There are times when the landing pad won't have a call to 'eh.selector' in

it. It's been assumed up til now that it would be in its immediate
successor. However, this isn't necessarily the case. It could be in one of its
successor's successors.

Modify the code to more thoroughly check for an 'eh.selector' call in
successors. It only looks at a successor if we get there as a result of an
unconditional branch.

Testcase ObjC/exceptions-4.m in r126968.

llvm-svn: 126969

1 files changed, 23 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 2ae3286829d..d8a5770d36c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -448,16 +448,30 @@ void llvm::AddCatchInfo(const CallInst &I, MachineModuleInfo *MMI,
   }
 }
 
-void llvm::CopyCatchInfo(const BasicBlock *SrcBB, const BasicBlock *DestBB,
+void llvm::CopyCatchInfo(const BasicBlock *SuccBB, const BasicBlock *LPad,
                          MachineModuleInfo *MMI, FunctionLoweringInfo &FLI) {
-  for (BasicBlock::const_iterator I = SrcBB->begin(), E = --SrcBB->end();
-       I != E; ++I)
-    if (const EHSelectorInst *EHSel = dyn_cast<EHSelectorInst>(I)) {
-      // Apply the catch info to DestBB.
-      AddCatchInfo(*EHSel, MMI, FLI.MBBMap[DestBB]);
+  SmallPtrSet<const BasicBlock*, 4> Visited;
+
+  // The 'eh.selector' call may not be in the direct successor of a basic block,
+  // but could be several successors deeper. If we don't find it, try going one
+  // level further. <rdar://problem/8824861>
+  while (Visited.insert(SuccBB)) {
+    for (BasicBlock::const_iterator I = SuccBB->begin(), E = --SuccBB->end();
+         I != E; ++I)
+      if (const EHSelectorInst *EHSel = dyn_cast<EHSelectorInst>(I)) {
+        // Apply the catch info to LPad.
+        AddCatchInfo(*EHSel, MMI, FLI.MBBMap[LPad]);
 #ifndef NDEBUG
-      if (!FLI.MBBMap[SrcBB]->isLandingPad())
-        FLI.CatchInfoFound.insert(EHSel);
+        if (!FLI.MBBMap[SuccBB]->isLandingPad())
+          FLI.CatchInfoFound.insert(EHSel);
 #endif
-    }
+        return;
+      }
+
+    const BranchInst *Br = dyn_cast<BranchInst>(SuccBB->getTerminator());
+    if (Br && Br->isUnconditional())
+      SuccBB = Br->getSuccessor(0);
+    else
+      break;
+  }
 }