Check for fromString failure in ModuleFile.cpp

Author: David Ungar

lib/Serialization/ModuleFile.cpp

@@ -986,7 +986,12 @@ void ModuleFile::collectBasicSourceFileInfo(
 
     BasicSourceFileInfo info;
     info.FilePath = filePath;
-    info.InterfaceHash = Fingerprint::fromString(fpStr);
+    if (auto fingerprint = Fingerprint::fromString(fpStr))
+      info.InterfaceHash = fingerprint.getValue();
+    else {
+      llvm::errs() << "Unconvertable fingerprint '" << fpStr << "'\n";
+      abort();
+    }
     info.LastModified =
         llvm::sys::TimePoint<>(std::chrono::nanoseconds(timestamp));
     info.FileSize = fileSize;