| 1 | // Copyright 2018 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // Package checker defines the implementation of the checker commands. |
| 6 | // The same code drives the multi-analysis driver, the single-analysis |
| 7 | // driver that is conventionally provided for convenience along with |
| 8 | // each analysis package, and the test driver. |
| 9 | package checker |
| 10 | |
| 11 | import ( |
| 12 | "bytes" |
| 13 | "encoding/gob" |
| 14 | "errors" |
| 15 | "flag" |
| 16 | "fmt" |
| 17 | "go/format" |
| 18 | "go/parser" |
| 19 | "go/token" |
| 20 | "go/types" |
| 21 | "io/ioutil" |
| 22 | "log" |
| 23 | "os" |
| 24 | "reflect" |
| 25 | "runtime" |
| 26 | "runtime/pprof" |
| 27 | "runtime/trace" |
| 28 | "sort" |
| 29 | "strings" |
| 30 | "sync" |
| 31 | "time" |
| 32 | |
| 33 | "golang.org/x/tools/go/analysis" |
| 34 | "golang.org/x/tools/go/analysis/internal/analysisflags" |
| 35 | "golang.org/x/tools/go/packages" |
| 36 | ) |
| 37 | |
| 38 | var ( |
| 39 | // Debug is a set of single-letter flags: |
| 40 | // |
| 41 | // f show [f]acts as they are created |
| 42 | // p disable [p]arallel execution of analyzers |
| 43 | // s do additional [s]anity checks on fact types and serialization |
| 44 | // t show [t]iming info (NB: use 'p' flag to avoid GC/scheduler noise) |
| 45 | // v show [v]erbose logging |
| 46 | // |
| 47 | Debug = "" |
| 48 | |
| 49 | // Log files for optional performance tracing. |
| 50 | CPUProfile, MemProfile, Trace string |
| 51 | |
| 52 | // IncludeTests indicates whether test files should be analyzed too. |
| 53 | IncludeTests = true |
| 54 | |
| 55 | // Fix determines whether to apply all suggested fixes. |
| 56 | Fix bool |
| 57 | ) |
| 58 | |
| 59 | // RegisterFlags registers command-line flags used by the analysis driver. |
| 60 | func RegisterFlags() { |
| 61 | // When adding flags here, remember to update |
| 62 | // the list of suppressed flags in analysisflags. |
| 63 | |
| 64 | flag.StringVar(&Debug, "debug", Debug, `debug flags, any subset of "fpstv"`) |
| 65 | |
| 66 | flag.StringVar(&CPUProfile, "cpuprofile", "", "write CPU profile to this file") |
| 67 | flag.StringVar(&MemProfile, "memprofile", "", "write memory profile to this file") |
| 68 | flag.StringVar(&Trace, "trace", "", "write trace log to this file") |
| 69 | flag.BoolVar(&IncludeTests, "test", IncludeTests, "indicates whether test files should be analyzed, too") |
| 70 | |
| 71 | flag.BoolVar(&Fix, "fix", false, "apply all suggested fixes") |
| 72 | } |
| 73 | |
| 74 | // Run loads the packages specified by args using go/packages, |
| 75 | // then applies the specified analyzers to them. |
| 76 | // Analysis flags must already have been set. |
| 77 | // It provides most of the logic for the main functions of both the |
| 78 | // singlechecker and the multi-analysis commands. |
| 79 | // It returns the appropriate exit code. |
| 80 | func Run(args []string, analyzers []*analysis.Analyzer) (exitcode int) { |
| 81 | if CPUProfile != "" { |
| 82 | f, err := os.Create(CPUProfile) |
| 83 | if err != nil { |
| 84 | log.Fatal(err) |
| 85 | } |
| 86 | if err := pprof.StartCPUProfile(f); err != nil { |
| 87 | log.Fatal(err) |
| 88 | } |
| 89 | // NB: profile won't be written in case of error. |
| 90 | defer pprof.StopCPUProfile() |
| 91 | } |
| 92 | |
| 93 | if Trace != "" { |
| 94 | f, err := os.Create(Trace) |
| 95 | if err != nil { |
| 96 | log.Fatal(err) |
| 97 | } |
| 98 | if err := trace.Start(f); err != nil { |
| 99 | log.Fatal(err) |
| 100 | } |
| 101 | // NB: trace log won't be written in case of error. |
| 102 | defer func() { |
| 103 | trace.Stop() |
| 104 | log.Printf("To view the trace, run:\n$ go tool trace view %s", Trace) |
| 105 | }() |
| 106 | } |
| 107 | |
| 108 | if MemProfile != "" { |
| 109 | f, err := os.Create(MemProfile) |
| 110 | if err != nil { |
| 111 | log.Fatal(err) |
| 112 | } |
| 113 | // NB: memprofile won't be written in case of error. |
| 114 | defer func() { |
| 115 | runtime.GC() // get up-to-date statistics |
| 116 | if err := pprof.WriteHeapProfile(f); err != nil { |
| 117 | log.Fatalf("Writing memory profile: %v", err) |
| 118 | } |
| 119 | f.Close() |
| 120 | }() |
| 121 | } |
| 122 | |
| 123 | // Load the packages. |
| 124 | if dbg('v') { |
| 125 | log.SetPrefix("") |
| 126 | log.SetFlags(log.Lmicroseconds) // display timing |
| 127 | log.Printf("load %s", args) |
| 128 | } |
| 129 | |
| 130 | // Optimization: if the selected analyzers don't produce/consume |
| 131 | // facts, we need source only for the initial packages. |
| 132 | allSyntax := needFacts(analyzers) |
| 133 | initial, err := load(args, allSyntax) |
| 134 | if err != nil { |
| 135 | if _, ok := err.(typeParseError); !ok { |
| 136 | // Fail when some of the errors are not |
| 137 | // related to parsing nor typing. |
| 138 | log.Print(err) |
| 139 | return 1 |
| 140 | } |
| 141 | // TODO: filter analyzers based on RunDespiteError? |
| 142 | } |
| 143 | |
| 144 | // Print the results. |
| 145 | roots := analyze(initial, analyzers) |
| 146 | |
| 147 | if Fix { |
| 148 | if err := applyFixes(roots); err != nil { |
| 149 | // Fail when applying fixes failed. |
| 150 | log.Print(err) |
| 151 | return 1 |
| 152 | } |
| 153 | } |
| 154 | return printDiagnostics(roots) |
| 155 | } |
| 156 | |
| 157 | // typeParseError represents a package load error |
| 158 | // that is related to typing and parsing. |
| 159 | type typeParseError struct { |
| 160 | error |
| 161 | } |
| 162 | |
| 163 | // load loads the initial packages. If all loading issues are related to |
| 164 | // typing and parsing, the returned error is of type typeParseError. |
| 165 | func load(patterns []string, allSyntax bool) ([]*packages.Package, error) { |
| 166 | mode := packages.LoadSyntax |
| 167 | if allSyntax { |
| 168 | mode = packages.LoadAllSyntax |
| 169 | } |
| 170 | conf := packages.Config{ |
| 171 | Mode: mode, |
| 172 | Tests: IncludeTests, |
| 173 | } |
| 174 | initial, err := packages.Load(&conf, patterns...) |
| 175 | if err == nil { |
| 176 | if len(initial) == 0 { |
| 177 | err = fmt.Errorf("%s matched no packages", strings.Join(patterns, " ")) |
| 178 | } else { |
| 179 | err = loadingError(initial) |
| 180 | } |
| 181 | } |
| 182 | return initial, err |
| 183 | } |
| 184 | |
| 185 | // loadingError checks for issues during the loading of initial |
| 186 | // packages. Returns nil if there are no issues. Returns error |
| 187 | // of type typeParseError if all errors, including those in |
| 188 | // dependencies, are related to typing or parsing. Otherwise, |
| 189 | // a plain error is returned with an appropriate message. |
| 190 | func loadingError(initial []*packages.Package) error { |
| 191 | var err error |
| 192 | if n := packages.PrintErrors(initial); n > 1 { |
| 193 | err = fmt.Errorf("%d errors during loading", n) |
| 194 | } else if n == 1 { |
| 195 | err = errors.New("error during loading") |
| 196 | } else { |
| 197 | // no errors |
| 198 | return nil |
| 199 | } |
| 200 | all := true |
| 201 | packages.Visit(initial, nil, func(pkg *packages.Package) { |
| 202 | for _, err := range pkg.Errors { |
| 203 | typeOrParse := err.Kind == packages.TypeError || err.Kind == packages.ParseError |
| 204 | all = all && typeOrParse |
| 205 | } |
| 206 | }) |
| 207 | if all { |
| 208 | return typeParseError{err} |
| 209 | } |
| 210 | return err |
| 211 | } |
| 212 | |
| 213 | // TestAnalyzer applies an analysis to a set of packages (and their |
| 214 | // dependencies if necessary) and returns the results. |
| 215 | // |
| 216 | // Facts about pkg are returned in a map keyed by object; package facts |
| 217 | // have a nil key. |
| 218 | // |
| 219 | // This entry point is used only by analysistest. |
| 220 | func TestAnalyzer(a *analysis.Analyzer, pkgs []*packages.Package) []*TestAnalyzerResult { |
| 221 | var results []*TestAnalyzerResult |
| 222 | for _, act := range analyze(pkgs, []*analysis.Analyzer{a}) { |
| 223 | facts := make(map[types.Object][]analysis.Fact) |
| 224 | for key, fact := range act.objectFacts { |
| 225 | if key.obj.Pkg() == act.pass.Pkg { |
| 226 | facts[key.obj] = append(facts[key.obj], fact) |
| 227 | } |
| 228 | } |
| 229 | for key, fact := range act.packageFacts { |
| 230 | if key.pkg == act.pass.Pkg { |
| 231 | facts[nil] = append(facts[nil], fact) |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | results = append(results, &TestAnalyzerResult{act.pass, act.diagnostics, facts, act.result, act.err}) |
| 236 | } |
| 237 | return results |
| 238 | } |
| 239 | |
| 240 | type TestAnalyzerResult struct { |
| 241 | Pass *analysis.Pass |
| 242 | Diagnostics []analysis.Diagnostic |
| 243 | Facts map[types.Object][]analysis.Fact |
| 244 | Result interface{} |
| 245 | Err error |
| 246 | } |
| 247 | |
| 248 | func analyze(pkgs []*packages.Package, analyzers []*analysis.Analyzer) []*action { |
| 249 | // Construct the action graph. |
| 250 | if dbg('v') { |
| 251 | log.Printf("building graph of analysis passes") |
| 252 | } |
| 253 | |
| 254 | // Each graph node (action) is one unit of analysis. |
| 255 | // Edges express package-to-package (vertical) dependencies, |
| 256 | // and analysis-to-analysis (horizontal) dependencies. |
| 257 | type key struct { |
| 258 | *analysis.Analyzer |
| 259 | *packages.Package |
| 260 | } |
| 261 | actions := make(map[key]*action) |
| 262 | |
| 263 | var mkAction func(a *analysis.Analyzer, pkg *packages.Package) *action |
| 264 | mkAction = func(a *analysis.Analyzer, pkg *packages.Package) *action { |
| 265 | k := key{a, pkg} |
| 266 | act, ok := actions[k] |
| 267 | if !ok { |
| 268 | act = &action{a: a, pkg: pkg} |
| 269 | |
| 270 | // Add a dependency on each required analyzers. |
| 271 | for _, req := range a.Requires { |
| 272 | act.deps = append(act.deps, mkAction(req, pkg)) |
| 273 | } |
| 274 | |
| 275 | // An analysis that consumes/produces facts |
| 276 | // must run on the package's dependencies too. |
| 277 | if len(a.FactTypes) > 0 { |
| 278 | paths := make([]string, 0, len(pkg.Imports)) |
| 279 | for path := range pkg.Imports { |
| 280 | paths = append(paths, path) |
| 281 | } |
| 282 | sort.Strings(paths) // for determinism |
| 283 | for _, path := range paths { |
| 284 | dep := mkAction(a, pkg.Imports[path]) |
| 285 | act.deps = append(act.deps, dep) |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | actions[k] = act |
| 290 | } |
| 291 | return act |
| 292 | } |
| 293 | |
| 294 | // Build nodes for initial packages. |
| 295 | var roots []*action |
| 296 | for _, a := range analyzers { |
| 297 | for _, pkg := range pkgs { |
| 298 | root := mkAction(a, pkg) |
| 299 | root.isroot = true |
| 300 | roots = append(roots, root) |
| 301 | } |
| 302 | } |
| 303 | |
| 304 | // Execute the graph in parallel. |
| 305 | execAll(roots) |
| 306 | |
| 307 | return roots |
| 308 | } |
| 309 | |
| 310 | func applyFixes(roots []*action) error { |
| 311 | visited := make(map[*action]bool) |
| 312 | var apply func(*action) error |
| 313 | var visitAll func(actions []*action) error |
| 314 | visitAll = func(actions []*action) error { |
| 315 | for _, act := range actions { |
| 316 | if !visited[act] { |
| 317 | visited[act] = true |
| 318 | if err := visitAll(act.deps); err != nil { |
| 319 | return err |
| 320 | } |
| 321 | if err := apply(act); err != nil { |
| 322 | return err |
| 323 | } |
| 324 | } |
| 325 | } |
| 326 | return nil |
| 327 | } |
| 328 | |
| 329 | // TODO(matloob): Is this tree business too complicated? (After all this is Go!) |
| 330 | // Just create a set (map) of edits, sort by pos and call it a day? |
| 331 | type offsetedit struct { |
| 332 | start, end int |
| 333 | newText []byte |
| 334 | } // TextEdit using byteOffsets instead of pos |
| 335 | type node struct { |
| 336 | edit offsetedit |
| 337 | left, right *node |
| 338 | } |
| 339 | // Edits x and y are equivalent. |
| 340 | equiv := func(x, y offsetedit) bool { |
| 341 | return x.start == y.start && x.end == y.end && bytes.Equal(x.newText, y.newText) |
| 342 | } |
| 343 | |
| 344 | var insert func(tree **node, edit offsetedit) error |
| 345 | insert = func(treeptr **node, edit offsetedit) error { |
| 346 | if *treeptr == nil { |
| 347 | *treeptr = &node{edit, nil, nil} |
| 348 | return nil |
| 349 | } |
| 350 | tree := *treeptr |
| 351 | if edit.end <= tree.edit.start { |
| 352 | return insert(&tree.left, edit) |
| 353 | } else if edit.start >= tree.edit.end { |
| 354 | return insert(&tree.right, edit) |
| 355 | } |
| 356 | if equiv(edit, tree.edit) { // equivalent edits? |
| 357 | // We skip over equivalent edits without considering them |
| 358 | // an error. This handles identical edits coming from the |
| 359 | // multiple ways of loading a package into a |
| 360 | // *go/packages.Packages for testing, e.g. packages "p" and "p [p.test]". |
| 361 | return nil |
| 362 | } |
| 363 | |
| 364 | // Overlapping text edit. |
| 365 | return fmt.Errorf("analyses applying overlapping text edits affecting pos range (%v, %v) and (%v, %v)", |
| 366 | edit.start, edit.end, tree.edit.start, tree.edit.end) |
| 367 | |
| 368 | } |
| 369 | |
| 370 | editsForFile := make(map[*token.File]*node) |
| 371 | |
| 372 | apply = func(act *action) error { |
| 373 | for _, diag := range act.diagnostics { |
| 374 | for _, sf := range diag.SuggestedFixes { |
| 375 | for _, edit := range sf.TextEdits { |
| 376 | // Validate the edit. |
| 377 | if edit.Pos > edit.End { |
| 378 | return fmt.Errorf( |
| 379 | "diagnostic for analysis %v contains Suggested Fix with malformed edit: pos (%v) > end (%v)", |
| 380 | act.a.Name, edit.Pos, edit.End) |
| 381 | } |
| 382 | file, endfile := act.pkg.Fset.File(edit.Pos), act.pkg.Fset.File(edit.End) |
| 383 | if file == nil || endfile == nil || file != endfile { |
| 384 | return (fmt.Errorf( |
| 385 | "diagnostic for analysis %v contains Suggested Fix with malformed spanning files %v and %v", |
| 386 | act.a.Name, file.Name(), endfile.Name())) |
| 387 | } |
| 388 | start, end := file.Offset(edit.Pos), file.Offset(edit.End) |
| 389 | |
| 390 | // TODO(matloob): Validate that edits do not affect other packages. |
| 391 | root := editsForFile[file] |
| 392 | if err := insert(&root, offsetedit{start, end, edit.NewText}); err != nil { |
| 393 | return err |
| 394 | } |
| 395 | editsForFile[file] = root // In case the root changed |
| 396 | } |
| 397 | } |
| 398 | } |
| 399 | return nil |
| 400 | } |
| 401 | |
| 402 | if err := visitAll(roots); err != nil { |
| 403 | return err |
| 404 | } |
| 405 | |
| 406 | fset := token.NewFileSet() // Shared by parse calls below |
| 407 | // Now we've got a set of valid edits for each file. Get the new file contents. |
| 408 | for f, tree := range editsForFile { |
| 409 | contents, err := ioutil.ReadFile(f.Name()) |
| 410 | if err != nil { |
| 411 | return err |
| 412 | } |
| 413 | |
| 414 | cur := 0 // current position in the file |
| 415 | |
| 416 | var out bytes.Buffer |
| 417 | |
| 418 | var recurse func(*node) |
| 419 | recurse = func(node *node) { |
| 420 | if node.left != nil { |
| 421 | recurse(node.left) |
| 422 | } |
| 423 | |
| 424 | edit := node.edit |
| 425 | if edit.start > cur { |
| 426 | out.Write(contents[cur:edit.start]) |
| 427 | out.Write(edit.newText) |
| 428 | } else if cur == 0 && edit.start == 0 { // edit starts at first character? |
| 429 | out.Write(edit.newText) |
| 430 | } |
| 431 | cur = edit.end |
| 432 | |
| 433 | if node.right != nil { |
| 434 | recurse(node.right) |
| 435 | } |
| 436 | } |
| 437 | recurse(tree) |
| 438 | // Write out the rest of the file. |
| 439 | if cur < len(contents) { |
| 440 | out.Write(contents[cur:]) |
| 441 | } |
| 442 | |
| 443 | // Try to format the file. |
| 444 | ff, err := parser.ParseFile(fset, f.Name(), out.Bytes(), parser.ParseComments) |
| 445 | if err == nil { |
| 446 | var buf bytes.Buffer |
| 447 | if err = format.Node(&buf, fset, ff); err == nil { |
| 448 | out = buf |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | if err := ioutil.WriteFile(f.Name(), out.Bytes(), 0644); err != nil { |
| 453 | return err |
| 454 | } |
| 455 | } |
| 456 | return nil |
| 457 | } |
| 458 | |
| 459 | // printDiagnostics prints the diagnostics for the root packages in either |
| 460 | // plain text or JSON format. JSON format also includes errors for any |
| 461 | // dependencies. |
| 462 | // |
| 463 | // It returns the exitcode: in plain mode, 0 for success, 1 for analysis |
| 464 | // errors, and 3 for diagnostics. We avoid 2 since the flag package uses |
| 465 | // it. JSON mode always succeeds at printing errors and diagnostics in a |
| 466 | // structured form to stdout. |
| 467 | func printDiagnostics(roots []*action) (exitcode int) { |
| 468 | // Print the output. |
| 469 | // |
| 470 | // Print diagnostics only for root packages, |
| 471 | // but errors for all packages. |
| 472 | printed := make(map[*action]bool) |
| 473 | var print func(*action) |
| 474 | var visitAll func(actions []*action) |
| 475 | visitAll = func(actions []*action) { |
| 476 | for _, act := range actions { |
| 477 | if !printed[act] { |
| 478 | printed[act] = true |
| 479 | visitAll(act.deps) |
| 480 | print(act) |
| 481 | } |
| 482 | } |
| 483 | } |
| 484 | |
| 485 | if analysisflags.JSON { |
| 486 | // JSON output |
| 487 | tree := make(analysisflags.JSONTree) |
| 488 | print = func(act *action) { |
| 489 | var diags []analysis.Diagnostic |
| 490 | if act.isroot { |
| 491 | diags = act.diagnostics |
| 492 | } |
| 493 | tree.Add(act.pkg.Fset, act.pkg.ID, act.a.Name, diags, act.err) |
| 494 | } |
| 495 | visitAll(roots) |
| 496 | tree.Print() |
| 497 | } else { |
| 498 | // plain text output |
| 499 | |
| 500 | // De-duplicate diagnostics by position (not token.Pos) to |
| 501 | // avoid double-reporting in source files that belong to |
| 502 | // multiple packages, such as foo and foo.test. |
| 503 | type key struct { |
| 504 | pos token.Position |
| 505 | end token.Position |
| 506 | *analysis.Analyzer |
| 507 | message string |
| 508 | } |
| 509 | seen := make(map[key]bool) |
| 510 | |
| 511 | print = func(act *action) { |
| 512 | if act.err != nil { |
| 513 | fmt.Fprintf(os.Stderr, "%s: %v\n", act.a.Name, act.err) |
| 514 | exitcode = 1 // analysis failed, at least partially |
| 515 | return |
| 516 | } |
| 517 | if act.isroot { |
| 518 | for _, diag := range act.diagnostics { |
| 519 | // We don't display a.Name/f.Category |
| 520 | // as most users don't care. |
| 521 | |
| 522 | posn := act.pkg.Fset.Position(diag.Pos) |
| 523 | end := act.pkg.Fset.Position(diag.End) |
| 524 | k := key{posn, end, act.a, diag.Message} |
| 525 | if seen[k] { |
| 526 | continue // duplicate |
| 527 | } |
| 528 | seen[k] = true |
| 529 | |
| 530 | analysisflags.PrintPlain(act.pkg.Fset, diag) |
| 531 | } |
| 532 | } |
| 533 | } |
| 534 | visitAll(roots) |
| 535 | |
| 536 | if exitcode == 0 && len(seen) > 0 { |
| 537 | exitcode = 3 // successfully produced diagnostics |
| 538 | } |
| 539 | } |
| 540 | |
| 541 | // Print timing info. |
| 542 | if dbg('t') { |
| 543 | if !dbg('p') { |
| 544 | log.Println("Warning: times are mostly GC/scheduler noise; use -debug=tp to disable parallelism") |
| 545 | } |
| 546 | var all []*action |
| 547 | var total time.Duration |
| 548 | for act := range printed { |
| 549 | all = append(all, act) |
| 550 | total += act.duration |
| 551 | } |
| 552 | sort.Slice(all, func(i, j int) bool { |
| 553 | return all[i].duration > all[j].duration |
| 554 | }) |
| 555 | |
| 556 | // Print actions accounting for 90% of the total. |
| 557 | var sum time.Duration |
| 558 | for _, act := range all { |
| 559 | fmt.Fprintf(os.Stderr, "%s\t%s\n", act.duration, act) |
| 560 | sum += act.duration |
| 561 | if sum >= total*9/10 { |
| 562 | break |
| 563 | } |
| 564 | } |
| 565 | } |
| 566 | |
| 567 | return exitcode |
| 568 | } |
| 569 | |
| 570 | // needFacts reports whether any analysis required by the specified set |
| 571 | // needs facts. If so, we must load the entire program from source. |
| 572 | func needFacts(analyzers []*analysis.Analyzer) bool { |
| 573 | seen := make(map[*analysis.Analyzer]bool) |
| 574 | var q []*analysis.Analyzer // for BFS |
| 575 | q = append(q, analyzers...) |
| 576 | for len(q) > 0 { |
| 577 | a := q[0] |
| 578 | q = q[1:] |
| 579 | if !seen[a] { |
| 580 | seen[a] = true |
| 581 | if len(a.FactTypes) > 0 { |
| 582 | return true |
| 583 | } |
| 584 | q = append(q, a.Requires...) |
| 585 | } |
| 586 | } |
| 587 | return false |
| 588 | } |
| 589 | |
| 590 | // An action represents one unit of analysis work: the application of |
| 591 | // one analysis to one package. Actions form a DAG, both within a |
| 592 | // package (as different analyzers are applied, either in sequence or |
| 593 | // parallel), and across packages (as dependencies are analyzed). |
| 594 | type action struct { |
| 595 | once sync.Once |
| 596 | a *analysis.Analyzer |
| 597 | pkg *packages.Package |
| 598 | pass *analysis.Pass |
| 599 | isroot bool |
| 600 | deps []*action |
| 601 | objectFacts map[objectFactKey]analysis.Fact |
| 602 | packageFacts map[packageFactKey]analysis.Fact |
| 603 | result interface{} |
| 604 | diagnostics []analysis.Diagnostic |
| 605 | err error |
| 606 | duration time.Duration |
| 607 | } |
| 608 | |
| 609 | type objectFactKey struct { |
| 610 | obj types.Object |
| 611 | typ reflect.Type |
| 612 | } |
| 613 | |
| 614 | type packageFactKey struct { |
| 615 | pkg *types.Package |
| 616 | typ reflect.Type |
| 617 | } |
| 618 | |
| 619 | func (act *action) String() string { |
| 620 | return fmt.Sprintf("%s@%s", act.a, act.pkg) |
| 621 | } |
| 622 | |
| 623 | func execAll(actions []*action) { |
| 624 | sequential := dbg('p') |
| 625 | var wg sync.WaitGroup |
| 626 | for _, act := range actions { |
| 627 | wg.Add(1) |
| 628 | work := func(act *action) { |
| 629 | act.exec() |
| 630 | wg.Done() |
| 631 | } |
| 632 | if sequential { |
| 633 | work(act) |
| 634 | } else { |
| 635 | go work(act) |
| 636 | } |
| 637 | } |
| 638 | wg.Wait() |
| 639 | } |
| 640 | |
| 641 | func (act *action) exec() { act.once.Do(act.execOnce) } |
| 642 | |
| 643 | func (act *action) execOnce() { |
| 644 | // Analyze dependencies. |
| 645 | execAll(act.deps) |
| 646 | |
| 647 | // TODO(adonovan): uncomment this during profiling. |
| 648 | // It won't build pre-go1.11 but conditional compilation |
| 649 | // using build tags isn't warranted. |
| 650 | // |
| 651 | // ctx, task := trace.NewTask(context.Background(), "exec") |
| 652 | // trace.Log(ctx, "pass", act.String()) |
| 653 | // defer task.End() |
| 654 | |
| 655 | // Record time spent in this node but not its dependencies. |
| 656 | // In parallel mode, due to GC/scheduler contention, the |
| 657 | // time is 5x higher than in sequential mode, even with a |
| 658 | // semaphore limiting the number of threads here. |
| 659 | // So use -debug=tp. |
| 660 | if dbg('t') { |
| 661 | t0 := time.Now() |
| 662 | defer func() { act.duration = time.Since(t0) }() |
| 663 | } |
| 664 | |
| 665 | // Report an error if any dependency failed. |
| 666 | var failed []string |
| 667 | for _, dep := range act.deps { |
| 668 | if dep.err != nil { |
| 669 | failed = append(failed, dep.String()) |
| 670 | } |
| 671 | } |
| 672 | if failed != nil { |
| 673 | sort.Strings(failed) |
| 674 | act.err = fmt.Errorf("failed prerequisites: %s", strings.Join(failed, ", ")) |
| 675 | return |
| 676 | } |
| 677 | |
| 678 | // Plumb the output values of the dependencies |
| 679 | // into the inputs of this action. Also facts. |
| 680 | inputs := make(map[*analysis.Analyzer]interface{}) |
| 681 | act.objectFacts = make(map[objectFactKey]analysis.Fact) |
| 682 | act.packageFacts = make(map[packageFactKey]analysis.Fact) |
| 683 | for _, dep := range act.deps { |
| 684 | if dep.pkg == act.pkg { |
| 685 | // Same package, different analysis (horizontal edge): |
| 686 | // in-memory outputs of prerequisite analyzers |
| 687 | // become inputs to this analysis pass. |
| 688 | inputs[dep.a] = dep.result |
| 689 | |
| 690 | } else if dep.a == act.a { // (always true) |
| 691 | // Same analysis, different package (vertical edge): |
| 692 | // serialized facts produced by prerequisite analysis |
| 693 | // become available to this analysis pass. |
| 694 | inheritFacts(act, dep) |
| 695 | } |
| 696 | } |
| 697 | |
| 698 | // Run the analysis. |
| 699 | pass := &analysis.Pass{ |
| 700 | Analyzer: act.a, |
| 701 | Fset: act.pkg.Fset, |
| 702 | Files: act.pkg.Syntax, |
| 703 | OtherFiles: act.pkg.OtherFiles, |
| 704 | IgnoredFiles: act.pkg.IgnoredFiles, |
| 705 | Pkg: act.pkg.Types, |
| 706 | TypesInfo: act.pkg.TypesInfo, |
| 707 | TypesSizes: act.pkg.TypesSizes, |
| 708 | TypeErrors: act.pkg.TypeErrors, |
| 709 | |
| 710 | ResultOf: inputs, |
| 711 | Report: func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) }, |
| 712 | ImportObjectFact: act.importObjectFact, |
| 713 | ExportObjectFact: act.exportObjectFact, |
| 714 | ImportPackageFact: act.importPackageFact, |
| 715 | ExportPackageFact: act.exportPackageFact, |
| 716 | AllObjectFacts: act.allObjectFacts, |
| 717 | AllPackageFacts: act.allPackageFacts, |
| 718 | } |
| 719 | act.pass = pass |
| 720 | |
| 721 | var err error |
| 722 | if act.pkg.IllTyped && !pass.Analyzer.RunDespiteErrors { |
| 723 | err = fmt.Errorf("analysis skipped due to errors in package") |
| 724 | } else { |
| 725 | act.result, err = pass.Analyzer.Run(pass) |
| 726 | if err == nil { |
| 727 | if got, want := reflect.TypeOf(act.result), pass.Analyzer.ResultType; got != want { |
| 728 | err = fmt.Errorf( |
| 729 | "internal error: on package %s, analyzer %s returned a result of type %v, but declared ResultType %v", |
| 730 | pass.Pkg.Path(), pass.Analyzer, got, want) |
| 731 | } |
| 732 | } |
| 733 | } |
| 734 | act.err = err |
| 735 | |
| 736 | // disallow calls after Run |
| 737 | pass.ExportObjectFact = nil |
| 738 | pass.ExportPackageFact = nil |
| 739 | } |
| 740 | |
| 741 | // inheritFacts populates act.facts with |
| 742 | // those it obtains from its dependency, dep. |
| 743 | func inheritFacts(act, dep *action) { |
| 744 | serialize := dbg('s') |
| 745 | |
| 746 | for key, fact := range dep.objectFacts { |
| 747 | // Filter out facts related to objects |
| 748 | // that are irrelevant downstream |
| 749 | // (equivalently: not in the compiler export data). |
| 750 | if !exportedFrom(key.obj, dep.pkg.Types) { |
| 751 | if false { |
| 752 | log.Printf("%v: discarding %T fact from %s for %s: %s", act, fact, dep, key.obj, fact) |
| 753 | } |
| 754 | continue |
| 755 | } |
| 756 | |
| 757 | // Optionally serialize/deserialize fact |
| 758 | // to verify that it works across address spaces. |
| 759 | if serialize { |
| 760 | encodedFact, err := codeFact(fact) |
| 761 | if err != nil { |
| 762 | log.Panicf("internal error: encoding of %T fact failed in %v: %v", fact, act, err) |
| 763 | } |
| 764 | fact = encodedFact |
| 765 | } |
| 766 | |
| 767 | if false { |
| 768 | log.Printf("%v: inherited %T fact for %s: %s", act, fact, key.obj, fact) |
| 769 | } |
| 770 | act.objectFacts[key] = fact |
| 771 | } |
| 772 | |
| 773 | for key, fact := range dep.packageFacts { |
| 774 | // TODO: filter out facts that belong to |
| 775 | // packages not mentioned in the export data |
| 776 | // to prevent side channels. |
| 777 | |
| 778 | // Optionally serialize/deserialize fact |
| 779 | // to verify that it works across address spaces |
| 780 | // and is deterministic. |
| 781 | if serialize { |
| 782 | encodedFact, err := codeFact(fact) |
| 783 | if err != nil { |
| 784 | log.Panicf("internal error: encoding of %T fact failed in %v", fact, act) |
| 785 | } |
| 786 | fact = encodedFact |
| 787 | } |
| 788 | |
| 789 | if false { |
| 790 | log.Printf("%v: inherited %T fact for %s: %s", act, fact, key.pkg.Path(), fact) |
| 791 | } |
| 792 | act.packageFacts[key] = fact |
| 793 | } |
| 794 | } |
| 795 | |
| 796 | // codeFact encodes then decodes a fact, |
| 797 | // just to exercise that logic. |
| 798 | func codeFact(fact analysis.Fact) (analysis.Fact, error) { |
| 799 | // We encode facts one at a time. |
| 800 | // A real modular driver would emit all facts |
| 801 | // into one encoder to improve gob efficiency. |
| 802 | var buf bytes.Buffer |
| 803 | if err := gob.NewEncoder(&buf).Encode(fact); err != nil { |
| 804 | return nil, err |
| 805 | } |
| 806 | |
| 807 | // Encode it twice and assert that we get the same bits. |
| 808 | // This helps detect nondeterministic Gob encoding (e.g. of maps). |
| 809 | var buf2 bytes.Buffer |
| 810 | if err := gob.NewEncoder(&buf2).Encode(fact); err != nil { |
| 811 | return nil, err |
| 812 | } |
| 813 | if !bytes.Equal(buf.Bytes(), buf2.Bytes()) { |
| 814 | return nil, fmt.Errorf("encoding of %T fact is nondeterministic", fact) |
| 815 | } |
| 816 | |
| 817 | new := reflect.New(reflect.TypeOf(fact).Elem()).Interface().(analysis.Fact) |
| 818 | if err := gob.NewDecoder(&buf).Decode(new); err != nil { |
| 819 | return nil, err |
| 820 | } |
| 821 | return new, nil |
| 822 | } |
| 823 | |
| 824 | // exportedFrom reports whether obj may be visible to a package that imports pkg. |
| 825 | // This includes not just the exported members of pkg, but also unexported |
| 826 | // constants, types, fields, and methods, perhaps belonging to other packages, |
| 827 | // that find there way into the API. |
| 828 | // This is an overapproximation of the more accurate approach used by |
| 829 | // gc export data, which walks the type graph, but it's much simpler. |
| 830 | // |
| 831 | // TODO(adonovan): do more accurate filtering by walking the type graph. |
| 832 | func exportedFrom(obj types.Object, pkg *types.Package) bool { |
| 833 | switch obj := obj.(type) { |
| 834 | case *types.Func: |
| 835 | return obj.Exported() && obj.Pkg() == pkg || |
| 836 | obj.Type().(*types.Signature).Recv() != nil |
| 837 | case *types.Var: |
| 838 | if obj.IsField() { |
| 839 | return true |
| 840 | } |
| 841 | // we can't filter more aggressively than this because we need |
| 842 | // to consider function parameters exported, but have no way |
| 843 | // of telling apart function parameters from local variables. |
| 844 | return obj.Pkg() == pkg |
| 845 | case *types.TypeName, *types.Const: |
| 846 | return true |
| 847 | } |
| 848 | return false // Nil, Builtin, Label, or PkgName |
| 849 | } |
| 850 | |
| 851 | // importObjectFact implements Pass.ImportObjectFact. |
| 852 | // Given a non-nil pointer ptr of type *T, where *T satisfies Fact, |
| 853 | // importObjectFact copies the fact value to *ptr. |
| 854 | func (act *action) importObjectFact(obj types.Object, ptr analysis.Fact) bool { |
| 855 | if obj == nil { |
| 856 | panic("nil object") |
| 857 | } |
| 858 | key := objectFactKey{obj, factType(ptr)} |
| 859 | if v, ok := act.objectFacts[key]; ok { |
| 860 | reflect.ValueOf(ptr).Elem().Set(reflect.ValueOf(v).Elem()) |
| 861 | return true |
| 862 | } |
| 863 | return false |
| 864 | } |
| 865 | |
| 866 | // exportObjectFact implements Pass.ExportObjectFact. |
| 867 | func (act *action) exportObjectFact(obj types.Object, fact analysis.Fact) { |
| 868 | if act.pass.ExportObjectFact == nil { |
| 869 | log.Panicf("%s: Pass.ExportObjectFact(%s, %T) called after Run", act, obj, fact) |
| 870 | } |
| 871 | |
| 872 | if obj.Pkg() != act.pkg.Types { |
| 873 | log.Panicf("internal error: in analysis %s of package %s: Fact.Set(%s, %T): can't set facts on objects belonging another package", |
| 874 | act.a, act.pkg, obj, fact) |
| 875 | } |
| 876 | |
| 877 | key := objectFactKey{obj, factType(fact)} |
| 878 | act.objectFacts[key] = fact // clobber any existing entry |
| 879 | if dbg('f') { |
| 880 | objstr := types.ObjectString(obj, (*types.Package).Name) |
| 881 | fmt.Fprintf(os.Stderr, "%s: object %s has fact %s\n", |
| 882 | act.pkg.Fset.Position(obj.Pos()), objstr, fact) |
| 883 | } |
| 884 | } |
| 885 | |
| 886 | // allObjectFacts implements Pass.AllObjectFacts. |
| 887 | func (act *action) allObjectFacts() []analysis.ObjectFact { |
| 888 | facts := make([]analysis.ObjectFact, 0, len(act.objectFacts)) |
| 889 | for k := range act.objectFacts { |
| 890 | facts = append(facts, analysis.ObjectFact{Object: k.obj, Fact: act.objectFacts[k]}) |
| 891 | } |
| 892 | return facts |
| 893 | } |
| 894 | |
| 895 | // importPackageFact implements Pass.ImportPackageFact. |
| 896 | // Given a non-nil pointer ptr of type *T, where *T satisfies Fact, |
| 897 | // fact copies the fact value to *ptr. |
| 898 | func (act *action) importPackageFact(pkg *types.Package, ptr analysis.Fact) bool { |
| 899 | if pkg == nil { |
| 900 | panic("nil package") |
| 901 | } |
| 902 | key := packageFactKey{pkg, factType(ptr)} |
| 903 | if v, ok := act.packageFacts[key]; ok { |
| 904 | reflect.ValueOf(ptr).Elem().Set(reflect.ValueOf(v).Elem()) |
| 905 | return true |
| 906 | } |
| 907 | return false |
| 908 | } |
| 909 | |
| 910 | // exportPackageFact implements Pass.ExportPackageFact. |
| 911 | func (act *action) exportPackageFact(fact analysis.Fact) { |
| 912 | if act.pass.ExportPackageFact == nil { |
| 913 | log.Panicf("%s: Pass.ExportPackageFact(%T) called after Run", act, fact) |
| 914 | } |
| 915 | |
| 916 | key := packageFactKey{act.pass.Pkg, factType(fact)} |
| 917 | act.packageFacts[key] = fact // clobber any existing entry |
| 918 | if dbg('f') { |
| 919 | fmt.Fprintf(os.Stderr, "%s: package %s has fact %s\n", |
| 920 | act.pkg.Fset.Position(act.pass.Files[0].Pos()), act.pass.Pkg.Path(), fact) |
| 921 | } |
| 922 | } |
| 923 | |
| 924 | func factType(fact analysis.Fact) reflect.Type { |
| 925 | t := reflect.TypeOf(fact) |
| 926 | if t.Kind() != reflect.Ptr { |
| 927 | log.Fatalf("invalid Fact type: got %T, want pointer", fact) |
| 928 | } |
| 929 | return t |
| 930 | } |
| 931 | |
| 932 | // allObjectFacts implements Pass.AllObjectFacts. |
| 933 | func (act *action) allPackageFacts() []analysis.PackageFact { |
| 934 | facts := make([]analysis.PackageFact, 0, len(act.packageFacts)) |
| 935 | for k := range act.packageFacts { |
| 936 | facts = append(facts, analysis.PackageFact{Package: k.pkg, Fact: act.packageFacts[k]}) |
| 937 | } |
| 938 | return facts |
| 939 | } |
| 940 | |
| 941 | func dbg(b byte) bool { return strings.IndexByte(Debug, b) >= 0 } |
| 942 |
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