blob: 6158f8eaf0cc2a9bb425568623aca02700d3bcef [file] [log] [blame]
// 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.
package cache
import (
"bytes"
"context"
"fmt"
"go/ast"
"go/token"
"go/types"
"sort"
"sync"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/lsp/telemetry"
"golang.org/x/tools/internal/memoize"
"golang.org/x/tools/internal/telemetry/log"
"golang.org/x/tools/internal/telemetry/trace"
errors "golang.org/x/xerrors"
)
// checkPackageHandle implements source.CheckPackageHandle.
type checkPackageHandle struct {
handle *memoize.Handle
// files are the ParseGoHandles that compose the package.
files []source.ParseGoHandle
// mode is the mode the the files were parsed in.
mode source.ParseMode
// m is the metadata associated with the package.
m *metadata
// key is the hashed key for the package.
key []byte
}
func (cph *checkPackageHandle) packageKey() packageKey {
return packageKey{
id: cph.m.id,
mode: cph.mode,
}
}
// checkPackageData contains the data produced by type-checking a package.
type checkPackageData struct {
memoize.NoCopy
pkg *pkg
err error
}
// checkPackageHandle returns a source.CheckPackageHandle for a given package and config.
func (s *snapshot) checkPackageHandle(ctx context.Context, id packageID, mode source.ParseMode) (*checkPackageHandle, error) {
// Check if we already have this CheckPackageHandle cached.
if cph := s.getPackage(id, mode); cph != nil {
return cph, nil
}
// Build the CheckPackageHandle for this ID and its dependencies.
cph, deps, err := s.buildKey(ctx, id, mode)
if err != nil {
return nil, err
}
// Do not close over the checkPackageHandle or the snapshot in the Bind function.
// This creates a cycle, which causes the finalizers to never run on the handles.
// The possible cycles are:
//
// checkPackageHandle.h.function -> checkPackageHandle
// checkPackageHandle.h.function -> snapshot -> checkPackageHandle
//
m := cph.m
files := cph.files
key := cph.key
fset := s.view.session.cache.fset
h := s.view.session.cache.store.Bind(string(key), func(ctx context.Context) interface{} {
// Begin loading the direct dependencies, in parallel.
for _, dep := range deps {
go func(dep *checkPackageHandle) {
dep.check(ctx)
}(dep)
}
data := &checkPackageData{}
data.pkg, data.err = typeCheck(ctx, fset, m, mode, files, deps)
return data
})
cph.handle = h
// Cache the CheckPackageHandle in the snapshot.
s.addPackage(cph)
return cph, nil
}
// buildKey computes the checkPackageKey for a given checkPackageHandle.
func (s *snapshot) buildKey(ctx context.Context, id packageID, mode source.ParseMode) (*checkPackageHandle, map[packagePath]*checkPackageHandle, error) {
m := s.getMetadata(id)
if m == nil {
return nil, nil, errors.Errorf("no metadata for %s", id)
}
phs, err := s.parseGoHandles(ctx, m, mode)
if err != nil {
return nil, nil, err
}
cph := &checkPackageHandle{
m: m,
files: phs,
mode: mode,
}
// Make sure all of the depList are sorted.
depList := append([]packageID{}, m.deps...)
sort.Slice(depList, func(i, j int) bool {
return depList[i] < depList[j]
})
deps := make(map[packagePath]*checkPackageHandle)
// Begin computing the key by getting the depKeys for all dependencies.
var depKeys [][]byte
for _, depID := range depList {
depHandle, err := s.checkPackageHandle(ctx, depID, source.ParseExported)
if err != nil {
log.Error(ctx, "no dep handle", err, telemetry.Package.Of(depID))
// One bad dependency should not prevent us from checking the entire package.
// Add a special key to mark a bad dependency.
depKeys = append(depKeys, []byte(fmt.Sprintf("%s import not found", id)))
continue
}
deps[depHandle.m.pkgPath] = depHandle
depKeys = append(depKeys, depHandle.key)
}
cph.key = checkPackageKey(cph.m.id, cph.files, m.config, depKeys)
return cph, deps, nil
}
func checkPackageKey(id packageID, phs []source.ParseGoHandle, cfg *packages.Config, deps [][]byte) []byte {
return []byte(hashContents([]byte(fmt.Sprintf("%s%s%s%s", id, hashParseKeys(phs), hashConfig(cfg), hashContents(bytes.Join(deps, nil))))))
}
// hashConfig returns the hash for the *packages.Config.
func hashConfig(config *packages.Config) string {
b := bytes.NewBuffer(nil)
// Dir, Mode, Env, BuildFlags are the parts of the config that can change.
b.WriteString(config.Dir)
b.WriteString(string(config.Mode))
for _, e := range config.Env {
b.WriteString(e)
}
for _, f := range config.BuildFlags {
b.WriteString(f)
}
return hashContents(b.Bytes())
}
func (cph *checkPackageHandle) Check(ctx context.Context) (source.Package, error) {
return cph.check(ctx)
}
func (cph *checkPackageHandle) check(ctx context.Context) (*pkg, error) {
v := cph.handle.Get(ctx)
if v == nil {
return nil, errors.Errorf("no package for %s", cph.m.id)
}
data := v.(*checkPackageData)
return data.pkg, data.err
}
func (cph *checkPackageHandle) Files() []source.ParseGoHandle {
return cph.files
}
func (cph *checkPackageHandle) ID() string {
return string(cph.m.id)
}
func (cph *checkPackageHandle) MissingDependencies() []string {
var md []string
for i := range cph.m.missingDeps {
md = append(md, string(i))
}
return md
}
func (cph *checkPackageHandle) Cached() (source.Package, error) {
return cph.cached()
}
func (cph *checkPackageHandle) cached() (*pkg, error) {
v := cph.handle.Cached()
if v == nil {
return nil, errors.Errorf("no cached type information for %s", cph.m.pkgPath)
}
data := v.(*checkPackageData)
return data.pkg, data.err
}
func (s *snapshot) parseGoHandles(ctx context.Context, m *metadata, mode source.ParseMode) ([]source.ParseGoHandle, error) {
phs := make([]source.ParseGoHandle, 0, len(m.files))
for _, uri := range m.files {
f, err := s.view.GetFile(ctx, uri)
if err != nil {
return nil, err
}
fh := s.Handle(ctx, f)
phs = append(phs, s.view.session.cache.ParseGoHandle(fh, mode))
}
return phs, nil
}
func typeCheck(ctx context.Context, fset *token.FileSet, m *metadata, mode source.ParseMode, phs []source.ParseGoHandle, deps map[packagePath]*checkPackageHandle) (*pkg, error) {
ctx, done := trace.StartSpan(ctx, "cache.importer.typeCheck", telemetry.Package.Of(m.id))
defer done()
var rawErrors []error
for _, err := range m.errors {
rawErrors = append(rawErrors, err)
}
pkg := &pkg{
id: m.id,
pkgPath: m.pkgPath,
mode: mode,
files: phs,
imports: make(map[packagePath]*pkg),
typesSizes: m.typesSizes,
typesInfo: &types.Info{
Types: make(map[ast.Expr]types.TypeAndValue),
Defs: make(map[*ast.Ident]types.Object),
Uses: make(map[*ast.Ident]types.Object),
Implicits: make(map[ast.Node]types.Object),
Selections: make(map[*ast.SelectorExpr]*types.Selection),
Scopes: make(map[ast.Node]*types.Scope),
},
}
var (
files = make([]*ast.File, len(pkg.files))
parseErrors = make([]error, len(pkg.files))
wg sync.WaitGroup
)
for i, ph := range pkg.files {
wg.Add(1)
go func(i int, ph source.ParseGoHandle) {
defer wg.Done()
files[i], _, parseErrors[i], _ = ph.Parse(ctx)
}(i, ph)
}
wg.Wait()
for _, e := range parseErrors {
if e != nil {
rawErrors = append(rawErrors, e)
}
}
var i int
for _, f := range files {
if f != nil {
files[i] = f
i++
}
}
files = files[:i]
// Use the default type information for the unsafe package.
if pkg.pkgPath == "unsafe" {
pkg.types = types.Unsafe
} else if len(files) == 0 { // not the unsafe package, no parsed files
return nil, errors.Errorf("no parsed files for package %s", pkg.pkgPath)
} else {
pkg.types = types.NewPackage(string(m.pkgPath), m.name)
}
cfg := &types.Config{
Error: func(e error) {
rawErrors = append(rawErrors, e)
},
Importer: importerFunc(func(pkgPath string) (*types.Package, error) {
dep := deps[packagePath(pkgPath)]
if dep == nil {
return nil, errors.Errorf("no package for import %s", pkgPath)
}
depPkg, err := dep.check(ctx)
if err != nil {
return nil, err
}
pkg.imports[depPkg.pkgPath] = depPkg
return depPkg.types, nil
}),
}
check := types.NewChecker(cfg, fset, pkg.types, pkg.typesInfo)
// Type checking errors are handled via the config, so ignore them here.
_ = check.Files(files)
// If the context was cancelled, we may have returned a ton of transient
// errors to the type checker. Swallow them.
if ctx.Err() != nil {
return nil, ctx.Err()
}
// We don't care about a package's errors unless we have parsed it in full.
if mode == source.ParseFull {
for _, e := range rawErrors {
srcErr, err := sourceError(ctx, fset, pkg, e)
if err != nil {
log.Error(ctx, "unable to compute error positions", err, telemetry.Package.Of(pkg.ID()))
continue
}
pkg.errors = append(pkg.errors, srcErr)
}
}
return pkg, nil
}
// An importFunc is an implementation of the single-method
// types.Importer interface based on a function value.
type importerFunc func(path string) (*types.Package, error)
func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) }