Summary:
This was voted into C++20 in San Diego. Note that there was a revision
D0318R2 which did include unwrap_reference_t, but we mistakingly voted
P0318R1 into the C++20 Working Draft (which does not include
unwrap_reference_t). This patch implements D0318R2, which is what
we'll end up with in the Working Draft once this mistake has been
fixed.
Reviewers: EricWF, mclow.lists
Subscribers: christof, dexonsmith, libcxx-commits
Differential Revision: https://reviews.llvm.org/D54485
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@348138 91177308-0d34-0410-b5e6-96231b3b80d8
We recently added libcxx-dev and libcxx-commits mailing lists.
This patch updates the libc++ documentation to correctly reference
the libc++ lists instead of the old Clang ones.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@342816 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r342566 as it causes on bots linker errors like
> Undefined symbols for architecture i386:
> "std::__1::basic_ostream<char, std::__1::char_traits<char> >::operator<<(std::nullptr_t)", referenced from:
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@342599 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the <filesystem> header and uses that
to provide <experimental/filesystem>.
Unlike other standard headers, the symbols needed for <filesystem>
have not yet been placed in libc++.so. Instead they live in the
new libc++fs.a library. Users of filesystem are required to link this
library. (Also note that libc++experimental no longer contains the
definition of <experimental/filesystem>, which now requires linking libc++fs).
The reason for keeping <filesystem> out of the dylib for now is that
it's still somewhat experimental, and the possibility of requiring an
ABI breaking change is very real. In the future the symbols will likely
be moved into the dylib, or the dylib will be made to link libc++fs automagically).
Note that moving the symbols out of libc++experimental may break user builds
until they update to -lc++fs. This should be OK, because the experimental
library provides no stability guarantees. However, I plan on looking into
ways we can force libc++experimental to automagically link libc++fs.
In order to use a single implementation and set of tests for <filesystem>, it
has been placed in a special `__fs` namespace. This namespace is inline in
C++17 onward, but not before that. As such implementation is available
in C++11 onward, but no filesystem namespace is present "directly", and
as such name conflicts shouldn't occur in C++11 or C++14.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@338093 91177308-0d34-0410-b5e6-96231b3b80d8
This patch implements the `what()` for filesystem errors. The message
includes the 'what_arg', any paths that were specified, and the
error code message.
Additionally this patch refactors how errors are created, making it easier
to report them correctly.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@337664 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch implements directory_entry caching *almost* as specified in P0317r1. However, I explicitly chose to deviate from the standard as I'll explain below.
The approach I decided to take is a fully caching one. When `refresh()` is called, the cache is populated by calls to `stat` and `lstat` as needed.
During directory iteration the cache is only populated with the `file_type` as reported by `readdir`.
The cache can be in the following states:
* `_Empty`: There is nothing in the cache (likely due to an error)
* `_IterSymlink`: Created by directory iteration when we walk onto a symlink only the symlink file type is known.
* `_IterNonSymlink`: Created by directory iteration when we walk onto a non-symlink. Both the regular file type and symlink file type are known.
* `_RefreshSymlink` and `_RefreshNonSymlink`: A full cache created by `refresh()`. This case includes dead symlinks.
* `_RefreshSymlinkUnresolved`: A partial cache created by refresh when we fail to resolve the file pointed to by a symlink (likely due to permissions). Symlink attributes are cached, but attributes about the linked entity are not.
As mentioned, this implementation purposefully deviates from the standard. According to some readings of the specification, and the Windows filesystem implementation, the constructors and modifiers which don't pass an `error_code` must throw when the `directory_entry` points to a entity which doesn't exist. or when attribute resolution fails for another reason.
@BillyONeal has proposed a more reasonable set of requirements, where modifiers other than refresh ignore errors. This is the behavior libc++ currently implements, with the expectation some form of the new language will be accepted into the standard.
Some additional semantics which differ from the Windows implementation:
1. `refresh` will not throw when the entry doesn't exist. In this case we can still meet the functions specification, so we don't treat it as an error.
2. We don't clear the path name when a constructor fails via refresh (this will hopefully be changed in the standard as well).
It should be noted that libstdc++'s current implementation has the same behavior as libc++, except for point (2).
If the changes to the specification don't get accepted, we'll be able to make the changes later.
[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0317r1.html
Reviewers: mclow.lists, gromer, ldionne, aaron.ballman
Subscribers: BillyONeal, christof, cfe-commits
Differential Revision: https://reviews.llvm.org/D49530
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@337516 91177308-0d34-0410-b5e6-96231b3b80d8
