core: implement LoadToken handler

pkg/core/blockchain.go

@@ -16,6 +16,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/blockchainer"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
+	"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
 	"github.com/nspcc-dev/neo-go/pkg/core/mempool"
 	"github.com/nspcc-dev/neo-go/pkg/core/mpt"
 	"github.com/nspcc-dev/neo-go/pkg/core/native"
@@ -625,6 +626,7 @@ func (bc *Blockchain) storeBlock(block *block.Block, txpool *mempool.Pool) error
 		v := systemInterop.SpawnVM()
 		v.LoadScriptWithFlags(tx.Script, callflag.All)
 		v.SetPriceGetter(bc.getPrice)
+		v.LoadToken = contract.LoadToken(systemInterop)
 		v.GasLimit = tx.SystemFee
 
 		err := v.Run()
@@ -1635,6 +1637,7 @@ func (bc *Blockchain) GetTestVM(t trigger.Type, tx *transaction.Transaction, b *
 	systemInterop := bc.newInteropContext(t, d, b, tx)
 	vm := systemInterop.SpawnVM()
 	vm.SetPriceGetter(bc.getPrice)
+	vm.LoadToken = contract.LoadToken(systemInterop)
 	return vm
 }
 
@@ -1670,6 +1673,7 @@ func (bc *Blockchain) initVerificationVM(ic *interop.Context, hash util.Uint160,
 		}
 		initMD := cs.Manifest.ABI.GetMethod(manifest.MethodInit)
 		v.LoadScriptWithHash(cs.NEF.Script, hash, callflag.ReadStates)
+		v.Context().NEF = &cs.NEF
 		v.Jump(v.Context(), md.Offset)
 
 		if cs.ID <= 0 {
@@ -1704,6 +1708,7 @@ func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transa
 
 	vm := interopCtx.SpawnVM()
 	vm.SetPriceGetter(bc.getPrice)
+	vm.LoadToken = contract.LoadToken(interopCtx)
 	vm.GasLimit = gas
 	if err := bc.initVerificationVM(interopCtx, hash, witness); err != nil {
 		return 0, err

pkg/core/interop/contract/call.go

@@ -15,6 +15,26 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
+// LoadToken calls method specified by token id.
+func LoadToken(ic *interop.Context) func(id int32) error {
+	return func(id int32) error {
+		ctx := ic.VM.Context()
+		tok := ctx.NEF.Tokens[id]
+		if int(tok.ParamCount) > ctx.Estack().Len() {
+			return errors.New("stack is too small")
+		}
+		args := make([]stackitem.Item, tok.ParamCount)
+		for i := range args {
+			args[i] = ic.VM.Estack().Pop().Item()
+		}
+		cs, err := ic.GetContract(tok.Hash)
+		if err != nil {
+			return fmt.Errorf("contract not found: %w", err)
+		}
+		return callInternal(ic, cs, tok.Method, tok.CallFlag, tok.HasReturn, args)
+	}
+}
+
 // Call calls a contract with flags.
 func Call(ic *interop.Context) error {
 	h := ic.VM.Estack().Pop().Bytes()
@@ -24,10 +44,6 @@ func Call(ic *interop.Context) error {
 		return errors.New("call flags out of range")
 	}
 	args := ic.VM.Estack().Pop().Array()
-	return callInternal(ic, h, method, fs, args)
-}
-
-func callInternal(ic *interop.Context, h []byte, name string, f callflag.CallFlag, args []stackitem.Item) error {
 	u, err := util.Uint160DecodeBytesBE(h)
 	if err != nil {
 		return errors.New("invalid contract hash")
@@ -36,10 +52,10 @@ func callInternal(ic *interop.Context, h []byte, name string, f callflag.CallFla
 	if err != nil {
 		return fmt.Errorf("contract not found: %w", err)
 	}
-	if strings.HasPrefix(name, "_") {
+	if strings.HasPrefix(method, "_") {
 		return errors.New("invalid method name (starts with '_')")
 	}
-	md := cs.Manifest.ABI.GetMethod(name)
+	md := cs.Manifest.ABI.GetMethod(method)
 	if md == nil {
 		return errors.New("method not found")
 	}
@@ -47,12 +63,18 @@ func callInternal(ic *interop.Context, h []byte, name string, f callflag.CallFla
 	if !hasReturn {
 		ic.VM.Estack().PushVal(stackitem.Null{})
 	}
+	return callInternal(ic, cs, method, fs, hasReturn, args)
+}
+
+func callInternal(ic *interop.Context, cs *state.Contract, name string, f callflag.CallFlag,
+	hasReturn bool, args []stackitem.Item) error {
+	md := cs.Manifest.ABI.GetMethod(name)
 	if md.Safe {
 		f &^= callflag.WriteStates
 	} else if ctx := ic.VM.Context(); ctx != nil && ctx.IsDeployed() {
 		curr, err := ic.GetContract(ic.VM.GetCurrentScriptHash())
 		if err == nil {
-			if !curr.Manifest.CanCall(u, &cs.Manifest, name) {
+			if !curr.Manifest.CanCall(cs.Hash, &cs.Manifest, name) {
 				return errors.New("disallowed method call")
 			}
 		}
@@ -74,6 +96,7 @@ func callExFromNative(ic *interop.Context, caller util.Uint160, cs *state.Contra
 
 	ic.VM.Invocations[cs.Hash]++
 	ic.VM.LoadScriptWithCallingHash(caller, cs.NEF.Script, cs.Hash, ic.VM.Context().GetCallFlags()&f, true, uint16(len(args)))
+	ic.VM.Context().NEF = &cs.NEF
 	var isNative bool
 	for i := range ic.Natives {
 		if ic.Natives[i].Metadata().Hash.Equals(cs.Hash) {

pkg/core/interop_system_test.go

@@ -513,6 +513,12 @@ func getTestContractState(bc *Blockchain) (*state.Contract, *state.Contract) {
 	emit.Opcodes(w.BinWriter, opcode.NEWARRAY0, opcode.DUP, opcode.DUP, opcode.APPEND, opcode.NEWMAP)
 	emit.Syscall(w.BinWriter, interopnames.SystemIteratorCreate)
 	emit.Opcodes(w.BinWriter, opcode.RET)
+	callT0Off := w.Len()
+	emit.Opcodes(w.BinWriter, opcode.CALLT, 0, 0, opcode.PUSH1, opcode.ADD, opcode.RET)
+	callT1Off := w.Len()
+	emit.Opcodes(w.BinWriter, opcode.CALLT, 1, 0, opcode.RET)
+	callT2Off := w.Len()
+	emit.Opcodes(w.BinWriter, opcode.CALLT, 0, 0, opcode.RET)
 
 	script := w.Bytes()
 	h := hash.Hash160(script)
@@ -616,7 +622,34 @@ func getTestContractState(bc *Blockchain) (*state.Contract, *state.Contract) {
 			Offset:     invalidStackOff,
 			ReturnType: smartcontract.VoidType,
 		},
+		{
+			Name:   "callT0",
+			Offset: callT0Off,
+			Parameters: []manifest.Parameter{
+				manifest.NewParameter("address", smartcontract.Hash160Type),
+			},
+			ReturnType: smartcontract.IntegerType,
+		},
+		{
+			Name:       "callT1",
+			Offset:     callT1Off,
+			ReturnType: smartcontract.IntegerType,
+		},
+		{
+			Name:       "callT2",
+			Offset:     callT2Off,
+			ReturnType: smartcontract.IntegerType,
+		},
 	}
+	m.Permissions = make([]manifest.Permission, 2)
+	m.Permissions[0].Contract.Type = manifest.PermissionHash
+	m.Permissions[0].Contract.Value = bc.contracts.NEO.Hash
+	m.Permissions[0].Methods.Add("balanceOf")
+
+	m.Permissions[1].Contract.Type = manifest.PermissionHash
+	m.Permissions[1].Contract.Value = util.Uint160{}
+	m.Permissions[1].Methods.Add("method")
+
 	cs := &state.Contract{
 		Hash:     h,
 		Manifest: *m,
@@ -626,6 +659,22 @@ func getTestContractState(bc *Blockchain) (*state.Contract, *state.Contract) {
 	if err != nil {
 		panic(err)
 	}
+	ne.Tokens = []nef.MethodToken{
+		{
+			Hash:       bc.contracts.NEO.Hash,
+			Method:     "balanceOf",
+			ParamCount: 1,
+			HasReturn:  true,
+			CallFlag:   callflag.ReadStates,
+		},
+		{
+			Hash:      util.Uint160{},
+			Method:    "method",
+			HasReturn: true,
+			CallFlag:  callflag.ReadStates,
+		},
+	}
+	ne.Checksum = ne.CalculateChecksum()
 	cs.NEF = *ne
 
 	currScript := []byte{byte(opcode.RET)}
@@ -980,3 +1029,28 @@ func TestRuntimeCheckWitness(t *testing.T) {
 		})
 	})
 }
+
+func TestLoadToken(t *testing.T) {
+	bc := newTestChain(t)
+	defer bc.Close()
+
+	cs, _ := getTestContractState(bc)
+	require.NoError(t, bc.contracts.Management.PutContractState(bc.dao, cs))
+
+	t.Run("good", func(t *testing.T) {
+		aer, err := invokeContractMethod(bc, 1_00000000, cs.Hash, "callT0", neoOwner.BytesBE())
+		require.NoError(t, err)
+		realBalance, _ := bc.GetGoverningTokenBalance(neoOwner)
+		checkResult(t, aer, stackitem.Make(realBalance.Int64()+1))
+	})
+	t.Run("invalid param count", func(t *testing.T) {
+		aer, err := invokeContractMethod(bc, 1_00000000, cs.Hash, "callT2")
+		require.NoError(t, err)
+		checkFAULTState(t, aer)
+	})
+	t.Run("invalid contract", func(t *testing.T) {
+		aer, err := invokeContractMethod(bc, 1_00000000, cs.Hash, "callT1")
+		require.NoError(t, err)
+		checkFAULTState(t, aer)
+	})
+}

pkg/core/native_management_test.go

@@ -83,9 +83,7 @@ func TestContractDeploy(t *testing.T) {
 	cs1.Hash = state.CreateContractHash(testchain.MultisigScriptHash(), cs1.NEF.Script)
 	manif1, err := json.Marshal(cs1.Manifest)
 	require.NoError(t, err)
-	nef1, err := nef.NewFile(cs1.NEF.Script)
+	nef1b, err := cs1.NEF.Bytes()
-	require.NoError(t, err)
-	nef1b, err := nef1.Bytes()
 	require.NoError(t, err)
 
 	t.Run("no NEF", func(t *testing.T) {

pkg/vm/context.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
@@ -42,9 +43,6 @@ type Context struct {
 	// Caller's contract script hash.
 	callingScriptHash util.Uint160
 
-	// Set to true when running deployed contracts.
-	isDeployed bool
-
 	// Call flags this context was created with.
 	callFlag callflag.CallFlag
 
@@ -52,6 +50,8 @@ type Context struct {
 	ParamCount int
 	// RetCount specifies number of return values.
 	RetCount int
+	// NEF represents NEF file for the current contract.
+	NEF *nef.File
 }
 
 // CheckReturnState represents possible states of stack after opcode.RET was processed.
@@ -273,7 +273,7 @@ func (c *Context) String() string {
 
 // IsDeployed returns whether this context contains deployed contract.
 func (c *Context) IsDeployed() bool {
-	return c.isDeployed
+	return c.NEF != nil
 }
 
 // getContextScriptHash returns script hash of the invocation stack element

pkg/vm/vm.go

@@ -308,7 +308,6 @@ func (v *VM) LoadScriptWithCallingHash(caller util.Uint160, b []byte, hash util.
 	f callflag.CallFlag, hasReturn bool, paramCount uint16) {
 	v.LoadScriptWithFlags(b, f)
 	ctx := v.Context()
-	ctx.isDeployed = true
 	ctx.scriptHash = hash
 	ctx.callingScriptHash = caller
 	if hasReturn {
@@ -1519,6 +1518,7 @@ func (v *VM) call(ctx *Context, offset int) {
 	newCtx.local = nil
 	newCtx.arguments = nil
 	newCtx.tryStack = NewStack("exception")
+	newCtx.NEF = ctx.NEF
 	v.istack.PushVal(newCtx)
 	v.Jump(newCtx, offset)
 }