1 // RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-negation-compare -Wno-constant-logical-operand %s
2 // RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-compare -Wno-constant-logical-operand %s
3 // RUN: %clang_cc1 -fsyntax-only -verify -Wall -Wno-unused -Wno-loop-analysis -Wno-constant-logical-operand %s
4
5 #define COPY(x) x
6
test_int(int x)7 void test_int(int x) {
8 if (x || !x) {} // expected-warning {{'||' of a value and its negation always evaluates to true}}
9 if (!x || x) {} // expected-warning {{'||' of a value and its negation always evaluates to true}}
10 if (x && !x) {} // expected-warning {{'&&' of a value and its negation always evaluates to false}}
11 if (!x && x) {} // expected-warning {{'&&' of a value and its negation always evaluates to false}}
12
13 // parentheses are ignored
14 if (x || (!x)) {} // expected-warning {{'||' of a value and its negation always evaluates to true}}
15 if (!(x) || x) {} // expected-warning {{'||' of a value and its negation always evaluates to true}}
16
17 // don't warn on macros
18 if (COPY(x) || !x) {}
19 if (!x || COPY(x)) {}
20 if (x && COPY(!x)) {}
21 if (COPY(!x && x)) {}
22
23 // dont' warn on literals
24 if (1 || !1) {}
25 if (!42 && 42) {}
26
27
28 // don't warn on overloads
29 struct Foo{
30 int val;
31 Foo operator!() const { return Foo{!val}; }
32 bool operator||(const Foo other) const { return val || other.val; }
33 bool operator&&(const Foo other) const { return val && other.val; }
34 };
35
36 Foo f{3};
37 if (f || !f) {}
38 if (!f || f) {}
39 if (f.val || !f.val) {} // expected-warning {{'||' of a value and its negation always evaluates to true}}
40 if (!f.val && f.val) {} // expected-warning {{'&&' of a value and its negation always evaluates to false}}
41 }
42