| 1 | // RUN: %clang_cc1 -fsyntax-only -fdouble-square-bracket-attributes -verify %s |
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| 2 | |
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| 3 | struct [[nodiscard]] S1 { // ok |
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| 4 | int i; |
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| 5 | }; |
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| 6 | struct [[nodiscard nodiscard]] S2 { // expected-error {{attribute 'nodiscard' cannot appear multiple times in an attribute specifier}} |
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| 7 | int i; |
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| 8 | }; |
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| 9 | struct [[nodiscard("Wrong")]] S3 { // expected-error {{'nodiscard' cannot have an argument list}} |
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| 10 | int i; |
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| 11 | }; |
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| 12 | |
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| 13 | [[nodiscard]] int f1(void); |
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| 14 | enum [[nodiscard]] E1 { One }; |
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| 15 | |
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| 16 | [[nodiscard]] int i; // expected-warning {{'nodiscard' attribute only applies to Objective-C methods, enums, structs, unions, classes, functions, and function pointers}} |
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| 17 | |
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| 18 | struct [[nodiscard]] S4 { |
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| 19 | int i; |
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| 20 | }; |
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| 21 | struct S4 get_s(void); |
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| 22 | |
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| 23 | enum [[nodiscard]] E2 { Two }; |
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| 24 | enum E2 get_e(void); |
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| 25 | |
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| 26 | [[nodiscard]] int get_i(); |
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| 27 | |
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| 28 | void f2(void) { |
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| 29 | get_s(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} |
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| 30 | get_i(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} |
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| 31 | get_e(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}} |
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| 32 | |
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| 33 | // Okay, warnings are not encouraged |
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| 34 | (void)get_s(); |
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| 35 | (void)get_i(); |
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| 36 | (void)get_e(); |
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| 37 | } |
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| 38 | |
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| 39 | struct [[nodiscard]] error_info{ |
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| 40 | int i; |
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| 41 | }; |
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| 42 | |
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| 43 | struct error_info enable_missile_safety_mode(void); |
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| 44 | void launch_missiles(void); |
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| 45 | void test_missiles(void) { |
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| 46 | enable_missile_safety_mode(); // expected-warning {{ignoring return value of function declared with 'nodiscard'}} |
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| 47 | launch_missiles(); |
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| 48 | } |
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| 49 | |
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| 50 | |
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