-
Notifications
You must be signed in to change notification settings - Fork 156
/
jen.go
174 lines (162 loc) · 4.28 KB
/
jen.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
// Package jen is a code generator for Go
package jen
import (
"bytes"
"fmt"
"go/format"
"io"
"os"
"sort"
"strconv"
)
// Code represents an item of code that can be rendered.
type Code interface {
render(f *File, w io.Writer, s *Statement) error
isNull(f *File) bool
}
// Save renders the file and saves to the filename provided.
func (f *File) Save(filename string) error {
// notest
buf := &bytes.Buffer{}
if err := f.Render(buf); err != nil {
return err
}
if err := os.WriteFile(filename, buf.Bytes(), 0644); err != nil {
return err
}
return nil
}
// Render renders the file to the provided writer.
func (f *File) Render(w io.Writer) error {
body := &bytes.Buffer{}
if err := f.render(f, body, nil); err != nil {
return err
}
source := &bytes.Buffer{}
if len(f.headers) > 0 {
for _, c := range f.headers {
if err := Comment(c).render(f, source, nil); err != nil {
return err
}
if _, err := fmt.Fprint(source, "\n"); err != nil {
return err
}
}
// Append an extra newline so that header comments don't get lumped in
// with package comments.
if _, err := fmt.Fprint(source, "\n"); err != nil {
return err
}
}
for _, c := range f.comments {
if err := Comment(c).render(f, source, nil); err != nil {
return err
}
if _, err := fmt.Fprint(source, "\n"); err != nil {
return err
}
}
if _, err := fmt.Fprintf(source, "package %s", f.name); err != nil {
return err
}
if f.CanonicalPath != "" {
if _, err := fmt.Fprintf(source, " // import %q", f.CanonicalPath); err != nil {
return err
}
}
if _, err := fmt.Fprint(source, "\n\n"); err != nil {
return err
}
if err := f.renderImports(source); err != nil {
return err
}
if _, err := source.Write(body.Bytes()); err != nil {
return err
}
var output []byte
if f.NoFormat {
output = source.Bytes()
} else {
var err error
output, err = format.Source(source.Bytes())
if err != nil {
return fmt.Errorf("Error %s while formatting source:\n%s", err, source.String())
}
}
if _, err := w.Write(output); err != nil {
return err
}
return nil
}
func (f *File) renderImports(source io.Writer) error {
// Render the "C" import if it's been used in a `Qual`, `Anon` or if there's a preamble comment
hasCgo := f.imports["C"].name != "" || len(f.cgoPreamble) > 0
// Only separate the import from the main imports block if there's a preamble
separateCgo := hasCgo && len(f.cgoPreamble) > 0
filtered := map[string]importdef{}
for path, def := range f.imports {
// filter out the "C" pseudo-package so it's not rendered in a block with the other
// imports, but only if it is accompanied by a preamble comment
if path == "C" && separateCgo {
continue
}
filtered[path] = def
}
if len(filtered) == 1 {
for path, def := range filtered {
if def.alias && path != "C" {
// "C" package should be rendered without alias even when used as an anonymous import
// (e.g. should never have an underscore).
if _, err := fmt.Fprintf(source, "import %s %s\n\n", def.name, strconv.Quote(path)); err != nil {
return err
}
} else {
if _, err := fmt.Fprintf(source, "import %s\n\n", strconv.Quote(path)); err != nil {
return err
}
}
}
} else if len(filtered) > 1 {
if _, err := fmt.Fprint(source, "import (\n"); err != nil {
return err
}
// We must sort the imports to ensure repeatable
// source.
paths := []string{}
for path := range filtered {
paths = append(paths, path)
}
sort.Strings(paths)
for _, path := range paths {
def := filtered[path]
if def.alias && path != "C" {
// "C" package should be rendered without alias even when used as an anonymous import
// (e.g. should never have an underscore).
if _, err := fmt.Fprintf(source, "%s %s\n", def.name, strconv.Quote(path)); err != nil {
return err
}
} else {
if _, err := fmt.Fprintf(source, "%s\n", strconv.Quote(path)); err != nil {
return err
}
}
}
if _, err := fmt.Fprint(source, ")\n\n"); err != nil {
return err
}
}
if separateCgo {
for _, c := range f.cgoPreamble {
if err := Comment(c).render(f, source, nil); err != nil {
return err
}
if _, err := fmt.Fprint(source, "\n"); err != nil {
return err
}
}
if _, err := fmt.Fprint(source, "import \"C\"\n\n"); err != nil {
return err
}
}
return nil
}