Add license notice for code adapted from Go

Fix https://github.com/prometheus/prometheus/issues/9884

Signed-off-by: Julius Volz <julius.volz@gmail.com>

NOTICE

@@ -91,6 +91,11 @@ https://github.com/dgryski/go-tsz
 Copyright (c) 2015,2016 Damian Gryski <damian@gryski.com>
 See https://github.com/dgryski/go-tsz/blob/master/LICENSE for license details.
 
+The Go programming language
+https://go.dev/
+Copyright (c) 2009 The Go Authors
+See https://go.dev/LICENSE for license details.
+
 The Codicon icon font from Microsoft
 https://github.com/microsoft/vscode-codicons
 Copyright (c) Microsoft Corporation and other contributors

util/strutil/quote.go

@@ -10,6 +10,45 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+//
+// NOTE: The functions in this file (Unquote, unquoteChar, contains, unhex)
+// have been adapted from the "strconv" package of the Go standard library
+// to work for Prometheus-style strings. Go's special-casing for single
+// quotes was removed and single quoted strings are now treated the same as
+// double-quoted ones.
+//
+// The original copyright notice from the Go project for these parts is
+// reproduced here:
+//
+// ========================================================================
+// Copyright (c) 2009 The Go Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// ========================================================================
 
 package strutil
 
@@ -24,13 +63,6 @@ var ErrSyntax = errors.New("invalid syntax")
 // Unquote interprets s as a single-quoted, double-quoted, or backquoted
 // Prometheus query language string literal, returning the string value that s
 // quotes.
-//
-// NOTE: This function as well as the necessary helper functions below
-// (unquoteChar, contains, unhex) and associated tests have been adapted from
-// the corresponding functions in the "strconv" package of the Go standard
-// library to work for Prometheus-style strings. Go's special-casing for single
-// quotes was removed and single quoted strings are now treated the same as
-// double quoted ones.
 func Unquote(s string) (t string, err error) {
 	n := len(s)
 	if n < 2 {

util/strutil/quote_test.go

@@ -10,6 +10,42 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+//
+// NOTE: The test code in this file has been adapted from the "strconv"
+// package of the Go standard library to work for Prometheus-style strings.
+//
+// The original copyright notice from the Go project for these parts is
+// reproduced here:
+//
+// ========================================================================
+// Copyright (c) 2009 The Go Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// ========================================================================
 
 package strutil