cmd/dist: read dependencies from source files

I do not remember why we require deps.go to have a hard-coded
copy of the dependency information for cmd/go, when we can
read it from the source files instead. The answer probably involves
cmd/dist once being a C program.

In any event, stop doing that, which will eliminate the builder-only
failures in the builder-only deps test.

Change-Id: I0abd384c47401940ca08427b5be544812edcbe7f
Reviewed-on: https://go-review.googlesource.com/76021
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index 1eba53ce2cd086bd8320d31a081eab59a41fae36..aa2402163d6963e94ae0370c5a51c280b13448df 100644 (file)
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -533,15 +533,35 @@ var gentab = []struct {
 // installed maps from a dir name (as given to install) to a chan
 // closed when the dir's package is installed.
 var installed = make(map[string]chan struct{})
+var installedMu sync.Mutex
 
-// install installs the library, package, or binary associated with dir,
-// which is relative to $GOROOT/src.
 func install(dir string) {
-       if ch, ok := installed[dir]; ok {
-               defer close(ch)
+       <-startInstall(dir)
+}
+
+func startInstall(dir string) chan struct{} {
+       installedMu.Lock()
+       ch := installed[dir]
+       if ch == nil {
+               ch = make(chan struct{})
+               installed[dir] = ch
+               go runInstall(dir, ch)
+       }
+       installedMu.Unlock()
+       return ch
+}
+
+// runInstall installs the library, package, or binary associated with dir,
+// which is relative to $GOROOT/src.
+func runInstall(dir string, ch chan struct{}) {
+       if dir == "net" || dir == "os/user" || dir == "crypto/x509" {
+               fatalf("go_bootstrap cannot depend on cgo package %s", dir)
        }
-       for _, dep := range builddeps[dir] {
-               <-installed[dep]
+
+       defer close(ch)
+
+       if dir == "unsafe" {
+               return
        }
 
        if vflag > 0 {
@@ -660,7 +680,7 @@ func install(dir string) {
        }
 
        // For package runtime, copy some files into the work space.
-       if dir == "runtime" || strings.HasPrefix(dir, "runtime/internal/") {
+       if dir == "runtime" {
                xmkdirall(pathf("%s/pkg/include", goroot))
                // For use by assembly and C files.
                copyfile(pathf("%s/pkg/include/textflag.h", goroot),
@@ -700,6 +720,18 @@ func install(dir string) {
        built:
        }
 
+       // Make sure dependencies are installed.
+       var deps []string
+       for _, p := range gofiles {
+               deps = append(deps, readimports(p)...)
+       }
+       for _, dir1 := range deps {
+               startInstall(dir1)
+       }
+       for _, dir1 := range deps {
+               install(dir1)
+       }
+
        if goos != gohostos || goarch != gohostarch {
                // We've generated the right files; the go command can do the build.
                if vflag > 1 {
@@ -906,28 +938,21 @@ func dopack(dst, src string, extra []string) {
        writefile(bdst.String(), dst, 0)
 }
 
-// builddeps records the build dependencies for the 'go bootstrap' command.
-// It is a map[string][]string and generated by mkdeps.bash into deps.go.
-
-// buildlist is the list of directories being built, sorted by name.
-var buildlist = makeBuildlist()
-
-func makeBuildlist() []string {
-       var all []string
-       for dir := range builddeps {
-               all = append(all, dir)
-       }
-       sort.Strings(all)
-       return all
-}
-
 var runtimegen = []string{
        "zaexperiment.h",
        "zversion.go",
 }
 
+// cleanlist is a list of packages with generated files and commands.
+var cleanlist = []string{
+       "runtime/internal/sys",
+       "cmd/cgo",
+       "cmd/go/internal/cfg",
+       "go/build",
+}
+
 func clean() {
-       for _, name := range buildlist {
+       for _, name := range cleanlist {
                path := pathf("%s/src/%s", goroot, name)
                // Remove generated files.
                for _, elem := range xreaddir(path) {
@@ -1110,13 +1135,8 @@ func cmdbootstrap() {
 
        timelog("build", "go_bootstrap")
        xprintf("Building Go bootstrap cmd/go (go_bootstrap) using Go toolchain1.\n")
-       for _, dir := range buildlist {
-               installed[dir] = make(chan struct{})
-       }
-       for _, dir := range buildlist {
-               go install(dir)
-       }
-       <-installed["cmd/go"]
+       install("runtime") // dependency not visible in sources; also sets up textflag.h
+       install("cmd/go")
        if vflag > 0 {
                xprintf("\n")
        }

diff --git a/src/cmd/dist/deps.go b/src/cmd/dist/deps.go
deleted file mode 100644 (file)
index 294ca22..0000000
--- a/src/cmd/dist/deps.go
+++ /dev/null
@@ -1,928 +0,0 @@
-// Code generated by mkdeps.bash; DO NOT EDIT.
-
-package main
-
-var builddeps = map[string][]string{
-
-       "bufio": {
-               "bytes",        // bufio
-               "errors",       // bufio
-               "io",           // bufio
-               "unicode/utf8", // bufio
-       },
-
-       "bytes": {
-               "errors",       // bytes
-               "internal/cpu", // bytes
-               "io",           // bytes
-               "unicode",      // bytes
-               "unicode/utf8", // bytes
-       },
-
-       "cmd/go": {
-               "cmd/go/internal/base",     // cmd/go
-               "cmd/go/internal/bug",      // cmd/go
-               "cmd/go/internal/cfg",      // cmd/go
-               "cmd/go/internal/clean",    // cmd/go
-               "cmd/go/internal/doc",      // cmd/go
-               "cmd/go/internal/envcmd",   // cmd/go
-               "cmd/go/internal/fix",      // cmd/go
-               "cmd/go/internal/fmtcmd",   // cmd/go
-               "cmd/go/internal/generate", // cmd/go
-               "cmd/go/internal/get",      // cmd/go
-               "cmd/go/internal/help",     // cmd/go
-               "cmd/go/internal/list",     // cmd/go
-               "cmd/go/internal/run",      // cmd/go
-               "cmd/go/internal/test",     // cmd/go
-               "cmd/go/internal/tool",     // cmd/go
-               "cmd/go/internal/version",  // cmd/go
-               "cmd/go/internal/vet",      // cmd/go
-               "cmd/go/internal/work",     // cmd/go
-               "flag",                     // cmd/go
-               "fmt",                      // cmd/go
-               "log",                      // cmd/go
-               "os",                       // cmd/go
-               "path/filepath",            // cmd/go
-               "runtime",                  // cmd/go
-               "strings",                  // cmd/go
-       },
-
-       "cmd/go/internal/base": {
-               "bytes",               // cmd/go/internal/base
-               "cmd/go/internal/cfg", // cmd/go/internal/base
-               "cmd/go/internal/str", // cmd/go/internal/base
-               "errors",              // cmd/go/internal/base
-               "flag",                // cmd/go/internal/base
-               "fmt",                 // cmd/go/internal/base
-               "go/build",            // cmd/go/internal/base
-               "go/scanner",          // cmd/go/internal/base
-               "log",                 // cmd/go/internal/base
-               "os",                  // cmd/go/internal/base
-               "os/exec",             // cmd/go/internal/base
-               "os/signal",           // cmd/go/internal/base
-               "path/filepath",       // cmd/go/internal/base
-               "runtime",             // cmd/go/internal/base
-               "strings",             // cmd/go/internal/base
-               "sync",                // cmd/go/internal/base
-               "syscall",             // cmd/go/internal/base
-       },
-
-       "cmd/go/internal/bug": {
-               "bytes",                  // cmd/go/internal/bug
-               "cmd/go/internal/base",   // cmd/go/internal/bug
-               "cmd/go/internal/cfg",    // cmd/go/internal/bug
-               "cmd/go/internal/envcmd", // cmd/go/internal/bug
-               "cmd/go/internal/web",    // cmd/go/internal/bug
-               "fmt",           // cmd/go/internal/bug
-               "io",            // cmd/go/internal/bug
-               "io/ioutil",     // cmd/go/internal/bug
-               "os",            // cmd/go/internal/bug
-               "os/exec",       // cmd/go/internal/bug
-               "path/filepath", // cmd/go/internal/bug
-               "regexp",        // cmd/go/internal/bug
-               "runtime",       // cmd/go/internal/bug
-               "strings",       // cmd/go/internal/bug
-       },
-
-       "cmd/go/internal/cache": {
-               "bytes",                // cmd/go/internal/cache
-               "cmd/go/internal/base", // cmd/go/internal/cache
-               "crypto/sha256",        // cmd/go/internal/cache
-               "encoding/hex",         // cmd/go/internal/cache
-               "errors",               // cmd/go/internal/cache
-               "fmt",                  // cmd/go/internal/cache
-               "hash",                 // cmd/go/internal/cache
-               "io",                   // cmd/go/internal/cache
-               "io/ioutil",            // cmd/go/internal/cache
-               "os",                   // cmd/go/internal/cache
-               "path/filepath",        // cmd/go/internal/cache
-               "runtime",              // cmd/go/internal/cache
-               "strconv",              // cmd/go/internal/cache
-               "strings",              // cmd/go/internal/cache
-               "sync",                 // cmd/go/internal/cache
-               "time",                 // cmd/go/internal/cache
-       },
-
-       "cmd/go/internal/cfg": {
-               "cmd/internal/objabi", // cmd/go/internal/cfg
-               "fmt",           // cmd/go/internal/cfg
-               "go/build",      // cmd/go/internal/cfg
-               "os",            // cmd/go/internal/cfg
-               "path/filepath", // cmd/go/internal/cfg
-               "runtime",       // cmd/go/internal/cfg
-       },
-
-       "cmd/go/internal/clean": {
-               "cmd/go/internal/base",  // cmd/go/internal/clean
-               "cmd/go/internal/cache", // cmd/go/internal/clean
-               "cmd/go/internal/cfg",   // cmd/go/internal/clean
-               "cmd/go/internal/load",  // cmd/go/internal/clean
-               "cmd/go/internal/work",  // cmd/go/internal/clean
-               "fmt",           // cmd/go/internal/clean
-               "io/ioutil",     // cmd/go/internal/clean
-               "os",            // cmd/go/internal/clean
-               "path/filepath", // cmd/go/internal/clean
-               "strings",       // cmd/go/internal/clean
-       },
-
-       "cmd/go/internal/cmdflag": {
-               "cmd/go/internal/base", // cmd/go/internal/cmdflag
-               "flag",                 // cmd/go/internal/cmdflag
-               "fmt",                  // cmd/go/internal/cmdflag
-               "os",                   // cmd/go/internal/cmdflag
-               "strconv",              // cmd/go/internal/cmdflag
-               "strings",              // cmd/go/internal/cmdflag
-       },
-
-       "cmd/go/internal/doc": {
-               "cmd/go/internal/base", // cmd/go/internal/doc
-               "cmd/go/internal/cfg",  // cmd/go/internal/doc
-       },
-
-       "cmd/go/internal/envcmd": {
-               "cmd/go/internal/base",  // cmd/go/internal/envcmd
-               "cmd/go/internal/cache", // cmd/go/internal/envcmd
-               "cmd/go/internal/cfg",   // cmd/go/internal/envcmd
-               "cmd/go/internal/load",  // cmd/go/internal/envcmd
-               "cmd/go/internal/work",  // cmd/go/internal/envcmd
-               "encoding/json",         // cmd/go/internal/envcmd
-               "fmt",                   // cmd/go/internal/envcmd
-               "os",                    // cmd/go/internal/envcmd
-               "runtime",               // cmd/go/internal/envcmd
-               "strings",               // cmd/go/internal/envcmd
-       },
-
-       "cmd/go/internal/fix": {
-               "cmd/go/internal/base", // cmd/go/internal/fix
-               "cmd/go/internal/cfg",  // cmd/go/internal/fix
-               "cmd/go/internal/load", // cmd/go/internal/fix
-               "cmd/go/internal/str",  // cmd/go/internal/fix
-       },
-
-       "cmd/go/internal/fmtcmd": {
-               "cmd/go/internal/base", // cmd/go/internal/fmtcmd
-               "cmd/go/internal/cfg",  // cmd/go/internal/fmtcmd
-               "cmd/go/internal/load", // cmd/go/internal/fmtcmd
-               "cmd/go/internal/str",  // cmd/go/internal/fmtcmd
-               "os",            // cmd/go/internal/fmtcmd
-               "path/filepath", // cmd/go/internal/fmtcmd
-               "runtime",       // cmd/go/internal/fmtcmd
-               "strings",       // cmd/go/internal/fmtcmd
-               "sync",          // cmd/go/internal/fmtcmd
-       },
-
-       "cmd/go/internal/generate": {
-               "bufio",                // cmd/go/internal/generate
-               "bytes",                // cmd/go/internal/generate
-               "cmd/go/internal/base", // cmd/go/internal/generate
-               "cmd/go/internal/cfg",  // cmd/go/internal/generate
-               "cmd/go/internal/load", // cmd/go/internal/generate
-               "cmd/go/internal/work", // cmd/go/internal/generate
-               "fmt",           // cmd/go/internal/generate
-               "io",            // cmd/go/internal/generate
-               "log",           // cmd/go/internal/generate
-               "os",            // cmd/go/internal/generate
-               "os/exec",       // cmd/go/internal/generate
-               "path/filepath", // cmd/go/internal/generate
-               "regexp",        // cmd/go/internal/generate
-               "strconv",       // cmd/go/internal/generate
-               "strings",       // cmd/go/internal/generate
-       },
-
-       "cmd/go/internal/get": {
-               "bytes",                 // cmd/go/internal/get
-               "cmd/go/internal/base",  // cmd/go/internal/get
-               "cmd/go/internal/cfg",   // cmd/go/internal/get
-               "cmd/go/internal/load",  // cmd/go/internal/get
-               "cmd/go/internal/str",   // cmd/go/internal/get
-               "cmd/go/internal/web",   // cmd/go/internal/get
-               "cmd/go/internal/work",  // cmd/go/internal/get
-               "encoding/json",         // cmd/go/internal/get
-               "encoding/xml",          // cmd/go/internal/get
-               "errors",                // cmd/go/internal/get
-               "fmt",                   // cmd/go/internal/get
-               "go/build",              // cmd/go/internal/get
-               "internal/singleflight", // cmd/go/internal/get
-               "io",            // cmd/go/internal/get
-               "log",           // cmd/go/internal/get
-               "net/url",       // cmd/go/internal/get
-               "os",            // cmd/go/internal/get
-               "os/exec",       // cmd/go/internal/get
-               "path/filepath", // cmd/go/internal/get
-               "regexp",        // cmd/go/internal/get
-               "runtime",       // cmd/go/internal/get
-               "strings",       // cmd/go/internal/get
-               "sync",          // cmd/go/internal/get
-       },
-
-       "cmd/go/internal/help": {
-               "bufio",                // cmd/go/internal/help
-               "bytes",                // cmd/go/internal/help
-               "cmd/go/internal/base", // cmd/go/internal/help
-               "fmt",           // cmd/go/internal/help
-               "io",            // cmd/go/internal/help
-               "os",            // cmd/go/internal/help
-               "strings",       // cmd/go/internal/help
-               "text/template", // cmd/go/internal/help
-               "unicode",       // cmd/go/internal/help
-               "unicode/utf8",  // cmd/go/internal/help
-       },
-
-       "cmd/go/internal/list": {
-               "bufio",                // cmd/go/internal/list
-               "cmd/go/internal/base", // cmd/go/internal/list
-               "cmd/go/internal/cfg",  // cmd/go/internal/list
-               "cmd/go/internal/load", // cmd/go/internal/list
-               "cmd/go/internal/work", // cmd/go/internal/list
-               "encoding/json",        // cmd/go/internal/list
-               "go/build",             // cmd/go/internal/list
-               "io",                   // cmd/go/internal/list
-               "os",                   // cmd/go/internal/list
-               "strings",              // cmd/go/internal/list
-               "text/template",        // cmd/go/internal/list
-       },
-
-       "cmd/go/internal/load": {
-               "cmd/go/internal/base", // cmd/go/internal/load
-               "cmd/go/internal/cfg",  // cmd/go/internal/load
-               "cmd/go/internal/str",  // cmd/go/internal/load
-               "fmt",           // cmd/go/internal/load
-               "go/build",      // cmd/go/internal/load
-               "go/token",      // cmd/go/internal/load
-               "io/ioutil",     // cmd/go/internal/load
-               "log",           // cmd/go/internal/load
-               "os",            // cmd/go/internal/load
-               "path",          // cmd/go/internal/load
-               "path/filepath", // cmd/go/internal/load
-               "regexp",        // cmd/go/internal/load
-               "sort",          // cmd/go/internal/load
-               "strings",       // cmd/go/internal/load
-               "unicode",       // cmd/go/internal/load
-       },
-
-       "cmd/go/internal/run": {
-               "cmd/go/internal/base", // cmd/go/internal/run
-               "cmd/go/internal/cfg",  // cmd/go/internal/run
-               "cmd/go/internal/load", // cmd/go/internal/run
-               "cmd/go/internal/str",  // cmd/go/internal/run
-               "cmd/go/internal/work", // cmd/go/internal/run
-               "fmt",     // cmd/go/internal/run
-               "os",      // cmd/go/internal/run
-               "strings", // cmd/go/internal/run
-       },
-
-       "cmd/go/internal/str": {
-               "bytes",        // cmd/go/internal/str
-               "fmt",          // cmd/go/internal/str
-               "unicode",      // cmd/go/internal/str
-               "unicode/utf8", // cmd/go/internal/str
-       },
-
-       "cmd/go/internal/test": {
-               "bytes",                   // cmd/go/internal/test
-               "cmd/go/internal/base",    // cmd/go/internal/test
-               "cmd/go/internal/cache",   // cmd/go/internal/test
-               "cmd/go/internal/cfg",     // cmd/go/internal/test
-               "cmd/go/internal/cmdflag", // cmd/go/internal/test
-               "cmd/go/internal/load",    // cmd/go/internal/test
-               "cmd/go/internal/str",     // cmd/go/internal/test
-               "cmd/go/internal/work",    // cmd/go/internal/test
-               "errors",                  // cmd/go/internal/test
-               "flag",                    // cmd/go/internal/test
-               "fmt",                     // cmd/go/internal/test
-               "go/ast",                  // cmd/go/internal/test
-               "go/build",                // cmd/go/internal/test
-               "go/doc",                  // cmd/go/internal/test
-               "go/parser",               // cmd/go/internal/test
-               "go/token",                // cmd/go/internal/test
-               "io",                      // cmd/go/internal/test
-               "os",                      // cmd/go/internal/test
-               "os/exec",                 // cmd/go/internal/test
-               "path",                    // cmd/go/internal/test
-               "path/filepath",           // cmd/go/internal/test
-               "regexp",                  // cmd/go/internal/test
-               "sort",                    // cmd/go/internal/test
-               "strings",                 // cmd/go/internal/test
-               "text/template",           // cmd/go/internal/test
-               "time",                    // cmd/go/internal/test
-               "unicode",                 // cmd/go/internal/test
-               "unicode/utf8",            // cmd/go/internal/test
-       },
-
-       "cmd/go/internal/tool": {
-               "cmd/go/internal/base", // cmd/go/internal/tool
-               "cmd/go/internal/cfg",  // cmd/go/internal/tool
-               "fmt",     // cmd/go/internal/tool
-               "os",      // cmd/go/internal/tool
-               "os/exec", // cmd/go/internal/tool
-               "sort",    // cmd/go/internal/tool
-               "strings", // cmd/go/internal/tool
-       },
-
-       "cmd/go/internal/version": {
-               "cmd/go/internal/base", // cmd/go/internal/version
-               "fmt",     // cmd/go/internal/version
-               "runtime", // cmd/go/internal/version
-       },
-
-       "cmd/go/internal/vet": {
-               "cmd/go/internal/base",    // cmd/go/internal/vet
-               "cmd/go/internal/cmdflag", // cmd/go/internal/vet
-               "cmd/go/internal/load",    // cmd/go/internal/vet
-               "cmd/go/internal/work",    // cmd/go/internal/vet
-               "flag",                    // cmd/go/internal/vet
-               "fmt",                     // cmd/go/internal/vet
-               "os",                      // cmd/go/internal/vet
-               "strings",                 // cmd/go/internal/vet
-       },
-
-       "cmd/go/internal/web": {
-               "errors", // cmd/go/internal/web
-               "io",     // cmd/go/internal/web
-       },
-
-       "cmd/go/internal/work": {
-               "bufio",                 // cmd/go/internal/work
-               "bytes",                 // cmd/go/internal/work
-               "cmd/go/internal/base",  // cmd/go/internal/work
-               "cmd/go/internal/cache", // cmd/go/internal/work
-               "cmd/go/internal/cfg",   // cmd/go/internal/work
-               "cmd/go/internal/load",  // cmd/go/internal/work
-               "cmd/go/internal/str",   // cmd/go/internal/work
-               "cmd/internal/buildid",  // cmd/go/internal/work
-               "container/heap",        // cmd/go/internal/work
-               "crypto/sha1",           // cmd/go/internal/work
-               "debug/elf",             // cmd/go/internal/work
-               "encoding/json",         // cmd/go/internal/work
-               "errors",                // cmd/go/internal/work
-               "flag",                  // cmd/go/internal/work
-               "fmt",                   // cmd/go/internal/work
-               "go/build",              // cmd/go/internal/work
-               "io",                    // cmd/go/internal/work
-               "io/ioutil",             // cmd/go/internal/work
-               "log",                   // cmd/go/internal/work
-               "os",                    // cmd/go/internal/work
-               "os/exec",               // cmd/go/internal/work
-               "path",                  // cmd/go/internal/work
-               "path/filepath",         // cmd/go/internal/work
-               "regexp",                // cmd/go/internal/work
-               "runtime",               // cmd/go/internal/work
-               "strconv",               // cmd/go/internal/work
-               "strings",               // cmd/go/internal/work
-               "sync",                  // cmd/go/internal/work
-       },
-
-       "cmd/internal/buildid": {
-               "bytes",           // cmd/internal/buildid
-               "crypto/sha256",   // cmd/internal/buildid
-               "debug/elf",       // cmd/internal/buildid
-               "debug/macho",     // cmd/internal/buildid
-               "encoding/binary", // cmd/internal/buildid
-               "fmt",             // cmd/internal/buildid
-               "io",              // cmd/internal/buildid
-               "os",              // cmd/internal/buildid
-               "strconv",         // cmd/internal/buildid
-       },
-
-       "cmd/internal/objabi": {
-               "flag",          // cmd/internal/objabi
-               "fmt",           // cmd/internal/objabi
-               "log",           // cmd/internal/objabi
-               "os",            // cmd/internal/objabi
-               "path/filepath", // cmd/internal/objabi
-               "runtime",       // cmd/internal/objabi
-               "strconv",       // cmd/internal/objabi
-               "strings",       // cmd/internal/objabi
-       },
-
-       "compress/flate": {
-               "bufio",     // compress/flate
-               "fmt",       // compress/flate
-               "io",        // compress/flate
-               "math",      // compress/flate
-               "math/bits", // compress/flate
-               "sort",      // compress/flate
-               "strconv",   // compress/flate
-               "sync",      // compress/flate
-       },
-
-       "compress/zlib": {
-               "bufio",          // compress/zlib
-               "compress/flate", // compress/zlib
-               "errors",         // compress/zlib
-               "fmt",            // compress/zlib
-               "hash",           // compress/zlib
-               "hash/adler32",   // compress/zlib
-               "io",             // compress/zlib
-       },
-
-       "container/heap": {
-               "sort", // container/heap
-       },
-
-       "context": {
-               "errors",  // context
-               "fmt",     // context
-               "reflect", // context
-               "sync",    // context
-               "time",    // context
-       },
-
-       "crypto": {
-               "hash",    // crypto
-               "io",      // crypto
-               "strconv", // crypto
-       },
-
-       "crypto/sha1": {
-               "crypto",       // crypto/sha1
-               "errors",       // crypto/sha1
-               "hash",         // crypto/sha1
-               "internal/cpu", // crypto/sha1
-       },
-
-       "crypto/sha256": {
-               "crypto",       // crypto/sha256
-               "errors",       // crypto/sha256
-               "hash",         // crypto/sha256
-               "internal/cpu", // crypto/sha256
-       },
-
-       "debug/dwarf": {
-               "encoding/binary", // debug/dwarf
-               "errors",          // debug/dwarf
-               "fmt",             // debug/dwarf
-               "io",              // debug/dwarf
-               "path",            // debug/dwarf
-               "sort",            // debug/dwarf
-               "strconv",         // debug/dwarf
-               "strings",         // debug/dwarf
-       },
-
-       "debug/elf": {
-               "bytes",           // debug/elf
-               "compress/zlib",   // debug/elf
-               "debug/dwarf",     // debug/elf
-               "encoding/binary", // debug/elf
-               "errors",          // debug/elf
-               "fmt",             // debug/elf
-               "io",              // debug/elf
-               "os",              // debug/elf
-               "strconv",         // debug/elf
-               "strings",         // debug/elf
-       },
-
-       "debug/macho": {
-               "bytes",           // debug/macho
-               "debug/dwarf",     // debug/macho
-               "encoding/binary", // debug/macho
-               "fmt",             // debug/macho
-               "io",              // debug/macho
-               "os",              // debug/macho
-               "strconv",         // debug/macho
-       },
-
-       "encoding": {
-               "runtime", // encoding
-       },
-
-       "encoding/base64": {
-               "encoding/binary", // encoding/base64
-               "io",              // encoding/base64
-               "strconv",         // encoding/base64
-       },
-
-       "encoding/binary": {
-               "errors",  // encoding/binary
-               "io",      // encoding/binary
-               "math",    // encoding/binary
-               "reflect", // encoding/binary
-       },
-
-       "encoding/hex": {
-               "bytes",  // encoding/hex
-               "errors", // encoding/hex
-               "fmt",    // encoding/hex
-               "io",     // encoding/hex
-       },
-
-       "encoding/json": {
-               "bytes",           // encoding/json
-               "encoding",        // encoding/json
-               "encoding/base64", // encoding/json
-               "errors",          // encoding/json
-               "fmt",             // encoding/json
-               "io",              // encoding/json
-               "math",            // encoding/json
-               "reflect",         // encoding/json
-               "runtime",         // encoding/json
-               "sort",            // encoding/json
-               "strconv",         // encoding/json
-               "strings",         // encoding/json
-               "sync",            // encoding/json
-               "sync/atomic",     // encoding/json
-               "unicode",         // encoding/json
-               "unicode/utf16",   // encoding/json
-               "unicode/utf8",    // encoding/json
-       },
-
-       "encoding/xml": {
-               "bufio",        // encoding/xml
-               "bytes",        // encoding/xml
-               "encoding",     // encoding/xml
-               "errors",       // encoding/xml
-               "fmt",          // encoding/xml
-               "io",           // encoding/xml
-               "reflect",      // encoding/xml
-               "strconv",      // encoding/xml
-               "strings",      // encoding/xml
-               "sync",         // encoding/xml
-               "unicode",      // encoding/xml
-               "unicode/utf8", // encoding/xml
-       },
-
-       "errors": {
-               "runtime", // errors
-       },
-
-       "flag": {
-               "errors",  // flag
-               "fmt",     // flag
-               "io",      // flag
-               "os",      // flag
-               "reflect", // flag
-               "sort",    // flag
-               "strconv", // flag
-               "strings", // flag
-               "time",    // flag
-       },
-
-       "fmt": {
-               "errors",       // fmt
-               "io",           // fmt
-               "math",         // fmt
-               "os",           // fmt
-               "reflect",      // fmt
-               "strconv",      // fmt
-               "sync",         // fmt
-               "unicode/utf8", // fmt
-       },
-
-       "go/ast": {
-               "bytes",        // go/ast
-               "fmt",          // go/ast
-               "go/scanner",   // go/ast
-               "go/token",     // go/ast
-               "io",           // go/ast
-               "os",           // go/ast
-               "reflect",      // go/ast
-               "sort",         // go/ast
-               "strconv",      // go/ast
-               "strings",      // go/ast
-               "unicode",      // go/ast
-               "unicode/utf8", // go/ast
-       },
-
-       "go/build": {
-               "bufio",         // go/build
-               "bytes",         // go/build
-               "errors",        // go/build
-               "fmt",           // go/build
-               "go/ast",        // go/build
-               "go/doc",        // go/build
-               "go/parser",     // go/build
-               "go/token",      // go/build
-               "io",            // go/build
-               "io/ioutil",     // go/build
-               "log",           // go/build
-               "os",            // go/build
-               "path",          // go/build
-               "path/filepath", // go/build
-               "runtime",       // go/build
-               "sort",          // go/build
-               "strconv",       // go/build
-               "strings",       // go/build
-               "unicode",       // go/build
-               "unicode/utf8",  // go/build
-       },
-
-       "go/doc": {
-               "go/ast",        // go/doc
-               "go/token",      // go/doc
-               "io",            // go/doc
-               "path",          // go/doc
-               "regexp",        // go/doc
-               "sort",          // go/doc
-               "strconv",       // go/doc
-               "strings",       // go/doc
-               "text/template", // go/doc
-               "unicode",       // go/doc
-               "unicode/utf8",  // go/doc
-       },
-
-       "go/parser": {
-               "bytes",         // go/parser
-               "errors",        // go/parser
-               "fmt",           // go/parser
-               "go/ast",        // go/parser
-               "go/scanner",    // go/parser
-               "go/token",      // go/parser
-               "io",            // go/parser
-               "io/ioutil",     // go/parser
-               "os",            // go/parser
-               "path/filepath", // go/parser
-               "strconv",       // go/parser
-               "strings",       // go/parser
-               "unicode",       // go/parser
-       },
-
-       "go/scanner": {
-               "bytes",         // go/scanner
-               "fmt",           // go/scanner
-               "go/token",      // go/scanner
-               "io",            // go/scanner
-               "path/filepath", // go/scanner
-               "sort",          // go/scanner
-               "strconv",       // go/scanner
-               "unicode",       // go/scanner
-               "unicode/utf8",  // go/scanner
-       },
-
-       "go/token": {
-               "fmt",     // go/token
-               "sort",    // go/token
-               "strconv", // go/token
-               "sync",    // go/token
-       },
-
-       "hash": {
-               "io", // hash
-       },
-
-       "hash/adler32": {
-               "errors", // hash/adler32
-               "hash",   // hash/adler32
-       },
-
-       "internal/cpu": {
-               "runtime", // internal/cpu
-       },
-
-       "internal/poll": {
-               "errors",        // internal/poll
-               "internal/race", // internal/poll
-               "io",            // internal/poll
-               "runtime",       // internal/poll
-               "sync",          // internal/poll
-               "sync/atomic",   // internal/poll
-               "syscall",       // internal/poll
-               "time",          // internal/poll
-               "unicode/utf16", // internal/poll
-               "unicode/utf8",  // internal/poll
-       },
-
-       "internal/race": {
-               "runtime", // internal/race
-       },
-
-       "internal/singleflight": {
-               "sync", // internal/singleflight
-       },
-
-       "internal/syscall/windows": {
-               "internal/syscall/windows/sysdll", // internal/syscall/windows
-               "syscall",                         // internal/syscall/windows
-       },
-
-       "internal/syscall/windows/registry": {
-               "errors", // internal/syscall/windows/registry
-               "internal/syscall/windows/sysdll", // internal/syscall/windows/registry
-               "io",            // internal/syscall/windows/registry
-               "syscall",       // internal/syscall/windows/registry
-               "unicode/utf16", // internal/syscall/windows/registry
-       },
-
-       "internal/syscall/windows/sysdll": {
-               "runtime", // internal/syscall/windows/sysdll
-       },
-
-       "io": {
-               "errors",      // io
-               "sync",        // io
-               "sync/atomic", // io
-       },
-
-       "io/ioutil": {
-               "bytes",         // io/ioutil
-               "io",            // io/ioutil
-               "os",            // io/ioutil
-               "path/filepath", // io/ioutil
-               "sort",          // io/ioutil
-               "strconv",       // io/ioutil
-               "sync",          // io/ioutil
-               "time",          // io/ioutil
-       },
-
-       "log": {
-               "fmt",     // log
-               "io",      // log
-               "os",      // log
-               "runtime", // log
-               "sync",    // log
-               "time",    // log
-       },
-
-       "math": {
-               "internal/cpu", // math
-       },
-
-       "math/bits": {
-               "runtime", // math/bits
-       },
-
-       "net/url": {
-               "bytes",   // net/url
-               "errors",  // net/url
-               "fmt",     // net/url
-               "sort",    // net/url
-               "strconv", // net/url
-               "strings", // net/url
-       },
-
-       "os": {
-               "errors",                   // os
-               "internal/poll",            // os
-               "internal/syscall/windows", // os
-               "io",            // os
-               "runtime",       // os
-               "sync",          // os
-               "sync/atomic",   // os
-               "syscall",       // os
-               "time",          // os
-               "unicode/utf16", // os
-       },
-
-       "os/exec": {
-               "bytes",         // os/exec
-               "context",       // os/exec
-               "errors",        // os/exec
-               "io",            // os/exec
-               "os",            // os/exec
-               "path/filepath", // os/exec
-               "runtime",       // os/exec
-               "strconv",       // os/exec
-               "strings",       // os/exec
-               "sync",          // os/exec
-               "syscall",       // os/exec
-       },
-
-       "os/signal": {
-               "os",      // os/signal
-               "sync",    // os/signal
-               "syscall", // os/signal
-       },
-
-       "path": {
-               "errors",       // path
-               "strings",      // path
-               "unicode/utf8", // path
-       },
-
-       "path/filepath": {
-               "errors",                   // path/filepath
-               "internal/syscall/windows", // path/filepath
-               "os",           // path/filepath
-               "runtime",      // path/filepath
-               "sort",         // path/filepath
-               "strings",      // path/filepath
-               "syscall",      // path/filepath
-               "unicode/utf8", // path/filepath
-       },
-
-       "reflect": {
-               "math",         // reflect
-               "runtime",      // reflect
-               "strconv",      // reflect
-               "sync",         // reflect
-               "unicode",      // reflect
-               "unicode/utf8", // reflect
-       },
-
-       "regexp": {
-               "bytes",         // regexp
-               "io",            // regexp
-               "regexp/syntax", // regexp
-               "sort",          // regexp
-               "strconv",       // regexp
-               "strings",       // regexp
-               "sync",          // regexp
-               "unicode",       // regexp
-               "unicode/utf8",  // regexp
-       },
-
-       "regexp/syntax": {
-               "bytes",        // regexp/syntax
-               "sort",         // regexp/syntax
-               "strconv",      // regexp/syntax
-               "strings",      // regexp/syntax
-               "unicode",      // regexp/syntax
-               "unicode/utf8", // regexp/syntax
-       },
-
-       "runtime": {
-               "runtime/internal/atomic", // runtime
-               "runtime/internal/sys",    // runtime
-       },
-
-       "runtime/internal/atomic": {
-               "runtime/internal/sys", // runtime/internal/atomic
-       },
-
-       "runtime/internal/sys": {},
-
-       "sort": {
-               "reflect", // sort
-       },
-
-       "strconv": {
-               "errors",       // strconv
-               "math",         // strconv
-               "unicode/utf8", // strconv
-       },
-
-       "strings": {
-               "errors",       // strings
-               "internal/cpu", // strings
-               "io",           // strings
-               "unicode",      // strings
-               "unicode/utf8", // strings
-       },
-
-       "sync": {
-               "internal/race", // sync
-               "runtime",       // sync
-               "sync/atomic",   // sync
-       },
-
-       "sync/atomic": {
-               "runtime", // sync/atomic
-       },
-
-       "syscall": {
-               "errors",                          // syscall
-               "internal/race",                   // syscall
-               "internal/syscall/windows/sysdll", // syscall
-               "runtime",                         // syscall
-               "sync",                            // syscall
-               "sync/atomic",                     // syscall
-               "unicode/utf16",                   // syscall
-       },
-
-       "text/template": {
-               "bytes",               // text/template
-               "errors",              // text/template
-               "fmt",                 // text/template
-               "io",                  // text/template
-               "io/ioutil",           // text/template
-               "net/url",             // text/template
-               "path/filepath",       // text/template
-               "reflect",             // text/template
-               "runtime",             // text/template
-               "sort",                // text/template
-               "strings",             // text/template
-               "sync",                // text/template
-               "text/template/parse", // text/template
-               "unicode",             // text/template
-               "unicode/utf8",        // text/template
-       },
-
-       "text/template/parse": {
-               "bytes",        // text/template/parse
-               "fmt",          // text/template/parse
-               "runtime",      // text/template/parse
-               "strconv",      // text/template/parse
-               "strings",      // text/template/parse
-               "unicode",      // text/template/parse
-               "unicode/utf8", // text/template/parse
-       },
-
-       "time": {
-               "errors", // time
-               "internal/syscall/windows/registry", // time
-               "runtime",                           // time
-               "sync",                              // time
-               "syscall",                           // time
-       },
-
-       "unicode": {
-               "runtime", // unicode
-       },
-
-       "unicode/utf16": {
-               "runtime", // unicode/utf16
-       },
-
-       "unicode/utf8": {
-               "runtime", // unicode/utf8
-       },
-}

diff --git a/src/cmd/dist/deps_test.go b/src/cmd/dist/deps_test.go
deleted file mode 100644 (file)
index 596e89b..0000000
--- a/src/cmd/dist/deps_test.go
+++ /dev/null
@@ -1,104 +0,0 @@
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main_test
-
-import (
-       "bytes"
-       "internal/testenv"
-       "io/ioutil"
-       "os"
-       "os/exec"
-       "strings"
-       "testing"
-)
-
-func TestDeps(t *testing.T) {
-       if testing.Short() && testenv.Builder() == "" {
-               t.Skip("skipping in short mode")
-       }
-
-       current, err := ioutil.ReadFile("deps.go")
-       if err != nil {
-               t.Fatal(err)
-       }
-
-       bash, err := exec.LookPath("bash")
-       if err != nil {
-               t.Skipf("skipping because bash not found: %v", err)
-       }
-
-       outf, err := ioutil.TempFile("", "dist-deps-test")
-       if err != nil {
-               t.Fatal(err)
-       }
-       outf.Close()
-       outname := outf.Name()
-       defer os.Remove(outname)
-
-       out, err := exec.Command(bash, "mkdeps.bash", outname).CombinedOutput()
-       if err != nil {
-               t.Fatal(err)
-       }
-       t.Logf("%s", out)
-
-       updated, err := ioutil.ReadFile(outname)
-       if err != nil {
-               t.Fatal(err)
-       }
-
-       if !bytes.Equal(current, updated) {
-               // Very simple minded diff.
-               t.Log("-current +generated")
-               clines := strings.Split(string(current), "\n")
-               for i, line := range clines {
-                       clines[i] = strings.Join(strings.Fields(line), " ")
-               }
-               ulines := strings.Split(string(updated), "\n")
-               for i, line := range ulines {
-                       ulines[i] = strings.Join(strings.Fields(line), " ")
-               }
-               for len(clines) > 0 {
-                       cl := clines[0]
-                       switch {
-                       case len(ulines) == 0:
-                               t.Logf("-%s", cl)
-                               clines = clines[1:]
-                       case cl == ulines[0]:
-                               clines = clines[1:]
-                               ulines = ulines[1:]
-                       case pkg(cl) == pkg(ulines[0]):
-                               t.Logf("-%s", cl)
-                               t.Logf("+%s", ulines[0])
-                               clines = clines[1:]
-                               ulines = ulines[1:]
-                       case pkg(cl) < pkg(ulines[0]):
-                               t.Logf("-%s", cl)
-                               clines = clines[1:]
-                       default:
-                               cp := pkg(cl)
-                               for len(ulines) > 0 && pkg(ulines[0]) < cp {
-                                       t.Logf("+%s", ulines[0])
-                                       ulines = ulines[1:]
-                               }
-                       }
-               }
-
-               t.Error("cmd/dist/deps.go is out of date; run cmd/dist/mkdeps.bash")
-       }
-}
-
-// pkg returns the package of a line in deps.go.
-func pkg(line string) string {
-       i := strings.Index(line, `"`)
-       if i < 0 {
-               return ""
-       }
-       line = line[i+1:]
-       i = strings.Index(line, `"`)
-       if i < 0 {
-               return ""
-       }
-       return line[:i]
-}

diff --git a/src/cmd/dist/imports.go b/src/cmd/dist/imports.go
new file mode 100644 (file)
index 0000000..bf64d66
--- /dev/null
+++ b/src/cmd/dist/imports.go
@@ -0,0 +1,245 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is forked from go/build/read.go.
+// (cmd/dist must not import go/build because we do not want it to be
+// sensitive to the specific version of go/build present in $GOROOT_BOOTSTRAP.)
+
+package main
+
+import (
+       "bufio"
+       "errors"
+       "io"
+       "strconv"
+       "strings"
+       "unicode/utf8"
+)
+
+type importReader struct {
+       b    *bufio.Reader
+       buf  []byte
+       peek byte
+       err  error
+       eof  bool
+       nerr int
+}
+
+func isIdent(c byte) bool {
+       return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '_' || c >= utf8.RuneSelf
+}
+
+var (
+       errSyntax = errors.New("syntax error")
+       errNUL    = errors.New("unexpected NUL in input")
+)
+
+// syntaxError records a syntax error, but only if an I/O error has not already been recorded.
+func (r *importReader) syntaxError() {
+       if r.err == nil {
+               r.err = errSyntax
+       }
+}
+
+// readByte reads the next byte from the input, saves it in buf, and returns it.
+// If an error occurs, readByte records the error in r.err and returns 0.
+func (r *importReader) readByte() byte {
+       c, err := r.b.ReadByte()
+       if err == nil {
+               r.buf = append(r.buf, c)
+               if c == 0 {
+                       err = errNUL
+               }
+       }
+       if err != nil {
+               if err == io.EOF {
+                       r.eof = true
+               } else if r.err == nil {
+                       r.err = err
+               }
+               c = 0
+       }
+       return c
+}
+
+// peekByte returns the next byte from the input reader but does not advance beyond it.
+// If skipSpace is set, peekByte skips leading spaces and comments.
+func (r *importReader) peekByte(skipSpace bool) byte {
+       if r.err != nil {
+               if r.nerr++; r.nerr > 10000 {
+                       panic("go/build: import reader looping")
+               }
+               return 0
+       }
+
+       // Use r.peek as first input byte.
+       // Don't just return r.peek here: it might have been left by peekByte(false)
+       // and this might be peekByte(true).
+       c := r.peek
+       if c == 0 {
+               c = r.readByte()
+       }
+       for r.err == nil && !r.eof {
+               if skipSpace {
+                       // For the purposes of this reader, semicolons are never necessary to
+                       // understand the input and are treated as spaces.
+                       switch c {
+                       case ' ', '\f', '\t', '\r', '\n', ';':
+                               c = r.readByte()
+                               continue
+
+                       case '/':
+                               c = r.readByte()
+                               if c == '/' {
+                                       for c != '\n' && r.err == nil && !r.eof {
+                                               c = r.readByte()
+                                       }
+                               } else if c == '*' {
+                                       var c1 byte
+                                       for (c != '*' || c1 != '/') && r.err == nil {
+                                               if r.eof {
+                                                       r.syntaxError()
+                                               }
+                                               c, c1 = c1, r.readByte()
+                                       }
+                               } else {
+                                       r.syntaxError()
+                               }
+                               c = r.readByte()
+                               continue
+                       }
+               }
+               break
+       }
+       r.peek = c
+       return r.peek
+}
+
+// nextByte is like peekByte but advances beyond the returned byte.
+func (r *importReader) nextByte(skipSpace bool) byte {
+       c := r.peekByte(skipSpace)
+       r.peek = 0
+       return c
+}
+
+// readKeyword reads the given keyword from the input.
+// If the keyword is not present, readKeyword records a syntax error.
+func (r *importReader) readKeyword(kw string) {
+       r.peekByte(true)
+       for i := 0; i < len(kw); i++ {
+               if r.nextByte(false) != kw[i] {
+                       r.syntaxError()
+                       return
+               }
+       }
+       if isIdent(r.peekByte(false)) {
+               r.syntaxError()
+       }
+}
+
+// readIdent reads an identifier from the input.
+// If an identifier is not present, readIdent records a syntax error.
+func (r *importReader) readIdent() {
+       c := r.peekByte(true)
+       if !isIdent(c) {
+               r.syntaxError()
+               return
+       }
+       for isIdent(r.peekByte(false)) {
+               r.peek = 0
+       }
+}
+
+// readString reads a quoted string literal from the input.
+// If an identifier is not present, readString records a syntax error.
+func (r *importReader) readString(save *[]string) {
+       switch r.nextByte(true) {
+       case '`':
+               start := len(r.buf) - 1
+               for r.err == nil {
+                       if r.nextByte(false) == '`' {
+                               if save != nil {
+                                       *save = append(*save, string(r.buf[start:]))
+                               }
+                               break
+                       }
+                       if r.eof {
+                               r.syntaxError()
+                       }
+               }
+       case '"':
+               start := len(r.buf) - 1
+               for r.err == nil {
+                       c := r.nextByte(false)
+                       if c == '"' {
+                               if save != nil {
+                                       *save = append(*save, string(r.buf[start:]))
+                               }
+                               break
+                       }
+                       if r.eof || c == '\n' {
+                               r.syntaxError()
+                       }
+                       if c == '\\' {
+                               r.nextByte(false)
+                       }
+               }
+       default:
+               r.syntaxError()
+       }
+}
+
+// readImport reads an import clause - optional identifier followed by quoted string -
+// from the input.
+func (r *importReader) readImport(imports *[]string) {
+       c := r.peekByte(true)
+       if c == '.' {
+               r.peek = 0
+       } else if isIdent(c) {
+               r.readIdent()
+       }
+       r.readString(imports)
+}
+
+// readComments is like ioutil.ReadAll, except that it only reads the leading
+// block of comments in the file.
+func readComments(f io.Reader) ([]byte, error) {
+       r := &importReader{b: bufio.NewReader(f)}
+       r.peekByte(true)
+       if r.err == nil && !r.eof {
+               // Didn't reach EOF, so must have found a non-space byte. Remove it.
+               r.buf = r.buf[:len(r.buf)-1]
+       }
+       return r.buf, r.err
+}
+
+// readimports returns the imports found in the named file.
+func readimports(file string) []string {
+       var imports []string
+       r := &importReader{b: bufio.NewReader(strings.NewReader(readfile(file)))}
+       r.readKeyword("package")
+       r.readIdent()
+       for r.peekByte(true) == 'i' {
+               r.readKeyword("import")
+               if r.peekByte(true) == '(' {
+                       r.nextByte(false)
+                       for r.peekByte(true) != ')' && r.err == nil {
+                               r.readImport(&imports)
+                       }
+                       r.nextByte(false)
+               } else {
+                       r.readImport(&imports)
+               }
+       }
+
+       for i := range imports {
+               unquoted, err := strconv.Unquote(imports[i])
+               if err != nil {
+                       fatalf("reading imports from %s: %v", file, err)
+               }
+               imports[i] = unquoted
+       }
+
+       return imports
+}

diff --git a/src/cmd/dist/mkdeps.bash b/src/cmd/dist/mkdeps.bash
deleted file mode 100755 (executable)
index 471306f..0000000
--- a/src/cmd/dist/mkdeps.bash
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/bin/bash
-# Copyright 2015 The Go Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style
-# license that can be found in the LICENSE file.
-
-# This script regenerates deps.go.
-# The script used to do all the work, but now a Go program does.
-# The script has been preserved so that people who learned to type
-# ./mkdeps.bash don't have to relearn a new method.
-# It's fine to run "go run mkdeps.go" directly instead.
-
-set -e
-go run mkdeps.go -- "$@"
-exit 0

diff --git a/src/cmd/dist/mkdeps.go b/src/cmd/dist/mkdeps.go
deleted file mode 100644 (file)
index d8da012..0000000
--- a/src/cmd/dist/mkdeps.go
+++ /dev/null
@@ -1,187 +0,0 @@
-// Copyright 2017 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// This program generates deps.go.
-// Run as "go run mkdeps.go" or, to redirect the output, "go run mkdeps.go x.txt".
-
-// +build ignore
-
-package main
-
-import (
-       "bytes"
-       "flag"
-       "fmt"
-       "io/ioutil"
-       "log"
-       "os"
-       "os/exec"
-       "sort"
-       "strings"
-)
-
-// We need to test enough GOOS/GOARCH combinations
-// to find all the package dependencies of cmd/go on all systems.
-var targetList = strings.Fields(`
-       linux/386
-       linux/amd64
-       windows/amd64
-`)
-
-func usage() {
-       fmt.Fprintf(os.Stderr, "usage: mkdeps [deps.go]\n")
-       os.Exit(2)
-}
-
-func main() {
-       log.SetPrefix("mkdeps: ")
-       log.SetFlags(0)
-       flag.Usage = usage
-       flag.Parse()
-       if flag.NArg() > 1 {
-               usage()
-       }
-
-       outfile := "deps.go"
-       if flag.NArg() == 1 {
-               outfile = flag.Arg(0)
-       }
-
-       _, deps := importsAndDepsOf("cmd/go")
-       all := deps["cmd/go"]
-       all = append(all, "cmd/go")
-       imports, deps := importsAndDepsOf(all...)
-
-       // Sort topologically, then by import path.
-       var topo []string
-       walked := make(map[string]bool)
-       var walk func(string)
-       walk = func(p string) {
-               if walked[p] {
-                       return
-               }
-               walked[p] = true
-               sort.Strings(deps[p])
-               for _, d := range deps[p] {
-                       walk(d)
-               }
-               topo = append(topo, p)
-       }
-       walk("cmd/go")
-
-       // We're only going to print imports, not deps,
-       // in hopes of making deps.go intelligible to people
-       // who need to debug it or attempt to resolve merge conflicts.
-       // For the most part, deps is just the transitive closure of imports,
-       // but sometimes there are implicit deps supplied by the go command
-       // that are not derivable from imports.
-       // Find those (if any) and copy them explicitly into imports.
-       for _, p := range topo {
-               for _, dp := range deps[p] {
-                       found := false
-                       for _, ip := range imports[p] {
-                               if dp == ip || inList(deps[ip], dp) {
-                                       found = true
-                                       break
-                               }
-                       }
-                       if !found {
-                               imports[p] = append(imports[p], dp)
-                       }
-               }
-               sort.Strings(imports[p])
-       }
-       sort.Strings(all)
-
-       // Print table.
-       var buf bytes.Buffer
-       fmt.Fprintf(&buf, "// Code generated by mkdeps.bash; DO NOT EDIT.\n\n")
-       fmt.Fprintf(&buf, "package main\n\n")
-       fmt.Fprintf(&buf, "var builddeps = map[string][]string{\n")
-       for _, p := range all {
-               if p == "unsafe" { // unsafe should not be built
-                       continue
-               }
-               // We're printing a multiline format here to make the output more
-               // intelligible both to people and to merge tools.
-               // We put the name of the parent package as a comment on every line
-               // to keep a merge tool from applying the diff for one package
-               // to the dependency list for a different package.
-               // The extra blank line at the start stops any attempt by gofmt at
-               // lining up the slice literals from different packages,
-               // even if they are empty slices (on a single line with the key).
-               fmt.Fprintf(&buf, "\n\t%q: {\n", p)
-               for _, d := range imports[p] {
-                       if d != "unsafe" {
-                               fmt.Fprintf(&buf, "\t\t%q, // %s\n", d, p)
-                       }
-               }
-               fmt.Fprintf(&buf, "\t},\n")
-       }
-       fmt.Fprintf(&buf, "\n}\n")
-
-       // Run the installed gofmt instead of using go/format,
-       // because, on the off chance they disagree,
-       // the installed gofmt binary is by definition the correct one.
-       cmd := exec.Command("gofmt")
-       cmd.Stdin = &buf
-       var out bytes.Buffer
-       cmd.Stdout = &out
-       if err := cmd.Run(); err != nil {
-               log.Fatalf("gofmt: %v", err)
-       }
-
-       if err := ioutil.WriteFile(outfile, out.Bytes(), 0666); err != nil {
-               log.Fatal(err)
-       }
-}
-
-func inList(xs []string, s string) bool {
-       for _, x := range xs {
-               if x == s {
-                       return true
-               }
-       }
-       return false
-}
-
-// importsAndDepsOf returns two maps, one giving the imports for each package in pkgs,
-// and one giving the dependencies for each package in pkgs.
-// Both the keys and the entries in the value slices are full import paths.
-func importsAndDepsOf(pkgs ...string) (map[string][]string, map[string][]string) {
-       imports := make(map[string][]string)
-       deps := make(map[string][]string)
-       for _, target := range targetList {
-               args := []string{"list", "-tags", "cmd_go_bootstrap", "-f", "{{range .Imports}}import {{$.ImportPath}} {{.}}\n{{end}}{{range .Deps}}dep {{$.ImportPath}} {{.}}\n{{end}}"}
-               args = append(args, pkgs...)
-               cmd := exec.Command("go", args...)
-               t := strings.Split(target, "/")
-               cmd.Env = append(os.Environ(), "GOOS="+t[0], "GOARCH="+t[1])
-               var stderr bytes.Buffer
-               cmd.Stderr = &stderr
-               out, err := cmd.Output()
-               if err != nil && !strings.Contains(stderr.String(), "build constraints exclude all Go files") {
-                       log.Fatalf("GOOS=%s GOARCH=%s go list: %v\n%s\n%s", t[0], t[1], err, stderr.Bytes(), out)
-               }
-               helped := false
-               for _, line := range strings.Split(string(out), "\n") {
-                       f := strings.Fields(line)
-                       if len(f) != 3 {
-                               continue
-                       }
-                       if f[0] == "import" && !inList(imports[f[1]], f[2]) {
-                               helped = true
-                               imports[f[1]] = append(imports[f[1]], f[2])
-                       }
-                       if f[0] == "dep" && !inList(deps[f[1]], f[2]) {
-                               helped = true
-                               deps[f[1]] = append(deps[f[1]], f[2])
-                       }
-               }
-               if !helped {
-                       fmt.Fprintf(os.Stderr, "mkdeps: note: %s did not contribute any new dependencies\n", target)
-               }
-       }
-       return imports, deps
-}