Refactoring BitcodeFile constructor. NFC.

[rdhindsa]

Summary

Instead of creating MemoryBufferRef for BitcodeFile in InputFile.cpp, this patch adds a generateMemoryBufferRef in LTO.h. This ensures that LTO processing based on LTO options is done in LTO.cpp/LTO.h files.

[ruiu]

Thank you for doing this, but I don't think this patch simplifies the code, because everything that was executed without this patch is still executed with this patch too. You just moved code from one place to another.

lld/ELF/InputFiles.cpp

   // Here we pass a new MemoryBufferRef which is identified by ArchiveName
   // (the fully resolved path of the archive) + member name + offset of the
   // member in the archive.
   // ThinLTO uses the MemoryBufferRef identifier to access its internal
   // data structures and if two archives define two members with the same name,
   // this causes a collision which result in only one of the objects being
   // taken into consideration at LTO time (which very likely causes undefined
   // symbols later in the link stage).
-  MemoryBufferRef MBRef(
-      MB.getBuffer(),
-      Saver.save(ArchiveName + MB.getBufferIdentifier() +
-                 (ArchiveName.empty() ? "" : utostr(OffsetInArchive))));
+
+  MemoryBufferRef MBRef =
+      generateMemoryBufferRef(MB, ArchiveName, OffsetInArchive);
   Obj = CHECK(lto::InputFile::create(MBRef), this);
 
   Triple T(Obj->getTargetTriple());
   EKind = getBitcodeELFKind(T);
   EMachine = getBitcodeMachineKind(MB.getBufferIdentifier(), T);
 }
 
 static uint8_t mapVisibility(GlobalValue::VisibilityTypes GvVisibility) {

lld/ELF/LTO.h

 // an ELF file that contains native code. This file provides that
 // functionality.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLD_ELF_LTO_H
 #define LLD_ELF_LTO_H
 
+#include "InputFiles.h"
 #include "lld/Common/LLVM.h"
+#include "lld/Common/Memory.h"
 #include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
 #include <vector>
 
 namespace llvm {
 namespace lto {
 class LTO;

 private:
   std::unique_ptr<llvm::lto::LTO> LTOObj;
   std::vector<SmallString<0>> Buff;
   std::vector<std::unique_ptr<MemoryBuffer>> Files;
   llvm::DenseSet<StringRef> UsedStartStop;
   std::unique_ptr<llvm::raw_fd_ostream> IndexFile;
   llvm::StringMap<bool> ObjectToIndexFileState;
 };
+
+inline MemoryBufferRef generateMemoryBufferRef(MemoryBufferRef MB,
+                                               StringRef ArchiveName,
+                                               uint64_t OffsetInArchive) {
+  // Here we pass a new MemoryBufferRef which is identified by ArchiveName
+  // (the fully resolved path of the archive) + member name + offset of the
+  // member in the archive.
+  // ThinLTO uses the MemoryBufferRef identifier to access its internal
+  // data structures and if two archives define two members with the same name,
+  // this causes a collision which result in only one of the objects being
+  // taken into consideration at LTO time (which very likely causes undefined
+  // symbols later in the link stage).
+  MemoryBufferRef MBRef(
+      MB.getBuffer(),
+      Saver.save(ArchiveName + MB.getBufferIdentifier() +
+                 (ArchiveName.empty() ? "" : llvm::utostr(OffsetInArchive))));
+  return MBRef;
+}
 } // namespace elf
 } // namespace lld
 
 #endif

lld/ELF/LTO.cpp

 //===- LTO.cpp ------------------------------------------------------------===//
 //
 //                             The LLVM Linker
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "LTO.h"
 #include "Config.h"
-#include "InputFiles.h"
 #include "LinkerScript.h"
 #include "SymbolTable.h"
 #include "Symbols.h"
 #include "lld/Common/ErrorHandler.h"
 #include "lld/Common/TargetOptionsCommandFlags.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/LTO/Caching.h"