Impala currently compiles with DWARF-2 for debugging information. Newer versions of DWARF provide additional support for new C++ features and reduced size of the debugging information in the binary. Now that we have dropped support for older OSes, the main limitation is what gdb supports.
We should look into what DWARF version is supported by the gdb versions on the platforms that we support. If possible, we should use a newer version of DWARF.