clang/test/CodeGenCXX/microsoft-abi-vtables-return-thunks.cpp

   1 // RUN: %clang_cc1 -fno-rtti %s -emit-llvm -o %t -triple=i386-pc-win32 -fdump-vtable-layouts 2>&1 | FileCheck --check-prefix=VFTABLES %s
   2 // RUN: FileCheck --check-prefix=GLOBALS %s < %t
   3 // RUN: FileCheck --check-prefix=CODEGEN %s < %t
   4
   5 namespace test1 {
   6
   7 // Some covariant types.
   8 struct A { int a; };
   9 struct B { int b; };
  10 struct C : A, B { int c; };
  11 struct D : C { int d; };
  12 struct E : D { int e; };
  13
  14 // One base class and two overrides, all with covariant return types.
  15 struct H     { virtual B *foo(); };
  16 struct I : H { virtual C *foo(); };
  17 struct J : I { virtual D *foo(); J(); };
  18 struct K : J { virtual E *foo(); K(); };
  19
  20 J::J() {}
  21
  22 // VFTABLES-LABEL: VFTable for 'test1::H' in 'test1::I' in 'test1::J' (3 entries).
  23 // VFTABLES-NEXT:   0 | test1::D *test1::J::foo()
  24 // VFTABLES-NEXT:       [return adjustment (to type 'struct test1::B *'): 4 non-virtual]
  25 // VFTABLES-NEXT:   1 | test1::D *test1::J::foo()
  26 // VFTABLES-NEXT:       [return adjustment (to type 'struct test1::C *'): 0 non-virtual]
  27 // VFTABLES-NEXT:   2 | test1::D *test1::J::foo()
  28
  29 // GLOBALS-LABEL: @"??_7J@test1@@6B@" = linkonce_odr unnamed_addr constant { [3 x i8*] }
  30 // GLOBALS: @"?foo@J@test1@@QAEPAUB@2@XZ"
  31 // GLOBALS: @"?foo@J@test1@@QAEPAUC@2@XZ"
  32 // GLOBALS: @"?foo@J@test1@@UAEPAUD@2@XZ"
  33
  34 K::K() {}
  35
  36 // VFTABLES-LABEL: VFTable for 'test1::H' in 'test1::I' in 'test1::J' in 'test1::K' (4 entries).
  37 // VFTABLES-NEXT:   0 | test1::E *test1::K::foo()
  38 // VFTABLES-NEXT:       [return adjustment (to type 'struct test1::B *'): 4 non-virtual]
  39 // VFTABLES-NEXT:   1 | test1::E *test1::K::foo()
  40 // VFTABLES-NEXT:       [return adjustment (to type 'struct test1::C *'): 0 non-virtual]
  41 // VFTABLES-NEXT:   2 | test1::E *test1::K::foo()
  42 // VFTABLES-NEXT:       [return adjustment (to type 'struct test1::D *'): 0 non-virtual]
  43 // VFTABLES-NEXT:   3 | test1::E *test1::K::foo()
  44
  45 // Only B to C requires adjustment, but we get 3 thunks in K's vftable, two of
  46 // which are trivial.
  47 // GLOBALS-LABEL: @"??_7K@test1@@6B@" = linkonce_odr unnamed_addr constant { [4 x i8*] }
  48 // GLOBALS: @"?foo@K@test1@@QAEPAUB@2@XZ"
  49 // GLOBALS: @"?foo@K@test1@@QAEPAUC@2@XZ"
  50 // GLOBALS: @"?foo@K@test1@@QAEPAUD@2@XZ"
  51 // GLOBALS: @"?foo@K@test1@@UAEPAUE@2@XZ"
  52
  53 //  This thunk has a return adjustment.
  54 // CODEGEN-LABEL: define {{.*}} @"?foo@K@test1@@QAEPAUB@2@XZ"
  55 // CODEGEN: call {{.*}} @"?foo@K@test1@@UAEPAUE@2@XZ"
  56 // CODEGEN: icmp {{.*}}, null
  57 // CODEGEN: getelementptr
  58 // CODEGEN: ret
  59
  60 //  These two don't.
  61 // CODEGEN-LABEL: define {{.*}} @"?foo@K@test1@@QAEPAUC@2@XZ"
  62 // CODEGEN: call {{.*}} @"?foo@K@test1@@UAEPAUE@2@XZ"
  63 // CODEGEN-NEXT: ret
  64
  65 // CODEGEN-LABEL: define {{.*}} @"?foo@K@test1@@QAEPAUD@2@XZ"
  66 // CODEGEN: call {{.*}} @"?foo@K@test1@@UAEPAUE@2@XZ"
  67 // CODEGEN-NEXT: ret
  68
  69 }
  70
  71 namespace test2 {
  72
  73 // Covariant types.  D* is not trivially convertible to C*.
  74 struct A { int a; };
  75 struct B { int b; };
  76 struct C : B { int c; };
  77 struct D : A, C { int d; };
  78 struct E : D { int e; };
  79
  80 // J's foo will require an adjusting thunk, and K will require a trivial thunk.
  81 struct H     { virtual B *foo(); };
  82 struct I : H { virtual C *foo(); };
  83 struct J : I { virtual D *foo(); J(); };
  84 struct K : J { virtual E *foo(); K(); };
  85
  86 J::J() {}
  87
  88 // VFTABLES-LABEL: VFTable for 'test2::H' in 'test2::I' in 'test2::J' (2 entries).
  89 // VFTABLES-NEXT:    0 | test2::D *test2::J::foo()
  90 // VFTABLES-NEXT:         [return adjustment (to type 'struct test2::B *'): 4 non-virtual]
  91 // VFTABLES-NEXT:    1 | test2::D *test2::J::foo()
  92
  93 // GLOBALS-LABEL: @"??_7J@test2@@6B@" = linkonce_odr unnamed_addr constant { [2 x i8*] }
  94
  95 K::K() {}
  96
  97 // VFTABLES-LABEL: VFTable for 'test2::H' in 'test2::I' in 'test2::J' in 'test2::K' (3 entries).
  98 // VFTABLES-NEXT:    0 | test2::E *test2::K::foo()
  99 // VFTABLES-NEXT:         [return adjustment (to type 'struct test2::B *'): 4 non-virtual]
 100 // VFTABLES-NEXT:    1 | test2::E *test2::K::foo()
 101 // VFTABLES-NEXT:         [return adjustment (to type 'struct test2::D *'): 0 non-virtual]
 102 // VFTABLES-NEXT:    2 | test2::E *test2::K::foo()
 103
 104 // GLOBALS-LABEL: @"??_7K@test2@@6B@" = linkonce_odr unnamed_addr constant { [3 x i8*] }
 105
 106 }
 107
 108 namespace pr20479 {
 109 struct A {
 110   virtual A *f();
 111 };
 112
 113 struct B : virtual A {
 114   virtual B *f();
 115 };
 116
 117 struct C : virtual A, B {
 118 // VFTABLES-LABEL: VFTable for 'pr20479::A' in 'pr20479::B' in 'pr20479::C' (2 entries).
 119 // VFTABLES-NEXT:   0 | pr20479::B *pr20479::B::f()
 120 // VFTABLES-NEXT:       [return adjustment (to type 'struct pr20479::A *'): vbase #1, 0 non-virtual]
 121 // VFTABLES-NEXT:   1 | pr20479::B *pr20479::B::f()
 122   C();
 123 };
 124
 125 C::C() {}
 126
 127 // GLOBALS-LABEL: @"??_7C@pr20479@@6B@" = linkonce_odr unnamed_addr constant { [2 x i8*] }
 128 // GLOBALS: @"?f@B@pr20479@@QAEPAUA@2@XZ"
 129 // GLOBALS: @"?f@B@pr20479@@UAEPAU12@XZ"
 130 }
 131
 132 namespace pr21073 {
 133 struct A {
 134   virtual A *f();
 135 };
 136
 137 struct B : virtual A {
 138   virtual B *f();
 139 };
 140
 141 struct C : virtual A, virtual B {
 142 // VFTABLES-LABEL: VFTable for 'pr21073::A' in 'pr21073::B' in 'pr21073::C' (2 entries).
 143 // VFTABLES-NEXT:   0 | pr21073::B *pr21073::B::f()
 144 // VFTABLES-NEXT:       [return adjustment (to type 'struct pr21073::A *'): vbase #1, 0 non-virtual]
 145 // VFTABLES-NEXT:       [this adjustment: 8 non-virtual]
 146 // VFTABLES-NEXT:   1 | pr21073::B *pr21073::B::f()
 147 // VFTABLES-NEXT:       [return adjustment (to type 'struct pr21073::B *'): 0 non-virtual]
 148 // VFTABLES-NEXT:       [this adjustment: 8 non-virtual]
 149   C();
 150 };
 151
 152 C::C() {}
 153
 154 // GLOBALS-LABEL: @"??_7C@pr21073@@6B@" = linkonce_odr unnamed_addr constant { [2 x i8*] }
 155 // GLOBALS: @"?f@B@pr21073@@WPPPPPPPI@AEPAUA@2@XZ"
 156 // GLOBALS: @"?f@B@pr21073@@WPPPPPPPI@AEPAU12@XZ"
 157 }
 158
 159 namespace pr21073_2 {
 160 struct A { virtual A *foo(); };
 161 struct B : virtual A {};
 162 struct C : virtual A { virtual C *foo(); };
 163 struct D : B, C { D(); };
 164 D::D() {}
 165
 166 // VFTABLES-LABEL: VFTable for 'pr21073_2::A' in 'pr21073_2::C' in 'pr21073_2::D' (2 entries)
 167 // VFTABLES-NEXT:   0 | pr21073_2::C *pr21073_2::C::foo()
 168 // VFTABLES-NEXT:       [return adjustment (to type 'struct pr21073_2::A *'): vbase #1, 0 non-virtual]
 169 // VFTABLES-NEXT:   1 | pr21073_2::C *pr21073_2::C::foo()
 170
 171 // GLOBALS-LABEL: @"??_7D@pr21073_2@@6B@" = {{.*}} constant { [2 x i8*] }
 172 // GLOBALS: @"?foo@C@pr21073_2@@QAEPAUA@2@XZ"
 173 // GLOBALS: @"?foo@C@pr21073_2@@UAEPAU12@XZ"
 174 }
 175
 176 namespace test3 {
 177 struct A { virtual A *fn(); };
 178 struct B : virtual A { virtual B *fn(); };
 179 struct X : virtual B {};
 180 struct Y : virtual B {};
 181 struct C : X, Y {};
 182 struct D : virtual B, virtual A, C {
 183   D *fn();
 184   D();
 185 };
 186 D::D() {}
 187
 188 // VFTABLES-LABEL: VFTable for 'test3::A' in 'test3::B' in 'test3::X' in 'test3::C' in 'test3::D' (3 entries).
 189 // VFTABLES-NEXT:   0 | test3::D *test3::D::fn()
 190 // VFTABLES-NEXT:       [return adjustment (to type 'struct test3::A *'): vbase #1, 0 non-virtual]
 191 // VFTABLES-NEXT:       [this adjustment: vtordisp at -4, 0 non-virtual]
 192 // VFTABLES-NEXT:   1 | test3::D *test3::D::fn()
 193 // VFTABLES-NEXT:       [return adjustment (to type 'struct test3::B *'): vbase #2, 0 non-virtual]
 194 // VFTABLES-NEXT:       [this adjustment: vtordisp at -4, 0 non-virtual]
 195 // VFTABLES-NEXT:   2 | test3::D *test3::D::fn()
 196 // VFTABLES-NEXT:       [return adjustment (to type 'struct test3::D *'): 0 non-virtual]
 197 // VFTABLES-NEXT:       [this adjustment: vtordisp at -4, 0 non-virtual]
 198
 199 // GLOBALS-LABEL: @"??_7D@test3@@6B@" = {{.*}} constant { [3 x i8*] }
 200 // GLOBALS: @"?fn@D@test3@@$4PPPPPPPM@A@AEPAUA@2@XZ"
 201 // GLOBALS: @"?fn@D@test3@@$4PPPPPPPM@A@AEPAUB@2@XZ"
 202 // GLOBALS: @"?fn@D@test3@@$4PPPPPPPM@A@AEPAU12@XZ"
 203 }
 204
 205 namespace pr34302 {
 206 // C::f is lives in the vftable inside its virtual B subobject. In the MS ABI,
 207 // covariant return type virtual methods extend vftables from virtual bases,
 208 // even though that can make it impossible to implement certain diamond
 209 // hierarchies correctly.
 210 struct A { virtual ~A(); };
 211 struct B : A { virtual B *f(); };
 212 struct C : virtual B { C *f(); };
 213 C c;
 214 // VFTABLES-LABEL: VFTable indices for 'pr34302::C' (2 entries).
 215 // VFTABLES-NEXT:  -- accessible via vbtable index 1, vfptr at offset 0 --
 216 // VFTABLES-NEXT:    0 | pr34302::C::~C() [scalar deleting]
 217 // VFTABLES-NEXT:    2 | pr34302::C *pr34302::C::f()
 218 }