Finish off zero check for typeid(*p) so that it will do a __cxa_bad_typeid.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@88852 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 39 insertions, 2 deletions

diff --git a/lib/CodeGen/CGCXXExpr.cpp b/lib/CodeGen/CGCXXExpr.cpp
index 565685c6d0..ccbb608553 100644
--- a/lib/CodeGen/CGCXXExpr.cpp
+++ b/lib/CodeGen/CGCXXExpr.cpp
@@ -357,8 +357,31 @@ llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
       // FIXME: if subE is an lvalue do
       LValue Obj = EmitLValue(subE);
       llvm::Value *This = Obj.getAddress();
-      // FIXME: need to do a 0 check here for *p on This
-      llvm::Value *V = Builder.CreateBitCast(This, LTy->getPointerTo()->getPointerTo());
+      LTy = LTy->getPointerTo()->getPointerTo();
+      llvm::Value *V = Builder.CreateBitCast(This, LTy);
+      // We need to do a zero check for *p, unless it has NonNullAttr.
+      // FIXME: PointerType->hasAttr<NonNullAttr>()
+      bool CanBeZero = false;
+      if (UnaryOperator *UO = dyn_cast<UnaryOperator>(subE))
+        if (UO->getOpcode() == UnaryOperator::Deref)
+          CanBeZero = true;
+      if (CanBeZero) {
+        llvm::BasicBlock *NonZeroBlock = createBasicBlock();
+        llvm::BasicBlock *ZeroBlock = createBasicBlock();
+        
+        llvm::Value *Zero = llvm::Constant::getNullValue(LTy);
+        Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
+                             NonZeroBlock, ZeroBlock);
+        EmitBlock(ZeroBlock);
+        /// Call __cxa_bad_typeid
+        const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext);
+        const llvm::FunctionType *FTy;
+        FTy = llvm::FunctionType::get(ResultType, false);
+        llvm::Value *F = CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
+        Builder.CreateCall(F);
+        Builder.CreateUnreachable();
+        EmitBlock(NonZeroBlock);
+      }
       V = Builder.CreateLoad(V, "vtable");
       V = Builder.CreateConstInBoundsGEP1_64(V, -1ULL);
       V = Builder.CreateLoad(V);
diff --git a/test/CodeGenCXX/rtti.cpp b/test/CodeGenCXX/rtti.cpp
index f89396dd11..3e41c72b2c 100644
--- a/test/CodeGenCXX/rtti.cpp
+++ b/test/CodeGenCXX/rtti.cpp
@@ -102,6 +102,8 @@ void test2_2(test1_D *dp) {
     test2_1();
   if (typeid(NP) == typeid(test1_D))
     test2_1();
+  if (typeid(*dp) == typeid(test1_D))
+    test2_1();
 }
 
 // CHECK-LL:define void @_Z7test2_2P7test1_D(%class.test1_B7* %dp) nounwind {
@@ -113,3 +115,15 @@ void test2_2(test1_D *dp) {
 // CHECK-LL-NEXT:  %call = call zeroext i1 @_ZNK3std9type_infoeqERKS0_(%"class.std::type_info"* %2, %"class.std::type_info"* bitcast (%1* @_ZTI7test1_D to %"class.std::type_info"*))
 
 // CHECK-LL:       %call2 = call zeroext i1 @_ZNK3std9type_infoeqERKS0_(%"class.std::type_info"* bitcast (%0* @_ZTI2NP to %"class.std::type_info"*), %"class.std::type_info"* bitcast (%1* @_ZTI7test1_D to %"class.std::type_info"*))
+
+// CHECK-LL:       %3 = bitcast %class.test1_B7* %tmp5 to %"class.std::type_info"***
+// CHECK-LL-NEXT:  %4 = icmp ne %"class.std::type_info"*** %3, null
+// CHECK-LL-NEXT:  br i1 %4, label %6, label %5
+// CHECK-LL:     ; <label>:5
+// CHECK-LL-NEXT:  call void @__cxa_bad_typeid()
+// CHECK-LL-NEXT:  unreachable
+// CHECK-LL:     ; <label>:6
+// CHECK-LL-NEXT:  %vtable6 = load %"class.std::type_info"*** %3
+// CHECK-LL-NEXT:  %7 = getelementptr inbounds %"class.std::type_info"** %vtable6, i64 -1
+// CHECK-LL-NEXT:  %8 = load %"class.std::type_info"** %7
+// CHECK-LL-NEXT:  %call7 = call zeroext i1 @_ZNK3std9type_infoeqERKS0_(%"class.std::type_info"* %8, %"class.std::type_info"* bitcast (%1* @_ZTI7test1_D to %"class.std::type_info"*))