Author: rsmith Date: Wed Nov 14 13:04:34 2018 New Revision: 346892 URL: http://llvm.org/viewvc/llvm-project?rev=346892&view=rev Log: [c++20] Implement P0482R6: enable -fchar8_t by default in C++20 mode.
This unfortunately results in a substantial breaking change when switching to C++20, but it's not yet clear what / how much we should do about that. We may want to add a compatibility conversion from u8 string literals to const char*, similar to how C++98 provided a compatibility conversion from string literals to non-const char*, but that's not handled by this patch. The feature can be disabled in C++20 mode with -fno-char8_t. Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td cfe/trunk/include/clang/Driver/Options.td cfe/trunk/lib/Driver/ToolChains/Clang.cpp cfe/trunk/lib/Frontend/CompilerInvocation.cpp cfe/trunk/lib/Frontend/InitPreprocessor.cpp cfe/trunk/lib/Sema/SemaExpr.cpp cfe/trunk/lib/Sema/SemaInit.cpp cfe/trunk/test/Lexer/cxx-features.cpp cfe/trunk/test/SemaCXX/char8_t.cpp cfe/trunk/test/SemaCXX/cxx2a-compat.cpp cfe/trunk/www/cxx_status.html Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original) +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Nov 14 13:04:34 2018 @@ -5809,8 +5809,14 @@ def err_array_init_plain_string_into_cha def note_array_init_plain_string_into_char8_t : Note< "add 'u8' prefix to form a 'char8_t' string literal">; def err_array_init_utf8_string_into_char : Error< - "initialization of char array with UTF-8 string literal is not permitted " - "by '-fchar8_t'">; + "%select{|ISO C++20 does not permit }0initialization of char array with " + "UTF-8 string literal%select{ is not permitted by '-fchar8_t'|}0">; +def warn_cxx2a_compat_utf8_string : Warning< + "type of UTF-8 string literal will change from array of const char to " + "array of const char8_t in C++2a">, InGroup<CXX2aCompat>, DefaultIgnore; +def note_cxx2a_compat_utf8_string_remove_u8 : Note< + "remove 'u8' prefix to avoid a change of behavior; " + "Clang encodes unprefixed narrow string literals as UTF-8">; def err_array_init_different_type : Error< "cannot initialize array %diff{of type $ with array of type $|" "with different type of array}0,1">; Modified: cfe/trunk/include/clang/Driver/Options.td URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/include/clang/Driver/Options.td (original) +++ cfe/trunk/include/clang/Driver/Options.td Wed Nov 14 13:04:34 2018 @@ -1600,7 +1600,7 @@ def fshort_enums : Flag<["-"], "fshort-e HelpText<"Allocate to an enum type only as many bytes as it needs for the declared range of possible values">; def fchar8__t : Flag<["-"], "fchar8_t">, Group<f_Group>, Flags<[CC1Option]>, HelpText<"Enable C++ builtin type char8_t">; -def fno_char8__t : Flag<["-"], "fno-char8_t">, Group<f_Group>, +def fno_char8__t : Flag<["-"], "fno-char8_t">, Group<f_Group>, Flags<[CC1Option]>, HelpText<"Disable C++ builtin type char8_t">; def fshort_wchar : Flag<["-"], "fshort-wchar">, Group<f_Group>, HelpText<"Force wchar_t to be a short unsigned int">; Modified: cfe/trunk/lib/Driver/ToolChains/Clang.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Clang.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/lib/Driver/ToolChains/Clang.cpp (original) +++ cfe/trunk/lib/Driver/ToolChains/Clang.cpp Wed Nov 14 13:04:34 2018 @@ -2772,8 +2772,10 @@ static void RenderCharacterOptions(const CmdArgs.push_back("-fno-signed-char"); } - if (Args.hasFlag(options::OPT_fchar8__t, options::OPT_fno_char8__t, false)) - CmdArgs.push_back("-fchar8_t"); + // The default depends on the language standard. + if (const Arg *A = + Args.getLastArg(options::OPT_fchar8__t, options::OPT_fno_char8__t)) + A->render(Args, CmdArgs); if (const Arg *A = Args.getLastArg(options::OPT_fshort_wchar, options::OPT_fno_short_wchar)) { Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original) +++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Wed Nov 14 13:04:34 2018 @@ -2475,7 +2475,7 @@ static void ParseLangArgs(LangOptions &O Opts.ImplicitModules = !Args.hasArg(OPT_fno_implicit_modules); Opts.CharIsSigned = Opts.OpenCL || !Args.hasArg(OPT_fno_signed_char); Opts.WChar = Opts.CPlusPlus && !Args.hasArg(OPT_fno_wchar); - Opts.Char8 = Args.hasArg(OPT_fchar8__t); + Opts.Char8 = Args.hasFlag(OPT_fchar8__t, OPT_fno_char8__t, Opts.CPlusPlus2a); if (const Arg *A = Args.getLastArg(OPT_fwchar_type_EQ)) { Opts.WCharSize = llvm::StringSwitch<unsigned>(A->getValue()) .Case("char", 1) Modified: cfe/trunk/lib/Frontend/InitPreprocessor.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/InitPreprocessor.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/lib/Frontend/InitPreprocessor.cpp (original) +++ cfe/trunk/lib/Frontend/InitPreprocessor.cpp Wed Nov 14 13:04:34 2018 @@ -558,15 +558,15 @@ static void InitializeCPlusPlusFeatureTe if (LangOpts.RelaxedTemplateTemplateArgs) Builder.defineMacro("__cpp_template_template_args", "201611L"); + // C++20 features. + if (LangOpts.Char8) + Builder.defineMacro("__cpp_char8_t", "201811L"); + // TS features. if (LangOpts.ConceptsTS) Builder.defineMacro("__cpp_experimental_concepts", "1L"); if (LangOpts.CoroutinesTS) Builder.defineMacro("__cpp_coroutines", "201703L"); - - // Potential future breaking changes. - if (LangOpts.Char8) - Builder.defineMacro("__cpp_char8_t", "201803L"); } static void InitializePredefinedMacros(const TargetInfo &TI, Modified: cfe/trunk/lib/Sema/SemaExpr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaExpr.cpp (original) +++ cfe/trunk/lib/Sema/SemaExpr.cpp Wed Nov 14 13:04:34 2018 @@ -1559,6 +1559,32 @@ Sema::ActOnStringLiteral(ArrayRef<Token> CharTy = Context.UnsignedCharTy; } + // Warn on initializing an array of char from a u8 string literal; this + // becomes ill-formed in C++2a. + if (getLangOpts().CPlusPlus && !getLangOpts().CPlusPlus2a && + !getLangOpts().Char8 && Kind == StringLiteral::UTF8) { + Diag(StringTokLocs.front(), diag::warn_cxx2a_compat_utf8_string); + + // Create removals for all 'u8' prefixes in the string literal(s). This + // ensures C++2a compatibility (but may change the program behavior when + // built by non-Clang compilers for which the execution character set is + // not always UTF-8). + auto RemovalDiag = PDiag(diag::note_cxx2a_compat_utf8_string_remove_u8); + SourceLocation RemovalDiagLoc; + for (const Token &Tok : StringToks) { + if (Tok.getKind() == tok::utf8_string_literal) { + if (RemovalDiagLoc.isInvalid()) + RemovalDiagLoc = Tok.getLocation(); + RemovalDiag << FixItHint::CreateRemoval(CharSourceRange::getCharRange( + Tok.getLocation(), + Lexer::AdvanceToTokenCharacter(Tok.getLocation(), 2, + getSourceManager(), getLangOpts()))); + } + } + Diag(RemovalDiagLoc, RemovalDiag); + } + + QualType CharTyConst = CharTy; // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings) Modified: cfe/trunk/lib/Sema/SemaInit.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaInit.cpp (original) +++ cfe/trunk/lib/Sema/SemaInit.cpp Wed Nov 14 13:04:34 2018 @@ -8268,7 +8268,8 @@ bool InitializationSequence::Diagnose(Se break; case FK_UTF8StringIntoPlainChar: S.Diag(Kind.getLocation(), - diag::err_array_init_utf8_string_into_char); + diag::err_array_init_utf8_string_into_char) + << S.getLangOpts().CPlusPlus2a; break; case FK_ArrayTypeMismatch: case FK_NonConstantArrayInit: Modified: cfe/trunk/test/Lexer/cxx-features.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Lexer/cxx-features.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/test/Lexer/cxx-features.cpp (original) +++ cfe/trunk/test/Lexer/cxx-features.cpp Wed Nov 14 13:04:34 2018 @@ -9,53 +9,64 @@ // RUN: %clang_cc1 -fno-rtti -fno-threadsafe-statics -verify %s -DNO_EXCEPTIONS -DNO_RTTI -DNO_THREADSAFE_STATICS -fsized-deallocation // RUN: %clang_cc1 -fcoroutines-ts -DNO_EXCEPTIONS -DCOROUTINES -verify -fsized-deallocation %s // RUN: %clang_cc1 -fchar8_t -DNO_EXCEPTIONS -DCHAR8_T -verify -fsized-deallocation %s +// RUN: %clang_cc1 -std=c++2a -fno-char8_t -DNO_EXCEPTIONS -DNO_CHAR8_T -verify -fsized-deallocation %s // expected-no-diagnostics // FIXME using `defined` in a macro has undefined behavior. #if __cplusplus < 201103L -#define check(macro, cxx98, cxx11, cxx14, cxx17) cxx98 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx98 +#define check(macro, cxx98, cxx11, cxx14, cxx17, cxx20) (cxx98 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx98) #elif __cplusplus < 201402L -#define check(macro, cxx98, cxx11, cxx14, cxx17) cxx11 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx11 -#elif __cplusplus < 201406L -#define check(macro, cxx98, cxx11, cxx14, cxx17) cxx14 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx14 +#define check(macro, cxx98, cxx11, cxx14, cxx17, cxx20) (cxx11 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx11) +#elif __cplusplus < 201703L +#define check(macro, cxx98, cxx11, cxx14, cxx17, cxx20) (cxx14 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx14) +#elif __cplusplus <= 201703L +#define check(macro, cxx98, cxx11, cxx14, cxx17, cxx20) (cxx17 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx17) #else -#define check(macro, cxx98, cxx11, cxx14, cxx17) cxx17 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx17 +#define check(macro, cxx98, cxx11, cxx14, cxx17, cxx20) (cxx20 == 0 ? defined(__cpp_##macro) : __cpp_##macro != cxx20) +#endif + +// --- C++20 features --- + +#if defined(CHAR8_T) ? check(char8_t, 201811, 201811, 201811, 201811, 201811) : \ + defined(NO_CHAR8_T) ? check(char8_t, 0, 0, 0, 0, 0) : \ + check(char8_t, 0, 0, 0, 0, 201811) +#error "wrong value for __cpp_char8_t" #endif // --- C++17 features --- -#if check(hex_float, 0, 0, 0, 201603) +#if check(hex_float, 0, 0, 0, 201603, 201603) #error "wrong value for __cpp_hex_float" #endif -#if check(inline_variables, 0, 0, 0, 201606) +#if check(inline_variables, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_inline_variables" #endif -#if check(aligned_new, 0, 0, 0, 201606) +#if check(aligned_new, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_aligned_new" #endif -#if check(guaranteed_copy_elision, 0, 0, 0, 201606) +#if check(guaranteed_copy_elision, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_guaranteed_copy_elision" #endif -#if check(noexcept_function_type, 0, 0, 0, 201510) +#if check(noexcept_function_type, 0, 0, 0, 201510, 201510) #error "wrong value for __cpp_noexcept_function_type" #endif -#if check(fold_expressions, 0, 0, 0, 201603) +#if check(fold_expressions, 0, 0, 0, 201603, 201603) #error "wrong value for __cpp_fold_expressions" #endif -#if check(capture_star_this, 0, 0, 0, 201603) +#if check(capture_star_this, 0, 0, 0, 201603, 201603) #error "wrong value for __cpp_capture_star_this" #endif // constexpr checked below -#if check(if_constexpr, 0, 0, 0, 201606) +#if check(if_constexpr, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_if_constexpr" #endif @@ -63,204 +74,199 @@ // static_assert checked below -#if check(deduction_guides, 0, 0, 0, 201703) +#if check(deduction_guides, 0, 0, 0, 201703, 201703) #error "wrong value for __cpp_deduction_guides" #endif -#if check(nontype_template_parameter_auto, 0, 0, 0, 201606) +#if check(nontype_template_parameter_auto, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_nontype_template_parameter_auto" #endif // This is the old name (from P0096R4) for // __cpp_nontype_template_parameter_auto -#if check(template_auto, 0, 0, 0, 201606) +#if check(template_auto, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_template_auto" #endif -#if check(namespace_attributes, 0, 0, 0, 201411) +#if check(namespace_attributes, 0, 0, 0, 201411, 201411) // FIXME: allowed without warning in C++14 and C++11 #error "wrong value for __cpp_namespace_attributes" #endif -#if check(enumerator_attributes, 0, 0, 0, 201411) +#if check(enumerator_attributes, 0, 0, 0, 201411, 201411) // FIXME: allowed without warning in C++14 and C++11 #error "wrong value for __cpp_enumerator_attributes" #endif // This is an old name (from P0096R4), now removed from SD-6. -#if check(nested_namespace_definitions, 0, 0, 0, 201411) +#if check(nested_namespace_definitions, 0, 0, 0, 201411, 201411) #error "wrong value for __cpp_nested_namespace_definitions" #endif // inheriting_constructors checked below -#if check(variadic_using, 0, 0, 0, 201611) +#if check(variadic_using, 0, 0, 0, 201611, 201611) #error "wrong value for __cpp_variadic_using" #endif -#if check(aggregate_bases, 0, 0, 0, 201603) +#if check(aggregate_bases, 0, 0, 0, 201603, 201603) #error "wrong value for __cpp_aggregate_bases" #endif -#if check(structured_bindings, 0, 0, 0, 201606) +#if check(structured_bindings, 0, 0, 0, 201606, 201606) #error "wrong value for __cpp_structured_bindings" #endif -#if check(nontype_template_args, 0, 0, 0, 201411) +#if check(nontype_template_args, 0, 0, 0, 201411, 201411) #error "wrong value for __cpp_nontype_template_args" #endif #if defined(RELAXED_TEMPLATE_TEMPLATE_ARGS) \ - ? check(template_template_args, 0, 0, 0, 201611) \ - : check(template_template_args, 0, 0, 0, 0) + ? check(template_template_args, 0, 0, 0, 201611, 201611) \ + : check(template_template_args, 0, 0, 0, 0, 0) #error "wrong value for __cpp_template_template_args" #endif // --- C++14 features --- -#if check(binary_literals, 0, 0, 201304, 201304) +#if check(binary_literals, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_binary_literals" #endif // (Removed from SD-6.) -#if check(digit_separators, 0, 0, 201309, 201309) +#if check(digit_separators, 0, 0, 201309, 201309, 201309) #error "wrong value for __cpp_digit_separators" #endif -#if check(init_captures, 0, 0, 201304, 201304) +#if check(init_captures, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_init_captures" #endif -#if check(generic_lambdas, 0, 0, 201304, 201304) +#if check(generic_lambdas, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_generic_lambdas" #endif -#if check(sized_deallocation, 0, 0, 201309, 201309) +#if check(sized_deallocation, 0, 0, 201309, 201309, 201309) #error "wrong value for __cpp_sized_deallocation" #endif // constexpr checked below -#if check(decltype_auto, 0, 0, 201304, 201304) +#if check(decltype_auto, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_decltype_auto" #endif -#if check(return_type_deduction, 0, 0, 201304, 201304) +#if check(return_type_deduction, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_return_type_deduction" #endif -#if check(runtime_arrays, 0, 0, 0, 0) +#if check(runtime_arrays, 0, 0, 0, 0, 0) #error "wrong value for __cpp_runtime_arrays" #endif -#if check(aggregate_nsdmi, 0, 0, 201304, 201304) +#if check(aggregate_nsdmi, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_aggregate_nsdmi" #endif -#if check(variable_templates, 0, 0, 201304, 201304) +#if check(variable_templates, 0, 0, 201304, 201304, 201304) #error "wrong value for __cpp_variable_templates" #endif // --- C++11 features --- -#if check(unicode_characters, 0, 200704, 200704, 200704) +#if check(unicode_characters, 0, 200704, 200704, 200704, 200704) #error "wrong value for __cpp_unicode_characters" #endif -#if check(raw_strings, 0, 200710, 200710, 200710) +#if check(raw_strings, 0, 200710, 200710, 200710, 200710) #error "wrong value for __cpp_raw_strings" #endif -#if check(unicode_literals, 0, 200710, 200710, 200710) +#if check(unicode_literals, 0, 200710, 200710, 200710, 200710) #error "wrong value for __cpp_unicode_literals" #endif -#if check(user_defined_literals, 0, 200809, 200809, 200809) +#if check(user_defined_literals, 0, 200809, 200809, 200809, 200809) #error "wrong value for __cpp_user_defined_literals" #endif -#if defined(NO_THREADSAFE_STATICS) ? check(threadsafe_static_init, 0, 0, 0, 0) : check(threadsafe_static_init, 200806, 200806, 200806, 200806) +#if defined(NO_THREADSAFE_STATICS) ? check(threadsafe_static_init, 0, 0, 0, 0, 0) : \ + check(threadsafe_static_init, 200806, 200806, 200806, 200806, 200806) #error "wrong value for __cpp_threadsafe_static_init" #endif -#if check(lambdas, 0, 200907, 200907, 200907) +#if check(lambdas, 0, 200907, 200907, 200907, 200907) #error "wrong value for __cpp_lambdas" #endif -#if check(constexpr, 0, 200704, 201304, 201603) +#if check(constexpr, 0, 200704, 201304, 201603, 201603) #error "wrong value for __cpp_constexpr" #endif -#if check(range_based_for, 0, 200907, 200907, 201603) +#if check(range_based_for, 0, 200907, 200907, 201603, 201603) #error "wrong value for __cpp_range_based_for" #endif -#if check(static_assert, 0, 200410, 200410, 201411) +#if check(static_assert, 0, 200410, 200410, 201411, 201411) #error "wrong value for __cpp_static_assert" #endif -#if check(decltype, 0, 200707, 200707, 200707) +#if check(decltype, 0, 200707, 200707, 200707, 200707) #error "wrong value for __cpp_decltype" #endif -#if check(attributes, 0, 200809, 200809, 200809) +#if check(attributes, 0, 200809, 200809, 200809, 200809) #error "wrong value for __cpp_attributes" #endif -#if check(rvalue_references, 0, 200610, 200610, 200610) +#if check(rvalue_references, 0, 200610, 200610, 200610, 200610) #error "wrong value for __cpp_rvalue_references" #endif -#if check(variadic_templates, 0, 200704, 200704, 200704) +#if check(variadic_templates, 0, 200704, 200704, 200704, 200704) #error "wrong value for __cpp_variadic_templates" #endif -#if check(initializer_lists, 0, 200806, 200806, 200806) +#if check(initializer_lists, 0, 200806, 200806, 200806, 200806) #error "wrong value for __cpp_initializer_lists" #endif -#if check(delegating_constructors, 0, 200604, 200604, 200604) +#if check(delegating_constructors, 0, 200604, 200604, 200604, 200604) #error "wrong value for __cpp_delegating_constructors" #endif -#if check(nsdmi, 0, 200809, 200809, 200809) +#if check(nsdmi, 0, 200809, 200809, 200809, 200809) #error "wrong value for __cpp_nsdmi" #endif -#if check(inheriting_constructors, 0, 201511, 201511, 201511) +#if check(inheriting_constructors, 0, 201511, 201511, 201511, 201511) #error "wrong value for __cpp_inheriting_constructors" #endif -#if check(ref_qualifiers, 0, 200710, 200710, 200710) +#if check(ref_qualifiers, 0, 200710, 200710, 200710, 200710) #error "wrong value for __cpp_ref_qualifiers" #endif -#if check(alias_templates, 0, 200704, 200704, 200704) +#if check(alias_templates, 0, 200704, 200704, 200704, 200704) #error "wrong value for __cpp_alias_templates" #endif // --- C++98 features --- -#if defined(NO_RTTI) ? check(rtti, 0, 0, 0, 0) : check(rtti, 199711, 199711, 199711, 199711) +#if defined(NO_RTTI) ? check(rtti, 0, 0, 0, 0, 0) : check(rtti, 199711, 199711, 199711, 199711, 199711) #error "wrong value for __cpp_rtti" #endif -#if defined(NO_EXCEPTIONS) ? check(exceptions, 0, 0, 0, 0) : check(exceptions, 199711, 199711, 199711, 199711) +#if defined(NO_EXCEPTIONS) ? check(exceptions, 0, 0, 0, 0, 0) : check(exceptions, 199711, 199711, 199711, 199711, 199711) #error "wrong value for __cpp_exceptions" #endif // --- TS features -- -#if check(experimental_concepts, 0, 0, CONCEPTS_TS, CONCEPTS_TS) +#if check(experimental_concepts, 0, 0, CONCEPTS_TS, CONCEPTS_TS, CONCEPTS_TS) #error "wrong value for __cpp_experimental_concepts" #endif -#if defined(COROUTINES) ? check(coroutines, 201703L, 201703L, 201703L, 201703L) : check(coroutines, 0, 0, 0, 0) +#if defined(COROUTINES) ? check(coroutines, 201703L, 201703L, 201703L, 201703L, 201703L) : check(coroutines, 0, 0, 0, 0, 0) #error "wrong value for __cpp_coroutines" #endif - -// --- not-yet-standard features -- - -#if defined(CHAR8_T) ? check(char8_t, 201803, 201803, 201803, 201803) : check(char8_t, 0, 0, 0, 0) -#error "wrong value for __cpp_char8_t" -#endif Modified: cfe/trunk/test/SemaCXX/char8_t.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/char8_t.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/char8_t.cpp (original) +++ cfe/trunk/test/SemaCXX/char8_t.cpp Wed Nov 14 13:04:34 2018 @@ -1,4 +1,5 @@ -// RUN: %clang_cc1 -fchar8_t -std=c++2a -verify %s +// RUN: %clang_cc1 -fchar8_t -std=c++17 -verify %s +// RUN: %clang_cc1 -std=c++2a -verify %s char8_t a = u8'a'; char8_t b[] = u8"foo"; @@ -6,7 +7,12 @@ char8_t c = 'a'; char8_t d[] = "foo"; // expected-error {{initializing 'char8_t' array with plain string literal}} expected-note {{add 'u8' prefix}} char e = u8'a'; -char f[] = u8"foo"; // expected-error {{initialization of char array with UTF-8 string literal is not permitted by '-fchar8_t'}} +char f[] = u8"foo"; +#if __cplusplus <= 201703L +// expected-error@-2 {{initialization of char array with UTF-8 string literal is not permitted by '-fchar8_t'}} +#else +// expected-error@-4 {{ISO C++20 does not permit initialization of char array with UTF-8 string literal}} +#endif char g = 'a'; char h[] = "foo"; Modified: cfe/trunk/test/SemaCXX/cxx2a-compat.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx2a-compat.cpp?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/cxx2a-compat.cpp (original) +++ cfe/trunk/test/SemaCXX/cxx2a-compat.cpp Wed Nov 14 13:04:34 2018 @@ -21,3 +21,19 @@ B b2 = {1, 2, 3, 4}; #else // expected-error@-4 2{{no viable conversion from 'int' to 'A'}} #endif + +// Essentially any use of a u8 string literal in C++<=17 is broken by C++20. +// Just warn on all such string literals. +struct string { string(const char*); }; // expected-note 0+{{candidate}} +char u8arr[] = u8"hello"; +const char *u8ptr = "wo" u8"rld"; +string u8str = u8"test" u8"test"; +#if __cplusplus <= 201703L +// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}} +// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}} +// expected-warning@-4 {{type of UTF-8 string literal will change}} expected-note@-4 {{remove 'u8' prefix}} +#else +// expected-error@-8 {{ISO C++20 does not permit initialization of char array with UTF-8 string literal}} +// expected-error@-8 {{cannot initialize a variable of type 'const char *' with an lvalue of type 'const char8_t [6]'}} +// expected-error@-8 {{no viable conversion from 'const char8_t [9]' to 'string'}} +#endif Modified: cfe/trunk/www/cxx_status.html URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/www/cxx_status.html?rev=346892&r1=346891&r2=346892&view=diff ============================================================================== --- cfe/trunk/www/cxx_status.html (original) +++ cfe/trunk/www/cxx_status.html Wed Nov 14 13:04:34 2018 @@ -996,7 +996,7 @@ as the draft C++2a standard evolves. <tr> <td><tt>char8_t</tt></td> <td><a href="http://wg21.link/p0482r6">P0482R6</a></td> - <td class="none" align="center">No</td> + <td class="full" align="center">Clang 7 <a href="#p0482">(11)</a></td> </tr> <tr> <td>Immediate functions (<tt>consteval</tt>)</td> @@ -1014,6 +1014,12 @@ as the draft C++2a standard evolves. <td class="svn" align="center">SVN</td> </tr> </table> + +<p> +<span id="p0482">(11): Prior to Clang 8, this feature is not enabled by +<tt>-std=c++2a</tt>, but can be enabled with <tt>-fchar8_t</tt>. +</span> +</p> </details> <h2 id="dr">Defect reports</h2> _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits