1// RUN: %clang_analyze_cc1 -analyzer-checker=core -analyzer-store=region %s -verify
2// expected-no-diagnostics
3
4//===-- unions-region.m ---------------------------------------------------===//
5//
6// This file tests the analyzer's reasoning about unions.
7//
8//===----------------------------------------------------------------------===//
9
10// [testA] When using RegionStore, this test case previously had a
11// false positive of a 'pass-by-value argument is uninitialized'
12// warning at the call to 'testA_aux' and 'testA_aux_2'.
13union u_testA {
14  unsigned i;
15  float f;
16};
17
18float testA(float f) {
19  int testA_aux(unsigned x);
20  int testA_aux_2(union u_testA z);
21
22  union u_testA swap;
23  swap.f = f;
24
25  if (testA_aux(swap.i))  // no-warning
26    swap.i = ((swap.i & 0xffff0000) >> 16) | ((swap.i & 0x0000fffff) << 16);
27
28  testA_aux_2(swap); // no-warning
29
30  return swap.f;
31}
32
33// [testB] When using RegionStore, this test case previously had a
34// false positive of a 'pass-by-value argument is uninitialized'
35// warning at the call to 'testB_aux'.
36void testB(int i) {
37  void testB_aux(short z);
38  union { short x[2]; unsigned y; } val;
39  val.y = 10;
40  testB_aux(val.x[1]); // no-warning
41}
42
43