clang/test/CodeGenCXX/cxx1y-variable-template-linkage.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -std=c++1y -O1 -disable-llvm-passes %s -o - | FileCheck %s -check-prefix=CHECKA -check-prefix=CHECK
   2 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -std=c++1y -O1 -disable-llvm-passes -fcxx-exceptions %s -o - | FileCheck %s -check-prefix=CHECKB -check-prefix=CHECK
   3 // expected-no-diagnostics
   4
   5 // The variable template specialization x<Foo> generated in each file
   6 // should be 'internal global' and not 'linkonce_odr global'.
   7
   8 template <typename T> int x = 42;
   9 // CHECK-DAG: @_Z1xIiE = linkonce_odr global
  10 // CHECK-DAG: @_Z1xIZL3foovE3FooE = internal global
  11
  12 // 'static' affects the linkage of the global
  13 template <typename T> static int y = 42;
  14 // CHECK-DAG: @_ZL1yIiE = internal global
  15 // CHECK-DAG: @_ZL1yIZL3foovE3FooE = internal global
  16
  17 // 'const' does not
  18 template <typename T> const int z = 42;
  19 // CHECK-DAG: @_Z1zIiE = linkonce_odr constant
  20 // CHECK-DAG: @_Z1zIZL3foovE3FooE = internal constant
  21
  22 template <typename T> T t = 42;
  23 // CHECK-DAG: @_Z1tIiE = linkonce_odr global
  24 // CHECK-DAG: @_Z1tIKiE = linkonce_odr constant
  25
  26 int mode;
  27
  28 // CHECK-DAG: define internal noundef nonnull align 4 dereferenceable(4) ptr @_ZL3foov(
  29 static const int &foo() {
  30    struct Foo { };
  31
  32    switch (mode) {
  33    case 0:
  34      // CHECK-DAG: @_Z1xIiE
  35      return x<int>;
  36    case 1:
  37      // CHECK-DAG: @_Z1xIZL3foovE3FooE
  38      return x<Foo>;
  39    case 2:
  40      // CHECK-DAG: @_ZL1yIiE
  41      return y<int>;
  42    case 3:
  43      // CHECK-DAG: @_ZL1yIZL3foovE3FooE
  44      return y<Foo>;
  45    case 4:
  46      // CHECK-DAG: @_Z1zIiE
  47      return z<int>;
  48    case 5:
  49      // CHECK-DAG: @_Z1zIZL3foovE3FooE
  50      return z<Foo>;
  51    case 6:
  52      // CHECK-DAG: @_Z1tIiE
  53      return t<int>;
  54    case 7:
  55      // CHECK-DAG: @_Z1tIKiE
  56      return t<const int>;
  57    }
  58 }
  59
  60
  61 #if !__has_feature(cxx_exceptions) // File A
  62 // CHECKA-DAG: define{{.*}} nonnull align 4 dereferenceable(4) ptr @_Z3barv(
  63 const int &bar() {
  64         // CHECKA-DAG: call noundef nonnull align 4 dereferenceable(4) ptr @_ZL3foov()
  65         return foo();
  66 }
  67
  68 #else // File B
  69
  70 // CHECKB-DAG: declare noundef nonnull align 4 dereferenceable(4) ptr @_Z3barv(
  71 const int &bar();
  72
  73 int main() {
  74         // CHECKB-DAG: call noundef nonnull align 4 dereferenceable(4) ptr @_Z3barv()
  75         // CHECKB-DAG: call noundef nonnull align 4 dereferenceable(4) ptr @_ZL3foov()
  76         &bar() == &foo() ? throw 0 : (void)0; // Should not throw exception at runtime.
  77 }
  78
  79 #endif // end of Files A and B
  80