Update vendors

vendor/github.com/derekparker/delve/pkg/dwarf/util/util.go

@@ -0,0 +1,126 @@
+package util
+
+import (
+	"bytes"
+	"io"
+)
+
+// The Little Endian Base 128 format is defined in the DWARF v4 standard,
+// section 7.6, page 161 and following.
+
+// DecodeULEB128 decodes an unsigned Little Endian Base 128
+// represented number.
+func DecodeULEB128(buf *bytes.Buffer) (uint64, uint32) {
+	var (
+		result uint64
+		shift  uint64
+		length uint32
+	)
+
+	if buf.Len() == 0 {
+		return 0, 0
+	}
+
+	for {
+		b, err := buf.ReadByte()
+		if err != nil {
+			panic("Could not parse ULEB128 value")
+		}
+		length++
+
+		result |= uint64((uint(b) & 0x7f) << shift)
+
+		// If high order bit is 1.
+		if b&0x80 == 0 {
+			break
+		}
+
+		shift += 7
+	}
+
+	return result, length
+}
+
+// DecodeSLEB128 decodes a signed Little Endian Base 128
+// represented number.
+func DecodeSLEB128(buf *bytes.Buffer) (int64, uint32) {
+	var (
+		b      byte
+		err    error
+		result int64
+		shift  uint64
+		length uint32
+	)
+
+	if buf.Len() == 0 {
+		return 0, 0
+	}
+
+	for {
+		b, err = buf.ReadByte()
+		if err != nil {
+			panic("Could not parse SLEB128 value")
+		}
+		length++
+
+		result |= int64((int64(b) & 0x7f) << shift)
+		shift += 7
+		if b&0x80 == 0 {
+			break
+		}
+	}
+
+	if (shift < 8*uint64(length)) && (b&0x40 > 0) {
+		result |= -(1 << shift)
+	}
+
+	return result, length
+}
+
+// EncodeULEB128 encodes x to the unsigned Little Endian Base 128 format
+// into out.
+func EncodeULEB128(out io.ByteWriter, x uint64) {
+	for {
+		b := byte(x & 0x7f)
+		x = x >> 7
+		if x != 0 {
+			b = b | 0x80
+		}
+		out.WriteByte(b)
+		if x == 0 {
+			break
+		}
+	}
+}
+
+// EncodeSLEB128 encodes x to the signed Little Endian Base 128 format
+// into out.
+func EncodeSLEB128(out io.ByteWriter, x int64) {
+	for {
+		b := byte(x & 0x7f)
+		x >>= 7
+
+		signb := b & 0x40
+
+		last := false
+		if (x == 0 && signb == 0) || (x == -1 && signb != 0) {
+			last = true
+		} else {
+			b = b | 0x80
+		}
+		out.WriteByte(b)
+
+		if last {
+			break
+		}
+	}
+}
+
+func ParseString(data *bytes.Buffer) (string, uint32) {
+	str, err := data.ReadString(0x0)
+	if err != nil {
+		panic("Could not parse string")
+	}
+
+	return str[:len(str)-1], uint32(len(str))
+}