clang/test/CodeGenCXX/value-init.cpp

   1 // RUN: %clang_cc1 -std=c++98 %s -triple x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CXX98
   2 // RUN: %clang_cc1 -std=c++17 %s -triple x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-CXX17
   3
   4 struct A {
   5   virtual ~A();
   6 };
   7
   8 struct B : A { };
   9
  10 struct C {
  11   int i;
  12   B b;
  13 };
  14
  15 // CHECK: _Z15test_value_initv
  16 void test_value_init() {
  17   // This value initialization requires zero initialization of the 'B'
  18   // subobject followed by a call to its constructor.
  19   // PR5800
  20
  21   // CHECK: store i32 17
  22   // CHECK: call void @llvm.memset.p0.i64
  23   // CHECK: call void @_ZN1BC1Ev
  24   C c = { 17 } ;
  25   // CHECK: call void @_ZN1CD1Ev
  26 }
  27
  28 enum enum_type { negative_number = -1, magic_number = 42 };
  29
  30 class enum_holder
  31 {
  32   enum_type m_enum;
  33
  34 public:
  35   enum_holder() : m_enum(magic_number) { }
  36 };
  37
  38 struct enum_holder_and_int
  39 {
  40   enum_holder e;
  41   int i;
  42 };
  43
  44 // CHECK: _Z24test_enum_holder_and_intv()
  45 void test_enum_holder_and_int() {
  46   // CHECK: alloca
  47   // CHECK-NEXT: call void @llvm.memset
  48   // CHECK-NEXT: call void @_ZN19enum_holder_and_intC1Ev
  49   enum_holder_and_int();
  50   // CHECK-NEXT: ret void
  51 }
  52
  53 // PR7834: don't crash.
  54 namespace test1 {
  55   struct A {
  56     int A::*f;
  57     A();
  58     A(const A&);
  59     A &operator=(const A &);
  60   };
  61
  62   struct B {
  63     A base;
  64   };
  65
  66   void foo() {
  67     B();
  68   }
  69 }
  70
  71 namespace ptrmem {
  72   struct S {
  73     int mem1;
  74     int S::*mem2;
  75   };
  76
  77   // CHECK-LABEL: define{{.*}} i32 @_ZN6ptrmem4testEPNS_1SE
  78   int test(S *s) {
  79     // CHECK: call void @llvm.memcpy.p0.p0.i64
  80     // CHECK: getelementptr
  81     // CHECK: ret
  82     return s->*S().mem2;
  83   }
  84 }
  85
  86 namespace PR9801 {
  87
  88 struct Test {
  89   Test() : i(10) {}
  90   Test(int i) : i(i) {}
  91   int i;
  92 private:
  93   int j;
  94 };
  95
  96 struct Test2 {
  97   Test t;
  98 };
  99
 100 struct Test3 : public Test { };
 101
 102 // CHECK-LABEL: define{{.*}} void @_ZN6PR98011fEv
 103 void f() {
 104   // CHECK-NOT: call void @llvm.memset.p0.i64
 105   // CHECK: call void @_ZN6PR98014TestC1Ei
 106   // CHECK-NOT: call void @llvm.memset.p0.i64
 107   // CHECK: call void @_ZN6PR98014TestC1Ev
 108   Test partial[3] = { 1 };
 109
 110   // CHECK-NOT: call void @llvm.memset.p0.i64
 111   // CHECK: call void @_ZN6PR98014TestC1Ev
 112   // CHECK-NOT: call void @_ZN6PR98014TestC1Ev
 113   Test empty[3] = {};
 114
 115   // CHECK: call void @llvm.memset.p0.i64
 116   // CHECK-NOT: call void @llvm.memset.p0.i64
 117   // CHECK-CXX98: call void @_ZN6PR98015Test2C1Ev
 118   // CHECK-CXX17: call void @_ZN6PR98014TestC1Ev
 119   // CHECK-NOT: call void @_ZN6PR98015Test2C1Ev
 120   Test2 empty2[3] = {};
 121
 122   // CHECK: call void @llvm.memset.p0.i64
 123   // CHECK-NOT: call void @llvm.memset.p0.i64
 124   // CHECK-CXX98: call void @_ZN6PR98015Test3C1Ev
 125   // CHECK-CXX17: call void @_ZN6PR98014TestC2Ev
 126   // CHECK-NOT: call void @llvm.memset.p0.i64
 127   // CHECK-NOT: call void @_ZN6PR98015Test3C1Ev
 128   Test3 empty3[3] = {};
 129 }
 130
 131 }
 132
 133 namespace zeroinit {
 134   struct S { int i; };
 135
 136   // CHECK-LABEL: define{{.*}} i32 @_ZN8zeroinit4testEv()
 137   int test() {
 138     // CHECK: call void @llvm.memset.p0.i64
 139     // CHECK: ret i32 0
 140     return S().i;
 141   }
 142
 143   struct X0 {
 144     X0() { }
 145     int x;
 146   };
 147
 148   struct X1 : X0 {
 149     int x1;
 150     void f();
 151   };
 152
 153   // CHECK-LABEL: define{{.*}} void @_ZN8zeroinit9testX0_X1Ev
 154   void testX0_X1() {
 155     // CHECK: call void @llvm.memset.p0.i64
 156     // CHECK-NEXT: call void @_ZN8zeroinit2X1C1Ev
 157     // CHECK-NEXT: call void @_ZN8zeroinit2X11fEv
 158     X1().f();
 159   }
 160
 161   template<typename>
 162   struct X2 : X0 {
 163     int x2;
 164     void f();
 165   };
 166
 167   template<typename>
 168   struct X3 : X2<int> {
 169     X3() : X2<int>() { }
 170     int i;
 171   };
 172
 173
 174   // CHECK-LABEL: define{{.*}} void @_ZN8zeroinit9testX0_X3Ev
 175   void testX0_X3() {
 176     // CHECK-NOT: call void @llvm.memset
 177     // CHECK: call void @_ZN8zeroinit2X3IiEC1Ev
 178     // CHECK: call void @_ZN8zeroinit2X2IiE1fEv
 179     // CHECK-NEXT: ret void
 180     X3<int>().f();
 181   }
 182
 183   // More checks at EOF
 184 }
 185
 186 namespace PR8726 {
 187 class C;
 188 struct S {
 189   const C &c1;
 190   int i;
 191   const C &c2;
 192 };
 193 void f(const C& c) {
 194   S s = {c, 42, c};
 195 }
 196
 197 }
 198
 199 // rdar://problem/9355931
 200 namespace test6 {
 201   struct A { A(); A(int); };
 202
 203   void test() {
 204     A arr[10][20] = { 5 };
 205   };
 206   // CHECK-LABEL:    define{{.*}} void @_ZN5test64testEv()
 207   // CHECK:      [[ARR:%.*]] = alloca [10 x [20 x [[A:%.*]]]],
 208
 209   // CHECK-NEXT: [[INNER:%.*]] = getelementptr inbounds [10 x [20 x [[A]]]], ptr [[ARR]], i64 0, i64 0
 210   // CHECK-NEXT: [[T0:%.*]] = getelementptr inbounds [20 x [[A]]], ptr [[INNER]], i64 0, i64 0
 211   // CHECK-NEXT: call void @_ZN5test61AC1Ei(ptr {{[^,]*}} [[T0]], i32 noundef 5)
 212   // CHECK-NEXT: [[BEGIN:%.*]] = getelementptr inbounds [[A]], ptr [[T0]], i64 1
 213   // CHECK-NEXT: [[END:%.*]] = getelementptr inbounds [[A]], ptr [[T0]], i64 20
 214   // CHECK-NEXT: br label
 215   // CHECK:      [[CUR:%.*]] = phi ptr [ [[BEGIN]], {{%.*}} ], [ [[NEXT:%.*]], {{%.*}} ]
 216   // CHECK-NEXT: call void @_ZN5test61AC1Ev(ptr {{[^,]*}} [[CUR]])
 217   // CHECK-NEXT: [[NEXT]] = getelementptr inbounds [[A]], ptr [[CUR]], i64 1
 218   // CHECK-NEXT: [[T0:%.*]] = icmp eq ptr [[NEXT]], [[END]]
 219   // CHECK-NEXT: br i1
 220
 221   // CHECK:      [[BEGIN:%.*]] = getelementptr inbounds [20 x [[A]]], ptr [[INNER]], i64 1
 222   // CHECK-NEXT: [[END:%.*]] = getelementptr inbounds [20 x [[A]]], ptr [[INNER]], i64 10
 223   // CHECK-NEXT: br label
 224   // CHECK:      [[CUR:%.*]] = phi ptr [ [[BEGIN]], {{%.*}} ], [ [[NEXT:%.*]], {{%.*}} ]
 225
 226   // Inner loop.
 227   // CHECK-NEXT: [[IBEGIN:%.*]] = getelementptr inbounds [20 x [[A]]], ptr [[CUR]], i{{32|64}} 0, i{{32|64}} 0
 228   // CHECK-NEXT: [[IEND:%.*]] = getelementptr inbounds [[A]], ptr [[IBEGIN]], i64 20
 229   // CHECK-NEXT: br label
 230   // CHECK:      [[ICUR:%.*]] = phi ptr [ [[IBEGIN]], {{%.*}} ], [ [[INEXT:%.*]], {{%.*}} ]
 231   // CHECK-NEXT: call void @_ZN5test61AC1Ev(ptr {{[^,]*}} [[ICUR]])
 232   // CHECK-NEXT: [[INEXT:%.*]] = getelementptr inbounds [[A]], ptr [[ICUR]], i64 1
 233   // CHECK-NEXT: [[T0:%.*]] = icmp eq ptr [[INEXT]], [[IEND]]
 234   // CHECK-NEXT: br i1 [[T0]],
 235
 236   // CHECK:      [[NEXT]] = getelementptr inbounds [20 x [[A]]], ptr [[CUR]], i64 1
 237   // CHECK-NEXT: [[T0:%.*]] = icmp eq ptr [[NEXT]], [[END]]
 238   // CHECK-NEXT: br i1 [[T0]]
 239   // CHECK:      ret void
 240 }
 241
 242 namespace PR11124 {
 243   // Make sure C::C doesn't overwrite parts of A while it is zero-initializing B
 244   struct A { int a; A(); A(int); };
 245   struct B : virtual A { int b; };
 246   struct C : B { C(); };
 247   C::C() : A(3), B() {}
 248   // CHECK-LABEL: define{{.*}} void @_ZN7PR111241CC1Ev
 249   // CHECK: call void @llvm.memset.p0.i64(ptr align 8 {{.*}}, i8 0, i64 12, i1 false)
 250   // CHECK-NEXT: call void @_ZN7PR111241BC2Ev
 251   // Make sure C::C doesn't overwrite parts of A while it is zero-initializing B
 252
 253   struct B2 : virtual A { int B::*b; };
 254   struct C2 : B2 { C2(); };
 255   C2::C2() : A(3), B2() {}
 256   // CHECK-LABEL: define{{.*}} void @_ZN7PR111242C2C1Ev
 257   // CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 8 %{{.*}}, ptr align 8 {{.*}}, i64 16, i1 false)
 258   // CHECK-NEXT: call void @_ZN7PR111242B2C2Ev
 259 }
 260
 261 // Ensure we produce an i1 here, and don't assert.
 262 // CHECK-LABEL: define{{.*}} void @_Z9r170806_bv(
 263 // CHECK: call void @_Z9r170806_ab(i1 noundef zeroext false)
 264 void r170806_a(bool b = bool());
 265 void r170806_b() { r170806_a(); }
 266
 267 namespace PR20256 {
 268   struct data { int i; };
 269
 270   template<typename T = int>
 271   data g() {
 272     data d; // not value-init
 273     return d;
 274   }
 275   template data g();
 276   // CHECK-LABEL: define {{.*}} @_ZN7PR202561gIiEENS_4dataEv(
 277   // CHECK-NOT: store
 278   // CHECK-NOT: memset
 279   // CHECK: }
 280
 281   template<typename ...T>
 282   data h(T ...t) {
 283     data d(t...); // value-init
 284     return d;
 285   }
 286   template data h();
 287   // CHECK-LABEL: define {{.*}} @_ZN7PR202561hIJEEENS_4dataEDpT_(
 288   // CHECK: call void @llvm.memset
 289   // CHECK: }
 290
 291
 292   template<typename T = int>
 293   data j() {
 294     data d = {}; // value-init
 295     return d;
 296   }
 297   template data j();
 298   // CHECK-LABEL: define {{.*}} @_ZN7PR202561jIiEENS_4dataEv(
 299   // CHECK: call void @llvm.memset
 300   // CHECK: }
 301
 302   data f() {
 303     data d; // not value-init
 304     return d;
 305   }
 306   // CHECK-LABEL: define {{.*}} @_ZN7PR202561fEv(
 307   // CHECK-NOT: store
 308   // CHECK-NOT: memset
 309   // CHECK: }
 310
 311   data i() {
 312     data d = {}; // value-init
 313     return d;
 314   }
 315   // CHECK-LABEL: define {{.*}} @_ZN7PR202561iEv(
 316   // CHECK: call void @llvm.memset
 317   // CHECK: }
 318 }
 319
 320 // CHECK-LABEL: define {{.*}}@_Z20explicitly_defaultedv
 321 int explicitly_defaulted() {
 322   struct A { A() = default; int n; };
 323   // CHECK: call void @llvm.memset
 324   A a = A();
 325   return a.n;
 326 } // CHECK-LABEL: }
 327
 328 // CHECK-LABEL: define linkonce_odr void @_ZN8zeroinit2X3IiEC2Ev(ptr {{[^,]*}} %this) unnamed_addr
 329 // CHECK: call void @llvm.memset.p0.i64
 330 // CHECK-NEXT: call void @_ZN8zeroinit2X2IiEC2Ev
 331 // CHECK-NEXT: ret void
 332
 333 #if __cplusplus >= 201103L
 334 namespace transparent_init_list {
 335   struct optional_assign_base {};
 336   struct optional_data_dtor_base { char dummy_[24]; };
 337   struct optional : optional_data_dtor_base, optional_assign_base {};
 338   optional f(optional a) { return {optional(a)}; }
 339 }
 340 #endif