add block hash read hook

core/tracing/hooks.go

@@ -189,6 +189,9 @@ type (
 
 	// StorageReadHook is called when EVM reads a storage slot of an account.
 	StorageReadHook = func(addr common.Address, slot, value common.Hash)
+
+	// BlockHashReadHook is called when EVM reads the blockhash of a block.
+	BlockHashReadHook = func(blockNumber uint64, hash common.Hash)
 )
 
 type Hooks struct {
@@ -223,6 +226,8 @@ type Hooks struct {
 	OnCodeSizeRead CodeSizeReadHook
 	OnCodeHashRead CodeHashReadHook
 	OnStorageRead  StorageReadHook
+	// Block hash read
+	OnBlockHashRead BlockHashReadHook
 }
 
 // BalanceChangeReason is used to indicate the reason for a balance change, useful

core/vm/instructions.go

@@ -455,6 +455,9 @@ func opBlockhash(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) (
 		if witness := interpreter.evm.StateDB.Witness(); witness != nil {
 			witness.AddBlockHash(num64)
 		}
+		if tracer := interpreter.evm.Config.Tracer; tracer != nil && tracer.OnBlockHashRead != nil {
+			tracer.OnBlockHashRead(num64, res)
+		}
 		num.SetBytes(res[:])
 	} else {
 		num.Clear()

eth/tracers/live/noop.go

@@ -48,6 +48,7 @@ func newNoopTracer(_ json.RawMessage) (*tracing.Hooks, error) {
 		OnCodeSizeRead:   t.OnCodeSizeRead,
 		OnCodeHashRead:   t.OnCodeHashRead,
 		OnStorageRead:    t.OnStorageRead,
+		OnBlockHashRead:  t.OnBlockHashRead,
 	}, nil
 }
 
@@ -113,5 +114,7 @@ func (t *noop) OnCodeHashRead(addr common.Address, hash common.Hash) {}
 
 func (t *noop) OnStorageRead(addr common.Address, slot, val common.Hash) {}
 
+func (t *noop) OnBlockHashRead(number uint64, hash common.Hash) {}
+
 func (t *noop) OnGasChange(old, new uint64, reason tracing.GasChangeReason) {
 }