Move CeloBackend from core to contracts

...and other import cleanups.

Goals:
* Prevent circular dependencies (being in core is really problematic in
  this regard)
* Avoid package aliases in imports

contracts/celo/celo.go

@@ -1,4 +1,4 @@
-package contracts
+package celo
 
 import _ "embed"
 

core/celo_backend.go → contracts/celo_backend.go

@@ -1,4 +1,4 @@
-package core
+package contracts
 
 import (
 	"context"
@@ -8,7 +8,6 @@ import (
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
-	contracts "github.com/ethereum/go-ethereum/contracts/celo"
 	"github.com/ethereum/go-ethereum/contracts/celo/abigen"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/log"
@@ -86,11 +85,11 @@ func (b *CeloBackend) GetFeeBalance(account common.Address, feeCurrency *common.
 // GetExchangeRates returns the exchange rates for all gas currencies from CELO
 func (b *CeloBackend) GetExchangeRates() (common.ExchangeRates, error) {
 	exchangeRates := map[common.Address]*big.Rat{}
-	whitelist, err := abigen.NewFeeCurrencyWhitelistCaller(contracts.FeeCurrencyWhitelistAddress, b)
+	whitelist, err := abigen.NewFeeCurrencyWhitelistCaller(FeeCurrencyWhitelistAddress, b)
 	if err != nil {
 		return exchangeRates, fmt.Errorf("Failed to access FeeCurrencyWhitelist: %w", err)
 	}
-	oracle, err := abigen.NewSortedOraclesCaller(contracts.SortedOraclesAddress, b)
+	oracle, err := abigen.NewSortedOraclesCaller(SortedOraclesAddress, b)
 	if err != nil {
 		return exchangeRates, fmt.Errorf("Failed to access SortedOracle: %w", err)
 	}

core/celo_read_only_statedb.go → contracts/read_only_statedb.go

@@ -1,4 +1,4 @@
-package core
+package contracts
 
 import (
 	"math/big"

core/blockchain_celo_test.go

@@ -23,7 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/exchange"
 	"github.com/ethereum/go-ethereum/consensus/ethash"
-	contracts "github.com/ethereum/go-ethereum/contracts/celo"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -100,7 +100,7 @@ func testNativeTransferWithFeeCurrency(t *testing.T, scheme string) {
 
 	state, _ := chain.State()
 
-	backend := CeloBackend{
+	backend := contracts.CeloBackend{
 		ChainConfig: chain.chainConfig,
 		State:       state,
 	}

core/celo_evm.go

@@ -6,7 +6,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/common"
-	contracts "github.com/ethereum/go-ethereum/contracts/celo"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/contracts/celo/abigen"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -51,7 +51,7 @@ func setCeloFieldsInBlockContext(blockContext *vm.BlockContext, header *types.He
 		return
 	}
 
-	caller := &CeloBackend{config, statedb}
+	caller := &contracts.CeloBackend{ChainConfig: config, State: statedb}
 
 	// Add fee currency exchange rates
 	var err error

core/celo_genesis.go

@@ -6,7 +6,8 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	contracts "github.com/ethereum/go-ethereum/contracts/celo"
+	"github.com/ethereum/go-ethereum/contracts"
+	"github.com/ethereum/go-ethereum/contracts/celo"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
@@ -48,32 +49,32 @@ func celoGenesisAccounts(fundedAddr common.Address) GenesisAlloc {
 	)
 
 	// Initialize Bytecodes
-	registryBytecode, err := DecodeHex(contracts.RegistryBytecodeRaw)
+	registryBytecode, err := DecodeHex(celo.RegistryBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	goldTokenBytecode, err := DecodeHex(contracts.GoldTokenBytecodeRaw)
+	goldTokenBytecode, err := DecodeHex(celo.GoldTokenBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	proxyBytecode, err := DecodeHex(contracts.ProxyBytecodeRaw)
+	proxyBytecode, err := DecodeHex(celo.ProxyBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	// sortedOraclesBytecodeLinked := bytes.Replace(contracts.SortedOraclesBytecodeRaw, []byte("__$c0b499b413513d0c67e2a6a17d90846cb3$__"), []byte("000000000000000000000000000000000000ce17"), -1)
-	sortedOraclesBytecode, err := DecodeHex(contracts.MockSortedOraclesBytecodeRaw)
+	// sortedOraclesBytecodeLinked := bytes.Replace(celo.SortedOraclesBytecodeRaw, []byte("__$c0b499b413513d0c67e2a6a17d90846cb3$__"), []byte("000000000000000000000000000000000000ce17"), -1)
+	sortedOraclesBytecode, err := DecodeHex(celo.MockSortedOraclesBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	feeCurrencyWhitelistBytecode, err := DecodeHex(contracts.FeeCurrencyWhitelistBytecodeRaw)
+	feeCurrencyWhitelistBytecode, err := DecodeHex(celo.FeeCurrencyWhitelistBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	feeCurrencyBytecode, err := DecodeHex(contracts.FeeCurrencyBytecodeRaw)
+	feeCurrencyBytecode, err := DecodeHex(celo.FeeCurrencyBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}
-	addressSortedLinkedListWithMedian, err := DecodeHex(contracts.AddressSortedLinkedListWithMedianBytecodeRaw)
+	addressSortedLinkedListWithMedian, err := DecodeHex(celo.AddressSortedLinkedListWithMedianBytecodeRaw)
 	if err != nil {
 		panic(err)
 	}

core/state_transition.go

@@ -25,8 +25,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/exchange"
 	cmath "github.com/ethereum/go-ethereum/common/math"
-	fee_currencies "github.com/ethereum/go-ethereum/contracts"
-	contracts "github.com/ethereum/go-ethereum/contracts/celo"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/log"
@@ -127,10 +126,10 @@ func IntrinsicGas(data []byte, accessList types.AccessList, isContractCreation b
 	// In this case, however, the user always ends up paying `maxGasForDebitAndCreditTransactions`
 	// keeping it consistent.
 	if feeCurrency != nil {
-		if (math.MaxUint64 - gas) < fee_currencies.IntrinsicGasForAlternativeFeeCurrency {
+		if (math.MaxUint64 - gas) < contracts.IntrinsicGasForAlternativeFeeCurrency {
 			return 0, ErrGasUintOverflow
 		}
-		gas += fee_currencies.IntrinsicGasForAlternativeFeeCurrency
+		gas += contracts.IntrinsicGasForAlternativeFeeCurrency
 	}
 
 	if accessList != nil {
@@ -345,7 +344,7 @@ func (st *StateTransition) canPayFee(checkAmount *big.Int) error {
 			return fmt.Errorf("%w: address %v have %v want %v", ErrInsufficientFunds, st.msg.From.Hex(), balance, checkAmount)
 		}
 	} else {
-		backend := &CeloBackend{
+		backend := &contracts.CeloBackend{
 			ChainConfig: st.evm.ChainConfig(),
 			State:       st.state,
 		}
@@ -369,7 +368,7 @@ func (st *StateTransition) subFees(effectiveFee *big.Int) (err error) {
 		st.state.SubBalance(st.msg.From, effectiveFee)
 		return nil
 	} else {
-		return fee_currencies.DebitFees(st.evm, st.msg.FeeCurrency, st.msg.From, effectiveFee)
+		return contracts.DebitFees(st.evm, st.msg.FeeCurrency, st.msg.From, effectiveFee)
 	}
 }
 
@@ -721,7 +720,7 @@ func (st *StateTransition) distributeTxFees() error {
 		if l1Cost != nil {
 			l1Cost, _ = exchange.ConvertGoldToCurrency(st.evm.Context.ExchangeRates, feeCurrency, l1Cost)
 		}
-		if err := fee_currencies.CreditFees(st.evm, feeCurrency, from, st.evm.Context.Coinbase, feeHandlerAddress, params.OptimismL1FeeRecipient, refund, tipTxFee, baseTxFee, l1Cost); err != nil {
+		if err := contracts.CreditFees(st.evm, feeCurrency, from, st.evm.Context.Coinbase, feeHandlerAddress, params.OptimismL1FeeRecipient, refund, tipTxFee, baseTxFee, l1Cost); err != nil {
 			log.Error("Error crediting", "from", from, "coinbase", st.evm.Context.Coinbase, "feeHandler", feeHandlerAddress)
 			return err
 		}

core/txpool/blobpool/blobpool.go

@@ -32,6 +32,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip1559"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip4844"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/txpool"
@@ -317,8 +318,8 @@ type BlobPool struct {
 	lock sync.RWMutex // Mutex protecting the pool during reorg handling
 
 	// Celo specific
-	celoBackend  *core.CeloBackend    // For fee currency balances & exchange rate calculation
-	currentRates common.ExchangeRates // current exchange rates for fee currencies
+	celoBackend  *contracts.CeloBackend // For fee currency balances & exchange rate calculation
+	currentRates common.ExchangeRates   // current exchange rates for fee currencies
 }
 
 // New creates a new blob transaction pool to gather, sort and filter inbound

core/txpool/blobpool/celo_blobpool.go

@@ -1,12 +1,12 @@
 package blobpool
 
 import (
-	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/log"
 )
 
 func (pool *BlobPool) recreateCeloProperties() {
-	pool.celoBackend = &core.CeloBackend{
+	pool.celoBackend = &contracts.CeloBackend{
 		ChainConfig: pool.chain.Config(),
 		State:       pool.state,
 	}

core/txpool/legacypool/celo_legacypool.go

@@ -4,7 +4,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
 )
@@ -31,7 +31,7 @@ func (pool *LegacyPool) getBalances(address common.Address, currencies []common.
 }
 
 func (pool *LegacyPool) recreateCeloProperties() {
-	pool.celoBackend = &core.CeloBackend{
+	pool.celoBackend = &contracts.CeloBackend{
 		ChainConfig: pool.chainconfig,
 		State:       pool.currentState,
 	}

core/txpool/legacypool/legacypool.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/prque"
 	"github.com/ethereum/go-ethereum/consensus/misc/eip1559"
+	"github.com/ethereum/go-ethereum/contracts"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/txpool"
@@ -238,8 +239,8 @@ type LegacyPool struct {
 	l1CostFn txpool.L1CostFunc // To apply L1 costs as rollup, optional field, may be nil.
 
 	// Celo specific
-	celoBackend  *core.CeloBackend    // For fee currency balances & exchange rate calculation
-	currentRates common.ExchangeRates // current exchange rates for fee currencies
+	celoBackend  *contracts.CeloBackend // For fee currency balances & exchange rate calculation
+	currentRates common.ExchangeRates   // current exchange rates for fee currencies
 }
 
 type txpoolResetRequest struct {