diff options
author | Jonathan Wakely <jwakely@redhat.com> | 2021-09-22 13:56:21 +0100 |
---|---|---|
committer | Jonathan Wakely <jwakely@redhat.com> | 2022-01-05 14:17:51 +0000 |
commit | 096228d84e9238d97fe115623126373f5b67bdc1 (patch) | |
tree | 1218ee5dd02f2ca0f02625d63dc2ed053fa9366d /libstdc++-v3/src/c++11 | |
parent | 1918067e2d0d79ccaf1e4ed98096060fc235e772 (diff) |
libstdc++: Improvements to standard error category objects (part deux)
In r12-3860 the error categories in <system_error> were made final and
immortal, but I missed the categories for <future> and <ios>. This makes
the same changes to those.
libstdc++-v3/ChangeLog:
* src/c++11/cxx11-ios_failure.cc (io_error_category): Define
class and virtual functions as 'final'.
(io_category_instance): Use constinit union to make the object
immortal.
* src/c++11/future.cc (future_error_category): Define class and
virtual functions as 'final'.
(future_category_instance): Use constinit union.
Diffstat (limited to 'libstdc++-v3/src/c++11')
-rw-r--r-- | libstdc++-v3/src/c++11/cxx11-ios_failure.cc | 25 | ||||
-rw-r--r-- | libstdc++-v3/src/c++11/future.cc | 26 |
2 files changed, 31 insertions, 20 deletions
diff --git a/libstdc++-v3/src/c++11/cxx11-ios_failure.cc b/libstdc++-v3/src/c++11/cxx11-ios_failure.cc index 5a151b6ec5c..ba4b1413bf9 100644 --- a/libstdc++-v3/src/c++11/cxx11-ios_failure.cc +++ b/libstdc++-v3/src/c++11/cxx11-ios_failure.cc @@ -44,14 +44,15 @@ namespace { - struct io_error_category : std::error_category + struct io_error_category final : std::error_category { - virtual const char* - name() const noexcept + const char* + name() const noexcept final { return "iostream"; } _GLIBCXX_DEFAULT_ABI_TAG - virtual std::string message(int __ec) const + std::string + message(int __ec) const final { std::string __msg; switch (std::io_errc(__ec)) @@ -67,13 +68,17 @@ namespace } }; - const io_error_category& - __io_category_instance() noexcept + struct constant_init { - static const io_error_category __ec{}; - return __ec; - } + union { + unsigned char unused; + io_error_category cat; + }; + constexpr constant_init() : cat() { } + ~constant_init() { /* do nothing, union member is not destroyed */ } + }; + __constinit constant_init io_category_instance{}; } // namespace namespace std _GLIBCXX_VISIBILITY(default) @@ -82,7 +87,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION const error_category& iostream_category() noexcept - { return __io_category_instance(); } + { return io_category_instance.cat; } ios_base::failure::failure(const string& __str) : system_error(io_errc::stream, __str) { } diff --git a/libstdc++-v3/src/c++11/future.cc b/libstdc++-v3/src/c++11/future.cc index c5423931eb3..488ff17a1e6 100644 --- a/libstdc++-v3/src/c++11/future.cc +++ b/libstdc++-v3/src/c++11/future.cc @@ -27,14 +27,15 @@ namespace { - struct future_error_category : public std::error_category + struct future_error_category final : public std::error_category { - virtual const char* - name() const noexcept + const char* + name() const noexcept final { return "future"; } _GLIBCXX_DEFAULT_ABI_TAG - virtual std::string message(int __ec) const + std::string + message(int __ec) const final { std::string __msg; switch (std::future_errc(__ec)) @@ -59,12 +60,17 @@ namespace } }; - const future_error_category& - __future_category_instance() noexcept + struct constant_init { - static const future_error_category __fec{}; - return __fec; - } + union { + unsigned char unused; + future_error_category cat; + }; + constexpr constant_init() : cat() { } + ~constant_init() { /* do nothing, union member is not destroyed */ } + }; + + __constinit constant_init future_category_instance{}; } namespace std _GLIBCXX_VISIBILITY(default) @@ -76,7 +82,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { _GLIBCXX_THROW_OR_ABORT(future_error(make_error_code(future_errc(__i)))); } const error_category& future_category() noexcept - { return __future_category_instance(); } + { return future_category_instance.cat; } future_error::~future_error() noexcept { } |