[BOLT] Add support for safe-icf (#116275)

Identical Code Folding (ICF) folds functions that are identical into one
function, and updates symbol addresses to the new address. This reduces
the size

[BOLT] Add support for safe-icf (#116275)

Identical Code Folding (ICF) folds functions that are identical into one
function, and updates symbol addresses to the new address. This reduces
the size of a binary, but can lead to problems. For example when
function pointers are compared. This can be done either explicitly in
the code or generated IR by optimization passes like Indirect Call
Promotion (ICP). After ICF what used to be two different addresses
become the same address. This can lead to a different code path being
taken.

This is where safe ICF comes in. Linker (LLD) does it using address
significant section generated by clang. If symbol is in it, or an object
doesn't have this section symbols are not folded.

BOLT does not have the information regarding which objects do not have
this section, so can't re-use this mechanism.

This implementation scans code section and conservatively marks
functions symbols as unsafe. It treats symbols as unsafe if they are
used in non-control flow instruction. It also scans through the data
relocation sections and does the same for relocations that reference a
function symbol. The latter handles the case when function pointer is
stored in a local or global variable, etc. If a relocation address
points within a vtable these symbols are skipped.

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[BOLT] Print program stats in perf2bolt/aggregate-only mode (#89763)

[BOLT][NFC] Log through JournalingStreams (#81524)

Make core BOLT functionality more friendly to being used as a
library instead of in our standalone driver llvm-bolt. To
accomplish this, we augme

[BOLT][NFC] Log through JournalingStreams (#81524)

Make core BOLT functionality more friendly to being used as a
library instead of in our standalone driver llvm-bolt. To
accomplish this, we augment BinaryContext with journaling streams
that are to be used by most BOLT code whenever something needs to
be logged to the screen. Users of the library can decide if logs
should be printed to a file, no file or to the screen, as
before. To illustrate this, this patch adds a new option
`--log-file` that allows the user to redirect BOLT logging to a
file on disk or completely hide it by using
`--log-file=/dev/null`. Future BOLT code should now use
`BinaryContext::outs()` for printing important messages instead of
`llvm::outs()`. A new test log.test enforces this by verifying that
no strings are print to screen once the `--log-file` option is
used.

In previous patches we also added a new BOLTError class to report
common and fatal errors, so code shouldn't call exit(1) now. To
easily handle problems as before (by quitting with exit(1)),
callers can now use
`BinaryContext::logBOLTErrorsAndQuitOnFatal(Error)` whenever code
needs to deal with BOLT errors. To test this, we have fatal.s
that checks we are correctly quitting and printing a fatal error
to the screen.

Because this is a significant change by itself, not all code was
yet ported. Code from Profiler libs (DataAggregator and friends)
still print errors directly to screen.

Co-authored-by: Rafael Auler <rafaelauler@fb.com>

Test Plan: NFC

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[BOLT][NFC] Return Error from BinaryFunctionPass::runOnFunctions (#81521)

As part of the effort to refactor old error handling code that
would directly call exit(1), in this patch we change the
in

[BOLT][NFC] Return Error from BinaryFunctionPass::runOnFunctions (#81521)

As part of the effort to refactor old error handling code that
would directly call exit(1), in this patch we change the
interface to `BinaryFunctionPass` to return an Error on
`runOnFunctions()`. This gives passes the ability to report a
serious problem to the caller (RewriteInstance class), so the
caller may decide how to best handle the exceptional situation.

Co-authored-by: Rafael Auler <rafaelauler@fb.com>

Test Plan: NFC

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[BOLT] Fix typos (#68121)

Closes https://github.com/llvm/llvm-project/issues/63097

Before merging please make sure the change to
bolt/include/bolt/Passes/StokeInfo.h is correct.

bolt/include/

[BOLT] Fix typos (#68121)

Closes https://github.com/llvm/llvm-project/issues/63097

Before merging please make sure the change to
bolt/include/bolt/Passes/StokeInfo.h is correct.

bolt/include/bolt/Passes/StokeInfo.h

```diff
// This Pass solves the two major problems to use the Stoke program without
- // proting its code:
+ // probing its code:
```

I'm still not happy about the awkward wording in this comment.

bolt/include/bolt/Passes/FixRelaxationPass.h

```
$ ed -s bolt/include/bolt/Passes/FixRelaxationPass.h <<<'9,12p'
// This file declares the FixRelaxations class, which locates instructions with
// wrong targets and fixes them. Such problems usually occures when linker
// relaxes (changes) instructions, but doesn't fix relocations types properly
// for them.
$
```


bolt/docs/doxygen.cfg.in
bolt/include/bolt/Core/BinaryContext.h
bolt/include/bolt/Core/BinaryFunction.h
bolt/include/bolt/Core/BinarySection.h
bolt/include/bolt/Core/DebugData.h
bolt/include/bolt/Core/DynoStats.h
bolt/include/bolt/Core/Exceptions.h
bolt/include/bolt/Core/MCPlusBuilder.h
bolt/include/bolt/Core/Relocation.h
bolt/include/bolt/Passes/FixRelaxationPass.h
bolt/include/bolt/Passes/InstrumentationSummary.h
bolt/include/bolt/Passes/ReorderAlgorithm.h
bolt/include/bolt/Passes/StackReachingUses.h
bolt/include/bolt/Passes/StokeInfo.h
bolt/include/bolt/Passes/TailDuplication.h
bolt/include/bolt/Profile/DataAggregator.h
bolt/include/bolt/Profile/DataReader.h
bolt/lib/Core/BinaryContext.cpp
bolt/lib/Core/BinarySection.cpp
bolt/lib/Core/DebugData.cpp
bolt/lib/Core/DynoStats.cpp
bolt/lib/Core/Relocation.cpp
bolt/lib/Passes/Instrumentation.cpp
bolt/lib/Passes/JTFootprintReduction.cpp
bolt/lib/Passes/ReorderData.cpp
bolt/lib/Passes/RetpolineInsertion.cpp
bolt/lib/Passes/ShrinkWrapping.cpp
bolt/lib/Passes/TailDuplication.cpp
bolt/lib/Rewrite/BoltDiff.cpp
bolt/lib/Rewrite/DWARFRewriter.cpp
bolt/lib/Rewrite/RewriteInstance.cpp
bolt/lib/Utils/CommandLineOpts.cpp
bolt/runtime/instr.cpp
bolt/test/AArch64/got-ld64-relaxation.test
bolt/test/AArch64/unmarked-data.test
bolt/test/X86/Inputs/dwarf5-cu-no-debug-addr-helper.s
bolt/test/X86/Inputs/linenumber.cpp
bolt/test/X86/double-jump.test
bolt/test/X86/dwarf5-call-pc-function-null-check.test
bolt/test/X86/dwarf5-split-dwarf4-monolithic.test
bolt/test/X86/dynrelocs.s
bolt/test/X86/fallthrough-to-noop.test
bolt/test/X86/tail-duplication-cache.s
bolt/test/runtime/X86/instrumentation-ind-calls.s

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[BOLT] Add skip-non-simple for boltdiff

Extra filtering for boltdiff, excluding non-simple functions from comparison.

Reviewed By: #bolt, maksfb

Differential Revision: https://reviews.llvm.org/D15

[BOLT] Add skip-non-simple for boltdiff

Extra filtering for boltdiff, excluding non-simple functions from comparison.

Reviewed By: #bolt, maksfb

Differential Revision: https://reviews.llvm.org/D151510

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[BOLT][NFC] Move getLTOCommonName to Utils

Reuse getLTOCommonName in components other than Profile (to be used in Core)

Reviewed By: #bolt, maksfb

Differential Revision: https://reviews.llvm.org/D

[BOLT][NFC] Move getLTOCommonName to Utils

Reuse getLTOCommonName in components other than Profile (to be used in Core)

Reviewed By: #bolt, maksfb

Differential Revision: https://reviews.llvm.org/D142259

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[BOLT][NFC] Use llvm::reverse

Use llvm::reverse instead of `for (auto I = rbegin(), E = rend(); I != E; ++I)`

Reviewed By: #bolt, rafauler

Differential Revision: https://reviews.llvm.org/D140516

[BOLT][NFC] Use std::optional for getLTOCommonName

[BOLT] Towards FunctionLayout const-correctness

A const-qualified reference to function layout allows accessing
non-const qualified basic blocks on a const-qualified function. This
patch adds or rem

[BOLT] Towards FunctionLayout const-correctness

A const-qualified reference to function layout allows accessing
non-const qualified basic blocks on a const-qualified function. This
patch adds or removes const-qualifiers where necessary to indicate where
basic blocks are used in a non-const manner.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D132049

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Revert "[BOLT] Towards FunctionLayout const-correctness"

This reverts commit 587d2653420d75ef10f30bd612d86f1e08fe9ea7.

[BOLT] Towards FunctionLayout const-correctness

A const-qualified reference to function layout allows accessing
non-const qualified basic blocks on a const-qualified function. This
patch adds or rem

[BOLT] Towards FunctionLayout const-correctness

A const-qualified reference to function layout allows accessing
non-const qualified basic blocks on a const-qualified function. This
patch adds or removes const-qualifiers where necessary to indicate where
basic blocks are used in a non-const manner.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D132049

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[BOLT] Add function layout class

This patch adds a dedicated class to keep track of each function's
layout. It also lays the groundwork for splitting functions into
multiple fragments (as opposed to

[BOLT] Add function layout class

This patch adds a dedicated class to keep track of each function's
layout. It also lays the groundwork for splitting functions into
multiple fragments (as opposed to a strict hot/cold split).

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D129518

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[BOLT][NFC] Use range-based STL wrappers

Replace `std::` algorithms taking begin/end iterators with `llvm::` counterparts
accepting ranges.

Reviewed By: rafauler

Differential Revision: https://rev

[BOLT][NFC] Use range-based STL wrappers

Replace `std::` algorithms taking begin/end iterators with `llvm::` counterparts
accepting ranges.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D128154

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[bolt] Remove unneeded cl::ZeroOrMore for cl::opt options

[BOLT][NFC] Use refs for loop variables to avoid copies

Addresses warnings when built with Apple Clang.

Reviewed By: yota9

Differential Revision: https://reviews.llvm.org/D125483

[BOLTRewrite][NFC] Fix braces usages

Summary:
Refactor bolt/*/Rewrite to follow the braces rule for if/else/loop from
LLVM Coding Standards.

(cherry picked from FBD33305364)

[BOLT][NFC] Fix file-description comments

Summary: Fix comments at the start of source files.

(cherry picked from FBD33274597)

[BOLT][NFC] Reformat with clang-format

Summary: Selectively apply clang-format to BOLT code base.

(cherry picked from FBD33119052)

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 h

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)

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