Merge #11043: Use std::unique_ptr (C++11) where possible

a357293 Use MakeUnique<Db>(...) (practicalswift)
3e09b39 Use MakeUnique<T>(...) instead of std::unique_ptr<T>(new T(...)) (practicalswift)
8617989 Add MakeUnique (substitute for C++14 std::make_unique) (practicalswift)
d223bc9 Use unique_ptr for pcoinscatcher/pcoinsdbview/pcoinsTip/pblocktree (practicalswift)
b45c597 Use unique_ptr for pdbCopy (Db) and fix potential memory leak (practicalswift)
29ab96d Use unique_ptr for dbenv (DbEnv) (practicalswift)
f72cbf9 Use unique_ptr for pfilter (CBloomFilter) (practicalswift)
8ccf1bb Use unique_ptr for sem{Addnode,Outbound} (CSemaphore) (practicalswift)
73db063 Use unique_ptr for upnp_thread (boost::thread) (practicalswift)
0024531 Use unique_ptr for dbw (CDBWrapper) (practicalswift)
fa6d122 Use unique_ptr:s for {fee,short,long}Stats (TxConfirmStats) (practicalswift)
5a6f768 Use unique_ptr for httpRPCTimerInterface (HTTPRPCTimerInterface) (practicalswift)
860e912 Use unique_ptr for pwalletMain (CWallet) (practicalswift)

Pull request description:

  Use `std::unique_ptr` (C++11) where possible.

  Rationale:
  1. Avoid resource leaks (specifically: forgetting to `delete` an object created using `new`)
  2. Avoid undefined behaviour (specifically: double `delete`:s)

  **Note to reviewers:** Please let me know if I've missed any obvious `std::unique_ptr` candidates. Hopefully this PR should cover all the trivial cases.

Tree-SHA512: 9fbeb47b800ab8ff4e0be9f2a22ab63c23d5c613a0c6716d9183db8d22ddbbce592fb8384a8b7874bf7375c8161efb13ca2197ad6f24b75967148037f0f7b20c

20 files changed, 104 insertions, 131 deletions

diff --git a/src/httprpc.cpp b/src/httprpc.cpp
index 93f0a18668..dbd09595c6 100644
--- a/src/httprpc.cpp
+++ b/src/httprpc.cpp
@@ -62,7 +62,7 @@ private:
 /* Pre-base64-encoded authentication token */
 static std::string strRPCUserColonPass;
 /* Stored RPC timer interface (for unregistration) */
-static HTTPRPCTimerInterface* httpRPCTimerInterface = nullptr;
+static std::unique_ptr<HTTPRPCTimerInterface> httpRPCTimerInterface;
 
 static void JSONErrorReply(HTTPRequest* req, const UniValue& objError, const UniValue& id)
 {
@@ -238,8 +238,8 @@ bool StartHTTPRPC()
     RegisterHTTPHandler("/wallet/", false, HTTPReq_JSONRPC);
 #endif
     assert(EventBase());
-    httpRPCTimerInterface = new HTTPRPCTimerInterface(EventBase());
-    RPCSetTimerInterface(httpRPCTimerInterface);
+    httpRPCTimerInterface = MakeUnique<HTTPRPCTimerInterface>(EventBase());
+    RPCSetTimerInterface(httpRPCTimerInterface.get());
     return true;
 }
 
@@ -253,8 +253,7 @@ void StopHTTPRPC()
     LogPrint(BCLog::RPC, "Stopping HTTP RPC server\n");
     UnregisterHTTPHandler("/", true);
     if (httpRPCTimerInterface) {
-        RPCUnsetTimerInterface(httpRPCTimerInterface);
-        delete httpRPCTimerInterface;
-        httpRPCTimerInterface = nullptr;
+        RPCUnsetTimerInterface(httpRPCTimerInterface.get());
+        httpRPCTimerInterface.reset();
     }
 }
diff --git a/src/init.cpp b/src/init.cpp
index ddac606a39..7ac2cf2d32 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -152,7 +152,7 @@ public:
     // Writes do not need similar protection, as failure to write is handled by the caller.
 };
 
-static CCoinsViewErrorCatcher *pcoinscatcher = nullptr;
+static std::unique_ptr<CCoinsViewErrorCatcher> pcoinscatcher;
 static std::unique_ptr<ECCVerifyHandle> globalVerifyHandle;
 
 void Interrupt(boost::thread_group& threadGroup)
@@ -235,14 +235,10 @@ void Shutdown()
         if (pcoinsTip != nullptr) {
             FlushStateToDisk();
         }
-        delete pcoinsTip;
-        pcoinsTip = nullptr;
-        delete pcoinscatcher;
-        pcoinscatcher = nullptr;
-        delete pcoinsdbview;
-        pcoinsdbview = nullptr;
-        delete pblocktree;
-        pblocktree = nullptr;
+        pcoinsTip.reset();
+        pcoinscatcher.reset();
+        pcoinsdbview.reset();
+        pblocktree.reset();
     }
 #ifdef ENABLE_WALLET
     StopWallets();
@@ -1406,12 +1402,10 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
         do {
             try {
                 UnloadBlockIndex();
-                delete pcoinsTip;
-                delete pcoinsdbview;
-                delete pcoinscatcher;
-                delete pblocktree;
-
-                pblocktree = new CBlockTreeDB(nBlockTreeDBCache, false, fReset);
+                pcoinsTip.reset();
+                pcoinsdbview.reset();
+                pcoinscatcher.reset();
+                pblocktree.reset(new CBlockTreeDB(nBlockTreeDBCache, false, fReset));
 
                 if (fReset) {
                     pblocktree->WriteReindexing(true);
@@ -1462,8 +1456,8 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
                 // At this point we're either in reindex or we've loaded a useful
                 // block tree into mapBlockIndex!
 
-                pcoinsdbview = new CCoinsViewDB(nCoinDBCache, false, fReset || fReindexChainState);
-                pcoinscatcher = new CCoinsViewErrorCatcher(pcoinsdbview);
+                pcoinsdbview.reset(new CCoinsViewDB(nCoinDBCache, false, fReset || fReindexChainState));
+                pcoinscatcher.reset(new CCoinsViewErrorCatcher(pcoinsdbview.get()));
 
                 // If necessary, upgrade from older database format.
                 // This is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
@@ -1473,13 +1467,13 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
                 }
 
                 // ReplayBlocks is a no-op if we cleared the coinsviewdb with -reindex or -reindex-chainstate
-                if (!ReplayBlocks(chainparams, pcoinsdbview)) {
+                if (!ReplayBlocks(chainparams, pcoinsdbview.get())) {
                     strLoadError = _("Unable to replay blocks. You will need to rebuild the database using -reindex-chainstate.");
                     break;
                 }
 
                 // The on-disk coinsdb is now in a good state, create the cache
-                pcoinsTip = new CCoinsViewCache(pcoinscatcher);
+                pcoinsTip.reset(new CCoinsViewCache(pcoinscatcher.get()));
 
                 bool is_coinsview_empty = fReset || fReindexChainState || pcoinsTip->GetBestBlock().IsNull();
                 if (!is_coinsview_empty) {
@@ -1521,7 +1515,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
                         }
                     }
 
-                    if (!CVerifyDB().VerifyDB(chainparams, pcoinsdbview, gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
+                    if (!CVerifyDB().VerifyDB(chainparams, pcoinsdbview.get(), gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
                                   gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS))) {
                         strLoadError = _("Corrupted block database detected");
                         break;
diff --git a/src/net.cpp b/src/net.cpp
index d5bd4c162b..0f9de81d7f 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1534,22 +1534,20 @@ void ThreadMapPort()
 
 void MapPort(bool fUseUPnP)
 {
-    static boost::thread* upnp_thread = nullptr;
+    static std::unique_ptr<boost::thread> upnp_thread;
 
     if (fUseUPnP)
     {
         if (upnp_thread) {
             upnp_thread->interrupt();
             upnp_thread->join();
-            delete upnp_thread;
         }
-        upnp_thread = new boost::thread(boost::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort));
+        upnp_thread.reset(new boost::thread(boost::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort)));
     }
     else if (upnp_thread) {
         upnp_thread->interrupt();
         upnp_thread->join();
-        delete upnp_thread;
-        upnp_thread = nullptr;
+        upnp_thread.reset();
     }
 }
 
@@ -2224,8 +2222,6 @@ CConnman::CConnman(uint64_t nSeed0In, uint64_t nSeed1In) : nSeed0(nSeed0In), nSe
     nLastNodeId = 0;
     nSendBufferMaxSize = 0;
     nReceiveFloodSize = 0;
-    semOutbound = nullptr;
-    semAddnode = nullptr;
     flagInterruptMsgProc = false;
     SetTryNewOutboundPeer(false);
 
@@ -2331,11 +2327,11 @@ bool CConnman::Start(CScheduler& scheduler, const Options& connOptions)
 
     if (semOutbound == nullptr) {
         // initialize semaphore
-        semOutbound = new CSemaphore(std::min((nMaxOutbound + nMaxFeeler), nMaxConnections));
+        semOutbound = MakeUnique<CSemaphore>(std::min((nMaxOutbound + nMaxFeeler), nMaxConnections));
     }
     if (semAddnode == nullptr) {
         // initialize semaphore
-        semAddnode = new CSemaphore(nMaxAddnode);
+        semAddnode = MakeUnique<CSemaphore>(nMaxAddnode);
     }
 
     //
@@ -2458,10 +2454,8 @@ void CConnman::Stop()
     vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
-    delete semOutbound;
-    semOutbound = nullptr;
-    delete semAddnode;
-    semAddnode = nullptr;
+    semOutbound.reset();
+    semAddnode.reset();
 }
 
 void CConnman::DeleteNode(CNode* pnode)
@@ -2747,7 +2741,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     nNextInvSend = 0;
     fRelayTxes = false;
     fSentAddr = false;
-    pfilter = new CBloomFilter();
+    pfilter = MakeUnique<CBloomFilter>();
     timeLastMempoolReq = 0;
     nLastBlockTime = 0;
     nLastTXTime = 0;
@@ -2777,8 +2771,6 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
 CNode::~CNode()
 {
     CloseSocket(hSocket);
-
-    delete pfilter;
 }
 
 void CNode::AskFor(const CInv& inv)
diff --git a/src/net.h b/src/net.h
index edca1171ab..8cb00dd5a5 100644
--- a/src/net.h
+++ b/src/net.h
@@ -399,8 +399,8 @@ private:
     /** Services this instance offers */
     ServiceFlags nLocalServices;
 
-    CSemaphore *semOutbound;
-    CSemaphore *semAddnode;
+    std::unique_ptr<CSemaphore> semOutbound;
+    std::unique_ptr<CSemaphore> semAddnode;
     int nMaxConnections;
     int nMaxOutbound;
     int nMaxAddnode;
@@ -648,7 +648,7 @@ public:
     bool fSentAddr;
     CSemaphoreGrant grantOutbound;
     CCriticalSection cs_filter;
-    CBloomFilter* pfilter;
+    std::unique_ptr<CBloomFilter> pfilter;
     std::atomic<int> nRefCount;
 
     const uint64_t nKeyedNetGroup;
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 52387b32f4..8e503f89db 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -2102,7 +2102,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
 
         if (!AlreadyHave(inv) &&
             AcceptToMemoryPool(mempool, state, ptx, &fMissingInputs, &lRemovedTxn, false /* bypass_limits */, 0 /* nAbsurdFee */)) {
-            mempool.check(pcoinsTip);
+            mempool.check(pcoinsTip.get());
             RelayTransaction(tx, connman);
             for (unsigned int i = 0; i < tx.vout.size(); i++) {
                 vWorkQueue.emplace_back(inv.hash, i);
@@ -2169,7 +2169,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
                             recentRejects->insert(orphanHash);
                         }
                     }
-                    mempool.check(pcoinsTip);
+                    mempool.check(pcoinsTip.get());
                 }
             }
 
@@ -2751,8 +2751,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
         else
         {
             LOCK(pfrom->cs_filter);
-            delete pfrom->pfilter;
-            pfrom->pfilter = new CBloomFilter(filter);
+            pfrom->pfilter.reset(new CBloomFilter(filter));
             pfrom->pfilter->UpdateEmptyFull();
             pfrom->fRelayTxes = true;
         }
@@ -2788,8 +2787,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
     {
         LOCK(pfrom->cs_filter);
         if (pfrom->GetLocalServices() & NODE_BLOOM) {
-            delete pfrom->pfilter;
-            pfrom->pfilter = new CBloomFilter();
+            pfrom->pfilter.reset(new CBloomFilter());
         }
         pfrom->fRelayTxes = true;
     }
diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index c7e57671c0..a459186359 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -548,16 +548,13 @@ CBlockPolicyEstimator::CBlockPolicyEstimator()
     bucketMap[INF_FEERATE] = bucketIndex;
     assert(bucketMap.size() == buckets.size());
 
-    feeStats = new TxConfirmStats(buckets, bucketMap, MED_BLOCK_PERIODS, MED_DECAY, MED_SCALE);
-    shortStats = new TxConfirmStats(buckets, bucketMap, SHORT_BLOCK_PERIODS, SHORT_DECAY, SHORT_SCALE);
-    longStats = new TxConfirmStats(buckets, bucketMap, LONG_BLOCK_PERIODS, LONG_DECAY, LONG_SCALE);
+    feeStats = std::unique_ptr<TxConfirmStats>(new TxConfirmStats(buckets, bucketMap, MED_BLOCK_PERIODS, MED_DECAY, MED_SCALE));
+    shortStats = std::unique_ptr<TxConfirmStats>(new TxConfirmStats(buckets, bucketMap, SHORT_BLOCK_PERIODS, SHORT_DECAY, SHORT_SCALE));
+    longStats = std::unique_ptr<TxConfirmStats>(new TxConfirmStats(buckets, bucketMap, LONG_BLOCK_PERIODS, LONG_DECAY, LONG_SCALE));
 }
 
 CBlockPolicyEstimator::~CBlockPolicyEstimator()
 {
-    delete feeStats;
-    delete shortStats;
-    delete longStats;
 }
 
 void CBlockPolicyEstimator::processTransaction(const CTxMemPoolEntry& entry, bool validFeeEstimate)
@@ -690,16 +687,16 @@ CFeeRate CBlockPolicyEstimator::estimateRawFee(int confTarget, double successThr
     double sufficientTxs = SUFFICIENT_FEETXS;
     switch (horizon) {
     case FeeEstimateHorizon::SHORT_HALFLIFE: {
-        stats = shortStats;
+        stats = shortStats.get();
         sufficientTxs = SUFFICIENT_TXS_SHORT;
         break;
     }
     case FeeEstimateHorizon::MED_HALFLIFE: {
-        stats = feeStats;
+        stats = feeStats.get();
         break;
     }
     case FeeEstimateHorizon::LONG_HALFLIFE: {
-        stats = longStats;
+        stats = longStats.get();
         break;
     }
     default: {
@@ -1002,12 +999,9 @@ bool CBlockPolicyEstimator::Read(CAutoFile& filein)
             }
 
             // Destroy old TxConfirmStats and point to new ones that already reference buckets and bucketMap
-            delete feeStats;
-            delete shortStats;
-            delete longStats;
-            feeStats = fileFeeStats.release();
-            shortStats = fileShortStats.release();
-            longStats = fileLongStats.release();
+            feeStats = std::move(fileFeeStats);
+            shortStats = std::move(fileShortStats);
+            longStats = std::move(fileLongStats);
 
             nBestSeenHeight = nFileBestSeenHeight;
             historicalFirst = nFileHistoricalFirst;
diff --git a/src/policy/fees.h b/src/policy/fees.h
index 6edaf28714..9c0937cbd6 100644
--- a/src/policy/fees.h
+++ b/src/policy/fees.h
@@ -245,9 +245,9 @@ private:
     std::map<uint256, TxStatsInfo> mapMemPoolTxs;
 
     /** Classes to track historical data on transaction confirmations */
-    TxConfirmStats* feeStats;
-    TxConfirmStats* shortStats;
-    TxConfirmStats* longStats;
+    std::unique_ptr<TxConfirmStats> feeStats;
+    std::unique_ptr<TxConfirmStats> shortStats;
+    std::unique_ptr<TxConfirmStats> longStats;
 
     unsigned int trackedTxs;
     unsigned int untrackedTxs;
diff --git a/src/qt/test/rpcnestedtests.h b/src/qt/test/rpcnestedtests.h
index 9ad409019f..59d7f37841 100644
--- a/src/qt/test/rpcnestedtests.h
+++ b/src/qt/test/rpcnestedtests.h
@@ -17,9 +17,6 @@ class RPCNestedTests : public QObject
 
     private Q_SLOTS:
     void rpcNestedTests();
-
-private:
-    CCoinsViewDB *pcoinsdbview;
 };
 
 #endif // BITCOIN_QT_TEST_RPC_NESTED_TESTS_H
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 8d01d8ba9c..4a3404308d 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -928,7 +928,7 @@ UniValue gettxoutsetinfo(const JSONRPCRequest& request)
 
     CCoinsStats stats;
     FlushStateToDisk();
-    if (GetUTXOStats(pcoinsdbview, stats)) {
+    if (GetUTXOStats(pcoinsdbview.get(), stats)) {
         ret.push_back(Pair("height", (int64_t)stats.nHeight));
         ret.push_back(Pair("bestblock", stats.hashBlock.GetHex()));
         ret.push_back(Pair("transactions", (int64_t)stats.nTransactions));
@@ -996,7 +996,7 @@ UniValue gettxout(const JSONRPCRequest& request)
     Coin coin;
     if (fMempool) {
         LOCK(mempool.cs);
-        CCoinsViewMemPool view(pcoinsTip, mempool);
+        CCoinsViewMemPool view(pcoinsTip.get(), mempool);
         if (!view.GetCoin(out, coin) || mempool.isSpent(out)) {
             return NullUniValue;
         }
@@ -1048,7 +1048,7 @@ UniValue verifychain(const JSONRPCRequest& request)
     if (!request.params[1].isNull())
         nCheckDepth = request.params[1].get_int();
 
-    return CVerifyDB().VerifyDB(Params(), pcoinsTip, nCheckLevel, nCheckDepth);
+    return CVerifyDB().VerifyDB(Params(), pcoinsTip.get(), nCheckLevel, nCheckDepth);
 }
 
 /** Implementation of IsSuperMajority with better feedback */
diff --git a/src/test/dbwrapper_tests.cpp b/src/test/dbwrapper_tests.cpp
index efddafe17e..c1625cf476 100644
--- a/src/test/dbwrapper_tests.cpp
+++ b/src/test/dbwrapper_tests.cpp
@@ -125,7 +125,7 @@ BOOST_AUTO_TEST_CASE(existing_data_no_obfuscate)
     create_directories(ph);
 
     // Set up a non-obfuscated wrapper to write some initial data.
-    CDBWrapper* dbw = new CDBWrapper(ph, (1 << 10), false, false, false);
+    std::unique_ptr<CDBWrapper> dbw = MakeUnique<CDBWrapper>(ph, (1 << 10), false, false, false);
     char key = 'k';
     uint256 in = InsecureRand256();
     uint256 res;
@@ -135,8 +135,7 @@ BOOST_AUTO_TEST_CASE(existing_data_no_obfuscate)
     BOOST_CHECK_EQUAL(res.ToString(), in.ToString());
 
     // Call the destructor to free leveldb LOCK
-    delete dbw;
-    dbw = nullptr;
+    dbw.reset();
 
     // Now, set up another wrapper that wants to obfuscate the same directory
     CDBWrapper odbw(ph, (1 << 10), false, false, true);
@@ -167,7 +166,7 @@ BOOST_AUTO_TEST_CASE(existing_data_reindex)
     create_directories(ph);
 
     // Set up a non-obfuscated wrapper to write some initial data.
-    CDBWrapper* dbw = new CDBWrapper(ph, (1 << 10), false, false, false);
+    std::unique_ptr<CDBWrapper> dbw = MakeUnique<CDBWrapper>(ph, (1 << 10), false, false, false);
     char key = 'k';
     uint256 in = InsecureRand256();
     uint256 res;
@@ -177,8 +176,7 @@ BOOST_AUTO_TEST_CASE(existing_data_reindex)
     BOOST_CHECK_EQUAL(res.ToString(), in.ToString());
 
     // Call the destructor to free leveldb LOCK
-    delete dbw;
-    dbw = nullptr;
+    dbw.reset();
 
     // Simulate a -reindex by wiping the existing data store
     CDBWrapper odbw(ph, (1 << 10), false, true, true);
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
index f9ce52c594..0d7d52478f 100644
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -81,9 +81,9 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
         GetMainSignals().RegisterBackgroundSignalScheduler(scheduler);
 
         mempool.setSanityCheck(1.0);
-        pblocktree = new CBlockTreeDB(1 << 20, true);
-        pcoinsdbview = new CCoinsViewDB(1 << 23, true);
-        pcoinsTip = new CCoinsViewCache(pcoinsdbview);
+        pblocktree.reset(new CBlockTreeDB(1 << 20, true));
+        pcoinsdbview.reset(new CCoinsViewDB(1 << 23, true));
+        pcoinsTip.reset(new CCoinsViewCache(pcoinsdbview.get()));
         if (!LoadGenesisBlock(chainparams)) {
             throw std::runtime_error("LoadGenesisBlock failed.");
         }
@@ -110,9 +110,9 @@ TestingSetup::~TestingSetup()
         g_connman.reset();
         peerLogic.reset();
         UnloadBlockIndex();
-        delete pcoinsTip;
-        delete pcoinsdbview;
-        delete pblocktree;
+        pcoinsTip.reset();
+        pcoinsdbview.reset();
+        pblocktree.reset();
         fs::remove_all(pathTemp);
 }
 
diff --git a/src/test/test_bitcoin.h b/src/test/test_bitcoin.h
index 62ded2aaf5..6398386d42 100644
--- a/src/test/test_bitcoin.h
+++ b/src/test/test_bitcoin.h
@@ -57,7 +57,6 @@ struct CConnmanTest {
 
 class PeerLogicValidation;
 struct TestingSetup: public BasicTestingSetup {
-    CCoinsViewDB *pcoinsdbview;
     fs::path pathTemp;
     boost::thread_group threadGroup;
     CConnman* connman;
diff --git a/src/test/txvalidationcache_tests.cpp b/src/test/txvalidationcache_tests.cpp
index 82ca93e7da..7d551a7bb4 100644
--- a/src/test/txvalidationcache_tests.cpp
+++ b/src/test/txvalidationcache_tests.cpp
@@ -119,7 +119,7 @@ void ValidateCheckInputsForAllFlags(CMutableTransaction &tx, uint32_t failing_fl
             // WITNESS requires P2SH
             test_flags |= SCRIPT_VERIFY_P2SH;
         }
-        bool ret = CheckInputs(tx, state, pcoinsTip, true, test_flags, true, add_to_cache, txdata, nullptr);
+        bool ret = CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, nullptr);
         // CheckInputs should succeed iff test_flags doesn't intersect with
         // failing_flags
         bool expected_return_value = !(test_flags & failing_flags);
@@ -135,13 +135,13 @@ void ValidateCheckInputsForAllFlags(CMutableTransaction &tx, uint32_t failing_fl
         if (ret && add_to_cache) {
             // Check that we get a cache hit if the tx was valid
             std::vector<CScriptCheck> scriptchecks;
-            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip, true, test_flags, true, add_to_cache, txdata, &scriptchecks));
+            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
             BOOST_CHECK(scriptchecks.empty());
         } else {
             // Check that we get script executions to check, if the transaction
             // was invalid, or we didn't add to cache.
             std::vector<CScriptCheck> scriptchecks;
-            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip, true, test_flags, true, add_to_cache, txdata, &scriptchecks));
+            BOOST_CHECK(CheckInputs(tx, state, pcoinsTip.get(), true, test_flags, true, add_to_cache, txdata, &scriptchecks));
             BOOST_CHECK_EQUAL(scriptchecks.size(), tx.vin.size());
         }
     }
@@ -201,13 +201,13 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         CValidationState state;
         PrecomputedTransactionData ptd_spend_tx(spend_tx);
 
-        BOOST_CHECK(!CheckInputs(spend_tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
+        BOOST_CHECK(!CheckInputs(spend_tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, nullptr));
 
         // If we call again asking for scriptchecks (as happens in
         // ConnectBlock), we should add a script check object for this -- we're
         // not caching invalidity (if that changes, delete this test case).
         std::vector<CScriptCheck> scriptchecks;
-        BOOST_CHECK(CheckInputs(spend_tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
+        BOOST_CHECK(CheckInputs(spend_tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_DERSIG, true, true, ptd_spend_tx, &scriptchecks));
         BOOST_CHECK_EQUAL(scriptchecks.size(), 1);
 
         // Test that CheckInputs returns true iff DERSIG-enforcing flags are
@@ -268,7 +268,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         invalid_with_cltv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         CValidationState state;
         PrecomputedTransactionData txdata(invalid_with_cltv_tx);
-        BOOST_CHECK(CheckInputs(invalid_with_cltv_tx, state, pcoinsTip, true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
+        BOOST_CHECK(CheckInputs(invalid_with_cltv_tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY, true, true, txdata, nullptr));
     }
 
     // TEST CHECKSEQUENCEVERIFY
@@ -296,7 +296,7 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         invalid_with_csv_tx.vin[0].scriptSig = CScript() << vchSig << 100;
         CValidationState state;
         PrecomputedTransactionData txdata(invalid_with_csv_tx);
-        BOOST_CHECK(CheckInputs(invalid_with_csv_tx, state, pcoinsTip, true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
+        BOOST_CHECK(CheckInputs(invalid_with_csv_tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_CHECKSEQUENCEVERIFY, true, true, txdata, nullptr));
     }
 
     // TODO: add tests for remaining script flags
@@ -358,12 +358,12 @@ BOOST_FIXTURE_TEST_CASE(checkinputs_test, TestChain100Setup)
         CValidationState state;
         PrecomputedTransactionData txdata(tx);
         // This transaction is now invalid under segwit, because of the second input.
-        BOOST_CHECK(!CheckInputs(tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
+        BOOST_CHECK(!CheckInputs(tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, nullptr));
 
         std::vector<CScriptCheck> scriptchecks;
         // Make sure this transaction was not cached (ie because the first
         // input was valid)
-        BOOST_CHECK(CheckInputs(tx, state, pcoinsTip, true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
+        BOOST_CHECK(CheckInputs(tx, state, pcoinsTip.get(), true, SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS, true, true, txdata, &scriptchecks));
         // Should get 2 script checks back -- caching is on a whole-transaction basis.
         BOOST_CHECK_EQUAL(scriptchecks.size(), 2);
     }
diff --git a/src/util.h b/src/util.h
index 480a80c0a3..43acd93ee2 100644
--- a/src/util.h
+++ b/src/util.h
@@ -326,4 +326,11 @@ template <typename Callable> void TraceThread(const char* name,  Callable func)
 
 std::string CopyrightHolders(const std::string& strPrefix);
 
+//! Substitute for C++14 std::make_unique.
+template <typename T, typename... Args>
+std::unique_ptr<T> MakeUnique(Args&&... args)
+{
+    return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+
 #endif // BITCOIN_UTIL_H
diff --git a/src/validation.cpp b/src/validation.cpp
index efabe6293f..e7b6fc52a8 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -201,9 +201,9 @@ CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& loc
     return chain.Genesis();
 }
 
-CCoinsViewDB *pcoinsdbview = nullptr;
-CCoinsViewCache *pcoinsTip = nullptr;
-CBlockTreeDB *pblocktree = nullptr;
+std::unique_ptr<CCoinsViewDB> pcoinsdbview;
+std::unique_ptr<CCoinsViewCache> pcoinsTip;
+std::unique_ptr<CBlockTreeDB> pblocktree;
 
 enum FlushStateMode {
     FLUSH_STATE_NONE,
@@ -295,7 +295,7 @@ bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool
     }
     else {
         // pcoinsTip contains the UTXO set for chainActive.Tip()
-        CCoinsViewMemPool viewMemPool(pcoinsTip, mempool);
+        CCoinsViewMemPool viewMemPool(pcoinsTip.get(), mempool);
         std::vector<int> prevheights;
         prevheights.resize(tx.vin.size());
         for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
@@ -424,7 +424,7 @@ void UpdateMempoolForReorg(DisconnectedBlockTransactions &disconnectpool, bool f
     mempool.UpdateTransactionsFromBlock(vHashUpdate);
 
     // We also need to remove any now-immature transactions
-    mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
+    mempool.removeForReorg(pcoinsTip.get(), chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
     // Re-limit mempool size, in case we added any transactions
     LimitMempoolSize(mempool, gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000, gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60);
 }
@@ -557,7 +557,7 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         LockPoints lp;
         {
         LOCK(pool.cs);
-        CCoinsViewMemPool viewMemPool(pcoinsTip, pool);
+        CCoinsViewMemPool viewMemPool(pcoinsTip.get(), pool);
         view.SetBackend(viewMemPool);
 
         // do all inputs exist?
@@ -2105,7 +2105,7 @@ bool static DisconnectTip(CValidationState& state, const CChainParams& chainpara
     // Apply the block atomically to the chain state.
     int64_t nStart = GetTimeMicros();
     {
-        CCoinsViewCache view(pcoinsTip);
+        CCoinsViewCache view(pcoinsTip.get());
         assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
         if (DisconnectBlock(block, pindexDelete, view) != DISCONNECT_OK)
             return error("DisconnectTip(): DisconnectBlock %s failed", pindexDelete->GetBlockHash().ToString());
@@ -2235,7 +2235,7 @@ bool static ConnectTip(CValidationState& state, const CChainParams& chainparams,
     int64_t nTime3;
     LogPrint(BCLog::BENCH, "  - Load block from disk: %.2fms [%.2fs]\n", (nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
     {
-        CCoinsViewCache view(pcoinsTip);
+        CCoinsViewCache view(pcoinsTip.get());
         bool rv = ConnectBlock(blockConnecting, state, pindexNew, view, chainparams);
         GetMainSignals().BlockChecked(blockConnecting, state);
         if (!rv) {
@@ -2413,7 +2413,7 @@ static bool ActivateBestChainStep(CValidationState& state, const CChainParams& c
         // any disconnected transactions back to the mempool.
         UpdateMempoolForReorg(disconnectpool, true);
     }
-    mempool.check(pcoinsTip);
+    mempool.check(pcoinsTip.get());
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound)
@@ -3275,7 +3275,7 @@ bool TestBlockValidity(CValidationState& state, const CChainParams& chainparams,
 {
     AssertLockHeld(cs_main);
     assert(pindexPrev && pindexPrev == chainActive.Tip());
-    CCoinsViewCache viewNew(pcoinsTip);
+    CCoinsViewCache viewNew(pcoinsTip.get());
     CBlockIndex indexDummy(block);
     indexDummy.pprev = pindexPrev;
     indexDummy.nHeight = pindexPrev->nHeight + 1;
diff --git a/src/validation.h b/src/validation.h
index 93669de6c4..f2ffdc8993 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -444,13 +444,13 @@ bool ResetBlockFailureFlags(CBlockIndex *pindex);
 extern CChain chainActive;
 
 /** Global variable that points to the coins database (protected by cs_main) */
-extern CCoinsViewDB *pcoinsdbview;
+extern std::unique_ptr<CCoinsViewDB> pcoinsdbview;
 
 /** Global variable that points to the active CCoinsView (protected by cs_main) */
-extern CCoinsViewCache *pcoinsTip;
+extern std::unique_ptr<CCoinsViewCache> pcoinsTip;
 
 /** Global variable that points to the active block tree (protected by cs_main) */
-extern CBlockTreeDB *pblocktree;
+extern std::unique_ptr<CBlockTreeDB> pblocktree;
 
 /**
  * Return the spend height, which is one more than the inputs.GetBestBlock().
diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 5d48b01c2e..ca8e680ff7 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -75,13 +75,12 @@ void CDBEnv::EnvShutdown()
 
 void CDBEnv::Reset()
 {
-    delete dbenv;
-    dbenv = new DbEnv(DB_CXX_NO_EXCEPTIONS);
+    dbenv.reset(new DbEnv(DB_CXX_NO_EXCEPTIONS));
     fDbEnvInit = false;
     fMockDb = false;
 }
 
-CDBEnv::CDBEnv() : dbenv(nullptr)
+CDBEnv::CDBEnv()
 {
     Reset();
 }
@@ -89,8 +88,6 @@ CDBEnv::CDBEnv() : dbenv(nullptr)
 CDBEnv::~CDBEnv()
 {
     EnvShutdown();
-    delete dbenv;
-    dbenv = nullptr;
 }
 
 void CDBEnv::Close()
@@ -182,7 +179,7 @@ CDBEnv::VerifyResult CDBEnv::Verify(const std::string& strFile, recoverFunc_type
     LOCK(cs_db);
     assert(mapFileUseCount.count(strFile) == 0);
 
-    Db db(dbenv, 0);
+    Db db(dbenv.get(), 0);
     int result = db.verify(strFile.c_str(), nullptr, nullptr, 0);
     if (result == 0)
         return VERIFY_OK;
@@ -225,7 +222,7 @@ bool CDB::Recover(const std::string& filename, void *callbackDataIn, bool (*reco
     }
     LogPrintf("Salvage(aggressive) found %u records\n", salvagedData.size());
 
-    std::unique_ptr<Db> pdbCopy(new Db(bitdb.dbenv, 0));
+    std::unique_ptr<Db> pdbCopy = MakeUnique<Db>(bitdb.dbenv.get(), 0);
     int ret = pdbCopy->open(nullptr,               // Txn pointer
                             filename.c_str(),   // Filename
                             "main",             // Logical db name
@@ -334,7 +331,7 @@ bool CDBEnv::Salvage(const std::string& strFile, bool fAggressive, std::vector<C
 
     std::stringstream strDump;
 
-    Db db(dbenv, 0);
+    Db db(dbenv.get(), 0);
     int result = db.verify(strFile.c_str(), nullptr, &strDump, flags);
     if (result == DB_VERIFY_BAD) {
         LogPrintf("CDBEnv::Salvage: Database salvage found errors, all data may not be recoverable.\n");
@@ -416,7 +413,7 @@ CDB::CDB(CWalletDBWrapper& dbw, const char* pszMode, bool fFlushOnCloseIn) : pdb
         pdb = env->mapDb[strFilename];
         if (pdb == nullptr) {
             int ret;
-            std::unique_ptr<Db> pdb_temp(new Db(env->dbenv, 0));
+            std::unique_ptr<Db> pdb_temp = MakeUnique<Db>(env->dbenv.get(), 0);
 
             bool fMockDb = env->IsMock();
             if (fMockDb) {
@@ -525,7 +522,7 @@ bool CDB::Rewrite(CWalletDBWrapper& dbw, const char* pszSkip)
                 std::string strFileRes = strFile + ".rewrite";
                 { // surround usage of db with extra {}
                     CDB db(dbw, "r");
-                    Db* pdbCopy = new Db(env->dbenv, 0);
+                    std::unique_ptr<Db> pdbCopy = MakeUnique<Db>(env->dbenv.get(), 0);
 
                     int ret = pdbCopy->open(nullptr,               // Txn pointer
                                             strFileRes.c_str(), // Filename
@@ -574,13 +571,12 @@ bool CDB::Rewrite(CWalletDBWrapper& dbw, const char* pszSkip)
                     } else {
                         pdbCopy->close(0);
                     }
-                    delete pdbCopy;
                 }
                 if (fSuccess) {
-                    Db dbA(env->dbenv, 0);
+                    Db dbA(env->dbenv.get(), 0);
                     if (dbA.remove(strFile.c_str(), nullptr, 0))
                         fSuccess = false;
-                    Db dbB(env->dbenv, 0);
+                    Db dbB(env->dbenv.get(), 0);
                     if (dbB.rename(strFileRes.c_str(), nullptr, strFile.c_str(), 0))
                         fSuccess = false;
                 }
diff --git a/src/wallet/db.h b/src/wallet/db.h
index 14283ac8f8..e6d5a9f293 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -36,7 +36,7 @@ private:
 
 public:
     mutable CCriticalSection cs_db;
-    DbEnv *dbenv;
+    std::unique_ptr<DbEnv> dbenv;
     std::map<std::string, int> mapFileUseCount;
     std::map<std::string, Db*> mapDb;
 
diff --git a/src/wallet/test/wallet_test_fixture.cpp b/src/wallet/test/wallet_test_fixture.cpp
index e2f48c45ab..34f210fcd7 100644
--- a/src/wallet/test/wallet_test_fixture.cpp
+++ b/src/wallet/test/wallet_test_fixture.cpp
@@ -8,7 +8,7 @@
 #include "wallet/db.h"
 #include "wallet/wallet.h"
 
-CWallet *pwalletMain;
+std::unique_ptr<CWallet> pwalletMain;
 
 WalletTestingSetup::WalletTestingSetup(const std::string& chainName):
     TestingSetup(chainName)
@@ -17,18 +17,17 @@ WalletTestingSetup::WalletTestingSetup(const std::string& chainName):
 
     bool fFirstRun;
     std::unique_ptr<CWalletDBWrapper> dbw(new CWalletDBWrapper(&bitdb, "wallet_test.dat"));
-    pwalletMain = new CWallet(std::move(dbw));
+    pwalletMain = MakeUnique<CWallet>(std::move(dbw));
     pwalletMain->LoadWallet(fFirstRun);
-    RegisterValidationInterface(pwalletMain);
+    RegisterValidationInterface(pwalletMain.get());
 
     RegisterWalletRPCCommands(tableRPC);
 }
 
 WalletTestingSetup::~WalletTestingSetup()
 {
-    UnregisterValidationInterface(pwalletMain);
-    delete pwalletMain;
-    pwalletMain = nullptr;
+    UnregisterValidationInterface(pwalletMain.get());
+    pwalletMain.reset();
 
     bitdb.Flush(true);
     bitdb.Reset();
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index a357224a86..dceb818b50 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3806,7 +3806,7 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
         uiInterface.InitMessage(_("Zapping all transactions from wallet..."));
 
         std::unique_ptr<CWalletDBWrapper> dbw(new CWalletDBWrapper(&bitdb, walletFile));
-        std::unique_ptr<CWallet> tempWallet(new CWallet(std::move(dbw)));
+        std::unique_ptr<CWallet> tempWallet = MakeUnique<CWallet>(std::move(dbw));
         DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
         if (nZapWalletRet != DB_LOAD_OK) {
             InitError(strprintf(_("Error loading %s: Wallet corrupted"), walletFile));