commit 3e7b7388d6e38371c1f0dbc4b68c9888dc6fc5b1
author simonb@chromium.org <simonb@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> Tue Jun 10 15:57:52 2014
committer simonb@chromium.org <simonb@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> Tue Jun 10 15:57:52 2014
tree cff40819e475cf90c4961c631eb7df5643e1da23
parent 7cdcd7969730e857ef5812f39c447669a490caef

Add a host tool to pack R_ARM_RELATIVE relocations in libchrome.<ver>.so.

R_ARM_RELATIVE relocations are the bulk of dynamic relocations (the .rel.dyn
section) in libchrome.<version>.so.  The ELF standard representation of them
is wasteful.

Packing uses run length encoding to store them more efficiently.  Packed
relocations are placed in a new .android.rel.dyn section.  Packing reduces
the footprint of libchrome.<version>.so in the filesystem, in APK downloads,
and in memory when loaded on the device.

A packed libchrome.<version>.so is designed so that it can be loaded directly
on Android, but requires the explicit support of a crazy linker that has been
extended to understand packed relocations.

A packed libchrome.<version>.so cannot currently be used with the standard
Android runtime linker.

See README.TXT and src/*.h for design and implementation notes.

BUG=

Review URL: https://codereview.chromium.org/310483003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276043 0039d316-1c4b-4281-b951-d872f2087c98