refactor: Move error() from util/system.h to logging.h

error is a low-level function with a sole dependency on LogPrintf, which
is defined in logging.h

The background of this commit is an ongoing effort to decouple the
libbitcoinkernel library from the ArgsManager defined in system.h.
Moving the function out of system.h allows including it from a separate
source file without including the ArgsManager definitions from system.h.

src/addrdb.cpp

@@ -11,6 +11,7 @@
 #include <cstdint>
 #include <fs.h>
 #include <hash.h>
+#include <logging.h>
 #include <logging/timer.h>
 #include <netbase.h>
 #include <netgroup.h>

src/index/base.cpp

@@ -6,6 +6,7 @@
 #include <index/base.h>
 #include <interfaces/chain.h>
 #include <kernel/chain.h>
+#include <logging.h>
 #include <node/blockstorage.h>
 #include <node/context.h>
 #include <node/database_args.h>

src/index/coinstatsindex.cpp

@@ -7,6 +7,7 @@
 #include <crypto/muhash.h>
 #include <index/coinstatsindex.h>
 #include <kernel/coinstats.h>
+#include <logging.h>
 #include <node/blockstorage.h>
 #include <serialize.h>
 #include <txdb.h>

src/index/txindex.cpp

@@ -5,6 +5,7 @@
 #include <index/txindex.h>
 
 #include <index/disktxpos.h>
+#include <logging.h>
 #include <node/blockstorage.h>
 #include <util/system.h>
 #include <validation.h>

src/kernel/coinstats.cpp

@@ -8,6 +8,7 @@
 #include <coins.h>
 #include <crypto/muhash.h>
 #include <hash.h>
+#include <logging.h>
 #include <node/blockstorage.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
@@ -19,7 +20,6 @@
 #include <uint256.h>
 #include <util/check.h>
 #include <util/overflow.h>
-#include <util/system.h>
 #include <validation.h>
 #include <version.h>
 

src/logging.h

@@ -257,4 +257,11 @@ static inline void LogPrintf_(const std::string& logging_function, const std::st
         }                                                 \
     } while (0)
 
+template <typename... Args>
+bool error(const char* fmt, const Args&... args)
+{
+    LogPrintf("ERROR: %s\n", tfm::format(fmt, args...));
+    return false;
+}
+
 #endif // BITCOIN_LOGGING_H

src/net.cpp

@@ -16,12 +16,13 @@
 #include <compat/compat.h>
 #include <consensus/consensus.h>
 #include <crypto/sha256.h>
-#include <node/eviction.h>
 #include <fs.h>
 #include <i2p.h>
+#include <logging.h>
 #include <net_permissions.h>
 #include <netaddress.h>
 #include <netbase.h>
+#include <node/eviction.h>
 #include <node/interface_ui.h>
 #include <protocol.h>
 #include <random.h>

src/netbase.cpp

@@ -6,12 +6,12 @@
 #include <netbase.h>
 
 #include <compat/compat.h>
+#include <logging.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <util/sock.h>
 #include <util/strencodings.h>
 #include <util/string.h>
-#include <util/system.h>
 #include <util/time.h>
 
 #include <atomic>

src/node/blockstorage.cpp

@@ -11,6 +11,7 @@
 #include <flatfile.h>
 #include <fs.h>
 #include <hash.h>
+#include <logging.h>
 #include <pow.h>
 #include <reverse_iterator.h>
 #include <shutdown.h>

src/script/signingprovider.cpp

@@ -7,7 +7,7 @@
 #include <script/signingprovider.h>
 #include <script/standard.h>
 
-#include <util/system.h>
+#include <logging.h>
 
 const SigningProvider& DUMMY_SIGNING_PROVIDER = SigningProvider();
 

src/txdb.cpp

@@ -6,11 +6,11 @@
 #include <txdb.h>
 
 #include <chain.h>
+#include <logging.h>
 #include <pow.h>
 #include <random.h>
 #include <shutdown.h>
 #include <uint256.h>
-#include <util/system.h>
 #include <util/translation.h>
 #include <util/vector.h>
 

src/util/system.h

@@ -43,13 +43,6 @@ extern const char * const BITCOIN_SETTINGS_FILENAME;
 void SetupEnvironment();
 bool SetupNetworking();
 
-template<typename... Args>
-bool error(const char* fmt, const Args&... args)
-{
-    LogPrintf("ERROR: %s\n", tfm::format(fmt, args...));
-    return false;
-}
-
 /**
  * Ensure file contents are fully committed to disk, using a platform-specific
  * feature analogous to fsync().