Fix a bug where we would not emit secondary vtables for bases of a primary base.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96351 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
index 970bbd7..6199c05 100644
--- a/lib/CodeGen/CGVtable.cpp
+++ b/lib/CodeGen/CGVtable.cpp
@@ -822,6 +822,10 @@
/// LayoutVtable - Layout a vtable and all its secondary vtables.
void LayoutVtable(BaseSubobject Base);
+ /// LayoutSecondaryVtables - Layout the secondary vtables for the given base
+ /// subobject.
+ void LayoutSecondaryVtables(BaseSubobject Base);
+
public:
VtableBuilder(CGVtableInfo &VtableInfo, const CXXRecordDecl *MostDerivedClass)
: VtableInfo(VtableInfo), MostDerivedClass(MostDerivedClass),
@@ -1070,36 +1074,49 @@
AddressPoints.insert(std::make_pair(PrimaryBase, AddressPoint));
}
+ // Layout secondary vtables.
+ LayoutSecondaryVtables(Base);
+
+ // FIXME: Emit vtables for virtual bases here.
+}
+
+void VtableBuilder::LayoutSecondaryVtables(BaseSubobject Base) {
+ // Itanium C++ ABI 2.5.2:
+ // Following the primary virtual table of a derived class are secondary
+ // virtual tables for each of its proper base classes, except any primary
+ // base(s) with which it shares its primary virtual table.
+
+ const CXXRecordDecl *RD = Base.getBase();
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
-
- // Layout secondary vtables.
+
for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
E = RD->bases_end(); I != E; ++I) {
+ // Ignore virtual bases, we'll emit them later.
+ if (I->isVirtual())
+ continue;
+
const CXXRecordDecl *BaseDecl =
cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
// Ignore bases that don't have a vtable.
if (!BaseDecl->isDynamicClass())
continue;
-
- // Ignore the primary base.
- if (BaseDecl == PrimaryBase)
- continue;
- // Ignore virtual bases, we'll emit them later.
- if (I->isVirtual())
- continue;
-
// Get the base offset of this base.
uint64_t BaseOffset = Base.getBaseOffset() +
Layout.getBaseClassOffset(BaseDecl);
+
+ // Don't emit a secondary vtable for a primary base. We might however want
+ // to emit secondary vtables for other bases of this base.
+ if (BaseDecl == PrimaryBase) {
+ LayoutSecondaryVtables(BaseSubobject(BaseDecl, BaseOffset));
+ continue;
+ }
// Layout this secondary vtable.
LayoutVtable(BaseSubobject(BaseDecl, BaseOffset));
}
-
- // FIXME: Emit vtables for virtual bases here.
}
/// dumpLayout - Dump the vtable layout.
diff --git a/test/CodeGenCXX/vtable-layout.cpp b/test/CodeGenCXX/vtable-layout.cpp
index 8fbe486..b714511 100644
--- a/test/CodeGenCXX/vtable-layout.cpp
+++ b/test/CodeGenCXX/vtable-layout.cpp
@@ -365,3 +365,33 @@
void B::f() { }
}
+
+namespace Test10 {
+
+// Test for a bug where we would not emit secondary vtables for bases
+// of a primary base.
+struct A1 { virtual void a1(); };
+struct A2 { virtual void a2(); };
+
+// CHECK: Vtable for 'Test10::C' (7 entries).
+// CHECK-NEXT: 0 | offset_to_top (0)
+// CHECK-NEXT: 1 | Test10::C RTTI
+// CHECK-NEXT: -- (Test10::A1, 0) vtable address --
+// CHECK-NEXT: -- (Test10::B, 0) vtable address --
+// CHECK-NEXT: -- (Test10::C, 0) vtable address --
+// CHECK-NEXT: 2 | void Test10::A1::a1()
+// CHECK-NEXT: 3 | void Test10::C::f()
+// CHECK-NEXT: 4 | offset_to_top (-8)
+// CHECK-NEXT: 5 | Test10::C RTTI
+// CHECK-NEXT: -- (Test10::A2, 8) vtable address --
+// CHECK-NEXT: 6 | void Test10::A2::a2()
+struct B : A1, A2 {
+ int b;
+};
+
+struct C : B {
+ virtual void f();
+};
+void C::f() { }
+
+}