1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wno-error=c++11-narrowing -triple x86_64-apple-macosx10.6.7 -verify %s 2 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wno-error=narrowing -triple x86_64-apple-macosx10.6.7 -verify %s 3 4 // Verify that narrowing conversions in initializer lists cause errors in C++0x 5 // mode. 6 7 void std_example() { 8 int x = 999; // x is not a constant expression 9 const int y = 999; 10 const int z = 99; 11 char c1 = x; // OK, though it might narrow (in this case, it does narrow) 12 char c2{x}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 13 char c3{y}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} 14 char c4{z}; // OK: no narrowing needed 15 unsigned char uc1 = {5}; // OK: no narrowing needed 16 unsigned char uc2 = {-1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 17 unsigned int ui1 = {-1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 18 signed int si1 = 19 { (unsigned int)-1 }; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 20 int ii = {2.0}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 21 float f1 { x }; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 22 float f2 { 7 }; // OK: 7 can be exactly represented as a float 23 int f(int); 24 int a[] = 25 { 2, f(2), f(2.0) }; // OK: the double-to-int conversion is not at the top level 26 } 27 28 // Test each rule individually. 29 30 template<typename T> 31 struct Agg { 32 T t; 33 }; 34 35 template<typename T> 36 struct Convert { 37 constexpr Convert(T v) : v(v) {} 38 constexpr operator T() const { return v; } 39 T v; 40 }; 41 template<typename T> Convert<T> ConvertVar(); 42 43 // C++0x [dcl.init.list]p7: A narrowing conversion is an implicit conversion 44 // 45 // * from a floating-point type to an integer type, or 46 47 void float_to_int() { 48 Agg<char> a1 = {1.0F}; // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{override}} 49 Agg<char> a2 = {1.0}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 50 Agg<char> a3 = {1.0L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 51 52 float f = 1.0; 53 double d = 1.0; 54 long double ld = 1.0; 55 Agg<char> a4 = {f}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 56 Agg<char> a5 = {d}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 57 Agg<char> a6 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 58 59 Agg<char> ce1 = { Convert<float>(1.0) }; // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{override}} 60 Agg<char> ce2 = { ConvertVar<double>() }; // expected-warning {{type 'double' cannot be narrowed to 'char'}} expected-note {{override}} 61 } 62 63 // * from long double to double or float, or from double to float, except where 64 // the source is a constant expression and the actual value after conversion 65 // is within the range of values that can be represented (even if it cannot be 66 // represented exactly), or 67 68 void shrink_float() { 69 // These aren't constant expressions. 70 float f = 1.0; 71 double d = 1.0; 72 long double ld = 1.0; 73 74 // Variables. 75 Agg<float> f1 = {f}; // OK (no-op) 76 Agg<float> f2 = {d}; // expected-warning {{non-constant-expression cannot be narrowed from type 'double' to 'float'}} expected-note {{override}} 77 Agg<float> f3 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 78 // Exact constants. 79 Agg<float> f4 = {1.0}; // OK (double constant represented exactly) 80 Agg<float> f5 = {1.0L}; // OK (long double constant represented exactly) 81 // Inexact but in-range constants. 82 Agg<float> f6 = {0.1}; // OK (double constant in range but rounded) 83 Agg<float> f7 = {0.1L}; // OK (long double constant in range but rounded) 84 // Out of range constants. 85 Agg<float> f8 = {1E50}; // expected-warning {{constant expression evaluates to 1.000000e+50 which cannot be narrowed to type 'float'}} expected-note {{override}} 86 Agg<float> f9 = {1E50L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 87 // More complex constant expression. 88 constexpr long double e40 = 1E40L, e30 = 1E30L, e39 = 1E39L; 89 Agg<float> f10 = {e40 - 5 * e39 + e30 - 5 * e39}; // OK 90 91 // Variables. 92 Agg<double> d1 = {f}; // OK (widening) 93 Agg<double> d2 = {d}; // OK (no-op) 94 Agg<double> d3 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 95 // Exact constant. 96 Agg<double> d4 = {1.0L}; // OK (long double constant represented exactly) 97 // Inexact but in-range constant. 98 Agg<double> d5 = {0.1L}; // OK (long double constant in range but rounded) 99 // Out of range constant. 100 Agg<double> d6 = {1E315L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 101 // More complex constant expression. 102 constexpr long double e315 = 1E315L, e305 = 1E305L, e314 = 1E314L; 103 Agg<double> d7 = {e315 - 5 * e314 + e305 - 5 * e314}; // OK 104 105 Agg<float> ce1 = { Convert<double>(1e300) }; // expected-warning {{constant expression evaluates to 1.000000e+300 which cannot be narrowed to type 'float'}} expected-note {{override}} 106 Agg<double> ce2 = { ConvertVar<long double>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long double' to 'double'}} expected-note {{override}} 107 } 108 109 // * from an integer type or unscoped enumeration type to a floating-point type, 110 // except where the source is a constant expression and the actual value after 111 // conversion will fit into the target type and will produce the original 112 // value when converted back to the original type, or 113 void int_to_float() { 114 // Not a constant expression. 115 char c = 1; 116 117 // Variables. Yes, even though all char's will fit into any floating type. 118 Agg<float> f1 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 119 Agg<double> f2 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 120 Agg<long double> f3 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 121 122 // Constants. 123 Agg<float> f4 = {12345678}; // OK (exactly fits in a float) 124 Agg<float> f5 = {123456789}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 125 126 Agg<float> ce1 = { Convert<int>(123456789) }; // expected-warning {{constant expression evaluates to 123456789 which cannot be narrowed to type 'float'}} expected-note {{override}} 127 Agg<double> ce2 = { ConvertVar<long long>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long long' to 'double'}} expected-note {{override}} 128 } 129 130 // * from an integer type or unscoped enumeration type to an integer type that 131 // cannot represent all the values of the original type, except where the 132 // source is a constant expression and the actual value after conversion will 133 // fit into the target type and will produce the original value when converted 134 // back to the original type. 135 void shrink_int() { 136 // Not a constant expression. 137 short s = 1; 138 unsigned short us = 1; 139 Agg<char> c1 = {s}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 140 Agg<unsigned short> s1 = {s}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 141 Agg<short> s2 = {us}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 142 143 // "that cannot represent all the values of the original type" means that the 144 // validity of the program depends on the relative sizes of integral types. 145 // This test compiles with -m64, so sizeof(int)<sizeof(long)==sizeof(long 146 // long). 147 long l1 = 1; 148 Agg<int> i1 = {l1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 149 long long ll = 1; 150 Agg<long> l2 = {ll}; // OK 151 152 // Constants. 153 Agg<char> c2 = {127}; // OK 154 Agg<char> c3 = {300}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} 155 156 Agg<int> i2 = {0x7FFFFFFFU}; // OK 157 Agg<int> i3 = {0x80000000U}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 158 Agg<unsigned int> i4 = {-0x80000000L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 159 160 // Bool is also an integer type, but conversions to it are a different AST 161 // node. 162 Agg<bool> b1 = {0}; // OK 163 Agg<bool> b2 = {1}; // OK 164 Agg<bool> b3 = {-1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 165 166 // Conversions from pointers to booleans aren't narrowing conversions. 167 Agg<bool> b = {&b1}; // OK 168 169 Agg<short> ce1 = { Convert<int>(100000) }; // expected-warning {{constant expression evaluates to 100000 which cannot be narrowed to type 'short'}} expected-note {{override}} expected-warning {{changes value from 100000 to -31072}} 170 Agg<char> ce2 = { ConvertVar<short>() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'short' to 'char'}} expected-note {{override}} 171 } 172 173 // Be sure that type- and value-dependent expressions in templates get the warning 174 // too. 175 176 template<int I, typename T> 177 void maybe_shrink_int(T t) { 178 Agg<short> s1 = {t}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 179 Agg<short> s2 = {I}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} 180 Agg<T> t2 = {700}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} 181 } 182 183 void test_template() { 184 maybe_shrink_int<15>((int)3); // expected-note {{in instantiation}} 185 maybe_shrink_int<70000>((char)3); // expected-note {{in instantiation}} 186 } 187 188 189 // We don't want qualifiers on the types in the diagnostic. 190 191 void test_qualifiers(int i) { 192 const int j = i; 193 struct {const unsigned char c;} c1 = {j}; // expected-warning {{from type 'int' to 'unsigned char' in}} expected-note {{override}} 194 // Template arguments make it harder to avoid printing qualifiers: 195 Agg<const unsigned char> c2 = {j}; // expected-warning {{from type 'int' to 'const unsigned char' in}} expected-note {{override}} 196 } 197 198 // Make sure we still get the right SFINAE behavior. 199 template<unsigned> struct Value { }; 200 201 template<typename T> 202 int &check_narrowed(Value<sizeof((T){1.1})>); 203 204 template<typename T> 205 float &check_narrowed(...); 206 207 void test_narrowed(Value<sizeof(int)> vi, Value<sizeof(double)> vd) { 208 int &ir = check_narrowed<double>(vd); 209 float &fr = check_narrowed<int>(vi); 210 } 211