gunk/loader/loader.go at master · gunk/gunk · GitHub

History

766 lines (737 loc) · 23.2 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

package loader

import (

"fmt"

"go/ast"

"go/constant"

"go/parser"

"go/scanner"

"go/token"

"go/types"

"html/template"

"io/ioutil"

"os"

"os/exec"

"path/filepath"

"reflect"

"strconv"

"strings"

"github.com/gunk/gunk/assets"

"github.com/gunk/gunk/log"

"golang.org/x/tools/go/packages"

"google.golang.org/protobuf/proto"

"google.golang.org/protobuf/types/descriptorpb"

)

type Loader struct {

Dir string

Fset *token.FileSet

// If Types is true, we parse and type-check the given packages and all

// transitive dependencies, including gunk tags. Otherwise, we only

// parse the given packages.

Types bool

cache map[string]*GunkPackage // map from import path to pkg

stack []string

// fakeFiles is a list of fake Go files added to make the Go compiler pick

// up gunk files in packages without Go files.

fakeFiles map[string][]byte

}

// addFakeFiles iterate over all module dependencies of the specified directory

// and adds a fake Go file for all directories inside the dependencies that

// only has Gunk files and no Go files.

// This allows the loader to process Gunk packages using regular Go package

// parsing code when fakeFiles is used as an overlay.

func (l *Loader) addFakeFiles() error {

l.fakeFiles = make(map[string][]byte)

// use "." if we encountered an error, for e.g. GOPATH mode

roots := []string{"."}

cmd := exec.Command("go", "list", "-m", "-f={{.Dir}}", "all")

cmd.Dir = l.Dir

if out, err := cmd.Output(); err == nil {

rootOutput := strings.Split(strings.TrimSpace(string(out)), "\n")

roots = make([]string, 0, len(rootOutput))

for _, v := range rootOutput {

roots = append(roots, strings.TrimSpace(v))

}

// Walk through all directories and add fake files for all packages that

// only have gunk files.

for _, root := range roots {

if err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {

if err != nil {

return err

}

if !info.IsDir() {

return nil

}

infos, err := ioutil.ReadDir(path)

if err != nil {

return err

}

pkgName := info.Name() // default to the directory basename

anyGunk := false

for _, info := range infos {

name := info.Name()

if strings.HasSuffix(name, ".go") {

// has Go files; nothing to do

return nil

}

if strings.HasSuffix(name, ".gunk") {

f, err := parser.ParseFile(token.NewFileSet(),

filepath.Join(path, name), nil, parser.PackageClauseOnly)

// Ignore errors, since Gunk packages being

// walked but not being loaded might have

// invalid syntax.

if err == nil {

pkgName = f.Name.Name

}

anyGunk = true

break

}

if !anyGunk {

return nil

}

tmpPath := filepath.Join(path, "gunkpkg.go")

l.fakeFiles[tmpPath] = []byte(`package ` + pkgName)

return nil

}); err != nil {

return err

}

return nil

}

// Load loads the Gunk packages on the provided patterns from the given dir and

// using the given fileset.

// Similar to Go, if a path begins with ".", it is interpreted as a file system

// path where a package is located, and "..." patterns are supported.

func (l *Loader) Load(patterns ...string) ([]*GunkPackage, error) {

if l.stack == nil {

l.stack = make([]string, 0, 1)

}

if len(patterns) == 1 {

pkgPath := patterns[0]

if pkg := l.cache[pkgPath]; pkg != nil {

return []*GunkPackage{pkg}, nil

}

var pkgs []*GunkPackage

loadFiles := len(patterns) > 0 && strings.HasSuffix(patterns[0], ".gunk")

if loadFiles {

// If we're given a number of files, construct a

// packages.Package manually. go/packages will treat foo.gunk as

// an import path instead of a file, as it's not a Go file.

pkgs = append(pkgs, &GunkPackage{

Package: packages.Package{

ID: "command-line-arguments",

Name: "", // will be filled later

PkgPath: "command-line-arguments",

GunkFiles: patterns,

})

} else {

// Generate fake files if it has not been initialized yet.

if l.fakeFiles == nil {

err := l.addFakeFiles()

if err != nil {

return nil, err

}

// Load the Gunk packages as Go packages.

cfg := &packages.Config{

Dir: l.Dir,

Mode: packages.NeedName | packages.NeedFiles,

Overlay: l.fakeFiles,

}

lpkgs, err := packages.Load(cfg, patterns...)

if err != nil {

return nil, err

}

for _, lpkg := range lpkgs {

pkg := &GunkPackage{Package: *lpkg}

findGunkFiles(pkg)

if len(pkg.GunkFiles) == 0 && len(pkg.Errors) == 0 {

// Not a Gunk package. Skip.

continue

}

pkgs = append(pkgs, pkg)

}

// Add the Gunk files to each package.

for _, pkg := range pkgs {

for _, v := range l.stack {

if v == pkg.PkgPath {

// Add the current package to the stack to demonstrate the import cycle.

l.stack = append(l.stack, pkg.PkgPath)

importLoop := strings.Join(l.stack, "\n\t\timports ")

return nil, fmt.Errorf("import cycle not allowed:\n\t%s", importLoop)

}

// Add entry to stack.

l.stack = append(l.stack, pkg.PkgPath)

l.parseGunkPackage(pkg)

l.validatePackage(pkg)

// Pop entry from stack.

l.stack = l.stack[:len(l.stack)-1]

if l.cache == nil {

l.cache = make(map[string]*GunkPackage)

}

l.cache[pkg.PkgPath] = pkg

}

return pkgs, nil

}

// findGunkFiles fills a package's GunkFiles field with the gunk files found in

// the package directory. This is used when loading a Gunk package via an import

// path or a directory.

// Note that this requires all the source files within the package to be in the

// same directory, which is true for Go Modules and GOPATH, but not other build

// systems like Bazel.

func findGunkFiles(pkg *GunkPackage) {

for _, gofile := range pkg.GoFiles {

dir := filepath.Dir(gofile)

if pkg.Dir == "" {

pkg.Dir = dir

} else if dir != pkg.Dir {

pkg.errorf(ListError, 0, nil, "multiple dirs for %s: %s %s",

pkg.PkgPath, pkg.Dir, dir)

return // we can't continue

}

matches, err := filepath.Glob(filepath.Join(pkg.Dir, "*.gunk"))

if err != nil {

// can only be a malformed pattern; should never happen.

panic(err.Error())

}

pkg.GunkFiles = matches

}

const (

UnknownError = packages.UnknownError

ListError = packages.ListError

ParseError = packages.ParseError

TypeError = packages.TypeError

// Our kinds of errors. Add a gap of 10 to be sure we won't conflict

// with previous enum values.

ValidateError = packages.TypeError + 10 + iota

)

// Import satisfies the go/types.Importer interface.

// Unlike standard Go ones like go/importer and x/tools/go/packages, this one is

// adapted to load Gunk packages.

// Aside from that, it is very similar to standard Go importers that load from

// source.

func (l *Loader) Import(path string) (*types.Package, error) {

if !strings.Contains(path, ".") {

cfg := &packages.Config{Mode: packages.LoadTypes}

pkgs, err := packages.Load(cfg, path)

if err != nil {

return nil, err

}

if len(pkgs) != 1 {

panic("expected go/packages.Load to return exactly one package")

}

return pkgs[0].Types, nil

}

pkgs, err := l.Load(path)

if err != nil {

return nil, err

}

if len(pkgs) != 1 {

panic("expected Loader.Load to return exactly one package")

}

if PrintErrors(pkgs) > 0 {

// NOTE: The string "error importing package" is used to detect this

// error as the Go importer does not wrap errors.

return nil, fmt.Errorf("error importing package %q", path)

}

if pkgs[0].Types == nil {

panic("expected packages to have non-nil Types")

}

return pkgs[0].Types, nil

}

type GunkPackage struct {

packages.Package

Dir string // for now, we require all files to be in the same dir

GunkFiles []string // absolute paths of the Gunk files

GunkSyntax []*ast.File // syntax trees for the files in GunkFiles

// GunkNames are unique arbitrary names for each gunk file in GunkFiles.

// We don't want to use absolute paths when referring to files in the

// CodeGeneratorRequest, because that will trigger many generators to

// write to disk.

GunkNames []string

// GunkTags stores the "+gunk" tags associated with each syntax tree

// node in GunkSyntax.

GunkTags map[ast.Node][]GunkTag

Imports map[string]*GunkPackage

ProtoName string // protobuf package name

// errorsPrinted is true if the errors have been printed. This is used to

// deduplicate errors.

errorsPrinted bool

}

func (g *GunkPackage) errorf(kind packages.ErrorKind, tokenPos token.Pos, fset *token.FileSet, format string, args ...interface{}) {

g.addError(kind, tokenPos, fset, fmt.Errorf(format, args...))

}

func (g *GunkPackage) addError(kind packages.ErrorKind, tokenPos token.Pos, fset *token.FileSet, err error) {

pos := ""

if tokenPos > 0 && fset != nil {

pos = fset.Position(tokenPos).String()

}

// errors.As is intentionally unused to prevent losing context.

if pkgErr, ok := err.(packages.Error); ok {

pkgErr.Kind = kind

pkgErr.Pos = pos

// Don't unnecessarily wrap the error if it is already the right type.

g.Errors = append(g.Errors, pkgErr)

return

}

// Create a packages.Error to add.

msg := err.Error()

if typeErr, ok := err.(types.Error); ok {

// Populate info if the error is a type-checking error from go/types.

// This prevents an unnecessary -: at the front of error messages.

msg = typeErr.Msg

if pos == "" || pos == "-" {

pos = typeErr.Fset.Position(typeErr.Pos).String()

}

g.Errors = append(g.Errors, packages.Error{

Pos: pos,

Msg: msg,

Kind: kind,

})

}

type GunkTag struct {

ast.Expr // original expression

Type types.Type // type of the expression

Value constant.Value // constant value of the expression, if any

}

// parseGunkPackage parses the package's GunkFiles, and type-checks the package

// if l.Types is set.

func (l *Loader) parseGunkPackage(pkg *GunkPackage) {

// Clear the name before parsing to avoid Go files from triggering package

// name mismatch

pkg.Name = ""

// parse the gunk files

for _, fpath := range pkg.GunkFiles {

file, err := parser.ParseFile(l.Fset, fpath, nil, parser.ParseComments)

if err != nil {

pkg.addError(ParseError, 0, nil, err)

continue

}

// to make the generated code independent of the current

// directory when running gunk

relPath := pkg.PkgPath + "/" + filepath.Base(fpath)

pkg.GunkNames = append(pkg.GunkNames, relPath)

pkg.GunkSyntax = append(pkg.GunkSyntax, file)

if name := file.Name.Name; pkg.Name == "" {

pkg.Name = name

} else if pkg.Name != name && l.Types {

pkg.errorf(ValidateError, 0, nil, "gunk package name mismatch: %q %q",

pkg.Name, name)

}

name, err := protoPackageName(l.Fset, file)

if err != nil {

pkg.addError(ParseError, 0, nil, err)

continue

}

if pkg.ProtoName == "" {

pkg.ProtoName = name

} else if name != "" && l.Types {

pkg.errorf(ValidateError, 0, nil, "proto package name mismatch: %q %q",

pkg.ProtoName, name)

continue

}

if pkg.ProtoName == "" {

pkg.ProtoName = pkg.Name

}

// the reported error will be handle at generate.Run function.

if len(pkg.Errors) > 0 {

return

}

if !l.Types {

return

}

pkg.Types = types.NewPackage(pkg.PkgPath, pkg.Name)

tconfig := &types.Config{

DisableUnusedImportCheck: true,

Importer: l,

}

pkg.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),

Scopes: make(map[ast.Node]*types.Scope),

Selections: make(map[*ast.SelectorExpr]*types.Selection),

}

check := types.NewChecker(tconfig, l.Fset, pkg.Types, pkg.TypesInfo)

if err := check.Files(pkg.GunkSyntax); err != nil {

pkg.addError(TypeError, 0, nil, err)

return

}

pkg.Imports = make(map[string]*GunkPackage)

for _, file := range pkg.GunkSyntax {

l.splitGunkTags(pkg, file)

for _, spec := range file.Imports {

// we can't error, since the file parsed correctly

pkgPath, _ := strconv.Unquote(spec.Path.Value)

pkgs, err := l.Load(pkgPath)

if err != nil {

// shouldn't happen?

panic(err)

}

if len(pkgs) == 1 {

pkg.Imports[pkgPath] = pkgs[0]

}

// validatePackage sanity checks a gunk package, to find common errors which are

// shared among all gunk commands.

func (l *Loader) validatePackage(pkg *GunkPackage) {

for _, file := range pkg.GunkSyntax {

ast.Inspect(file, func(node ast.Node) bool {

st, ok := node.(*ast.StructType)

if !ok || st.Fields == nil {

return true

}

// Look through all fields for anonymous/unnamed types.

for _, field := range st.Fields.List {

if len(field.Names) < 1 {

pkg.errorf(ParseError, st.Pos(), l.Fset, "anonymous struct fields are not supported")

return false

}

// Check for struct tag 'pb' and ensure that if it does exist

// it is a valid integer, and it is unique in that struct.

// The other validation should happen in format and generate

// as they both treat the same error cases differently.

usedSequences := make(map[int]bool, len(st.Fields.List))

jsonNamesSeen := map[string]bool{}

for _, f := range st.Fields.List {

if f.Tag == nil {

continue

}

fieldName := f.Names[0].Name

str, _ := strconv.Unquote(f.Tag.Value)

if err := validateStructTag(str); err != nil {

pkg.errorf(ValidateError, st.Pos(), l.Fset, "error in struct tag on %s: %w", fieldName, err)

continue

}

stag := reflect.StructTag(str)

val, ok := stag.Lookup("pb")

if !ok || val == "" {

continue

}

valJson, ok := stag.Lookup("json")

if ok && valJson != "" {

if jsonNamesSeen[valJson] {

err := fmt.Errorf("json tag %q seen twice", valJson)

pkg.errorf(ValidateError, st.Pos(), l.Fset, "error in struct tag on %s: %w", fieldName, err)

continue

}

jsonNamesSeen[valJson] = true

}

sequence, err := strconv.Atoi(val)

if err != nil {

pkg.errorf(ValidateError, st.Pos(), l.Fset, "unable to convert tag to number on %s: %w", fieldName, err)

continue

}

if usedSequences[sequence] {

pkg.errorf(ValidateError, st.Pos(), l.Fset, "sequence %q on %s has already been used in this struct", val, fieldName)

continue

}

usedSequences[sequence] = true

}

return true

})

}

const protoCommentPrefix = "// proto "

func protoPackageName(fset *token.FileSet, file *ast.File) (string, error) {

packageLine := fset.Position(file.Package).Line

allComments:

for _, cgroup := range file.Comments {

for _, comment := range cgroup.List {

cline := fset.Position(comment.Pos()).Line

if cline < packageLine {

continue // comment before package line

} else if cline > packageLine {

break allComments // we're past the package line

}

quoted := strings.TrimPrefix(comment.Text, protoCommentPrefix)

if quoted == comment.Text {

continue // comment doesn't have the prefix

}

unquoted, err := strconv.Unquote(quoted)

return unquoted, err

}

// none found

return "", nil

}

type ProtoLoader struct {

// Dir is the absolute path from where the LoadProto method

// will load proto files.

// If empty, it will load from executing directory

Dir string

ProtocPath string

}

// LoadProto loads the specified protobuf packages as if they were dependencies.

// It does so with protoc, to leverage protoc's features such as locating the

// files, and the protoc parser to get a FileDescriptorProto out of the proto

// file content.

func (l *ProtoLoader) LoadProto(names ...string) ([]*descriptorpb.FileDescriptorProto, error) {

tmpl := template.Must(template.New("letter").Parse(`

syntax = "proto3";

{{range $_, $name := .}}import "{{$name}}";

`))

// Imports to load from in-memory

generatedFilesToLoad := []string{}

// Imports to load using protoc

filteredNames := make([]string, 0, len(names))

// Check to see if we are trying to load any libraries that we have

// bundled with Gunk. If so, load the generated libraries. If not, use

// protoc to load those libraries from disk.

for _, n := range names {

switch n {

case "google/api/annotations.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "google_api_annotations.fdp")

case "google/protobuf/empty.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "google_protobuf_empty.fdp")

case "google/protobuf/timestamp.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "google_protobuf_timestamp.fdp")

case "google/protobuf/duration.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "google_protobuf_duration.fdp")

case "google/protobuf/struct.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "google_protobuf_struct.fdp")

case "protoc-gen-openapiv2/options/annotations.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "protoc-gen-openapiv2_options_annotations.fdp")

case "xo/xo.proto":

generatedFilesToLoad = append(generatedFilesToLoad, "xo_xo.fdp")

default:

filteredNames = append(filteredNames, n)

}

var combinedFset descriptorpb.FileDescriptorSet

// Use protoc to load any imports that aren't currently bundles with

// Gunk.

if len(filteredNames) > 0 {

gunkProtoFile := "gunk-proto"

if l.Dir != "" {

gunkProtoFile = filepath.Join(l.Dir, gunkProtoFile)

}

importsFile, err := os.Create(gunkProtoFile)

if err != nil {

return nil, err

}

if err := tmpl.Execute(importsFile, filteredNames); err != nil {

return nil, err

}

if err := importsFile.Close(); err != nil {

return nil, err

}

defer os.Remove(gunkProtoFile)

// TODO(mvdan): any way to specify stdout while being portable?

// See https://github.com/protocolbuffers/protobuf/issues/4163.

args := []string{

"-o/dev/stdout",

"--include_imports",

gunkProtoFile,

}

if l.Dir != "" {

args = append(args, "-I"+l.Dir)

}

protocPath := "protoc"

if l.ProtocPath != "" {

protocPath = l.ProtocPath

}

cmd := log.ExecCommand(protocPath, args...)

out, err := cmd.Output()

if err != nil {

if e, ok := err.(*exec.ExitError); ok {

return nil, fmt.Errorf("protoc %s: %s", e, e.Stderr)

}

return nil, err

}

var fset descriptorpb.FileDescriptorSet

if err := proto.Unmarshal(out, &fset); err != nil {

return nil, err

}

for i := 0; i < len(fset.File); i++ {

if *fset.File[i].Name != "gunk-proto" {

continue

}

combinedFset.File = append(fset.File[:i], fset.File[i+1:]...)

}

// Load any bundled libraries.

for _, fileToLoad := range generatedFilesToLoad {

buf, err := assets.ReadFile(fileToLoad)

if err != nil {

return nil, err

}

var fset descriptorpb.FileDescriptorSet

if err := proto.Unmarshal(buf, &fset); err != nil {

return nil, err

}

combinedFset.File = append(combinedFset.File, fset.File...)

}

return combinedFset.File, nil

}

// splitGunkTags parses and typechecks gunk tags from the comments in a Gunk

// file, adding them to pkg.GunkTags and removing the source lines from each

// comment.

func (l *Loader) splitGunkTags(pkg *GunkPackage, file *ast.File) {

hadError := false

ast.Inspect(file, func(node ast.Node) bool {

if gd, ok := node.(*ast.GenDecl); ok {

if len(gd.Specs) != 1 {

return true

}

if doc := nodeDoc(gd.Specs[0]); doc != nil {

// Move the doc to the only spec, since we want +gunk tags

// attached to the type specs.

*doc = gd.Doc

}

return true

}

doc := nodeDoc(node)

if doc == nil {

return true

}

docText, exprs, err := SplitGunkTag(pkg, l.Fset, *doc)

if err != nil {

hadError = true

pkg.addError(ParseError, (*doc).Pos(), l.Fset, err)

return false

}

if len(exprs) > 0 {

if pkg.GunkTags == nil {

pkg.GunkTags = make(map[ast.Node][]GunkTag)

}

pkg.GunkTags[node] = exprs

**doc = *CommentFromText(*doc, docText)

}

return true

})

if !hadError {

for _, cg := range file.Comments {

for _, c := range cg.List {

if strings.Contains(c.Text, "+gunk") {

pkg.errorf(ParseError, c.Pos(), l.Fset, "gunk tag without declaration: %s", c.Text)

}

func nodeDoc(node ast.Node) **ast.CommentGroup {

switch node := node.(type) {

case *ast.File:

return &node.Doc

case *ast.Field:

return &node.Doc

case *ast.TypeSpec:

return &node.Doc

case *ast.ValueSpec:

return &node.Doc

}

return nil

}

// TODO(mvdan): both loader and format use CommentFromText, but it feels awkward

// to have it here.

// CommentFromText creates a multi-line comment from the given text, with its

// start and end positions matching the given node's.

func CommentFromText(orig ast.Node, text string) *ast.CommentGroup {

group := &ast.CommentGroup{}

lines := strings.Split(text, "\n")

for i, line := range lines {

comment := &ast.Comment{Text: "// " + line}

// Ensure that group.Pos() and group.End() stay on the same

// lines, to ensure that printing doesn't move the comment

// around or introduce newlines.

switch i {

case 0:

comment.Slash = orig.Pos()

case len(lines) - 1:

comment.Slash = orig.End()

}

group.List = append(group.List, comment)

}

return group

}

// SplitGunkTag splits '+gunk' tags from a comment group, returning the leading

// documentation and the tags Go expressions.

// If pkg is not nil, the tag is also type-checked using the package's type

// information.

func SplitGunkTag(pkg *GunkPackage, fset *token.FileSet, comment *ast.CommentGroup) (string, []GunkTag, error) {

// Remove the comment leading and / or trailing identifier; // and /* */ and `

docLines := strings.Split(comment.Text(), "\n")

var gunkTagLines []string

var gunkTagPos []int

var commentLines []string

foundGunkTag := false

for i, line := range docLines {

if strings.HasPrefix(line, "+gunk ") {

// Replace "+gunk" with spaces, so that we keep the

// tag's lines all starting at the same column, for

// accurate position information later.

gunkTagLine := strings.Replace(line, "+gunk", " ", 1)

gunkTagLines = append(gunkTagLines, gunkTagLine)

gunkTagPos = append(gunkTagPos, i)

foundGunkTag = true

} else if foundGunkTag {

gunkTagLines[len(gunkTagLines)-1] += "\n" + line

} else {

commentLines = append(commentLines, line)

}

if len(gunkTagLines) == 0 {

return comment.Text(), nil, nil

}

var tags []GunkTag

for i, gunkTag := range gunkTagLines {

expr, err := parser.ParseExprFrom(fset, "", gunkTag, 0)

if err != nil {

tagPos := fset.Position(comment.Pos())

tagPos.Line += gunkTagPos[i] // relative to the "+gunk" line

tagPos.Column += len("// ") // .Text() stripped these prefixes

return "", nil, ErrorAbsolutePos(err, tagPos)

}

tag := GunkTag{Expr: expr}

if pkg != nil {

tv, err := types.Eval(fset, pkg.Types, comment.Pos(), gunkTag)

if err != nil {

return "", nil, err

}

tag.Type, tag.Value = tv.Type, tv.Value

}

tags = append(tags, tag)

}

// TODO: make positions in the tag expression absolute too

strComment := strings.Join(commentLines, "\n")

return strings.TrimSpace(strComment), tags, nil

}

// ErrorAbsolutePos modifies all positions in err, considered to be relative to

// pos. This is useful so that the position information of syntax tree nodes

// parsed from a comment are relative to the entire file, and not only relative

// to the comment containing the source.

func ErrorAbsolutePos(err error, pos token.Position) error {

list, ok := err.(scanner.ErrorList)

if !ok {

return err

}

for i, err := range list {

err.Pos.Filename = pos.Filename

err.Pos.Line += pos.Line

err.Pos.Line-- // since these numbers are 1-based

err.Pos.Column += pos.Column

err.Pos.Column-- // since these numbers are 1-based

list[i] = err

}

return list

}

gunk/loader/loader.go at master · gunk/gunk · GitHub

Expand file tree

Breadcrumbs

loader.go

Latest commit

History

Breadcrumbs

loader.go

File metadata and controls