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
The meta-programming that attempted to form the invoke call expression
was not in a SFINAE context. This made it a hard error to provide
non-referencable types like 'void' or 'void (...) const'.
This patch fixes the error by checking the validity of the call
expression within a SFINAE context.
llvm-svn: 352522
glibc supports versioning, so it's possible to build against older
version and run against newer version. This is sometimes relied on
in practice, e.g. in Fuchsia build we build against older sysroot
(equivalent to Ubuntu Trusty) to cover the broadest possible range
of host systems, but that doesn't necessarily match the system that
binary is going to run on which may have newer version, in which case
the compile test used in curr_symbol is going to fail. Using runtime
check is more reliable.
Differential Revision: https://reviews.llvm.org/D56702
llvm-svn: 352425
The unordered_set and unordered_multiset iterators are specified in the standard as follows:
using iterator = implementation-defined; // see [container.requirements]
using const_iterator = implementation-defined; // see [container.requirements]
using local_iterator = implementation-defined; // see [container.requirements]
using const_local_iterator = implementation-defined; // see [container.requirements]
The pairs iterator/const_iterator and local_iterator/const_local_iterator
are not required to be the same. The reasonable requirement would be that
iterator can convert to const_iterator and local_iterator can convert to
const_local_iterator. This patch weakens the check and makes the test
more portable.
Reviewed as https://reviews.llvm.org/D56493.
Thanks to Andrey Maksimov for the patch.
llvm-svn: 352083
D56445 bumped the minimum Mac OS X version required for aligned
allocation from 10.13 to 10.14. This caused libc++ tests depending
on the old value to break.
This patch updates the XFAILs for those tests to include 10.13.
llvm-svn: 351670
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
D56445 bumped the minimum Mac OS X version required for aligned
allocation from 10.13 to 10.14. This caused libc++ tests depending
on the old value to break.
This patch updates the XFAILs for those tests to include 10.13.
llvm-svn: 351625
Summary:
Starting in Clang 8.0 and GCC 8.0, `alignof` and `__alignof` return different values in same cases. Specifically `alignof` and `_Alignof` return the minimum alignment for a type, where as `__alignof` returns the preferred alignment. libc++ currently uses `__alignof` but means to use `alignof`. See llvm.org/PR39713
This patch introduces the macro `_LIBCPP_ALIGNOF` so we can control which spelling gets used.
This patch does not introduce any ABI guard to provide the old behavior with newer compilers. However, if we decide that is needed, this patch makes it trivial to implement.
I think we should commit this change immediately, and decide what we want to do about the ABI afterwards.
Reviewers: ldionne, EricWF
Reviewed By: ldionne, EricWF
Subscribers: jyknight, christof, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54814
llvm-svn: 351289
Summary:
This patch implements all the feature test macros libc++ currently supports, as specified by the standard or cppreference prior to C++2a.
The tests and `<version>` header are generated using a script. The script contains a table of each feature test macro, the headers it should be accessible from, and its values of each dialect of C++.
When a new feature test macro is added or needed, the table should be updated and the script re-run.
Reviewers: mclow.lists, jfb, serge-sans-paille
Reviewed By: mclow.lists
Subscribers: arphaman, jfb, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D56750
llvm-svn: 351286
libc++ allows changing the namespace, don't assume __1 in the test
to avoid the test failure if different namespace is being used.
Differential Revision: https://reviews.llvm.org/D56698
llvm-svn: 351220
Summary:
P0602R4 makes the special member functions of optional and variant
conditionally trivial based on the types in the optional/variant.
We already implemented that, but the tests were organized as if this
were a non-standard extension. This patch reorganizes the tests in a
way that makes more sense since this is not an extension anymore.
Reviewers: EricWF, mpark, mclow.lists
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54772
llvm-svn: 350884
I have a big patch coming up, and this indirection is required to avoid hitting the following after my big change:
error: empty struct has size 0 in C, size 1 in C++ [-Werror,-Wextern-c-compat]
llvm-svn: 350772
There were 3 tests with 'int main(void)', and 6 with the return type on a different line. I'm about to send a patch for main in tests, and this NFC change is unrelated.
llvm-svn: 350770
We already have a specialization that will use memcpy for construction
of trivial types from an iterator range like
std::vector<int>(int *, int *);
But if we have const-ness mismatch like
std::vector<int>(const int *, const int *);
we would use a slow path that copies each element individually. This change
enables the optimal specialization for const-ness mismatch. Fixes PR37574.
Contributions to the patch are made by Arthur O'Dwyer, Louis Dionne.
rdar://problem/40485845
Reviewers: mclow.lists, EricWF, ldionne, scanon
Reviewed By: ldionne
Subscribers: christof, ldionne, howard.hinnant, cfe-commits
Differential Revision: https://reviews.llvm.org/D48342
llvm-svn: 350583
last_write_time(sym, new_time) changes the modification time of the file
referenced by the symlink. But reading through the symlink may change the
symlinks's access time.
This meant the previous test that checked that the symlinks access
time was unchanged was incorrect and made the test flaky.
This patch removes this test (there really is no non-flaky way
to test that the new access time coorisponds to the time at which
the symlink was last dereferenced). This should unflake the test.
llvm-svn: 350478
JF Bastien