The output of
template<class charT, class traits>
basic_ostream<charT, traits>&
operator<<(basic_ostream<charT, traits>& out, thread::id id);
is affected by the state of out. The wording states
[thread.thread.id]/2
The text representation for the character type charT of an object of
type thread::id is an unspecified sequence of charT such that, for two
objects of type thread::id x and y, if x == y is true, the thread::id
objects have the same text representation, and if x != y is true, the
thread::id objects have distinct text representations.
[thread.thread.id]/9
template<class charT, class traits>
basic_ostream<charT, traits>&
operator<< (basic_ostream<charT, traits>& out, thread::id id);
Effects: Inserts the text representation for charT of id into out.
This wording changed in C++23 due to adding a formatter specialization for
thread::id. However the requirement was the same in older versions of C++.
This issue is that thread::id is an integral or pointer and affected by the
formatting manipulators for them. Thus the text representation can differ if
x == y which violates the requirements.
The fix has to hard-code some formatting style for the text
representation. It uses the Standard specified default values
Table 124: basic_ios::init() effects [tab:basic.ios.cons] flags()
flags() skipws | dec
Fixes PR: https://llvm.org/PR62073
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D153336
This makes <__threading_support> closer to handling only the bridge
between the system's implementation of threading and the rest of libc++.
Differential Revision: https://reviews.llvm.org/D154464
Replace most uses of `_LIBCPP_ASSERT` with
`_LIBCPP_ASSERT_UNCATEGORIZED`.
This is done as a prerequisite to introducing hardened mode to libc++.
The idea is to make enabling assertions an opt-in with (somewhat)
fine-grained controls over which categories of assertions are enabled.
The vast majority of assertions are currently uncategorized; the new
macro will allow turning on `_LIBCPP_ASSERT` (the underlying mechanism
for all kinds of assertions) without enabling all the uncategorized
assertions (in the future; this patch preserves the current behavior).
Differential Revision: https://reviews.llvm.org/D153816
This commit reverts 5aaefa51 (and also partly 7f285f48e77 and b6d75682f9,
which were related to the original commit). As landed, 5aaefa51 had
unintended consequences on some downstream bots and didn't have proper
coverage upstream due to a few subtle things. Implementing this is
something we should do in libc++, however we'll first need to address
a few issues listed in https://reviews.llvm.org/D106124#3349710.
Differential Revision: https://reviews.llvm.org/D120683
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.
Differential Revision: https://reviews.llvm.org/D106124
This change is the basis for a further refactoring where I'm going to
split up the various implementations we have in __threading_support to
make that code easier to understand.
Note that I had to make __convert_to_timespec a template to break
circular dependencies. Concretely, we never seem to use it with anything
other than ::timespec, but I am wary of hardcoding that assumption as
part of this change, since I suspect there's a reason for going through
these hoops in the first place.
Differential Revision: https://reviews.llvm.org/D116944
I didn't split the calendar bits more than this because there was little
benefit to doing it, and I know our calendar support is incomplete.
Whoever picks up the missing calendar bits can organize these headers
at their leisure.
Differential Revision: https://reviews.llvm.org/D116965
std::atomic is, for the most part, just a thin veneer on top of compiler
builtins. Hence, it should be available even when threads are not available
on the system, and in fact there has been requests for such support.
This patch:
- Moves __libcpp_thread_poll_with_backoff to its own header so it can
be used in <atomic> when threads are disabled.
- Adds a dummy backoff policy for atomic polling that doesn't know about
threads.
- Adjusts the <atomic> feature-test macros so they are provided even when
threads are disabled.
- Runs the <atomic> tests when threads are disabled.
rdar://77873569
Differential Revision: https://reviews.llvm.org/D114109
