add tbaa metadata to vtable pointer loads/stores
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153447 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index ee79c39..b452c1b 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -1514,7 +1514,8 @@
llvm::Type *AddressPointPtrTy =
VTableAddressPoint->getType()->getPointerTo();
VTableField = Builder.CreateBitCast(VTableField, AddressPointPtrTy);
- Builder.CreateStore(VTableAddressPoint, VTableField);
+ llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
+ CGM.DecorateInstruction(Store, CGM.getTBAAInfoForVTablePtr());
}
void
@@ -1597,7 +1598,9 @@
llvm::Value *CodeGenFunction::GetVTablePtr(llvm::Value *This,
llvm::Type *Ty) {
llvm::Value *VTablePtrSrc = Builder.CreateBitCast(This, Ty->getPointerTo());
- return Builder.CreateLoad(VTablePtrSrc, "vtable");
+ llvm::Instruction *VTable = Builder.CreateLoad(VTablePtrSrc, "vtable");
+ CGM.DecorateInstruction(VTable, CGM.getTBAAInfoForVTablePtr());
+ return VTable;
}
static const CXXRecordDecl *getMostDerivedClassDecl(const Expr *Base) {
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 1c8f5f6..cc19d95 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -182,6 +182,12 @@
return TBAA->getTBAAInfo(QTy);
}
+llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() {
+ if (!TBAA)
+ return 0;
+ return TBAA->getTBAAInfoForVTablePtr();
+}
+
void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
llvm::MDNode *TBAAInfo) {
Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 8f9cdcd..5719afb 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -448,6 +448,7 @@
bool shouldUseTBAA() const { return TBAA != 0; }
llvm::MDNode *getTBAAInfo(QualType QTy);
+ llvm::MDNode *getTBAAInfoForVTablePtr();
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor);
diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp
index 148081e..9ee3f1d 100644
--- a/lib/CodeGen/CodeGenTBAA.cpp
+++ b/lib/CodeGen/CodeGenTBAA.cpp
@@ -179,3 +179,7 @@
// For now, handle any other kind of type conservatively.
return MetadataCache[Ty] = getChar();
}
+
+llvm::MDNode *CodeGenTBAA::getTBAAInfoForVTablePtr() {
+ return getTBAAInfoForNamedType("vtable pointer", getRoot());
+}
diff --git a/lib/CodeGen/CodeGenTBAA.h b/lib/CodeGen/CodeGenTBAA.h
index 9fe51fb..8e08498 100644
--- a/lib/CodeGen/CodeGenTBAA.h
+++ b/lib/CodeGen/CodeGenTBAA.h
@@ -68,6 +68,10 @@
/// getTBAAInfo - Get the TBAA MDNode to be used for a dereference
/// of the given type.
llvm::MDNode *getTBAAInfo(QualType QTy);
+
+ /// getTBAAInfoForVTablePtr - Get the TBAA MDNode to be used for a
+ /// dereference of a vtable pointer.
+ llvm::MDNode *getTBAAInfoForVTablePtr();
};
} // end namespace CodeGen
diff --git a/test/CodeGen/tbaa-for-vptr.cpp b/test/CodeGen/tbaa-for-vptr.cpp
new file mode 100644
index 0000000..c63c736
--- /dev/null
+++ b/test/CodeGen/tbaa-for-vptr.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -emit-llvm -o - -O1 %s | FileCheck %s
+// Check that we generate TBAA for vtable pointer loads and stores.
+struct A {
+ virtual int foo() const ;
+ virtual ~A();
+};
+
+void CreateA() {
+ new A;
+}
+
+void CallFoo(A *a) {
+ a->foo();
+}
+
+// CHECK: %vtable = load {{.*}} !tbaa !0
+// CHECK: store {{.*}} !tbaa !0
+// CHECK: !0 = metadata !{metadata !"vtable pointer", metadata !1}
+// CHECK: !1 = metadata !{metadata !"Simple C/C++ TBAA", null}
