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
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@353086 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@351648 91177308-0d34-0410-b5e6-96231b3b80d8
Clang and C1XX both complain about mismatched class/struct, but libc++ and MSVC's STL
differ on what they use for tuple_element/tuple_size, so there's no way to win here.
I'm reverting this part of my previous change. In the future, I'll have to suppress
the warning for one compiler or the other.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@305854 91177308-0d34-0410-b5e6-96231b3b80d8
Style/paranoia: 42.1 doesn't have an exact binary representation. Although this doesn't
cause failures, it makes me uncomfortable, so I'm changing it to 42.5.
C1XX rightly warns about unreferenced variables. Adding tests for their values
makes C1XX happy and improves test coverage.
C1XX (somewhat obnoxiously) warns about seeing a struct specialized as a class.
Although the Standard doesn't care, saying struct consistently is better.
(The Standard itself is still inconsistent about whether to depict tuple_element
and tuple_size as structs or classes.)
Fixes D33953.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@305843 91177308-0d34-0410-b5e6-96231b3b80d8
The test was previously set to XFAIL if __cpp_structured_bindings
wasn't defined. However there are Clang 4.0 versions which do not
define this macro but do provide structured bindings, which causes
the test to pass unexpectedly.
This patch changes the XFAIL to an UNSUPPORTED.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291060 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch attempts to re-implement a fix for LWG 2770, but not the actual specified PR.
The PR for 2770 specifies tuple_size<T const> as only conditionally providing a `::value` member. However C++17 structured bindings require `tuple_size<T const>` to be complete only if `tuple_size<T>` is also complete. Therefore this patch implements only provides the specialization `tuple_size<T CV>` iff `tuple_size<T>` is a complete type.
This fixes http://llvm.org/PR31513.
Reviewers: mclow.lists, rsmith, mpark
Subscribers: mpark, cfe-commits
Differential Revision: https://reviews.llvm.org/D28222
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@291019 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the correct PR for LWG 2770. It also makes the primary
tuple_size template incomplete again which fixes part of llvm.org/PR31513.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290846 91177308-0d34-0410-b5e6-96231b3b80d8
This patch upgrades <tuple> to be C++17 compliant by implementing:
* tuple_size_v: This was forgotten when implementing the other _v traits.
* std::apply: This was added via LFTS v1 in p0220r1.
* std::make_from_tuple: This was added in p0209r2.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@275745 91177308-0d34-0410-b5e6-96231b3b80d8
This patch attempts to improve the QoI of std::tuples tuple_element and
__make_tuple_types helpers. Previously they required O(N) instantiations,
one for every element in the tuple
The new implementations are O(1) after __tuple_indices<Id...> is created.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@274330 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: No declaration for the type `tuple` is given in c++03 or c++98 modes. Mark all tests that use the actual `tuple` type as UNSUPPORTED.
Reviewers: jroelofs, mclow.lists, danalbert
Reviewed By: danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D5956
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@229808 91177308-0d34-0410-b5e6-96231b3b80d8
