LWG reflector consensus is that this was a bug in libc++.
(In particular, MSVC also will fix it in their STL, soon.)
Bug originally discovered by Logan Smith.
Also fix `std::function<const void()>`, which should work
the same way as `std::function<void()>` in terms of allowing
"conversions" from non-void types.
Differential Revision: https://reviews.llvm.org/D94452
After this patch, the only parts of P0879 that remain missing will be
std::nth_element, std::sort, and the heap/partial_sort algorithms.
Differential Revision: https://reviews.llvm.org/D93443
Implements parts of:
- P0898R3 Standard Library Concepts
- P1754 Rename concepts to standard_case for C++20, while we still can
Reviewed By: ldionne, miscco, #libc
Differential Revision: https://reviews.llvm.org/D91004
It has the low-level bit fiddling operations from bit. It eliminates a cyclic dependency between __bit_reference, bits, and vector. I want to exploit this in later patches.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D94908
local __libcpp_asprintf_l() -> libc asprintf() was inspecting the pointer (with
indeterminate value) for failure, rather than the return value of -1.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D94564
Previously, LIBCXX_ENABLE_FILESYSTEM controlled only whether the filesystem
support was compiled into libc++'s library. This commit promotes the
setting to a first-class option like LIBCXX_ENABLE_LOCALIZATION, where
the whole library is aware of the setting and features that depend on
<filesystem> won't be provided at all. The test suite is also properly
annotated such that tests that depend on <filesystem> are disabled when
the library doesn't support it.
This is an alternative to https://llvm.org/D94824, but also an improvement
along the lines of LIBCXX_ENABLE_LOCALIZATION that I had been wanting to
make for a while.
Differential Revision: https://reviews.llvm.org/D94921
When the Debug mode is enabled, we disable extern declarations because we
don't want to use the functions compiled in the library, which might not
have had the debug mode enabled when built. However, some extern declarations
need to be kept, because code correctness depends on it.
31e820378b removed those declarations, which had the unintended
consequence of breaking the debug build. This commit fixes that by
re-introducing a separate macro for the required extern declarations,
and adds a comment so that we don't fall into that trap in the future.
Differential Revision: https://reviews.llvm.org/D94718
The implementation had a lot of boilerplate and was more complicated than
necessary. This NFC refactoring introduces a few macros to reduce code
duplication, and uses a consistent style and formatting for the whole file.
Differential Revision: https://reviews.llvm.org/D94544
Clang insists that __attribute__ attributes precede __declspec
attributes. This is a longstanding known issue:
https://llvm.org/pr24559. Re-order the visibility and deprecation macros
to fix the build.
Differential Revision: https://reviews.llvm.org/D94788
Contrary to the current visibility macro documentation, it appears that
gcc does handle visibility attribute on extern templates correctly, e.g.
https://godbolt.org/g/EejuV7. We need this so that extern template
instantiations of classes not marked _LIBCPP_TEMPLATE_VIS (e.g.
__vector_base_common) are correctly exported with gcc when building with
hidden visibility.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D35388
Sometimes `_Compare` is an lvalue reference type, so letting it be
deduced is pretty much always wrong. (Well, less efficient than
it could be, anyway.)
Differential Revision: https://reviews.llvm.org/D93562
I accidentally disabled this feature-test macro in my D93830,
due to a rebasing conflict. It had been enabled by my D93815,
and should have remained enabled.
This patch updates `allocate_shared` to call `allocator_traits::construct`
when creating the object held inside the shared_pointer, and
`allocator_traits::destroy` when destroying it. This resolves
the part of P0674R1 that was originally filed as LWG2070.
This change is landed separately from the rest of P0674R1 because it is
incredibly tricky from an ABI perspective.
This is the reason why this change is so tricky is that we previously
used EBO in a compressed pair to store both the allocator and the object
type stored in the `shared_ptr`. However, starting in C++20, P0674
requires us to use Allocator construction for initializing the object type.
That requirement rules out the use of the EBO for the object type, since
using the EBO implies that the base will be initialized when the control
block is initialized (and hence we can't do it through Allocator construction).
Hence, supporting P0674 requires changing how we store the object type
inside the control block, which we do while being ABI compatible by using
some trickery with a properly aligned char buffer.
Fixes https://llvm.org/PR41900
Supersedes https://llvm.org/D62760
Differential Revision: https://reviews.llvm.org/D91201
It's still a little confusing because in many cases C++17 and C++20
have different values, and libc++ implements the C++17 behavior but
not the C++20 behavior; 'unimplemented' can't represent that scenario.
Ultimately we probably ought to completely redesign the script to be
in terms of paper numbers, rather than language revisions, and make
it generate the CSV files like "Cxx2aStatusPaperStatus.csv" as well.
Most newly added macros are unimplemented. I've marked a few as implemented,
though, based on my reading of the code; for example I was pretty sure
`__cpp_lib_latch` is implemented since we have `<latch>`.
Differential Revision: https://reviews.llvm.org/D93830
* The only exception is that the flag -std=c++2a is still used not to break compatibility with older compilers (clang <= 9, gcc <= 9).
* Bump _LIBCPP_STD_VER for C++20 to 20 and use 21 for the future standard (C++2b).
That's a preparation step to add c++2b support to libc++.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D93383
This affects only vectors with weird/malicious allocators,
the same corner case covered in D91708, but for `vector<bool>` this time.
Also ADL-proof <__tree>, which affects only sets and maps with weird/malicious
allocators where the ADL trap is in the *fancy pointer type*.
Also drive-by _VSTD:: qualification in the guts of std::bind,
std::packaged_task, std::condition_variable.
Differential Revision: https://reviews.llvm.org/D93424
On windows, the narrow, char based paths normally don't use utf8, but
can use many different native code pages, and this is what system
functions that operate on files, taking such paths/file names, interpret
them as.
Differential Revision: https://reviews.llvm.org/D91137
Also set the preferred separator to backslash.
libc++ doesn't compile successfully for windows prior to this change,
and this change on its own isn't enough to make it compile successfully
either, but is the first stepping stone towards making it work correctly.
Most of operations.cpp will need to be touched, both for calling
functions that take wchar paths, but also for using other windows
specific functions instead of the posix functions used so far; that is
handled in later commits.
Changing parts of operations.cpp to generalize the string type handling
in code that doesn't touch system functions.
Differential Revision: https://reviews.llvm.org/D91135
When the allocator is only explicitly convertible from other specializations
of itself, the new version of std::allocate_shared would not work because
it would try to do an implicit conversion. This patch fixes the problem
and adds a test so that we don't fall into the same trap in the future.
Checking that `T` is constructible from `Args...` is technically not
required by the Standard, although any implementation will obviously
error out if that's not satisfied. However, this check is incompatible
with using Allocator construction in the control block (upcoming change
as part of implementing P0674), so I'm removing it now to reduce the
upcoming diff as much as possible.
Differential Revision: https://reviews.llvm.org/D93246
This commit is a step towards making it easier to add support for arrays
in allocate_shared. Adding support for arrays will require writing multiple
functions, and the current complexity of writing allocate_shared is
prohibitive for understanding.
Differential Revision: https://reviews.llvm.org/D93130
In addition to making the code a lot easier to grasp by localizing many
helper functions to the only file where they are actually needed, this
will allow creating helper functions that depend on allocator_traits
outside of <memory>.
This is done as part of implementing array support in allocate_shared,
which requires non-trivial array initialization algorithms that would be
better to keep out of <memory> for sanity. It's also a first step towards
splitting up our monolithic headers into finer grained ones, which will
make it easier to reuse functionality across the library. For example,
it's just weird that we had to define `addressof` inside <type_traits>
to avoid circular dependencies -- instead it's better to implement those
in true helper headers.
Differential Revision: https://reviews.llvm.org/D93074
- std::reference_wrapper
- std::function
- std::mem_fn
While I'm here, remove _VSTD:: qualification from calls to `declval`
because it takes no arguments and thus isn't susceptible to ADL.
Differential Revision: https://reviews.llvm.org/D92884
Everywhere, normalize the whitespace to `::new (EXPR) T`.
Everywhere, normalize the spelling of the cast to `(void*)EXPR`.
Without the cast to `(void*)`, the expression triggers ADL on GCC.
(I think this is a GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98249)
Even if it doesn't trigger ADL, it still seems incorrect to use any argument
that's not exactly `(void*)` because that opens the possibility of overload
resolution picking a user-defined overload of `operator new`, which would be
wrong.
Differential Revision: https://reviews.llvm.org/D93153
This simplifies the implementation, and it appears to be equivalent since
make_shared was allocating memory with std::allocator anyway.
Differential Revision: https://reviews.llvm.org/D93071
Generally these calls aren't vulnerable to ADL because they involve only
primitive types. The ones in <list> and <vector> drag in namespace std
but that's OK; the ones in <fstream> and <strstream> are vulnerable
iff `CharT` is an enum type, which seems far-fetched.
But absolutely zero of them *need* ADL to happen; so in my opinion
they should all be consistently qualified, just like calls to any
other (non-user-customizable) functions in namespace std.
Also: Include <cstring> and <cwchar> in <__string>.
We seemed to be getting lucky that <memory> included <iterator>
included <iosfwd> included <wchar.h>. That gave us the
global-namespace `wmemmove`, but not `_VSTD::wmemmove`.
This is now fixed.
I didn't touch these headers:
<ext/__hash> uses strlen, safely
<support/ibm/locale_mgmt_aix.h> uses memcpy, safely
<string.h> uses memchr and strchr, safely
<wchar.h> uses wcschr, safely
<__bsd_locale_fallbacks.h> uses wcsnrtombs, safely
Differential Revision: https://reviews.llvm.org/D93061
This matches how libc++ does it in all other C++ headers
(that is, headers not ending in ".h").
We need to include <cstring> if we want to use `_VSTD::memmove`
instead of unqualified ADL `memmove`. Even though ADL doesn't
physically matter in <charconv>'s specific case, I'm trying
to migrate libc++ to using `_VSTD::memmove` for all cases
(because some of them do matter, and this way it's easier to
grep for outliers).
Differential Revision: https://reviews.llvm.org/D92875
This is the first of a series of patches leading up to the implementation
of P0674r1, i.e. array support in allocate_shared. I am splitting this
up into multiple patches because the overall change is very tricky and
I want to isolate potential breakage.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.
The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.
This is a re-commit. The previous commit was reverted because it exposed
a pre-existing bug that has since been fixed / worked around; see
PR48434.
Differential Revision: https://reviews.llvm.org/D91311
Arthur O'Dwyer