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 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(); 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 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); 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 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
