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
|
// Copyright 2015 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 importer provides access to export data importers.
package importer
import (
"go/build"
"go/internal/gccgoimporter"
"go/internal/gcimporter"
"go/internal/srcimporter"
"go/token"
"go/types"
"io"
"os"
"runtime"
)
// A Lookup function returns a reader to access package data for
// a given import path, or an error if no matching package is found.
type Lookup func(path string) (io.ReadCloser, error)
// For returns an Importer for importing from installed packages
// for the compilers "gc" and "gccgo", or for importing directly
// from the source if the compiler argument is "source". In this
// latter case, importing may fail under circumstances where the
// exported API is not entirely defined in pure Go source code
// (if the package API depends on cgo-defined entities, the type
// checker won't have access to those).
//
// If lookup is nil, the default package lookup mechanism for the
// given compiler is used, and the resulting importer attempts
// to resolve relative and absolute import paths to canonical
// import path IDs before finding the imported file.
//
// If lookup is non-nil, then the returned importer calls lookup
// each time it needs to resolve an import path. In this mode
// the importer can only be invoked with canonical import paths
// (not relative or absolute ones); it is assumed that the translation
// to canonical import paths is being done by the client of the
// importer.
func For(compiler string, lookup Lookup) types.Importer {
switch compiler {
case "gc":
return &gcimports{
packages: make(map[string]*types.Package),
lookup: lookup,
}
case "gccgo":
var inst gccgoimporter.GccgoInstallation
gccgo := os.Getenv("GCCGO")
if gccgo == "" {
gccgo = "gccgo"
}
if err := inst.InitFromDriver(gccgo); err != nil {
return nil
}
return &gccgoimports{
packages: make(map[string]*types.Package),
importer: inst.GetImporter(nil, nil),
lookup: lookup,
}
case "source":
if lookup != nil {
panic("source importer for custom import path lookup not supported (issue #13847).")
}
return srcimporter.New(&build.Default, token.NewFileSet(), make(map[string]*types.Package))
}
// compiler not supported
return nil
}
// Default returns an Importer for the compiler that built the running binary.
// If available, the result implements types.ImporterFrom.
func Default() types.Importer {
return For(runtime.Compiler, nil)
}
// gc importer
type gcimports struct {
packages map[string]*types.Package
lookup Lookup
}
func (m *gcimports) Import(path string) (*types.Package, error) {
return m.ImportFrom(path, "" /* no vendoring */, 0)
}
func (m *gcimports) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
if mode != 0 {
panic("mode must be 0")
}
return gcimporter.Import(m.packages, path, srcDir, m.lookup)
}
// gccgo importer
type gccgoimports struct {
packages map[string]*types.Package
importer gccgoimporter.Importer
lookup Lookup
}
func (m *gccgoimports) Import(path string) (*types.Package, error) {
return m.ImportFrom(path, "" /* no vendoring */, 0)
}
func (m *gccgoimports) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
if mode != 0 {
panic("mode must be 0")
}
return m.importer(m.packages, path, srcDir, m.lookup)
}
|
