* [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor. @ 2020-04-04 23:30 Marek Polacek 2020-04-06 1:46 ` Jason Merrill 0 siblings, 1 reply; 5+ messages in thread From: Marek Polacek @ 2020-04-04 23:30 UTC (permalink / raw) To: Jason Merrill, GCC Patches This patch implements DR 2237 which says that a simple-template-id is no longer valid as the declarator-id of a constructor or destructor; see <https://eel.is/c++draft/diff.cpp17.class#2>. It is not explicitly stated but out-of-line destructors with a simple-template-id are also meant to be ill-formed now. (Out-of-line constructors like that are invalid since DR1435 I think.) This change only applies to C++20; it is not a DR against C++17. I'm not crazy about the diagnostic in constructors but ISTM that cp_parser_constructor_declarator_p shouldn't print errors. Does it seem reasonable to apply this now or should I defer to GCC 11? Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? 2020-04-04 Marek Polacek <polacek@redhat.com> DR 2237 * parser.c (cp_parser_unqualified_id): Reject simple-template-id as the declarator-id of a destructor. (cp_parser_constructor_declarator_p): Reject simple-template-id as the declarator-id of a constructor. * g++.dg/DRs/dr2237.C: New test. * g++.dg/parse/constructor2.C: Add dg-error for C++20. * g++.dg/parse/dtor12.C: Likewise. * g++.dg/parse/dtor4.C: Likewise. * g++.dg/template/dtor4.C: Adjust dg-error. * g++.dg/template/error34.C: Likewise. * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. --- gcc/cp/parser.c | 16 ++++++++++++++++ gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- gcc/testsuite/g++.dg/template/dtor4.C | 2 +- gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- .../g++.old-deja/g++.other/inline15.C | 2 +- gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- 9 files changed, 46 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 7e5921e039f..810edfa87a9 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -6114,6 +6114,16 @@ cp_parser_unqualified_id (cp_parser* parser, return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); } + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the + declarator-id of a constructor or destructor. */ + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) + { + if (!cp_parser_uncommitted_to_tentative_parse_p (parser)) + error_at (tilde_loc, "template-id not allowed for destructor"); + cp_parser_simulate_error (parser); + return error_mark_node; + } + /* If there was an explicit qualification (S::~T), first look in the scope given by the qualification (i.e., S). @@ -28675,6 +28685,12 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, if (!constructor_name_p (id, nested_name_specifier)) constructor_p = false; } + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the + declarator-id of a constructor or destructor. */ + else if (constructor_p + && cxx_dialect >= cxx2a + && cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)) + constructor_p = false; /* If we still think that this might be a constructor-declarator, look for a class-name. */ else if (constructor_p) diff --git a/gcc/testsuite/g++.dg/DRs/dr2237.C b/gcc/testsuite/g++.dg/DRs/dr2237.C new file mode 100644 index 00000000000..17abdf179c1 --- /dev/null +++ b/gcc/testsuite/g++.dg/DRs/dr2237.C @@ -0,0 +1,18 @@ +// DR 2237 - Can a template-id name a constructor? + +template<class T> +struct X { + X<T>(); // { dg-error "expected" "" { target c++2a } } + X(int); // OK, injected-class-name used + ~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } +}; + +// ill-formed since DR1435 +template<typename T> X<T>::X<T>() {} // { dg-error "names the constructor|as no template constructors" } +template<typename T> X<T>::~X<T>() {} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } + +struct Q { + // ill-formed since DR1435 + template<typename T> friend X<T>::X<T>(); // { dg-error "names the constructor|as no template constructors" } + template<typename T> friend X<T>::~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } +}; diff --git a/gcc/testsuite/g++.dg/parse/constructor2.C b/gcc/testsuite/g++.dg/parse/constructor2.C index e514e9397e9..87007e9c715 100644 --- a/gcc/testsuite/g++.dg/parse/constructor2.C +++ b/gcc/testsuite/g++.dg/parse/constructor2.C @@ -5,7 +5,7 @@ class T { public: T(short,short f=0) {} - T<TClass>(int f) {} - T<TClass>(int f=0,const char* b=0) {} + T<TClass>(int f) {} // { dg-error "expected" "" { target c++2a } } + T<TClass>(int f=0,const char* b=0) {} // { dg-error "expected" "" { target c++2a } } }; diff --git a/gcc/testsuite/g++.dg/parse/dtor12.C b/gcc/testsuite/g++.dg/parse/dtor12.C index 1acdfa36b69..d758d3e861d 100644 --- a/gcc/testsuite/g++.dg/parse/dtor12.C +++ b/gcc/testsuite/g++.dg/parse/dtor12.C @@ -2,5 +2,5 @@ template <class T> class a { - ~a<T>(); + ~a<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } }; diff --git a/gcc/testsuite/g++.dg/parse/dtor4.C b/gcc/testsuite/g++.dg/parse/dtor4.C index 729ee2fa130..1059c189eff 100644 --- a/gcc/testsuite/g++.dg/parse/dtor4.C +++ b/gcc/testsuite/g++.dg/parse/dtor4.C @@ -7,4 +7,4 @@ template <int N> struct X { }; template <int N> -X<N>::~X<N>(){} +X<N>::~X<N>(){} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } diff --git a/gcc/testsuite/g++.dg/template/dtor4.C b/gcc/testsuite/g++.dg/template/dtor4.C index 4f277b248bd..917681fc13e 100644 --- a/gcc/testsuite/g++.dg/template/dtor4.C +++ b/gcc/testsuite/g++.dg/template/dtor4.C @@ -5,5 +5,5 @@ template<int> struct A { - ~A<0>(); // { dg-error "parse error|declaration" } + ~A<0>(); // { dg-error "parse error|declaration|template-id" } }; diff --git a/gcc/testsuite/g++.dg/template/error34.C b/gcc/testsuite/g++.dg/template/error34.C index d0cbcaef28e..ab688d9ba8c 100644 --- a/gcc/testsuite/g++.dg/template/error34.C +++ b/gcc/testsuite/g++.dg/template/error34.C @@ -3,27 +3,27 @@ template<typename T> struct A { - A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)" } + A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)|expected" } }; template<typename T> struct B { - B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)" } + B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)|expected" } }; template<typename T> struct C { - C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)" } + C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)|expected" } }; template<typename T> struct D { - D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)" } + D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)|expected" } }; struct E { int x; }; template<typename T> struct F { - F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)" } + F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)|expected" } }; diff --git a/gcc/testsuite/g++.old-deja/g++.other/inline15.C b/gcc/testsuite/g++.old-deja/g++.other/inline15.C index 43f7f5e3025..a31c60960a5 100644 --- a/gcc/testsuite/g++.old-deja/g++.other/inline15.C +++ b/gcc/testsuite/g++.old-deja/g++.other/inline15.C @@ -1,4 +1,4 @@ -// { dg-do assemble } +// { dg-do assemble { target c++17_down } } // { dg-options "-O1" } // Origin: Jakub Jelinek <jakub@redhat.com> diff --git a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C index a8be91ddbb9..4159c84ff56 100644 --- a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C +++ b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C @@ -4,7 +4,7 @@ template <class T> struct A { - A<T>(); + A<T>(); // { dg-error "expected" "" { target c++2a } } }; template <class T> base-commit: 49a86fce1a879a206fb4b27f097910005d968fda -- Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor. 2020-04-04 23:30 [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor Marek Polacek @ 2020-04-06 1:46 ` Jason Merrill 2020-05-11 20:23 ` Marek Polacek 0 siblings, 1 reply; 5+ messages in thread From: Jason Merrill @ 2020-04-06 1:46 UTC (permalink / raw) To: Marek Polacek, GCC Patches On 4/4/20 7:30 PM, Marek Polacek wrote: > This patch implements DR 2237 which says that a simple-template-id is > no longer valid as the declarator-id of a constructor or destructor; > see <https://eel.is/c++draft/diff.cpp17.class#2>. It is not explicitly > stated but out-of-line destructors with a simple-template-id are also > meant to be ill-formed now. (Out-of-line constructors like that are > invalid since DR1435 I think.) This change only applies to C++20; it > is not a DR against C++17. > > I'm not crazy about the diagnostic in constructors but ISTM that > cp_parser_constructor_declarator_p shouldn't print errors. > > Does it seem reasonable to apply this now or should I defer to GCC 11? A new error should wait for GCC 11. > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > 2020-04-04 Marek Polacek <polacek@redhat.com> > > DR 2237 > * parser.c (cp_parser_unqualified_id): Reject simple-template-id as > the declarator-id of a destructor. > (cp_parser_constructor_declarator_p): Reject simple-template-id as > the declarator-id of a constructor. > > * g++.dg/DRs/dr2237.C: New test. > * g++.dg/parse/constructor2.C: Add dg-error for C++20. > * g++.dg/parse/dtor12.C: Likewise. > * g++.dg/parse/dtor4.C: Likewise. > * g++.dg/template/dtor4.C: Adjust dg-error. > * g++.dg/template/error34.C: Likewise. > * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. > * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. > --- > gcc/cp/parser.c | 16 ++++++++++++++++ > gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ > gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- > gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- > gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- > gcc/testsuite/g++.dg/template/dtor4.C | 2 +- > gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- > .../g++.old-deja/g++.other/inline15.C | 2 +- > gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- > 9 files changed, 46 insertions(+), 12 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c > index 7e5921e039f..810edfa87a9 100644 > --- a/gcc/cp/parser.c > +++ b/gcc/cp/parser.c > @@ -6114,6 +6114,16 @@ cp_parser_unqualified_id (cp_parser* parser, > return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); > } > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > + declarator-id of a constructor or destructor. */ > + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) > + { > + if (!cp_parser_uncommitted_to_tentative_parse_p (parser)) > + error_at (tilde_loc, "template-id not allowed for destructor"); > + cp_parser_simulate_error (parser); The usual pattern is if (!cp_parser_simulate_error (parser)) error... > + return error_mark_node; > + } > + > /* If there was an explicit qualification (S::~T), first look > in the scope given by the qualification (i.e., S). > > @@ -28675,6 +28685,12 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, > if (!constructor_name_p (id, nested_name_specifier)) > constructor_p = false; > } > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > + declarator-id of a constructor or destructor. */ > + else if (constructor_p > + && cxx_dialect >= cxx2a > + && cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)) > + constructor_p = false; > /* If we still think that this might be a constructor-declarator, > look for a class-name. */ > else if (constructor_p) Do you also want to exclude CPP_TEMPLATE_ID from the test at the top of the function for C++20? > if (next_token->type != CPP_NAME > && next_token->type != CPP_SCOPE > && next_token->type != CPP_NESTED_NAME_SPECIFIER > && next_token->type != CPP_TEMPLATE_ID) > return false; Jason ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor. 2020-04-06 1:46 ` Jason Merrill @ 2020-05-11 20:23 ` Marek Polacek 2020-05-20 18:05 ` Marek Polacek 0 siblings, 1 reply; 5+ messages in thread From: Marek Polacek @ 2020-05-11 20:23 UTC (permalink / raw) To: Jason Merrill; +Cc: GCC Patches On Sun, Apr 05, 2020 at 09:46:09PM -0400, Jason Merrill wrote: > On 4/4/20 7:30 PM, Marek Polacek wrote: > > This patch implements DR 2237 which says that a simple-template-id is > > no longer valid as the declarator-id of a constructor or destructor; > > see <https://eel.is/c++draft/diff.cpp17.class#2>. It is not explicitly > > stated but out-of-line destructors with a simple-template-id are also > > meant to be ill-formed now. (Out-of-line constructors like that are > > invalid since DR1435 I think.) This change only applies to C++20; it > > is not a DR against C++17. > > > > I'm not crazy about the diagnostic in constructors but ISTM that > > cp_parser_constructor_declarator_p shouldn't print errors. > > > > Does it seem reasonable to apply this now or should I defer to GCC 11? > > A new error should wait for GCC 11. Coming back to this now that we're again in stage 1. > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > > > 2020-04-04 Marek Polacek <polacek@redhat.com> > > > > DR 2237 > > * parser.c (cp_parser_unqualified_id): Reject simple-template-id as > > the declarator-id of a destructor. > > (cp_parser_constructor_declarator_p): Reject simple-template-id as > > the declarator-id of a constructor. > > > > * g++.dg/DRs/dr2237.C: New test. > > * g++.dg/parse/constructor2.C: Add dg-error for C++20. > > * g++.dg/parse/dtor12.C: Likewise. > > * g++.dg/parse/dtor4.C: Likewise. > > * g++.dg/template/dtor4.C: Adjust dg-error. > > * g++.dg/template/error34.C: Likewise. > > * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. > > * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. > > --- > > gcc/cp/parser.c | 16 ++++++++++++++++ > > gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ > > gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- > > gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- > > gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- > > gcc/testsuite/g++.dg/template/dtor4.C | 2 +- > > gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- > > .../g++.old-deja/g++.other/inline15.C | 2 +- > > gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- > > 9 files changed, 46 insertions(+), 12 deletions(-) > > create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C > > > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c > > index 7e5921e039f..810edfa87a9 100644 > > --- a/gcc/cp/parser.c > > +++ b/gcc/cp/parser.c > > @@ -6114,6 +6114,16 @@ cp_parser_unqualified_id (cp_parser* parser, > > return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); > > } > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > > + declarator-id of a constructor or destructor. */ > > + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) > > + { > > + if (!cp_parser_uncommitted_to_tentative_parse_p (parser)) > > + error_at (tilde_loc, "template-id not allowed for destructor"); > > + cp_parser_simulate_error (parser); > > The usual pattern is > > if (!cp_parser_simulate_error (parser)) > error... Fixed. > > + return error_mark_node; > > + } > > + > > /* If there was an explicit qualification (S::~T), first look > > in the scope given by the qualification (i.e., S). > > @@ -28675,6 +28685,12 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, > > if (!constructor_name_p (id, nested_name_specifier)) > > constructor_p = false; > > } > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > > + declarator-id of a constructor or destructor. */ > > + else if (constructor_p > > + && cxx_dialect >= cxx2a > > + && cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)) > > + constructor_p = false; > > /* If we still think that this might be a constructor-declarator, > > look for a class-name. */ > > else if (constructor_p) > > Do you also want to exclude CPP_TEMPLATE_ID from the test at the top of the > function for C++20? In fact we can get away with only excluding CPP_TEMPLATE_ID in C++20 there, because for e.g. X<T>::X<T>(); we'll give the "names the constructor, not the type" error, so we won't even get here. Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? -- >8 -- This patch implements DR 2237 which says that a simple-template-id is no longer valid as the declarator-id of a constructor or destructor; see [diff.cpp17.class]#2. It is not explicitly stated but out-of-line destructors with a simple-template-id are also meant to be ill-formed now. (Out-of-line constructors like that are invalid since DR1435 I think.) This change only applies to C++20; it is not a DR against C++17. I'm not crazy about the diagnostic in constructors but ISTM that cp_parser_constructor_declarator_p shouldn't print errors. DR 2237 * parser.c (cp_parser_unqualified_id): Reject simple-template-id as the declarator-id of a destructor. (cp_parser_constructor_declarator_p): Reject simple-template-id as the declarator-id of a constructor. * g++.dg/DRs/dr2237.C: New test. * g++.dg/parse/constructor2.C: Add dg-error for C++20. * g++.dg/parse/dtor12.C: Likewise. * g++.dg/parse/dtor4.C: Likewise. * g++.dg/template/dtor4.C: Adjust dg-error. * g++.dg/template/error34.C: Likewise. * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. --- gcc/cp/parser.c | 13 ++++++++++++- gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- gcc/testsuite/g++.dg/template/dtor4.C | 2 +- gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- .../g++.old-deja/g++.other/inline15.C | 2 +- gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- 9 files changed, 42 insertions(+), 13 deletions(-) create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 591f44f4934..593c45b5888 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -6114,6 +6114,15 @@ cp_parser_unqualified_id (cp_parser* parser, return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); } + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the + declarator-id of a constructor or destructor. */ + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) + { + if (!cp_parser_simulate_error (parser)) + error_at (tilde_loc, "template-id not allowed for destructor"); + return error_mark_node; + } + /* If there was an explicit qualification (S::~T), first look in the scope given by the qualification (i.e., S). @@ -28636,7 +28645,9 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, if (next_token->type != CPP_NAME && next_token->type != CPP_SCOPE && next_token->type != CPP_NESTED_NAME_SPECIFIER - && next_token->type != CPP_TEMPLATE_ID) + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the + declarator-id of a constructor or destructor. */ + && (next_token->type != CPP_TEMPLATE_ID || cxx_dialect >= cxx2a)) return false; /* Parse tentatively; we are going to roll back all of the tokens diff --git a/gcc/testsuite/g++.dg/DRs/dr2237.C b/gcc/testsuite/g++.dg/DRs/dr2237.C new file mode 100644 index 00000000000..17abdf179c1 --- /dev/null +++ b/gcc/testsuite/g++.dg/DRs/dr2237.C @@ -0,0 +1,18 @@ +// DR 2237 - Can a template-id name a constructor? + +template<class T> +struct X { + X<T>(); // { dg-error "expected" "" { target c++2a } } + X(int); // OK, injected-class-name used + ~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } +}; + +// ill-formed since DR1435 +template<typename T> X<T>::X<T>() {} // { dg-error "names the constructor|as no template constructors" } +template<typename T> X<T>::~X<T>() {} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } + +struct Q { + // ill-formed since DR1435 + template<typename T> friend X<T>::X<T>(); // { dg-error "names the constructor|as no template constructors" } + template<typename T> friend X<T>::~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } +}; diff --git a/gcc/testsuite/g++.dg/parse/constructor2.C b/gcc/testsuite/g++.dg/parse/constructor2.C index e514e9397e9..87007e9c715 100644 --- a/gcc/testsuite/g++.dg/parse/constructor2.C +++ b/gcc/testsuite/g++.dg/parse/constructor2.C @@ -5,7 +5,7 @@ class T { public: T(short,short f=0) {} - T<TClass>(int f) {} - T<TClass>(int f=0,const char* b=0) {} + T<TClass>(int f) {} // { dg-error "expected" "" { target c++2a } } + T<TClass>(int f=0,const char* b=0) {} // { dg-error "expected" "" { target c++2a } } }; diff --git a/gcc/testsuite/g++.dg/parse/dtor12.C b/gcc/testsuite/g++.dg/parse/dtor12.C index 1acdfa36b69..d758d3e861d 100644 --- a/gcc/testsuite/g++.dg/parse/dtor12.C +++ b/gcc/testsuite/g++.dg/parse/dtor12.C @@ -2,5 +2,5 @@ template <class T> class a { - ~a<T>(); + ~a<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } }; diff --git a/gcc/testsuite/g++.dg/parse/dtor4.C b/gcc/testsuite/g++.dg/parse/dtor4.C index 729ee2fa130..1059c189eff 100644 --- a/gcc/testsuite/g++.dg/parse/dtor4.C +++ b/gcc/testsuite/g++.dg/parse/dtor4.C @@ -7,4 +7,4 @@ template <int N> struct X { }; template <int N> -X<N>::~X<N>(){} +X<N>::~X<N>(){} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } diff --git a/gcc/testsuite/g++.dg/template/dtor4.C b/gcc/testsuite/g++.dg/template/dtor4.C index 4f277b248bd..917681fc13e 100644 --- a/gcc/testsuite/g++.dg/template/dtor4.C +++ b/gcc/testsuite/g++.dg/template/dtor4.C @@ -5,5 +5,5 @@ template<int> struct A { - ~A<0>(); // { dg-error "parse error|declaration" } + ~A<0>(); // { dg-error "parse error|declaration|template-id" } }; diff --git a/gcc/testsuite/g++.dg/template/error34.C b/gcc/testsuite/g++.dg/template/error34.C index d0cbcaef28e..ab688d9ba8c 100644 --- a/gcc/testsuite/g++.dg/template/error34.C +++ b/gcc/testsuite/g++.dg/template/error34.C @@ -3,27 +3,27 @@ template<typename T> struct A { - A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)" } + A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)|expected" } }; template<typename T> struct B { - B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)" } + B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)|expected" } }; template<typename T> struct C { - C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)" } + C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)|expected" } }; template<typename T> struct D { - D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)" } + D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)|expected" } }; struct E { int x; }; template<typename T> struct F { - F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)" } + F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)|expected" } }; diff --git a/gcc/testsuite/g++.old-deja/g++.other/inline15.C b/gcc/testsuite/g++.old-deja/g++.other/inline15.C index 43f7f5e3025..a31c60960a5 100644 --- a/gcc/testsuite/g++.old-deja/g++.other/inline15.C +++ b/gcc/testsuite/g++.old-deja/g++.other/inline15.C @@ -1,4 +1,4 @@ -// { dg-do assemble } +// { dg-do assemble { target c++17_down } } // { dg-options "-O1" } // Origin: Jakub Jelinek <jakub@redhat.com> diff --git a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C index a8be91ddbb9..4159c84ff56 100644 --- a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C +++ b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C @@ -4,7 +4,7 @@ template <class T> struct A { - A<T>(); + A<T>(); // { dg-error "expected" "" { target c++2a } } }; template <class T> base-commit: 2b2d298ff845ab7a07ffbd51da79473736da3324 -- Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor. 2020-05-11 20:23 ` Marek Polacek @ 2020-05-20 18:05 ` Marek Polacek 2020-05-20 20:45 ` Jason Merrill 0 siblings, 1 reply; 5+ messages in thread From: Marek Polacek @ 2020-05-20 18:05 UTC (permalink / raw) To: Jason Merrill, GCC Patches Ping. On Mon, May 11, 2020 at 04:23:17PM -0400, Marek Polacek via Gcc-patches wrote: > On Sun, Apr 05, 2020 at 09:46:09PM -0400, Jason Merrill wrote: > > On 4/4/20 7:30 PM, Marek Polacek wrote: > > > This patch implements DR 2237 which says that a simple-template-id is > > > no longer valid as the declarator-id of a constructor or destructor; > > > see <https://eel.is/c++draft/diff.cpp17.class#2>. It is not explicitly > > > stated but out-of-line destructors with a simple-template-id are also > > > meant to be ill-formed now. (Out-of-line constructors like that are > > > invalid since DR1435 I think.) This change only applies to C++20; it > > > is not a DR against C++17. > > > > > > I'm not crazy about the diagnostic in constructors but ISTM that > > > cp_parser_constructor_declarator_p shouldn't print errors. > > > > > > Does it seem reasonable to apply this now or should I defer to GCC 11? > > > > A new error should wait for GCC 11. > > Coming back to this now that we're again in stage 1. > > > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > > > > > 2020-04-04 Marek Polacek <polacek@redhat.com> > > > > > > DR 2237 > > > * parser.c (cp_parser_unqualified_id): Reject simple-template-id as > > > the declarator-id of a destructor. > > > (cp_parser_constructor_declarator_p): Reject simple-template-id as > > > the declarator-id of a constructor. > > > > > > * g++.dg/DRs/dr2237.C: New test. > > > * g++.dg/parse/constructor2.C: Add dg-error for C++20. > > > * g++.dg/parse/dtor12.C: Likewise. > > > * g++.dg/parse/dtor4.C: Likewise. > > > * g++.dg/template/dtor4.C: Adjust dg-error. > > > * g++.dg/template/error34.C: Likewise. > > > * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. > > > * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. > > > --- > > > gcc/cp/parser.c | 16 ++++++++++++++++ > > > gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ > > > gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- > > > gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- > > > gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- > > > gcc/testsuite/g++.dg/template/dtor4.C | 2 +- > > > gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- > > > .../g++.old-deja/g++.other/inline15.C | 2 +- > > > gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- > > > 9 files changed, 46 insertions(+), 12 deletions(-) > > > create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C > > > > > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c > > > index 7e5921e039f..810edfa87a9 100644 > > > --- a/gcc/cp/parser.c > > > +++ b/gcc/cp/parser.c > > > @@ -6114,6 +6114,16 @@ cp_parser_unqualified_id (cp_parser* parser, > > > return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); > > > } > > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > > > + declarator-id of a constructor or destructor. */ > > > + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) > > > + { > > > + if (!cp_parser_uncommitted_to_tentative_parse_p (parser)) > > > + error_at (tilde_loc, "template-id not allowed for destructor"); > > > + cp_parser_simulate_error (parser); > > > > The usual pattern is > > > > if (!cp_parser_simulate_error (parser)) > > error... > > Fixed. > > > > + return error_mark_node; > > > + } > > > + > > > /* If there was an explicit qualification (S::~T), first look > > > in the scope given by the qualification (i.e., S). > > > @@ -28675,6 +28685,12 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, > > > if (!constructor_name_p (id, nested_name_specifier)) > > > constructor_p = false; > > > } > > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > > > + declarator-id of a constructor or destructor. */ > > > + else if (constructor_p > > > + && cxx_dialect >= cxx2a > > > + && cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)) > > > + constructor_p = false; > > > /* If we still think that this might be a constructor-declarator, > > > look for a class-name. */ > > > else if (constructor_p) > > > > Do you also want to exclude CPP_TEMPLATE_ID from the test at the top of the > > function for C++20? > > In fact we can get away with only excluding CPP_TEMPLATE_ID in C++20 there, > because for e.g. X<T>::X<T>(); we'll give the "names the constructor, not the > type" error, so we won't even get here. > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > -- >8 -- > This patch implements DR 2237 which says that a simple-template-id is > no longer valid as the declarator-id of a constructor or destructor; > see [diff.cpp17.class]#2. It is not explicitly stated but out-of-line > destructors with a simple-template-id are also meant to be ill-formed > now. (Out-of-line constructors like that are invalid since DR1435 I > think.) This change only applies to C++20; it is not a DR against C++17. > > I'm not crazy about the diagnostic in constructors but ISTM that > cp_parser_constructor_declarator_p shouldn't print errors. > > DR 2237 > * parser.c (cp_parser_unqualified_id): Reject simple-template-id as > the declarator-id of a destructor. > (cp_parser_constructor_declarator_p): Reject simple-template-id as > the declarator-id of a constructor. > > * g++.dg/DRs/dr2237.C: New test. > * g++.dg/parse/constructor2.C: Add dg-error for C++20. > * g++.dg/parse/dtor12.C: Likewise. > * g++.dg/parse/dtor4.C: Likewise. > * g++.dg/template/dtor4.C: Adjust dg-error. > * g++.dg/template/error34.C: Likewise. > * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. > * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. > --- > gcc/cp/parser.c | 13 ++++++++++++- > gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ > gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- > gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- > gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- > gcc/testsuite/g++.dg/template/dtor4.C | 2 +- > gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- > .../g++.old-deja/g++.other/inline15.C | 2 +- > gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- > 9 files changed, 42 insertions(+), 13 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c > index 591f44f4934..593c45b5888 100644 > --- a/gcc/cp/parser.c > +++ b/gcc/cp/parser.c > @@ -6114,6 +6114,15 @@ cp_parser_unqualified_id (cp_parser* parser, > return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); > } > > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > + declarator-id of a constructor or destructor. */ > + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) > + { > + if (!cp_parser_simulate_error (parser)) > + error_at (tilde_loc, "template-id not allowed for destructor"); > + return error_mark_node; > + } > + > /* If there was an explicit qualification (S::~T), first look > in the scope given by the qualification (i.e., S). > > @@ -28636,7 +28645,9 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, > if (next_token->type != CPP_NAME > && next_token->type != CPP_SCOPE > && next_token->type != CPP_NESTED_NAME_SPECIFIER > - && next_token->type != CPP_TEMPLATE_ID) > + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the > + declarator-id of a constructor or destructor. */ > + && (next_token->type != CPP_TEMPLATE_ID || cxx_dialect >= cxx2a)) > return false; > > /* Parse tentatively; we are going to roll back all of the tokens > diff --git a/gcc/testsuite/g++.dg/DRs/dr2237.C b/gcc/testsuite/g++.dg/DRs/dr2237.C > new file mode 100644 > index 00000000000..17abdf179c1 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/DRs/dr2237.C > @@ -0,0 +1,18 @@ > +// DR 2237 - Can a template-id name a constructor? > + > +template<class T> > +struct X { > + X<T>(); // { dg-error "expected" "" { target c++2a } } > + X(int); // OK, injected-class-name used > + ~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } > +}; > + > +// ill-formed since DR1435 > +template<typename T> X<T>::X<T>() {} // { dg-error "names the constructor|as no template constructors" } > +template<typename T> X<T>::~X<T>() {} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } > + > +struct Q { > + // ill-formed since DR1435 > + template<typename T> friend X<T>::X<T>(); // { dg-error "names the constructor|as no template constructors" } > + template<typename T> friend X<T>::~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } > +}; > diff --git a/gcc/testsuite/g++.dg/parse/constructor2.C b/gcc/testsuite/g++.dg/parse/constructor2.C > index e514e9397e9..87007e9c715 100644 > --- a/gcc/testsuite/g++.dg/parse/constructor2.C > +++ b/gcc/testsuite/g++.dg/parse/constructor2.C > @@ -5,7 +5,7 @@ class T > { > public: > T(short,short f=0) {} > - T<TClass>(int f) {} > - T<TClass>(int f=0,const char* b=0) {} > + T<TClass>(int f) {} // { dg-error "expected" "" { target c++2a } } > + T<TClass>(int f=0,const char* b=0) {} // { dg-error "expected" "" { target c++2a } } > }; > > diff --git a/gcc/testsuite/g++.dg/parse/dtor12.C b/gcc/testsuite/g++.dg/parse/dtor12.C > index 1acdfa36b69..d758d3e861d 100644 > --- a/gcc/testsuite/g++.dg/parse/dtor12.C > +++ b/gcc/testsuite/g++.dg/parse/dtor12.C > @@ -2,5 +2,5 @@ > > template <class T> class a > { > - ~a<T>(); > + ~a<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } > }; > diff --git a/gcc/testsuite/g++.dg/parse/dtor4.C b/gcc/testsuite/g++.dg/parse/dtor4.C > index 729ee2fa130..1059c189eff 100644 > --- a/gcc/testsuite/g++.dg/parse/dtor4.C > +++ b/gcc/testsuite/g++.dg/parse/dtor4.C > @@ -7,4 +7,4 @@ template <int N> struct X { > }; > > template <int N> > -X<N>::~X<N>(){} > +X<N>::~X<N>(){} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } > diff --git a/gcc/testsuite/g++.dg/template/dtor4.C b/gcc/testsuite/g++.dg/template/dtor4.C > index 4f277b248bd..917681fc13e 100644 > --- a/gcc/testsuite/g++.dg/template/dtor4.C > +++ b/gcc/testsuite/g++.dg/template/dtor4.C > @@ -5,5 +5,5 @@ > > template<int> struct A > { > - ~A<0>(); // { dg-error "parse error|declaration" } > + ~A<0>(); // { dg-error "parse error|declaration|template-id" } > }; > diff --git a/gcc/testsuite/g++.dg/template/error34.C b/gcc/testsuite/g++.dg/template/error34.C > index d0cbcaef28e..ab688d9ba8c 100644 > --- a/gcc/testsuite/g++.dg/template/error34.C > +++ b/gcc/testsuite/g++.dg/template/error34.C > @@ -3,27 +3,27 @@ > > template<typename T> struct A > { > - A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)" } > + A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)|expected" } > }; > > template<typename T> struct B > { > - B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)" } > + B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)|expected" } > }; > > template<typename T> struct C > { > - C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)" } > + C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)|expected" } > }; > > template<typename T> struct D > { > - D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)" } > + D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)|expected" } > }; > > struct E { int x; }; > > template<typename T> struct F > { > - F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)" } > + F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)|expected" } > }; > diff --git a/gcc/testsuite/g++.old-deja/g++.other/inline15.C b/gcc/testsuite/g++.old-deja/g++.other/inline15.C > index 43f7f5e3025..a31c60960a5 100644 > --- a/gcc/testsuite/g++.old-deja/g++.other/inline15.C > +++ b/gcc/testsuite/g++.old-deja/g++.other/inline15.C > @@ -1,4 +1,4 @@ > -// { dg-do assemble } > +// { dg-do assemble { target c++17_down } } > // { dg-options "-O1" } > // Origin: Jakub Jelinek <jakub@redhat.com> > > diff --git a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C > index a8be91ddbb9..4159c84ff56 100644 > --- a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C > +++ b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C > @@ -4,7 +4,7 @@ > > template <class T> > struct A { > - A<T>(); > + A<T>(); // { dg-error "expected" "" { target c++2a } } > }; > > template <class T> > > base-commit: 2b2d298ff845ab7a07ffbd51da79473736da3324 > -- > Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA > Marek ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor. 2020-05-20 18:05 ` Marek Polacek @ 2020-05-20 20:45 ` Jason Merrill 0 siblings, 0 replies; 5+ messages in thread From: Jason Merrill @ 2020-05-20 20:45 UTC (permalink / raw) To: Marek Polacek, GCC Patches On 5/20/20 2:05 PM, Marek Polacek wrote: > Ping. OK (with 2a->20, of course). Jason > On Mon, May 11, 2020 at 04:23:17PM -0400, Marek Polacek via Gcc-patches wrote: >> On Sun, Apr 05, 2020 at 09:46:09PM -0400, Jason Merrill wrote: >>> On 4/4/20 7:30 PM, Marek Polacek wrote: >>>> This patch implements DR 2237 which says that a simple-template-id is >>>> no longer valid as the declarator-id of a constructor or destructor; >>>> see <https://eel.is/c++draft/diff.cpp17.class#2>. It is not explicitly >>>> stated but out-of-line destructors with a simple-template-id are also >>>> meant to be ill-formed now. (Out-of-line constructors like that are >>>> invalid since DR1435 I think.) This change only applies to C++20; it >>>> is not a DR against C++17. >>>> >>>> I'm not crazy about the diagnostic in constructors but ISTM that >>>> cp_parser_constructor_declarator_p shouldn't print errors. >>>> >>>> Does it seem reasonable to apply this now or should I defer to GCC 11? >>> >>> A new error should wait for GCC 11. >> >> Coming back to this now that we're again in stage 1. >> >>>> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? >>>> >>>> 2020-04-04 Marek Polacek <polacek@redhat.com> >>>> >>>> DR 2237 >>>> * parser.c (cp_parser_unqualified_id): Reject simple-template-id as >>>> the declarator-id of a destructor. >>>> (cp_parser_constructor_declarator_p): Reject simple-template-id as >>>> the declarator-id of a constructor. >>>> >>>> * g++.dg/DRs/dr2237.C: New test. >>>> * g++.dg/parse/constructor2.C: Add dg-error for C++20. >>>> * g++.dg/parse/dtor12.C: Likewise. >>>> * g++.dg/parse/dtor4.C: Likewise. >>>> * g++.dg/template/dtor4.C: Adjust dg-error. >>>> * g++.dg/template/error34.C: Likewise. >>>> * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. >>>> * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. >>>> --- >>>> gcc/cp/parser.c | 16 ++++++++++++++++ >>>> gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ >>>> gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- >>>> gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- >>>> gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- >>>> gcc/testsuite/g++.dg/template/dtor4.C | 2 +- >>>> gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- >>>> .../g++.old-deja/g++.other/inline15.C | 2 +- >>>> gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- >>>> 9 files changed, 46 insertions(+), 12 deletions(-) >>>> create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C >>>> >>>> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c >>>> index 7e5921e039f..810edfa87a9 100644 >>>> --- a/gcc/cp/parser.c >>>> +++ b/gcc/cp/parser.c >>>> @@ -6114,6 +6114,16 @@ cp_parser_unqualified_id (cp_parser* parser, >>>> return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); >>>> } >>>> + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the >>>> + declarator-id of a constructor or destructor. */ >>>> + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) >>>> + { >>>> + if (!cp_parser_uncommitted_to_tentative_parse_p (parser)) >>>> + error_at (tilde_loc, "template-id not allowed for destructor"); >>>> + cp_parser_simulate_error (parser); >>> >>> The usual pattern is >>> >>> if (!cp_parser_simulate_error (parser)) >>> error... >> >> Fixed. >> >>>> + return error_mark_node; >>>> + } >>>> + >>>> /* If there was an explicit qualification (S::~T), first look >>>> in the scope given by the qualification (i.e., S). >>>> @@ -28675,6 +28685,12 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, >>>> if (!constructor_name_p (id, nested_name_specifier)) >>>> constructor_p = false; >>>> } >>>> + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the >>>> + declarator-id of a constructor or destructor. */ >>>> + else if (constructor_p >>>> + && cxx_dialect >= cxx2a >>>> + && cp_lexer_next_token_is (parser->lexer, CPP_TEMPLATE_ID)) >>>> + constructor_p = false; >>>> /* If we still think that this might be a constructor-declarator, >>>> look for a class-name. */ >>>> else if (constructor_p) >>> >>> Do you also want to exclude CPP_TEMPLATE_ID from the test at the top of the >>> function for C++20? >> >> In fact we can get away with only excluding CPP_TEMPLATE_ID in C++20 there, >> because for e.g. X<T>::X<T>(); we'll give the "names the constructor, not the >> type" error, so we won't even get here. >> >> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? >> >> -- >8 -- >> This patch implements DR 2237 which says that a simple-template-id is >> no longer valid as the declarator-id of a constructor or destructor; >> see [diff.cpp17.class]#2. It is not explicitly stated but out-of-line >> destructors with a simple-template-id are also meant to be ill-formed >> now. (Out-of-line constructors like that are invalid since DR1435 I >> think.) This change only applies to C++20; it is not a DR against C++17. >> >> I'm not crazy about the diagnostic in constructors but ISTM that >> cp_parser_constructor_declarator_p shouldn't print errors. >> >> DR 2237 >> * parser.c (cp_parser_unqualified_id): Reject simple-template-id as >> the declarator-id of a destructor. >> (cp_parser_constructor_declarator_p): Reject simple-template-id as >> the declarator-id of a constructor. >> >> * g++.dg/DRs/dr2237.C: New test. >> * g++.dg/parse/constructor2.C: Add dg-error for C++20. >> * g++.dg/parse/dtor12.C: Likewise. >> * g++.dg/parse/dtor4.C: Likewise. >> * g++.dg/template/dtor4.C: Adjust dg-error. >> * g++.dg/template/error34.C: Likewise. >> * g++.old-deja/g++.other/inline15.C: Only run for C++17 and lesses. >> * g++.old-deja/g++.pt/ctor2.C: Add dg-error for C++20. >> --- >> gcc/cp/parser.c | 13 ++++++++++++- >> gcc/testsuite/g++.dg/DRs/dr2237.C | 18 ++++++++++++++++++ >> gcc/testsuite/g++.dg/parse/constructor2.C | 4 ++-- >> gcc/testsuite/g++.dg/parse/dtor12.C | 2 +- >> gcc/testsuite/g++.dg/parse/dtor4.C | 2 +- >> gcc/testsuite/g++.dg/template/dtor4.C | 2 +- >> gcc/testsuite/g++.dg/template/error34.C | 10 +++++----- >> .../g++.old-deja/g++.other/inline15.C | 2 +- >> gcc/testsuite/g++.old-deja/g++.pt/ctor2.C | 2 +- >> 9 files changed, 42 insertions(+), 13 deletions(-) >> create mode 100644 gcc/testsuite/g++.dg/DRs/dr2237.C >> >> diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c >> index 591f44f4934..593c45b5888 100644 >> --- a/gcc/cp/parser.c >> +++ b/gcc/cp/parser.c >> @@ -6114,6 +6114,15 @@ cp_parser_unqualified_id (cp_parser* parser, >> return build_min_nt_loc (loc, BIT_NOT_EXPR, make_auto ()); >> } >> >> + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the >> + declarator-id of a constructor or destructor. */ >> + if (token->type == CPP_TEMPLATE_ID && cxx_dialect >= cxx2a) >> + { >> + if (!cp_parser_simulate_error (parser)) >> + error_at (tilde_loc, "template-id not allowed for destructor"); >> + return error_mark_node; >> + } >> + >> /* If there was an explicit qualification (S::~T), first look >> in the scope given by the qualification (i.e., S). >> >> @@ -28636,7 +28645,9 @@ cp_parser_constructor_declarator_p (cp_parser *parser, cp_parser_flags flags, >> if (next_token->type != CPP_NAME >> && next_token->type != CPP_SCOPE >> && next_token->type != CPP_NESTED_NAME_SPECIFIER >> - && next_token->type != CPP_TEMPLATE_ID) >> + /* DR 2237 (C++20 only): A simple-template-id is no longer valid as the >> + declarator-id of a constructor or destructor. */ >> + && (next_token->type != CPP_TEMPLATE_ID || cxx_dialect >= cxx2a)) >> return false; >> >> /* Parse tentatively; we are going to roll back all of the tokens >> diff --git a/gcc/testsuite/g++.dg/DRs/dr2237.C b/gcc/testsuite/g++.dg/DRs/dr2237.C >> new file mode 100644 >> index 00000000000..17abdf179c1 >> --- /dev/null >> +++ b/gcc/testsuite/g++.dg/DRs/dr2237.C >> @@ -0,0 +1,18 @@ >> +// DR 2237 - Can a template-id name a constructor? >> + >> +template<class T> >> +struct X { >> + X<T>(); // { dg-error "expected" "" { target c++2a } } >> + X(int); // OK, injected-class-name used >> + ~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } >> +}; >> + >> +// ill-formed since DR1435 >> +template<typename T> X<T>::X<T>() {} // { dg-error "names the constructor|as no template constructors" } >> +template<typename T> X<T>::~X<T>() {} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } >> + >> +struct Q { >> + // ill-formed since DR1435 >> + template<typename T> friend X<T>::X<T>(); // { dg-error "names the constructor|as no template constructors" } >> + template<typename T> friend X<T>::~X<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } >> +}; >> diff --git a/gcc/testsuite/g++.dg/parse/constructor2.C b/gcc/testsuite/g++.dg/parse/constructor2.C >> index e514e9397e9..87007e9c715 100644 >> --- a/gcc/testsuite/g++.dg/parse/constructor2.C >> +++ b/gcc/testsuite/g++.dg/parse/constructor2.C >> @@ -5,7 +5,7 @@ class T >> { >> public: >> T(short,short f=0) {} >> - T<TClass>(int f) {} >> - T<TClass>(int f=0,const char* b=0) {} >> + T<TClass>(int f) {} // { dg-error "expected" "" { target c++2a } } >> + T<TClass>(int f=0,const char* b=0) {} // { dg-error "expected" "" { target c++2a } } >> }; >> >> diff --git a/gcc/testsuite/g++.dg/parse/dtor12.C b/gcc/testsuite/g++.dg/parse/dtor12.C >> index 1acdfa36b69..d758d3e861d 100644 >> --- a/gcc/testsuite/g++.dg/parse/dtor12.C >> +++ b/gcc/testsuite/g++.dg/parse/dtor12.C >> @@ -2,5 +2,5 @@ >> >> template <class T> class a >> { >> - ~a<T>(); >> + ~a<T>(); // { dg-error "template-id not allowed for destructor" "" { target c++2a } } >> }; >> diff --git a/gcc/testsuite/g++.dg/parse/dtor4.C b/gcc/testsuite/g++.dg/parse/dtor4.C >> index 729ee2fa130..1059c189eff 100644 >> --- a/gcc/testsuite/g++.dg/parse/dtor4.C >> +++ b/gcc/testsuite/g++.dg/parse/dtor4.C >> @@ -7,4 +7,4 @@ template <int N> struct X { >> }; >> >> template <int N> >> -X<N>::~X<N>(){} >> +X<N>::~X<N>(){} // { dg-error "template-id not allowed for destructor" "" { target c++2a } } >> diff --git a/gcc/testsuite/g++.dg/template/dtor4.C b/gcc/testsuite/g++.dg/template/dtor4.C >> index 4f277b248bd..917681fc13e 100644 >> --- a/gcc/testsuite/g++.dg/template/dtor4.C >> +++ b/gcc/testsuite/g++.dg/template/dtor4.C >> @@ -5,5 +5,5 @@ >> >> template<int> struct A >> { >> - ~A<0>(); // { dg-error "parse error|declaration" } >> + ~A<0>(); // { dg-error "parse error|declaration|template-id" } >> }; >> diff --git a/gcc/testsuite/g++.dg/template/error34.C b/gcc/testsuite/g++.dg/template/error34.C >> index d0cbcaef28e..ab688d9ba8c 100644 >> --- a/gcc/testsuite/g++.dg/template/error34.C >> +++ b/gcc/testsuite/g++.dg/template/error34.C >> @@ -3,27 +3,27 @@ >> >> template<typename T> struct A >> { >> - A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)" } >> + A<__builtin_offsetof(T, x)>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\)|expected" } >> }; >> >> template<typename T> struct B >> { >> - B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)" } >> + B<__builtin_offsetof(T, x.y)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\)|expected" } >> }; >> >> template<typename T> struct C >> { >> - C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)" } >> + C<__builtin_offsetof(T, x[6])>(); // { dg-error "type/value mismatch|offsetof\\(T, x\\\[6\\\]\\)|expected" } >> }; >> >> template<typename T> struct D >> { >> - D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)" } >> + D<__builtin_offsetof(T, x.y[6].z)>(); // { dg-error "type/value mismatch|offsetof\\(T, x.y\\\[6\\\].z\\)|expected" } >> }; >> >> struct E { int x; }; >> >> template<typename T> struct F >> { >> - F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)" } >> + F<__builtin_offsetof(E, x)>(); // { dg-error "type/value mismatch|offsetof\\(E, x\\)|expected" } >> }; >> diff --git a/gcc/testsuite/g++.old-deja/g++.other/inline15.C b/gcc/testsuite/g++.old-deja/g++.other/inline15.C >> index 43f7f5e3025..a31c60960a5 100644 >> --- a/gcc/testsuite/g++.old-deja/g++.other/inline15.C >> +++ b/gcc/testsuite/g++.old-deja/g++.other/inline15.C >> @@ -1,4 +1,4 @@ >> -// { dg-do assemble } >> +// { dg-do assemble { target c++17_down } } >> // { dg-options "-O1" } >> // Origin: Jakub Jelinek <jakub@redhat.com> >> >> diff --git a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C >> index a8be91ddbb9..4159c84ff56 100644 >> --- a/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C >> +++ b/gcc/testsuite/g++.old-deja/g++.pt/ctor2.C >> @@ -4,7 +4,7 @@ >> >> template <class T> >> struct A { >> - A<T>(); >> + A<T>(); // { dg-error "expected" "" { target c++2a } } >> }; >> >> template <class T> >> >> base-commit: 2b2d298ff845ab7a07ffbd51da79473736da3324 >> -- >> Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA >> > > Marek > ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-05-20 20:45 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-04-04 23:30 [PATCH] c++: C++20 DR 2237, disallow simple-template-id in cdtor Marek Polacek 2020-04-06 1:46 ` Jason Merrill 2020-05-11 20:23 ` Marek Polacek 2020-05-20 18:05 ` Marek Polacek 2020-05-20 20:45 ` Jason Merrill
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