if !found {
		base.Fatalf("go: -replace=%s: need old[@v]=new[@w] (missing =)", arg)
	}
	old, new := strings.TrimSpace(before), strings.TrimSpace(after)
	if strings.HasPrefix(new, ">") {
		base.Fatalf("go: -replace=%s: separator between old and new is =, not =>", arg)
	}
	oldPath, oldVersion, err := parsePathVersionOptional("old", old, false)
	if err != nil {
		base.Fatalf("go: -replace=%s: %v", arg, err)
	}

)

func TestBuiltin(t *testing.T) {
	testenv.MustHaveGoRun(t)
	t.Parallel()

	old, err := os.ReadFile("builtin.go")
	if err != nil {
		t.Fatal(err)
	}

	new, err := testenv.Command(t, testenv.GoToolPath(t), "run", "mkbuiltin.go", "-stdout").Output()
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(old, new) {
		t.Fatal("builtin.go out of date; run mkbuiltin.go")
	}

func (r *gitRepo) CheckReuse(ctx context.Context, old *Origin, subdir string) error {
	if old == nil {
		return fmt.Errorf("missing origin")
	}
	if old.VCS != "git" || old.URL != r.remoteURL {
		return fmt.Errorf("origin moved from %v %q to %v %q", old.VCS, old.URL, "git", r.remoteURL)
	}
	if old.Subdir != subdir {
		return fmt.Errorf("origin moved from %v %q %q to %v %q %q", old.VCS, old.URL, old.Subdir, "git", r.remoteURL, subdir)
	}

	}

	alldocs, err := format.Source(out)
	if err != nil {
		t.Fatalf("format.Source($(%v)): %v", cmd, err)
	}

	const srcPath = `alldocs.go`
	old, err := os.ReadFile(srcPath)
	if err != nil {
		t.Fatalf("error reading %s: %v", srcPath, err)
	}
	diff := diff.Diff(srcPath, old, "go help documentation | gofmt", alldocs)
	if diff == nil {
		t.Logf("%s is up to date.", srcPath)
		return
	}

	if *fixDocs {

		debugPrintf("releaseLock %s: unlocked\n", c.name)
		return
	}
}

func (c *Counter) add(n uint64) uint64 {
	count := c.ptr.count
	for {
		old := count.Load()
		sum := old + n
		if sum < old {
			sum = ^uint64(0)
		}
		if count.CompareAndSwap(old, sum) {
			runtime.KeepAlive(c.ptr.m)
			return sum
		}
	}
}

func (c *Counter) invalidate() {
	for {
		state := c.state.load()

				// The only incoming memory value doesn't belong to this block.
				mem = a
			}
			if mem != nil {
				if old := startMem[b.ID]; old != nil {
					if old == mem {
						continue
					}
					f.Fatalf("func %s, startMem[%v] has different values, old %v, new %v", f.Name, b, old, mem)
				}
				startMem[b.ID] = mem
				changed = append(changed, b)
			}
		}
	}

				}
				if prev, ok := replacements[r.Old]; ok && !curModuleReplaces[r.Old] && prev != newV {
					base.Fatalf("go: conflicting replacements for %v:\n\t%v\n\t%v\nuse \"go work edit -replace %v=[override]\" to resolve", r.Old, prev, newV, r.Old)
				}
				curModuleReplaces[r.Old] = true
				replacements[r.Old] = newV

				v, ok := mainModules.highestReplaced[r.Old.Path]

		err = e1
	}
	return
}

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

func bind(name string, old string, flag int) (err error) {
	var _p0 *byte
	_p0, err = BytePtrFromString(name)
	if err != nil {
		return
	}
	var _p1 *byte
	_p1, err = BytePtrFromString(old)
	if err != nil {
		return
	}

					if replacementWritten[r.Old] {
						// We already recorded this replacement.
						continue
					}
					replacementWritten[r.Old] = true
					rNew := modload.Replacement(r.Old)
					if rNew == (module.Version{}) {
						// There is no replacement. Don't try to write it.
						continue
					}

					line := moduleLine(r.Old, rNew)
					buf.WriteString(line)
					if cfg.BuildV {

source directories corresponding to the import paths:

	_obj/            old object directory, left from Makefiles
	_test/           old test directory, left from Makefiles
	_testmain.go     old gotest file, left from Makefiles
	test.out         old test log, left from Makefiles
	build.out        old test log, left from Makefiles
	*.[568ao]        object files, left from Makefiles

	DIR(.exe)        from go build