Tracking issue: #30014
This implements the RFC and makes a few other changes.
I have added a few extra tests, and made the Windows and
Unix code as similar as possible.
Part of the RFC mentions the unstable OpenOptionsExt trait
on Windows (see #27720). I have added a few extra methods
to future-proof it for CreateFile2.
This is a standard "clean out libstd" commit which removes all 1.5-and-before
deprecated functionality as it's now all been deprecated for at least one entire
cycle.
This commit is an implementation of [RFC 1288][rfc] which adds two new unstable
types to the `std::time` module. The `Instant` type is used to represent
measurements of a monotonically increasing clock suitable for measuring time
withing a process for operations such as benchmarks or just the elapsed time to
do something. An `Instant` favors panicking when bugs are found as the bugs are
programmer errors rather than typical errors that can be encountered.
[rfc]: https://github.com/rust-lang/rfcs/pull/1288
The `SystemTime` type is used to represent a system timestamp and is not
monotonic. Very few guarantees are provided about this measurement of the system
clock, but a fixed point in time (`UNIX_EPOCH`) is provided to learn about the
relative distance from this point for any particular time stamp.
This PR takes the same implementation strategy as the `time` crate on crates.io,
namely:
| Platform | Instant | SystemTime |
|------------|--------------------------|--------------------------|
| Windows | QueryPerformanceCounter | GetSystemTimeAsFileTime |
| OSX | mach_absolute_time | gettimeofday |
| Unix | CLOCK_MONOTONIC | CLOCK_REALTIME |
These implementations can perhaps be refined over time, but they currently
satisfy the requirements of the `Instant` and `SystemTime` types while also
being portable across implementations and revisions of each platform.
* Delete `sys::unix::{c, sync}` as these are now all folded into libc itself
* Update all references to use `libc` as a result.
* Update all references to the new flat namespace.
* Moves all windows bindings into sys::c
As discovered in #29298, `env::set_var("", "")` will panic, but it turns out
that it *also* deadlocks on Unix systems. This happens because if a panic
happens while holding the environment lock, we then go try to read
RUST_BACKTRACE, grabbing the environment lock, causing a deadlock.
Specifically, the changes made here are:
* The environment lock is pushed into `std::sys` instead of `std::env`. This
also only puts it in the Unix implementation, not Windows where the functions
are already threadsafe.
* The `std::sys` implementation now returns `io::Result` so panics are
explicitly at the `std::env` level.
Note: for now, this change only affects `-windows-gnu` builds.
So why was this `libgcc` dylib dependency needed in the first place?
The stack unwinder needs to know about locations of unwind tables of all the modules loaded in the current process. The easiest portable way of achieving this is to have each module register itself with the unwinder when loaded into the process. All modules compiled by GCC do this by calling the __register_frame_info() in their startup code (that's `crtbegin.o` and `crtend.o`, which are automatically linked into any gcc output).
Another important piece is that there should be only one copy of the unwinder (and thus unwind tables registry) in the process. This pretty much means that the unwinder must be in a shared library (unless everything is statically linked).
Now, Rust compiler tries very hard to make sure that any given Rust crate appears in the final output just once. So if we link the unwinder statically to one of Rust's crates, everything should be fine.
Unfortunately, GCC startup objects are built under assumption that `libgcc` is the one true place for the unwind info registry, so I couldn't find any better way than to replace them. So out go `crtbegin`/`crtend`, in come `rsbegin`/`rsend`!
A side benefit of this change is that rustc is now more in control of the command line that goes to the linker, so we could stop using `gcc` as the linker driver and just invoke `ld` directly.
As discovered in #29298, `env::set_var("", "")` will panic, but it turns out
that it *also* deadlocks on Unix systems. This happens because if a panic
happens while holding the environment lock, we then go try to read
RUST_BACKTRACE, grabbing the environment lock, causing a deadlock.
Specifically, the changes made here are:
* The environment lock is pushed into `std::sys` instead of `std::env`. This
also only puts it in the Unix implementation, not Windows where the functions
are already threadsafe.
* The `std::sys` implementation now returns `io::Result` so panics are
explicitly at the `std::env` level. The panic messages have also been improved
in these situations.
This commit adds #[derive(Clone)] to std::fs::Metadata, making that struct
cloneable. Although the exact contents of that struct differ between OSes,
they all have it contain only value types, meaning that the data can be re-used without repercussions.
It also adds #[derive(Clone)] to every type used by that struct across all
OSes, including the various Unix `stat` structs and Windows's
`WIN32_FILE_ATTRIBUTE_DATA`.
This commit removes all morestack support from the compiler which entails:
* Segmented stacks are no longer emitted in codegen.
* We no longer build or distribute libmorestack.a
* The `stack_exhausted` lang item is no longer required
The only current use of the segmented stack support in LLVM is to detect stack
overflow. This is no longer really required, however, because we already have
guard pages for all threads and registered signal handlers watching for a
segfault on those pages (to print out a stack overflow message). Additionally,
major platforms (aka Windows) already don't use morestack.
This means that Rust is by default less likely to catch stack overflows because
if a function takes up more than one page of stack space it won't hit the guard
page. This is what the purpose of morestack was (to catch this case), but it's
better served with stack probes which have more cross platform support and no
runtime support necessary. Until LLVM supports this for all platform it looks
like morestack isn't really buying us much.
cc #16012 (still need stack probes)
Closes#26458 (a drive-by fix to help diagnostics on stack overflow)
Previously on Windows a directory junction would return false from `is_dir`,
causing various odd behavior, specifically calls to `create_dir_all` might fail
when they would otherwise continue to succeed.
Closes#26716
This was added after Windows 7 SP1, so it's not always available. Instead use
the `SetHandleInformation` function to flag a socket as not inheritable. This is
not atomic with respect to creating new processes, but it mirrors what Unix does
with respect to possibly using the atomic option in the future.
Closes#26543
This commit enables executables linked against the standard library to run on
Windows XP. There are two main components of this commit:
* APIs not available on XP are shimmed to have a fallback implementation and use
runtime detection to determine if they are available.
* Mutexes on Windows were reimplemented to use critical sections on XP where
rwlocks are not available.
The APIs which are not available on XP are:
* SetFileInformationByHandle - this is just used by `File::truncate` and that
function just returns an error now.
* SetThreadStackGuarantee - this is used by the stack overflow support on
windows, but if this isn't available then it's just ignored (it seems
non-critical).
* All condition variable APIs are missing - the shims added for these apis
simply always panic for now. We may eventually provide a fallback
implementation, but for now the standard library does not rely on condition
variables for normal use.
* RWLocks, like condition variables, are missing entirely. The same story for
condition variables is taken here. These APIs are all now panicking stubs as
the standard library doesn't rely on RWLocks for normal use.
Currently, as an optimization, we use SRWLOCKs for the standard `sync::Mutex`
implementation on Windows, which is indeed required for normal operation of the
standard library. To allow the standard library to run on XP, this commit
reimplements mutexes on Windows to use SRWLOCK instances *if available* and
otherwise a CriticalSection is used (with some checking for recursive
locking).
With all these changes put together, a 32-bit MSVC-built executable can run on
Windows XP and print "hello world"
Closes#12842Closes#19992Closes#24776
This commits adds a method to the `std::process` module to get the process
identifier of the child as a `u32`. On Windows the underlying identifier is
already a `u32`, and on Unix the type is typically defined as `c_int` (`i32` for
almost all our supported platforms), but the actually pid is normally a small
positive number.
Eventually we may add functions to load information about a process based on its
identifier or the ability to terminate a process based on its identifier, but
for now this function should enable this sort of functionality to exist outside
the standard library.
Much of this code hasn't been updated in quite some time and this commit does a
small audit of the functionality:
* Implementation functions now centralize all functionality on a locally defined
`Thread` type.
* The `detach` method has been removed in favor of a `Drop` implementation. This
notably fixes leaking thread handles on Windows.
* The `Thread` structure is now appropriately annotated with `Send` and `Sync`
automatically on Windows and in a custom fashion on Unix.
* The unsafety of creating a thread has been pushed out to the right boundaries
now.
Closes#24442
On Windows, when you create a symbolic link you must specify whether it
points to a directory or a file, even if it is created dangling, while
on Unix, the same symbolic link could point to a directory, a file, or
nothing at all. Furthermore, on Windows special privilege is necessary
to use a symbolic link, while on Unix, you can generally create a
symbolic link in any directory you have write privileges to.
This means that it is unlikely to be able to use symbolic links purely
portably; anyone who uses them will need to think about the cross
platform implications. This means that using platform-specific APIs
will make it easier to see where code will need to differ between the
platforms, rather than trying to provide some kind of compatibility
wrapper.
Furthermore, `soft_link` has no precedence in any other API, so to avoid
confusion, move back to the more standard `symlink` terminology.
Create a `std::os::unix::symlink` for the Unix version that is
destination type agnostic, as well as `std::os::windows::{symlink_file,
symlink_dir}` for Windows.
Because this is a stable API, leave a compatibility wrapper in
`std::fs::soft_link`, which calls `symlink` on Unix and `symlink_file`
on Windows, preserving the existing behavior of `soft_link`.
This commit removes the last remnants of file descriptors from the Windows
implementation of `std::sys` by using `CreatePipe` to create anonymous pipes
instead of the `pipe` shim provided in msvcrt.
This commit modifies the socket creation functions on windows to always specify
the `WSA_FLAG_OVERLAPPED` and `WSA_FLAG_NO_HANDLE_INHERIT` flags by default. The
overlapped flag enables IOCP APIs on Windows to be used with the socket at no
cost, enabling better interoperation with external libraries. The no handle
inherit flag mirrors the upcoming change to Unix to set CLOEXEC by default for
all handles.
Closes#24206
This commit removes the last remnants of file descriptors from the Windows
implementation of `std::sys` by using `CreatePipe` to create anonymous pipes
instead of the `pipe` shim provided in msvcrt.
This commit modifies the socket creation functions on windows to always specify
the `WSA_FLAG_OVERLAPPED` and `WSA_FLAG_NO_HANDLE_INHERIT` flags by default. The
overlapped flag enables IOCP APIs on Windows to be used with the socket at no
cost, enabling better interoperation with external libraries. The no handle
inherit flag mirrors the upcoming change to Unix to set CLOEXEC by default for
all handles.
Closes#24206
The current implementation of using GetFinalPathNameByHandle actually reads all
intermediate links instead of just looking at the current link. This commit
alters the behavior of the function to use a different API which correctly reads
only one level of the soft link.
[breaking-change]
This commit is an implementation of [RFC #1011][rfc] which adds an `exit`
function to the standard library for immediately terminating the current process
with a specified exit code.
[rfc]: https://github.com/rust-lang/rfcs/pull/1011
This is an implementation of RFC 899 and adds stdio functionality to the new
`std::io` module. Details of the API can be found on the RFC, but from a high
level:
* `io::{stdin, stdout, stderr}` constructors are now available. There are also
`*_raw` variants for unbuffered and unlocked access.
* All handles are globally shared (excluding raw variants).
* The stderr handle is no longer buffered.
* All handles can be explicitly locked (excluding the raw variants).
The `print!` and `println!` machinery has not yet been hooked up to these
streams just yet. The `std::fmt::output` module has also not yet been
implemented as part of this commit.
This is an implementation of [RFC 578][rfc] which adds a new `std::env` module
to replace most of the functionality in the current `std::os` module. More
details can be found in the RFC itself, but as a summary the following methods
have all been deprecated:
[rfc]: https://github.com/rust-lang/rfcs/pull/578
* `os::args_as_bytes` => `env::args`
* `os::args` => `env::args`
* `os::consts` => `env::consts`
* `os::dll_filename` => no replacement, use `env::consts` directly
* `os::page_size` => `env::page_size`
* `os::make_absolute` => use `env::current_dir` + `join` instead
* `os::getcwd` => `env::current_dir`
* `os::change_dir` => `env::set_current_dir`
* `os::homedir` => `env::home_dir`
* `os::tmpdir` => `env::temp_dir`
* `os::join_paths` => `env::join_paths`
* `os::split_paths` => `env::split_paths`
* `os::self_exe_name` => `env::current_exe`
* `os::self_exe_path` => use `env::current_exe` + `pop`
* `os::set_exit_status` => `env::set_exit_status`
* `os::get_exit_status` => `env::get_exit_status`
* `os::env` => `env::vars`
* `os::env_as_bytes` => `env::vars`
* `os::getenv` => `env::var` or `env::var_string`
* `os::getenv_as_bytes` => `env::var`
* `os::setenv` => `env::set_var`
* `os::unsetenv` => `env::remove_var`
Many function signatures have also been tweaked for various purposes, but the
main changes were:
* `Vec`-returning APIs now all return iterators instead
* All APIs are now centered around `OsString` instead of `Vec<u8>` or `String`.
There is currently on convenience API, `env::var_string`, which can be used to
get the value of an environment variable as a unicode `String`.
All old APIs are `#[deprecated]` in-place and will remain for some time to allow
for migrations. The semantics of the APIs have been tweaked slightly with regard
to dealing with invalid unicode (panic instead of replacement).
The new `std::env` module is all contained within the `env` feature, so crates
must add the following to access the new APIs:
#![feature(env)]
[breaking-change]
This is a [breaking-change] since `std::dynamic_lib::dl` is now
private.
When `LoadLibraryW()` fails, original code called `errno()` to get error
code. However, there was local allocation of `Vec` before
`LoadLibraryW()`, and it drops before `errno()`, and the drop
(deallocation) changed `errno`! Therefore `dynamic_lib::open()` thought
it always succeeded.
This commit fixes the issue.
This commit also sets Windows error mode during `LoadLibrary()` to
prevent "dll load failed" dialog.
This calculates the width and height using the bounding box of the window in the buffer. Bounding box coordinates are inclusive so I have to add 1 to both dimensions.
This commit is an implementation of [RFC 494][rfc] which removes the entire
`std::c_vec` module and redesigns the `std::c_str` module as `std::ffi`.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0494-c_str-and-c_vec-stability.md
The interface of the new `CString` is outlined in the linked RFC, the primary
changes being:
* The `ToCStr` trait is gone, meaning the `with_c_str` and `to_c_str` methods
are now gone. These two methods are replaced with a `CString::from_slice`
method.
* The `CString` type is now just a wrapper around `Vec<u8>` with a static
guarantee that there is a trailing nul byte with no internal nul bytes. This
means that `CString` now implements `Deref<Target = [c_char]>`, which is where
it gains most of its methods from. A few helper methods are added to acquire a
slice of `u8` instead of `c_char`, as well as including a slice with the
trailing nul byte if necessary.
* All usage of non-owned `CString` values is now done via two functions inside
of `std::ffi`, called `c_str_to_bytes` and `c_str_to_bytes_with_nul`. These
functions are now the one method used to convert a `*const c_char` to a Rust
slice of `u8`.
Many more details, including newly deprecated methods, can be found linked in
the RFC. This is a:
[breaking-change]
Closes#20444
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:
* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
at once to `std::io::prelude::*`.
This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.
[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]
Closes#20068
followed by a semicolon.
This allows code like `vec![1i, 2, 3].len();` to work.
This breaks code that uses macros as statements without putting
semicolons after them, such as:
fn main() {
...
assert!(a == b)
assert!(c == d)
println(...);
}
It also breaks code that uses macros as items without semicolons:
local_data_key!(foo)
fn main() {
println("hello world")
}
Add semicolons to fix this code. Those two examples can be fixed as
follows:
fn main() {
...
assert!(a == b);
assert!(c == d);
println(...);
}
local_data_key!(foo);
fn main() {
println("hello world")
}
RFC #378.
Closes#18635.
[breaking-change]
These modules will house the code that used to be part of the runtime system
in libnative. The `sys_common` module contains a few low-level but
cross-platform details. The `sys` module is set up using `#[cfg()]` to
include either a unix or windows implementation of a common API
surface. This API surface is *not* exported directly in `libstd`, but is
instead used to bulid `std::os` and `std::io`.
Ultimately, the low-level details in `sys` will be exposed in a
controlled way through a separate platform-specific surface, but that
setup is not part of this patch.
