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gecko-dev/build/unix/elfhack
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Mike Hommey d8daefaa34 Bug 664362 - Generate depfiles for host objects/programs/libraries. r=gps
2013-10-22 13:40:27 +09:00
..
inject Bug 895047 - Make char16_t available everywhere and use that to define PRUnichar and jschar; r=jcranmer,jorendorff,glandium 2013-10-17 00:36:13 -04:00
dummy.c Bug 716295 part 6 - Create elfhack tests for both DT_INIT and DT_INIT_ARRAY. r=nfroyd 2012-08-09 16:34:26 +02:00
elf.cpp Bug 654087 - Don't error out on gold special treatment of PT_TLS segment memsize. r=nfroyd 2013-01-16 09:15:07 +01:00
elfhack.cpp Bug 898998 - Turn BL into BLX when doing thumb call relocations and the target is ARM. r=nfroyd 2013-07-30 08:57:28 +09:00
elfxx.h Bug 822584 - Workaround in elfhack to accomodate for breakpad not handling the memory mapping induced by the elfhack/bionic linker combination. r=nfroyd 2013-01-02 10:17:32 +01:00
inject.c Bug 925330 - don't use HAVE_64BIT_OS when building elfhack; r=glandium 2013-10-10 09:31:29 -04:00
Makefile.in Bug 664362 - Generate depfiles for host objects/programs/libraries. r=gps 2013-10-22 13:40:27 +09:00
moz.build bug 870406: move CSRCS to mozbuild - patch #4. r=mshal 2013-09-20 16:46:57 -04:00
README
test-array.c Bug 716295 part 6 - Create elfhack tests for both DT_INIT and DT_INIT_ARRAY. r=nfroyd 2012-08-09 16:34:26 +02:00
test-ctors.c Bug 716295 part 6 - Create elfhack tests for both DT_INIT and DT_INIT_ARRAY. r=nfroyd 2012-08-09 16:34:26 +02:00
test.c Bug 654087 - Don't error out on gold special treatment of PT_TLS segment memsize. r=nfroyd 2013-01-16 09:15:07 +01:00

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.