If the path is longer than sockaddr_un's buffer, it will be truncated,
at which point it may become indistinguishable from similar truncated
paths. This will cause `bind` to fail with an "Address already in use"
error. There is some existing code that checks `fs::exists` to catch
these errors, but since `fs::exists` compares the full un-truncated
paths, a too-long path will prevent those checks from working.
rdar://154397133
On Cygwin, UNIX sockets involve a handshake between connect and accept
to enable SO_PEERCRED/getpeereid handling. This necessitates accept
being called before connect can return, but at least the tests in
llvm/unittests/Support/raw_socket_stream_test do both on the same thread
(first connect and then accept), resulting in a deadlock. Add a call to
both places sockets are created that turns off the handshake (and
SO_PEERCRED/getpeereid support).
References:
* cec8a6680e/winsup/cygwin/fhandler/socket_local.cc (L1462-L1471)
* https://inbox.sourceware.org/cygwin/Z_UERXFI1g-1v3p2@calimero.vinschen.de/T/#u
This PR implements `raw_socket_stream::read`, which overloads the base
class `raw_fd_stream::read`. `raw_socket_stream::read` provides a way to
timeout the underlying `::read`. The timeout functionality was not added
to `raw_fd_stream::read` to avoid needlessly increasing compile times
and allow for convenient code reuse with `raw_socket_stream::accept`,
which also requires timeout functionality. This PR supports the module
build daemon and will help guarantee it never becomes a zombie process.
If `::poll` returns and `FD` equals -1, then `ListeningSocket::shutdown`
has been called. So, regardless of any other information that could be
gleaned from `FDs.revents` or `PollStatus`, it is appropriate to return
`std::errc::operation_canceled`. `ListeningSocket::shutdown` copies
`FD`'s value to `ObservedFD` then sets `FD` to -1 before canceling
`::poll` by calling `::close(ObservedFD)` and writing to the pipe.
Commit 87e6f87fe7e343eb656e9b49d30cbb065c086651 adds a call to `::write()`, which may be annotated w/ `warn_unused_result`, leading to `-Wunused-result` failures.
Improvements include
* Enable `ListeningSocket::accept` to timeout after a specified amount
of time or block indefinitely
* Enable `ListeningSocket::createUnix` to handle instances where the
target socket address already exists and differentiate between
situations where the existing file does and does not already have a
bound socket
* Doxygen comments
Functionality added for the module build daemon
---------
Co-authored-by: Michael Spencer <bigcheesegs@gmail.com>
LLVM is inconsistent about how it converts `errno` to `std::error_code`.
This can cause problems because values outside of `std::errc` compare
differently if one is system and one is generic on POSIX systems.
This is even more of a problem on Windows where use of the system
category is just wrong, as that is for Windows errors, which have a
completely different mapping than POSIX/generic errors. This patch fixes
one instance of this mistake in `JSONTransport.cpp`.
This patch adds `errnoAsErrorCode()` which makes it so people do not
need to think about this issue in the future. It also cleans up a lot of
usage of `errno` in LLVM and Clang.
The implementation of raw_string_ostream::write_impl() was moved to
raw_socket_stream.cpp when the raw_socket_ostream support was separated.
This patch moves it back to facilitate disabling socket support in
downstream projects.
