| 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 | // The unitchecker package defines the main function for an analysis |
| 6 | // driver that analyzes a single compilation unit during a build. |
| 7 | // It is invoked by a build system such as "go vet": |
| 8 | // |
| 9 | // $ go vet -vettool=$(which vet) |
| 10 | // |
| 11 | // It supports the following command-line protocol: |
| 12 | // |
| 13 | // -V=full describe executable (to the build tool) |
| 14 | // -flags describe flags (to the build tool) |
| 15 | // foo.cfg description of compilation unit (from the build tool) |
| 16 | // |
| 17 | // This package does not depend on go/packages. |
| 18 | // If you need a standalone tool, use multichecker, |
| 19 | // which supports this mode but can also load packages |
| 20 | // from source using go/packages. |
| 21 | package unitchecker |
| 22 | |
| 23 | // TODO(adonovan): |
| 24 | // - with gccgo, go build does not build standard library, |
| 25 | // so we will not get to analyze it. Yet we must in order |
| 26 | // to create base facts for, say, the fmt package for the |
| 27 | // printf checker. |
| 28 | |
| 29 | import ( |
| 30 | "encoding/gob" |
| 31 | "encoding/json" |
| 32 | "flag" |
| 33 | "fmt" |
| 34 | "go/ast" |
| 35 | "go/build" |
| 36 | "go/importer" |
| 37 | "go/parser" |
| 38 | "go/token" |
| 39 | "go/types" |
| 40 | "io" |
| 41 | "io/ioutil" |
| 42 | "log" |
| 43 | "os" |
| 44 | "path/filepath" |
| 45 | "reflect" |
| 46 | "sort" |
| 47 | "strings" |
| 48 | "sync" |
| 49 | "time" |
| 50 | |
| 51 | "golang.org/x/tools/go/analysis" |
| 52 | "golang.org/x/tools/go/analysis/internal/analysisflags" |
| 53 | "golang.org/x/tools/internal/facts" |
| 54 | "golang.org/x/tools/internal/typeparams" |
| 55 | ) |
| 56 | |
| 57 | // A Config describes a compilation unit to be analyzed. |
| 58 | // It is provided to the tool in a JSON-encoded file |
| 59 | // whose name ends with ".cfg". |
| 60 | type Config struct { |
| 61 | ID string // e.g. "fmt [fmt.test]" |
| 62 | Compiler string |
| 63 | Dir string |
| 64 | ImportPath string |
| 65 | GoFiles []string |
| 66 | NonGoFiles []string |
| 67 | IgnoredFiles []string |
| 68 | ImportMap map[string]string |
| 69 | PackageFile map[string]string |
| 70 | Standard map[string]bool |
| 71 | PackageVetx map[string]string |
| 72 | VetxOnly bool |
| 73 | VetxOutput string |
| 74 | SucceedOnTypecheckFailure bool |
| 75 | } |
| 76 | |
| 77 | // Main is the main function of a vet-like analysis tool that must be |
| 78 | // invoked by a build system to analyze a single package. |
| 79 | // |
| 80 | // The protocol required by 'go vet -vettool=...' is that the tool must support: |
| 81 | // |
| 82 | // -flags describe flags in JSON |
| 83 | // -V=full describe executable for build caching |
| 84 | // foo.cfg perform separate modular analyze on the single |
| 85 | // unit described by a JSON config file foo.cfg. |
| 86 | func Main(analyzers ...*analysis.Analyzer) { |
| 87 | progname := filepath.Base(os.Args[0]) |
| 88 | log.SetFlags(0) |
| 89 | log.SetPrefix(progname + ": ") |
| 90 | |
| 91 | if err := analysis.Validate(analyzers); err != nil { |
| 92 | log.Fatal(err) |
| 93 | } |
| 94 | |
| 95 | flag.Usage = func() { |
| 96 | fmt.Fprintf(os.Stderr, `%[1]s is a tool for static analysis of Go programs. |
| 97 | |
| 98 | Usage of %[1]s: |
| 99 | %.16[1]s unit.cfg # execute analysis specified by config file |
| 100 | %.16[1]s help # general help, including listing analyzers and flags |
| 101 | %.16[1]s help name # help on specific analyzer and its flags |
| 102 | `, progname) |
| 103 | os.Exit(1) |
| 104 | } |
| 105 | |
| 106 | analyzers = analysisflags.Parse(analyzers, true) |
| 107 | |
| 108 | args := flag.Args() |
| 109 | if len(args) == 0 { |
| 110 | flag.Usage() |
| 111 | } |
| 112 | if args[0] == "help" { |
| 113 | analysisflags.Help(progname, analyzers, args[1:]) |
| 114 | os.Exit(0) |
| 115 | } |
| 116 | if len(args) != 1 || !strings.HasSuffix(args[0], ".cfg") { |
| 117 | log.Fatalf(`invoking "go tool vet" directly is unsupported; use "go vet"`) |
| 118 | } |
| 119 | Run(args[0], analyzers) |
| 120 | } |
| 121 | |
| 122 | // Run reads the *.cfg file, runs the analysis, |
| 123 | // and calls os.Exit with an appropriate error code. |
| 124 | // It assumes flags have already been set. |
| 125 | func Run(configFile string, analyzers []*analysis.Analyzer) { |
| 126 | cfg, err := readConfig(configFile) |
| 127 | if err != nil { |
| 128 | log.Fatal(err) |
| 129 | } |
| 130 | |
| 131 | fset := token.NewFileSet() |
| 132 | results, err := run(fset, cfg, analyzers) |
| 133 | if err != nil { |
| 134 | log.Fatal(err) |
| 135 | } |
| 136 | |
| 137 | // In VetxOnly mode, the analysis is run only for facts. |
| 138 | if !cfg.VetxOnly { |
| 139 | if analysisflags.JSON { |
| 140 | // JSON output |
| 141 | tree := make(analysisflags.JSONTree) |
| 142 | for _, res := range results { |
| 143 | tree.Add(fset, cfg.ID, res.a.Name, res.diagnostics, res.err) |
| 144 | } |
| 145 | tree.Print() |
| 146 | } else { |
| 147 | // plain text |
| 148 | exit := 0 |
| 149 | for _, res := range results { |
| 150 | if res.err != nil { |
| 151 | log.Println(res.err) |
| 152 | exit = 1 |
| 153 | } |
| 154 | } |
| 155 | for _, res := range results { |
| 156 | for _, diag := range res.diagnostics { |
| 157 | analysisflags.PrintPlain(fset, diag) |
| 158 | exit = 1 |
| 159 | } |
| 160 | } |
| 161 | os.Exit(exit) |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | os.Exit(0) |
| 166 | } |
| 167 | |
| 168 | func readConfig(filename string) (*Config, error) { |
| 169 | data, err := ioutil.ReadFile(filename) |
| 170 | if err != nil { |
| 171 | return nil, err |
| 172 | } |
| 173 | cfg := new(Config) |
| 174 | if err := json.Unmarshal(data, cfg); err != nil { |
| 175 | return nil, fmt.Errorf("cannot decode JSON config file %s: %v", filename, err) |
| 176 | } |
| 177 | if len(cfg.GoFiles) == 0 { |
| 178 | // The go command disallows packages with no files. |
| 179 | // The only exception is unsafe, but the go command |
| 180 | // doesn't call vet on it. |
| 181 | return nil, fmt.Errorf("package has no files: %s", cfg.ImportPath) |
| 182 | } |
| 183 | return cfg, nil |
| 184 | } |
| 185 | |
| 186 | var importerForCompiler = func(_ *token.FileSet, compiler string, lookup importer.Lookup) types.Importer { |
| 187 | // broken legacy implementation (https://golang.org/issue/28995) |
| 188 | return importer.For(compiler, lookup) |
| 189 | } |
| 190 | |
| 191 | func run(fset *token.FileSet, cfg *Config, analyzers []*analysis.Analyzer) ([]result, error) { |
| 192 | // Load, parse, typecheck. |
| 193 | var files []*ast.File |
| 194 | for _, name := range cfg.GoFiles { |
| 195 | f, err := parser.ParseFile(fset, name, nil, parser.ParseComments) |
| 196 | if err != nil { |
| 197 | if cfg.SucceedOnTypecheckFailure { |
| 198 | // Silently succeed; let the compiler |
| 199 | // report parse errors. |
| 200 | err = nil |
| 201 | } |
| 202 | return nil, err |
| 203 | } |
| 204 | files = append(files, f) |
| 205 | } |
| 206 | compilerImporter := importerForCompiler(fset, cfg.Compiler, func(path string) (io.ReadCloser, error) { |
| 207 | // path is a resolved package path, not an import path. |
| 208 | file, ok := cfg.PackageFile[path] |
| 209 | if !ok { |
| 210 | if cfg.Compiler == "gccgo" && cfg.Standard[path] { |
| 211 | return nil, nil // fall back to default gccgo lookup |
| 212 | } |
| 213 | return nil, fmt.Errorf("no package file for %q", path) |
| 214 | } |
| 215 | return os.Open(file) |
| 216 | }) |
| 217 | importer := importerFunc(func(importPath string) (*types.Package, error) { |
| 218 | path, ok := cfg.ImportMap[importPath] // resolve vendoring, etc |
| 219 | if !ok { |
| 220 | return nil, fmt.Errorf("can't resolve import %q", path) |
| 221 | } |
| 222 | return compilerImporter.Import(path) |
| 223 | }) |
| 224 | tc := &types.Config{ |
| 225 | Importer: importer, |
| 226 | Sizes: types.SizesFor("gc", build.Default.GOARCH), // assume gccgo ≡ gc? |
| 227 | } |
| 228 | info := &types.Info{ |
| 229 | Types: make(map[ast.Expr]types.TypeAndValue), |
| 230 | Defs: make(map[*ast.Ident]types.Object), |
| 231 | Uses: make(map[*ast.Ident]types.Object), |
| 232 | Implicits: make(map[ast.Node]types.Object), |
| 233 | Scopes: make(map[ast.Node]*types.Scope), |
| 234 | Selections: make(map[*ast.SelectorExpr]*types.Selection), |
| 235 | } |
| 236 | typeparams.InitInstanceInfo(info) |
| 237 | |
| 238 | pkg, err := tc.Check(cfg.ImportPath, fset, files, info) |
| 239 | if err != nil { |
| 240 | if cfg.SucceedOnTypecheckFailure { |
| 241 | // Silently succeed; let the compiler |
| 242 | // report type errors. |
| 243 | err = nil |
| 244 | } |
| 245 | return nil, err |
| 246 | } |
| 247 | |
| 248 | // Register fact types with gob. |
| 249 | // In VetxOnly mode, analyzers are only for their facts, |
| 250 | // so we can skip any analysis that neither produces facts |
| 251 | // nor depends on any analysis that produces facts. |
| 252 | // |
| 253 | // TODO(adonovan): fix: the command (and logic!) here are backwards. |
| 254 | // It should say "...nor is required by any...". (Issue 443099) |
| 255 | // |
| 256 | // Also build a map to hold working state and result. |
| 257 | type action struct { |
| 258 | once sync.Once |
| 259 | result interface{} |
| 260 | err error |
| 261 | usesFacts bool // (transitively uses) |
| 262 | diagnostics []analysis.Diagnostic |
| 263 | } |
| 264 | actions := make(map[*analysis.Analyzer]*action) |
| 265 | var registerFacts func(a *analysis.Analyzer) bool |
| 266 | registerFacts = func(a *analysis.Analyzer) bool { |
| 267 | act, ok := actions[a] |
| 268 | if !ok { |
| 269 | act = new(action) |
| 270 | var usesFacts bool |
| 271 | for _, f := range a.FactTypes { |
| 272 | usesFacts = true |
| 273 | gob.Register(f) |
| 274 | } |
| 275 | for _, req := range a.Requires { |
| 276 | if registerFacts(req) { |
| 277 | usesFacts = true |
| 278 | } |
| 279 | } |
| 280 | act.usesFacts = usesFacts |
| 281 | actions[a] = act |
| 282 | } |
| 283 | return act.usesFacts |
| 284 | } |
| 285 | var filtered []*analysis.Analyzer |
| 286 | for _, a := range analyzers { |
| 287 | if registerFacts(a) || !cfg.VetxOnly { |
| 288 | filtered = append(filtered, a) |
| 289 | } |
| 290 | } |
| 291 | analyzers = filtered |
| 292 | |
| 293 | // Read facts from imported packages. |
| 294 | read := func(imp *types.Package) ([]byte, error) { |
| 295 | if vetx, ok := cfg.PackageVetx[imp.Path()]; ok { |
| 296 | return ioutil.ReadFile(vetx) |
| 297 | } |
| 298 | return nil, nil // no .vetx file, no facts |
| 299 | } |
| 300 | facts, err := facts.NewDecoder(pkg).Decode(read) |
| 301 | if err != nil { |
| 302 | return nil, err |
| 303 | } |
| 304 | |
| 305 | // In parallel, execute the DAG of analyzers. |
| 306 | var exec func(a *analysis.Analyzer) *action |
| 307 | var execAll func(analyzers []*analysis.Analyzer) |
| 308 | exec = func(a *analysis.Analyzer) *action { |
| 309 | act := actions[a] |
| 310 | act.once.Do(func() { |
| 311 | execAll(a.Requires) // prefetch dependencies in parallel |
| 312 | |
| 313 | // The inputs to this analysis are the |
| 314 | // results of its prerequisites. |
| 315 | inputs := make(map[*analysis.Analyzer]interface{}) |
| 316 | var failed []string |
| 317 | for _, req := range a.Requires { |
| 318 | reqact := exec(req) |
| 319 | if reqact.err != nil { |
| 320 | failed = append(failed, req.String()) |
| 321 | continue |
| 322 | } |
| 323 | inputs[req] = reqact.result |
| 324 | } |
| 325 | |
| 326 | // Report an error if any dependency failed. |
| 327 | if failed != nil { |
| 328 | sort.Strings(failed) |
| 329 | act.err = fmt.Errorf("failed prerequisites: %s", strings.Join(failed, ", ")) |
| 330 | return |
| 331 | } |
| 332 | |
| 333 | factFilter := make(map[reflect.Type]bool) |
| 334 | for _, f := range a.FactTypes { |
| 335 | factFilter[reflect.TypeOf(f)] = true |
| 336 | } |
| 337 | |
| 338 | pass := &analysis.Pass{ |
| 339 | Analyzer: a, |
| 340 | Fset: fset, |
| 341 | Files: files, |
| 342 | OtherFiles: cfg.NonGoFiles, |
| 343 | IgnoredFiles: cfg.IgnoredFiles, |
| 344 | Pkg: pkg, |
| 345 | TypesInfo: info, |
| 346 | TypesSizes: tc.Sizes, |
| 347 | TypeErrors: nil, // unitchecker doesn't RunDespiteErrors |
| 348 | ResultOf: inputs, |
| 349 | Report: func(d analysis.Diagnostic) { act.diagnostics = append(act.diagnostics, d) }, |
| 350 | ImportObjectFact: facts.ImportObjectFact, |
| 351 | ExportObjectFact: facts.ExportObjectFact, |
| 352 | AllObjectFacts: func() []analysis.ObjectFact { return facts.AllObjectFacts(factFilter) }, |
| 353 | ImportPackageFact: facts.ImportPackageFact, |
| 354 | ExportPackageFact: facts.ExportPackageFact, |
| 355 | AllPackageFacts: func() []analysis.PackageFact { return facts.AllPackageFacts(factFilter) }, |
| 356 | } |
| 357 | |
| 358 | t0 := time.Now() |
| 359 | act.result, act.err = a.Run(pass) |
| 360 | if false { |
| 361 | log.Printf("analysis %s = %s", pass, time.Since(t0)) |
| 362 | } |
| 363 | }) |
| 364 | return act |
| 365 | } |
| 366 | execAll = func(analyzers []*analysis.Analyzer) { |
| 367 | var wg sync.WaitGroup |
| 368 | for _, a := range analyzers { |
| 369 | wg.Add(1) |
| 370 | go func(a *analysis.Analyzer) { |
| 371 | _ = exec(a) |
| 372 | wg.Done() |
| 373 | }(a) |
| 374 | } |
| 375 | wg.Wait() |
| 376 | } |
| 377 | |
| 378 | execAll(analyzers) |
| 379 | |
| 380 | // Return diagnostics and errors from root analyzers. |
| 381 | results := make([]result, len(analyzers)) |
| 382 | for i, a := range analyzers { |
| 383 | act := actions[a] |
| 384 | results[i].a = a |
| 385 | results[i].err = act.err |
| 386 | results[i].diagnostics = act.diagnostics |
| 387 | } |
| 388 | |
| 389 | data := facts.Encode() |
| 390 | if err := ioutil.WriteFile(cfg.VetxOutput, data, 0666); err != nil { |
| 391 | return nil, fmt.Errorf("failed to write analysis facts: %v", err) |
| 392 | } |
| 393 | |
| 394 | return results, nil |
| 395 | } |
| 396 | |
| 397 | type result struct { |
| 398 | a *analysis.Analyzer |
| 399 | diagnostics []analysis.Diagnostic |
| 400 | err error |
| 401 | } |
| 402 | |
| 403 | type importerFunc func(path string) (*types.Package, error) |
| 404 | |
| 405 | func (f importerFunc) Import(path string) (*types.Package, error) { return f(path) } |
| 406 |
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