// 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 {{override}} char c3{y}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 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 {{override}} unsigned int ui1 = {-1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} signed int si1 = { (unsigned int)-1 }; // expected-warning {{ cannot be narrowed }} expected-note {{override}} int ii = {2.0}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} float f1 { x }; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 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 struct Agg { T t; }; template struct Convert { constexpr Convert(T v) : v(v) {} constexpr operator T() const { return v; } T v; }; template Convert 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 a1 = {1.0F}; // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{override}} Agg a2 = {1.0}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg a3 = {1.0L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} float f = 1.0; double d = 1.0; long double ld = 1.0; Agg a4 = {f}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg a5 = {d}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg a6 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg ce1 = { Convert(1.0) }; // expected-warning {{type 'float' cannot be narrowed to 'char'}} expected-note {{override}} Agg ce2 = { ConvertVar() }; // expected-warning {{type 'double' cannot be narrowed to 'char'}} expected-note {{override}} } // * 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 f1 = {f}; // OK (no-op) Agg f2 = {d}; // expected-warning {{non-constant-expression cannot be narrowed from type 'double' to 'float'}} expected-note {{override}} Agg f3 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // Exact constants. Agg f4 = {1.0}; // OK (double constant represented exactly) Agg f5 = {1.0L}; // OK (long double constant represented exactly) // Inexact but in-range constants. Agg f6 = {0.1}; // OK (double constant in range but rounded) Agg f7 = {0.1L}; // OK (long double constant in range but rounded) // Out of range constants. Agg f8 = {1E50}; // expected-warning {{constant expression evaluates to 1.000000e+50 which cannot be narrowed to type 'float'}} expected-note {{override}} Agg f9 = {1E50L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // More complex constant expression. constexpr long double e40 = 1E40L, e30 = 1E30L, e39 = 1E39L; Agg f10 = {e40 - 5 * e39 + e30 - 5 * e39}; // OK // Variables. Agg d1 = {f}; // OK (widening) Agg d2 = {d}; // OK (no-op) Agg d3 = {ld}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // Exact constant. Agg d4 = {1.0L}; // OK (long double constant represented exactly) // Inexact but in-range constant. Agg d5 = {0.1L}; // OK (long double constant in range but rounded) // Out of range constant. Agg d6 = {1E315L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // More complex constant expression. constexpr long double e315 = 1E315L, e305 = 1E305L, e314 = 1E314L; Agg d7 = {e315 - 5 * e314 + e305 - 5 * e314}; // OK Agg ce1 = { Convert(1e300) }; // expected-warning {{constant expression evaluates to 1.000000e+300 which cannot be narrowed to type 'float'}} expected-note {{override}} Agg ce2 = { ConvertVar() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long double' to 'double'}} expected-note {{override}} } // * 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 f1 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg f2 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg f3 = {c}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // Constants. Agg f4 = {12345678}; // OK (exactly fits in a float) Agg f5 = {123456789}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg ce1 = { Convert(123456789) }; // expected-warning {{constant expression evaluates to 123456789 which cannot be narrowed to type 'float'}} expected-note {{override}} Agg ce2 = { ConvertVar() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'long long' to 'double'}} expected-note {{override}} } // * 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 c1 = {s}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg s1 = {s}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg s2 = {us}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // "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) i1 = {l1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} long long ll = 1; Agg l2 = {ll}; // OK // Constants. Agg c2 = {127}; // OK Agg c3 = {300}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} Agg i2 = {0x7FFFFFFFU}; // OK Agg i3 = {0x80000000U}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg i4 = {-0x80000000L}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // Bool is also an integer type, but conversions to it are a different AST // node. Agg b1 = {0}; // OK Agg b2 = {1}; // OK Agg b3 = {-1}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} // Conversions from pointers to booleans aren't narrowing conversions. Agg b = {&b1}; // OK Agg ce1 = { Convert(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}} Agg ce2 = { ConvertVar() }; // expected-warning {{non-constant-expression cannot be narrowed from type 'short' to 'char'}} expected-note {{override}} } // Be sure that type- and value-dependent expressions in templates get the warning // too. template void maybe_shrink_int(T t) { Agg s1 = {t}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} Agg s2 = {I}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} expected-warning {{changes value}} Agg t2 = {700}; // expected-warning {{ cannot be narrowed }} expected-note {{override}} 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 {{override}} // Template arguments make it harder to avoid printing qualifiers: Agg c2 = {j}; // expected-warning {{from type 'int' to 'const unsigned char' in}} expected-note {{override}} } // Make sure we still get the right SFINAE behavior. template struct Value { }; template int &check_narrowed(Value); template float &check_narrowed(...); void test_narrowed(Value vi, Value vd) { int &ir = check_narrowed(vd); float &fr = check_narrowed(vi); }