clang/test/CodeGenCXX/derived-to-base-conv.cpp

   1 // RUN: %clang_cc1 -triple x86_64-apple-darwin -std=c++11 -emit-llvm %s -o - | FileCheck %s
   2
   3 struct A {
   4   A(const A&);
   5   A();
   6   ~A();
   7 };
   8
   9 struct B : public A {
  10   B();
  11   B(const B& Other);
  12   ~B();
  13 };
  14
  15 struct C : public B {
  16   C();
  17   C(const C& Other);
  18   ~C();
  19 };
  20
  21 struct X {
  22   operator B&();
  23   operator C&();
  24   X(const X&);
  25   X();
  26   ~X();
  27   B b;
  28   C c;
  29 };
  30
  31 void test0_helper(A);
  32 void test0(X x) {
  33   test0_helper(x);
  34   // CHECK-LABEL:    define{{.*}} void @_Z5test01X(
  35   // CHECK-SAME: ptr noundef [[ARG:%.*]])
  36   // CHECK:      [[ARG_ADDR:%.*]] = alloca ptr
  37   // CHECK-NEXT: [[TMP:%.*]] = alloca [[A:%.*]], align
  38   // CHECK-NEXT: store ptr [[ARG]], ptr [[ARG_ADDR]]
  39   // CHECK-NEXT: [[T0:%.*]] = call noundef nonnull align {{[0-9]+}} dereferenceable({{[0-9]+}}) ptr @_ZN1XcvR1BEv(
  40   // CHECK-NEXT: call void @_ZN1AC1ERKS_(ptr {{[^,]*}} [[TMP]], ptr noundef nonnull align {{[0-9]+}} dereferenceable({{[0-9]+}}) [[T0]])
  41   // CHECK-NEXT: call void @_Z12test0_helper1A(ptr noundef [[TMP]])
  42   // CHECK-NEXT: call void @_ZN1AD1Ev(ptr {{[^,]*}} [[TMP]])
  43   // CHECK-NEXT: ret void
  44 }
  45
  46 struct Base;
  47
  48 struct Root {
  49   operator Base&();
  50 };
  51
  52 struct Derived;
  53
  54 struct Base : Root {
  55   Base(const Base &);
  56   Base();
  57   operator Derived &();
  58 };
  59
  60 struct Derived : Base {
  61 };
  62
  63 void test1_helper(Base);
  64 void test1(Derived bb) {
  65   // CHECK-LABEL:     define{{.*}} void @_Z5test17Derived(
  66   // CHECK-NOT: call {{.*}} @_ZN4BasecvR7DerivedEv(
  67   // CHECK:     call void @_ZN4BaseC1ERKS_(
  68   // CHECK-NOT: call {{.*}} @_ZN4BasecvR7DerivedEv(
  69   // CHECK:     call void @_Z12test1_helper4Base(
  70   test1_helper(bb);
  71 }
  72
  73 // Don't crash after devirtualizing a derived-to-base conversion
  74 // to an empty base allocated at offset zero.
  75 // rdar://problem/11993704
  76 class Test2a {};
  77 class Test2b final : public virtual Test2a {};
  78 void test2(Test2b &x) {
  79   Test2a &y = x;
  80   // CHECK-LABEL:    define{{.*}} void @_Z5test2R6Test2b(
  81   // CHECK:      [[X:%.*]] = alloca ptr, align 8
  82   // CHECK-NEXT: [[Y:%.*]] = alloca ptr, align 8
  83   // CHECK-NEXT: store ptr {{%.*}}, ptr [[X]], align 8
  84   // CHECK-NEXT: [[T0:%.*]] = load ptr, ptr [[X]], align 8
  85   // CHECK-NEXT: store ptr [[T0]], ptr [[Y]], align 8
  86   // CHECK-NEXT: ret void
  87 }