public inbox for libstdc++-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc r11-9912] libstdc++: Improvements to standard error category objects (part deux)
@ 2022-04-21 12:33 Jonathan Wakely
0 siblings, 0 replies; only message in thread
From: Jonathan Wakely @ 2022-04-21 12:33 UTC (permalink / raw)
To: gcc-cvs, libstdc++-cvs
https://gcc.gnu.org/g:948ee24748520f2793d879254ad56e2a0cafdb1d
commit r11-9912-g948ee24748520f2793d879254ad56e2a0cafdb1d
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Sep 22 13:56:21 2021 +0100
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.
(cherry picked from commit 096228d84e9238d97fe115623126373f5b67bdc1)
Diff:
---
libstdc++-v3/src/c++11/cxx11-ios_failure.cc | 25 +++++++++++++++----------
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 a918ab21015..e40685bf45a 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 c1a1a828e27..75f832ec1c5 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 { }
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2022-04-21 12:33 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-21 12:33 [gcc r11-9912] libstdc++: Improvements to standard error category objects (part deux) Jonathan Wakely
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).