{2, PageBase(BaseChunkIdx, 6), PageSize},
				{2, PageBase(BaseChunkIdx, 8), 0},
			},
			after: map[ChunkIdx][]BitRange{
				BaseChunkIdx: {{0, 10}},
			},
		},
		"Straddle2": {
			before: map[ChunkIdx][]BitRange{
				BaseChunkIdx:     {{0, PallocChunkPages - 1}},
				BaseChunkIdx + 1: {{1, PallocChunkPages - 1}},
			},
			scav: map[ChunkIdx][]BitRange{

}

func unsafestringcheckptr(ptr unsafe.Pointer, len64 int64) {
	unsafestring64(ptr, len64)

	// Check that underlying array doesn't straddle multiple heap objects.
	// unsafestring64 has already checked for overflow.
	if checkptrStraddles(ptr, uintptr(len64)) {
		throw("checkptr: unsafe.String result straddles multiple allocations")
	}
}

func panicunsafestringlen() {
	panic(errorString("unsafe.String: len out of range"))
}

	}

	// Check that (*[n]elem)(p) doesn't straddle multiple heap objects.
	// TODO(mdempsky): Fix #46938 so we don't need to worry about overflow here.
	if checkptrStraddles(p, n*elem.Size_) {
		throw("checkptr: converted pointer straddles multiple allocations")
	}
}

// checkptrStraddles reports whether the first size-bytes of memory
// addressed by ptr is known to straddle more than one Go allocation.

		{"CheckPtrSmall", "fatal error: checkptr: pointer arithmetic computed bad pointer value\n"},
		{"CheckPtrSliceOK", ""},
		{"CheckPtrSliceFail", "fatal error: checkptr: unsafe.Slice result straddles multiple allocations\n"},
		{"CheckPtrStringOK", ""},
		{"CheckPtrStringFail", "fatal error: checkptr: unsafe.String result straddles multiple allocations\n"},
	}

			return nil
		}
		req = newRequest(rec.h.Id, br.flags)
		c.requests[rec.h.Id] = req
		return nil
	case typeParams:
		// NOTE(eds): Technically a key-value pair can straddle the boundary
		// between two packets. We buffer until we've received all parameters.
		if len(rec.content()) > 0 {
			req.rawParams = append(req.rawParams, rec.content()...)
			return nil
		}
		req.parseParams()

// part of the line returned by ReadLine.
func (b *Reader) ReadLine() (line []byte, isPrefix bool, err error) {
	line, err = b.ReadSlice('\n')
	if err == ErrBufferFull {
		// Handle the case where "\r\n" straddles the buffer.
		if len(line) > 0 && line[len(line)-1] == '\r' {
			// Put the '\r' back on buf and drop it from line.
			// Let the next call to ReadLine check for "\r\n".
			if b.r == 0 {
				// should be unreachable

	var buf [sizeofPtr]byte

	// Leading edge. PEEKTEXT/PEEKDATA don't require aligned
	// access (PEEKUSER warns that it might), but if we don't
	// align our reads, we might straddle an unmapped page
	// boundary and not get the bytes leading up to the page
	// boundary.
	n := 0
	if addr%sizeofPtr != 0 {
		err = ptracePtr(req, pid, addr-addr%sizeofPtr, unsafe.Pointer(&buf[0]))
		if err != nil {

		const maxN = 16
		n := uintptr(maxN)
		// We have to be careful, though. If we're near the end of
		// a page and the following page isn't mapped, we could
		// segfault. So make sure we don't straddle a page (even though
		// that could lead to printing an incomplete instruction).
		// We're assuming here we can read at least the page containing the PC.

	var buf [SizeofPtr]byte

	// Leading edge. PEEKTEXT/PEEKDATA don't require aligned
	// access (PEEKUSER warns that it might), but if we don't
	// align our reads, we might straddle an unmapped page
	// boundary and not get the bytes leading up to the page
	// boundary.
	n := 0
	if addr%SizeofPtr != 0 {
		err = ptracePtr(req, pid, addr-addr%SizeofPtr, unsafe.Pointer(&buf[0]))

		return l
	}
	return q
}

// isJump returns whether p is a jump instruction.
// It is used to ensure that no standalone or macro-fused jump will straddle
// or end on a 32 byte boundary by inserting NOPs before the jumps.
func isJump(p *obj.Prog) bool {
	return p.To.Target() != nil || p.As == obj.AJMP || p.As == obj.ACALL ||