core, core/vm: implemented a generic environment (#3348)

Environment is now a struct (not an interface). This
reduces a lot of tech-debt throughout the codebase where a virtual
machine environment had to be implemented in order to test or run it.

The new environment is suitable to be used en the json tests, core
consensus and light client.

2 files changed, 9 insertions, 5 deletions

diff --git a/eth/api.go b/eth/api.go
index b3185c392..a86ed95cf 100644
--- a/eth/api.go
+++ b/eth/api.go
@@ -515,9 +515,11 @@ func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.
 		if err != nil {
 			return nil, fmt.Errorf("sender retrieval failed: %v", err)
 		}
+		context := core.NewEVMContext(msg, block.Header(), api.eth.BlockChain())
+
 		// Mutate the state if we haven't reached the tracing transaction yet
 		if uint64(idx) < txIndex {
-			vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{})
+			vmenv := vm.NewEnvironment(context, stateDb, api.config, vm.Config{})
 			_, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
 			if err != nil {
 				return nil, fmt.Errorf("mutation failed: %v", err)
@@ -525,8 +527,8 @@ func (api *PrivateDebugAPI) TraceTransaction(ctx context.Context, txHash common.
 			stateDb.DeleteSuicides()
 			continue
 		}
-		// Otherwise trace the transaction and return
-		vmenv := core.NewEnv(stateDb, api.config, api.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Tracer: tracer})
+
+		vmenv := vm.NewEnvironment(context, stateDb, api.config, vm.Config{Debug: true, Tracer: tracer})
 		ret, gas, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
 		if err != nil {
 			return nil, fmt.Errorf("tracing failed: %v", err)
diff --git a/eth/api_backend.go b/eth/api_backend.go
index 7858dee2e..b95ef79c5 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -106,12 +106,14 @@ func (b *EthApiBackend) GetTd(blockHash common.Hash) *big.Int {
 	return b.eth.blockchain.GetTdByHash(blockHash)
 }
 
-func (b *EthApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header) (vm.Environment, func() error, error) {
+func (b *EthApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header) (*vm.Environment, func() error, error) {
 	statedb := state.(EthApiState).state
 	from := statedb.GetOrNewStateObject(msg.From())
 	from.SetBalance(common.MaxBig)
 	vmError := func() error { return nil }
-	return core.NewEnv(statedb, b.eth.chainConfig, b.eth.blockchain, msg, header, vm.Config{}), vmError, nil
+
+	context := core.NewEVMContext(msg, header, b.eth.BlockChain())
+	return vm.NewEnvironment(context, statedb, b.eth.chainConfig, vm.Config{}), vmError, nil
 }
 
 func (b *EthApiBackend) SendTx(ctx context.Context, signedTx *types.Transaction) error {