Rename scripts to build and add revive command as a new build tool command (#10942)

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

4 files changed, 1151 insertions, 0 deletions

diff --git a/vendor/golang.org/x/mod/LICENSE b/vendor/golang.org/x/mod/LICENSE
new file mode 100644
index 0000000000..6a66aea5ea
--- /dev/null
+++ b/vendor/golang.org/x/mod/LICENSE
@@ -0,0 +1,27 @@
+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.
diff --git a/vendor/golang.org/x/mod/PATENTS b/vendor/golang.org/x/mod/PATENTS
new file mode 100644
index 0000000000..733099041f
--- /dev/null
+++ b/vendor/golang.org/x/mod/PATENTS
@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.
diff --git a/vendor/golang.org/x/mod/module/module.go b/vendor/golang.org/x/mod/module/module.go
new file mode 100644
index 0000000000..21f123957d
--- /dev/null
+++ b/vendor/golang.org/x/mod/module/module.go
@@ -0,0 +1,714 @@
+// 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 module defines the module.Version type along with support code.
+//
+// The module.Version type is a simple Path, Version pair:
+//
+//	type Version struct {
+//		Path string
+//		Version string
+//	}
+//
+// There are no restrictions imposed directly by use of this structure,
+// but additional checking functions, most notably Check, verify that
+// a particular path, version pair is valid.
+//
+// Escaped Paths
+//
+// Module paths appear as substrings of file system paths
+// (in the download cache) and of web server URLs in the proxy protocol.
+// In general we cannot rely on file systems to be case-sensitive,
+// nor can we rely on web servers, since they read from file systems.
+// That is, we cannot rely on the file system to keep rsc.io/QUOTE
+// and rsc.io/quote separate. Windows and macOS don't.
+// Instead, we must never require two different casings of a file path.
+// Because we want the download cache to match the proxy protocol,
+// and because we want the proxy protocol to be possible to serve
+// from a tree of static files (which might be stored on a case-insensitive
+// file system), the proxy protocol must never require two different casings
+// of a URL path either.
+//
+// One possibility would be to make the escaped form be the lowercase
+// hexadecimal encoding of the actual path bytes. This would avoid ever
+// needing different casings of a file path, but it would be fairly illegible
+// to most programmers when those paths appeared in the file system
+// (including in file paths in compiler errors and stack traces)
+// in web server logs, and so on. Instead, we want a safe escaped form that
+// leaves most paths unaltered.
+//
+// The safe escaped form is to replace every uppercase letter
+// with an exclamation mark followed by the letter's lowercase equivalent.
+//
+// For example,
+//
+//	github.com/Azure/azure-sdk-for-go ->  github.com/!azure/azure-sdk-for-go.
+//	github.com/GoogleCloudPlatform/cloudsql-proxy -> github.com/!google!cloud!platform/cloudsql-proxy
+//	github.com/Sirupsen/logrus -> github.com/!sirupsen/logrus.
+//
+// Import paths that avoid upper-case letters are left unchanged.
+// Note that because import paths are ASCII-only and avoid various
+// problematic punctuation (like : < and >), the escaped form is also ASCII-only
+// and avoids the same problematic punctuation.
+//
+// Import paths have never allowed exclamation marks, so there is no
+// need to define how to escape a literal !.
+//
+// Unicode Restrictions
+//
+// Today, paths are disallowed from using Unicode.
+//
+// Although paths are currently disallowed from using Unicode,
+// we would like at some point to allow Unicode letters as well, to assume that
+// file systems and URLs are Unicode-safe (storing UTF-8), and apply
+// the !-for-uppercase convention for escaping them in the file system.
+// But there are at least two subtle considerations.
+//
+// First, note that not all case-fold equivalent distinct runes
+// form an upper/lower pair.
+// For example, U+004B ('K'), U+006B ('k'), and U+212A ('K' for Kelvin)
+// are three distinct runes that case-fold to each other.
+// When we do add Unicode letters, we must not assume that upper/lower
+// are the only case-equivalent pairs.
+// Perhaps the Kelvin symbol would be disallowed entirely, for example.
+// Or perhaps it would escape as "!!k", or perhaps as "(212A)".
+//
+// Second, it would be nice to allow Unicode marks as well as letters,
+// but marks include combining marks, and then we must deal not
+// only with case folding but also normalization: both U+00E9 ('é')
+// and U+0065 U+0301 ('e' followed by combining acute accent)
+// look the same on the page and are treated by some file systems
+// as the same path. If we do allow Unicode marks in paths, there
+// must be some kind of normalization to allow only one canonical
+// encoding of any character used in an import path.
+package module
+
+// IMPORTANT NOTE
+//
+// This file essentially defines the set of valid import paths for the go command.
+// There are many subtle considerations, including Unicode ambiguity,
+// security, network, and file system representations.
+//
+// This file also defines the set of valid module path and version combinations,
+// another topic with many subtle considerations.
+//
+// Changes to the semantics in this file require approval from rsc.
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/mod/semver"
+	errors "golang.org/x/xerrors"
+)
+
+// A Version (for clients, a module.Version) is defined by a module path and version pair.
+// These are stored in their plain (unescaped) form.
+type Version struct {
+	// Path is a module path, like "golang.org/x/text" or "rsc.io/quote/v2".
+	Path string
+
+	// Version is usually a semantic version in canonical form.
+	// There are three exceptions to this general rule.
+	// First, the top-level target of a build has no specific version
+	// and uses Version = "".
+	// Second, during MVS calculations the version "none" is used
+	// to represent the decision to take no version of a given module.
+	// Third, filesystem paths found in "replace" directives are
+	// represented by a path with an empty version.
+	Version string `json:",omitempty"`
+}
+
+// String returns the module version syntax Path@Version.
+func (m Version) String() string {
+	return m.Path + "@" + m.Version
+}
+
+// A ModuleError indicates an error specific to a module.
+type ModuleError struct {
+	Path    string
+	Version string
+	Err     error
+}
+
+// VersionError returns a ModuleError derived from a Version and error,
+// or err itself if it is already such an error.
+func VersionError(v Version, err error) error {
+	var mErr *ModuleError
+	if errors.As(err, &mErr) && mErr.Path == v.Path && mErr.Version == v.Version {
+		return err
+	}
+	return &ModuleError{
+		Path:    v.Path,
+		Version: v.Version,
+		Err:     err,
+	}
+}
+
+func (e *ModuleError) Error() string {
+	if v, ok := e.Err.(*InvalidVersionError); ok {
+		return fmt.Sprintf("%s@%s: invalid %s: %v", e.Path, v.Version, v.noun(), v.Err)
+	}
+	if e.Version != "" {
+		return fmt.Sprintf("%s@%s: %v", e.Path, e.Version, e.Err)
+	}
+	return fmt.Sprintf("module %s: %v", e.Path, e.Err)
+}
+
+func (e *ModuleError) Unwrap() error { return e.Err }
+
+// An InvalidVersionError indicates an error specific to a version, with the
+// module path unknown or specified externally.
+//
+// A ModuleError may wrap an InvalidVersionError, but an InvalidVersionError
+// must not wrap a ModuleError.
+type InvalidVersionError struct {
+	Version string
+	Pseudo  bool
+	Err     error
+}
+
+// noun returns either "version" or "pseudo-version", depending on whether
+// e.Version is a pseudo-version.
+func (e *InvalidVersionError) noun() string {
+	if e.Pseudo {
+		return "pseudo-version"
+	}
+	return "version"
+}
+
+func (e *InvalidVersionError) Error() string {
+	return fmt.Sprintf("%s %q invalid: %s", e.noun(), e.Version, e.Err)
+}
+
+func (e *InvalidVersionError) Unwrap() error { return e.Err }
+
+// Check checks that a given module path, version pair is valid.
+// In addition to the path being a valid module path
+// and the version being a valid semantic version,
+// the two must correspond.
+// For example, the path "yaml/v2" only corresponds to
+// semantic versions beginning with "v2.".
+func Check(path, version string) error {
+	if err := CheckPath(path); err != nil {
+		return err
+	}
+	if !semver.IsValid(version) {
+		return &ModuleError{
+			Path: path,
+			Err:  &InvalidVersionError{Version: version, Err: errors.New("not a semantic version")},
+		}
+	}
+	_, pathMajor, _ := SplitPathVersion(path)
+	if err := CheckPathMajor(version, pathMajor); err != nil {
+		return &ModuleError{Path: path, Err: err}
+	}
+	return nil
+}
+
+// firstPathOK reports whether r can appear in the first element of a module path.
+// The first element of the path must be an LDH domain name, at least for now.
+// To avoid case ambiguity, the domain name must be entirely lower case.
+func firstPathOK(r rune) bool {
+	return r == '-' || r == '.' ||
+		'0' <= r && r <= '9' ||
+		'a' <= r && r <= 'z'
+}
+
+// pathOK reports whether r can appear in an import path element.
+// Paths can be ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~.
+// This matches what "go get" has historically recognized in import paths.
+// TODO(rsc): We would like to allow Unicode letters, but that requires additional
+// care in the safe encoding (see "escaped paths" above).
+func pathOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		return r == '+' || r == '-' || r == '.' || r == '_' || r == '~' ||
+			'0' <= r && r <= '9' ||
+			'A' <= r && r <= 'Z' ||
+			'a' <= r && r <= 'z'
+	}
+	return false
+}
+
+// fileNameOK reports whether r can appear in a file name.
+// For now we allow all Unicode letters but otherwise limit to pathOK plus a few more punctuation characters.
+// If we expand the set of allowed characters here, we have to
+// work harder at detecting potential case-folding and normalization collisions.
+// See note about "escaped paths" above.
+func fileNameOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		// Entire set of ASCII punctuation, from which we remove characters:
+		//     ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+		// We disallow some shell special characters: " ' * < > ? ` |
+		// (Note that some of those are disallowed by the Windows file system as well.)
+		// We also disallow path separators / : and \ (fileNameOK is only called on path element characters).
+		// We allow spaces (U+0020) in file names.
+		const allowed = "!#$%&()+,-.=@[]^_{}~ "
+		if '0' <= r && r <= '9' || 'A' <= r && r <= 'Z' || 'a' <= r && r <= 'z' {
+			return true
+		}
+		for i := 0; i < len(allowed); i++ {
+			if rune(allowed[i]) == r {
+				return true
+			}
+		}
+		return false
+	}
+	// It may be OK to add more ASCII punctuation here, but only carefully.
+	// For example Windows disallows < > \, and macOS disallows :, so we must not allow those.
+	return unicode.IsLetter(r)
+}
+
+// CheckPath checks that a module path is valid.
+// A valid module path is a valid import path, as checked by CheckImportPath,
+// with two additional constraints.
+// First, the leading path element (up to the first slash, if any),
+// by convention a domain name, must contain only lower-case ASCII letters,
+// ASCII digits, dots (U+002E), and dashes (U+002D);
+// it must contain at least one dot and cannot start with a dash.
+// Second, for a final path element of the form /vN, where N looks numeric
+// (ASCII digits and dots) must not begin with a leading zero, must not be /v1,
+// and must not contain any dots. For paths beginning with "gopkg.in/",
+// this second requirement is replaced by a requirement that the path
+// follow the gopkg.in server's conventions.
+func CheckPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed module path %q: %v", path, err)
+	}
+	i := strings.Index(path, "/")
+	if i < 0 {
+		i = len(path)
+	}
+	if i == 0 {
+		return fmt.Errorf("malformed module path %q: leading slash", path)
+	}
+	if !strings.Contains(path[:i], ".") {
+		return fmt.Errorf("malformed module path %q: missing dot in first path element", path)
+	}
+	if path[0] == '-' {
+		return fmt.Errorf("malformed module path %q: leading dash in first path element", path)
+	}
+	for _, r := range path[:i] {
+		if !firstPathOK(r) {
+			return fmt.Errorf("malformed module path %q: invalid char %q in first path element", path, r)
+		}
+	}
+	if _, _, ok := SplitPathVersion(path); !ok {
+		return fmt.Errorf("malformed module path %q: invalid version", path)
+	}
+	return nil
+}
+
+// CheckImportPath checks that an import path is valid.
+//
+// A valid import path consists of one or more valid path elements
+// separated by slashes (U+002F). (It must not begin with nor end in a slash.)
+//
+// A valid path element is a non-empty string made up of
+// ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~.
+// It must not begin or end with a dot (U+002E), nor contain two dots in a row.
+//
+// The element prefix up to the first dot must not be a reserved file name
+// on Windows, regardless of case (CON, com1, NuL, and so on).
+//
+// CheckImportPath may be less restrictive in the future, but see the
+// top-level package documentation for additional information about
+// subtleties of Unicode.
+func CheckImportPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed import path %q: %v", path, err)
+	}
+	return nil
+}
+
+// checkPath checks that a general path is valid.
+// It returns an error describing why but not mentioning path.
+// Because these checks apply to both module paths and import paths,
+// the caller is expected to add the "malformed ___ path %q: " prefix.
+// fileName indicates whether the final element of the path is a file name
+// (as opposed to a directory name).
+func checkPath(path string, fileName bool) error {
+	if !utf8.ValidString(path) {
+		return fmt.Errorf("invalid UTF-8")
+	}
+	if path == "" {
+		return fmt.Errorf("empty string")
+	}
+	if path[0] == '-' {
+		return fmt.Errorf("leading dash")
+	}
+	if strings.Contains(path, "//") {
+		return fmt.Errorf("double slash")
+	}
+	if path[len(path)-1] == '/' {
+		return fmt.Errorf("trailing slash")
+	}
+	elemStart := 0
+	for i, r := range path {
+		if r == '/' {
+			if err := checkElem(path[elemStart:i], fileName); err != nil {
+				return err
+			}
+			elemStart = i + 1
+		}
+	}
+	if err := checkElem(path[elemStart:], fileName); err != nil {
+		return err
+	}
+	return nil
+}
+
+// checkElem checks whether an individual path element is valid.
+// fileName indicates whether the element is a file name (not a directory name).
+func checkElem(elem string, fileName bool) error {
+	if elem == "" {
+		return fmt.Errorf("empty path element")
+	}
+	if strings.Count(elem, ".") == len(elem) {
+		return fmt.Errorf("invalid path element %q", elem)
+	}
+	if elem[0] == '.' && !fileName {
+		return fmt.Errorf("leading dot in path element")
+	}
+	if elem[len(elem)-1] == '.' {
+		return fmt.Errorf("trailing dot in path element")
+	}
+	charOK := pathOK
+	if fileName {
+		charOK = fileNameOK
+	}
+	for _, r := range elem {
+		if !charOK(r) {
+			return fmt.Errorf("invalid char %q", r)
+		}
+	}
+
+	// Windows disallows a bunch of path elements, sadly.
+	// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+	short := elem
+	if i := strings.Index(short, "."); i >= 0 {
+		short = short[:i]
+	}
+	for _, bad := range badWindowsNames {
+		if strings.EqualFold(bad, short) {
+			return fmt.Errorf("%q disallowed as path element component on Windows", short)
+		}
+	}
+	return nil
+}
+
+// CheckFilePath checks that a slash-separated file path is valid.
+// The definition of a valid file path is the same as the definition
+// of a valid import path except that the set of allowed characters is larger:
+// all Unicode letters, ASCII digits, the ASCII space character (U+0020),
+// and the ASCII punctuation characters
+// “!#$%&()+,-.=@[]^_{}~”.
+// (The excluded punctuation characters, " * < > ? ` ' | / \ and :,
+// have special meanings in certain shells or operating systems.)
+//
+// CheckFilePath may be less restrictive in the future, but see the
+// top-level package documentation for additional information about
+// subtleties of Unicode.
+func CheckFilePath(path string) error {
+	if err := checkPath(path, true); err != nil {
+		return fmt.Errorf("malformed file path %q: %v", path, err)
+	}
+	return nil
+}
+
+// badWindowsNames are the reserved file path elements on Windows.
+// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+var badWindowsNames = []string{
+	"CON",
+	"PRN",
+	"AUX",
+	"NUL",
+	"COM1",
+	"COM2",
+	"COM3",
+	"COM4",
+	"COM5",
+	"COM6",
+	"COM7",
+	"COM8",
+	"COM9",
+	"LPT1",
+	"LPT2",
+	"LPT3",
+	"LPT4",
+	"LPT5",
+	"LPT6",
+	"LPT7",
+	"LPT8",
+	"LPT9",
+}
+
+// SplitPathVersion returns prefix and major version such that prefix+pathMajor == path
+// and version is either empty or "/vN" for N >= 2.
+// As a special case, gopkg.in paths are recognized directly;
+// they require ".vN" instead of "/vN", and for all N, not just N >= 2.
+// SplitPathVersion returns with ok = false when presented with
+// a path whose last path element does not satisfy the constraints
+// applied by CheckPath, such as "example.com/pkg/v1" or "example.com/pkg/v1.2".
+func SplitPathVersion(path string) (prefix, pathMajor string, ok bool) {
+	if strings.HasPrefix(path, "gopkg.in/") {
+		return splitGopkgIn(path)
+	}
+
+	i := len(path)
+	dot := false
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9' || path[i-1] == '.') {
+		if path[i-1] == '.' {
+			dot = true
+		}
+		i--
+	}
+	if i <= 1 || i == len(path) || path[i-1] != 'v' || path[i-2] != '/' {
+		return path, "", true
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if dot || len(pathMajor) <= 2 || pathMajor[2] == '0' || pathMajor == "/v1" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// splitGopkgIn is like SplitPathVersion but only for gopkg.in paths.
+func splitGopkgIn(path string) (prefix, pathMajor string, ok bool) {
+	if !strings.HasPrefix(path, "gopkg.in/") {
+		return path, "", false
+	}
+	i := len(path)
+	if strings.HasSuffix(path, "-unstable") {
+		i -= len("-unstable")
+	}
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9') {
+		i--
+	}
+	if i <= 1 || path[i-1] != 'v' || path[i-2] != '.' {
+		// All gopkg.in paths must end in vN for some N.
+		return path, "", false
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if len(pathMajor) <= 2 || pathMajor[2] == '0' && pathMajor != ".v0" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// MatchPathMajor reports whether the semantic version v
+// matches the path major version pathMajor.
+//
+// MatchPathMajor returns true if and only if CheckPathMajor returns nil.
+func MatchPathMajor(v, pathMajor string) bool {
+	return CheckPathMajor(v, pathMajor) == nil
+}
+
+// CheckPathMajor returns a non-nil error if the semantic version v
+// does not match the path major version pathMajor.
+func CheckPathMajor(v, pathMajor string) error {
+	// TODO(jayconrod): return errors or panic for invalid inputs. This function
+	// (and others) was covered by integration tests for cmd/go, and surrounding
+	// code protected against invalid inputs like non-canonical versions.
+	if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") {
+		pathMajor = strings.TrimSuffix(pathMajor, "-unstable")
+	}
+	if strings.HasPrefix(v, "v0.0.0-") && pathMajor == ".v1" {
+		// Allow old bug in pseudo-versions that generated v0.0.0- pseudoversion for gopkg .v1.
+		// For example, gopkg.in/yaml.v2@v2.2.1's go.mod requires gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405.
+		return nil
+	}
+	m := semver.Major(v)
+	if pathMajor == "" {
+		if m == "v0" || m == "v1" || semver.Build(v) == "+incompatible" {
+			return nil
+		}
+		pathMajor = "v0 or v1"
+	} else if pathMajor[0] == '/' || pathMajor[0] == '.' {
+		if m == pathMajor[1:] {
+			return nil
+		}
+		pathMajor = pathMajor[1:]
+	}
+	return &InvalidVersionError{
+		Version: v,
+		Err:     fmt.Errorf("should be %s, not %s", pathMajor, semver.Major(v)),
+	}
+}
+
+// PathMajorPrefix returns the major-version tag prefix implied by pathMajor.
+// An empty PathMajorPrefix allows either v0 or v1.
+//
+// Note that MatchPathMajor may accept some versions that do not actually begin
+// with this prefix: namely, it accepts a 'v0.0.0-' prefix for a '.v1'
+// pathMajor, even though that pathMajor implies 'v1' tagging.
+func PathMajorPrefix(pathMajor string) string {
+	if pathMajor == "" {
+		return ""
+	}
+	if pathMajor[0] != '/' && pathMajor[0] != '.' {
+		panic("pathMajor suffix " + pathMajor + " passed to PathMajorPrefix lacks separator")
+	}
+	if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") {
+		pathMajor = strings.TrimSuffix(pathMajor, "-unstable")
+	}
+	m := pathMajor[1:]
+	if m != semver.Major(m) {
+		panic("pathMajor suffix " + pathMajor + "passed to PathMajorPrefix is not a valid major version")
+	}
+	return m
+}
+
+// CanonicalVersion returns the canonical form of the version string v.
+// It is the same as semver.Canonical(v) except that it preserves the special build suffix "+incompatible".
+func CanonicalVersion(v string) string {
+	cv := semver.Canonical(v)
+	if semver.Build(v) == "+incompatible" {
+		cv += "+incompatible"
+	}
+	return cv
+}
+
+// Sort sorts the list by Path, breaking ties by comparing Version fields.
+// The Version fields are interpreted as semantic versions (using semver.Compare)
+// optionally followed by a tie-breaking suffix introduced by a slash character,
+// like in "v0.0.1/go.mod".
+func Sort(list []Version) {
+	sort.Slice(list, func(i, j int) bool {
+		mi := list[i]
+		mj := list[j]
+		if mi.Path != mj.Path {
+			return mi.Path < mj.Path
+		}
+		// To help go.sum formatting, allow version/file.
+		// Compare semver prefix by semver rules,
+		// file by string order.
+		vi := mi.Version
+		vj := mj.Version
+		var fi, fj string
+		if k := strings.Index(vi, "/"); k >= 0 {
+			vi, fi = vi[:k], vi[k:]
+		}
+		if k := strings.Index(vj, "/"); k >= 0 {
+			vj, fj = vj[:k], vj[k:]
+		}
+		if vi != vj {
+			return semver.Compare(vi, vj) < 0
+		}
+		return fi < fj
+	})
+}
+
+// EscapePath returns the escaped form of the given module path.
+// It fails if the module path is invalid.
+func EscapePath(path string) (escaped string, err error) {
+	if err := CheckPath(path); err != nil {
+		return "", err
+	}
+
+	return escapeString(path)
+}
+
+// EscapeVersion returns the escaped form of the given module version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func EscapeVersion(v string) (escaped string, err error) {
+	if err := checkElem(v, true); err != nil || strings.Contains(v, "!") {
+		return "", &InvalidVersionError{
+			Version: v,
+			Err:     fmt.Errorf("disallowed version string"),
+		}
+	}
+	return escapeString(v)
+}
+
+func escapeString(s string) (escaped string, err error) {
+	haveUpper := false
+	for _, r := range s {
+		if r == '!' || r >= utf8.RuneSelf {
+			// This should be disallowed by CheckPath, but diagnose anyway.
+			// The correctness of the escaping loop below depends on it.
+			return "", fmt.Errorf("internal error: inconsistency in EscapePath")
+		}
+		if 'A' <= r && r <= 'Z' {
+			haveUpper = true
+		}
+	}
+
+	if !haveUpper {
+		return s, nil
+	}
+
+	var buf []byte
+	for _, r := range s {
+		if 'A' <= r && r <= 'Z' {
+			buf = append(buf, '!', byte(r+'a'-'A'))
+		} else {
+			buf = append(buf, byte(r))
+		}
+	}
+	return string(buf), nil
+}
+
+// UnescapePath returns the module path for the given escaped path.
+// It fails if the escaped path is invalid or describes an invalid path.
+func UnescapePath(escaped string) (path string, err error) {
+	path, ok := unescapeString(escaped)
+	if !ok {
+		return "", fmt.Errorf("invalid escaped module path %q", escaped)
+	}
+	if err := CheckPath(path); err != nil {
+		return "", fmt.Errorf("invalid escaped module path %q: %v", escaped, err)
+	}
+	return path, nil
+}
+
+// UnescapeVersion returns the version string for the given escaped version.
+// It fails if the escaped form is invalid or describes an invalid version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func UnescapeVersion(escaped string) (v string, err error) {
+	v, ok := unescapeString(escaped)
+	if !ok {
+		return "", fmt.Errorf("invalid escaped version %q", escaped)
+	}
+	if err := checkElem(v, true); err != nil {
+		return "", fmt.Errorf("invalid escaped version %q: %v", v, err)
+	}
+	return v, nil
+}
+
+func unescapeString(escaped string) (string, bool) {
+	var buf []byte
+
+	bang := false
+	for _, r := range escaped {
+		if r >= utf8.RuneSelf {
+			return "", false
+		}
+		if bang {
+			bang = false
+			if r < 'a' || 'z' < r {
+				return "", false
+			}
+			buf = append(buf, byte(r+'A'-'a'))
+			continue
+		}
+		if r == '!' {
+			bang = true
+			continue
+		}
+		if 'A' <= r && r <= 'Z' {
+			return "", false
+		}
+		buf = append(buf, byte(r))
+	}
+	if bang {
+		return "", false
+	}
+	return string(buf), true
+}
diff --git a/vendor/golang.org/x/mod/semver/semver.go b/vendor/golang.org/x/mod/semver/semver.go
new file mode 100644
index 0000000000..2988e3cf9c
--- /dev/null
+++ b/vendor/golang.org/x/mod/semver/semver.go
@@ -0,0 +1,388 @@
+// 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 semver implements comparison of semantic version strings.
+// In this package, semantic version strings must begin with a leading "v",
+// as in "v1.0.0".
+//
+// The general form of a semantic version string accepted by this package is
+//
+//	vMAJOR[.MINOR[.PATCH[-PRERELEASE][+BUILD]]]
+//
+// where square brackets indicate optional parts of the syntax;
+// MAJOR, MINOR, and PATCH are decimal integers without extra leading zeros;
+// PRERELEASE and BUILD are each a series of non-empty dot-separated identifiers
+// using only alphanumeric characters and hyphens; and
+// all-numeric PRERELEASE identifiers must not have leading zeros.
+//
+// This package follows Semantic Versioning 2.0.0 (see semver.org)
+// with two exceptions. First, it requires the "v" prefix. Second, it recognizes
+// vMAJOR and vMAJOR.MINOR (with no prerelease or build suffixes)
+// as shorthands for vMAJOR.0.0 and vMAJOR.MINOR.0.
+package semver
+
+// parsed returns the parsed form of a semantic version string.
+type parsed struct {
+	major      string
+	minor      string
+	patch      string
+	short      string
+	prerelease string
+	build      string
+	err        string
+}
+
+// IsValid reports whether v is a valid semantic version string.
+func IsValid(v string) bool {
+	_, ok := parse(v)
+	return ok
+}
+
+// Canonical returns the canonical formatting of the semantic version v.
+// It fills in any missing .MINOR or .PATCH and discards build metadata.
+// Two semantic versions compare equal only if their canonical formattings
+// are identical strings.
+// The canonical invalid semantic version is the empty string.
+func Canonical(v string) string {
+	p, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	if p.build != "" {
+		return v[:len(v)-len(p.build)]
+	}
+	if p.short != "" {
+		return v + p.short
+	}
+	return v
+}
+
+// Major returns the major version prefix of the semantic version v.
+// For example, Major("v2.1.0") == "v2".
+// If v is an invalid semantic version string, Major returns the empty string.
+func Major(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return v[:1+len(pv.major)]
+}
+
+// MajorMinor returns the major.minor version prefix of the semantic version v.
+// For example, MajorMinor("v2.1.0") == "v2.1".
+// If v is an invalid semantic version string, MajorMinor returns the empty string.
+func MajorMinor(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	i := 1 + len(pv.major)
+	if j := i + 1 + len(pv.minor); j <= len(v) && v[i] == '.' && v[i+1:j] == pv.minor {
+		return v[:j]
+	}
+	return v[:i] + "." + pv.minor
+}
+
+// Prerelease returns the prerelease suffix of the semantic version v.
+// For example, Prerelease("v2.1.0-pre+meta") == "-pre".
+// If v is an invalid semantic version string, Prerelease returns the empty string.
+func Prerelease(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return pv.prerelease
+}
+
+// Build returns the build suffix of the semantic version v.
+// For example, Build("v2.1.0+meta") == "+meta".
+// If v is an invalid semantic version string, Build returns the empty string.
+func Build(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return pv.build
+}
+
+// Compare returns an integer comparing two versions according to
+// semantic version precedence.
+// The result will be 0 if v == w, -1 if v < w, or +1 if v > w.
+//
+// An invalid semantic version string is considered less than a valid one.
+// All invalid semantic version strings compare equal to each other.
+func Compare(v, w string) int {
+	pv, ok1 := parse(v)
+	pw, ok2 := parse(w)
+	if !ok1 && !ok2 {
+		return 0
+	}
+	if !ok1 {
+		return -1
+	}
+	if !ok2 {
+		return +1
+	}
+	if c := compareInt(pv.major, pw.major); c != 0 {
+		return c
+	}
+	if c := compareInt(pv.minor, pw.minor); c != 0 {
+		return c
+	}
+	if c := compareInt(pv.patch, pw.patch); c != 0 {
+		return c
+	}
+	return comparePrerelease(pv.prerelease, pw.prerelease)
+}
+
+// Max canonicalizes its arguments and then returns the version string
+// that compares greater.
+func Max(v, w string) string {
+	v = Canonical(v)
+	w = Canonical(w)
+	if Compare(v, w) > 0 {
+		return v
+	}
+	return w
+}
+
+func parse(v string) (p parsed, ok bool) {
+	if v == "" || v[0] != 'v' {
+		p.err = "missing v prefix"
+		return
+	}
+	p.major, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad major version"
+		return
+	}
+	if v == "" {
+		p.minor = "0"
+		p.patch = "0"
+		p.short = ".0.0"
+		return
+	}
+	if v[0] != '.' {
+		p.err = "bad minor prefix"
+		ok = false
+		return
+	}
+	p.minor, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad minor version"
+		return
+	}
+	if v == "" {
+		p.patch = "0"
+		p.short = ".0"
+		return
+	}
+	if v[0] != '.' {
+		p.err = "bad patch prefix"
+		ok = false
+		return
+	}
+	p.patch, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad patch version"
+		return
+	}
+	if len(v) > 0 && v[0] == '-' {
+		p.prerelease, v, ok = parsePrerelease(v)
+		if !ok {
+			p.err = "bad prerelease"
+			return
+		}
+	}
+	if len(v) > 0 && v[0] == '+' {
+		p.build, v, ok = parseBuild(v)
+		if !ok {
+			p.err = "bad build"
+			return
+		}
+	}
+	if v != "" {
+		p.err = "junk on end"
+		ok = false
+		return
+	}
+	ok = true
+	return
+}
+
+func parseInt(v string) (t, rest string, ok bool) {
+	if v == "" {
+		return
+	}
+	if v[0] < '0' || '9' < v[0] {
+		return
+	}
+	i := 1
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	if v[0] == '0' && i != 1 {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func parsePrerelease(v string) (t, rest string, ok bool) {
+	// "A pre-release version MAY be denoted by appending a hyphen and
+	// a series of dot separated identifiers immediately following the patch version.
+	// Identifiers MUST comprise only ASCII alphanumerics and hyphen [0-9A-Za-z-].
+	// Identifiers MUST NOT be empty. Numeric identifiers MUST NOT include leading zeroes."
+	if v == "" || v[0] != '-' {
+		return
+	}
+	i := 1
+	start := 1
+	for i < len(v) && v[i] != '+' {
+		if !isIdentChar(v[i]) && v[i] != '.' {
+			return
+		}
+		if v[i] == '.' {
+			if start == i || isBadNum(v[start:i]) {
+				return
+			}
+			start = i + 1
+		}
+		i++
+	}
+	if start == i || isBadNum(v[start:i]) {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func parseBuild(v string) (t, rest string, ok bool) {
+	if v == "" || v[0] != '+' {
+		return
+	}
+	i := 1
+	start := 1
+	for i < len(v) {
+		if !isIdentChar(v[i]) && v[i] != '.' {
+			return
+		}
+		if v[i] == '.' {
+			if start == i {
+				return
+			}
+			start = i + 1
+		}
+		i++
+	}
+	if start == i {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func isIdentChar(c byte) bool {
+	return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '-'
+}
+
+func isBadNum(v string) bool {
+	i := 0
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	return i == len(v) && i > 1 && v[0] == '0'
+}
+
+func isNum(v string) bool {
+	i := 0
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	return i == len(v)
+}
+
+func compareInt(x, y string) int {
+	if x == y {
+		return 0
+	}
+	if len(x) < len(y) {
+		return -1
+	}
+	if len(x) > len(y) {
+		return +1
+	}
+	if x < y {
+		return -1
+	} else {
+		return +1
+	}
+}
+
+func comparePrerelease(x, y string) int {
+	// "When major, minor, and patch are equal, a pre-release version has
+	// lower precedence than a normal version.
+	// Example: 1.0.0-alpha < 1.0.0.
+	// Precedence for two pre-release versions with the same major, minor,
+	// and patch version MUST be determined by comparing each dot separated
+	// identifier from left to right until a difference is found as follows:
+	// identifiers consisting of only digits are compared numerically and
+	// identifiers with letters or hyphens are compared lexically in ASCII
+	// sort order. Numeric identifiers always have lower precedence than
+	// non-numeric identifiers. A larger set of pre-release fields has a
+	// higher precedence than a smaller set, if all of the preceding
+	// identifiers are equal.
+	// Example: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta <
+	// 1.0.0-beta < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0."
+	if x == y {
+		return 0
+	}
+	if x == "" {
+		return +1
+	}
+	if y == "" {
+		return -1
+	}
+	for x != "" && y != "" {
+		x = x[1:] // skip - or .
+		y = y[1:] // skip - or .
+		var dx, dy string
+		dx, x = nextIdent(x)
+		dy, y = nextIdent(y)
+		if dx != dy {
+			ix := isNum(dx)
+			iy := isNum(dy)
+			if ix != iy {
+				if ix {
+					return -1
+				} else {
+					return +1
+				}
+			}
+			if ix {
+				if len(dx) < len(dy) {
+					return -1
+				}
+				if len(dx) > len(dy) {
+					return +1
+				}
+			}
+			if dx < dy {
+				return -1
+			} else {
+				return +1
+			}
+		}
+	}
+	if x == "" {
+		return -1
+	} else {
+		return +1
+	}
+}
+
+func nextIdent(x string) (dx, rest string) {
+	i := 0
+	for i < len(x) && x[i] != '.' {
+		i++
+	}
+	return x[:i], x[i:]
+}