test/CodeGenCXX/ms-thunks-unprototyped.cpp

// RUN: %clang_cc1 -fno-rtti-data -triple x86_64-windows-msvc -emit-llvm %s -o - | FileCheck %s

// In this example, C does not override B::foo, but it needs to emit a thunk to
// adjust for the relative difference of position between A-in-B and A-in-C.

struct Incomplete;
template <typename T>
struct DoNotInstantiate {
  typename T::does_not_exist field;
};
template <typename T>
struct InstantiateLater;

struct A {
  virtual void foo(Incomplete p) = 0;
  virtual void bar(DoNotInstantiate<int> p) = 0;
  virtual int baz(InstantiateLater<int> p) = 0;
};
struct B : virtual A {
  void foo(Incomplete p) override;
  void bar(DoNotInstantiate<int> p) override;
  inline int baz(InstantiateLater<int> p) override;
};
struct C : B { int c; };
C c;

// Do the same thing, but with an incomplete return type.
struct B1 { virtual DoNotInstantiate<void> f() = 0; };
struct B2 { virtual DoNotInstantiate<void> f() = 0; };
struct S : B1, B2 { DoNotInstantiate<void> f() override; };
S s;

// CHECK: @"??_7S@@6BB2@@@" = linkonce_odr unnamed_addr constant
// CHECK-SAME: ptr @"?f@S@@W7EAA?AU?$DoNotInstantiate@X@@XZ"

// CHECK: @"??_7C@@6B@" = linkonce_odr unnamed_addr constant
// CHECK-SAME: ptr @"?foo@B@@W7EAAXUIncomplete@@@Z"
// CHECK-SAME: ptr @"?bar@B@@W7EAAXU?$DoNotInstantiate@H@@@Z"
// CHECK-SAME: ptr @"?baz@B@@W7EAAHU?$InstantiateLater@H@@@Z"


// CHECK-LABEL: define linkonce_odr dso_local void @"?f@S@@W7EAA?AU?$DoNotInstantiate@X@@XZ"(ptr noundef %this, ...)
// CHECK: %[[THIS_ADJ_i8:[^ ]*]] = getelementptr i8, ptr {{.*}}, i32 -8
// CHECK: musttail call void (ptr, ...) {{.*}}@"?f@S@@UEAA?AU?$DoNotInstantiate@X@@XZ"
// CHECK-SAME: (ptr noundef %[[THIS_ADJ_i8]], ...)
// CHECK: ret void

// The thunks should have a -8 adjustment.

// CHECK-LABEL: define linkonce_odr dso_local void @"?foo@B@@W7EAAXUIncomplete@@@Z"(ptr noundef %this, ...)
// CHECK: %[[THIS_ADJ_i8:[^ ]*]] = getelementptr i8, ptr {{.*}}, i32 -8
// CHECK: musttail call void (ptr, ...) {{.*}}@"?foo@B@@UEAAXUIncomplete@@@Z"
// CHECK-SAME: (ptr noundef %[[THIS_ADJ_i8]], ...)
// CHECK-NEXT: ret void

// CHECK-LABEL: define linkonce_odr dso_local void @"?bar@B@@W7EAAXU?$DoNotInstantiate@H@@@Z"(ptr noundef %this, ...)
// CHECK: %[[THIS_ADJ_i8:[^ ]*]] = getelementptr i8, ptr {{.*}}, i32 -8
// CHECK: musttail call void (ptr, ...) {{.*}}@"?bar@B@@UEAAXU?$DoNotInstantiate@H@@@Z"
// CHECK-SAME: (ptr noundef %[[THIS_ADJ_i8]], ...)
// CHECK-NEXT: ret void

// If we complete the definition later, things work out.
template <typename T> struct InstantiateLater { T x; };
inline int B::baz(InstantiateLater<int> p) { return p.x; }

// CHECK-LABEL: define linkonce_odr dso_local noundef i32 @"?baz@B@@W7EAAHU?$InstantiateLater@H@@@Z"(ptr noundef %this, i32 %p.coerce)
// CHECK: = getelementptr i8, ptr {{.*}}, i32 -8
// CHECK: tail call noundef i32 @"?baz@B@@UEAAHU?$InstantiateLater@H@@@Z"(ptr {{[^,]*}}, i32 {{.*}})

// CHECK-LABEL: define linkonce_odr dso_local noundef i32 @"?baz@B@@UEAAHU?$InstantiateLater@H@@@Z"(ptr noundef %this, i32 %p.coerce)