This alias is needed whether or not the install rules of `ghcfilesystem`
are enabled. It allows projects to use the same target regardless of
where `ghcfilesystem` comes from, `add_subdirectory` or `find_package`.
There is no path length limitation there, even via pathconf. But glibc
provides a getcwd function that allocates the buffer dynamically so we can
just leverage that.
The previous implementation tried to detect old deployment targets for macOS that doesn't have the newer `utimensat` call. Unfortunately, it would just detect macOS, and didn't check for the corresponding iOS/tvOS/watchOS version numbers. On those platforms, last_write_time() was effectively a no-op, failing silently and not modifying the mtime of the file.
This patch adds detection for these platforms. It also removes the special casing when newer versions of macOS/iOS/tvOS/watchOS are used as the deployment targets, and instead folds it into the default POSIX branch.
CMakeLists.txt:
Write a ghc_filesystem-config-version.cmake file and install it, so that
other projects may rely on the exact version of ghc_filesystem.
The compatibility mode implies, that any version of ghc_filesystem with
the same major version is feature compatible.
CMakeLists.txt:
Declare the project's version in the cmake project() call so that it may
be exported to the project's cmake integration (used by other projects).
The old code truncated time_t to a 32-bit value
when using Int32x32To64. This example code has been fixed
on MSDN a while ago, so this change only updates it to
the current version.
More on this issue:
https://cookieplmonster.github.io/2022/02/17/year-2038-problem/
This ensures that all cases where the result actually does fit in a
uintmax_t are correctly handled. Before, the multiplication could be
performed in a smaller type, leading to an incorrect result or, worse,
undefined behavior due to signed integer overflow.
This fixes a test failure that was actually observed on an i686 Linux
system.
