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)
Summary:
Since nops are now removed in a separate pass, the profile is consumed
on a CFG with nops. If previously a profile was generated without nops,
the offsets in the profile could be different if branches included nops
either as a source or a destination.
This diff adjust offsets to make the profile reading backwards
compatible.
(cherry picked from FBD33231254)
Summary:
Gracefully handle binaries with split functions where two fragments are folded
into one, resulting in a fragment with two parent functions.
This behavior is expected in GCC8+ with -O2 optimization level, where both
function splitting and ICF are enabled by default.
On the BOLT side, the changes are:
- BinaryFunction: allow multiple parent fragments:
- `ParentFragment` --> `ParentFragments`,
- `setParentFragment` --> `addParentFragment`.
- BinaryContext:
- `populateJumpTables`: mark fragments to be skipped later,
- `registerFragment`: add a name heuristic check, return false if it failed,
- `processInterproceduralReferences`: check if `registerFragment`
succeeded, otherwise issue a warning,
- `skipMarkedFragments`: move out fragment traversal and skipping from
`populateJumpTables` into a separate function.
This change fixes an issue where unrelated functions might be registered
as fragments:
```
BOLT-WARNING: interprocedural reference between unrelated fragments:
bad_gs/1(*2) and amd_decode_mce.cold.27/1(*2)
```
(Linux kernel binary)
(cherry picked from FBD32786688)
Summary:
As pointed out by Vladislav in issue 217, if our RTDyld-based
linker fails to locate a symbol, it will crash with segfault. Fix that.
(cherry picked from FBD32481543)
Summary:
Currently there are two issues rendering the use of bughunter/BOLT on a binary
with a large number of functions (100k) impossible:
1) `selectFunctionsToProcess` has O(binary_fn * force_fn) run-time, which is up
to quadratic with the number of functions in the binary.
2) It unnecessarily treats supplied function names as regexes.
This diff proposes the following changes to address the issue:
1. Add two options that treat function names as is, not as regexes, matching
bughunter usage model: `-funcs-no-regex`/`-funcs-file-no-regex`.
These options are complementary to `-funcs`/`-funcs-file` and `-skip-funcs`/
`-skip-funcs-file`. `funcs` takes precedence over `funcs-no-regex`.
2. Use string set to speed up function eligibility checking with
`-funcs-file-no-regex` to O(binary_fn * log force_fn).
(cherry picked from FBD28917225)
Summary:
Make BOLT build in VisualStudio compiler and run without
crashing on a simple test. Other tests are not running.
(cherry picked from FBD32378736)
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)
Maksim Panchenko