internal/lsp: use new go/packages LoadMode to get TypesSizes

This change also fixes the corresponding code in go/packages, which was
actually not filling in the TypesSizes if the bit was set.

Change-Id: I2d5a849045768a81c94218eb41da2faec26189a3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/170010
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>

go/packages/packages.go

@@ -554,6 +554,9 @@ func (ld *loader) refine(roots []string, list ...*Package) ([]*Package, error) {
 		if lpkg.needsrc {
 			srcPkgs = append(srcPkgs, lpkg)
 		}
+		if ld.Mode&NeedTypesSizes != 0 {
+			lpkg.TypesSizes = ld.sizes
+		}
 		stack = stack[:len(stack)-1] // pop
 		lpkg.color = black
 

internal/lsp/cache/check.go

@@ -92,7 +92,7 @@ func (v *View) cachePackage(pkg *Package) {
 func (v *View) checkMetadata(ctx context.Context, f *File) ([]packages.Error, error) {
 	if v.reparseImports(ctx, f, f.filename) {
 		cfg := v.Config
-		cfg.Mode = packages.LoadImports
+		cfg.Mode = packages.LoadImports | packages.NeedTypesSizes
 		pkgs, err := packages.Load(&cfg, fmt.Sprintf("file=%s", f.filename))
 		if len(pkgs) == 0 {
 			if err == nil {
@@ -141,6 +141,7 @@ func (v *View) link(pkgPath string, pkg *packages.Package, parent *metadata) *me
 		m = &metadata{
 			pkgPath:    pkgPath,
 			id:         pkg.ID,
+			typesSizes: pkg.TypesSizes,
 			parents:    make(map[string]bool),
 			children:   make(map[string]bool),
 		}
@@ -230,6 +231,7 @@ func (imp *importer) typeCheck(pkgPath string) (*Package, error) {
 		files:      meta.files,
 		imports:    make(map[string]*Package),
 		types:      typ,
+		typesSizes: meta.typesSizes,
 		typesInfo: &types.Info{
 			Types:      make(map[ast.Expr]types.TypeAndValue),
 			Defs:       make(map[*ast.Ident]types.Object),

internal/lsp/cache/pkg.go

@@ -21,6 +21,7 @@ type Package struct {
 	imports     map[string]*Package
 	types       *types.Package
 	typesInfo   *types.Info
+	typesSizes  types.Sizes
 
 	// The analysis cache holds analysis information for all the packages in a view.
 	// Each graph node (action) is one unit of analysis.
@@ -118,6 +119,10 @@ func (pkg *Package) GetTypesInfo() *types.Info {
 	return pkg.typesInfo
 }
 
+func (pkg *Package) GetTypesSizes() types.Sizes {
+	return pkg.typesSizes
+}
+
 func (pkg *Package) IsIllTyped() bool {
 	return pkg.types == nil && pkg.typesInfo == nil
 }

internal/lsp/cache/view.go

@@ -7,6 +7,7 @@ package cache
 import (
 	"context"
 	"go/token"
+	"go/types"
 	"os"
 	"sync"
 
@@ -64,6 +65,7 @@ type metadataCache struct {
 type metadata struct {
 	id, pkgPath, name string
 	files             []string
+	typesSizes        types.Sizes
 	parents, children map[string]bool
 }
 

internal/lsp/source/analysis.go

@@ -138,8 +138,7 @@ func (act *Action) execOnce(fset *token.FileSet) {
 		Files:             act.Pkg.GetSyntax(),
 		Pkg:               act.Pkg.GetTypes(),
 		TypesInfo:         act.Pkg.GetTypesInfo(),
-		// TODO(rstambler): Get real TypeSizes from go/packages (golang.org/issues/30139).
+		TypesSizes:        act.Pkg.GetTypesSizes(),
-		TypesSizes:        &types.StdSizes{},
 		ResultOf:          inputs,
 		Report:            func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) },
 		ImportObjectFact:  act.importObjectFact,

internal/lsp/source/view.go

@@ -45,6 +45,7 @@ type Package interface {
 	GetErrors() []packages.Error
 	GetTypes() *types.Package
 	GetTypesInfo() *types.Info
+	GetTypesSizes() types.Sizes
 	IsIllTyped() bool
 	GetActionGraph(ctx context.Context, a *analysis.Analyzer) (*Action, error)
 }