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[clang] Ensure correct metadata for relative vtables

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Prior to this, metadata pertaining to the size or address point offsets
into a relative vtable were twice the value they should be (treating
component widths as pointer width rather than 4 bytes). This prevented
some vtables from being devirtualized with D134320. This ensures the
correct metadata is written so whole program devirtualization can catch
these remaining devirt targets.

Differential Revision: https://reviews.llvm.org/D134687
This commit is contained in:
Leonard Chan 2022-09-29 21:53:30 +00:00
parent 2a1100cd65
commit 003b6033e1
4 changed files with 119 additions and 51 deletions
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23
clang/lib/CodeGen/CGVTables.cpp
View File

@ -678,15 +678,23 @@ void CodeGenVTables::addRelativeComponent(ConstantArrayBuilder &builder,
/*position=*/vtableAddressPoint);
}
bool CodeGenVTables::useRelativeLayout() const {
static bool UseRelativeLayout(const CodeGenModule &CGM) {
return CGM.getTarget().getCXXABI().isItaniumFamily() &&
CGM.getItaniumVTableContext().isRelativeLayout();
}
bool CodeGenVTables::useRelativeLayout() const {
return UseRelativeLayout(CGM);
}
llvm::Type *CodeGenModule::getVTableComponentType() const {
if (UseRelativeLayout(*this))
return Int32Ty;
return Int8PtrTy;
}
llvm::Type *CodeGenVTables::getVTableComponentType() const {
if (useRelativeLayout())
return CGM.Int32Ty;
return CGM.Int8PtrTy;
return CGM.getVTableComponentType();
}
static void AddPointerLayoutOffset(const CodeGenModule &CGM,
@ -1281,8 +1289,7 @@ void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
if (!getCodeGenOpts().LTOUnit)
return;
CharUnits PointerWidth = Context.toCharUnitsFromBits(
Context.getTargetInfo().getPointerWidth(LangAS::Default));
CharUnits ComponentWidth = GetTargetTypeStoreSize(getVTableComponentType());
typedef std::pair<const CXXRecordDecl *, unsigned> AddressPoint;
std::vector<AddressPoint> AddressPoints;
@ -1320,7 +1327,7 @@ void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
ArrayRef<VTableComponent> Comps = VTLayout.vtable_components();
for (auto AP : AddressPoints) {
// Create type metadata for the address point.
AddVTableTypeMetadata(VTable, PointerWidth * AP.second, AP.first);
AddVTableTypeMetadata(VTable, ComponentWidth * AP.second, AP.first);
// The class associated with each address point could also potentially be
// used for indirect calls via a member function pointer, so we need to
@ -1333,7 +1340,7 @@ void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
Context.getMemberPointerType(
Comps[I].getFunctionDecl()->getType(),
Context.getRecordType(AP.first).getTypePtr()));
VTable->addTypeMetadata((PointerWidth * I).getQuantity(), MD);
VTable->addTypeMetadata((ComponentWidth * I).getQuantity(), MD);
}
}

4
clang/lib/CodeGen/CGVTables.h
View File

@ -102,6 +102,10 @@ public:
return *cast<ItaniumVTableContext>(VTContext);
}
const ItaniumVTableContext &getItaniumVTableContext() const {
return *cast<ItaniumVTableContext>(VTContext);
}
MicrosoftVTableContext &getMicrosoftVTableContext() {
return *cast<MicrosoftVTableContext>(VTContext);
}

6
clang/lib/CodeGen/CodeGenModule.h
View File

@ -760,6 +760,10 @@ public:
return VTables.getItaniumVTableContext();
}
const ItaniumVTableContext &getItaniumVTableContext() const {
return VTables.getItaniumVTableContext();
}
MicrosoftVTableContext &getMicrosoftVTableContext() {
return VTables.getMicrosoftVTableContext();
}
@ -1444,6 +1448,8 @@ public:
llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout);
llvm::Type *getVTableComponentType() const;
/// Generate a cross-DSO type identifier for MD.
llvm::ConstantInt *CreateCrossDsoCfiTypeId(llvm::Metadata *MD);

137
clang/test/CodeGenCXX/type-metadata.cpp
View File

@ -1,19 +1,33 @@
// Tests for the cfi-vcall feature:
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=ITANIUM --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=NDIAG %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=ITANIUM --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-DIAG --check-prefix=DIAG --check-prefix=DIAG-ABORT %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-recover=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=ITANIUM --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-DIAG --check-prefix=DIAG --check-prefix=DIAG-RECOVER %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=MS --check-prefix=TT-MS --check-prefix=NDIAG %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT-NO-RV --check-prefix=ITANIUM --check-prefix=ITANIUM-MD --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=NDIAG %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT-NO-RV --check-prefix=ITANIUM --check-prefix=ITANIUM-MD --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-MD-DIAG --check-prefix=ITANIUM-DIAG --check-prefix=DIAG --check-prefix=DIAG-ABORT %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-recover=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT-NO-RV --check-prefix=ITANIUM --check-prefix=ITANIUM-MD --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-MD-DIAG --check-prefix=ITANIUM-DIAG --check-prefix=DIAG --check-prefix=DIAG-RECOVER %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT-NO-RV --check-prefix=MS --check-prefix=TT-MS --check-prefix=NDIAG %s
// Tests for the whole-program-vtables feature:
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=ITANIUM --check-prefix=TT-ITANIUM-HIDDEN %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=ITANIUM --check-prefix=ITANIUM-MD --check-prefix=TT-ITANIUM-HIDDEN %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=ITANIUM-DEFAULTVIS --check-prefix=TT-ITANIUM-DEFAULT %s
// RUN: %clang_cc1 -O2 -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=ITANIUM-OPT %s
// RUN: %clang_cc1 -O2 -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=ITANIUM-OPT --check-prefix=ITANIUM-OPT-LAYOUT %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=MS --check-prefix=TT-MS %s
// Tests for cfi + whole-program-vtables:
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=ITANIUM --check-prefix=TC-ITANIUM %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=ITANIUM --check-prefix=TC-ITANIUM --check-prefix=ITANIUM-MD %s
// RUN: %clang_cc1 -flto -flto-unit -triple x86_64-pc-windows-msvc -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=MS --check-prefix=TC-MS %s
// Equivalent tests for above, but with relative-vtables.
// Tests for the cfi-vcall feature:
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=RV-MD --check-prefix=ITANIUM --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=NDIAG --check-prefix=CFI-NVT-RV %s
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=CFI-NVT-RV --check-prefix=ITANIUM --check-prefix=RV-MD --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-DIAG --check-prefix=RV-MD-DIAG --check-prefix=DIAG --check-prefix=DIAG-ABORT %s
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-recover=cfi-vcall -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-NVT --check-prefix=CFI-NVT-RV --check-prefix=ITANIUM --check-prefix=RV-MD --check-prefix=TT-ITANIUM-HIDDEN --check-prefix=ITANIUM-DIAG --check-prefix=RV-MD-DIAG --check-prefix=DIAG --check-prefix=DIAG-RECOVER %s
// Tests for the whole-program-vtables feature:
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=ITANIUM -check-prefix=RV-MD --check-prefix=TT-ITANIUM-HIDDEN %s
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=VTABLE-OPT --check-prefix=ITANIUM-DEFAULTVIS --check-prefix=TT-ITANIUM-DEFAULT %s
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -O2 -flto -flto-unit -triple x86_64-unknown-linux -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=ITANIUM-OPT --check-prefix=RV-OPT-LAYOUT %s
// Tests for cfi + whole-program-vtables:
// RUN: %clang_cc1 -fexperimental-relative-c++-abi-vtables -flto -flto-unit -triple x86_64-unknown-linux -fvisibility=hidden -fsanitize=cfi-vcall -fsanitize-trap=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CFI --check-prefix=CFI-VT --check-prefix=ITANIUM --check-prefix=RV-MD --check-prefix=TC-ITANIUM %s
// ITANIUM: @_ZTV1A = {{[^!]*}}, !type [[A16:![0-9]+]]
// ITANIUM-DIAG-SAME: !type [[ALL16:![0-9]+]]
// ITANIUM-SAME: !type [[AF16:![0-9]+]]
@ -163,8 +177,10 @@ void af(A *a) {
// DIAG-RECOVER-NEXT: br label %[[CONTBB]]
// CFI: [[CONTBB]]
// CFI-NVT: [[PTR:%[^ ]*]] = load
// CFI-VT: [[PTRI8:%[^ ]*]] = extractvalue { ptr, i1 } [[PAIR]], 0
// CFI-NVT-NO-RV: [[PTR:%[^ ]*]] = load
// CFI-NVT-RV: [[PTR:%[^ ]*]] = call ptr @llvm.load.relative.i32
// CFI-VT: [[PTR:%[^ ]*]] = extractvalue { ptr, i1 } [[PAIR]], 0
// CFI: call void [[PTR]]
#line 123
a->f();
}
@ -278,41 +294,76 @@ void g() {
} // Test9
// ITANIUM: [[A16]] = !{i64 16, !"_ZTS1A"}
// ITANIUM-DIAG: [[ALL16]] = !{i64 16, !"all-vtables"}
// ITANIUM: [[AF16]] = !{i64 16, !"_ZTSM1AFvvE.virtual"}
// ITANIUM: [[A32]] = !{i64 32, !"_ZTS1A"}
// ITANIUM-DIAG: [[ALL32]] = !{i64 32, !"all-vtables"}
// ITANIUM: [[AF32]] = !{i64 32, !"_ZTSM1AFvvE.virtual"}
// ITANIUM: [[AF40]] = !{i64 40, !"_ZTSM1AFvvE.virtual"}
// ITANIUM: [[AF48]] = !{i64 48, !"_ZTSM1AFvvE.virtual"}
// ITANIUM: [[B32]] = !{i64 32, !"_ZTS1B"}
// ITANIUM: [[BF32]] = !{i64 32, !"_ZTSM1BFvvE.virtual"}
// ITANIUM: [[BF40]] = !{i64 40, !"_ZTSM1BFvvE.virtual"}
// ITANIUM: [[BF48]] = !{i64 48, !"_ZTSM1BFvvE.virtual"}
// ITANIUM: [[C32]] = !{i64 32, !"_ZTS1C"}
// ITANIUM: [[CF32]] = !{i64 32, !"_ZTSM1CFvvE.virtual"}
// ITANIUM: [[C88]] = !{i64 88, !"_ZTS1C"}
// ITANIUM-DIAG: [[ALL88]] = !{i64 88, !"all-vtables"}
// ITANIUM: [[CF40]] = !{i64 40, !"_ZTSM1CFvvE.virtual"}
// ITANIUM: [[CF48]] = !{i64 48, !"_ZTSM1CFvvE.virtual"}
// ITANIUM: [[D32]] = !{i64 32, [[D_ID:![0-9]+]]}
// ITANIUM: [[D_ID]] = distinct !{}
// ITANIUM: [[DF32]] = !{i64 32, [[DF_ID:![0-9]+]]}
// ITANIUM: [[DF_ID]] = distinct !{}
// ITANIUM: [[DF40]] = !{i64 40, [[DF_ID]]}
// ITANIUM: [[DF48]] = !{i64 48, [[DF_ID]]}
// ITANIUM: [[A64]] = !{i64 64, !"_ZTS1A"}
// ITANIUM-DIAG: [[ALL64]] = !{i64 64, !"all-vtables"}
// ITANIUM: [[AF64]] = !{i64 64, !"_ZTSM1AFvvE.virtual"}
// ITANIUM: [[CF64]] = !{i64 64, !"_ZTSM1CFvvE.virtual"}
// ITANIUM: [[FA16]] = !{i64 16, [[FA_ID:![0-9]+]]}
// ITANIUM: [[FA_ID]] = distinct !{}
// ITANIUM: [[FAF16]] = !{i64 16, [[FAF_ID:![0-9]+]]}
// ITANIUM: [[FAF_ID]] = distinct !{}
// RV-MD: [[A16]] = !{i64 8, !"_ZTS1A"}
// RV-MD-DIAG: [[ALL16]] = !{i64 8, !"all-vtables"}
// RV-MD: [[AF16]] = !{i64 8, !"_ZTSM1AFvvE.virtual"}
// RV-MD: [[A32]] = !{i64 16, !"_ZTS1A"}
// RV-MD-DIAG: [[ALL32]] = !{i64 16, !"all-vtables"}
// RV-MD: [[AF32]] = !{i64 16, !"_ZTSM1AFvvE.virtual"}
// RV-MD: [[AF40]] = !{i64 20, !"_ZTSM1AFvvE.virtual"}
// RV-MD: [[AF48]] = !{i64 24, !"_ZTSM1AFvvE.virtual"}
// RV-MD: [[B32]] = !{i64 16, !"_ZTS1B"}
// RV-MD: [[BF32]] = !{i64 16, !"_ZTSM1BFvvE.virtual"}
// RV-MD: [[BF40]] = !{i64 20, !"_ZTSM1BFvvE.virtual"}
// RV-MD: [[BF48]] = !{i64 24, !"_ZTSM1BFvvE.virtual"}
// RV-MD: [[C32]] = !{i64 16, !"_ZTS1C"}
// RV-MD: [[CF32]] = !{i64 16, !"_ZTSM1CFvvE.virtual"}
// RV-MD: [[C88]] = !{i64 44, !"_ZTS1C"}
// RV-MD-DIAG: [[ALL88]] = !{i64 44, !"all-vtables"}
// RV-MD: [[CF40]] = !{i64 20, !"_ZTSM1CFvvE.virtual"}
// RV-MD: [[CF48]] = !{i64 24, !"_ZTSM1CFvvE.virtual"}
// RV-MD: [[D32]] = !{i64 16, [[D_ID:![0-9]+]]}
// RV-MD: [[D_ID]] = distinct !{}
// RV-MD: [[DF32]] = !{i64 16, [[DF_ID:![0-9]+]]}
// RV-MD: [[DF_ID]] = distinct !{}
// RV-MD: [[DF40]] = !{i64 20, [[DF_ID]]}
// RV-MD: [[DF48]] = !{i64 24, [[DF_ID]]}
// RV-MD: [[A64]] = !{i64 32, !"_ZTS1A"}
// RV-MD-DIAG: [[ALL64]] = !{i64 32, !"all-vtables"}
// RV-MD: [[AF64]] = !{i64 32, !"_ZTSM1AFvvE.virtual"}
// RV-MD: [[CF64]] = !{i64 32, !"_ZTSM1CFvvE.virtual"}
// RV-MD: [[FA16]] = !{i64 8, [[FA_ID:![0-9]+]]}
// RV-MD: [[FA_ID]] = distinct !{}
// RV-MD: [[FAF16]] = !{i64 8, [[FAF_ID:![0-9]+]]}
// RV-MD: [[FAF_ID]] = distinct !{}
// ITANIUM-OPT: [[E16]] = !{i64 16, !"_ZTSN5test31EE"}
// ITANIUM-OPT: [[EF16]] = !{i64 16, !"_ZTSMN5test31EEFvvE.virtual"}
// ITANIUM-MD: [[A16]] = !{i64 16, !"_ZTS1A"}
// ITANIUM-MD-DIAG: [[ALL16]] = !{i64 16, !"all-vtables"}
// ITANIUM-MD: [[AF16]] = !{i64 16, !"_ZTSM1AFvvE.virtual"}
// ITANIUM-MD: [[A32]] = !{i64 32, !"_ZTS1A"}
// ITANIUM-MD-DIAG: [[ALL32]] = !{i64 32, !"all-vtables"}
// ITANIUM-MD: [[AF32]] = !{i64 32, !"_ZTSM1AFvvE.virtual"}
// ITANIUM-MD: [[AF40]] = !{i64 40, !"_ZTSM1AFvvE.virtual"}
// ITANIUM-MD: [[AF48]] = !{i64 48, !"_ZTSM1AFvvE.virtual"}
// ITANIUM-MD: [[B32]] = !{i64 32, !"_ZTS1B"}
// ITANIUM-MD: [[BF32]] = !{i64 32, !"_ZTSM1BFvvE.virtual"}
// ITANIUM-MD: [[BF40]] = !{i64 40, !"_ZTSM1BFvvE.virtual"}
// ITANIUM-MD: [[BF48]] = !{i64 48, !"_ZTSM1BFvvE.virtual"}
// ITANIUM-MD: [[C32]] = !{i64 32, !"_ZTS1C"}
// ITANIUM-MD: [[CF32]] = !{i64 32, !"_ZTSM1CFvvE.virtual"}
// ITANIUM-MD: [[C88]] = !{i64 88, !"_ZTS1C"}
// ITANIUM-MD-DIAG: [[ALL88]] = !{i64 88, !"all-vtables"}
// ITANIUM-MD: [[CF40]] = !{i64 40, !"_ZTSM1CFvvE.virtual"}
// ITANIUM-MD: [[CF48]] = !{i64 48, !"_ZTSM1CFvvE.virtual"}
// ITANIUM-MD: [[D32]] = !{i64 32, [[D_ID:![0-9]+]]}
// ITANIUM-MD: [[D_ID]] = distinct !{}
// ITANIUM-MD: [[DF32]] = !{i64 32, [[DF_ID:![0-9]+]]}
// ITANIUM-MD: [[DF_ID]] = distinct !{}
// ITANIUM-MD: [[DF40]] = !{i64 40, [[DF_ID]]}
// ITANIUM-MD: [[DF48]] = !{i64 48, [[DF_ID]]}
// ITANIUM-MD: [[A64]] = !{i64 64, !"_ZTS1A"}
// ITANIUM-MD-DIAG: [[ALL64]] = !{i64 64, !"all-vtables"}
// ITANIUM-MD: [[AF64]] = !{i64 64, !"_ZTSM1AFvvE.virtual"}
// ITANIUM-MD: [[CF64]] = !{i64 64, !"_ZTSM1CFvvE.virtual"}
// ITANIUM-MD: [[FA16]] = !{i64 16, [[FA_ID:![0-9]+]]}
// ITANIUM-MD: [[FA_ID]] = distinct !{}
// ITANIUM-MD: [[FAF16]] = !{i64 16, [[FAF_ID:![0-9]+]]}
// ITANIUM-MD: [[FAF_ID]] = distinct !{}
// ITANIUM-OPT-LAYOUT: [[E16]] = !{i64 16, !"_ZTSN5test31EE"}
// ITANIUM-OPT-LAYOUT: [[EF16]] = !{i64 16, !"_ZTSMN5test31EEFvvE.virtual"}
// RV-OPT-LAYOUT: [[E16]] = !{i64 8, !"_ZTSN5test31EE"}
// RV-OPT-LAYOUT: [[EF16]] = !{i64 8, !"_ZTSMN5test31EEFvvE.virtual"}
// MS: [[A8]] = !{i64 8, !"?AUA@@"}
// MS: [[B8]] = !{i64 8, !"?AUB@@"}