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.

1 files changed, 0 insertions, 217 deletions

diff --git a/core/execution.go b/core/execution.go
deleted file mode 100644
index e3ea1006c..000000000
--- a/core/execution.go
+++ /dev/null
@@ -1,217 +0,0 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package core
-
-import (
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core/vm"
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/params"
-)
-
-// Call executes within the given contract
-func Call(env vm.Environment, caller vm.ContractRef, addr common.Address, input []byte, gas, gasPrice, value *big.Int) (ret []byte, err error) {
-	// Depth check execution. Fail if we're trying to execute above the
-	// limit.
-	if env.Depth() > int(params.CallCreateDepth.Int64()) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, vm.DepthError
-	}
-	if !env.CanTransfer(caller.Address(), value) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", value, env.Db().GetBalance(caller.Address()))
-	}
-
-	snapshotPreTransfer := env.SnapshotDatabase()
-	var (
-		from = env.Db().GetAccount(caller.Address())
-		to   vm.Account
-	)
-	if !env.Db().Exist(addr) {
-		if vm.Precompiled[addr.Str()] == nil && env.ChainConfig().IsEIP158(env.BlockNumber()) && value.BitLen() == 0 {
-			caller.ReturnGas(gas, gasPrice)
-			return nil, nil
-		}
-
-		to = env.Db().CreateAccount(addr)
-	} else {
-		to = env.Db().GetAccount(addr)
-	}
-	env.Transfer(from, to, value)
-
-	// initialise a new contract and set the code that is to be used by the
-	// EVM. The contract is a scoped environment for this execution context
-	// only.
-	contract := vm.NewContract(caller, to, value, gas, gasPrice)
-	contract.SetCallCode(&addr, env.Db().GetCodeHash(addr), env.Db().GetCode(addr))
-	defer contract.Finalise()
-
-	ret, err = env.Vm().Run(contract, input)
-	// When an error was returned by the EVM or when setting the creation code
-	// above we revert to the snapshot and consume any gas remaining. Additionally
-	// when we're in homestead this also counts for code storage gas errors.
-	if err != nil {
-		contract.UseGas(contract.Gas)
-
-		env.RevertToSnapshot(snapshotPreTransfer)
-	}
-	return ret, err
-}
-
-// CallCode executes the given address' code as the given contract address
-func CallCode(env vm.Environment, caller vm.ContractRef, addr common.Address, input []byte, gas, gasPrice, value *big.Int) (ret []byte, err error) {
-	// Depth check execution. Fail if we're trying to execute above the
-	// limit.
-	if env.Depth() > int(params.CallCreateDepth.Int64()) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, vm.DepthError
-	}
-	if !env.CanTransfer(caller.Address(), value) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", value, env.Db().GetBalance(caller.Address()))
-	}
-
-	var (
-		snapshotPreTransfer = env.SnapshotDatabase()
-		to                  = env.Db().GetAccount(caller.Address())
-	)
-	// initialise a new contract and set the code that is to be used by the
-	// EVM. The contract is a scoped environment for this execution context
-	// only.
-	contract := vm.NewContract(caller, to, value, gas, gasPrice)
-	contract.SetCallCode(&addr, env.Db().GetCodeHash(addr), env.Db().GetCode(addr))
-	defer contract.Finalise()
-
-	ret, err = env.Vm().Run(contract, input)
-	if err != nil {
-		contract.UseGas(contract.Gas)
-
-		env.RevertToSnapshot(snapshotPreTransfer)
-	}
-
-	return ret, err
-}
-
-// Create creates a new contract with the given code
-func Create(env vm.Environment, caller vm.ContractRef, code []byte, gas, gasPrice, value *big.Int) (ret []byte, address common.Address, err error) {
-	// Depth check execution. Fail if we're trying to execute above the
-	// limit.
-	if env.Depth() > int(params.CallCreateDepth.Int64()) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, common.Address{}, vm.DepthError
-	}
-	if !env.CanTransfer(caller.Address(), value) {
-		caller.ReturnGas(gas, gasPrice)
-
-		return nil, common.Address{}, ValueTransferErr("insufficient funds to transfer value. Req %v, has %v", value, env.Db().GetBalance(caller.Address()))
-	}
-
-	// Create a new account on the state
-	nonce := env.Db().GetNonce(caller.Address())
-	env.Db().SetNonce(caller.Address(), nonce+1)
-
-	snapshotPreTransfer := env.SnapshotDatabase()
-	var (
-		addr = crypto.CreateAddress(caller.Address(), nonce)
-		from = env.Db().GetAccount(caller.Address())
-		to   = env.Db().CreateAccount(addr)
-	)
-	if env.ChainConfig().IsEIP158(env.BlockNumber()) {
-		env.Db().SetNonce(addr, 1)
-	}
-	env.Transfer(from, to, value)
-
-	// initialise a new contract and set the code that is to be used by the
-	// EVM. The contract is a scoped environment for this execution context
-	// only.
-	contract := vm.NewContract(caller, to, value, gas, gasPrice)
-	contract.SetCallCode(&addr, crypto.Keccak256Hash(code), code)
-	defer contract.Finalise()
-
-	ret, err = env.Vm().Run(contract, nil)
-	// check whether the max code size has been exceeded
-	maxCodeSizeExceeded := len(ret) > params.MaxCodeSize
-	// if the contract creation ran successfully and no errors were returned
-	// calculate the gas required to store the code. If the code could not
-	// be stored due to not enough gas set an error and let it be handled
-	// by the error checking condition below.
-	if err == nil && !maxCodeSizeExceeded {
-		dataGas := big.NewInt(int64(len(ret)))
-		dataGas.Mul(dataGas, params.CreateDataGas)
-		if contract.UseGas(dataGas) {
-			env.Db().SetCode(addr, ret)
-		} else {
-			err = vm.CodeStoreOutOfGasError
-		}
-	}
-
-	// When an error was returned by the EVM or when setting the creation code
-	// above we revert to the snapshot and consume any gas remaining. Additionally
-	// when we're in homestead this also counts for code storage gas errors.
-	if maxCodeSizeExceeded ||
-		(err != nil && (env.ChainConfig().IsHomestead(env.BlockNumber()) || err != vm.CodeStoreOutOfGasError)) {
-		contract.UseGas(contract.Gas)
-		env.RevertToSnapshot(snapshotPreTransfer)
-
-		// Nothing should be returned when an error is thrown.
-		return nil, addr, err
-	}
-
-	return ret, addr, err
-}
-
-// DelegateCall is equivalent to CallCode except that sender and value propagates from parent scope to child scope
-func DelegateCall(env vm.Environment, caller vm.ContractRef, addr common.Address, input []byte, gas, gasPrice *big.Int) (ret []byte, err error) {
-	// Depth check execution. Fail if we're trying to execute above the
-	// limit.
-	if env.Depth() > int(params.CallCreateDepth.Int64()) {
-		caller.ReturnGas(gas, gasPrice)
-		return nil, vm.DepthError
-	}
-
-	var (
-		snapshot = env.SnapshotDatabase()
-		to       = env.Db().GetAccount(caller.Address())
-	)
-
-	// Iinitialise a new contract and make initialise the delegate values
-	contract := vm.NewContract(caller, to, caller.Value(), gas, gasPrice).AsDelegate()
-	contract.SetCallCode(&addr, env.Db().GetCodeHash(addr), env.Db().GetCode(addr))
-	defer contract.Finalise()
-
-	ret, err = env.Vm().Run(contract, input)
-	if err != nil {
-		contract.UseGas(contract.Gas)
-
-		env.RevertToSnapshot(snapshot)
-	}
-
-	return ret, err
-}
-
-// generic transfer method
-func Transfer(from, to vm.Account, amount *big.Int) {
-	from.SubBalance(amount)
-	to.AddBalance(amount)
-}