54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
// RUN: %clang_cc1 -fsyntax-only -std=c2x -verify %s
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struct [[nodiscard]] S1 { // ok
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int i;
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};
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struct [[nodiscard nodiscard]] S2 { // expected-error {{attribute 'nodiscard' cannot appear multiple times in an attribute specifier}}
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int i;
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};
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struct [[nodiscard("Wrong")]] S3 { // FIXME: may need an extension warning.
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int i;
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};
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struct S3 get_s3(void);
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[[nodiscard]] int f1(void);
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enum [[nodiscard]] E1 { One };
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[[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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struct [[nodiscard]] S4 {
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int i;
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};
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struct S4 get_s(void);
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enum [[nodiscard]] E2 { Two };
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enum E2 get_e(void);
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[[nodiscard]] int get_i();
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void f2(void) {
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get_s(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
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get_s3(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute: Wrong}}
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get_i(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
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get_e(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
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// Okay, warnings are not encouraged
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(void)get_s();
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(void)get_s3();
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(void)get_i();
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(void)get_e();
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}
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struct [[nodiscard]] error_info{
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int i;
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};
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struct error_info enable_missile_safety_mode(void);
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void launch_missiles(void);
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void test_missiles(void) {
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enable_missile_safety_mode(); // expected-warning {{ignoring return value of function declared with 'nodiscard'}}
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launch_missiles();
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}
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