1 files changed, 27 insertions, 1 deletions
diff --git a/llvm/lib/IR/PassManager.cpp b/llvm/lib/IR/PassManager.cpp
index 171805f7d24..7c478ea1cf6 100644
--- a/llvm/lib/IR/PassManager.cpp
+++ b/llvm/lib/IR/PassManager.cpp
@@ -13,7 +13,8 @@
 
 using namespace llvm;
 
-// Explicit template instantiations for core template typedefs.
+// Explicit template instantiations and specialization defininitions for core
+// template typedefs.
 namespace llvm {
 template class AllAnalysesOn<Module>;
 template class AllAnalysesOn<Function>;
@@ -23,6 +24,31 @@ template class AnalysisManager<Module>;
 template class AnalysisManager<Function>;
 template class InnerAnalysisManagerProxy<FunctionAnalysisManager, Module>;
 template class OuterAnalysisManagerProxy<ModuleAnalysisManager, Function>;
+
+template <>
+bool FunctionAnalysisManagerModuleProxy::Result::invalidate(
+    Module &M, const PreservedAnalyses &PA,
+    ModuleAnalysisManager::Invalidator &Inv) {
+  // If this proxy isn't marked as preserved, then even if the result remains
+  // valid, the key itself may no longer be valid, so we clear everything.
+  //
+  // Note that in order to preserve this proxy, a module pass must ensure that
+  // the FAM has been completely updated to handle the deletion of functions.
+  // Specifically, any FAM-cached results for those functions need to have been
+  // forcibly cleared. When preserved, this proxy will only invalidate results
+  // cached on functions *still in the module* at the end of the module pass.
+  if (!PA.preserved(FunctionAnalysisManagerModuleProxy::ID())) {
+    InnerAM->clear();
+    return true;
+  }
+
+  // Otherwise propagate the invalidation event to all the remaining IR units.
+  for (Function &F : M)
+    InnerAM->invalidate(F, PA);
+
+  // Return false to indicate that this result is still a valid proxy.
+  return false;
+}
 }
 
 AnalysisKey PreservedAnalyses::AllAnalysesKey;