Gocore VM and security updates

accounts/abi/abi.go

@@ -19,7 +19,9 @@ package abi
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"github.com/core-coin/go-core/crypto"
 	"io"
 
 	"github.com/core-coin/go-core/common"
@@ -32,6 +34,12 @@ type ABI struct {
 	Constructor Method
 	Methods     map[string]Method
 	Events      map[string]Event
+
+	// Additional "special" functions introduced in ylem v0.6.0.
+	// It's separated from the original default fallback. Each contract
+	// can only define one fallback and receive function.
+	Fallback Method // Note it's also used to represent legacy fallback before v0.6.0
+	Receive  Method
 }
 
 // JSON returns a parsed ABI interface and error if it failed.
@@ -70,7 +78,7 @@ func (abi ABI) Pack(name string, args ...interface{}) ([]byte, error) {
 		return nil, err
 	}
 	// Pack up the method ID too if not a constructor and return
-	return append(method.ID(), arguments...), nil
+	return append(method.ID, arguments...), nil
 }
 
 // Unpack output in v according to the abi specification
@@ -108,13 +116,22 @@ func (abi ABI) UnpackIntoMap(v map[string]interface{}, name string, data []byte)
 // UnmarshalJSON implements json.Unmarshaler interface
 func (abi *ABI) UnmarshalJSON(data []byte) error {
 	var fields []struct {
-		Type            string
-		Name            string
-		Constant        bool
+		Type    string
+		Name    string
+		Inputs  []Argument
+		Outputs []Argument
+
+		// Status indicator which can be: "pure", "view",
+		// "nonpayable" or "payable".
 		StateMutability string
-		Anonymous       bool
-		Inputs          []Argument
-		Outputs         []Argument
+
+		// Deprecated Status indicators, but removed in v0.6.0.
+		Constant bool // True if function is either pure or view
+		Payable  bool // True if function is payable
+
+		// Event relevant indicator represents the event is
+		// declared as anonymous.
+		Anonymous bool
 	}
 	if err := json.Unmarshal(data, &fields); err != nil {
 		return err
@@ -124,52 +141,76 @@ func (abi *ABI) UnmarshalJSON(data []byte) error {
 	for _, field := range fields {
 		switch field.Type {
 		case "constructor":
-			abi.Constructor = Method{
-				Inputs: field.Inputs,
+			abi.Constructor = NewMethod("", "", Constructor, field.StateMutability, field.Constant, field.Payable, field.Inputs, nil)
+		case "function":
+			name := abi.overloadedMethodName(field.Name)
+			abi.Methods[name] = NewMethod(name, field.Name, Function, field.StateMutability, field.Constant, field.Payable, field.Inputs, field.Outputs)
+		case "fallback":
+			// New introduced function type in v0.6.0, check more detail
+			// here https://solidity.readthedocs.io/en/v0.6.0/contracts.html#fallback-function
+			if abi.HasFallback() {
+				return errors.New("only single fallback is allowed")
 			}
-		// empty defaults to function according to the abi spec
-		case "function", "":
-			name := field.Name
-			_, ok := abi.Methods[name]
-			for idx := 0; ok; idx++ {
-				name = fmt.Sprintf("%s%d", field.Name, idx)
-				_, ok = abi.Methods[name]
+			abi.Fallback = NewMethod("", "", Fallback, field.StateMutability, field.Constant, field.Payable, nil, nil)
+		case "receive":
+			// New introduced function type in v0.6.0, check more detail
+			// here https://solidity.readthedocs.io/en/v0.6.0/contracts.html#fallback-function
+			if abi.HasReceive() {
+				return errors.New("only single receive is allowed")
 			}
-			isConst := field.Constant || field.StateMutability == "pure" || field.StateMutability == "view"
-			abi.Methods[name] = Method{
-				Name:    name,
-				RawName: field.Name,
-				Const:   isConst,
-				Inputs:  field.Inputs,
-				Outputs: field.Outputs,
+			if field.StateMutability != "payable" {
+				return errors.New("the statemutability of receive can only be payable")
 			}
+			abi.Receive = NewMethod("", "", Receive, field.StateMutability, field.Constant, field.Payable, nil, nil)
 		case "event":
-			name := field.Name
-			_, ok := abi.Events[name]
-			for idx := 0; ok; idx++ {
-				name = fmt.Sprintf("%s%d", field.Name, idx)
-				_, ok = abi.Events[name]
-			}
-			abi.Events[name] = Event{
-				Name:      name,
-				RawName:   field.Name,
-				Anonymous: field.Anonymous,
-				Inputs:    field.Inputs,
-			}
+			name := abi.overloadedEventName(field.Name)
+			abi.Events[name] = NewEvent(name, field.Name, field.Anonymous, field.Inputs)
+		default:
+			return fmt.Errorf("abi: could not recognize type %v of field %v", field.Type, field.Name)
 		}
 	}
 
 	return nil
 }
 
+// overloadedMethodName returns the next available name for a given function.
+// Needed since ylem allows for function overload.
+//
+// e.g. if the abi contains Methods send, send1
+// overloadedMethodName would return send2 for input send.
+func (abi *ABI) overloadedMethodName(rawName string) string {
+	name := rawName
+	_, ok := abi.Methods[name]
+	for idx := 0; ok; idx++ {
+		name = fmt.Sprintf("%s%d", rawName, idx)
+		_, ok = abi.Methods[name]
+	}
+	return name
+}
+
+// overloadedEventName returns the next available name for a given event.
+// Needed since ylem allows for event overload.
+//
+// e.g. if the abi contains events received, received1
+// overloadedEventName would return received2 for input received.
+func (abi *ABI) overloadedEventName(rawName string) string {
+	name := rawName
+	_, ok := abi.Events[name]
+	for idx := 0; ok; idx++ {
+		name = fmt.Sprintf("%s%d", rawName, idx)
+		_, ok = abi.Events[name]
+	}
+	return name
+}
+
 // MethodById looks up a method by the 4-byte id
 // returns nil if none found
 func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
 	if len(sigdata) < 4 {
 		return nil, fmt.Errorf("data too short (%d bytes) for abi method lookup", len(sigdata))
 	}
 	for _, method := range abi.Methods {
-		if bytes.Equal(method.ID(), sigdata[:4]) {
+		if bytes.Equal(method.ID, sigdata[:4]) {
 			return &method, nil
 		}
 	}
@@ -180,9 +221,41 @@ func (abi *ABI) MethodById(sigdata []byte) (*Method, error) {
 // ABI and returns nil if none found.
 func (abi *ABI) EventByID(topic common.Hash) (*Event, error) {
 	for _, event := range abi.Events {
-		if bytes.Equal(event.ID().Bytes(), topic.Bytes()) {
+		if bytes.Equal(event.ID.Bytes(), topic.Bytes()) {
 			return &event, nil
 		}
 	}
 	return nil, fmt.Errorf("no event with id: %#x", topic.Hex())
 }
+
+// HasFallback returns an indicator whether a fallback function is included.
+func (abi *ABI) HasFallback() bool {
+	return abi.Fallback.Type == Fallback
+}
+
+// HasReceive returns an indicator whether a receive function is included.
+func (abi *ABI) HasReceive() bool {
+	return abi.Receive.Type == Receive
+}
+
+// revertSelector is a special function selector for revert reason unpacking.
+var revertSelector = crypto.SHA3([]byte("Error(string)"))[:4]
+
+// UnpackRevert resolves the abi-encoded revert reason. According to the solidity
+// spec https://solidity.readthedocs.io/en/latest/control-structures.html#revert,
+// the provided revert reason is abi-encoded as if it were a call to a function
+// `Error(string)`. So it's a special tool for it.
+func UnpackRevert(data []byte) (string, error) {
+	if len(data) < 4 {
+		return "", errors.New("invalid data for unpacking")
+	}
+	if !bytes.Equal(data[:4], revertSelector) {
+		return "", errors.New("invalid data for unpacking")
+	}
+	var reason string
+	typ, _ := NewType("string", "", nil)
+	if err := (Arguments{{Type: typ}}).Unpack(&reason, data[4:]); err != nil {
+		return "", err
+	}
+	return reason, nil
+}