clang/test/SemaCXX/cxx98-compat.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wc++98-compat -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -std=c++14 -Wc++98-compat -verify %s -DCXX14COMPAT
   3 // RUN: %clang_cc1 -fsyntax-only -std=c++17 -Wc++98-compat -verify %s -DCXX14COMPAT -DCXX17COMPAT
   4
   5 namespace std {
   6   struct type_info;
   7   using size_t = decltype(sizeof(0)); // expected-warning {{decltype}} expected-warning {{alias}}
   8   template<typename T> struct initializer_list {
   9     initializer_list(const T*, size_t);
  10     const T *p;
  11     size_t n;
  12     const T *begin();
  13     const T *end();
  14   };
  15 }
  16
  17 template<typename ...T>  // expected-warning {{variadic templates are incompatible with C++98}}
  18 class Variadic1 {};
  19
  20 template<template<typename> class ...T>  // expected-warning {{variadic templates are incompatible with C++98}}
  21 class Variadic2 {};
  22
  23 template<int ...I>  // expected-warning {{variadic templates are incompatible with C++98}}
  24 class Variadic3 {};
  25
  26 alignas(8) int with_alignas; // expected-warning {{'alignas' is incompatible with C++98}}
  27 int with_attribute [[ ]]; // expected-warning {{[[]] attributes are incompatible with C++ standards before C++11}}
  28
  29 void Literals() {
  30   (void)u8"str"; // expected-warning {{unicode literals are incompatible with C++98}}
  31   (void)u"str"; // expected-warning {{unicode literals are incompatible with C++98}}
  32   (void)U"str"; // expected-warning {{unicode literals are incompatible with C++98}}
  33   (void)u'x'; // expected-warning {{unicode literals are incompatible with C++98}}
  34   (void)U'x'; // expected-warning {{unicode literals are incompatible with C++98}}
  35
  36   (void)u8R"X(str)X"; // expected-warning {{raw string literals are incompatible with C++98}}
  37   (void)uR"X(str)X"; // expected-warning {{raw string literals are incompatible with C++98}}
  38   (void)UR"X(str)X"; // expected-warning {{raw string literals are incompatible with C++98}}
  39   (void)R"X(str)X"; // expected-warning {{raw string literals are incompatible with C++98}}
  40   (void)LR"X(str)X"; // expected-warning {{raw string literals are incompatible with C++98}}
  41 }
  42
  43 template<typename T> struct S {};
  44 namespace TemplateParsing {
  45   S<::S<void> > s; // expected-warning {{'<::' is treated as digraph '<:' (aka '[') followed by ':' in C++98}}
  46   S< ::S<void>> t; // expected-warning {{consecutive right angle brackets are incompatible with C++98 (use '> >')}}
  47 }
  48
  49 void Lambda() {
  50   []{}(); // expected-warning {{lambda expressions are incompatible with C++98}}
  51   // Don't warn about implicit "-> auto" here.
  52   [](){}(); // expected-warning {{lambda expressions are incompatible with C++98}}
  53 }
  54
  55 struct Ctor {
  56   Ctor(int, char);
  57   Ctor(double, long);
  58 };
  59 struct InitListCtor {
  60   InitListCtor(std::initializer_list<bool>);
  61 };
  62
  63 int InitList(int i = {}) { // expected-warning {{generalized initializer lists are incompatible with C++98}} \
  64                            // expected-warning {{scalar initialized from empty initializer list is incompatible with C++98}}
  65   (void)new int {}; // expected-warning {{generalized initializer lists are incompatible with C++98}} \
  66                     // expected-warning {{scalar initialized from empty initializer list is incompatible with C++98}}
  67   (void)int{}; // expected-warning {{generalized initializer lists are incompatible with C++98}} \
  68                // expected-warning {{scalar initialized from empty initializer list is incompatible with C++98}}
  69   int x { 0 }; // expected-warning {{generalized initializer lists are incompatible with C++98}}
  70   S<int> s = {}; // ok, aggregate
  71   s = {}; // expected-warning {{generalized initializer lists are incompatible with C++98}}
  72   std::initializer_list<int> xs = { 1, 2, 3 }; // expected-warning {{initialization of initializer_list object is incompatible with C++98}}
  73   auto ys = { 1, 2, 3 }; // expected-warning {{initialization of initializer_list object is incompatible with C++98}} \
  74                          // expected-warning {{'auto' type specifier is incompatible with C++98}}
  75   Ctor c1 = { 1, 2 }; // expected-warning {{constructor call from initializer list is incompatible with C++98}}
  76   Ctor c2 = { 3.0, 4l }; // expected-warning {{constructor call from initializer list is incompatible with C++98}}
  77   InitListCtor ilc = { true, false }; // expected-warning {{initialization of initializer_list object is incompatible with C++98}}
  78   const int &r = { 0 }; // expected-warning {{reference initialized from initializer list is incompatible with C++98}}
  79   struct { int a; const int &r; } rr = { 0, {0} }; // expected-warning {{reference initialized from initializer list is incompatible with C++98}}
  80   return { 0 }; // expected-warning {{generalized initializer lists are incompatible with C++98}} expected-warning {{scalar}}
  81 }
  82 struct DelayedDefaultArgumentParseInitList {
  83   void f(int i = {1}) { // expected-warning {{generalized initializer lists are incompatible with C++98}} expected-warning {{scalar}}
  84   }
  85 };
  86
  87 int operator""_hello(const char *); // expected-warning {{literal operators are incompatible with C++98}}
  88
  89 enum EnumFixed : int { // expected-warning {{enumeration types with a fixed underlying type are incompatible with C++98}}
  90 };
  91
  92 enum class EnumScoped { // expected-warning {{scoped enumerations are incompatible with C++98}}
  93 };
  94
  95 void Deleted() = delete; // expected-warning {{deleted function definitions are incompatible with C++98}}
  96 struct Defaulted {
  97   Defaulted() = default; // expected-warning {{defaulted function definitions are incompatible with C++98}}
  98 };
  99
 100 int &&RvalueReference = 0; // expected-warning {{rvalue references are incompatible with C++98}}
 101 struct RefQualifier {
 102   void f() &; // expected-warning {{reference qualifiers on functions are incompatible with C++98}}
 103 };
 104
 105 auto f() -> int; // expected-warning {{trailing return types are incompatible with C++98}}
 106 #ifdef CXX14COMPAT
 107 auto ff() { return 5; } // expected-warning {{'auto' type specifier is incompatible with C++98}}
 108 // expected-warning@-1 {{return type deduction is incompatible with C++ standards before C++14}}
 109 #endif
 110
 111 void RangeFor() {
 112   int xs[] = {1, 2, 3};
 113   for (int &a : xs) { // expected-warning {{range-based for loop is incompatible with C++98}}
 114   }
 115   for (auto &b : {1, 2, 3}) {
 116   // expected-warning@-1 {{range-based for loop is incompatible with C++98}}
 117   // expected-warning@-2 {{'auto' type specifier is incompatible with C++98}}
 118   // expected-warning@-3 {{initialization of initializer_list object is incompatible with C++98}}
 119   // expected-warning@-4 {{reference initialized from initializer list is incompatible with C++98}}
 120   }
 121   struct Agg { int a, b; } const &agg = { 1, 2 }; // expected-warning {{reference initialized from initializer list is incompatible with C++98}}
 122 }
 123
 124 struct InClassInit {
 125   int n = 0; // expected-warning {{default member initializer for non-static data members is incompatible with C++98}}
 126 };
 127
 128 struct OverrideControlBase {
 129   virtual void f();
 130   virtual void g();
 131 };
 132 struct OverrideControl final : OverrideControlBase { // expected-warning {{'final' keyword is incompatible with C++98}}
 133   virtual void f() override; // expected-warning {{'override' keyword is incompatible with C++98}}
 134   virtual void g() final; // expected-warning {{'final' keyword is incompatible with C++98}}
 135 };
 136
 137 using AliasDecl = int; // expected-warning {{alias declarations are incompatible with C++98}}
 138 template<typename T> using AliasTemplate = T; // expected-warning {{alias declarations are incompatible with C++98}}
 139
 140 inline namespace InlineNS { // expected-warning {{inline namespaces are incompatible with C++98}}
 141 }
 142
 143 auto auto_deduction = 0; // expected-warning {{'auto' type specifier is incompatible with C++98}}
 144 int *p = new auto(0); // expected-warning {{'auto' type specifier is incompatible with C++98}}
 145
 146 const int align_of = alignof(int); // expected-warning {{alignof expressions are incompatible with C++98}}
 147 char16_t c16 = 0; // expected-warning {{'char16_t' type specifier is incompatible with C++98}}
 148 char32_t c32 = 0; // expected-warning {{'char32_t' type specifier is incompatible with C++98}}
 149 constexpr int const_expr = 0; // expected-warning {{'constexpr' specifier is incompatible with C++98}}
 150 decltype(const_expr) decl_type = 0; // expected-warning {{'decltype' type specifier is incompatible with C++98}}
 151 __decltype(const_expr) decl_type2 = 0; // ok
 152 void no_except() noexcept; // expected-warning {{noexcept specifications are incompatible with C++98}}
 153 bool no_except_expr = noexcept(1 + 1); // expected-warning {{noexcept expressions are incompatible with C++98}}
 154 void *null = nullptr; // expected-warning {{'nullptr' is incompatible with C++98}}
 155 static_assert(true, "!"); // expected-warning {{'static_assert' declarations are incompatible with C++98}}
 156
 157 struct InhCtorBase {
 158   InhCtorBase(int);
 159 };
 160 struct InhCtorDerived : InhCtorBase {
 161   using InhCtorBase::InhCtorBase; // expected-warning {{inheriting constructors are incompatible with C++98}}
 162 };
 163
 164 struct FriendMember {
 165   static void MemberFn();
 166   friend void FriendMember::MemberFn(); // expected-warning {{friend declaration naming a member of the declaring class is incompatible with C++98}}
 167 };
 168
 169 struct DelegCtor {
 170   DelegCtor(int) : DelegCtor() {} // expected-warning {{delegating constructors are incompatible with C++98}}
 171   DelegCtor();
 172 };
 173
 174 template<int n = 0> void DefaultFuncTemplateArg(); // expected-warning {{default template arguments for a function template are incompatible with C++98}}
 175
 176 template<typename T> int TemplateFn(T) { return 0; }
 177 void LocalTemplateArg() {
 178   struct S {};
 179   TemplateFn(S()); // expected-warning {{local type 'S' as template argument is incompatible with C++98}}
 180 }
 181 struct {} obj_of_unnamed_type; // expected-note {{here}}
 182 int UnnamedTemplateArg = TemplateFn(obj_of_unnamed_type); // expected-warning {{unnamed type as template argument is incompatible with C++98}}
 183
 184 // FIXME: We do not implement C++98 compatibility warnings for the C++17
 185 // template argument evaluation rules.
 186 #ifndef CXX17COMPAT
 187 namespace RedundantParensInAddressTemplateParam {
 188   int n;
 189   template<int*p> struct S {};
 190   S<(&n)> s; // expected-warning {{redundant parentheses surrounding address non-type template argument are incompatible with C++98}}
 191   S<(((&n)))> t; // expected-warning {{redundant parentheses surrounding address non-type template argument are incompatible with C++98}}
 192 }
 193 #endif
 194
 195 namespace TemplateSpecOutOfScopeNs {
 196   template<typename T> struct S {};
 197 }
 198 template<> struct TemplateSpecOutOfScopeNs::S<char> {};
 199
 200 struct Typename {
 201   template<typename T> struct Inner {};
 202 };
 203 typename ::Typename TypenameOutsideTemplate(); // expected-warning {{use of 'typename' outside of a template is incompatible with C++98}}
 204 Typename::template Inner<int> TemplateOutsideTemplate(); // expected-warning {{use of 'template' keyword outside of a template is incompatible with C++98}}
 205
 206 struct TrivialButNonPOD {
 207   int f(int);
 208 private:
 209   int k;
 210 };
 211 void Ellipsis(int n, ...);
 212 void TrivialButNonPODThroughEllipsis() {
 213   Ellipsis(1, TrivialButNonPOD()); // expected-warning {{passing object of trivial but non-POD type 'TrivialButNonPOD' through variadic function is incompatible with C++98}}
 214 }
 215
 216 struct HasExplicitConversion {
 217   explicit operator bool(); // expected-warning {{explicit conversion functions are incompatible with C++98}}
 218 };
 219
 220 struct Struct {};
 221 enum Enum { enum_val = 0 };
 222 struct BadFriends {
 223   friend enum ::Enum; // expected-warning {{elaborated enum specifier cannot be declared as a friend}}
 224                       // expected-note@-1 {{remove 'enum' to befriend an enum}}
 225   friend int; // expected-warning {{non-class friend type 'int' is incompatible with C++98}}
 226   friend Struct; // expected-warning {{befriending 'Struct' without 'struct' keyword is incompatible with C++98}}
 227 };
 228
 229 int n = {}; // expected-warning {{scalar initialized from empty initializer list is incompatible with C++98}}
 230
 231 class PrivateMember {
 232   struct ImPrivate {};
 233 };
 234 template<typename T> typename T::ImPrivate SFINAEAccessControl(T t) { // expected-warning {{substitution failure due to access control is incompatible with C++98}}
 235   return typename T::ImPrivate();
 236 }
 237 int SFINAEAccessControl(...) { return 0; }
 238 int CheckSFINAEAccessControl = SFINAEAccessControl(PrivateMember()); // expected-note {{while substituting deduced template arguments into function template 'SFINAEAccessControl' [with T = PrivateMember]}}
 239
 240 namespace UnionOrAnonStructMembers {
 241   struct NonTrivCtor {
 242     NonTrivCtor(); // expected-note 2{{user-provided default constructor}}
 243   };
 244   struct NonTrivCopy {
 245     NonTrivCopy(const NonTrivCopy&); // expected-note 2{{user-provided copy constructor}}
 246   };
 247   struct NonTrivDtor {
 248     ~NonTrivDtor(); // expected-note 2{{user-provided destructor}}
 249   };
 250   union BadUnion {
 251     NonTrivCtor ntc; // expected-warning {{union member 'ntc' with a non-trivial default constructor is incompatible with C++98}}
 252     NonTrivCopy ntcp; // expected-warning {{union member 'ntcp' with a non-trivial copy constructor is incompatible with C++98}}
 253     NonTrivDtor ntd; // expected-warning {{union member 'ntd' with a non-trivial destructor is incompatible with C++98}}
 254   };
 255   struct Wrap {
 256     struct {
 257       NonTrivCtor ntc; // expected-warning {{anonymous struct member 'ntc' with a non-trivial default constructor is incompatible with C++98}}
 258       NonTrivCopy ntcp; // expected-warning {{anonymous struct member 'ntcp' with a non-trivial copy constructor is incompatible with C++98}}
 259       NonTrivDtor ntd; // expected-warning {{anonymous struct member 'ntd' with a non-trivial destructor is incompatible with C++98}}
 260     };
 261   };
 262   union WithStaticDataMember {
 263     static constexpr double d = 0.0; // expected-warning {{static data member 'd' in union is incompatible with C++98}} expected-warning {{'constexpr' specifier is incompatible with C++98}}
 264     static const int n = 0; // expected-warning {{static data member 'n' in union is incompatible with C++98}}
 265     static int k; // expected-warning {{static data member 'k' in union is incompatible with C++98}}
 266   };
 267 }
 268
 269 int EnumNNS = Enum::enum_val; // expected-warning {{enumeration type in nested name specifier is incompatible with C++98}}
 270 template<typename T> void EnumNNSFn() {
 271   int k = T::enum_val; // expected-warning {{enumeration type in nested name specifier is incompatible with C++98}}
 272 };
 273 template void EnumNNSFn<Enum>(); // expected-note {{in instantiation}}
 274
 275 void JumpDiagnostics(int n) {
 276   goto DirectJump; // expected-warning {{jump from this goto statement to its label is incompatible with C++98}}
 277   TrivialButNonPOD tnp1; // expected-note {{jump bypasses initialization of non-POD variable}}
 278
 279 DirectJump:
 280   void *Table[] = {&&DirectJump, &&Later};
 281   goto *Table[n]; // expected-warning {{jump from this indirect goto statement to one of its possible targets is incompatible with C++98}}
 282
 283   TrivialButNonPOD tnp2; // expected-note {{jump bypasses initialization of non-POD variable}}
 284 Later: // expected-note {{possible target of indirect goto statement}}
 285   switch (n) {
 286     TrivialButNonPOD tnp3; // expected-note {{jump bypasses initialization of non-POD variable}}
 287   default: // expected-warning {{jump from switch statement to this case label is incompatible with C++98}}
 288     return;
 289   }
 290 }
 291
 292 namespace UnevaluatedMemberAccess {
 293   struct S {
 294     int n;
 295     int f() { return sizeof(S::n); } // ok
 296   };
 297   int k = sizeof(S::n); // expected-warning {{use of non-static data member 'n' in an unevaluated context is incompatible with C++98}}
 298   const std::type_info &ti = typeid(S::n); // expected-warning {{use of non-static data member 'n' in an unevaluated context is incompatible with C++98}}
 299 }
 300
 301 namespace LiteralUCNs {
 302   char c1 = '\u001e'; // expected-warning {{universal character name referring to a control character is incompatible with C++98}}
 303   wchar_t c2 = L'\u0041'; // expected-warning {{specifying character 'A' with a universal character name is incompatible with C++98}}
 304   const char *s1 = "foo\u0031"; // expected-warning {{specifying character '1' with a universal character name is incompatible with C++98}}
 305   const wchar_t *s2 = L"bar\u0085"; // expected-warning {{universal character name referring to a control character is incompatible with C++98}}
 306 }
 307
 308 // FIXME: We do not implement C++98 compatibility warnings for the C++17
 309 // template argument evaluation rules.
 310 #ifndef CXX17COMPAT
 311 namespace NonTypeTemplateArgs {
 312   template<typename T, T v> struct S {};
 313   const int k = 5; // expected-note {{here}}
 314   static void f() {} // expected-note {{here}}
 315   S<const int&, k> s1; // expected-warning {{non-type template argument referring to object 'k' with internal linkage is incompatible with C++98}}
 316   S<void(&)(), f> s2; // expected-warning {{non-type template argument referring to function 'f' with internal linkage is incompatible with C++98}}
 317 }
 318
 319 namespace NullPointerTemplateArg {
 320   struct A {};
 321   template<int*> struct X {};
 322   template<int A::*> struct Y {};
 323   X<(int*)0> x; // expected-warning {{use of null pointer as non-type template argument is incompatible with C++98}}
 324   Y<(int A::*)0> y; // expected-warning {{use of null pointer as non-type template argument is incompatible with C++98}}
 325 }
 326 #endif
 327
 328 namespace PR13480 {
 329   struct basic_iterator {
 330     basic_iterator(const basic_iterator &it) {} // expected-note {{because type 'PR13480::basic_iterator' has a user-provided copy constructor}}
 331     basic_iterator(basic_iterator &it) {}
 332   };
 333
 334   union test {
 335     basic_iterator it; // expected-warning {{union member 'it' with a non-trivial copy constructor is incompatible with C++98}}
 336   };
 337 }
 338
 339 namespace AssignOpUnion {
 340   struct a {
 341     void operator=(const a &it) {} // expected-note {{because type 'AssignOpUnion::a' has a user-provided copy assignment operator}}
 342     void operator=(a &it) {}
 343   };
 344
 345   struct b {
 346     void operator=(const b &it) {} // expected-note {{because type 'AssignOpUnion::b' has a user-provided copy assignment operator}}
 347   };
 348
 349   union test1 {
 350     a x; // expected-warning {{union member 'x' with a non-trivial copy assignment operator is incompatible with C++98}}
 351     b y; // expected-warning {{union member 'y' with a non-trivial copy assignment operator is incompatible with C++98}}
 352   };
 353 }
 354
 355 namespace rdar11736429 {
 356   struct X { // expected-note {{because type 'rdar11736429::X' has no default constructor}}
 357     X(const X&) = delete; // expected-warning{{deleted function definitions are incompatible with C++98}} \
 358     // expected-note {{implicit default constructor suppressed by user-declared constructor}}
 359   };
 360
 361   union S {
 362     X x; // expected-warning{{union member 'x' with a non-trivial default constructor is incompatible with C++98}}
 363   };
 364 }
 365
 366 template<typename T> T var = T(10);
 367 #ifdef CXX14COMPAT
 368 // expected-warning@-2 {{variable templates are incompatible with C++ standards before C++14}}
 369 #else
 370 // expected-warning@-4 {{variable templates are a C++14 extension}}
 371 #endif
 372
 373 // No diagnostic for specializations of variable templates; we will have
 374 // diagnosed the primary template.
 375 template<typename T> T* var<T*> = new T();
 376 template<> int var<int> = 10;
 377 template char var<char>;
 378 float fvar = var<float>;
 379
 380 class A {
 381   template<typename T> static T var = T(10);
 382 #ifdef CXX14COMPAT
 383 // expected-warning@-2 {{variable templates are incompatible with C++ standards before C++14}}
 384 #else
 385 // expected-warning@-4 {{variable templates are a C++14 extension}}
 386 #endif
 387
 388   template<typename T> static T* var<T*> = new T();
 389 };
 390
 391 struct B {  template<typename T> static T v; };
 392 #ifdef CXX14COMPAT
 393 // expected-warning@-2 {{variable templates are incompatible with C++ standards before C++14}}
 394 #else
 395 // expected-warning@-4 {{variable templates are a C++14 extension}}
 396 #endif
 397
 398 template<typename T> T B::v = T();
 399 #ifdef CXX14COMPAT
 400 // expected-warning@-2 {{variable templates are incompatible with C++ standards before C++14}}
 401 #else
 402 // expected-warning@-4 {{variable templates are a C++14 extension}}
 403 #endif
 404
 405 template<typename T> T* B::v<T*> = new T();
 406 template<> int B::v<int> = 10;
 407 template char B::v<char>;
 408 float fsvar = B::v<float>;
 409
 410 #ifdef CXX14COMPAT
 411 int digit_seps = 123'456; // expected-warning {{digit separators are incompatible with C++ standards before C++14}}
 412 #endif
 413
 414 #ifdef CXX17COMPAT
 415 template<class T> struct CTAD {};
 416 void ctad_test() {
 417   CTAD<int> s;
 418   CTAD t = s; // expected-warning {{class template argument deduction is incompatible with C++ standards before C++17}}
 419 }
 420 #endif