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

1 files changed, 14 insertions, 20 deletions

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;