Source file src/go/types/check_test.go

     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/buildcfg"
    42  	"internal/testenv"
    43  	"internal/types/errors"
    44  	"os"
    45  	"path/filepath"
    46  	"reflect"
    47  	"regexp"
    48  	"runtime"
    49  	"strconv"
    50  	"strings"
    51  	"testing"
    52  
    53  	. "go/types"
    54  )
    55  
    56  var (
    57  	haltOnError  = flag.Bool("halt", false, "halt on error")
    58  	verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual")
    59  )
    60  
    61  var fset = token.NewFileSet()
    62  
    63  func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode parser.Mode) ([]*ast.File, []error) {
    64  	var files []*ast.File
    65  	var errlist []error
    66  	for i, filename := range filenames {
    67  		file, err := parser.ParseFile(fset, filename, srcs[i], mode)
    68  		if file == nil {
    69  			t.Fatalf("%s: %s", filename, err)
    70  		}
    71  		files = append(files, file)
    72  		if err != nil {
    73  			if list, _ := err.(scanner.ErrorList); len(list) > 0 {
    74  				for _, err := range list {
    75  					errlist = append(errlist, err)
    76  				}
    77  			} else {
    78  				errlist = append(errlist, err)
    79  			}
    80  		}
    81  	}
    82  	return files, errlist
    83  }
    84  
    85  func unpackError(fset *token.FileSet, err error) (token.Position, string) {
    86  	switch err := err.(type) {
    87  	case *scanner.Error:
    88  		return err.Pos, err.Msg
    89  	case Error:
    90  		return fset.Position(err.Pos), err.Msg
    91  	}
    92  	panic("unreachable")
    93  }
    94  
    95  // absDiff returns the absolute difference between x and y.
    96  func absDiff(x, y int) int {
    97  	if x < y {
    98  		return y - x
    99  	}
   100  	return x - y
   101  }
   102  
   103  // parseFlags parses flags from the first line of the given source if the line
   104  // starts with "//" (line comment) followed by "-" (possibly with spaces
   105  // between). Otherwise the line is ignored.
   106  func parseFlags(src []byte, flags *flag.FlagSet) error {
   107  	// we must have a line comment that starts with a "-"
   108  	const prefix = "//"
   109  	if !bytes.HasPrefix(src, []byte(prefix)) {
   110  		return nil // first line is not a line comment
   111  	}
   112  	src = src[len(prefix):]
   113  	if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 {
   114  		return nil // comment doesn't start with a "-"
   115  	}
   116  	end := bytes.Index(src, []byte("\n"))
   117  	const maxLen = 256
   118  	if end < 0 || end > maxLen {
   119  		return fmt.Errorf("flags comment line too long")
   120  	}
   121  
   122  	return flags.Parse(strings.Fields(string(src[:end])))
   123  }
   124  
   125  // testFiles type-checks the package consisting of the given files, and
   126  // compares the resulting errors with the ERROR annotations in the source.
   127  // Except for manual tests, each package is type-checked twice, once without
   128  // use of Alias types, and once with Alias types.
   129  //
   130  // The srcs slice contains the file content for the files named in the
   131  // filenames slice. The colDelta parameter specifies the tolerance for position
   132  // mismatch when comparing errors. The manual parameter specifies whether this
   133  // is a 'manual' test.
   134  //
   135  // If provided, opts may be used to mutate the Config before type-checking.
   136  func testFiles(t *testing.T, filenames []string, srcs [][]byte, manual bool, opts ...func(*Config)) {
   137  	// Alias types are disabled by default
   138  	testFilesImpl(t, filenames, srcs, manual, opts...)
   139  	if !manual {
   140  		t.Setenv("GODEBUG", "gotypesalias=1")
   141  		testFilesImpl(t, filenames, srcs, manual, opts...)
   142  	}
   143  }
   144  
   145  func testFilesImpl(t *testing.T, filenames []string, srcs [][]byte, manual bool, opts ...func(*Config)) {
   146  	if len(filenames) == 0 {
   147  		t.Fatal("no source files")
   148  	}
   149  
   150  	// parse files
   151  	files, errlist := parseFiles(t, filenames, srcs, parser.AllErrors)
   152  	pkgName := "<no package>"
   153  	if len(files) > 0 {
   154  		pkgName = files[0].Name.Name
   155  	}
   156  	listErrors := manual && !*verifyErrors
   157  	if listErrors && len(errlist) > 0 {
   158  		t.Errorf("--- %s:", pkgName)
   159  		for _, err := range errlist {
   160  			t.Error(err)
   161  		}
   162  	}
   163  
   164  	// set up typechecker
   165  	var conf Config
   166  	*boolFieldAddr(&conf, "_Trace") = manual && testing.Verbose()
   167  	conf.Importer = importer.Default()
   168  	conf.Error = func(err error) {
   169  		if *haltOnError {
   170  			defer panic(err)
   171  		}
   172  		if listErrors {
   173  			t.Error(err)
   174  			return
   175  		}
   176  		// Ignore secondary error messages starting with "\t";
   177  		// they are clarifying messages for a primary error.
   178  		if !strings.Contains(err.Error(), ": \t") {
   179  			errlist = append(errlist, err)
   180  		}
   181  	}
   182  
   183  	// apply custom configuration
   184  	for _, opt := range opts {
   185  		opt(&conf)
   186  	}
   187  
   188  	// apply flag setting (overrides custom configuration)
   189  	var goexperiment, gotypesalias string
   190  	flags := flag.NewFlagSet("", flag.PanicOnError)
   191  	flags.StringVar(&conf.GoVersion, "lang", "", "")
   192  	flags.StringVar(&goexperiment, "goexperiment", "", "")
   193  	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
   194  	flags.StringVar(&gotypesalias, "gotypesalias", "", "")
   195  	if err := parseFlags(srcs[0], flags); err != nil {
   196  		t.Fatal(err)
   197  	}
   198  
   199  	exp, err := buildcfg.ParseGOEXPERIMENT(runtime.GOOS, runtime.GOARCH, goexperiment)
   200  	if err != nil {
   201  		t.Fatal(err)
   202  	}
   203  	old := buildcfg.Experiment
   204  	defer func() {
   205  		buildcfg.Experiment = old
   206  	}()
   207  	buildcfg.Experiment = *exp
   208  
   209  	// By default, gotypesalias is not set.
   210  	if gotypesalias != "" {
   211  		t.Setenv("GODEBUG", "gotypesalias="+gotypesalias)
   212  	}
   213  
   214  	// Provide Config.Info with all maps so that info recording is tested.
   215  	info := Info{
   216  		Types:        make(map[ast.Expr]TypeAndValue),
   217  		Instances:    make(map[*ast.Ident]Instance),
   218  		Defs:         make(map[*ast.Ident]Object),
   219  		Uses:         make(map[*ast.Ident]Object),
   220  		Implicits:    make(map[ast.Node]Object),
   221  		Selections:   make(map[*ast.SelectorExpr]*Selection),
   222  		Scopes:       make(map[ast.Node]*Scope),
   223  		FileVersions: make(map[*ast.File]string),
   224  	}
   225  
   226  	// typecheck
   227  	conf.Check(pkgName, fset, files, &info)
   228  	if listErrors {
   229  		return
   230  	}
   231  
   232  	// collect expected errors
   233  	errmap := make(map[string]map[int][]comment)
   234  	for i, filename := range filenames {
   235  		if m := commentMap(srcs[i], regexp.MustCompile("^ ERRORx? ")); len(m) > 0 {
   236  			errmap[filename] = m
   237  		}
   238  	}
   239  
   240  	// match against found errors
   241  	var indices []int // list indices of matching errors, reused for each error
   242  	for _, err := range errlist {
   243  		gotPos, gotMsg := unpackError(fset, err)
   244  
   245  		// find list of errors for the respective error line
   246  		filename := gotPos.Filename
   247  		filemap := errmap[filename]
   248  		line := gotPos.Line
   249  		var errList []comment
   250  		if filemap != nil {
   251  			errList = filemap[line]
   252  		}
   253  
   254  		// At least one of the errors in errList should match the current error.
   255  		indices = indices[:0]
   256  		for i, want := range errList {
   257  			pattern, substr := strings.CutPrefix(want.text, " ERROR ")
   258  			if !substr {
   259  				var found bool
   260  				pattern, found = strings.CutPrefix(want.text, " ERRORx ")
   261  				if !found {
   262  					panic("unreachable")
   263  				}
   264  			}
   265  			pattern, err := strconv.Unquote(strings.TrimSpace(pattern))
   266  			if err != nil {
   267  				t.Errorf("%s:%d:%d: %v", filename, line, want.col, err)
   268  				continue
   269  			}
   270  			if substr {
   271  				if !strings.Contains(gotMsg, pattern) {
   272  					continue
   273  				}
   274  			} else {
   275  				rx, err := regexp.Compile(pattern)
   276  				if err != nil {
   277  					t.Errorf("%s:%d:%d: %v", filename, line, want.col, err)
   278  					continue
   279  				}
   280  				if !rx.MatchString(gotMsg) {
   281  					continue
   282  				}
   283  			}
   284  			indices = append(indices, i)
   285  		}
   286  		if len(indices) == 0 {
   287  			t.Errorf("%s: no error expected: %q", gotPos, gotMsg)
   288  			continue
   289  		}
   290  		// len(indices) > 0
   291  
   292  		// If there are multiple matching errors, select the one with the closest column position.
   293  		index := -1 // index of matching error
   294  		var delta int
   295  		for _, i := range indices {
   296  			if d := absDiff(gotPos.Column, errList[i].col); index < 0 || d < delta {
   297  				index, delta = i, d
   298  			}
   299  		}
   300  
   301  		// The closest column position must be within expected colDelta.
   302  		const colDelta = 0 // go/types errors are positioned correctly
   303  		if delta > colDelta {
   304  			t.Errorf("%s: got col = %d; want %d", gotPos, gotPos.Column, errList[index].col)
   305  		}
   306  
   307  		// eliminate from errList
   308  		if n := len(errList) - 1; n > 0 {
   309  			// not the last entry - slide entries down (don't reorder)
   310  			copy(errList[index:], errList[index+1:])
   311  			filemap[line] = errList[:n]
   312  		} else {
   313  			// last entry - remove errList from filemap
   314  			delete(filemap, line)
   315  		}
   316  
   317  		// if filemap is empty, eliminate from errmap
   318  		if len(filemap) == 0 {
   319  			delete(errmap, filename)
   320  		}
   321  	}
   322  
   323  	// there should be no expected errors left
   324  	if len(errmap) > 0 {
   325  		t.Errorf("--- %s: unreported errors:", pkgName)
   326  		for filename, filemap := range errmap {
   327  			for line, errList := range filemap {
   328  				for _, err := range errList {
   329  					t.Errorf("%s:%d:%d: %s", filename, line, err.col, err.text)
   330  				}
   331  			}
   332  		}
   333  	}
   334  }
   335  
   336  func readCode(err Error) errors.Code {
   337  	v := reflect.ValueOf(err)
   338  	return errors.Code(v.FieldByName("go116code").Int())
   339  }
   340  
   341  // boolFieldAddr(conf, name) returns the address of the boolean field conf.<name>.
   342  // For accessing unexported fields.
   343  func boolFieldAddr(conf *Config, name string) *bool {
   344  	v := reflect.Indirect(reflect.ValueOf(conf))
   345  	return (*bool)(v.FieldByName(name).Addr().UnsafePointer())
   346  }
   347  
   348  // stringFieldAddr(conf, name) returns the address of the string field conf.<name>.
   349  // For accessing unexported fields.
   350  func stringFieldAddr(conf *Config, name string) *string {
   351  	v := reflect.Indirect(reflect.ValueOf(conf))
   352  	return (*string)(v.FieldByName(name).Addr().UnsafePointer())
   353  }
   354  
   355  // TestManual is for manual testing of a package - either provided
   356  // as a list of filenames belonging to the package, or a directory
   357  // name containing the package files - after the test arguments
   358  // (and a separating "--"). For instance, to test the package made
   359  // of the files foo.go and bar.go, use:
   360  //
   361  //	go test -run Manual -- foo.go bar.go
   362  //
   363  // If no source arguments are provided, the file testdata/manual.go
   364  // is used instead.
   365  // Provide the -verify flag to verify errors against ERROR comments
   366  // in the input files rather than having a list of errors reported.
   367  // The accepted Go language version can be controlled with the -lang
   368  // flag.
   369  func TestManual(t *testing.T) {
   370  	testenv.MustHaveGoBuild(t)
   371  
   372  	filenames := flag.Args()
   373  	if len(filenames) == 0 {
   374  		filenames = []string{filepath.FromSlash("testdata/manual.go")}
   375  	}
   376  
   377  	info, err := os.Stat(filenames[0])
   378  	if err != nil {
   379  		t.Fatalf("TestManual: %v", err)
   380  	}
   381  
   382  	DefPredeclaredTestFuncs()
   383  	if info.IsDir() {
   384  		if len(filenames) > 1 {
   385  			t.Fatal("TestManual: must have only one directory argument")
   386  		}
   387  		testDir(t, filenames[0], true)
   388  	} else {
   389  		testPkg(t, filenames, true)
   390  	}
   391  }
   392  
   393  func TestLongConstants(t *testing.T) {
   394  	format := `package longconst; const _ = %s /* ERROR "constant overflow" */; const _ = %s // ERROR "excessively long constant"`
   395  	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
   396  	testFiles(t, []string{"longconst.go"}, [][]byte{[]byte(src)}, false)
   397  }
   398  
   399  func withSizes(sizes Sizes) func(*Config) {
   400  	return func(cfg *Config) {
   401  		cfg.Sizes = sizes
   402  	}
   403  }
   404  
   405  // TestIndexRepresentability tests that constant index operands must
   406  // be representable as int even if they already have a type that can
   407  // represent larger values.
   408  func TestIndexRepresentability(t *testing.T) {
   409  	const src = `package index; var s []byte; var _ = s[int64 /* ERRORx "int64\\(1\\) << 40 \\(.*\\) overflows int" */ (1) << 40]`
   410  	testFiles(t, []string{"index.go"}, [][]byte{[]byte(src)}, false, withSizes(&StdSizes{4, 4}))
   411  }
   412  
   413  func TestIssue47243_TypedRHS(t *testing.T) {
   414  	// The RHS of the shift expression below overflows uint on 32bit platforms,
   415  	// but this is OK as it is explicitly typed.
   416  	const src = `package issue47243; var a uint64; var _ = a << uint64(4294967296)` // uint64(1<<32)
   417  	testFiles(t, []string{"p.go"}, [][]byte{[]byte(src)}, false, withSizes(&StdSizes{4, 4}))
   418  }
   419  
   420  func TestCheck(t *testing.T) {
   421  	old := buildcfg.Experiment.RangeFunc
   422  	defer func() {
   423  		buildcfg.Experiment.RangeFunc = old
   424  	}()
   425  	buildcfg.Experiment.RangeFunc = true
   426  
   427  	DefPredeclaredTestFuncs()
   428  	testDirFiles(t, "../../internal/types/testdata/check", false)
   429  }
   430  func TestSpec(t *testing.T)      { testDirFiles(t, "../../internal/types/testdata/spec", false) }
   431  func TestExamples(t *testing.T)  { testDirFiles(t, "../../internal/types/testdata/examples", false) }
   432  func TestFixedbugs(t *testing.T) { testDirFiles(t, "../../internal/types/testdata/fixedbugs", false) }
   433  func TestLocal(t *testing.T)     { testDirFiles(t, "testdata/local", false) }
   434  
   435  func testDirFiles(t *testing.T, dir string, manual bool) {
   436  	testenv.MustHaveGoBuild(t)
   437  	dir = filepath.FromSlash(dir)
   438  
   439  	fis, err := os.ReadDir(dir)
   440  	if err != nil {
   441  		t.Error(err)
   442  		return
   443  	}
   444  
   445  	for _, fi := range fis {
   446  		path := filepath.Join(dir, fi.Name())
   447  
   448  		// If fi is a directory, its files make up a single package.
   449  		if fi.IsDir() {
   450  			testDir(t, path, manual)
   451  		} else {
   452  			t.Run(filepath.Base(path), func(t *testing.T) {
   453  				testPkg(t, []string{path}, manual)
   454  			})
   455  		}
   456  	}
   457  }
   458  
   459  func testDir(t *testing.T, dir string, manual bool) {
   460  	testenv.MustHaveGoBuild(t)
   461  
   462  	fis, err := os.ReadDir(dir)
   463  	if err != nil {
   464  		t.Error(err)
   465  		return
   466  	}
   467  
   468  	var filenames []string
   469  	for _, fi := range fis {
   470  		filenames = append(filenames, filepath.Join(dir, fi.Name()))
   471  	}
   472  
   473  	t.Run(filepath.Base(dir), func(t *testing.T) {
   474  		testPkg(t, filenames, manual)
   475  	})
   476  }
   477  
   478  func testPkg(t *testing.T, filenames []string, manual bool) {
   479  	srcs := make([][]byte, len(filenames))
   480  	for i, filename := range filenames {
   481  		src, err := os.ReadFile(filename)
   482  		if err != nil {
   483  			t.Fatalf("could not read %s: %v", filename, err)
   484  		}
   485  		srcs[i] = src
   486  	}
   487  	testFiles(t, filenames, srcs, manual)
   488  }
   489  

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