clang/test/SemaCXX/warn-unused-local-typedef.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -Wunused-local-typedef -verify -std=c++1y %s
   2
   3 struct S {
   4   typedef int Foo;  // no diag
   5 };
   6
   7 namespace N {
   8   typedef int Foo;  // no diag
   9   typedef int Foo2;  // no diag
  10 }
  11
  12 template <class T> class Vec {};
  13
  14 typedef int global_foo;  // no diag
  15
  16 void f() {
  17   typedef int foo0;  // expected-warning {{unused typedef 'foo0'}}
  18   using foo0alias = int ;  // expected-warning {{unused type alias 'foo0alias'}}
  19
  20   typedef int foo1 __attribute__((unused));  // no diag
  21
  22   typedef int foo2;
  23   {
  24     typedef int foo2;  // expected-warning {{unused typedef 'foo2'}}
  25   }
  26   typedef foo2 foo3; // expected-warning {{unused typedef 'foo3'}}
  27
  28   typedef int foo2_2;  // expected-warning {{unused typedef 'foo2_2'}}
  29   {
  30     typedef int foo2_2;
  31     typedef foo2_2 foo3_2; // expected-warning {{unused typedef 'foo3_2'}}
  32   }
  33
  34   typedef int foo4;
  35   foo4 the_thing;
  36
  37   typedef int* foo5;
  38   typedef foo5* foo6;  // no diag
  39   foo6 *myptr;
  40
  41   struct S2 {
  42     typedef int Foo; // no diag
  43     typedef int Foo2; // expected-warning {{unused typedef 'Foo2'}}
  44
  45     struct Deeper {
  46       typedef int DeepFoo;  // expected-warning {{unused typedef 'DeepFoo'}}
  47     };
  48   };
  49
  50   S2::Foo s2foo;
  51
  52   typedef struct {} foostruct; // expected-warning {{unused typedef 'foostruct'}}
  53
  54   typedef struct {} foostruct2; // no diag
  55   foostruct2 fs2;
  56
  57   typedef int vecint;  // no diag
  58   Vec<vecint> v;
  59
  60   N::Foo nfoo;
  61
  62   typedef int ConstExprInt;
  63   static constexpr int a = (ConstExprInt)4;
  64 }
  65
  66 int printf(char const *, ...);
  67
  68 void test() {
  69   typedef signed long int superint; // no diag
  70   printf("%ld", (superint)42);
  71
  72   typedef signed long int superint2; // no diag
  73   printf("%ld", static_cast<superint2>(42));
  74
  75 #pragma clang diagnostic push
  76 #pragma clang diagnostic ignored "-Wunused-local-typedef"
  77   typedef int trungl_bot_was_here; // no diag
  78 #pragma clang diagnostic pop
  79
  80   typedef int foo; // expected-warning {{unused typedef 'foo'}}
  81 }
  82
  83 template <class T>
  84 void template_fun(T t) {
  85   typedef int foo; // expected-warning {{unused typedef 'foo'}}
  86   typedef int bar; // no-diag
  87   bar asdf;
  88
  89   struct S2 {
  90     typedef int Foo; // no diag
  91
  92     typedef int Foo2; // expected-warning {{unused typedef 'Foo2'}}
  93
  94     typedef int Foo3; // no diag
  95   };
  96
  97   typename S2::Foo s2foo;
  98   typename T::Foo s3foo;
  99
 100   typedef typename S2::Foo3 TTSF;  // expected-warning {{unused typedef 'TTSF'}}
 101 }
 102 void template_fun_user() {
 103   struct Local {
 104     typedef int Foo; // no-diag
 105     typedef int Bar; // expected-warning {{unused typedef 'Bar'}}
 106   } p;
 107   template_fun(p);
 108 }
 109
 110 void typedef_in_nested_name() {
 111   typedef struct { // expected-warning {{add a tag name}}
 112     typedef int Foo; // expected-note {{}}
 113   } A; // expected-note {{}}
 114   A::Foo adsf;
 115
 116   using A2 = struct { // expected-warning {{add a tag name}} expected-note {{this alias declaration}}
 117     typedef int Foo; // expected-note {{}}
 118   };
 119   A2::Foo adsf2;
 120 }
 121
 122 auto sneaky() {
 123   struct S {
 124     // Local typedefs can be used after the scope they were in has closed:
 125     typedef int t;
 126
 127     // Even if they aren't, this could be an inline function that could be used
 128     // in another TU, so this shouldn't warn either:
 129     typedef int s;
 130
 131   private:
 132     typedef int p; // expected-warning{{unused typedef 'p'}}
 133   };
 134   return S();
 135 }
 136 auto x = sneaky();
 137 decltype(x)::t y;
 138
 139 static auto static_sneaky() {
 140   struct S {
 141     typedef int t;
 142     // This function has internal linkage, so we can warn:
 143     typedef int s; // expected-warning {{unused typedef 's'}}
 144   };
 145   return S();
 146 }
 147 auto sx = static_sneaky();
 148 decltype(sx)::t sy;
 149
 150 auto sneaky_with_friends() {
 151   struct S {
 152   private:
 153     friend class G;
 154     // Can't warn if we have friends:
 155     typedef int p;
 156   };
 157   return S();
 158 }
 159
 160 namespace {
 161 auto nstatic_sneaky() {
 162   struct S {
 163     typedef int t;
 164     // This function has internal linkage, so we can warn:
 165     typedef int s; // expected-warning {{unused typedef 's'}}
 166   };
 167   return S();
 168 }
 169 auto nsx = nstatic_sneaky();
 170 decltype(nsx)::t nsy;
 171 }
 172
 173 // Like sneaky(), but returning pointer to local type
 174 template<typename T>
 175 struct remove_reference { typedef T type; };
 176 template<typename T> struct remove_reference<T&> { typedef T type; };
 177 auto pointer_sneaky() {
 178   struct S {
 179     typedef int t;
 180     typedef int s;
 181   };
 182   return (S*)nullptr;
 183 }
 184 remove_reference<decltype(*pointer_sneaky())>::type::t py;
 185
 186 // Like sneaky(), but returning templated struct referencing local type.
 187 template <class T> struct container { int a; T t; };
 188 auto template_sneaky() {
 189   struct S {
 190     typedef int t;
 191     typedef int s;
 192   };
 193   return container<S>();
 194 }
 195 auto tx = template_sneaky();
 196 decltype(tx.t)::t ty;
 197
 198 // Like sneaky(), but doing its sneakiness by returning a member function
 199 // pointer.
 200 auto sneaky_memfun() {
 201   struct S {
 202     typedef int type;
 203     int n;
 204   };
 205   return &S::n;
 206 }
 207
 208 template <class T> void sneaky_memfun_g(int T::*p) {
 209   typename T::type X;
 210 }
 211
 212 void sneaky_memfun_h() {
 213   sneaky_memfun_g(sneaky_memfun());
 214 }
 215
 216 void typedefs_in_constructors() {
 217   struct A {};
 218   struct B : public A {
 219     // Neither of these two should warn:
 220     typedef A INHERITED;
 221     B() : INHERITED() {}
 222
 223     typedef B SELF;
 224     B(int) : SELF() {}
 225   };
 226 }
 227
 228 void *operator new(__SIZE_TYPE__, void *p) throw() { return p; }
 229 void placement_new_and_delete() {
 230   struct MyStruct { };
 231   char memory[sizeof(MyStruct)];
 232   void *p = memory;
 233
 234   typedef MyStruct A_t1;
 235   MyStruct *a = new (p) A_t1();
 236
 237   typedef MyStruct A_t2;
 238   a->~A_t2();
 239 }
 240
 241 // This should not disable any warnings:
 242 #pragma clang diagnostic ignored "-Wunused-local-typedef"