clang/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp

   1 // RUN: %clang_cc1 %s -fno-rtti -triple=i386-pc-win32 -emit-llvm -o %t.ll -fdump-vtable-layouts >%t
   2 // RUN: FileCheck %s < %t
   3 // RUN: FileCheck --check-prefix=BITCODE %s < %t.ll
   4
   5 namespace test1 {
   6 struct A {
   7   virtual void g();
   8   // Add an extra virtual method so it's easier to check for the absence of thunks.
   9   virtual void h();
  10 };
  11
  12 struct B {
  13   virtual void g();  // Collides with A::g if both are bases of some class.
  14 };
  15
  16 // Overrides methods of two bases at the same time, thus needing thunks.
  17 struct X : A, B {
  18   // CHECK-LABEL: VFTable for 'test1::A' in 'test1::X' (2 entries).
  19   // CHECK-NEXT:   0 | void test1::X::g()
  20   // CHECK-NEXT:   1 | void test1::A::h()
  21
  22   // CHECK-LABEL: VFTable for 'test1::B' in 'test1::X' (1 entry).
  23   // CHECK-NEXT:   0 | void test1::X::g()
  24   // CHECK-NEXT:       [this adjustment: -4 non-virtual]
  25
  26   // CHECK-LABEL: Thunks for 'void test1::X::g()' (1 entry).
  27   // CHECK-NEXT:   0 | [this adjustment: -4 non-virtual]
  28
  29   // CHECK-LABEL: VFTable indices for 'test1::X' (1 entry).
  30   // CHECK-NEXT:   0 | void test1::X::g()
  31
  32   // BITCODE-DAG: @"??_7X@test1@@6BA@1@@"
  33   // BITCODE-DAG: @"??_7X@test1@@6BB@1@@"
  34
  35   virtual void g();
  36 } x;
  37
  38 void build_vftable(X *obj) { obj->g(); }
  39 }
  40
  41 namespace test2 {
  42 struct A {
  43   virtual void f();
  44 };
  45
  46 struct B {
  47   virtual void g();
  48   virtual void h();
  49 };
  50
  51 struct C {
  52   virtual void g();
  53 };
  54
  55 struct X : A, B, C {
  56   // CHECK-LABEL: VFTable for 'test2::A' in 'test2::X' (1 entry).
  57   // CHECK-NEXT:   0 | void test2::A::f()
  58
  59   // CHECK-LABEL: VFTable for 'test2::B' in 'test2::X' (2 entries).
  60   // CHECK-NEXT:   0 | void test2::X::g()
  61   // CHECK-NEXT:   1 | void test2::B::h()
  62
  63   // CHECK-LABEL: VFTable for 'test2::C' in 'test2::X' (1 entry).
  64   // CHECK-NEXT:   0 | void test2::X::g()
  65   // CHECK-NEXT:       [this adjustment: -4 non-virtual]
  66
  67   // CHECK-LABEL: Thunks for 'void test2::X::g()' (1 entry).
  68   // CHECK-NEXT:   0 | [this adjustment: -4 non-virtual]
  69
  70   // CHECK-LABEL: VFTable indices for 'test2::X' (1 entry).
  71   // CHECK-NEXT:   via vfptr at offset 4
  72   // CHECK-NEXT:   0 | void test2::X::g()
  73
  74   // BITCODE-DAG: @"??_7X@test2@@6BA@1@@"
  75   // BITCODE-DAG: @"??_7X@test2@@6BB@1@@"
  76   // BITCODE-DAG: @"??_7X@test2@@6BC@1@@"
  77
  78   virtual void g();
  79 } x;
  80
  81 void build_vftable(X *obj) { obj->g(); }
  82 }
  83
  84 namespace test3 {
  85 struct A {
  86   virtual void f();
  87 };
  88
  89 struct B {
  90   virtual void g();
  91   virtual void h();
  92 };
  93
  94 struct C: A, B {
  95   // Overrides only the left child's method (A::f), needs no thunks.
  96   virtual void f();
  97 };
  98
  99 struct D: A, B {
 100   // Overrides only the right child's method (B::g),
 101   // needs this adjustment but not thunks.
 102   virtual void g();
 103 };
 104
 105 // Overrides methods of two bases at the same time, thus needing thunks.
 106 struct X: C, D {
 107   // CHECK-LABEL: VFTable for 'test3::A' in 'test3::C' in 'test3::X' (1 entry).
 108   // CHECK-NEXT:   0 | void test3::X::f()
 109
 110   // CHECK-LABEL: VFTable for 'test3::B' in 'test3::C' in 'test3::X' (2 entries).
 111   // CHECK-NEXT:   0 | void test3::X::g()
 112   // CHECK-NEXT:   1 | void test3::B::h()
 113
 114   // CHECK-LABEL: VFTable for 'test3::A' in 'test3::D' in 'test3::X' (1 entry).
 115   // CHECK-NEXT:   0 | void test3::X::f()
 116   // CHECK-NEXT:       [this adjustment: -8 non-virtual]
 117
 118   // CHECK-LABEL: Thunks for 'void test3::X::f()' (1 entry).
 119   // CHECK-NEXT:   0 | [this adjustment: -8 non-virtual]
 120
 121   // CHECK-LABEL: VFTable for 'test3::B' in 'test3::D' in 'test3::X' (2 entries).
 122   // CHECK-NEXT:   0 | void test3::X::g()
 123   // CHECK-NEXT:       [this adjustment: -8 non-virtual]
 124   // CHECK-NEXT:   1 | void test3::B::h()
 125
 126   // CHECK-LABEL: Thunks for 'void test3::X::g()' (1 entry).
 127   // CHECK-NEXT:   0 | [this adjustment: -8 non-virtual]
 128
 129   // CHECK-LABEL: VFTable indices for 'test3::X' (2 entries).
 130   // CHECK-NEXT:   via vfptr at offset 0
 131   // CHECK-NEXT:   0 | void test3::X::f()
 132   // CHECK-NEXT:   via vfptr at offset 4
 133   // CHECK-NEXT:   0 | void test3::X::g()
 134
 135   virtual void f();
 136   virtual void g();
 137 } x;
 138
 139 void build_vftable(X *obj) { obj->g(); }
 140 }
 141
 142 namespace test4 {
 143 struct A {
 144   virtual void foo();
 145 };
 146 struct B {
 147   virtual int filler();
 148   virtual int operator-();
 149   virtual int bar();
 150 };
 151 struct C : public A, public B {
 152   virtual int filler();
 153   virtual int operator-();
 154   virtual int bar();
 155 };
 156
 157 // BITCODE-LABEL: define {{.*}}"?ffun@test4@@YAXAAUC@1@@Z
 158 void ffun(C &c) {
 159   // BITCODE: [[THIS2:%.+]] = getelementptr inbounds i8, ptr {{.*}}, i32 4
 160   // BITCODE: call x86_thiscallcc {{.*}}(ptr noundef [[THIS2]])
 161   c.bar();
 162 }
 163
 164 // BITCODE-LABEL: define {{.*}}"?fop@test4@@YAXAAUC@1@@Z
 165 void fop(C &c) {
 166   // BITCODE: [[THIS2:%.+]] = getelementptr inbounds i8, ptr {{.*}}, i32 4
 167   // BITCODE: call x86_thiscallcc {{.*}}(ptr noundef [[THIS2]])
 168   -c;
 169 }
 170
 171 }
 172
 173 namespace pr30293 {
 174 struct NonTrivial {
 175   ~NonTrivial();
 176   int x;
 177 };
 178 struct A { virtual void f(); };
 179 struct B { virtual void __cdecl g(NonTrivial); };
 180 struct C final : A, B {
 181   void f() override;
 182   void __cdecl g(NonTrivial) override;
 183 };
 184 C *whatsthis;
 185 void C::f() { g(NonTrivial()); }
 186 void C::g(NonTrivial o) {
 187   whatsthis = this;
 188 }
 189
 190 // BITCODE-LABEL: define dso_local void @"?g@C@pr30293@@UAAXUNonTrivial@2@@Z"(ptr inalloca(<{ ptr, %"struct.pr30293::NonTrivial" }>) %0)
 191 // BITCODE: %[[thisaddr:[^ ]*]] = getelementptr inbounds <{ ptr, %"struct.pr30293::NonTrivial" }>, ptr {{.*}}, i32 0, i32 0
 192 // BITCODE: %[[this1:[^ ]*]] = load ptr, ptr %[[thisaddr]], align 4
 193 // BITCODE: %[[this3:[^ ]*]] = getelementptr inbounds i8, ptr %[[this1]], i32 -4
 194 // BITCODE: store ptr %[[this3]], ptr @"?whatsthis@pr30293@@3PAUC@1@A", align 4
 195 }