Commit Graph

11 Commits

Author SHA1 Message Date
Maksim Panchenko 4d3a0cade2 [BOLT] Section-handling refactoring/overhaul
Simplify the logic of handling sections in BOLT. This change brings more
direct and predictable mapping of BinarySection instances to sections in
the input and output files.

* Only sections from the input binary will have a non-null SectionRef.
  When a new section is created as a copy of the input section,
  its SectionRef is reset to null.

* RewriteInstance::getOutputSectionName() is removed as the section name
  in the output file is now defined by BinarySection::getOutputName().

* Querying BinaryContext for sections by name uses their original name.
  E.g., getUniqueSectionByName(".rodata") will return the original
  section even if the new .rodata section was created.

* Input file sections (with relocations applied) are emitted via MC with
  ".bolt.org" prefix. However, their name in the output binary is
  unchanged unless a new section with the same name is created.

* New sections are emitted internally with ".bolt.new" prefix if there's
  a name conflict with an input file section. Their original name is
  preserved in the output file.

* Section header string table is properly populated with section names
  that are actually used. Previously we used to include discarded
  section names as well.

* Fix the problem when dynamic relocations were propagated to a new
  section with a name that matched a section in the input binary.
  E.g., the new .rodata with jump tables had dynamic relocations from
  the original .rodata.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D135494
2022-10-13 23:10:39 -07:00
Maksim Panchenko 5fca9c5763 [BOLT] Change order of new sections
While the order of new sections in the output binary was deterministic
in the past (i.e. there was no run-to-run variation), it wasn't always
rational as we used size to define the precedence of allocatable
sections within "code" or "data" groups (probably unintentionally).
Fix that by defining stricter section-ordering rules.

Other than the order of sections, this should be NFC.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D135235
2022-10-07 11:20:42 -07:00
Maksim Panchenko 1d5393526c [BOLT] Change base class of ExecutableFileMemoryManager
When we derive EFMM from SectionMemoryManager, it brings into EFMM extra
functionality, such as the registry of exception handling sections,
page permission management, etc. Such functionality is of no use to
llvm-bolt and can even be detrimental (see
https://github.com/llvm/llvm-project/issues/56726).

Change the base class of ExecutableFileMemoryManager to MemoryManager,
avoid registering EH sections, and skip memory finalization.

Fixes #56726

Reviewed By: yota9

Differential Revision: https://reviews.llvm.org/D133994
2022-09-16 13:39:12 -07:00
Amir Ayupov 129dfc8a9a Revert "[BOLT][NFC] Simplify addRelocation"
This reverts commit 29f2301322.

This change breaks one of the internal tests.
2022-08-18 17:26:26 -07:00
Amir Ayupov 29f2301322 [BOLT][NFC] Simplify addRelocation
Move the implementation out of the header file.
Simplify the method.
Add debug logging.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D131811
2022-08-17 16:07:28 -07:00
Fangrui Song adf4142f76 [MC] De-capitalize SwitchSection. NFC
Add SwitchSection to return switchSection. The API will be removed soon.
2022-06-10 22:50:55 -07:00
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
Elvina Yakubova 4a4045f740 [PR] Fix update-debug-sections for AArch64
Summary:
This patch adds AArch64 relocations handling in case updating of
debug sections is enabled

Elvina Yakubova,
Advanced Software Technology Lab, Huawei

(cherry picked from FBD33077609)
2021-12-08 16:53:38 +03:00
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
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