[Metadata] Add 'exclude' metadata to add the exclude flags on globals

This patchs adds a new metadata kind `exclude` which implies that the
global variable should be given the necessary flags during code
generation to not be included in the final executable. This is done
using the ``SHF_EXCLUDE`` flag on ELF for example. This should make it
easier to specify this flag on a variable without needing to explicitly
check the section name in the target backend.

Depends on D129053 D129052

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D129151

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
index a3529bf..4dcba65 100644
--- a/llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -281,6 +281,7 @@ void llvm::embedBufferInModule(Module &M, MemoryBufferRef Buf,
                         MDString::get(Ctx, SectionName)};
 
   MD->addOperand(llvm::MDNode::get(Ctx, MDVals));
+  GV->setMetadata(LLVMContext::MD_exclude, llvm::MDNode::get(Ctx, {}));
 
   appendToCompilerUsed(M, GV);
 }