Previously __libcpp_is_constructible checked the validity of reference
construction using 'eat<To>(declval<From>())' but this doesn't consider
From's explicit conversion operators. This patch teaches __libcpp_is_constructible
how to handle these cases. To do this we need to check the validity
using 'static_cast<To>(declval<From>())'. Unfortunately static_cast allows
additional base-to-derived and lvalue-to-rvalue conversions, which have to be
checked for and manually rejected.
While implementing these changes I discovered that Clang incorrectly
rejects `static_cast<int&&>(declval<float&>())` even though
`int &&X(declval<float&>())` is well formed. In order to tolerate this bug
the `__eat<T>(...)` needs to be left in-place. Otherwise it could be replaced
entirely with the new static_cast implementation.
Thanks to Walter Brown for providing the test cases.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285786 91177308-0d34-0410-b5e6-96231b3b80d8
Create this define in __config and use it elsewhere, instead of checking
the operating system/library defines in other files. The aim is to
reduce the usage of _WIN32 outside __config. No functional change.
Differential Revision: https://reviews.llvm.org/D25741
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285582 91177308-0d34-0410-b5e6-96231b3b80d8
Adding both 'inline' and 'always_inline' to the destructor has been contentious.
However most of the performance benefits can be gained by only adding 'inline',
and there is no reason to hold up that change while discussing the other.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285538 91177308-0d34-0410-b5e6-96231b3b80d8
path uses string::append to construct, append, and concatenate paths. Unfortunatly
string::append has a strong exception safety guaranteed and if it can't prove
that the iterator operations don't throw then it will allocate a temporary
string copy to append to. However this extra allocation and copy is very
undesirable for path which doesn't have the same exception guarantees.
To work around this this patch adds string::__append_forward_unsafe which exposes
the std::string::append interface for forward iterators without enforcing
that the iterator is noexcept.
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This prevent the symbols from being both externally available and hidden, which
causes them to be linked incorrectly. This is only a problem when the address
of the function is explicitly taken since it will always be inlined otherwise.
This patch fixes the issues that caused r285456 to be reverted, and can
now be reapplied.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285531 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes a performance bug when constructing or appending to a path
from a string or c-string. Previously we called 'push_back' to append every
single character. This caused multiple re-allocation and copies when at most
one reallocation is necessary. The new behavior is to simply call
`string::append` so it can correctly handle reallocation.
For large strings this change is a ~4x improvement. This also makes our path
faster to construct than libstdc++'s.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285530 91177308-0d34-0410-b5e6-96231b3b80d8
This patch entirely rewrites the parsing logic for paths. Unlike the previous
implementation this one stores information about the current state; For example
if we are in a trailing separator or a root separator. This avoids the need for
extra lookahead (and extra work) when incrementing or decrementing an iterator.
Roughly this gives us a 15% speedup over the previous implementation.
Unfortunately this implementation is still a lot slower than libstdc++'s.
Because libstdc++ pre-parses and splits the path upon construction their
iterators are trivial to increment/decrement. This makes libc++ lazy parsing
100x slower than libstdc++. However the pre-parsing libstdc++ causes a ton
of extra and unneeded allocations when constructing the string. For example
`path("/foo/bar/")` would require at least 5 allocations with libstdc++
whereas libc++ uses only one. The non-allocating behavior is much preferable
when you consider filesystem usages like 'exists("/foo/bar/")'.
Even then libc++'s path seems to be twice as slow to simply construct compared
to libstdc++. More investigation is needed about this.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285526 91177308-0d34-0410-b5e6-96231b3b80d8
This patch does two seperate things. First it adds a file called
"__libcpp_version" which only contains the current libc++ version
(currently 4000). This file is not intended for use as a header. This file
is used by Clang in order to easily determine the installed libc++ version.
This allows Clang to enable/disable certain language features only when the
library supports them.
The second change is the addition of _LIBCPP_LIBRARY_VERSION macro, which
returns the version of the installed dylib since it may be different than
the headers.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285382 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fixes PR19851.
alg.re.match/ecma.pass.cpp still XFAILS on linux, but after commenting out
locale-related tests, it passes. I don't have a freebsd machine to produce a
full pass.
Reviewers: mclow.lists
Subscribers: cfe-commits, emaste
Differential Revision: https://reviews.llvm.org/D26026
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285352 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
`__libcpp_refstring` currently has two different definitions. First there is the complete definition in `<__refstring>` but there is also a second in `<stdexcept>`. The historical reason for this split is because both libc++ and libc++abi need to see the inline definitions of __libcpp_refstrings methods, but the `<stdexcept>` header doesn't. However this is an ODR violation and breaks the modules build.
This patch fixes the issue by creating a single class definition in `<stdexcept>` and changing `<__refstring>` to contain only the inline method definitions. This way both `libcxx/src/stdexcept.cpp` and `libcxxabi/src/stdexcept.cpp` see the same declaration in `<stdexcept>` and definitions in `<__refstring>`
Reviewers: mclow.lists, EricWF
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25603
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285100 91177308-0d34-0410-b5e6-96231b3b80d8
These modules are necessary on Darwin to allow modules with
'no_undeclared_includes' (introduced in clang r284797) to work properly
while using libc++ headers.
Patch extracted from a suggested module.modulemap from Richard Smith!
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@284801 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a small omission where even when __external_threading is provided,
we attempt to declare a pthread based threading API. Instead, we should leave
out everything for the __external_threading header to take care of.
The __threading_support header provides a proof-of-concept externally threaded
libc++ variant when _LIBCPP_HAS_THREAD_API_EXTERNAL is defined. But if the
__external_threading header is present, we should exclude all of that POC stuff.
Reviewers: EricWF
Differential revision: https://reviews.llvm.org/D25468
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@284232 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch implements the library side of P0035R4. The implementation is thanks to @rsmith.
In addition to the C++17 implementation, the library implementation can be explicitly turned on using `-faligned-allocation` in all dialects.
Reviewers: mclow.lists, rsmith
Subscribers: rsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D25591
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@284206 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.
- Update relational operators per http://wg21.link/P0307
- Update to requirements of http://wg21.link/P0032
- Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.
Audit P/Rs for optional LWG issues:
- 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
- 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
- 2740 "constexpr optional<T>::operator->" Already conforming.
- 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
- 2748 "swappable traits for optionals" Already conforming.
- 2753 "Optional's constructors and assignments need constraints" Implemented.
Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!
Reviewers: mclow.lists, CaseyCarter, EricWF
Differential Revision: https://reviews.llvm.org/D22741
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283980 91177308-0d34-0410-b5e6-96231b3b80d8
This patch is largely thanks to Casey Carter @ Microsoft. He did the initial
work of porting our experimental implementation and tests over to namespace
std.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283977 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
FreeBSD ships an old ABI for std::pair which requires that it have non-trivial copy/move constructors. Currently the non-trivial copy/move is achieved by providing explicit definitions of the constructors. This is problematic because it means the constructors don't SFINAE properly. In order to SFINAE copy/move constructors they have to be explicitly defaulted and hense non-trivial.
This patch attempts to provide SFINAE'ing copy/move constructors for std::pair while still making them non-trivial. It does this by adding a base class with a non-trivial copy constructor and then allowing pair's constructors to be generated by the compiler. This also allows the constructors to be constexpr.
Reviewers: emaste, theraven, rsmith, dim
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25389
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283944 91177308-0d34-0410-b5e6-96231b3b80d8
The implementation of [depr.c.headers] in D12747 introduced the necessary
C headers into libc++. This patch adds one more missing headers: limits.h
We spotted this due to a failing C++03 test [limits_h.pass.cpp] in our libc++
configuration; when the limits.h header is included from a C++ program, it now
bypassed the __config header and went directly into the underlying C library's
limits.h header, which is problematic for us because we use __config header to
configure the underlying C library's behaviour when used from a C++ context.
Reviewers: mclow.lists, rsmith
Differential revision: https://reviews.llvm.org/D25361
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283726 91177308-0d34-0410-b5e6-96231b3b80d8
__builtin_addressof was added to the GCC trunk in the past week. This patch
teaches libc++ about it so it can correctly provide constexpr addressof.
Unfortunately this patch will break users of earlier GCC 7 builds, since
we expect __builtin_addressof but one won't be provided. One option would be
to only use __builtin_addressof for GCC 7.1 and above, but that means
waiting for another release.
Instead I've specifically chosen to break older GCC 7 versions. Since GCC 7
has yet to be released, and the 7.0 release is a development release, I
believe that anybody currently using GCC 7.0 will have no issue upgrading.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283715 91177308-0d34-0410-b5e6-96231b3b80d8
