clang/test/Sema/tautological-unsigned-char-zero-compare.cc

   1 // RUN: %clang_cc1 -fsyntax-only \
   2 // RUN:            -fno-signed-char \
   3 // RUN:            -Wtautological-unsigned-zero-compare \
   4 // RUN:            -Wtautological-unsigned-char-zero-compare \
   5 // RUN:            -verify=unsigned %s
   6 // RUN: %clang_cc1 -fsyntax-only \
   7 // RUN:            -Wtautological-unsigned-zero-compare \
   8 // RUN:            -Wtautological-unsigned-char-zero-compare \
   9 // RUN:            -verify=signed %s
  10
  11 void f(char c, unsigned char uc, signed char cc) {
  12   if (c < 0)
  13     return;
  14   // unsigned-warning@-2 {{comparison of char expression < 0 is always false, since char is interpreted as unsigned}}
  15   if (uc < 0)
  16     return;
  17   // unsigned-warning@-2 {{comparison of unsigned expression < 0 is always false}}
  18   // signed-warning@-3 {{comparison of unsigned expression < 0 is always false}}
  19   if (cc < 0)
  20     return;
  21   // Promoted to integer expressions should not warn.
  22   if (c - 4 < 0)
  23     return;
  24 }
  25
  26 void ref(char &c, unsigned char &uc, signed char &cc) {
  27   if (c < 0)
  28     return;
  29   // unsigned-warning@-2 {{comparison of char expression < 0 is always false, since char is interpreted as unsigned}}
  30   if (uc < 0)
  31     return;
  32   // unsigned-warning@-2 {{comparison of unsigned expression < 0 is always false}}
  33   // signed-warning@-3 {{comparison of unsigned expression < 0 is always false}}
  34   if (cc < 0)
  35     return;
  36   // Promoted to integer expressions should not warn.
  37   if (c - 4 < 0)
  38     return;
  39 }