[LLVM] Add file magic detection for SPIR-V files. (#75363)

Summary:
More SPIR-V related patches are being upstreamed. We should add support
to detect when a binary file is SPIR-V. This will be used in the future
when support for SPIR-V is added to the offloading runtime or more
support for bundling.

The magic number is described in the official documentation:
https://registry.khronos.org/SPIR-V/specs/1.0/SPIRV.html#Magic. Notably,
SPIR-V files are streams of 32-bit words. This means that the magic
numbers differ depending on the endianness. Here we simply check the
strandard and byte-reversed versions.

2 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Object/Binary.cpp b/llvm/lib/Object/Binary.cpp
index 0ee9f7f..0b9d954 100644
--- a/llvm/lib/Object/Binary.cpp
+++ b/llvm/lib/Object/Binary.cpp
@@ -89,6 +89,7 @@ Expected<std::unique_ptr<Binary>> object::createBinary(MemoryBufferRef Buffer,
   case file_magic::dxcontainer_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:
diff --git a/llvm/lib/Object/ObjectFile.cpp b/llvm/lib/Object/ObjectFile.cpp
index 428166f..ca92183 100644
--- a/llvm/lib/Object/ObjectFile.cpp
+++ b/llvm/lib/Object/ObjectFile.cpp
@@ -160,6 +160,7 @@ ObjectFile::createObjectFile(MemoryBufferRef Object, file_magic Type,
   case file_magic::dxcontainer_object:
   case file_magic::offload_bundle:
   case file_magic::offload_bundle_compressed:
+  case file_magic::spirv_object:
     return errorCodeToError(object_error::invalid_file_type);
   case file_magic::tapi_file:
     return errorCodeToError(object_error::invalid_file_type);