ELF: Implement --start-lib and --end-lib

start-lib and end-lib are options to link object files in the same
semantics as archive files. If an object is in start-lib and end-lib,
the object is linked only when the file is needed to resolve
undefined symbols. That means, if an object is in start-lib and end-lib,
it behaves as if it were in an archive file.

In this patch, I introduced a new notion, LazyObjectFile. That is
analogous to Archive file type, but that works for a single object
file instead of for an archive file.

http://reviews.llvm.org/D18814

llvm-svn: 265710

1 files changed, 2 insertions, 1 deletions

diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index cb82e22eec9..f79a1d3a923 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -1501,7 +1501,8 @@ SymbolTableSection<ELFT>::getOutputSection(SymbolBody *Sym) {
     break;
   case SymbolBody::UndefinedElfKind:
   case SymbolBody::UndefinedBitcodeKind:
-  case SymbolBody::LazyKind:
+  case SymbolBody::LazyArchiveKind:
+  case SymbolBody::LazyObjectKind:
     break;
   case SymbolBody::DefinedBitcodeKind:
     llvm_unreachable("should have been replaced");