gold has an option --print-symbol-counts= which prints:
// For each archive archive $archive $members $fetched_members // For each object file symbols $object $defined_symbols $used_defined_symbols
In most cases, $defined_symbols = $used_defined_symbols unless weak
symbols are present. Strangely $used_defined_symbols includes symbols defined relative to --gc-sections discarded sections.
The symbols lines do not appear to be useful.
archive lines are useful: $fetched_members=0 lines correspond to
unused archives. The information can be used to trim dependencies.
This patch implements --print-archive-stats= which prints the number of
members and the number of fetched members for each archive.