Remove LazyObjFile::AddedToLink.

Instead we can just clear a MemoryBuffer so that we cannot get the
same buffer more than once.

llvm-svn: 361477

Author: rui314

lld/ELF/InputFiles.cpp

@@ -1469,21 +1469,15 @@ InputFile *elf::createSharedFile(MemoryBufferRef MB, StringRef DefaultSoName) {
   return F;
 }
 
-MemoryBufferRef LazyObjFile::getBuffer() {
-  if (AddedToLink)
-    return MemoryBufferRef();
-  AddedToLink = true;
-  return MB;
-}
-
 InputFile *LazyObjFile::fetch() {
-  MemoryBufferRef MBRef = getBuffer();
-  if (MBRef.getBuffer().empty())
+  if (MB.getBuffer().empty())
     return nullptr;
 
-  InputFile *File = createObjectFile(MBRef, ArchiveName, OffsetInArchive);
+  InputFile *File = createObjectFile(MB, ArchiveName, OffsetInArchive);
   File->GroupId = GroupId;
 
+  MB = {};
+
   // Copy symbol vector so that the new InputFile doesn't have to
   // insert the same defined symbols to the symbol table again.
   File->Symbols = std::move(Symbols);
@@ -1538,7 +1532,9 @@ template <class ELFT> void LazyObjFile::parse() {
       if (!Sym)
         continue;
       Sym->resolve(LazyObject{*this, Sym->getName()});
-      if (AddedToLink)
+
+      // MemoryBuffer is emptied if this file is instantiated as ObjFile.
+      if (MB.getBuffer().empty())
         return;
     }
     return;

lld/ELF/InputFiles.h

@@ -307,9 +307,7 @@ class LazyObjFile : public InputFile {
   static bool classof(const InputFile *F) { return F->kind() == LazyObjKind; }
 
   template <class ELFT> void parse();
-  MemoryBufferRef getBuffer();
   InputFile *fetch();
-  bool AddedToLink = false;
 
 private:
   uint64_t OffsetInArchive;

lld/ELF/LTO.cpp

@@ -212,7 +212,7 @@ void BitcodeCompiler::add(BitcodeFile &F) {
 // distributed build system that depends on that behavior.
 static void thinLTOCreateEmptyIndexFiles() {
   for (LazyObjFile *F : LazyObjFiles) {
-    if (F->AddedToLink || !isBitcode(F->MB))
+    if (!isBitcode(F->MB))
       continue;
     std::string Path = replaceThinLTOSuffix(getThinLTOOutputFile(F->getName()));
     std::unique_ptr<raw_fd_ostream> OS = openFile(Path + ".thinlto.bc");