Make module files passed to a module build via -fmodule-file= available to

consumers of that module.

Previously, such a file would only be available if the module happened to
actually import something from that module.

llvm-svn: 232583

clang/lib/Serialization/ModuleManager.cpp

@@ -227,6 +227,15 @@ ModuleManager::addInMemoryBuffer(StringRef FileName,
   InMemoryBuffers[Entry] = std::move(Buffer);
 }
 
+bool ModuleManager::addKnownModuleFile(StringRef FileName) {
+  const FileEntry *File;
+  if (lookupModuleFile(FileName, 0, 0, File))
+    return true;
+  if (!Modules.count(File))
+    AdditionalKnownModuleFiles.insert(File);
+  return false;
+}
+
 ModuleManager::VisitState *ModuleManager::allocateVisitState() {
   // Fast path: if we have a cached state, use it.
   if (FirstVisitState) {
@@ -263,6 +272,8 @@ void ModuleManager::setGlobalIndex(GlobalModuleIndex *Index) {
 }
 
 void ModuleManager::moduleFileAccepted(ModuleFile *MF) {
+  AdditionalKnownModuleFiles.remove(MF->File);
+
   if (!GlobalIndex || GlobalIndex->loadedModuleFile(MF))
     return;