llvm-project/clang/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp

// RUN: %clang_cc1 -fno-rtti -emit-llvm %s -o - -cxx-abi microsoft -triple=i386-pc-win32 | FileCheck %s

struct Left {
  virtual void left();
};

struct Right {
  virtual void right();
};

struct ChildNoOverride : Left, Right {
};

struct ChildOverride : Left, Right {
  virtual void left();
  virtual void right();
};

extern "C" void foo(void *);

void call_left_no_override(ChildNoOverride *child) {
// CHECK: define void @"\01?call_left_no_override
// CHECK: %[[CHILD:.*]] = load %struct.ChildNoOverride

  child->left();
// Only need to cast 'this' to Left*.
// CHECK: %[[LEFT:.*]] = bitcast %struct.ChildNoOverride* %[[CHILD]] to %struct.Left*
// CHECK: %[[VFPTR:.*]] = bitcast %struct.Left* %[[LEFT]] to void (%struct.Left*)***
// CHECK: %[[VFTABLE:.*]] = load void (%struct.Left*)*** %[[VFPTR]]
// CHECK: %[[VFUN:.*]] = getelementptr inbounds void (%struct.Left*)** %[[VFTABLE]], i64 0
// CHECK: %[[VFUN_VALUE:.*]] = load void (%struct.Left*)** %[[VFUN]]
// CHECK: call x86_thiscallcc void %[[VFUN_VALUE]](%struct.Left* %[[LEFT]])
// CHECK: ret
}

void ChildOverride::left() {
// CHECK: define x86_thiscallcc void @"\01?left@ChildOverride@@UAEXXZ"(%struct.ChildOverride* %[[THIS:.*]])
//
// No need to adjust 'this' as the ChildOverride's layout begins with Left.
// CHECK: %[[THIS_ADDR:.*]] = alloca %struct.ChildOverride*, align 4
// CHECK: store %struct.ChildOverride* %[[THIS]], %struct.ChildOverride** %[[THIS_ADDR]], align 4

  foo(this);
// CHECK: %[[THIS:.*]] = load %struct.ChildOverride** %[[THIS_ADDR]]
// CHECK: %[[THIS_i8:.*]] = bitcast %struct.ChildOverride* %[[THIS]] to i8*
// CHECK: call void @foo(i8* %[[THIS_i8]])
// CHECK: ret
}

void call_left_override(ChildOverride *child) {
// CHECK: define void @"\01?call_left_override
// CHECK: %[[CHILD:.*]] = load %struct.ChildOverride

  child->left();
// CHECK: %[[VFPTR:.*]] = bitcast %struct.ChildOverride* %[[CHILD]] to void (%struct.ChildOverride*)***
// CHECK: %[[VFTABLE:.*]] = load void (%struct.ChildOverride*)*** %[[VFPTR]]
// CHECK: %[[VFUN:.*]] = getelementptr inbounds void (%struct.ChildOverride*)** %[[VFTABLE]], i64 0
// CHECK: %[[VFUN_VALUE:.*]] = load void (%struct.ChildOverride*)** %[[VFUN]]
//
// CHECK: call x86_thiscallcc void %[[VFUN_VALUE]](%struct.ChildOverride* %[[CHILD]])
// CHECK: ret
}

void call_right_no_override(ChildNoOverride *child) {
// CHECK: define void @"\01?call_right_no_override
// CHECK: %[[CHILD:.*]] = load %struct.ChildNoOverride

  child->right();
// When calling a right base's virtual method, one needs to adjust 'this' at
// the caller site.
//
// CHECK: %[[CHILD_i8:.*]] = bitcast %struct.ChildNoOverride* %[[CHILD]] to i8*
// CHECK: %[[RIGHT_i8:.*]] = getelementptr inbounds i8* %[[CHILD_i8]], i32 4
// CHECK: %[[RIGHT:.*]] = bitcast i8* %[[RIGHT_i8]] to %struct.Right*
//
// CHECK: %[[VFPTR:.*]] = bitcast %struct.Right* %[[RIGHT]] to void (%struct.Right*)***
// CHECK: %[[VFTABLE:.*]] = load void (%struct.Right*)*** %[[VFPTR]]
// CHECK: %[[VFUN:.*]] = getelementptr inbounds void (%struct.Right*)** %[[VFTABLE]], i64 0
// CHECK: %[[VFUN_VALUE:.*]] = load void (%struct.Right*)** %[[VFUN]]
// CHECK: call x86_thiscallcc void %[[VFUN_VALUE]](%struct.Right* %[[RIGHT]])
// CHECK: ret
}

void ChildOverride::right() {
// CHECK: define x86_thiscallcc void @"\01?right@ChildOverride@@UAEXXZ"(i8*
//
// ChildOverride::right gets 'this' cast to Right* in ECX (i.e. this+4) so we
// need to adjust 'this' before use.
//
// CHECK: %[[THIS_ADDR:.*]] = alloca %struct.ChildOverride*, align 4
// CHECK: %[[THIS_i8:.*]] = getelementptr i8* %[[ECX:.*]], i64 -4
// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.ChildOverride*
// CHECK: store %struct.ChildOverride* %[[THIS]], %struct.ChildOverride** %[[THIS_ADDR]], align 4

  foo(this);
// CHECK: %[[THIS:.*]] = load %struct.ChildOverride** %[[THIS_ADDR]]
// CHECK: %[[THIS_PARAM:.*]] = bitcast %struct.ChildOverride* %[[THIS]] to i8*
// CHECK: call void @foo(i8* %[[THIS_PARAM]])
// CHECK: ret
}

void call_right_override(ChildOverride *child) {
// CHECK: define void @"\01?call_right_override
// CHECK: %[[CHILD:.*]] = load %struct.ChildOverride

  child->right();
// When calling a right child's virtual method, one needs to adjust 'this' at
// the caller site.
//
// CHECK: %[[CHILD_i8:.*]] = bitcast %struct.ChildOverride* %[[CHILD]] to i8*
//
// CHECK: %[[VFPTR_i8:.*]] = getelementptr inbounds i8* %[[CHILD_i8]], i64 4
// CHECK: %[[VFPTR:.*]] = bitcast i8* %[[VFPTR_i8]] to void (i8*)***
// CHECK: %[[VFTABLE:.*]] = load void (i8*)*** %[[VFPTR]]
// CHECK: %[[VFUN:.*]] = getelementptr inbounds void (i8*)** %[[VFTABLE]], i64 0
// CHECK: %[[VFUN_VALUE:.*]] = load void (i8*)** %[[VFUN]]
//
// CHECK: %[[CHILD_i8:.*]] = bitcast %struct.ChildOverride* %[[CHILD]] to i8*
// CHECK: %[[RIGHT:.*]] = getelementptr inbounds i8* %[[CHILD_i8]], i64 4
//
// CHECK: call x86_thiscallcc void %[[VFUN_VALUE]](i8* %[[RIGHT]])
// CHECK: ret
}

struct GrandchildOverride : ChildOverride {
  virtual void right();
};

void GrandchildOverride::right() {
// CHECK: define x86_thiscallcc void @"\01?right@GrandchildOverride@@UAEXXZ"(i8*
//
// CHECK: %[[THIS_ADDR:.*]] = alloca %struct.GrandchildOverride*, align 4
// CHECK: %[[THIS_i8:.*]] = getelementptr i8* %[[ECX:.*]], i64 -4
// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.GrandchildOverride*
// CHECK: store %struct.GrandchildOverride* %[[THIS]], %struct.GrandchildOverride** %[[THIS_ADDR]], align 4

  foo(this);
// CHECK: %[[THIS:.*]] = load %struct.GrandchildOverride** %[[THIS_ADDR]]
// CHECK: %[[THIS_PARAM:.*]] = bitcast %struct.GrandchildOverride* %[[THIS]] to i8*
// CHECK: call void @foo(i8* %[[THIS_PARAM]])
// CHECK: ret
}

void call_grandchild_right(GrandchildOverride *obj) {
  // Just make sure we don't crash.
  obj->right();
}