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Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/encoding/text/decode_string.go')
-rw-r--r--vendor/google.golang.org/protobuf/internal/encoding/text/decode_string.go161
1 files changed, 161 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/encoding/text/decode_string.go b/vendor/google.golang.org/protobuf/internal/encoding/text/decode_string.go
new file mode 100644
index 000000000..d4d349023
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/internal/encoding/text/decode_string.go
@@ -0,0 +1,161 @@
+// Copyright 2018 The Go 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 text
+
+import (
+ "bytes"
+ "strconv"
+ "strings"
+ "unicode"
+ "unicode/utf16"
+ "unicode/utf8"
+
+ "google.golang.org/protobuf/internal/strs"
+)
+
+// parseStringValue parses string field token.
+// This differs from parseString since the text format allows
+// multiple back-to-back string literals where they are semantically treated
+// as a single large string with all values concatenated.
+//
+// E.g., `"foo" "bar" "baz"` => "foobarbaz"
+func (d *Decoder) parseStringValue() (Token, error) {
+ // Note that the ending quote is sufficient to unambiguously mark the end
+ // of a string. Thus, the text grammar does not require intervening
+ // whitespace or control characters in-between strings.
+ // Thus, the following is valid:
+ // `"foo"'bar'"baz"` => "foobarbaz"
+ in0 := d.in
+ var ss []string
+ for len(d.in) > 0 && (d.in[0] == '"' || d.in[0] == '\'') {
+ s, err := d.parseString()
+ if err != nil {
+ return Token{}, err
+ }
+ ss = append(ss, s)
+ }
+ // d.in already points to the end of the value at this point.
+ return Token{
+ kind: Scalar,
+ attrs: stringValue,
+ pos: len(d.orig) - len(in0),
+ raw: in0[:len(in0)-len(d.in)],
+ str: strings.Join(ss, ""),
+ }, nil
+}
+
+// parseString parses a string value enclosed in " or '.
+func (d *Decoder) parseString() (string, error) {
+ in := d.in
+ if len(in) == 0 {
+ return "", ErrUnexpectedEOF
+ }
+ quote := in[0]
+ in = in[1:]
+ i := indexNeedEscapeInBytes(in)
+ in, out := in[i:], in[:i:i] // set cap to prevent mutations
+ for len(in) > 0 {
+ switch r, n := utf8.DecodeRune(in); {
+ case r == utf8.RuneError && n == 1:
+ return "", d.newSyntaxError("invalid UTF-8 detected")
+ case r == 0 || r == '\n':
+ return "", d.newSyntaxError("invalid character %q in string", r)
+ case r == rune(quote):
+ in = in[1:]
+ d.consume(len(d.in) - len(in))
+ return string(out), nil
+ case r == '\\':
+ if len(in) < 2 {
+ return "", ErrUnexpectedEOF
+ }
+ switch r := in[1]; r {
+ case '"', '\'', '\\', '?':
+ in, out = in[2:], append(out, r)
+ case 'a':
+ in, out = in[2:], append(out, '\a')
+ case 'b':
+ in, out = in[2:], append(out, '\b')
+ case 'n':
+ in, out = in[2:], append(out, '\n')
+ case 'r':
+ in, out = in[2:], append(out, '\r')
+ case 't':
+ in, out = in[2:], append(out, '\t')
+ case 'v':
+ in, out = in[2:], append(out, '\v')
+ case 'f':
+ in, out = in[2:], append(out, '\f')
+ case '0', '1', '2', '3', '4', '5', '6', '7':
+ // One, two, or three octal characters.
+ n := len(in[1:]) - len(bytes.TrimLeft(in[1:], "01234567"))
+ if n > 3 {
+ n = 3
+ }
+ v, err := strconv.ParseUint(string(in[1:1+n]), 8, 8)
+ if err != nil {
+ return "", d.newSyntaxError("invalid octal escape code %q in string", in[:1+n])
+ }
+ in, out = in[1+n:], append(out, byte(v))
+ case 'x':
+ // One or two hexadecimal characters.
+ n := len(in[2:]) - len(bytes.TrimLeft(in[2:], "0123456789abcdefABCDEF"))
+ if n > 2 {
+ n = 2
+ }
+ v, err := strconv.ParseUint(string(in[2:2+n]), 16, 8)
+ if err != nil {
+ return "", d.newSyntaxError("invalid hex escape code %q in string", in[:2+n])
+ }
+ in, out = in[2+n:], append(out, byte(v))
+ case 'u', 'U':
+ // Four or eight hexadecimal characters
+ n := 6
+ if r == 'U' {
+ n = 10
+ }
+ if len(in) < n {
+ return "", ErrUnexpectedEOF
+ }
+ v, err := strconv.ParseUint(string(in[2:n]), 16, 32)
+ if utf8.MaxRune < v || err != nil {
+ return "", d.newSyntaxError("invalid Unicode escape code %q in string", in[:n])
+ }
+ in = in[n:]
+
+ r := rune(v)
+ if utf16.IsSurrogate(r) {
+ if len(in) < 6 {
+ return "", ErrUnexpectedEOF
+ }
+ v, err := strconv.ParseUint(string(in[2:6]), 16, 16)
+ r = utf16.DecodeRune(r, rune(v))
+ if in[0] != '\\' || in[1] != 'u' || r == unicode.ReplacementChar || err != nil {
+ return "", d.newSyntaxError("invalid Unicode escape code %q in string", in[:6])
+ }
+ in = in[6:]
+ }
+ out = append(out, string(r)...)
+ default:
+ return "", d.newSyntaxError("invalid escape code %q in string", in[:2])
+ }
+ default:
+ i := indexNeedEscapeInBytes(in[n:])
+ in, out = in[n+i:], append(out, in[:n+i]...)
+ }
+ }
+ return "", ErrUnexpectedEOF
+}
+
+// indexNeedEscapeInString returns the index of the character that needs
+// escaping. If no characters need escaping, this returns the input length.
+func indexNeedEscapeInBytes(b []byte) int { return indexNeedEscapeInString(strs.UnsafeString(b)) }
+
+// UnmarshalString returns an unescaped string given a textproto string value.
+// String value needs to contain single or double quotes. This is only used by
+// internal/encoding/defval package for unmarshaling bytes.
+func UnmarshalString(s string) (string, error) {
+ d := NewDecoder([]byte(s))
+ return d.parseString()
+}