if _, err := r.f.Seek(r.offset+offset, 0); err != nil {
		return err
	}
	return binary.Write(r.f, r.order, data)
}

// machoCombineDwarf merges dwarf info generated by dsymutil into a macho executable.
//
// With internal linking, DWARF is embedded into the executable, this lets us do the
// same for external linking.

	sym, base := s.Ranges, s.StartPC

	if s.UseBASEntries {
		// Using a Base Address Selection Entry reduces the number of relocations, but
		// this is not done on macOS because it is not supported by dsymutil/dwarfdump/lldb
		ctxt.AddInt(sym, ps, -1)
		ctxt.AddAddress(sym, base, 0)
		PutBasedRanges(ctxt, sym, ranges)
		return
	}

	// Write ranges full of relocations
	for _, r := range ranges {

func TestRuntimeTypeAttrExternal(t *testing.T) {
	testenv.MustHaveGoBuild(t)
	testenv.MustHaveCGO(t)

	mustHaveDWARF(t)

	// Explicitly test external linking, for dsymutil compatibility on Darwin.
	if runtime.GOARCH == "ppc64" {
		t.Skip("-linkmode=external not supported on ppc64")
	}

	testRuntimeTypeAttr(t, "-ldflags=-linkmode=external")
}