}

func (m *gcimports) Import(path string) (*types2.Package, error) {
	return m.ImportFrom(path, "" /* no vendoring */, 0)
}

func (m *gcimports) ImportFrom(path, srcDir string, mode types2.ImportMode) (*types2.Package, error) {
	if mode != 0 {
		panic("mode must be 0")
	}
	return gcimporter.Import(m.packages, path, srcDir, m.lookup)

	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.fset, m.packages, path, srcDir, m.lookup)
}

// gccgo importer

type gccgoimports struct {

pkg go/build, const IgnoreVendor ImportMode
pkg go/build, type Package struct, InvalidGoFiles []string
pkg go/constant, func ToComplex(Value) Value
pkg go/constant, func ToFloat(Value) Value
pkg go/constant, func ToInt(Value) Value
pkg go/constant, type Value interface, ExactString() string
pkg go/types, method (*Package) SetName(string)
pkg go/types, type ImportMode int

	// The semantics is like for ImporterFrom.ImportFrom except that
	// dir and mode are ignored (since they are not present).
	Import(path string) (*Package, error)
}

// ImportMode is reserved for future use.
type ImportMode int

// An ImporterFrom resolves import paths to packages; it
// supports vendoring per https://golang.org/s/go15vendor.
// Use go/importer to obtain an ImporterFrom implementation.

	imported map[string]bool
}

func (imp *resolveTestImporter) Import(string) (*Package, error) {
	panic("should not be called")
}

func (imp *resolveTestImporter) ImportFrom(path, srcDir string, mode ImportMode) (*Package, error) {
	if mode != 0 {
		panic("mode must be 0")
	}
	if imp.importer == nil {
		imp.importer = defaultImporter().(ImporterFrom)
		imp.imported = make(map[string]bool)
	}

	imported map[string]bool
}

func (imp *resolveTestImporter) Import(string) (*Package, error) {
	panic("should not be called")
}

func (imp *resolveTestImporter) ImportFrom(path, srcDir string, mode ImportMode) (*Package, error) {
	if mode != 0 {
		panic("mode must be 0")
	}
	if imp.importer == nil {
		imp.importer = importer.Default().(ImporterFrom)
		imp.imported = make(map[string]bool)
	}

	// The semantics is like for ImporterFrom.ImportFrom except that
	// dir and mode are ignored (since they are not present).
	Import(path string) (*Package, error)
}

// ImportMode is reserved for future use.
type ImportMode int

// An ImporterFrom resolves import paths to packages; it
// supports vendoring per https://golang.org/s/go15vendor.
// Use go/importer to obtain an ImporterFrom implementation.

	if s == "" {
		return def
	}
	return s
}

// An ImportMode controls the behavior of the Import method.
type ImportMode uint

const (
	// If FindOnly is set, Import stops after locating the directory
	// that should contain the sources for a package. It does not
	// read any files in the directory.
	FindOnly ImportMode = 1 << iota

	// If AllowBinary is set, Import can be satisfied by a compiled

// type checker may not be able to determine all exported entities (e.g. due to cgo dependencies).
func (p *Importer) ImportFrom(path, srcDir string, mode types.ImportMode) (*types.Package, error) {
	if mode != 0 {
		panic("non-zero import mode")
	}

	if abs, err := p.absPath(srcDir); err == nil { // see issue #14282
		srcDir = abs
	}
	bp, err := p.ctxt.Import(path, srcDir, 0)

	pkg  *Package
	err  error
}

func (c *stdlibChecker) Import(path string) (*Package, error) {
	panic("unimplemented: use ImportFrom")
}

func (c *stdlibChecker) ImportFrom(path, dir string, _ ImportMode) (*Package, error) {
	if path == "unsafe" {
		// unsafe cannot be type checked normally.
		return Unsafe, nil
	}

	p, err := build.Default.Import(path, dir, build.FindOnly)
	if err != nil {