Eip 1884 v3 (#19743)

* core/vm, tests: implement EIP 1884, add support for feature-tests

* core/vm: 1884-changes to extcodehash, move selfbalance opcode

* tests: fix statetests

* core/vm: move constants, address review concerns

* core/vm: word formatting

Co-Authored-By: Péter Szilágyi <peterke@gmail.com>

core/vm/eips.go

@@ -0,0 +1,63 @@
+// Copyright 2019 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 vm
+
+import (
+	"fmt"
+	
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// EnableEIP enables the given EIP on the config.
+// This operation writes in-place, and callers need to ensure that the globally
+// defined jump tables are not polluted.
+func EnableEIP(eipNum int, jt *JumpTable) error {
+	switch eipNum {
+	case 1884:
+		enable1884(jt)
+	default:
+		return fmt.Errorf("undefined eip %d", eipNum)
+	}
+	return nil
+}
+
+// enable1884 applies EIP-1884 to the given jump table:
+// - Increase cost of BALANCE to 700
+// - Increase cost of EXTCODEHASH to 700
+// - Increase cost of SLOAD to 800
+// - Define SELFBALANCE, with cost GasFastStep (5)
+func enable1884(jt *JumpTable) {
+	// Gas cost changes
+	jt[BALANCE].constantGas = params.BalanceGasEIP1884
+	jt[EXTCODEHASH].constantGas = params.ExtcodeHashGasEIP1884
+	jt[SLOAD].constantGas = params.SloadGasEIP1884
+
+	// New opcode
+	jt[SELFBALANCE] = operation{
+		execute:     opSelfBalance,
+		constantGas: GasFastStep,
+		minStack:    minStack(0, 1),
+		maxStack:    maxStack(0, 1),
+		valid:       true,
+	}
+}
+
+func opSelfBalance(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	balance := interpreter.intPool.get().Set(interpreter.evm.StateDB.GetBalance(contract.Address()))
+	stack.push(balance)
+	return nil, nil
+}