13 Commits

Author SHA1 Message Date
Alexander Yermolovich
9f3f9d19c7 [BOLT][DWARF] Handle shared abbrev section
We can have a scenario where multiple CUs share an abbrev table.
We modify or don't modify one CU, which leads to other CUs having invalid abbrev section.
Example that caused it.
All of CUs shared the same abbrev table. First CU just had compile_unit and sub_program.
It was not modified. Next CU had DW_TAG_lexical_block with
DW_AT_low_pc/DW_AT_high_pc converted to DW_AT_low_pc/DW_AT_ranges.
We used unmodified abbrev section for first and subsequent CUs.
So when parsing subsequent CUs debug info was corrupted.

In this patch we will now duplicate all sections that are modified and are different.
This also means that if .debug_types is present and it shares Abbrev table, and
they usually are, we now can have two Abbrev tables. One for CU that was modified,
and unmodified one for TU.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D118517
2022-01-31 11:10:23 -08:00
Alexander Yermolovich
612f0f4568 [BOLT][DWARF] Fix gdb index section
Since we now re-write .debug_info the DWARF CU Offsets can change.
Just like for .debug_aranges the GDB Index will need to be updated.

Reviewed By: Amir, maksfb

Differential Revision: https://reviews.llvm.org/D118273
2022-01-27 12:07:58 -08:00
Amir Ayupov
f8c7fb499b [BOLT][NFC] Reduce includes with include-what-you-use
Summary: Removed redundant includes with IWYU

Test Plan: ninja bolt

Reviewers: maksfb

FBD32043568
2022-01-21 12:05:47 -08:00
Alexander Yermolovich
ea6c8b013e [BOLT][DWARF] Reduce overhead for sized dealloc
This is a follow up to Fix size mismatch error with jemalloc.
4243b6582cf3bb5fbcde908913d4779ded731321
Although that fix works it increased memory footprint.
With this patch we go back to original memory footprint.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D117341
2022-01-14 17:32:48 -08:00
Alexander Yermolovich
e579f5c6e7 [BOLT][DWARF] Fix race conditions for debug fission in non-deterministic mode
Summary: Adding mutexes to avoid runtime race conditions.

(cherry picked from FBD33439854)
2022-01-05 15:27:21 -08:00
Alexander Yermolovich
1c2f4bbe99 [BOLT] Rewrite of .debug_info section
Summary:
Changed the behavior of how we handle .debug_info section.
Instead of patching it will now rewrite it.
With this approach we are no longer constrained to having new values
 of the same size.
It handles re-writing by treating .debug_info as raw data.
It copies chunks of data between patches, with new data written in
 between.

(cherry picked from FBD32519952)
2021-11-15 17:19:24 -08:00
Rafael Auler
3652483c8e [BOLTCore] [NFC] Fix braces usages according to LLVM
Summary:
Fix according to Coding Standards doc, section Don't Use
Braces on Simple Single-Statement Bodies of if/else/loop Statements.
This set of changes applies to lib Core only.

(cherry picked from FBD33240028)
2021-12-20 11:07:46 -08:00
Maksim Panchenko
2f09f445b2 [BOLT][NFC] Fix file-description comments
Summary: Fix comments at the start of source files.

(cherry picked from FBD33274597)
2021-12-21 10:21:41 -08:00
Maksim Panchenko
40c2e0fafe [BOLT][NFC] Reformat with clang-format
Summary: Selectively apply clang-format to BOLT code base.

(cherry picked from FBD33119052)
2021-12-14 16:52:51 -08:00
Alexander Yermolovich
1417f607bd [BOLT][DWARF] Fix for abbrev check in DWP case
Summary:
For DWP case the AbbreviationsOffset is the offset of the abbrev
 contribution in the DWP file, so can be none zero.

(cherry picked from FBD32961240)
2021-12-08 12:04:45 -08:00
Maksim Panchenko
b73c87bc4f [BOLT][DWARF] Force allocation of debug_line in RuntimeDyld
Summary:
Currently, RuntimeDyld will not allocate a section without relocations
even if such a section is marked allocatable and defines symbols.

When we emit .debug_line for compile units with unchanged code, we
output original (input) data, without relocations. If all units are
emitted in this way, we will have no relocations in the emitted
.debug_line. RuntimeDyld will not allocate the section and as a result
we will write an empty .debug_line section.

To workaround the issue, always emit a relocation of RELOC_NONE type
when emitting raw contents to debug_line.

(cherry picked from FBD32909869)
2021-12-06 23:32:40 -08:00
Maksim Panchenko
45f94abcd9 [BOLT][DWARF] Fix rare problem while rewriting debug_abbrev after LTO
Summary:
With LTO, it's possible for multiple DWARF compile units to share the
same abbreviation section set, i.e. to have the same abbrev_offset.
When units sharing the same abbrev set are located next to each other
and neither of them is being processed (i.e. contain processed
functions), it can trigger a bug in BOLT. When this happened,
the abbrev set is considered empty. Additionally, different units
may patch abbrev section differently.

The fix is to not rely on the next unit offset when detecting
abbreviation set boundaries and to delay writing abbrev section
until all units are processed.

(cherry picked from FBD31985046)
2021-10-27 20:28:17 -07:00
Rafael Auler
a34c753fe7 Rebase: [NFC] Refactor sources to be buildable in shared mode
Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows how to
build BOLT in BUILD_SHARED_LIBS=ON.

Please use the -c merge.renamelimit=230 git option when rebasing your
work on top of this change.

To achieve this, we create a new library to hold core IR files (most
classes beginning with Binary in their names), a new library to hold
Utils, some command line options shared across both RewriteInstance
and core IR files, a new library called Rewrite to hold most classes
concerned with running top-level functions coordinating the binary
rewriting process, and a new library called Profile to hold classes
dealing with profile reading and writing.

To remove the dependency from BinaryContext into X86-specific classes,
we do some refactoring on the BinaryContext constructor to receive a
reference to the specific backend directly from RewriteInstance. Then,
the dependency on X86 or AArch64-specific classes is transfered to the
Rewrite library. We can't have the Core library depend on targets
because targets depend on Core (which would create a cycle).

Files implementing the entry point of a tool are transferred to the
tools/ folder. All header files are transferred to the include/
folder. The src/ folder was renamed to lib/.

(cherry picked from FBD32746834)
2021-10-08 11:47:10 -07:00