params: additional ChainConfig hooks

params/config.go

@@ -478,7 +478,7 @@ func (c *ChainConfig) Description() string {
 	if c.VerkleTime != nil {
 		banner += fmt.Sprintf(" - Verkle:                      @%-10v\n", *c.VerkleTime)
 	}
-	return banner
+	return banner + c.Hooks().Description()
 }
 
 // IsHomestead returns whether num is either equal to the homestead block or greater.
@@ -671,7 +671,7 @@ func (c *ChainConfig) CheckConfigForkOrder() error {
 			lastFork = cur
 		}
 	}
-	return nil
+	return c.Hooks().CheckConfigForkOrder()
 }
 
 func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, headNumber *big.Int, headTimestamp uint64) *ConfigCompatError {
@@ -742,7 +742,7 @@ func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, headNumber *big.Int,
 	if isForkTimestampIncompatible(c.VerkleTime, newcfg.VerkleTime, headTimestamp) {
 		return newTimestampCompatError("Verkle fork timestamp", c.VerkleTime, newcfg.VerkleTime)
 	}
-	return nil
+	return c.Hooks().CheckCompatible(newcfg, headNumber, headTimestamp)
 }
 
 // BaseFeeChangeDenominator bounds the amount the base fee can change between blocks.

params/hooks.libevm.go

@@ -1,13 +1,19 @@
 package params
 
 import (
+	"math/big"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/libevm"
 )
 
 // ChainConfigHooks are required for all types registered as [Extras] for
 // [ChainConfig] payloads.
-type ChainConfigHooks interface{}
+type ChainConfigHooks interface {
+	CheckCompatible(newcfg *ChainConfig, headNumber *big.Int, headTimestamp uint64) *ConfigCompatError
+	CheckConfigForkOrder() error
+	Description() string
+}
 
 // TODO(arr4n): given the choice of whether a hook should be defined on a
 // ChainConfig or on the Rules, what are the guiding principles? A ChainConfig
@@ -66,6 +72,18 @@ var _ interface {
 	RulesHooks
 } = NOOPHooks{}
 
+func (NOOPHooks) CheckCompatible(_ *ChainConfig, _ *big.Int, _ uint64) *ConfigCompatError {
+	return nil
+}
+
+func (NOOPHooks) CheckConfigForkOrder() error {
+	return nil
+}
+
+func (NOOPHooks) Description() string {
+	return ""
+}
+
 // CanExecuteTransaction allows all (otherwise valid) transactions.
 func (NOOPHooks) CanExecuteTransaction(_ common.Address, _ *common.Address, _ libevm.StateReader) error {
 	return nil