1 // RUN: %check_clang_tidy %s bugprone-narrowing-conversions %t \
2 // RUN: -- -- -target x86_64-unknown-linux -fsigned-char
3 
4 namespace floats {
5 
6 void narrow_constant_floating_point_to_int_not_ok(double d) {
7   int i = 0;
8   i += 0.5;
9   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from constant 'double' to 'int' [bugprone-narrowing-conversions]
10   i += 0.5f;
11   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from constant 'float' to 'int' [bugprone-narrowing-conversions]
12   i *= 0.5f;
13   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from constant 'float' to 'int' [bugprone-narrowing-conversions]
14   i /= 0.5f;
15   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from constant 'float' to 'int' [bugprone-narrowing-conversions]
16   i += (double)0.5f;
17   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from constant 'double' to 'int' [bugprone-narrowing-conversions]
18   i += 2.0;
19   i += 2.0f;
20 }
21 
22 double operator"" _double(unsigned long long);
23 
24 float narrow_double_to_float_return() {
25   return 0.5;
26 }
27 
28 void narrow_double_to_float_not_ok(double d) {
29   float f;
30   f = d;
31   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: narrowing conversion from 'double' to 'float' [bugprone-narrowing-conversions]
32   f = 15_double;
33   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: narrowing conversion from 'double' to 'float' [bugprone-narrowing-conversions]
34   f += d;
35   // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: narrowing conversion from 'double' to 'float' [bugprone-narrowing-conversions]
36   f = narrow_double_to_float_return();
37 }
38 
39 float narrow_float16_to_float_return(_Float16 f) {
40   return f;
41 }
42 
43 _Float16 narrow_float_to_float16_return(float f) {
44   return f;
45   // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: narrowing conversion from 'float' to '_Float16' [bugprone-narrowing-conversions]
46 }
47 
48 void narrow_fp_constants() {
49   float f;
50   f = 0.5; // [dcl.init.list] 7.2 : in-range fp constant to narrower float is not a narrowing.
51 
52   f = __builtin_huge_valf();  // max float is not narrowing.
53   f = -__builtin_huge_valf(); // -max float is not narrowing.
54   f = __builtin_inff();       // float infinity is not narrowing.
55   f = __builtin_nanf("0");    // float NaN is not narrowing.
56 
57   f = __builtin_huge_val(); // max double is not within-range of float.
58   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: narrowing conversion from constant 'double' to 'float' [bugprone-narrowing-conversions]
59   f = -__builtin_huge_val(); // -max double is not within-range of float.
60   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: narrowing conversion from constant 'double' to 'float' [bugprone-narrowing-conversions]
61   f = __builtin_inf(); // double infinity is not within-range of float.
62   // CHECK-MESSAGES: :[[@LINE-1]]:7: warning: narrowing conversion from constant 'double' to 'float' [bugprone-narrowing-conversions]
63   f = __builtin_nan("0"); // double NaN is not narrowing.
64 }
65 
66 double false_positive_const_qualified_cast(bool t) {
67   double b = 1.0;
68   constexpr double a = __builtin_huge_val();
69   // PR49498 The constness difference of 'a' and 'b' results in an implicit cast.
70   return t ? b : a;
71 }
72 
73 } // namespace floats
74