src/cmd/dist/buildtool.go

   1 // Copyright 2015 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 // Build toolchain using Go 1.4.
   6 //
   7 // The general strategy is to copy the source files we need into
   8 // a new GOPATH workspace, adjust import paths appropriately,
   9 // invoke the Go 1.4 go command to build those sources,
  10 // and then copy the binaries back.
  11
  12 package main
  13
  14 import (
  15         "fmt"
  16         "os"
  17         "path/filepath"
  18         "regexp"
  19         "runtime"
  20         "strings"
  21 )
  22
  23 // bootstrapDirs is a list of directories holding code that must be
  24 // compiled with a Go 1.4 toolchain to produce the bootstrapTargets.
  25 // All directories in this list are relative to and must be below $GOROOT/src.
  26 //
  27 // The list has two kinds of entries: names beginning with cmd/ with
  28 // no other slashes, which are commands, and other paths, which are packages
  29 // supporting the commands. Packages in the standard library can be listed
  30 // if a newer copy needs to be substituted for the Go 1.4 copy when used
  31 // by the command packages. Paths ending with /... automatically
  32 // include all packages within subdirectories as well.
  33 // These will be imported during bootstrap as bootstrap/name, like bootstrap/math/big.
  34 var bootstrapDirs = []string{
  35         "cmd/asm",
  36         "cmd/asm/internal/...",
  37         "cmd/cgo",
  38         "cmd/compile",
  39         "cmd/compile/internal/...",
  40         "cmd/internal/archive",
  41         "cmd/internal/bio",
  42         "cmd/internal/codesign",
  43         "cmd/internal/dwarf",
  44         "cmd/internal/edit",
  45         "cmd/internal/gcprog",
  46         "cmd/internal/goobj",
  47         "cmd/internal/obj/...",
  48         "cmd/internal/objabi",
  49         "cmd/internal/pkgpath",
  50         "cmd/internal/quoted",
  51         "cmd/internal/src",
  52         "cmd/internal/sys",
  53         "cmd/link",
  54         "cmd/link/internal/...",
  55         "compress/flate",
  56         "compress/zlib",
  57         "container/heap",
  58         "debug/dwarf",
  59         "debug/elf",
  60         "debug/macho",
  61         "debug/pe",
  62         "go/constant",
  63         "internal/buildcfg",
  64         "internal/goexperiment",
  65         "internal/goversion",
  66         "internal/pkgbits",
  67         "internal/race",
  68         "internal/unsafeheader",
  69         "internal/xcoff",
  70         "math/big",
  71         "math/bits",
  72         "sort",
  73         "strconv",
  74 }
  75
  76 // File prefixes that are ignored by go/build anyway, and cause
  77 // problems with editor generated temporary files (#18931).
  78 var ignorePrefixes = []string{
  79         ".",
  80         "_",
  81         "#",
  82 }
  83
  84 // File suffixes that use build tags introduced since Go 1.4.
  85 // These must not be copied into the bootstrap build directory.
  86 // Also ignore test files.
  87 var ignoreSuffixes = []string{
  88         "_arm64.s",
  89         "_arm64.go",
  90         "_loong64.s",
  91         "_loong64.go",
  92         "_riscv64.s",
  93         "_riscv64.go",
  94         "_wasm.s",
  95         "_wasm.go",
  96         "_test.s",
  97         "_test.go",
  98 }
  99
 100 var tryDirs = []string{
 101         "sdk/go1.17",
 102         "go1.17",
 103 }
 104
 105 func bootstrapBuildTools() {
 106         goroot_bootstrap := os.Getenv("GOROOT_BOOTSTRAP")
 107         if goroot_bootstrap == "" {
 108                 home := os.Getenv("HOME")
 109                 goroot_bootstrap = pathf("%s/go1.4", home)
 110                 for _, d := range tryDirs {
 111                         if p := pathf("%s/%s", home, d); isdir(p) {
 112                                 goroot_bootstrap = p
 113                         }
 114                 }
 115         }
 116         xprintf("Building Go toolchain1 using %s.\n", goroot_bootstrap)
 117
 118         mkbuildcfg(pathf("%s/src/internal/buildcfg/zbootstrap.go", goroot))
 119         mkobjabi(pathf("%s/src/cmd/internal/objabi/zbootstrap.go", goroot))
 120
 121         // Use $GOROOT/pkg/bootstrap as the bootstrap workspace root.
 122         // We use a subdirectory of $GOROOT/pkg because that's the
 123         // space within $GOROOT where we store all generated objects.
 124         // We could use a temporary directory outside $GOROOT instead,
 125         // but it is easier to debug on failure if the files are in a known location.
 126         workspace := pathf("%s/pkg/bootstrap", goroot)
 127         xremoveall(workspace)
 128         xatexit(func() { xremoveall(workspace) })
 129         base := pathf("%s/src/bootstrap", workspace)
 130         xmkdirall(base)
 131
 132         // Copy source code into $GOROOT/pkg/bootstrap and rewrite import paths.
 133         writefile("module bootstrap\n", pathf("%s/%s", base, "go.mod"), 0)
 134         for _, dir := range bootstrapDirs {
 135                 recurse := strings.HasSuffix(dir, "/...")
 136                 dir = strings.TrimSuffix(dir, "/...")
 137                 filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 138                         if err != nil {
 139                                 fatalf("walking bootstrap dirs failed: %v: %v", path, err)
 140                         }
 141
 142                         name := filepath.Base(path)
 143                         src := pathf("%s/src/%s", goroot, path)
 144                         dst := pathf("%s/%s", base, path)
 145
 146                         if info.IsDir() {
 147                                 if !recurse && path != dir || name == "testdata" {
 148                                         return filepath.SkipDir
 149                                 }
 150
 151                                 xmkdirall(dst)
 152                                 if path == "cmd/cgo" {
 153                                         // Write to src because we need the file both for bootstrap
 154                                         // and for later in the main build.
 155                                         mkzdefaultcc("", pathf("%s/zdefaultcc.go", src))
 156                                         mkzdefaultcc("", pathf("%s/zdefaultcc.go", dst))
 157                                 }
 158                                 return nil
 159                         }
 160
 161                         for _, pre := range ignorePrefixes {
 162                                 if strings.HasPrefix(name, pre) {
 163                                         return nil
 164                                 }
 165                         }
 166                         for _, suf := range ignoreSuffixes {
 167                                 if strings.HasSuffix(name, suf) {
 168                                         return nil
 169                                 }
 170                         }
 171
 172                         text := bootstrapRewriteFile(src)
 173                         writefile(text, dst, 0)
 174                         return nil
 175                 })
 176         }
 177
 178         // Set up environment for invoking Go 1.4 go command.
 179         // GOROOT points at Go 1.4 GOROOT,
 180         // GOPATH points at our bootstrap workspace,
 181         // GOBIN is empty, so that binaries are installed to GOPATH/bin,
 182         // and GOOS, GOHOSTOS, GOARCH, and GOHOSTOS are empty,
 183         // so that Go 1.4 builds whatever kind of binary it knows how to build.
 184         // Restore GOROOT, GOPATH, and GOBIN when done.
 185         // Don't bother with GOOS, GOHOSTOS, GOARCH, and GOHOSTARCH,
 186         // because setup will take care of those when bootstrapBuildTools returns.
 187
 188         defer os.Setenv("GOROOT", os.Getenv("GOROOT"))
 189         os.Setenv("GOROOT", goroot_bootstrap)
 190
 191         defer os.Setenv("GOPATH", os.Getenv("GOPATH"))
 192         os.Setenv("GOPATH", workspace)
 193
 194         defer os.Setenv("GOBIN", os.Getenv("GOBIN"))
 195         os.Setenv("GOBIN", "")
 196
 197         os.Setenv("GOOS", "")
 198         os.Setenv("GOHOSTOS", "")
 199         os.Setenv("GOARCH", "")
 200         os.Setenv("GOHOSTARCH", "")
 201
 202         // Run Go 1.4 to build binaries. Use -gcflags=-l to disable inlining to
 203         // workaround bugs in Go 1.4's compiler. See discussion thread:
 204         // https://groups.google.com/d/msg/golang-dev/Ss7mCKsvk8w/Gsq7VYI0AwAJ
 205         // Use the math_big_pure_go build tag to disable the assembly in math/big
 206         // which may contain unsupported instructions.
 207         // Note that if we are using Go 1.10 or later as bootstrap, the -gcflags=-l
 208         // only applies to the final cmd/go binary, but that's OK: if this is Go 1.10
 209         // or later we don't need to disable inlining to work around bugs in the Go 1.4 compiler.
 210         cmd := []string{
 211                 pathf("%s/bin/go", goroot_bootstrap),
 212                 "install",
 213                 "-gcflags=-l",
 214                 "-tags=math_big_pure_go compiler_bootstrap",
 215         }
 216         if vflag > 0 {
 217                 cmd = append(cmd, "-v")
 218         }
 219         if tool := os.Getenv("GOBOOTSTRAP_TOOLEXEC"); tool != "" {
 220                 cmd = append(cmd, "-toolexec="+tool)
 221         }
 222         cmd = append(cmd, "bootstrap/cmd/...")
 223         run(base, ShowOutput|CheckExit, cmd...)
 224
 225         // Copy binaries into tool binary directory.
 226         for _, name := range bootstrapDirs {
 227                 if !strings.HasPrefix(name, "cmd/") {
 228                         continue
 229                 }
 230                 name = name[len("cmd/"):]
 231                 if !strings.Contains(name, "/") {
 232                         copyfile(pathf("%s/%s%s", tooldir, name, exe), pathf("%s/bin/%s%s", workspace, name, exe), writeExec)
 233                 }
 234         }
 235
 236         if vflag > 0 {
 237                 xprintf("\n")
 238         }
 239 }
 240
 241 var ssaRewriteFileSubstring = filepath.FromSlash("src/cmd/compile/internal/ssa/rewrite")
 242
 243 // isUnneededSSARewriteFile reports whether srcFile is a
 244 // src/cmd/compile/internal/ssa/rewriteARCHNAME.go file for an
 245 // architecture that isn't for the current runtime.GOARCH.
 246 //
 247 // When unneeded is true archCaps is the rewrite base filename without
 248 // the "rewrite" prefix or ".go" suffix: AMD64, 386, ARM, ARM64, etc.
 249 func isUnneededSSARewriteFile(srcFile string) (archCaps string, unneeded bool) {
 250         if !strings.Contains(srcFile, ssaRewriteFileSubstring) {
 251                 return "", false
 252         }
 253         fileArch := strings.TrimSuffix(strings.TrimPrefix(filepath.Base(srcFile), "rewrite"), ".go")
 254         if fileArch == "" {
 255                 return "", false
 256         }
 257         b := fileArch[0]
 258         if b == '_' || ('a' <= b && b <= 'z') {
 259                 return "", false
 260         }
 261         archCaps = fileArch
 262         fileArch = strings.ToLower(fileArch)
 263         fileArch = strings.TrimSuffix(fileArch, "splitload")
 264         if fileArch == os.Getenv("GOHOSTARCH") {
 265                 return "", false
 266         }
 267         if fileArch == strings.TrimSuffix(runtime.GOARCH, "le") {
 268                 return "", false
 269         }
 270         if fileArch == strings.TrimSuffix(os.Getenv("GOARCH"), "le") {
 271                 return "", false
 272         }
 273         return archCaps, true
 274 }
 275
 276 func bootstrapRewriteFile(srcFile string) string {
 277         // During bootstrap, generate dummy rewrite files for
 278         // irrelevant architectures. We only need to build a bootstrap
 279         // binary that works for the current runtime.GOARCH.
 280         // This saves 6+ seconds of bootstrap.
 281         if archCaps, ok := isUnneededSSARewriteFile(srcFile); ok {
 282                 return fmt.Sprintf(`// Code generated by go tool dist; DO NOT EDIT.
 283
 284 package ssa
 285
 286 func rewriteValue%s(v *Value) bool { panic("unused during bootstrap") }
 287 func rewriteBlock%s(b *Block) bool { panic("unused during bootstrap") }
 288 `, archCaps, archCaps)
 289         }
 290
 291         return bootstrapFixImports(srcFile)
 292 }
 293
 294 func bootstrapFixImports(srcFile string) string {
 295         text := readfile(srcFile)
 296         if !strings.Contains(srcFile, "/cmd/") && !strings.Contains(srcFile, `\cmd\`) {
 297                 text = regexp.MustCompile(`\bany\b`).ReplaceAllString(text, "interface{}")
 298         }
 299         lines := strings.SplitAfter(text, "\n")
 300         inBlock := false
 301         for i, line := range lines {
 302                 if strings.HasPrefix(line, "import (") {
 303                         inBlock = true
 304                         continue
 305                 }
 306                 if inBlock && strings.HasPrefix(line, ")") {
 307                         inBlock = false
 308                         continue
 309                 }
 310                 if strings.HasPrefix(line, `import "`) || strings.HasPrefix(line, `import . "`) ||
 311                         inBlock && (strings.HasPrefix(line, "\t\"") || strings.HasPrefix(line, "\t. \"") || strings.HasPrefix(line, "\texec \"")) {
 312                         line = strings.Replace(line, `"cmd/`, `"bootstrap/cmd/`, -1)
 313                         for _, dir := range bootstrapDirs {
 314                                 if strings.HasPrefix(dir, "cmd/") {
 315                                         continue
 316                                 }
 317                                 line = strings.Replace(line, `"`+dir+`"`, `"bootstrap/`+dir+`"`, -1)
 318                         }
 319                         lines[i] = line
 320                 }
 321         }
 322
 323         lines[0] = "// Code generated by go tool dist; DO NOT EDIT.\n// This is a bootstrap copy of " + srcFile + "\n\n//line " + srcFile + ":1\n" + lines[0]
 324
 325         return strings.Join(lines, "")
 326 }