clang/test/Sema/rounding-math.c

   1 // RUN: %clang_cc1 -triple x86_64-linux -std=c17 -verify=expected,norounding %s
   2 // RUN: %clang_cc1 -triple x86_64-linux -std=gnu17 -verify=expected,norounding %s
   3 // RUN: %clang_cc1 -triple x86_64-linux -std=c17 -verify=expected,rounding %s -frounding-math
   4 // RUN: %clang_cc1 -triple x86_64-linux -std=gnu17 -verify=expected,rounding %s -frounding-math
   5
   6 #define fold(x) (__builtin_constant_p(x) ? (x) : (x))
   7
   8 double a = 1.0 / 3.0;
   9
  10 #define f(n) ((n) * (1.0 / 3.0))
  11 _Static_assert(fold((int)f(3)) == 1, "");
  12
  13 typedef int T[fold((int)f(3))];
  14 typedef int T[1];
  15
  16 enum Enum { enum_a = (int)f(3) };
  17
  18 struct Bitfield {
  19   unsigned int n : 1;
  20   unsigned int m : fold((int)f(3));
  21 };
  22
  23 void bitfield(struct Bitfield *b) {
  24   b->n = (int)(6 * (1.0 / 3.0)); // norounding-warning {{changes value from 2 to 0}}
  25 }
  26
  27 void vlas(void) {
  28   // This is always a VLA due to its syntactic form.
  29   typedef int vla1[(int)(-3 * (1.0 / 3.0))];
  30   struct X1 { vla1 v; }; // expected-error {{fields must have a constant size}}
  31
  32   // This is always folded to a constant.
  33   typedef int vla2[fold((int)(-3 * (1.0 / 3.0)))]; // expected-error {{negative size}}
  34   struct X2 { vla2 v; };
  35 }