[ThinLTO] Make sure the Context used for the ThinLTO backend has all the appropriate options

An important performance setting on the LLVMContext for LTO is
enableDebugTypeODRUniquing(), this adds an automatic merging of
debug information in the context based on type ids.

Also, the lto::Config includes a diagnostic handler that needs to
be set on the Context, as well as the setDiscardValueNames() setting.

llvm-svn: 279532

2 files changed, 3 insertions, 1 deletions

diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index 39ec4e26c4f..8d4f1a48d93 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -468,7 +468,7 @@ public:
                           const FunctionImporter::ImportMapTy &ImportList,
                           const GVSummaryMapTy &DefinedGlobals,
                           MapVector<StringRef, MemoryBufferRef> &ModuleMap) {
-    LLVMContext BackendContext;
+    LTOLLVMContext BackendContext(Conf);
 
     ErrorOr<std::unique_ptr<Module>> MOrErr =
         parseBitcodeFile(MBRef, BackendContext);
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 732f35a56b2..20e2b9edf97 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -271,6 +271,8 @@ Error lto::thinBackend(Config &Conf, unsigned Task, AddOutputFn AddOutput,
     return Error();
 
   auto ModuleLoader = [&](StringRef Identifier) {
+    assert(Mod.getContext().isODRUniquingDebugTypes() &&
+           "ODR Type uniquing shoudl be enabled on the context");
     return std::move(getLazyBitcodeModule(MemoryBuffer::getMemBuffer(
                                               ModuleMap[Identifier], false),
                                           Mod.getContext(),