Merge pull request #1425 from nspcc-dev/compiler/byteslice

Support variables in slice literals.

pkg/compiler/codegen.go

@@ -1594,13 +1594,24 @@ func (c *codegen) emitConvert(typ stackitem.Type) {
 
 func (c *codegen) convertByteArray(lit *ast.CompositeLit) {
 	buf := make([]byte, len(lit.Elts))
+	varIndices := []int{}
 	for i := 0; i < len(lit.Elts); i++ {
 		t := c.typeAndValueOf(lit.Elts[i])
+		if t.Value != nil {
 			val, _ := constant.Int64Val(t.Value)
 			buf[i] = byte(val)
+		} else {
+			varIndices = append(varIndices, i)
+		}
 	}
 	emit.Bytes(c.prog.BinWriter, buf)
 	c.emitConvert(stackitem.BufferT)
+	for _, i := range varIndices {
+		emit.Opcode(c.prog.BinWriter, opcode.DUP)
+		emit.Int(c.prog.BinWriter, int64(i))
+		ast.Walk(c, lit.Elts[i])
+		emit.Opcode(c.prog.BinWriter, opcode.SETITEM)
+	}
 }
 
 func (c *codegen) convertMap(lit *ast.CompositeLit) {

pkg/compiler/func_scope.go

@@ -136,6 +136,18 @@ func (c *funcScope) analyzeVoidCalls(node ast.Node) bool {
 			c.voidCalls[n] = true
 		}
 		return false
+	case *ast.CompositeLit:
+		for _, e := range n.Elts {
+			switch val := e.(type) {
+			case *ast.CallExpr: // slice
+				c.voidCalls[val] = false
+			case *ast.KeyValueExpr: // struct and map
+				ce, ok := val.Value.(*ast.CallExpr)
+				if ok {
+					c.voidCalls[ce] = false
+				}
+			}
+		}
 	}
 	return true
 }

pkg/compiler/slice_test.go

@@ -310,6 +310,26 @@ var sliceTestCases = []testCase{
 		`,
 		big.NewInt(2),
 	},
+	{
+		"literal byte-slice with variable values",
+		`package foo
+		const sym1 = 's'
+		func Main() []byte {
+			sym2 := byte('t')
+			sym4 := byte('i')
+			return []byte{sym1, sym2, 'r', sym4, 'n', 'g'}
+		}`,
+		[]byte("string"),
+	},
+	{
+		"literal slice with function call",
+		`package foo
+		func fn() byte { return 't' }
+		func Main() []byte {
+			return []byte{'s', fn(), 'r'}
+		}`,
+		[]byte("str"),
+	},
 }
 
 func TestSliceOperations(t *testing.T) {

pkg/compiler/struct_test.go

@@ -29,6 +29,19 @@ var structTestCases = []testCase{
 		`,
 		big.NewInt(2),
 	},
+	{
+		"struct field from func result",
+		`
+		package foo
+		type S struct { x int }
+		func fn() int { return 2 }
+		func Main() int {
+			t := S{x: fn()}
+			return t.x
+		}
+		`,
+		big.NewInt(2),
+	},
 	{
 		"struct field return",
 		`