compiler: refactor syscall handling

Close #941.

pkg/compiler/analysis.go

@@ -277,8 +277,7 @@ func isSyscall(fun *funcScope) bool {
 	if fun.selector == nil || fun.pkg == nil || !isInteropPath(fun.pkg.Path()) {
 		return false
 	}
-	_, ok := syscalls[fun.pkg.Name()][fun.name]
-	return ok
+	return fun.pkg.Name() == "neogointernal" && strings.HasPrefix(fun.name, "Syscall")
 }
 
 const interopPrefix = "github.com/nspcc-dev/neo-go/pkg/interop"
@@ -309,6 +308,13 @@ func canConvert(s string) bool {
 // Currently there is a static list of function which are inlined,
 // this may change in future.
 func canInline(s string) bool {
-	return isNativeHelpersPath(s) ||
-		strings.HasPrefix(s, "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline")
+	if strings.HasPrefix(s, "github.com/nspcc-dev/neo-go/pkg/compiler/testdata/inline") {
+		return true
+	}
+	if !isInteropPath(s) {
+		return false
+	}
+	return !strings.HasPrefix(s[len(interopPrefix):], "/neogointernal") &&
+		!strings.HasPrefix(s[len(interopPrefix):], "/util") &&
+		!strings.HasPrefix(s[len(interopPrefix):], "/convert")
 }

pkg/compiler/codegen.go

@@ -872,7 +872,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 
 		c.saveSequencePoint(n)
 
-		args := transformArgs(n.Fun, n.Args)
+		args := transformArgs(f, n.Fun, n.Args)
 
 		// Handle the arguments
 		for _, arg := range args {
@@ -888,7 +888,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 			}
 		}
 		// Do not swap for builtin functions.
-		if !isBuiltin {
+		if !isBuiltin && (f != nil && !isSyscall(f)) {
 			typ, ok := c.typeOf(n.Fun).(*types.Signature)
 			if ok && typ.Variadic() && !n.Ellipsis.IsValid() {
 				// pack variadic args into an array only if last argument is not of form `...`
@@ -932,7 +932,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 					c.emittedEvents[name] = append(c.emittedEvents[name], params)
 				}
 			}
-			c.convertSyscall(n, f.pkg.Name(), f.name)
+			c.convertSyscall(n)
 		default:
 			emit.Call(c.prog.BinWriter, opcode.CALLL, f.label)
 		}
@@ -1523,12 +1523,13 @@ func (c *codegen) getByteArray(expr ast.Expr) []byte {
 	}
 }
 
-func (c *codegen) convertSyscall(expr *ast.CallExpr, api, name string) {
-	syscall, ok := syscalls[api][name]
-	if !ok {
-		c.prog.Err = fmt.Errorf("unknown VM syscall api: %s.%s", api, name)
-		return
+func (c *codegen) convertSyscall(expr *ast.CallExpr) {
+	for _, arg := range expr.Args[1:] {
+		ast.Walk(c, arg)
 	}
+	c.emitReverse(len(expr.Args) - 1)
+	tv := c.typeAndValueOf(expr.Args[0])
+	syscall := constant.StringVal(tv.Value)
 	emit.Syscall(c.prog.BinWriter, syscall)
 
 	// This NOP instruction is basically not needed, but if we do, we have a
@@ -1714,12 +1715,15 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
 //    so there is no need to push parameters on stack and perform an actual call
 // 2. With panic, generated code depends on if argument was nil or a string so
 //    it should be handled accordingly.
-func transformArgs(fun ast.Expr, args []ast.Expr) []ast.Expr {
+func transformArgs(fs *funcScope, fun ast.Expr, args []ast.Expr) []ast.Expr {
 	switch f := fun.(type) {
 	case *ast.SelectorExpr:
 		if f.Sel.Name == "FromAddress" {
 			return args[1:]
 		}
+		if fs != nil && isSyscall(fs) {
+			return nil
+		}
 	case *ast.Ident:
 		switch f.Name {
 		case "make", "copy", "append":

pkg/compiler/syscall.go

@@ -1,66 +0,0 @@
-package compiler
-
-import "github.com/nspcc-dev/neo-go/pkg/core/interop/interopnames"
-
-// All lists are sorted, keep 'em this way, please.
-var syscalls = map[string]map[string]string{
-	"binary": {
-		"Atoi":         interopnames.SystemBinaryAtoi,
-		"Base58Decode": interopnames.SystemBinaryBase58Decode,
-		"Base58Encode": interopnames.SystemBinaryBase58Encode,
-		"Base64Decode": interopnames.SystemBinaryBase64Decode,
-		"Base64Encode": interopnames.SystemBinaryBase64Encode,
-		"Deserialize":  interopnames.SystemBinaryDeserialize,
-		"Itoa":         interopnames.SystemBinaryItoa,
-		"Serialize":    interopnames.SystemBinarySerialize,
-	},
-	"contract": {
-		"Call":                  interopnames.SystemContractCall,
-		"CreateMultisigAccount": interopnames.SystemContractCreateMultisigAccount,
-		"CreateStandardAccount": interopnames.SystemContractCreateStandardAccount,
-		"IsStandard":            interopnames.SystemContractIsStandard,
-		"GetCallFlags":          interopnames.SystemContractGetCallFlags,
-	},
-	"crypto": {
-		"ECDsaSecp256k1Verify":        interopnames.NeoCryptoVerifyWithECDsaSecp256k1,
-		"ECDSASecp256k1CheckMultisig": interopnames.NeoCryptoCheckMultisigWithECDsaSecp256k1,
-		"ECDsaSecp256r1Verify":        interopnames.NeoCryptoVerifyWithECDsaSecp256r1,
-		"ECDSASecp256r1CheckMultisig": interopnames.NeoCryptoCheckMultisigWithECDsaSecp256r1,
-		"RIPEMD160":                   interopnames.NeoCryptoRIPEMD160,
-		"SHA256":                      interopnames.NeoCryptoSHA256,
-	},
-	"iterator": {
-		"Create": interopnames.SystemIteratorCreate,
-		"Next":   interopnames.SystemIteratorNext,
-		"Value":  interopnames.SystemIteratorValue,
-	},
-	"json": {
-		"Deserialize": interopnames.SystemJSONDeserialize,
-		"Serialize":   interopnames.SystemJSONSerialize,
-	},
-	"runtime": {
-		"GasLeft":                interopnames.SystemRuntimeGasLeft,
-		"GetInvocationCounter":   interopnames.SystemRuntimeGetInvocationCounter,
-		"GetCallingScriptHash":   interopnames.SystemRuntimeGetCallingScriptHash,
-		"GetEntryScriptHash":     interopnames.SystemRuntimeGetEntryScriptHash,
-		"GetExecutingScriptHash": interopnames.SystemRuntimeGetExecutingScriptHash,
-		"GetNotifications":       interopnames.SystemRuntimeGetNotifications,
-		"GetScriptContainer":     interopnames.SystemRuntimeGetScriptContainer,
-		"GetTime":                interopnames.SystemRuntimeGetTime,
-		"GetTrigger":             interopnames.SystemRuntimeGetTrigger,
-		"CheckWitness":           interopnames.SystemRuntimeCheckWitness,
-		"Log":                    interopnames.SystemRuntimeLog,
-		"Notify":                 interopnames.SystemRuntimeNotify,
-		"Platform":               interopnames.SystemRuntimePlatform,
-	},
-	"storage": {
-		"ConvertContextToReadOnly": interopnames.SystemStorageAsReadOnly,
-		"Delete":                   interopnames.SystemStorageDelete,
-		"Find":                     interopnames.SystemStorageFind,
-		"Get":                      interopnames.SystemStorageGet,
-		"GetContext":               interopnames.SystemStorageGetContext,
-		"GetReadOnlyContext":       interopnames.SystemStorageGetReadOnlyContext,
-		"Put":                      interopnames.SystemStoragePut,
-		"PutEx":                    interopnames.SystemStoragePutEx,
-	},
-}

pkg/interop/binary/binary.go

@@ -3,52 +3,56 @@ Package binary provides binary serialization routines.
 */
 package binary
 
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+)
+
 // Serialize serializes any given item into a byte slice. It works for all
 // regular VM types (not ones from interop package) and allows to save them in
 // storage or pass into Notify and then Deserialize them on the next run or in
 // the external event receiver. It uses `System.Binary.Serialize` syscall.
 func Serialize(item interface{}) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Binary.Serialize", item).([]byte)
 }
 
 // Deserialize unpacks previously serialized value from a byte slice, it's the
 // opposite of Serialize. It uses `System.Binary.Deserialize` syscall.
 func Deserialize(b []byte) interface{} {
-	return nil
+	return neogointernal.Syscall1("System.Binary.Deserialize", b)
 }
 
 // Base64Encode encodes given byte slice into a base64 string and returns byte
 // representation of this string. It uses `System.Binary.Base64Encode` interop.
 func Base64Encode(b []byte) string {
-	return ""
+	return neogointernal.Syscall1("System.Binary.Base64Encode", b).(string)
 }
 
 // Base64Decode decodes given base64 string represented as a byte slice into
 // byte slice. It uses `System.Binary.Base64Decode` interop.
 func Base64Decode(b []byte) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Binary.Base64Decode", b).([]byte)
 }
 
 // Base58Encode encodes given byte slice into a base58 string and returns byte
 // representation of this string. It uses `System.Binary.Base58Encode` syscall.
 func Base58Encode(b []byte) string {
-	return ""
+	return neogointernal.Syscall1("System.Binary.Base58Encode", b).(string)
 }
 
 // Base58Decode decodes given base58 string represented as a byte slice into
 // a new byte slice. It uses `System.Binary.Base58Decode` syscall.
 func Base58Decode(b []byte) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Binary.Base64Decode", b).([]byte)
 }
 
 // Itoa converts num in a given base to string. Base should be either 10 or 16.
 // It uses `System.Binary.Itoa` syscall.
 func Itoa(num int, base int) string {
-	return ""
+	return neogointernal.Syscall2("System.Binary.Itoa", num, base).(string)
 }
 
 // Atoi converts string to a number in a given base. Base should be either 10 or 16.
 // It uses `System.Binary.Atoi` syscall.
 func Atoi(s string, base int) int {
-	return 0
+	return neogointernal.Syscall2("System.Binary.Atoi", s, base).(int)
 }

pkg/interop/contract/contract.go

@@ -3,7 +3,10 @@ Package contract provides functions to work with contracts.
 */
 package contract
 
-import "github.com/nspcc-dev/neo-go/pkg/interop"
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+)
 
 // CallFlag specifies valid call flags.
 type CallFlag byte
@@ -24,26 +27,26 @@ const (
 // IsStandard checks if contract with provided hash is a standard signature/multisig contract.
 // This function uses `System.Contract.IsStandard` syscall.
 func IsStandard(h interop.Hash160) bool {
-	return false
+	return neogointernal.Syscall1("System.Contract.IsStandard", h).(bool)
 }
 
 // CreateMultisigAccount calculates script hash of an m out of n multisignature
 // script using given m and a set of public keys bytes. This function uses
 // `System.Contract.CreateMultisigAccount` syscall.
 func CreateMultisigAccount(m int, pubs []interop.PublicKey) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Contract.CreateMultisigAccount", pubs).([]byte)
 }
 
 // CreateStandardAccount calculates script hash of a given public key.
 // This function uses `System.Contract.CreateStandardAccount` syscall.
 func CreateStandardAccount(pub interop.PublicKey) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Contract.CreateStandardAccount", pub).([]byte)
 }
 
 // GetCallFlags returns calling flags which execution context was created with.
 // This function uses `System.Contract.GetCallFlags` syscall.
 func GetCallFlags() int64 {
-	return 0
+	return neogointernal.Syscall0("System.Contract.GetFlags").(int64)
 }
 
 // Call executes previously deployed blockchain contract with specified hash
@@ -51,5 +54,5 @@ func GetCallFlags() int64 {
 // It returns whatever this contract returns. This function uses
 // `System.Contract.Call` syscall.
 func Call(scriptHash interop.Hash160, method string, f CallFlag, args ...interface{}) interface{} {
-	return nil
+	return neogointernal.Syscall4("System.Contract.Call", scriptHash, method, f, args)
 }

pkg/interop/crypto/crypto.go

@@ -3,38 +3,41 @@ Package crypto provides an interface to cryptographic syscalls.
 */
 package crypto
 
-import "github.com/nspcc-dev/neo-go/pkg/interop"
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+)
 
 // SHA256 computes SHA256 hash of b. It uses `Neo.Crypto.SHA256` syscall.
 func SHA256(b []byte) interop.Hash256 {
-	return nil
+	return neogointernal.Syscall1("Neo.Crypto.SHA256", b).(interop.Hash256)
 }
 
 // RIPEMD160 computes RIPEMD160 hash of b. It uses `Neo.Crypto.RIPEMD160` syscall.
 func RIPEMD160(b []byte) interop.Hash160 {
-	return nil
+	return neogointernal.Syscall1("Neo.Crypto.RIPEMD160", b).(interop.Hash160)
 }
 
 // ECDsaSecp256r1Verify checks that sig is correct msg's signature for a given pub
 // (serialized public key). It uses `Neo.Crypto.VerifyWithECDsaSecp256r1` syscall.
 func ECDsaSecp256r1Verify(msg []byte, pub interop.PublicKey, sig interop.Signature) bool {
-	return false
+	return neogointernal.Syscall3("Neo.Crypto.VerifyWithECDsaSecp256r1", msg, pub, sig).(bool)
 }
 
 // ECDsaSecp256k1Verify checks that sig is correct msg's signature for a given pub
 // (serialized public key). It uses `Neo.Crypto.VerifyWithECDsaSecp256k1` syscall.
 func ECDsaSecp256k1Verify(msg []byte, pub interop.PublicKey, sig interop.Signature) bool {
-	return false
+	return neogointernal.Syscall3("Neo.Crypto.VerifyWithECDsaSecp256k1", msg, pub, sig).(bool)
 }
 
 // ECDSASecp256r1CheckMultisig checks multiple ECDSA signatures at once. It uses
 // `Neo.Crypto.CheckMultisigWithECDsaSecp256r1` syscall.
 func ECDSASecp256r1CheckMultisig(msg []byte, pubs []interop.PublicKey, sigs []interop.Signature) bool {
-	return false
+	return neogointernal.Syscall3("Neo.Crypto.CheckMultisigWithECDsaSecp256r1", msg, pubs, sigs).(bool)
 }
 
 // ECDSASecp256k1CheckMultisig checks multiple ECDSA signatures at once. It uses
 // `Neo.Crypto.CheckMultisigWithECDsaSecp256k1` syscall.
 func ECDSASecp256k1CheckMultisig(msg []byte, pubs []interop.PublicKey, sigs []interop.Signature) bool {
-	return false
+	return neogointernal.Syscall3("Neo.Crypto.CheckMultisigWithECDsaSecp256k1", msg, pubs, sigs).(bool)
 }

pkg/interop/iterator/iterator.go

@@ -3,6 +3,8 @@ Package iterator provides functions to work with Neo iterators.
 */
 package iterator
 
+import "github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+
 // Iterator represents a Neo iterator, it's an opaque data structure that can
 // be properly created by Create or storage.Find. Unlike enumerators, iterators
 // range over key-value pairs, so it's convenient to use them for maps. This
@@ -14,14 +16,14 @@ type Iterator struct{}
 // to point at element -1, so to access its first element you need to call Next
 // first. This function uses `System.Iterator.Create` syscall.
 func Create(items interface{}) Iterator {
-	return Iterator{}
+	return neogointernal.Syscall1("System.Iterator.Create", items).(Iterator)
 }
 
 // Next advances the iterator returning true if it is was successful (and you
 // can use Key or Value) and false otherwise (and there are no more elements in
 // this Iterator). This function uses `System.Iterator.Next` syscall.
 func Next(it Iterator) bool {
-	return true
+	return neogointernal.Syscall1("System.Iterator.Next", it).(bool)
 }
 
 // Value returns iterator's current value. It's only valid to call after
@@ -30,5 +32,5 @@ func Next(it Iterator) bool {
 // For maps the result can be casted to a slice of 2 elements: key and value.
 // For storage iterators refer to `storage.FindFlags` documentation.
 func Value(it Iterator) interface{} {
-	return nil
+	return neogointernal.Syscall1("System.Iterator.Value", it)
 }

pkg/interop/json/json.go

@@ -3,6 +3,8 @@ Package json provides various JSON serialization/deserialization routines.
 */
 package json
 
+import "github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+
 // ToJSON serializes value to json. It uses `System.Json.Serialize` syscall.
 // Serialization format is the following:
 // []byte -> base64 string
@@ -13,7 +15,7 @@ package json
 // []interface{} -> json array
 // map[type1]type2 -> json object with string keys marshaled as strings (not base64).
 func ToJSON(item interface{}) []byte {
-	return nil
+	return neogointernal.Syscall1("System.Json.Serialize", item).([]byte)
 }
 
 // FromJSON deserializes value from json. It uses `System.Json.Deserialize` syscall.
@@ -24,5 +26,5 @@ func ToJSON(item interface{}) []byte {
 // arrays -> []interface{}
 // maps -> map[string]interface{}
 func FromJSON(data []byte) interface{} {
-	return nil
+	return neogointernal.Syscall1("System.Json.Deserialize", data).(interface{})
 }

pkg/interop/neogointernal/syscall.go

@@ -0,0 +1,46 @@
+package neogointernal
+
+// Syscall0 performs syscall with 0 arguments.
+func Syscall0(name string) interface{} {
+	return nil
+}
+
+// Syscall0NoReturn performs syscall with 0 arguments.
+func Syscall0NoReturn(name string) {
+}
+
+// Syscall1 performs syscall with 1 arguments.
+func Syscall1(name string, arg interface{}) interface{} {
+	return nil
+}
+
+// Syscall1NoReturn performs syscall with 1 arguments.
+func Syscall1NoReturn(name string, arg interface{}) {
+}
+
+// Syscall2 performs syscall with 2 arguments.
+func Syscall2(name string, arg1, arg2 interface{}) interface{} {
+	return nil
+}
+
+// Syscall2NoReturn performs syscall with 2 arguments.
+func Syscall2NoReturn(name string, arg1, arg2 interface{}) {
+}
+
+// Syscall3 performs syscall with 3 arguments.
+func Syscall3(name string, arg1, arg2, arg3 interface{}) interface{} {
+	return nil
+}
+
+// Syscall3NoReturn performs syscall with 3 arguments.
+func Syscall3NoReturn(name string, arg1, arg2, arg3 interface{}) {
+}
+
+// Syscall4 performs syscall with 4 arguments.
+func Syscall4(name string, arg1, arg2, arg3, arg4 interface{}) interface{} {
+	return nil
+}
+
+// Syscall4NoReturn performs syscall with 4 arguments.
+func Syscall4NoReturn(name string, arg1, arg2, arg3, arg4 interface{}) {
+}

pkg/interop/runtime/engine.go

@@ -3,6 +3,7 @@ package runtime
 import (
 	"github.com/nspcc-dev/neo-go/pkg/interop"
 	"github.com/nspcc-dev/neo-go/pkg/interop/native/ledger"
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
 )
 
 // GetScriptContainer returns the transaction that initially triggered current
@@ -10,7 +11,7 @@ import (
 // this execution goes. This function uses
 // `System.Runtime.GetScriptContainer` syscall.
 func GetScriptContainer() *ledger.Transaction {
-	return &ledger.Transaction{}
+	return neogointernal.Syscall0("System.Runtime.GetScriptContainer").(*ledger.Transaction)
 }
 
 // GetExecutingScriptHash returns script hash (160 bit in BE form represented
@@ -19,7 +20,7 @@ func GetScriptContainer() *ledger.Transaction {
 // different contract. This function uses
 // `System.Runtime.GetExecutingScriptHash` syscall.
 func GetExecutingScriptHash() interop.Hash160 {
-	return nil
+	return neogointernal.Syscall0("System.Runtime.GetExecutingScriptHash").(interop.Hash160)
 }
 
 // GetCallingScriptHash returns script hash (160 bit in BE form represented
@@ -28,7 +29,7 @@ func GetExecutingScriptHash() interop.Hash160 {
 // above the GetExecutingScriptHash in the call stack. It uses
 // `System.Runtime.GetCallingScriptHash` syscall.
 func GetCallingScriptHash() interop.Hash160 {
-	return nil
+	return neogointernal.Syscall0("System.Runtime.GetCallingScriptHash").(interop.Hash160)
 }
 
 // GetEntryScriptHash returns script hash (160 bit in BE form represented
@@ -37,5 +38,5 @@ func GetCallingScriptHash() interop.Hash160 {
 // GetScriptContainer) execution from the start. This function uses
 // `System.Runtime.GetEntryScriptHash` syscall.
 func GetEntryScriptHash() interop.Hash160 {
-	return nil
+	return neogointernal.Syscall0("System.Runtime.GetEntryScriptHash").(interop.Hash160)
 }

pkg/interop/runtime/runtime.go

@@ -4,7 +4,10 @@ It has similar function to Runtime class in .net framwork for Neo.
 */
 package runtime
 
-import "github.com/nspcc-dev/neo-go/pkg/interop"
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+)
 
 // Trigger values to compare with GetTrigger result.
 const (
@@ -18,13 +21,15 @@ const (
 // slice) or key (compressed serialized 33-byte form) is one of the signers of
 // this invocation. It uses `System.Runtime.CheckWitness` syscall.
 func CheckWitness(hashOrKey []byte) bool {
-	return true
+	return neogointernal.Syscall1("System.Runtime.CheckWitness", hashOrKey).(bool)
 }
 
 // Log instructs VM to log the given message. It's mostly used for debugging
 // purposes as these messages are not saved anywhere normally and usually are
 // only visible in the VM logs. This function uses `System.Runtime.Log` syscall.
-func Log(message string) {}
+func Log(message string) {
+	neogointernal.Syscall1NoReturn("System.Runtime.Log", message)
+}
 
 // Notify sends a notification (collecting all arguments in an array) to the
 // executing environment. Unlike Log it can accept any data along with the event name
@@ -32,7 +37,9 @@ func Log(message string) {}
 // part of contract's API to external systems, these events can be monitored
 // from outside and act upon accordingly. This function uses
 // `System.Runtime.Notify` syscall.
-func Notify(name string, arg ...interface{}) {}
+func Notify(name string, args ...interface{}) {
+	neogointernal.Syscall2NoReturn("System.Runtime.Notify", name, args)
+}
 
 // GetTime returns the timestamp of the most recent block. Note that when running
 // script in test mode this would be the last accepted (persisted) block in the
@@ -40,7 +47,7 @@ func Notify(name string, arg ...interface{}) {}
 // time of this (currently being processed) block. This function uses
 // `System.Runtime.GetTime` syscall.
 func GetTime() int {
-	return 0
+	return neogointernal.Syscall0("System.Runtime.GetTime").(int)
 }
 
 // GetTrigger returns the smart contract invocation trigger which can be either
@@ -50,13 +57,13 @@ func GetTime() int {
 // not available when running with verification trigger. This function uses
 // `System.Runtime.GetTrigger` syscall.
 func GetTrigger() byte {
-	return 0x00
+	return neogointernal.Syscall0("System.Runtime.GetTrigger").(byte)
 }
 
 // GasLeft returns the amount of gas available for the current execution.
 // This function uses `System.Runtime.GasLeft` syscall.
 func GasLeft() int64 {
-	return 0
+	return neogointernal.Syscall0("System.Runtime.GasLeft").(int64)
 }
 
 // GetNotifications returns notifications emitted by contract h.
@@ -64,17 +71,17 @@ func GasLeft() int64 {
 // [  scripthash of notification's contract  ,  emitted item  ].
 // This function uses `System.Runtime.GetNotifications` syscall.
 func GetNotifications(h interop.Hash160) [][]interface{} {
-	return nil
+	return neogointernal.Syscall1("System.Runtime.GetNotifications", h).([][]interface{})
 }
 
 // GetInvocationCounter returns how many times current contract was invoked during current tx execution.
 // This function uses `System.Runtime.GetInvocationCounter` syscall.
 func GetInvocationCounter() int {
-	return 0
+	return neogointernal.Syscall0("System.Runtime.GetInvocationCounter").(int)
 }
 
 // Platform returns the platform name, which is set to be `NEO`. This function uses
 // `System.Runtime.Platform` syscall.
 func Platform() []byte {
-	return nil
+	return neogointernal.Syscall0("System.Runtime.Platform").([]byte)
 }

pkg/interop/storage/storage.go

@@ -6,7 +6,10 @@ contract.
 */
 package storage
 
-import "github.com/nspcc-dev/neo-go/pkg/interop/iterator"
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop/iterator"
+	"github.com/nspcc-dev/neo-go/pkg/interop/neogointernal"
+)
 
 // Context represents storage context that is mandatory for Put/Get/Delete
 // operations. It's an opaque type that can only be created properly by
@@ -39,46 +42,60 @@ const (
 // writing capability turned off, so that you could only invoke Get and Find
 // using this new Context. If Context is already read-only this function is a
 // no-op. It uses `System.Storage.AsReadOnly` syscall.
-func ConvertContextToReadOnly(ctx Context) Context { return Context{} }
+func ConvertContextToReadOnly(ctx Context) Context {
+	return neogointernal.Syscall0("System.Storage.AsReadOnly").(Context)
+}
 
 // GetContext returns current contract's (that invokes this function) storage
 // context. It uses `System.Storage.GetContext` syscall.
-func GetContext() Context { return Context{} }
+func GetContext() Context {
+	return neogointernal.Syscall0("System.Storage.GetContext").(Context)
+}
 
 // GetReadOnlyContext returns current contract's (that invokes this function)
 // storage context in read-only mode, you can use this context for Get and Find
 // functions, but using it for Put and Delete will fail. It uses
 // `System.Storage.GetReadOnlyContext` syscall.
-func GetReadOnlyContext() Context { return Context{} }
+func GetReadOnlyContext() Context {
+	return neogointernal.Syscall0("System.Storage.GetReadOnlyContext").(Context)
+}
 
 // Put saves given value with given key in the storage using given Context.
 // Even though it accepts interface{} for both, you can only pass simple types
 // there like string, []byte, int or bool (not structures or slices of more
 // complex types). To put more complex types there serialize them first using
 // runtime.Serialize. This function uses `System.Storage.Put` syscall.
-func Put(ctx Context, key interface{}, value interface{}) {}
+func Put(ctx Context, key interface{}, value interface{}) {
+	neogointernal.Syscall3NoReturn("System.Storage.Put", ctx, key, value)
+}
 
 // PutEx is an advanced version of Put which saves given value with given key
 // and given ReadOnly flag in the storage using given Context. `flag` argument
 // can either be odd for constant storage items or even for variable storage items.
 // Refer to Put function description for details on how to pass the remaining
 // arguments. This function uses `System.Storage.PutEx` syscall.
-func PutEx(ctx Context, key interface{}, value interface{}, flag int64) {}
+func PutEx(ctx Context, key interface{}, value interface{}, flag int64) {
+	neogointernal.Syscall4NoReturn("System.Storage.PutEx", ctx, key, value, flag)
+}
 
 // Get retrieves value stored for the given key using given Context. See Put
 // documentation on possible key and value types. If the value is not present in
 // the database it returns nil. This function uses `System.Storage.Get` syscall.
-func Get(ctx Context, key interface{}) interface{} { return nil }
+func Get(ctx Context, key interface{}) interface{} {
+	return neogointernal.Syscall2("System.Storage.Get", ctx, key)
+}
 
 // Delete removes key-value pair from storage by the given key using given
 // Context. See Put documentation on possible key types. This function uses
 // `System.Storage.Delete` syscall.
-func Delete(ctx Context, key interface{}) {}
+func Delete(ctx Context, key interface{}) {
+	neogointernal.Syscall2NoReturn("System.Storage.Delete", ctx, key)
+}
 
 // Find returns an iterator.Iterator over key-value pairs in the given Context
 // that match the given key (contain it as a prefix). See Put documentation on
 // possible key types and iterator package documentation on how to use the
 // returned value. This function uses `System.Storage.Find` syscall.
 func Find(ctx Context, key interface{}, options FindFlags) iterator.Iterator {
-	return iterator.Iterator{}
+	return neogointernal.Syscall3("System.Storage.Find", ctx, key, options).(iterator.Iterator)
 }