refactor fork consistency checking and gate compilation on it (#3704)

beacon_chain/consensus_object_pools/blockchain_dag.nim

@@ -665,32 +665,7 @@ proc init*(T: type ChainDAGRef, cfg: RuntimeConfig, db: BeaconChainDB,
            serveLightClientData = false,
            importLightClientData = ImportLightClientData.None,
            vanityLogs = default(VanityLogs)): ChainDAGRef =
-  # TODO move fork version sanity checking elsewhere?
+  cfg.checkForkConsistency()
-
-  # TODO re-add cfg.CAPELLA_FORK_VERSION once eth-clients repos include it and
-  # fix SHARDING_FORK_VERSION to be its new FORK_VERSION. Until then make sure
-  # that it will never actually use the Capella fork.
-  doAssert cfg.CAPELLA_FORK_EPOCH == FAR_FUTURE_EPOCH
-
-  let forkVersions =
-    [cfg.GENESIS_FORK_VERSION, cfg.ALTAIR_FORK_VERSION,
-     cfg.BELLATRIX_FORK_VERSION, cfg.SHARDING_FORK_VERSION]
-  for i in 0 ..< forkVersions.len:
-    for j in i+1 ..< forkVersions.len:
-      doAssert forkVersions[i] != forkVersions[j]
-
-  template assertForkEpochOrder(
-      firstForkEpoch: Epoch, secondForkEpoch: Epoch) =
-    doAssert firstForkEpoch <= secondForkEpoch
-
-    # TODO https://github.com/ethereum/consensus-specs/issues/2902 multiple
-    # fork transitions per epoch don't work in a well-defined way.
-    doAssert firstForkEpoch < secondForkEpoch or
-             firstForkEpoch in [GENESIS_EPOCH, FAR_FUTURE_EPOCH]
-
-  assertForkEpochOrder(cfg.ALTAIR_FORK_EPOCH, cfg.BELLATRIX_FORK_EPOCH)
-  assertForkEpochOrder(cfg.BELLATRIX_FORK_EPOCH, cfg.CAPELLA_FORK_EPOCH)
-  assertForkEpochOrder(cfg.CAPELLA_FORK_EPOCH, cfg.SHARDING_FORK_EPOCH)
 
   doAssert updateFlags in [{}, {verifyFinalization}],
     "Other flags not supported in ChainDAG"

beacon_chain/networking/network_metadata.nim

@@ -240,6 +240,9 @@ when not defined(gnosisChainBinary):
       mainnetMetadata* = eth2Network("shared/mainnet", mainnet)
       praterMetadata* = eth2Network("shared/prater", goerli)
       ropstenMetadata = mergeTestnet("ropsten-beacon-chain", ropsten)
+    static:
+      for network in [mainnetMetadata, praterMetadata, ropstenMetadata]:
+        checkForkConsistency(network.cfg)
 
   proc getMetadataForNetwork*(networkName: string): Eth2NetworkMetadata {.raises: [Defect, IOError].} =
     template loadRuntimeMetadata: auto =
@@ -284,6 +287,8 @@ else:
     gnosisMetadata* = loadCompileTimeNetworkMetadata(
       currentSourcePath.parentDir.replace('\\', '/') & "/../../media/gnosis")
 
+  static: checkForkConsistency(gnosisMetadata.cfg)
+
   proc checkNetworkParameterUse*(eth2Network: Option[string]) =
     # Support `gnosis-chain` as network name which was used in v22.3
     if eth2Network.isSome and eth2Network.get notin ["gnosis", "gnosis-chain"]:

beacon_chain/spec/datatypes/base.nim

@@ -958,3 +958,29 @@ func clear*(cache: var StateCache) =
   cache.shuffled_active_validator_indices.clear
   cache.beacon_proposer_indices.clear
   cache.sync_committees.clear
+
+func checkForkConsistency*(cfg: RuntimeConfig) =
+  # TODO re-add cfg.CAPELLA_FORK_VERSION once eth-clients repos include it and
+  # fix SHARDING_FORK_VERSION to be its new FORK_VERSION. Until then make sure
+  # that it will never actually use the Capella fork.
+  doAssert cfg.CAPELLA_FORK_EPOCH == FAR_FUTURE_EPOCH
+
+  let forkVersions =
+    [cfg.GENESIS_FORK_VERSION, cfg.ALTAIR_FORK_VERSION,
+     cfg.BELLATRIX_FORK_VERSION, cfg.SHARDING_FORK_VERSION]
+  for i in 0 ..< forkVersions.len:
+    for j in i+1 ..< forkVersions.len:
+      doAssert distinctBase(forkVersions[i]) != distinctBase(forkVersions[j])
+
+  template assertForkEpochOrder(
+      firstForkEpoch: Epoch, secondForkEpoch: Epoch) =
+    doAssert distinctBase(firstForkEpoch) <= distinctBase(secondForkEpoch)
+
+    # TODO https://github.com/ethereum/consensus-specs/issues/2902 multiple
+    # fork transitions per epoch don't work in a well-defined way.
+    doAssert distinctBase(firstForkEpoch) < distinctBase(secondForkEpoch) or
+             firstForkEpoch in [GENESIS_EPOCH, FAR_FUTURE_EPOCH]
+
+  assertForkEpochOrder(cfg.ALTAIR_FORK_EPOCH, cfg.BELLATRIX_FORK_EPOCH)
+  assertForkEpochOrder(cfg.BELLATRIX_FORK_EPOCH, cfg.CAPELLA_FORK_EPOCH)
+  assertForkEpochOrder(cfg.CAPELLA_FORK_EPOCH, cfg.SHARDING_FORK_EPOCH)