From f81855bba7e58f94949004658b7f850114f965ca Mon Sep 17 00:00:00 2001 From: Philippe Proulx Date: Wed, 3 Apr 2024 00:48:40 -0400 Subject: [PATCH] Fix: enable `FMT_NORETURN` without exception support too MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When building `format.cc` as such with GCC 13.2.1: $ g++ -c format.cc -DFMT_EXCEPTIONS=0 -Wmissing-noreturn -Werror I get: In file included from format.cc:8: fmt/format-inl.h: In function ‘void fmt::v10::detail::assert_fail(const char*, int, const char*)’: fmt/format-inl.h:30:15: error: function might be candidate for attribute ‘noreturn’ [-Werror=suggest-attribute=noreturn] 30 | FMT_FUNC void assert_fail(const char* file, int line, const char* message) { | ^~~~~~~~~~~ fmt/format-inl.h: In function ‘void fmt::v10::report_error(const char*)’: fmt/format-inl.h:129:15: error: function might be candidate for attribute ‘noreturn’ [-Werror=suggest-attribute=noreturn] 129 | FMT_FUNC void report_error(const char* message) { | ^~~~~~~~~~~~ cc1plus: all warnings being treated as errors Note that, with `FMT_EXCEPTIONS` defined to 0: ‣ report_error(const char *) uses FMT_THROW() which expands to calling assert_fail(). ‣ assert_fail() calls std::terminate() which has the `[[noreturn]]` attribute since C++11 [1]. Therefore, with `FMT_EXCEPTIONS` defined to 0, both assert_fail() and report_error() need to have the `[[noreturn]]` attribute too (if available). In other words, `FMT_NORETURN` doesn't depend on `FMT_EXCEPTIONS`. Also adding `FMT_NORETURN` to two on_error() functions which call report_error(const char *). Other report_error() overloads eventually return, therefore they don't need `FMT_NORETURN`. [1]: https://en.cppreference.com/w/cpp/error/terminate Signed-off-by: Philippe Proulx --- include/fmt/base.h | 5 ++--- include/fmt/format.h | 2 +- 2 files changed, 3 insertions(+), 4 deletions(-) diff --git a/include/fmt/base.h b/include/fmt/base.h index bc9cfb2f7056b..ec78ae28da53c 100644 --- a/include/fmt/base.h +++ b/include/fmt/base.h @@ -175,8 +175,7 @@ #endif // Disable [[noreturn]] on MSVC/NVCC because of bogus unreachable code warnings. -#if FMT_HAS_CPP_ATTRIBUTE(noreturn) && FMT_EXCEPTIONS && !FMT_MSC_VERSION && \ - !defined(__NVCC__) +#if FMT_HAS_CPP_ATTRIBUTE(noreturn) && !FMT_MSC_VERSION && !defined(__NVCC__) # define FMT_NORETURN [[noreturn]] #else # define FMT_NORETURN @@ -2754,7 +2753,7 @@ template class format_string_checker { return id >= 0 && id < num_args ? parse_funcs_[id](context_) : begin; } - FMT_CONSTEXPR void on_error(const char* message) { report_error(message); } + FMT_NORETURN FMT_CONSTEXPR void on_error(const char* message) { report_error(message); } }; // A base class for compile-time strings. diff --git a/include/fmt/format.h b/include/fmt/format.h index 3aaee42f67080..541bf11d51272 100644 --- a/include/fmt/format.h +++ b/include/fmt/format.h @@ -4302,7 +4302,7 @@ void vformat_to(buffer& buf, basic_string_view fmt, return begin; } - void on_error(const char* message) { report_error(message); } + FMT_NORETURN void on_error(const char* message) { report_error(message); } }; detail::parse_format_string(fmt, format_handler(out, fmt, args, loc)); }