manifest: add Offset in method descriptor

pkg/compiler/debug.go

@@ -270,6 +270,7 @@ func (m *MethodDebugInfo) ToManifestMethod() (manifest.Method, error) {
 		return result, err
 	}
 	result.Name = strings.ToLower(string(m.Name.Name[0])) + m.Name.Name[1:]
+	result.Offset = int(m.Range.Start)
 	result.Parameters = parameters
 	result.ReturnType = returnType
 	return result, nil

pkg/compiler/debug_test.go

@@ -129,19 +129,22 @@ func unexportedMethod() int { return 1 }
 	t.Run("convert to Manifest", func(t *testing.T) {
 		actual, err := d.convertToManifest(smartcontract.HasStorage)
 		require.NoError(t, err)
+		// note: offsets are hard to predict, so we just take them from the output
 		expected := &manifest.Manifest{
 			ABI: manifest.ABI{
 				Hash: hash.Hash160(buf),
 				Methods: []manifest.Method{
 					{
-						Name: "main",
+						Name:   "main",
+						Offset: 0,
 						Parameters: []manifest.Parameter{
 							manifest.NewParameter("op", smartcontract.StringType),
 						},
 						ReturnType: smartcontract.BoolType,
 					},
 					{
-						Name: "methodInt",
+						Name:   "methodInt",
+						Offset: 66,
 						Parameters: []manifest.Parameter{
 							{
 								Name: "a",
@@ -152,26 +155,31 @@ func unexportedMethod() int { return 1 }
 					},
 					{
 						Name:       "methodString",
+						Offset:     97,
 						Parameters: []manifest.Parameter{},
 						ReturnType: smartcontract.StringType,
 					},
 					{
 						Name:       "methodByteArray",
+						Offset:     103,
 						Parameters: []manifest.Parameter{},
 						ReturnType: smartcontract.ByteArrayType,
 					},
 					{
 						Name:       "methodArray",
+						Offset:     108,
 						Parameters: []manifest.Parameter{},
 						ReturnType: smartcontract.ArrayType,
 					},
 					{
 						Name:       "methodStruct",
+						Offset:     113,
 						Parameters: []manifest.Parameter{},
 						ReturnType: smartcontract.ArrayType,
 					},
 					{
-						Name: "methodConcat",
+						Name:   "methodConcat",
+						Offset: 88,
 						Parameters: []manifest.Parameter{
 							{
 								Name: "a",

pkg/smartcontract/manifest/method.go

@@ -38,6 +38,7 @@ type groupAux struct {
 // Method represents method's metadata.
 type Method struct {
 	Name       string                  `json:"name"`
+	Offset     int                     `json:"offset"`
 	Parameters []Parameter             `json:"parameters"`
 	ReturnType smartcontract.ParamType `json:"returntype"`
 }