Merge pull request #800 from nspcc-dev/fix/slice

compiler: declare compoud types with var keyword

pkg/compiler/analysis.go

@@ -187,6 +187,35 @@ func isBuiltin(expr ast.Expr) bool {
 	return false
 }
 
+func (c *codegen) isCompoundArrayType(t ast.Expr) bool {
+	switch s := t.(type) {
+	case *ast.ArrayType:
+		return true
+	case *ast.Ident:
+		arr, ok := c.typeInfo.Types[s].Type.Underlying().(*types.Slice)
+		return ok && !isByte(arr.Elem())
+	}
+	return false
+}
+
+func isByte(t types.Type) bool {
+	e, ok := t.(*types.Basic)
+	return ok && e.Kind() == types.Byte
+}
+
+func (c *codegen) isStructType(t ast.Expr) (int, bool) {
+	switch s := t.(type) {
+	case *ast.StructType:
+		return s.Fields.NumFields(), true
+	case *ast.Ident:
+		st, ok := c.typeInfo.Types[s].Type.Underlying().(*types.Struct)
+		if ok {
+			return st.NumFields(), true
+		}
+	}
+	return 0, false
+}
+
 func isByteArray(lit *ast.CompositeLit, tInfo *types.Info) bool {
 	if len(lit.Elts) == 0 {
 		if typ, ok := lit.Type.(*ast.ArrayType); ok {
@@ -199,14 +228,7 @@ func isByteArray(lit *ast.CompositeLit, tInfo *types.Info) bool {
 	}
 
 	typ := tInfo.Types[lit.Elts[0]].Type.Underlying()
-	switch t := typ.(type) {
-	case *types.Basic:
-		switch t.Kind() {
-		case types.Byte:
-			return true
-		}
-	}
-	return false
+	return isByte(typ)
 }
 
 func isSyscall(fun *funcScope) bool {

pkg/compiler/codegen.go

@@ -276,9 +276,21 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 		for _, spec := range n.Specs {
 			switch t := spec.(type) {
 			case *ast.ValueSpec:
-				for i, val := range t.Values {
-					ast.Walk(c, val)
-					l := c.scope.newLocal(t.Names[i].Name)
+				if len(t.Values) != 0 {
+					for i, val := range t.Values {
+						ast.Walk(c, val)
+						l := c.scope.newLocal(t.Names[i].Name)
+						c.emitStoreLocal(l)
+					}
+				} else if c.isCompoundArrayType(t.Type) {
+					emit.Opcode(c.prog.BinWriter, opcode.PUSH0)
+					emit.Opcode(c.prog.BinWriter, opcode.NEWARRAY)
+					l := c.scope.newLocal(t.Names[0].Name)
+					c.emitStoreLocal(l)
+				} else if n, ok := c.isStructType(t.Type); ok {
+					emit.Int(c.prog.BinWriter, int64(n))
+					emit.Opcode(c.prog.BinWriter, opcode.NEWSTRUCT)
+					l := c.scope.newLocal(t.Names[0].Name)
 					c.emitStoreLocal(l)
 				}
 			}

pkg/compiler/slice_test.go

@@ -3,6 +3,8 @@ package compiler_test
 import (
 	"math/big"
 	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/vm"
 )
 
 var sliceTestCases = []testCase{
@@ -128,6 +130,35 @@ var sliceTestCases = []testCase{
 		}`,
 		[]byte{2, 3},
 	},
+	{
+		"declare compound slice",
+		`package foo
+		func Main() []string {
+			var a []string
+			a = append(a, "a")
+			a = append(a, "b")
+			return a
+		}`,
+		[]vm.StackItem{
+			vm.NewByteArrayItem([]byte("a")),
+			vm.NewByteArrayItem([]byte("b")),
+		},
+	},
+	{
+		"declare compound slice alias",
+		`package foo
+		type strs []string
+		func Main() []string {
+			var a strs
+			a = append(a, "a")
+			a = append(a, "b")
+			return a
+		}`,
+		[]vm.StackItem{
+			vm.NewByteArrayItem([]byte("a")),
+			vm.NewByteArrayItem([]byte("b")),
+		},
+	},
 }
 
 func TestSliceOperations(t *testing.T) {

pkg/compiler/struct_test.go

@@ -302,6 +302,31 @@ var structTestCases = []testCase{
 		`,
 		big.NewInt(14),
 	},
+	{
+		"declare struct literal",
+		`package foo
+		func Main() int {
+			var x struct {
+				a int
+			}
+			x.a = 2
+			return x.a
+		}`,
+		big.NewInt(2),
+	},
+	{
+		"declare struct type",
+		`package foo
+		type withA struct {
+			a int
+		}
+		func Main() int {
+			var x withA
+			x.a = 2
+			return x.a
+		}`,
+		big.NewInt(2),
+	},
 }
 
 func TestStructs(t *testing.T) {