github.com/dannin/go@v0.0.0-20161031215817-d35dfd405eaa/src/cmd/go/alldocs.go (about)

     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  // DO NOT EDIT THIS FILE. GENERATED BY mkalldocs.sh.
     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  // 	build       compile packages and dependencies
    17  // 	clean       remove object files
    18  // 	doc         show documentation for package or symbol
    19  // 	env         print Go environment information
    20  // 	bug         print information for bug reports
    21  // 	fix         run go tool fix on packages
    22  // 	fmt         run gofmt on package sources
    23  // 	generate    generate Go files by processing source
    24  // 	get         download and install packages and dependencies
    25  // 	install     compile and install packages and dependencies
    26  // 	list        list packages
    27  // 	run         compile and run Go program
    28  // 	test        test packages
    29  // 	tool        run specified go tool
    30  // 	version     print Go version
    31  // 	vet         run go tool vet on packages
    32  //
    33  // Use "go help [command]" for more information about a command.
    34  //
    35  // Additional help topics:
    36  //
    37  // 	c           calling between Go and C
    38  // 	buildmode   description of build modes
    39  // 	filetype    file types
    40  // 	gopath      GOPATH environment variable
    41  // 	environment environment variables
    42  // 	importpath  import path syntax
    43  // 	packages    description of package lists
    44  // 	testflag    description of testing flags
    45  // 	testfunc    description of testing functions
    46  //
    47  // Use "go help [topic]" for more information about that topic.
    48  //
    49  //
    50  // Compile packages and dependencies
    51  //
    52  // Usage:
    53  //
    54  // 	go build [-o output] [-i] [build flags] [packages]
    55  //
    56  // Build compiles the packages named by the import paths,
    57  // along with their dependencies, but it does not install the results.
    58  //
    59  // If the arguments to build are a list of .go files, build treats
    60  // them as a list of source files specifying a single package.
    61  //
    62  // When compiling a single main package, build writes
    63  // the resulting executable to an output file named after
    64  // the first source file ('go build ed.go rx.go' writes 'ed' or 'ed.exe')
    65  // or the source code directory ('go build unix/sam' writes 'sam' or 'sam.exe').
    66  // The '.exe' suffix is added when writing a Windows executable.
    67  //
    68  // When compiling multiple packages or a single non-main package,
    69  // build compiles the packages but discards the resulting object,
    70  // serving only as a check that the packages can be built.
    71  //
    72  // When compiling packages, build ignores files that end in '_test.go'.
    73  //
    74  // The -o flag, only allowed when compiling a single package,
    75  // forces build to write the resulting executable or object
    76  // to the named output file, instead of the default behavior described
    77  // in the last two paragraphs.
    78  //
    79  // The -i flag installs the packages that are dependencies of the target.
    80  //
    81  // The build flags are shared by the build, clean, get, install, list, run,
    82  // and test commands:
    83  //
    84  // 	-a
    85  // 		force rebuilding of packages that are already up-to-date.
    86  // 	-n
    87  // 		print the commands but do not run them.
    88  // 	-p n
    89  // 		the number of programs, such as build commands or
    90  // 		test binaries, that can be run in parallel.
    91  // 		The default is the number of CPUs available.
    92  // 	-race
    93  // 		enable data race detection.
    94  // 		Supported only on linux/amd64, freebsd/amd64, darwin/amd64 and windows/amd64.
    95  // 	-msan
    96  // 		enable interoperation with memory sanitizer.
    97  // 		Supported only on linux/amd64,
    98  // 		and only with Clang/LLVM as the host C compiler.
    99  // 	-v
   100  // 		print the names of packages as they are compiled.
   101  // 	-work
   102  // 		print the name of the temporary work directory and
   103  // 		do not delete it when exiting.
   104  // 	-x
   105  // 		print the commands.
   106  //
   107  // 	-asmflags 'flag list'
   108  // 		arguments to pass on each go tool asm invocation.
   109  // 	-buildmode mode
   110  // 		build mode to use. See 'go help buildmode' for more.
   111  // 	-compiler name
   112  // 		name of compiler to use, as in runtime.Compiler (gccgo or gc).
   113  // 	-gccgoflags 'arg list'
   114  // 		arguments to pass on each gccgo compiler/linker invocation.
   115  // 	-gcflags 'arg list'
   116  // 		arguments to pass on each go tool compile invocation.
   117  // 	-installsuffix suffix
   118  // 		a suffix to use in the name of the package installation directory,
   119  // 		in order to keep output separate from default builds.
   120  // 		If using the -race flag, the install suffix is automatically set to race
   121  // 		or, if set explicitly, has _race appended to it.  Likewise for the -msan
   122  // 		flag.  Using a -buildmode option that requires non-default compile flags
   123  // 		has a similar effect.
   124  // 	-ldflags 'flag list'
   125  // 		arguments to pass on each go tool link invocation.
   126  // 	-linkshared
   127  // 		link against shared libraries previously created with
   128  // 		-buildmode=shared.
   129  // 	-pkgdir dir
   130  // 		install and load all packages from dir instead of the usual locations.
   131  // 		For example, when building with a non-standard configuration,
   132  // 		use -pkgdir to keep generated packages in a separate location.
   133  // 	-tags 'tag list'
   134  // 		a list of build tags to consider satisfied during the build.
   135  // 		For more information about build tags, see the description of
   136  // 		build constraints in the documentation for the go/build package.
   137  // 	-toolexec 'cmd args'
   138  // 		a program to use to invoke toolchain programs like vet and asm.
   139  // 		For example, instead of running asm, the go command will run
   140  // 		'cmd args /path/to/asm <arguments for asm>'.
   141  //
   142  // The list flags accept a space-separated list of strings. To embed spaces
   143  // in an element in the list, surround it with either single or double quotes.
   144  //
   145  // For more about specifying packages, see 'go help packages'.
   146  // For more about where packages and binaries are installed,
   147  // run 'go help gopath'.
   148  // For more about calling between Go and C/C++, run 'go help c'.
   149  //
   150  // Note: Build adheres to certain conventions such as those described
   151  // by 'go help gopath'. Not all projects can follow these conventions,
   152  // however. Installations that have their own conventions or that use
   153  // a separate software build system may choose to use lower-level
   154  // invocations such as 'go tool compile' and 'go tool link' to avoid
   155  // some of the overheads and design decisions of the build tool.
   156  //
   157  // See also: go install, go get, go clean.
   158  //
   159  //
   160  // Remove object files
   161  //
   162  // Usage:
   163  //
   164  // 	go clean [-i] [-r] [-n] [-x] [build flags] [packages]
   165  //
   166  // Clean removes object files from package source directories.
   167  // The go command builds most objects in a temporary directory,
   168  // so go clean is mainly concerned with object files left by other
   169  // tools or by manual invocations of go build.
   170  //
   171  // Specifically, clean removes the following files from each of the
   172  // source directories corresponding to the import paths:
   173  //
   174  // 	_obj/            old object directory, left from Makefiles
   175  // 	_test/           old test directory, left from Makefiles
   176  // 	_testmain.go     old gotest file, left from Makefiles
   177  // 	test.out         old test log, left from Makefiles
   178  // 	build.out        old test log, left from Makefiles
   179  // 	*.[568ao]        object files, left from Makefiles
   180  //
   181  // 	DIR(.exe)        from go build
   182  // 	DIR.test(.exe)   from go test -c
   183  // 	MAINFILE(.exe)   from go build MAINFILE.go
   184  // 	*.so             from SWIG
   185  //
   186  // In the list, DIR represents the final path element of the
   187  // directory, and MAINFILE is the base name of any Go source
   188  // file in the directory that is not included when building
   189  // the package.
   190  //
   191  // The -i flag causes clean to remove the corresponding installed
   192  // archive or binary (what 'go install' would create).
   193  //
   194  // The -n flag causes clean to print the remove commands it would execute,
   195  // but not run them.
   196  //
   197  // The -r flag causes clean to be applied recursively to all the
   198  // dependencies of the packages named by the import paths.
   199  //
   200  // The -x flag causes clean to print remove commands as it executes them.
   201  //
   202  // For more about build flags, see 'go help build'.
   203  //
   204  // For more about specifying packages, see 'go help packages'.
   205  //
   206  //
   207  // Show documentation for package or symbol
   208  //
   209  // Usage:
   210  //
   211  // 	go doc [-u] [-c] [package|[package.]symbol[.method]]
   212  //
   213  // Doc prints the documentation comments associated with the item identified by its
   214  // arguments (a package, const, func, type, var, or method) followed by a one-line
   215  // summary of each of the first-level items "under" that item (package-level
   216  // declarations for a package, methods for a type, etc.).
   217  //
   218  // Doc accepts zero, one, or two arguments.
   219  //
   220  // Given no arguments, that is, when run as
   221  //
   222  // 	go doc
   223  //
   224  // it prints the package documentation for the package in the current directory.
   225  // If the package is a command (package main), the exported symbols of the package
   226  // are elided from the presentation unless the -cmd flag is provided.
   227  //
   228  // When run with one argument, the argument is treated as a Go-syntax-like
   229  // representation of the item to be documented. What the argument selects depends
   230  // on what is installed in GOROOT and GOPATH, as well as the form of the argument,
   231  // which is schematically one of these:
   232  //
   233  // 	go doc <pkg>
   234  // 	go doc <sym>[.<method>]
   235  // 	go doc [<pkg>.]<sym>[.<method>]
   236  // 	go doc [<pkg>.][<sym>.]<method>
   237  //
   238  // The first item in this list matched by the argument is the one whose documentation
   239  // is printed. (See the examples below.) However, if the argument starts with a capital
   240  // letter it is assumed to identify a symbol or method in the current directory.
   241  //
   242  // For packages, the order of scanning is determined lexically in breadth-first order.
   243  // That is, the package presented is the one that matches the search and is nearest
   244  // the root and lexically first at its level of the hierarchy.  The GOROOT tree is
   245  // always scanned in its entirety before GOPATH.
   246  //
   247  // If there is no package specified or matched, the package in the current
   248  // directory is selected, so "go doc Foo" shows the documentation for symbol Foo in
   249  // the current package.
   250  //
   251  // The package path must be either a qualified path or a proper suffix of a
   252  // path. The go tool's usual package mechanism does not apply: package path
   253  // elements like . and ... are not implemented by go doc.
   254  //
   255  // When run with two arguments, the first must be a full package path (not just a
   256  // suffix), and the second is a symbol or symbol and method; this is similar to the
   257  // syntax accepted by godoc:
   258  //
   259  // 	go doc <pkg> <sym>[.<method>]
   260  //
   261  // In all forms, when matching symbols, lower-case letters in the argument match
   262  // either case but upper-case letters match exactly. This means that there may be
   263  // multiple matches of a lower-case argument in a package if different symbols have
   264  // different cases. If this occurs, documentation for all matches is printed.
   265  //
   266  // Examples:
   267  // 	go doc
   268  // 		Show documentation for current package.
   269  // 	go doc Foo
   270  // 		Show documentation for Foo in the current package.
   271  // 		(Foo starts with a capital letter so it cannot match
   272  // 		a package path.)
   273  // 	go doc encoding/json
   274  // 		Show documentation for the encoding/json package.
   275  // 	go doc json
   276  // 		Shorthand for encoding/json.
   277  // 	go doc json.Number (or go doc json.number)
   278  // 		Show documentation and method summary for json.Number.
   279  // 	go doc json.Number.Int64 (or go doc json.number.int64)
   280  // 		Show documentation for json.Number's Int64 method.
   281  // 	go doc cmd/doc
   282  // 		Show package docs for the doc command.
   283  // 	go doc -cmd cmd/doc
   284  // 		Show package docs and exported symbols within the doc command.
   285  // 	go doc template.new
   286  // 		Show documentation for html/template's New function.
   287  // 		(html/template is lexically before text/template)
   288  // 	go doc text/template.new # One argument
   289  // 		Show documentation for text/template's New function.
   290  // 	go doc text/template new # Two arguments
   291  // 		Show documentation for text/template's New function.
   292  //
   293  // 	At least in the current tree, these invocations all print the
   294  // 	documentation for json.Decoder's Decode method:
   295  //
   296  // 	go doc json.Decoder.Decode
   297  // 	go doc json.decoder.decode
   298  // 	go doc json.decode
   299  // 	cd go/src/encoding/json; go doc decode
   300  //
   301  // Flags:
   302  // 	-c
   303  // 		Respect case when matching symbols.
   304  // 	-cmd
   305  // 		Treat a command (package main) like a regular package.
   306  // 		Otherwise package main's exported symbols are hidden
   307  // 		when showing the package's top-level documentation.
   308  // 	-u
   309  // 		Show documentation for unexported as well as exported
   310  // 		symbols and methods.
   311  //
   312  //
   313  // Print Go environment information
   314  //
   315  // Usage:
   316  //
   317  // 	go env [var ...]
   318  //
   319  // Env prints Go environment information.
   320  //
   321  // By default env prints information as a shell script
   322  // (on Windows, a batch file).  If one or more variable
   323  // names is given as arguments,  env prints the value of
   324  // each named variable on its own line.
   325  //
   326  //
   327  // Print information for bug reports
   328  //
   329  // Usage:
   330  //
   331  // 	go bug
   332  //
   333  // Bug prints information that helps file effective bug reports.
   334  //
   335  // Bugs may be reported at https://golang.org/issue/new.
   336  //
   337  //
   338  // Run go tool fix on packages
   339  //
   340  // Usage:
   341  //
   342  // 	go fix [packages]
   343  //
   344  // Fix runs the Go fix command on the packages named by the import paths.
   345  //
   346  // For more about fix, see 'go doc cmd/fix'.
   347  // For more about specifying packages, see 'go help packages'.
   348  //
   349  // To run fix with specific options, run 'go tool fix'.
   350  //
   351  // See also: go fmt, go vet.
   352  //
   353  //
   354  // Run gofmt on package sources
   355  //
   356  // Usage:
   357  //
   358  // 	go fmt [-n] [-x] [packages]
   359  //
   360  // Fmt runs the command 'gofmt -l -w' on the packages named
   361  // by the import paths.  It prints the names of the files that are modified.
   362  //
   363  // For more about gofmt, see 'go doc cmd/gofmt'.
   364  // For more about specifying packages, see 'go help packages'.
   365  //
   366  // The -n flag prints commands that would be executed.
   367  // The -x flag prints commands as they are executed.
   368  //
   369  // To run gofmt with specific options, run gofmt itself.
   370  //
   371  // See also: go fix, go vet.
   372  //
   373  //
   374  // Generate Go files by processing source
   375  //
   376  // Usage:
   377  //
   378  // 	go generate [-run regexp] [-n] [-v] [-x] [build flags] [file.go... | packages]
   379  //
   380  // Generate runs commands described by directives within existing
   381  // files. Those commands can run any process but the intent is to
   382  // create or update Go source files.
   383  //
   384  // Go generate is never run automatically by go build, go get, go test,
   385  // and so on. It must be run explicitly.
   386  //
   387  // Go generate scans the file for directives, which are lines of
   388  // the form,
   389  //
   390  // 	//go:generate command argument...
   391  //
   392  // (note: no leading spaces and no space in "//go") where command
   393  // is the generator to be run, corresponding to an executable file
   394  // that can be run locally. It must either be in the shell path
   395  // (gofmt), a fully qualified path (/usr/you/bin/mytool), or a
   396  // command alias, described below.
   397  //
   398  // Note that go generate does not parse the file, so lines that look
   399  // like directives in comments or multiline strings will be treated
   400  // as directives.
   401  //
   402  // The arguments to the directive are space-separated tokens or
   403  // double-quoted strings passed to the generator as individual
   404  // arguments when it is run.
   405  //
   406  // Quoted strings use Go syntax and are evaluated before execution; a
   407  // quoted string appears as a single argument to the generator.
   408  //
   409  // Go generate sets several variables when it runs the generator:
   410  //
   411  // 	$GOARCH
   412  // 		The execution architecture (arm, amd64, etc.)
   413  // 	$GOOS
   414  // 		The execution operating system (linux, windows, etc.)
   415  // 	$GOFILE
   416  // 		The base name of the file.
   417  // 	$GOLINE
   418  // 		The line number of the directive in the source file.
   419  // 	$GOPACKAGE
   420  // 		The name of the package of the file containing the directive.
   421  // 	$DOLLAR
   422  // 		A dollar sign.
   423  //
   424  // Other than variable substitution and quoted-string evaluation, no
   425  // special processing such as "globbing" is performed on the command
   426  // line.
   427  //
   428  // As a last step before running the command, any invocations of any
   429  // environment variables with alphanumeric names, such as $GOFILE or
   430  // $HOME, are expanded throughout the command line. The syntax for
   431  // variable expansion is $NAME on all operating systems.  Due to the
   432  // order of evaluation, variables are expanded even inside quoted
   433  // strings. If the variable NAME is not set, $NAME expands to the
   434  // empty string.
   435  //
   436  // A directive of the form,
   437  //
   438  // 	//go:generate -command xxx args...
   439  //
   440  // specifies, for the remainder of this source file only, that the
   441  // string xxx represents the command identified by the arguments. This
   442  // can be used to create aliases or to handle multiword generators.
   443  // For example,
   444  //
   445  // 	//go:generate -command foo go tool foo
   446  //
   447  // specifies that the command "foo" represents the generator
   448  // "go tool foo".
   449  //
   450  // Generate processes packages in the order given on the command line,
   451  // one at a time. If the command line lists .go files, they are treated
   452  // as a single package. Within a package, generate processes the
   453  // source files in a package in file name order, one at a time. Within
   454  // a source file, generate runs generators in the order they appear
   455  // in the file, one at a time.
   456  //
   457  // If any generator returns an error exit status, "go generate" skips
   458  // all further processing for that package.
   459  //
   460  // The generator is run in the package's source directory.
   461  //
   462  // Go generate accepts one specific flag:
   463  //
   464  // 	-run=""
   465  // 		if non-empty, specifies a regular expression to select
   466  // 		directives whose full original source text (excluding
   467  // 		any trailing spaces and final newline) matches the
   468  // 		expression.
   469  //
   470  // It also accepts the standard build flags including -v, -n, and -x.
   471  // The -v flag prints the names of packages and files as they are
   472  // processed.
   473  // The -n flag prints commands that would be executed.
   474  // The -x flag prints commands as they are executed.
   475  //
   476  // For more about build flags, see 'go help build'.
   477  //
   478  // For more about specifying packages, see 'go help packages'.
   479  //
   480  //
   481  // Download and install packages and dependencies
   482  //
   483  // Usage:
   484  //
   485  // 	go get [-d] [-f] [-fix] [-insecure] [-t] [-u] [build flags] [packages]
   486  //
   487  // Get downloads the packages named by the import paths, along with their
   488  // dependencies. It then installs the named packages, like 'go install'.
   489  //
   490  // The -d flag instructs get to stop after downloading the packages; that is,
   491  // it instructs get not to install the packages.
   492  //
   493  // The -f flag, valid only when -u is set, forces get -u not to verify that
   494  // each package has been checked out from the source control repository
   495  // implied by its import path. This can be useful if the source is a local fork
   496  // of the original.
   497  //
   498  // The -fix flag instructs get to run the fix tool on the downloaded packages
   499  // before resolving dependencies or building the code.
   500  //
   501  // The -insecure flag permits fetching from repositories and resolving
   502  // custom domains using insecure schemes such as HTTP. Use with caution.
   503  //
   504  // The -t flag instructs get to also download the packages required to build
   505  // the tests for the specified packages.
   506  //
   507  // The -u flag instructs get to use the network to update the named packages
   508  // and their dependencies.  By default, get uses the network to check out
   509  // missing packages but does not use it to look for updates to existing packages.
   510  //
   511  // The -v flag enables verbose progress and debug output.
   512  //
   513  // Get also accepts build flags to control the installation. See 'go help build'.
   514  //
   515  // When checking out a new package, get creates the target directory
   516  // GOPATH/src/<import-path>. If the GOPATH contains multiple entries,
   517  // get uses the first one. For more details see: 'go help gopath'.
   518  //
   519  // When checking out or updating a package, get looks for a branch or tag
   520  // that matches the locally installed version of Go. The most important
   521  // rule is that if the local installation is running version "go1", get
   522  // searches for a branch or tag named "go1". If no such version exists it
   523  // retrieves the most recent version of the package.
   524  //
   525  // When go get checks out or updates a Git repository,
   526  // it also updates any git submodules referenced by the repository.
   527  //
   528  // Get never checks out or updates code stored in vendor directories.
   529  //
   530  // For more about specifying packages, see 'go help packages'.
   531  //
   532  // For more about how 'go get' finds source code to
   533  // download, see 'go help importpath'.
   534  //
   535  // See also: go build, go install, go clean.
   536  //
   537  //
   538  // Compile and install packages and dependencies
   539  //
   540  // Usage:
   541  //
   542  // 	go install [build flags] [packages]
   543  //
   544  // Install compiles and installs the packages named by the import paths,
   545  // along with their dependencies.
   546  //
   547  // For more about the build flags, see 'go help build'.
   548  // For more about specifying packages, see 'go help packages'.
   549  //
   550  // See also: go build, go get, go clean.
   551  //
   552  //
   553  // List packages
   554  //
   555  // Usage:
   556  //
   557  // 	go list [-e] [-f format] [-json] [build flags] [packages]
   558  //
   559  // List lists the packages named by the import paths, one per line.
   560  //
   561  // The default output shows the package import path:
   562  //
   563  //     bytes
   564  //     encoding/json
   565  //     github.com/gorilla/mux
   566  //     golang.org/x/net/html
   567  //
   568  // The -f flag specifies an alternate format for the list, using the
   569  // syntax of package template.  The default output is equivalent to -f
   570  // '{{.ImportPath}}'. The struct being passed to the template is:
   571  //
   572  //     type Package struct {
   573  //         Dir           string // directory containing package sources
   574  //         ImportPath    string // import path of package in dir
   575  //         ImportComment string // path in import comment on package statement
   576  //         Name          string // package name
   577  //         Doc           string // package documentation string
   578  //         Target        string // install path
   579  //         Shlib         string // the shared library that contains this package (only set when -linkshared)
   580  //         Goroot        bool   // is this package in the Go root?
   581  //         Standard      bool   // is this package part of the standard Go library?
   582  //         Stale         bool   // would 'go install' do anything for this package?
   583  //         StaleReason   string // explanation for Stale==true
   584  //         Root          string // Go root or Go path dir containing this package
   585  //         ConflictDir   string // this directory shadows Dir in $GOPATH
   586  //         BinaryOnly    bool   // binary-only package: cannot be recompiled from sources
   587  //
   588  //         // Source files
   589  //         GoFiles        []string // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
   590  //         CgoFiles       []string // .go sources files that import "C"
   591  //         IgnoredGoFiles []string // .go sources ignored due to build constraints
   592  //         CFiles         []string // .c source files
   593  //         CXXFiles       []string // .cc, .cxx and .cpp source files
   594  //         MFiles         []string // .m source files
   595  //         HFiles         []string // .h, .hh, .hpp and .hxx source files
   596  //         FFiles         []string // .f, .F, .for and .f90 Fortran source files
   597  //         SFiles         []string // .s source files
   598  //         SwigFiles      []string // .swig files
   599  //         SwigCXXFiles   []string // .swigcxx files
   600  //         SysoFiles      []string // .syso object files to add to archive
   601  //
   602  //         // Cgo directives
   603  //         CgoCFLAGS    []string // cgo: flags for C compiler
   604  //         CgoCPPFLAGS  []string // cgo: flags for C preprocessor
   605  //         CgoCXXFLAGS  []string // cgo: flags for C++ compiler
   606  //         CgoFFLAGS    []string // cgo: flags for Fortran compiler
   607  //         CgoLDFLAGS   []string // cgo: flags for linker
   608  //         CgoPkgConfig []string // cgo: pkg-config names
   609  //
   610  //         // Dependency information
   611  //         Imports []string // import paths used by this package
   612  //         Deps    []string // all (recursively) imported dependencies
   613  //
   614  //         // Error information
   615  //         Incomplete bool            // this package or a dependency has an error
   616  //         Error      *PackageError   // error loading package
   617  //         DepsErrors []*PackageError // errors loading dependencies
   618  //
   619  //         TestGoFiles  []string // _test.go files in package
   620  //         TestImports  []string // imports from TestGoFiles
   621  //         XTestGoFiles []string // _test.go files outside package
   622  //         XTestImports []string // imports from XTestGoFiles
   623  //     }
   624  //
   625  // The error information, if any, is
   626  //
   627  //     type PackageError struct {
   628  //         ImportStack   []string // shortest path from package named on command line to this one
   629  //         Pos           string   // position of error (if present, file:line:col)
   630  //         Err           string   // the error itself
   631  //     }
   632  //
   633  // The template function "join" calls strings.Join.
   634  //
   635  // The template function "context" returns the build context, defined as:
   636  //
   637  // 	type Context struct {
   638  // 		GOARCH        string   // target architecture
   639  // 		GOOS          string   // target operating system
   640  // 		GOROOT        string   // Go root
   641  // 		GOPATH        string   // Go path
   642  // 		CgoEnabled    bool     // whether cgo can be used
   643  // 		UseAllFiles   bool     // use files regardless of +build lines, file names
   644  // 		Compiler      string   // compiler to assume when computing target paths
   645  // 		BuildTags     []string // build constraints to match in +build lines
   646  // 		ReleaseTags   []string // releases the current release is compatible with
   647  // 		InstallSuffix string   // suffix to use in the name of the install dir
   648  // 	}
   649  //
   650  // For more information about the meaning of these fields see the documentation
   651  // for the go/build package's Context type.
   652  //
   653  // The -json flag causes the package data to be printed in JSON format
   654  // instead of using the template format.
   655  //
   656  // The -e flag changes the handling of erroneous packages, those that
   657  // cannot be found or are malformed.  By default, the list command
   658  // prints an error to standard error for each erroneous package and
   659  // omits the packages from consideration during the usual printing.
   660  // With the -e flag, the list command never prints errors to standard
   661  // error and instead processes the erroneous packages with the usual
   662  // printing.  Erroneous packages will have a non-empty ImportPath and
   663  // a non-nil Error field; other information may or may not be missing
   664  // (zeroed).
   665  //
   666  // For more about build flags, see 'go help build'.
   667  //
   668  // For more about specifying packages, see 'go help packages'.
   669  //
   670  //
   671  // Compile and run Go program
   672  //
   673  // Usage:
   674  //
   675  // 	go run [build flags] [-exec xprog] gofiles... [arguments...]
   676  //
   677  // Run compiles and runs the main package comprising the named Go source files.
   678  // A Go source file is defined to be a file ending in a literal ".go" suffix.
   679  //
   680  // By default, 'go run' runs the compiled binary directly: 'a.out arguments...'.
   681  // If the -exec flag is given, 'go run' invokes the binary using xprog:
   682  // 	'xprog a.out arguments...'.
   683  // If the -exec flag is not given, GOOS or GOARCH is different from the system
   684  // default, and a program named go_$GOOS_$GOARCH_exec can be found
   685  // on the current search path, 'go run' invokes the binary using that program,
   686  // for example 'go_nacl_386_exec a.out arguments...'. This allows execution of
   687  // cross-compiled programs when a simulator or other execution method is
   688  // available.
   689  //
   690  // For more about build flags, see 'go help build'.
   691  //
   692  // See also: go build.
   693  //
   694  //
   695  // Test packages
   696  //
   697  // Usage:
   698  //
   699  // 	go test [build/test flags] [packages] [build/test flags & test binary flags]
   700  //
   701  // 'Go test' automates testing the packages named by the import paths.
   702  // It prints a summary of the test results in the format:
   703  //
   704  // 	ok   archive/tar   0.011s
   705  // 	FAIL archive/zip   0.022s
   706  // 	ok   compress/gzip 0.033s
   707  // 	...
   708  //
   709  // followed by detailed output for each failed package.
   710  //
   711  // 'Go test' recompiles each package along with any files with names matching
   712  // the file pattern "*_test.go".
   713  // Files whose names begin with "_" (including "_test.go") or "." are ignored.
   714  // These additional files can contain test functions, benchmark functions, and
   715  // example functions.  See 'go help testfunc' for more.
   716  // Each listed package causes the execution of a separate test binary.
   717  //
   718  // Test files that declare a package with the suffix "_test" will be compiled as a
   719  // separate package, and then linked and run with the main test binary.
   720  //
   721  // The go tool will ignore a directory named "testdata", making it available
   722  // to hold ancillary data needed by the tests.
   723  //
   724  // By default, go test needs no arguments.  It compiles and tests the package
   725  // with source in the current directory, including tests, and runs the tests.
   726  //
   727  // The package is built in a temporary directory so it does not interfere with the
   728  // non-test installation.
   729  //
   730  // In addition to the build flags, the flags handled by 'go test' itself are:
   731  //
   732  // 	-args
   733  // 	    Pass the remainder of the command line (everything after -args)
   734  // 	    to the test binary, uninterpreted and unchanged.
   735  // 	    Because this flag consumes the remainder of the command line,
   736  // 	    the package list (if present) must appear before this flag.
   737  //
   738  // 	-c
   739  // 	    Compile the test binary to pkg.test but do not run it
   740  // 	    (where pkg is the last element of the package's import path).
   741  // 	    The file name can be changed with the -o flag.
   742  //
   743  // 	-exec xprog
   744  // 	    Run the test binary using xprog. The behavior is the same as
   745  // 	    in 'go run'. See 'go help run' for details.
   746  //
   747  // 	-i
   748  // 	    Install packages that are dependencies of the test.
   749  // 	    Do not run the test.
   750  //
   751  // 	-o file
   752  // 	    Compile the test binary to the named file.
   753  // 	    The test still runs (unless -c or -i is specified).
   754  //
   755  // The test binary also accepts flags that control execution of the test; these
   756  // flags are also accessible by 'go test'. See 'go help testflag' for details.
   757  //
   758  // For more about build flags, see 'go help build'.
   759  // For more about specifying packages, see 'go help packages'.
   760  //
   761  // See also: go build, go vet.
   762  //
   763  //
   764  // Run specified go tool
   765  //
   766  // Usage:
   767  //
   768  // 	go tool [-n] command [args...]
   769  //
   770  // Tool runs the go tool command identified by the arguments.
   771  // With no arguments it prints the list of known tools.
   772  //
   773  // The -n flag causes tool to print the command that would be
   774  // executed but not execute it.
   775  //
   776  // For more about each tool command, see 'go tool command -h'.
   777  //
   778  //
   779  // Print Go version
   780  //
   781  // Usage:
   782  //
   783  // 	go version
   784  //
   785  // Version prints the Go version, as reported by runtime.Version.
   786  //
   787  //
   788  // Run go tool vet on packages
   789  //
   790  // Usage:
   791  //
   792  // 	go vet [-n] [-x] [build flags] [packages]
   793  //
   794  // Vet runs the Go vet command on the packages named by the import paths.
   795  //
   796  // For more about vet, see 'go doc cmd/vet'.
   797  // For more about specifying packages, see 'go help packages'.
   798  //
   799  // To run the vet tool with specific options, run 'go tool vet'.
   800  //
   801  // The -n flag prints commands that would be executed.
   802  // The -x flag prints commands as they are executed.
   803  //
   804  // For more about build flags, see 'go help build'.
   805  //
   806  // See also: go fmt, go fix.
   807  //
   808  //
   809  // Calling between Go and C
   810  //
   811  // There are two different ways to call between Go and C/C++ code.
   812  //
   813  // The first is the cgo tool, which is part of the Go distribution.  For
   814  // information on how to use it see the cgo documentation (go doc cmd/cgo).
   815  //
   816  // The second is the SWIG program, which is a general tool for
   817  // interfacing between languages.  For information on SWIG see
   818  // http://swig.org/.  When running go build, any file with a .swig
   819  // extension will be passed to SWIG.  Any file with a .swigcxx extension
   820  // will be passed to SWIG with the -c++ option.
   821  //
   822  // When either cgo or SWIG is used, go build will pass any .c, .m, .s,
   823  // or .S files to the C compiler, and any .cc, .cpp, .cxx files to the C++
   824  // compiler.  The CC or CXX environment variables may be set to determine
   825  // the C or C++ compiler, respectively, to use.
   826  //
   827  //
   828  // Description of build modes
   829  //
   830  // The 'go build' and 'go install' commands take a -buildmode argument which
   831  // indicates which kind of object file is to be built. Currently supported values
   832  // are:
   833  //
   834  // 	-buildmode=archive
   835  // 		Build the listed non-main packages into .a files. Packages named
   836  // 		main are ignored.
   837  //
   838  // 	-buildmode=c-archive
   839  // 		Build the listed main package, plus all packages it imports,
   840  // 		into a C archive file. The only callable symbols will be those
   841  // 		functions exported using a cgo //export comment. Requires
   842  // 		exactly one main package to be listed.
   843  //
   844  // 	-buildmode=c-shared
   845  // 		Build the listed main packages, plus all packages that they
   846  // 		import, into C shared libraries. The only callable symbols will
   847  // 		be those functions exported using a cgo //export comment.
   848  // 		Non-main packages are ignored.
   849  //
   850  // 	-buildmode=default
   851  // 		Listed main packages are built into executables and listed
   852  // 		non-main packages are built into .a files (the default
   853  // 		behavior).
   854  //
   855  // 	-buildmode=shared
   856  // 		Combine all the listed non-main packages into a single shared
   857  // 		library that will be used when building with the -linkshared
   858  // 		option. Packages named main are ignored.
   859  //
   860  // 	-buildmode=exe
   861  // 		Build the listed main packages and everything they import into
   862  // 		executables. Packages not named main are ignored.
   863  //
   864  // 	-buildmode=pie
   865  // 		Build the listed main packages and everything they import into
   866  // 		position independent executables (PIE). Packages not named
   867  // 		main are ignored.
   868  //
   869  // 	-buildmode=plugin
   870  // 		Build the listed main packages, plus all packages that they
   871  // 		import, into a Go plugin. Packages not named main are ignored.
   872  //
   873  //
   874  // File types
   875  //
   876  // The go command examines the contents of a restricted set of files
   877  // in each directory. It identifies which files to examine based on
   878  // the extension of the file name. These extensions are:
   879  //
   880  // 	.go
   881  // 		Go source files.
   882  // 	.c, .h
   883  // 		C source files.
   884  // 		If the package uses cgo or SWIG, these will be compiled with the
   885  // 		OS-native compiler (typically gcc); otherwise they will
   886  // 		trigger an error.
   887  // 	.cc, .cpp, .cxx, .hh, .hpp, .hxx
   888  // 		C++ source files. Only useful with cgo or SWIG, and always
   889  // 		compiled with the OS-native compiler.
   890  // 	.m
   891  // 		Objective-C source files. Only useful with cgo, and always
   892  // 		compiled with the OS-native compiler.
   893  // 	.s, .S
   894  // 		Assembler source files.
   895  // 		If the package uses cgo or SWIG, these will be assembled with the
   896  // 		OS-native assembler (typically gcc (sic)); otherwise they
   897  // 		will be assembled with the Go assembler.
   898  // 	.swig, .swigcxx
   899  // 		SWIG definition files.
   900  // 	.syso
   901  // 		System object files.
   902  //
   903  // Files of each of these types except .syso may contain build
   904  // constraints, but the go command stops scanning for build constraints
   905  // at the first item in the file that is not a blank line or //-style
   906  // line comment. See the go/build package documentation for
   907  // more details.
   908  //
   909  // Non-test Go source files can also include a //go:binary-only-package
   910  // comment, indicating that the package sources are included
   911  // for documentation only and must not be used to build the
   912  // package binary. This enables distribution of Go packages in
   913  // their compiled form alone. See the go/build package documentation
   914  // for more details.
   915  //
   916  //
   917  // GOPATH environment variable
   918  //
   919  // The Go path is used to resolve import statements.
   920  // It is implemented by and documented in the go/build package.
   921  //
   922  // The GOPATH environment variable lists places to look for Go code.
   923  // On Unix, the value is a colon-separated string.
   924  // On Windows, the value is a semicolon-separated string.
   925  // On Plan 9, the value is a list.
   926  //
   927  // GOPATH must be set to get, build and install packages outside the
   928  // standard Go tree.
   929  //
   930  // Each directory listed in GOPATH must have a prescribed structure:
   931  //
   932  // The src directory holds source code.  The path below src
   933  // determines the import path or executable name.
   934  //
   935  // The pkg directory holds installed package objects.
   936  // As in the Go tree, each target operating system and
   937  // architecture pair has its own subdirectory of pkg
   938  // (pkg/GOOS_GOARCH).
   939  //
   940  // If DIR is a directory listed in the GOPATH, a package with
   941  // source in DIR/src/foo/bar can be imported as "foo/bar" and
   942  // has its compiled form installed to "DIR/pkg/GOOS_GOARCH/foo/bar.a".
   943  //
   944  // The bin directory holds compiled commands.
   945  // Each command is named for its source directory, but only
   946  // the final element, not the entire path.  That is, the
   947  // command with source in DIR/src/foo/quux is installed into
   948  // DIR/bin/quux, not DIR/bin/foo/quux.  The "foo/" prefix is stripped
   949  // so that you can add DIR/bin to your PATH to get at the
   950  // installed commands.  If the GOBIN environment variable is
   951  // set, commands are installed to the directory it names instead
   952  // of DIR/bin. GOBIN must be an absolute path.
   953  //
   954  // Here's an example directory layout:
   955  //
   956  //     GOPATH=/home/user/gocode
   957  //
   958  //     /home/user/gocode/
   959  //         src/
   960  //             foo/
   961  //                 bar/               (go code in package bar)
   962  //                     x.go
   963  //                 quux/              (go code in package main)
   964  //                     y.go
   965  //         bin/
   966  //             quux                   (installed command)
   967  //         pkg/
   968  //             linux_amd64/
   969  //                 foo/
   970  //                     bar.a          (installed package object)
   971  //
   972  // Go searches each directory listed in GOPATH to find source code,
   973  // but new packages are always downloaded into the first directory
   974  // in the list.
   975  //
   976  // See https://golang.org/doc/code.html for an example.
   977  //
   978  // Internal Directories
   979  //
   980  // Code in or below a directory named "internal" is importable only
   981  // by code in the directory tree rooted at the parent of "internal".
   982  // Here's an extended version of the directory layout above:
   983  //
   984  //     /home/user/gocode/
   985  //         src/
   986  //             crash/
   987  //                 bang/              (go code in package bang)
   988  //                     b.go
   989  //             foo/                   (go code in package foo)
   990  //                 f.go
   991  //                 bar/               (go code in package bar)
   992  //                     x.go
   993  //                 internal/
   994  //                     baz/           (go code in package baz)
   995  //                         z.go
   996  //                 quux/              (go code in package main)
   997  //                     y.go
   998  //
   999  //
  1000  // The code in z.go is imported as "foo/internal/baz", but that
  1001  // import statement can only appear in source files in the subtree
  1002  // rooted at foo. The source files foo/f.go, foo/bar/x.go, and
  1003  // foo/quux/y.go can all import "foo/internal/baz", but the source file
  1004  // crash/bang/b.go cannot.
  1005  //
  1006  // See https://golang.org/s/go14internal for details.
  1007  //
  1008  // Vendor Directories
  1009  //
  1010  // Go 1.6 includes support for using local copies of external dependencies
  1011  // to satisfy imports of those dependencies, often referred to as vendoring.
  1012  //
  1013  // Code below a directory named "vendor" is importable only
  1014  // by code in the directory tree rooted at the parent of "vendor",
  1015  // and only using an import path that omits the prefix up to and
  1016  // including the vendor element.
  1017  //
  1018  // Here's the example from the previous section,
  1019  // but with the "internal" directory renamed to "vendor"
  1020  // and a new foo/vendor/crash/bang directory added:
  1021  //
  1022  //     /home/user/gocode/
  1023  //         src/
  1024  //             crash/
  1025  //                 bang/              (go code in package bang)
  1026  //                     b.go
  1027  //             foo/                   (go code in package foo)
  1028  //                 f.go
  1029  //                 bar/               (go code in package bar)
  1030  //                     x.go
  1031  //                 vendor/
  1032  //                     crash/
  1033  //                         bang/      (go code in package bang)
  1034  //                             b.go
  1035  //                     baz/           (go code in package baz)
  1036  //                         z.go
  1037  //                 quux/              (go code in package main)
  1038  //                     y.go
  1039  //
  1040  // The same visibility rules apply as for internal, but the code
  1041  // in z.go is imported as "baz", not as "foo/vendor/baz".
  1042  //
  1043  // Code in vendor directories deeper in the source tree shadows
  1044  // code in higher directories. Within the subtree rooted at foo, an import
  1045  // of "crash/bang" resolves to "foo/vendor/crash/bang", not the
  1046  // top-level "crash/bang".
  1047  //
  1048  // Code in vendor directories is not subject to import path
  1049  // checking (see 'go help importpath').
  1050  //
  1051  // When 'go get' checks out or updates a git repository, it now also
  1052  // updates submodules.
  1053  //
  1054  // Vendor directories do not affect the placement of new repositories
  1055  // being checked out for the first time by 'go get': those are always
  1056  // placed in the main GOPATH, never in a vendor subtree.
  1057  //
  1058  // See https://golang.org/s/go15vendor for details.
  1059  //
  1060  //
  1061  // Environment variables
  1062  //
  1063  // The go command, and the tools it invokes, examine a few different
  1064  // environment variables. For many of these, you can see the default
  1065  // value of on your system by running 'go env NAME', where NAME is the
  1066  // name of the variable.
  1067  //
  1068  // General-purpose environment variables:
  1069  //
  1070  // 	GCCGO
  1071  // 		The gccgo command to run for 'go build -compiler=gccgo'.
  1072  // 	GOARCH
  1073  // 		The architecture, or processor, for which to compile code.
  1074  // 		Examples are amd64, 386, arm, ppc64.
  1075  // 	GOBIN
  1076  // 		The directory where 'go install' will install a command.
  1077  // 	GOOS
  1078  // 		The operating system for which to compile code.
  1079  // 		Examples are linux, darwin, windows, netbsd.
  1080  // 	GOPATH
  1081  // 		For more details see: 'go help gopath'.
  1082  // 	GORACE
  1083  // 		Options for the race detector.
  1084  // 		See https://golang.org/doc/articles/race_detector.html.
  1085  // 	GOROOT
  1086  // 		The root of the go tree.
  1087  //
  1088  // Environment variables for use with cgo:
  1089  //
  1090  // 	CC
  1091  // 		The command to use to compile C code.
  1092  // 	CGO_ENABLED
  1093  // 		Whether the cgo command is supported.  Either 0 or 1.
  1094  // 	CGO_CFLAGS
  1095  // 		Flags that cgo will pass to the compiler when compiling
  1096  // 		C code.
  1097  // 	CGO_CPPFLAGS
  1098  // 		Flags that cgo will pass to the compiler when compiling
  1099  // 		C or C++ code.
  1100  // 	CGO_CXXFLAGS
  1101  // 		Flags that cgo will pass to the compiler when compiling
  1102  // 		C++ code.
  1103  // 	CGO_FFLAGS
  1104  // 		Flags that cgo will pass to the compiler when compiling
  1105  // 		Fortran code.
  1106  // 	CGO_LDFLAGS
  1107  // 		Flags that cgo will pass to the compiler when linking.
  1108  // 	CXX
  1109  // 		The command to use to compile C++ code.
  1110  // 	PKG_CONFIG
  1111  // 		Path to pkg-config tool.
  1112  //
  1113  // Architecture-specific environment variables:
  1114  //
  1115  // 	GOARM
  1116  // 		For GOARCH=arm, the ARM architecture for which to compile.
  1117  // 		Valid values are 5, 6, 7.
  1118  // 	GO386
  1119  // 		For GOARCH=386, the floating point instruction set.
  1120  // 		Valid values are 387, sse2.
  1121  //
  1122  // Special-purpose environment variables:
  1123  //
  1124  // 	GOROOT_FINAL
  1125  // 		The root of the installed Go tree, when it is
  1126  // 		installed in a location other than where it is built.
  1127  // 		File names in stack traces are rewritten from GOROOT to
  1128  // 		GOROOT_FINAL.
  1129  // 	GO_EXTLINK_ENABLED
  1130  // 		Whether the linker should use external linking mode
  1131  // 		when using -linkmode=auto with code that uses cgo.
  1132  // 		Set to 0 to disable external linking mode, 1 to enable it.
  1133  // 	GIT_ALLOW_PROTOCOL
  1134  // 		Defined by Git. A colon-separated list of schemes that are allowed to be used
  1135  // 		with git fetch/clone. If set, any scheme not explicitly mentioned will be
  1136  // 		considered insecure by 'go get'.
  1137  //
  1138  //
  1139  // Import path syntax
  1140  //
  1141  // An import path (see 'go help packages') denotes a package stored in the local
  1142  // file system.  In general, an import path denotes either a standard package (such
  1143  // as "unicode/utf8") or a package found in one of the work spaces (For more
  1144  // details see: 'go help gopath').
  1145  //
  1146  // Relative import paths
  1147  //
  1148  // An import path beginning with ./ or ../ is called a relative path.
  1149  // The toolchain supports relative import paths as a shortcut in two ways.
  1150  //
  1151  // First, a relative path can be used as a shorthand on the command line.
  1152  // If you are working in the directory containing the code imported as
  1153  // "unicode" and want to run the tests for "unicode/utf8", you can type
  1154  // "go test ./utf8" instead of needing to specify the full path.
  1155  // Similarly, in the reverse situation, "go test .." will test "unicode" from
  1156  // the "unicode/utf8" directory. Relative patterns are also allowed, like
  1157  // "go test ./..." to test all subdirectories. See 'go help packages' for details
  1158  // on the pattern syntax.
  1159  //
  1160  // Second, if you are compiling a Go program not in a work space,
  1161  // you can use a relative path in an import statement in that program
  1162  // to refer to nearby code also not in a work space.
  1163  // This makes it easy to experiment with small multipackage programs
  1164  // outside of the usual work spaces, but such programs cannot be
  1165  // installed with "go install" (there is no work space in which to install them),
  1166  // so they are rebuilt from scratch each time they are built.
  1167  // To avoid ambiguity, Go programs cannot use relative import paths
  1168  // within a work space.
  1169  //
  1170  // Remote import paths
  1171  //
  1172  // Certain import paths also
  1173  // describe how to obtain the source code for the package using
  1174  // a revision control system.
  1175  //
  1176  // A few common code hosting sites have special syntax:
  1177  //
  1178  // 	Bitbucket (Git, Mercurial)
  1179  //
  1180  // 		import "bitbucket.org/user/project"
  1181  // 		import "bitbucket.org/user/project/sub/directory"
  1182  //
  1183  // 	GitHub (Git)
  1184  //
  1185  // 		import "github.com/user/project"
  1186  // 		import "github.com/user/project/sub/directory"
  1187  //
  1188  // 	Launchpad (Bazaar)
  1189  //
  1190  // 		import "launchpad.net/project"
  1191  // 		import "launchpad.net/project/series"
  1192  // 		import "launchpad.net/project/series/sub/directory"
  1193  //
  1194  // 		import "launchpad.net/~user/project/branch"
  1195  // 		import "launchpad.net/~user/project/branch/sub/directory"
  1196  //
  1197  // 	IBM DevOps Services (Git)
  1198  //
  1199  // 		import "hub.jazz.net/git/user/project"
  1200  // 		import "hub.jazz.net/git/user/project/sub/directory"
  1201  //
  1202  // For code hosted on other servers, import paths may either be qualified
  1203  // with the version control type, or the go tool can dynamically fetch
  1204  // the import path over https/http and discover where the code resides
  1205  // from a <meta> tag in the HTML.
  1206  //
  1207  // To declare the code location, an import path of the form
  1208  //
  1209  // 	repository.vcs/path
  1210  //
  1211  // specifies the given repository, with or without the .vcs suffix,
  1212  // using the named version control system, and then the path inside
  1213  // that repository.  The supported version control systems are:
  1214  //
  1215  // 	Bazaar      .bzr
  1216  // 	Git         .git
  1217  // 	Mercurial   .hg
  1218  // 	Subversion  .svn
  1219  //
  1220  // For example,
  1221  //
  1222  // 	import "example.org/user/foo.hg"
  1223  //
  1224  // denotes the root directory of the Mercurial repository at
  1225  // example.org/user/foo or foo.hg, and
  1226  //
  1227  // 	import "example.org/repo.git/foo/bar"
  1228  //
  1229  // denotes the foo/bar directory of the Git repository at
  1230  // example.org/repo or repo.git.
  1231  //
  1232  // When a version control system supports multiple protocols,
  1233  // each is tried in turn when downloading.  For example, a Git
  1234  // download tries https://, then git+ssh://.
  1235  //
  1236  // By default, downloads are restricted to known secure protocols
  1237  // (e.g. https, ssh). To override this setting for Git downloads, the
  1238  // GIT_ALLOW_PROTOCOL environment variable can be set (For more details see:
  1239  // 'go help environment').
  1240  //
  1241  // If the import path is not a known code hosting site and also lacks a
  1242  // version control qualifier, the go tool attempts to fetch the import
  1243  // over https/http and looks for a <meta> tag in the document's HTML
  1244  // <head>.
  1245  //
  1246  // The meta tag has the form:
  1247  //
  1248  // 	<meta name="go-import" content="import-prefix vcs repo-root">
  1249  //
  1250  // The import-prefix is the import path corresponding to the repository
  1251  // root. It must be a prefix or an exact match of the package being
  1252  // fetched with "go get". If it's not an exact match, another http
  1253  // request is made at the prefix to verify the <meta> tags match.
  1254  //
  1255  // The meta tag should appear as early in the file as possible.
  1256  // In particular, it should appear before any raw JavaScript or CSS,
  1257  // to avoid confusing the go command's restricted parser.
  1258  //
  1259  // The vcs is one of "git", "hg", "svn", etc,
  1260  //
  1261  // The repo-root is the root of the version control system
  1262  // containing a scheme and not containing a .vcs qualifier.
  1263  //
  1264  // For example,
  1265  //
  1266  // 	import "example.org/pkg/foo"
  1267  //
  1268  // will result in the following requests:
  1269  //
  1270  // 	https://example.org/pkg/foo?go-get=1 (preferred)
  1271  // 	http://example.org/pkg/foo?go-get=1  (fallback, only with -insecure)
  1272  //
  1273  // If that page contains the meta tag
  1274  //
  1275  // 	<meta name="go-import" content="example.org git https://code.org/r/p/exproj">
  1276  //
  1277  // the go tool will verify that https://example.org/?go-get=1 contains the
  1278  // same meta tag and then git clone https://code.org/r/p/exproj into
  1279  // GOPATH/src/example.org.
  1280  //
  1281  // New downloaded packages are written to the first directory listed in the GOPATH
  1282  // environment variable (For more details see: 'go help gopath').
  1283  //
  1284  // The go command attempts to download the version of the
  1285  // package appropriate for the Go release being used.
  1286  // Run 'go help get' for more.
  1287  //
  1288  // Import path checking
  1289  //
  1290  // When the custom import path feature described above redirects to a
  1291  // known code hosting site, each of the resulting packages has two possible
  1292  // import paths, using the custom domain or the known hosting site.
  1293  //
  1294  // A package statement is said to have an "import comment" if it is immediately
  1295  // followed (before the next newline) by a comment of one of these two forms:
  1296  //
  1297  // 	package math // import "path"
  1298  // 	package math /* import "path" */
  1299  //
  1300  // The go command will refuse to install a package with an import comment
  1301  // unless it is being referred to by that import path. In this way, import comments
  1302  // let package authors make sure the custom import path is used and not a
  1303  // direct path to the underlying code hosting site.
  1304  //
  1305  // Import path checking is disabled for code found within vendor trees.
  1306  // This makes it possible to copy code into alternate locations in vendor trees
  1307  // without needing to update import comments.
  1308  //
  1309  // See https://golang.org/s/go14customimport for details.
  1310  //
  1311  //
  1312  // Description of package lists
  1313  //
  1314  // Many commands apply to a set of packages:
  1315  //
  1316  // 	go action [packages]
  1317  //
  1318  // Usually, [packages] is a list of import paths.
  1319  //
  1320  // An import path that is a rooted path or that begins with
  1321  // a . or .. element is interpreted as a file system path and
  1322  // denotes the package in that directory.
  1323  //
  1324  // Otherwise, the import path P denotes the package found in
  1325  // the directory DIR/src/P for some DIR listed in the GOPATH
  1326  // environment variable (For more details see: 'go help gopath').
  1327  //
  1328  // If no import paths are given, the action applies to the
  1329  // package in the current directory.
  1330  //
  1331  // There are four reserved names for paths that should not be used
  1332  // for packages to be built with the go tool:
  1333  //
  1334  // - "main" denotes the top-level package in a stand-alone executable.
  1335  //
  1336  // - "all" expands to all package directories found in all the GOPATH
  1337  // trees. For example, 'go list all' lists all the packages on the local
  1338  // system.
  1339  //
  1340  // - "std" is like all but expands to just the packages in the standard
  1341  // Go library.
  1342  //
  1343  // - "cmd" expands to the Go repository's commands and their
  1344  // internal libraries.
  1345  //
  1346  // An import path is a pattern if it includes one or more "..." wildcards,
  1347  // each of which can match any string, including the empty string and
  1348  // strings containing slashes.  Such a pattern expands to all package
  1349  // directories found in the GOPATH trees with names matching the
  1350  // patterns.  As a special case, x/... matches x as well as x's subdirectories.
  1351  // For example, net/... expands to net and packages in its subdirectories.
  1352  //
  1353  // An import path can also name a package to be downloaded from
  1354  // a remote repository.  Run 'go help importpath' for details.
  1355  //
  1356  // Every package in a program must have a unique import path.
  1357  // By convention, this is arranged by starting each path with a
  1358  // unique prefix that belongs to you.  For example, paths used
  1359  // internally at Google all begin with 'google', and paths
  1360  // denoting remote repositories begin with the path to the code,
  1361  // such as 'github.com/user/repo'.
  1362  //
  1363  // Packages in a program need not have unique package names,
  1364  // but there are two reserved package names with special meaning.
  1365  // The name main indicates a command, not a library.
  1366  // Commands are built into binaries and cannot be imported.
  1367  // The name documentation indicates documentation for
  1368  // a non-Go program in the directory. Files in package documentation
  1369  // are ignored by the go command.
  1370  //
  1371  // As a special case, if the package list is a list of .go files from a
  1372  // single directory, the command is applied to a single synthesized
  1373  // package made up of exactly those files, ignoring any build constraints
  1374  // in those files and ignoring any other files in the directory.
  1375  //
  1376  // Directory and file names that begin with "." or "_" are ignored
  1377  // by the go tool, as are directories named "testdata".
  1378  //
  1379  //
  1380  // Description of testing flags
  1381  //
  1382  // The 'go test' command takes both flags that apply to 'go test' itself
  1383  // and flags that apply to the resulting test binary.
  1384  //
  1385  // Several of the flags control profiling and write an execution profile
  1386  // suitable for "go tool pprof"; run "go tool pprof -h" for more
  1387  // information.  The --alloc_space, --alloc_objects, and --show_bytes
  1388  // options of pprof control how the information is presented.
  1389  //
  1390  // The following flags are recognized by the 'go test' command and
  1391  // control the execution of any test:
  1392  //
  1393  // 	-bench regexp
  1394  // 	    Run (sub)benchmarks matching a regular expression.
  1395  // 	    The given regular expression is split into smaller ones by
  1396  // 	    top-level '/', where each must match the corresponding part of a
  1397  // 	    benchmark's identifier.
  1398  // 	    By default, no benchmarks run. To run all benchmarks,
  1399  // 	    use '-bench .' or '-bench=.'.
  1400  //
  1401  // 	-benchtime t
  1402  // 	    Run enough iterations of each benchmark to take t, specified
  1403  // 	    as a time.Duration (for example, -benchtime 1h30s).
  1404  // 	    The default is 1 second (1s).
  1405  //
  1406  // 	-count n
  1407  // 	    Run each test and benchmark n times (default 1).
  1408  // 	    If -cpu is set, run n times for each GOMAXPROCS value.
  1409  // 	    Examples are always run once.
  1410  //
  1411  // 	-cover
  1412  // 	    Enable coverage analysis.
  1413  //
  1414  // 	-covermode set,count,atomic
  1415  // 	    Set the mode for coverage analysis for the package[s]
  1416  // 	    being tested. The default is "set" unless -race is enabled,
  1417  // 	    in which case it is "atomic".
  1418  // 	    The values:
  1419  // 		set: bool: does this statement run?
  1420  // 		count: int: how many times does this statement run?
  1421  // 		atomic: int: count, but correct in multithreaded tests;
  1422  // 			significantly more expensive.
  1423  // 	    Sets -cover.
  1424  //
  1425  // 	-coverpkg pkg1,pkg2,pkg3
  1426  // 	    Apply coverage analysis in each test to the given list of packages.
  1427  // 	    The default is for each test to analyze only the package being tested.
  1428  // 	    Packages are specified as import paths.
  1429  // 	    Sets -cover.
  1430  //
  1431  // 	-cpu 1,2,4
  1432  // 	    Specify a list of GOMAXPROCS values for which the tests or
  1433  // 	    benchmarks should be executed.  The default is the current value
  1434  // 	    of GOMAXPROCS.
  1435  //
  1436  // 	-parallel n
  1437  // 	    Allow parallel execution of test functions that call t.Parallel.
  1438  // 	    The value of this flag is the maximum number of tests to run
  1439  // 	    simultaneously; by default, it is set to the value of GOMAXPROCS.
  1440  // 	    Note that -parallel only applies within a single test binary.
  1441  // 	    The 'go test' command may run tests for different packages
  1442  // 	    in parallel as well, according to the setting of the -p flag
  1443  // 	    (see 'go help build').
  1444  //
  1445  // 	-run regexp
  1446  // 	    Run only those tests and examples matching the regular expression.
  1447  // 	    For tests the regular expression is split into smaller ones by
  1448  // 	    top-level '/', where each must match the corresponding part of a
  1449  // 	    test's identifier.
  1450  //
  1451  // 	-short
  1452  // 	    Tell long-running tests to shorten their run time.
  1453  // 	    It is off by default but set during all.bash so that installing
  1454  // 	    the Go tree can run a sanity check but not spend time running
  1455  // 	    exhaustive tests.
  1456  //
  1457  // 	-timeout t
  1458  // 	    If a test runs longer than t, panic.
  1459  // 	    The default is 10 minutes (10m).
  1460  //
  1461  // 	-v
  1462  // 	    Verbose output: log all tests as they are run. Also print all
  1463  // 	    text from Log and Logf calls even if the test succeeds.
  1464  //
  1465  // The following flags are also recognized by 'go test' and can be used to
  1466  // profile the tests during execution::
  1467  //
  1468  // 	-benchmem
  1469  // 	    Print memory allocation statistics for benchmarks.
  1470  //
  1471  // 	-blockprofile block.out
  1472  // 	    Write a goroutine blocking profile to the specified file
  1473  // 	    when all tests are complete.
  1474  // 	    Writes test binary as -c would.
  1475  //
  1476  // 	-blockprofilerate n
  1477  // 	    Control the detail provided in goroutine blocking profiles by
  1478  // 	    calling runtime.SetBlockProfileRate with n.
  1479  // 	    See 'go doc runtime.SetBlockProfileRate'.
  1480  // 	    The profiler aims to sample, on average, one blocking event every
  1481  // 	    n nanoseconds the program spends blocked.  By default,
  1482  // 	    if -test.blockprofile is set without this flag, all blocking events
  1483  // 	    are recorded, equivalent to -test.blockprofilerate=1.
  1484  //
  1485  // 	-coverprofile cover.out
  1486  // 	    Write a coverage profile to the file after all tests have passed.
  1487  // 	    Sets -cover.
  1488  //
  1489  // 	-cpuprofile cpu.out
  1490  // 	    Write a CPU profile to the specified file before exiting.
  1491  // 	    Writes test binary as -c would.
  1492  //
  1493  // 	-memprofile mem.out
  1494  // 	    Write a memory profile to the file after all tests have passed.
  1495  // 	    Writes test binary as -c would.
  1496  //
  1497  // 	-memprofilerate n
  1498  // 	    Enable more precise (and expensive) memory profiles by setting
  1499  // 	    runtime.MemProfileRate.  See 'go doc runtime.MemProfileRate'.
  1500  // 	    To profile all memory allocations, use -test.memprofilerate=1
  1501  // 	    and pass --alloc_space flag to the pprof tool.
  1502  //
  1503  // 	-outputdir directory
  1504  // 	    Place output files from profiling in the specified directory,
  1505  // 	    by default the directory in which "go test" is running.
  1506  //
  1507  // 	-trace trace.out
  1508  // 	    Write an execution trace to the specified file before exiting.
  1509  //
  1510  // Each of these flags is also recognized with an optional 'test.' prefix,
  1511  // as in -test.v. When invoking the generated test binary (the result of
  1512  // 'go test -c') directly, however, the prefix is mandatory.
  1513  //
  1514  // The 'go test' command rewrites or removes recognized flags,
  1515  // as appropriate, both before and after the optional package list,
  1516  // before invoking the test binary.
  1517  //
  1518  // For instance, the command
  1519  //
  1520  // 	go test -v -myflag testdata -cpuprofile=prof.out -x
  1521  //
  1522  // will compile the test binary and then run it as
  1523  //
  1524  // 	pkg.test -test.v -myflag testdata -test.cpuprofile=prof.out
  1525  //
  1526  // (The -x flag is removed because it applies only to the go command's
  1527  // execution, not to the test itself.)
  1528  //
  1529  // The test flags that generate profiles (other than for coverage) also
  1530  // leave the test binary in pkg.test for use when analyzing the profiles.
  1531  //
  1532  // When 'go test' runs a test binary, it does so from within the
  1533  // corresponding package's source code directory. Depending on the test,
  1534  // it may be necessary to do the same when invoking a generated test
  1535  // binary directly.
  1536  //
  1537  // The command-line package list, if present, must appear before any
  1538  // flag not known to the go test command. Continuing the example above,
  1539  // the package list would have to appear before -myflag, but could appear
  1540  // on either side of -v.
  1541  //
  1542  // To keep an argument for a test binary from being interpreted as a
  1543  // known flag or a package name, use -args (see 'go help test') which
  1544  // passes the remainder of the command line through to the test binary
  1545  // uninterpreted and unaltered.
  1546  //
  1547  // For instance, the command
  1548  //
  1549  // 	go test -v -args -x -v
  1550  //
  1551  // will compile the test binary and then run it as
  1552  //
  1553  // 	pkg.test -test.v -x -v
  1554  //
  1555  // Similarly,
  1556  //
  1557  // 	go test -args math
  1558  //
  1559  // will compile the test binary and then run it as
  1560  //
  1561  // 	pkg.test math
  1562  //
  1563  // In the first example, the -x and the second -v are passed through to the
  1564  // test binary unchanged and with no effect on the go command itself.
  1565  // In the second example, the argument math is passed through to the test
  1566  // binary, instead of being interpreted as the package list.
  1567  //
  1568  //
  1569  // Description of testing functions
  1570  //
  1571  // The 'go test' command expects to find test, benchmark, and example functions
  1572  // in the "*_test.go" files corresponding to the package under test.
  1573  //
  1574  // A test function is one named TestXXX (where XXX is any alphanumeric string
  1575  // not starting with a lower case letter) and should have the signature,
  1576  //
  1577  // 	func TestXXX(t *testing.T) { ... }
  1578  //
  1579  // A benchmark function is one named BenchmarkXXX and should have the signature,
  1580  //
  1581  // 	func BenchmarkXXX(b *testing.B) { ... }
  1582  //
  1583  // An example function is similar to a test function but, instead of using
  1584  // *testing.T to report success or failure, prints output to os.Stdout.
  1585  // If the last comment in the function starts with "Output:" then the output
  1586  // is compared exactly against the comment (see examples below). If the last
  1587  // comment begins with "Unordered output:" then the output is compared to the
  1588  // comment, however the order of the lines is ignored. An example with no such
  1589  // comment, or with no text after "Output:" is compiled but not executed.
  1590  //
  1591  // Godoc displays the body of ExampleXXX to demonstrate the use
  1592  // of the function, constant, or variable XXX.  An example of a method M with
  1593  // receiver type T or *T is named ExampleT_M.  There may be multiple examples
  1594  // for a given function, constant, or variable, distinguished by a trailing _xxx,
  1595  // where xxx is a suffix not beginning with an upper case letter.
  1596  //
  1597  // Here is an example of an example:
  1598  //
  1599  // 	func ExamplePrintln() {
  1600  // 		Println("The output of\nthis example.")
  1601  // 		// Output: The output of
  1602  // 		// this example.
  1603  // 	}
  1604  //
  1605  // Here is another example where the ordering of the output is ignored:
  1606  //
  1607  // 	func ExamplePerm() {
  1608  // 		for _, value := range Perm(4) {
  1609  // 			fmt.Println(value)
  1610  // 		}
  1611  //
  1612  // 		// Unordered output: 4
  1613  // 		// 2
  1614  // 		// 1
  1615  // 		// 3
  1616  // 		// 0
  1617  // 	}
  1618  //
  1619  // The entire test file is presented as the example when it contains a single
  1620  // example function, at least one other function, type, variable, or constant
  1621  // declaration, and no test or benchmark functions.
  1622  //
  1623  // See the documentation of the testing package for more information.
  1624  //
  1625  //
  1626  package main