Revert "[gold] Add preliminary FatLTO support to the Gold plugin"

This reverts commit 421e4026111315d002879b1e7a0cf3aacd00f488.

One of the test needs a requires line, but we've also seen some issues
for downstream projects that may need coordination, so I'm reverting
this for until we can address those issues. see
https://reviews.llvm.org/D152973#4520240 for context.

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/tools/gold/gold-plugin.cpp b/llvm/tools/gold/gold-plugin.cpp
index 59bd3f6..a47dba3 100644
--- a/llvm/tools/gold/gold-plugin.cpp
+++ b/llvm/tools/gold/gold-plugin.cpp
@@ -538,6 +538,14 @@ static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
     BufferRef = Buffer->getMemBufferRef();
   }
 
+  // Only use bitcode files for LTO.  InputFile::create() will load bitcode
+  // from the .llvmbc section within a binary object, this bitcode is typically
+  // generated by -fembed-bitcode and is not to be used by LLVMgold.so for LTO.
+  if (identify_magic(BufferRef.getBuffer()) != file_magic::bitcode) {
+    *claimed = 0;
+    return LDPS_OK;
+  }
+
   *claimed = 1;
 
   Expected<std::unique_ptr<InputFile>> ObjOrErr = InputFile::create(BufferRef);