Summary:
While disassembling instructions, we need to replace certain immediate
operands with symbols. This symbolizing process relies on reading
relocations against instructions. However, some X86 instructions can
have multiple immediate operands and up to two relocations against
them. Thus, correctly matching a relocation to an operand is not
always possible without knowing the operand offset within the
instruction.
Luckily, LLVM provides an interface for passing the required info from
the disassembler via a virtual MCSymbolizer class. Creating a
target-specific version allows a precise matching of relocations to
operands.
This diff adds X86MCSymbolizer class that performs X86-specific
symbolizing (currently limited to non-branch instructions).
Reviewers: yota9, Amir, ayermolo, rafauler, zr33
Differential Revision: https://reviews.llvm.org/D120928
We don't actually depend on entire X86/AArch64 components that pull in CodeGen,
SelectionDAG etc., just the Desc part with opcode and other definitions.
Note that it doesn't decouple BOLT from these components - we still pull in X86
and AArch64 from top-level llvm-bolt dependencies as we use assembler and
disassembler. It's difficult to reduce these as this requires non-trivial
changes to X86/AArch64 components themselves (e.g. moving out AsmPrinter).
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D124206
Since LLVM MC now preserves redundant AdSize override prefix (0x67), remove it
in BOLT explicitly (-x86-strip-redundant-adsize, on by default).
Test Plan:
`bin/llvm-lit -a bolt/test/X86/addr32.s`
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D120975
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