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d0d2772379
Implement P2513 This change allows initializing an array of unsigned char, or char from u8 string literals. This was done both to support legacy code and for compatibility with C where char8_t will be typedef to unsigned char. This is backported to C++20 as per WG21 guidance. Reviewed By: aaron.ballman Differential Revision: https://reviews.llvm.org/D136449
68 lines
2.5 KiB
C++
68 lines
2.5 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -std=c++17 -Wc++20-compat-pedantic -verify %s
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// RUN: %clang_cc1 -fsyntax-only -std=c++20 -pedantic -verify %s
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struct A { // expected-note 0+{{candidate}}
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A() = default; // expected-note 0+{{candidate}}
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int x, y;
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};
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A a1 = {1, 2};
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#if __cplusplus <= 201703L
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// expected-warning@-2 {{aggregate initialization of type 'A' with user-declared constructors is incompatible with C++20}}
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#else
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// expected-error@-4 {{no matching constructor}}
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#endif
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A a2 = {};
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struct B : A { A a; };
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B b1 = {{}, {}}; // ok
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B b2 = {1, 2, 3, 4};
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#if __cplusplus <= 201703L
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// expected-warning@-2 2{{aggregate initialization of type 'A' with user-declared constructors is incompatible with C++20}}
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#else
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// expected-error@-4 2{{no viable conversion from 'int' to 'A'}}
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#endif
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// Essentially any use of a u8 string literal in C++<=17 is broken by C++20.
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// Just warn on all such string literals.
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struct string { string(const char*); }; // expected-note 0+{{candidate}}
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char u8arr[] = u8"hello";
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const char *u8ptr = "wo" u8"rld";
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string u8str = u8"test" u8"test";
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#if __cplusplus <= 201703L
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// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}}
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// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}}
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// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}}
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#else
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// expected-error@-7 {{cannot initialize a variable of type 'const char *' with an lvalue of type 'const char8_t[6]'}}
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// expected-error@-7 {{no viable conversion from 'const char8_t[9]' to 'string'}}
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#endif
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template<bool b>
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struct C {
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explicit(C)(int);
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};
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#if __cplusplus <= 201703L
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// expected-warning@-3 {{this expression will be parsed as explicit(bool) in C++20}}
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#if defined(__cpp_conditional_explicit)
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#error "the feature test macro __cpp_conditional_explicit isn't correct"
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#endif
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#else
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// expected-error@-8 {{does not refer to a value}}
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// expected-error@-9 {{expected member name or ';'}}
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// expected-error@-10 {{expected ')'}}
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// expected-note@-12 {{declared here}}
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// expected-note@-12 {{to match this '('}}
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#if !defined(__cpp_conditional_explicit) || __cpp_conditional_explicit != 201806L
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#error "the feature test macro __cpp_conditional_explicit isn't correct"
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#endif
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#endif
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auto l = []() consteval {};
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int consteval();
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#if __cplusplus <= 201703L
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// expected-warning@-3 {{'consteval' is a keyword in C++20}}
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// expected-error@-4 {{expected body of lambda expression}}
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#else
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// expected-error@-5 {{expected unqualified-id}}
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#endif
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