| 1 | // RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++2a |
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| 2 | |
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| 3 | int foo(int x) { |
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| 4 | return x == x; // expected-warning {{self-comparison always evaluates to true}} |
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| 5 | } |
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| 6 | |
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| 7 | struct X { |
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| 8 | bool operator==(const X &x); |
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| 9 | }; |
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| 10 | |
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| 11 | struct A { |
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| 12 | int x; |
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| 13 | X x2; |
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| 14 | int a[3]; |
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| 15 | int b[3]; |
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| 16 | bool f() { return x == x; } // expected-warning {{self-comparison always evaluates to true}} |
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| 17 | bool g() { return x2 == x2; } // no-warning |
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| 18 | bool h() { return a == b; } // expected-warning {{array comparison always evaluates to false}} |
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| 19 | bool i() { |
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| 20 | int c[3]; |
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| 21 | return a == c; // expected-warning {{array comparison always evaluates to false}} |
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| 22 | } |
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| 23 | }; |
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| 24 | |
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| 25 | namespace NA { extern "C" int x[3]; } |
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| 26 | namespace NB { extern "C" int x[3]; } |
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| 27 | bool k = NA::x == NB::x; // expected-warning {{self-comparison always evaluates to true}} |
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| 28 | |
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| 29 | template<typename T> struct Y { static inline int n; }; |
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| 30 | bool f() { |
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| 31 | return |
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| 32 | Y<int>::n == Y<int>::n || // expected-warning {{self-comparison always evaluates to true}} |
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| 33 | Y<void>::n == Y<int>::n; |
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| 34 | } |
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| 35 | template<typename T, typename U> |
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| 36 | bool g() { |
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| 37 | // FIXME: Ideally we'd produce a self-comparison warning on the first of these. |
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| 38 | return |
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| 39 | Y<T>::n == Y<T>::n || |
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| 40 | Y<T>::n == Y<U>::n; |
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| 41 | } |
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| 42 | template bool g<int, int>(); // should not produce any warnings |
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| 43 | |
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