refactor: Avoid copies by using const references or by move-construction

src/external_signer.cpp

@@ -15,14 +15,15 @@
 #include <string>
 #include <vector>
 
-ExternalSigner::ExternalSigner(const std::string& command, const std::string chain, const std::string& fingerprint, const std::string name): m_command(command), m_chain(chain), m_fingerprint(fingerprint), m_name(name) {}
+ExternalSigner::ExternalSigner(std::string command, std::string chain, std::string fingerprint, std::string name)
+    : m_command{std::move(command)}, m_chain{std::move(chain)}, m_fingerprint{std::move(fingerprint)}, m_name{std::move(name)} {}
 
 std::string ExternalSigner::NetworkArg() const
 {
     return " --chain " + m_chain;
 }
 
-bool ExternalSigner::Enumerate(const std::string& command, std::vector<ExternalSigner>& signers, const std::string chain)
+bool ExternalSigner::Enumerate(const std::string& command, std::vector<ExternalSigner>& signers, const std::string& chain)
 {
     // Call <command> enumerate
     const UniValue result = RunCommandParseJSON(command + " enumerate");

src/external_signer.h

@@ -31,7 +31,7 @@ public:
     //! @param[in] fingerprint  master key fingerprint of the signer
     //! @param[in] chain        "main", "test", "regtest" or "signet"
     //! @param[in] name         device name
-    ExternalSigner(const std::string& command, const std::string chain, const std::string& fingerprint, const std::string name);
+    ExternalSigner(std::string command, std::string chain, std::string fingerprint, std::string name);
 
     //! Master key fingerprint of the signer
     std::string m_fingerprint;
@@ -44,7 +44,7 @@ public:
     //! @param[in,out] signers  vector to which new signers (with a unique master key fingerprint) are added
     //! @param chain            "main", "test", "regtest" or "signet"
     //! @returns success
-    static bool Enumerate(const std::string& command, std::vector<ExternalSigner>& signers, const std::string chain);
+    static bool Enumerate(const std::string& command, std::vector<ExternalSigner>& signers, const std::string& chain);
 
     //! Display address on the device. Calls `<command> displayaddress --desc <descriptor>`.
     //! @param[in] descriptor Descriptor specifying which address to display.

src/netbase.h

@@ -60,7 +60,8 @@ class Proxy
 public:
     Proxy() : m_is_unix_socket(false), m_tor_stream_isolation(false) {}
     explicit Proxy(const CService& _proxy, bool tor_stream_isolation = false) : proxy(_proxy), m_is_unix_socket(false), m_tor_stream_isolation(tor_stream_isolation) {}
-    explicit Proxy(const std::string path, bool tor_stream_isolation = false) : m_unix_socket_path(path), m_is_unix_socket(true), m_tor_stream_isolation(tor_stream_isolation) {}
+    explicit Proxy(std::string path, bool tor_stream_isolation = false)
+        : m_unix_socket_path(std::move(path)), m_is_unix_socket(true), m_tor_stream_isolation(tor_stream_isolation) {}
 
     CService proxy;
     std::string m_unix_socket_path;

src/psbt.cpp

@@ -322,7 +322,7 @@ bool PSBTInputSigned(const PSBTInput& input)
     return !input.final_script_sig.empty() || !input.final_script_witness.IsNull();
 }
 
-bool PSBTInputSignedAndVerified(const PartiallySignedTransaction psbt, unsigned int input_index, const PrecomputedTransactionData* txdata)
+bool PSBTInputSignedAndVerified(const PartiallySignedTransaction& psbt, unsigned int input_index, const PrecomputedTransactionData* txdata)
 {
     CTxOut utxo;
     assert(input_index < psbt.inputs.size());

src/psbt.h

@@ -1413,7 +1413,7 @@ PrecomputedTransactionData PrecomputePSBTData(const PartiallySignedTransaction&
 bool PSBTInputSigned(const PSBTInput& input);
 
 /** Checks whether a PSBTInput is already signed by doing script verification using final fields. */
-bool PSBTInputSignedAndVerified(const PartiallySignedTransaction psbt, unsigned int input_index, const PrecomputedTransactionData* txdata);
+bool PSBTInputSignedAndVerified(const PartiallySignedTransaction& psbt, unsigned int input_index, const PrecomputedTransactionData* txdata);
 
 /** Signs a PSBTInput, verifying that all provided data matches what is being signed.
  *

src/test/argsman_tests.cpp

@@ -52,7 +52,7 @@ BOOST_AUTO_TEST_CASE(util_datadir)
 struct TestArgsManager : public ArgsManager
 {
     TestArgsManager() { m_network_only_args.clear(); }
-    void ReadConfigString(const std::string str_config)
+    void ReadConfigString(const std::string& str_config)
     {
         std::istringstream streamConfig(str_config);
         {
@@ -63,7 +63,7 @@ struct TestArgsManager : public ArgsManager
         std::string error;
         BOOST_REQUIRE(ReadConfigStream(streamConfig, "", error));
     }
-    void SetNetworkOnlyArg(const std::string arg)
+    void SetNetworkOnlyArg(const std::string& arg)
     {
         LOCK(cs_args);
         m_network_only_args.insert(arg);

src/wallet/rpc/util.cpp

@@ -124,7 +124,7 @@ void PushParentDescriptors(const CWallet& wallet, const CScript& script_pubkey,
     entry.pushKV("parent_descs", std::move(parent_descs));
 }
 
-void HandleWalletError(const std::shared_ptr<CWallet> wallet, DatabaseStatus& status, bilingual_str& error)
+void HandleWalletError(const std::shared_ptr<CWallet>& wallet, DatabaseStatus& status, bilingual_str& error)
 {
     if (!wallet) {
         // Map bad format to not found, since bad format is returned when the

src/wallet/rpc/util.h

@@ -54,7 +54,7 @@ std::string LabelFromValue(const UniValue& value);
 //! Fetch parent descriptors of this scriptPubKey.
 void PushParentDescriptors(const CWallet& wallet, const CScript& script_pubkey, UniValue& entry);
 
-void HandleWalletError(const std::shared_ptr<CWallet> wallet, DatabaseStatus& status, bilingual_str& error);
+void HandleWalletError(const std::shared_ptr<CWallet>& wallet, DatabaseStatus& status, bilingual_str& error);
 void AppendLastProcessedBlock(UniValue& entry, const CWallet& wallet) EXCLUSIVE_LOCKS_REQUIRED(wallet.cs_wallet);
 } //  namespace wallet
 

src/wallet/wallet.cpp

@@ -2534,7 +2534,7 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
     return res;
 }
 
-util::Result<CTxDestination> CWallet::GetNewDestination(const OutputType type, const std::string label)
+util::Result<CTxDestination> CWallet::GetNewDestination(const OutputType type, const std::string& label)
 {
     LOCK(cs_wallet);
     auto spk_man = GetScriptPubKeyMan(type, /*internal=*/false);

src/wallet/wallet.h

@@ -783,7 +783,7 @@ public:
      */
     void MarkDestinationsDirty(const std::set<CTxDestination>& destinations) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
 
-    util::Result<CTxDestination> GetNewDestination(const OutputType type, const std::string label);
+    util::Result<CTxDestination> GetNewDestination(const OutputType type, const std::string& label);
     util::Result<CTxDestination> GetNewChangeDestination(const OutputType type);
 
     bool IsMine(const CTxDestination& dest) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);