vendor test dependencies instead of installing via network

We can vendor the test dependencies such as go-md2man, git-validation
and goimports. This allows us to always install the same version as
specified in go.mod. Also we do not rely on a network connection for
this.

The advantage with this method is that dependabot will also update the
dependencies for us and we do not have to hardcode versions in the
Makefile.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

7 files changed, 459 insertions, 0 deletions

diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk.go
new file mode 100644
index 000000000..9887f7e7a
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk.go
@@ -0,0 +1,196 @@
+// Copyright 2016 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 fastwalk provides a faster version of filepath.Walk for file system
+// scanning tools.
+package fastwalk
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"runtime"
+	"sync"
+)
+
+// ErrTraverseLink is used as a return value from WalkFuncs to indicate that the
+// symlink named in the call may be traversed.
+var ErrTraverseLink = errors.New("fastwalk: traverse symlink, assuming target is a directory")
+
+// ErrSkipFiles is a used as a return value from WalkFuncs to indicate that the
+// callback should not be called for any other files in the current directory.
+// Child directories will still be traversed.
+var ErrSkipFiles = errors.New("fastwalk: skip remaining files in directory")
+
+// Walk is a faster implementation of filepath.Walk.
+//
+// filepath.Walk's design necessarily calls os.Lstat on each file,
+// even if the caller needs less info.
+// Many tools need only the type of each file.
+// On some platforms, this information is provided directly by the readdir
+// system call, avoiding the need to stat each file individually.
+// fastwalk_unix.go contains a fork of the syscall routines.
+//
+// See golang.org/issue/16399
+//
+// Walk walks the file tree rooted at root, calling walkFn for
+// each file or directory in the tree, including root.
+//
+// If fastWalk returns filepath.SkipDir, the directory is skipped.
+//
+// Unlike filepath.Walk:
+//   * file stat calls must be done by the user.
+//     The only provided metadata is the file type, which does not include
+//     any permission bits.
+//   * multiple goroutines stat the filesystem concurrently. The provided
+//     walkFn must be safe for concurrent use.
+//   * fastWalk can follow symlinks if walkFn returns the TraverseLink
+//     sentinel error. It is the walkFn's responsibility to prevent
+//     fastWalk from going into symlink cycles.
+func Walk(root string, walkFn func(path string, typ os.FileMode) error) error {
+	// TODO(bradfitz): make numWorkers configurable? We used a
+	// minimum of 4 to give the kernel more info about multiple
+	// things we want, in hopes its I/O scheduling can take
+	// advantage of that. Hopefully most are in cache. Maybe 4 is
+	// even too low of a minimum. Profile more.
+	numWorkers := 4
+	if n := runtime.NumCPU(); n > numWorkers {
+		numWorkers = n
+	}
+
+	// Make sure to wait for all workers to finish, otherwise
+	// walkFn could still be called after returning. This Wait call
+	// runs after close(e.donec) below.
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	w := &walker{
+		fn:       walkFn,
+		enqueuec: make(chan walkItem, numWorkers), // buffered for performance
+		workc:    make(chan walkItem, numWorkers), // buffered for performance
+		donec:    make(chan struct{}),
+
+		// buffered for correctness & not leaking goroutines:
+		resc: make(chan error, numWorkers),
+	}
+	defer close(w.donec)
+
+	for i := 0; i < numWorkers; i++ {
+		wg.Add(1)
+		go w.doWork(&wg)
+	}
+	todo := []walkItem{{dir: root}}
+	out := 0
+	for {
+		workc := w.workc
+		var workItem walkItem
+		if len(todo) == 0 {
+			workc = nil
+		} else {
+			workItem = todo[len(todo)-1]
+		}
+		select {
+		case workc <- workItem:
+			todo = todo[:len(todo)-1]
+			out++
+		case it := <-w.enqueuec:
+			todo = append(todo, it)
+		case err := <-w.resc:
+			out--
+			if err != nil {
+				return err
+			}
+			if out == 0 && len(todo) == 0 {
+				// It's safe to quit here, as long as the buffered
+				// enqueue channel isn't also readable, which might
+				// happen if the worker sends both another unit of
+				// work and its result before the other select was
+				// scheduled and both w.resc and w.enqueuec were
+				// readable.
+				select {
+				case it := <-w.enqueuec:
+					todo = append(todo, it)
+				default:
+					return nil
+				}
+			}
+		}
+	}
+}
+
+// doWork reads directories as instructed (via workc) and runs the
+// user's callback function.
+func (w *walker) doWork(wg *sync.WaitGroup) {
+	defer wg.Done()
+	for {
+		select {
+		case <-w.donec:
+			return
+		case it := <-w.workc:
+			select {
+			case <-w.donec:
+				return
+			case w.resc <- w.walk(it.dir, !it.callbackDone):
+			}
+		}
+	}
+}
+
+type walker struct {
+	fn func(path string, typ os.FileMode) error
+
+	donec    chan struct{} // closed on fastWalk's return
+	workc    chan walkItem // to workers
+	enqueuec chan walkItem // from workers
+	resc     chan error    // from workers
+}
+
+type walkItem struct {
+	dir          string
+	callbackDone bool // callback already called; don't do it again
+}
+
+func (w *walker) enqueue(it walkItem) {
+	select {
+	case w.enqueuec <- it:
+	case <-w.donec:
+	}
+}
+
+func (w *walker) onDirEnt(dirName, baseName string, typ os.FileMode) error {
+	joined := dirName + string(os.PathSeparator) + baseName
+	if typ == os.ModeDir {
+		w.enqueue(walkItem{dir: joined})
+		return nil
+	}
+
+	err := w.fn(joined, typ)
+	if typ == os.ModeSymlink {
+		if err == ErrTraverseLink {
+			// Set callbackDone so we don't call it twice for both the
+			// symlink-as-symlink and the symlink-as-directory later:
+			w.enqueue(walkItem{dir: joined, callbackDone: true})
+			return nil
+		}
+		if err == filepath.SkipDir {
+			// Permit SkipDir on symlinks too.
+			return nil
+		}
+	}
+	return err
+}
+
+func (w *walker) walk(root string, runUserCallback bool) error {
+	if runUserCallback {
+		err := w.fn(root, os.ModeDir)
+		if err == filepath.SkipDir {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+	}
+
+	return readDir(root, w.onDirEnt)
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_fileno.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_fileno.go
new file mode 100644
index 000000000..d58595dbd
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_fileno.go
@@ -0,0 +1,14 @@
+// Copyright 2016 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.
+
+//go:build freebsd || openbsd || netbsd
+// +build freebsd openbsd netbsd
+
+package fastwalk
+
+import "syscall"
+
+func direntInode(dirent *syscall.Dirent) uint64 {
+	return uint64(dirent.Fileno)
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_ino.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_ino.go
new file mode 100644
index 000000000..ea02b9ebf
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_ino.go
@@ -0,0 +1,15 @@
+// Copyright 2016 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.
+
+//go:build (linux || darwin) && !appengine
+// +build linux darwin
+// +build !appengine
+
+package fastwalk
+
+import "syscall"
+
+func direntInode(dirent *syscall.Dirent) uint64 {
+	return uint64(dirent.Ino)
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_bsd.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_bsd.go
new file mode 100644
index 000000000..d5c9c321e
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_bsd.go
@@ -0,0 +1,14 @@
+// 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.
+
+//go:build darwin || freebsd || openbsd || netbsd
+// +build darwin freebsd openbsd netbsd
+
+package fastwalk
+
+import "syscall"
+
+func direntNamlen(dirent *syscall.Dirent) uint64 {
+	return uint64(dirent.Namlen)
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_linux.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_linux.go
new file mode 100644
index 000000000..c82e57df8
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_linux.go
@@ -0,0 +1,29 @@
+// 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.
+
+//go:build linux && !appengine
+// +build linux,!appengine
+
+package fastwalk
+
+import (
+	"bytes"
+	"syscall"
+	"unsafe"
+)
+
+func direntNamlen(dirent *syscall.Dirent) uint64 {
+	const fixedHdr = uint16(unsafe.Offsetof(syscall.Dirent{}.Name))
+	nameBuf := (*[unsafe.Sizeof(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
+	const nameBufLen = uint16(len(nameBuf))
+	limit := dirent.Reclen - fixedHdr
+	if limit > nameBufLen {
+		limit = nameBufLen
+	}
+	nameLen := bytes.IndexByte(nameBuf[:limit], 0)
+	if nameLen < 0 {
+		panic("failed to find terminating 0 byte in dirent")
+	}
+	return uint64(nameLen)
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_portable.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_portable.go
new file mode 100644
index 000000000..085d31160
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_portable.go
@@ -0,0 +1,38 @@
+// Copyright 2016 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.
+
+//go:build appengine || (!linux && !darwin && !freebsd && !openbsd && !netbsd)
+// +build appengine !linux,!darwin,!freebsd,!openbsd,!netbsd
+
+package fastwalk
+
+import (
+	"io/ioutil"
+	"os"
+)
+
+// readDir calls fn for each directory entry in dirName.
+// It does not descend into directories or follow symlinks.
+// If fn returns a non-nil error, readDir returns with that error
+// immediately.
+func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) error) error {
+	fis, err := ioutil.ReadDir(dirName)
+	if err != nil {
+		return err
+	}
+	skipFiles := false
+	for _, fi := range fis {
+		if fi.Mode().IsRegular() && skipFiles {
+			continue
+		}
+		if err := fn(dirName, fi.Name(), fi.Mode()&os.ModeType); err != nil {
+			if err == ErrSkipFiles {
+				skipFiles = true
+				continue
+			}
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_unix.go b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_unix.go
new file mode 100644
index 000000000..58bd87841
--- /dev/null
+++ b/vendor/golang.org/x/tools/internal/fastwalk/fastwalk_unix.go
@@ -0,0 +1,153 @@
+// Copyright 2016 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.
+
+//go:build (linux || darwin || freebsd || openbsd || netbsd) && !appengine
+// +build linux darwin freebsd openbsd netbsd
+// +build !appengine
+
+package fastwalk
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+const blockSize = 8 << 10
+
+// unknownFileMode is a sentinel (and bogus) os.FileMode
+// value used to represent a syscall.DT_UNKNOWN Dirent.Type.
+const unknownFileMode os.FileMode = os.ModeNamedPipe | os.ModeSocket | os.ModeDevice
+
+func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) error) error {
+	fd, err := open(dirName, 0, 0)
+	if err != nil {
+		return &os.PathError{Op: "open", Path: dirName, Err: err}
+	}
+	defer syscall.Close(fd)
+
+	// The buffer must be at least a block long.
+	buf := make([]byte, blockSize) // stack-allocated; doesn't escape
+	bufp := 0                      // starting read position in buf
+	nbuf := 0                      // end valid data in buf
+	skipFiles := false
+	for {
+		if bufp >= nbuf {
+			bufp = 0
+			nbuf, err = readDirent(fd, buf)
+			if err != nil {
+				return os.NewSyscallError("readdirent", err)
+			}
+			if nbuf <= 0 {
+				return nil
+			}
+		}
+		consumed, name, typ := parseDirEnt(buf[bufp:nbuf])
+		bufp += consumed
+		if name == "" || name == "." || name == ".." {
+			continue
+		}
+		// Fallback for filesystems (like old XFS) that don't
+		// support Dirent.Type and have DT_UNKNOWN (0) there
+		// instead.
+		if typ == unknownFileMode {
+			fi, err := os.Lstat(dirName + "/" + name)
+			if err != nil {
+				// It got deleted in the meantime.
+				if os.IsNotExist(err) {
+					continue
+				}
+				return err
+			}
+			typ = fi.Mode() & os.ModeType
+		}
+		if skipFiles && typ.IsRegular() {
+			continue
+		}
+		if err := fn(dirName, name, typ); err != nil {
+			if err == ErrSkipFiles {
+				skipFiles = true
+				continue
+			}
+			return err
+		}
+	}
+}
+
+func parseDirEnt(buf []byte) (consumed int, name string, typ os.FileMode) {
+	// golang.org/issue/37269
+	dirent := &syscall.Dirent{}
+	copy((*[unsafe.Sizeof(syscall.Dirent{})]byte)(unsafe.Pointer(dirent))[:], buf)
+	if v := unsafe.Offsetof(dirent.Reclen) + unsafe.Sizeof(dirent.Reclen); uintptr(len(buf)) < v {
+		panic(fmt.Sprintf("buf size of %d smaller than dirent header size %d", len(buf), v))
+	}
+	if len(buf) < int(dirent.Reclen) {
+		panic(fmt.Sprintf("buf size %d < record length %d", len(buf), dirent.Reclen))
+	}
+	consumed = int(dirent.Reclen)
+	if direntInode(dirent) == 0 { // File absent in directory.
+		return
+	}
+	switch dirent.Type {
+	case syscall.DT_REG:
+		typ = 0
+	case syscall.DT_DIR:
+		typ = os.ModeDir
+	case syscall.DT_LNK:
+		typ = os.ModeSymlink
+	case syscall.DT_BLK:
+		typ = os.ModeDevice
+	case syscall.DT_FIFO:
+		typ = os.ModeNamedPipe
+	case syscall.DT_SOCK:
+		typ = os.ModeSocket
+	case syscall.DT_UNKNOWN:
+		typ = unknownFileMode
+	default:
+		// Skip weird things.
+		// It's probably a DT_WHT (http://lwn.net/Articles/325369/)
+		// or something. Revisit if/when this package is moved outside
+		// of goimports. goimports only cares about regular files,
+		// symlinks, and directories.
+		return
+	}
+
+	nameBuf := (*[unsafe.Sizeof(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
+	nameLen := direntNamlen(dirent)
+
+	// Special cases for common things:
+	if nameLen == 1 && nameBuf[0] == '.' {
+		name = "."
+	} else if nameLen == 2 && nameBuf[0] == '.' && nameBuf[1] == '.' {
+		name = ".."
+	} else {
+		name = string(nameBuf[:nameLen])
+	}
+	return
+}
+
+// According to https://golang.org/doc/go1.14#runtime
+// A consequence of the implementation of preemption is that on Unix systems, including Linux and macOS
+// systems, programs built with Go 1.14 will receive more signals than programs built with earlier releases.
+//
+// This causes syscall.Open and syscall.ReadDirent sometimes fail with EINTR errors.
+// We need to retry in this case.
+func open(path string, mode int, perm uint32) (fd int, err error) {
+	for {
+		fd, err := syscall.Open(path, mode, perm)
+		if err != syscall.EINTR {
+			return fd, err
+		}
+	}
+}
+
+func readDirent(fd int, buf []byte) (n int, err error) {
+	for {
+		nbuf, err := syscall.ReadDirent(fd, buf)
+		if err != syscall.EINTR {
+			return nbuf, err
+		}
+	}
+}