Consistently log CValidationState on failure

Seems providing at least minimal visibility to the failure is a good practice.

The only remaining ignored state is in LoadExternalBlockFile, where logging
would likely be spammy.

src/init.cpp

@@ -684,7 +684,7 @@ void ThreadImport(std::vector<fs::path> vImportFiles)
     // scan for better chains in the block chain database, that are not yet connected in the active best chain
     CValidationState state;
     if (!ActivateBestChain(state, chainparams)) {
-        LogPrintf("Failed to connect best block\n");
+        LogPrintf("Failed to connect best block (%s)\n", FormatStateMessage(state));
         StartShutdown();
         return;
     }

src/net_processing.cpp

@@ -1100,8 +1100,10 @@ void static ProcessGetBlockData(CNode* pfrom, const Consensus::Params& consensus
         }
     } // release cs_main before calling ActivateBestChain
     if (need_activate_chain) {
-        CValidationState dummy;
+        CValidationState state;
-        ActivateBestChain(dummy, Params(), a_recent_block);
+        if (!ActivateBestChain(state, Params(), a_recent_block)) {
+            LogPrint(BCLog::NET, "failed to activate chain (%s)\n", FormatStateMessage(state));
+        }
     }
 
     LOCK(cs_main);
@@ -1992,8 +1994,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
                 LOCK(cs_most_recent_block);
                 a_recent_block = most_recent_block;
             }
-            CValidationState dummy;
+            CValidationState state;
-            ActivateBestChain(dummy, Params(), a_recent_block);
+            if (!ActivateBestChain(state, Params(), a_recent_block)) {
+                LogPrint(BCLog::NET, "failed to activate chain (%s)\n", FormatStateMessage(state));
+            }
         }
 
         LOCK(cs_main);

src/test/test_bitcoin.cpp

@@ -85,7 +85,7 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
         {
             CValidationState state;
             if (!ActivateBestChain(state, chainparams)) {
-                throw std::runtime_error("ActivateBestChain failed.");
+                throw std::runtime_error(strprintf("ActivateBestChain failed. (%s)", FormatStateMessage(state)));
             }
         }
         nScriptCheckThreads = 3;

src/validation.cpp

@@ -2181,14 +2181,18 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
 void FlushStateToDisk() {
     CValidationState state;
     const CChainParams& chainparams = Params();
-    FlushStateToDisk(chainparams, state, FlushStateMode::ALWAYS);
+    if (!FlushStateToDisk(chainparams, state, FlushStateMode::ALWAYS)) {
+        LogPrintf("%s: failed to flush state (%s)\n", __func__, FormatStateMessage(state));
+    }
 }
 
 void PruneAndFlush() {
     CValidationState state;
     fCheckForPruning = true;
     const CChainParams& chainparams = Params();
-    FlushStateToDisk(chainparams, state, FlushStateMode::NONE);
+    if (!FlushStateToDisk(chainparams, state, FlushStateMode::NONE)) {
+        LogPrintf("%s: failed to flush state (%s)\n", __func__, FormatStateMessage(state));
+    }
 }
 
 static void DoWarning(const std::string& strWarning)
@@ -3489,7 +3493,7 @@ bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<cons
         }
         if (!ret) {
             GetMainSignals().BlockChecked(*pblock, state);
-            return error("%s: AcceptBlock FAILED (%s)", __func__, state.GetDebugMessage());
+            return error("%s: AcceptBlock FAILED (%s)", __func__, FormatStateMessage(state));
         }
     }
 
@@ -3497,7 +3501,7 @@ bool ProcessNewBlock(const CChainParams& chainparams, const std::shared_ptr<cons
 
     CValidationState state; // Only used to report errors, not invalidity - ignore it
     if (!g_chainstate.ActivateBestChain(state, chainparams, pblock))
-        return error("%s: ActivateBestChain failed", __func__);
+        return error("%s: ActivateBestChain failed (%s)", __func__, FormatStateMessage(state));
 
     return true;
 }
@@ -3615,7 +3619,9 @@ void PruneBlockFilesManual(int nManualPruneHeight)
 {
     CValidationState state;
     const CChainParams& chainparams = Params();
-    FlushStateToDisk(chainparams, state, FlushStateMode::NONE, nManualPruneHeight);
+    if (!FlushStateToDisk(chainparams, state, FlushStateMode::NONE, nManualPruneHeight)) {
+        LogPrintf("%s: failed to flush state (%s)\n", __func__, FormatStateMessage(state));
+    }
 }
 
 /**
@@ -3869,6 +3875,7 @@ bool LoadChainTip(const CChainParams& chainparams)
         LogPrintf("%s: Connecting genesis block...\n", __func__);
         CValidationState state;
         if (!ActivateBestChain(state, chainparams)) {
+            LogPrintf("%s: failed to activate chain (%s)\n", __func__, FormatStateMessage(state));
             return false;
         }
     }
@@ -3983,7 +3990,7 @@ bool CVerifyDB::VerifyDB(const CChainParams& chainparams, CCoinsView *coinsview,
             if (!ReadBlockFromDisk(block, pindex, chainparams.GetConsensus()))
                 return error("VerifyDB(): *** ReadBlockFromDisk failed at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
             if (!g_chainstate.ConnectBlock(block, state, pindex, coins, chainparams))
-                return error("VerifyDB(): *** found unconnectable block at %d, hash=%s", pindex->nHeight, pindex->GetBlockHash().ToString());
+                return error("VerifyDB(): *** found unconnectable block at %d, hash=%s (%s)", pindex->nHeight, pindex->GetBlockHash().ToString(), FormatStateMessage(state));
         }
     }
 
@@ -4110,12 +4117,14 @@ bool CChainState::RewindBlockIndex(const CChainParams& params)
             break;
         }
         if (!DisconnectTip(state, params, nullptr)) {
-            return error("RewindBlockIndex: unable to disconnect block at height %i", pindex->nHeight);
+            return error("RewindBlockIndex: unable to disconnect block at height %i (%s)", pindex->nHeight, FormatStateMessage(state));
         }
         // Occasionally flush state to disk.
-        if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC))
+        if (!FlushStateToDisk(params, state, FlushStateMode::PERIODIC)) {
+            LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", FormatStateMessage(state));
             return false;
         }
+    }
 
     // Reduce validity flag and have-data flags.
     // We do this after actual disconnecting, otherwise we'll end up writing the lack of data
@@ -4180,6 +4189,7 @@ bool RewindBlockIndex(const CChainParams& params) {
         // it'll get called a bunch real soon.
         CValidationState state;
         if (!FlushStateToDisk(params, state, FlushStateMode::ALWAYS)) {
+            LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", FormatStateMessage(state));
             return false;
         }
     }
@@ -4266,7 +4276,7 @@ bool CChainState::LoadGenesisBlock(const CChainParams& chainparams)
         CBlockIndex *pindex = AddToBlockIndex(block);
         CValidationState state;
         if (!ReceivedBlockTransactions(block, state, pindex, blockPos, chainparams.GetConsensus()))
-            return error("%s: genesis block not accepted", __func__);
+            return error("%s: genesis block not accepted (%s)", __func__, FormatStateMessage(state));
     } catch (const std::runtime_error& e) {
         return error("%s: failed to write genesis block: %s", __func__, e.what());
     }