Summary:
FreeBSD ships a very old and deprecated ABI for std::pair where the copy and move constructors are not allowed to be trivial. D25389 change how this was implemented by introducing a non-trivial base class. This patch, introduced in October 2016, introduced an ABI bug that caused nested `std::pair` instantiations to have padding. For example:
```
using PairT = std::pair< std::pair<char, char>, char >;
static_assert(offsetof(PairT, first) == 0, "First member should exist at offset zero"); // Fails on FreeBSD!
```
The bug occurs because the base class for the first element (the nested pair) cannot be put at offset zero because the top-level pair already has the same base class laid out there.
This patch fixes that ABI bug by templating the dummy base class on the same parameters as the pair.
Technically this fix is an ABI break for users who depend on the "broken" ABI introduced in 2016. I'm putting this up for review so that the FreeBSD maintainers can sign off on fixing the ABI by breaking the ABI.
Another option, since we have to "break" the ABI to fix it, would be to move FreeBSD off the deprecated non-trivial pair ABI instead.
Also see:
* https://llvm.org/PR40230
* https://reviews.llvm.org/D21329
Reviewers: rsmith, dim, emaste
Reviewed By: rsmith
Subscribers: mclow.lists, krytarowski, christof, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D56357
llvm-svn: 351290
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
Summary:
The tests need to create files larger than 2GB, but size_t is 32-bit
on a 32-bit system. Make use of explicit off64_t APIs so we can still
use a default off_t for the tests while enabling 64-bit file offsets
for create_file.
Reviewers: mclow.lists, EricWF
Reviewed By: EricWF
Subscribers: christof, ldionne, libcxx-commits
Differential Revision: https://reviews.llvm.org/D56619
llvm-svn: 351225
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
When catopen is missing, do_open, do_get and do_close end up being
no-op, and as such their parameters will be unused which triggers a
warning/error when building with -Wunused-parameter.
Differential Revision: https://reviews.llvm.org/D56023
llvm-svn: 351027
This patch aims to help clang with better information so it can inline
__bit_reference count function usage for both std::biset. Current clang
inliner can not infer that the passed typed will be used only to select
the optimized variant, it evaluates the type argument and type check as
a load plus compare (although later optimization phases correctly
optimized this out).
It is mainly to help llvm inliner to generate better code for std::bitset
count for aarch64. It helps on both runtime and code size, since if inline
decides that _VSTD::count should not be inlined the vectorization will
create both aligned and unaligned variants (which add both code size and
runtime costs)
llvm-svn: 350936
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
This script can be used by CI systems to test things like availability
markup and binary compatibility on older MacOS versions. This is still
a bit rough on the edges, for example we don't test libc++abi yet.
llvm-svn: 350752
Summary:
r306722 added diagnostics when aligned allocation is used with deployment
targets that do not support it, but the first macosx supporting aligned
allocation was incorrectly set to 10.13. In reality, the dylib shipped
with macosx10.13 does not support aligned allocation, but the dylib
shipped with macosx10.14 does.
Reviewers: ahatanak
Subscribers: christof, jkorous, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D56445
llvm-svn: 350649
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
This is useful when static libc++ library is being linked into
shared libraries that may be used in combination with libraries.
We want to avoid we exporting libc++ symbols in those cases where
this option is useful. This is provided as a CMake option and can
be enabled by libc++ vendors as needed.
Differential Revision: https://reviews.llvm.org/D55404
llvm-svn: 350489
This patch changes <experimental/foo> to use #warning instead of
is harmful to common feature detection idioms.
We should also consider only emitting the warning when __DEPRECATED is
defined, like we do in the <ext/foo> headers. Users may want to specify
"-Werror=-W#warnings" while still ignoring the libc++ warnings.
llvm-svn: 350485
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
Summary:
Tests marked with the flaky attribute ("FLAKY_TEST.")
can still report false positives in local tests and on the
NetBSD buildbot.
Additionally a number of tests (probably all threaded
ones) unmarked with the flaky attribute is flaky on
NetBSD.
An ideal solution on the libcxx side would be to raise
max retries for NetBSD and mark failing tests with
the flaky flag, however this adds more maintenance
burden and constant monitoring of flaky tests.
Reduce the work and handle flaky tests as more flaky
on NetBSD and allow flakiness of other tests on
NetBSD.
Reviewers: mgorny, EricWF
Reviewed By: mgorny
Subscribers: christof, llvm-commits, libcxx-commits
Differential Revision: https://reviews.llvm.org/D56064
llvm-svn: 350170
Summary:
We already have the negation of that as _LIBCPP_HAS_NONUNIQUE_TYPEINFO.
Having both defined is confusing, since only one of them is used.
Reviewers: EricWF, mclow.lists
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54537
llvm-svn: 349947
This patch implements path::compare according to the current spec. The
only observable change is the ordering of "/foo" and "foo", which orders
the two paths based on having or not having a root directory (instead
of lexically comparing "/" to "foo").
llvm-svn: 349881
Some tests assume that iteration through an unordered multimap elements
will return them in the same order as at the container creation. This
assumption is not true since the container is unordered, so that no
specific order of elements is ever guaranteed for such container. This
patch introduces checks verifying that any iteration will return elements
exactly from a set of valid values and without repetition, but in no
particular order.
Reviewed as https://reviews.llvm.org/D54838.
Thanks to Andrey Maksimov for the patch.
llvm-svn: 349780
Makes libc++ behavior consistent between C++03 and C++11.
Can use `decltype` in C++03 because `include/__config` defines a macro when
`decltype` is not available.
Reviewers: mclow.lists, EricWF, erik.pilkington, ldionne
Reviewed By: ldionne
Subscribers: dexonsmith, cfe-commits, howard.hinnant, ldionne, christof, jkorous, Quuxplusone
Differential Revision: https://reviews.llvm.org/D48753
llvm-svn: 349676
Eric Fiselier