add function to get blockchain id from warp precompile (#2633)

* add function to get blockchain id from warp precompile

* empty commit

* address PR comments

pkg/precompiles/precompiles.go

@@ -5,7 +5,11 @@ package precompiles
 import (
 	_ "embed"
 
-	"github.com/ethereum/go-ethereum/common"
+	"github.com/ava-labs/subnet-evm/precompile/contracts/nativeminter"
+	"github.com/ava-labs/subnet-evm/precompile/contracts/warp"
 )
 
-var NativeMinterPrecompile = common.HexToAddress("0x0200000000000000000000000000000000000001")
+var (
+	NativeMinterPrecompile = nativeminter.ContractAddress
+	WarpPrecompile         = warp.ContractAddress
+)

pkg/precompiles/warp.go

@@ -0,0 +1,32 @@
+// Copyright (C) 2022, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+package precompiles
+
+import (
+	_ "embed"
+	"fmt"
+
+	"github.com/ava-labs/avalanche-cli/pkg/contract"
+	"github.com/ava-labs/avalanchego/ids"
+)
+
+func WarpPrecompileGetBlockchainID(
+	rpcURL string,
+) (ids.ID, error) {
+	out, err := contract.CallToMethod(
+		rpcURL,
+		WarpPrecompile,
+		"getBlockchainID()->(bytes32)",
+	)
+	if err != nil {
+		return ids.Empty, err
+	}
+	if len(out) == 0 {
+		return ids.Empty, fmt.Errorf("error at getBlockchainID call: no return value")
+	}
+	received, ok := out[0].([32]byte)
+	if !ok {
+		return ids.Empty, fmt.Errorf("error at getBlockchainID call, expected ids.ID, got %T", out[0])
+	}
+	return received, nil
+}