// RUN: %clang_cc1 -fsyntax-only -std=c++11 -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-error {{ cannot be narrowed }} expected-note {{silence}} char c3{y}; // expected-error {{ 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-error {{ cannot be narrowed }} expected-note {{silence}} unsigned int ui1 = {-1}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} signed int si1 = { (unsigned int)-1 }; // expected-error {{ cannot be narrowed }} expected-note {{silence}} int ii = {2.0}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} float f1 { x }; // expected-error {{ 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-error {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}} Agg<char> a2 = {1.0}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<char> a3 = {1.0L}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} float f = 1.0; double d = 1.0; long double ld = 1.0; Agg<char> a4 = {f}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<char> a5 = {d}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<char> a6 = {ld}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<char> ce1 = { Convert<float>(1.0) }; // expected-error {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}} Agg<char> ce2 = { ConvertVar<double>() }; // expected-error {{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-error {{non-constant-expression cannot be narrowed from type 'double' to 'float'}} expected-note {{silence}} Agg<float> f3 = {ld}; // expected-error {{ 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-error {{constant expression evaluates to 1.000000e+50 which cannot be narrowed to type 'float'}} expected-note {{silence}} Agg<float> f9 = {1E50L}; // expected-error {{ 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-error {{ 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-error {{ 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-error {{constant expression evaluates to 1.000000e+300 which cannot be narrowed to type 'float'}} expected-note {{silence}} Agg<double> ce2 = { ConvertVar<long double>() }; // expected-error {{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-error {{ cannot be narrowed }} expected-note {{silence}} Agg<double> f2 = {c}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<long double> f3 = {c}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} // Constants. Agg<float> f4 = {12345678}; // OK (exactly fits in a float) Agg<float> f5 = {123456789}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<float> ce1 = { Convert<int>(123456789) }; // expected-error {{constant expression evaluates to 123456789 which cannot be narrowed to type 'float'}} expected-note {{silence}} Agg<double> ce2 = { ConvertVar<long long>() }; // expected-error {{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-error {{ cannot be narrowed }} expected-note {{silence}} Agg<unsigned short> s1 = {s}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<short> s2 = {us}; // expected-error {{ 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-error {{ 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-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}} Agg<int> i2 = {0x7FFFFFFFU}; // OK Agg<int> i3 = {0x80000000U}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<unsigned int> i4 = {-0x80000000L}; // expected-error {{ 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-error {{ 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-error {{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-error {{non-constant-expression cannot be narrowed from type 'short' to 'char'}} expected-note {{silence}} // Negative -> larger unsigned type. unsigned long long ll1 = { -1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}} unsigned long long ll2 = { 1 }; // OK unsigned long long ll3 = { s }; // expected-error {{cannot be narrowed from type 'short'}} expected-note {{silence}} unsigned long long ll4 = { us }; // OK unsigned long long ll5 = { ll }; // expected-error {{cannot be narrowed from type 'long long'}} expected-note {{silence}} Agg<unsigned long long> ll6 = { -1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}} Agg<unsigned long long> ll7 = { 18446744073709551615ULL }; // OK Agg<unsigned long long> ll8 = { __int128(18446744073709551615ULL) + 1 }; // expected-error {{ 18446744073709551616 which cannot be narrowed}} expected-note {{silence}} expected-warning {{changes value}} signed char c = 'x'; unsigned short usc1 = { c }; // expected-error {{non-constant-expression cannot be narrowed from type 'signed char'}} expected-note {{silence}} unsigned short usc2 = { (signed char)'x' }; // OK unsigned short usc3 = { (signed char)-1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}} } // Be sure that type- and value-dependent expressions in templates get the error // too. template<int I, typename T> void maybe_shrink_int(T t) { Agg<short> s1 = {t}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} Agg<short> s2 = {I}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}} Agg<T> t2 = {700}; // expected-error {{ 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-error {{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-error {{from type 'int' to 'const unsigned char' in}} expected-note {{silence}} } // Test SFINAE checks. 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); }