Drive-by:
* Fix potential race between check and update of `throw_one` in `operator new`
* Fix latent bug in `operator delete`, which shouldn't decrement `outstanding_new` when passed a null pointer
* Specifically catch the expected `bad_alloc` in `main` instead of `...`
Differential Revision: https://reviews.llvm.org/D50860
llvm-svn: 359827
Summary:
Freestanding is *weird*. The standard allows it to differ in a bunch of odd
manners from regular C++, and the committee would like to improve that
situation. I'd like to make libc++ behave better with what freestanding should
be, so that it can be a tool we use in improving the standard. To do that we
need to try stuff out, both with "freestanding the language mode" and
"freestanding the library subset".
Let's start with the super basic: run the libc++ tests in freestanding, using
clang as the compiler, and see what works. The easiest hack to do this:
In utils/libcxx/test/config.py add:
self.cxx.compile_flags += ['-ffreestanding']
Run the tests and they all fail.
Why? Because in freestanding `main` isn't special. This "not special" property
has two effects: main doesn't get mangled, and main isn't allowed to omit its
`return` statement. The first means main gets mangled and the linker can't
create a valid executable for us to test. The second means we spew out warnings
(ew) and the compiler doesn't insert the `return` we omitted, and main just
falls of the end and does whatever undefined behavior (if you're luck, ud2
leading to non-zero return code).
Let's start my work with the basics. This patch changes all libc++ tests to
declare `main` as `int main(int, char**` so it mangles consistently (enabling us
to declare another `extern "C"` main for freestanding which calls the mangled
one), and adds `return 0;` to all places where it was missing. This touches 6124
files, and I apologize.
The former was done with The Magic Of Sed.
The later was done with a (not quite correct but decent) clang tool:
https://gist.github.com/jfbastien/793819ff360baa845483dde81170feed
This works for most tests, though I did have to adjust a few places when e.g.
the test runs with `-x c`, macros are used for main (such as for the filesystem
tests), etc.
Once this is in we can create a freestanding bot which will prevent further
regressions. After that, we can start the real work of supporting C++
freestanding fairly well in libc++.
<rdar://problem/47754795>
Reviewers: ldionne, mclow.lists, EricWF
Subscribers: christof, jkorous, dexonsmith, arphaman, miyuki, libcxx-commits
Differential Revision: https://reviews.llvm.org/D57624
llvm-svn: 353086
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351648
In this example, the ctor of G runs in the main thread in the expression G(), and also in the copy ctor of G() in the DECAY_COPY inside std::thread. The main thread destroys the G() instance at the semicolon, and the started thread destroys the G() after it returns. Thus there is a race between the threads on the n_alive variable.
The fix is to join with the background thread before attempting to destroy the G in the main thread.
llvm-svn: 344820
Libc++ is used as a system library on macOS and iOS (amongst others). In order
for users to be able to compile a binary that is intended to be deployed to an
older version of the platform, clang provides the
availability attribute <https://clang.llvm.org/docs/AttributeReference.html#availability>_
that can be placed on declarations to describe the lifecycle of a symbol in the
library.
See docs/DesignDocs/AvailabilityMarkup.rst for more information.
Differential Revision: https://reviews.llvm.org/D31739
llvm-svn: 302172
Summary:
Exactly what the title says.
This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it.
See http://wg21.link/P0513R0 for more info.
If there are no comments in the next couple of days I'll commit this
Reviewers: mclow.lists, K-ballo, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28938
llvm-svn: 292684
First batch of changes to get some of these XFAILs working in the
no-exceptions libc++ variant.
Changed some XFAILs to UNSUPPORTED where the test is all about exception
handling. In other cases, used the test macros TEST_THROW and
TEST_HAS_NO_EXCEPTIONS to conditionally exclude those parts of the test
that concerns exception handling behaviour.
Reviewers: EricWF, mclow.lists
Differential revision: https://reviews.llvm.org/D24562
llvm-svn: 283441
Summary:
Hi,
When creating a new thread libc++ performs at least 2 allocations. The first allocates a tuple of args and the functor that will be passed to the new thread. The second allocation is for the thread local storage needed internally by libc++. Currently the second allocation happens in the child thread, meaning that if it throws the program will terminate with an uncaught bad alloc.
The solution to this is to allocate ALL memory in the parent thread and then pass it to the child.
See https://llvm.org/bugs/show_bug.cgi?id=15638
Reviewers: mclow.lists, danalbert, jroelofs, EricWF
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D13748
llvm-svn: 266851
Fixes a small omission in libcxx that prevents libcxx being built when
-DLIBCXX_ENABLE_EXCEPTIONS=0 is specified.
This patch adds XFAILS to all those tests that are currently failing
on the new -fno-exceptions library variant. Follow-up patches will
update the tests (progressively) to cope with the new library variant.
Change-Id: I4b801bd8d8e4fe7193df9e55f39f1f393a8ba81a
llvm-svn: 252598
Because <atomic> can now be used in C++03 there is no need for the test_atomic.h header.
This commit removes the header and converts all usages to use <atomic> instead.
llvm-svn: 245468
Summary:
This patch attempts to fix the last 3 TSAN failures on the libc++ bot (http://lab.llvm.org:8011/builders/libcxx-libcxxabi-x86_64-linux-ubuntu-tsan/builds/143). This patch also adds a `Atomic` test type that can be used where `<atomic>` cannot.
`wait.exception.pass.cpp` and `wait_for.exception.pass.cpp` were failing because the test replaced `std::terminate` with `std::exit`. `std::exit` would asynchronously run the TLS and static destructors and this would cause a race condition. See PR22606 and D8802 for more details.
This is fixed by using `_Exit` to prevent cleanup.
`notify_all_at_thread_exit.pass.cpp` exercises the same race condition but for different reasons. I fixed this test by manually joining the thread before beginning program termination.
Reviewers: EricWF, mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D11046
llvm-svn: 245389
The test class 'G' reads and writes to the same static variables in its
constructor, destructor and call operator. When threads are
constructed using `std::thread t((G()))` there is a race condition between the
destruction of the temporary and the execution of `G::operator()()`.
The fix is to simply create the input before creating the thread.
llvm-svn: 233946
Marshall Clow