├── README.md
└── codesweep.go


/README.md:
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 1 | About:
 2 | 
 3 | The codesweep program analyzes a collection of Go packages to identify
 4 | objects that are never used.
 5 | 
 6 | Install:
 7 | 
 8 |     $ go get github.com/mdempsky/codesweep
 9 | 
10 | Usage:
11 | 
12 |     $ codesweep cmd/compile/...
13 | 
14 | Caveats:
15 | 
16 | Codesweep's primary use case is for cleaning up the Go toolchain's
17 | machine-translated and non-idiomatic Go source code.
18 | 
19 | At this time, I suspect https://github.com/dominikh/go-unused with its
20 | -exported flag does everything I want with fewer false positives.
21 | 


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/codesweep.go:
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 1 | package main
 2 | 
 3 | import (
 4 | 	"flag"
 5 | 	"fmt"
 6 | 	"go/ast"
 7 | 	"go/types"
 8 | 	"log"
 9 | 	"sort"
10 | 
11 | 	"github.com/kisielk/gotool"
12 | 	"golang.org/x/tools/go/loader"
13 | )
14 | 
15 | func main() {
16 | 	flag.Parse()
17 | 
18 | 	importPaths := gotool.ImportPaths(flag.Args())
19 | 	if len(importPaths) == 0 {
20 | 		return
21 | 	}
22 | 
23 | 	var conf loader.Config
24 | 	for _, importPath := range importPaths {
25 | 		conf.Import(importPath)
26 | 	}
27 | 	prog, err := conf.Load()
28 | 	if err != nil {
29 | 		log.Fatal(err)
30 | 	}
31 | 
32 | 	used := make(map[string]bool)
33 | 	for _, pkg := range prog.InitialPackages() {
34 | 		for sym, obj := range pkg.Uses {
35 | 			if !interesting(sym, obj) {
36 | 				continue
37 | 			}
38 | 			used[obj.Id()] = true
39 | 		}
40 | 	}
41 | 
42 | 	var msgs []string
43 | 	for _, pkg := range prog.InitialPackages() {
44 | 		for sym, obj := range pkg.Defs {
45 | 			if !interesting(sym, obj) {
46 | 				continue
47 | 			}
48 | 			if !used[obj.Id()] {
49 | 				msgs = append(msgs, fmt.Sprint(conf.Fset.Position(sym.Pos()), obj))
50 | 			}
51 | 		}
52 | 	}
53 | 
54 | 	sort.Strings(msgs)
55 | 	for _, msg := range msgs {
56 | 		fmt.Println(msg)
57 | 	}
58 | }
59 | 
60 | func interesting(sym *ast.Ident, obj types.Object) bool {
61 | 	// Skip blank identifiers.
62 | 	if sym.Name == "_" {
63 | 		return false
64 | 	}
65 | 
66 | 	// Skip identifiers that don't actually declare objects (e.g., package names).
67 | 	if obj == nil {
68 | 		return false
69 | 	}
70 | 
71 | 	// Skip universal objects.
72 | 	if obj.Pkg() == nil {
73 | 		return false
74 | 	}
75 | 
76 | 	// Fields and methods are interesting.
77 | 	if obj, ok := obj.(*types.Var); ok && obj.IsField() {
78 | 		return true
79 | 	}
80 | 	if sig, ok := obj.Type().(*types.Signature); ok && sig.Recv() != nil {
81 | 		return true
82 | 	}
83 | 
84 | 	// Objects declared at packages scope are interesting,
85 | 	// except for init and main.
86 | 	if obj.Parent() == obj.Pkg().Scope() && !(sym.Name == "init" || sym.Name == "main" && obj.Pkg().Name() == "main") {
87 | 		return true
88 | 	}
89 | 
90 | 	// Otherwise, ignore for now.
91 | 	return false
92 | }
93 | 


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