1// RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wunused-value -Wunused-label %s
2// RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wunused %s
3// RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wall %s
4
5int i = 0;
6int j = 0;
7
8void foo();
9
10// PR4806
11void pr4806() {
12  1,foo();          // expected-warning {{expression result unused}}
13
14  // other
15  foo();
16  i;                // expected-warning {{expression result unused}}
17
18  i,foo();          // expected-warning {{expression result unused}}
19  foo(),i;          // expected-warning {{expression result unused}}
20
21  i,j,foo();        // expected-warning {{expression result unused}} expected-warning {{expression result unused}}
22  i,foo(),j;        // expected-warning {{expression result unused}} expected-warning {{expression result unused}}
23  foo(),i,j;        // expected-warning {{expression result unused}} expected-warning {{expression result unused}}
24
25  i++;
26
27  i++,foo();
28  foo(),i++;
29
30  i++,j,foo();      // expected-warning {{expression result unused}}
31  i++,foo(),j;      // expected-warning {{expression result unused}}
32  foo(),i++,j;      // expected-warning {{expression result unused}}
33
34  i,j++,foo();      // expected-warning {{expression result unused}}
35  i,foo(),j++;      // expected-warning {{expression result unused}}
36  foo(),i,j++;      // expected-warning {{expression result unused}}
37
38  i++,j++,foo();
39  i++,foo(),j++;
40  foo(),i++,j++;
41
42  {};
43  ({});
44  ({}),foo();
45  foo(),({});
46
47  (int)1U;          // expected-warning {{expression result unused}}
48  (void)1U;
49
50  // pointer to volatile has side effect (thus no warning)
51  int* pi = &i;
52  volatile int* pj = &j;
53  *pi;              // expected-warning {{expression result unused}}
54  *pj;
55
56  foo_label:        // expected-warning {{unused label}}
57  i;                // expected-warning {{expression result unused}}
58}
59
60// Don't warn about unused '||', '&&' expressions that contain assignments.
61int test_logical_foo1();
62int test_logical_foo2();
63int test_logical_foo3();
64int test_logical_bar() {
65  int x = 0;
66  (x = test_logical_foo1()) ||  // no-warning
67  (x = test_logical_foo2()) ||  // no-warning
68  (x = test_logical_foo3());    // no-warning
69
70  x || test_logical_foo1();     // no-warning
71
72  return x;
73}
74
75// PR8282
76void conditional_for_control_flow(int cond, int x, int y)
77{
78    cond? y++ : x; // no-warning
79    cond? y : ++x; // no-warning
80    cond? (x |= y) : ++x; // no-warning
81    cond? y : x; // expected-warning {{expression result unused}}
82}
83
84struct s0 { int f0; };
85
86void f0(int a);
87void f1(struct s0 *a) {
88  // rdar://8139785
89  f0((int)(a->f0 + 1, 10)); // expected-warning {{expression result unused}}
90}
91
92void blah(int a);
93#define GenTest(x) _Generic(x, default : blah)(x)
94
95void unevaluated_operands(void) {
96  int val = 0;
97
98  (void)sizeof(++val); // expected-warning {{expression with side effects has no effect in an unevaluated context}}
99  (void)_Generic(val++, default : 0); // expected-warning {{expression with side effects has no effect in an unevaluated context}}
100  (void)_Alignof(val++);  // expected-warning {{expression with side effects has no effect in an unevaluated context}} expected-warning {{'_Alignof' applied to an expression is a GNU extension}}
101
102  // VLAs can have side effects so long as it's part of the type and not
103  // an expression.
104  (void)sizeof(int[++val]); // Ok
105  (void)_Alignof(int[++val]); // Ok
106
107  // Side effects as part of macro expansion are ok.
108  GenTest(val++);
109}
110