clang/test/CodeGenCXX/RelativeVTablesABI/diamond-inheritance.cpp

// Diamond inheritance.
// A more complicated multiple inheritance example that includes longer chain of inheritance and a common ancestor.

// RUN: %clang_cc1 %s -triple=aarch64-unknown-fuchsia -O1 -S -o - -emit-llvm -fhalf-no-semantic-interposition | FileCheck %s

// CHECK-DAG: %class.B = type { %class.A }
// CHECK-DAG: %class.A = type { i32 (...)** }
// CHECK-DAG: %class.C = type { %class.A }
// CHECK-DAG: %class.D = type { %class.B, %class.C }

// VTable for B should contain offset to top (0), RTTI pointer, A::foo(), and B::barB().
// CHECK: @_ZTV1B.local = private unnamed_addr constant { [4 x i32] } { [4 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i8* }** @_ZTI1B.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1B.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.A*)* dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1B.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.B*)* dso_local_equivalent @_ZN1B4barBEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1B.local, i32 0, i32 0, i32 2) to i64)) to i32)] }, align 4

// VTable for C should contain offset to top (0), RTTI pointer, A::foo(), and C::barC().
// CHECK: @_ZTV1C.local = private unnamed_addr constant { [4 x i32] } { [4 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i8* }** @_ZTI1C.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.A*)* dso_local_equivalent @_ZN1A3fooEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.C*)* dso_local_equivalent @_ZN1C4barCEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [4 x i32] }, { [4 x i32] }* @_ZTV1C.local, i32 0, i32 0, i32 2) to i64)) to i32)] }, align 4

// VTable for D should be similar to the mutiple inheritance example where this
// vtable contains 2 inner vtables:
// - 1st table containing D::foo(), B::barB(), and D::baz().
// - 2nd table containing a thunk to D::foo() and C::barC().
// CHECK: @_ZTV1D.local = private unnamed_addr constant { [5 x i32], [4 x i32] } { [5 x i32] [i32 0, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i32, i32, i8*, i64, i8*, i64 }** @_ZTI1D.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.D*)* dso_local_equivalent @_ZN1D3fooEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.B*)* dso_local_equivalent @_ZN1B4barBEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 0, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.D*)* dso_local_equivalent @_ZN1D3bazEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 0, i32 2) to i64)) to i32)], [4 x i32] [i32 -8, i32 trunc (i64 sub (i64 ptrtoint ({ i8*, i8*, i32, i32, i8*, i64, i8*, i64 }** @_ZTI1D.rtti_proxy to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 1, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.D*)* dso_local_equivalent @_ZThn8_N1D3fooEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 1, i32 2) to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint (void (%class.C*)* dso_local_equivalent @_ZN1C4barCEv to i64), i64 ptrtoint (i32* getelementptr inbounds ({ [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local, i32 0, i32 1, i32 2) to i64)) to i32)] }, align 4

// @_ZTV1B ={{.*}} unnamed_addr alias { [4 x i32] }, { [4 x i32] }* @_ZTV1B.local
// @_ZTV1C ={{.*}} unnamed_addr alias { [4 x i32] }, { [4 x i32] }* @_ZTV1C.local
// @_ZTV1D ={{.*}} unnamed_addr alias { [5 x i32], [4 x i32] }, { [5 x i32], [4 x i32] }* @_ZTV1D.local

class A {
public:
  virtual void foo();
};

class B : public A {
public:
  virtual void barB();
};

class C : public A {
  virtual void barC();
};

// Should be a struct with 2 arrays from 2 parents.
// The 1st contains D::foo(), B::barB(), and D::baz().
// The 2nd contains C::barC(), and a thunk that points to D::foo().
class D : public B, C {
public:
  virtual void baz();
  void foo() override;
};

void B::barB() {}
void C::barC() {}
void D::foo() {}
void D::baz() {}

void D_foo(D *d) {
  d->foo();
}