• Felix Lange's avatar
    common: move big integer math to common/math (#3699) · 5c8fe28b
    Felix Lange authored
    * common: remove CurrencyToString
    
    Move denomination values to params instead.
    
    * common: delete dead code
    
    * common: move big integer operations to common/math
    
    This commit consolidates all big integer operations into common/math and
    adds tests and documentation.
    
    There should be no change in semantics for BigPow, BigMin, BigMax, S256,
    U256, Exp and their behaviour is now locked in by tests.
    
    The BigD, BytesToBig and Bytes2Big functions don't provide additional
    value, all uses are replaced by new(big.Int).SetBytes().
    
    BigToBytes is now called PaddedBigBytes, its minimum output size
    parameter is now specified as the number of bytes instead of bits. The
    single use of this function is in the EVM's MSTORE instruction.
    
    Big and String2Big are replaced by ParseBig, which is slightly stricter.
    It previously accepted leading zeros for hexadecimal inputs but treated
    decimal inputs as octal if a leading zero digit was present.
    
    ParseUint64 is used in places where String2Big was used to decode a
    uint64.
    
    The new functions MustParseBig and MustParseUint64 are now used in many
    places where parsing errors were previously ignored.
    
    * common: delete unused big integer variables
    
    * accounts/abi: replace uses of BytesToBig with use of encoding/binary
    
    * common: remove BytesToBig
    
    * common: remove Bytes2Big
    
    * common: remove BigTrue
    
    * cmd/utils: add BigFlag and use it for error-checked integer flags
    
    While here, remove environment variable processing for DirectoryFlag
    because we don't use it.
    
    * core: add missing error checks in genesis block parser
    
    * common: remove String2Big
    
    * cmd/evm: use utils.BigFlag
    
    * common/math: check for 256 bit overflow in ParseBig
    
    This is supposed to prevent silent overflow/truncation of values in the
    genesis block JSON. Without this check, a genesis block that set a
    balance larger than 256 bits would lead to weird behaviour in the VM.
    
    * cmd/utils: fixup import
    5c8fe28b
vm_test_util.go 5.99 KB
// Copyright 2015 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 tests

import (
	"bytes"
	"fmt"
	"io"
	"math/big"
	"strconv"
	"testing"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/math"
	"github.com/ethereum/go-ethereum/core/state"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/core/vm"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/params"
)

func RunVmTestWithReader(r io.Reader, skipTests []string) error {
	tests := make(map[string]VmTest)
	err := readJson(r, &tests)
	if err != nil {
		return err
	}

	if err != nil {
		return err
	}

	if err := runVmTests(tests, skipTests); err != nil {
		return err
	}

	return nil
}

type bconf struct {
	name    string
	precomp bool
	jit     bool
}

func BenchVmTest(p string, conf bconf, b *testing.B) error {
	tests := make(map[string]VmTest)
	err := readJsonFile(p, &tests)
	if err != nil {
		return err
	}

	test, ok := tests[conf.name]
	if !ok {
		return fmt.Errorf("test not found: %s", conf.name)
	}

	env := make(map[string]string)
	env["currentCoinbase"] = test.Env.CurrentCoinbase
	env["currentDifficulty"] = test.Env.CurrentDifficulty
	env["currentGasLimit"] = test.Env.CurrentGasLimit
	env["currentNumber"] = test.Env.CurrentNumber
	env["previousHash"] = test.Env.PreviousHash
	if n, ok := test.Env.CurrentTimestamp.(float64); ok {
		env["currentTimestamp"] = strconv.Itoa(int(n))
	} else {
		env["currentTimestamp"] = test.Env.CurrentTimestamp.(string)
	}

	/*
		if conf.precomp {
			program := vm.NewProgram(test.code)
			err := vm.AttachProgram(program)
			if err != nil {
				return err
			}
		}
	*/

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		benchVmTest(test, env, b)
	}

	return nil
}

func benchVmTest(test VmTest, env map[string]string, b *testing.B) {
	b.StopTimer()
	db, _ := ethdb.NewMemDatabase()
	statedb := makePreState(db, test.Pre)
	b.StartTimer()

	RunVm(statedb, env, test.Exec)
}

func RunVmTest(p string, skipTests []string) error {
	tests := make(map[string]VmTest)
	err := readJsonFile(p, &tests)
	if err != nil {
		return err
	}

	if err := runVmTests(tests, skipTests); err != nil {
		return err
	}

	return nil
}

func runVmTests(tests map[string]VmTest, skipTests []string) error {
	skipTest := make(map[string]bool, len(skipTests))
	for _, name := range skipTests {
		skipTest[name] = true
	}

	for name, test := range tests {
		if skipTest[name] /*|| name != "exp0"*/ {
			log.Info(fmt.Sprint("Skipping VM test", name))
			continue
		}

		if err := runVmTest(test); err != nil {
			return fmt.Errorf("%s %s", name, err.Error())
		}

		log.Info(fmt.Sprint("VM test passed: ", name))
		//fmt.Println(string(statedb.Dump()))
	}
	return nil
}

func runVmTest(test VmTest) error {
	db, _ := ethdb.NewMemDatabase()
	statedb := makePreState(db, test.Pre)

	// XXX Yeah, yeah...
	env := make(map[string]string)
	env["currentCoinbase"] = test.Env.CurrentCoinbase
	env["currentDifficulty"] = test.Env.CurrentDifficulty
	env["currentGasLimit"] = test.Env.CurrentGasLimit
	env["currentNumber"] = test.Env.CurrentNumber
	env["previousHash"] = test.Env.PreviousHash
	if n, ok := test.Env.CurrentTimestamp.(float64); ok {
		env["currentTimestamp"] = strconv.Itoa(int(n))
	} else {
		env["currentTimestamp"] = test.Env.CurrentTimestamp.(string)
	}

	var (
		ret  []byte
		gas  *big.Int
		err  error
		logs []*types.Log
	)

	ret, logs, gas, err = RunVm(statedb, env, test.Exec)

	// Compare expected and actual return
	rexp := common.FromHex(test.Out)
	if !bytes.Equal(rexp, ret) {
		return fmt.Errorf("return failed. Expected %x, got %x\n", rexp, ret)
	}

	// Check gas usage
	if len(test.Gas) == 0 && err == nil {
		return fmt.Errorf("gas unspecified, indicating an error. VM returned (incorrectly) successful")
	} else {
		gexp := math.MustParseBig256(test.Gas)
		if gexp.Cmp(gas) != 0 {
			return fmt.Errorf("gas failed. Expected %v, got %v\n", gexp, gas)
		}
	}

	// check post state
	for address, account := range test.Post {
		accountAddr := common.HexToAddress(address)
		if !statedb.Exist(accountAddr) {
			continue
		}
		for addr, value := range account.Storage {
			v := statedb.GetState(accountAddr, common.HexToHash(addr))
			vexp := common.HexToHash(value)
			if v != vexp {
				return fmt.Errorf("(%x: %s) storage failed. Expected %x, got %x (%v %v)\n", addr[:4], addr, vexp, v, vexp.Big(), v.Big())
			}
		}
	}

	// check logs
	if len(test.Logs) > 0 {
		lerr := checkLogs(test.Logs, logs)
		if lerr != nil {
			return lerr
		}
	}

	return nil
}

func RunVm(statedb *state.StateDB, env, exec map[string]string) ([]byte, []*types.Log, *big.Int, error) {
	chainConfig := &params.ChainConfig{
		HomesteadBlock: params.MainNetHomesteadBlock,
		DAOForkBlock:   params.MainNetDAOForkBlock,
		DAOForkSupport: true,
	}
	var (
		to    = common.HexToAddress(exec["address"])
		from  = common.HexToAddress(exec["caller"])
		data  = common.FromHex(exec["data"])
		gas   = math.MustParseBig256(exec["gas"])
		value = math.MustParseBig256(exec["value"])
	)
	caller := statedb.GetOrNewStateObject(from)
	vm.PrecompiledContracts = make(map[common.Address]vm.PrecompiledContract)

	environment, _ := NewEVMEnvironment(true, chainConfig, statedb, env, exec)
	ret, g, err := environment.Call(caller, to, data, gas.Uint64(), value)
	return ret, statedb.Logs(), new(big.Int).SetUint64(g), err
}