1 // Copyright 2015 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 // Package importer provides access to export data importers. 6 package importer 7 8 import ( 9 "go/internal/gccgoimporter" 10 "go/internal/gcimporter" 11 "go/types" 12 "io" 13 "runtime" 14 ) 15 16 // A Lookup function returns a reader to access package data for 17 // a given import path, or an error if no matching package is found. 18 type Lookup func(path string) (io.ReadCloser, error) 19 20 // For returns an Importer for the given compiler and lookup interface, 21 // or nil. Supported compilers are "gc", and "gccgo". If lookup is nil, 22 // the default package lookup mechanism for the given compiler is used. 23 func For(compiler string, lookup Lookup) types.Importer { 24 switch compiler { 25 case "gc": 26 if lookup == nil { 27 return make(gcimports) 28 } 29 panic("gc importer for custom import path lookup not yet implemented") 30 case "gccgo": 31 if lookup == nil { 32 var inst gccgoimporter.GccgoInstallation 33 if err := inst.InitFromDriver("gccgo"); err != nil { 34 return nil 35 } 36 return &gccgoimports{ 37 packages: make(map[string]*types.Package), 38 importer: inst.GetImporter(nil, nil), 39 } 40 } 41 panic("gccgo importer for custom import path lookup not yet implemented") 42 } 43 // compiler not supported 44 return nil 45 } 46 47 // Default returns an Importer for the compiler that built the running binary. 48 func Default() types.Importer { 49 return For(runtime.Compiler, nil) 50 } 51 52 // gc support 53 54 type gcimports map[string]*types.Package 55 56 func (m gcimports) Import(path string) (*types.Package, error) { 57 return gcimporter.Import(m, path) 58 } 59 60 // gccgo support 61 62 type gccgoimports struct { 63 packages map[string]*types.Package 64 importer gccgoimporter.Importer 65 } 66 67 func (m *gccgoimports) Import(path string) (*types.Package, error) { 68 return m.importer(m.packages, path) 69 } 70
