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
The destructor of std::promise needs to construct a std::future_error
exception so it calls std::make_exception_ptr. But under
libcpp-no-exceptions this will trigger an abort.
Differential Revision: https://reviews.llvm.org/D27614
llvm-svn: 291550
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
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
Summary:
This patch marks *most* tests for `std::promise`, `std::future` and `std::shared_future` as unsupported in C++03. These tests fail in C++03 mode because they attempt to copy a `std::future` even though it is a `MoveOnly` type. AFAIK the missing move-semantics in `std::future` is the only reason these tests fail but without move semantics these classes are useless. For example even though `std::promise::set_value` and `std::promise::set_exception(...)` work in C++03 `std::promise` is still useless because we cannot call `std::promise::get_future(...)`.
It might be possible to hack `std::move(...)` like we do for `std::unique_ptr` to make the move semantics work but I don't think it is worth the effort. Instead I think we should leave the `<future>` header as-is and mark the failing tests as `UNSUPPORTED`. I don't believe there are any users of `std::future` or `std::promise` in C++03 because they are so unusable. Therefore I am not concerned about losing test coverage and possibly breaking users. However because there are still parts of `<future>` that work in C++03 it would be wrong to `#ifdef` out the entire header.
@mclow.lists Should we take further steps to prevent the use of `std::promise`, `std::future` and `std::shared_future` in C++03?
Note: This patch also cleans up the tests and converts them to use `support/test_allocator.h` instead of a duplicate class in `test/std/futures/test_allocator.h`.
Reviewers: mclow.lists
Subscribers: vsk, mclow.lists, cfe-commits
Differential Revision: http://reviews.llvm.org/D12135
llvm-svn: 246271
Summary:
Hello Howard,
While running the libc++ tests on our ARM boards, we encounter sporadic failures of the two tests:
test/std/thread/futures/futures.shared_future/wait_until.pass.cpp
test/std/thread/futures/futures.unique_future/wait_until.pass.cpp
The worker thread might not finish yet when the main thread checks its result.
I filed the bug 21998 for this case: http://llvm.org/bugs/show_bug.cgi?id=21998
Would you be able to review this please?
Thank you.
Oleg
Reviewers: howard.hinnant, mclow.lists, danalbert, jroelofs, EricWF
Reviewed By: jroelofs, EricWF
Subscribers: EricWF, mclow.lists, aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D6750
llvm-svn: 228783
Louis Dionne