Merge bitcoin/bitcoin#25707: refactor: Make const references to avoid unnecessarily copying objects and enable two clang-tidy checks

ae7ae36d311a869b3bda41d29dc0e47fade77d28 tidy: Enable two clang-tidy checks (Aurèle Oulès)
081b0e53e3adca7ea57d23e5fcd9db4b86415a72 refactor: Make const refs vars where applicable (Aurèle Oulès)

Pull request description:

  I added const references to some variables to avoid unnecessarily copying objects.

  Also added two clang-tidy checks : [performance-for-range-copy](https://releases.llvm.org/11.1.0/tools/clang/tools/extra/docs/clang-tidy/checks/performance-for-range-copy.html) and [performance-unnecessary-copy-initialization](https://releases.llvm.org/12.0.0/tools/clang/tools/extra/docs/clang-tidy/checks/performance-unnecessary-copy-initialization.html).

ACKs for top commit:
  vasild:
    ACK ae7ae36d311a869b3bda41d29dc0e47fade77d28
  MarcoFalke:
    review ACK ae7ae36d311a869b3bda41d29dc0e47fade77d28

Tree-SHA512: f6ac6b0cd0eee1e0c34d2f186484bc0f7ec6071451cccb33fa88a67d93d92b304e2fac378b88f087e94657745bca4e966dbc443759587400eb01b1f3061fde8c

6 files changed, 8 insertions, 8 deletions

diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp
index 60715ff3c8..deb1293cd4 100644
--- a/src/wallet/bdb.cpp
+++ b/src/wallet/bdb.cpp
@@ -432,7 +432,7 @@ void BerkeleyEnvironment::ReloadDbEnv()
     });
 
     std::vector<fs::path> filenames;
-    for (auto it : m_databases) {
+    for (const auto& it : m_databases) {
         filenames.push_back(it.first);
     }
     // Close the individual Db's
diff --git a/src/wallet/receive.cpp b/src/wallet/receive.cpp
index db169aad12..7fbf2ff8cf 100644
--- a/src/wallet/receive.cpp
+++ b/src/wallet/receive.cpp
@@ -416,7 +416,7 @@ std::set< std::set<CTxDestination> > GetAddressGroupings(const CWallet& wallet)
 
     std::set< std::set<CTxDestination>* > uniqueGroupings; // a set of pointers to groups of addresses
     std::map< CTxDestination, std::set<CTxDestination>* > setmap;  // map addresses to the unique group containing it
-    for (std::set<CTxDestination> _grouping : groupings)
+    for (const std::set<CTxDestination>& _grouping : groupings)
     {
         // make a set of all the groups hit by this new group
         std::set< std::set<CTxDestination>* > hits;
diff --git a/src/wallet/rpc/spend.cpp b/src/wallet/rpc/spend.cpp
index 8bbb862a7b..c6e7588fb4 100644
--- a/src/wallet/rpc/spend.cpp
+++ b/src/wallet/rpc/spend.cpp
@@ -1407,7 +1407,7 @@ RPCHelpMan sendall()
             }
 
             CAmount output_amounts_claimed{0};
-            for (CTxOut out : rawTx.vout) {
+            for (const CTxOut& out : rawTx.vout) {
                 output_amounts_claimed += out.nValue;
             }
 
diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index 8d40846332..40d5ecd755 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -1788,7 +1788,7 @@ std::map<CKeyID, CKey> DescriptorScriptPubKeyMan::GetKeys() const
     AssertLockHeld(cs_desc_man);
     if (m_storage.HasEncryptionKeys() && !m_storage.IsLocked()) {
         KeyMap keys;
-        for (auto key_pair : m_map_crypted_keys) {
+        for (const auto& key_pair : m_map_crypted_keys) {
             const CPubKey& pubkey = key_pair.second.first;
             const std::vector<unsigned char>& crypted_secret = key_pair.second.second;
             CKey key;
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 45d2c3692d..752aad2378 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3474,7 +3474,7 @@ void CWallet::SetupDescriptorScriptPubKeyMans()
             const UniValue& descriptor_vals = find_value(signer_res, internal ? "internal" : "receive");
             if (!descriptor_vals.isArray()) throw std::runtime_error(std::string(__func__) + ": Unexpected result");
             for (const UniValue& desc_val : descriptor_vals.get_array().getValues()) {
-                std::string desc_str = desc_val.getValStr();
+                const std::string& desc_str = desc_val.getValStr();
                 FlatSigningProvider keys;
                 std::string desc_error;
                 std::unique_ptr<Descriptor> desc = Parse(desc_str, keys, desc_error, false);
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 8afd3f416d..0d85652c0c 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -856,18 +856,18 @@ DBErrors WalletBatch::LoadWallet(CWallet* pwallet)
     }
 
     // Set the descriptor caches
-    for (auto desc_cache_pair : wss.m_descriptor_caches) {
+    for (const auto& desc_cache_pair : wss.m_descriptor_caches) {
         auto spk_man = pwallet->GetScriptPubKeyMan(desc_cache_pair.first);
         assert(spk_man);
         ((DescriptorScriptPubKeyMan*)spk_man)->SetCache(desc_cache_pair.second);
     }
 
     // Set the descriptor keys
-    for (auto desc_key_pair : wss.m_descriptor_keys) {
+    for (const auto& desc_key_pair : wss.m_descriptor_keys) {
         auto spk_man = pwallet->GetScriptPubKeyMan(desc_key_pair.first.first);
         ((DescriptorScriptPubKeyMan*)spk_man)->AddKey(desc_key_pair.first.second, desc_key_pair.second);
     }
-    for (auto desc_key_pair : wss.m_descriptor_crypt_keys) {
+    for (const auto& desc_key_pair : wss.m_descriptor_crypt_keys) {
         auto spk_man = pwallet->GetScriptPubKeyMan(desc_key_pair.first.first);
         ((DescriptorScriptPubKeyMan*)spk_man)->AddCryptedKey(desc_key_pair.first.second, desc_key_pair.second.first, desc_key_pair.second.second);
     }