Fix build warning issues

src/hash.h

@@ -153,7 +153,7 @@ inline std::string Hash(std::string input)
     unsigned char hash[CSHA256::OUTPUT_SIZE];
     CSHA256().Write((const unsigned char*)input.data(), input.size()).Finalize(hash);
     stringstream ss;
-    for (int i = 0; i < CSHA256::OUTPUT_SIZE; i++) {
+    for (size_t i = 0; i < CSHA256::OUTPUT_SIZE; i++) {
         ss << hex << setw(2) << setfill('0') << (int)hash[i];
     }
     return ss.str();

src/invalid.cpp

@@ -33,7 +33,7 @@ namespace invalid_out
             const UniValue &val = v[idx];
             const UniValue &o = val.get_obj();
 
-            const UniValue &vTxid = find_value(o, "txid");
+            const UniValue vTxid = find_value(o, "txid");
             if (!vTxid.isStr())
                 return false;
 
@@ -41,7 +41,7 @@ namespace invalid_out
             if (txid == 0)
                 return false;
 
-            const UniValue &vN = find_value(o, "n");
+            const UniValue vN = find_value(o, "n");
             if (!vN.isNum())
                 return false;
 
@@ -63,7 +63,7 @@ namespace invalid_out
             const UniValue &val = v[idx];
             const UniValue &o = val.get_obj();
 
-            const UniValue &vSerial = find_value(o, "s");
+            const UniValue vSerial = find_value(o, "s");
             if (!vSerial.isStr())
                 return false;
 
@@ -87,4 +87,3 @@ namespace invalid_out
         return static_cast<bool>(setInvalidSerials.count(bnSerial));
     }
 }
-

src/libzerocoin/SerialNumberSignatureOfKnowledge.cpp

@@ -170,7 +170,7 @@ bool SerialNumberSignatureOfKnowledge::Verify(const CBigNum& coinSerialNumber, c
             hasher << tprime[i];
         }
         return hasher.GetHash() == hash;
-    }catch (std::range_error e){
+    }catch (const std::range_error& e){
         return error("SoK Verify() :: sprime invalid range.");
     }
 }

src/masternodeconfig.cpp

@@ -96,7 +96,7 @@ bool CMasternodeConfig::CMasternodeEntry::castOutputIndex(int &n)
 {
     try {
         n = std::stoi(outputIndex);
-    } catch (const std::exception e) {
+    } catch (const std::exception& e) {
         LogPrintf("%s: %s on getOutputIndex\n", __func__, e.what());
         return false;
     }

src/rpc/blockchain.cpp

@@ -434,7 +434,7 @@ UniValue mempoolToJSON(bool fVerbose = false)
     if (fVerbose) {
         LOCK(mempool.cs);
         UniValue o(UniValue::VOBJ);
-        for (const PAIRTYPE(uint256, CTxMemPoolEntry) & entry : mempool.mapTx) {
+        for (const auto& entry : mempool.mapTx) {
             const uint256& hash = entry.first;
             const CTxMemPoolEntry& e = entry.second;
             UniValue info(UniValue::VOBJ);

src/rpc/mining.cpp

@@ -418,7 +418,7 @@ UniValue getblocktemplate(const UniValue& params, bool fHelp)
     UniValue lpval = NullUniValue;
     if (params.size() > 0) {
         const UniValue& oparam = params[0].get_obj();
-        const UniValue& modeval = find_value(oparam, "mode");
+        const UniValue modeval = find_value(oparam, "mode");
         if (modeval.isStr())
             strMode = modeval.get_str();
         else if (modeval.isNull()) {
@@ -428,7 +428,7 @@ UniValue getblocktemplate(const UniValue& params, bool fHelp)
         lpval = find_value(oparam, "longpollid");
 
         if (strMode == "proposal") {
-            const UniValue& dataval = find_value(oparam, "data");
+            const UniValue dataval = find_value(oparam, "data");
             if (!dataval.isStr())
                 throw JSONRPCError(RPC_TYPE_ERROR, "Missing data String key for proposal");
 

src/rpc/rawtransaction.cpp

@@ -383,7 +383,7 @@ UniValue createrawtransaction(const UniValue& params, bool fHelp)
 
         uint256 txid = ParseHashO(o, "txid");
 
-        const UniValue& vout_v = find_value(o, "vout");
+        const UniValue vout_v = find_value(o, "vout");
         if (!vout_v.isNum())
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, missing vout key");
         int nOutput = vout_v.get_int();
@@ -393,7 +393,7 @@ UniValue createrawtransaction(const UniValue& params, bool fHelp)
         uint32_t nSequence = (rawTx.nLockTime ? std::numeric_limits<uint32_t>::max() - 1 : std::numeric_limits<uint32_t>::max());
 
         // set the sequence number if passed in the parameters object
-        const UniValue& sequenceObj = find_value(o, "sequence");
+        const UniValue sequenceObj = find_value(o, "sequence");
         if (sequenceObj.isNum()) {
             int64_t seqNr64 = sequenceObj.get_int64();
             if (seqNr64 < 0 || seqNr64 > std::numeric_limits<uint32_t>::max())
@@ -1057,4 +1057,3 @@ UniValue createrawzerocoinpublicspend(const UniValue& params, bool fHelp)
     return EncodeHexTx(rawTx);
 }
 #endif
-

src/rpc/server.cpp

@@ -93,8 +93,8 @@ void RPCTypeCheckObj(const UniValue& o,
                   const map<string, UniValue::VType>& typesExpected,
                   bool fAllowNull)
 {
-    for (const PAIRTYPE(string, UniValue::VType)& t : typesExpected) {
-        const UniValue& v = find_value(o, t.first);
+    for (const auto& t : typesExpected) {
+        const UniValue v = find_value(o, t.first);
         if (!fAllowNull && v.isNull())
             throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing %s", t.first));
 

src/wallet/rpcwallet.cpp

@@ -3365,7 +3365,7 @@ UniValue importzerocoins(const UniValue& params, bool fHelp)
         const UniValue &val = arrMints[idx];
         const UniValue &o = val.get_obj();
 
-        const UniValue& vDenom = find_value(o, "d");
+        const UniValue vDenom = find_value(o, "d");
         if (!vDenom.isNum())
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, missing d key");
         int d = vDenom.get_int();
@@ -3389,7 +3389,7 @@ UniValue importzerocoins(const UniValue& params, bool fHelp)
 
         //Assume coin is version 1 unless it has the version actually set
         uint8_t nVersion = 1;
-        const UniValue& vVersion = find_value(o, "v");
+        const UniValue vVersion = find_value(o, "v");
         if (vVersion.isNum())
             nVersion = static_cast<uint8_t>(vVersion.get_int());
 

src/wallet/walletdb.cpp

@@ -1077,7 +1077,7 @@ bool AttemptBackupWallet(const CWallet& wallet, const filesystem::path& pathSrc,
             return false;
         }
 #if BOOST_VERSION >= 105800 /* BOOST_LIB_VERSION 1_58 */
-        filesystem::copy_file(pathSrc.c_str(), pathDest, filesystem::copy_options::overwrite_existing);
+        filesystem::copy_file(pathSrc.c_str(), pathDest, filesystem::copy_option::overwrite_if_exists);
 #else
         std::ifstream src(pathSrc.c_str(),  std::ios::binary | std::ios::in);
         std::ofstream dst(pathDest.c_str(), std::ios::binary | std::ios::out | std::ios::trunc);

src/zagr/accumulatorcheckpoints.cpp

@@ -39,7 +39,7 @@ namespace AccumulatorCheckpoints
             const UniValue &val = v[idx];
             const UniValue &o = val.get_obj();
 
-            const UniValue &vHeight = find_value(o, "height");
+            const UniValue vHeight = find_value(o, "height");
             if (!vHeight.isNum())
                 return false;
 
@@ -49,7 +49,7 @@ namespace AccumulatorCheckpoints
 
             Checkpoint checkpoint;
             for (auto denom : libzerocoin::zerocoinDenomList) {
-                const UniValue& vDenomValue = find_value(o, std::to_string(denom));
+                const UniValue vDenomValue = find_value(o, std::to_string(denom));
                 if (!vDenomValue.isStr()) {
                     return false;
                 }
@@ -82,4 +82,3 @@ namespace AccumulatorCheckpoints
         return Checkpoint();
     }
 }
-