gecko/build/unix/elfhack
Mike Hommey 49e4fef21e Bug 1167474 - Remove ELFHACK_BUILD hack. r=mshal
It used to be necessary because of how elfhack was built in the past, but it
happens to be unnecessary nowadays.
2015-05-26 16:17:55 +09:00
..
inject Bug 1167474 - Remove ELFHACK_BUILD hack. r=mshal 2015-05-26 16:17:55 +09:00
dummy.c
elf.cpp Bug 784739 - Switch from NULL to nullptr in build/; r=ehsan 2013-11-11 14:13:38 -05:00
elfhack.cpp Bug 982014 - Fix what sections are copied from injection object after bug 932737. r=nfroyd 2014-04-04 14:56:36 +09:00
elfxx.h Bug 1120062 - Part 1: Remove most Nullptr.h includes. r=waldo 2015-01-11 11:34:52 +09:00
inject.c
Makefile.in Bug 1077148 part 4 - Add and use new moz.build templates for Gecko programs and libraries. r=gps 2014-10-30 13:06:12 +09:00
moz.build Bug 1167474 - Remove ELFHACK_BUILD hack. r=mshal 2015-05-26 16:17:55 +09:00
README
test-array.c
test-ctors.c
test.c

Elfhack is a program to optimize ELF binaries for size and cold startup
speed.

Presently, it is quite experimental, though it works well for the target
it was created for: Firefox's libxul.so.

Elfhack currently only does one thing: packing dynamic relocations ;
which ends up being a quite complex task, that can be summarized this
way:
- Remove RELATIVE relocations from the .rel.dyn/.rela.dyn section.
- Inject a small code able to apply relative relocations "by hand"
  after the .rel.dyn/.rela.dyn section.
- Inject a section containing relocative relocations in a different
  and more packed format, after the small code.
- Register the small code as DT_INIT function. Make the small code call
  what was initially the DT_INIT function, if there was one.
- Remove the hole between the new section containing relative
  relocations and the following sections, adjusting offsets and base
  addresses accordingly.
- Adjust PT_LOAD entries to fit new offsets, and add an additional
  PT_LOAD entry when that is necessary to handle the discrepancy between
  offsets and base addresses, meaning the section offsets may yet again
  need adjustments.
- Adjust various DT_* dynamic tags to fit the new ELF layout.
- Adjust section headers.
- Adjust ELF headers.

See http://glandium.org/blog/?p=1177#relocations for some figures.