go/bindings: adding validation tests input format parser

mojo/go/tests/testutil.go

Index: mojo/go/tests/testutil.go
diff --git a/mojo/go/tests/testutil.go b/mojo/go/tests/testutil.go
new file mode 100644
index 0000000000000000000000000000000000000000..334650d8556223b6e55156bb38268ece7a0837dd
--- /dev/null
+++ b/mojo/go/tests/testutil.go
@@ -0,0 +1,158 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package tests
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"strings"
+
+	"mojo/public/go/system"
+)
+
+// inputParser parses validation tests input format as described in
+// |mojo/public/cpp/bindings/tests/validation_test_input_parser.h|
+type inputParser struct {
+}
+
+type dataItem struct {
+	Type  string
+	Value string
+}
+
+type pointerPlaceholder struct {
+	Position int
+	Size     int
+}
+
+func (p *inputParser) parseToDataItems(s string) []dataItem {
+	var items []dataItem
+	s = strings.TrimSpace(s)
+	for len(s) > 0 {
+		// Parsing data item type.
+		var itemType string
+		if s[0] == '[' {
+			closeBracket := strings.Index(s, "]")
+			if closeBracket == -1 {
+				panic("unmatched left [")
+			}
+			itemType = strings.TrimSpace(s[1:closeBracket])
+			s = strings.TrimSpace(s[closeBracket+1:])
+		} else {
+			itemType = "u1"
+		}
+
+		// Parsing data item value.
+		itemEnd := strings.IndexAny(s, "[ \t\n\r")
+		if itemEnd == -1 {
+			items = append(items, dataItem{itemType, strings.TrimSpace(s)})
+			s = ""
+		} else {
+			items = append(items, dataItem{itemType, strings.TrimSpace(s[:itemEnd])})
+			s = strings.TrimSpace(s[itemEnd:])
+		}
+	}
+	return items
+}
+
+// Parse parses a validation tests input string that has no comments.
+// Panics if input has errors.
+func (p *inputParser) Parse(s string) ([]byte, []system.Handle) {
+	var bytes []byte
+	var handles []system.Handle
+	var buf [8]byte
+	pointers := make(map[string]pointerPlaceholder)
+	for _, item := range p.parseToDataItems(s) {
+		switch item.Type {
+		case "u1":
+			var value uint8
+			fmt.Sscan(item.Value, &value)
+			bytes = append(bytes, byte(value))
+		case "u2":
+			var value uint16
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint16(buf[:2], value)
+			bytes = append(bytes, buf[:2]...)
+		case "u4":
+			var value uint32
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint32(buf[:4], value)
+			bytes = append(bytes, buf[:4]...)
+		case "u8":
+			var value uint64
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint64(buf[:8], value)
+			bytes = append(bytes, buf[:8]...)
+		case "s1":
+			var value int8
+			fmt.Sscan(item.Value, &value)
+			bytes = append(bytes, byte(value))
+		case "s2":
+			var value int16
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint16(buf[:2], uint16(value))
+			bytes = append(bytes, buf[:2]...)
+		case "s4":
+			var value int32
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint32(buf[:4], uint32(value))
+			bytes = append(bytes, buf[:4]...)
+		case "s8":
+			var value int64
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint64(buf[:8], uint64(value))
+			bytes = append(bytes, buf[:8]...)
+		case "b":
+			var value byte
+			for i := 0; i < 8; i++ {
+				value <<= 1
+				if item.Value[i] == '1' {
+					value++
+				}
+			}
+			bytes = append(bytes, value)
+		case "f":
+			var value float32
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint32(buf[:4], math.Float32bits(value))
+			bytes = append(bytes, buf[:4]...)
+		case "d":
+			var value float64
+			fmt.Sscan(item.Value, &value)
+			binary.LittleEndian.PutUint64(buf[:8], math.Float64bits(value))
+			bytes = append(bytes, buf[:8]...)
+		case "dist4":
+			pointers[item.Value] = pointerPlaceholder{len(bytes), 4}
+			bytes = append(bytes, buf[:4]...)
+		case "dist8":
+			pointers[item.Value] = pointerPlaceholder{len(bytes), 8}
+			bytes = append(bytes, buf[:8]...)
+		case "anchr":
+			placeholder := pointers[item.Value]
+			dist := len(bytes) - placeholder.Position
+			switch placeholder.Size {
+			case 4:
+				binary.LittleEndian.PutUint32(bytes[placeholder.Position:], uint32(dist))
+			case 8:
+				binary.LittleEndian.PutUint64(bytes[placeholder.Position:], uint64(dist))
+			}
+			delete(pointers, item.Value)
+		case "handles":
+			var value int
+			fmt.Sscan(item.Value, &value)
+			handles = make([]system.Handle, value)
+			for i, _ := range handles {
+				handles[i] = system.GetCore().AcquireNativeHandle(0)
+			}
+		default:
+			panic(fmt.Sprintf("unsupported item type: %v", item.Type))
+		}
+	}
+	if len(pointers) != 0 {
+		panic(fmt.Sprintf("unmatched pointers: %v", pointers))
+	}
+	return bytes, handles
+}