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 bootstrap version.
   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 bootstrap toolchains 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         "strings"
  20 )
  21
  22 // bootstrapDirs is a list of directories holding code that must be
  23 // compiled with the Go bootstrap toolchain to produce the bootstrapTargets.
  24 // All directories in this list are relative to and must be below $GOROOT/src.
  25 //
  26 // The list has two kinds of entries: names beginning with cmd/ with
  27 // no other slashes, which are commands, and other paths, which are packages
  28 // supporting the commands. Packages in the standard library can be listed
  29 // if a newer copy needs to be substituted for the Go bootstrap copy when used
  30 // by the command packages. Paths ending with /... automatically
  31 // include all packages within subdirectories as well.
  32 // These will be imported during bootstrap as bootstrap/name, like bootstrap/math/big.
  33 var bootstrapDirs = []string{
  34         "cmd/asm",
  35         "cmd/asm/internal/...",
  36         "cmd/cgo",
  37         "cmd/compile",
  38         "cmd/compile/internal/...",
  39         "cmd/internal/archive",
  40         "cmd/internal/bio",
  41         "cmd/internal/codesign",
  42         "cmd/internal/dwarf",
  43         "cmd/internal/edit",
  44         "cmd/internal/gcprog",
  45         "cmd/internal/goobj",
  46         "cmd/internal/notsha256",
  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/build/constraint",
  63         "go/constant",
  64         "internal/abi",
  65         "internal/coverage",
  66         "internal/buildcfg",
  67         "internal/goarch",
  68         "internal/godebugs",
  69         "internal/goexperiment",
  70         "internal/goroot",
  71         "internal/goversion",
  72         "internal/pkgbits",
  73         "internal/platform",
  74         "internal/profile",
  75         "internal/race",
  76         "internal/saferio",
  77         "internal/syscall/unix",
  78         "internal/types/errors",
  79         "internal/unsafeheader",
  80         "internal/xcoff",
  81         "internal/zstd",
  82         "math/big",
  83         "math/bits",
  84         "sort",
  85         "strconv",
  86 }
  87
  88 // File prefixes that are ignored by go/build anyway, and cause
  89 // problems with editor generated temporary files (#18931).
  90 var ignorePrefixes = []string{
  91         ".",
  92         "_",
  93         "#",
  94 }
  95
  96 // File suffixes that use build tags introduced since Go 1.17.
  97 // These must not be copied into the bootstrap build directory.
  98 // Also ignore test files.
  99 var ignoreSuffixes = []string{
 100         "_test.s",
 101         "_test.go",
 102 }
 103
 104 var tryDirs = []string{
 105         "sdk/go1.17",
 106         "go1.17",
 107 }
 108
 109 func bootstrapBuildTools() {
 110         goroot_bootstrap := os.Getenv("GOROOT_BOOTSTRAP")
 111         if goroot_bootstrap == "" {
 112                 home := os.Getenv("HOME")
 113                 goroot_bootstrap = pathf("%s/go1.4", home)
 114                 for _, d := range tryDirs {
 115                         if p := pathf("%s/%s", home, d); isdir(p) {
 116                                 goroot_bootstrap = p
 117                         }
 118                 }
 119         }
 120         xprintf("Building Go toolchain1 using %s.\n", goroot_bootstrap)
 121
 122         mkbuildcfg(pathf("%s/src/internal/buildcfg/zbootstrap.go", goroot))
 123         mkobjabi(pathf("%s/src/cmd/internal/objabi/zbootstrap.go", goroot))
 124         mkzosarch("", pathf("%s/src/internal/platform/zosarch.go", goroot))
 125
 126         // Use $GOROOT/pkg/bootstrap as the bootstrap workspace root.
 127         // We use a subdirectory of $GOROOT/pkg because that's the
 128         // space within $GOROOT where we store all generated objects.
 129         // We could use a temporary directory outside $GOROOT instead,
 130         // but it is easier to debug on failure if the files are in a known location.
 131         workspace := pathf("%s/pkg/bootstrap", goroot)
 132         xremoveall(workspace)
 133         xatexit(func() { xremoveall(workspace) })
 134         base := pathf("%s/src/bootstrap", workspace)
 135         xmkdirall(base)
 136
 137         // Copy source code into $GOROOT/pkg/bootstrap and rewrite import paths.
 138         writefile("module bootstrap\n", pathf("%s/%s", base, "go.mod"), 0)
 139         for _, dir := range bootstrapDirs {
 140                 recurse := strings.HasSuffix(dir, "/...")
 141                 dir = strings.TrimSuffix(dir, "/...")
 142                 filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
 143                         if err != nil {
 144                                 fatalf("walking bootstrap dirs failed: %v: %v", path, err)
 145                         }
 146
 147                         name := filepath.Base(path)
 148                         src := pathf("%s/src/%s", goroot, path)
 149                         dst := pathf("%s/%s", base, path)
 150
 151                         if info.IsDir() {
 152                                 if !recurse && path != dir || name == "testdata" {
 153                                         return filepath.SkipDir
 154                                 }
 155
 156                                 xmkdirall(dst)
 157                                 if path == "cmd/cgo" {
 158                                         // Write to src because we need the file both for bootstrap
 159                                         // and for later in the main build.
 160                                         mkzdefaultcc("", pathf("%s/zdefaultcc.go", src))
 161                                         mkzdefaultcc("", pathf("%s/zdefaultcc.go", dst))
 162                                 }
 163                                 return nil
 164                         }
 165
 166                         for _, pre := range ignorePrefixes {
 167                                 if strings.HasPrefix(name, pre) {
 168                                         return nil
 169                                 }
 170                         }
 171                         for _, suf := range ignoreSuffixes {
 172                                 if strings.HasSuffix(name, suf) {
 173                                         return nil
 174                                 }
 175                         }
 176
 177                         text := bootstrapRewriteFile(src)
 178                         writefile(text, dst, 0)
 179                         return nil
 180                 })
 181         }
 182
 183         // Set up environment for invoking Go bootstrap toolchains go command.
 184         // GOROOT points at Go bootstrap GOROOT,
 185         // GOPATH points at our bootstrap workspace,
 186         // GOBIN is empty, so that binaries are installed to GOPATH/bin,
 187         // and GOOS, GOHOSTOS, GOARCH, and GOHOSTOS are empty,
 188         // so that Go bootstrap toolchain builds whatever kind of binary it knows how to build.
 189         // Restore GOROOT, GOPATH, and GOBIN when done.
 190         // Don't bother with GOOS, GOHOSTOS, GOARCH, and GOHOSTARCH,
 191         // because setup will take care of those when bootstrapBuildTools returns.
 192
 193         defer os.Setenv("GOROOT", os.Getenv("GOROOT"))
 194         os.Setenv("GOROOT", goroot_bootstrap)
 195
 196         defer os.Setenv("GOPATH", os.Getenv("GOPATH"))
 197         os.Setenv("GOPATH", workspace)
 198
 199         defer os.Setenv("GOBIN", os.Getenv("GOBIN"))
 200         os.Setenv("GOBIN", "")
 201
 202         os.Setenv("GOOS", "")
 203         os.Setenv("GOHOSTOS", "")
 204         os.Setenv("GOARCH", "")
 205         os.Setenv("GOHOSTARCH", "")
 206
 207         // Run Go bootstrap to build binaries.
 208         // Use the math_big_pure_go build tag to disable the assembly in math/big
 209         // which may contain unsupported instructions.
 210         // Use the purego build tag to disable other assembly code,
 211         // such as in cmd/internal/notsha256.
 212         cmd := []string{
 213                 pathf("%s/bin/go", goroot_bootstrap),
 214                 "install",
 215                 "-tags=math_big_pure_go compiler_bootstrap purego",
 216         }
 217         if vflag > 0 {
 218                 cmd = append(cmd, "-v")
 219         }
 220         if tool := os.Getenv("GOBOOTSTRAP_TOOLEXEC"); tool != "" {
 221                 cmd = append(cmd, "-toolexec="+tool)
 222         }
 223         cmd = append(cmd, "bootstrap/cmd/...")
 224         run(base, ShowOutput|CheckExit, cmd...)
 225
 226         // Copy binaries into tool binary directory.
 227         for _, name := range bootstrapDirs {
 228                 if !strings.HasPrefix(name, "cmd/") {
 229                         continue
 230                 }
 231                 name = name[len("cmd/"):]
 232                 if !strings.Contains(name, "/") {
 233                         copyfile(pathf("%s/%s%s", tooldir, name, exe), pathf("%s/bin/%s%s", workspace, name, exe), writeExec)
 234                 }
 235         }
 236
 237         if vflag > 0 {
 238                 xprintf("\n")
 239         }
 240 }
 241
 242 var ssaRewriteFileSubstring = filepath.FromSlash("src/cmd/compile/internal/ssa/rewrite")
 243
 244 // isUnneededSSARewriteFile reports whether srcFile is a
 245 // src/cmd/compile/internal/ssa/rewriteARCHNAME.go file for an
 246 // architecture that isn't for the given GOARCH.
 247 //
 248 // When unneeded is true archCaps is the rewrite base filename without
 249 // the "rewrite" prefix or ".go" suffix: AMD64, 386, ARM, ARM64, etc.
 250 func isUnneededSSARewriteFile(srcFile, goArch string) (archCaps string, unneeded bool) {
 251         if !strings.Contains(srcFile, ssaRewriteFileSubstring) {
 252                 return "", false
 253         }
 254         fileArch := strings.TrimSuffix(strings.TrimPrefix(filepath.Base(srcFile), "rewrite"), ".go")
 255         if fileArch == "" {
 256                 return "", false
 257         }
 258         b := fileArch[0]
 259         if b == '_' || ('a' <= b && b <= 'z') {
 260                 return "", false
 261         }
 262         archCaps = fileArch
 263         fileArch = strings.ToLower(fileArch)
 264         fileArch = strings.TrimSuffix(fileArch, "splitload")
 265         fileArch = strings.TrimSuffix(fileArch, "latelower")
 266         if fileArch == goArch {
 267                 return "", false
 268         }
 269         if fileArch == strings.TrimSuffix(goArch, "le") {
 270                 return "", false
 271         }
 272         return archCaps, true
 273 }
 274
 275 func bootstrapRewriteFile(srcFile string) string {
 276         // During bootstrap, generate dummy rewrite files for
 277         // irrelevant architectures. We only need to build a bootstrap
 278         // binary that works for the current gohostarch.
 279         // This saves 6+ seconds of bootstrap.
 280         if archCaps, ok := isUnneededSSARewriteFile(srcFile, gohostarch); ok {
 281                 return fmt.Sprintf(`// Code generated by go tool dist; DO NOT EDIT.
 282
 283 package ssa
 284
 285 func rewriteValue%s(v *Value) bool { panic("unused during bootstrap") }
 286 func rewriteBlock%s(b *Block) bool { panic("unused during bootstrap") }
 287 `, archCaps, archCaps)
 288         }
 289
 290         return bootstrapFixImports(srcFile)
 291 }
 292
 293 func bootstrapFixImports(srcFile string) string {
 294         text := readfile(srcFile)
 295         if !strings.Contains(srcFile, "/cmd/") && !strings.Contains(srcFile, `\cmd\`) {
 296                 text = regexp.MustCompile(`\bany\b`).ReplaceAllString(text, "interface{}")
 297         }
 298         lines := strings.SplitAfter(text, "\n")
 299         inBlock := false
 300         for i, line := range lines {
 301                 if strings.HasPrefix(line, "import (") {
 302                         inBlock = true
 303                         continue
 304                 }
 305                 if inBlock && strings.HasPrefix(line, ")") {
 306                         inBlock = false
 307                         continue
 308                 }
 309                 if strings.HasPrefix(line, `import "`) || strings.HasPrefix(line, `import . "`) ||
 310                         inBlock && (strings.HasPrefix(line, "\t\"") || strings.HasPrefix(line, "\t. \"") || strings.HasPrefix(line, "\texec \"")) {
 311                         line = strings.Replace(line, `"cmd/`, `"bootstrap/cmd/`, -1)
 312                         for _, dir := range bootstrapDirs {
 313                                 if strings.HasPrefix(dir, "cmd/") {
 314                                         continue
 315                                 }
 316                                 line = strings.Replace(line, `"`+dir+`"`, `"bootstrap/`+dir+`"`, -1)
 317                         }
 318                         lines[i] = line
 319                 }
 320         }
 321
 322         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]
 323
 324         return strings.Join(lines, "")
 325 }