clang/test/SemaCXX/linkage-spec.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -Wretained-language-linkage -DW_RETAINED_LANGUAGE_LINKAGE  %s
   3 extern "C" {
   4   extern "C" void f(int);
   5 }
   6
   7 extern "C++" {
   8   extern "C++" int& g(int);
   9   float& g();
  10 }
  11 double& g(double);
  12
  13 void test(int x, double d) {
  14   f(x);
  15   float &f1 = g();
  16   int& i1 = g(x);
  17   double& d1 = g(d);
  18 }
  19
  20 extern "C" int foo;
  21 extern "C" int foo;
  22
  23 extern "C" const int bar;
  24 extern "C" int const bar;
  25
  26 extern "C" struct bar d;
  27 extern struct bar e;
  28
  29 extern "C++" {
  30   namespace N0 {
  31     struct X0 {
  32       int foo(int x) { return x; }
  33     };
  34   }
  35 }
  36
  37 // PR5430
  38 namespace pr5430 {
  39   extern "C" void func(void);
  40 }
  41 using namespace pr5430;
  42 extern "C" void pr5430::func(void) { }
  43
  44 // PR5405
  45 int f2(char *)
  46 {
  47         return 0;
  48 }
  49
  50 extern "C"
  51 {
  52     int f2(int)
  53     {
  54         return f2((char *)0);
  55     }
  56 }
  57
  58 namespace PR5405 {
  59   int f2b(char *) {
  60     return 0;
  61   }
  62
  63   extern "C" {
  64     int f2b(int) {
  65       return f2b((char *)0); // ok
  66     }
  67   }
  68 }
  69
  70 // PR6991
  71 extern "C" typedef int (*PutcFunc_t)(int);
  72
  73
  74 // PR7859
  75 extern "C" void pr7859_a(int) {} // expected-note {{previous definition}}
  76 extern "C" void pr7859_a(int) {} // expected-error {{redefinition}}
  77
  78 extern "C" void pr7859_b() {} // expected-note {{previous definition}}
  79 extern "C" void pr7859_b(int) {} // expected-error {{conflicting}}
  80
  81 extern "C" void pr7859_c(short) {} // expected-note {{previous definition}}
  82 extern "C" void pr7859_c(int) {} // expected-error {{conflicting}}
  83
  84 extern "C" {
  85   struct s0 {
  86   private:
  87     s0();
  88     s0(const s0 &);
  89   };
  90 }
  91
  92 //PR7754
  93 extern "C++" template <class T> int pr7754(T param);
  94
  95 namespace N {
  96   int value;
  97 }
  98
  99 extern "C++" using N::value;
 100
 101 // PR7076
 102 extern "C" const char *Version_string = "2.9";
 103
 104 extern "C" {
 105   extern const char *Version_string2 = "2.9";
 106 }
 107
 108 namespace PR9162 {
 109   extern "C" {
 110     typedef struct _ArtsSink ArtsSink;
 111     struct _ArtsSink {
 112       int sink;
 113     };
 114   }
 115   int arts_sink_get_type()
 116   {
 117     return sizeof(ArtsSink);
 118   }
 119 }
 120
 121 namespace pr14958 {
 122   namespace js { extern int ObjectClass; }
 123   extern "C" {
 124     namespace js {}
 125   }
 126   int js::ObjectClass;
 127 }
 128
 129 extern "C" void PR16167; // expected-error {{variable has incomplete type 'void'}}
 130 extern void PR16167_0; // expected-error {{variable has incomplete type 'void'}}
 131
 132 // PR7927
 133 enum T_7927 {
 134   E_7927
 135 };
 136
 137 extern "C" void f_pr7927(int);
 138
 139 namespace {
 140   extern "C" void f_pr7927(int);
 141
 142   void foo_pr7927() {
 143     f_pr7927(E_7927);
 144     f_pr7927(0);
 145     ::f_pr7927(E_7927);
 146     ::f_pr7927(0);
 147   }
 148 }
 149
 150 void bar_pr7927() {
 151   f_pr7927(E_7927);
 152   f_pr7927(0);
 153   ::f_pr7927(E_7927);
 154   ::f_pr7927(0);
 155 }
 156
 157 namespace PR17337 {
 158   extern "C++" {
 159     class Foo;
 160     extern "C" int bar3(Foo *y);
 161     class Foo {
 162       int x;
 163       friend int bar3(Foo *y);
 164 #ifdef W_RETAINED_LANGUAGE_LINKAGE
 165 // expected-note@-5 {{previous declaration is here}}
 166 // expected-warning@-3 {{retaining previous language linkage}}
 167 #endif
 168     };
 169     extern "C" int bar3(Foo *y) {
 170       return y->x;
 171     }
 172   }
 173 }