[WinEH] Fix endpad coloring/numbering

Summary:
When a cleanup's cleanupendpad or cleanupret targets a catchendpad, stop
trying to propagate the cleanup's parent's color to the catchendpad, since
what's needed is the cleanup's grandparent's color and the catchendpad
will get that color from the catchpad linkage already.  We already had
this exclusion for invokes, but were missing it for
cleanupendpad/cleanupret.

Also add a missing line that tags cleanupendpads' states in the
EHPadStateMap, without with lowering invokes that target cleanupendpads
which unwind to other handlers (and so don't have the -1 state) will fail.

This fixes the reduced IR repro in PR25163.


Reviewers: majnemer, andrew.w.kaylor, rnk

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13797

llvm-svn: 250534

1 files changed, 12 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 56648538f98..122d2fa2ce7 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -306,6 +306,7 @@ static void calculateExplicitCXXStateNumbers(WinEHFuncInfo &FuncInfo,
     BasicBlock *CleanupBlock = CEPI->getCleanupPad()->getParent();
     calculateExplicitCXXStateNumbers(FuncInfo, *CleanupBlock, ParentState);
     // Anything unwinding through CleanupEndPadInst is in ParentState.
+    FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
     for (const BasicBlock *PredBlock : predecessors(&BB))
       if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
         calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, ParentState);
@@ -614,12 +615,20 @@ colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks,
         !isa<CleanupEndPadInst>(VisitingHead)) {
       // Mark this as a funclet head as a member of itself.
       FuncletBlocks[Visiting].insert(Visiting);
-      // Queue exits with the parent color.
+      // Queue exits (i.e. successors of rets/endpads) with the parent color.
+      // Skip any exits that are catchendpads, since the parent color must then
+      // represent one of the catches chained to that catchendpad, but the
+      // catchendpad should get the color of the common parent of all its
+      // chained catches (i.e. the grandparent color of the current pad).
+      // We don't need to worry abou catchendpads going unvisited, since the
+      // catches chained to them must have unwind edges to them by which we will
+      // visit them.
       for (User *U : VisitingHead->users()) {
         if (auto *Exit = dyn_cast<TerminatorInst>(U)) {
           for (BasicBlock *Succ : successors(Exit->getParent()))
-            if (BlockColors[Succ].insert(Color).second)
-              Worklist.push_back({Succ, Color});
+            if (!isa<CatchEndPadInst>(*Succ->getFirstNonPHI()))
+              if (BlockColors[Succ].insert(Color).second)
+                Worklist.push_back({Succ, Color});
         }
       }
       // Handle CatchPad specially since its successors need different colors.