cosmopolitan/third_party/chibicc/test/union_test.c

#include "third_party/chibicc/test/test.h"

int main() {
  ASSERT(8, ({
           union {
             int a;
             char b[6];
           } x;
           sizeof(x);
         }));
  ASSERT(3, ({
           union {
             int a;
             char b[4];
           } x;
           x.a = 515;
           x.b[0];
         }));
  ASSERT(2, ({
           union {
             int a;
             char b[4];
           } x;
           x.a = 515;
           x.b[1];
         }));
  ASSERT(0, ({
           union {
             int a;
             char b[4];
           } x;
           x.a = 515;
           x.b[2];
         }));
  ASSERT(0, ({
           union {
             int a;
             char b[4];
           } x;
           x.a = 515;
           x.b[3];
         }));

  ASSERT(3, ({
           union {
             int a, b;
           } x, y;
           x.a = 3;
           y.a = 5;
           y = x;
           y.a;
         }));
  ASSERT(3, ({
           union {
             struct {
               int a, b;
             } c;
           } x, y;
           x.c.b = 3;
           y.c.b = 5;
           y = x;
           y.c.b;
         }));

  ASSERT(0xef, ({
           union {
             struct {
               unsigned char a, b, c, d;
             };
             long e;
           } x;
           x.e = 0xdeadbeef;
           x.a;
         }));
  ASSERT(0xbe, ({
           union {
             struct {
               unsigned char a, b, c, d;
             };
             long e;
           } x;
           x.e = 0xdeadbeef;
           x.b;
         }));
  ASSERT(0xad, ({
           union {
             struct {
               unsigned char a, b, c, d;
             };
             long e;
           } x;
           x.e = 0xdeadbeef;
           x.c;
         }));
  ASSERT(0xde, ({
           union {
             struct {
               unsigned char a, b, c, d;
             };
             long e;
           } x;
           x.e = 0xdeadbeef;
           x.d;
         }));

  ASSERT(3, ({
           struct {
             union {
               int a, b;
             };
             union {
               int c, d;
             };
           } x;
           x.a = 3;
           x.b;
         }));
  ASSERT(5, ({
           struct {
             union {
               int a, b;
             };
             union {
               int c, d;
             };
           } x;
           x.d = 5;
           x.c;
         }));

  return 0;
}