clang/test/SemaCXX/warn-float-conversion.cpp

   1 // RUN: %clang_cc1 -verify -fsyntax-only -triple x86_64-pc-linux-gnu %s -Wno-literal-conversion -Wfloat-conversion -DFLOAT_CONVERSION -DZERO -DBOOL -DCONSTANT_BOOL -DOVERFLOW
   2 // RUN: %clang_cc1 -verify -fsyntax-only -triple x86_64-pc-linux-gnu %s -Wno-conversion -Wfloat-overflow-conversion -DOVERFLOW
   3 // RUN: %clang_cc1 -verify -fsyntax-only -triple x86_64-pc-linux-gnu %s -Wno-conversion -Wfloat-zero-conversion -DZERO
   4
   5 float ReturnFloat();
   6
   7 #ifdef FLOAT_CONVERSION
   8 bool ReturnBool(float f) {
   9   return f;  //expected-warning{{conversion}}
  10 }
  11
  12 char ReturnChar(float f) {
  13   return f;  //expected-warning{{conversion}}
  14 }
  15
  16 int ReturnInt(float f) {
  17   return f;  //expected-warning{{conversion}}
  18 }
  19
  20 long ReturnLong(float f) {
  21   return f;  //expected-warning{{conversion}}
  22 }
  23
  24 void Convert(float f, double d, long double ld) {
  25   bool b;
  26   char c;
  27   int i;
  28   long l;
  29
  30   b = f;  //expected-warning{{conversion}}
  31   b = d;  //expected-warning{{conversion}}
  32   b = ld;  //expected-warning{{conversion}}
  33   c = f;  //expected-warning{{conversion}}
  34   c = d;  //expected-warning{{conversion}}
  35   c = ld;  //expected-warning{{conversion}}
  36   i = f;  //expected-warning{{conversion}}
  37   i = d;  //expected-warning{{conversion}}
  38   i = ld;  //expected-warning{{conversion}}
  39   l = f;  //expected-warning{{conversion}}
  40   l = d;  //expected-warning{{conversion}}
  41   l = ld;  //expected-warning{{conversion}}
  42 }
  43
  44 void CompoundAssignment() {
  45   int x = 3;
  46
  47   x += 1.234; // expected-warning {{implicit conversion turns floating-point number into integer: 'double' to 'int'}}
  48   x -= -0.0;  // expected-warning {{implicit conversion turns floating-point number into integer: 'double' to 'int'}}
  49   x *= 1.1f;  // expected-warning {{implicit conversion turns floating-point number into integer: 'float' to 'int'}}
  50   x /= -2.2f; // expected-warning {{implicit conversion turns floating-point number into integer: 'float' to 'int'}}
  51
  52   int y = x += 1.4f; // expected-warning {{implicit conversion turns floating-point number into integer: 'float' to 'int'}}
  53
  54   float z = 1.1f;
  55   double w = -2.2;
  56
  57   y += z + w; // expected-warning {{implicit conversion turns floating-point number into integer: 'double' to 'int'}}
  58 }
  59
  60 # 1 "foo.h" 3
  61 //          ^ the following text comes from a system header file.
  62 #define SYSTEM_MACRO_FLOAT(x) do { (x) += 1.1; } while(0)
  63 # 1 "warn-float-conversion.cpp" 1
  64 //                              ^ start of a new file.
  65 void SystemMacro() {
  66   float x = 0.0f;
  67   SYSTEM_MACRO_FLOAT(x);
  68 }
  69
  70 void Test() {
  71   int a1 = 10.0/2.0;  //expected-warning{{conversion}}
  72   int a2 = 1.0/2.0;  //expected-warning{{conversion}}
  73   bool a3 = ReturnFloat();  //expected-warning{{conversion}}
  74   int a4 = 1e30 + 1;  //expected-warning{{conversion}}
  75 }
  76
  77 void TestConstantFloat() {
  78   // Don't warn on exact floating literals.
  79   int a1 = 5.0;
  80   int a2 = 1e3;
  81
  82   int a3 = 5.5;  // caught by -Wliteral-conversion
  83   int a4 = 500.44;  // caught by -Wliteral-convserion
  84
  85   int b1 = 5.0 / 1.0;  //expected-warning{{conversion}}
  86   int b2 = 5.0 / 2.0;  //expected-warning{{conversion}}
  87
  88   const float five = 5.0;
  89
  90   int b3 = five / 1.0;  //expected-warning{{conversion}}
  91   int b4 = five / 2.0;  //expected-warning{{conversion}}
  92
  93   int f = 2147483646.5 + 1; // expected-warning{{implicit conversion from 'double' to 'int' changes value from 2147483647.5 to 2147483647}}
  94   unsigned g = -.5 + .01; // expected-warning{{implicit conversion from 'double' to 'unsigned int' changes non-zero value from -0.49 to 0}}
  95 }
  96 #endif  // FLOAT_CONVERSION
  97
  98 #ifdef ZERO
  99 void TestZero() {
 100   const float half = .5;
 101   int a1 = half;  // expected-warning{{implicit conversion from 'const float' to 'int' changes non-zero value from 0.5 to 0}}
 102   int a2 = 1.0 / 2.0;  // expected-warning{{implicit conversion from 'double' to 'int' changes non-zero value from 0.5 to 0}}
 103   int a3 = 5;
 104 }
 105 #endif  // ZERO
 106
 107 #ifdef OVERFLOW
 108 void TestOverflow() {
 109   char a = 500.0;  // caught by -Wliteral-conversion
 110   char b = -500.0;  // caught by -Wliteral-conversion
 111
 112   const float LargeNumber = 1024;
 113   char c = LargeNumber;  // expected-warning{{implicit conversion of out of range value from 'const float' to 'char' is undefined}}
 114   char d = 400.0 + 400.0;  // expected-warning{{implicit conversion of out of range value from 'double' to 'char' is undefined}}
 115
 116   char e = 1.0 / 0.0;  // expected-warning{{implicit conversion of out of range value from 'double' to 'char' is undefined}}
 117 }
 118
 119
 120 template <typename T>
 121 class Check {
 122  public:
 123   static constexpr bool Safe();
 124 };
 125
 126 template<>
 127 constexpr bool Check<char>::Safe() { return false; }
 128
 129 template<>
 130 constexpr bool Check<float>::Safe() { return true; }
 131
 132 template <typename T>
 133 T run1(T t) {
 134   const float ret = 800;
 135   return ret;  // expected-warning {{implicit conversion of out of range value from 'const float' to 'char' is undefined}}
 136 }
 137
 138 template <typename T>
 139 T run2(T t) {
 140   const float ret = 800;
 141   if (Check<T>::Safe())
 142     return ret;
 143   else
 144     return t;
 145 }
 146
 147 void test() {
 148   float a = run1(a) + run2(a);
 149   char b = run1(b) + run2(b);  // expected-note {{in instantiation of function template specialization 'run1<char>' requested here}}
 150 }
 151
 152 #endif  // OVERFLOW