Merge bitcoin/bitcoin#28583: refactor: [tidy] modernize-use-emplace

fa05a72 tidy: modernize-use-emplace (MarcoFalke)

Pull request description:

  Constructing a temporary unnamed object only to copy or move it into a container seems both verbose in code and a strict performance penalty.

  Fix both issues via the `modernize-use-emplace` tidy check.

ACKs for top commit:
  Sjors:
    re-utACK fa05a72
  hebasto:
    ACK fa05a72.
  TheCharlatan:
    ACK fa05a72

Tree-SHA512: 4408a094f406e7bf6c1468c2b0798f68f4d952a1253cf5b20bdc648ad7eea4a2c070051fed46d66fd37bce2ce6f85962484a1d32826b7ab8c9baba431eaa2765

Author: fanquake

src/.bear-tidy-config

@@ -8,6 +8,8 @@
         "src/crypto/ctaes",
         "src/leveldb",
         "src/minisketch",
+        "src/bench/nanobench.cpp",
+        "src/bench/nanobench.h",
         "src/secp256k1"
       ]
     },

src/.clang-tidy

@@ -5,6 +5,7 @@ bugprone-argument-comment,
 bugprone-use-after-move,
 misc-unused-using-decls,
 modernize-use-default-member-init,
+modernize-use-emplace,
 modernize-use-noexcept,
 modernize-use-nullptr,
 performance-*,

src/addrman.cpp

@@ -854,7 +854,7 @@ std::vector<std::pair<AddrInfo, AddressPosition>> AddrManImpl::GetEntries_(bool
                     /*multiplicity_in=*/from_tried ? 1 : info.nRefCount,
                     bucket,
                     position);
-                infos.push_back(std::make_pair(info, location));
+                infos.emplace_back(info, location);
             }
         }
     }

src/bench/block_assemble.cpp

@@ -28,7 +28,7 @@ static void AssembleBlock(benchmark::Bench& bench)
     std::array<CTransactionRef, NUM_BLOCKS - COINBASE_MATURITY + 1> txs;
     for (size_t b{0}; b < NUM_BLOCKS; ++b) {
         CMutableTransaction tx;
-        tx.vin.push_back(CTxIn{MineBlock(test_setup->m_node, P2WSH_OP_TRUE)});
+        tx.vin.emplace_back(MineBlock(test_setup->m_node, P2WSH_OP_TRUE));
         tx.vin.back().scriptWitness = witness;
         tx.vout.emplace_back(1337, P2WSH_OP_TRUE);
         if (NUM_BLOCKS - b >= COINBASE_MATURITY)

src/bench/disconnected_transactions.cpp

@@ -36,8 +36,8 @@ static BlockTxns CreateRandomTransactions(size_t num_txns)
     CScript spk = CScript() << OP_TRUE;
     for (uint32_t i = 0; i < num_txns; ++i) {
         CMutableTransaction tx;
-        tx.vin.emplace_back(CTxIn{COutPoint{prevout_hash, 0}});
-        tx.vout.emplace_back(CTxOut{CENT, spk});
+        tx.vin.emplace_back(COutPoint{prevout_hash, 0});
+        tx.vout.emplace_back(CENT, spk);
         auto ptx{MakeTransactionRef(tx)};
         txns.emplace_back(ptx);
         prevout_hash = ptx->GetHash();

src/bench/wallet_loading.cpp

@@ -20,8 +20,8 @@ namespace wallet{
 static void AddTx(CWallet& wallet)
 {
     CMutableTransaction mtx;
-    mtx.vout.push_back({COIN, GetScriptForDestination(*Assert(wallet.GetNewDestination(OutputType::BECH32, "")))});
-    mtx.vin.push_back(CTxIn());
+    mtx.vout.emplace_back(COIN, GetScriptForDestination(*Assert(wallet.GetNewDestination(OutputType::BECH32, ""))));
+    mtx.vin.emplace_back();
 
     wallet.AddToWallet(MakeTransactionRef(mtx), TxStateInactive{});
 }

src/common/args.cpp

@@ -216,7 +216,7 @@ bool ArgsManager::ParseParameters(int argc, const char* const argv[], std::strin
             m_command.push_back(key);
             while (++i < argc) {
                 // The remaining args are command args
-                m_command.push_back(argv[i]);
+                m_command.emplace_back(argv[i]);
             }
             break;
         }

src/external_signer.cpp

@@ -54,7 +54,7 @@ bool ExternalSigner::Enumerate(const std::string& command, std::vector<ExternalS
         if (model_field.isStr() && model_field.getValStr() != "") {
             name += model_field.getValStr();
         }
-        signers.push_back(ExternalSigner(command, chain, fingerprintStr, name));
+        signers.emplace_back(command, chain, fingerprintStr, name);
     }
     return true;
 }

src/headerssync.cpp

@@ -271,7 +271,7 @@ bool HeadersSyncState::ValidateAndStoreRedownloadedHeader(const CBlockHeader& he
     }
 
     // Store this header for later processing.
-    m_redownloaded_headers.push_back(header);
+    m_redownloaded_headers.emplace_back(header);
     m_redownload_buffer_last_height = next_height;
     m_redownload_buffer_last_hash = header.GetHash();
 

src/httpserver.cpp

@@ -221,8 +221,8 @@ static bool ClientAllowed(const CNetAddr& netaddr)
 static bool InitHTTPAllowList()
 {
     rpc_allow_subnets.clear();
-    rpc_allow_subnets.push_back(CSubNet{LookupHost("127.0.0.1", false).value(), 8});  // always allow IPv4 local subnet
-    rpc_allow_subnets.push_back(CSubNet{LookupHost("::1", false).value()});  // always allow IPv6 localhost
+    rpc_allow_subnets.emplace_back(LookupHost("127.0.0.1", false).value(), 8);  // always allow IPv4 local subnet
+    rpc_allow_subnets.emplace_back(LookupHost("::1", false).value());  // always allow IPv6 localhost
     for (const std::string& strAllow : gArgs.GetArgs("-rpcallowip")) {
         CSubNet subnet;
         LookupSubNet(strAllow, subnet);
@@ -364,8 +364,8 @@ static bool HTTPBindAddresses(struct evhttp* http)
 
     // Determine what addresses to bind to
     if (!(gArgs.IsArgSet("-rpcallowip") && gArgs.IsArgSet("-rpcbind"))) { // Default to loopback if not allowing external IPs
-        endpoints.push_back(std::make_pair("::1", http_port));
-        endpoints.push_back(std::make_pair("127.0.0.1", http_port));
+        endpoints.emplace_back("::1", http_port);
+        endpoints.emplace_back("127.0.0.1", http_port);
         if (gArgs.IsArgSet("-rpcallowip")) {
             LogPrintf("WARNING: option -rpcallowip was specified without -rpcbind; this doesn't usually make sense\n");
         }
@@ -377,7 +377,7 @@ static bool HTTPBindAddresses(struct evhttp* http)
             uint16_t port{http_port};
             std::string host;
             SplitHostPort(strRPCBind, port, host);
-            endpoints.push_back(std::make_pair(host, port));
+            endpoints.emplace_back(host, port);
         }
     }
 
@@ -746,7 +746,7 @@ void RegisterHTTPHandler(const std::string &prefix, bool exactMatch, const HTTPR
 {
     LogPrint(BCLog::HTTP, "Registering HTTP handler for %s (exactmatch %d)\n", prefix, exactMatch);
     LOCK(g_httppathhandlers_mutex);
-    pathHandlers.push_back(HTTPPathHandler(prefix, exactMatch, handler));
+    pathHandlers.emplace_back(prefix, exactMatch, handler);
 }
 
 void UnregisterHTTPHandler(const std::string &prefix, bool exactMatch)