std: Render large exit codes as hex on Windows
On Windows process exit codes are never signals but rather always 32-bit
integers. Most faults like segfaults and such end up having large
integers used to represent them, like STATUS_ACCESS_VIOLATION being
0xC0000005. Currently, however, when an `ExitStatus` is printed this
ends up getting rendered as 3221225477 which is somewhat more difficult
to debug.
This commit adds a branch in `Display for ExitStatus` on Windows which
handles exit statuses where the high bit is set and prints those exit
statuses as hex instead of with decimals. This will hopefully preserve
the current display for small exit statuses (like `exit code: 22`), but
assist in quickly debugging segfaults/access violations/etc. I've
found at least that the hex codes are easier to search for than decimal.
I wasn't able to find any official documentation saying that all system
exit codes have the high bit set, but I figure it's a good enough
heuristic for now.
Fix undefined behavior
From the [`MaybeUninit::get_mut` docs](https://doc.rust-lang.org/std/mem/union.MaybeUninit.html):
> It is up to the caller to guarantee that the the MaybeUninit really is in an initialized state, otherwise this will immediately cause undefined behavior.
r? @joshtriplett
Supporting backtrace for x86_64-fortanix-unknown-sgx.
# Overview
Implementing following functions required by `libstd/sys_common` to support `backtrace`:
```
1. unwind_backtrace
2. trace_fn
3. resolve_symname
```
# Description:
The changes here are quite similar to the Cloudabi target `src/libstd/sys/cloudabi/backtrace.rs`
The first 2 functions are implemented via calls to libunwind.a that is linked to the `x86_64-fortanix-unknown-sgx` (#56979), we have not implemented functionality needed by `resolve_symname` (or `dladdr`) to reduce SGX TCB. Rather, we print the function address (relative to enclave image base) in `resolve_symname` which can be later translated to correct symbol name (say, via `addr2line`).
# Note:
For `x86_64-fortanix-unknown-sgx`, the `RUST_BACKTRACE` environment has to be set from within the program running in an enclave.
cc: @jethrogb
r? @alexcrichton
Fixed the link to the ? operator
I'm working on updating all broken links, but figured I'd break up the pull requests so they are easier to review, versus just one big pull request.
On Windows process exit codes are never signals but rather always 32-bit
integers. Most faults like segfaults and such end up having large
integers used to represent them, like STATUS_ACCESS_VIOLATION being
0xC0000005. Currently, however, when an `ExitStatus` is printed this
ends up getting rendered as 3221225477 which is somewhat more difficult
to debug.
This commit adds a branch in `Display for ExitStatus` on Windows which
handles exit statuses where the high bit is set and prints those exit
statuses as hex instead of with decimals. This will hopefully preserve
the current display for small exit statuses (like `exit code: 22`), but
assist in quickly debugging segfaults/access violations/etc. I've
found at least that the hex codes are easier to search for than decimal.
I wasn't able to find any official documentation saying that all system
exit codes have the high bit set, but I figure it's a good enough
heuristic for now.
std: Force `Instant::now()` to be monotonic
This commit is an attempt to force `Instant::now` to be monotonic
through any means possible. We tried relying on OS/hardware/clock
implementations, but those seem buggy enough that we can't rely on them
in practice. This commit implements the same hammer Firefox recently
implemented (noted in #56612) which is to just keep whatever the lastest
`Instant::now()` return value was in memory, returning that instead of
the OS looks like it's moving backwards.
Closes#48514Closes#49281
cc #51648
cc #56560Closes#56612Closes#56940
This commit is an attempt to force `Instant::now` to be monotonic
through any means possible. We tried relying on OS/hardware/clock
implementations, but those seem buggy enough that we can't rely on them
in practice. This commit implements the same hammer Firefox recently
implemented (noted in #56612) which is to just keep whatever the lastest
`Instant::now()` return value was in memory, returning that instead of
the OS looks like it's moving backwards.
Closes#48514Closes#49281
cc #51648
cc #56560Closes#56612Closes#56940
Add duration constants
Add constants `SECOND`, `MILLISECOND`, `MICROSECOND`, and `NANOSECOND` to `core::time`.
This will make working with durations more ergonomic. Compare:
```rust
// Convenient, but deprecated function.
thread::sleep_ms(2000);
// The current canonical way to sleep for two seconds.
thread::sleep(Duration::from_secs(2));
// Sleeping using one of the new constants.
thread::sleep(2 * SECOND);
```
`const fn` is no longer coming soon (const keyword docs)
The `const` keyword [documentation](https://doc.rust-lang.org/std/keyword.const.html) mentions that `const fn`s are coming soon, but they have already been added.
Bound sgx target_env with fortanix as target_vendor
This PR adds `target_vendor` check, as discussed in issue [57231](https://github.com/rust-lang/rust/issues/57231)
Signed-off-by: Yu Ding <dingelish@gmail.com>
Eliminate Receiver::recv_timeout panic
Fixes#54552.
This panic is because `recv_timeout` uses `Instant::now() + timeout` internally. This possible panic is not mentioned in the documentation for this method.
Very recently we merged (still unstable) support for checked addition (#56490) of `Instant + Duration`, so it's now finally possible to add these together without risking a panic.
