clang/test/CXX/basic/basic.link/p8.cpp

   1 // RUN: %clang_cc1 -std=c++2a -verify %s -pedantic
   2
   3 template<typename T> struct Template {};
   4
   5 struct Linkage1 { struct Inner {}; };
   6 typedef struct { struct Inner {}; } Linkage2;
   7
   8 typedef struct {} const NoLinkage1;
   9 auto x = [] {};
  10 typedef decltype(x) NoLinkage2;
  11 auto f() { return [] {}; }
  12 typedef decltype(f()) NoLinkage3;
  13
  14 inline auto g() { return [] {}; }
  15 typedef decltype(g()) VisibleNoLinkage1;
  16 inline auto y = [] {};
  17 typedef decltype(y) VisibleNoLinkage2;
  18 inline auto h() { struct {} x; return x; }
  19 typedef decltype(h()) VisibleNoLinkage3;
  20
  21 extern Linkage1 linkage1v;
  22 extern Linkage1::Inner linkage1iv;
  23 extern Linkage2 linkage2v;
  24 extern Linkage2::Inner linkage2iv;
  25 extern Template<Linkage1> linkaget1v;
  26 extern Linkage1 linkage1f();
  27 void linkage2f(Linkage2);
  28
  29 void use_linkage() {
  30   &linkage1v, &linkage1iv, &linkage2v, &linkage2iv, &linkaget1v; // expected-warning 4{{left operand of comma operator has no effect}} expected-warning {{unused}}
  31   linkage1f();
  32   linkage2f({});
  33 }
  34
  35 extern NoLinkage1 no_linkage1(); // expected-error {{function 'no_linkage1' is used but not defined in this translation unit}}
  36 extern NoLinkage2 no_linkage2(); // expected-error {{function 'no_linkage2' is used but not defined in this translation unit}}
  37 extern NoLinkage3 no_linkage3(); // expected-error {{function 'no_linkage3' is used but not defined in this translation unit}}
  38
  39 void use_no_linkage() {
  40   no_linkage1(); // expected-note {{used here}}
  41   no_linkage2(); // expected-note {{used here}}
  42   no_linkage3(); // expected-note {{used here}}
  43 }
  44
  45 extern VisibleNoLinkage1 visible_no_linkage1(); // expected-warning {{ISO C++ requires a definition}}
  46 extern VisibleNoLinkage2 visible_no_linkage2(); // expected-warning {{ISO C++ requires a definition}}
  47 extern VisibleNoLinkage3 visible_no_linkage3(); // expected-warning {{ISO C++ requires a definition}}
  48
  49 void use_visible_no_linkage() {
  50   visible_no_linkage1(); // expected-note {{used here}}
  51   visible_no_linkage2(); // expected-note {{used here}}
  52   visible_no_linkage3(); // expected-note {{used here}}
  53 }
  54
  55 namespace {
  56   struct InternalLinkage {};
  57 }
  58 InternalLinkage internal_linkage(); // expected-error {{used but not defined}}
  59 void use_internal_linkage() {
  60   internal_linkage(); // expected-note {{used here}}
  61 }
  62
  63 extern inline int not_defined; // expected-error {{not defined}}
  64 extern inline int defined_after_use;
  65 void use_inline_vars() {
  66   not_defined = 1; // expected-note {{used here}}
  67   defined_after_use = 2;
  68 }
  69 inline int defined_after_use;
  70
  71 namespace {
  72   template<typename T> struct A {
  73     static const int n;
  74   };
  75   template<typename T> const int A<T>::n = 3;
  76   static_assert(A<int>::n == 3);
  77   int k = A<float>::n;
  78 }