Source file src/cmd/go/alldocs.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  // Code generated by mkalldocs.sh; DO NOT EDIT.
     6  // Edit the documentation in other files and rerun mkalldocs.sh to generate this one.
     7  
     8  // Go is a tool for managing Go source code.
     9  //
    10  // Usage:
    11  //
    12  // 	go <command> [arguments]
    13  //
    14  // The commands are:
    15  //
    16  // 	bug         start a bug report
    17  // 	build       compile packages and dependencies
    18  // 	clean       remove object files and cached files
    19  // 	doc         show documentation for package or symbol
    20  // 	env         print Go environment information
    21  // 	fix         update packages to use new APIs
    22  // 	fmt         gofmt (reformat) package sources
    23  // 	generate    generate Go files by processing source
    24  // 	get         add dependencies to current module and install them
    25  // 	install     compile and install packages and dependencies
    26  // 	list        list packages or modules
    27  // 	mod         module maintenance
    28  // 	work        workspace maintenance
    29  // 	run         compile and run Go program
    30  // 	test        test packages
    31  // 	tool        run specified go tool
    32  // 	version     print Go version
    33  // 	vet         report likely mistakes in packages
    34  //
    35  // Use "go help <command>" for more information about a command.
    36  //
    37  // Additional help topics:
    38  //
    39  // 	buildconstraint build constraints
    40  // 	buildmode       build modes
    41  // 	c               calling between Go and C
    42  // 	cache           build and test caching
    43  // 	environment     environment variables
    44  // 	filetype        file types
    45  // 	go.mod          the go.mod file
    46  // 	gopath          GOPATH environment variable
    47  // 	gopath-get      legacy GOPATH go get
    48  // 	goproxy         module proxy protocol
    49  // 	importpath      import path syntax
    50  // 	modules         modules, module versions, and more
    51  // 	module-get      module-aware go get
    52  // 	module-auth     module authentication using go.sum
    53  // 	packages        package lists and patterns
    54  // 	private         configuration for downloading non-public code
    55  // 	testflag        testing flags
    56  // 	testfunc        testing functions
    57  // 	vcs             controlling version control with GOVCS
    58  //
    59  // Use "go help <topic>" for more information about that topic.
    60  //
    61  //
    62  // Start a bug report
    63  //
    64  // Usage:
    65  //
    66  // 	go bug
    67  //
    68  // Bug opens the default browser and starts a new bug report.
    69  // The report includes useful system information.
    70  //
    71  //
    72  // Compile packages and dependencies
    73  //
    74  // Usage:
    75  //
    76  // 	go build [-o output] [build flags] [packages]
    77  //
    78  // Build compiles the packages named by the import paths,
    79  // along with their dependencies, but it does not install the results.
    80  //
    81  // If the arguments to build are a list of .go files from a single directory,
    82  // build treats them as a list of source files specifying a single package.
    83  //
    84  // When compiling packages, build ignores files that end in '_test.go'.
    85  //
    86  // When compiling a single main package, build writes
    87  // the resulting executable to an output file named after
    88  // the first source file ('go build ed.go rx.go' writes 'ed' or 'ed.exe')
    89  // or the source code directory ('go build unix/sam' writes 'sam' or 'sam.exe').
    90  // The '.exe' suffix is added when writing a Windows executable.
    91  //
    92  // When compiling multiple packages or a single non-main package,
    93  // build compiles the packages but discards the resulting object,
    94  // serving only as a check that the packages can be built.
    95  //
    96  // The -o flag forces build to write the resulting executable or object
    97  // to the named output file or directory, instead of the default behavior described
    98  // in the last two paragraphs. If the named output is an existing directory or
    99  // ends with a slash or backslash, then any resulting executables
   100  // will be written to that directory.
   101  //
   102  // The -i flag installs the packages that are dependencies of the target.
   103  // The -i flag is deprecated. Compiled packages are cached automatically.
   104  //
   105  // The build flags are shared by the build, clean, get, install, list, run,
   106  // and test commands:
   107  //
   108  // 	-a
   109  // 		force rebuilding of packages that are already up-to-date.
   110  // 	-n
   111  // 		print the commands but do not run them.
   112  // 	-p n
   113  // 		the number of programs, such as build commands or
   114  // 		test binaries, that can be run in parallel.
   115  // 		The default is GOMAXPROCS, normally the number of CPUs available.
   116  // 	-race
   117  // 		enable data race detection.
   118  // 		Supported only on linux/amd64, freebsd/amd64, darwin/amd64, darwin/arm64, windows/amd64,
   119  // 		linux/ppc64le and linux/arm64 (only for 48-bit VMA).
   120  // 	-msan
   121  // 		enable interoperation with memory sanitizer.
   122  // 		Supported only on linux/amd64, linux/arm64
   123  // 		and only with Clang/LLVM as the host C compiler.
   124  // 		On linux/arm64, pie build mode will be used.
   125  // 	-asan
   126  // 		enable interoperation with address sanitizer.
   127  // 		Supported only on linux/arm64, linux/amd64.
   128  // 	-v
   129  // 		print the names of packages as they are compiled.
   130  // 	-work
   131  // 		print the name of the temporary work directory and
   132  // 		do not delete it when exiting.
   133  // 	-x
   134  // 		print the commands.
   135  //
   136  // 	-asmflags '[pattern=]arg list'
   137  // 		arguments to pass on each go tool asm invocation.
   138  // 	-buildmode mode
   139  // 		build mode to use. See 'go help buildmode' for more.
   140  // 	-buildvcs
   141  // 		Whether to stamp binaries with version control information
   142  // 		("true", "false", or "auto"). By default ("auto"), version control
   143  // 		information is stamped into a binary if the main package, the main module
   144  // 		containing it, and the current directory are all in the same repository.
   145  // 		Use -buildvcs=false to always omit version control information, or
   146  // 		-buildvcs=true to error out if version control information is available but
   147  // 		cannot be included due to a missing tool or ambiguous directory structure.
   148  // 	-compiler name
   149  // 		name of compiler to use, as in runtime.Compiler (gccgo or gc).
   150  // 	-gccgoflags '[pattern=]arg list'
   151  // 		arguments to pass on each gccgo compiler/linker invocation.
   152  // 	-gcflags '[pattern=]arg list'
   153  // 		arguments to pass on each go tool compile invocation.
   154  // 	-installsuffix suffix
   155  // 		a suffix to use in the name of the package installation directory,
   156  // 		in order to keep output separate from default builds.
   157  // 		If using the -race flag, the install suffix is automatically set to race
   158  // 		or, if set explicitly, has _race appended to it. Likewise for the -msan
   159  // 		and -asan flags. Using a -buildmode option that requires non-default compile
   160  // 		flags has a similar effect.
   161  // 	-ldflags '[pattern=]arg list'
   162  // 		arguments to pass on each go tool link invocation.
   163  // 	-linkshared
   164  // 		build code that will be linked against shared libraries previously
   165  // 		created with -buildmode=shared.
   166  // 	-mod mode
   167  // 		module download mode to use: readonly, vendor, or mod.
   168  // 		By default, if a vendor directory is present and the go version in go.mod
   169  // 		is 1.14 or higher, the go command acts as if -mod=vendor were set.
   170  // 		Otherwise, the go command acts as if -mod=readonly were set.
   171  // 		See https://golang.org/ref/mod#build-commands for details.
   172  // 	-modcacherw
   173  // 		leave newly-created directories in the module cache read-write
   174  // 		instead of making them read-only.
   175  // 	-modfile file
   176  // 		in module aware mode, read (and possibly write) an alternate go.mod
   177  // 		file instead of the one in the module root directory. A file named
   178  // 		"go.mod" must still be present in order to determine the module root
   179  // 		directory, but it is not accessed. When -modfile is specified, an
   180  // 		alternate go.sum file is also used: its path is derived from the
   181  // 		-modfile flag by trimming the ".mod" extension and appending ".sum".
   182  // 	-overlay file
   183  // 		read a JSON config file that provides an overlay for build operations.
   184  // 		The file is a JSON struct with a single field, named 'Replace', that
   185  // 		maps each disk file path (a string) to its backing file path, so that
   186  // 		a build will run as if the disk file path exists with the contents
   187  // 		given by the backing file paths, or as if the disk file path does not
   188  // 		exist if its backing file path is empty. Support for the -overlay flag
   189  // 		has some limitations: importantly, cgo files included from outside the
   190  // 		include path must be in the same directory as the Go package they are
   191  // 		included from, and overlays will not appear when binaries and tests are
   192  // 		run through go run and go test respectively.
   193  // 	-pkgdir dir
   194  // 		install and load all packages from dir instead of the usual locations.
   195  // 		For example, when building with a non-standard configuration,
   196  // 		use -pkgdir to keep generated packages in a separate location.
   197  // 	-tags tag,list
   198  // 		a comma-separated list of build tags to consider satisfied during the
   199  // 		build. For more information about build tags, see the description of
   200  // 		build constraints in the documentation for the go/build package.
   201  // 		(Earlier versions of Go used a space-separated list, and that form
   202  // 		is deprecated but still recognized.)
   203  // 	-trimpath
   204  // 		remove all file system paths from the resulting executable.
   205  // 		Instead of absolute file system paths, the recorded file names
   206  // 		will begin either a module path@version (when using modules),
   207  // 		or a plain import path (when using the standard library, or GOPATH).
   208  // 	-toolexec 'cmd args'
   209  // 		a program to use to invoke toolchain programs like vet and asm.
   210  // 		For example, instead of running asm, the go command will run
   211  // 		'cmd args /path/to/asm <arguments for asm>'.
   212  // 		The TOOLEXEC_IMPORTPATH environment variable will be set,
   213  // 		matching 'go list -f {{.ImportPath}}' for the package being built.
   214  //
   215  // The -asmflags, -gccgoflags, -gcflags, and -ldflags flags accept a
   216  // space-separated list of arguments to pass to an underlying tool
   217  // during the build. To embed spaces in an element in the list, surround
   218  // it with either single or double quotes. The argument list may be
   219  // preceded by a package pattern and an equal sign, which restricts
   220  // the use of that argument list to the building of packages matching
   221  // that pattern (see 'go help packages' for a description of package
   222  // patterns). Without a pattern, the argument list applies only to the
   223  // packages named on the command line. The flags may be repeated
   224  // with different patterns in order to specify different arguments for
   225  // different sets of packages. If a package matches patterns given in
   226  // multiple flags, the latest match on the command line wins.
   227  // For example, 'go build -gcflags=-S fmt' prints the disassembly
   228  // only for package fmt, while 'go build -gcflags=all=-S fmt'
   229  // prints the disassembly for fmt and all its dependencies.
   230  //
   231  // For more about specifying packages, see 'go help packages'.
   232  // For more about where packages and binaries are installed,
   233  // run 'go help gopath'.
   234  // For more about calling between Go and C/C++, run 'go help c'.
   235  //
   236  // Note: Build adheres to certain conventions such as those described
   237  // by 'go help gopath'. Not all projects can follow these conventions,
   238  // however. Installations that have their own conventions or that use
   239  // a separate software build system may choose to use lower-level
   240  // invocations such as 'go tool compile' and 'go tool link' to avoid
   241  // some of the overheads and design decisions of the build tool.
   242  //
   243  // See also: go install, go get, go clean.
   244  //
   245  //
   246  // Remove object files and cached files
   247  //
   248  // Usage:
   249  //
   250  // 	go clean [clean flags] [build flags] [packages]
   251  //
   252  // Clean removes object files from package source directories.
   253  // The go command builds most objects in a temporary directory,
   254  // so go clean is mainly concerned with object files left by other
   255  // tools or by manual invocations of go build.
   256  //
   257  // If a package argument is given or the -i or -r flag is set,
   258  // clean removes the following files from each of the
   259  // source directories corresponding to the import paths:
   260  //
   261  // 	_obj/            old object directory, left from Makefiles
   262  // 	_test/           old test directory, left from Makefiles
   263  // 	_testmain.go     old gotest file, left from Makefiles
   264  // 	test.out         old test log, left from Makefiles
   265  // 	build.out        old test log, left from Makefiles
   266  // 	*.[568ao]        object files, left from Makefiles
   267  //
   268  // 	DIR(.exe)        from go build
   269  // 	DIR.test(.exe)   from go test -c
   270  // 	MAINFILE(.exe)   from go build MAINFILE.go
   271  // 	*.so             from SWIG
   272  //
   273  // In the list, DIR represents the final path element of the
   274  // directory, and MAINFILE is the base name of any Go source
   275  // file in the directory that is not included when building
   276  // the package.
   277  //
   278  // The -i flag causes clean to remove the corresponding installed
   279  // archive or binary (what 'go install' would create).
   280  //
   281  // The -n flag causes clean to print the remove commands it would execute,
   282  // but not run them.
   283  //
   284  // The -r flag causes clean to be applied recursively to all the
   285  // dependencies of the packages named by the import paths.
   286  //
   287  // The -x flag causes clean to print remove commands as it executes them.
   288  //
   289  // The -cache flag causes clean to remove the entire go build cache.
   290  //
   291  // The -testcache flag causes clean to expire all test results in the
   292  // go build cache.
   293  //
   294  // The -modcache flag causes clean to remove the entire module
   295  // download cache, including unpacked source code of versioned
   296  // dependencies.
   297  //
   298  // The -fuzzcache flag causes clean to remove files stored in the Go build
   299  // cache for fuzz testing. The fuzzing engine caches files that expand
   300  // code coverage, so removing them may make fuzzing less effective until
   301  // new inputs are found that provide the same coverage. These files are
   302  // distinct from those stored in testdata directory; clean does not remove
   303  // those files.
   304  //
   305  // For more about build flags, see 'go help build'.
   306  //
   307  // For more about specifying packages, see 'go help packages'.
   308  //
   309  //
   310  // Show documentation for package or symbol
   311  //
   312  // Usage:
   313  //
   314  // 	go doc [doc flags] [package|[package.]symbol[.methodOrField]]
   315  //
   316  // Doc prints the documentation comments associated with the item identified by its
   317  // arguments (a package, const, func, type, var, method, or struct field)
   318  // followed by a one-line summary of each of the first-level items "under"
   319  // that item (package-level declarations for a package, methods for a type,
   320  // etc.).
   321  //
   322  // Doc accepts zero, one, or two arguments.
   323  //
   324  // Given no arguments, that is, when run as
   325  //
   326  // 	go doc
   327  //
   328  // it prints the package documentation for the package in the current directory.
   329  // If the package is a command (package main), the exported symbols of the package
   330  // are elided from the presentation unless the -cmd flag is provided.
   331  //
   332  // When run with one argument, the argument is treated as a Go-syntax-like
   333  // representation of the item to be documented. What the argument selects depends
   334  // on what is installed in GOROOT and GOPATH, as well as the form of the argument,
   335  // which is schematically one of these:
   336  //
   337  // 	go doc <pkg>
   338  // 	go doc <sym>[.<methodOrField>]
   339  // 	go doc [<pkg>.]<sym>[.<methodOrField>]
   340  // 	go doc [<pkg>.][<sym>.]<methodOrField>
   341  //
   342  // The first item in this list matched by the argument is the one whose documentation
   343  // is printed. (See the examples below.) However, if the argument starts with a capital
   344  // letter it is assumed to identify a symbol or method in the current directory.
   345  //
   346  // For packages, the order of scanning is determined lexically in breadth-first order.
   347  // That is, the package presented is the one that matches the search and is nearest
   348  // the root and lexically first at its level of the hierarchy. The GOROOT tree is
   349  // always scanned in its entirety before GOPATH.
   350  //
   351  // If there is no package specified or matched, the package in the current
   352  // directory is selected, so "go doc Foo" shows the documentation for symbol Foo in
   353  // the current package.
   354  //
   355  // The package path must be either a qualified path or a proper suffix of a
   356  // path. The go tool's usual package mechanism does not apply: package path
   357  // elements like . and ... are not implemented by go doc.
   358  //
   359  // When run with two arguments, the first is a package path (full path or suffix),
   360  // and the second is a symbol, or symbol with method or struct field:
   361  //
   362  // 	go doc <pkg> <sym>[.<methodOrField>]
   363  //
   364  // In all forms, when matching symbols, lower-case letters in the argument match
   365  // either case but upper-case letters match exactly. This means that there may be
   366  // multiple matches of a lower-case argument in a package if different symbols have
   367  // different cases. If this occurs, documentation for all matches is printed.
   368  //
   369  // Examples:
   370  // 	go doc
   371  // 		Show documentation for current package.
   372  // 	go doc Foo
   373  // 		Show documentation for Foo in the current package.
   374  // 		(Foo starts with a capital letter so it cannot match
   375  // 		a package path.)
   376  // 	go doc encoding/json
   377  // 		Show documentation for the encoding/json package.
   378  // 	go doc json
   379  // 		Shorthand for encoding/json.
   380  // 	go doc json.Number (or go doc json.number)
   381  // 		Show documentation and method summary for json.Number.
   382  // 	go doc json.Number.Int64 (or go doc json.number.int64)
   383  // 		Show documentation for json.Number's Int64 method.
   384  // 	go doc cmd/doc
   385  // 		Show package docs for the doc command.
   386  // 	go doc -cmd cmd/doc
   387  // 		Show package docs and exported symbols within the doc command.
   388  // 	go doc template.new
   389  // 		Show documentation for html/template's New function.
   390  // 		(html/template is lexically before text/template)
   391  // 	go doc text/template.new # One argument
   392  // 		Show documentation for text/template's New function.
   393  // 	go doc text/template new # Two arguments
   394  // 		Show documentation for text/template's New function.
   395  //
   396  // 	At least in the current tree, these invocations all print the
   397  // 	documentation for json.Decoder's Decode method:
   398  //
   399  // 	go doc json.Decoder.Decode
   400  // 	go doc json.decoder.decode
   401  // 	go doc json.decode
   402  // 	cd go/src/encoding/json; go doc decode
   403  //
   404  // Flags:
   405  // 	-all
   406  // 		Show all the documentation for the package.
   407  // 	-c
   408  // 		Respect case when matching symbols.
   409  // 	-cmd
   410  // 		Treat a command (package main) like a regular package.
   411  // 		Otherwise package main's exported symbols are hidden
   412  // 		when showing the package's top-level documentation.
   413  // 	-short
   414  // 		One-line representation for each symbol.
   415  // 	-src
   416  // 		Show the full source code for the symbol. This will
   417  // 		display the full Go source of its declaration and
   418  // 		definition, such as a function definition (including
   419  // 		the body), type declaration or enclosing const
   420  // 		block. The output may therefore include unexported
   421  // 		details.
   422  // 	-u
   423  // 		Show documentation for unexported as well as exported
   424  // 		symbols, methods, and fields.
   425  //
   426  //
   427  // Print Go environment information
   428  //
   429  // Usage:
   430  //
   431  // 	go env [-json] [-u] [-w] [var ...]
   432  //
   433  // Env prints Go environment information.
   434  //
   435  // By default env prints information as a shell script
   436  // (on Windows, a batch file). If one or more variable
   437  // names is given as arguments, env prints the value of
   438  // each named variable on its own line.
   439  //
   440  // The -json flag prints the environment in JSON format
   441  // instead of as a shell script.
   442  //
   443  // The -u flag requires one or more arguments and unsets
   444  // the default setting for the named environment variables,
   445  // if one has been set with 'go env -w'.
   446  //
   447  // The -w flag requires one or more arguments of the
   448  // form NAME=VALUE and changes the default settings
   449  // of the named environment variables to the given values.
   450  //
   451  // For more about environment variables, see 'go help environment'.
   452  //
   453  //
   454  // Update packages to use new APIs
   455  //
   456  // Usage:
   457  //
   458  // 	go fix [-fix list] [packages]
   459  //
   460  // Fix runs the Go fix command on the packages named by the import paths.
   461  //
   462  // The -fix flag sets a comma-separated list of fixes to run.
   463  // The default is all known fixes.
   464  // (Its value is passed to 'go tool fix -r'.)
   465  //
   466  // For more about fix, see 'go doc cmd/fix'.
   467  // For more about specifying packages, see 'go help packages'.
   468  //
   469  // To run fix with other options, run 'go tool fix'.
   470  //
   471  // See also: go fmt, go vet.
   472  //
   473  //
   474  // Gofmt (reformat) package sources
   475  //
   476  // Usage:
   477  //
   478  // 	go fmt [-n] [-x] [packages]
   479  //
   480  // Fmt runs the command 'gofmt -l -w' on the packages named
   481  // by the import paths. It prints the names of the files that are modified.
   482  //
   483  // For more about gofmt, see 'go doc cmd/gofmt'.
   484  // For more about specifying packages, see 'go help packages'.
   485  //
   486  // The -n flag prints commands that would be executed.
   487  // The -x flag prints commands as they are executed.
   488  //
   489  // The -mod flag's value sets which module download mode
   490  // to use: readonly or vendor. See 'go help modules' for more.
   491  //
   492  // To run gofmt with specific options, run gofmt itself.
   493  //
   494  // See also: go fix, go vet.
   495  //
   496  //
   497  // Generate Go files by processing source
   498  //
   499  // Usage:
   500  //
   501  // 	go generate [-run regexp] [-n] [-v] [-x] [build flags] [file.go... | packages]
   502  //
   503  // Generate runs commands described by directives within existing
   504  // files. Those commands can run any process but the intent is to
   505  // create or update Go source files.
   506  //
   507  // Go generate is never run automatically by go build, go test,
   508  // and so on. It must be run explicitly.
   509  //
   510  // Go generate scans the file for directives, which are lines of
   511  // the form,
   512  //
   513  // 	//go:generate command argument...
   514  //
   515  // (note: no leading spaces and no space in "//go") where command
   516  // is the generator to be run, corresponding to an executable file
   517  // that can be run locally. It must either be in the shell path
   518  // (gofmt), a fully qualified path (/usr/you/bin/mytool), or a
   519  // command alias, described below.
   520  //
   521  // Note that go generate does not parse the file, so lines that look
   522  // like directives in comments or multiline strings will be treated
   523  // as directives.
   524  //
   525  // The arguments to the directive are space-separated tokens or
   526  // double-quoted strings passed to the generator as individual
   527  // arguments when it is run.
   528  //
   529  // Quoted strings use Go syntax and are evaluated before execution; a
   530  // quoted string appears as a single argument to the generator.
   531  //
   532  // To convey to humans and machine tools that code is generated,
   533  // generated source should have a line that matches the following
   534  // regular expression (in Go syntax):
   535  //
   536  // 	^// Code generated .* DO NOT EDIT\.$
   537  //
   538  // This line must appear before the first non-comment, non-blank
   539  // text in the file.
   540  //
   541  // Go generate sets several variables when it runs the generator:
   542  //
   543  // 	$GOARCH
   544  // 		The execution architecture (arm, amd64, etc.)
   545  // 	$GOOS
   546  // 		The execution operating system (linux, windows, etc.)
   547  // 	$GOFILE
   548  // 		The base name of the file.
   549  // 	$GOLINE
   550  // 		The line number of the directive in the source file.
   551  // 	$GOPACKAGE
   552  // 		The name of the package of the file containing the directive.
   553  // 	$DOLLAR
   554  // 		A dollar sign.
   555  //
   556  // Other than variable substitution and quoted-string evaluation, no
   557  // special processing such as "globbing" is performed on the command
   558  // line.
   559  //
   560  // As a last step before running the command, any invocations of any
   561  // environment variables with alphanumeric names, such as $GOFILE or
   562  // $HOME, are expanded throughout the command line. The syntax for
   563  // variable expansion is $NAME on all operating systems. Due to the
   564  // order of evaluation, variables are expanded even inside quoted
   565  // strings. If the variable NAME is not set, $NAME expands to the
   566  // empty string.
   567  //
   568  // A directive of the form,
   569  //
   570  // 	//go:generate -command xxx args...
   571  //
   572  // specifies, for the remainder of this source file only, that the
   573  // string xxx represents the command identified by the arguments. This
   574  // can be used to create aliases or to handle multiword generators.
   575  // For example,
   576  //
   577  // 	//go:generate -command foo go tool foo
   578  //
   579  // specifies that the command "foo" represents the generator
   580  // "go tool foo".
   581  //
   582  // Generate processes packages in the order given on the command line,
   583  // one at a time. If the command line lists .go files from a single directory,
   584  // they are treated as a single package. Within a package, generate processes the
   585  // source files in a package in file name order, one at a time. Within
   586  // a source file, generate runs generators in the order they appear
   587  // in the file, one at a time. The go generate tool also sets the build
   588  // tag "generate" so that files may be examined by go generate but ignored
   589  // during build.
   590  //
   591  // For packages with invalid code, generate processes only source files with a
   592  // valid package clause.
   593  //
   594  // If any generator returns an error exit status, "go generate" skips
   595  // all further processing for that package.
   596  //
   597  // The generator is run in the package's source directory.
   598  //
   599  // Go generate accepts one specific flag:
   600  //
   601  // 	-run=""
   602  // 		if non-empty, specifies a regular expression to select
   603  // 		directives whose full original source text (excluding
   604  // 		any trailing spaces and final newline) matches the
   605  // 		expression.
   606  //
   607  // It also accepts the standard build flags including -v, -n, and -x.
   608  // The -v flag prints the names of packages and files as they are
   609  // processed.
   610  // The -n flag prints commands that would be executed.
   611  // The -x flag prints commands as they are executed.
   612  //
   613  // For more about build flags, see 'go help build'.
   614  //
   615  // For more about specifying packages, see 'go help packages'.
   616  //
   617  //
   618  // Add dependencies to current module and install them
   619  //
   620  // Usage:
   621  //
   622  // 	go get [-t] [-u] [-v] [build flags] [packages]
   623  //
   624  // Get resolves its command-line arguments to packages at specific module versions,
   625  // updates go.mod to require those versions, and downloads source code into the
   626  // module cache.
   627  //
   628  // To add a dependency for a package or upgrade it to its latest version:
   629  //
   630  // 	go get example.com/pkg
   631  //
   632  // To upgrade or downgrade a package to a specific version:
   633  //
   634  // 	go get example.com/pkg@v1.2.3
   635  //
   636  // To remove a dependency on a module and downgrade modules that require it:
   637  //
   638  // 	go get example.com/mod@none
   639  //
   640  // See https://golang.org/ref/mod#go-get for details.
   641  //
   642  // In earlier versions of Go, 'go get' was used to build and install packages.
   643  // Now, 'go get' is dedicated to adjusting dependencies in go.mod. 'go install'
   644  // may be used to build and install commands instead. When a version is specified,
   645  // 'go install' runs in module-aware mode and ignores the go.mod file in the
   646  // current directory. For example:
   647  //
   648  // 	go install example.com/pkg@v1.2.3
   649  // 	go install example.com/pkg@latest
   650  //
   651  // See 'go help install' or https://golang.org/ref/mod#go-install for details.
   652  //
   653  // 'go get' accepts the following flags.
   654  //
   655  // The -t flag instructs get to consider modules needed to build tests of
   656  // packages specified on the command line.
   657  //
   658  // The -u flag instructs get to update modules providing dependencies
   659  // of packages named on the command line to use newer minor or patch
   660  // releases when available.
   661  //
   662  // The -u=patch flag (not -u patch) also instructs get to update dependencies,
   663  // but changes the default to select patch releases.
   664  //
   665  // When the -t and -u flags are used together, get will update
   666  // test dependencies as well.
   667  //
   668  // The -x flag prints commands as they are executed. This is useful for
   669  // debugging version control commands when a module is downloaded directly
   670  // from a repository.
   671  //
   672  // For more about modules, see https://golang.org/ref/mod.
   673  //
   674  // For more about specifying packages, see 'go help packages'.
   675  //
   676  // This text describes the behavior of get using modules to manage source
   677  // code and dependencies. If instead the go command is running in GOPATH
   678  // mode, the details of get's flags and effects change, as does 'go help get'.
   679  // See 'go help gopath-get'.
   680  //
   681  // See also: go build, go install, go clean, go mod.
   682  //
   683  //
   684  // Compile and install packages and dependencies
   685  //
   686  // Usage:
   687  //
   688  // 	go install [build flags] [packages]
   689  //
   690  // Install compiles and installs the packages named by the import paths.
   691  //
   692  // Executables are installed in the directory named by the GOBIN environment
   693  // variable, which defaults to $GOPATH/bin or $HOME/go/bin if the GOPATH
   694  // environment variable is not set. Executables in $GOROOT
   695  // are installed in $GOROOT/bin or $GOTOOLDIR instead of $GOBIN.
   696  //
   697  // If the arguments have version suffixes (like @latest or @v1.0.0), "go install"
   698  // builds packages in module-aware mode, ignoring the go.mod file in the current
   699  // directory or any parent directory, if there is one. This is useful for
   700  // installing executables without affecting the dependencies of the main module.
   701  // To eliminate ambiguity about which module versions are used in the build, the
   702  // arguments must satisfy the following constraints:
   703  //
   704  // - Arguments must be package paths or package patterns (with "..." wildcards).
   705  // They must not be standard packages (like fmt), meta-patterns (std, cmd,
   706  // all), or relative or absolute file paths.
   707  //
   708  // - All arguments must have the same version suffix. Different queries are not
   709  // allowed, even if they refer to the same version.
   710  //
   711  // - All arguments must refer to packages in the same module at the same version.
   712  //
   713  // - Package path arguments must refer to main packages. Pattern arguments
   714  // will only match main packages.
   715  //
   716  // - No module is considered the "main" module. If the module containing
   717  // packages named on the command line has a go.mod file, it must not contain
   718  // directives (replace and exclude) that would cause it to be interpreted
   719  // differently than if it were the main module. The module must not require
   720  // a higher version of itself.
   721  //
   722  // - Vendor directories are not used in any module. (Vendor directories are not
   723  // included in the module zip files downloaded by 'go install'.)
   724  //
   725  // If the arguments don't have version suffixes, "go install" may run in
   726  // module-aware mode or GOPATH mode, depending on the GO111MODULE environment
   727  // variable and the presence of a go.mod file. See 'go help modules' for details.
   728  // If module-aware mode is enabled, "go install" runs in the context of the main
   729  // module.
   730  //
   731  // When module-aware mode is disabled, other packages are installed in the
   732  // directory $GOPATH/pkg/$GOOS_$GOARCH. When module-aware mode is enabled,
   733  // other packages are built and cached but not installed.
   734  //
   735  // The -i flag installs the dependencies of the named packages as well.
   736  // The -i flag is deprecated. Compiled packages are cached automatically.
   737  //
   738  // For more about the build flags, see 'go help build'.
   739  // For more about specifying packages, see 'go help packages'.
   740  //
   741  // See also: go build, go get, go clean.
   742  //
   743  //
   744  // List packages or modules
   745  //
   746  // Usage:
   747  //
   748  // 	go list [-f format] [-json] [-m] [list flags] [build flags] [packages]
   749  //
   750  // List lists the named packages, one per line.
   751  // The most commonly-used flags are -f and -json, which control the form
   752  // of the output printed for each package. Other list flags, documented below,
   753  // control more specific details.
   754  //
   755  // The default output shows the package import path:
   756  //
   757  //     bytes
   758  //     encoding/json
   759  //     github.com/gorilla/mux
   760  //     golang.org/x/net/html
   761  //
   762  // The -f flag specifies an alternate format for the list, using the
   763  // syntax of package template. The default output is equivalent
   764  // to -f '{{.ImportPath}}'. The struct being passed to the template is:
   765  //
   766  //     type Package struct {
   767  //         Dir           string   // directory containing package sources
   768  //         ImportPath    string   // import path of package in dir
   769  //         ImportComment string   // path in import comment on package statement
   770  //         Name          string   // package name
   771  //         Doc           string   // package documentation string
   772  //         Target        string   // install path
   773  //         Shlib         string   // the shared library that contains this package (only set when -linkshared)
   774  //         Goroot        bool     // is this package in the Go root?
   775  //         Standard      bool     // is this package part of the standard Go library?
   776  //         Stale         bool     // would 'go install' do anything for this package?
   777  //         StaleReason   string   // explanation for Stale==true
   778  //         Root          string   // Go root or Go path dir containing this package
   779  //         ConflictDir   string   // this directory shadows Dir in $GOPATH
   780  //         BinaryOnly    bool     // binary-only package (no longer supported)
   781  //         ForTest       string   // package is only for use in named test
   782  //         Export        string   // file containing export data (when using -export)
   783  //         BuildID       string   // build ID of the compiled package (when using -export)
   784  //         Module        *Module  // info about package's containing module, if any (can be nil)
   785  //         Match         []string // command-line patterns matching this package
   786  //         DepOnly       bool     // package is only a dependency, not explicitly listed
   787  //
   788  //         // Source files
   789  //         GoFiles         []string   // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
   790  //         CgoFiles        []string   // .go source files that import "C"
   791  //         CompiledGoFiles []string   // .go files presented to compiler (when using -compiled)
   792  //         IgnoredGoFiles  []string   // .go source files ignored due to build constraints
   793  //         IgnoredOtherFiles []string // non-.go source files ignored due to build constraints
   794  //         CFiles          []string   // .c source files
   795  //         CXXFiles        []string   // .cc, .cxx and .cpp source files
   796  //         MFiles          []string   // .m source files
   797  //         HFiles          []string   // .h, .hh, .hpp and .hxx source files
   798  //         FFiles          []string   // .f, .F, .for and .f90 Fortran source files
   799  //         SFiles          []string   // .s source files
   800  //         SwigFiles       []string   // .swig files
   801  //         SwigCXXFiles    []string   // .swigcxx files
   802  //         SysoFiles       []string   // .syso object files to add to archive
   803  //         TestGoFiles     []string   // _test.go files in package
   804  //         XTestGoFiles    []string   // _test.go files outside package
   805  //
   806  //         // Embedded files
   807  //         EmbedPatterns      []string // //go:embed patterns
   808  //         EmbedFiles         []string // files matched by EmbedPatterns
   809  //         TestEmbedPatterns  []string // //go:embed patterns in TestGoFiles
   810  //         TestEmbedFiles     []string // files matched by TestEmbedPatterns
   811  //         XTestEmbedPatterns []string // //go:embed patterns in XTestGoFiles
   812  //         XTestEmbedFiles    []string // files matched by XTestEmbedPatterns
   813  //
   814  //         // Cgo directives
   815  //         CgoCFLAGS    []string // cgo: flags for C compiler
   816  //         CgoCPPFLAGS  []string // cgo: flags for C preprocessor
   817  //         CgoCXXFLAGS  []string // cgo: flags for C++ compiler
   818  //         CgoFFLAGS    []string // cgo: flags for Fortran compiler
   819  //         CgoLDFLAGS   []string // cgo: flags for linker
   820  //         CgoPkgConfig []string // cgo: pkg-config names
   821  //
   822  //         // Dependency information
   823  //         Imports      []string          // import paths used by this package
   824  //         ImportMap    map[string]string // map from source import to ImportPath (identity entries omitted)
   825  //         Deps         []string          // all (recursively) imported dependencies
   826  //         TestImports  []string          // imports from TestGoFiles
   827  //         XTestImports []string          // imports from XTestGoFiles
   828  //
   829  //         // Error information
   830  //         Incomplete bool            // this package or a dependency has an error
   831  //         Error      *PackageError   // error loading package
   832  //         DepsErrors []*PackageError // errors loading dependencies
   833  //     }
   834  //
   835  // Packages stored in vendor directories report an ImportPath that includes the
   836  // path to the vendor directory (for example, "d/vendor/p" instead of "p"),
   837  // so that the ImportPath uniquely identifies a given copy of a package.
   838  // The Imports, Deps, TestImports, and XTestImports lists also contain these
   839  // expanded import paths. See golang.org/s/go15vendor for more about vendoring.
   840  //
   841  // The error information, if any, is
   842  //
   843  //     type PackageError struct {
   844  //         ImportStack   []string // shortest path from package named on command line to this one
   845  //         Pos           string   // position of error (if present, file:line:col)
   846  //         Err           string   // the error itself
   847  //     }
   848  //
   849  // The module information is a Module struct, defined in the discussion
   850  // of list -m below.
   851  //
   852  // The template function "join" calls strings.Join.
   853  //
   854  // The template function "context" returns the build context, defined as:
   855  //
   856  //     type Context struct {
   857  //         GOARCH        string   // target architecture
   858  //         GOOS          string   // target operating system
   859  //         GOROOT        string   // Go root
   860  //         GOPATH        string   // Go path
   861  //         CgoEnabled    bool     // whether cgo can be used
   862  //         UseAllFiles   bool     // use files regardless of +build lines, file names
   863  //         Compiler      string   // compiler to assume when computing target paths
   864  //         BuildTags     []string // build constraints to match in +build lines
   865  //         ToolTags      []string // toolchain-specific build constraints
   866  //         ReleaseTags   []string // releases the current release is compatible with
   867  //         InstallSuffix string   // suffix to use in the name of the install dir
   868  //     }
   869  //
   870  // For more information about the meaning of these fields see the documentation
   871  // for the go/build package's Context type.
   872  //
   873  // The -json flag causes the package data to be printed in JSON format
   874  // instead of using the template format.
   875  //
   876  // The -compiled flag causes list to set CompiledGoFiles to the Go source
   877  // files presented to the compiler. Typically this means that it repeats
   878  // the files listed in GoFiles and then also adds the Go code generated
   879  // by processing CgoFiles and SwigFiles. The Imports list contains the
   880  // union of all imports from both GoFiles and CompiledGoFiles.
   881  //
   882  // The -deps flag causes list to iterate over not just the named packages
   883  // but also all their dependencies. It visits them in a depth-first post-order
   884  // traversal, so that a package is listed only after all its dependencies.
   885  // Packages not explicitly listed on the command line will have the DepOnly
   886  // field set to true.
   887  //
   888  // The -e flag changes the handling of erroneous packages, those that
   889  // cannot be found or are malformed. By default, the list command
   890  // prints an error to standard error for each erroneous package and
   891  // omits the packages from consideration during the usual printing.
   892  // With the -e flag, the list command never prints errors to standard
   893  // error and instead processes the erroneous packages with the usual
   894  // printing. Erroneous packages will have a non-empty ImportPath and
   895  // a non-nil Error field; other information may or may not be missing
   896  // (zeroed).
   897  //
   898  // The -export flag causes list to set the Export field to the name of a
   899  // file containing up-to-date export information for the given package.
   900  //
   901  // The -find flag causes list to identify the named packages but not
   902  // resolve their dependencies: the Imports and Deps lists will be empty.
   903  //
   904  // The -test flag causes list to report not only the named packages
   905  // but also their test binaries (for packages with tests), to convey to
   906  // source code analysis tools exactly how test binaries are constructed.
   907  // The reported import path for a test binary is the import path of
   908  // the package followed by a ".test" suffix, as in "math/rand.test".
   909  // When building a test, it is sometimes necessary to rebuild certain
   910  // dependencies specially for that test (most commonly the tested
   911  // package itself). The reported import path of a package recompiled
   912  // for a particular test binary is followed by a space and the name of
   913  // the test binary in brackets, as in "math/rand [math/rand.test]"
   914  // or "regexp [sort.test]". The ForTest field is also set to the name
   915  // of the package being tested ("math/rand" or "sort" in the previous
   916  // examples).
   917  //
   918  // The Dir, Target, Shlib, Root, ConflictDir, and Export file paths
   919  // are all absolute paths.
   920  //
   921  // By default, the lists GoFiles, CgoFiles, and so on hold names of files in Dir
   922  // (that is, paths relative to Dir, not absolute paths).
   923  // The generated files added when using the -compiled and -test flags
   924  // are absolute paths referring to cached copies of generated Go source files.
   925  // Although they are Go source files, the paths may not end in ".go".
   926  //
   927  // The -m flag causes list to list modules instead of packages.
   928  //
   929  // When listing modules, the -f flag still specifies a format template
   930  // applied to a Go struct, but now a Module struct:
   931  //
   932  //     type Module struct {
   933  //         Path      string       // module path
   934  //         Version   string       // module version
   935  //         Versions  []string     // available module versions (with -versions)
   936  //         Replace   *Module      // replaced by this module
   937  //         Time      *time.Time   // time version was created
   938  //         Update    *Module      // available update, if any (with -u)
   939  //         Main      bool         // is this the main module?
   940  //         Indirect  bool         // is this module only an indirect dependency of main module?
   941  //         Dir       string       // directory holding files for this module, if any
   942  //         GoMod     string       // path to go.mod file used when loading this module, if any
   943  //         GoVersion string       // go version used in module
   944  //         Retracted string       // retraction information, if any (with -retracted or -u)
   945  //         Error     *ModuleError // error loading module
   946  //     }
   947  //
   948  //     type ModuleError struct {
   949  //         Err string // the error itself
   950  //     }
   951  //
   952  // The file GoMod refers to may be outside the module directory if the
   953  // module is in the module cache or if the -modfile flag is used.
   954  //
   955  // The default output is to print the module path and then
   956  // information about the version and replacement if any.
   957  // For example, 'go list -m all' might print:
   958  //
   959  //     my/main/module
   960  //     golang.org/x/text v0.3.0 => /tmp/text
   961  //     rsc.io/pdf v0.1.1
   962  //
   963  // The Module struct has a String method that formats this
   964  // line of output, so that the default format is equivalent
   965  // to -f '{{.String}}'.
   966  //
   967  // Note that when a module has been replaced, its Replace field
   968  // describes the replacement module, and its Dir field is set to
   969  // the replacement's source code, if present. (That is, if Replace
   970  // is non-nil, then Dir is set to Replace.Dir, with no access to
   971  // the replaced source code.)
   972  //
   973  // The -u flag adds information about available upgrades.
   974  // When the latest version of a given module is newer than
   975  // the current one, list -u sets the Module's Update field
   976  // to information about the newer module. list -u will also set
   977  // the module's Retracted field if the current version is retracted.
   978  // The Module's String method indicates an available upgrade by
   979  // formatting the newer version in brackets after the current version.
   980  // If a version is retracted, the string "(retracted)" will follow it.
   981  // For example, 'go list -m -u all' might print:
   982  //
   983  //     my/main/module
   984  //     golang.org/x/text v0.3.0 [v0.4.0] => /tmp/text
   985  //     rsc.io/pdf v0.1.1 (retracted) [v0.1.2]
   986  //
   987  // (For tools, 'go list -m -u -json all' may be more convenient to parse.)
   988  //
   989  // The -versions flag causes list to set the Module's Versions field
   990  // to a list of all known versions of that module, ordered according
   991  // to semantic versioning, earliest to latest. The flag also changes
   992  // the default output format to display the module path followed by the
   993  // space-separated version list.
   994  //
   995  // The -retracted flag causes list to report information about retracted
   996  // module versions. When -retracted is used with -f or -json, the Retracted
   997  // field will be set to a string explaining why the version was retracted.
   998  // The string is taken from comments on the retract directive in the
   999  // module's go.mod file. When -retracted is used with -versions, retracted
  1000  // versions are listed together with unretracted versions. The -retracted
  1001  // flag may be used with or without -m.
  1002  //
  1003  // The arguments to list -m are interpreted as a list of modules, not packages.
  1004  // The main module is the module containing the current directory.
  1005  // The active modules are the main module and its dependencies.
  1006  // With no arguments, list -m shows the main module.
  1007  // With arguments, list -m shows the modules specified by the arguments.
  1008  // Any of the active modules can be specified by its module path.
  1009  // The special pattern "all" specifies all the active modules, first the main
  1010  // module and then dependencies sorted by module path.
  1011  // A pattern containing "..." specifies the active modules whose
  1012  // module paths match the pattern.
  1013  // A query of the form path@version specifies the result of that query,
  1014  // which is not limited to active modules.
  1015  // See 'go help modules' for more about module queries.
  1016  //
  1017  // The template function "module" takes a single string argument
  1018  // that must be a module path or query and returns the specified
  1019  // module as a Module struct. If an error occurs, the result will
  1020  // be a Module struct with a non-nil Error field.
  1021  //
  1022  // For more about build flags, see 'go help build'.
  1023  //
  1024  // For more about specifying packages, see 'go help packages'.
  1025  //
  1026  // For more about modules, see https://golang.org/ref/mod.
  1027  //
  1028  //
  1029  // Module maintenance
  1030  //
  1031  // Go mod provides access to operations on modules.
  1032  //
  1033  // Note that support for modules is built into all the go commands,
  1034  // not just 'go mod'. For example, day-to-day adding, removing, upgrading,
  1035  // and downgrading of dependencies should be done using 'go get'.
  1036  // See 'go help modules' for an overview of module functionality.
  1037  //
  1038  // Usage:
  1039  //
  1040  // 	go mod <command> [arguments]
  1041  //
  1042  // The commands are:
  1043  //
  1044  // 	download    download modules to local cache
  1045  // 	edit        edit go.mod from tools or scripts
  1046  // 	graph       print module requirement graph
  1047  // 	init        initialize new module in current directory
  1048  // 	tidy        add missing and remove unused modules
  1049  // 	vendor      make vendored copy of dependencies
  1050  // 	verify      verify dependencies have expected content
  1051  // 	why         explain why packages or modules are needed
  1052  //
  1053  // Use "go help mod <command>" for more information about a command.
  1054  //
  1055  // Download modules to local cache
  1056  //
  1057  // Usage:
  1058  //
  1059  // 	go mod download [-x] [-json] [modules]
  1060  //
  1061  // Download downloads the named modules, which can be module patterns selecting
  1062  // dependencies of the main module or module queries of the form path@version.
  1063  //
  1064  // With no arguments, download applies to the modules needed to build and test
  1065  // the packages in the main module: the modules explicitly required by the main
  1066  // module if it is at 'go 1.17' or higher, or all transitively-required modules
  1067  // if at 'go 1.16' or lower.
  1068  //
  1069  // The go command will automatically download modules as needed during ordinary
  1070  // execution. The "go mod download" command is useful mainly for pre-filling
  1071  // the local cache or to compute the answers for a Go module proxy.
  1072  //
  1073  // By default, download writes nothing to standard output. It may print progress
  1074  // messages and errors to standard error.
  1075  //
  1076  // The -json flag causes download to print a sequence of JSON objects
  1077  // to standard output, describing each downloaded module (or failure),
  1078  // corresponding to this Go struct:
  1079  //
  1080  //     type Module struct {
  1081  //         Path     string // module path
  1082  //         Version  string // module version
  1083  //         Error    string // error loading module
  1084  //         Info     string // absolute path to cached .info file
  1085  //         GoMod    string // absolute path to cached .mod file
  1086  //         Zip      string // absolute path to cached .zip file
  1087  //         Dir      string // absolute path to cached source root directory
  1088  //         Sum      string // checksum for path, version (as in go.sum)
  1089  //         GoModSum string // checksum for go.mod (as in go.sum)
  1090  //     }
  1091  //
  1092  // The -x flag causes download to print the commands download executes.
  1093  //
  1094  // See https://golang.org/ref/mod#go-mod-download for more about 'go mod download'.
  1095  //
  1096  // See https://golang.org/ref/mod#version-queries for more about version queries.
  1097  //
  1098  //
  1099  // Edit go.mod from tools or scripts
  1100  //
  1101  // Usage:
  1102  //
  1103  // 	go mod edit [editing flags] [-fmt|-print|-json] [go.mod]
  1104  //
  1105  // Edit provides a command-line interface for editing go.mod,
  1106  // for use primarily by tools or scripts. It reads only go.mod;
  1107  // it does not look up information about the modules involved.
  1108  // By default, edit reads and writes the go.mod file of the main module,
  1109  // but a different target file can be specified after the editing flags.
  1110  //
  1111  // The editing flags specify a sequence of editing operations.
  1112  //
  1113  // The -fmt flag reformats the go.mod file without making other changes.
  1114  // This reformatting is also implied by any other modifications that use or
  1115  // rewrite the go.mod file. The only time this flag is needed is if no other
  1116  // flags are specified, as in 'go mod edit -fmt'.
  1117  //
  1118  // The -module flag changes the module's path (the go.mod file's module line).
  1119  //
  1120  // The -require=path@version and -droprequire=path flags
  1121  // add and drop a requirement on the given module path and version.
  1122  // Note that -require overrides any existing requirements on path.
  1123  // These flags are mainly for tools that understand the module graph.
  1124  // Users should prefer 'go get path@version' or 'go get path@none',
  1125  // which make other go.mod adjustments as needed to satisfy
  1126  // constraints imposed by other modules.
  1127  //
  1128  // The -exclude=path@version and -dropexclude=path@version flags
  1129  // add and drop an exclusion for the given module path and version.
  1130  // Note that -exclude=path@version is a no-op if that exclusion already exists.
  1131  //
  1132  // The -replace=old[@v]=new[@v] flag adds a replacement of the given
  1133  // module path and version pair. If the @v in old@v is omitted, a
  1134  // replacement without a version on the left side is added, which applies
  1135  // to all versions of the old module path. If the @v in new@v is omitted,
  1136  // the new path should be a local module root directory, not a module
  1137  // path. Note that -replace overrides any redundant replacements for old[@v],
  1138  // so omitting @v will drop existing replacements for specific versions.
  1139  //
  1140  // The -dropreplace=old[@v] flag drops a replacement of the given
  1141  // module path and version pair. If the @v is omitted, a replacement without
  1142  // a version on the left side is dropped.
  1143  //
  1144  // The -retract=version and -dropretract=version flags add and drop a
  1145  // retraction on the given version. The version may be a single version
  1146  // like "v1.2.3" or a closed interval like "[v1.1.0,v1.1.9]". Note that
  1147  // -retract=version is a no-op if that retraction already exists.
  1148  //
  1149  // The -require, -droprequire, -exclude, -dropexclude, -replace,
  1150  // -dropreplace, -retract, and -dropretract editing flags may be repeated,
  1151  // and the changes are applied in the order given.
  1152  //
  1153  // The -go=version flag sets the expected Go language version.
  1154  //
  1155  // The -print flag prints the final go.mod in its text format instead of
  1156  // writing it back to go.mod.
  1157  //
  1158  // The -json flag prints the final go.mod file in JSON format instead of
  1159  // writing it back to go.mod. The JSON output corresponds to these Go types:
  1160  //
  1161  // 	type Module struct {
  1162  // 		Path    string
  1163  // 		Version string
  1164  // 	}
  1165  //
  1166  // 	type GoMod struct {
  1167  // 		Module  ModPath
  1168  // 		Go      string
  1169  // 		Require []Require
  1170  // 		Exclude []Module
  1171  // 		Replace []Replace
  1172  // 		Retract []Retract
  1173  // 	}
  1174  //
  1175  // 	type ModPath struct {
  1176  // 		Path       string
  1177  // 		Deprecated string
  1178  // 	}
  1179  //
  1180  // 	type Require struct {
  1181  // 		Path string
  1182  // 		Version string
  1183  // 		Indirect bool
  1184  // 	}
  1185  //
  1186  // 	type Replace struct {
  1187  // 		Old Module
  1188  // 		New Module
  1189  // 	}
  1190  //
  1191  // 	type Retract struct {
  1192  // 		Low       string
  1193  // 		High      string
  1194  // 		Rationale string
  1195  // 	}
  1196  //
  1197  // Retract entries representing a single version (not an interval) will have
  1198  // the "Low" and "High" fields set to the same value.
  1199  //
  1200  // Note that this only describes the go.mod file itself, not other modules
  1201  // referred to indirectly. For the full set of modules available to a build,
  1202  // use 'go list -m -json all'.
  1203  //
  1204  // See https://golang.org/ref/mod#go-mod-edit for more about 'go mod edit'.
  1205  //
  1206  //
  1207  // Print module requirement graph
  1208  //
  1209  // Usage:
  1210  //
  1211  // 	go mod graph [-go=version]
  1212  //
  1213  // Graph prints the module requirement graph (with replacements applied)
  1214  // in text form. Each line in the output has two space-separated fields: a module
  1215  // and one of its requirements. Each module is identified as a string of the form
  1216  // path@version, except for the main module, which has no @version suffix.
  1217  //
  1218  // The -go flag causes graph to report the module graph as loaded by the
  1219  // given Go version, instead of the version indicated by the 'go' directive
  1220  // in the go.mod file.
  1221  //
  1222  // See https://golang.org/ref/mod#go-mod-graph for more about 'go mod graph'.
  1223  //
  1224  //
  1225  // Initialize new module in current directory
  1226  //
  1227  // Usage:
  1228  //
  1229  // 	go mod init [module-path]
  1230  //
  1231  // Init initializes and writes a new go.mod file in the current directory, in
  1232  // effect creating a new module rooted at the current directory. The go.mod file
  1233  // must not already exist.
  1234  //
  1235  // Init accepts one optional argument, the module path for the new module. If the
  1236  // module path argument is omitted, init will attempt to infer the module path
  1237  // using import comments in .go files, vendoring tool configuration files (like
  1238  // Gopkg.lock), and the current directory (if in GOPATH).
  1239  //
  1240  // If a configuration file for a vendoring tool is present, init will attempt to
  1241  // import module requirements from it.
  1242  //
  1243  // See https://golang.org/ref/mod#go-mod-init for more about 'go mod init'.
  1244  //
  1245  //
  1246  // Add missing and remove unused modules
  1247  //
  1248  // Usage:
  1249  //
  1250  // 	go mod tidy [-e] [-v] [-go=version] [-compat=version]
  1251  //
  1252  // Tidy makes sure go.mod matches the source code in the module.
  1253  // It adds any missing modules necessary to build the current module's
  1254  // packages and dependencies, and it removes unused modules that
  1255  // don't provide any relevant packages. It also adds any missing entries
  1256  // to go.sum and removes any unnecessary ones.
  1257  //
  1258  // The -v flag causes tidy to print information about removed modules
  1259  // to standard error.
  1260  //
  1261  // The -e flag causes tidy to attempt to proceed despite errors
  1262  // encountered while loading packages.
  1263  //
  1264  // The -go flag causes tidy to update the 'go' directive in the go.mod
  1265  // file to the given version, which may change which module dependencies
  1266  // are retained as explicit requirements in the go.mod file.
  1267  // (Go versions 1.17 and higher retain more requirements in order to
  1268  // support lazy module loading.)
  1269  //
  1270  // The -compat flag preserves any additional checksums needed for the
  1271  // 'go' command from the indicated major Go release to successfully load
  1272  // the module graph, and causes tidy to error out if that version of the
  1273  // 'go' command would load any imported package from a different module
  1274  // version. By default, tidy acts as if the -compat flag were set to the
  1275  // version prior to the one indicated by the 'go' directive in the go.mod
  1276  // file.
  1277  //
  1278  // See https://golang.org/ref/mod#go-mod-tidy for more about 'go mod tidy'.
  1279  //
  1280  //
  1281  // Make vendored copy of dependencies
  1282  //
  1283  // Usage:
  1284  //
  1285  // 	go mod vendor [-e] [-v] [-o outdir]
  1286  //
  1287  // Vendor resets the main module's vendor directory to include all packages
  1288  // needed to build and test all the main module's packages.
  1289  // It does not include test code for vendored packages.
  1290  //
  1291  // The -v flag causes vendor to print the names of vendored
  1292  // modules and packages to standard error.
  1293  //
  1294  // The -e flag causes vendor to attempt to proceed despite errors
  1295  // encountered while loading packages.
  1296  //
  1297  // The -o flag causes vendor to create the vendor directory at the given
  1298  // path instead of "vendor". The go command can only use a vendor directory
  1299  // named "vendor" within the module root directory, so this flag is
  1300  // primarily useful for other tools.
  1301  //
  1302  // See https://golang.org/ref/mod#go-mod-vendor for more about 'go mod vendor'.
  1303  //
  1304  //
  1305  // Verify dependencies have expected content
  1306  //
  1307  // Usage:
  1308  //
  1309  // 	go mod verify
  1310  //
  1311  // Verify checks that the dependencies of the current module,
  1312  // which are stored in a local downloaded source cache, have not been
  1313  // modified since being downloaded. If all the modules are unmodified,
  1314  // verify prints "all modules verified." Otherwise it reports which
  1315  // modules have been changed and causes 'go mod' to exit with a
  1316  // non-zero status.
  1317  //
  1318  // See https://golang.org/ref/mod#go-mod-verify for more about 'go mod verify'.
  1319  //
  1320  //
  1321  // Explain why packages or modules are needed
  1322  //
  1323  // Usage:
  1324  //
  1325  // 	go mod why [-m] [-vendor] packages...
  1326  //
  1327  // Why shows a shortest path in the import graph from the main module to
  1328  // each of the listed packages. If the -m flag is given, why treats the
  1329  // arguments as a list of modules and finds a path to any package in each
  1330  // of the modules.
  1331  //
  1332  // By default, why queries the graph of packages matched by "go list all",
  1333  // which includes tests for reachable packages. The -vendor flag causes why
  1334  // to exclude tests of dependencies.
  1335  //
  1336  // The output is a sequence of stanzas, one for each package or module
  1337  // name on the command line, separated by blank lines. Each stanza begins
  1338  // with a comment line "# package" or "# module" giving the target
  1339  // package or module. Subsequent lines give a path through the import
  1340  // graph, one package per line. If the package or module is not
  1341  // referenced from the main module, the stanza will display a single
  1342  // parenthesized note indicating that fact.
  1343  //
  1344  // For example:
  1345  //
  1346  // 	$ go mod why golang.org/x/text/language golang.org/x/text/encoding
  1347  // 	# golang.org/x/text/language
  1348  // 	rsc.io/quote
  1349  // 	rsc.io/sampler
  1350  // 	golang.org/x/text/language
  1351  //
  1352  // 	# golang.org/x/text/encoding
  1353  // 	(main module does not need package golang.org/x/text/encoding)
  1354  // 	$
  1355  //
  1356  // See https://golang.org/ref/mod#go-mod-why for more about 'go mod why'.
  1357  //
  1358  //
  1359  // Workspace maintenance
  1360  //
  1361  // Work provides access to operations on workspaces.
  1362  //
  1363  // Note that support for workspaces is built into many other commands, not
  1364  // just 'go work'.
  1365  //
  1366  // See 'go help modules' for information about Go's module system of which
  1367  // workspaces are a part.
  1368  //
  1369  // See https://go.dev/ref/mod#workspaces for an in-depth reference on
  1370  // workspaces.
  1371  //
  1372  // See https://go.dev/doc/tutorial/workspaces for an introductory
  1373  // tutorial on workspaces.
  1374  //
  1375  // A workspace is specified by a go.work file that specifies a set of
  1376  // module directories with the "use" directive. These modules are used as
  1377  // root modules by the go command for builds and related operations.  A
  1378  // workspace that does not specify modules to be used cannot be used to do
  1379  // builds from local modules.
  1380  //
  1381  // go.work files are line-oriented. Each line holds a single directive,
  1382  // made up of a keyword followed by arguments. For example:
  1383  //
  1384  // 	go 1.18
  1385  //
  1386  // 	use ../foo/bar
  1387  // 	use ./baz
  1388  //
  1389  // 	replace example.com/foo v1.2.3 => example.com/bar v1.4.5
  1390  //
  1391  // The leading keyword can be factored out of adjacent lines to create a block,
  1392  // like in Go imports.
  1393  //
  1394  // 	use (
  1395  // 	  ../foo/bar
  1396  // 	  ./baz
  1397  // 	)
  1398  //
  1399  // The use directive specifies a module to be included in the workspace's
  1400  // set of main modules. The argument to the use directive is the directory
  1401  // containing the module's go.mod file.
  1402  //
  1403  // The go directive specifies the version of Go the file was written at. It
  1404  // is possible there may be future changes in the semantics of workspaces
  1405  // that could be controlled by this version, but for now the version
  1406  // specified has no effect.
  1407  //
  1408  // The replace directive has the same syntax as the replace directive in a
  1409  // go.mod file and takes precedence over replaces in go.mod files.  It is
  1410  // primarily intended to override conflicting replaces in different workspace
  1411  // modules.
  1412  //
  1413  // To determine whether the go command is operating in workspace mode, use
  1414  // the "go env GOWORK" command. This will specify the workspace file being
  1415  // used.
  1416  //
  1417  // Usage:
  1418  //
  1419  // 	go work <command> [arguments]
  1420  //
  1421  // The commands are:
  1422  //
  1423  // 	edit        edit go.work from tools or scripts
  1424  // 	init        initialize workspace file
  1425  // 	sync        sync workspace build list to modules
  1426  // 	use         add modules to workspace file
  1427  //
  1428  // Use "go help work <command>" for more information about a command.
  1429  //
  1430  // Edit go.work from tools or scripts
  1431  //
  1432  // Usage:
  1433  //
  1434  // 	go work edit [editing flags] [go.work]
  1435  //
  1436  // Edit provides a command-line interface for editing go.work,
  1437  // for use primarily by tools or scripts. It only reads go.work;
  1438  // it does not look up information about the modules involved.
  1439  // If no file is specified, Edit looks for a go.work file in the current
  1440  // directory and its parent directories
  1441  //
  1442  // The editing flags specify a sequence of editing operations.
  1443  //
  1444  // The -fmt flag reformats the go.work file without making other changes.
  1445  // This reformatting is also implied by any other modifications that use or
  1446  // rewrite the go.mod file. The only time this flag is needed is if no other
  1447  // flags are specified, as in 'go work edit -fmt'.
  1448  //
  1449  // The -use=path and -dropuse=path flags
  1450  // add and drop a use directive from the go.work file's set of module directories.
  1451  //
  1452  // The -replace=old[@v]=new[@v] flag adds a replacement of the given
  1453  // module path and version pair. If the @v in old@v is omitted, a
  1454  // replacement without a version on the left side is added, which applies
  1455  // to all versions of the old module path. If the @v in new@v is omitted,
  1456  // the new path should be a local module root directory, not a module
  1457  // path. Note that -replace overrides any redundant replacements for old[@v],
  1458  // so omitting @v will drop existing replacements for specific versions.
  1459  //
  1460  // The -dropreplace=old[@v] flag drops a replacement of the given
  1461  // module path and version pair. If the @v is omitted, a replacement without
  1462  // a version on the left side is dropped.
  1463  //
  1464  // The -use, -dropuse, -replace, and -dropreplace,
  1465  // editing flags may be repeated, and the changes are applied in the order given.
  1466  //
  1467  // The -go=version flag sets the expected Go language version.
  1468  //
  1469  // The -print flag prints the final go.work in its text format instead of
  1470  // writing it back to go.mod.
  1471  //
  1472  // The -json flag prints the final go.work file in JSON format instead of
  1473  // writing it back to go.mod. The JSON output corresponds to these Go types:
  1474  //
  1475  // 	type GoWork struct {
  1476  // 		Go      string
  1477  // 		Use     []Use
  1478  // 		Replace []Replace
  1479  // 	}
  1480  //
  1481  // 	type Use struct {
  1482  // 		DiskPath   string
  1483  // 		ModulePath string
  1484  // 	}
  1485  //
  1486  // 	type Replace struct {
  1487  // 		Old Module
  1488  // 		New Module
  1489  // 	}
  1490  //
  1491  // 	type Module struct {
  1492  // 		Path    string
  1493  // 		Version string
  1494  // 	}
  1495  //
  1496  // See the workspaces reference at https://go.dev/ref/mod#workspaces
  1497  // for more information.
  1498  //
  1499  //
  1500  // Initialize workspace file
  1501  //
  1502  // Usage:
  1503  //
  1504  // 	go work init [moddirs]
  1505  //
  1506  // Init initializes and writes a new go.work file in the
  1507  // current directory, in effect creating a new workspace at the current
  1508  // directory.
  1509  //
  1510  // go work init optionally accepts paths to the workspace modules as
  1511  // arguments. If the argument is omitted, an empty workspace with no
  1512  // modules will be created.
  1513  //
  1514  // Each argument path is added to a use directive in the go.work file. The
  1515  // current go version will also be listed in the go.work file.
  1516  //
  1517  // See the workspaces reference at https://go.dev/ref/mod#workspaces
  1518  // for more information.
  1519  //
  1520  //
  1521  // Sync workspace build list to modules
  1522  //
  1523  // Usage:
  1524  //
  1525  // 	go work sync
  1526  //
  1527  // Sync syncs the workspace's build list back to the
  1528  // workspace's modules
  1529  //
  1530  // The workspace's build list is the set of versions of all the
  1531  // (transitive) dependency modules used to do builds in the workspace. go
  1532  // work sync generates that build list using the Minimal Version Selection
  1533  // algorithm, and then syncs those versions back to each of modules
  1534  // specified in the workspace (with use directives).
  1535  //
  1536  // The syncing is done by sequentially upgrading each of the dependency
  1537  // modules specified in a workspace module to the version in the build list
  1538  // if the dependency module's version is not already the same as the build
  1539  // list's version. Note that Minimal Version Selection guarantees that the
  1540  // build list's version of each module is always the same or higher than
  1541  // that in each workspace module.
  1542  //
  1543  // See the workspaces reference at https://go.dev/ref/mod#workspaces
  1544  // for more information.
  1545  //
  1546  //
  1547  // Add modules to workspace file
  1548  //
  1549  // Usage:
  1550  //
  1551  // 	go work use [-r] moddirs
  1552  //
  1553  // Use provides a command-line interface for adding
  1554  // directories, optionally recursively, to a go.work file.
  1555  //
  1556  // A use directive will be added to the go.work file for each argument
  1557  // directory listed on the command line go.work file, if it exists on disk,
  1558  // or removed from the go.work file if it does not exist on disk.
  1559  //
  1560  // The -r flag searches recursively for modules in the argument
  1561  // directories, and the use command operates as if each of the directories
  1562  // were specified as arguments: namely, use directives will be added for
  1563  // directories that exist, and removed for directories that do not exist.
  1564  //
  1565  // See the workspaces reference at https://go.dev/ref/mod#workspaces
  1566  // for more information.
  1567  //
  1568  //
  1569  // Compile and run Go program
  1570  //
  1571  // Usage:
  1572  //
  1573  // 	go run [build flags] [-exec xprog] package [arguments...]
  1574  //
  1575  // Run compiles and runs the named main Go package.
  1576  // Typically the package is specified as a list of .go source files from a single
  1577  // directory, but it may also be an import path, file system path, or pattern
  1578  // matching a single known package, as in 'go run .' or 'go run my/cmd'.
  1579  //
  1580  // If the package argument has a version suffix (like @latest or @v1.0.0),
  1581  // "go run" builds the program in module-aware mode, ignoring the go.mod file in
  1582  // the current directory or any parent directory, if there is one. This is useful
  1583  // for running programs without affecting the dependencies of the main module.
  1584  //
  1585  // If the package argument doesn't have a version suffix, "go run" may run in
  1586  // module-aware mode or GOPATH mode, depending on the GO111MODULE environment
  1587  // variable and the presence of a go.mod file. See 'go help modules' for details.
  1588  // If module-aware mode is enabled, "go run" runs in the context of the main
  1589  // module.
  1590  //
  1591  // By default, 'go run' runs the compiled binary directly: 'a.out arguments...'.
  1592  // If the -exec flag is given, 'go run' invokes the binary using xprog:
  1593  // 	'xprog a.out arguments...'.
  1594  // If the -exec flag is not given, GOOS or GOARCH is different from the system
  1595  // default, and a program named go_$GOOS_$GOARCH_exec can be found
  1596  // on the current search path, 'go run' invokes the binary using that program,
  1597  // for example 'go_js_wasm_exec a.out arguments...'. This allows execution of
  1598  // cross-compiled programs when a simulator or other execution method is
  1599  // available.
  1600  //
  1601  // The exit status of Run is not the exit status of the compiled binary.
  1602  //
  1603  // For more about build flags, see 'go help build'.
  1604  // For more about specifying packages, see 'go help packages'.
  1605  //
  1606  // See also: go build.
  1607  //
  1608  //
  1609  // Test packages
  1610  //
  1611  // Usage:
  1612  //
  1613  // 	go test [build/test flags] [packages] [build/test flags & test binary flags]
  1614  //
  1615  // 'Go test' automates testing the packages named by the import paths.
  1616  // It prints a summary of the test results in the format:
  1617  //
  1618  // 	ok   archive/tar   0.011s
  1619  // 	FAIL archive/zip   0.022s
  1620  // 	ok   compress/gzip 0.033s
  1621  // 	...
  1622  //
  1623  // followed by detailed output for each failed package.
  1624  //
  1625  // 'Go test' recompiles each package along with any files with names matching
  1626  // the file pattern "*_test.go".
  1627  // These additional files can contain test functions, benchmark functions, fuzz
  1628  // tests and example functions. See 'go help testfunc' for more.
  1629  // Each listed package causes the execution of a separate test binary.
  1630  // Files whose names begin with "_" (including "_test.go") or "." are ignored.
  1631  //
  1632  // Test files that declare a package with the suffix "_test" will be compiled as a
  1633  // separate package, and then linked and run with the main test binary.
  1634  //
  1635  // The go tool will ignore a directory named "testdata", making it available
  1636  // to hold ancillary data needed by the tests.
  1637  //
  1638  // As part of building a test binary, go test runs go vet on the package
  1639  // and its test source files to identify significant problems. If go vet
  1640  // finds any problems, go test reports those and does not run the test
  1641  // binary. Only a high-confidence subset of the default go vet checks are
  1642  // used. That subset is: 'atomic', 'bool', 'buildtags', 'errorsas',
  1643  // 'ifaceassert', 'nilfunc', 'printf', and 'stringintconv'. You can see
  1644  // the documentation for these and other vet tests via "go doc cmd/vet".
  1645  // To disable the running of go vet, use the -vet=off flag. To run all
  1646  // checks, use the -vet=all flag.
  1647  //
  1648  // All test output and summary lines are printed to the go command's
  1649  // standard output, even if the test printed them to its own standard
  1650  // error. (The go command's standard error is reserved for printing
  1651  // errors building the tests.)
  1652  //
  1653  // Go test runs in two different modes:
  1654  //
  1655  // The first, called local directory mode, occurs when go test is
  1656  // invoked with no package arguments (for example, 'go test' or 'go
  1657  // test -v'). In this mode, go test compiles the package sources and
  1658  // tests found in the current directory and then runs the resulting
  1659  // test binary. In this mode, caching (discussed below) is disabled.
  1660  // After the package test finishes, go test prints a summary line
  1661  // showing the test status ('ok' or 'FAIL'), package name, and elapsed
  1662  // time.
  1663  //
  1664  // The second, called package list mode, occurs when go test is invoked
  1665  // with explicit package arguments (for example 'go test math', 'go
  1666  // test ./...', and even 'go test .'). In this mode, go test compiles
  1667  // and tests each of the packages listed on the command line. If a
  1668  // package test passes, go test prints only the final 'ok' summary
  1669  // line. If a package test fails, go test prints the full test output.
  1670  // If invoked with the -bench or -v flag, go test prints the full
  1671  // output even for passing package tests, in order to display the
  1672  // requested benchmark results or verbose logging. After the package
  1673  // tests for all of the listed packages finish, and their output is
  1674  // printed, go test prints a final 'FAIL' status if any package test
  1675  // has failed.
  1676  //
  1677  // In package list mode only, go test caches successful package test
  1678  // results to avoid unnecessary repeated running of tests. When the
  1679  // result of a test can be recovered from the cache, go test will
  1680  // redisplay the previous output instead of running the test binary
  1681  // again. When this happens, go test prints '(cached)' in place of the
  1682  // elapsed time in the summary line.
  1683  //
  1684  // The rule for a match in the cache is that the run involves the same
  1685  // test binary and the flags on the command line come entirely from a
  1686  // restricted set of 'cacheable' test flags, defined as -benchtime, -cpu,
  1687  // -list, -parallel, -run, -short, -timeout, -failfast, and -v.
  1688  // If a run of go test has any test or non-test flags outside this set,
  1689  // the result is not cached. To disable test caching, use any test flag
  1690  // or argument other than the cacheable flags. The idiomatic way to disable
  1691  // test caching explicitly is to use -count=1. Tests that open files within
  1692  // the package's source root (usually $GOPATH) or that consult environment
  1693  // variables only match future runs in which the files and environment
  1694  // variables are unchanged. A cached test result is treated as executing
  1695  // in no time at all,so a successful package test result will be cached and
  1696  // reused regardless of -timeout setting.
  1697  //
  1698  // In addition to the build flags, the flags handled by 'go test' itself are:
  1699  //
  1700  // 	-args
  1701  // 	    Pass the remainder of the command line (everything after -args)
  1702  // 	    to the test binary, uninterpreted and unchanged.
  1703  // 	    Because this flag consumes the remainder of the command line,
  1704  // 	    the package list (if present) must appear before this flag.
  1705  //
  1706  // 	-c
  1707  // 	    Compile the test binary to pkg.test but do not run it
  1708  // 	    (where pkg is the last element of the package's import path).
  1709  // 	    The file name can be changed with the -o flag.
  1710  //
  1711  // 	-exec xprog
  1712  // 	    Run the test binary using xprog. The behavior is the same as
  1713  // 	    in 'go run'. See 'go help run' for details.
  1714  //
  1715  // 	-i
  1716  // 	    Install packages that are dependencies of the test.
  1717  // 	    Do not run the test.
  1718  // 	    The -i flag is deprecated. Compiled packages are cached automatically.
  1719  //
  1720  // 	-json
  1721  // 	    Convert test output to JSON suitable for automated processing.
  1722  // 	    See 'go doc test2json' for the encoding details.
  1723  //
  1724  // 	-o file
  1725  // 	    Compile the test binary to the named file.
  1726  // 	    The test still runs (unless -c or -i is specified).
  1727  //
  1728  // The test binary also accepts flags that control execution of the test; these
  1729  // flags are also accessible by 'go test'. See 'go help testflag' for details.
  1730  //
  1731  // For more about build flags, see 'go help build'.
  1732  // For more about specifying packages, see 'go help packages'.
  1733  //
  1734  // See also: go build, go vet.
  1735  //
  1736  //
  1737  // Run specified go tool
  1738  //
  1739  // Usage:
  1740  //
  1741  // 	go tool [-n] command [args...]
  1742  //
  1743  // Tool runs the go tool command identified by the arguments.
  1744  // With no arguments it prints the list of known tools.
  1745  //
  1746  // The -n flag causes tool to print the command that would be
  1747  // executed but not execute it.
  1748  //
  1749  // For more about each tool command, see 'go doc cmd/<command>'.
  1750  //
  1751  //
  1752  // Print Go version
  1753  //
  1754  // Usage:
  1755  //
  1756  // 	go version [-m] [-v] [file ...]
  1757  //
  1758  // Version prints the build information for Go executables.
  1759  //
  1760  // Go version reports the Go version used to build each of the named
  1761  // executable files.
  1762  //
  1763  // If no files are named on the command line, go version prints its own
  1764  // version information.
  1765  //
  1766  // If a directory is named, go version walks that directory, recursively,
  1767  // looking for recognized Go binaries and reporting their versions.
  1768  // By default, go version does not report unrecognized files found
  1769  // during a directory scan. The -v flag causes it to report unrecognized files.
  1770  //
  1771  // The -m flag causes go version to print each executable's embedded
  1772  // module version information, when available. In the output, the module
  1773  // information consists of multiple lines following the version line, each
  1774  // indented by a leading tab character.
  1775  //
  1776  // See also: go doc runtime/debug.BuildInfo.
  1777  //
  1778  //
  1779  // Report likely mistakes in packages
  1780  //
  1781  // Usage:
  1782  //
  1783  // 	go vet [-n] [-x] [-vettool prog] [build flags] [vet flags] [packages]
  1784  //
  1785  // Vet runs the Go vet command on the packages named by the import paths.
  1786  //
  1787  // For more about vet and its flags, see 'go doc cmd/vet'.
  1788  // For more about specifying packages, see 'go help packages'.
  1789  // For a list of checkers and their flags, see 'go tool vet help'.
  1790  // For details of a specific checker such as 'printf', see 'go tool vet help printf'.
  1791  //
  1792  // The -n flag prints commands that would be executed.
  1793  // The -x flag prints commands as they are executed.
  1794  //
  1795  // The -vettool=prog flag selects a different analysis tool with alternative
  1796  // or additional checks.
  1797  // For example, the 'shadow' analyzer can be built and run using these commands:
  1798  //
  1799  //   go install golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow
  1800  //   go vet -vettool=$(which shadow)
  1801  //
  1802  // The build flags supported by go vet are those that control package resolution
  1803  // and execution, such as -n, -x, -v, -tags, and -toolexec.
  1804  // For more about these flags, see 'go help build'.
  1805  //
  1806  // See also: go fmt, go fix.
  1807  //
  1808  //
  1809  // Build constraints
  1810  //
  1811  // A build constraint, also known as a build tag, is a line comment that begins
  1812  //
  1813  // 	//go:build
  1814  //
  1815  // that lists the conditions under which a file should be included in the package.
  1816  // Constraints may appear in any kind of source file (not just Go), but
  1817  // they must appear near the top of the file, preceded
  1818  // only by blank lines and other line comments. These rules mean that in Go
  1819  // files a build constraint must appear before the package clause.
  1820  //
  1821  // To distinguish build constraints from package documentation,
  1822  // a build constraint should be followed by a blank line.
  1823  //
  1824  // A build constraint is evaluated as an expression containing options
  1825  // combined by ||, &&, and ! operators and parentheses. Operators have
  1826  // the same meaning as in Go.
  1827  //
  1828  // For example, the following build constraint constrains a file to
  1829  // build when the "linux" and "386" constraints are satisfied, or when
  1830  // "darwin" is satisfied and "cgo" is not:
  1831  //
  1832  // 	//go:build (linux && 386) || (darwin && !cgo)
  1833  //
  1834  // It is an error for a file to have more than one //go:build line.
  1835  //
  1836  // During a particular build, the following words are satisfied:
  1837  //
  1838  // 	- the target operating system, as spelled by runtime.GOOS, set with the
  1839  // 	  GOOS environment variable.
  1840  // 	- the target architecture, as spelled by runtime.GOARCH, set with the
  1841  // 	  GOARCH environment variable.
  1842  // 	- the compiler being used, either "gc" or "gccgo"
  1843  // 	- "cgo", if the cgo command is supported (see CGO_ENABLED in
  1844  // 	  'go help environment').
  1845  // 	- a term for each Go major release, through the current version:
  1846  // 	  "go1.1" from Go version 1.1 onward, "go1.12" from Go 1.12, and so on.
  1847  // 	- any additional tags given by the -tags flag (see 'go help build').
  1848  //
  1849  // There are no separate build tags for beta or minor releases.
  1850  //
  1851  // If a file's name, after stripping the extension and a possible _test suffix,
  1852  // matches any of the following patterns:
  1853  // 	*_GOOS
  1854  // 	*_GOARCH
  1855  // 	*_GOOS_GOARCH
  1856  // (example: source_windows_amd64.go) where GOOS and GOARCH represent
  1857  // any known operating system and architecture values respectively, then
  1858  // the file is considered to have an implicit build constraint requiring
  1859  // those terms (in addition to any explicit constraints in the file).
  1860  //
  1861  // Using GOOS=android matches build tags and files as for GOOS=linux
  1862  // in addition to android tags and files.
  1863  //
  1864  // Using GOOS=illumos matches build tags and files as for GOOS=solaris
  1865  // in addition to illumos tags and files.
  1866  //
  1867  // Using GOOS=ios matches build tags and files as for GOOS=darwin
  1868  // in addition to ios tags and files.
  1869  //
  1870  // To keep a file from being considered for the build:
  1871  //
  1872  // 	//go:build ignore
  1873  //
  1874  // (any other unsatisfied word will work as well, but "ignore" is conventional.)
  1875  //
  1876  // To build a file only when using cgo, and only on Linux and OS X:
  1877  //
  1878  // 	//go:build cgo && (linux || darwin)
  1879  //
  1880  // Such a file is usually paired with another file implementing the
  1881  // default functionality for other systems, which in this case would
  1882  // carry the constraint:
  1883  //
  1884  // 	//go:build !(cgo && (linux || darwin))
  1885  //
  1886  // Naming a file dns_windows.go will cause it to be included only when
  1887  // building the package for Windows; similarly, math_386.s will be included
  1888  // only when building the package for 32-bit x86.
  1889  //
  1890  // Go versions 1.16 and earlier used a different syntax for build constraints,
  1891  // with a "// +build" prefix. The gofmt command will add an equivalent //go:build
  1892  // constraint when encountering the older syntax.
  1893  //
  1894  //
  1895  // Build modes
  1896  //
  1897  // The 'go build' and 'go install' commands take a -buildmode argument which
  1898  // indicates which kind of object file is to be built. Currently supported values
  1899  // are:
  1900  //
  1901  // 	-buildmode=archive
  1902  // 		Build the listed non-main packages into .a files. Packages named
  1903  // 		main are ignored.
  1904  //
  1905  // 	-buildmode=c-archive
  1906  // 		Build the listed main package, plus all packages it imports,
  1907  // 		into a C archive file. The only callable symbols will be those
  1908  // 		functions exported using a cgo //export comment. Requires
  1909  // 		exactly one main package to be listed.
  1910  //
  1911  // 	-buildmode=c-shared
  1912  // 		Build the listed main package, plus all packages it imports,
  1913  // 		into a C shared library. The only callable symbols will
  1914  // 		be those functions exported using a cgo //export comment.
  1915  // 		Requires exactly one main package to be listed.
  1916  //
  1917  // 	-buildmode=default
  1918  // 		Listed main packages are built into executables and listed
  1919  // 		non-main packages are built into .a files (the default
  1920  // 		behavior).
  1921  //
  1922  // 	-buildmode=shared
  1923  // 		Combine all the listed non-main packages into a single shared
  1924  // 		library that will be used when building with the -linkshared
  1925  // 		option. Packages named main are ignored.
  1926  //
  1927  // 	-buildmode=exe
  1928  // 		Build the listed main packages and everything they import into
  1929  // 		executables. Packages not named main are ignored.
  1930  //
  1931  // 	-buildmode=pie
  1932  // 		Build the listed main packages and everything they import into
  1933  // 		position independent executables (PIE). Packages not named
  1934  // 		main are ignored.
  1935  //
  1936  // 	-buildmode=plugin
  1937  // 		Build the listed main packages, plus all packages that they
  1938  // 		import, into a Go plugin. Packages not named main are ignored.
  1939  //
  1940  // On AIX, when linking a C program that uses a Go archive built with
  1941  // -buildmode=c-archive, you must pass -Wl,-bnoobjreorder to the C compiler.
  1942  //
  1943  //
  1944  // Calling between Go and C
  1945  //
  1946  // There are two different ways to call between Go and C/C++ code.
  1947  //
  1948  // The first is the cgo tool, which is part of the Go distribution. For
  1949  // information on how to use it see the cgo documentation (go doc cmd/cgo).
  1950  //
  1951  // The second is the SWIG program, which is a general tool for
  1952  // interfacing between languages. For information on SWIG see
  1953  // http://swig.org/. When running go build, any file with a .swig
  1954  // extension will be passed to SWIG. Any file with a .swigcxx extension
  1955  // will be passed to SWIG with the -c++ option.
  1956  //
  1957  // When either cgo or SWIG is used, go build will pass any .c, .m, .s, .S
  1958  // or .sx files to the C compiler, and any .cc, .cpp, .cxx files to the C++
  1959  // compiler. The CC or CXX environment variables may be set to determine
  1960  // the C or C++ compiler, respectively, to use.
  1961  //
  1962  //
  1963  // Build and test caching
  1964  //
  1965  // The go command caches build outputs for reuse in future builds.
  1966  // The default location for cache data is a subdirectory named go-build
  1967  // in the standard user cache directory for the current operating system.
  1968  // Setting the GOCACHE environment variable overrides this default,
  1969  // and running 'go env GOCACHE' prints the current cache directory.
  1970  //
  1971  // The go command periodically deletes cached data that has not been
  1972  // used recently. Running 'go clean -cache' deletes all cached data.
  1973  //
  1974  // The build cache correctly accounts for changes to Go source files,
  1975  // compilers, compiler options, and so on: cleaning the cache explicitly
  1976  // should not be necessary in typical use. However, the build cache
  1977  // does not detect changes to C libraries imported with cgo.
  1978  // If you have made changes to the C libraries on your system, you
  1979  // will need to clean the cache explicitly or else use the -a build flag
  1980  // (see 'go help build') to force rebuilding of packages that
  1981  // depend on the updated C libraries.
  1982  //
  1983  // The go command also caches successful package test results.
  1984  // See 'go help test' for details. Running 'go clean -testcache' removes
  1985  // all cached test results (but not cached build results).
  1986  //
  1987  // The go command also caches values used in fuzzing with 'go test -fuzz',
  1988  // specifically, values that expanded code coverage when passed to a
  1989  // fuzz function. These values are not used for regular building and
  1990  // testing, but they're stored in a subdirectory of the build cache.
  1991  // Running 'go clean -fuzzcache' removes all cached fuzzing values.
  1992  // This may make fuzzing less effective, temporarily.
  1993  //
  1994  // The GODEBUG environment variable can enable printing of debugging
  1995  // information about the state of the cache:
  1996  //
  1997  // GODEBUG=gocacheverify=1 causes the go command to bypass the
  1998  // use of any cache entries and instead rebuild everything and check
  1999  // that the results match existing cache entries.
  2000  //
  2001  // GODEBUG=gocachehash=1 causes the go command to print the inputs
  2002  // for all of the content hashes it uses to construct cache lookup keys.
  2003  // The output is voluminous but can be useful for debugging the cache.
  2004  //
  2005  // GODEBUG=gocachetest=1 causes the go command to print details of its
  2006  // decisions about whether to reuse a cached test result.
  2007  //
  2008  //
  2009  // Environment variables
  2010  //
  2011  // The go command and the tools it invokes consult environment variables
  2012  // for configuration. If an environment variable is unset, the go command
  2013  // uses a sensible default setting. To see the effective setting of the
  2014  // variable <NAME>, run 'go env <NAME>'. To change the default setting,
  2015  // run 'go env -w <NAME>=<VALUE>'. Defaults changed using 'go env -w'
  2016  // are recorded in a Go environment configuration file stored in the
  2017  // per-user configuration directory, as reported by os.UserConfigDir.
  2018  // The location of the configuration file can be changed by setting
  2019  // the environment variable GOENV, and 'go env GOENV' prints the
  2020  // effective location, but 'go env -w' cannot change the default location.
  2021  // See 'go help env' for details.
  2022  //
  2023  // General-purpose environment variables:
  2024  //
  2025  // 	GO111MODULE
  2026  // 		Controls whether the go command runs in module-aware mode or GOPATH mode.
  2027  // 		May be "off", "on", or "auto".
  2028  // 		See https://golang.org/ref/mod#mod-commands.
  2029  // 	GCCGO
  2030  // 		The gccgo command to run for 'go build -compiler=gccgo'.
  2031  // 	GOARCH
  2032  // 		The architecture, or processor, for which to compile code.
  2033  // 		Examples are amd64, 386, arm, ppc64.
  2034  // 	GOBIN
  2035  // 		The directory where 'go install' will install a command.
  2036  // 	GOCACHE
  2037  // 		The directory where the go command will store cached
  2038  // 		information for reuse in future builds.
  2039  // 	GOMODCACHE
  2040  // 		The directory where the go command will store downloaded modules.
  2041  // 	GODEBUG
  2042  // 		Enable various debugging facilities. See 'go doc runtime'
  2043  // 		for details.
  2044  // 	GOENV
  2045  // 		The location of the Go environment configuration file.
  2046  // 		Cannot be set using 'go env -w'.
  2047  // 		Setting GOENV=off in the environment disables the use of the
  2048  // 		default configuration file.
  2049  // 	GOFLAGS
  2050  // 		A space-separated list of -flag=value settings to apply
  2051  // 		to go commands by default, when the given flag is known by
  2052  // 		the current command. Each entry must be a standalone flag.
  2053  // 		Because the entries are space-separated, flag values must
  2054  // 		not contain spaces. Flags listed on the command line
  2055  // 		are applied after this list and therefore override it.
  2056  // 	GOINSECURE
  2057  // 		Comma-separated list of glob patterns (in the syntax of Go's path.Match)
  2058  // 		of module path prefixes that should always be fetched in an insecure
  2059  // 		manner. Only applies to dependencies that are being fetched directly.
  2060  // 		GOINSECURE does not disable checksum database validation. GOPRIVATE or
  2061  // 		GONOSUMDB may be used to achieve that.
  2062  // 	GOOS
  2063  // 		The operating system for which to compile code.
  2064  // 		Examples are linux, darwin, windows, netbsd.
  2065  // 	GOPATH
  2066  // 		For more details see: 'go help gopath'.
  2067  // 	GOPROXY
  2068  // 		URL of Go module proxy. See https://golang.org/ref/mod#environment-variables
  2069  // 		and https://golang.org/ref/mod#module-proxy for details.
  2070  // 	GOPRIVATE, GONOPROXY, GONOSUMDB
  2071  // 		Comma-separated list of glob patterns (in the syntax of Go's path.Match)
  2072  // 		of module path prefixes that should always be fetched directly
  2073  // 		or that should not be compared against the checksum database.
  2074  // 		See https://golang.org/ref/mod#private-modules.
  2075  // 	GOROOT
  2076  // 		The root of the go tree.
  2077  // 	GOSUMDB
  2078  // 		The name of checksum database to use and optionally its public key and
  2079  // 		URL. See https://golang.org/ref/mod#authenticating.
  2080  // 	GOTMPDIR
  2081  // 		The directory where the go command will write
  2082  // 		temporary source files, packages, and binaries.
  2083  // 	GOVCS
  2084  // 		Lists version control commands that may be used with matching servers.
  2085  // 		See 'go help vcs'.
  2086  // 	GOWORK
  2087  // 		In module aware mode, use the given go.work file as a workspace file.
  2088  // 		By default or when GOWORK is "auto", the go command searches for a
  2089  // 		file named go.work in the current directory and then containing directories
  2090  // 		until one is found. If a valid go.work file is found, the modules
  2091  // 		specified will collectively be used as the main modules. If GOWORK
  2092  // 		is "off", or a go.work file is not found in "auto" mode, workspace
  2093  // 		mode is disabled.
  2094  //
  2095  // Environment variables for use with cgo:
  2096  //
  2097  // 	AR
  2098  // 		The command to use to manipulate library archives when
  2099  // 		building with the gccgo compiler.
  2100  // 		The default is 'ar'.
  2101  // 	CC
  2102  // 		The command to use to compile C code.
  2103  // 	CGO_ENABLED
  2104  // 		Whether the cgo command is supported. Either 0 or 1.
  2105  // 	CGO_CFLAGS
  2106  // 		Flags that cgo will pass to the compiler when compiling
  2107  // 		C code.
  2108  // 	CGO_CFLAGS_ALLOW
  2109  // 		A regular expression specifying additional flags to allow
  2110  // 		to appear in #cgo CFLAGS source code directives.
  2111  // 		Does not apply to the CGO_CFLAGS environment variable.
  2112  // 	CGO_CFLAGS_DISALLOW
  2113  // 		A regular expression specifying flags that must be disallowed
  2114  // 		from appearing in #cgo CFLAGS source code directives.
  2115  // 		Does not apply to the CGO_CFLAGS environment variable.
  2116  // 	CGO_CPPFLAGS, CGO_CPPFLAGS_ALLOW, CGO_CPPFLAGS_DISALLOW
  2117  // 		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
  2118  // 		but for the C preprocessor.
  2119  // 	CGO_CXXFLAGS, CGO_CXXFLAGS_ALLOW, CGO_CXXFLAGS_DISALLOW
  2120  // 		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
  2121  // 		but for the C++ compiler.
  2122  // 	CGO_FFLAGS, CGO_FFLAGS_ALLOW, CGO_FFLAGS_DISALLOW
  2123  // 		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
  2124  // 		but for the Fortran compiler.
  2125  // 	CGO_LDFLAGS, CGO_LDFLAGS_ALLOW, CGO_LDFLAGS_DISALLOW
  2126  // 		Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
  2127  // 		but for the linker.
  2128  // 	CXX
  2129  // 		The command to use to compile C++ code.
  2130  // 	FC
  2131  // 		The command to use to compile Fortran code.
  2132  // 	PKG_CONFIG
  2133  // 		Path to pkg-config tool.
  2134  //
  2135  // Architecture-specific environment variables:
  2136  //
  2137  // 	GOARM
  2138  // 		For GOARCH=arm, the ARM architecture for which to compile.
  2139  // 		Valid values are 5, 6, 7.
  2140  // 	GO386
  2141  // 		For GOARCH=386, how to implement floating point instructions.
  2142  // 		Valid values are sse2 (default), softfloat.
  2143  // 	GOAMD64
  2144  // 		For GOARCH=amd64, the microarchitecture level for which to compile.
  2145  // 		Valid values are v1 (default), v2, v3, v4.
  2146  // 		See https://golang.org/wiki/MinimumRequirements#amd64
  2147  // 	GOMIPS
  2148  // 		For GOARCH=mips{,le}, whether to use floating point instructions.
  2149  // 		Valid values are hardfloat (default), softfloat.
  2150  // 	GOMIPS64
  2151  // 		For GOARCH=mips64{,le}, whether to use floating point instructions.
  2152  // 		Valid values are hardfloat (default), softfloat.
  2153  // 	GOPPC64
  2154  // 		For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
  2155  // 		Valid values are power8 (default), power9.
  2156  // 	GOWASM
  2157  // 		For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
  2158  // 		Valid values are satconv, signext.
  2159  //
  2160  // Special-purpose environment variables:
  2161  //
  2162  // 	GCCGOTOOLDIR
  2163  // 		If set, where to find gccgo tools, such as cgo.
  2164  // 		The default is based on how gccgo was configured.
  2165  // 	GOEXPERIMENT
  2166  // 		Comma-separated list of toolchain experiments to enable or disable.
  2167  // 		The list of available experiments may change arbitrarily over time.
  2168  // 		See src/internal/goexperiment/flags.go for currently valid values.
  2169  // 		Warning: This variable is provided for the development and testing
  2170  // 		of the Go toolchain itself. Use beyond that purpose is unsupported.
  2171  // 	GOROOT_FINAL
  2172  // 		The root of the installed Go tree, when it is
  2173  // 		installed in a location other than where it is built.
  2174  // 		File names in stack traces are rewritten from GOROOT to
  2175  // 		GOROOT_FINAL.
  2176  // 	GO_EXTLINK_ENABLED
  2177  // 		Whether the linker should use external linking mode
  2178  // 		when using -linkmode=auto with code that uses cgo.
  2179  // 		Set to 0 to disable external linking mode, 1 to enable it.
  2180  // 	GIT_ALLOW_PROTOCOL
  2181  // 		Defined by Git. A colon-separated list of schemes that are allowed
  2182  // 		to be used with git fetch/clone. If set, any scheme not explicitly
  2183  // 		mentioned will be considered insecure by 'go get'.
  2184  // 		Because the variable is defined by Git, the default value cannot
  2185  // 		be set using 'go env -w'.
  2186  //
  2187  // Additional information available from 'go env' but not read from the environment:
  2188  //
  2189  // 	GOEXE
  2190  // 		The executable file name suffix (".exe" on Windows, "" on other systems).
  2191  // 	GOGCCFLAGS
  2192  // 		A space-separated list of arguments supplied to the CC command.
  2193  // 	GOHOSTARCH
  2194  // 		The architecture (GOARCH) of the Go toolchain binaries.
  2195  // 	GOHOSTOS
  2196  // 		The operating system (GOOS) of the Go toolchain binaries.
  2197  // 	GOMOD
  2198  // 		The absolute path to the go.mod of the main module.
  2199  // 		If module-aware mode is enabled, but there is no go.mod, GOMOD will be
  2200  // 		os.DevNull ("/dev/null" on Unix-like systems, "NUL" on Windows).
  2201  // 		If module-aware mode is disabled, GOMOD will be the empty string.
  2202  // 	GOTOOLDIR
  2203  // 		The directory where the go tools (compile, cover, doc, etc...) are installed.
  2204  // 	GOVERSION
  2205  // 		The version of the installed Go tree, as reported by runtime.Version.
  2206  //
  2207  //
  2208  // File types
  2209  //
  2210  // The go command examines the contents of a restricted set of files
  2211  // in each directory. It identifies which files to examine based on
  2212  // the extension of the file name. These extensions are:
  2213  //
  2214  // 	.go
  2215  // 		Go source files.
  2216  // 	.c, .h
  2217  // 		C source files.
  2218  // 		If the package uses cgo or SWIG, these will be compiled with the
  2219  // 		OS-native compiler (typically gcc); otherwise they will
  2220  // 		trigger an error.
  2221  // 	.cc, .cpp, .cxx, .hh, .hpp, .hxx
  2222  // 		C++ source files. Only useful with cgo or SWIG, and always
  2223  // 		compiled with the OS-native compiler.
  2224  // 	.m
  2225  // 		Objective-C source files. Only useful with cgo, and always
  2226  // 		compiled with the OS-native compiler.
  2227  // 	.s, .S, .sx
  2228  // 		Assembler source files.
  2229  // 		If the package uses cgo or SWIG, these will be assembled with the
  2230  // 		OS-native assembler (typically gcc (sic)); otherwise they
  2231  // 		will be assembled with the Go assembler.
  2232  // 	.swig, .swigcxx
  2233  // 		SWIG definition files.
  2234  // 	.syso
  2235  // 		System object files.
  2236  //
  2237  // Files of each of these types except .syso may contain build
  2238  // constraints, but the go command stops scanning for build constraints
  2239  // at the first item in the file that is not a blank line or //-style
  2240  // line comment. See the go/build package documentation for
  2241  // more details.
  2242  //
  2243  //
  2244  // The go.mod file
  2245  //
  2246  // A module version is defined by a tree of source files, with a go.mod
  2247  // file in its root. When the go command is run, it looks in the current
  2248  // directory and then successive parent directories to find the go.mod
  2249  // marking the root of the main (current) module.
  2250  //
  2251  // The go.mod file format is described in detail at
  2252  // https://golang.org/ref/mod#go-mod-file.
  2253  //
  2254  // To create a new go.mod file, use 'go mod init'. For details see
  2255  // 'go help mod init' or https://golang.org/ref/mod#go-mod-init.
  2256  //
  2257  // To add missing module requirements or remove unneeded requirements,
  2258  // use 'go mod tidy'. For details, see 'go help mod tidy' or
  2259  // https://golang.org/ref/mod#go-mod-tidy.
  2260  //
  2261  // To add, upgrade, downgrade, or remove a specific module requirement, use
  2262  // 'go get'. For details, see 'go help module-get' or
  2263  // https://golang.org/ref/mod#go-get.
  2264  //
  2265  // To make other changes or to parse go.mod as JSON for use by other tools,
  2266  // use 'go mod edit'. See 'go help mod edit' or
  2267  // https://golang.org/ref/mod#go-mod-edit.
  2268  //
  2269  //
  2270  // GOPATH environment variable
  2271  //
  2272  // The Go path is used to resolve import statements.
  2273  // It is implemented by and documented in the go/build package.
  2274  //
  2275  // The GOPATH environment variable lists places to look for Go code.
  2276  // On Unix, the value is a colon-separated string.
  2277  // On Windows, the value is a semicolon-separated string.
  2278  // On Plan 9, the value is a list.
  2279  //
  2280  // If the environment variable is unset, GOPATH defaults
  2281  // to a subdirectory named "go" in the user's home directory
  2282  // ($HOME/go on Unix, %USERPROFILE%\go on Windows),
  2283  // unless that directory holds a Go distribution.
  2284  // Run "go env GOPATH" to see the current GOPATH.
  2285  //
  2286  // See https://golang.org/wiki/SettingGOPATH to set a custom GOPATH.
  2287  //
  2288  // Each directory listed in GOPATH must have a prescribed structure:
  2289  //
  2290  // The src directory holds source code. The path below src
  2291  // determines the import path or executable name.
  2292  //
  2293  // The pkg directory holds installed package objects.
  2294  // As in the Go tree, each target operating system and
  2295  // architecture pair has its own subdirectory of pkg
  2296  // (pkg/GOOS_GOARCH).
  2297  //
  2298  // If DIR is a directory listed in the GOPATH, a package with
  2299  // source in DIR/src/foo/bar can be imported as "foo/bar" and
  2300  // has its compiled form installed to "DIR/pkg/GOOS_GOARCH/foo/bar.a".
  2301  //
  2302  // The bin directory holds compiled commands.
  2303  // Each command is named for its source directory, but only
  2304  // the final element, not the entire path. That is, the
  2305  // command with source in DIR/src/foo/quux is installed into
  2306  // DIR/bin/quux, not DIR/bin/foo/quux. The "foo/" prefix is stripped
  2307  // so that you can add DIR/bin to your PATH to get at the
  2308  // installed commands. If the GOBIN environment variable is
  2309  // set, commands are installed to the directory it names instead
  2310  // of DIR/bin. GOBIN must be an absolute path.
  2311  //
  2312  // Here's an example directory layout:
  2313  //
  2314  //     GOPATH=/home/user/go
  2315  //
  2316  //     /home/user/go/
  2317  //         src/
  2318  //             foo/
  2319  //                 bar/               (go code in package bar)
  2320  //                     x.go
  2321  //                 quux/              (go code in package main)
  2322  //                     y.go
  2323  //         bin/
  2324  //             quux                   (installed command)
  2325  //         pkg/
  2326  //             linux_amd64/
  2327  //                 foo/
  2328  //                     bar.a          (installed package object)
  2329  //
  2330  // Go searches each directory listed in GOPATH to find source code,
  2331  // but new packages are always downloaded into the first directory
  2332  // in the list.
  2333  //
  2334  // See https://golang.org/doc/code.html for an example.
  2335  //
  2336  // GOPATH and Modules
  2337  //
  2338  // When using modules, GOPATH is no longer used for resolving imports.
  2339  // However, it is still used to store downloaded source code (in GOPATH/pkg/mod)
  2340  // and compiled commands (in GOPATH/bin).
  2341  //
  2342  // Internal Directories
  2343  //
  2344  // Code in or below a directory named "internal" is importable only
  2345  // by code in the directory tree rooted at the parent of "internal".
  2346  // Here's an extended version of the directory layout above:
  2347  //
  2348  //     /home/user/go/
  2349  //         src/
  2350  //             crash/
  2351  //                 bang/              (go code in package bang)
  2352  //                     b.go
  2353  //             foo/                   (go code in package foo)
  2354  //                 f.go
  2355  //                 bar/               (go code in package bar)
  2356  //                     x.go
  2357  //                 internal/
  2358  //                     baz/           (go code in package baz)
  2359  //                         z.go
  2360  //                 quux/              (go code in package main)
  2361  //                     y.go
  2362  //
  2363  //
  2364  // The code in z.go is imported as "foo/internal/baz", but that
  2365  // import statement can only appear in source files in the subtree
  2366  // rooted at foo. The source files foo/f.go, foo/bar/x.go, and
  2367  // foo/quux/y.go can all import "foo/internal/baz", but the source file
  2368  // crash/bang/b.go cannot.
  2369  //
  2370  // See https://golang.org/s/go14internal for details.
  2371  //
  2372  // Vendor Directories
  2373  //
  2374  // Go 1.6 includes support for using local copies of external dependencies
  2375  // to satisfy imports of those dependencies, often referred to as vendoring.
  2376  //
  2377  // Code below a directory named "vendor" is importable only
  2378  // by code in the directory tree rooted at the parent of "vendor",
  2379  // and only using an import path that omits the prefix up to and
  2380  // including the vendor element.
  2381  //
  2382  // Here's the example from the previous section,
  2383  // but with the "internal" directory renamed to "vendor"
  2384  // and a new foo/vendor/crash/bang directory added:
  2385  //
  2386  //     /home/user/go/
  2387  //         src/
  2388  //             crash/
  2389  //                 bang/              (go code in package bang)
  2390  //                     b.go
  2391  //             foo/                   (go code in package foo)
  2392  //                 f.go
  2393  //                 bar/               (go code in package bar)
  2394  //                     x.go
  2395  //                 vendor/
  2396  //                     crash/
  2397  //                         bang/      (go code in package bang)
  2398  //                             b.go
  2399  //                     baz/           (go code in package baz)
  2400  //                         z.go
  2401  //                 quux/              (go code in package main)
  2402  //                     y.go
  2403  //
  2404  // The same visibility rules apply as for internal, but the code
  2405  // in z.go is imported as "baz", not as "foo/vendor/baz".
  2406  //
  2407  // Code in vendor directories deeper in the source tree shadows
  2408  // code in higher directories. Within the subtree rooted at foo, an import
  2409  // of "crash/bang" resolves to "foo/vendor/crash/bang", not the
  2410  // top-level "crash/bang".
  2411  //
  2412  // Code in vendor directories is not subject to import path
  2413  // checking (see 'go help importpath').
  2414  //
  2415  // When 'go get' checks out or updates a git repository, it now also
  2416  // updates submodules.
  2417  //
  2418  // Vendor directories do not affect the placement of new repositories
  2419  // being checked out for the first time by 'go get': those are always
  2420  // placed in the main GOPATH, never in a vendor subtree.
  2421  //
  2422  // See https://golang.org/s/go15vendor for details.
  2423  //
  2424  //
  2425  // Legacy GOPATH go get
  2426  //
  2427  // The 'go get' command changes behavior depending on whether the
  2428  // go command is running in module-aware mode or legacy GOPATH mode.
  2429  // This help text, accessible as 'go help gopath-get' even in module-aware mode,
  2430  // describes 'go get' as it operates in legacy GOPATH mode.
  2431  //
  2432  // Usage: go get [-d] [-f] [-t] [-u] [-v] [-fix] [build flags] [packages]
  2433  //
  2434  // Get downloads the packages named by the import paths, along with their
  2435  // dependencies. It then installs the named packages, like 'go install'.
  2436  //
  2437  // The -d flag instructs get to stop after downloading the packages; that is,
  2438  // it instructs get not to install the packages.
  2439  //
  2440  // The -f flag, valid only when -u is set, forces get -u not to verify that
  2441  // each package has been checked out from the source control repository
  2442  // implied by its import path. This can be useful if the source is a local fork
  2443  // of the original.
  2444  //
  2445  // The -fix flag instructs get to run the fix tool on the downloaded packages
  2446  // before resolving dependencies or building the code.
  2447  //
  2448  // The -t flag instructs get to also download the packages required to build
  2449  // the tests for the specified packages.
  2450  //
  2451  // The -u flag instructs get to use the network to update the named packages
  2452  // and their dependencies. By default, get uses the network to check out
  2453  // missing packages but does not use it to look for updates to existing packages.
  2454  //
  2455  // The -v flag enables verbose progress and debug output.
  2456  //
  2457  // Get also accepts build flags to control the installation. See 'go help build'.
  2458  //
  2459  // When checking out a new package, get creates the target directory
  2460  // GOPATH/src/<import-path>. If the GOPATH contains multiple entries,
  2461  // get uses the first one. For more details see: 'go help gopath'.
  2462  //
  2463  // When checking out or updating a package, get looks for a branch or tag
  2464  // that matches the locally installed version of Go. The most important
  2465  // rule is that if the local installation is running version "go1", get
  2466  // searches for a branch or tag named "go1". If no such version exists
  2467  // it retrieves the default branch of the package.
  2468  //
  2469  // When go get checks out or updates a Git repository,
  2470  // it also updates any git submodules referenced by the repository.
  2471  //
  2472  // Get never checks out or updates code stored in vendor directories.
  2473  //
  2474  // For more about specifying packages, see 'go help packages'.
  2475  //
  2476  // For more about how 'go get' finds source code to
  2477  // download, see 'go help importpath'.
  2478  //
  2479  // This text describes the behavior of get when using GOPATH
  2480  // to manage source code and dependencies.
  2481  // If instead the go command is running in module-aware mode,
  2482  // the details of get's flags and effects change, as does 'go help get'.
  2483  // See 'go help modules' and 'go help module-get'.
  2484  //
  2485  // See also: go build, go install, go clean.
  2486  //
  2487  //
  2488  // Module proxy protocol
  2489  //
  2490  // A Go module proxy is any web server that can respond to GET requests for
  2491  // URLs of a specified form. The requests have no query parameters, so even
  2492  // a site serving from a fixed file system (including a file:/// URL)
  2493  // can be a module proxy.
  2494  //
  2495  // For details on the GOPROXY protocol, see
  2496  // https://golang.org/ref/mod#goproxy-protocol.
  2497  //
  2498  //
  2499  // Import path syntax
  2500  //
  2501  // An import path (see 'go help packages') denotes a package stored in the local
  2502  // file system. In general, an import path denotes either a standard package (such
  2503  // as "unicode/utf8") or a package found in one of the work spaces (For more
  2504  // details see: 'go help gopath').
  2505  //
  2506  // Relative import paths
  2507  //
  2508  // An import path beginning with ./ or ../ is called a relative path.
  2509  // The toolchain supports relative import paths as a shortcut in two ways.
  2510  //
  2511  // First, a relative path can be used as a shorthand on the command line.
  2512  // If you are working in the directory containing the code imported as
  2513  // "unicode" and want to run the tests for "unicode/utf8", you can type
  2514  // "go test ./utf8" instead of needing to specify the full path.
  2515  // Similarly, in the reverse situation, "go test .." will test "unicode" from
  2516  // the "unicode/utf8" directory. Relative patterns are also allowed, like
  2517  // "go test ./..." to test all subdirectories. See 'go help packages' for details
  2518  // on the pattern syntax.
  2519  //
  2520  // Second, if you are compiling a Go program not in a work space,
  2521  // you can use a relative path in an import statement in that program
  2522  // to refer to nearby code also not in a work space.
  2523  // This makes it easy to experiment with small multipackage programs
  2524  // outside of the usual work spaces, but such programs cannot be
  2525  // installed with "go install" (there is no work space in which to install them),
  2526  // so they are rebuilt from scratch each time they are built.
  2527  // To avoid ambiguity, Go programs cannot use relative import paths
  2528  // within a work space.
  2529  //
  2530  // Remote import paths
  2531  //
  2532  // Certain import paths also
  2533  // describe how to obtain the source code for the package using
  2534  // a revision control system.
  2535  //
  2536  // A few common code hosting sites have special syntax:
  2537  //
  2538  // 	Bitbucket (Git, Mercurial)
  2539  //
  2540  // 		import "bitbucket.org/user/project"
  2541  // 		import "bitbucket.org/user/project/sub/directory"
  2542  //
  2543  // 	GitHub (Git)
  2544  //
  2545  // 		import "github.com/user/project"
  2546  // 		import "github.com/user/project/sub/directory"
  2547  //
  2548  // 	Launchpad (Bazaar)
  2549  //
  2550  // 		import "launchpad.net/project"
  2551  // 		import "launchpad.net/project/series"
  2552  // 		import "launchpad.net/project/series/sub/directory"
  2553  //
  2554  // 		import "launchpad.net/~user/project/branch"
  2555  // 		import "launchpad.net/~user/project/branch/sub/directory"
  2556  //
  2557  // 	IBM DevOps Services (Git)
  2558  //
  2559  // 		import "hub.jazz.net/git/user/project"
  2560  // 		import "hub.jazz.net/git/user/project/sub/directory"
  2561  //
  2562  // For code hosted on other servers, import paths may either be qualified
  2563  // with the version control type, or the go tool can dynamically fetch
  2564  // the import path over https/http and discover where the code resides
  2565  // from a <meta> tag in the HTML.
  2566  //
  2567  // To declare the code location, an import path of the form
  2568  //
  2569  // 	repository.vcs/path
  2570  //
  2571  // specifies the given repository, with or without the .vcs suffix,
  2572  // using the named version control system, and then the path inside
  2573  // that repository. The supported version control systems are:
  2574  //
  2575  // 	Bazaar      .bzr
  2576  // 	Fossil      .fossil
  2577  // 	Git         .git
  2578  // 	Mercurial   .hg
  2579  // 	Subversion  .svn
  2580  //
  2581  // For example,
  2582  //
  2583  // 	import "example.org/user/foo.hg"
  2584  //
  2585  // denotes the root directory of the Mercurial repository at
  2586  // example.org/user/foo or foo.hg, and
  2587  //
  2588  // 	import "example.org/repo.git/foo/bar"
  2589  //
  2590  // denotes the foo/bar directory of the Git repository at
  2591  // example.org/repo or repo.git.
  2592  //
  2593  // When a version control system supports multiple protocols,
  2594  // each is tried in turn when downloading. For example, a Git
  2595  // download tries https://, then git+ssh://.
  2596  //
  2597  // By default, downloads are restricted to known secure protocols
  2598  // (e.g. https, ssh). To override this setting for Git downloads, the
  2599  // GIT_ALLOW_PROTOCOL environment variable can be set (For more details see:
  2600  // 'go help environment').
  2601  //
  2602  // If the import path is not a known code hosting site and also lacks a
  2603  // version control qualifier, the go tool attempts to fetch the import
  2604  // over https/http and looks for a <meta> tag in the document's HTML
  2605  // <head>.
  2606  //
  2607  // The meta tag has the form:
  2608  //
  2609  // 	<meta name="go-import" content="import-prefix vcs repo-root">
  2610  //
  2611  // The import-prefix is the import path corresponding to the repository
  2612  // root. It must be a prefix or an exact match of the package being
  2613  // fetched with "go get". If it's not an exact match, another http
  2614  // request is made at the prefix to verify the <meta> tags match.
  2615  //
  2616  // The meta tag should appear as early in the file as possible.
  2617  // In particular, it should appear before any raw JavaScript or CSS,
  2618  // to avoid confusing the go command's restricted parser.
  2619  //
  2620  // The vcs is one of "bzr", "fossil", "git", "hg", "svn".
  2621  //
  2622  // The repo-root is the root of the version control system
  2623  // containing a scheme and not containing a .vcs qualifier.
  2624  //
  2625  // For example,
  2626  //
  2627  // 	import "example.org/pkg/foo"
  2628  //
  2629  // will result in the following requests:
  2630  //
  2631  // 	https://example.org/pkg/foo?go-get=1 (preferred)
  2632  // 	http://example.org/pkg/foo?go-get=1  (fallback, only with use of correctly set GOINSECURE)
  2633  //
  2634  // If that page contains the meta tag
  2635  //
  2636  // 	<meta name="go-import" content="example.org git https://code.org/r/p/exproj">
  2637  //
  2638  // the go tool will verify that https://example.org/?go-get=1 contains the
  2639  // same meta tag and then git clone https://code.org/r/p/exproj into
  2640  // GOPATH/src/example.org.
  2641  //
  2642  // When using GOPATH, downloaded packages are written to the first directory
  2643  // listed in the GOPATH environment variable.
  2644  // (See 'go help gopath-get' and 'go help gopath'.)
  2645  //
  2646  // When using modules, downloaded packages are stored in the module cache.
  2647  // See https://golang.org/ref/mod#module-cache.
  2648  //
  2649  // When using modules, an additional variant of the go-import meta tag is
  2650  // recognized and is preferred over those listing version control systems.
  2651  // That variant uses "mod" as the vcs in the content value, as in:
  2652  //
  2653  // 	<meta name="go-import" content="example.org mod https://code.org/moduleproxy">
  2654  //
  2655  // This tag means to fetch modules with paths beginning with example.org
  2656  // from the module proxy available at the URL https://code.org/moduleproxy.
  2657  // See https://golang.org/ref/mod#goproxy-protocol for details about the
  2658  // proxy protocol.
  2659  //
  2660  // Import path checking
  2661  //
  2662  // When the custom import path feature described above redirects to a
  2663  // known code hosting site, each of the resulting packages has two possible
  2664  // import paths, using the custom domain or the known hosting site.
  2665  //
  2666  // A package statement is said to have an "import comment" if it is immediately
  2667  // followed (before the next newline) by a comment of one of these two forms:
  2668  //
  2669  // 	package math // import "path"
  2670  // 	package math /* import "path" */
  2671  //
  2672  // The go command will refuse to install a package with an import comment
  2673  // unless it is being referred to by that import path. In this way, import comments
  2674  // let package authors make sure the custom import path is used and not a
  2675  // direct path to the underlying code hosting site.
  2676  //
  2677  // Import path checking is disabled for code found within vendor trees.
  2678  // This makes it possible to copy code into alternate locations in vendor trees
  2679  // without needing to update import comments.
  2680  //
  2681  // Import path checking is also disabled when using modules.
  2682  // Import path comments are obsoleted by the go.mod file's module statement.
  2683  //
  2684  // See https://golang.org/s/go14customimport for details.
  2685  //
  2686  //
  2687  // Modules, module versions, and more
  2688  //
  2689  // Modules are how Go manages dependencies.
  2690  //
  2691  // A module is a collection of packages that are released, versioned, and
  2692  // distributed together. Modules may be downloaded directly from version control
  2693  // repositories or from module proxy servers.
  2694  //
  2695  // For a series of tutorials on modules, see
  2696  // https://golang.org/doc/tutorial/create-module.
  2697  //
  2698  // For a detailed reference on modules, see https://golang.org/ref/mod.
  2699  //
  2700  // By default, the go command may download modules from https://proxy.golang.org.
  2701  // It may authenticate modules using the checksum database at
  2702  // https://sum.golang.org. Both services are operated by the Go team at Google.
  2703  // The privacy policies for these services are available at
  2704  // https://proxy.golang.org/privacy and https://sum.golang.org/privacy,
  2705  // respectively.
  2706  //
  2707  // The go command's download behavior may be configured using GOPROXY, GOSUMDB,
  2708  // GOPRIVATE, and other environment variables. See 'go help environment'
  2709  // and https://golang.org/ref/mod#private-module-privacy for more information.
  2710  //
  2711  //
  2712  // Module authentication using go.sum
  2713  //
  2714  // When the go command downloads a module zip file or go.mod file into the
  2715  // module cache, it computes a cryptographic hash and compares it with a known
  2716  // value to verify the file hasn't changed since it was first downloaded. Known
  2717  // hashes are stored in a file in the module root directory named go.sum. Hashes
  2718  // may also be downloaded from the checksum database depending on the values of
  2719  // GOSUMDB, GOPRIVATE, and GONOSUMDB.
  2720  //
  2721  // For details, see https://golang.org/ref/mod#authenticating.
  2722  //
  2723  //
  2724  // Package lists and patterns
  2725  //
  2726  // Many commands apply to a set of packages:
  2727  //
  2728  // 	go action [packages]
  2729  //
  2730  // Usually, [packages] is a list of import paths.
  2731  //
  2732  // An import path that is a rooted path or that begins with
  2733  // a . or .. element is interpreted as a file system path and
  2734  // denotes the package in that directory.
  2735  //
  2736  // Otherwise, the import path P denotes the package found in
  2737  // the directory DIR/src/P for some DIR listed in the GOPATH
  2738  // environment variable (For more details see: 'go help gopath').
  2739  //
  2740  // If no import paths are given, the action applies to the
  2741  // package in the current directory.
  2742  //
  2743  // There are four reserved names for paths that should not be used
  2744  // for packages to be built with the go tool:
  2745  //
  2746  // - "main" denotes the top-level package in a stand-alone executable.
  2747  //
  2748  // - "all" expands to all packages found in all the GOPATH
  2749  // trees. For example, 'go list all' lists all the packages on the local
  2750  // system. When using modules, "all" expands to all packages in
  2751  // the main module and their dependencies, including dependencies
  2752  // needed by tests of any of those.
  2753  //
  2754  // - "std" is like all but expands to just the packages in the standard
  2755  // Go library.
  2756  //
  2757  // - "cmd" expands to the Go repository's commands and their
  2758  // internal libraries.
  2759  //
  2760  // Import paths beginning with "cmd/" only match source code in
  2761  // the Go repository.
  2762  //
  2763  // An import path is a pattern if it includes one or more "..." wildcards,
  2764  // each of which can match any string, including the empty string and
  2765  // strings containing slashes. Such a pattern expands to all package
  2766  // directories found in the GOPATH trees with names matching the
  2767  // patterns.
  2768  //
  2769  // To make common patterns more convenient, there are two special cases.
  2770  // First, /... at the end of the pattern can match an empty string,
  2771  // so that net/... matches both net and packages in its subdirectories, like net/http.
  2772  // Second, any slash-separated pattern element containing a wildcard never
  2773  // participates in a match of the "vendor" element in the path of a vendored
  2774  // package, so that ./... does not match packages in subdirectories of
  2775  // ./vendor or ./mycode/vendor, but ./vendor/... and ./mycode/vendor/... do.
  2776  // Note, however, that a directory named vendor that itself contains code
  2777  // is not a vendored package: cmd/vendor would be a command named vendor,
  2778  // and the pattern cmd/... matches it.
  2779  // See golang.org/s/go15vendor for more about vendoring.
  2780  //
  2781  // An import path can also name a package to be downloaded from
  2782  // a remote repository. Run 'go help importpath' for details.
  2783  //
  2784  // Every package in a program must have a unique import path.
  2785  // By convention, this is arranged by starting each path with a
  2786  // unique prefix that belongs to you. For example, paths used
  2787  // internally at Google all begin with 'google', and paths
  2788  // denoting remote repositories begin with the path to the code,
  2789  // such as 'github.com/user/repo'.
  2790  //
  2791  // Packages in a program need not have unique package names,
  2792  // but there are two reserved package names with special meaning.
  2793  // The name main indicates a command, not a library.
  2794  // Commands are built into binaries and cannot be imported.
  2795  // The name documentation indicates documentation for
  2796  // a non-Go program in the directory. Files in package documentation
  2797  // are ignored by the go command.
  2798  //
  2799  // As a special case, if the package list is a list of .go files from a
  2800  // single directory, the command is applied to a single synthesized
  2801  // package made up of exactly those files, ignoring any build constraints
  2802  // in those files and ignoring any other files in the directory.
  2803  //
  2804  // Directory and file names that begin with "." or "_" are ignored
  2805  // by the go tool, as are directories named "testdata".
  2806  //
  2807  //
  2808  // Configuration for downloading non-public code
  2809  //
  2810  // The go command defaults to downloading modules from the public Go module
  2811  // mirror at proxy.golang.org. It also defaults to validating downloaded modules,
  2812  // regardless of source, against the public Go checksum database at sum.golang.org.
  2813  // These defaults work well for publicly available source code.
  2814  //
  2815  // The GOPRIVATE environment variable controls which modules the go command
  2816  // considers to be private (not available publicly) and should therefore not use
  2817  // the proxy or checksum database. The variable is a comma-separated list of
  2818  // glob patterns (in the syntax of Go's path.Match) of module path prefixes.
  2819  // For example,
  2820  //
  2821  // 	GOPRIVATE=*.corp.example.com,rsc.io/private
  2822  //
  2823  // causes the go command to treat as private any module with a path prefix
  2824  // matching either pattern, including git.corp.example.com/xyzzy, rsc.io/private,
  2825  // and rsc.io/private/quux.
  2826  //
  2827  // For fine-grained control over module download and validation, the GONOPROXY
  2828  // and GONOSUMDB environment variables accept the same kind of glob list
  2829  // and override GOPRIVATE for the specific decision of whether to use the proxy
  2830  // and checksum database, respectively.
  2831  //
  2832  // For example, if a company ran a module proxy serving private modules,
  2833  // users would configure go using:
  2834  //
  2835  // 	GOPRIVATE=*.corp.example.com
  2836  // 	GOPROXY=proxy.example.com
  2837  // 	GONOPROXY=none
  2838  //
  2839  // The GOPRIVATE variable is also used to define the "public" and "private"
  2840  // patterns for the GOVCS variable; see 'go help vcs'. For that usage,
  2841  // GOPRIVATE applies even in GOPATH mode. In that case, it matches import paths
  2842  // instead of module paths.
  2843  //
  2844  // The 'go env -w' command (see 'go help env') can be used to set these variables
  2845  // for future go command invocations.
  2846  //
  2847  // For more details, see https://golang.org/ref/mod#private-modules.
  2848  //
  2849  //
  2850  // Testing flags
  2851  //
  2852  // The 'go test' command takes both flags that apply to 'go test' itself
  2853  // and flags that apply to the resulting test binary.
  2854  //
  2855  // Several of the flags control profiling and write an execution profile
  2856  // suitable for "go tool pprof"; run "go tool pprof -h" for more
  2857  // information. The --alloc_space, --alloc_objects, and --show_bytes
  2858  // options of pprof control how the information is presented.
  2859  //
  2860  // The following flags are recognized by the 'go test' command and
  2861  // control the execution of any test:
  2862  //
  2863  // 	-bench regexp
  2864  // 	    Run only those benchmarks matching a regular expression.
  2865  // 	    By default, no benchmarks are run.
  2866  // 	    To run all benchmarks, use '-bench .' or '-bench=.'.
  2867  // 	    The regular expression is split by unbracketed slash (/)
  2868  // 	    characters into a sequence of regular expressions, and each
  2869  // 	    part of a benchmark's identifier must match the corresponding
  2870  // 	    element in the sequence, if any. Possible parents of matches
  2871  // 	    are run with b.N=1 to identify sub-benchmarks. For example,
  2872  // 	    given -bench=X/Y, top-level benchmarks matching X are run
  2873  // 	    with b.N=1 to find any sub-benchmarks matching Y, which are
  2874  // 	    then run in full.
  2875  //
  2876  // 	-benchtime t
  2877  // 	    Run enough iterations of each benchmark to take t, specified
  2878  // 	    as a time.Duration (for example, -benchtime 1h30s).
  2879  // 	    The default is 1 second (1s).
  2880  // 	    The special syntax Nx means to run the benchmark N times
  2881  // 	    (for example, -benchtime 100x).
  2882  //
  2883  // 	-count n
  2884  // 	    Run each test, benchmark, and fuzz seed n times (default 1).
  2885  // 	    If -cpu is set, run n times for each GOMAXPROCS value.
  2886  // 	    Examples are always run once. -count does not apply to
  2887  // 	    fuzz tests matched by -fuzz.
  2888  //
  2889  // 	-cover
  2890  // 	    Enable coverage analysis.
  2891  // 	    Note that because coverage works by annotating the source
  2892  // 	    code before compilation, compilation and test failures with
  2893  // 	    coverage enabled may report line numbers that don't correspond
  2894  // 	    to the original sources.
  2895  //
  2896  // 	-covermode set,count,atomic
  2897  // 	    Set the mode for coverage analysis for the package[s]
  2898  // 	    being tested. The default is "set" unless -race is enabled,
  2899  // 	    in which case it is "atomic".
  2900  // 	    The values:
  2901  // 		set: bool: does this statement run?
  2902  // 		count: int: how many times does this statement run?
  2903  // 		atomic: int: count, but correct in multithreaded tests;
  2904  // 			significantly more expensive.
  2905  // 	    Sets -cover.
  2906  //
  2907  // 	-coverpkg pattern1,pattern2,pattern3
  2908  // 	    Apply coverage analysis in each test to packages matching the patterns.
  2909  // 	    The default is for each test to analyze only the package being tested.
  2910  // 	    See 'go help packages' for a description of package patterns.
  2911  // 	    Sets -cover.
  2912  //
  2913  // 	-cpu 1,2,4
  2914  // 	    Specify a list of GOMAXPROCS values for which the tests, benchmarks or
  2915  // 	    fuzz tests should be executed. The default is the current value
  2916  // 	    of GOMAXPROCS. -cpu does not apply to fuzz tests matched by -fuzz.
  2917  //
  2918  // 	-failfast
  2919  // 	    Do not start new tests after the first test failure.
  2920  //
  2921  // 	-fuzz regexp
  2922  // 	    Run the fuzz test matching the regular expression. When specified,
  2923  // 	    the command line argument must match exactly one package within the
  2924  // 	    main module, and regexp must match exactly one fuzz test within
  2925  // 	    that package. Fuzzing will occur after tests, benchmarks, seed corpora
  2926  // 	    of other fuzz tests, and examples have completed. See the Fuzzing
  2927  // 	    section of the testing package documentation for details.
  2928  //
  2929  // 	-fuzztime t
  2930  // 	    Run enough iterations of the fuzz target during fuzzing to take t,
  2931  // 	    specified as a time.Duration (for example, -fuzztime 1h30s).
  2932  // 		The default is to run forever.
  2933  // 	    The special syntax Nx means to run the fuzz target N times
  2934  // 	    (for example, -fuzztime 1000x).
  2935  //
  2936  // 	-fuzzminimizetime t
  2937  // 	    Run enough iterations of the fuzz target during each minimization
  2938  // 	    attempt to take t, as specified as a time.Duration (for example,
  2939  // 	    -fuzzminimizetime 30s).
  2940  // 		The default is 60s.
  2941  // 	    The special syntax Nx means to run the fuzz target N times
  2942  // 	    (for example, -fuzzminimizetime 100x).
  2943  //
  2944  // 	-json
  2945  // 	    Log verbose output and test results in JSON. This presents the
  2946  // 	    same information as the -v flag in a machine-readable format.
  2947  //
  2948  // 	-list regexp
  2949  // 	    List tests, benchmarks, fuzz tests, or examples matching the regular
  2950  // 	    expression. No tests, benchmarks, fuzz tests, or examples will be run.
  2951  // 	    This will only list top-level tests. No subtest or subbenchmarks will be
  2952  // 	    shown.
  2953  //
  2954  // 	-parallel n
  2955  // 	    Allow parallel execution of test functions that call t.Parallel, and
  2956  // 	    fuzz targets that call t.Parallel when running the seed corpus.
  2957  // 	    The value of this flag is the maximum number of tests to run
  2958  // 	    simultaneously.
  2959  // 	    While fuzzing, the value of this flag is the maximum number of
  2960  // 	    subprocesses that may call the fuzz function simultaneously, regardless of
  2961  // 	    whether T.Parallel is called.
  2962  // 	    By default, -parallel is set to the value of GOMAXPROCS.
  2963  // 	    Setting -parallel to values higher than GOMAXPROCS may cause degraded
  2964  // 	    performance due to CPU contention, especially when fuzzing.
  2965  // 	    Note that -parallel only applies within a single test binary.
  2966  // 	    The 'go test' command may run tests for different packages
  2967  // 	    in parallel as well, according to the setting of the -p flag
  2968  // 	    (see 'go help build').
  2969  //
  2970  // 	-run regexp
  2971  // 	    Run only those tests, examples, and fuzz tests matching the regular
  2972  // 	    expression. For tests, the regular expression is split by unbracketed
  2973  // 	    slash (/) characters into a sequence of regular expressions, and each
  2974  // 	    part of a test's identifier must match the corresponding element in
  2975  // 	    the sequence, if any. Note that possible parents of matches are
  2976  // 	    run too, so that -run=X/Y matches and runs and reports the result
  2977  // 	    of all tests matching X, even those without sub-tests matching Y,
  2978  // 	    because it must run them to look for those sub-tests.
  2979  //
  2980  // 	-short
  2981  // 	    Tell long-running tests to shorten their run time.
  2982  // 	    It is off by default but set during all.bash so that installing
  2983  // 	    the Go tree can run a sanity check but not spend time running
  2984  // 	    exhaustive tests.
  2985  //
  2986  // 	-shuffle off,on,N
  2987  // 	    Randomize the execution order of tests and benchmarks.
  2988  // 	    It is off by default. If -shuffle is set to on, then it will seed
  2989  // 	    the randomizer using the system clock. If -shuffle is set to an
  2990  // 	    integer N, then N will be used as the seed value. In both cases,
  2991  // 	    the seed will be reported for reproducibility.
  2992  //
  2993  // 	-timeout d
  2994  // 	    If a test binary runs longer than duration d, panic.
  2995  // 	    If d is 0, the timeout is disabled.
  2996  // 	    The default is 10 minutes (10m).
  2997  //
  2998  // 	-v
  2999  // 	    Verbose output: log all tests as they are run. Also print all
  3000  // 	    text from Log and Logf calls even if the test succeeds.
  3001  //
  3002  // 	-vet list
  3003  // 	    Configure the invocation of "go vet" during "go test"
  3004  // 	    to use the comma-separated list of vet checks.
  3005  // 	    If list is empty, "go test" runs "go vet" with a curated list of
  3006  // 	    checks believed to be always worth addressing.
  3007  // 	    If list is "off", "go test" does not run "go vet" at all.
  3008  //
  3009  // The following flags are also recognized by 'go test' and can be used to
  3010  // profile the tests during execution:
  3011  //
  3012  // 	-benchmem
  3013  // 	    Print memory allocation statistics for benchmarks.
  3014  //
  3015  // 	-blockprofile block.out
  3016  // 	    Write a goroutine blocking profile to the specified file
  3017  // 	    when all tests are complete.
  3018  // 	    Writes test binary as -c would.
  3019  //
  3020  // 	-blockprofilerate n
  3021  // 	    Control the detail provided in goroutine blocking profiles by
  3022  // 	    calling runtime.SetBlockProfileRate with n.
  3023  // 	    See 'go doc runtime.SetBlockProfileRate'.
  3024  // 	    The profiler aims to sample, on average, one blocking event every
  3025  // 	    n nanoseconds the program spends blocked. By default,
  3026  // 	    if -test.blockprofile is set without this flag, all blocking events
  3027  // 	    are recorded, equivalent to -test.blockprofilerate=1.
  3028  //
  3029  // 	-coverprofile cover.out
  3030  // 	    Write a coverage profile to the file after all tests have passed.
  3031  // 	    Sets -cover.
  3032  //
  3033  // 	-cpuprofile cpu.out
  3034  // 	    Write a CPU profile to the specified file before exiting.
  3035  // 	    Writes test binary as -c would.
  3036  //
  3037  // 	-memprofile mem.out
  3038  // 	    Write an allocation profile to the file after all tests have passed.
  3039  // 	    Writes test binary as -c would.
  3040  //
  3041  // 	-memprofilerate n
  3042  // 	    Enable more precise (and expensive) memory allocation profiles by
  3043  // 	    setting runtime.MemProfileRate. See 'go doc runtime.MemProfileRate'.
  3044  // 	    To profile all memory allocations, use -test.memprofilerate=1.
  3045  //
  3046  // 	-mutexprofile mutex.out
  3047  // 	    Write a mutex contention profile to the specified file
  3048  // 	    when all tests are complete.
  3049  // 	    Writes test binary as -c would.
  3050  //
  3051  // 	-mutexprofilefraction n
  3052  // 	    Sample 1 in n stack traces of goroutines holding a
  3053  // 	    contended mutex.
  3054  //
  3055  // 	-outputdir directory
  3056  // 	    Place output files from profiling in the specified directory,
  3057  // 	    by default the directory in which "go test" is running.
  3058  //
  3059  // 	-trace trace.out
  3060  // 	    Write an execution trace to the specified file before exiting.
  3061  //
  3062  // Each of these flags is also recognized with an optional 'test.' prefix,
  3063  // as in -test.v. When invoking the generated test binary (the result of
  3064  // 'go test -c') directly, however, the prefix is mandatory.
  3065  //
  3066  // The 'go test' command rewrites or removes recognized flags,
  3067  // as appropriate, both before and after the optional package list,
  3068  // before invoking the test binary.
  3069  //
  3070  // For instance, the command
  3071  //
  3072  // 	go test -v -myflag testdata -cpuprofile=prof.out -x
  3073  //
  3074  // will compile the test binary and then run it as
  3075  //
  3076  // 	pkg.test -test.v -myflag testdata -test.cpuprofile=prof.out
  3077  //
  3078  // (The -x flag is removed because it applies only to the go command's
  3079  // execution, not to the test itself.)
  3080  //
  3081  // The test flags that generate profiles (other than for coverage) also
  3082  // leave the test binary in pkg.test for use when analyzing the profiles.
  3083  //
  3084  // When 'go test' runs a test binary, it does so from within the
  3085  // corresponding package's source code directory. Depending on the test,
  3086  // it may be necessary to do the same when invoking a generated test
  3087  // binary directly. Because that directory may be located within the
  3088  // module cache, which may be read-only and is verified by checksums, the
  3089  // test must not write to it or any other directory within the module
  3090  // unless explicitly requested by the user (such as with the -fuzz flag,
  3091  // which writes failures to testdata/fuzz).
  3092  //
  3093  // The command-line package list, if present, must appear before any
  3094  // flag not known to the go test command. Continuing the example above,
  3095  // the package list would have to appear before -myflag, but could appear
  3096  // on either side of -v.
  3097  //
  3098  // When 'go test' runs in package list mode, 'go test' caches successful
  3099  // package test results to avoid unnecessary repeated running of tests. To
  3100  // disable test caching, use any test flag or argument other than the
  3101  // cacheable flags. The idiomatic way to disable test caching explicitly
  3102  // is to use -count=1.
  3103  //
  3104  // To keep an argument for a test binary from being interpreted as a
  3105  // known flag or a package name, use -args (see 'go help test') which
  3106  // passes the remainder of the command line through to the test binary
  3107  // uninterpreted and unaltered.
  3108  //
  3109  // For instance, the command
  3110  //
  3111  // 	go test -v -args -x -v
  3112  //
  3113  // will compile the test binary and then run it as
  3114  //
  3115  // 	pkg.test -test.v -x -v
  3116  //
  3117  // Similarly,
  3118  //
  3119  // 	go test -args math
  3120  //
  3121  // will compile the test binary and then run it as
  3122  //
  3123  // 	pkg.test math
  3124  //
  3125  // In the first example, the -x and the second -v are passed through to the
  3126  // test binary unchanged and with no effect on the go command itself.
  3127  // In the second example, the argument math is passed through to the test
  3128  // binary, instead of being interpreted as the package list.
  3129  //
  3130  //
  3131  // Testing functions
  3132  //
  3133  // The 'go test' command expects to find test, benchmark, and example functions
  3134  // in the "*_test.go" files corresponding to the package under test.
  3135  //
  3136  // A test function is one named TestXxx (where Xxx does not start with a
  3137  // lower case letter) and should have the signature,
  3138  //
  3139  // 	func TestXxx(t *testing.T) { ... }
  3140  //
  3141  // A benchmark function is one named BenchmarkXxx and should have the signature,
  3142  //
  3143  // 	func BenchmarkXxx(b *testing.B) { ... }
  3144  //
  3145  // A fuzz test is one named FuzzXxx and should have the signature,
  3146  //
  3147  // 	func FuzzXxx(f *testing.F) { ... }
  3148  //
  3149  // An example function is similar to a test function but, instead of using
  3150  // *testing.T to report success or failure, prints output to os.Stdout.
  3151  // If the last comment in the function starts with "Output:" then the output
  3152  // is compared exactly against the comment (see examples below). If the last
  3153  // comment begins with "Unordered output:" then the output is compared to the
  3154  // comment, however the order of the lines is ignored. An example with no such
  3155  // comment is compiled but not executed. An example with no text after
  3156  // "Output:" is compiled, executed, and expected to produce no output.
  3157  //
  3158  // Godoc displays the body of ExampleXxx to demonstrate the use
  3159  // of the function, constant, or variable Xxx. An example of a method M with
  3160  // receiver type T or *T is named ExampleT_M. There may be multiple examples
  3161  // for a given function, constant, or variable, distinguished by a trailing _xxx,
  3162  // where xxx is a suffix not beginning with an upper case letter.
  3163  //
  3164  // Here is an example of an example:
  3165  //
  3166  // 	func ExamplePrintln() {
  3167  // 		Println("The output of\nthis example.")
  3168  // 		// Output: The output of
  3169  // 		// this example.
  3170  // 	}
  3171  //
  3172  // Here is another example where the ordering of the output is ignored:
  3173  //
  3174  // 	func ExamplePerm() {
  3175  // 		for _, value := range Perm(4) {
  3176  // 			fmt.Println(value)
  3177  // 		}
  3178  //
  3179  // 		// Unordered output: 4
  3180  // 		// 2
  3181  // 		// 1
  3182  // 		// 3
  3183  // 		// 0
  3184  // 	}
  3185  //
  3186  // The entire test file is presented as the example when it contains a single
  3187  // example function, at least one other function, type, variable, or constant
  3188  // declaration, and no tests, benchmarks, or fuzz tests.
  3189  //
  3190  // See the documentation of the testing package for more information.
  3191  //
  3192  //
  3193  // Controlling version control with GOVCS
  3194  //
  3195  // The 'go get' command can run version control commands like git
  3196  // to download imported code. This functionality is critical to the decentralized
  3197  // Go package ecosystem, in which code can be imported from any server,
  3198  // but it is also a potential security problem, if a malicious server finds a
  3199  // way to cause the invoked version control command to run unintended code.
  3200  //
  3201  // To balance the functionality and security concerns, the 'go get' command
  3202  // by default will only use git and hg to download code from public servers.
  3203  // But it will use any known version control system (bzr, fossil, git, hg, svn)
  3204  // to download code from private servers, defined as those hosting packages
  3205  // matching the GOPRIVATE variable (see 'go help private'). The rationale behind
  3206  // allowing only Git and Mercurial is that these two systems have had the most
  3207  // attention to issues of being run as clients of untrusted servers. In contrast,
  3208  // Bazaar, Fossil, and Subversion have primarily been used in trusted,
  3209  // authenticated environments and are not as well scrutinized as attack surfaces.
  3210  //
  3211  // The version control command restrictions only apply when using direct version
  3212  // control access to download code. When downloading modules from a proxy,
  3213  // 'go get' uses the proxy protocol instead, which is always permitted.
  3214  // By default, the 'go get' command uses the Go module mirror (proxy.golang.org)
  3215  // for public packages and only falls back to version control for private
  3216  // packages or when the mirror refuses to serve a public package (typically for
  3217  // legal reasons). Therefore, clients can still access public code served from
  3218  // Bazaar, Fossil, or Subversion repositories by default, because those downloads
  3219  // use the Go module mirror, which takes on the security risk of running the
  3220  // version control commands using a custom sandbox.
  3221  //
  3222  // The GOVCS variable can be used to change the allowed version control systems
  3223  // for specific packages (identified by a module or import path).
  3224  // The GOVCS variable applies when building package in both module-aware mode
  3225  // and GOPATH mode. When using modules, the patterns match against the module path.
  3226  // When using GOPATH, the patterns match against the import path corresponding to
  3227  // the root of the version control repository.
  3228  //
  3229  // The general form of the GOVCS setting is a comma-separated list of
  3230  // pattern:vcslist rules. The pattern is a glob pattern that must match
  3231  // one or more leading elements of the module or import path. The vcslist
  3232  // is a pipe-separated list of allowed version control commands, or "all"
  3233  // to allow use of any known command, or "off" to disallow all commands.
  3234  // Note that if a module matches a pattern with vcslist "off", it may still be
  3235  // downloaded if the origin server uses the "mod" scheme, which instructs the
  3236  // go command to download the module using the GOPROXY protocol.
  3237  // The earliest matching pattern in the list applies, even if later patterns
  3238  // might also match.
  3239  //
  3240  // For example, consider:
  3241  //
  3242  // 	GOVCS=github.com:git,evil.com:off,*:git|hg
  3243  //
  3244  // With this setting, code with a module or import path beginning with
  3245  // github.com/ can only use git; paths on evil.com cannot use any version
  3246  // control command, and all other paths (* matches everything) can use
  3247  // only git or hg.
  3248  //
  3249  // The special patterns "public" and "private" match public and private
  3250  // module or import paths. A path is private if it matches the GOPRIVATE
  3251  // variable; otherwise it is public.
  3252  //
  3253  // If no rules in the GOVCS variable match a particular module or import path,
  3254  // the 'go get' command applies its default rule, which can now be summarized
  3255  // in GOVCS notation as 'public:git|hg,private:all'.
  3256  //
  3257  // To allow unfettered use of any version control system for any package, use:
  3258  //
  3259  // 	GOVCS=*:all
  3260  //
  3261  // To disable all use of version control, use:
  3262  //
  3263  // 	GOVCS=*:off
  3264  //
  3265  // The 'go env -w' command (see 'go help env') can be used to set the GOVCS
  3266  // variable for future go command invocations.
  3267  //
  3268  //
  3269  package main
  3270  

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