https://github.com/Sirraide created https://github.com/llvm/llvm-project/pull/89078
[[dcl.fct]p6](https://eel.is/c++draft/dcl.fct#6) states: > [...] An explicit-object-parameter-declaration shall appear only as the first > parameter-declaration of a parameter-declaration-list of either: > - a member-declarator that declares a member function [class.mem], or > - a lambda-declarator [expr.prim.lambda]. The intent of this pr is to disallow explicit object parameters in all other contexts early on when we handle the function declarator. This fixes #85992. >From c611122688657287e8285edd9a2875e4975d26dd Mon Sep 17 00:00:00 2001 From: Sirraide <aeternalm...@gmail.com> Date: Wed, 17 Apr 2024 16:15:39 +0200 Subject: [PATCH 1/3] [Clang] Disallow explicit object parameters in more contexts --- .../clang/Basic/DiagnosticSemaKinds.td | 2 ++ clang/lib/Sema/SemaDeclCXX.cpp | 6 ++-- clang/lib/Sema/SemaType.cpp | 30 +++++++++++++++++++ clang/test/SemaCXX/cxx2b-deducing-this.cpp | 22 ++++++++++++-- 4 files changed, 54 insertions(+), 6 deletions(-) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 5ec0218aedfe86..680638d2e59c6a 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -7494,6 +7494,8 @@ def err_explicit_object_parameter_mutable: Error< def err_invalid_explicit_object_type_in_lambda: Error< "invalid explicit object parameter type %0 in lambda with capture; " "the type must be the same as, or derived from, the lambda">; +def err_explicit_object_parameter_invalid: Error< + "an explicit object parameter is not allowed here">; def err_ref_qualifier_overload : Error< "cannot overload a member function %select{without a ref-qualifier|with " diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp index 7669171fea56ff..ea634df48e5deb 100644 --- a/clang/lib/Sema/SemaDeclCXX.cpp +++ b/clang/lib/Sema/SemaDeclCXX.cpp @@ -11469,10 +11469,8 @@ void Sema::CheckExplicitObjectMemberFunction(Declarator &D, return; if (!DC || !DC->isRecord()) { - Diag(ExplicitObjectParam->getLocation(), - diag::err_explicit_object_parameter_nonmember) - << D.getSourceRange() << /*non-member=*/2 << IsLambda; - D.setInvalidType(); + assert(D.isInvalidType() && "Explicit object parameter in non-member " + "should have been diagnosed already"); return; } diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp index 404c4e8e31b558..406065741bf2d9 100644 --- a/clang/lib/Sema/SemaType.cpp +++ b/clang/lib/Sema/SemaType.cpp @@ -5287,6 +5287,36 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state, // Check for auto functions and trailing return type and adjust the // return type accordingly. if (!D.isInvalidType()) { + // [dcl.fct]p6: + // + // An explicit-object-parameter-declaration is a parameter-declaration + // with a this specifier. An explicit-object-parameter-declaration shall + // appear only as the first parameter-declaration of a + // parameter-declaration-list of either: + // + // - a member-declarator that declares a member function [class.mem], or + // - a lambda-declarator [expr.prim.lambda]. + DeclaratorContext C = D.getContext(); + ParmVarDecl *First = + FTI.NumParams + ? dyn_cast_if_present<ParmVarDecl>(FTI.Params[0].Param) + : nullptr; + if (First && First->isExplicitObjectParameter() && + C != DeclaratorContext::LambdaExpr && + + // Either not a member or nested declarator in a member. + (C != DeclaratorContext::Member || + D.getInnermostNonParenChunk() != &DeclType) && + + // Allow out-of-line definitions if we have a scope spec. + D.getCXXScopeSpec().isEmpty()) { + S.Diag(First->getBeginLoc(), + diag::err_explicit_object_parameter_invalid) + << First->getSourceRange(); + D.setInvalidType(); + AreDeclaratorChunksValid = false; + } + // trailing-return-type is only required if we're declaring a function, // and not, for instance, a pointer to a function. if (D.getDeclSpec().hasAutoTypeSpec() && diff --git a/clang/test/SemaCXX/cxx2b-deducing-this.cpp b/clang/test/SemaCXX/cxx2b-deducing-this.cpp index 5f29a955e053c3..ddb770a92db0f9 100644 --- a/clang/test/SemaCXX/cxx2b-deducing-this.cpp +++ b/clang/test/SemaCXX/cxx2b-deducing-this.cpp @@ -5,7 +5,7 @@ void f(this); // expected-error{{variable has incomplete type 'void'}} \ // expected-error{{invalid use of 'this' outside of a non-static member function}} -void g(this auto); // expected-error{{an explicit object parameter cannot appear in a non-member function}} +void g(this auto); // expected-error{{an explicit object parameter is not allowed here}} auto l1 = [] (this auto) static {}; // expected-error{{an explicit object parameter cannot appear in a static lambda}} auto l2 = [] (this auto) mutable {}; // expected-error{{a lambda with an explicit object parameter cannot be mutable}} @@ -685,7 +685,7 @@ struct S { static void j(this S s); // expected-error {{an explicit object parameter cannot appear in a static function}} }; -void nonmember(this S s); // expected-error {{an explicit object parameter cannot appear in a non-member function}} +void nonmember(this S s); // expected-error {{an explicit object parameter is not allowed here}} int test() { S s; @@ -838,3 +838,21 @@ int h() { }(); } } + +namespace GH85992 { +struct S { + int (S::*x)(this int); // expected-error {{an explicit object parameter is not allowed here}} + int (*y)(this int); // expected-error {{an explicit object parameter is not allowed here}} + int (***z)(this int); // expected-error {{an explicit object parameter is not allowed here}} + + int f(this S); + int ((g))(this S); + int h(int x, int (*)(this S)); // expected-error {{an explicit object parameter is not allowed here}} +}; + +using T = int (*)(this int); // expected-error {{an explicit object parameter is not allowed here}} +using U = int (S::*)(this int); // expected-error {{an explicit object parameter is not allowed here}} +int h(this int); // expected-error {{an explicit object parameter is not allowed here}} + +int S::f(this S) { return 1; } +} >From c27a3ff93474bc890de2b66ab7f486bb59e3b6d8 Mon Sep 17 00:00:00 2001 From: Sirraide <aeternalm...@gmail.com> Date: Wed, 17 Apr 2024 16:16:47 +0200 Subject: [PATCH 2/3] [NFC] clang-format --- clang/lib/Sema/SemaType.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp index 406065741bf2d9..23f2b9d74931bd 100644 --- a/clang/lib/Sema/SemaType.cpp +++ b/clang/lib/Sema/SemaType.cpp @@ -5294,7 +5294,8 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state, // appear only as the first parameter-declaration of a // parameter-declaration-list of either: // - // - a member-declarator that declares a member function [class.mem], or + // - a member-declarator that declares a member function [class.mem], + // or // - a lambda-declarator [expr.prim.lambda]. DeclaratorContext C = D.getContext(); ParmVarDecl *First = >From 0c1239a85159aaa4958bb574a326e85f50719b1b Mon Sep 17 00:00:00 2001 From: Sirraide <aeternalm...@gmail.com> Date: Wed, 17 Apr 2024 16:23:15 +0200 Subject: [PATCH 3/3] [NFC] Reformat comment --- clang/lib/Sema/SemaType.cpp | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp index 23f2b9d74931bd..95257b801c8a6c 100644 --- a/clang/lib/Sema/SemaType.cpp +++ b/clang/lib/Sema/SemaType.cpp @@ -5294,9 +5294,8 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state, // appear only as the first parameter-declaration of a // parameter-declaration-list of either: // - // - a member-declarator that declares a member function [class.mem], - // or - // - a lambda-declarator [expr.prim.lambda]. + // - a member-declarator that declares a member function [class.mem], or + // - a lambda-declarator [expr.prim.lambda]. DeclaratorContext C = D.getContext(); ParmVarDecl *First = FTI.NumParams _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
