cmd/evm: add state transition tool for testing (#20958)

This PR implements the EVM state transition tool, which is intended
to be the replacement for our retesteth client implementation.
Documentation is present in the cmd/evm/README.md file.

Co-authored-by: Felix Lange <fjl@twurst.com>

cmd/evm/internal/t8ntool/flags.go

@@ -0,0 +1,99 @@
+// Copyright 2020 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 t8ntool
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/tests"
+	"gopkg.in/urfave/cli.v1"
+)
+
+var (
+	TraceFlag = cli.BoolFlag{
+		Name:  "trace",
+		Usage: "Output full trace logs to files <txhash>.jsonl",
+	}
+	TraceDisableMemoryFlag = cli.BoolFlag{
+		Name:  "trace.nomemory",
+		Usage: "Disable full memory dump in traces",
+	}
+	TraceDisableStackFlag = cli.BoolFlag{
+		Name:  "trace.nostack",
+		Usage: "Disable stack output in traces",
+	}
+	OutputAllocFlag = cli.StringFlag{
+		Name: "output.alloc",
+		Usage: "Determines where to put the `alloc` of the post-state.\n" +
+			"\t`stdout` - into the stdout output\n" +
+			"\t`stderr` - into the stderr output\n" +
+			"\t<file> - into the file <file> ",
+		Value: "alloc.json",
+	}
+	OutputResultFlag = cli.StringFlag{
+		Name: "output.result",
+		Usage: "Determines where to put the `result` (stateroot, txroot etc) of the post-state.\n" +
+			"\t`stdout` - into the stdout output\n" +
+			"\t`stderr` - into the stderr output\n" +
+			"\t<file> - into the file <file> ",
+		Value: "result.json",
+	}
+	InputAllocFlag = cli.StringFlag{
+		Name:  "input.alloc",
+		Usage: "`stdin` or file name of where to find the prestate alloc to use.",
+		Value: "alloc.json",
+	}
+	InputEnvFlag = cli.StringFlag{
+		Name:  "input.env",
+		Usage: "`stdin` or file name of where to find the prestate env to use.",
+		Value: "env.json",
+	}
+	InputTxsFlag = cli.StringFlag{
+		Name:  "input.txs",
+		Usage: "`stdin` or file name of where to find the transactions to apply.",
+		Value: "txs.json",
+	}
+	RewardFlag = cli.Int64Flag{
+		Name:  "state.reward",
+		Usage: "Mining reward. Set to -1 to disable",
+		Value: 0,
+	}
+	ChainIDFlag = cli.Int64Flag{
+		Name:  "state.chainid",
+		Usage: "ChainID to use",
+		Value: 1,
+	}
+	ForknameFlag = cli.StringFlag{
+		Name: "state.fork",
+		Usage: fmt.Sprintf("Name of ruleset to use."+
+			"\n\tAvailable forknames:"+
+			"\n\t    %v"+
+			"\n\tAvailable extra eips:"+
+			"\n\t    %v"+
+			"\n\tSyntax <forkname>(+ExtraEip)",
+			strings.Join(tests.AvailableForks(), "\n\t    "),
+			strings.Join(vm.ActivateableEips(), ", ")),
+		Value: "Istanbul",
+	}
+	VerbosityFlag = cli.IntFlag{
+		Name:  "verbosity",
+		Usage: "sets the verbosity level",
+		Value: 3,
+	}
+)