clang/test/Sema/tautological-unsigned-enum-zero-compare.c

   1 // RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -fsyntax-only \
   2 // RUN:            -Wtautological-unsigned-enum-zero-compare \
   3 // RUN:            -verify=unsigned,unsigned-signed %s
   4 // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \
   5 // RUN:            -Wtautological-unsigned-enum-zero-compare \
   6 // RUN:            -verify=unsigned-signed %s
   7 // RUN: %clang_cc1 -triple=x86_64-pc-win32 -fsyntax-only \
   8 // RUN:            -verify=silence %s
   9
  10 // Okay, this is where it gets complicated.
  11 // Then default enum sigdness is target-specific.
  12 // On windows, it is signed by default. We do not want to warn in that case.
  13
  14 int main(void) {
  15   enum A { A_a = 0 };
  16   enum A a;
  17   enum B { B_a = -1 };
  18   enum B b;
  19
  20   // silence-no-diagnostics
  21
  22   if (a < 0) // unsigned-warning {{comparison of unsigned enum expression < 0 is always false}}
  23     return 0;
  24   if (0 >= a)
  25     return 0;
  26   if (a > 0)
  27     return 0;
  28   if (0 <= a) // unsigned-warning {{comparison of 0 <= unsigned enum expression is always true}}
  29     return 0;
  30   if (a <= 0)
  31     return 0;
  32   if (0 > a) // unsigned-warning {{comparison of 0 > unsigned enum expression is always false}}
  33     return 0;
  34   if (a >= 0) // unsigned-warning {{comparison of unsigned enum expression >= 0 is always true}}
  35     return 0;
  36   if (0 < a)
  37     return 0;
  38
  39   if (a < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
  40     return 0;
  41   if (0U >= a)
  42     return 0;
  43   if (a > 0U)
  44     return 0;
  45   if (0U <= a) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
  46     return 0;
  47   if (a <= 0U)
  48     return 0;
  49   if (0U > a) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
  50     return 0;
  51   if (a >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
  52     return 0;
  53   if (0U < a)
  54     return 0;
  55
  56   if (b < 0)
  57     return 0;
  58   if (0 >= b)
  59     return 0;
  60   if (b > 0)
  61     return 0;
  62   if (0 <= b)
  63     return 0;
  64   if (b <= 0)
  65     return 0;
  66   if (0 > b)
  67     return 0;
  68   if (b >= 0)
  69     return 0;
  70   if (0 < b)
  71     return 0;
  72
  73   if (b < 0U) // unsigned-signed-warning {{comparison of unsigned enum expression < 0 is always false}}
  74     return 0;
  75   if (0U >= b)
  76     return 0;
  77   if (b > 0U)
  78     return 0;
  79   if (0U <= b) // unsigned-signed-warning {{comparison of 0 <= unsigned enum expression is always true}}
  80     return 0;
  81   if (b <= 0U)
  82     return 0;
  83   if (0U > b) // unsigned-signed-warning {{comparison of 0 > unsigned enum expression is always false}}
  84     return 0;
  85   if (b >= 0U) // unsigned-signed-warning {{comparison of unsigned enum expression >= 0 is always true}}
  86     return 0;
  87   if (0U < b)
  88     return 0;
  89
  90   if (a == 0)
  91     return 0;
  92   if (0 != a)
  93     return 0;
  94   if (a != 0)
  95     return 0;
  96   if (0 == a)
  97     return 0;
  98
  99   if (a == 0U)
 100     return 0;
 101   if (0U != a)
 102     return 0;
 103   if (a != 0U)
 104     return 0;
 105   if (0U == a)
 106     return 0;
 107
 108   if (b == 0)
 109     return 0;
 110   if (0 != b)
 111     return 0;
 112   if (b != 0)
 113     return 0;
 114   if (0 == b)
 115     return 0;
 116
 117   if (b == 0U)
 118     return 0;
 119   if (0U != b)
 120     return 0;
 121   if (b != 0U)
 122     return 0;
 123   if (0U == b)
 124     return 0;
 125
 126   return 1;
 127 }