clang/test/SemaTemplate/instantiate-sizeof.cpp

   1 // RUN: %clang_cc1 -triple x86_64-linux-gnu -fsyntax-only -verify -std=c++11 %s
   2
   3 // Make sure we handle contexts correctly with sizeof
   4 template<typename T> void f(T n) { // expected-note {{declared here}}
   5   int buffer[n]; // expected-warning {{variable length arrays in C++ are a Clang extension}} \
   6                     expected-note {{function parameter 'n' with unknown value cannot be used in a constant expression}} \
   7                     expected-note@#instantiate {{in instantiation of function template specialization 'f<int>' requested here}}
   8   [] { int x = sizeof(sizeof(buffer)); }();
   9 }
  10 int main() {
  11   f<int>(1); // #instantiate
  12 }
  13
  14 // Make sure we handle references to non-static data members in unevaluated
  15 // contexts in class template methods correctly. Previously we assumed these
  16 // would be valid MemberRefExprs, but they have no 'this' so we need to form a
  17 // DeclRefExpr to the FieldDecl instead.
  18 // PR26893
  19 template <class T>
  20 struct M {
  21   M() {}; // expected-note {{in instantiation of default member initializer 'M<S>::m' requested here}}
  22   int m = *T::x; // expected-error {{invalid use of non-static data member 'x'}}
  23   void f() {
  24     // These are valid.
  25     static_assert(sizeof(T::x) == 8, "ptr");
  26     static_assert(sizeof(*T::x) == 4, "int");
  27   }
  28 };
  29 struct S { int *x; };
  30 template struct M<S>; // expected-note {{in instantiation of member function 'M<S>::M' requested here}}
  31
  32 // Similar test case for PR26893.
  33 template <typename T=void>
  34 struct bar {
  35   struct foo { int array[10]; };
  36   int baz() { return sizeof(foo::array); }
  37 };
  38 template struct bar<>;