CityOfZion/neo-storm#17 Implemented util.CompareBytes (CityOfZion/neo-storm#21)

Imported from CityOfZion/neo-storm (c0ee185a7cfd2c222fb7b4c8ca19885844d53855).

examples/token/token/token.go

@@ -4,6 +4,7 @@ import (
 	"github.com/CityOfZion/neo-storm/interop/engine"
 	"github.com/CityOfZion/neo-storm/interop/runtime"
 	"github.com/CityOfZion/neo-storm/interop/storage"
+	"github.com/CityOfZion/neo-storm/interop/util"
 )
 
 // Token holds all token info
@@ -81,35 +82,16 @@ func (t Token) CanTransfer(ctx storage.Context, from []byte, to []byte, amount i
 // IsUsableAddress checks if the sender is either the correct NEO address or SC address
 func IsUsableAddress(addr []byte) bool {
 	if len(addr) == 20 {
-
 		if runtime.CheckWitness(addr) {
 			return true
 		}
 
 		// Check if a smart contract is calling scripthash
 		callingScriptHash := engine.GetCallingScriptHash()
-		if EqualAddresses(callingScriptHash, addr) {
+		if util.CompareBytes(callingScriptHash, addr) {
 			return true
 		}
 	}
 
 	return false
 }
-
-// EqualAddresses compares two addresses if they're equal
-// also returns false if one of the two - or both - aren't actual addresses
-func EqualAddresses(a []byte, b []byte) bool {
-	aLen := len(a)
-	bLen := len(b)
-	if aLen != bLen || aLen != 20 || bLen != 20 {
-		return false
-	}
-
-	for i := 0; i < aLen; i++ {
-		if a[i] != b[i] {
-			return false
-		}
-	}
-
-	return true
-}

interop/util/util.go

@@ -4,3 +4,9 @@ package util
 func FromAddress(address string) []byte {
 	return nil
 }
+
+// CompareBytes compares a with b and will return true whether a and b
+// are equal.
+func CompareBytes(a, b []byte) bool {
+	return false
+}

pkg/vm/compiler/analysis.go

@@ -13,14 +13,8 @@ var (
 	// Go language builtin functions and custom builtin utility functions.
 	builtinFuncs = []string{
 		"len", "append", "SHA256",
-		"SHA1", "Hash256", "Hash160", "FromAddress",
+		"SHA1", "Hash256", "Hash160",
-	}
+		"FromAddress", "CompareBytes",
-
-	// VM system calls that have no return value.
-	noRetSyscalls = []string{
-		"Notify", "Log", "Put", "Register", "Delete",
-		"SetVotes", "ContractDestroy", "MerkleRoot", "Hash",
-		"PrevHash", "GetHeader",
 	}
 )
 

pkg/vm/compiler/codegen.go

@@ -571,6 +571,8 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
 		emitOpcode(c.prog, vm.HASH256)
 	case "Hash160":
 		emitOpcode(c.prog, vm.HASH160)
+	case "CompareBytes":
+		emitOpcode(c.prog, vm.EQUAL)
 	case "FromAddress":
 		// We can be sure that this is a ast.BasicLit just containing a simple
 		// address string. Note that the string returned from calling Value will