• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
5 int i = 0;
6 int j = 0;
7 
8 void foo();
9 
10 // PR4806
pr4806()11 void 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.
61 int test_logical_foo1();
62 int test_logical_foo2();
63 int test_logical_foo3();
test_logical_bar()64 int 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
conditional_for_control_flow(int cond,int x,int y)76 void 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 
84 struct s0 { int f0; };
85 
86 void f0(int a);
f1(struct s0 * a)87 void f1(struct s0 *a) {
88   // rdar://8139785
89   f0((int)(a->f0 + 1, 10)); // expected-warning {{expression result unused}}
90 }
91 
92 void blah(int a);
93 #define GenTest(x) _Generic(x, default : blah)(x)
94 
unevaluated_operands(void)95 void 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