1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -triple x86_64-apple-macosx10.6.7 -verify %s
2
3 // Verify that narrowing conversions in initializer lists cause errors in C++0x
4 // mode.
5
std_example()6 void std_example() {
7 int x = 999; // x is not a constant expression
8 const int y = 999;
9 const int z = 99;
10 char c1 = x; // OK, though it might narrow (in this case, it does narrow)
11 char c2{x}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
12 char c3{y}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
13 char c4{z}; // OK: no narrowing needed
14 unsigned char uc1 = {5}; // OK: no narrowing needed
15 unsigned char uc2 = {-1}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
16 unsigned int ui1 = {-1}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
17 signed int si1 =
18 { (unsigned int)-1 }; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
19 int ii = {2.0}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
20 float f1 { x }; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
21 float f2 { 7 }; // OK: 7 can be exactly represented as a float
22 int f(int);
23 int a[] =
24 { 2, f(2), f(2.0) }; // OK: the double-to-int conversion is not at the top level
25 }
26
27 // Test each rule individually.
28
29 template<typename T>
30 struct Agg {
31 T t;
32 };
33
34 template<typename T>
35 struct Convert {
ConvertConvert36 constexpr Convert(T v) : v(v) {}
operator TConvert37 constexpr operator T() const { return v; }
38 T v;
39 };
40 template<typename T> Convert<T> ConvertVar();
41
42 // C++0x [dcl.init.list]p7: A narrowing conversion is an implicit conversion
43 //
44 // * from a floating-point type to an integer type, or
45
float_to_int()46 void float_to_int() {
47 Agg<char> a1 = {1.0F}; // expected-error {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}}
48 Agg<char> a2 = {1.0}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
49 Agg<char> a3 = {1.0L}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
50
51 float f = 1.0;
52 double d = 1.0;
53 long double ld = 1.0;
54 Agg<char> a4 = {f}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
55 Agg<char> a5 = {d}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
56 Agg<char> a6 = {ld}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
57
58 Agg<char> ce1 = { Convert<float>(1.0) }; // expected-error {{type 'float' cannot be narrowed to 'char'}} expected-note {{silence}}
59 Agg<char> ce2 = { ConvertVar<double>() }; // expected-error {{type 'double' cannot be narrowed to 'char'}} expected-note {{silence}}
60
61 bool b{1.0}; // expected-error {{type 'double' cannot be narrowed to 'bool'}} expected-note {{silence}}
62 Agg<bool> ab = {0.0}; // expected-error {{type 'double' cannot be narrowed to 'bool'}} expected-note {{silence}}
63 }
64
65 // * from long double to double or float, or from double to float, except where
66 // the source is a constant expression and the actual value after conversion
67 // is within the range of values that can be represented (even if it cannot be
68 // represented exactly), or
69
shrink_float()70 void shrink_float() {
71 // These aren't constant expressions.
72 float f = 1.0;
73 double d = 1.0;
74 long double ld = 1.0;
75
76 // Variables.
77 Agg<float> f1 = {f}; // OK (no-op)
78 Agg<float> f2 = {d}; // expected-error {{non-constant-expression cannot be narrowed from type 'double' to 'float'}} expected-note {{silence}}
79 Agg<float> f3 = {ld}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
80 // Exact constants.
81 Agg<float> f4 = {1.0}; // OK (double constant represented exactly)
82 Agg<float> f5 = {1.0L}; // OK (long double constant represented exactly)
83 // Inexact but in-range constants.
84 Agg<float> f6 = {0.1}; // OK (double constant in range but rounded)
85 Agg<float> f7 = {0.1L}; // OK (long double constant in range but rounded)
86 // Out of range constants.
87 Agg<float> f8 = {1E50}; // expected-error {{constant expression evaluates to 1.000000e+50 which cannot be narrowed to type 'float'}} expected-note {{silence}}
88 Agg<float> f9 = {1E50L}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
89 // More complex constant expression.
90 constexpr long double e40 = 1E40L, e30 = 1E30L, e39 = 1E39L;
91 Agg<float> f10 = {e40 - 5 * e39 + e30 - 5 * e39}; // OK
92
93 // Variables.
94 Agg<double> d1 = {f}; // OK (widening)
95 Agg<double> d2 = {d}; // OK (no-op)
96 Agg<double> d3 = {ld}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
97 // Exact constant.
98 Agg<double> d4 = {1.0L}; // OK (long double constant represented exactly)
99 // Inexact but in-range constant.
100 Agg<double> d5 = {0.1L}; // OK (long double constant in range but rounded)
101 // Out of range constant.
102 Agg<double> d6 = {1E315L}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
103 // More complex constant expression.
104 constexpr long double e315 = 1E315L, e305 = 1E305L, e314 = 1E314L;
105 Agg<double> d7 = {e315 - 5 * e314 + e305 - 5 * e314}; // OK
106
107 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}}
108 Agg<double> ce2 = { ConvertVar<long double>() }; // expected-error {{non-constant-expression cannot be narrowed from type 'long double' to 'double'}} expected-note {{silence}}
109 }
110
111 // * from an integer type or unscoped enumeration type to a floating-point type,
112 // except where the source is a constant expression and the actual value after
113 // conversion will fit into the target type and will produce the original
114 // value when converted back to the original type, or
int_to_float()115 void int_to_float() {
116 // Not a constant expression.
117 char c = 1;
118
119 // Variables. Yes, even though all char's will fit into any floating type.
120 Agg<float> f1 = {c}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
121 Agg<double> f2 = {c}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
122 Agg<long double> f3 = {c}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
123
124 // Constants.
125 Agg<float> f4 = {12345678}; // OK (exactly fits in a float)
126 Agg<float> f5 = {123456789}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
127
128 Agg<float> ce1 = { Convert<int>(123456789) }; // expected-error {{constant expression evaluates to 123456789 which cannot be narrowed to type 'float'}} expected-note {{silence}}
129 Agg<double> ce2 = { ConvertVar<long long>() }; // expected-error {{non-constant-expression cannot be narrowed from type 'long long' to 'double'}} expected-note {{silence}}
130 }
131
132 // * from an integer type or unscoped enumeration type to an integer type that
133 // cannot represent all the values of the original type, except where the
134 // source is a constant expression and the actual value after conversion will
135 // fit into the target type and will produce the original value when converted
136 // back to the original type.
shrink_int()137 void shrink_int() {
138 // Not a constant expression.
139 short s = 1;
140 unsigned short us = 1;
141 Agg<char> c1 = {s}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
142 Agg<unsigned short> s1 = {s}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
143 Agg<short> s2 = {us}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
144
145 // "that cannot represent all the values of the original type" means that the
146 // validity of the program depends on the relative sizes of integral types.
147 // This test compiles with -m64, so sizeof(int)<sizeof(long)==sizeof(long
148 // long).
149 long l1 = 1;
150 Agg<int> i1 = {l1}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
151 long long ll = 1;
152 Agg<long> l2 = {ll}; // OK
153
154 // Constants.
155 Agg<char> c2 = {127}; // OK
156 Agg<char> c3 = {300}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
157
158 Agg<int> i2 = {0x7FFFFFFFU}; // OK
159 Agg<int> i3 = {0x80000000U}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
160 Agg<unsigned int> i4 = {-0x80000000L}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
161
162 // Bool is also an integer type, but conversions to it are a different AST
163 // node.
164 Agg<bool> b1 = {0}; // OK
165 Agg<bool> b2 = {1}; // OK
166 Agg<bool> b3 = {-1}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
167
168 // Conversions from pointers to booleans aren't narrowing conversions.
169 Agg<bool>* ptr = &b1;
170 Agg<bool> b = {ptr}; // OK
171
172 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}}
173 Agg<char> ce2 = { ConvertVar<short>() }; // expected-error {{non-constant-expression cannot be narrowed from type 'short' to 'char'}} expected-note {{silence}}
174
175 // Negative -> larger unsigned type.
176 unsigned long long ll1 = { -1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}}
177 unsigned long long ll2 = { 1 }; // OK
178 unsigned long long ll3 = { s }; // expected-error {{cannot be narrowed from type 'short'}} expected-note {{silence}}
179 unsigned long long ll4 = { us }; // OK
180 unsigned long long ll5 = { ll }; // expected-error {{cannot be narrowed from type 'long long'}} expected-note {{silence}}
181 Agg<unsigned long long> ll6 = { -1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}}
182 Agg<unsigned long long> ll7 = { 18446744073709551615ULL }; // OK
183 Agg<unsigned long long> ll8 = { __int128(18446744073709551615ULL) + 1 }; // expected-error {{ 18446744073709551616 which cannot be narrowed}} expected-note {{silence}} expected-warning {{changes value}}
184 signed char c = 'x';
185 unsigned short usc1 = { c }; // expected-error {{non-constant-expression cannot be narrowed from type 'signed char'}} expected-note {{silence}}
186 unsigned short usc2 = { (signed char)'x' }; // OK
187 unsigned short usc3 = { (signed char)-1 }; // expected-error {{ -1 which cannot be narrowed}} expected-note {{silence}}
188 }
189
190 // Be sure that type- and value-dependent expressions in templates get the error
191 // too.
192
193 template<int I, typename T>
maybe_shrink_int(T t)194 void maybe_shrink_int(T t) {
195 Agg<short> s1 = {t}; // expected-error {{ cannot be narrowed }} expected-note {{silence}}
196 Agg<short> s2 = {I}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
197 Agg<T> t2 = {700}; // expected-error {{ cannot be narrowed }} expected-note {{silence}} expected-warning {{changes value}}
198 }
199
test_template()200 void test_template() {
201 maybe_shrink_int<15>((int)3); // expected-note {{in instantiation}}
202 maybe_shrink_int<70000>((char)3); // expected-note {{in instantiation}}
203 }
204
205
206 // We don't want qualifiers on the types in the diagnostic.
207
test_qualifiers(int i)208 void test_qualifiers(int i) {
209 const int j = i;
210 struct {const unsigned char c;} c1 = {j}; // expected-error {{from type 'int' to 'unsigned char' in}} expected-note {{silence}}
211 // Template arguments make it harder to avoid printing qualifiers:
212 Agg<const unsigned char> c2 = {j}; // expected-error {{from type 'int' to 'const unsigned char' in}} expected-note {{silence}}
213 }
214
215 // Test SFINAE checks.
216 template<unsigned> struct Value { };
217
218 template<typename T>
219 int &check_narrowed(Value<sizeof((T){1.1})>);
220
221 template<typename T>
222 float &check_narrowed(...);
223
test_narrowed(Value<sizeof (int)> vi,Value<sizeof (double)> vd)224 void test_narrowed(Value<sizeof(int)> vi, Value<sizeof(double)> vd) {
225 int &ir = check_narrowed<double>(vd);
226 float &fr = check_narrowed<int>(vi);
227 }
228