When a failed dynamic_cast<T&> (which is an lvalue) results in a

throw, it should use invoke when needed. The fixes the
Boost.Statechrt failures that motivated PR7132, but there are a few
side issues to tackle as well.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103803 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 3 deletions

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 2b0938ab84..3a2882e24b 100644
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -867,6 +867,8 @@ llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
       ToVoid = true;
   } else {
     LTy = LTy->getPointerTo();
+    
+    // FIXME: What if exceptions are disabled?
     ThrowOnBad = true;
   }
 
@@ -933,15 +935,21 @@ llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
 
     if (ThrowOnBad) {
       BadCastBlock = createBasicBlock();
-
       Builder.CreateCondBr(Builder.CreateIsNotNull(V), ContBlock, BadCastBlock);
       EmitBlock(BadCastBlock);
-      /// Call __cxa_bad_cast
+      /// Invoke __cxa_bad_cast
       ResultType = llvm::Type::getVoidTy(VMContext);
       const llvm::FunctionType *FBadTy;
       FBadTy = llvm::FunctionType::get(ResultType, false);
       llvm::Value *F = CGM.CreateRuntimeFunction(FBadTy, "__cxa_bad_cast");
-      Builder.CreateCall(F)->setDoesNotReturn();
+      if (llvm::BasicBlock *InvokeDest = getInvokeDest()) {
+        llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
+        Builder.CreateInvoke(F, Cont, InvokeDest)->setDoesNotReturn();
+        EmitBlock(Cont);
+      } else {
+        // FIXME: Does this ever make sense?
+        Builder.CreateCall(F)->setDoesNotReturn();
+      }
       Builder.CreateUnreachable();
     }
   }