| Message ID | 20240903220018.2785461-1-jason@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [pushed] c++: support C++11 attributes in C++98 | expand |
On Tue, Sep 3, 2024 at 3:01 PM Jason Merrill <jason@redhat.com> wrote: > > Tested x86_64-pc-linux-gnu, applying to trunk. > > -- 8< -- > > I don't see any reason why we can't allow the [[]] attribute syntax in C++98 > mode with a pedwarn just like many other C++11 features. In fact, we > already do support it in some places in the grammar, but not in places that > check cp_nth_tokens_can_be_std_attribute_p. > > Let's also follow the C front-end's lead in only warning about them when > -pedantic. > > It still isn't necessary for this function to guard against Objective-C > message passing syntax; we handle that with tentative parsing in > cp_parser_statement, and we don't call this function in that context anyway. > > gcc/cp/ChangeLog: > > * parser.cc (cp_nth_tokens_can_be_std_attribute_p): Don't check > cxx_dialect. > * error.cc (maybe_warn_cpp0x): Only complain about C++11 attributes > if pedantic. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp0x/gen-attrs-1.C: Also run in C++98 mode. > * g++.dg/cpp0x/gen-attrs-11.C: Likewise. > * g++.dg/cpp0x/gen-attrs-13.C: Likewise. > * g++.dg/cpp0x/gen-attrs-15.C: Likewise. > * g++.dg/cpp0x/gen-attrs-75.C: Don't expect C++98 warning after > __extension__. > --- > gcc/cp/error.cc | 7 ++++--- > gcc/cp/parser.cc | 9 ++++----- > gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C | 2 +- > gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C | 2 +- > gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C | 2 +- > gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C | 2 +- > gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C | 10 +++++----- > 7 files changed, 17 insertions(+), 17 deletions(-) > > diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc > index 57cd76caf49..4a9e9aa3cdc 100644 > --- a/gcc/cp/error.cc > +++ b/gcc/cp/error.cc > @@ -4735,9 +4735,10 @@ maybe_warn_cpp0x (cpp0x_warn_str str, location_t loc/*=input_location*/) > "only available with %<-std=c++11%> or %<-std=gnu++11%>"); > break; > case CPP0X_ATTRIBUTES: > - pedwarn (loc, OPT_Wc__11_extensions, > - "C++11 attributes " > - "only available with %<-std=c++11%> or %<-std=gnu++11%>"); > + if (pedantic) > + pedwarn (loc, OPT_Wc__11_extensions, > + "C++11 attributes " > + "only available with %<-std=c++11%> or %<-std=gnu++11%>"); Shouldn't the warning also change to mention -std=gnu++98 now? Or maybe reworded a little more? Thanks, Andrew Pinski > break; > case CPP0X_REF_QUALIFIER: > pedwarn (loc, OPT_Wc__11_extensions, > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc > index edfa5a49440..64122d937fa 100644 > --- a/gcc/cp/parser.cc > +++ b/gcc/cp/parser.cc > @@ -29924,11 +29924,10 @@ cp_nth_tokens_can_be_std_attribute_p (cp_parser *parser, size_t n) > { > cp_token *token = cp_lexer_peek_nth_token (parser->lexer, n); > > - return (cxx_dialect >= cxx11 > - && ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS) > - || (token->type == CPP_OPEN_SQUARE > - && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1)) > - && token->type == CPP_OPEN_SQUARE))); > + return ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS) > + || (token->type == CPP_OPEN_SQUARE > + && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1)) > + && token->type == CPP_OPEN_SQUARE)); > } > > /* Return TRUE iff the next Nth tokens in the stream are possibly the > diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C > index c2cf912047e..b1625d96916 100644 > --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C > +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C > @@ -1,3 +1,3 @@ > -// { dg-do compile { target c++11 } } > +// { dg-additional-options "-Wno-c++11-extensions" } > > int **** [[gnu::format(printf, 1, 2)]] foo(const char *, ...); // { dg-warning "only applies to function types" } > diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C > index 504b4565679..040f15c9dbb 100644 > --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C > +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C > @@ -1,4 +1,4 @@ > -// { dg-do compile { target c++11 } } > +// { dg-additional-options "-Wno-c++11-extensions" } > // PR c++/13791 > > template <typename T> struct O { > diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C > index a1b4a84b7e5..8997b845dfd 100644 > --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C > +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C > @@ -1,4 +1,4 @@ > -// { dg-do compile { target c++11 } } > +// { dg-additional-options "-Wno-c++11-extensions" } > // PR c++/13854 > > extern char *rindex [[gnu::__pure__]] (__const char *__s, int __c) throw (); > diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C > index bf05dbeb31b..8b552ca1fbe 100644 > --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C > +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C > @@ -1,4 +1,4 @@ > -// { dg-do compile { target c++11 } } > +// { dg-additional-options "-Wno-c++11-extensions" } > // PR c++/15317 > > struct A > diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C > index bac80aa02ff..c2a328c7c7f 100644 > --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C > +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C > @@ -1,6 +1,6 @@ > // PR c++/101582 > // { dg-do compile } > -// { dg-options "" } > +// { dg-options "-pedantic -Wno-extra-semi" } > > ; > [[]] [[]] [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > @@ -12,9 +12,9 @@ extern "C" [[]]; // { dg-warning "attributes only available with" "" { target c+ > extern "C" extern "C" ; > extern "C" extern "C" [[]][[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > __extension__ ; > -__extension__ [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > +__extension__ [[]]; > __extension__ __extension__ ; > -__extension__ __extension__ [[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > +__extension__ __extension__ [[]][[]]; > > namespace N { > > @@ -28,8 +28,8 @@ extern "C" [[]]; // { dg-warning "attributes only available with" "" { target c+ > extern "C" extern "C" ; > extern "C" extern "C" [[]][[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > __extension__ ; > -__extension__ [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > +__extension__ [[]]; > __extension__ __extension__ ; > -__extension__ __extension__ [[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } > +__extension__ __extension__ [[]][[]]; > > } > > base-commit: 1fad396dd467326251572811b703e788e62a2588 > -- > 2.46.0 >
On 9/3/24 7:00 PM, Andrew Pinski wrote: > On Tue, Sep 3, 2024 at 3:01 PM Jason Merrill <jason@redhat.com> wrote: >> >> Tested x86_64-pc-linux-gnu, applying to trunk. >> >> -- 8< -- >> >> I don't see any reason why we can't allow the [[]] attribute syntax in C++98 >> mode with a pedwarn just like many other C++11 features. In fact, we >> already do support it in some places in the grammar, but not in places that >> check cp_nth_tokens_can_be_std_attribute_p. >> >> Let's also follow the C front-end's lead in only warning about them when >> -pedantic. >> >> It still isn't necessary for this function to guard against Objective-C >> message passing syntax; we handle that with tentative parsing in >> cp_parser_statement, and we don't call this function in that context anyway. >> >> gcc/cp/ChangeLog: >> >> * parser.cc (cp_nth_tokens_can_be_std_attribute_p): Don't check >> cxx_dialect. >> * error.cc (maybe_warn_cpp0x): Only complain about C++11 attributes >> if pedantic. >> >> gcc/testsuite/ChangeLog: >> >> * g++.dg/cpp0x/gen-attrs-1.C: Also run in C++98 mode. >> * g++.dg/cpp0x/gen-attrs-11.C: Likewise. >> * g++.dg/cpp0x/gen-attrs-13.C: Likewise. >> * g++.dg/cpp0x/gen-attrs-15.C: Likewise. >> * g++.dg/cpp0x/gen-attrs-75.C: Don't expect C++98 warning after >> __extension__. >> --- >> gcc/cp/error.cc | 7 ++++--- >> gcc/cp/parser.cc | 9 ++++----- >> gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C | 2 +- >> gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C | 2 +- >> gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C | 2 +- >> gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C | 2 +- >> gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C | 10 +++++----- >> 7 files changed, 17 insertions(+), 17 deletions(-) >> >> diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc >> index 57cd76caf49..4a9e9aa3cdc 100644 >> --- a/gcc/cp/error.cc >> +++ b/gcc/cp/error.cc >> @@ -4735,9 +4735,10 @@ maybe_warn_cpp0x (cpp0x_warn_str str, location_t loc/*=input_location*/) >> "only available with %<-std=c++11%> or %<-std=gnu++11%>"); >> break; >> case CPP0X_ATTRIBUTES: >> - pedwarn (loc, OPT_Wc__11_extensions, >> - "C++11 attributes " >> - "only available with %<-std=c++11%> or %<-std=gnu++11%>"); >> + if (pedantic) >> + pedwarn (loc, OPT_Wc__11_extensions, >> + "C++11 attributes " >> + "only available with %<-std=c++11%> or %<-std=gnu++11%>"); > > Shouldn't the warning also change to mention -std=gnu++98 now? Or > maybe reworded a little more? That's the conventional wording for pedwarns about extensions from later standards; I wouldn't change this one alone, though I agree a general rewording might make sense. Jason
diff --git a/gcc/cp/error.cc b/gcc/cp/error.cc index 57cd76caf49..4a9e9aa3cdc 100644 --- a/gcc/cp/error.cc +++ b/gcc/cp/error.cc @@ -4735,9 +4735,10 @@ maybe_warn_cpp0x (cpp0x_warn_str str, location_t loc/*=input_location*/) "only available with %<-std=c++11%> or %<-std=gnu++11%>"); break; case CPP0X_ATTRIBUTES: - pedwarn (loc, OPT_Wc__11_extensions, - "C++11 attributes " - "only available with %<-std=c++11%> or %<-std=gnu++11%>"); + if (pedantic) + pedwarn (loc, OPT_Wc__11_extensions, + "C++11 attributes " + "only available with %<-std=c++11%> or %<-std=gnu++11%>"); break; case CPP0X_REF_QUALIFIER: pedwarn (loc, OPT_Wc__11_extensions, diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index edfa5a49440..64122d937fa 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -29924,11 +29924,10 @@ cp_nth_tokens_can_be_std_attribute_p (cp_parser *parser, size_t n) { cp_token *token = cp_lexer_peek_nth_token (parser->lexer, n); - return (cxx_dialect >= cxx11 - && ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS) - || (token->type == CPP_OPEN_SQUARE - && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1)) - && token->type == CPP_OPEN_SQUARE))); + return ((token->type == CPP_KEYWORD && token->keyword == RID_ALIGNAS) + || (token->type == CPP_OPEN_SQUARE + && (token = cp_lexer_peek_nth_token (parser->lexer, n + 1)) + && token->type == CPP_OPEN_SQUARE)); } /* Return TRUE iff the next Nth tokens in the stream are possibly the diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C index c2cf912047e..b1625d96916 100644 --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C @@ -1,3 +1,3 @@ -// { dg-do compile { target c++11 } } +// { dg-additional-options "-Wno-c++11-extensions" } int **** [[gnu::format(printf, 1, 2)]] foo(const char *, ...); // { dg-warning "only applies to function types" } diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C index 504b4565679..040f15c9dbb 100644 --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-11.C @@ -1,4 +1,4 @@ -// { dg-do compile { target c++11 } } +// { dg-additional-options "-Wno-c++11-extensions" } // PR c++/13791 template <typename T> struct O { diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C index a1b4a84b7e5..8997b845dfd 100644 --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-13.C @@ -1,4 +1,4 @@ -// { dg-do compile { target c++11 } } +// { dg-additional-options "-Wno-c++11-extensions" } // PR c++/13854 extern char *rindex [[gnu::__pure__]] (__const char *__s, int __c) throw (); diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C index bf05dbeb31b..8b552ca1fbe 100644 --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-15.C @@ -1,4 +1,4 @@ -// { dg-do compile { target c++11 } } +// { dg-additional-options "-Wno-c++11-extensions" } // PR c++/15317 struct A diff --git a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C index bac80aa02ff..c2a328c7c7f 100644 --- a/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C +++ b/gcc/testsuite/g++.dg/cpp0x/gen-attrs-75.C @@ -1,6 +1,6 @@ // PR c++/101582 // { dg-do compile } -// { dg-options "" } +// { dg-options "-pedantic -Wno-extra-semi" } ; [[]] [[]] [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } @@ -12,9 +12,9 @@ extern "C" [[]]; // { dg-warning "attributes only available with" "" { target c+ extern "C" extern "C" ; extern "C" extern "C" [[]][[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } __extension__ ; -__extension__ [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } +__extension__ [[]]; __extension__ __extension__ ; -__extension__ __extension__ [[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } +__extension__ __extension__ [[]][[]]; namespace N { @@ -28,8 +28,8 @@ extern "C" [[]]; // { dg-warning "attributes only available with" "" { target c+ extern "C" extern "C" ; extern "C" extern "C" [[]][[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } __extension__ ; -__extension__ [[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } +__extension__ [[]]; __extension__ __extension__ ; -__extension__ __extension__ [[]][[]]; // { dg-warning "attributes only available with" "" { target c++98_only } } +__extension__ __extension__ [[]][[]]; }