blob: a3fb2d4f29d0f16e2ddeef88ecbdbb2fcc001e32 (
plain) (
blame)
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
|
// Copyright 2023 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.
// package tokeninternal provides access to some internal features of the token
// package.
package tokeninternal
import (
"go/token"
"sync"
"unsafe"
)
// GetLines returns the table of line-start offsets from a token.File.
func GetLines(file *token.File) []int {
// token.File has a Lines method on Go 1.21 and later.
if file, ok := (interface{})(file).(interface{ Lines() []int }); ok {
return file.Lines()
}
// This declaration must match that of token.File.
// This creates a risk of dependency skew.
// For now we check that the size of the two
// declarations is the same, on the (fragile) assumption
// that future changes would add fields.
type tokenFile119 struct {
_ string
_ int
_ int
mu sync.Mutex // we're not complete monsters
lines []int
_ []struct{}
}
type tokenFile118 struct {
_ *token.FileSet // deleted in go1.19
tokenFile119
}
type uP = unsafe.Pointer
switch unsafe.Sizeof(*file) {
case unsafe.Sizeof(tokenFile118{}):
var ptr *tokenFile118
*(*uP)(uP(&ptr)) = uP(file)
ptr.mu.Lock()
defer ptr.mu.Unlock()
return ptr.lines
case unsafe.Sizeof(tokenFile119{}):
var ptr *tokenFile119
*(*uP)(uP(&ptr)) = uP(file)
ptr.mu.Lock()
defer ptr.mu.Unlock()
return ptr.lines
default:
panic("unexpected token.File size")
}
}
|
