gecko-dev/build/unix/elfhack
Ricky Stewart c010710916 Bug 1586358 - Replace existing instances of GENERATED_FILES with references to the GeneratedFile template r=firefox-build-system-reviewers,mshal
(Same content as bad revision https://phabricator.services.mozilla.com/D48230, but with a very small change to config/external/icu/data/moz.build to fix the build breakage.)

Try push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=833f6a69fcac689488a640b43e8e0bdaa086a56c

Differential Revision: https://phabricator.services.mozilla.com/D48409

--HG--
extra : moz-landing-system : lando
2019-10-07 21:15:19 +00:00
..
inject Bug 1586358 - Replace existing instances of GENERATED_FILES with references to the GeneratedFile template r=firefox-build-system-reviewers,mshal 2019-10-07 21:15:19 +00:00
Makefile.in Bug 1403346 - Implement cflags filtering for elfhack in mozbuild COMPILE_FLAGS r=glandium 2017-10-25 15:12:10 -07:00
README
dummy.c Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format 2018-11-30 11:46:48 +01:00
elf.cpp Bug 1547143 - Format the tree: Be prescriptive with the pointer style (left) r=Ehsan 2019-05-01 08:47:10 +00:00
elfhack.cpp Bug 1579430 - mark some elfhack methods as `override`; r=glandium 2019-09-09 23:54:34 +00:00
elfxx.h Bug 1547143 - Format the tree: Be prescriptive with the pointer style (left) r=Ehsan 2019-05-01 08:47:10 +00:00
inject.c Bug 1547143 - Format the tree: Be prescriptive with the pointer style (left) r=Ehsan 2019-05-01 08:47:10 +00:00
moz.build Bug 1484872 - Move LTO flags to python configure. r=froydnj 2018-08-21 08:40:26 +09:00
test-array.c Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format 2018-11-30 11:46:48 +01:00
test-ctors.c Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format 2018-11-30 11:46:48 +01:00
test.c Bug 1547143 - Format the tree: Be prescriptive with the pointer style (left) r=Ehsan 2019-05-01 08:47:10 +00:00

README

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.