github.com/muesli/go@v0.0.0-20170208044820-e410d2a81ef2/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         start a bug report
    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 space-separated list of build tags to consider satisfied during the
   135  // 		build. 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  // All the flags that take a list of arguments accept a space-separated
   143  // list of strings. To embed spaces in an element in the list, surround
   144  // it with either single or double quotes.
   145  //
   146  // For more about specifying packages, see 'go help packages'.
   147  // For more about where packages and binaries are installed,
   148  // run 'go help gopath'.
   149  // For more about calling between Go and C/C++, run 'go help c'.
   150  //
   151  // Note: Build adheres to certain conventions such as those described
   152  // by 'go help gopath'. Not all projects can follow these conventions,
   153  // however. Installations that have their own conventions or that use
   154  // a separate software build system may choose to use lower-level
   155  // invocations such as 'go tool compile' and 'go tool link' to avoid
   156  // some of the overheads and design decisions of the build tool.
   157  //
   158  // See also: go install, go get, go clean.
   159  //
   160  //
   161  // Remove object files
   162  //
   163  // Usage:
   164  //
   165  // 	go clean [-i] [-r] [-n] [-x] [build flags] [packages]
   166  //
   167  // Clean removes object files from package source directories.
   168  // The go command builds most objects in a temporary directory,
   169  // so go clean is mainly concerned with object files left by other
   170  // tools or by manual invocations of go build.
   171  //
   172  // Specifically, clean removes the following files from each of the
   173  // source directories corresponding to the import paths:
   174  //
   175  // 	_obj/            old object directory, left from Makefiles
   176  // 	_test/           old test directory, left from Makefiles
   177  // 	_testmain.go     old gotest file, left from Makefiles
   178  // 	test.out         old test log, left from Makefiles
   179  // 	build.out        old test log, left from Makefiles
   180  // 	*.[568ao]        object files, left from Makefiles
   181  //
   182  // 	DIR(.exe)        from go build
   183  // 	DIR.test(.exe)   from go test -c
   184  // 	MAINFILE(.exe)   from go build MAINFILE.go
   185  // 	*.so             from SWIG
   186  //
   187  // In the list, DIR represents the final path element of the
   188  // directory, and MAINFILE is the base name of any Go source
   189  // file in the directory that is not included when building
   190  // the package.
   191  //
   192  // The -i flag causes clean to remove the corresponding installed
   193  // archive or binary (what 'go install' would create).
   194  //
   195  // The -n flag causes clean to print the remove commands it would execute,
   196  // but not run them.
   197  //
   198  // The -r flag causes clean to be applied recursively to all the
   199  // dependencies of the packages named by the import paths.
   200  //
   201  // The -x flag causes clean to print remove commands as it executes them.
   202  //
   203  // For more about build flags, see 'go help build'.
   204  //
   205  // For more about specifying packages, see 'go help packages'.
   206  //
   207  //
   208  // Show documentation for package or symbol
   209  //
   210  // Usage:
   211  //
   212  // 	go doc [-u] [-c] [package|[package.]symbol[.method]]
   213  //
   214  // Doc prints the documentation comments associated with the item identified by its
   215  // arguments (a package, const, func, type, var, or method) followed by a one-line
   216  // summary of each of the first-level items "under" that item (package-level
   217  // declarations for a package, methods for a type, etc.).
   218  //
   219  // Doc accepts zero, one, or two arguments.
   220  //
   221  // Given no arguments, that is, when run as
   222  //
   223  // 	go doc
   224  //
   225  // it prints the package documentation for the package in the current directory.
   226  // If the package is a command (package main), the exported symbols of the package
   227  // are elided from the presentation unless the -cmd flag is provided.
   228  //
   229  // When run with one argument, the argument is treated as a Go-syntax-like
   230  // representation of the item to be documented. What the argument selects depends
   231  // on what is installed in GOROOT and GOPATH, as well as the form of the argument,
   232  // which is schematically one of these:
   233  //
   234  // 	go doc <pkg>
   235  // 	go doc <sym>[.<method>]
   236  // 	go doc [<pkg>.]<sym>[.<method>]
   237  // 	go doc [<pkg>.][<sym>.]<method>
   238  //
   239  // The first item in this list matched by the argument is the one whose documentation
   240  // is printed. (See the examples below.) However, if the argument starts with a capital
   241  // letter it is assumed to identify a symbol or method in the current directory.
   242  //
   243  // For packages, the order of scanning is determined lexically in breadth-first order.
   244  // That is, the package presented is the one that matches the search and is nearest
   245  // the root and lexically first at its level of the hierarchy.  The GOROOT tree is
   246  // always scanned in its entirety before GOPATH.
   247  //
   248  // If there is no package specified or matched, the package in the current
   249  // directory is selected, so "go doc Foo" shows the documentation for symbol Foo in
   250  // the current package.
   251  //
   252  // The package path must be either a qualified path or a proper suffix of a
   253  // path. The go tool's usual package mechanism does not apply: package path
   254  // elements like . and ... are not implemented by go doc.
   255  //
   256  // When run with two arguments, the first must be a full package path (not just a
   257  // suffix), and the second is a symbol or symbol and method; this is similar to the
   258  // syntax accepted by godoc:
   259  //
   260  // 	go doc <pkg> <sym>[.<method>]
   261  //
   262  // In all forms, when matching symbols, lower-case letters in the argument match
   263  // either case but upper-case letters match exactly. This means that there may be
   264  // multiple matches of a lower-case argument in a package if different symbols have
   265  // different cases. If this occurs, documentation for all matches is printed.
   266  //
   267  // Examples:
   268  // 	go doc
   269  // 		Show documentation for current package.
   270  // 	go doc Foo
   271  // 		Show documentation for Foo in the current package.
   272  // 		(Foo starts with a capital letter so it cannot match
   273  // 		a package path.)
   274  // 	go doc encoding/json
   275  // 		Show documentation for the encoding/json package.
   276  // 	go doc json
   277  // 		Shorthand for encoding/json.
   278  // 	go doc json.Number (or go doc json.number)
   279  // 		Show documentation and method summary for json.Number.
   280  // 	go doc json.Number.Int64 (or go doc json.number.int64)
   281  // 		Show documentation for json.Number's Int64 method.
   282  // 	go doc cmd/doc
   283  // 		Show package docs for the doc command.
   284  // 	go doc -cmd cmd/doc
   285  // 		Show package docs and exported symbols within the doc command.
   286  // 	go doc template.new
   287  // 		Show documentation for html/template's New function.
   288  // 		(html/template is lexically before text/template)
   289  // 	go doc text/template.new # One argument
   290  // 		Show documentation for text/template's New function.
   291  // 	go doc text/template new # Two arguments
   292  // 		Show documentation for text/template's New function.
   293  //
   294  // 	At least in the current tree, these invocations all print the
   295  // 	documentation for json.Decoder's Decode method:
   296  //
   297  // 	go doc json.Decoder.Decode
   298  // 	go doc json.decoder.decode
   299  // 	go doc json.decode
   300  // 	cd go/src/encoding/json; go doc decode
   301  //
   302  // Flags:
   303  // 	-c
   304  // 		Respect case when matching symbols.
   305  // 	-cmd
   306  // 		Treat a command (package main) like a regular package.
   307  // 		Otherwise package main's exported symbols are hidden
   308  // 		when showing the package's top-level documentation.
   309  // 	-u
   310  // 		Show documentation for unexported as well as exported
   311  // 		symbols and methods.
   312  //
   313  //
   314  // Print Go environment information
   315  //
   316  // Usage:
   317  //
   318  // 	go env [var ...]
   319  //
   320  // Env prints Go environment information.
   321  //
   322  // By default env prints information as a shell script
   323  // (on Windows, a batch file).  If one or more variable
   324  // names is given as arguments,  env prints the value of
   325  // each named variable on its own line.
   326  //
   327  //
   328  // Start a bug report
   329  //
   330  // Usage:
   331  //
   332  // 	go bug
   333  //
   334  // Bug opens the default browser and starts a new bug report.
   335  // The report includes useful system information.
   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  //         TestGoFiles    []string // _test.go files in package
   602  //         XTestGoFiles   []string // _test.go files outside package
   603  //
   604  //         // Cgo directives
   605  //         CgoCFLAGS    []string // cgo: flags for C compiler
   606  //         CgoCPPFLAGS  []string // cgo: flags for C preprocessor
   607  //         CgoCXXFLAGS  []string // cgo: flags for C++ compiler
   608  //         CgoFFLAGS    []string // cgo: flags for Fortran compiler
   609  //         CgoLDFLAGS   []string // cgo: flags for linker
   610  //         CgoPkgConfig []string // cgo: pkg-config names
   611  //
   612  //         // Dependency information
   613  //         Imports      []string // import paths used by this package
   614  //         Deps         []string // all (recursively) imported dependencies
   615  //         TestImports  []string // imports from TestGoFiles
   616  //         XTestImports []string // imports from XTestGoFiles
   617  //
   618  //         // Error information
   619  //         Incomplete bool            // this package or a dependency has an error
   620  //         Error      *PackageError   // error loading package
   621  //         DepsErrors []*PackageError // errors loading dependencies
   622  //     }
   623  //
   624  // Packages stored in vendor directories report an ImportPath that includes the
   625  // path to the vendor directory (for example, "d/vendor/p" instead of "p"),
   626  // so that the ImportPath uniquely identifies a given copy of a package.
   627  // The Imports, Deps, TestImports, and XTestImports lists also contain these
   628  // expanded imports paths. See golang.org/s/go15vendor for more about vendoring.
   629  //
   630  // The error information, if any, is
   631  //
   632  //     type PackageError struct {
   633  //         ImportStack   []string // shortest path from package named on command line to this one
   634  //         Pos           string   // position of error (if present, file:line:col)
   635  //         Err           string   // the error itself
   636  //     }
   637  //
   638  // The template function "join" calls strings.Join.
   639  //
   640  // The template function "context" returns the build context, defined as:
   641  //
   642  // 	type Context struct {
   643  // 		GOARCH        string   // target architecture
   644  // 		GOOS          string   // target operating system
   645  // 		GOROOT        string   // Go root
   646  // 		GOPATH        string   // Go path
   647  // 		CgoEnabled    bool     // whether cgo can be used
   648  // 		UseAllFiles   bool     // use files regardless of +build lines, file names
   649  // 		Compiler      string   // compiler to assume when computing target paths
   650  // 		BuildTags     []string // build constraints to match in +build lines
   651  // 		ReleaseTags   []string // releases the current release is compatible with
   652  // 		InstallSuffix string   // suffix to use in the name of the install dir
   653  // 	}
   654  //
   655  // For more information about the meaning of these fields see the documentation
   656  // for the go/build package's Context type.
   657  //
   658  // The -json flag causes the package data to be printed in JSON format
   659  // instead of using the template format.
   660  //
   661  // The -e flag changes the handling of erroneous packages, those that
   662  // cannot be found or are malformed.  By default, the list command
   663  // prints an error to standard error for each erroneous package and
   664  // omits the packages from consideration during the usual printing.
   665  // With the -e flag, the list command never prints errors to standard
   666  // error and instead processes the erroneous packages with the usual
   667  // printing.  Erroneous packages will have a non-empty ImportPath and
   668  // a non-nil Error field; other information may or may not be missing
   669  // (zeroed).
   670  //
   671  // For more about build flags, see 'go help build'.
   672  //
   673  // For more about specifying packages, see 'go help packages'.
   674  //
   675  //
   676  // Compile and run Go program
   677  //
   678  // Usage:
   679  //
   680  // 	go run [build flags] [-exec xprog] gofiles... [arguments...]
   681  //
   682  // Run compiles and runs the main package comprising the named Go source files.
   683  // A Go source file is defined to be a file ending in a literal ".go" suffix.
   684  //
   685  // By default, 'go run' runs the compiled binary directly: 'a.out arguments...'.
   686  // If the -exec flag is given, 'go run' invokes the binary using xprog:
   687  // 	'xprog a.out arguments...'.
   688  // If the -exec flag is not given, GOOS or GOARCH is different from the system
   689  // default, and a program named go_$GOOS_$GOARCH_exec can be found
   690  // on the current search path, 'go run' invokes the binary using that program,
   691  // for example 'go_nacl_386_exec a.out arguments...'. This allows execution of
   692  // cross-compiled programs when a simulator or other execution method is
   693  // available.
   694  //
   695  // For more about build flags, see 'go help build'.
   696  //
   697  // See also: go build.
   698  //
   699  //
   700  // Test packages
   701  //
   702  // Usage:
   703  //
   704  // 	go test [build/test flags] [packages] [build/test flags & test binary flags]
   705  //
   706  // 'Go test' automates testing the packages named by the import paths.
   707  // It prints a summary of the test results in the format:
   708  //
   709  // 	ok   archive/tar   0.011s
   710  // 	FAIL archive/zip   0.022s
   711  // 	ok   compress/gzip 0.033s
   712  // 	...
   713  //
   714  // followed by detailed output for each failed package.
   715  //
   716  // 'Go test' recompiles each package along with any files with names matching
   717  // the file pattern "*_test.go".
   718  // Files whose names begin with "_" (including "_test.go") or "." are ignored.
   719  // These additional files can contain test functions, benchmark functions, and
   720  // example functions.  See 'go help testfunc' for more.
   721  // Each listed package causes the execution of a separate test binary.
   722  //
   723  // Test files that declare a package with the suffix "_test" will be compiled as a
   724  // separate package, and then linked and run with the main test binary.
   725  //
   726  // The go tool will ignore a directory named "testdata", making it available
   727  // to hold ancillary data needed by the tests.
   728  //
   729  // By default, go test needs no arguments.  It compiles and tests the package
   730  // with source in the current directory, including tests, and runs the tests.
   731  //
   732  // The package is built in a temporary directory so it does not interfere with the
   733  // non-test installation.
   734  //
   735  // In addition to the build flags, the flags handled by 'go test' itself are:
   736  //
   737  // 	-args
   738  // 	    Pass the remainder of the command line (everything after -args)
   739  // 	    to the test binary, uninterpreted and unchanged.
   740  // 	    Because this flag consumes the remainder of the command line,
   741  // 	    the package list (if present) must appear before this flag.
   742  //
   743  // 	-c
   744  // 	    Compile the test binary to pkg.test but do not run it
   745  // 	    (where pkg is the last element of the package's import path).
   746  // 	    The file name can be changed with the -o flag.
   747  //
   748  // 	-exec xprog
   749  // 	    Run the test binary using xprog. The behavior is the same as
   750  // 	    in 'go run'. See 'go help run' for details.
   751  //
   752  // 	-i
   753  // 	    Install packages that are dependencies of the test.
   754  // 	    Do not run the test.
   755  //
   756  // 	-o file
   757  // 	    Compile the test binary to the named file.
   758  // 	    The test still runs (unless -c or -i is specified).
   759  //
   760  // The test binary also accepts flags that control execution of the test; these
   761  // flags are also accessible by 'go test'. See 'go help testflag' for details.
   762  //
   763  // For more about build flags, see 'go help build'.
   764  // For more about specifying packages, see 'go help packages'.
   765  //
   766  // See also: go build, go vet.
   767  //
   768  //
   769  // Run specified go tool
   770  //
   771  // Usage:
   772  //
   773  // 	go tool [-n] command [args...]
   774  //
   775  // Tool runs the go tool command identified by the arguments.
   776  // With no arguments it prints the list of known tools.
   777  //
   778  // The -n flag causes tool to print the command that would be
   779  // executed but not execute it.
   780  //
   781  // For more about each tool command, see 'go tool command -h'.
   782  //
   783  //
   784  // Print Go version
   785  //
   786  // Usage:
   787  //
   788  // 	go version
   789  //
   790  // Version prints the Go version, as reported by runtime.Version.
   791  //
   792  //
   793  // Run go tool vet on packages
   794  //
   795  // Usage:
   796  //
   797  // 	go vet [-n] [-x] [build flags] [packages]
   798  //
   799  // Vet runs the Go vet command on the packages named by the import paths.
   800  //
   801  // For more about vet, see 'go doc cmd/vet'.
   802  // For more about specifying packages, see 'go help packages'.
   803  //
   804  // To run the vet tool with specific options, run 'go tool vet'.
   805  //
   806  // The -n flag prints commands that would be executed.
   807  // The -x flag prints commands as they are executed.
   808  //
   809  // For more about build flags, see 'go help build'.
   810  //
   811  // See also: go fmt, go fix.
   812  //
   813  //
   814  // Calling between Go and C
   815  //
   816  // There are two different ways to call between Go and C/C++ code.
   817  //
   818  // The first is the cgo tool, which is part of the Go distribution.  For
   819  // information on how to use it see the cgo documentation (go doc cmd/cgo).
   820  //
   821  // The second is the SWIG program, which is a general tool for
   822  // interfacing between languages.  For information on SWIG see
   823  // http://swig.org/.  When running go build, any file with a .swig
   824  // extension will be passed to SWIG.  Any file with a .swigcxx extension
   825  // will be passed to SWIG with the -c++ option.
   826  //
   827  // When either cgo or SWIG is used, go build will pass any .c, .m, .s,
   828  // or .S files to the C compiler, and any .cc, .cpp, .cxx files to the C++
   829  // compiler.  The CC or CXX environment variables may be set to determine
   830  // the C or C++ compiler, respectively, to use.
   831  //
   832  //
   833  // Description of build modes
   834  //
   835  // The 'go build' and 'go install' commands take a -buildmode argument which
   836  // indicates which kind of object file is to be built. Currently supported values
   837  // are:
   838  //
   839  // 	-buildmode=archive
   840  // 		Build the listed non-main packages into .a files. Packages named
   841  // 		main are ignored.
   842  //
   843  // 	-buildmode=c-archive
   844  // 		Build the listed main package, plus all packages it imports,
   845  // 		into a C archive file. The only callable symbols will be those
   846  // 		functions exported using a cgo //export comment. Requires
   847  // 		exactly one main package to be listed.
   848  //
   849  // 	-buildmode=c-shared
   850  // 		Build the listed main packages, plus all packages that they
   851  // 		import, into C shared libraries. The only callable symbols will
   852  // 		be those functions exported using a cgo //export comment.
   853  // 		Non-main packages are ignored.
   854  //
   855  // 	-buildmode=default
   856  // 		Listed main packages are built into executables and listed
   857  // 		non-main packages are built into .a files (the default
   858  // 		behavior).
   859  //
   860  // 	-buildmode=shared
   861  // 		Combine all the listed non-main packages into a single shared
   862  // 		library that will be used when building with the -linkshared
   863  // 		option. Packages named main are ignored.
   864  //
   865  // 	-buildmode=exe
   866  // 		Build the listed main packages and everything they import into
   867  // 		executables. Packages not named main are ignored.
   868  //
   869  // 	-buildmode=pie
   870  // 		Build the listed main packages and everything they import into
   871  // 		position independent executables (PIE). Packages not named
   872  // 		main are ignored.
   873  //
   874  // 	-buildmode=plugin
   875  // 		Build the listed main packages, plus all packages that they
   876  // 		import, into a Go plugin. Packages not named main are ignored.
   877  //
   878  //
   879  // File types
   880  //
   881  // The go command examines the contents of a restricted set of files
   882  // in each directory. It identifies which files to examine based on
   883  // the extension of the file name. These extensions are:
   884  //
   885  // 	.go
   886  // 		Go source files.
   887  // 	.c, .h
   888  // 		C source files.
   889  // 		If the package uses cgo or SWIG, these will be compiled with the
   890  // 		OS-native compiler (typically gcc); otherwise they will
   891  // 		trigger an error.
   892  // 	.cc, .cpp, .cxx, .hh, .hpp, .hxx
   893  // 		C++ source files. Only useful with cgo or SWIG, and always
   894  // 		compiled with the OS-native compiler.
   895  // 	.m
   896  // 		Objective-C source files. Only useful with cgo, and always
   897  // 		compiled with the OS-native compiler.
   898  // 	.s, .S
   899  // 		Assembler source files.
   900  // 		If the package uses cgo or SWIG, these will be assembled with the
   901  // 		OS-native assembler (typically gcc (sic)); otherwise they
   902  // 		will be assembled with the Go assembler.
   903  // 	.swig, .swigcxx
   904  // 		SWIG definition files.
   905  // 	.syso
   906  // 		System object files.
   907  //
   908  // Files of each of these types except .syso may contain build
   909  // constraints, but the go command stops scanning for build constraints
   910  // at the first item in the file that is not a blank line or //-style
   911  // line comment. See the go/build package documentation for
   912  // more details.
   913  //
   914  // Non-test Go source files can also include a //go:binary-only-package
   915  // comment, indicating that the package sources are included
   916  // for documentation only and must not be used to build the
   917  // package binary. This enables distribution of Go packages in
   918  // their compiled form alone. See the go/build package documentation
   919  // for more details.
   920  //
   921  //
   922  // GOPATH environment variable
   923  //
   924  // The Go path is used to resolve import statements.
   925  // It is implemented by and documented in the go/build package.
   926  //
   927  // The GOPATH environment variable lists places to look for Go code.
   928  // On Unix, the value is a colon-separated string.
   929  // On Windows, the value is a semicolon-separated string.
   930  // On Plan 9, the value is a list.
   931  //
   932  // If the environment variable is unset, GOPATH defaults
   933  // to a subdirectory named "go" in the user's home directory
   934  // ($HOME/go on Unix, %USERPROFILE%\go on Windows),
   935  // unless that directory holds a Go distribution.
   936  // Run "go env GOPATH" to see the current GOPATH.
   937  //
   938  // See https://golang.org/wiki/SettingGOPATH to set a custom GOPATH.
   939  //
   940  // Each directory listed in GOPATH must have a prescribed structure:
   941  //
   942  // The src directory holds source code.  The path below src
   943  // determines the import path or executable name.
   944  //
   945  // The pkg directory holds installed package objects.
   946  // As in the Go tree, each target operating system and
   947  // architecture pair has its own subdirectory of pkg
   948  // (pkg/GOOS_GOARCH).
   949  //
   950  // If DIR is a directory listed in the GOPATH, a package with
   951  // source in DIR/src/foo/bar can be imported as "foo/bar" and
   952  // has its compiled form installed to "DIR/pkg/GOOS_GOARCH/foo/bar.a".
   953  //
   954  // The bin directory holds compiled commands.
   955  // Each command is named for its source directory, but only
   956  // the final element, not the entire path.  That is, the
   957  // command with source in DIR/src/foo/quux is installed into
   958  // DIR/bin/quux, not DIR/bin/foo/quux.  The "foo/" prefix is stripped
   959  // so that you can add DIR/bin to your PATH to get at the
   960  // installed commands.  If the GOBIN environment variable is
   961  // set, commands are installed to the directory it names instead
   962  // of DIR/bin. GOBIN must be an absolute path.
   963  //
   964  // Here's an example directory layout:
   965  //
   966  //     GOPATH=/home/user/go
   967  //
   968  //     /home/user/go/
   969  //         src/
   970  //             foo/
   971  //                 bar/               (go code in package bar)
   972  //                     x.go
   973  //                 quux/              (go code in package main)
   974  //                     y.go
   975  //         bin/
   976  //             quux                   (installed command)
   977  //         pkg/
   978  //             linux_amd64/
   979  //                 foo/
   980  //                     bar.a          (installed package object)
   981  //
   982  // Go searches each directory listed in GOPATH to find source code,
   983  // but new packages are always downloaded into the first directory
   984  // in the list.
   985  //
   986  // See https://golang.org/doc/code.html for an example.
   987  //
   988  // Internal Directories
   989  //
   990  // Code in or below a directory named "internal" is importable only
   991  // by code in the directory tree rooted at the parent of "internal".
   992  // Here's an extended version of the directory layout above:
   993  //
   994  //     /home/user/go/
   995  //         src/
   996  //             crash/
   997  //                 bang/              (go code in package bang)
   998  //                     b.go
   999  //             foo/                   (go code in package foo)
  1000  //                 f.go
  1001  //                 bar/               (go code in package bar)
  1002  //                     x.go
  1003  //                 internal/
  1004  //                     baz/           (go code in package baz)
  1005  //                         z.go
  1006  //                 quux/              (go code in package main)
  1007  //                     y.go
  1008  //
  1009  //
  1010  // The code in z.go is imported as "foo/internal/baz", but that
  1011  // import statement can only appear in source files in the subtree
  1012  // rooted at foo. The source files foo/f.go, foo/bar/x.go, and
  1013  // foo/quux/y.go can all import "foo/internal/baz", but the source file
  1014  // crash/bang/b.go cannot.
  1015  //
  1016  // See https://golang.org/s/go14internal for details.
  1017  //
  1018  // Vendor Directories
  1019  //
  1020  // Go 1.6 includes support for using local copies of external dependencies
  1021  // to satisfy imports of those dependencies, often referred to as vendoring.
  1022  //
  1023  // Code below a directory named "vendor" is importable only
  1024  // by code in the directory tree rooted at the parent of "vendor",
  1025  // and only using an import path that omits the prefix up to and
  1026  // including the vendor element.
  1027  //
  1028  // Here's the example from the previous section,
  1029  // but with the "internal" directory renamed to "vendor"
  1030  // and a new foo/vendor/crash/bang directory added:
  1031  //
  1032  //     /home/user/go/
  1033  //         src/
  1034  //             crash/
  1035  //                 bang/              (go code in package bang)
  1036  //                     b.go
  1037  //             foo/                   (go code in package foo)
  1038  //                 f.go
  1039  //                 bar/               (go code in package bar)
  1040  //                     x.go
  1041  //                 vendor/
  1042  //                     crash/
  1043  //                         bang/      (go code in package bang)
  1044  //                             b.go
  1045  //                     baz/           (go code in package baz)
  1046  //                         z.go
  1047  //                 quux/              (go code in package main)
  1048  //                     y.go
  1049  //
  1050  // The same visibility rules apply as for internal, but the code
  1051  // in z.go is imported as "baz", not as "foo/vendor/baz".
  1052  //
  1053  // Code in vendor directories deeper in the source tree shadows
  1054  // code in higher directories. Within the subtree rooted at foo, an import
  1055  // of "crash/bang" resolves to "foo/vendor/crash/bang", not the
  1056  // top-level "crash/bang".
  1057  //
  1058  // Code in vendor directories is not subject to import path
  1059  // checking (see 'go help importpath').
  1060  //
  1061  // When 'go get' checks out or updates a git repository, it now also
  1062  // updates submodules.
  1063  //
  1064  // Vendor directories do not affect the placement of new repositories
  1065  // being checked out for the first time by 'go get': those are always
  1066  // placed in the main GOPATH, never in a vendor subtree.
  1067  //
  1068  // See https://golang.org/s/go15vendor for details.
  1069  //
  1070  //
  1071  // Environment variables
  1072  //
  1073  // The go command, and the tools it invokes, examine a few different
  1074  // environment variables. For many of these, you can see the default
  1075  // value of on your system by running 'go env NAME', where NAME is the
  1076  // name of the variable.
  1077  //
  1078  // General-purpose environment variables:
  1079  //
  1080  // 	GCCGO
  1081  // 		The gccgo command to run for 'go build -compiler=gccgo'.
  1082  // 	GOARCH
  1083  // 		The architecture, or processor, for which to compile code.
  1084  // 		Examples are amd64, 386, arm, ppc64.
  1085  // 	GOBIN
  1086  // 		The directory where 'go install' will install a command.
  1087  // 	GOOS
  1088  // 		The operating system for which to compile code.
  1089  // 		Examples are linux, darwin, windows, netbsd.
  1090  // 	GOPATH
  1091  // 		For more details see: 'go help gopath'.
  1092  // 	GORACE
  1093  // 		Options for the race detector.
  1094  // 		See https://golang.org/doc/articles/race_detector.html.
  1095  // 	GOROOT
  1096  // 		The root of the go tree.
  1097  //
  1098  // Environment variables for use with cgo:
  1099  //
  1100  // 	CC
  1101  // 		The command to use to compile C code.
  1102  // 	CGO_ENABLED
  1103  // 		Whether the cgo command is supported.  Either 0 or 1.
  1104  // 	CGO_CFLAGS
  1105  // 		Flags that cgo will pass to the compiler when compiling
  1106  // 		C code.
  1107  // 	CGO_CPPFLAGS
  1108  // 		Flags that cgo will pass to the compiler when compiling
  1109  // 		C or C++ code.
  1110  // 	CGO_CXXFLAGS
  1111  // 		Flags that cgo will pass to the compiler when compiling
  1112  // 		C++ code.
  1113  // 	CGO_FFLAGS
  1114  // 		Flags that cgo will pass to the compiler when compiling
  1115  // 		Fortran code.
  1116  // 	CGO_LDFLAGS
  1117  // 		Flags that cgo will pass to the compiler when linking.
  1118  // 	CXX
  1119  // 		The command to use to compile C++ code.
  1120  // 	PKG_CONFIG
  1121  // 		Path to pkg-config tool.
  1122  //
  1123  // Architecture-specific environment variables:
  1124  //
  1125  // 	GOARM
  1126  // 		For GOARCH=arm, the ARM architecture for which to compile.
  1127  // 		Valid values are 5, 6, 7.
  1128  // 	GO386
  1129  // 		For GOARCH=386, the floating point instruction set.
  1130  // 		Valid values are 387, sse2.
  1131  //
  1132  // Special-purpose environment variables:
  1133  //
  1134  // 	GOROOT_FINAL
  1135  // 		The root of the installed Go tree, when it is
  1136  // 		installed in a location other than where it is built.
  1137  // 		File names in stack traces are rewritten from GOROOT to
  1138  // 		GOROOT_FINAL.
  1139  // 	GO_EXTLINK_ENABLED
  1140  // 		Whether the linker should use external linking mode
  1141  // 		when using -linkmode=auto with code that uses cgo.
  1142  // 		Set to 0 to disable external linking mode, 1 to enable it.
  1143  // 	GIT_ALLOW_PROTOCOL
  1144  // 		Defined by Git. A colon-separated list of schemes that are allowed to be used
  1145  // 		with git fetch/clone. If set, any scheme not explicitly mentioned will be
  1146  // 		considered insecure by 'go get'.
  1147  //
  1148  //
  1149  // Import path syntax
  1150  //
  1151  // An import path (see 'go help packages') denotes a package stored in the local
  1152  // file system.  In general, an import path denotes either a standard package (such
  1153  // as "unicode/utf8") or a package found in one of the work spaces (For more
  1154  // details see: 'go help gopath').
  1155  //
  1156  // Relative import paths
  1157  //
  1158  // An import path beginning with ./ or ../ is called a relative path.
  1159  // The toolchain supports relative import paths as a shortcut in two ways.
  1160  //
  1161  // First, a relative path can be used as a shorthand on the command line.
  1162  // If you are working in the directory containing the code imported as
  1163  // "unicode" and want to run the tests for "unicode/utf8", you can type
  1164  // "go test ./utf8" instead of needing to specify the full path.
  1165  // Similarly, in the reverse situation, "go test .." will test "unicode" from
  1166  // the "unicode/utf8" directory. Relative patterns are also allowed, like
  1167  // "go test ./..." to test all subdirectories. See 'go help packages' for details
  1168  // on the pattern syntax.
  1169  //
  1170  // Second, if you are compiling a Go program not in a work space,
  1171  // you can use a relative path in an import statement in that program
  1172  // to refer to nearby code also not in a work space.
  1173  // This makes it easy to experiment with small multipackage programs
  1174  // outside of the usual work spaces, but such programs cannot be
  1175  // installed with "go install" (there is no work space in which to install them),
  1176  // so they are rebuilt from scratch each time they are built.
  1177  // To avoid ambiguity, Go programs cannot use relative import paths
  1178  // within a work space.
  1179  //
  1180  // Remote import paths
  1181  //
  1182  // Certain import paths also
  1183  // describe how to obtain the source code for the package using
  1184  // a revision control system.
  1185  //
  1186  // A few common code hosting sites have special syntax:
  1187  //
  1188  // 	Bitbucket (Git, Mercurial)
  1189  //
  1190  // 		import "bitbucket.org/user/project"
  1191  // 		import "bitbucket.org/user/project/sub/directory"
  1192  //
  1193  // 	GitHub (Git)
  1194  //
  1195  // 		import "github.com/user/project"
  1196  // 		import "github.com/user/project/sub/directory"
  1197  //
  1198  // 	Launchpad (Bazaar)
  1199  //
  1200  // 		import "launchpad.net/project"
  1201  // 		import "launchpad.net/project/series"
  1202  // 		import "launchpad.net/project/series/sub/directory"
  1203  //
  1204  // 		import "launchpad.net/~user/project/branch"
  1205  // 		import "launchpad.net/~user/project/branch/sub/directory"
  1206  //
  1207  // 	IBM DevOps Services (Git)
  1208  //
  1209  // 		import "hub.jazz.net/git/user/project"
  1210  // 		import "hub.jazz.net/git/user/project/sub/directory"
  1211  //
  1212  // For code hosted on other servers, import paths may either be qualified
  1213  // with the version control type, or the go tool can dynamically fetch
  1214  // the import path over https/http and discover where the code resides
  1215  // from a <meta> tag in the HTML.
  1216  //
  1217  // To declare the code location, an import path of the form
  1218  //
  1219  // 	repository.vcs/path
  1220  //
  1221  // specifies the given repository, with or without the .vcs suffix,
  1222  // using the named version control system, and then the path inside
  1223  // that repository.  The supported version control systems are:
  1224  //
  1225  // 	Bazaar      .bzr
  1226  // 	Git         .git
  1227  // 	Mercurial   .hg
  1228  // 	Subversion  .svn
  1229  //
  1230  // For example,
  1231  //
  1232  // 	import "example.org/user/foo.hg"
  1233  //
  1234  // denotes the root directory of the Mercurial repository at
  1235  // example.org/user/foo or foo.hg, and
  1236  //
  1237  // 	import "example.org/repo.git/foo/bar"
  1238  //
  1239  // denotes the foo/bar directory of the Git repository at
  1240  // example.org/repo or repo.git.
  1241  //
  1242  // When a version control system supports multiple protocols,
  1243  // each is tried in turn when downloading.  For example, a Git
  1244  // download tries https://, then git+ssh://.
  1245  //
  1246  // By default, downloads are restricted to known secure protocols
  1247  // (e.g. https, ssh). To override this setting for Git downloads, the
  1248  // GIT_ALLOW_PROTOCOL environment variable can be set (For more details see:
  1249  // 'go help environment').
  1250  //
  1251  // If the import path is not a known code hosting site and also lacks a
  1252  // version control qualifier, the go tool attempts to fetch the import
  1253  // over https/http and looks for a <meta> tag in the document's HTML
  1254  // <head>.
  1255  //
  1256  // The meta tag has the form:
  1257  //
  1258  // 	<meta name="go-import" content="import-prefix vcs repo-root">
  1259  //
  1260  // The import-prefix is the import path corresponding to the repository
  1261  // root. It must be a prefix or an exact match of the package being
  1262  // fetched with "go get". If it's not an exact match, another http
  1263  // request is made at the prefix to verify the <meta> tags match.
  1264  //
  1265  // The meta tag should appear as early in the file as possible.
  1266  // In particular, it should appear before any raw JavaScript or CSS,
  1267  // to avoid confusing the go command's restricted parser.
  1268  //
  1269  // The vcs is one of "git", "hg", "svn", etc,
  1270  //
  1271  // The repo-root is the root of the version control system
  1272  // containing a scheme and not containing a .vcs qualifier.
  1273  //
  1274  // For example,
  1275  //
  1276  // 	import "example.org/pkg/foo"
  1277  //
  1278  // will result in the following requests:
  1279  //
  1280  // 	https://example.org/pkg/foo?go-get=1 (preferred)
  1281  // 	http://example.org/pkg/foo?go-get=1  (fallback, only with -insecure)
  1282  //
  1283  // If that page contains the meta tag
  1284  //
  1285  // 	<meta name="go-import" content="example.org git https://code.org/r/p/exproj">
  1286  //
  1287  // the go tool will verify that https://example.org/?go-get=1 contains the
  1288  // same meta tag and then git clone https://code.org/r/p/exproj into
  1289  // GOPATH/src/example.org.
  1290  //
  1291  // New downloaded packages are written to the first directory listed in the GOPATH
  1292  // environment variable (For more details see: 'go help gopath').
  1293  //
  1294  // The go command attempts to download the version of the
  1295  // package appropriate for the Go release being used.
  1296  // Run 'go help get' for more.
  1297  //
  1298  // Import path checking
  1299  //
  1300  // When the custom import path feature described above redirects to a
  1301  // known code hosting site, each of the resulting packages has two possible
  1302  // import paths, using the custom domain or the known hosting site.
  1303  //
  1304  // A package statement is said to have an "import comment" if it is immediately
  1305  // followed (before the next newline) by a comment of one of these two forms:
  1306  //
  1307  // 	package math // import "path"
  1308  // 	package math /* import "path" */
  1309  //
  1310  // The go command will refuse to install a package with an import comment
  1311  // unless it is being referred to by that import path. In this way, import comments
  1312  // let package authors make sure the custom import path is used and not a
  1313  // direct path to the underlying code hosting site.
  1314  //
  1315  // Import path checking is disabled for code found within vendor trees.
  1316  // This makes it possible to copy code into alternate locations in vendor trees
  1317  // without needing to update import comments.
  1318  //
  1319  // See https://golang.org/s/go14customimport for details.
  1320  //
  1321  //
  1322  // Description of package lists
  1323  //
  1324  // Many commands apply to a set of packages:
  1325  //
  1326  // 	go action [packages]
  1327  //
  1328  // Usually, [packages] is a list of import paths.
  1329  //
  1330  // An import path that is a rooted path or that begins with
  1331  // a . or .. element is interpreted as a file system path and
  1332  // denotes the package in that directory.
  1333  //
  1334  // Otherwise, the import path P denotes the package found in
  1335  // the directory DIR/src/P for some DIR listed in the GOPATH
  1336  // environment variable (For more details see: 'go help gopath').
  1337  //
  1338  // If no import paths are given, the action applies to the
  1339  // package in the current directory.
  1340  //
  1341  // There are four reserved names for paths that should not be used
  1342  // for packages to be built with the go tool:
  1343  //
  1344  // - "main" denotes the top-level package in a stand-alone executable.
  1345  //
  1346  // - "all" expands to all package directories found in all the GOPATH
  1347  // trees. For example, 'go list all' lists all the packages on the local
  1348  // system.
  1349  //
  1350  // - "std" is like all but expands to just the packages in the standard
  1351  // Go library.
  1352  //
  1353  // - "cmd" expands to the Go repository's commands and their
  1354  // internal libraries.
  1355  //
  1356  // Import paths beginning with "cmd/" only match source code in
  1357  // the Go repository.
  1358  //
  1359  // An import path is a pattern if it includes one or more "..." wildcards,
  1360  // each of which can match any string, including the empty string and
  1361  // strings containing slashes.  Such a pattern expands to all package
  1362  // directories found in the GOPATH trees with names matching the
  1363  // patterns.  As a special case, x/... matches x as well as x's subdirectories.
  1364  // For example, net/... expands to net and packages in its subdirectories.
  1365  //
  1366  // An import path can also name a package to be downloaded from
  1367  // a remote repository.  Run 'go help importpath' for details.
  1368  //
  1369  // Every package in a program must have a unique import path.
  1370  // By convention, this is arranged by starting each path with a
  1371  // unique prefix that belongs to you.  For example, paths used
  1372  // internally at Google all begin with 'google', and paths
  1373  // denoting remote repositories begin with the path to the code,
  1374  // such as 'github.com/user/repo'.
  1375  //
  1376  // Packages in a program need not have unique package names,
  1377  // but there are two reserved package names with special meaning.
  1378  // The name main indicates a command, not a library.
  1379  // Commands are built into binaries and cannot be imported.
  1380  // The name documentation indicates documentation for
  1381  // a non-Go program in the directory. Files in package documentation
  1382  // are ignored by the go command.
  1383  //
  1384  // As a special case, if the package list is a list of .go files from a
  1385  // single directory, the command is applied to a single synthesized
  1386  // package made up of exactly those files, ignoring any build constraints
  1387  // in those files and ignoring any other files in the directory.
  1388  //
  1389  // Directory and file names that begin with "." or "_" are ignored
  1390  // by the go tool, as are directories named "testdata".
  1391  //
  1392  //
  1393  // Description of testing flags
  1394  //
  1395  // The 'go test' command takes both flags that apply to 'go test' itself
  1396  // and flags that apply to the resulting test binary.
  1397  //
  1398  // Several of the flags control profiling and write an execution profile
  1399  // suitable for "go tool pprof"; run "go tool pprof -h" for more
  1400  // information.  The --alloc_space, --alloc_objects, and --show_bytes
  1401  // options of pprof control how the information is presented.
  1402  //
  1403  // The following flags are recognized by the 'go test' command and
  1404  // control the execution of any test:
  1405  //
  1406  // 	-bench regexp
  1407  // 	    Run (sub)benchmarks matching a regular expression.
  1408  // 	    The given regular expression is split into smaller ones by
  1409  // 	    top-level '/', where each must match the corresponding part of a
  1410  // 	    benchmark's identifier.
  1411  // 	    By default, no benchmarks run. To run all benchmarks,
  1412  // 	    use '-bench .' or '-bench=.'.
  1413  //
  1414  // 	-benchtime t
  1415  // 	    Run enough iterations of each benchmark to take t, specified
  1416  // 	    as a time.Duration (for example, -benchtime 1h30s).
  1417  // 	    The default is 1 second (1s).
  1418  //
  1419  // 	-count n
  1420  // 	    Run each test and benchmark n times (default 1).
  1421  // 	    If -cpu is set, run n times for each GOMAXPROCS value.
  1422  // 	    Examples are always run once.
  1423  //
  1424  // 	-cover
  1425  // 	    Enable coverage analysis.
  1426  //
  1427  // 	-covermode set,count,atomic
  1428  // 	    Set the mode for coverage analysis for the package[s]
  1429  // 	    being tested. The default is "set" unless -race is enabled,
  1430  // 	    in which case it is "atomic".
  1431  // 	    The values:
  1432  // 		set: bool: does this statement run?
  1433  // 		count: int: how many times does this statement run?
  1434  // 		atomic: int: count, but correct in multithreaded tests;
  1435  // 			significantly more expensive.
  1436  // 	    Sets -cover.
  1437  //
  1438  // 	-coverpkg pkg1,pkg2,pkg3
  1439  // 	    Apply coverage analysis in each test to the given list of packages.
  1440  // 	    The default is for each test to analyze only the package being tested.
  1441  // 	    Packages are specified as import paths.
  1442  // 	    Sets -cover.
  1443  //
  1444  // 	-cpu 1,2,4
  1445  // 	    Specify a list of GOMAXPROCS values for which the tests or
  1446  // 	    benchmarks should be executed.  The default is the current value
  1447  // 	    of GOMAXPROCS.
  1448  //
  1449  // 	-parallel n
  1450  // 	    Allow parallel execution of test functions that call t.Parallel.
  1451  // 	    The value of this flag is the maximum number of tests to run
  1452  // 	    simultaneously; by default, it is set to the value of GOMAXPROCS.
  1453  // 	    Note that -parallel only applies within a single test binary.
  1454  // 	    The 'go test' command may run tests for different packages
  1455  // 	    in parallel as well, according to the setting of the -p flag
  1456  // 	    (see 'go help build').
  1457  //
  1458  // 	-run regexp
  1459  // 	    Run only those tests and examples matching the regular expression.
  1460  // 	    For tests the regular expression is split into smaller ones by
  1461  // 	    top-level '/', where each must match the corresponding part of a
  1462  // 	    test's identifier.
  1463  //
  1464  // 	-short
  1465  // 	    Tell long-running tests to shorten their run time.
  1466  // 	    It is off by default but set during all.bash so that installing
  1467  // 	    the Go tree can run a sanity check but not spend time running
  1468  // 	    exhaustive tests.
  1469  //
  1470  // 	-timeout t
  1471  // 	    If a test runs longer than t, panic.
  1472  // 	    The default is 10 minutes (10m).
  1473  //
  1474  // 	-v
  1475  // 	    Verbose output: log all tests as they are run. Also print all
  1476  // 	    text from Log and Logf calls even if the test succeeds.
  1477  //
  1478  // The following flags are also recognized by 'go test' and can be used to
  1479  // profile the tests during execution:
  1480  //
  1481  // 	-benchmem
  1482  // 	    Print memory allocation statistics for benchmarks.
  1483  //
  1484  // 	-blockprofile block.out
  1485  // 	    Write a goroutine blocking profile to the specified file
  1486  // 	    when all tests are complete.
  1487  // 	    Writes test binary as -c would.
  1488  //
  1489  // 	-blockprofilerate n
  1490  // 	    Control the detail provided in goroutine blocking profiles by
  1491  // 	    calling runtime.SetBlockProfileRate with n.
  1492  // 	    See 'go doc runtime.SetBlockProfileRate'.
  1493  // 	    The profiler aims to sample, on average, one blocking event every
  1494  // 	    n nanoseconds the program spends blocked.  By default,
  1495  // 	    if -test.blockprofile is set without this flag, all blocking events
  1496  // 	    are recorded, equivalent to -test.blockprofilerate=1.
  1497  //
  1498  // 	-coverprofile cover.out
  1499  // 	    Write a coverage profile to the file after all tests have passed.
  1500  // 	    Sets -cover.
  1501  //
  1502  // 	-cpuprofile cpu.out
  1503  // 	    Write a CPU profile to the specified file before exiting.
  1504  // 	    Writes test binary as -c would.
  1505  //
  1506  // 	-memprofile mem.out
  1507  // 	    Write a memory profile to the file after all tests have passed.
  1508  // 	    Writes test binary as -c would.
  1509  //
  1510  // 	-memprofilerate n
  1511  // 	    Enable more precise (and expensive) memory profiles by setting
  1512  // 	    runtime.MemProfileRate.  See 'go doc runtime.MemProfileRate'.
  1513  // 	    To profile all memory allocations, use -test.memprofilerate=1
  1514  // 	    and pass --alloc_space flag to the pprof tool.
  1515  //
  1516  // 	-mutexprofile mutex.out
  1517  // 	    Write a mutex contention profile to the specified file
  1518  // 	    when all tests are complete.
  1519  // 	    Writes test binary as -c would.
  1520  //
  1521  // 	-mutexprofilefraction n
  1522  // 	    Sample 1 in n stack traces of goroutines holding a
  1523  // 	    contended mutex.
  1524  //
  1525  // 	-outputdir directory
  1526  // 	    Place output files from profiling in the specified directory,
  1527  // 	    by default the directory in which "go test" is running.
  1528  //
  1529  // 	-trace trace.out
  1530  // 	    Write an execution trace to the specified file before exiting.
  1531  //
  1532  // Each of these flags is also recognized with an optional 'test.' prefix,
  1533  // as in -test.v. When invoking the generated test binary (the result of
  1534  // 'go test -c') directly, however, the prefix is mandatory.
  1535  //
  1536  // The 'go test' command rewrites or removes recognized flags,
  1537  // as appropriate, both before and after the optional package list,
  1538  // before invoking the test binary.
  1539  //
  1540  // For instance, the command
  1541  //
  1542  // 	go test -v -myflag testdata -cpuprofile=prof.out -x
  1543  //
  1544  // will compile the test binary and then run it as
  1545  //
  1546  // 	pkg.test -test.v -myflag testdata -test.cpuprofile=prof.out
  1547  //
  1548  // (The -x flag is removed because it applies only to the go command's
  1549  // execution, not to the test itself.)
  1550  //
  1551  // The test flags that generate profiles (other than for coverage) also
  1552  // leave the test binary in pkg.test for use when analyzing the profiles.
  1553  //
  1554  // When 'go test' runs a test binary, it does so from within the
  1555  // corresponding package's source code directory. Depending on the test,
  1556  // it may be necessary to do the same when invoking a generated test
  1557  // binary directly.
  1558  //
  1559  // The command-line package list, if present, must appear before any
  1560  // flag not known to the go test command. Continuing the example above,
  1561  // the package list would have to appear before -myflag, but could appear
  1562  // on either side of -v.
  1563  //
  1564  // To keep an argument for a test binary from being interpreted as a
  1565  // known flag or a package name, use -args (see 'go help test') which
  1566  // passes the remainder of the command line through to the test binary
  1567  // uninterpreted and unaltered.
  1568  //
  1569  // For instance, the command
  1570  //
  1571  // 	go test -v -args -x -v
  1572  //
  1573  // will compile the test binary and then run it as
  1574  //
  1575  // 	pkg.test -test.v -x -v
  1576  //
  1577  // Similarly,
  1578  //
  1579  // 	go test -args math
  1580  //
  1581  // will compile the test binary and then run it as
  1582  //
  1583  // 	pkg.test math
  1584  //
  1585  // In the first example, the -x and the second -v are passed through to the
  1586  // test binary unchanged and with no effect on the go command itself.
  1587  // In the second example, the argument math is passed through to the test
  1588  // binary, instead of being interpreted as the package list.
  1589  //
  1590  //
  1591  // Description of testing functions
  1592  //
  1593  // The 'go test' command expects to find test, benchmark, and example functions
  1594  // in the "*_test.go" files corresponding to the package under test.
  1595  //
  1596  // A test function is one named TestXXX (where XXX is any alphanumeric string
  1597  // not starting with a lower case letter) and should have the signature,
  1598  //
  1599  // 	func TestXXX(t *testing.T) { ... }
  1600  //
  1601  // A benchmark function is one named BenchmarkXXX and should have the signature,
  1602  //
  1603  // 	func BenchmarkXXX(b *testing.B) { ... }
  1604  //
  1605  // An example function is similar to a test function but, instead of using
  1606  // *testing.T to report success or failure, prints output to os.Stdout.
  1607  // If the last comment in the function starts with "Output:" then the output
  1608  // is compared exactly against the comment (see examples below). If the last
  1609  // comment begins with "Unordered output:" then the output is compared to the
  1610  // comment, however the order of the lines is ignored. An example with no such
  1611  // comment is compiled but not executed. An example with no text after
  1612  // "Output:" is compiled, executed, and expected to produce no output.
  1613  //
  1614  // Godoc displays the body of ExampleXXX to demonstrate the use
  1615  // of the function, constant, or variable XXX.  An example of a method M with
  1616  // receiver type T or *T is named ExampleT_M.  There may be multiple examples
  1617  // for a given function, constant, or variable, distinguished by a trailing _xxx,
  1618  // where xxx is a suffix not beginning with an upper case letter.
  1619  //
  1620  // Here is an example of an example:
  1621  //
  1622  // 	func ExamplePrintln() {
  1623  // 		Println("The output of\nthis example.")
  1624  // 		// Output: The output of
  1625  // 		// this example.
  1626  // 	}
  1627  //
  1628  // Here is another example where the ordering of the output is ignored:
  1629  //
  1630  // 	func ExamplePerm() {
  1631  // 		for _, value := range Perm(4) {
  1632  // 			fmt.Println(value)
  1633  // 		}
  1634  //
  1635  // 		// Unordered output: 4
  1636  // 		// 2
  1637  // 		// 1
  1638  // 		// 3
  1639  // 		// 0
  1640  // 	}
  1641  //
  1642  // The entire test file is presented as the example when it contains a single
  1643  // example function, at least one other function, type, variable, or constant
  1644  // declaration, and no test or benchmark functions.
  1645  //
  1646  // See the documentation of the testing package for more information.
  1647  //
  1648  //
  1649  package main