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go/internal/gcimporter: write export data for go/types

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Add an iexport.go (and corresponding iexport_test.go) file, which is an
adapted version of $GOROOT/src/cmd/compile/internal/gc/iexport.go. This
code writes exportdata for a *go/types.Package.

A majority of this code is directly copied from iexport.go, with a
change of types, while some of it had to be modified slightly.

Updates golang/go#28260

Change-Id: Ic7e8e99f0c6b886839280b410afffb037da8a79b
Reviewed-on: https://go-review.googlesource.com/c/156901
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
This commit is contained in:
Rebecca Stambler 2019-01-07 14:50:49 -05:00
parent 9bdeaddf5f
commit 58ecf64b2c
5 changed files with 1088 additions and 44 deletions
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4
go/internal/gcimporter/bexport.go
View File

@ -127,10 +127,10 @@ func BExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error)
// --- generic export data ---
// populate type map with predeclared "known" types
for index, typ := range predeclared {
for index, typ := range predeclared() {
p.typIndex[typ] = index
}
if len(p.typIndex) != len(predeclared) {
if len(p.typIndex) != len(predeclared()) {
return nil, internalError("duplicate entries in type map?")
}

86
go/internal/gcimporter/bimport.go
View File

@ -126,7 +126,7 @@ func BImportData(fset *token.FileSet, imports map[string]*types.Package, data []
// --- generic export data ---
// populate typList with predeclared "known" types
p.typList = append(p.typList, predeclared...)
p.typList = append(p.typList, predeclared()...)
// read package data
pkg = p.pkg()
@ -976,50 +976,58 @@ const (
aliasTag
)
var predeclared = []types.Type{
// basic types
types.Typ[types.Bool],
types.Typ[types.Int],
types.Typ[types.Int8],
types.Typ[types.Int16],
types.Typ[types.Int32],
types.Typ[types.Int64],
types.Typ[types.Uint],
types.Typ[types.Uint8],
types.Typ[types.Uint16],
types.Typ[types.Uint32],
types.Typ[types.Uint64],
types.Typ[types.Uintptr],
types.Typ[types.Float32],
types.Typ[types.Float64],
types.Typ[types.Complex64],
types.Typ[types.Complex128],
types.Typ[types.String],
var predecl []types.Type // initialized lazily
// basic type aliases
types.Universe.Lookup("byte").Type(),
types.Universe.Lookup("rune").Type(),
func predeclared() []types.Type {
if predecl == nil {
// initialize lazily to be sure that all
// elements have been initialized before
predecl = []types.Type{ // basic types
types.Typ[types.Bool],
types.Typ[types.Int],
types.Typ[types.Int8],
types.Typ[types.Int16],
types.Typ[types.Int32],
types.Typ[types.Int64],
types.Typ[types.Uint],
types.Typ[types.Uint8],
types.Typ[types.Uint16],
types.Typ[types.Uint32],
types.Typ[types.Uint64],
types.Typ[types.Uintptr],
types.Typ[types.Float32],
types.Typ[types.Float64],
types.Typ[types.Complex64],
types.Typ[types.Complex128],
types.Typ[types.String],
// error
types.Universe.Lookup("error").Type(),
// basic type aliases
types.Universe.Lookup("byte").Type(),
types.Universe.Lookup("rune").Type(),
// untyped types
types.Typ[types.UntypedBool],
types.Typ[types.UntypedInt],
types.Typ[types.UntypedRune],
types.Typ[types.UntypedFloat],
types.Typ[types.UntypedComplex],
types.Typ[types.UntypedString],
types.Typ[types.UntypedNil],
// error
types.Universe.Lookup("error").Type(),
// package unsafe
types.Typ[types.UnsafePointer],
// untyped types
types.Typ[types.UntypedBool],
types.Typ[types.UntypedInt],
types.Typ[types.UntypedRune],
types.Typ[types.UntypedFloat],
types.Typ[types.UntypedComplex],
types.Typ[types.UntypedString],
types.Typ[types.UntypedNil],
// invalid type
types.Typ[types.Invalid], // only appears in packages with errors
// package unsafe
types.Typ[types.UnsafePointer],
// used internally by gc; never used by this package or in .a files
anyType{},
// invalid type
types.Typ[types.Invalid], // only appears in packages with errors
// used internally by gc; never used by this package or in .a files
anyType{},
}
}
return predecl
}
type anyType struct{}

723
go/internal/gcimporter/iexport.go Normal file
View File

@ -0,0 +1,723 @@
// Copyright 2019 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 binary package export.
// This file was derived from $GOROOT/src/cmd/compile/internal/gc/iexport.go;
// see that file for specification of the format.
// +build go1.11
package gcimporter
import (
"bytes"
"encoding/binary"
"go/ast"
"go/constant"
"go/token"
"go/types"
"io"
"math/big"
"reflect"
"sort"
)
// Current indexed export format version. Increase with each format change.
// 0: Go1.11 encoding
const iexportVersion = 0
// IExportData returns the binary export data for pkg.
// If no file set is provided, position info will be missing.
func IExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error) {
defer func() {
if e := recover(); e != nil {
if ierr, ok := e.(internalError); ok {
err = ierr
return
}
// Not an internal error; panic again.
panic(e)
}
}()
p := iexporter{
out: bytes.NewBuffer(nil),
fset: fset,
allPkgs: map[*types.Package]bool{},
stringIndex: map[string]uint64{},
declIndex: map[types.Object]uint64{},
typIndex: map[types.Type]uint64{},
}
for i, pt := range predeclared() {
p.typIndex[pt] = uint64(i)
}
if len(p.typIndex) > predeclReserved {
panic(internalErrorf("too many predeclared types: %d > %d", len(p.typIndex), predeclReserved))
}
// Initialize work queue with exported declarations.
scope := pkg.Scope()
for _, name := range scope.Names() {
if ast.IsExported(name) {
p.pushDecl(scope.Lookup(name))
}
}
// Loop until no more work.
for !p.declTodo.empty() {
p.doDecl(p.declTodo.popHead())
}
// Append indices to data0 section.
dataLen := uint64(p.data0.Len())
w := p.newWriter()
w.writeIndex(p.declIndex, pkg)
w.flush()
// Assemble header.
var hdr intWriter
hdr.WriteByte('i')
hdr.uint64(iexportVersion)
hdr.uint64(uint64(p.strings.Len()))
hdr.uint64(dataLen)
// Flush output.
io.Copy(p.out, &hdr)
io.Copy(p.out, &p.strings)
io.Copy(p.out, &p.data0)
return p.out.Bytes(), nil
}
// writeIndex writes out an object index. mainIndex indicates whether
// we're writing out the main index, which is also read by
// non-compiler tools and includes a complete package description
// (i.e., name and height).
func (w *exportWriter) writeIndex(index map[types.Object]uint64, localpkg *types.Package) {
// Build a map from packages to objects from that package.
pkgObjs := map[*types.Package][]types.Object{}
// For the main index, make sure to include every package that
// we reference, even if we're not exporting (or reexporting)
// any symbols from it.
pkgObjs[localpkg] = nil
for pkg := range w.p.allPkgs {
pkgObjs[pkg] = nil
}
for obj := range index {
pkgObjs[obj.Pkg()] = append(pkgObjs[obj.Pkg()], obj)
}
var pkgs []*types.Package
for pkg, objs := range pkgObjs {
pkgs = append(pkgs, pkg)
sort.Slice(objs, func(i, j int) bool {
return objs[i].Name() < objs[j].Name()
})
}
sort.Slice(pkgs, func(i, j int) bool {
return pkgs[i].Path() < pkgs[j].Path()
})
w.uint64(uint64(len(pkgs)))
for _, pkg := range pkgs {
w.string(pkg.Path())
w.string(pkg.Name())
w.uint64(uint64(0)) // package height is not needed for go/types
objs := pkgObjs[pkg]
w.uint64(uint64(len(objs)))
for _, obj := range objs {
w.string(obj.Name())
w.uint64(index[obj])
}
}
}
type iexporter struct {
fset *token.FileSet
out *bytes.Buffer
// allPkgs tracks all packages that have been referenced by
// the export data, so we can ensure to include them in the
// main index.
allPkgs map[*types.Package]bool
declTodo objQueue
strings intWriter
stringIndex map[string]uint64
data0 intWriter
declIndex map[types.Object]uint64
typIndex map[types.Type]uint64
}
// stringOff returns the offset of s within the string section.
// If not already present, it's added to the end.
func (p *iexporter) stringOff(s string) uint64 {
off, ok := p.stringIndex[s]
if !ok {
off = uint64(p.strings.Len())
p.stringIndex[s] = off
p.strings.uint64(uint64(len(s)))
p.strings.WriteString(s)
}
return off
}
// pushDecl adds n to the declaration work queue, if not already present.
func (p *iexporter) pushDecl(obj types.Object) {
// Package unsafe is known to the compiler and predeclared.
assert(obj.Pkg() != types.Unsafe)
if _, ok := p.declIndex[obj]; ok {
return
}
p.declIndex[obj] = ^uint64(0) // mark n present in work queue
p.declTodo.pushTail(obj)
}
// exportWriter handles writing out individual data section chunks.
type exportWriter struct {
p *iexporter
data intWriter
currPkg *types.Package
prevFile string
prevLine int64
}
func (p *iexporter) doDecl(obj types.Object) {
w := p.newWriter()
w.setPkg(obj.Pkg(), false)
switch obj := obj.(type) {
case *types.Var:
w.tag('V')
w.pos(obj.Pos())
w.typ(obj.Type(), obj.Pkg())
case *types.Func:
sig, _ := obj.Type().(*types.Signature)
if sig.Recv() != nil {
panic(internalErrorf("unexpected method: %v", sig))
}
w.tag('F')
w.pos(obj.Pos())
w.signature(sig)
case *types.Const:
w.tag('C')
w.pos(obj.Pos())
w.value(obj.Type(), obj.Val())
case *types.TypeName:
if obj.IsAlias() {
w.tag('A')
w.pos(obj.Pos())
w.typ(obj.Type(), obj.Pkg())
break
}
// Defined type.
w.tag('T')
w.pos(obj.Pos())
underlying := obj.Type().Underlying()
w.typ(underlying, obj.Pkg())
t := obj.Type()
if types.IsInterface(t) {
break
}
named, ok := t.(*types.Named)
if !ok {
panic(internalErrorf("%s is not a defined type", t))
}
n := named.NumMethods()
w.uint64(uint64(n))
for i := 0; i < n; i++ {
m := named.Method(i)
w.pos(m.Pos())
w.string(m.Name())
sig, _ := m.Type().(*types.Signature)
w.param(sig.Recv())
w.signature(sig)
}
default:
panic(internalErrorf("unexpected object: %v", obj))
}
p.declIndex[obj] = w.flush()
}
func (w *exportWriter) tag(tag byte) {
w.data.WriteByte(tag)
}
func (w *exportWriter) pos(pos token.Pos) {
p := w.p.fset.Position(pos)
file := p.Filename
line := int64(p.Line)
// When file is the same as the last position (common case),
// we can save a few bytes by delta encoding just the line
// number.
//
// Note: Because data objects may be read out of order (or not
// at all), we can only apply delta encoding within a single
// object. This is handled implicitly by tracking prevFile and
// prevLine as fields of exportWriter.
if file == w.prevFile {
delta := line - w.prevLine
w.int64(delta)
if delta == deltaNewFile {
w.int64(-1)
}
} else {
w.int64(deltaNewFile)
w.int64(line) // line >= 0
w.string(file)
w.prevFile = file
}
w.prevLine = line
}
func (w *exportWriter) pkg(pkg *types.Package) {
// Ensure any referenced packages are declared in the main index.
w.p.allPkgs[pkg] = true
w.string(pkg.Path())
}
func (w *exportWriter) qualifiedIdent(obj types.Object) {
// Ensure any referenced declarations are written out too.
w.p.pushDecl(obj)
w.string(obj.Name())
w.pkg(obj.Pkg())
}
func (w *exportWriter) typ(t types.Type, pkg *types.Package) {
w.data.uint64(w.p.typOff(t, pkg))
}
func (p *iexporter) newWriter() *exportWriter {
return &exportWriter{p: p}
}
func (w *exportWriter) flush() uint64 {
off := uint64(w.p.data0.Len())
io.Copy(&w.p.data0, &w.data)
return off
}
func (p *iexporter) typOff(t types.Type, pkg *types.Package) uint64 {
off, ok := p.typIndex[t]
if !ok {
w := p.newWriter()
w.doTyp(t, pkg)
off = predeclReserved + w.flush()
p.typIndex[t] = off
}
return off
}
func (w *exportWriter) startType(k itag) {
w.data.uint64(uint64(k))
}
func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
switch t := t.(type) {
case *types.Named:
w.startType(definedType)
w.qualifiedIdent(t.Obj())
case *types.Pointer:
w.startType(pointerType)
w.typ(t.Elem(), pkg)
case *types.Slice:
w.startType(sliceType)
w.typ(t.Elem(), pkg)
case *types.Array:
w.startType(arrayType)
w.uint64(uint64(t.Len()))
w.typ(t.Elem(), pkg)
case *types.Chan:
w.startType(chanType)
// 1 RecvOnly; 2 SendOnly; 3 SendRecv
var dir uint64
switch t.Dir() {
case types.RecvOnly:
dir = 1
case types.SendOnly:
dir = 2
case types.SendRecv:
dir = 3
}
w.uint64(dir)
w.typ(t.Elem(), pkg)
case *types.Map:
w.startType(mapType)
w.typ(t.Key(), pkg)
w.typ(t.Elem(), pkg)
case *types.Signature:
w.startType(signatureType)
w.setPkg(pkg, true)
w.signature(t)
case *types.Struct:
w.startType(structType)
w.setPkg(pkg, true)
n := t.NumFields()
w.uint64(uint64(n))
for i := 0; i < n; i++ {
f := t.Field(i)
w.pos(f.Pos())
w.string(f.Name())
w.typ(f.Type(), pkg)
w.bool(f.Embedded())
w.string(t.Tag(i)) // note (or tag)
}
case *types.Interface:
w.startType(interfaceType)
w.setPkg(pkg, true)
n := t.NumEmbeddeds()
w.uint64(uint64(n))
for i := 0; i < n; i++ {
f := t.Embedded(i)
w.pos(f.Obj().Pos())
w.typ(f.Obj().Type(), f.Obj().Pkg())
}
n = t.NumExplicitMethods()
w.uint64(uint64(n))
for i := 0; i < n; i++ {
m := t.ExplicitMethod(i)
w.pos(m.Pos())
w.string(m.Name())
sig, _ := m.Type().(*types.Signature)
w.signature(sig)
}
default:
panic(internalErrorf("unexpected type: %v, %v", t, reflect.TypeOf(t)))
}
}
func (w *exportWriter) setPkg(pkg *types.Package, write bool) {
if write {
w.pkg(pkg)
}
w.currPkg = pkg
}
func (w *exportWriter) signature(sig *types.Signature) {
w.paramList(sig.Params())
w.paramList(sig.Results())
if sig.Params().Len() > 0 {
w.bool(sig.Variadic())
}
}
func (w *exportWriter) paramList(tup *types.Tuple) {
n := tup.Len()
w.uint64(uint64(n))
for i := 0; i < n; i++ {
w.param(tup.At(i))
}
}
func (w *exportWriter) param(obj types.Object) {
w.pos(obj.Pos())
w.localIdent(obj)
w.typ(obj.Type(), obj.Pkg())
}
func (w *exportWriter) value(typ types.Type, v constant.Value) {
w.typ(typ, nil)
switch v.Kind() {
case constant.Bool:
w.bool(constant.BoolVal(v))
case constant.Int:
var i big.Int
if i64, exact := constant.Int64Val(v); exact {
i.SetInt64(i64)
} else if ui64, exact := constant.Uint64Val(v); exact {
i.SetUint64(ui64)
} else {
i.SetString(v.ExactString(), 10)
}
w.mpint(&i, typ)
case constant.Float:
f := constantToFloat(v)
w.mpfloat(f, typ)
case constant.Complex:
w.mpfloat(constantToFloat(constant.Real(v)), typ)
w.mpfloat(constantToFloat(constant.Imag(v)), typ)
case constant.String:
w.string(constant.StringVal(v))
case constant.Unknown:
// package contains type errors
default:
panic(internalErrorf("unexpected value %v (%T)", v, v))
}
}
// constantToFloat converts a constant.Value with kind constant.Float to a
// big.Float.
func constantToFloat(x constant.Value) *big.Float {
assert(x.Kind() == constant.Float)
// Use the same floating-point precision (512) as cmd/compile
// (see Mpprec in cmd/compile/internal/gc/mpfloat.go).
const mpprec = 512
var f big.Float
f.SetPrec(mpprec)
if v, exact := constant.Float64Val(x); exact {
// float64
f.SetFloat64(v)
} else if num, denom := constant.Num(x), constant.Denom(x); num.Kind() == constant.Int {
// TODO(gri): add big.Rat accessor to constant.Value.
n := valueToRat(num)
d := valueToRat(denom)
f.SetRat(n.Quo(n, d))
} else {
// Value too large to represent as a fraction => inaccessible.
// TODO(gri): add big.Float accessor to constant.Value.
_, ok := f.SetString(x.ExactString())
assert(ok)
}
return &f
}
// mpint exports a multi-precision integer.
//
// For unsigned types, small values are written out as a single
// byte. Larger values are written out as a length-prefixed big-endian
// byte string, where the length prefix is encoded as its complement.
// For example, bytes 0, 1, and 2 directly represent the integer
// values 0, 1, and 2; while bytes 255, 254, and 253 indicate a 1-,
// 2-, and 3-byte big-endian string follow.
//
// Encoding for signed types use the same general approach as for
// unsigned types, except small values use zig-zag encoding and the
// bottom bit of length prefix byte for large values is reserved as a
// sign bit.
//
// The exact boundary between small and large encodings varies
// according to the maximum number of bytes needed to encode a value
// of type typ. As a special case, 8-bit types are always encoded as a
// single byte.
//
// TODO(mdempsky): Is this level of complexity really worthwhile?
func (w *exportWriter) mpint(x *big.Int, typ types.Type) {
basic, ok := typ.Underlying().(*types.Basic)
if !ok {
panic(internalErrorf("unexpected type %v (%T)", typ.Underlying(), typ.Underlying()))
}
signed, maxBytes := intSize(basic)
negative := x.Sign() < 0
if !signed && negative {
panic(internalErrorf("negative unsigned integer; type %v, value %v", typ, x))
}
b := x.Bytes()
if len(b) > 0 && b[0] == 0 {
panic(internalErrorf("leading zeros"))
}
if uint(len(b)) > maxBytes {
panic(internalErrorf("bad mpint length: %d > %d (type %v, value %v)", len(b), maxBytes, typ, x))
}
maxSmall := 256 - maxBytes
if signed {
maxSmall = 256 - 2*maxBytes
}
if maxBytes == 1 {
maxSmall = 256
}
// Check if x can use small value encoding.
if len(b) <= 1 {
var ux uint
if len(b) == 1 {
ux = uint(b[0])
}
if signed {
ux <<= 1
if negative {
ux--
}
}
if ux < maxSmall {
w.data.WriteByte(byte(ux))
return
}
}
n := 256 - uint(len(b))
if signed {
n = 256 - 2*uint(len(b))
if negative {
n |= 1
}
}
if n < maxSmall || n >= 256 {
panic(internalErrorf("encoding mistake: %d, %v, %v => %d", len(b), signed, negative, n))
}
w.data.WriteByte(byte(n))
w.data.Write(b)
}
// mpfloat exports a multi-precision floating point number.
//
// The number's value is decomposed into mantissa × 2**exponent, where
// mantissa is an integer. The value is written out as mantissa (as a
// multi-precision integer) and then the exponent, except exponent is
// omitted if mantissa is zero.
func (w *exportWriter) mpfloat(f *big.Float, typ types.Type) {
if f.IsInf() {
panic("infinite constant")
}
// Break into f = mant × 2**exp, with 0.5 <= mant < 1.
var mant big.Float
exp := int64(f.MantExp(&mant))
// Scale so that mant is an integer.
prec := mant.MinPrec()
mant.SetMantExp(&mant, int(prec))
exp -= int64(prec)
manti, acc := mant.Int(nil)
if acc != big.Exact {
panic(internalErrorf("mantissa scaling failed for %f (%s)", f, acc))
}
w.mpint(manti, typ)
if manti.Sign() != 0 {
w.int64(exp)
}
}
func (w *exportWriter) bool(b bool) bool {
var x uint64
if b {
x = 1
}
w.uint64(x)
return b
}
func (w *exportWriter) int64(x int64) { w.data.int64(x) }
func (w *exportWriter) uint64(x uint64) { w.data.uint64(x) }
func (w *exportWriter) string(s string) { w.uint64(w.p.stringOff(s)) }
func (w *exportWriter) localIdent(obj types.Object) {
// Anonymous parameters.
if obj == nil {
w.string("")
return
}
name := obj.Name()
if name == "_" {
w.string("_")
return
}
w.string(name)
}
type intWriter struct {
bytes.Buffer
}
func (w *intWriter) int64(x int64) {
var buf [binary.MaxVarintLen64]byte
n := binary.PutVarint(buf[:], x)
w.Write(buf[:n])
}
func (w *intWriter) uint64(x uint64) {
var buf [binary.MaxVarintLen64]byte
n := binary.PutUvarint(buf[:], x)
w.Write(buf[:n])
}
func assert(cond bool) {
if !cond {
panic("internal error: assertion failed")
}
}
// The below is copied from go/src/cmd/compile/internal/gc/syntax.go.
// objQueue is a FIFO queue of types.Object. The zero value of objQueue is
// a ready-to-use empty queue.
type objQueue struct {
ring []types.Object
head, tail int
}
// empty returns true if q contains no Nodes.
func (q *objQueue) empty() bool {
return q.head == q.tail
}
// pushTail appends n to the tail of the queue.
func (q *objQueue) pushTail(obj types.Object) {
if len(q.ring) == 0 {
q.ring = make([]types.Object, 16)
} else if q.head+len(q.ring) == q.tail {
// Grow the ring.
nring := make([]types.Object, len(q.ring)*2)
// Copy the old elements.
part := q.ring[q.head%len(q.ring):]
if q.tail-q.head <= len(part) {
part = part[:q.tail-q.head]
copy(nring, part)
} else {
pos := copy(nring, part)
copy(nring[pos:], q.ring[:q.tail%len(q.ring)])
}
q.ring, q.head, q.tail = nring, 0, q.tail-q.head
}
q.ring[q.tail%len(q.ring)] = obj
q.tail++
}
// popHead pops a node from the head of the queue. It panics if q is empty.
func (q *objQueue) popHead() types.Object {
if q.empty() {
panic("dequeue empty")
}
obj := q.ring[q.head%len(q.ring)]
q.head++
return obj
}

305
go/internal/gcimporter/iexport_test.go Normal file
View File

@ -0,0 +1,305 @@
// Copyright 2019 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.
// This is a copy of bexport_test.go for iexport.go.
// +build go1.11
package gcimporter_test
import (
"fmt"
"go/ast"
"go/build"
"go/constant"
"go/parser"
"go/token"
"go/types"
"math/big"
"reflect"
"runtime"
"sort"
"strings"
"testing"
"golang.org/x/tools/go/buildutil"
"golang.org/x/tools/go/internal/gcimporter"
"golang.org/x/tools/go/loader"
)
func TestIExportData_stdlib(t *testing.T) {
if runtime.Compiler == "gccgo" {
t.Skip("gccgo standard library is inaccessible")
}
if runtime.GOOS == "android" {
t.Skipf("incomplete std lib on %s", runtime.GOOS)
}
// Load, parse and type-check the program.
ctxt := build.Default // copy
ctxt.GOPATH = "" // disable GOPATH
conf := loader.Config{
Build: &ctxt,
AllowErrors: true,
}
for _, path := range buildutil.AllPackages(conf.Build) {
conf.Import(path)
}
// Create a package containing type and value errors to ensure
// they are properly encoded/decoded.
f, err := conf.ParseFile("haserrors/haserrors.go", `package haserrors
const UnknownValue = "" + 0
type UnknownType undefined
`)
if err != nil {
t.Fatal(err)
}
conf.CreateFromFiles("haserrors", f)
prog, err := conf.Load()
if err != nil {
t.Fatalf("Load failed: %v", err)
}
numPkgs := len(prog.AllPackages)
if want := 248; numPkgs < want {
t.Errorf("Loaded only %d packages, want at least %d", numPkgs, want)
}
var sorted []*types.Package
for pkg := range prog.AllPackages {
sorted = append(sorted, pkg)
}
sort.Slice(sorted, func(i, j int) bool {
return sorted[i].Path() < sorted[j].Path()
})
for _, pkg := range sorted {
info := prog.AllPackages[pkg]
if info.Files == nil {
continue // empty directory
}
exportdata, err := gcimporter.IExportData(conf.Fset, pkg)
if err != nil {
t.Fatal(err)
}
if exportdata[0] == 'i' {
exportdata = exportdata[1:] // trim the 'i' in the header
} else {
t.Fatalf("unexpected first character of export data: %v", exportdata[0])
}
imports := make(map[string]*types.Package)
fset2 := token.NewFileSet()
n, pkg2, err := gcimporter.IImportData(fset2, imports, exportdata, pkg.Path())
if err != nil {
t.Errorf("IImportData(%s): %v", pkg.Path(), err)
continue
}
if n != len(exportdata) {
t.Errorf("IImportData(%s) decoded %d bytes, want %d",
pkg.Path(), n, len(exportdata))
}
// Compare the packages' corresponding members.
for _, name := range pkg.Scope().Names() {
if !ast.IsExported(name) {
continue
}
obj1 := pkg.Scope().Lookup(name)
obj2 := pkg2.Scope().Lookup(name)
if obj2 == nil {
t.Fatalf("%s.%s not found, want %s", pkg.Path(), name, obj1)
continue
}
fl1 := fileLine(conf.Fset, obj1)
fl2 := fileLine(fset2, obj2)
if fl1 != fl2 {
t.Errorf("%s.%s: got posn %s, want %s",
pkg.Path(), name, fl2, fl1)
}
if err := cmpObj(obj1, obj2); err != nil {
t.Errorf("%s.%s: %s\ngot: %s\nwant: %s",
pkg.Path(), name, err, obj2, obj1)
}
}
}
}
// TestVeryLongFile tests the position of an import object declared in
// a very long input file. Line numbers greater than maxlines are
// reported as line 1, not garbage or token.NoPos.
func TestIExportData_long(t *testing.T) {
// parse and typecheck
longFile := "package foo" + strings.Repeat("\n", 123456) + "var X int"
fset1 := token.NewFileSet()
f, err := parser.ParseFile(fset1, "foo.go", longFile, 0)
if err != nil {
t.Fatal(err)
}
var conf types.Config
pkg, err := conf.Check("foo", fset1, []*ast.File{f}, nil)
if err != nil {
t.Fatal(err)
}
// export
exportdata, err := gcimporter.IExportData(fset1, pkg)
if err != nil {
t.Fatal(err)
}
if exportdata[0] == 'i' {
exportdata = exportdata[1:] // trim the 'i' in the header
} else {
t.Fatalf("unexpected first character of export data: %v", exportdata[0])
}
// import
imports := make(map[string]*types.Package)
fset2 := token.NewFileSet()
_, pkg2, err := gcimporter.IImportData(fset2, imports, exportdata, pkg.Path())
if err != nil {
t.Fatalf("IImportData(%s): %v", pkg.Path(), err)
}
// compare
posn1 := fset1.Position(pkg.Scope().Lookup("X").Pos())
posn2 := fset2.Position(pkg2.Scope().Lookup("X").Pos())
if want := "foo.go:1:1"; posn2.String() != want {
t.Errorf("X position = %s, want %s (orig was %s)",
posn2, want, posn1)
}
}
func TestIExportData_typealiases(t *testing.T) {
// parse and typecheck
fset1 := token.NewFileSet()
f, err := parser.ParseFile(fset1, "p.go", src, 0)
if err != nil {
t.Fatal(err)
}
var conf types.Config
pkg1, err := conf.Check("p", fset1, []*ast.File{f}, nil)
if err == nil {
// foo in undeclared in src; we should see an error
t.Fatal("invalid source type-checked without error")
}
if pkg1 == nil {
// despite incorrect src we should see a (partially) type-checked package
t.Fatal("nil package returned")
}
checkPkg(t, pkg1, "export")
// export
exportdata, err := gcimporter.IExportData(fset1, pkg1)
if err != nil {
t.Fatal(err)
}
if exportdata[0] == 'i' {
exportdata = exportdata[1:] // trim the 'i' in the header
} else {
t.Fatalf("unexpected first character of export data: %v", exportdata[0])
}
// import
imports := make(map[string]*types.Package)
fset2 := token.NewFileSet()
_, pkg2, err := gcimporter.IImportData(fset2, imports, exportdata, pkg1.Path())
if err != nil {
t.Fatalf("IImportData(%s): %v", pkg1.Path(), err)
}
checkPkg(t, pkg2, "import")
}
// cmpObj reports how x and y differ. They are assumed to belong to different
// universes so cannot be compared directly. It is an adapted version of
// equalObj in bexport_test.go.
func cmpObj(x, y types.Object) error {
if reflect.TypeOf(x) != reflect.TypeOf(y) {
return fmt.Errorf("%T vs %T", x, y)
}
xt := x.Type()
yt := y.Type()
switch x.(type) {
case *types.Var, *types.Func:
// ok
case *types.Const:
xval := x.(*types.Const).Val()
yval := y.(*types.Const).Val()
equal := constant.Compare(xval, token.EQL, yval)
if !equal {
// try approx. comparison
xkind := xval.Kind()
ykind := yval.Kind()
if xkind == constant.Complex || ykind == constant.Complex {
equal = same(constant.Real(xval), constant.Real(yval)) &&
same(constant.Imag(xval), constant.Imag(yval))
} else if xkind == constant.Float || ykind == constant.Float {
equal = same(xval, yval)
} else if xkind == constant.Unknown && ykind == constant.Unknown {
equal = true
}
}
if !equal {
return fmt.Errorf("unequal constants %s vs %s", xval, yval)
}
case *types.TypeName:
xt = xt.Underlying()
yt = yt.Underlying()
default:
return fmt.Errorf("unexpected %T", x)
}
return equalType(xt, yt)
}
// Use the same floating-point precision (512) as cmd/compile
// (see Mpprec in cmd/compile/internal/gc/mpfloat.go).
const mpprec = 512
// same compares non-complex numeric values and reports if they are approximately equal.
func same(x, y constant.Value) bool {
xf := constantToFloat(x)
yf := constantToFloat(y)
d := new(big.Float).Sub(xf, yf)
d.Abs(d)
eps := big.NewFloat(1.0 / (1 << (mpprec - 1))) // allow for 1 bit of error
return d.Cmp(eps) < 0
}
// copy of the function with the same name in iexport.go.
func constantToFloat(x constant.Value) *big.Float {
var f big.Float
f.SetPrec(mpprec)
if v, exact := constant.Float64Val(x); exact {
// float64
f.SetFloat64(v)
} else if num, denom := constant.Num(x), constant.Denom(x); num.Kind() == constant.Int {
// TODO(gri): add big.Rat accessor to constant.Value.
n := valueToRat(num)
d := valueToRat(denom)
f.SetRat(n.Quo(n, d))
} else {
// Value too large to represent as a fraction => inaccessible.
// TODO(gri): add big.Float accessor to constant.Value.
_, ok := f.SetString(x.ExactString())
if !ok {
panic("should not reach here")
}
}
return &f
}
// copy of the function with the same name in iexport.go.
func valueToRat(x constant.Value) *big.Rat {
// Convert little-endian to big-endian.
// I can't believe this is necessary.
bytes := constant.Bytes(x)
for i := 0; i < len(bytes)/2; i++ {
bytes[i], bytes[len(bytes)-1-i] = bytes[len(bytes)-1-i], bytes[i]
}
return new(big.Rat).SetInt(new(big.Int).SetBytes(bytes))
}

14
go/internal/gcimporter/iimport.go
View File

@ -109,7 +109,7 @@ func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []
},
}
for i, pt := range predeclared {
for i, pt := range predeclared() {
p.typCache[uint64(i)] = pt
}
@ -142,8 +142,12 @@ func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []
p.pkgIndex[pkg] = nameIndex
pkgList[i] = pkg
}
localpkg := pkgList[0]
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] {
@ -330,6 +334,10 @@ func (r *importReader) value() (typ types.Type, val constant.Value) {
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")
}