testflag.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  package test
     6  
     7  import (
     8  	"cmd/go/internal/base"
     9  	"cmd/go/internal/cfg"
    10  	"cmd/go/internal/cmdflag"
    11  	"cmd/go/internal/work"
    12  	"errors"
    13  	"flag"
    14  	"fmt"
    15  	"internal/godebug"
    16  	"os"
    17  	"path/filepath"
    18  	"strconv"
    19  	"strings"
    20  	"time"
    21  )
    22  
    23  //go:generate go run ./genflags.go
    24  
    25  // The flag handling part of go test is large and distracting.
    26  // We can't use (*flag.FlagSet).Parse because some of the flags from
    27  // our command line are for us, and some are for the test binary, and
    28  // some are for both.
    29  
    30  var gotestjsonbuildtext = godebug.New("gotestjsonbuildtext")
    31  
    32  func init() {
    33  	work.AddBuildFlags(CmdTest, work.OmitVFlag|work.OmitJSONFlag)
    34  
    35  	cf := CmdTest.Flag
    36  	cf.BoolVar(&testC, "c", false, "")
    37  	cf.StringVar(&testO, "o", "", "")
    38  	work.AddCoverFlags(CmdTest, &testCoverProfile)
    39  	cf.Var((*base.StringsFlag)(&work.ExecCmd), "exec", "")
    40  	cf.BoolVar(&testJSON, "json", false, "")
    41  	cf.Var(&testVet, "vet", "")
    42  
    43  	// Register flags to be forwarded to the test binary. We retain variables for
    44  	// some of them so that cmd/go knows what to do with the test output, or knows
    45  	// to build the test in a way that supports the use of the flag.
    46  
    47  	cf.StringVar(&testBench, "bench", "", "")
    48  	cf.Bool("benchmem", false, "")
    49  	cf.String("benchtime", "", "")
    50  	cf.StringVar(&testBlockProfile, "blockprofile", "", "")
    51  	cf.String("blockprofilerate", "", "")
    52  	cf.Int("count", 0, "")
    53  	cf.String("cpu", "", "")
    54  	cf.StringVar(&testCPUProfile, "cpuprofile", "", "")
    55  	cf.BoolVar(&testFailFast, "failfast", false, "")
    56  	cf.StringVar(&testFuzz, "fuzz", "", "")
    57  	cf.Bool("fullpath", false, "")
    58  	cf.StringVar(&testList, "list", "", "")
    59  	cf.StringVar(&testMemProfile, "memprofile", "", "")
    60  	cf.String("memprofilerate", "", "")
    61  	cf.StringVar(&testMutexProfile, "mutexprofile", "", "")
    62  	cf.String("mutexprofilefraction", "", "")
    63  	cf.Var(&testOutputDir, "outputdir", "")
    64  	cf.Int("parallel", 0, "")
    65  	cf.String("run", "", "")
    66  	cf.Bool("short", false, "")
    67  	cf.String("skip", "", "")
    68  	cf.DurationVar(&testTimeout, "timeout", 10*time.Minute, "") // known to cmd/dist
    69  	cf.String("fuzztime", "", "")
    70  	cf.String("fuzzminimizetime", "", "")
    71  	cf.StringVar(&testTrace, "trace", "", "")
    72  	cf.Var(&testV, "v", "")
    73  	cf.Var(&testShuffle, "shuffle", "")
    74  
    75  	for name, ok := range passFlagToTest {
    76  		if ok {
    77  			cf.Var(cf.Lookup(name).Value, "test."+name, "")
    78  		}
    79  	}
    80  }
    81  
    82  // outputdirFlag implements the -outputdir flag.
    83  // It interprets an empty value as the working directory of the 'go' command.
    84  type outputdirFlag struct {
    85  	abs string
    86  }
    87  
    88  func (f *outputdirFlag) String() string {
    89  	return f.abs
    90  }
    91  
    92  func (f *outputdirFlag) Set(value string) (err error) {
    93  	if value == "" {
    94  		f.abs = ""
    95  	} else {
    96  		f.abs, err = filepath.Abs(value)
    97  	}
    98  	return err
    99  }
   100  
   101  func (f *outputdirFlag) getAbs() string {
   102  	if f.abs == "" {
   103  		return base.Cwd()
   104  	}
   105  	return f.abs
   106  }
   107  
   108  // vetFlag implements the special parsing logic for the -vet flag:
   109  // a comma-separated list, with distinguished values "all" and
   110  // "off", plus a boolean tracking whether it was set explicitly.
   111  //
   112  // "all" is encoded as vetFlag{true, false, nil}, since it will
   113  // pass no flags to the vet binary, and by default, it runs all
   114  // analyzers.
   115  type vetFlag struct {
   116  	explicit bool
   117  	off      bool
   118  	flags    []string // passed to vet when invoked automatically during 'go test'
   119  }
   120  
   121  func (f *vetFlag) String() string {
   122  	switch {
   123  	case !f.off && !f.explicit && len(f.flags) == 0:
   124  		return "all"
   125  	case f.off:
   126  		return "off"
   127  	}
   128  
   129  	var buf strings.Builder
   130  	for i, f := range f.flags {
   131  		if i > 0 {
   132  			buf.WriteByte(',')
   133  		}
   134  		buf.WriteString(f)
   135  	}
   136  	return buf.String()
   137  }
   138  
   139  func (f *vetFlag) Set(value string) error {
   140  	switch {
   141  	case value == "":
   142  		*f = vetFlag{flags: defaultVetFlags}
   143  		return nil
   144  	case strings.Contains(value, "="):
   145  		return fmt.Errorf("-vet argument cannot contain equal signs")
   146  	case strings.Contains(value, " "):
   147  		return fmt.Errorf("-vet argument is comma-separated list, cannot contain spaces")
   148  	}
   149  
   150  	*f = vetFlag{explicit: true}
   151  	var single string
   152  	for _, arg := range strings.Split(value, ",") {
   153  		switch arg {
   154  		case "":
   155  			return fmt.Errorf("-vet argument contains empty list element")
   156  		case "all":
   157  			single = arg
   158  			*f = vetFlag{explicit: true}
   159  			continue
   160  		case "off":
   161  			single = arg
   162  			*f = vetFlag{
   163  				explicit: true,
   164  				off:      true,
   165  			}
   166  			continue
   167  		default:
   168  			if _, ok := passAnalyzersToVet[arg]; !ok {
   169  				return fmt.Errorf("-vet argument must be a supported analyzer or a distinguished value; found %s", arg)
   170  			}
   171  			f.flags = append(f.flags, "-"+arg)
   172  		}
   173  	}
   174  	if len(f.flags) > 1 && single != "" {
   175  		return fmt.Errorf("-vet does not accept %q in a list with other analyzers", single)
   176  	}
   177  	if len(f.flags) > 1 && single != "" {
   178  		return fmt.Errorf("-vet does not accept %q in a list with other analyzers", single)
   179  	}
   180  	return nil
   181  }
   182  
   183  type shuffleFlag struct {
   184  	on   bool
   185  	seed *int64
   186  }
   187  
   188  func (f *shuffleFlag) String() string {
   189  	if !f.on {
   190  		return "off"
   191  	}
   192  	if f.seed == nil {
   193  		return "on"
   194  	}
   195  	return fmt.Sprintf("%d", *f.seed)
   196  }
   197  
   198  func (f *shuffleFlag) Set(value string) error {
   199  	if value == "off" {
   200  		*f = shuffleFlag{on: false}
   201  		return nil
   202  	}
   203  
   204  	if value == "on" {
   205  		*f = shuffleFlag{on: true}
   206  		return nil
   207  	}
   208  
   209  	seed, err := strconv.ParseInt(value, 10, 64)
   210  	if err != nil {
   211  		return fmt.Errorf(`-shuffle argument must be "on", "off", or an int64: %v`, err)
   212  	}
   213  
   214  	*f = shuffleFlag{on: true, seed: &seed}
   215  	return nil
   216  }
   217  
   218  // testFlags processes the command line, grabbing -x and -c, rewriting known flags
   219  // to have "test" before them, and reading the command line for the test binary.
   220  // Unfortunately for us, we need to do our own flag processing because go test
   221  // grabs some flags but otherwise its command line is just a holding place for
   222  // pkg.test's arguments.
   223  // We allow known flags both before and after the package name list,
   224  // to allow both
   225  //
   226  //	go test fmt -custom-flag-for-fmt-test
   227  //	go test -x math
   228  func testFlags(args []string) (packageNames, passToTest []string) {
   229  	base.SetFromGOFLAGS(&CmdTest.Flag)
   230  	addFromGOFLAGS := map[string]bool{}
   231  	CmdTest.Flag.Visit(func(f *flag.Flag) {
   232  		if short := strings.TrimPrefix(f.Name, "test."); passFlagToTest[short] {
   233  			addFromGOFLAGS[f.Name] = true
   234  		}
   235  	})
   236  
   237  	// firstUnknownFlag helps us report an error when flags not known to 'go
   238  	// test' are used along with -i or -c.
   239  	firstUnknownFlag := ""
   240  
   241  	explicitArgs := make([]string, 0, len(args))
   242  	inPkgList := false
   243  	afterFlagWithoutValue := false
   244  	for len(args) > 0 {
   245  		f, remainingArgs, err := cmdflag.ParseOne(&CmdTest.Flag, args)
   246  
   247  		wasAfterFlagWithoutValue := afterFlagWithoutValue
   248  		afterFlagWithoutValue = false // provisionally
   249  
   250  		if errors.Is(err, flag.ErrHelp) {
   251  			exitWithUsage()
   252  		}
   253  
   254  		if errors.Is(err, cmdflag.ErrFlagTerminator) {
   255  			// 'go list' allows package arguments to be named either before or after
   256  			// the terminator, but 'go test' has historically allowed them only
   257  			// before. Preserve that behavior and treat all remaining arguments —
   258  			// including the terminator itself! — as arguments to the test.
   259  			explicitArgs = append(explicitArgs, args...)
   260  			break
   261  		}
   262  
   263  		if nf := (cmdflag.NonFlagError{}); errors.As(err, &nf) {
   264  			if !inPkgList && packageNames != nil {
   265  				// We already saw the package list previously, and this argument is not
   266  				// a flag, so it — and everything after it — must be either a value for
   267  				// a preceding flag or a literal argument to the test binary.
   268  				if wasAfterFlagWithoutValue {
   269  					// This argument could syntactically be a flag value, so
   270  					// optimistically assume that it is and keep looking for go command
   271  					// flags after it.
   272  					//
   273  					// (If we're wrong, we'll at least be consistent with historical
   274  					// behavior; see https://golang.org/issue/40763.)
   275  					explicitArgs = append(explicitArgs, nf.RawArg)
   276  					args = remainingArgs
   277  					continue
   278  				} else {
   279  					// This argument syntactically cannot be a flag value, so it must be a
   280  					// positional argument, and so must everything after it.
   281  					explicitArgs = append(explicitArgs, args...)
   282  					break
   283  				}
   284  			}
   285  
   286  			inPkgList = true
   287  			packageNames = append(packageNames, nf.RawArg)
   288  			args = remainingArgs // Consume the package name.
   289  			continue
   290  		}
   291  
   292  		if inPkgList {
   293  			// This argument is syntactically a flag, so if we were in the package
   294  			// list we're not anymore.
   295  			inPkgList = false
   296  		}
   297  
   298  		if nd := (cmdflag.FlagNotDefinedError{}); errors.As(err, &nd) {
   299  			// This is a flag we do not know. We must assume that any args we see
   300  			// after this might be flag arguments, not package names, so make
   301  			// packageNames non-nil to indicate that the package list is complete.
   302  			//
   303  			// (Actually, we only strictly need to assume that if the flag is not of
   304  			// the form -x=value, but making this more precise would be a breaking
   305  			// change in the command line API.)
   306  			if packageNames == nil {
   307  				packageNames = []string{}
   308  			}
   309  
   310  			if nd.RawArg == "-args" || nd.RawArg == "--args" {
   311  				// -args or --args signals that everything that follows
   312  				// should be passed to the test.
   313  				explicitArgs = append(explicitArgs, remainingArgs...)
   314  				break
   315  			}
   316  
   317  			if firstUnknownFlag == "" {
   318  				firstUnknownFlag = nd.RawArg
   319  			}
   320  
   321  			explicitArgs = append(explicitArgs, nd.RawArg)
   322  			args = remainingArgs
   323  			if !nd.HasValue {
   324  				afterFlagWithoutValue = true
   325  			}
   326  			continue
   327  		}
   328  
   329  		if err != nil {
   330  			fmt.Fprintln(os.Stderr, err)
   331  			exitWithUsage()
   332  		}
   333  
   334  		if short := strings.TrimPrefix(f.Name, "test."); passFlagToTest[short] {
   335  			explicitArgs = append(explicitArgs, fmt.Sprintf("-test.%s=%v", short, f.Value))
   336  
   337  			// This flag has been overridden explicitly, so don't forward its implicit
   338  			// value from GOFLAGS.
   339  			delete(addFromGOFLAGS, short)
   340  			delete(addFromGOFLAGS, "test."+short)
   341  		}
   342  
   343  		args = remainingArgs
   344  	}
   345  	if firstUnknownFlag != "" && testC {
   346  		fmt.Fprintf(os.Stderr, "go: unknown flag %s cannot be used with -c\n", firstUnknownFlag)
   347  		exitWithUsage()
   348  	}
   349  
   350  	var injectedFlags []string
   351  	if testJSON {
   352  		// If converting to JSON, we need the full output in order to pipe it to test2json.
   353  		// The -test.v=test2json flag is like -test.v=true but causes the test to add
   354  		// extra ^V characters before testing output lines and other framing,
   355  		// which helps test2json do a better job creating the JSON events.
   356  		injectedFlags = append(injectedFlags, "-test.v=test2json")
   357  		delete(addFromGOFLAGS, "v")
   358  		delete(addFromGOFLAGS, "test.v")
   359  
   360  		if gotestjsonbuildtext.Value() == "1" {
   361  			gotestjsonbuildtext.IncNonDefault()
   362  		} else {
   363  			cfg.BuildJSON = true
   364  		}
   365  	}
   366  
   367  	// Inject flags from GOFLAGS before the explicit command-line arguments.
   368  	// (They must appear before the flag terminator or first non-flag argument.)
   369  	// Also determine whether flags with awkward defaults have already been set.
   370  	var timeoutSet, outputDirSet bool
   371  	CmdTest.Flag.Visit(func(f *flag.Flag) {
   372  		short := strings.TrimPrefix(f.Name, "test.")
   373  		if addFromGOFLAGS[f.Name] {
   374  			injectedFlags = append(injectedFlags, fmt.Sprintf("-test.%s=%v", short, f.Value))
   375  		}
   376  		switch short {
   377  		case "timeout":
   378  			timeoutSet = true
   379  		case "outputdir":
   380  			outputDirSet = true
   381  		}
   382  	})
   383  
   384  	// 'go test' has a default timeout, but the test binary itself does not.
   385  	// If the timeout wasn't set (and forwarded) explicitly, add the default
   386  	// timeout to the command line.
   387  	if testTimeout > 0 && !timeoutSet {
   388  		injectedFlags = append(injectedFlags, fmt.Sprintf("-test.timeout=%v", testTimeout))
   389  	}
   390  
   391  	// Similarly, the test binary defaults -test.outputdir to its own working
   392  	// directory, but 'go test' defaults it to the working directory of the 'go'
   393  	// command. Set it explicitly if it is needed due to some other flag that
   394  	// requests output.
   395  	if testProfile() != "" && !outputDirSet {
   396  		injectedFlags = append(injectedFlags, "-test.outputdir="+testOutputDir.getAbs())
   397  	}
   398  
   399  	// If the user is explicitly passing -help or -h, show output
   400  	// of the test binary so that the help output is displayed
   401  	// even though the test will exit with success.
   402  	// This loop is imperfect: it will do the wrong thing for a case
   403  	// like -args -test.outputdir -help. Such cases are probably rare,
   404  	// and getting this wrong doesn't do too much harm.
   405  helpLoop:
   406  	for _, arg := range explicitArgs {
   407  		switch arg {
   408  		case "--":
   409  			break helpLoop
   410  		case "-h", "-help", "--help":
   411  			testHelp = true
   412  			break helpLoop
   413  		}
   414  	}
   415  
   416  	// Forward any unparsed arguments (following --args) to the test binary.
   417  	return packageNames, append(injectedFlags, explicitArgs...)
   418  }
   419  
   420  func exitWithUsage() {
   421  	fmt.Fprintf(os.Stderr, "usage: %s\n", CmdTest.UsageLine)
   422  	fmt.Fprintf(os.Stderr, "Run 'go help %s' and 'go help %s' for details.\n", CmdTest.LongName(), HelpTestflag.LongName())
   423  
   424  	base.SetExitStatus(2)
   425  	base.Exit()
   426  }
   427
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