You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: gcimporter.go
    path of file: ./repos/ko/vendor/golang.org/x/tools/internal/gcimporter
    
    the code of the file until where you have to start completion: // Copyright 2011 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.

// This file is a reduced copy of $GOROOT/src/go/internal/gcimporter/gcimporter.go.

// Package gcimporter provides various functions for reading
// gc-generated object files that can be used to implement the
// Importer interface defined by the Go 1.5 standard library package.
//
// The encoding is deterministic: if the encoder is applied twice to
// the same types.Package data structure, both encodings are equal.
// This property may be important to avoid spurious changes in
// applications such as build systems.
//
// However, the encoder is not necessarily idempotent. Importing an
// exported package may yield a types.Package that, while it
// represents the same set of Go types as the original, may differ in
// the details of its internal representation. Because of these
// differences, re-encoding the imported package may yield a
// different, but equally valid, encoding of the package.
package gcimporter // import "golang.org/x/tools/internal/gcimporter"

import (
	"bufio"
	"bytes"
	"fmt"
	"go/build"
	"go/token"
	"go/types"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"sync"
)

const (
	// Enable debug during development: it adds some additional 
    
func FindPkg(path, srcDir string) (filename, id string) {
	if path == "" {
		return
	}

	var noext string
	switch {
	default:
		// "x" -> "$GOPATH/pkg/$GOOS_$GOARCH/x.ext", "x"
		// Don't require the source files to be present.
		if abs, err := filepath.Abs(srcDir); err == nil { // see issue 14282
			srcDir = abs
		}
		bp, _ := build.Import(path, srcDir, build.FindOnly|build.AllowBinary)
		if bp.PkgObj == "" {
			var ok bool
			if bp.Goroot && bp.Dir != "" {
				filename, ok = lookupGorootExport(bp.Dir)
			}
			if !ok {
				id = path // make sure we have an id to print in error message
				return
			}
		} else {
			noext = strings.TrimSuffix(bp.PkgObj, ".a")
			id = bp.ImportPath
		}

	case build.IsLocalImport(path):
		// "./x" -> "/this/directory/x.ext", "/this/directory/x"
		noext = filepath.Join(srcDir, path)
		id = noext

	case filepath.IsAbs(path):
		// for completeness only - go/build.Import
		// does not support absolute imports
		// "/x" -> "/x.ext", "/x"
		noext = path
		id = path
	}

	if false { // for debugging
		if path != id {
			fmt.Printf("%s -> %s\n", path, id)
		}
	}

	if filename != "" {
		if f, err := os.Stat(filename); err == nil && !f.IsDir() {
			return
		}
	}

	// try extensions
	for _, ext := range pkgExts {
		filename = noext + ext
		if f, err := os.Stat(filename); err == nil && !f.IsDir() {
			return
		}
	}

	filename = "" // not found
	return
}