rpcbinding: generate bindings using new extended type data

cli/smartcontract/generate_test.go

@@ -401,6 +401,7 @@ func TestAssistedRPCBindings(t *testing.T) {
 	}
 
 	checkBinding(filepath.Join("testdata", "types"))
+	checkBinding(filepath.Join("testdata", "structs"))
 }
 
 func TestGenerate_Errors(t *testing.T) {

cli/smartcontract/testdata/structs/config.yml

@@ -0,0 +1,3 @@
+name: "Types"
+sourceurl: https://github.com/nspcc-dev/neo-go/
+safemethods: ["contract", "block", "transaction", "struct"]

cli/smartcontract/testdata/structs/structs.go

@@ -0,0 +1,39 @@
+package structs
+
+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/native/management"
+)
+
+type Internal struct {
+	Bool       bool
+	Int        int
+	Bytes      []byte
+	String     string
+	H160       interop.Hash160
+	H256       interop.Hash256
+	PK         interop.PublicKey
+	PubKey     interop.PublicKey
+	Sign       interop.Signature
+	ArrOfBytes [][]byte
+	ArrOfH160  []interop.Hash160
+	Map        map[int][]interop.PublicKey
+	Struct     *Internal
+}
+
+func Contract(mc management.Contract) management.Contract {
+	return mc
+}
+
+func Block(b *ledger.Block) *ledger.Block {
+	return b
+}
+
+func Transaction(t *ledger.Transaction) *ledger.Transaction {
+	return t
+}
+
+func Struct(s *Internal) *Internal {
+	return s
+}

docs/compiler.md

@@ -459,8 +459,9 @@ result. This pair can then be used in Invoker `TraverseIterator` method to
 retrieve actual resulting items.
 
 Go contracts can also make use of additional type data from bindings
-configuration file generated during compilation. At the moment it allows to
-generate proper wrappers for simple array types, but doesn't cover structures:
+configuration file generated during compilation. This can cover arrays, maps
+and structures. Notice that structured types returned by methods can't be Null
+at the moment (see #2795).
 
 ```
 $ ./bin/neo-go contract compile -i contract.go --config contract.yml -o contract.nef --manifest manifest.json --bindings contract.bindings.yml

pkg/smartcontract/binding/generate.go

@@ -119,8 +119,8 @@ func Generate(cfg Config) error {
 	return srcTemplate.Execute(cfg.Output, ctr)
 }
 
-func scTypeToGo(name string, typ smartcontract.ParamType, overrides map[string]Override) (string, string) {
-	if over, ok := overrides[name]; ok {
+func scTypeToGo(name string, typ smartcontract.ParamType, cfg *Config) (string, string) {
+	if over, ok := cfg.Overrides[name]; ok {
 		return over.TypeName, over.Package
 	}
 
@@ -159,7 +159,7 @@ func scTypeToGo(name string, typ smartcontract.ParamType, overrides map[string]O
 // TemplateFromManifest create a contract template using the given configuration
 // and type conversion function. It assumes manifest to be present in the
 // configuration and assumes it to be correct (passing IsValid check).
-func TemplateFromManifest(cfg Config, scTypeConverter func(string, smartcontract.ParamType, map[string]Override) (string, string)) ContractTmpl {
+func TemplateFromManifest(cfg Config, scTypeConverter func(string, smartcontract.ParamType, *Config) (string, string)) ContractTmpl {
 	hStr := ""
 	for _, b := range cfg.Hash.BytesBE() {
 		hStr += fmt.Sprintf("\\x%02x", b)
@@ -221,7 +221,7 @@ func TemplateFromManifest(cfg Config, scTypeConverter func(string, smartcontract
 		var varnames = make(map[string]bool)
 		for i := range m.Parameters {
 			name := m.Parameters[i].Name
-			typeStr, pkg := scTypeConverter(m.Name+"."+name, m.Parameters[i].Type, cfg.Overrides)
+			typeStr, pkg := scTypeConverter(m.Name+"."+name, m.Parameters[i].Type, &cfg)
 			if pkg != "" {
 				imports[pkg] = struct{}{}
 			}
@@ -238,7 +238,7 @@ func TemplateFromManifest(cfg Config, scTypeConverter func(string, smartcontract
 			})
 		}
 
-		typeStr, pkg := scTypeConverter(m.Name, m.ReturnType, cfg.Overrides)
+		typeStr, pkg := scTypeConverter(m.Name, m.ReturnType, &cfg)
 		if pkg != "" {
 			imports[pkg] = struct{}{}
 		}

pkg/smartcontract/rpcbinding/binding.go

@@ -3,6 +3,7 @@ package rpcbinding
 import (
 	"fmt"
 	"sort"
+	"strings"
 	"text/template"
 
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
@@ -18,8 +19,12 @@ func (c *ContractReader) {{.Name}}({{range $index, $arg := .Arguments -}}
 	{{- if ne $index 0}}, {{end}}
 		{{- .Name}} {{.Type}}
 	{{- end}}) {{if .ReturnType }}({{ .ReturnType }}, error) {
-	return unwrap.{{.CallFlag}}(c.invoker.Call(Hash, "{{ .NameABI }}"{{/* CallFlag field is used for function name */}}
-		{{- range $arg := .Arguments -}}, {{.Name}}{{end}}))
+	return {{if .CallFlag -}}
+			unwrap.{{.CallFlag}}(c.invoker.Call(Hash, "{{ .NameABI }}"{{/* CallFlag field is used for function name */}}
+		{{- else -}}
+			itemTo{{ cutPointer .ReturnType }}(unwrap.Item(c.invoker.Call(Hash, "{{ .NameABI }}"{{/* CallFlag field is used for function name */}}
+		{{- end -}}
+		{{- range $arg := .Arguments -}}, {{.Name}}{{end}})){{if not .CallFlag}}){{end}}
 	{{- else -}} (*result.Invoke, error) {
 	c.invoker.Call(Hash, "{{ .NameABI }}"
 		{{- range $arg := .Arguments -}}, {{.Name}}{{end}})
@@ -101,6 +106,14 @@ import (
 // Hash contains contract hash.
 var Hash = {{ .Hash }}
 
+{{range $name, $typ := .NamedTypes}}
+// {{toTypeName $name}} is a contract-specific {{$name}} type used by its methods.
+type {{toTypeName $name}} struct {
+{{- range $m := $typ.Fields}}
+	{{.Field}} {{etTypeToStr .ExtendedType}}
+{{- end}}
+}
+{{end -}}
 {{if .HasReader}}// Invoker is used by ContractReader to call various safe methods.
 type Invoker interface {
 {{if or .IsNep11D .IsNep11ND}}	nep11.Invoker
@@ -199,15 +212,41 @@ func New(actor Actor) *Contract {
 {{end}}
 {{- range $m := .Methods}}
 {{template "METHOD" $m }}
-{{end}}`
+{{end}}
+{{- range $name, $typ := .NamedTypes}}
+// itemTo{{toTypeName $name}} converts stack item into *{{toTypeName $name}}.
+func itemTo{{toTypeName $name}}(item stackitem.Item, err error) (*{{toTypeName $name}}, error) {
+	if err != nil {
+		return nil, err
+	}
+	arr, ok := item.Value().([]stackitem.Item)
+	if !ok {
+		return nil, errors.New("not an array")
+	}
+	if len(arr) != {{len $typ.Fields}} {
+		return nil, errors.New("wrong number of structure elements")
+	}
 
-var srcTemplate = template.Must(template.New("generate").Parse(srcTmpl))
+	var res = new({{toTypeName $name}})
+{{if len .Fields}}	var index = -1
+{{- range $m := $typ.Fields}}
+	index++
+	res.{{.Field}}, err = {{etTypeConverter .ExtendedType "arr[index]"}}
+	if err != nil {
+		return nil, err
+	}
+{{end}}
+{{end}}
+	return res, err
+}
+{{end}}`
 
 type (
 	ContractTmpl struct {
 		binding.ContractTmpl
 
 		SafeMethods []binding.MethodTmpl
+		NamedTypes  map[string]binding.ExtendedType
 
 		IsNep11D  bool
 		IsNep11ND bool
@@ -268,6 +307,17 @@ func Generate(cfg binding.Config) error {
 
 	ctr.ContractTmpl = binding.TemplateFromManifest(cfg, scTypeToGo)
 	ctr = scTemplateToRPC(cfg, ctr, imports)
+	ctr.NamedTypes = cfg.NamedTypes
+
+	var srcTemplate = template.Must(template.New("generate").Funcs(template.FuncMap{
+		"etTypeConverter": etTypeConverter,
+		"etTypeToStr": func(et binding.ExtendedType) string {
+			r, _ := extendedTypeToGo(et, ctr.NamedTypes)
+			return r
+		},
+		"toTypeName": toTypeName,
+		"cutPointer": cutPointer,
+	}).Parse(srcTmpl))
 
 	return srcTemplate.Execute(cfg.Output, ctr)
 }
@@ -295,31 +345,8 @@ func dropStdMethods(meths []manifest.Method, std *standard.Standard) []manifest.
 	return meths
 }
 
-func scTypeToGo(name string, typ smartcontract.ParamType, overrides map[string]binding.Override) (string, string) {
-	over, ok := overrides[name]
-	if ok {
-		switch over.TypeName {
-		case "[]bool":
-			return "[]bool", ""
-		case "[]int", "[]uint", "[]int8", "[]uint8", "[]int16",
-			"[]uint16", "[]int32", "[]uint32", "[]int64", "[]uint64":
-			return "[]*big.Int", "math/big"
-		case "[][]byte":
-			return "[][]byte", ""
-		case "[]string":
-			return "[]string", ""
-		case "[]interop.Hash160":
-			return "[]util.Uint160", "github.com/nspcc-dev/neo-go/pkg/util"
-		case "[]interop.Hash256":
-			return "[]util.Uint256", "github.com/nspcc-dev/neo-go/pkg/util"
-		case "[]interop.PublicKey":
-			return "keys.PublicKeys", "github.com/nspcc-dev/neo-go/pkg/crypto/keys"
-		case "[]interop.Signature":
-			return "[][]byte", ""
-		}
-	}
-
-	switch typ {
+func extendedTypeToGo(et binding.ExtendedType, named map[string]binding.ExtendedType) (string, string) {
+	switch et.Base {
 	case smartcontract.AnyType:
 		return "interface{}", ""
 	case smartcontract.BoolType:
@@ -339,16 +366,132 @@ func scTypeToGo(name string, typ smartcontract.ParamType, overrides map[string]b
 	case smartcontract.SignatureType:
 		return "[]byte", ""
 	case smartcontract.ArrayType:
+		if len(et.Name) > 0 {
+			return "*" + toTypeName(et.Name), "github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
+		} else if et.Value != nil {
+			if et.Value.Base == smartcontract.PublicKeyType { // Special array wrapper.
+				return "keys.PublicKeys", "github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+			}
+			sub, pkg := extendedTypeToGo(*et.Value, named)
+			return "[]" + sub, pkg
+		}
 		return "[]interface{}", ""
+
 	case smartcontract.MapType:
 		return "*stackitem.Map", "github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 	case smartcontract.InteropInterfaceType:
 		return "interface{}", ""
 	case smartcontract.VoidType:
 		return "", ""
-	default:
-		panic("unreachable")
 	}
+	panic("unreachable")
+}
+
+func etTypeConverter(et binding.ExtendedType, v string) string {
+	switch et.Base {
+	case smartcontract.AnyType:
+		return v + ".Value(), nil"
+	case smartcontract.BoolType:
+		return v + ".TryBool()"
+	case smartcontract.IntegerType:
+		return v + ".TryInteger()"
+	case smartcontract.ByteArrayType, smartcontract.SignatureType:
+		return v + ".TryBytes()"
+	case smartcontract.StringType:
+		return `func (item stackitem.Item) (string, error) {
+		b, err := item.TryBytes()
+		if err != nil {
+			return "", err
+		}
+		if !utf8.Valid(b) {
+			return "", errors.New("not a UTF-8 string")
+		}
+		return string(b), nil
+	} (` + v + `)`
+	case smartcontract.Hash160Type:
+		return `func (item stackitem.Item) (util.Uint160, error) {
+		b, err := item.TryBytes()
+		if err != nil {
+			return util.Uint160{}, err
+		}
+		u, err := util.Uint160DecodeBytesBE(b)
+		if err != nil {
+			return util.Uint160{}, err
+		}
+		return u, nil
+	} (` + v + `)`
+	case smartcontract.Hash256Type:
+		return `func (item stackitem.Item) (util.Uint256, error) {
+		b, err := item.TryBytes()
+		if err != nil {
+			return util.Uint256{}, err
+		}
+		u, err := util.Uint256DecodeBytesBE(b)
+		if err != nil {
+			return util.Uint256{}, err
+		}
+		return u, nil
+	} (` + v + `)`
+	case smartcontract.PublicKeyType:
+		return `func (item stackitem.Item) (*keys.PublicKey, error) {
+		b, err := item.TryBytes()
+		if err != nil {
+			return nil, err
+		}
+		k, err := keys.NewPublicKeyFromBytes(b, elliptic.P256())
+		if err != nil {
+			return nil, err
+		}
+		return k, nil
+	} (` + v + `)`
+	case smartcontract.ArrayType:
+		if len(et.Name) > 0 {
+			return "itemTo" + toTypeName(et.Name) + "(" + v + ", nil)"
+		} else if et.Value != nil {
+			at, _ := extendedTypeToGo(et, nil)
+			return `func (item stackitem.Item) (` + at + `, error) {
+		arr, ok := item.Value().([]stackitem.Item)
+		if !ok {
+			return nil, errors.New("not an array")
+		}
+		res := make(` + at + `, len(arr))
+		for i := range res {
+			res[i], err = ` + etTypeConverter(*et.Value, "arr[i]") + `
+			if err != nil {
+				return nil, err
+			}
+		}
+		return res, nil
+	} (` + v + `)`
+		}
+		return etTypeConverter(binding.ExtendedType{
+			Base: smartcontract.ArrayType,
+			Value: &binding.ExtendedType{
+				Base: smartcontract.AnyType,
+			},
+		}, v)
+
+	case smartcontract.MapType:
+		return `func (item stackitem.Item) (*stackitem.Map, error) {
+		if t := item.Type(); t != stackitem.MapT {
+			return nil, fmt.Errorf("%s is not a map", t.String())
+		}
+		return item.(*stackitem.Map), nil
+	} (` + v + `)`
+	case smartcontract.InteropInterfaceType:
+		return "item.Value(), nil"
+	case smartcontract.VoidType:
+		return ""
+	}
+	panic("unreachable")
+}
+
+func scTypeToGo(name string, typ smartcontract.ParamType, cfg *binding.Config) (string, string) {
+	et, ok := cfg.Types[name]
+	if !ok {
+		et = binding.ExtendedType{Base: typ}
+	}
+	return extendedTypeToGo(et, cfg.NamedTypes)
 }
 
 func scTemplateToRPC(cfg binding.Config, ctr ContractTmpl, imports map[string]struct{}) ContractTmpl {
@@ -369,6 +512,27 @@ func scTemplateToRPC(cfg binding.Config, ctr ContractTmpl, imports map[string]st
 			}
 		}
 	}
+	for _, et := range cfg.NamedTypes {
+		for _, fet := range et.Fields {
+			_, pkg := extendedTypeToGo(fet.ExtendedType, ctr.NamedTypes)
+			if pkg != "" {
+				imports[pkg] = struct{}{}
+			}
+			// Additional packages used during decoding.
+			switch fet.Base {
+			case smartcontract.StringType:
+				imports["unicode/utf8"] = struct{}{}
+			case smartcontract.PublicKeyType:
+				imports["crypto/elliptic"] = struct{}{}
+			case smartcontract.MapType:
+				imports["fmt"] = struct{}{}
+			}
+		}
+	}
+	if len(cfg.NamedTypes) > 0 {
+		imports["errors"] = struct{}{}
+	}
+
 	// We're misusing CallFlag field for function name here.
 	for i := range ctr.SafeMethods {
 		switch ctr.SafeMethods[i].ReturnType {
@@ -420,6 +584,8 @@ func scTemplateToRPC(cfg binding.Config, ctr ContractTmpl, imports map[string]st
 			ctr.SafeMethods[i].CallFlag = "ArrayOfUint256"
 		case "keys.PublicKeys":
 			ctr.SafeMethods[i].CallFlag = "ArrayOfPublicKeys"
+		default:
+			ctr.SafeMethods[i].CallFlag = ""
 		}
 	}
 
@@ -446,3 +612,19 @@ func scTemplateToRPC(cfg binding.Config, ctr ContractTmpl, imports map[string]st
 	sort.Strings(ctr.Imports)
 	return ctr
 }
+
+func cutPointer(s string) string {
+	if s[0] == '*' {
+		return s[1:]
+	}
+	return s
+}
+
+func toTypeName(s string) string {
+	return strings.Map(func(c rune) rune {
+		if c == '.' {
+			return -1
+		}
+		return c
+	}, strings.ToUpper(s[0:1])+s[1:])
+}