github.com/lovishpuri/go-40569/src@v0.0.0-20230519171745-f8623e7c56cf/go/types/check_test.go (about) 1 // Copyright 2011 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 // This file implements a typechecker test harness. The packages specified 6 // in tests are typechecked. Error messages reported by the typechecker are 7 // compared against the errors expected in the test files. 8 // 9 // Expected errors are indicated in the test files by putting comments 10 // of the form /* ERROR pattern */ or /* ERRORx pattern */ (or a similar 11 // //-style line comment) immediately following the tokens where errors 12 // are reported. There must be exactly one blank before and after the 13 // ERROR/ERRORx indicator, and the pattern must be a properly quoted Go 14 // string. 15 // 16 // The harness will verify that each ERROR pattern is a substring of the 17 // error reported at that source position, and that each ERRORx pattern 18 // is a regular expression matching the respective error. 19 // Consecutive comments may be used to indicate multiple errors reported 20 // at the same position. 21 // 22 // For instance, the following test source indicates that an "undeclared" 23 // error should be reported for the undeclared variable x: 24 // 25 // package p 26 // func f() { 27 // _ = x /* ERROR "undeclared" */ + 1 28 // } 29 30 package types_test 31 32 import ( 33 "bytes" 34 "flag" 35 "fmt" 36 "go/ast" 37 "go/importer" 38 "go/parser" 39 "go/scanner" 40 "go/token" 41 "internal/testenv" 42 "internal/types/errors" 43 "os" 44 "path/filepath" 45 "reflect" 46 "regexp" 47 "strconv" 48 "strings" 49 "testing" 50 51 . "go/types" 52 ) 53 54 var ( 55 haltOnError = flag.Bool("halt", false, "halt on error") 56 verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual") 57 ) 58 59 var fset = token.NewFileSet() 60 61 func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode parser.Mode) ([]*ast.File, []error) { 62 var files []*ast.File 63 var errlist []error 64 for i, filename := range filenames { 65 file, err := parser.ParseFile(fset, filename, srcs[i], mode) 66 if file == nil { 67 t.Fatalf("%s: %s", filename, err) 68 } 69 files = append(files, file) 70 if err != nil { 71 if list, _ := err.(scanner.ErrorList); len(list) > 0 { 72 for _, err := range list { 73 errlist = append(errlist, err) 74 } 75 } else { 76 errlist = append(errlist, err) 77 } 78 } 79 } 80 return files, errlist 81 } 82 83 func unpackError(fset *token.FileSet, err error) (token.Position, string) { 84 switch err := err.(type) { 85 case *scanner.Error: 86 return err.Pos, err.Msg 87 case Error: 88 return fset.Position(err.Pos), err.Msg 89 } 90 panic("unreachable") 91 } 92 93 // absDiff returns the absolute difference between x and y. 94 func absDiff(x, y int) int { 95 if x < y { 96 return y - x 97 } 98 return x - y 99 } 100 101 // parseFlags parses flags from the first line of the given source 102 // (from src if present, or by reading from the file) if the line 103 // starts with "//" (line comment) followed by "-" (possibly with 104 // spaces between). Otherwise the line is ignored. 105 func parseFlags(filename string, src []byte, flags *flag.FlagSet) error { 106 // If there is no src, read from the file. 107 const maxLen = 256 108 if len(src) == 0 { 109 f, err := os.Open(filename) 110 if err != nil { 111 return err 112 } 113 114 var buf [maxLen]byte 115 n, err := f.Read(buf[:]) 116 if err != nil { 117 return err 118 } 119 src = buf[:n] 120 } 121 122 // we must have a line comment that starts with a "-" 123 const prefix = "//" 124 if !bytes.HasPrefix(src, []byte(prefix)) { 125 return nil // first line is not a line comment 126 } 127 src = src[len(prefix):] 128 if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 { 129 return nil // comment doesn't start with a "-" 130 } 131 end := bytes.Index(src, []byte("\n")) 132 if end < 0 || end > maxLen { 133 return fmt.Errorf("flags comment line too long") 134 } 135 136 return flags.Parse(strings.Fields(string(src[:end]))) 137 } 138 139 func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, manual bool, imp Importer) { 140 if len(filenames) == 0 { 141 t.Fatal("no source files") 142 } 143 144 var conf Config 145 conf.Sizes = sizes 146 flags := flag.NewFlagSet("", flag.PanicOnError) 147 flags.StringVar(&conf.GoVersion, "lang", "", "") 148 flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "") 149 if err := parseFlags(filenames[0], srcs[0], flags); err != nil { 150 t.Fatal(err) 151 } 152 153 files, errlist := parseFiles(t, filenames, srcs, parser.AllErrors) 154 155 pkgName := "<no package>" 156 if len(files) > 0 { 157 pkgName = files[0].Name.Name 158 } 159 160 listErrors := manual && !*verifyErrors 161 if listErrors && len(errlist) > 0 { 162 t.Errorf("--- %s:", pkgName) 163 for _, err := range errlist { 164 t.Error(err) 165 } 166 } 167 168 // typecheck and collect typechecker errors 169 *boolFieldAddr(&conf, "_Trace") = manual && testing.Verbose() 170 if imp == nil { 171 imp = importer.Default() 172 } 173 conf.Importer = imp 174 conf.Error = func(err error) { 175 if *haltOnError { 176 defer panic(err) 177 } 178 if listErrors { 179 t.Error(err) 180 return 181 } 182 // Ignore secondary error messages starting with "\t"; 183 // they are clarifying messages for a primary error. 184 if !strings.Contains(err.Error(), ": \t") { 185 errlist = append(errlist, err) 186 } 187 } 188 conf.Check(pkgName, fset, files, nil) 189 190 if listErrors { 191 return 192 } 193 194 // collect expected errors 195 errmap := make(map[string]map[int][]comment) 196 for i, filename := range filenames { 197 if m := commentMap(srcs[i], regexp.MustCompile("^ ERRORx? ")); len(m) > 0 { 198 errmap[filename] = m 199 } 200 } 201 202 // match against found errors 203 var indices []int // list indices of matching errors, reused for each error 204 for _, err := range errlist { 205 gotPos, gotMsg := unpackError(fset, err) 206 207 // find list of errors for the respective error line 208 filename := gotPos.Filename 209 filemap := errmap[filename] 210 line := gotPos.Line 211 var errList []comment 212 if filemap != nil { 213 errList = filemap[line] 214 } 215 216 // At least one of the errors in errList should match the current error. 217 indices = indices[:0] 218 for i, want := range errList { 219 pattern, substr := strings.CutPrefix(want.text, " ERROR ") 220 if !substr { 221 var found bool 222 pattern, found = strings.CutPrefix(want.text, " ERRORx ") 223 if !found { 224 panic("unreachable") 225 } 226 } 227 pattern, err := strconv.Unquote(strings.TrimSpace(pattern)) 228 if err != nil { 229 t.Errorf("%s:%d:%d: %v", filename, line, want.col, err) 230 continue 231 } 232 if substr { 233 if !strings.Contains(gotMsg, pattern) { 234 continue 235 } 236 } else { 237 rx, err := regexp.Compile(pattern) 238 if err != nil { 239 t.Errorf("%s:%d:%d: %v", filename, line, want.col, err) 240 continue 241 } 242 if !rx.MatchString(gotMsg) { 243 continue 244 } 245 } 246 indices = append(indices, i) 247 } 248 if len(indices) == 0 { 249 t.Errorf("%s: no error expected: %q", gotPos, gotMsg) 250 continue 251 } 252 // len(indices) > 0 253 254 // If there are multiple matching errors, select the one with the closest column position. 255 index := -1 // index of matching error 256 var delta int 257 for _, i := range indices { 258 if d := absDiff(gotPos.Column, errList[i].col); index < 0 || d < delta { 259 index, delta = i, d 260 } 261 } 262 263 // The closest column position must be within expected colDelta. 264 const colDelta = 0 // go/types errors are positioned correctly 265 if delta > colDelta { 266 t.Errorf("%s: got col = %d; want %d", gotPos, gotPos.Column, errList[index].col) 267 } 268 269 // eliminate from errList 270 if n := len(errList) - 1; n > 0 { 271 // not the last entry - slide entries down (don't reorder) 272 copy(errList[index:], errList[index+1:]) 273 filemap[line] = errList[:n] 274 } else { 275 // last entry - remove errList from filemap 276 delete(filemap, line) 277 } 278 279 // if filemap is empty, eliminate from errmap 280 if len(filemap) == 0 { 281 delete(errmap, filename) 282 } 283 } 284 285 // there should be no expected errors left 286 if len(errmap) > 0 { 287 t.Errorf("--- %s: unreported errors:", pkgName) 288 for filename, filemap := range errmap { 289 for line, errList := range filemap { 290 for _, err := range errList { 291 t.Errorf("%s:%d:%d: %s", filename, line, err.col, err.text) 292 } 293 } 294 } 295 } 296 } 297 298 func readCode(err Error) errors.Code { 299 v := reflect.ValueOf(err) 300 return errors.Code(v.FieldByName("go116code").Int()) 301 } 302 303 // boolFieldAddr(conf, name) returns the address of the boolean field conf.<name>. 304 // For accessing unexported fields. 305 func boolFieldAddr(conf *Config, name string) *bool { 306 v := reflect.Indirect(reflect.ValueOf(conf)) 307 return (*bool)(v.FieldByName(name).Addr().UnsafePointer()) 308 } 309 310 // TestManual is for manual testing of a package - either provided 311 // as a list of filenames belonging to the package, or a directory 312 // name containing the package files - after the test arguments 313 // (and a separating "--"). For instance, to test the package made 314 // of the files foo.go and bar.go, use: 315 // 316 // go test -run Manual -- foo.go bar.go 317 // 318 // If no source arguments are provided, the file testdata/manual.go 319 // is used instead. 320 // Provide the -verify flag to verify errors against ERROR comments 321 // in the input files rather than having a list of errors reported. 322 // The accepted Go language version can be controlled with the -lang 323 // flag. 324 func TestManual(t *testing.T) { 325 testenv.MustHaveGoBuild(t) 326 327 filenames := flag.Args() 328 if len(filenames) == 0 { 329 filenames = []string{filepath.FromSlash("testdata/manual.go")} 330 } 331 332 info, err := os.Stat(filenames[0]) 333 if err != nil { 334 t.Fatalf("TestManual: %v", err) 335 } 336 337 DefPredeclaredTestFuncs() 338 if info.IsDir() { 339 if len(filenames) > 1 { 340 t.Fatal("TestManual: must have only one directory argument") 341 } 342 testDir(t, filenames[0], true) 343 } else { 344 testPkg(t, filenames, true) 345 } 346 } 347 348 func TestLongConstants(t *testing.T) { 349 format := `package longconst; const _ = %s /* ERROR "constant overflow" */; const _ = %s // ERROR "excessively long constant"` 350 src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001)) 351 testFiles(t, nil, []string{"longconst.go"}, [][]byte{[]byte(src)}, false, nil) 352 } 353 354 // TestIndexRepresentability tests that constant index operands must 355 // be representable as int even if they already have a type that can 356 // represent larger values. 357 func TestIndexRepresentability(t *testing.T) { 358 const src = `package index; var s []byte; var _ = s[int64 /* ERRORx "int64\\(1\\) << 40 \\(.*\\) overflows int" */ (1) << 40]` 359 testFiles(t, &StdSizes{4, 4}, []string{"index.go"}, [][]byte{[]byte(src)}, false, nil) 360 } 361 362 func TestIssue47243_TypedRHS(t *testing.T) { 363 // The RHS of the shift expression below overflows uint on 32bit platforms, 364 // but this is OK as it is explicitly typed. 365 const src = `package issue47243; var a uint64; var _ = a << uint64(4294967296)` // uint64(1<<32) 366 testFiles(t, &StdSizes{4, 4}, []string{"p.go"}, [][]byte{[]byte(src)}, false, nil) 367 } 368 369 func TestCheck(t *testing.T) { 370 DefPredeclaredTestFuncs() 371 testDirFiles(t, "../../internal/types/testdata/check", false) 372 } 373 func TestSpec(t *testing.T) { testDirFiles(t, "../../internal/types/testdata/spec", false) } 374 func TestExamples(t *testing.T) { testDirFiles(t, "../../internal/types/testdata/examples", false) } 375 func TestFixedbugs(t *testing.T) { testDirFiles(t, "../../internal/types/testdata/fixedbugs", false) } 376 func TestLocal(t *testing.T) { testDirFiles(t, "testdata/local", false) } 377 378 func testDirFiles(t *testing.T, dir string, manual bool) { 379 testenv.MustHaveGoBuild(t) 380 dir = filepath.FromSlash(dir) 381 382 fis, err := os.ReadDir(dir) 383 if err != nil { 384 t.Error(err) 385 return 386 } 387 388 for _, fi := range fis { 389 path := filepath.Join(dir, fi.Name()) 390 391 // If fi is a directory, its files make up a single package. 392 if fi.IsDir() { 393 testDir(t, path, manual) 394 } else { 395 t.Run(filepath.Base(path), func(t *testing.T) { 396 testPkg(t, []string{path}, manual) 397 }) 398 } 399 } 400 } 401 402 func testDir(t *testing.T, dir string, manual bool) { 403 testenv.MustHaveGoBuild(t) 404 405 fis, err := os.ReadDir(dir) 406 if err != nil { 407 t.Error(err) 408 return 409 } 410 411 var filenames []string 412 for _, fi := range fis { 413 filenames = append(filenames, filepath.Join(dir, fi.Name())) 414 } 415 416 t.Run(filepath.Base(dir), func(t *testing.T) { 417 testPkg(t, filenames, manual) 418 }) 419 } 420 421 // TODO(rFindley) reconcile the different test setup in go/types with types2. 422 func testPkg(t *testing.T, filenames []string, manual bool) { 423 srcs := make([][]byte, len(filenames)) 424 for i, filename := range filenames { 425 src, err := os.ReadFile(filename) 426 if err != nil { 427 t.Fatalf("could not read %s: %v", filename, err) 428 } 429 srcs[i] = src 430 } 431 testFiles(t, nil, filenames, srcs, manual, nil) 432 }