Add console2 log support (#126)

* Add console log support

* Fix lint

accounts/abi/type2.go

@@ -21,10 +21,8 @@ func (t Type) Pack(v interface{}) ([]byte, error) {
 	return t.pack(reflect.ValueOf(v))
 }
 
-func (t Type) Unpack(data []byte, obj interface{}) error {
-	fmt.Println(toGoType(0, t, data))
-
-	return nil
+func (t Type) Unpack(data []byte) (interface{}, error) {
+	return toGoType(0, t, data)
 }
 
 // newTypeForTuple implements the format described in https://blog.ricmoo.com/human-readable-contract-abis-in-ethers-js-141902f4d917
@@ -76,25 +74,33 @@ func newTypeForTuple(s string) (string, []ArgumentMarshaling, error) {
 		}
 	}
 
+	if len(fields) == 1 && fields[0] == "" {
+		// empty tuple (i.e. tuple())
+		fields = []string{}
+	}
+
 	// trim the args of spaces
 	for i := range fields {
 		fields[i] = strings.TrimSpace(fields[i])
 	}
 
 	// decode the type of each field
 	var args []ArgumentMarshaling
-	for _, field := range fields {
+	for indx, field := range fields {
 		// anonymous fields are not supported so the first
 		// string should be the identifier of the field.
+		var name string
 
 		spacePos := strings.Index(field, " ")
 		if spacePos == -1 {
-			return "", nil, fmt.Errorf("invalid tuple field name not found '%s'", field)
+			// it has no name
+			name = fmt.Sprintf("arg%d", indx)
+		} else {
+			// it has name and field (name field)
+			name = field[:spacePos]
+			field = field[spacePos+1:]
 		}
 
-		name := field[:spacePos]
-		field = field[spacePos+1:]
-
 		if strings.HasPrefix(field, "tuple") {
 			// decode a recursive tuple
 			sig, elems, err := newTypeForTuple(field)

accounts/abi/type2_test.go

@@ -40,15 +40,22 @@ func TestNewType2FromString(t *testing.T) {
 			}{A: 1, B: 2},
 		},
 		{
-			"tuple(a uint64, b tuple(c uint64), d uint64)",
+			// empty tuple
+			"tuple()",
+			"()",
+			&struct{}{},
+		},
+		{
+			// anonymous type
+			"tuple(uint64,tuple(uint64),uint64)",
 			"(uint64,(uint64),uint64)",
 			&struct {
-				A uint64
-				B struct {
-					C uint64
+				Arg0 uint64
+				Arg1 struct {
+					Arg0 uint64
 				}
-				D uint64
-			}{A: 1, B: struct{ C uint64 }{C: 2}, D: 3},
+				Arg2 uint64
+			}{Arg0: 1, Arg1: struct{ Arg0 uint64 }{Arg0: 2}, Arg2: 3},
 		},
 		{
 			"tuple(a uint64, b tuple[](x tuple(c uint64), d uint64), e tuple(f uint64, g uint64))",

core/vm/contracts_suave.go

@@ -15,6 +15,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/suave/consolelog"
 	suave "github.com/ethereum/go-ethereum/suave/core"
 )
 
@@ -149,6 +150,18 @@ type suaveRuntime struct {
 
 var _ SuaveRuntime = &suaveRuntime{}
 
+type consoleLogPrecompile struct {
+}
+
+func (c *consoleLogPrecompile) RequiredGas(input []byte) uint64 {
+	return 0
+}
+
+func (c *consoleLogPrecompile) Run(input []byte) ([]byte, error) {
+	consolelog.Print(input)
+	return nil, nil
+}
+
 func (s *suaveRuntime) doHTTPRequest(request types.HttpRequest) ([]byte, error) {
 	if request.Method != "GET" && request.Method != "POST" {
 		return nil, fmt.Errorf("only GET and POST methods are supported")

core/vm/evm.go

@@ -23,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/suave/consolelog"
 	"github.com/holiman/uint256"
 )
 
@@ -43,6 +44,11 @@ type (
 func (evm *EVM) precompile(addr common.Address) (PrecompiledContract, bool) {
 	// First check confidential precompiles, only then continue to the regular ones
 	if evm.chainRules.IsSuave {
+		// console-log precompile available in the suave context
+		if addr == consolelog.Console2ContractAddr {
+			return &consoleLogPrecompile{}, true
+		}
+
 		if isPrecompileAddr(addr) && evm.Config.IsConfidential {
 			suaveContext := NewRuntimeSuaveContext(evm, addr)
 			return NewSuavePrecompiledContractWrapper(addr, suaveContext), true