Merge bitcoin/bitcoin#27357: validation: Move warningcache to ChainstateManager and rename to m_warningcache

5526849 validation: Move warningcache to ChainstateManager (dimitaracev)

Pull request description:

  Removes `warningcache`  and moves it to `ChainstateManager`. Also removes the respective `TODO`  completely.

ACKs for top commit:
  ajtowns:
    ACK 5526849
  dimitaracev:
    > ACK [5526849](bitcoin/bitcoin@5526849)
  TheCharlatan:
    ACK 5526849
  ryanofsky:
    Code review ACK 5526849

Tree-SHA512: 6869bd7aa4f0b59324e12eb8e3df47f2c9a3f3b0d9b7d45857426ec9e8b71c5573bdcf71db822f8c10aff7d8679a00a4bedc7a256c28f325e744e5d7267b41e9

Author: fanquake

src/validation.cpp

@@ -1993,8 +1993,6 @@ class WarningBitsConditionChecker : public AbstractThresholdConditionChecker
     }
 };
 
-static std::array<ThresholdConditionCache, VERSIONBITS_NUM_BITS> warningcache GUARDED_BY(cs_main);
-
 static unsigned int GetBlockScriptFlags(const CBlockIndex& block_index, const ChainstateManager& chainman)
 {
     const Consensus::Params& consensusparams = chainman.GetConsensus();
@@ -2640,7 +2638,7 @@ void Chainstate::UpdateTip(const CBlockIndex* pindexNew)
         const CBlockIndex* pindex = pindexNew;
         for (int bit = 0; bit < VERSIONBITS_NUM_BITS; bit++) {
             WarningBitsConditionChecker checker(m_chainman, bit);
-            ThresholdState state = checker.GetStateFor(pindex, params.GetConsensus(), warningcache.at(bit));
+            ThresholdState state = checker.GetStateFor(pindex, params.GetConsensus(), m_chainman.m_warningcache.at(bit));
             if (state == ThresholdState::ACTIVE || state == ThresholdState::LOCKED_IN) {
                 const bilingual_str warning = strprintf(_("Unknown new rules activated (versionbit %i)"), bit);
                 if (state == ThresholdState::ACTIVE) {
@@ -5586,11 +5584,6 @@ ChainstateManager::~ChainstateManager()
     LOCK(::cs_main);
 
     m_versionbitscache.Clear();
-
-    // TODO: The warning cache should probably become non-global
-    for (auto& i : warningcache) {
-        i.clear();
-    }
 }
 
 bool ChainstateManager::DetectSnapshotChainstate(CTxMemPool* mempool)

src/validation.h

@@ -938,6 +938,8 @@ class ChainstateManager
     //! nullopt.
     std::optional<int> GetSnapshotBaseHeight() const EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 
+    std::array<ThresholdConditionCache, VERSIONBITS_NUM_BITS> m_warningcache GUARDED_BY(::cs_main);
+
     //! Return true if a chainstate is considered usable.
     //!
     //! This is false when a background validation chainstate has completed its