Source file src/cmd/vet/vet_test.go

Documentation: cmd/vet

     1  // Copyright 2013 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  package main
     6  
     7  import (
     8  	"bytes"
     9  	"errors"
    10  	"fmt"
    11  	"internal/testenv"
    12  	"log"
    13  	"os"
    14  	"os/exec"
    15  	"path"
    16  	"path/filepath"
    17  	"regexp"
    18  	"strconv"
    19  	"strings"
    20  	"sync"
    21  	"testing"
    22  )
    23  
    24  // TestMain executes the test binary as the vet command if
    25  // GO_VETTEST_IS_VET is set, and runs the tests otherwise.
    26  func TestMain(m *testing.M) {
    27  	if os.Getenv("GO_VETTEST_IS_VET") != "" {
    28  		main()
    29  		os.Exit(0)
    30  	}
    31  
    32  	os.Setenv("GO_VETTEST_IS_VET", "1") // Set for subprocesses to inherit.
    33  	os.Exit(m.Run())
    34  }
    35  
    36  // vetPath returns the path to the "vet" binary to run.
    37  func vetPath(t testing.TB) string {
    38  	t.Helper()
    39  	testenv.MustHaveExec(t)
    40  
    41  	vetPathOnce.Do(func() {
    42  		vetExePath, vetPathErr = os.Executable()
    43  	})
    44  	if vetPathErr != nil {
    45  		t.Fatal(vetPathErr)
    46  	}
    47  	return vetExePath
    48  }
    49  
    50  var (
    51  	vetPathOnce sync.Once
    52  	vetExePath  string
    53  	vetPathErr  error
    54  )
    55  
    56  func vetCmd(t *testing.T, arg, pkg string) *exec.Cmd {
    57  	cmd := testenv.Command(t, testenv.GoToolPath(t), "vet", "-vettool="+vetPath(t), arg, path.Join("cmd/vet/testdata", pkg))
    58  	cmd.Env = os.Environ()
    59  	return cmd
    60  }
    61  
    62  func TestVet(t *testing.T) {
    63  	t.Parallel()
    64  	for _, pkg := range []string{
    65  		"appends",
    66  		"asm",
    67  		"assign",
    68  		"atomic",
    69  		"bool",
    70  		"buildtag",
    71  		"cgo",
    72  		"composite",
    73  		"copylock",
    74  		"deadcode",
    75  		"directive",
    76  		"httpresponse",
    77  		"lostcancel",
    78  		"method",
    79  		"nilfunc",
    80  		"print",
    81  		"shift",
    82  		"slog",
    83  		"structtag",
    84  		"testingpkg",
    85  		// "testtag" has its own test
    86  		"unmarshal",
    87  		"unsafeptr",
    88  		"unused",
    89  	} {
    90  		pkg := pkg
    91  		t.Run(pkg, func(t *testing.T) {
    92  			t.Parallel()
    93  
    94  			// Skip cgo test on platforms without cgo.
    95  			if pkg == "cgo" && !cgoEnabled(t) {
    96  				return
    97  			}
    98  
    99  			cmd := vetCmd(t, "-printfuncs=Warn,Warnf", pkg)
   100  
   101  			// The asm test assumes amd64.
   102  			if pkg == "asm" {
   103  				cmd.Env = append(cmd.Env, "GOOS=linux", "GOARCH=amd64")
   104  			}
   105  
   106  			dir := filepath.Join("testdata", pkg)
   107  			gos, err := filepath.Glob(filepath.Join(dir, "*.go"))
   108  			if err != nil {
   109  				t.Fatal(err)
   110  			}
   111  			asms, err := filepath.Glob(filepath.Join(dir, "*.s"))
   112  			if err != nil {
   113  				t.Fatal(err)
   114  			}
   115  			var files []string
   116  			files = append(files, gos...)
   117  			files = append(files, asms...)
   118  
   119  			errchk(cmd, files, t)
   120  		})
   121  	}
   122  
   123  	// The loopclosure analyzer (aka "rangeloop" before CL 140578)
   124  	// is a no-op for files whose version >= go1.22, so we use a
   125  	// go.mod file in the rangeloop directory to "downgrade".
   126  	//
   127  	// TOOD(adonovan): delete when go1.21 goes away.
   128  	t.Run("loopclosure", func(t *testing.T) {
   129  		cmd := testenv.Command(t, testenv.GoToolPath(t), "vet", "-vettool="+vetPath(t), ".")
   130  		cmd.Env = append(os.Environ(), "GOWORK=off")
   131  		cmd.Dir = "testdata/rangeloop"
   132  		cmd.Stderr = new(strings.Builder) // all vet output goes to stderr
   133  		cmd.Run()
   134  		stderr := cmd.Stderr.(fmt.Stringer).String()
   135  
   136  		filename := filepath.FromSlash("testdata/rangeloop/rangeloop.go")
   137  
   138  		// Unlike the tests above, which runs vet in cmd/vet/, this one
   139  		// runs it in subdirectory, so the "full names" in the output
   140  		// are in fact short "./rangeloop.go".
   141  		// But we can't just pass "./rangeloop.go" as the "full name"
   142  		// argument to errorCheck as it does double duty as both a
   143  		// string that appears in the output, and as file name
   144  		// openable relative to the test directory, containing text
   145  		// expectations.
   146  		//
   147  		// So, we munge the file.
   148  		stderr = strings.ReplaceAll(stderr, filepath.FromSlash("./rangeloop.go"), filename)
   149  
   150  		if err := errorCheck(stderr, false, filename, filepath.Base(filename)); err != nil {
   151  			t.Errorf("error check failed: %s", err)
   152  			t.Log("vet stderr:\n", cmd.Stderr)
   153  		}
   154  	})
   155  
   156  	// The stdversion analyzer requires a lower-than-tip go
   157  	// version in its go.mod file for it to report anything.
   158  	// So again we use a testdata go.mod file to "downgrade".
   159  	t.Run("stdversion", func(t *testing.T) {
   160  		cmd := testenv.Command(t, testenv.GoToolPath(t), "vet", "-vettool="+vetPath(t), ".")
   161  		cmd.Env = append(os.Environ(), "GOWORK=off")
   162  		cmd.Dir = "testdata/stdversion"
   163  		cmd.Stderr = new(strings.Builder) // all vet output goes to stderr
   164  		cmd.Run()
   165  		stderr := cmd.Stderr.(fmt.Stringer).String()
   166  
   167  		filename := filepath.FromSlash("testdata/stdversion/stdversion.go")
   168  
   169  		// Unlike the tests above, which runs vet in cmd/vet/, this one
   170  		// runs it in subdirectory, so the "full names" in the output
   171  		// are in fact short "./rangeloop.go".
   172  		// But we can't just pass "./rangeloop.go" as the "full name"
   173  		// argument to errorCheck as it does double duty as both a
   174  		// string that appears in the output, and as file name
   175  		// openable relative to the test directory, containing text
   176  		// expectations.
   177  		//
   178  		// So, we munge the file.
   179  		stderr = strings.ReplaceAll(stderr, filepath.FromSlash("./stdversion.go"), filename)
   180  
   181  		if err := errorCheck(stderr, false, filename, filepath.Base(filename)); err != nil {
   182  			t.Errorf("error check failed: %s", err)
   183  			t.Log("vet stderr:\n", cmd.Stderr)
   184  		}
   185  	})
   186  }
   187  
   188  func cgoEnabled(t *testing.T) bool {
   189  	// Don't trust build.Default.CgoEnabled as it is false for
   190  	// cross-builds unless CGO_ENABLED is explicitly specified.
   191  	// That's fine for the builders, but causes commands like
   192  	// 'GOARCH=386 go test .' to fail.
   193  	// Instead, we ask the go command.
   194  	cmd := testenv.Command(t, testenv.GoToolPath(t), "list", "-f", "{{context.CgoEnabled}}")
   195  	out, _ := cmd.CombinedOutput()
   196  	return string(out) == "true\n"
   197  }
   198  
   199  func errchk(c *exec.Cmd, files []string, t *testing.T) {
   200  	output, err := c.CombinedOutput()
   201  	if _, ok := err.(*exec.ExitError); !ok {
   202  		t.Logf("vet output:\n%s", output)
   203  		t.Fatal(err)
   204  	}
   205  	fullshort := make([]string, 0, len(files)*2)
   206  	for _, f := range files {
   207  		fullshort = append(fullshort, f, filepath.Base(f))
   208  	}
   209  	err = errorCheck(string(output), false, fullshort...)
   210  	if err != nil {
   211  		t.Errorf("error check failed: %s", err)
   212  	}
   213  }
   214  
   215  // TestTags verifies that the -tags argument controls which files to check.
   216  func TestTags(t *testing.T) {
   217  	t.Parallel()
   218  	for tag, wantFile := range map[string]int{
   219  		"testtag":     1, // file1
   220  		"x testtag y": 1,
   221  		"othertag":    2,
   222  	} {
   223  		tag, wantFile := tag, wantFile
   224  		t.Run(tag, func(t *testing.T) {
   225  			t.Parallel()
   226  			t.Logf("-tags=%s", tag)
   227  			cmd := vetCmd(t, "-tags="+tag, "tagtest")
   228  			output, err := cmd.CombinedOutput()
   229  
   230  			want := fmt.Sprintf("file%d.go", wantFile)
   231  			dontwant := fmt.Sprintf("file%d.go", 3-wantFile)
   232  
   233  			// file1 has testtag and file2 has !testtag.
   234  			if !bytes.Contains(output, []byte(filepath.Join("tagtest", want))) {
   235  				t.Errorf("%s: %s was excluded, should be included", tag, want)
   236  			}
   237  			if bytes.Contains(output, []byte(filepath.Join("tagtest", dontwant))) {
   238  				t.Errorf("%s: %s was included, should be excluded", tag, dontwant)
   239  			}
   240  			if t.Failed() {
   241  				t.Logf("err=%s, output=<<%s>>", err, output)
   242  			}
   243  		})
   244  	}
   245  }
   246  
   247  // All declarations below were adapted from test/run.go.
   248  
   249  // errorCheck matches errors in outStr against comments in source files.
   250  // For each line of the source files which should generate an error,
   251  // there should be a comment of the form // ERROR "regexp".
   252  // If outStr has an error for a line which has no such comment,
   253  // this function will report an error.
   254  // Likewise if outStr does not have an error for a line which has a comment,
   255  // or if the error message does not match the <regexp>.
   256  // The <regexp> syntax is Perl but it's best to stick to egrep.
   257  //
   258  // Sources files are supplied as fullshort slice.
   259  // It consists of pairs: full path to source file and its base name.
   260  func errorCheck(outStr string, wantAuto bool, fullshort ...string) (err error) {
   261  	var errs []error
   262  	out := splitOutput(outStr, wantAuto)
   263  	// Cut directory name.
   264  	for i := range out {
   265  		for j := 0; j < len(fullshort); j += 2 {
   266  			full, short := fullshort[j], fullshort[j+1]
   267  			out[i] = strings.ReplaceAll(out[i], full, short)
   268  		}
   269  	}
   270  
   271  	var want []wantedError
   272  	for j := 0; j < len(fullshort); j += 2 {
   273  		full, short := fullshort[j], fullshort[j+1]
   274  		want = append(want, wantedErrors(full, short)...)
   275  	}
   276  	for _, we := range want {
   277  		var errmsgs []string
   278  		if we.auto {
   279  			errmsgs, out = partitionStrings("<autogenerated>", out)
   280  		} else {
   281  			errmsgs, out = partitionStrings(we.prefix, out)
   282  		}
   283  		if len(errmsgs) == 0 {
   284  			errs = append(errs, fmt.Errorf("%s:%d: missing error %q", we.file, we.lineNum, we.reStr))
   285  			continue
   286  		}
   287  		matched := false
   288  		n := len(out)
   289  		for _, errmsg := range errmsgs {
   290  			// Assume errmsg says "file:line: foo".
   291  			// Cut leading "file:line: " to avoid accidental matching of file name instead of message.
   292  			text := errmsg
   293  			if _, suffix, ok := strings.Cut(text, " "); ok {
   294  				text = suffix
   295  			}
   296  			if we.re.MatchString(text) {
   297  				matched = true
   298  			} else {
   299  				out = append(out, errmsg)
   300  			}
   301  		}
   302  		if !matched {
   303  			errs = append(errs, fmt.Errorf("%s:%d: no match for %#q in:\n\t%s", we.file, we.lineNum, we.reStr, strings.Join(out[n:], "\n\t")))
   304  			continue
   305  		}
   306  	}
   307  
   308  	if len(out) > 0 {
   309  		errs = append(errs, fmt.Errorf("Unmatched Errors:"))
   310  		for _, errLine := range out {
   311  			errs = append(errs, fmt.Errorf("%s", errLine))
   312  		}
   313  	}
   314  
   315  	if len(errs) == 0 {
   316  		return nil
   317  	}
   318  	if len(errs) == 1 {
   319  		return errs[0]
   320  	}
   321  	var buf strings.Builder
   322  	fmt.Fprintf(&buf, "\n")
   323  	for _, err := range errs {
   324  		fmt.Fprintf(&buf, "%s\n", err.Error())
   325  	}
   326  	return errors.New(buf.String())
   327  }
   328  
   329  func splitOutput(out string, wantAuto bool) []string {
   330  	// gc error messages continue onto additional lines with leading tabs.
   331  	// Split the output at the beginning of each line that doesn't begin with a tab.
   332  	// <autogenerated> lines are impossible to match so those are filtered out.
   333  	var res []string
   334  	for _, line := range strings.Split(out, "\n") {
   335  		line = strings.TrimSuffix(line, "\r") // normalize Windows output
   336  		if strings.HasPrefix(line, "\t") {
   337  			res[len(res)-1] += "\n" + line
   338  		} else if strings.HasPrefix(line, "go tool") || strings.HasPrefix(line, "#") || !wantAuto && strings.HasPrefix(line, "<autogenerated>") {
   339  			continue
   340  		} else if strings.TrimSpace(line) != "" {
   341  			res = append(res, line)
   342  		}
   343  	}
   344  	return res
   345  }
   346  
   347  // matchPrefix reports whether s starts with file name prefix followed by a :,
   348  // and possibly preceded by a directory name.
   349  func matchPrefix(s, prefix string) bool {
   350  	i := strings.Index(s, ":")
   351  	if i < 0 {
   352  		return false
   353  	}
   354  	j := strings.LastIndex(s[:i], "/")
   355  	s = s[j+1:]
   356  	if len(s) <= len(prefix) || s[:len(prefix)] != prefix {
   357  		return false
   358  	}
   359  	if s[len(prefix)] == ':' {
   360  		return true
   361  	}
   362  	return false
   363  }
   364  
   365  func partitionStrings(prefix string, strs []string) (matched, unmatched []string) {
   366  	for _, s := range strs {
   367  		if matchPrefix(s, prefix) {
   368  			matched = append(matched, s)
   369  		} else {
   370  			unmatched = append(unmatched, s)
   371  		}
   372  	}
   373  	return
   374  }
   375  
   376  type wantedError struct {
   377  	reStr   string
   378  	re      *regexp.Regexp
   379  	lineNum int
   380  	auto    bool // match <autogenerated> line
   381  	file    string
   382  	prefix  string
   383  }
   384  
   385  var (
   386  	errRx       = regexp.MustCompile(`// (?:GC_)?ERROR(NEXT)? (.*)`)
   387  	errAutoRx   = regexp.MustCompile(`// (?:GC_)?ERRORAUTO(NEXT)? (.*)`)
   388  	errQuotesRx = regexp.MustCompile(`"([^"]*)"`)
   389  	lineRx      = regexp.MustCompile(`LINE(([+-])(\d+))?`)
   390  )
   391  
   392  // wantedErrors parses expected errors from comments in a file.
   393  func wantedErrors(file, short string) (errs []wantedError) {
   394  	cache := make(map[string]*regexp.Regexp)
   395  
   396  	src, err := os.ReadFile(file)
   397  	if err != nil {
   398  		log.Fatal(err)
   399  	}
   400  	for i, line := range strings.Split(string(src), "\n") {
   401  		lineNum := i + 1
   402  		if strings.Contains(line, "////") {
   403  			// double comment disables ERROR
   404  			continue
   405  		}
   406  		var auto bool
   407  		m := errAutoRx.FindStringSubmatch(line)
   408  		if m != nil {
   409  			auto = true
   410  		} else {
   411  			m = errRx.FindStringSubmatch(line)
   412  		}
   413  		if m == nil {
   414  			continue
   415  		}
   416  		if m[1] == "NEXT" {
   417  			lineNum++
   418  		}
   419  		all := m[2]
   420  		mm := errQuotesRx.FindAllStringSubmatch(all, -1)
   421  		if mm == nil {
   422  			log.Fatalf("%s:%d: invalid errchk line: %s", file, lineNum, line)
   423  		}
   424  		for _, m := range mm {
   425  			replacedOnce := false
   426  			rx := lineRx.ReplaceAllStringFunc(m[1], func(m string) string {
   427  				if replacedOnce {
   428  					return m
   429  				}
   430  				replacedOnce = true
   431  				n := lineNum
   432  				if strings.HasPrefix(m, "LINE+") {
   433  					delta, _ := strconv.Atoi(m[5:])
   434  					n += delta
   435  				} else if strings.HasPrefix(m, "LINE-") {
   436  					delta, _ := strconv.Atoi(m[5:])
   437  					n -= delta
   438  				}
   439  				return fmt.Sprintf("%s:%d", short, n)
   440  			})
   441  			re := cache[rx]
   442  			if re == nil {
   443  				var err error
   444  				re, err = regexp.Compile(rx)
   445  				if err != nil {
   446  					log.Fatalf("%s:%d: invalid regexp \"%#q\" in ERROR line: %v", file, lineNum, rx, err)
   447  				}
   448  				cache[rx] = re
   449  			}
   450  			prefix := fmt.Sprintf("%s:%d", short, lineNum)
   451  			errs = append(errs, wantedError{
   452  				reStr:   rx,
   453  				re:      re,
   454  				prefix:  prefix,
   455  				auto:    auto,
   456  				lineNum: lineNum,
   457  				file:    short,
   458  			})
   459  		}
   460  	}
   461  
   462  	return
   463  }
   464  

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