libelf: add compression header support

GNU and Oracle libelf implementations added support for section
compression, intended to reduce the size of DWARF debug info (which
might be an order of magnit

libelf: add compression header support

GNU and Oracle libelf implementations added support for section
compression, intended to reduce the size of DWARF debug info (which
might be an order of magnitude larger than the code).

There are two compressed ELF section formats:

1. Old GNU - sections are renmaed to start with 'z'. Section contains
a magic number, uncompressed size, and compressed data.

2. Oracle and New GNU - compressed sections use the SHF_COMPRESSED flag.
The compression header contains the compression type, uncompressed
size, and uncompressed alignment.

The second style is preferred and this change implements only that one.

Submitted by: Tiger Gao <tig@FreeBSDFoundation.org>
Reviewed by: markj
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D24566

show more ...

Catch up with HEAD (r280229-r284686).

Merge sync of head

MFH: r280643-r281852

Sponsored by: The FreeBSD Foundation

Merge from HEAD

Update elftoolchain to upstream revision 3179

Some notable changes:
- libdwarf: Fixed DWARF4 line section
- elfcopy: Implement --localize-hidden
- nm: handle object name referenced by DW_AT_specific

Update elftoolchain to upstream revision 3179

Some notable changes:
- libdwarf: Fixed DWARF4 line section
- elfcopy: Implement --localize-hidden
- nm: handle object name referenced by DW_AT_specification
- elfcopy: Add --strip-dwo and --extract-dwo options for split DWARF
- readelf: add remaining arm64 dynamic relocation names
- nm: Avoid integer overflow in value comparison

Relnotes: Yes
Sponsored by: The FreeBSD Foundation

show more ...

MFC @ r266724

An SVM update will follow this.

Merge head

IFC @264767

MFH: tracking commit

Sponsored by: The FreeBSD Foundation

Merge head up to r262222 (last merge was incomplete).

Merge from projects/elftoolchain: Upgrade libelf and libdwarf to newer
versions from elftoolchain upstream (r2974). Convert ctfconvert to
use the APIs from the new libdwarf and make ctfconvert work

Merge from projects/elftoolchain: Upgrade libelf and libdwarf to newer
versions from elftoolchain upstream (r2974). Convert ctfconvert to
use the APIs from the new libdwarf and make ctfconvert work with Clang
3.4.

__FreeBSD_version is bumped to 1100006.

A list of notable changes:

[libelf]

* The old libelf source code in lib/libelf has been removed.
Instead, the new libelf is built from contrib/elftoolchain/libelf.
* Manual pages are largely improved.
* Internal implementation was refactored and improved for better
correctness and portability.
* Fixed a few memory leaks.
* Extended with extension APIs `elf_open()` and `elf_openmemory()`.
These APIs are similar to `elf_begin()` and `elf_memory()`
respectively, except that they return an ELF descriptor of kind
`ELF_K_NONE` instead of an error if the object being opened could
not be parsed.
* Implement support for translating sections of type ELF_T_VDEF and
ELF_T_VNEED.
* Improve `elf_update()` to check that the executable header, the
program header table, section contents and the section header table
do not overlap, and to ensure that gaps between extents are
filled with the fill character specified by `elf_fill()`.
* Allow `Elf_Data` descriptors to have types and alignments differing
from their containing section.
* Remove functionality controlled by `LIBELF_TEST_HOOKS`.
* Support processing of BSD-flavor archives.
* Add knowledge of section types `SHT_GNU_ATTRIBUTES` and
`SHT_GNU_LIBLIST`.
* Use elftoolchain style symbol versioning.
* Shared library version is bumped.

[libdwarf]

* The old libdwarf source code in lib/libdwarf has been removed.
Instead, the new libdwarf is built from contrib/elftoolchain/libdwarf.
* Support full DWARF3 and partial DWARF4 parsing.
* Support DWARF2 generation.
* Support for DWARF line number, call frame, location expression,
macro info and address ranges, among other things.
* The APIs for the new libdwarf are mostly compatible with the widely
used LGPL libdwarf. Some of the incompatible APIs from the old
libdwarf are kept as its own extensions. All the APIs are documented.
* Use elftoolchain style symbol versioning.
* Shared library version is bumped.

[ctfconvert]

* Switch to the APIs from the new libdwarf.
* Improve die_mem_offset() so that DW_AT_data_member_location attributes
generated by Clang 3.4 can be handled properly.
* Make use of DW_AT_byte_size attribute of the member DIE to calculate
the bits occupied by the member's type, without actually resolving
the type. This way ctfconvert can deal with the case that Clang 3.4
sometimes emits DIE for struct/union member before emitting the DIE
for the type of that member.

Obtained from: elftoolchain
No objection: -toolchain mailing list

show more ...

Copy libelf, libdwarf and common files from vendor/ to contrib/.