Re: [PATCH] libcpp: Implement P2362R3 - Remove non-encodable wide character literals and multicharacter [PR106647]

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From: Jason Merrill <jason@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] libcpp: Implement P2362R3 - Remove non-encodable wide character literals and multicharacter [PR106647]
Date: Fri, 26 Aug 2022 09:59:08 -0400	[thread overview]
Message-ID: <7762dd3e-9afd-f72f-7137-bd430618a5cb@redhat.com> (raw)
In-Reply-To: <Ywh3t1fvp+IGEBGa@tucnak>

On 8/26/22 03:35, Jakub Jelinek wrote:
> Hi!
> 
> My understanding of the paper is that we just want to promote the CPP_WCHAR
> "character constant too long for its type" warning to error as it is already
> error for u8, u and U literals.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

> 2022-08-26  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR c++/106647
> 	* charset.cc (wide_str_to_charconst): Implement P2362R3 - Remove
> 	non-encodable wide character literals and multicharacter.  For
> 	C++23 use CPP_DL_ERROR instead of CPP_DL_WARNING for
> 	"character constant too long for its type" diagnostics on CPP_WCHAR
> 	literals.
> 
> 	* g++.dg/cpp23/wchar-multi1.C: New test.
> 	* g++.dg/cpp23/wchar-multi2.C: New test.
> 
> --- libcpp/charset.cc.jj	2022-08-25 11:54:38.849924475 +0200
> +++ libcpp/charset.cc	2022-08-25 18:36:20.650415220 +0200
> @@ -2170,7 +2170,11 @@ wide_str_to_charconst (cpp_reader *pfile
>        character constant is guaranteed to overflow.  */
>     if (str.len > nbwc * 2)
>       cpp_error (pfile, (CPP_OPTION (pfile, cplusplus)
> -		       && (type == CPP_CHAR16 || type == CPP_CHAR32))
> +		       && (type == CPP_CHAR16
> +			   || type == CPP_CHAR32
> +			   /* In C++23 this is error even for L'ab'.  */
> +			   || (type == CPP_WCHAR
> +			       && CPP_OPTION (pfile, size_t_literals))))
>   		      ? CPP_DL_ERROR : CPP_DL_WARNING,
>   	       "character constant too long for its type");
>   
> --- gcc/testsuite/g++.dg/cpp23/wchar-multi1.C.jj	2022-08-25 18:08:01.973426155 +0200
> +++ gcc/testsuite/g++.dg/cpp23/wchar-multi1.C	2022-08-25 18:51:30.476687112 +0200
> @@ -0,0 +1,42 @@
> +// P2362R3 - Remove non-encodable wide character literals and multicharacter
> +// wide character literals.
> +// { dg-do compile }
> +
> +char a = 'a';
> +int b = 'ab';			// { dg-warning "multi-character character constant" }
> +int c = '\u05D9';		// { dg-warning "multi-character character constant" }
> +#if __SIZEOF_INT__ > 2
> +int d = '\U0001F525';		// { dg-warning "multi-character character constant" "" { target int32 } }
> +#endif
> +int e = 'abcd';			// { dg-warning "multi-character character constant" }
> +wchar_t f = L'f';
> +wchar_t g = L'gh';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t h = L'ijkl';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t i = L'\U0001F525';	// { dg-error "character constant too long for its type" "" { target { c++23 && { ! 4byte_wchar_t } } } }
> +				// { dg-warning "character constant too long for its type" "" { target { c++20_down && { ! 4byte_wchar_t } } } .-1 }
> +#ifdef __cpp_char8_t
> +typedef char8_t u8;
> +#else
> +typedef char u8;
> +#endif
> +#if __cpp_unicode_characters >= 201411
> +u8 j = u8'j';
> +u8 k = u8'kl';			// { dg-error "character constant too long for its type" "" { target c++17 } }
> +u8 l = u8'\U0001F525';		// { dg-error "character constant too long for its type" "" { target c++17 }  }
> +#endif
> +#if __cpp_unicode_characters >= 200704
> +char16_t m = u'm';
> +char16_t n = u'no';		// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char16_t o = u'\u05D9';
> +char16_t p = u'\U0001F525';	// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char32_t q = U'm';
> +char32_t r = U'no';		// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char32_t s = U'\u05D9';
> +char32_t t = U'\U0001F525';
> +#endif
> +wchar_t u = L'\u0065\u0301';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t v = L'é';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> --- gcc/testsuite/g++.dg/cpp23/wchar-multi2.C.jj	2022-08-25 18:51:53.744386945 +0200
> +++ gcc/testsuite/g++.dg/cpp23/wchar-multi2.C	2022-08-25 18:53:03.317489442 +0200
> @@ -0,0 +1,43 @@
> +// P2362R3 - Remove non-encodable wide character literals and multicharacter
> +// wide character literals.
> +// { dg-do compile }
> +// { dg-options "-fshort-wchar" }
> +
> +char a = 'a';
> +int b = 'ab';			// { dg-warning "multi-character character constant" }
> +int c = '\u05D9';		// { dg-warning "multi-character character constant" }
> +#if __SIZEOF_INT__ > 2
> +int d = '\U0001F525';		// { dg-warning "multi-character character constant" "" { target int32 } }
> +#endif
> +int e = 'abcd';			// { dg-warning "multi-character character constant" }
> +wchar_t f = L'f';
> +wchar_t g = L'gh';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t h = L'ijkl';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t i = L'\U0001F525';	// { dg-error "character constant too long for its type" "" { target { c++23 } } }
> +				// { dg-warning "character constant too long for its type" "" { target { c++20_down } } .-1 }
> +#ifdef __cpp_char8_t
> +typedef char8_t u8;
> +#else
> +typedef char u8;
> +#endif
> +#if __cpp_unicode_characters >= 201411
> +u8 j = u8'j';
> +u8 k = u8'kl';			// { dg-error "character constant too long for its type" "" { target c++17 } }
> +u8 l = u8'\U0001F525';		// { dg-error "character constant too long for its type" "" { target c++17 }  }
> +#endif
> +#if __cpp_unicode_characters >= 200704
> +char16_t m = u'm';
> +char16_t n = u'no';		// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char16_t o = u'\u05D9';
> +char16_t p = u'\U0001F525';	// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char32_t q = U'm';
> +char32_t r = U'no';		// { dg-error "character constant too long for its type" "" { target c++11 } }
> +char32_t s = U'\u05D9';
> +char32_t t = U'\U0001F525';
> +#endif
> +wchar_t u = L'\u0065\u0301';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> +wchar_t v = L'é';		// { dg-error "character constant too long for its type" "" { target c++23 } }
> +				// { dg-warning "character constant too long for its type" "" { target c++20_down } .-1 }
> 
> 	Jakub
>

     prev parent reply	other threads:[~2022-08-26 13:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-26  7:35 Jakub Jelinek
2022-08-26 13:59 ` Jason Merrill [this message]

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