// Copyright 2018 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.
// Indexed package import.
// See cmd/compile/internal/gc/iexport.go for the export data format.
// This file is a copy of $GOROOT/src/go/internal/gcimporter/iimport.go.
package gcimporter
import (
"bytes"
"encoding/binary"
"fmt"
"go/constant"
"go/token"
"go/types"
"io"
"sort"
)
type intReader struct {
*bytes.Reader
path string
}
func (r *intReader) int64() int64 {
i, err := binary.ReadVarint(r.Reader)
if err != nil {
errorf("import %q: read varint error: %v", r.path, err)
}
return i
}
func (r *intReader) uint64() uint64 {
i, err := binary.ReadUvarint(r.Reader)
if err != nil {
errorf("import %q: read varint error: %v", r.path, err)
}
return i
}
const predeclReserved = 32
type itag uint64
const (
// Types
definedType itag = iota
pointerType
sliceType
arrayType
chanType
mapType
signatureType
structType
interfaceType
)
// IImportData imports a package from the serialized package data
// and returns the number of bytes consumed and a reference to the package.
// If the export data version is not recognized or the format is otherwise
// compromised, an error is returned.
func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
const currentVersion = 0
version := -1
defer func() {
if e := recover(); e != nil {
if version > currentVersion {
err = fmt.Errorf("cannot import %q (%v), export data is newer version - update tool", path, e)
} else {
err = fmt.Errorf("cannot import %q (%v), possibly version skew - reinstall package", path, e)
}
}
}()
r := &intReader{bytes.NewReader(data), path}
version = int(r.uint64())
switch version {
case currentVersion:
default:
errorf("unknown iexport format version %d", version)
}
sLen := int64(r.uint64())
dLen := int64(r.uint64())
whence, _ := r.Seek(0, io.SeekCurrent)
stringData := data[whence : whence+sLen]
declData := data[whence+sLen : whence+sLen+dLen]
r.Seek(sLen+dLen, io.SeekCurrent)
p := iimporter{
ipath: path,
stringData: stringData,
stringCache: make(map[uint64]string),
pkgCache: make(map[uint64]*types.Package),
declData: declData,
pkgIndex: make(map[*types.Package]map[string]uint64),
typCache: make(map[uint64]types.Type),
fake: fakeFileSet{
fset: fset,
files: make(map[string]*token.File),
},
}
for i, pt := range predeclared() {
p.typCache[uint64(i)] = pt
}
pkgList := make([]*types.Package, r.uint64())
for i := range pkgList {
pkgPathOff := r.uint64()
pkgPath := p.stringAt(pkgPathOff)
pkgName := p.stringAt(r.uint64())
_ = r.uint64() // package height; unused by go/types
if pkgPath == "" {
pkgPath = path
}
pkg := imports[pkgPath]
if pkg == nil {
pkg = types.NewPackage(pkgPath, pkgName)
imports[pkgPath] = pkg
} else if pkg.Name() != pkgName {
errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
}
p.pkgCache[pkgPathOff] = pkg
nameIndex := make(map[string]uint64)
for nSyms := r.uint64(); nSyms > 0; nSyms-- {
name := p.stringAt(r.uint64())
nameIndex[name] = r.uint64()
}
p.pkgIndex[pkg] = nameIndex
pkgList[i] = pkg
}
var localpkg *types.Package
for _, pkg := range pkgList {
if pkg.Path() == path {
localpkg = pkg
}
}
names := make([]string, 0, len(p.pkgIndex[localpkg]))
for name := range p.pkgIndex[localpkg] {
names = append(names, name)
}
sort.Strings(names)
for _, name := range names {
p.doDecl(localpkg, name)
}
for _, typ := range p.interfaceList {
typ.Complete()
}
// record all referenced packages as imports
list := append(([]*types.Package)(nil), pkgList[1:]...)
sort.Sort(byPath(list))
localpkg.SetImports(list)
// package was imported completely and without errors
localpkg.MarkComplete()
consumed, _ := r.Seek(0, io.SeekCurrent)
return int(consumed), localpkg, nil
}
type iimporter struct {
ipath string
stringData []byte
stringCache map[uint64]string
pkgCache map[uint64]*types.Package
declData []byte
pkgIndex map[*types.Package]map[string]uint64
typCache map[uint64]types.Type
fake fakeFileSet
interfaceList []*types.Interface
}
func (p *iimporter) doDecl(pkg *types.Package, name string) {
// See if we've already imported this declaration.
if obj := pkg.Scope().Lookup(name); obj != nil {
return
}
off, ok := p.pkgIndex[pkg][name]
if !ok {
errorf("%v.%v not in index", pkg, name)
}
r := &importReader{p: p, currPkg: pkg}
r.declReader.Reset(p.declData[off:])
r.obj(name)
}
func (p *iimporter) stringAt(off uint64) string {
if s, ok := p.stringCache[off]; ok {
return s
}
slen, n := binary.Uvarint(p.stringData[off:])
if n <= 0 {
errorf("varint failed")
}
spos := off + uint64(n)
s := string(p.stringData[spos : spos+slen])
p.stringCache[off] = s
return s
}
func (p *iimporter) pkgAt(off uint64) *types.Package {
if pkg, ok := p.pkgCache[off]; ok {
return pkg
}
path := p.stringAt(off)
errorf("missing package %q in %q", path, p.ipath)
return nil
}
func (p *iimporter) typAt(off uint64, base *types.Named) types.Type {
if t, ok := p.typCache[off]; ok && (base == nil || !isInterface(t)) {
return t
}
if off < predeclReserved {
errorf("predeclared type missing from cache: %v", off)
}
r := &importReader{p: p}
r.declReader.Reset(p.declData[off-predeclReserved:])
t := r.doType(base)
if base == nil || !isInterface(t) {
p.typCache[off] = t
}
return t
}
type importReader struct {
p *iimporter
declReader bytes.Reader
currPkg *types.Package
prevFile string
prevLine int64
}
func (r *importReader) obj(name string) {
tag := r.byte()
pos := r.pos()
switch tag {
case 'A':
typ := r.typ()
r.declare(types.NewTypeName(pos, r.currPkg, name, typ))
case 'C':
typ, val := r.value()
r.declare(types.NewConst(pos, r.currPkg, name, typ, val))
case 'F':
sig := r.signature(nil)
r.declare(types.NewFunc(pos, r.currPkg, name, sig))
case 'T':
// Types can be recursive. We need to setup a stub
// declaration before recursing.
obj := types.NewTypeName(pos, r.currPkg, name, nil)
named := types.NewNamed(obj, nil, nil)
r.declare(obj)
underlying := r.p.typAt(r.uint64(), named).Underlying()
named.SetUnderlying(underlying)
if !isInterface(underlying) {
for n := r.uint64(); n > 0; n-- {
mpos := r.pos()
mname := r.ident()
recv := r.param()
msig := r.signature(recv)
named.AddMethod(types.NewFunc(mpos, r.currPkg, mname, msig))
}
}
case 'V':
typ := r.typ()
r.declare(types.NewVar(pos, r.currPkg, name, typ))
default:
errorf("unexpected tag: %v", tag)
}
}
func (r *importReader) declare(obj types.Object) {
obj.Pkg().Scope().Insert(obj)
}
func (r *importReader) value() (typ types.Type, val constant.Value) {
typ = r.typ()
switch b := typ.Underlying().(*types.Basic); b.Info() & types.IsConstType {
case types.IsBoolean:
val = constant.MakeBool(r.bool())
case types.IsString:
val = constant.MakeString(r.string())
case types.IsInteger:
val = r.mpint(b)
case types.IsFloat:
val = r.mpfloat(b)
case types.IsComplex:
re := r.mpfloat(b)
im := r.mpfloat(b)
val = constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
default:
if b.Kind() == types.Invalid {
val = constant.MakeUnknown()
return
}
errorf("unexpected type %v", typ) // panics
panic("unreachable")
}
return
}
func intSize(b *types.Basic) (signed bool, maxBytes uint) {
if (b.Info() & types.IsUntyped) != 0 {
return true, 64
}
switch b.Kind() {
case types.Float32, types.Complex64:
return true, 3
case types.Float64, types.Complex128:
return true, 7
}
signed = (b.Info() & types.IsUnsigned) == 0
switch b.Kind() {
case types.Int8, types.Uint8:
maxBytes = 1
case types.Int16, types.Uint16:
maxBytes = 2
case types.Int32, types.Uint32:
maxBytes = 4
default:
maxBytes = 8
}
return
}
func (r *importReader) mpint(b *types.Basic) constant.Value {
signed, maxBytes := intSize(b)
maxSmall := 256 - maxBytes
if signed {
maxSmall = 256 - 2*maxBytes
}
if maxBytes == 1 {
maxSmall = 256
}
n, _ := r.declReader.ReadByte()
if uint(n) < maxSmall {
v := int64(n)
if signed {
v >>= 1
if n&1 != 0 {
v = ^v
}
}
return constant.MakeInt64(v)
}
v := -n
if signed {
v = -(n &^ 1) >> 1
}
if v < 1 || uint(v) > maxBytes {
errorf("weird decoding: %v, %v => %v", n, signed, v)
}
buf := make([]byte, v)
io.ReadFull(&r.declReader, buf)
// convert to little endian
// TODO(gri) go/constant should have a more direct conversion function
// (e.g., once it supports a big.Float based implementation)
for i, j := 0, len(buf)-1; i < j; i, j = i+1, j-1 {
buf[i], buf[j] = buf[j], buf[i]
}
x := constant.MakeFromBytes(buf)
if signed && n&1 != 0 {
x = constant.UnaryOp(token.SUB, x, 0)
}
return x
}
func (r *importReader) mpfloat(b *types.Basic) constant.Value {
x := r.mpint(b)
if constant.Sign(x) == 0 {
return x
}
exp := r.int64()
switch {
case exp > 0:
x = constant.Shift(x, token.SHL, uint(exp))
case exp < 0:
d := constant.Shift(constant.MakeInt64(1), token.SHL, uint(-exp))
x = constant.BinaryOp(x, token.QUO, d)
}
return x
}
func (r *importReader) ident() string {
return r.string()
}
func (r *importReader) qualifiedIdent() (*types.Package, string) {
name := r.string()
pkg := r.pkg()
return pkg, name
}
func (r *importReader) pos() token.Pos {
delta := r.int64()
if delta != deltaNewFile {
r.prevLine += delta
} else if l := r.int64(); l == -1 {
r.prevLine += deltaNewFile
} else {
r.prevFile = r.string()
r.prevLine = l
}
if r.prevFile == "" && r.prevLine == 0 {
return token.NoPos
}
return r.p.fake.pos(r.prevFile, int(r.prevLine))
}
func (r *importReader) typ() types.Type {
return r.p.typAt(r.uint64(), nil)
}
func isInterface(t types.Type) bool {
_, ok := t.(*types.Interface)
return ok
}
func (r *importReader) pkg() *types.Package { return r.p.pkgAt(r.uint64()) }
func (r *importReader) string() string { return r.p.stringAt(r.uint64()) }
func (r *importReader) doType(base *types.Named) types.Type {
switch k := r.kind(); k {
default:
errorf("unexpected kind tag in %q: %v", r.p.ipath, k)
return nil
case definedType:
pkg, name := r.qualifiedIdent()
r.p.doDecl(pkg, name)
return pkg.Scope().Lookup(name).(*types.TypeName).Type()
case pointerType:
return types.NewPointer(r.typ())
case sliceType:
return types.NewSlice(r.typ())
case arrayType:
n := r.uint64()
return types.NewArray(r.typ(), int64(n))
case chanType:
dir := chanDir(int(r.uint64()))
return types.NewChan(dir, r.typ())
case mapType:
return types.NewMap(r.typ(), r.typ())
case signatureType:
r.currPkg = r.pkg()
return r.signature(nil)
case structType:
r.currPkg = r.pkg()
fields := make([]*types.Var, r.uint64())
tags := make([]string, len(fields))
for i := range fields {
fpos := r.pos()
fname := r.ident()
ftyp := r.typ()
emb := r.bool()
tag := r.string()
fields[i] = types.NewField(fpos, r.currPkg, fname, ftyp, emb)
tags[i] = tag
}
return types.NewStruct(fields, tags)
case interfaceType:
r.currPkg = r.pkg()
embeddeds := make([]types.Type, r.uint64())
for i := range embeddeds {
_ = r.pos()
embeddeds[i] = r.typ()
}
methods := make([]*types.Func, r.uint64())
for i := range methods {
mpos := r.pos()
mname := r.ident()
// TODO(mdempsky): Matches bimport.go, but I
// don't agree with this.
var recv *types.Var
if base != nil {
recv = types.NewVar(token.NoPos, r.currPkg, "", base)
}
msig := r.signature(recv)
methods[i] = types.NewFunc(mpos, r.currPkg, mname, msig)
}
typ := newInterface(methods, embeddeds)
r.p.interfaceList = append(r.p.interfaceList, typ)
return typ
}
}
func (r *importReader) kind() itag {
return itag(r.uint64())
}
func (r *importReader) signature(recv *types.Var) *types.Signature {
params := r.paramList()
results := r.paramList()
variadic := params.Len() > 0 && r.bool()
return types.NewSignature(recv, params, results, variadic)
}
func (r *importReader) paramList() *types.Tuple {
xs := make([]*types.Var, r.uint64())
for i := range xs {
xs[i] = r.param()
}
return types.NewTuple(xs...)
}
func (r *importReader) param() *types.Var {
pos := r.pos()
name := r.ident()
typ := r.typ()
return types.NewParam(pos, r.currPkg, name, typ)
}
func (r *importReader) bool() bool {
return r.uint64() != 0
}
func (r *importReader) int64() int64 {
n, err := binary.ReadVarint(&r.declReader)
if err != nil {
errorf("readVarint: %v", err)
}
return n
}
func (r *importReader) uint64() uint64 {
n, err := binary.ReadUvarint(&r.declReader)
if err != nil {
errorf("readUvarint: %v", err)
}
return n
}
func (r *importReader) byte() byte {
x, err := r.declReader.ReadByte()
if err != nil {
errorf("declReader.ReadByte: %v", err)
}
return x
}
