check_test.go

Documentation: cmd/compile/internal/types2

     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 types2_test
    31  
    32  import (
    33  	"bytes"
    34  	"cmd/compile/internal/syntax"
    35  	"flag"
    36  	"fmt"
    37  	"internal/buildcfg"
    38  	"internal/testenv"
    39  	"os"
    40  	"path/filepath"
    41  	"reflect"
    42  	"regexp"
    43  	"runtime"
    44  	"strconv"
    45  	"strings"
    46  	"testing"
    47  
    48  	. "cmd/compile/internal/types2"
    49  )
    50  
    51  var (
    52  	haltOnError  = flag.Bool("halt", false, "halt on error")
    53  	verifyErrors = flag.Bool("verify", false, "verify errors (rather than list them) in TestManual")
    54  )
    55  
    56  func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode syntax.Mode) ([]*syntax.File, []error) {
    57  	var files []*syntax.File
    58  	var errlist []error
    59  	errh := func(err error) { errlist = append(errlist, err) }
    60  	for i, filename := range filenames {
    61  		base := syntax.NewFileBase(filename)
    62  		r := bytes.NewReader(srcs[i])
    63  		file, err := syntax.Parse(base, r, errh, nil, mode)
    64  		if file == nil {
    65  			t.Fatalf("%s: %s", filename, err)
    66  		}
    67  		files = append(files, file)
    68  	}
    69  	return files, errlist
    70  }
    71  
    72  func unpackError(err error) (syntax.Pos, string) {
    73  	switch err := err.(type) {
    74  	case syntax.Error:
    75  		return err.Pos, err.Msg
    76  	case Error:
    77  		return err.Pos, err.Msg
    78  	default:
    79  		return nopos, err.Error()
    80  	}
    81  }
    82  
    83  // absDiff returns the absolute difference between x and y.
    84  func absDiff(x, y uint) uint {
    85  	if x < y {
    86  		return y - x
    87  	}
    88  	return x - y
    89  }
    90  
    91  // parseFlags parses flags from the first line of the given source if the line
    92  // starts with "//" (line comment) followed by "-" (possibly with spaces
    93  // between). Otherwise the line is ignored.
    94  func parseFlags(src []byte, flags *flag.FlagSet) error {
    95  	// we must have a line comment that starts with a "-"
    96  	const prefix = "//"
    97  	if !bytes.HasPrefix(src, []byte(prefix)) {
    98  		return nil // first line is not a line comment
    99  	}
   100  	src = src[len(prefix):]
   101  	if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 {
   102  		return nil // comment doesn't start with a "-"
   103  	}
   104  	end := bytes.Index(src, []byte("\n"))
   105  	const maxLen = 256
   106  	if end < 0 || end > maxLen {
   107  		return fmt.Errorf("flags comment line too long")
   108  	}
   109  
   110  	return flags.Parse(strings.Fields(string(src[:end])))
   111  }
   112  
   113  // testFiles type-checks the package consisting of the given files, and
   114  // compares the resulting errors with the ERROR annotations in the source.
   115  // Except for manual tests, each package is type-checked twice, once without
   116  // use of Alias types, and once with Alias types.
   117  //
   118  // The srcs slice contains the file content for the files named in the
   119  // filenames slice. The colDelta parameter specifies the tolerance for position
   120  // mismatch when comparing errors. The manual parameter specifies whether this
   121  // is a 'manual' test.
   122  //
   123  // If provided, opts may be used to mutate the Config before type-checking.
   124  func testFiles(t *testing.T, filenames []string, srcs [][]byte, colDelta uint, manual bool, opts ...func(*Config)) {
   125  	// Alias types are disabled by default
   126  	testFilesImpl(t, filenames, srcs, colDelta, manual, opts...)
   127  	if !manual {
   128  		t.Setenv("GODEBUG", "gotypesalias=1")
   129  		testFilesImpl(t, filenames, srcs, colDelta, manual, opts...)
   130  	}
   131  }
   132  
   133  func testFilesImpl(t *testing.T, filenames []string, srcs [][]byte, colDelta uint, manual bool, opts ...func(*Config)) {
   134  	if len(filenames) == 0 {
   135  		t.Fatal("no source files")
   136  	}
   137  
   138  	// parse files
   139  	files, errlist := parseFiles(t, filenames, srcs, 0)
   140  	pkgName := "<no package>"
   141  	if len(files) > 0 {
   142  		pkgName = files[0].PkgName.Value
   143  	}
   144  	listErrors := manual && !*verifyErrors
   145  	if listErrors && len(errlist) > 0 {
   146  		t.Errorf("--- %s:", pkgName)
   147  		for _, err := range errlist {
   148  			t.Error(err)
   149  		}
   150  	}
   151  
   152  	// set up typechecker
   153  	var conf Config
   154  	conf.Trace = manual && testing.Verbose()
   155  	conf.Importer = defaultImporter()
   156  	conf.Error = func(err error) {
   157  		if *haltOnError {
   158  			defer panic(err)
   159  		}
   160  		if listErrors {
   161  			t.Error(err)
   162  			return
   163  		}
   164  		errlist = append(errlist, err)
   165  	}
   166  
   167  	// apply custom configuration
   168  	for _, opt := range opts {
   169  		opt(&conf)
   170  	}
   171  
   172  	// apply flag setting (overrides custom configuration)
   173  	var goexperiment, gotypesalias string
   174  	flags := flag.NewFlagSet("", flag.PanicOnError)
   175  	flags.StringVar(&conf.GoVersion, "lang", "", "")
   176  	flags.StringVar(&goexperiment, "goexperiment", "", "")
   177  	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
   178  	flags.StringVar(&gotypesalias, "gotypesalias", "", "")
   179  	if err := parseFlags(srcs[0], flags); err != nil {
   180  		t.Fatal(err)
   181  	}
   182  
   183  	exp, err := buildcfg.ParseGOEXPERIMENT(runtime.GOOS, runtime.GOARCH, goexperiment)
   184  	if err != nil {
   185  		t.Fatal(err)
   186  	}
   187  	old := buildcfg.Experiment
   188  	defer func() {
   189  		buildcfg.Experiment = old
   190  	}()
   191  	buildcfg.Experiment = *exp
   192  
   193  	// By default, gotypesalias is not set.
   194  	if gotypesalias != "" {
   195  		t.Setenv("GODEBUG", "gotypesalias="+gotypesalias)
   196  	}
   197  
   198  	// Provide Config.Info with all maps so that info recording is tested.
   199  	info := Info{
   200  		Types:        make(map[syntax.Expr]TypeAndValue),
   201  		Instances:    make(map[*syntax.Name]Instance),
   202  		Defs:         make(map[*syntax.Name]Object),
   203  		Uses:         make(map[*syntax.Name]Object),
   204  		Implicits:    make(map[syntax.Node]Object),
   205  		Selections:   make(map[*syntax.SelectorExpr]*Selection),
   206  		Scopes:       make(map[syntax.Node]*Scope),
   207  		FileVersions: make(map[*syntax.PosBase]string),
   208  	}
   209  
   210  	// typecheck
   211  	conf.Check(pkgName, files, &info)
   212  	if listErrors {
   213  		return
   214  	}
   215  
   216  	// collect expected errors
   217  	errmap := make(map[string]map[uint][]syntax.Error)
   218  	for i, filename := range filenames {
   219  		if m := syntax.CommentMap(bytes.NewReader(srcs[i]), regexp.MustCompile("^ ERRORx? ")); len(m) > 0 {
   220  			errmap[filename] = m
   221  		}
   222  	}
   223  
   224  	// match against found errors
   225  	var indices []int // list indices of matching errors, reused for each error
   226  	for _, err := range errlist {
   227  		gotPos, gotMsg := unpackError(err)
   228  
   229  		// find list of errors for the respective error line
   230  		filename := gotPos.Base().Filename()
   231  		filemap := errmap[filename]
   232  		line := gotPos.Line()
   233  		var errList []syntax.Error
   234  		if filemap != nil {
   235  			errList = filemap[line]
   236  		}
   237  
   238  		// At least one of the errors in errList should match the current error.
   239  		indices = indices[:0]
   240  		for i, want := range errList {
   241  			pattern, substr := strings.CutPrefix(want.Msg, " ERROR ")
   242  			if !substr {
   243  				var found bool
   244  				pattern, found = strings.CutPrefix(want.Msg, " ERRORx ")
   245  				if !found {
   246  					panic("unreachable")
   247  				}
   248  			}
   249  			pattern, err := strconv.Unquote(strings.TrimSpace(pattern))
   250  			if err != nil {
   251  				t.Errorf("%s:%d:%d: %v", filename, line, want.Pos.Col(), err)
   252  				continue
   253  			}
   254  			if substr {
   255  				if !strings.Contains(gotMsg, pattern) {
   256  					continue
   257  				}
   258  			} else {
   259  				rx, err := regexp.Compile(pattern)
   260  				if err != nil {
   261  					t.Errorf("%s:%d:%d: %v", filename, line, want.Pos.Col(), err)
   262  					continue
   263  				}
   264  				if !rx.MatchString(gotMsg) {
   265  					continue
   266  				}
   267  			}
   268  			indices = append(indices, i)
   269  		}
   270  		if len(indices) == 0 {
   271  			t.Errorf("%s: no error expected: %q", gotPos, gotMsg)
   272  			continue
   273  		}
   274  		// len(indices) > 0
   275  
   276  		// If there are multiple matching errors, select the one with the closest column position.
   277  		index := -1 // index of matching error
   278  		var delta uint
   279  		for _, i := range indices {
   280  			if d := absDiff(gotPos.Col(), errList[i].Pos.Col()); index < 0 || d < delta {
   281  				index, delta = i, d
   282  			}
   283  		}
   284  
   285  		// The closest column position must be within expected colDelta.
   286  		if delta > colDelta {
   287  			t.Errorf("%s: got col = %d; want %d", gotPos, gotPos.Col(), errList[index].Pos.Col())
   288  		}
   289  
   290  		// eliminate from errList
   291  		if n := len(errList) - 1; n > 0 {
   292  			// not the last entry - slide entries down (don't reorder)
   293  			copy(errList[index:], errList[index+1:])
   294  			filemap[line] = errList[:n]
   295  		} else {
   296  			// last entry - remove errList from filemap
   297  			delete(filemap, line)
   298  		}
   299  
   300  		// if filemap is empty, eliminate from errmap
   301  		if len(filemap) == 0 {
   302  			delete(errmap, filename)
   303  		}
   304  	}
   305  
   306  	// there should be no expected errors left
   307  	if len(errmap) > 0 {
   308  		t.Errorf("--- %s: unreported errors:", pkgName)
   309  		for filename, filemap := range errmap {
   310  			for line, errList := range filemap {
   311  				for _, err := range errList {
   312  					t.Errorf("%s:%d:%d: %s", filename, line, err.Pos.Col(), err.Msg)
   313  				}
   314  			}
   315  		}
   316  	}
   317  }
   318  
   319  // boolFieldAddr(conf, name) returns the address of the boolean field conf.<name>.
   320  // For accessing unexported fields.
   321  func boolFieldAddr(conf *Config, name string) *bool {
   322  	v := reflect.Indirect(reflect.ValueOf(conf))
   323  	return (*bool)(v.FieldByName(name).Addr().UnsafePointer())
   324  }
   325  
   326  // TestManual is for manual testing of a package - either provided
   327  // as a list of filenames belonging to the package, or a directory
   328  // name containing the package files - after the test arguments
   329  // (and a separating "--"). For instance, to test the package made
   330  // of the files foo.go and bar.go, use:
   331  //
   332  //	go test -run Manual -- foo.go bar.go
   333  //
   334  // If no source arguments are provided, the file testdata/manual.go
   335  // is used instead.
   336  // Provide the -verify flag to verify errors against ERROR comments
   337  // in the input files rather than having a list of errors reported.
   338  // The accepted Go language version can be controlled with the -lang
   339  // flag.
   340  func TestManual(t *testing.T) {
   341  	testenv.MustHaveGoBuild(t)
   342  
   343  	filenames := flag.Args()
   344  	if len(filenames) == 0 {
   345  		filenames = []string{filepath.FromSlash("testdata/manual.go")}
   346  	}
   347  
   348  	info, err := os.Stat(filenames[0])
   349  	if err != nil {
   350  		t.Fatalf("TestManual: %v", err)
   351  	}
   352  
   353  	DefPredeclaredTestFuncs()
   354  	if info.IsDir() {
   355  		if len(filenames) > 1 {
   356  			t.Fatal("TestManual: must have only one directory argument")
   357  		}
   358  		testDir(t, filenames[0], 0, true)
   359  	} else {
   360  		testPkg(t, filenames, 0, true)
   361  	}
   362  }
   363  
   364  func TestLongConstants(t *testing.T) {
   365  	format := `package longconst; const _ = %s /* ERROR "constant overflow" */; const _ = %s // ERROR "excessively long constant"`
   366  	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
   367  	testFiles(t, []string{"longconst.go"}, [][]byte{[]byte(src)}, 0, false)
   368  }
   369  
   370  func withSizes(sizes Sizes) func(*Config) {
   371  	return func(cfg *Config) {
   372  		cfg.Sizes = sizes
   373  	}
   374  }
   375  
   376  // TestIndexRepresentability tests that constant index operands must
   377  // be representable as int even if they already have a type that can
   378  // represent larger values.
   379  func TestIndexRepresentability(t *testing.T) {
   380  	const src = `package index; var s []byte; var _ = s[int64 /* ERRORx "int64\\(1\\) << 40 \\(.*\\) overflows int" */ (1) << 40]`
   381  	testFiles(t, []string{"index.go"}, [][]byte{[]byte(src)}, 0, false, withSizes(&StdSizes{4, 4}))
   382  }
   383  
   384  func TestIssue47243_TypedRHS(t *testing.T) {
   385  	// The RHS of the shift expression below overflows uint on 32bit platforms,
   386  	// but this is OK as it is explicitly typed.
   387  	const src = `package issue47243; var a uint64; var _ = a << uint64(4294967296)` // uint64(1<<32)
   388  	testFiles(t, []string{"p.go"}, [][]byte{[]byte(src)}, 0, false, withSizes(&StdSizes{4, 4}))
   389  }
   390  
   391  func TestCheck(t *testing.T) {
   392  	old := buildcfg.Experiment.RangeFunc
   393  	defer func() {
   394  		buildcfg.Experiment.RangeFunc = old
   395  	}()
   396  	buildcfg.Experiment.RangeFunc = true
   397  
   398  	DefPredeclaredTestFuncs()
   399  	testDirFiles(t, "../../../../internal/types/testdata/check", 50, false) // TODO(gri) narrow column tolerance
   400  }
   401  func TestSpec(t *testing.T) { testDirFiles(t, "../../../../internal/types/testdata/spec", 0, false) }
   402  func TestExamples(t *testing.T) {
   403  	testDirFiles(t, "../../../../internal/types/testdata/examples", 125, false)
   404  } // TODO(gri) narrow column tolerance
   405  func TestFixedbugs(t *testing.T) {
   406  	testDirFiles(t, "../../../../internal/types/testdata/fixedbugs", 100, false)
   407  }                            // TODO(gri) narrow column tolerance
   408  func TestLocal(t *testing.T) { testDirFiles(t, "testdata/local", 0, false) }
   409  
   410  func testDirFiles(t *testing.T, dir string, colDelta uint, manual bool) {
   411  	testenv.MustHaveGoBuild(t)
   412  	dir = filepath.FromSlash(dir)
   413  
   414  	fis, err := os.ReadDir(dir)
   415  	if err != nil {
   416  		t.Error(err)
   417  		return
   418  	}
   419  
   420  	for _, fi := range fis {
   421  		path := filepath.Join(dir, fi.Name())
   422  
   423  		// If fi is a directory, its files make up a single package.
   424  		if fi.IsDir() {
   425  			testDir(t, path, colDelta, manual)
   426  		} else {
   427  			t.Run(filepath.Base(path), func(t *testing.T) {
   428  				testPkg(t, []string{path}, colDelta, manual)
   429  			})
   430  		}
   431  	}
   432  }
   433  
   434  func testDir(t *testing.T, dir string, colDelta uint, manual bool) {
   435  	fis, err := os.ReadDir(dir)
   436  	if err != nil {
   437  		t.Error(err)
   438  		return
   439  	}
   440  
   441  	var filenames []string
   442  	for _, fi := range fis {
   443  		filenames = append(filenames, filepath.Join(dir, fi.Name()))
   444  	}
   445  
   446  	t.Run(filepath.Base(dir), func(t *testing.T) {
   447  		testPkg(t, filenames, colDelta, manual)
   448  	})
   449  }
   450  
   451  func testPkg(t *testing.T, filenames []string, colDelta uint, manual bool) {
   452  	srcs := make([][]byte, len(filenames))
   453  	for i, filename := range filenames {
   454  		src, err := os.ReadFile(filename)
   455  		if err != nil {
   456  			t.Fatalf("could not read %s: %v", filename, err)
   457  		}
   458  		srcs[i] = src
   459  	}
   460  	testFiles(t, filenames, srcs, colDelta, manual)
   461  }
   462
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