| 1 | // RUN: %clang_cc1 -fsyntax-only -Wself-assign -verify %s |
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| 2 | |
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| 3 | void f() { |
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| 4 | int a = 42, b = 42; |
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| 5 | a = a; // expected-warning{{explicitly assigning}} |
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| 6 | b = b; // expected-warning{{explicitly assigning}} |
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| 7 | a = b; |
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| 8 | b = a = b; |
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| 9 | a = a = a; // expected-warning{{explicitly assigning}} |
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| 10 | a = b = b = a; |
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| 11 | |
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| 12 | a *= a; |
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| 13 | a /= a; |
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| 14 | a %= a; |
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| 15 | a += a; |
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| 16 | a -= a; |
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| 17 | a <<= a; |
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| 18 | a >>= a; |
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| 19 | a &= a; // expected-warning {{explicitly assigning}} |
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| 20 | a |= a; // expected-warning {{explicitly assigning}} |
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| 21 | a ^= a; |
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| 22 | } |
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| 23 | |
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| 24 | // Dummy type. |
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| 25 | struct S {}; |
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| 26 | |
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| 27 | void false_positives() { |
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| 28 | #define OP = |
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| 29 | #define LHS a |
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| 30 | #define RHS a |
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| 31 | int a = 42; |
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| 32 | // These shouldn't warn due to the use of the preprocessor. |
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| 33 | a OP a; |
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| 34 | LHS = a; |
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| 35 | a = RHS; |
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| 36 | LHS OP RHS; |
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| 37 | #undef OP |
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| 38 | #undef LHS |
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| 39 | #undef RHS |
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| 40 | |
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| 41 | // A way to silence the warning. |
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| 42 | a = (int &)a; |
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| 43 | |
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| 44 | // Volatile stores aren't side-effect free. |
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| 45 | volatile int vol_a; |
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| 46 | vol_a = vol_a; |
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| 47 | volatile int &vol_a_ref = vol_a; |
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| 48 | vol_a_ref = vol_a_ref; |
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| 49 | } |
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| 50 | |
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| 51 | // Do not diagnose self-assigment in an unevaluated context |
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| 52 | void false_positives_unevaluated_ctx(int a) noexcept(noexcept(a = a)) // expected-warning {{expression with side effects has no effect in an unevaluated context}} |
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| 53 | { |
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| 54 | decltype(a = a) b = a; // expected-warning {{expression with side effects has no effect in an unevaluated context}} |
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| 55 | static_assert(noexcept(a = a), ""); // expected-warning {{expression with side effects has no effect in an unevaluated context}} |
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| 56 | static_assert(sizeof(a = a), ""); // expected-warning {{expression with side effects has no effect in an unevaluated context}} |
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| 57 | } |
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| 58 | |
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| 59 | template <typename T> |
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| 60 | void g() { |
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| 61 | T a; |
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| 62 | a = a; // expected-warning{{explicitly assigning}} |
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| 63 | } |
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| 64 | void instantiate() { |
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| 65 | g<int>(); |
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| 66 | g<S>(); |
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| 67 | } |
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| 68 | |
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