1 files changed, 51 insertions, 6 deletions

diff --git a/llvm/lib/Analysis/CGSCCPassManager.cpp b/llvm/lib/Analysis/CGSCCPassManager.cpp
index b0a7d306b26..8205bba0f57 100644
--- a/llvm/lib/Analysis/CGSCCPassManager.cpp
+++ b/llvm/lib/Analysis/CGSCCPassManager.cpp
@@ -262,6 +262,51 @@ bool FunctionAnalysisManagerCGSCCProxy::Result::invalidate(
 
 } // End llvm namespace
 
+/// When a new SCC is created for the graph and there might be function
+/// analysis results cached for the functions now in that SCC two forms of
+/// updates are required.
+///
+/// First, a proxy from the SCC to the FunctionAnalysisManager needs to be
+/// created so that any subsequent invalidation events to the SCC are
+/// propagated to the function analysis results cached for functions within it.
+///
+/// Second, if any of the functions within the SCC have analysis results with
+/// outer analysis dependencies, then those dependencies would point to the
+/// *wrong* SCC's analysis result. We forcibly invalidate the necessary
+/// function analyses so that they don't retain stale handles.
+static void updateNewSCCFunctionAnalyses(LazyCallGraph::SCC &C,
+                                         LazyCallGraph &G,
+                                         CGSCCAnalysisManager &AM) {
+  // Get the relevant function analysis manager.
+  auto &FAM =
+      AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, G).getManager();
+
+  // Now walk the functions in this SCC and invalidate any function analysis
+  // results that might have outer dependencies on an SCC analysis.
+  for (LazyCallGraph::Node &N : C) {
+    Function &F = N.getFunction();
+
+    auto *OuterProxy =
+        FAM.getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F);
+    if (!OuterProxy)
+      // No outer analyses were queried, nothing to do.
+      continue;
+
+    // Forcibly abandon all the inner analyses with dependencies, but
+    // invalidate nothing else.
+    auto PA = PreservedAnalyses::all();
+    for (const auto &OuterInvalidationPair :
+         OuterProxy->getOuterInvalidations()) {
+      const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
+      for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
+        PA.abandon(InnerAnalysisID);
+    }
+
+    // Now invalidate anything we found.
+    FAM.invalidate(F, PA);
+  }
+}
+
 namespace {
 /// Helper function to update both the \c CGSCCAnalysisManager \p AM and the \c
 /// CGSCCPassManager's \c CGSCCUpdateResult \p UR based on a range of newly
@@ -314,9 +359,9 @@ incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
   PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
   AM.invalidate(*OldC, PA);
 
-  // Ensure we have a proxy for the now-current SCC if needed.
+  // Ensure the now-current SCC's function analyses are updated.
   if (NeedFAMProxy)
-    (void)AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G);
+    updateNewSCCFunctionAnalyses(*C, G, AM);
 
   for (SCC &NewC :
        reverse(make_range(std::next(NewSCCRange.begin()), NewSCCRange.end()))) {
@@ -326,12 +371,12 @@ incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
     if (DebugLogging)
       dbgs() << "Enqueuing a newly formed SCC:" << NewC << "\n";
 
-    // Ensure new SCCs have a FAM proxy if needed.
+    // Ensure new SCCs' function analyses are updated.
     if (NeedFAMProxy)
-      (void)AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G);
+      updateNewSCCFunctionAnalyses(*C, G, AM);
 
-    // And propagate an invalidation to the new SCC as only the current will
-    // get one from the pass manager infrastructure.
+    // Also propagate a normal invalidation to the new SCC as only the current
+    // will get one from the pass manager infrastructure.
     AM.invalidate(NewC, PA);
   }
   return C;