clang/test/Sema/unary-minus-integer-impcast.c

   1 // RUN: %clang_cc1 %s -verify -Wconversion -fsyntax-only -triple x86_64-pc-linux-gnu
   2 // RUN: %clang_cc1 %s -verify -Wconversion -fsyntax-only -triple i386-pc-linux-gnu
   3
   4 void test(void) {
   5   unsigned int a = 1;
   6
   7   unsigned long long b = -a; // expected-warning {{higher order bits are zeroes after implicit conversion}}
   8   long long c = -a;          // expected-warning {{the resulting value is always non-negative after implicit conversion}}
   9
  10   unsigned long b2 = -a;
  11 #ifdef __x86_64__
  12 // expected-warning@-2 {{higher order bits are zeroes after implicit conversion}}
  13 #endif
  14   long c2 = -a;
  15 #ifdef __x86_64__
  16 // expected-warning@-2 {{the resulting value is always non-negative after implicit conversion}}
  17 #else
  18 // expected-warning@-4 {{implicit conversion changes signedness: 'unsigned int' to 'long'}}
  19 #endif
  20
  21   unsigned m;
  22   int n = -(m & 0xff); // no warning
  23 }