clang/test/SemaCXX/offsetof.cpp

   1 // RUN: %clang_cc1 -triple x86_64-apple-darwin10.0.0 -fsyntax-only -verify %s -Winvalid-offsetof -std=c++98
   2 // RUN: %clang_cc1 -triple x86_64-apple-darwin10.0.0 -fsyntax-only -verify %s -Winvalid-offsetof -std=c++98 -fexperimental-new-constant-interpreter
   3
   4 struct NonPOD {
   5   virtual void f();
   6   int m;
   7 };
   8
   9 struct P {
  10   NonPOD fieldThatPointsToANonPODType;
  11 };
  12
  13 void f() {
  14   int i = __builtin_offsetof(P, fieldThatPointsToANonPODType.m); // expected-warning{{offset of on non-POD type 'P'}}
  15 }
  16
  17 struct Base { int x; };
  18 struct Derived : Base { int y; };
  19 int o = __builtin_offsetof(Derived, x); // expected-warning{{offset of on non-POD type}}
  20
  21 const int o2 = sizeof(__builtin_offsetof(Derived, x));
  22
  23 struct HasArray {
  24   int array[17];
  25 };
  26
  27 // Constant and non-constant offsetof expressions
  28 void test_ice(int i) {
  29   int array0[__builtin_offsetof(HasArray, array[5])];
  30   int array1[__builtin_offsetof(HasArray, array[i])]; // expected-warning {{variable length arrays in C++ are a Clang extension}}
  31 }
  32
  33 // Bitfields
  34 struct has_bitfields {
  35   int i : 7;
  36   int j : 12; // expected-note{{bit-field is declared here}}
  37 };
  38
  39 int test3 = __builtin_offsetof(struct has_bitfields, j); // expected-error{{cannot compute offset of bit-field 'j'}}
  40
  41 // offsetof referring to members of a base class.
  42 struct Base1 {
  43   int x;
  44 };
  45
  46 struct Base2 {
  47   int y;
  48 };
  49
  50 struct Derived2 : public Base1, public Base2 {
  51   int z;
  52 };
  53
  54 int derived1[__builtin_offsetof(Derived2, x) == 0? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
  55 int derived2[__builtin_offsetof(Derived2, y)  == 4? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
  56 int derived3[__builtin_offsetof(Derived2, z)  == 8? 1 : -1]; // expected-warning{{offset of on non-POD type 'Derived2'}}
  57
  58 // offsetof referring to anonymous struct in base.
  59 // PR7769
  60 struct foo {
  61     struct {
  62         int x;
  63     };
  64 };
  65
  66 struct bar : public foo  {
  67 };
  68
  69 int anonstruct[__builtin_offsetof(bar, x) == 0 ? 1 : -1]; // expected-warning{{offset of on non-POD type 'bar'}}
  70
  71
  72 struct LtoRCheck {
  73   int a[10];
  74   int f();
  75 };
  76 int ltor = __builtin_offsetof(struct LtoRCheck, a[LtoRCheck().f]); // \
  77   expected-error {{reference to non-static member function must be called}}
  78
  79 namespace PR17578 {
  80 struct Base {
  81   int Field;
  82 };
  83 struct Derived : virtual Base {
  84   void Fun() { (void)__builtin_offsetof(Derived, Field); } // expected-warning {{offset of on non-POD type}} \
  85                                                               expected-error {{invalid application of 'offsetof' to a field of a virtual base}}
  86 };
  87 }
  88
  89 int test_definition(void) {
  90   return __builtin_offsetof(struct A // expected-error {{'A' cannot be defined in a type specifier}}
  91   {
  92     int a;
  93     struct B // FIXME: error diagnostic message for nested definitions
  94              // https://reviews.llvm.org/D133574
  95              // fixme-error{{'A' cannot be defined in '__builtin_offsetof'}}
  96     {
  97       int c;
  98       int d;
  99     };
 100     B x;
 101   }, a);
 102 }