text: // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wno-error=c++11-narrowing -triple x86_64-apple-macosx10.6.7 -verify %s
  // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wno-error=narrowing -triple x86_64-apple-macosx10.6.7 -verify %s
  
  // Verify that narrowing conversions in initializer lists cause errors in C++0x
  // mode.
  
  void std_example() {
    int x = 999;  // x is not a constant expression
    const int y = 999;
    const int z = 99;
    char c1 = x;  // OK, though it might narrow (in this case, it does narrow)
    char c2{x};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    char c3{y};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
    char c4{z};  // OK: no narrowing needed
    unsigned char uc1 = {5};  // OK: no narrowing needed
    unsigned char uc2 = {-1};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    unsigned int ui1 = {-1};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    signed int si1 =
      { (unsigned int)-1 };  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    int ii = {2.0};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    float f1 { x };  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    float f2 { 7 };  // OK: 7 can be exactly represented as a float
    int f(int);
    int a[] =
      { 2, f(2), f(2.0) };  // OK: the double-to-int conversion is not at the top level
  }
  
  // Test each rule individually.
  
  template<typename T>
  struct Agg {
    T t;
  };
  
  template<typename T>
  struct Convert {
    constexpr Convert(T v) : v(v) {}
    constexpr operator T() const { return v; }
    T v;
  };
  template<typename T> Convert<T> ConvertVar();
  
  // C++0x [dcl.init.list]p7: A narrowing conversion is an implicit conversion
  //
  // * from a floating-point type to an integer type, or
  
  void float_to_int() {
    Agg<char> a1 = {1.0F};  // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}}
    Agg<char> a2 = {1.0};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<char> a3 = {1.0L};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    float f = 1.0;
    double d = 1.0;
    long double ld = 1.0;
    Agg<char> a4 = {f};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<char> a5 = {d};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<char> a6 = {ld};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    Agg<char> ce1 = { Convert<float>(1.0) }; // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}}
    Agg<char> ce2 = { ConvertVar<double>() }; // expected-warning {{type 'double' cannot be narrowed to 'char'}} expected-note {{silence}}
  }
  
  // * from long double to double or float, or from double to float, except where
  //   the source is a constant expression and the actual value after conversion
  //   is within the range of values that can be represented (even if it cannot be
  //   represented exactly), or
  
  void shrink_float() {
    // These aren't constant expressions.
    float f = 1.0;
    double d = 1.0;
    long double ld = 1.0;
  
    // Variables.
    Agg<float> f1 = {f};  // OK  (no-op)
    Agg<float> f2 = {d};  // expected-warning {{non-constant-expression cannot be narrowed from type 'double' to 'float'}} expected-note {{silence}}
    Agg<float> f3 = {ld};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    // Exact constants.
    Agg<float> f4 = {1.0};  // OK  (double constant represented exactly)
    Agg<float> f5 = {1.0L};  // OK  (long double constant represented exactly)
    // Inexact but in-range constants.
    Agg<float> f6 = {0.1};  // OK (double constant in range but rounded)
    Agg<float> f7 = {0.1L};  // OK (long double constant in range but rounded)
    // Out of range constants.
    Agg<float> f8 = {1E50};  // expected-warning {{constant expression evaluates to 1.000000e+50 which cannot be narrowed to type 'float'}} expected-note {{silence}}
    Agg<float> f9 = {1E50L};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    // More complex constant expression.
    constexpr long double e40 = 1E40L, e30 = 1E30L, e39 = 1E39L;
    Agg<float> f10 = {e40 - 5 * e39 + e30 - 5 * e39};  // OK
  
    // Variables.
    Agg<double> d1 = {f};  // OK  (widening)
    Agg<double> d2 = {d};  // OK  (no-op)
    Agg<double> d3 = {ld};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    // Exact constant.
    Agg<double> d4 = {1.0L};  // OK  (long double constant represented exactly)
    // Inexact but in-range constant.
    Agg<double> d5 = {0.1L};  // OK (long double constant in range but rounded)
    // Out of range constant.
    Agg<double> d6 = {1E315L};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    // More complex constant expression.
    constexpr long double e315 = 1E315L, e305 = 1E305L, e314 = 1E314L;
    Agg<double> d7 = {e315 - 5 * e314 + e305 - 5 * e314};  // OK
  
    Agg<float> ce1 = { Convert<double>(1e300) }; // expected-warning {{constant expression evaluates to 1.000000e+300 which cannot be narrowed to type 'float'}} expected-note {{silence}}
    Agg<double> ce2 = { ConvertVar<long double>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long double' to 'double'}} expected-note {{silence}}
  }
  
  // * from an integer type or unscoped enumeration type to a floating-point type,
  //   except where the source is a constant expression and the actual value after
  //   conversion will fit into the target type and will produce the original
  //   value when converted back to the original type, or
  void int_to_float() {
    // Not a constant expression.
    char c = 1;
  
    // Variables.  Yes, even though all char's will fit into any floating type.
    Agg<float> f1 = {c};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<double> f2 = {c};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<long double> f3 = {c};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    // Constants.
    Agg<float> f4 = {12345678};  // OK (exactly fits in a float)
    Agg<float> f5 = {123456789};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    Agg<float> ce1 = { Convert<int>(123456789) }; // expected-warning {{constant expression evaluates to 123456789 which cannot be narrowed to type 'float'}} expected-note {{silence}}
    Agg<double> ce2 = { ConvertVar<long long>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long long' to 'double'}} expected-note {{silence}}
  }
  
  // * from an integer type or unscoped enumeration type to an integer type that
  //   cannot represent all the values of the original type, except where the
  //   source is a constant expression and the actual value after conversion will
  //   fit into the target type and will produce the original value when converted
  //   back to the original type.
  void shrink_int() {
    // Not a constant expression.
    short s = 1;
    unsigned short us = 1;
    Agg<char> c1 = {s};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<unsigned short> s1 = {s};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<short> s2 = {us};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    // "that cannot represent all the values of the original type" means that the
    // validity of the program depends on the relative sizes of integral types.
    // This test compiles with -m64, so sizeof(int)<sizeof(long)==sizeof(long
    // long).
    long l1 = 1;
    Agg<int> i1 = {l1};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    long long ll = 1;
    Agg<long> l2 = {ll};  // OK
  
    // Constants.
    Agg<char> c2 = {127};  // OK
    Agg<char> c3 = {300};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
  
    Agg<int> i2 = {0x7FFFFFFFU};  // OK
    Agg<int> i3 = {0x80000000U};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<unsigned int> i4 = {-0x80000000L};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    // Bool is also an integer type, but conversions to it are a different AST
    // node.
    Agg<bool> b1 = {0};  // OK
    Agg<bool> b2 = {1};  // OK
    Agg<bool> b3 = {-1};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
  
    // Conversions from pointers to booleans aren't narrowing conversions.
    Agg<bool>* ptr = &b1;
    Agg<bool> b = {ptr};  // OK
  
    Agg<short> ce1 = { Convert<int>(100000) }; // expected-warning {{constant expression evaluates to 100000 which cannot be narrowed to type 'short'}} expected-note {{silence}} expected-warning {{changes value from 100000 to -31072}}
    Agg<char> ce2 = { ConvertVar<short>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'short' to 'char'}} expected-note {{silence}}
  }
  
  // Be sure that type- and value-dependent expressions in templates get the warning
  // too.
  
  template<int I, typename T>
  void maybe_shrink_int(T t) {
    Agg<short> s1 = {t};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}}
    Agg<short> s2 = {I};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
    Agg<T> t2 = {700};  // expected-warning {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
  }
  
  void test_template() {
    maybe_shrink_int<15>((int)3);  // expected-note {{in instantiation}}
    maybe_shrink_int<70000>((char)3);  // expected-note {{in instantiation}}
  }
  
  
  // We don't want qualifiers on the types in the diagnostic.
  
  void test_qualifiers(int i) {
    const int j = i;
    struct {const unsigned char c;} c1 = {j};  // expected-warning {{from type 'int' to 'unsigned char' in}} expected-note {{silence}}
    // Template arguments make it harder to avoid printing qualifiers:
    Agg<const unsigned char> c2 = {j};  // expected-warning {{from type 'int' to 'const unsigned char' in}} expected-note {{silence}}
  }
  
  // Make sure we still get the right SFINAE behavior.
  template<unsigned> struct Value { };
  
  template<typename T>
  int &check_narrowed(Value<sizeof((T){1.1})>);
  
  template<typename T>
  float &check_narrowed(...);
  
  void test_narrowed(Value<sizeof(int)> vi, Value<sizeof(double)> vd) {
    int &ir = check_narrowed<double>(vd);
    float &fr = check_narrowed<int>(vi);
  }
  