blob: efe221e7e1423e370d968eb512be02bb7ea6601e [file] [log] [blame]
// Copyright 2016 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 gcexportdata
import (
"fmt"
"go/token"
"go/types"
"os"
)
// NewImporter returns a new instance of the types.Importer interface
// that reads type information from export data files written by gc.
// The Importer also satisfies types.ImporterFrom.
//
// Export data files are located using "go build" workspace conventions
// and the build.Default context.
//
// Use this importer instead of go/importer.For("gc", ...) to avoid the
// version-skew problems described in the documentation of this package,
// or to control the FileSet or access the imports map populated during
// package loading.
//
func NewImporter(fset *token.FileSet, imports map[string]*types.Package) types.ImporterFrom {
return importer{fset, imports}
}
type importer struct {
fset *token.FileSet
imports map[string]*types.Package
}
func (imp importer) Import(importPath string) (*types.Package, error) {
return imp.ImportFrom(importPath, "", 0)
}
func (imp importer) ImportFrom(importPath, srcDir string, mode types.ImportMode) (_ *types.Package, err error) {
filename, path := Find(importPath, srcDir)
if filename == "" {
if importPath == "unsafe" {
// Even for unsafe, call Find first in case
// the package was vendored.
return types.Unsafe, nil
}
return nil, fmt.Errorf("can't find import: %s", importPath)
}
if pkg, ok := imp.imports[path]; ok && pkg.Complete() {
return pkg, nil // cache hit
}
// open file
f, err := os.Open(filename)
if err != nil {
return nil, err
}
defer func() {
f.Close()
if err != nil {
// add file name to error
err = fmt.Errorf("reading export data: %s: %v", filename, err)
}
}()
r, err := NewReader(f)
if err != nil {
return nil, err
}
return Read(r, imp.fset, imp.imports, path)
}