clang/test/SemaCXX/builtins.cpp

   1 // RUN: %clang_cc1 %s -fsyntax-only -verify -std=c++11 -fcxx-exceptions -fptrauth-intrinsics
   2 // RUN: %clang_cc1 %s -fsyntax-only -verify -std=c++1z -fcxx-exceptions -fptrauth-intrinsics
   3 typedef const struct __CFString * CFStringRef;
   4 #define CFSTR __builtin___CFStringMakeConstantString
   5 #define NSSTR __builtin___NSStringMakeConstantString
   6
   7 void f() {
   8 #if !defined(__MVS__) && !defined(_AIX)
   9   // Builtin function __builtin___CFStringMakeConstantString is currently
  10   // unsupported on z/OS and AIX.
  11   (void)CFStringRef(CFSTR("Hello"));
  12
  13   constexpr bool a = CFSTR("Hello") == CFSTR("Hello");
  14   // expected-error@-1 {{constant expression}}
  15   // expected-note@-2 {{comparison against opaque constant address '&__builtin___CFStringMakeConstantString("Hello")'}}
  16   constexpr bool b = NSSTR("Hello") == NSSTR("Hello");
  17   // expected-error@-1 {{constant expression}}
  18   // expected-note@-2 {{comparison against opaque constant address '&__builtin___NSStringMakeConstantString("Hello")'}}
  19 #endif
  20 }
  21
  22 void a() { __builtin_va_list x, y; ::__builtin_va_copy(x, y); }
  23
  24 template<int (*Compare)(const char *s1, const char *s2)>
  25 int equal(const char *s1, const char *s2) {
  26   return Compare(s1, s2) == 0;
  27 }
  28 template int equal<&__builtin_strcmp>(const char*, const char*); // expected-error {{builtin functions must be directly called}}
  29
  30 // PR13195
  31 void f2() {
  32   __builtin_isnan; // expected-error {{builtin functions must be directly called}}
  33 }
  34
  35 // pr14895
  36 typedef __typeof(sizeof(int)) size_t;
  37 extern "C" void *__builtin_alloca (size_t);
  38
  39 namespace addressof {
  40   struct S {} s;
  41   static_assert(__builtin_addressof(s) == &s, "");
  42
  43   struct T { constexpr T *operator&() const { return nullptr; } int n; } t;
  44   constexpr T *pt = __builtin_addressof(t);
  45   static_assert(&pt->n == &t.n, "");
  46
  47   struct U { int n : 5; } u;
  48   int *pbf = __builtin_addressof(u.n); // expected-error {{address of bit-field requested}}
  49
  50   S *ptmp = __builtin_addressof(S{}); // expected-error {{taking the address of a temporary}} expected-warning {{temporary whose address is used as value of local variable 'ptmp' will be destroyed at the end of the full-expression}}
  51 }
  52
  53 namespace function_start {
  54 void a(void) {}
  55 int n;
  56 void *p = __builtin_function_start(n);               // expected-error {{argument must be a function}}
  57 static_assert(__builtin_function_start(a) == a, ""); // expected-error {{static assertion expression is not an integral constant expression}}
  58 // expected-note@-1 {{comparison against opaque constant address '&__builtin_function_start(a)'}}
  59 } // namespace function_start
  60
  61 void no_ms_builtins() {
  62   __assume(1); // expected-error {{use of undeclared}}
  63   __noop(1); // expected-error {{use of undeclared}}
  64   __debugbreak(); // expected-error {{use of undeclared}}
  65 }
  66
  67 struct FILE;
  68 extern "C" int vfprintf(FILE *__restrict, const char *__restrict,
  69                         __builtin_va_list va);
  70
  71 void synchronize_args() {
  72   __sync_synchronize(0); // expected-error {{too many arguments}}
  73 }
  74
  75 namespace test_launder {
  76 #define TEST_TYPE(Ptr, Type) \
  77   static_assert(__is_same(decltype(__builtin_launder(Ptr)), Type), "expected same type")
  78
  79 struct Dummy {};
  80
  81 using FnType = int(char);
  82 using MemFnType = int (Dummy::*)(char);
  83 using ConstMemFnType = int (Dummy::*)() const;
  84
  85 void foo() {}
  86
  87 void test_builtin_empty_parentheses_diags() {
  88   __is_trivially_copyable(); // expected-error {{expected a type}}
  89   __is_trivially_copyable(1); // expected-error {{expected a type}}
  90 }
  91
  92 void test_builtin_launder_diags(void *vp, const void *cvp, FnType *fnp,
  93                                 MemFnType mfp, ConstMemFnType cmfp, int (&Arr)[5]) {
  94   __builtin_launder(vp);   // expected-error {{void pointer argument to '__builtin_launder' is not allowed}}
  95   __builtin_launder(cvp);  // expected-error {{void pointer argument to '__builtin_launder' is not allowed}}
  96   __builtin_launder(fnp);  // expected-error {{function pointer argument to '__builtin_launder' is not allowed}}
  97   __builtin_launder(mfp);  // expected-error {{non-pointer argument to '__builtin_launder' is not allowed}}
  98   __builtin_launder(cmfp); // expected-error {{non-pointer argument to '__builtin_launder' is not allowed}}
  99   (void)__builtin_launder(&fnp);
 100   __builtin_launder(42);      // expected-error {{non-pointer argument to '__builtin_launder' is not allowed}}
 101   __builtin_launder(nullptr); // expected-error {{non-pointer argument to '__builtin_launder' is not allowed}}
 102   __builtin_launder(foo);     // expected-error {{function pointer argument to '__builtin_launder' is not allowed}}
 103   (void)__builtin_launder(Arr);
 104 }
 105
 106 void test_builtin_launder(char *p, const volatile int *ip, const float *&fp,
 107                           double *__restrict dp) {
 108   int x;
 109   __builtin_launder(x); // expected-error {{non-pointer argument to '__builtin_launder' is not allowed}}
 110
 111   TEST_TYPE(p, char*);
 112   TEST_TYPE(ip, const volatile int*);
 113   TEST_TYPE(fp, const float*);
 114   TEST_TYPE(dp, double *__restrict);
 115
 116   char *d = __builtin_launder(p);
 117   const volatile int *id = __builtin_launder(ip);
 118   int *id2 = __builtin_launder(ip); // expected-error {{cannot initialize a variable of type 'int *' with an rvalue of type 'const volatile int *'}}
 119   const float* fd = __builtin_launder(fp);
 120 }
 121
 122 void test_launder_return_type(const int (&ArrayRef)[101], int (&MArrRef)[42][13],
 123                               void (**&FuncPtrRef)()) {
 124   TEST_TYPE(ArrayRef, const int *);
 125   TEST_TYPE(MArrRef, int(*)[13]);
 126   TEST_TYPE(FuncPtrRef, void (**)());
 127 }
 128
 129 template <class Tp>
 130 constexpr Tp *test_constexpr_launder(Tp *tp) {
 131   return __builtin_launder(tp);
 132 }
 133 constexpr int const_int = 42;
 134 constexpr int const_int2 = 101;
 135 constexpr const int *const_ptr = test_constexpr_launder(&const_int);
 136 static_assert(&const_int == const_ptr, "");
 137 static_assert(const_ptr != test_constexpr_launder(&const_int2), "");
 138
 139 void test_non_constexpr() {
 140   constexpr int i = 42;                            // expected-note {{address of non-static constexpr variable 'i' may differ on each invocation}}
 141   constexpr const int *ip = __builtin_launder(&i); // expected-error {{constexpr variable 'ip' must be initialized by a constant expression}}
 142   // expected-note@-1 {{pointer to 'i' is not a constant expression}}
 143 }
 144
 145 constexpr bool test_in_constexpr(const int &i) {
 146   return (__builtin_launder(&i) == &i);
 147 }
 148
 149 static_assert(test_in_constexpr(const_int), "");
 150 void f() {
 151   constexpr int i = 42;
 152   static_assert(test_in_constexpr(i), "");
 153 }
 154
 155 struct Incomplete; // expected-note {{forward declaration}}
 156 struct IncompleteMember {
 157   Incomplete &i;
 158 };
 159 void test_incomplete(Incomplete *i, IncompleteMember *im) {
 160   // expected-error@+1 {{incomplete type 'Incomplete' where a complete type is required}}
 161   __builtin_launder(i);
 162   __builtin_launder(&i); // OK
 163   __builtin_launder(im); // OK
 164 }
 165
 166 void test_noexcept(int *i) {
 167   static_assert(noexcept(__builtin_launder(i)), "");
 168 }
 169 #undef TEST_TYPE
 170 } // end namespace test_launder
 171
 172 template<typename T> void test_builtin_complex(T v, double d) {
 173   (void)__builtin_complex(v, d); // expected-error {{different types}} expected-error {{not a real floating}}
 174   (void)__builtin_complex(d, v); // expected-error {{different types}} expected-error {{not a real floating}}
 175   (void)__builtin_complex(v, v); // expected-error {{not a real floating}}
 176 }
 177 template void test_builtin_complex(double, double);
 178 template void test_builtin_complex(float, double); // expected-note {{instantiation of}}
 179 template void test_builtin_complex(int, double); // expected-note {{instantiation of}}
 180
 181 #ifdef __x86_64__
 182 // This previously would cause an assertion when emitting the note diagnostic.
 183 static void __builtin_cpu_init(); // expected-error {{static declaration of '__builtin_cpu_init' follows non-static declaration}} \
 184                                      expected-note {{'__builtin_cpu_init' is a builtin with type 'void () noexcept'}}
 185 #endif
 186
 187 #ifdef _MSC_VER
 188 constexpr int x = [] {
 189   __noop;
 190   return 0;
 191 }(); // expected-no-diagnostics
 192 static_assert([] { return __noop; }() == 0);
 193 static_assert([] { return __noop(4); }() == 0);
 194 extern int not_accessed;
 195 void not_called();
 196 static_assert([] { return __noop(not_accessed *= 6); }() == 0);
 197 static_assert([] { return __noop(not_called()); }() == 0);
 198 static_assert([] { return __noop(throw ""); }() == 0);
 199 static_assert([] { return __noop(throw "", throw ""); }() == 0);
 200 static_assert([] {
 201   int a = 5;
 202   __noop(++a);
 203   return a;
 204 }() == 5);
 205 #endif