1 | // Copyright 2019 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 | // TODO: show that two-non-empty dotjoin can happen, by using an anon struct as a field type |
6 | // TODO: don't report removed/changed methods for both value and pointer method sets? |
7 | |
8 | package apidiff |
9 | |
10 | import ( |
11 | "fmt" |
12 | "go/types" |
13 | "sort" |
14 | "strings" |
15 | ) |
16 | |
17 | // There can be at most one message for each object or part thereof. |
18 | // Parts include interface methods and struct fields. |
19 | // |
20 | // The part thing is necessary. Method (Func) objects have sufficient info, but field |
21 | // Vars do not: they just have a field name and a type, without the enclosing struct. |
22 | type messageSet map[types.Object]map[string]string |
23 | |
24 | // Add a message for obj and part, overwriting a previous message |
25 | // (shouldn't happen). |
26 | // obj is required but part can be empty. |
27 | func (m messageSet) add(obj types.Object, part, msg string) { |
28 | s := m[obj] |
29 | if s == nil { |
30 | s = map[string]string{} |
31 | m[obj] = s |
32 | } |
33 | if f, ok := s[part]; ok && f != msg { |
34 | fmt.Printf("! second, different message for obj %s, part %q\n", obj, part) |
35 | fmt.Printf(" first: %s\n", f) |
36 | fmt.Printf(" second: %s\n", msg) |
37 | } |
38 | s[part] = msg |
39 | } |
40 | |
41 | func (m messageSet) collect() []string { |
42 | var s []string |
43 | for obj, parts := range m { |
44 | // Format each object name relative to its own package. |
45 | objstring := objectString(obj) |
46 | for part, msg := range parts { |
47 | var p string |
48 | |
49 | if strings.HasPrefix(part, ",") { |
50 | p = objstring + part |
51 | } else { |
52 | p = dotjoin(objstring, part) |
53 | } |
54 | s = append(s, p+": "+msg) |
55 | } |
56 | } |
57 | sort.Strings(s) |
58 | return s |
59 | } |
60 | |
61 | func objectString(obj types.Object) string { |
62 | if f, ok := obj.(*types.Func); ok { |
63 | sig := f.Type().(*types.Signature) |
64 | if recv := sig.Recv(); recv != nil { |
65 | tn := types.TypeString(recv.Type(), types.RelativeTo(obj.Pkg())) |
66 | if tn[0] == '*' { |
67 | tn = "(" + tn + ")" |
68 | } |
69 | return fmt.Sprintf("%s.%s", tn, obj.Name()) |
70 | } |
71 | } |
72 | return obj.Name() |
73 | } |
74 | |
75 | func dotjoin(s1, s2 string) string { |
76 | if s1 == "" { |
77 | return s2 |
78 | } |
79 | if s2 == "" { |
80 | return s1 |
81 | } |
82 | return s1 + "." + s2 |
83 | } |
84 |
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