Source file src/cmd/compile/internal/types2/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 types2_test
    31  
    32  import (
    33  	"bytes"
    34  	"cmd/compile/internal/syntax"
    35  	"flag"
    36  	"fmt"
    37  	"go/build"
    38  	"go/build/constraint"
    39  	"internal/buildcfg"
    40  	"internal/testenv"
    41  	"os"
    42  	"path/filepath"
    43  	"reflect"
    44  	"regexp"
    45  	"runtime"
    46  	"slices"
    47  	"strconv"
    48  	"strings"
    49  	"testing"
    50  
    51  	. "cmd/compile/internal/types2"
    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  func parseFiles(t *testing.T, filenames []string, srcs [][]byte, mode syntax.Mode) ([]*syntax.File, []error) {
    60  	var files []*syntax.File
    61  	var errlist []error
    62  	errh := func(err error) { errlist = append(errlist, err) }
    63  	for i, filename := range filenames {
    64  		base := syntax.NewFileBase(filename)
    65  		r := bytes.NewReader(srcs[i])
    66  		file, err := syntax.Parse(base, r, errh, nil, mode)
    67  		if file == nil {
    68  			t.Fatalf("%s: %s", filename, err)
    69  		}
    70  		files = append(files, file)
    71  	}
    72  	return files, errlist
    73  }
    74  
    75  func unpackError(err error) (syntax.Pos, string) {
    76  	switch err := err.(type) {
    77  	case syntax.Error:
    78  		return err.Pos, err.Msg
    79  	case Error:
    80  		return err.Pos, err.Msg
    81  	default:
    82  		return nopos, err.Error()
    83  	}
    84  }
    85  
    86  // absDiff returns the absolute difference between x and y.
    87  func absDiff(x, y uint) uint {
    88  	if x < y {
    89  		return y - x
    90  	}
    91  	return x - y
    92  }
    93  
    94  // parseFlags parses flags from the first line of the given source if the line
    95  // starts with "//" (line comment) followed by "-" (possibly with spaces
    96  // between). Otherwise the line is ignored.
    97  func parseFlags(src []byte, flags *flag.FlagSet) error {
    98  	// we must have a line comment that starts with a "-"
    99  	const prefix = "//"
   100  	if !bytes.HasPrefix(src, []byte(prefix)) {
   101  		return nil // first line is not a line comment
   102  	}
   103  	src = src[len(prefix):]
   104  	if i := bytes.Index(src, []byte("-")); i < 0 || len(bytes.TrimSpace(src[:i])) != 0 {
   105  		return nil // comment doesn't start with a "-"
   106  	}
   107  	end := bytes.Index(src, []byte("\n"))
   108  	const maxLen = 256
   109  	if end < 0 || end > maxLen {
   110  		return fmt.Errorf("flags comment line too long")
   111  	}
   112  
   113  	return flags.Parse(strings.Fields(string(src[:end])))
   114  }
   115  
   116  // testFiles type-checks the package consisting of the given files, and
   117  // compares the resulting errors with the ERROR annotations in the source.
   118  //
   119  // The srcs slice contains the file content for the files named in the
   120  // filenames slice. The colDelta parameter specifies the tolerance for position
   121  // mismatch when comparing errors. The manual parameter specifies whether this
   122  // is a 'manual' test.
   123  //
   124  // If provided, opts may be used to mutate the Config before type-checking.
   125  func testFiles(t *testing.T, filenames []string, srcs [][]byte, colDelta uint, manual bool, opts ...func(*Config)) {
   126  	if len(filenames) == 0 {
   127  		t.Fatal("no source files")
   128  	}
   129  
   130  	// parse files
   131  	files, errlist := parseFiles(t, filenames, srcs, 0)
   132  	pkgName := "<no package>"
   133  	if len(files) > 0 {
   134  		pkgName = files[0].PkgName.Value
   135  	}
   136  	listErrors := manual && !*verifyErrors
   137  	if listErrors && len(errlist) > 0 {
   138  		t.Errorf("--- %s:", pkgName)
   139  		for _, err := range errlist {
   140  			t.Error(err)
   141  		}
   142  	}
   143  
   144  	// set up typechecker
   145  	var conf Config
   146  	conf.Trace = manual && testing.Verbose()
   147  	conf.Importer = defaultImporter()
   148  	conf.Error = func(err error) {
   149  		if *haltOnError {
   150  			defer panic(err)
   151  		}
   152  		if listErrors {
   153  			t.Error(err)
   154  			return
   155  		}
   156  		errlist = append(errlist, err)
   157  	}
   158  
   159  	// apply custom configuration
   160  	for _, opt := range opts {
   161  		opt(&conf)
   162  	}
   163  
   164  	// apply flag setting (overrides custom configuration)
   165  	var goexperiment string
   166  	flags := flag.NewFlagSet("", flag.PanicOnError)
   167  	flags.StringVar(&conf.GoVersion, "lang", "", "")
   168  	flags.StringVar(&goexperiment, "goexperiment", "", "")
   169  	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
   170  	if err := parseFlags(srcs[0], flags); err != nil {
   171  		t.Fatal(err)
   172  	}
   173  
   174  	if goexperiment != "" {
   175  		revert := setGOEXPERIMENT(goexperiment)
   176  		defer revert()
   177  	}
   178  
   179  	// Provide Config.Info with all maps so that info recording is tested.
   180  	info := Info{
   181  		Types:        make(map[syntax.Expr]TypeAndValue),
   182  		Instances:    make(map[*syntax.Name]Instance),
   183  		Defs:         make(map[*syntax.Name]Object),
   184  		Uses:         make(map[*syntax.Name]Object),
   185  		Implicits:    make(map[syntax.Node]Object),
   186  		Selections:   make(map[*syntax.SelectorExpr]*Selection),
   187  		Scopes:       make(map[syntax.Node]*Scope),
   188  		FileVersions: make(map[*syntax.PosBase]string),
   189  	}
   190  
   191  	// typecheck
   192  	pkg, err := conf.Check(pkgName, files, &info)
   193  	// errlist holds parse errors from parseFiles (and type-checking errors from
   194  	// conf.Error when !listErrors); err is the first type-checking error from Check.
   195  	hasErrors := len(errlist) > 0 || err != nil
   196  	if errs := checkInvariants(pkg, &info, hasErrors); len(errs) > 0 {
   197  		for _, err := range errs {
   198  			t.Errorf("%s: invariant failure: %v", pkgName, err)
   199  		}
   200  	}
   201  	if listErrors {
   202  		return
   203  	}
   204  
   205  	// collect expected errors
   206  	errmap := make(map[string]map[uint][]syntax.Error)
   207  	for i, filename := range filenames {
   208  		if m := syntax.CommentMap(bytes.NewReader(srcs[i]), regexp.MustCompile("^ ERRORx? ")); len(m) > 0 {
   209  			errmap[filename] = m
   210  		}
   211  	}
   212  
   213  	// match against found errors
   214  	var indices []int // list indices of matching errors, reused for each error
   215  	for _, err := range errlist {
   216  		gotPos, gotMsg := unpackError(err)
   217  
   218  		// find list of errors for the respective error line
   219  		filename := gotPos.Base().Filename()
   220  		filemap := errmap[filename]
   221  		line := gotPos.Line()
   222  		var errList []syntax.Error
   223  		if filemap != nil {
   224  			errList = filemap[line]
   225  		}
   226  
   227  		// At least one of the errors in errList should match the current error.
   228  		indices = indices[:0]
   229  		for i, want := range errList {
   230  			pattern, substr := strings.CutPrefix(want.Msg, " ERROR ")
   231  			if !substr {
   232  				var found bool
   233  				pattern, found = strings.CutPrefix(want.Msg, " ERRORx ")
   234  				if !found {
   235  					panic("unreachable")
   236  				}
   237  			}
   238  			unquoted, err := strconv.Unquote(strings.TrimSpace(pattern))
   239  			if err != nil {
   240  				t.Errorf("%s:%d:%d: invalid ERROR pattern (cannot unquote %s)", filename, line, want.Pos.Col(), pattern)
   241  				continue
   242  			}
   243  			if substr {
   244  				if !strings.Contains(gotMsg, unquoted) {
   245  					continue
   246  				}
   247  			} else {
   248  				rx, err := regexp.Compile(unquoted)
   249  				if err != nil {
   250  					t.Errorf("%s:%d:%d: %v", filename, line, want.Pos.Col(), err)
   251  					continue
   252  				}
   253  				if !rx.MatchString(gotMsg) {
   254  					continue
   255  				}
   256  			}
   257  			indices = append(indices, i)
   258  		}
   259  		if len(indices) == 0 {
   260  			t.Errorf("%s: no error expected: %q", gotPos, gotMsg)
   261  			continue
   262  		}
   263  		// len(indices) > 0
   264  
   265  		// If there are multiple matching errors, select the one with the closest column position.
   266  		index := -1 // index of matching error
   267  		var delta uint
   268  		for _, i := range indices {
   269  			if d := absDiff(gotPos.Col(), errList[i].Pos.Col()); index < 0 || d < delta {
   270  				index, delta = i, d
   271  			}
   272  		}
   273  
   274  		// The closest column position must be within expected colDelta.
   275  		if delta > colDelta {
   276  			t.Errorf("%s: got col = %d; want %d", gotPos, gotPos.Col(), errList[index].Pos.Col())
   277  		}
   278  
   279  		// eliminate from errList
   280  		if n := len(errList) - 1; n > 0 {
   281  			// not the last entry - slide entries down (don't reorder)
   282  			copy(errList[index:], errList[index+1:])
   283  			filemap[line] = errList[:n]
   284  		} else {
   285  			// last entry - remove errList from filemap
   286  			delete(filemap, line)
   287  		}
   288  
   289  		// if filemap is empty, eliminate from errmap
   290  		if len(filemap) == 0 {
   291  			delete(errmap, filename)
   292  		}
   293  	}
   294  
   295  	// there should be no expected errors left
   296  	if len(errmap) > 0 {
   297  		t.Errorf("--- %s: unreported errors:", pkgName)
   298  		for filename, filemap := range errmap {
   299  			for line, errList := range filemap {
   300  				for _, err := range errList {
   301  					t.Errorf("%s:%d:%d: %s", filename, line, err.Pos.Col(), err.Msg)
   302  				}
   303  			}
   304  		}
   305  	}
   306  }
   307  
   308  // boolFieldAddr(conf, name) returns the address of the boolean field conf.<name>.
   309  // For accessing unexported fields.
   310  func boolFieldAddr(conf *Config, name string) *bool {
   311  	v := reflect.Indirect(reflect.ValueOf(conf))
   312  	return (*bool)(v.FieldByName(name).Addr().UnsafePointer())
   313  }
   314  
   315  // setGOEXPERIMENT overwrites the existing buildcfg.Experiment with a new one
   316  // based on the provided goexperiment string. Calling the result function
   317  // (typically via defer), reverts buildcfg.Experiment to the prior value.
   318  // For testing use, only.
   319  func setGOEXPERIMENT(goexperiment string) func() {
   320  	exp, err := buildcfg.ParseGOEXPERIMENT(runtime.GOOS, runtime.GOARCH, goexperiment)
   321  	if err != nil {
   322  		panic(err)
   323  	}
   324  	old := buildcfg.Experiment
   325  	buildcfg.Experiment = *exp
   326  	return func() { buildcfg.Experiment = old }
   327  }
   328  
   329  // TestManual is for manual testing of a package - either provided
   330  // as a list of filenames belonging to the package, or a directory
   331  // name containing the package files - after the test arguments
   332  // (and a separating "--"). For instance, to test the package made
   333  // of the files foo.go and bar.go, use:
   334  //
   335  //	go test -run Manual -- foo.go bar.go
   336  //
   337  // If no source arguments are provided, the file testdata/manual.go
   338  // is used instead.
   339  // Provide the -verify flag to verify errors against ERROR comments
   340  // in the input files rather than having a list of errors reported.
   341  // The accepted Go language version can be controlled with the -lang
   342  // flag.
   343  func TestManual(t *testing.T) {
   344  	testenv.MustHaveGoBuild(t)
   345  
   346  	filenames := flag.Args()
   347  	if len(filenames) == 0 {
   348  		filenames = []string{filepath.FromSlash("testdata/manual.go")}
   349  	}
   350  
   351  	info, err := os.Stat(filenames[0])
   352  	if err != nil {
   353  		t.Fatalf("TestManual: %v", err)
   354  	}
   355  
   356  	DefPredeclaredTestFuncs()
   357  	if info.IsDir() {
   358  		if len(filenames) > 1 {
   359  			t.Fatal("TestManual: must have only one directory argument")
   360  		}
   361  		testDir(t, filenames[0], 0, true)
   362  	} else {
   363  		testPkg(t, filenames, 0, true)
   364  	}
   365  }
   366  
   367  func TestLongConstants(t *testing.T) {
   368  	t.Parallel()
   369  	format := `package longconst; const _ = %s /* ERROR "constant overflow" */; const _ = %s // ERROR "excessively long constant"`
   370  	src := fmt.Sprintf(format, strings.Repeat("1", 9999), strings.Repeat("1", 10001))
   371  	testFiles(t, []string{"longconst.go"}, [][]byte{[]byte(src)}, 0, false)
   372  }
   373  
   374  func withSizes(sizes Sizes) func(*Config) {
   375  	return func(cfg *Config) {
   376  		cfg.Sizes = sizes
   377  	}
   378  }
   379  
   380  // TestIndexRepresentability tests that constant index operands must
   381  // be representable as int even if they already have a type that can
   382  // represent larger values.
   383  func TestIndexRepresentability(t *testing.T) {
   384  	t.Parallel()
   385  	const src = `package index; var s []byte; var _ = s[int64 /* ERRORx "int64\\(1\\) << 40 \\(.*\\) overflows int" */ (1) << 40]`
   386  	testFiles(t, []string{"index.go"}, [][]byte{[]byte(src)}, 0, false, withSizes(&StdSizes{4, 4}))
   387  }
   388  
   389  func TestIssue47243_TypedRHS(t *testing.T) {
   390  	t.Parallel()
   391  	// The RHS of the shift expression below overflows uint on 32bit platforms,
   392  	// but this is OK as it is explicitly typed.
   393  	const src = `package issue47243; var a uint64; var _ = a << uint64(4294967296)` // uint64(1<<32)
   394  	testFiles(t, []string{"p.go"}, [][]byte{[]byte(src)}, 0, false, withSizes(&StdSizes{4, 4}))
   395  }
   396  
   397  func TestCheck(t *testing.T) {
   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", 20, false) } // TODO(gri) narrow column tolerance
   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  	fs := filenames[:0]
   453  	srcs := make([][]byte, 0, len(filenames))
   454  	for _, filename := range filenames {
   455  		src, err := os.ReadFile(filename)
   456  		if err != nil {
   457  			t.Fatalf("could not read %s: %v", filename, err)
   458  		}
   459  		if !shouldTest(src) {
   460  			continue
   461  		}
   462  		fs = append(fs, filename)
   463  		srcs = append(srcs, src)
   464  	}
   465  	if len(fs) == 0 {
   466  		t.Skip("all files skipped by build tags")
   467  	}
   468  	testFiles(t, fs, srcs, colDelta, manual)
   469  }
   470  
   471  // shouldTest checks build tags in src and returns whether the file
   472  // should be tested according to the tags.
   473  func shouldTest(src []byte) bool {
   474  	match := func(tag string) bool {
   475  		// We only care GOOS, GOARCH, and go version tags.
   476  		if slices.Contains(build.Default.ReleaseTags, tag) {
   477  			return true
   478  		}
   479  		return tag == runtime.GOOS || tag == runtime.GOARCH
   480  	}
   481  	for line := range strings.SplitSeq(string(src), "\n") {
   482  		if strings.HasPrefix(line, "package ") {
   483  			break
   484  		}
   485  		if expr, err := constraint.Parse(line); err == nil {
   486  			return expr.Eval(match)
   487  		}
   488  	}
   489  	return true
   490  }
   491  

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