Add missing error handling in llvm-lto

Annoyingly, ErrorOr allows to *not check* the error when things go
well. It will crash badly when there is an error though. It should
runtime assert when it is used without being checked!

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263577 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/llvm-lto/llvm-lto.cpp b/tools/llvm-lto/llvm-lto.cpp
index 8aadc406f99..d6f3d8a39f3 100644
--- a/tools/llvm-lto/llvm-lto.cpp
+++ b/tools/llvm-lto/llvm-lto.cpp
@@ -258,6 +258,7 @@ static void createCombinedModuleSummaryIndex() {
     CurrentActivity = "loading file '" + Filename + "'";
     ErrorOr<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
         llvm::getModuleSummaryIndexForFile(Filename, diagnosticHandler);
+    error(IndexOrErr, "error: " + CurrentActivity);
     std::unique_ptr<ModuleSummaryIndex> Index = std::move(IndexOrErr.get());
     CurrentActivity = "";
     // Skip files without a module summary.