[gold patch] Incremental 9/18: Apply incremental relocations

[Cary Coutant <ccoutant at google dot com>]

This patch implements the part where we apply the incremental
relocations during an incremental update. Incremental relocations are
applied at the end of the Layout task, just before resizing the file
and calling queue_final_tasks. At that point in time, the output file
has not yet been modified, so we can safely apply all the incremental
relocations for each symbol that has been updated (when traversing the
per-symbol list of relocations, they're chained together in such a way
that it's expensive to figure out the input file to which a relocation
comes from). The do_relocate function for an incremental object just
rewrites the incremental relocations to the new incremental relocs
section. I've added a new target hook to apply a single relocation;
x86_64 is the only supported target at the moment.

-cary


2011-03-30 Cary Coutant  <ccoutant@google.com>

	* incremental.cc (Sized_incremental_binary::setup_readers): Allocate
	global symbol map.
	(Sized_incremental_binary::do_apply_incremental_relocs): New function.
	(Sized_incr_relobj::do_add_symbols): Add symbols to global symbol map.
	(Sized_incr_relobj::do_relocate): Remap section indices in incremental
	relocations.
	(Sized_incr_dynobj::do_add_symbols): Add symbols to global symbol map.
	(Sized_incr_dynobj::do_for_all_global_symbols): Remove FIXME.
	(Sized_incr_dynobj::do_for_all_local_got_entries): Likewise.
	* incremental.h
	(Incremental_inputs_reader::global_symbol_reader_at_offset): New
	function.
	(Incremental_binary::apply_incremental_relocs): New function.
	(Incremental_binary::do_apply_incremental_relocs): New function.
	(Sized_incremental_binary::Sized_incremental_binary): Initialize new
	data member.
	(Sized_incremental_binary::add_global_symbol): New function.
	(Sized_incremental_binary::global_symbol): New function.
	(Sized_incremental_binary::do_apply_incremental_relocs): New function.
	(Sized_incremental_binary::symbol_map_): New data member.
	* layout.cc (Layout_task_runner::run): Apply incremental relocations.
	* target.h (Sized_target::apply_relocation): New function.
	* x86_64.cc (Target_x86_64::apply_relocation): New function.

Attachment: incr-patch-9.txt
Description: Text document