gecko-dev/build/unix/elfhack
Ricky Stewart 02a7b4ebdf Bug 1654103: Standardize on Black for Python code in `mozilla-central`.
Allow-list all Python code in tree for use with the black linter, and re-format all code in-tree accordingly.

To produce this patch I did all of the following:

1. Make changes to tools/lint/black.yml to remove include: stanza and update list of source extensions.

2. Run ./mach lint --linter black --fix

3. Make some ad-hoc manual updates to python/mozbuild/mozbuild/test/configure/test_configure.py -- it has some hard-coded line numbers that the reformat breaks.

4. Make some ad-hoc manual updates to `testing/marionette/client/setup.py`, `testing/marionette/harness/setup.py`, and `testing/firefox-ui/harness/setup.py`, which have hard-coded regexes that break after the reformat.

5. Add a set of exclusions to black.yml. These will be deleted in a follow-up bug (1672023).

# ignore-this-changeset

Differential Revision: https://phabricator.services.mozilla.com/D94045
2020-10-26 18:34:53 +00:00
..
inject Bug 1654103: Standardize on Black for Python code in `mozilla-central`. 2020-10-26 18:34:53 +00:00
Makefile.in
README
dummy.c
elf.cpp
elfhack.cpp
elfxx.h
inject.c
moz.build Bug 1654103: Standardize on Black for Python code in `mozilla-central`. 2020-10-26 18:34:53 +00:00
test-array.c
test-ctors.c
test.c

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.