* NEWS: Mention new linker map file generation and the

	--reduce-memory-overheads option.
	* ld.texinfo: Document --reduce-memory-overheads option.
	* ld.h (map_symbol_def): New struct.
	(struct user_section_struct, section_userdata_type): Rename to:
	(struct lean_user_section_struct, lean_section_userdata_type).
	(struct fat_user_section_struct, fat_section_userdata_type): New.
	(SECTION_USERDATA_SIZE): Define.
	(args_type): New member reduce_memory_overheads.
	* ldlang.c (map_obstack): New static variable.
	(init_map_userdata, print_all_symbols, sort_def_symbol): New functions.
	(lang_map): Unless command_line.reduce_memory_overheads is set,
	initialize lists of defined symbols for each section.
	(print_input_section): Unless command_line.reduce_memory_overheads
	is set, use print_all_symbols.
	(init_os): Use lean_section_userdata_type / SECTION_USERDATA_SIZE.
	* ldmain.c (main): Initialize command_line.reduce_memory_overheads.
	* lexsup.c (enum option_values): Add OPTION_REDUCE_MEMORY_OVERHEADS.
	(ld_options): Add entry for --reduce-memory-overheads.
	(parse_args): Handle OPTION_REDUCE_MEMORY_OVERHEADS.

1 files changed, 8 insertions, 0 deletions

diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index ceaecd1..b78d1b0 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -1734,6 +1734,14 @@ If you specify @option{--disable-new-dtags}, no new dynamic tags will be
 created. By default, the new dynamic tags are not created. Note that
 those options are only available for ELF systems.
 
+@kindex --reduce-memory-overheads
+@item --reduce-memory-overheads
+This option reduces memory requirements at ld runtime, at the expense of
+linking speed.  This was introduced to to select the old O(n^2) algorithm
+for link map file generation, rather than the new O(n) algorithm which uses
+about 40% more memory for symbol storage.  It may be also be used for
+similar such tradeoffs in the future.
+
 @end table
 
 @c man end