& fuzzed_data_provider, const std::optional<N
 }
 inline std::unique_ptr<CNode> ConsumeNodeAsUniquePtr(FuzzedDataProvider& fdp, const std::optional<NodeId>& node_id_in = nullopt) { return ConsumeNode<true>(fdp, node_id_in); }
 
-inline void FillNode(FuzzedDataProvider& fuzzed_data_provider, CNode& node, const std::optional<int32_t>& version_in = std::nullopt) noexcept
+void FillNode(FuzzedDataProvider& fuzzed_data_provider, CNode& node, const std::optional<int32_t>& version_in = std::nullopt) noexcept;
-{
-    const ServiceFlags remote_services = ConsumeWeakEnum(fuzzed_data_provider, ALL_SERVICE_FLAGS);
-    const NetPermissionFlags permission_flags = ConsumeWeakEnum(fuzzed_data_provider, ALL_NET_PERMISSION_FLAGS);
-    const int32_t version = version_in.value_or(fuzzed_data_provider.ConsumeIntegral<int32_t>());
-    const bool filter_txs = fuzzed_data_provider.ConsumeBool();
-
-    node.nServices = remote_services;
-    node.m_permissionFlags = permission_flags;
-    node.nVersion = version;
-    node.SetCommonVersion(version);
-    if (node.m_tx_relay != nullptr) {
-        LOCK(node.m_tx_relay->cs_filter);
-        node.m_tx_relay->fRelayTxes = filter_txs;
-    }
-}
 
 template <class T = const BasicTestingSetup>
 std::unique_ptr<T> MakeFuzzingContext(const std::string& chain_name = CBaseChainParams::REGTEST, const std::vector<const char*>& extra_args = {})