From f63adf5b67f7a25b15f81d3a1a207aba4f226dc4 Mon Sep 17 00:00:00 2001 From: Nico Weber Date: Fri, 28 May 2021 14:49:18 -0400 Subject: [PATCH] Revert "[clang][Parse] Add parsing support for C++ attributes on using-declarations" This reverts commit dc672999a9b12a156991891dc400308b52d569ba. Breaks check-clang everywhere, see https://reviews.llvm.org/D91630 --- clang/docs/LanguageExtensions.rst | 14 ----- clang/docs/ReleaseNotes.rst | 3 - .../clang/Basic/DiagnosticParseKinds.td | 3 - .../clang/Basic/DiagnosticSemaKinds.td | 3 - clang/include/clang/Basic/Features.def | 1 - clang/include/clang/Parse/Parser.h | 5 -- clang/lib/Parse/ParseDecl.cpp | 7 --- clang/lib/Parse/ParseDeclCXX.cpp | 55 ++++++++++--------- clang/lib/Sema/SemaDeclAttr.cpp | 12 ---- clang/lib/Sema/SemaDeclCXX.cpp | 4 +- clang/test/Parser/cxx0x-attributes.cpp | 15 +---- .../cxx11-attributes-on-using-declaration.cpp | 42 -------------- 12 files changed, 34 insertions(+), 130 deletions(-) delete mode 100644 clang/test/SemaCXX/cxx11-attributes-on-using-declaration.cpp diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst index c60b8b39e1c9..129e73345b2a 100644 --- a/clang/docs/LanguageExtensions.rst +++ b/clang/docs/LanguageExtensions.rst @@ -632,20 +632,6 @@ Attributes on the ``enum`` declaration do not apply to individual enumerators. Query for this feature with ``__has_extension(enumerator_attributes)``. -C++11 Attributes on using-declarations -====================================== - -Clang allows C++-style ``[[]]`` attributes to be written on using-declarations. -For instance: - -.. code-block:: c++ - - [[clang::using_if_exists]] using foo::bar; - using foo::baz [[clang::using_if_exists]]; - -You can test for support for this extension with -``__has_extension(cxx_attributes_on_using_declarations)``. - 'User-Specified' System Frameworks ================================== diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index b43300ad6646..81609fa6efdf 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -113,9 +113,6 @@ Attribute Changes in Clang - ... -- Added support for C++11-style ``[[]]`` attributes on using-declarations, as a - clang extension. - Windows Support --------------- diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td index 6d5d08e5fbad..97cb7020f345 100644 --- a/clang/include/clang/Basic/DiagnosticParseKinds.td +++ b/clang/include/clang/Basic/DiagnosticParseKinds.td @@ -693,9 +693,6 @@ def ext_using_attribute_ns : ExtWarn< def err_using_attribute_ns_conflict : Error< "attribute with scope specifier cannot follow default scope specifier">; def err_attributes_not_allowed : Error<"an attribute list cannot appear here">; -def ext_cxx11_attr_placement : ExtWarn< - "ISO C++ does not allow an attribute list to appear here">, - InGroup>; def err_attributes_misplaced : Error<"misplaced attributes; expected attributes here">; def err_l_square_l_square_not_attribute : Error< "C++11 only allows consecutive left square brackets when " diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 80130c2584fe..4b653b8b4737 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -3957,9 +3957,6 @@ def warn_attribute_sentinel_named_arguments : Warning< def warn_attribute_sentinel_not_variadic : Warning< "'sentinel' attribute only supported for variadic %select{functions|blocks}0">, InGroup; -def warn_deprecated_ignored_on_using : Warning< - "%0 currently has no effect on a using declaration">, - InGroup; def err_attribute_sentinel_less_than_zero : Error< "'sentinel' parameter 1 less than zero">; def err_attribute_sentinel_not_zero_or_one : Error< diff --git a/clang/include/clang/Basic/Features.def b/clang/include/clang/Basic/Features.def index 592e3e33baf1..a7a5e06a937e 100644 --- a/clang/include/clang/Basic/Features.def +++ b/clang/include/clang/Basic/Features.def @@ -259,7 +259,6 @@ EXTENSION(gnu_asm, LangOpts.GNUAsm) EXTENSION(gnu_asm_goto_with_outputs, LangOpts.GNUAsm) EXTENSION(matrix_types, LangOpts.MatrixTypes) EXTENSION(matrix_types_scalar_division, true) -EXTENSION(cxx_attributes_on_using_declarations, LangOpts.CPlusPlus11) FEATURE(cxx_abi_relative_vtable, LangOpts.CPlusPlus && LangOpts.RelativeCXXABIVTables) diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h index cb618d172c5b..e3e6509b025e 100644 --- a/clang/include/clang/Parse/Parser.h +++ b/clang/include/clang/Parse/Parser.h @@ -2634,10 +2634,6 @@ private: /// locations where attributes are not allowed. void DiagnoseAndSkipCXX11Attributes(); - /// Emit warnings for C++11 and C2x attributes that are in a position that - /// clang accepts as an extension. - void DiagnoseCXX11AttributeExtension(ParsedAttributesWithRange &Attrs); - /// Parses syntax-generic attribute arguments for attributes which are /// known to the implementation, and adds them to the given ParsedAttributes /// list with the given attribute syntax. Returns the number of arguments @@ -3063,7 +3059,6 @@ private: const ParsedTemplateInfo &TemplateInfo, SourceLocation UsingLoc, SourceLocation &DeclEnd, - ParsedAttributesWithRange &Attrs, AccessSpecifier AS = AS_none); Decl *ParseAliasDeclarationAfterDeclarator( const ParsedTemplateInfo &TemplateInfo, SourceLocation UsingLoc, diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp index 76d031b62e9d..fda427508c05 100644 --- a/clang/lib/Parse/ParseDecl.cpp +++ b/clang/lib/Parse/ParseDecl.cpp @@ -1650,13 +1650,6 @@ void Parser::ProhibitCXX11Attributes(ParsedAttributesWithRange &Attrs, } } -void Parser::DiagnoseCXX11AttributeExtension(ParsedAttributesWithRange &Attrs) { - for (const ParsedAttr &PA : Attrs) { - if (PA.isCXX11Attribute() || PA.isC2xAttribute()) - Diag(PA.getLoc(), diag::ext_cxx11_attr_placement) << PA << PA.getRange(); - } -} - // Usually, `__attribute__((attrib)) class Foo {} var` means that attribute // applies to var, not the type Foo. // As an exception to the rule, __declspec(align(...)) before the diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp index 1d7b953a627b..af3d0df53e91 100644 --- a/clang/lib/Parse/ParseDeclCXX.cpp +++ b/clang/lib/Parse/ParseDeclCXX.cpp @@ -497,7 +497,11 @@ Parser::ParseUsingDirectiveOrDeclaration(DeclaratorContext Context, } // Otherwise, it must be a using-declaration or an alias-declaration. - return ParseUsingDeclaration(Context, TemplateInfo, UsingLoc, DeclEnd, attrs, + + // Using declarations can't have attributes. + ProhibitAttributes(attrs); + + return ParseUsingDeclaration(Context, TemplateInfo, UsingLoc, DeclEnd, AS_none); } @@ -623,8 +627,7 @@ bool Parser::ParseUsingDeclarator(DeclaratorContext Context, if (getLangOpts().CPlusPlus11 && Context == DeclaratorContext::Member && Tok.is(tok::identifier) && (NextToken().is(tok::semi) || NextToken().is(tok::comma) || - NextToken().is(tok::ellipsis) || NextToken().is(tok::l_square) || - NextToken().is(tok::kw___attribute)) && + NextToken().is(tok::ellipsis)) && D.SS.isNotEmpty() && LastII == Tok.getIdentifierInfo() && !D.SS.getScopeRep()->getAsNamespace() && !D.SS.getScopeRep()->getAsNamespaceAlias()) { @@ -667,10 +670,11 @@ bool Parser::ParseUsingDeclarator(DeclaratorContext Context, /// alias-declaration: C++11 [dcl.dcl]p1 /// 'using' identifier attribute-specifier-seq[opt] = type-id ; /// -Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration( - DeclaratorContext Context, const ParsedTemplateInfo &TemplateInfo, - SourceLocation UsingLoc, SourceLocation &DeclEnd, - ParsedAttributesWithRange &PrefixAttrs, AccessSpecifier AS) { +Parser::DeclGroupPtrTy +Parser::ParseUsingDeclaration(DeclaratorContext Context, + const ParsedTemplateInfo &TemplateInfo, + SourceLocation UsingLoc, SourceLocation &DeclEnd, + AccessSpecifier AS) { // Check for misplaced attributes before the identifier in an // alias-declaration. ParsedAttributesWithRange MisplacedAttrs(AttrFactory); @@ -682,17 +686,6 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration( ParsedAttributesWithRange Attrs(AttrFactory); MaybeParseAttributes(PAKM_GNU | PAKM_CXX11, Attrs); - // If we had any misplaced attributes from earlier, this is where they - // should have been written. - if (MisplacedAttrs.Range.isValid()) { - Diag(MisplacedAttrs.Range.getBegin(), diag::err_attributes_not_allowed) - << FixItHint::CreateInsertionFromRange( - Tok.getLocation(), - CharSourceRange::getTokenRange(MisplacedAttrs.Range)) - << FixItHint::CreateRemoval(MisplacedAttrs.Range); - Attrs.takeAllFrom(MisplacedAttrs); - } - // Maybe this is an alias-declaration. if (Tok.is(tok::equal)) { if (InvalidDeclarator) { @@ -700,7 +693,16 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration( return nullptr; } - ProhibitAttributes(PrefixAttrs); + // If we had any misplaced attributes from earlier, this is where they + // should have been written. + if (MisplacedAttrs.Range.isValid()) { + Diag(MisplacedAttrs.Range.getBegin(), diag::err_attributes_not_allowed) + << FixItHint::CreateInsertionFromRange( + Tok.getLocation(), + CharSourceRange::getTokenRange(MisplacedAttrs.Range)) + << FixItHint::CreateRemoval(MisplacedAttrs.Range); + Attrs.takeAllFrom(MisplacedAttrs); + } Decl *DeclFromDeclSpec = nullptr; Decl *AD = ParseAliasDeclarationAfterDeclarator( @@ -708,7 +710,10 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration( return Actions.ConvertDeclToDeclGroup(AD, DeclFromDeclSpec); } - DiagnoseCXX11AttributeExtension(PrefixAttrs); + // C++11 attributes are not allowed on a using-declaration, but GNU ones + // are. + ProhibitAttributes(MisplacedAttrs); + ProhibitAttributes(Attrs); // Diagnose an attempt to declare a templated using-declaration. // In C++11, alias-declarations can be templates: @@ -726,10 +731,8 @@ Parser::DeclGroupPtrTy Parser::ParseUsingDeclaration( SmallVector DeclsInGroup; while (true) { - // Parse (optional) attributes. - MaybeParseAttributes(PAKM_GNU | PAKM_CXX11, Attrs); - DiagnoseCXX11AttributeExtension(Attrs); - Attrs.addAll(PrefixAttrs.begin(), PrefixAttrs.end()); + // Parse (optional) attributes (most likely GNU strong-using extension). + MaybeParseGNUAttributes(Attrs); if (InvalidDeclarator) SkipUntil(tok::comma, tok::semi, StopBeforeMatch); @@ -2615,6 +2618,8 @@ Parser::ParseCXXClassMemberDeclaration(AccessSpecifier AS, MaybeParseMicrosoftAttributes(attrs); if (Tok.is(tok::kw_using)) { + ProhibitAttributes(attrs); + // Eat 'using'. SourceLocation UsingLoc = ConsumeToken(); @@ -2633,7 +2638,7 @@ Parser::ParseCXXClassMemberDeclaration(AccessSpecifier AS, SourceLocation DeclEnd; // Otherwise, it must be a using-declaration or an alias-declaration. return ParseUsingDeclaration(DeclaratorContext::Member, TemplateInfo, - UsingLoc, DeclEnd, attrs, AS); + UsingLoc, DeclEnd, AS); } // Hold late-parsed attributes so we can attach a Decl to them later. diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 130ec7675820..65467a828a5a 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -2446,13 +2446,6 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr( } static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) { - if (isa( - D)) { - S.Diag(AL.getRange().getBegin(), diag::warn_deprecated_ignored_on_using) - << AL; - return; - } - if (!AL.checkExactlyNumArgs(S, 1)) return; IdentifierLoc *Platform = AL.getArgAsIdent(0); @@ -7264,11 +7257,6 @@ static void handleDeprecatedAttr(Sema &S, Decl *D, const ParsedAttr &AL) { // namespace. return; } - } else if (isa(D)) { - S.Diag(AL.getRange().getBegin(), diag::warn_deprecated_ignored_on_using) - << AL; - return; } // Handle the cases where the attribute has a text message. diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 7739625c1b9f..f4d8f4d9aa33 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -12071,9 +12071,9 @@ NamedDecl *Sema::BuildUsingDeclaration( return nullptr; DeclContext *LookupContext = computeDeclContext(SS); + NamedDecl *D; NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); if (!LookupContext || EllipsisLoc.isValid()) { - NamedDecl *D; if (HasTypenameKeyword) { // FIXME: not all declaration name kinds are legal here D = UnresolvedUsingTypenameDecl::Create(Context, CurContext, @@ -12087,7 +12087,6 @@ NamedDecl *Sema::BuildUsingDeclaration( } D->setAccess(AS); CurContext->addDecl(D); - ProcessDeclAttributeList(S, D, AttrList); return D; } @@ -12097,7 +12096,6 @@ NamedDecl *Sema::BuildUsingDeclaration( UsingName, HasTypenameKeyword); UD->setAccess(AS); CurContext->addDecl(UD); - ProcessDeclAttributeList(S, UD, AttrList); UD->setInvalidDecl(Invalid); return UD; }; diff --git a/clang/test/Parser/cxx0x-attributes.cpp b/clang/test/Parser/cxx0x-attributes.cpp index 1b34c8cfd103..0b2bad6b0002 100644 --- a/clang/test/Parser/cxx0x-attributes.cpp +++ b/clang/test/Parser/cxx0x-attributes.cpp @@ -131,12 +131,12 @@ extern "C++" [[]] { } // expected-error {{an attribute list cannot appear here}} [[]] static_assert(true, ""); //expected-error {{an attribute list cannot appear here}} [[]] asm(""); // expected-error {{an attribute list cannot appear here}} -[[]] using ns::i; +[[]] using ns::i; // expected-error {{an attribute list cannot appear here}} [[unknown]] using namespace ns; // expected-warning {{unknown attribute 'unknown' ignored}} [[noreturn]] using namespace ns; // expected-error {{'noreturn' attribute only applies to functions}} namespace [[]] ns2 {} // expected-warning {{attributes on a namespace declaration are a C++17 extension}} -using[[]] alignas(4)[[]] ns::i; // expected-error {{an attribute list cannot appear here}} expected-error {{'alignas' attribute only applies to variables, data members and tag types}} expected-warning {{ISO C++}} +using [[]] alignas(4) [[]] ns::i; // expected-error {{an attribute list cannot appear here}} using [[]] alignas(4) [[]] foobar = int; // expected-error {{an attribute list cannot appear here}} expected-error {{'alignas' attribute only applies to}} void bad_attributes_in_do_while() { @@ -157,16 +157,7 @@ void bad_attributes_in_do_while() { [[]] using T = int; // expected-error {{an attribute list cannot appear here}} using T [[]] = int; // ok template using U [[]] = T; -using ns::i [[]]; -using ns::i [[]], ns::i [[]]; // expected-warning {{use of multiple declarators in a single using declaration is a C++17 extension}} -struct using_in_struct_base { - typedef int i, j, k, l; -}; -struct using_in_struct : using_in_struct_base { - [[]] using using_in_struct_base::i; - using using_in_struct_base::j [[]]; - [[]] using using_in_struct_base::k [[]], using_in_struct_base::l [[]]; // expected-warning {{use of multiple declarators in a single using declaration is a C++17 extension}} -}; +using ns::i [[]]; // expected-error {{an attribute list cannot appear here}} using [[]] ns::i; // expected-error {{an attribute list cannot appear here}} using T [[unknown]] = int; // expected-warning {{unknown attribute 'unknown' ignored}} using T [[noreturn]] = int; // expected-error {{'noreturn' attribute only applies to functions}} diff --git a/clang/test/SemaCXX/cxx11-attributes-on-using-declaration.cpp b/clang/test/SemaCXX/cxx11-attributes-on-using-declaration.cpp deleted file mode 100644 index 0377a5920358..000000000000 --- a/clang/test/SemaCXX/cxx11-attributes-on-using-declaration.cpp +++ /dev/null @@ -1,42 +0,0 @@ -// RUN: %clang_cc1 -pedantic -triple x86_64-apple-macos11 -std=c++20 -fsyntax-only -verify %s - -static_assert(__has_extension(cxx_attributes_on_using_declarations), ""); - -namespace NS { typedef int x; } - -[[clang::annotate("foo")]] using NS::x; // expected-warning{{ISO C++ does not allow an attribute list to appear here}} - - -[[deprecated]] using NS::x; // expected-warning {{'deprecated' currently has no effect on using-declarations}} expected-warning{{ISO C++ does not allow}} -using NS::x [[deprecated]]; // expected-warning {{'deprecated' currently has no effect on using-declarations}} expected-warning{{ISO C++ does not allow}} -using NS::x __attribute__((deprecated)); // expected-warning {{'deprecated' currently has no effect on using-declarations}} -using NS::x __attribute__((availability(macos,introduced=1))); // expected-warning {{'availability' currently has no effect on using-declarations}} - -[[clang::availability(macos,introduced=1)]] using NS::x; // expected-warning {{'availability' currently has no effect on using-declarations}} expected-warning{{ISO C++ does not allow}} - -// expected-warning@+1 3 {{ISO C++ does not allow an attribute list to appear here}} -[[clang::annotate("A")]] using NS::x [[clang::annotate("Y")]], NS::x [[clang::annotate("Z")]]; - -template -struct S : T { - [[deprecated]] using typename T::x; // expected-warning{{ISO C++ does not allow}} expected-warning {{'deprecated' currently has no effect on using-declarations}} - [[deprecated]] using T::y; // expected-warning{{ISO C++ does not allow}} expected-warning {{'deprecated' currently has no effect on using-declarations}} - - using typename T::z [[deprecated]]; // expected-warning{{ISO C++ does not allow}} expected-warning {{'deprecated' currently has no effect on using-declarations}} - using T::a [[deprecated]]; // expected-warning{{ISO C++ does not allow}} expected-warning {{'deprecated' currently has no effect on using-declarations}} -}; - -struct Base {}; - -template -struct DepBase1 : B { - using B::B [[]]; - -}; -template -struct DepBase2 : B { - using B::B __attribute__(()); -}; - -DepBase1 db1; -DepBase2 db2;