github.com/gocuntian/go@v0.0.0-20160610041250-fee02d270bf8/src/go/doc/headscan.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build ignore
     6  
     7  /*
     8  	The headscan command extracts comment headings from package files;
     9  	it is used to detect false positives which may require an adjustment
    10  	to the comment formatting heuristics in comment.go.
    11  
    12  	Usage: headscan [-root root_directory]
    13  
    14  	By default, the $GOROOT/src directory is scanned.
    15  */
    16  package main
    17  
    18  import (
    19  	"bytes"
    20  	"flag"
    21  	"fmt"
    22  	"go/doc"
    23  	"go/parser"
    24  	"go/token"
    25  	"os"
    26  	"path/filepath"
    27  	"regexp"
    28  	"runtime"
    29  	"strings"
    30  )
    31  
    32  var (
    33  	root    = flag.String("root", filepath.Join(runtime.GOROOT(), "src"), "root of filesystem tree to scan")
    34  	verbose = flag.Bool("v", false, "verbose mode")
    35  )
    36  
    37  // ToHTML in comment.go assigns a (possibly blank) ID to each heading
    38  var html_h = regexp.MustCompile(`<h3 id="[^"]*">`)
    39  
    40  const html_endh = "</h3>\n"
    41  
    42  func isGoFile(fi os.FileInfo) bool {
    43  	return strings.HasSuffix(fi.Name(), ".go") &&
    44  		!strings.HasSuffix(fi.Name(), "_test.go")
    45  }
    46  
    47  func appendHeadings(list []string, comment string) []string {
    48  	var buf bytes.Buffer
    49  	doc.ToHTML(&buf, comment, nil)
    50  	for s := buf.String(); ; {
    51  		loc := html_h.FindStringIndex(s)
    52  		if len(loc) == 0 {
    53  			break
    54  		}
    55  		i := loc[1]
    56  		j := strings.Index(s, html_endh)
    57  		if j < 0 {
    58  			list = append(list, s[i:]) // incorrect HTML
    59  			break
    60  		}
    61  		list = append(list, s[i:j])
    62  		s = s[j+len(html_endh):]
    63  	}
    64  	return list
    65  }
    66  
    67  func main() {
    68  	flag.Parse()
    69  	fset := token.NewFileSet()
    70  	nheadings := 0
    71  	err := filepath.Walk(*root, func(path string, fi os.FileInfo, err error) error {
    72  		if !fi.IsDir() {
    73  			return nil
    74  		}
    75  		pkgs, err := parser.ParseDir(fset, path, isGoFile, parser.ParseComments)
    76  		if err != nil {
    77  			if *verbose {
    78  				fmt.Fprintln(os.Stderr, err)
    79  			}
    80  			return nil
    81  		}
    82  		for _, pkg := range pkgs {
    83  			d := doc.New(pkg, path, doc.Mode(0))
    84  			list := appendHeadings(nil, d.Doc)
    85  			for _, d := range d.Consts {
    86  				list = appendHeadings(list, d.Doc)
    87  			}
    88  			for _, d := range d.Types {
    89  				list = appendHeadings(list, d.Doc)
    90  			}
    91  			for _, d := range d.Vars {
    92  				list = appendHeadings(list, d.Doc)
    93  			}
    94  			for _, d := range d.Funcs {
    95  				list = appendHeadings(list, d.Doc)
    96  			}
    97  			if len(list) > 0 {
    98  				// directories may contain multiple packages;
    99  				// print path and package name
   100  				fmt.Printf("%s (package %s)\n", path, pkg.Name)
   101  				for _, h := range list {
   102  					fmt.Printf("\t%s\n", h)
   103  				}
   104  				nheadings += len(list)
   105  			}
   106  		}
   107  		return nil
   108  	})
   109  	if err != nil {
   110  		fmt.Fprintln(os.Stderr, err)
   111  		os.Exit(1)
   112  	}
   113  	fmt.Println(nheadings, "headings found")
   114  }