clang/test/CodeGenCXX/class-layout.cpp

   1 // RUN: %clang_cc1 %s -triple x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s
   2
   3 // An extra byte should be allocated for an empty class.
   4 namespace Test1 {
   5   // CHECK: %"struct.Test1::A" = type { i8 }
   6   struct A { } a;
   7 }
   8
   9 namespace Test2 {
  10   // No need to add tail padding here.
  11   // CHECK: %"struct.Test2::A" = type { ptr, i32 }
  12   struct A { void *a; int b; } a;
  13 }
  14
  15 namespace Test3 {
  16   // C should have a vtable pointer.
  17   // CHECK: %"struct.Test3::A" = type <{ ptr, i32, [4 x i8] }>
  18   struct A { virtual void f(); int a; } a;
  19 }
  20
  21 namespace Test4 {
  22   // Test from PR5589.
  23   // CHECK: %"struct.Test4::B" = type { %"struct.Test4::A", i16, double }
  24   // CHECK: %"struct.Test4::A" = type { i32, i8, float }
  25   struct A {
  26     int a;
  27     char c;
  28     float b;
  29   };
  30   struct B : public A {
  31     short d;
  32     double e;
  33   } b;
  34 }
  35
  36 namespace Test5 {
  37   struct A {
  38     virtual void f();
  39     char a;
  40   };
  41
  42   // CHECK: %"struct.Test5::B" = type {  %"struct.Test5::A.base", i8, i8, [5 x i8] }
  43   struct B : A {
  44     char b : 1;
  45     char c;
  46   } b;
  47 }
  48
  49 // PR10912: don't crash
  50 namespace Test6 {
  51   template <typename T> class A {
  52     // If T is complete, IR-gen will want to translate it recursively
  53     // when translating T*.
  54     T *foo;
  55   };
  56
  57   class B;
  58
  59   // This causes IR-gen to have an incomplete translation of A<B>
  60   // sitting around.
  61   A<B> *a;
  62
  63   class C {};
  64   class B : public C {
  65     // This forces Sema to instantiate A<B>, which triggers a callback
  66     // to IR-gen.  Because of the previous, incomplete translation,
  67     // IR-gen actually cares, and it immediately tries to complete
  68     // A<B>'s IR type.  That, in turn, causes the translation of B*.
  69     // B isn't complete yet, but it has a definition, and if we try to
  70     // compute a record layout for that definition then we'll really
  71     // regret it later.
  72     A<B> a;
  73   };
  74
  75   // The derived class E and empty base class C are required to
  76   // provoke the original assertion.
  77   class E : public B {};
  78   E *e;
  79 }
  80
  81 // Make sure this doesn't crash. (It's okay if we start rejecting it at some
  82 // point.)
  83 namespace Test7 {
  84   #pragma pack (1)
  85   class A {};
  86   // CHECK: %"class.Test7::B" = type <{ ptr, %"class.Test7::A" }>
  87   class B {
  88      virtual ~B();
  89      A a;
  90   };
  91   B test(B b) { return b; }
  92   #pragma pack ()
  93 }
  94
  95 // Shouldn't crash.
  96 namespace Test8 {
  97   struct A {};
  98   struct D { int a; };
  99   struct B : virtual D, A { };
 100   struct C : B, A { void f() {} };
 101   C c;
 102 }