Files
llvm-project/llvm/lib/Object/Binary.cpp
Yury Plyakhin 4d27530c69 [Offloading] Offload Binary Format V2: Support Multiple Entries (#169425)
This PR updates the OffloadBinary format from version 1 to version 2,
enabling support for multiple offloading entries in a single binary.
This allows combining multiple device images into a single binary with
common global metadata while maintaining backwards compatibility with
version 1 binaries.

# Key Changes
## Binary Format Enhancements
  **Version 2 Format Changes:**
  - Changed from single-entry to multi-entry design
  - Updated `Header` structure:
    - Renamed `EntryOffset` → `EntriesOffset` (offset to entries array)
    - Renamed `EntrySize` → `EntriesCount` (number of entries)
- Added `StringEntry::ValueSize` field to support explicit string value
sizes (enables non-null-terminated strings)
- Introduced `OffloadEntryFlags` enum with `OIF_Metadata` flag for
metadata-only entries (entries without binary images)

  **API Changes:**
- `OffloadBinary::create()` now returns
`Expected<SmallVector<std::unique_ptr<OffloadBinary>>>` instead of
single binary
- Added optional `Index` parameter to extract specific entry:
`create(Buffer, std::optional<uint64_t> Index)`
- `OffloadBinary::write()` now accepts `ArrayRef<OffloadingImage>`
instead of single image
  - Added `OffloadBinary::extractHeader()` for header extraction

  **Memory Management:**
- Implemented `SharedMemoryBuffer` class to enable memory sharing across
multiple `OffloadBinary` instances from the same file
- Multiple entries from a single serialized binary share the underlying
buffer

## Testing
  **Unit Tests (`unittests/Object/OffloadingTest.cpp`):**
- `checkMultiEntryBinaryExtraction`: Tests extracting all entries from a
multi-entry binary
- `checkIndexBasedExtraction`: Tests extracting specific entries by
index, including out-of-bounds validation
  - `checkEdgeCases`: Tests edge cases including:
    - Empty string metadata
    - Empty image data
    - Large string values (4KB)

  **Other Tests:**
- Updated `test/ObjectYAML/Offload/multiple_members.yaml` to include
metadata-only entry

---------

Co-authored-by: Joseph Huber <huberjn@outlook.com>
2026-02-05 07:46:57 -08:00

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4.6 KiB
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//===- Binary.cpp - A generic binary file ---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the Binary class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/Binary.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/MachOUniversal.h"
#include "llvm/Object/Minidump.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/OffloadBinary.h"
#include "llvm/Object/TapiUniversal.h"
#include "llvm/Object/WindowsResource.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/MemoryBuffer.h"
#include <memory>
#include <system_error>
using namespace llvm;
using namespace object;
Binary::~Binary() = default;
Binary::Binary(unsigned int Type, MemoryBufferRef Source)
: TypeID(Type), Data(Source) {}
StringRef Binary::getData() const { return Data.getBuffer(); }
StringRef Binary::getFileName() const { return Data.getBufferIdentifier(); }
MemoryBufferRef Binary::getMemoryBufferRef() const { return Data; }
Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
LLVMContext *Context,
bool InitContent) {
file_magic Type = identify_magic(Buffer.getBuffer());
switch (Type) {
case file_magic::archive:
return Archive::create(Buffer);
case file_magic::elf:
case file_magic::elf_relocatable:
case file_magic::elf_executable:
case file_magic::elf_shared_object:
case file_magic::elf_core:
case file_magic::goff_object:
case file_magic::macho_object:
case file_magic::macho_executable:
case file_magic::macho_fixed_virtual_memory_shared_lib:
case file_magic::macho_core:
case file_magic::macho_preload_executable:
case file_magic::macho_dynamically_linked_shared_lib:
case file_magic::macho_dynamic_linker:
case file_magic::macho_bundle:
case file_magic::macho_dynamically_linked_shared_lib_stub:
case file_magic::macho_dsym_companion:
case file_magic::macho_kext_bundle:
case file_magic::macho_file_set:
case file_magic::coff_object:
case file_magic::coff_import_library:
case file_magic::pecoff_executable:
case file_magic::bitcode:
case file_magic::xcoff_object_32:
case file_magic::xcoff_object_64:
case file_magic::wasm_object:
case file_magic::dxcontainer_object:
return ObjectFile::createSymbolicFile(Buffer, Type, Context, InitContent);
case file_magic::macho_universal_binary:
return MachOUniversalBinary::create(Buffer);
case file_magic::windows_resource:
return WindowsResource::createWindowsResource(Buffer);
case file_magic::pdb:
// PDB does not support the Binary interface.
return errorCodeToError(object_error::invalid_file_type);
case file_magic::unknown:
case file_magic::clang_ast:
case file_magic::cuda_fatbinary:
case file_magic::coff_cl_gl_object:
case file_magic::offload_bundle:
case file_magic::offload_bundle_compressed:
case file_magic::spirv_object:
// Unrecognized object file format.
return errorCodeToError(object_error::invalid_file_type);
case file_magic::offload_binary: {
auto OffloadBinaryOrErr = OffloadBinary::create(Buffer);
if (!OffloadBinaryOrErr)
return OffloadBinaryOrErr.takeError();
return std::move((*OffloadBinaryOrErr)[0]);
}
case file_magic::minidump:
return MinidumpFile::create(Buffer);
case file_magic::tapi_file:
return TapiUniversal::create(Buffer);
}
llvm_unreachable("Unexpected Binary File Type");
}
Expected<OwningBinary<Binary>>
object::createBinary(StringRef Path, LLVMContext *Context, bool InitContent) {
ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
MemoryBuffer::getFileOrSTDIN(Path, /*IsText=*/false,
/*RequiresNullTerminator=*/false);
if (std::error_code EC = FileOrErr.getError())
return errorCodeToError(EC);
std::unique_ptr<MemoryBuffer> &Buffer = FileOrErr.get();
Expected<std::unique_ptr<Binary>> BinOrErr =
createBinary(Buffer->getMemBufferRef(), Context, InitContent);
if (!BinOrErr)
return BinOrErr.takeError();
std::unique_ptr<Binary> &Bin = BinOrErr.get();
return OwningBinary<Binary>(std::move(Bin), std::move(Buffer));
}