Sorry for the delay, I'm travelling with limited internet. I will commit it early next week if no one beats me to it.
On Thu, Aug 11, 2022, 2:45 PM Tom Honermann via Gcc-patches < gcc-patches@gcc.gnu.org> wrote: > If there are no further concerns, could a C++ or libcpp maintainer > please commit this for me? > > Thank you! > > Tom. > > On 8/4/22 12:42 PM, Tom Honermann via Gcc-patches wrote: > > Are there any further concerns with this patch? If not, I extend my > > gratitude to anyone so kind as to commit this for me as I don't have > > commit access. > > > > I just noticed that I neglected to add a ChangeLog entry for the > > comment addition to gcc/cp/parser.cc. Noted inline below. I can > > re-send the patch with that update if desired. > > > > Tom. > > > > On 8/1/22 2:49 PM, Tom Honermann wrote: > >> Gcc's '#pragma GCC diagnostic' directives are processed in "early mode" > >> (see handle_pragma_diagnostic_early) for the C++ frontend and, as such, > >> require that the target diagnostic option be enabled for the > >> preprocessor > >> (see c_option_is_from_cpp_diagnostics). This change modifies the > >> -Wc++20-compat option definition to register it as a preprocessor option > >> so that its associated diagnostics can be suppressed. The changes also > >> implicitly disable the option in C++20 and later modes. These changes > >> are consistent with the definition of the -Wc++11-compat option. > >> > >> This support is motivated by the need to suppress the following > >> diagnostic > >> otherwise issued in C++17 and earlier modes due to the char8_t typedef > >> present in the uchar.h header file in glibc 2.36. > >> warning: identifier ‘char8_t’ is a keyword in C++20 [-Wc++20-compat] > >> > >> Tests are added to validate suppression of both -Wc++11-compat and > >> -Wc++20-compat related diagnostics (fixes were only needed for the C++20 > >> case). > >> > >> Fixeshttps://gcc.gnu.org/PR106423. > >> > >> gcc/c-family/ChangeLog: > >> * c-opts.cc (c_common_post_options): Disable -Wc++20-compat > >> diagnostics > >> in C++20 and later. > >> * c.opt (Wc++20-compat): Enable hooks for the preprocessor. > > > > gcc/cp/ChangeLog: > > * parser.cc (cp_lexer_saving_tokens): Add comment regarding > > diagnostic requirements. > > > >> > >> gcc/testsuite/ChangeLog: > >> * g++.dg/cpp0x/keywords2.C: New test. > >> * g++.dg/cpp2a/keywords2.C: New test. > >> > >> libcpp/ChangeLog: > >> * include/cpplib.h (cpp_warning_reason): Add CPP_W_CXX20_COMPAT. > >> * init.cc (cpp_create_reader): Add cpp_warn_cxx20_compat. > >> --- > >> gcc/c-family/c-opts.cc | 7 +++++++ > >> gcc/c-family/c.opt | 2 +- > >> gcc/cp/parser.cc | 5 ++++- > >> gcc/testsuite/g++.dg/cpp0x/keywords2.C | 16 ++++++++++++++++ > >> gcc/testsuite/g++.dg/cpp2a/keywords2.C | 13 +++++++++++++ > >> libcpp/include/cpplib.h | 4 ++++ > >> libcpp/init.cc | 1 + > >> 7 files changed, 46 insertions(+), 2 deletions(-) > >> create mode 100644 gcc/testsuite/g++.dg/cpp0x/keywords2.C > >> create mode 100644 gcc/testsuite/g++.dg/cpp2a/keywords2.C > >> > >> diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc > >> index b9f01a65ed7..1ea37ba9742 100644 > >> --- a/gcc/c-family/c-opts.cc > >> +++ b/gcc/c-family/c-opts.cc > >> @@ -1046,6 +1046,13 @@ c_common_post_options (const char **pfilename) > >> else if (warn_narrowing == -1) > >> warn_narrowing = 0; > >> + if (cxx_dialect >= cxx20) > >> + { > >> + /* Don't warn about C++20 compatibility changes in C++20 or > >> later. */ > >> + warn_cxx20_compat = 0; > >> + cpp_opts->cpp_warn_cxx20_compat = 0; > >> + } > >> + > >> /* C++17 has stricter evaluation order requirements; let's use > >> some of them > >> for earlier C++ as well, so chaining works as expected. */ > >> if (c_dialect_cxx () > >> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > >> index 44e1a60ce24..dfdebd596ef 100644 > >> --- a/gcc/c-family/c.opt > >> +++ b/gcc/c-family/c.opt > >> @@ -455,7 +455,7 @@ Wc++2a-compat > >> C++ ObjC++ Warning Alias(Wc++20-compat) Undocumented > >> Wc++20-compat > >> -C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ > >> ObjC++,Wall) > >> +C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ > >> ObjC++,Wall) Init(0) CPP(cpp_warn_cxx20_compat) > >> CppReason(CPP_W_CXX20_COMPAT) > >> Warn about C++ constructs whose meaning differs between ISO C++ > >> 2017 and ISO C++ 2020. > >> Wc++11-extensions > >> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc > >> index 4f67441eeb1..c3584446827 100644 > >> --- a/gcc/cp/parser.cc > >> +++ b/gcc/cp/parser.cc > >> @@ -924,7 +924,10 @@ cp_lexer_saving_tokens (const cp_lexer* lexer) > >> /* Store the next token from the preprocessor in *TOKEN. Return true > >> if we reach EOF. If LEXER is NULL, assume we are handling an > >> initial #pragma pch_preprocess, and thus want the lexer to return > >> - processed strings. */ > >> + processed strings. > >> + > >> + Diagnostics issued from this function must have their controlling > >> option (if > >> + any) in c.opt annotated as a libcpp option via the CppReason > >> property. */ > >> static void > >> cp_lexer_get_preprocessor_token (unsigned flags, cp_token *token) > >> diff --git a/gcc/testsuite/g++.dg/cpp0x/keywords2.C > >> b/gcc/testsuite/g++.dg/cpp0x/keywords2.C > >> new file mode 100644 > >> index 00000000000..d67d01e31ed > >> --- /dev/null > >> +++ b/gcc/testsuite/g++.dg/cpp0x/keywords2.C > >> @@ -0,0 +1,16 @@ > >> +// { dg-do compile { target c++98_only } } > >> +// { dg-options "-Wc++11-compat" } > >> + > >> +// Validate suppression of -Wc++11-compat diagnostics. > >> +#pragma GCC diagnostic ignored "-Wc++11-compat" > >> +int alignof; > >> +int alignas; > >> +int constexpr; > >> +int decltype; > >> +int noexcept; > >> +int nullptr; > >> +int static_assert; > >> +int thread_local; > >> +int _Alignas; > >> +int _Alignof; > >> +int _Thread_local; > >> diff --git a/gcc/testsuite/g++.dg/cpp2a/keywords2.C > >> b/gcc/testsuite/g++.dg/cpp2a/keywords2.C > >> new file mode 100644 > >> index 00000000000..8714a7b26b7 > >> --- /dev/null > >> +++ b/gcc/testsuite/g++.dg/cpp2a/keywords2.C > >> @@ -0,0 +1,13 @@ > >> +// { dg-do compile { target c++17_down } } > >> +// { dg-options "-Wc++20-compat" } > >> + > >> +// Validate suppression of -Wc++20-compat diagnostics. > >> +#pragma GCC diagnostic ignored "-Wc++20-compat" > >> +int constinit; > >> +int consteval; > >> +int requires; > >> +int concept; > >> +int co_await; > >> +int co_yield; > >> +int co_return; > >> +int char8_t; > >> diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h > >> index 3eba6f74b57..9d90c18e4f2 100644 > >> --- a/libcpp/include/cpplib.h > >> +++ b/libcpp/include/cpplib.h > >> @@ -547,6 +547,9 @@ struct cpp_options > >> /* True if warn about differences between C++98 and C++11. */ > >> bool cpp_warn_cxx11_compat; > >> + /* True if warn about differences between C++17 and C++20. */ > >> + bool cpp_warn_cxx20_compat; > >> + > >> /* Nonzero if bidirectional control characters checking is on. > >> See enum > >> cpp_bidirectional_level. */ > >> unsigned char cpp_warn_bidirectional; > >> @@ -655,6 +658,7 @@ enum cpp_warning_reason { > >> CPP_W_C90_C99_COMPAT, > >> CPP_W_C11_C2X_COMPAT, > >> CPP_W_CXX11_COMPAT, > >> + CPP_W_CXX20_COMPAT, > >> CPP_W_EXPANSION_TO_DEFINED, > >> CPP_W_BIDIRECTIONAL > >> }; > >> diff --git a/libcpp/init.cc b/libcpp/init.cc > >> index f4ab83d2145..cca3c1dc1e7 100644 > >> --- a/libcpp/init.cc > >> +++ b/libcpp/init.cc > >> @@ -202,6 +202,7 @@ cpp_create_reader (enum c_lang lang, > >> cpp_hash_table *table, > >> CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1; > >> CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) = -1; > >> CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0; > >> + CPP_OPTION (pfile, cpp_warn_cxx20_compat) = 0; > >> CPP_OPTION (pfile, cpp_warn_deprecated) = 1; > >> CPP_OPTION (pfile, cpp_warn_long_long) = 0; > >> CPP_OPTION (pfile, dollars_in_ident) = 1; > >
