2007-07-17 Doug Kwan <dougkwan@google.com>
Speed up bfd_dwarf2_find_line.
* dwarf2.c (struct dwarf2_debug): Add new fields to support function
and variable info hash tables. Add last_comp_unit, info_hash_count,
funcinfo_hash_table, varinfo_hash_table, hash_units_head.
(struct comp_unit): Add prev_unit, cached.
(struct info_list_node, struct info_hash_entry,
struct info_hash_table): New.
(info_hash_table_newfunc, create_info_hash_table,
insert_info_hash_table, lookup_info_hash_table): New functions
implementing function and variable info hash tables.
(scan_unit_for_symbols): Add checks to make sure hash tables are
consistent with compilation units.
(comp_unit_maybe_decode_line_info): New function.
(comp_unit_find_line): Use comp_unit_maybe_decode_line_info.
(reverse_funcinfo_list, reverse_varinfo_list, comp_unit_hash_info,
info_hash_lookup_funcinfo, info_hash_lookup_varinfo,
stash_maybe_update_info_hash_table, stash_verify_info_hash_table,
stash_maybe_enable_info_hash_tables, stash_find_line_fast): New
functions. Make use of info hash tables to speed up
bfd_dwarf2_find_line.
(find_line): Use hash table for faster lookup if it is turned on.
Also add code to maintain bi-directional link in comp units.