// the write barrier flag.
		// It is unlikely to have more than one of them. Just do a linear
		// search instead of using a map.
		// See issue 15854.
		type volatileCopy struct {
			src *Value // address of original volatile value
			tmp *Value // address of temporary we've copied the volatile value into
		}
		var volatiles []volatileCopy

		if !(f.ABIDefault == f.ABI1 && len(f.Config.intParamRegs) >= 3) {

//
//go:nowritebarrier
func scanblock(b0, n0 uintptr, ptrmask *uint8, gcw *gcWork, stk *stackScanState) {
	// Use local copies of original parameters, so that a stack trace
	// due to one of the throws below shows the original block
	// base and extent.
	b := b0
	n := n0

	for i := uintptr(0); i < n; {
		// Find bits for the next word.

	// Display options.
	"relative_percentages": helpText(
		"Show percentages relative to focused subgraph",
		"If unset, percentages are relative to full graph before focusing",
		"to facilitate comparison with original graph."),
	"unit": helpText(
		"Measurement units to display",
		"Scale the sample values to this unit.",
		"For time-based profiles, use seconds, milliseconds, nanoseconds, etc.",

		after[p.ID] = []*Block{b}
		for {
			nextIdx := idToIdx[b.ID] + 1
			if nextIdx >= len(f.Blocks) { // reached end of function (maybe impossible?)
				break
			}
			nextb := f.Blocks[nextIdx]
			if nextb == p { // original loop predecessor is next
				break
			}
			if loopnest.b2l[nextb.ID] == loop {
				after[p.ID] = append(after[p.ID], nextb)
			}
			b = nextb
		}

	z := NewWriter(buf)
	msg := []byte("hello world")
	z.Write(msg)
	z.Close()
	z.Reset(buf2)
	z.Write(msg)
	z.Close()
	if buf.String() != buf2.String() {
		t.Errorf("buf2 %q != original buf of %q", buf2.String(), buf.String())
	}
}

type limitedWriter struct {
	N int
}

func (l *limitedWriter) Write(p []byte) (n int, err error) {
	if n := l.N; n < len(p) {
		l.N = 0

type ReverseProxy struct {
	// Rewrite must be a function which modifies
	// the request into a new request to be sent
	// using Transport. Its response is then copied
	// back to the original client unmodified.
	// Rewrite must not access the provided ProxyRequest
	// or its contents after returning.
	//
	// The Forwarded, X-Forwarded, X-Forwarded-Host,
	// and X-Forwarded-Proto headers are removed from the

	// underlying file descriptor with reference counting.
	RefCountPtr *int32

	// RefCount is the reference count of Sysfd. When a copy of an FD is made,
	// it points to the reference count of the original FD instance.
	RefCount int32

	// Cache for the file type, lazily initialized when Seek is called.
	Filetype uint32

	// If the file represents a directory, this field contains the current

			// It's not safe to continue with tests if we can't get back to
			// the original working directory.
			panic(err)
		}
	}()

	// Note the deferred Wait must be called after the deferred close(done),
	// to ensure the N goroutines have been released even if the main goroutine
	// calls Fatalf. It must be called before the Chdir back to the original
	// directory, and before the deferred deletion implied by TempDir,

	}
	return modulePath + "/..."
}

// makeGOROOTCopy makes a temporary copy of the current GOROOT tree.
// The goal is to allow the calling test t to safely mutate a GOROOT
// copy without also modifying the original GOROOT.
//
// It copies the entire tree as is, with the exception of the GOROOT/.git
// directory, which is skipped, and the GOROOT/{bin,pkg} directories,

		// scanDir ignores files with import "C" when collecting the list
		// of imports unless the "cgo" tag is provided. The following comment
		// is copied from the original.
		//
		// import "C" is implicit requirement of cgo tag.
		// When listing files on the command line (explicitFiles=true)
		// we do not apply build tag filtering but we still do apply