1 files changed, 4 insertions, 3 deletions
diff --git a/include/llvm/LTO/LTOBackend.h b/include/llvm/LTO/LTOBackend.h
index 933503afddc89..d4743f6940ff9 100644
--- a/include/llvm/LTO/LTOBackend.h
+++ b/include/llvm/LTO/LTOBackend.h
@@ -34,14 +34,15 @@ class Target;
 
 namespace lto {
 
-/// Runs a regular LTO backend.
+/// Runs a regular LTO backend. The regular LTO backend can also act as the
+/// regular LTO phase of ThinLTO, which may need to access the combined index.
 Error backend(Config &C, AddStreamFn AddStream,
               unsigned ParallelCodeGenParallelismLevel,
-              std::unique_ptr<Module> M);
+              std::unique_ptr<Module> M, ModuleSummaryIndex &CombinedIndex);
 
 /// Runs a ThinLTO backend.
 Error thinBackend(Config &C, unsigned Task, AddStreamFn AddStream, Module &M,
-                  ModuleSummaryIndex &CombinedIndex,
+                  const ModuleSummaryIndex &CombinedIndex,
                   const FunctionImporter::ImportMapTy &ImportList,
                   const GVSummaryMapTy &DefinedGlobals,
                   MapVector<StringRef, BitcodeModule> &ModuleMap);