## Purpose
This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates symbols that were recently
added to LLVM without proper annotations. The annotations currently have
no meaningful impact on the LLVM build; however, they are a prerequisite
to support an LLVM Windows DLL (shared library) build.
## Background
This effort is tracked in #109483. Additional context is provided in
[this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307),
and documentation for `LLVM_ABI` and related annotations is found in the
LLVM repo
[here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst).
## Overview
The bulk of these changes were generated automatically using the
[Interface Definition Scanner (IDS)](https://github.com/compnerd/ids)
tool, followed formatting with `git clang-format`.
The following manual adjustments were also applied after running IDS:
- Add `LLVM_EXPORT_TEMPLATE` and `LLVM_TEMPLATE_ABI` annotations to
explicitly instantiated instances of `llvm::object::SFrameParser`.
## Validation
Local builds and tests to validate cross-platform compatibility. This
included llvm, clang, and lldb on the following configurations:
- Windows with MSVC
- Windows with Clang
- Linux with GCC
- Linux with Clang
- Darwin with Clang
This PR adds the SFrameParser class and uses it from llvm-readobj to
dump the section contents. Currently, it only supports parsing the
SFrame section header. Other parts of the section will be added in
follow-up patches.
llvm-readobj uses the same sframe flag syntax as GNU readelf, but I have
not attempted match the output format of the tool. I'm starting with the
"llvm" output format because it's easier to generate and lets us
tweak the format to make it useful for testing the generation code. If
needed, support for the GNU format could be added by overriding this
functionality in the GNU ELF Dumper.
For more information, see the [sframe
specification](https://sourceware.org/binutils/wiki/sframe) and the
related
[RFC](https://discourse.llvm.org/t/rfc-adding-sframe-support-to-llvm/86900).
