testflag.go

Documentation: cmd/go/internal/test

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