Bitcode: Make the summary reader responsible for merging. NFCI.

This is to prepare for an upcoming change which uses pointers instead of
GUIDs to represent references.

Differential Revision: https://reviews.llvm.org/D32469

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301843 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 5 deletions

diff --git a/lib/LTO/LTO.cpp b/lib/LTO/LTO.cpp
index cc3d96401ab..0afa1ba6ecd 100644
--- a/lib/LTO/LTO.cpp
+++ b/lib/LTO/LTO.cpp
@@ -591,11 +591,9 @@ Error LTO::addThinLTO(BitcodeModule BM,
                       ArrayRef<InputFile::Symbol> Syms,
                       const SymbolResolution *&ResI,
                       const SymbolResolution *ResE) {
-  Expected<std::unique_ptr<ModuleSummaryIndex>> SummaryOrErr = BM.getSummary();
-  if (!SummaryOrErr)
-    return SummaryOrErr.takeError();
-  ThinLTO.CombinedIndex.mergeFrom(std::move(*SummaryOrErr),
-                                  ThinLTO.ModuleMap.size());
+  if (Error Err =
+          BM.readSummary(ThinLTO.CombinedIndex, ThinLTO.ModuleMap.size()))
+    return Err;
 
   for (const InputFile::Symbol &Sym : Syms) {
     assert(ResI != ResE);