Being a person who somehow has taken a liking to premature optimisation, my knee-jerk reaction to
locking in std handles was preamble resembling following snippet:
let stdout = stdout();
let lstdout = stdout.lock();
let stdin = stdin();
let lstdin = stdin.lock();
and then reading from the locked handle like this:
let mut letter = [0; 1];
lstdin.read(&mut letter).unwrap();
As it is now this code will deadlock because the `read` method attempts to lock stdout as well!
r? @alexcrichton
---
Either way, I find flushing stdout when stdin is used debatable. I believe people who write prompts should take care to flush stdout when necessary themselves.
Another idea: Would be cool if locks on std handles would be taken for a thread, rather than a handle, so given preamble (first code snippet)
stdin.lock()
or more generally
stdin.read(…)
worked fine. I.e. if more than a single lock are all taken inside the same thread, it would work, though not sure if our synchronisation primitives are expressive enough to make it possible.
The `std::net` primitives should be ready for use now and as a result the old
ones are now deprecated and slated for removal. Most TCP/UDP functionality is
now available through `std::net` but the `std::old_io::net::pipe` module is
removed entirely from the standard library.
Unix socket funtionality can be found in sfackler's [`unix_socket`][unix] crate
and there is currently no replacement for named pipes on Windows.
[unix]: https://crates.io/crates/unix_socket
[breaking-change]
The `std::net` primitives should be ready for use now and as a result the old
ones are now deprecated and slated for removal. Most TCP/UDP functionality is
now available through `std::net` but the `std::old_io::net::pipe` module is
removed entirely from the standard library.
Unix socket funtionality can be found in sfackler's [`unix_socket`][unix] crate
and there is currently no replacement for named pipes on Windows.
[unix]: https://crates.io/crates/unix_socket
[breaking-change]
Being a person who somehow has taken a liking to premature optimisation, my knee-jerk reaction to
locking in std handles was preamble resembling following snippet:
let stdout = stdout();
let lstdout = stdout.lock();
let stdin = stdin();
let lstdin = stdin.lock();
and then reading from the locked handle like this:
let mut letter = [0; 1];
lstdin.read(&mut letter).unwrap();
As it is now this code will deadlock because the `read` method attempts to lock stdout as well!
This commit performs a stabilization pass over the `std::fs` module now that
it's had some time to bake. The change was largely just adding `#[stable]` tags,
but there are a few APIs that remain `#[unstable]`.
The following apis are now marked `#[stable]`:
* `std::fs` (the name)
* `File`
* `Metadata`
* `ReadDir`
* `DirEntry`
* `OpenOptions`
* `Permissions`
* `File::{open, create}`
* `File::{sync_all, sync_data}`
* `File::set_len`
* `File::metadata`
* Trait implementations for `File` and `&File`
* `OpenOptions::new`
* `OpenOptions::{read, write, append, truncate, create}`
* `OpenOptions::open` - this function was modified, however, to not attempt to
reject cross-platform openings of directories. This means that some platforms
will succeed in opening a directory and others will fail.
* `Metadata::{is_dir, is_file, len, permissions}`
* `Permissions::{readonly, set_readonly}`
* `Iterator for ReadDir`
* `DirEntry::path`
* `remove_file` - like with `OpenOptions::open`, the extra windows code to
remove a readonly file has been removed. This means that removing a readonly
file will succeed on some platforms but fail on others.
* `metadata`
* `rename`
* `copy`
* `hard_link`
* `soft_link`
* `read_link`
* `create_dir`
* `create_dir_all`
* `remove_dir`
* `remove_dir_all`
* `read_dir`
The following apis remain `#[unstable]`.
* `WalkDir` and `walk` - there are many methods by which a directory walk can be
constructed, and it's unclear whether the current semantics are the right
ones. For example symlinks are not handled super well currently. This is now
behind a new `fs_walk` feature.
* `File::path` - this is an extra abstraction which the standard library
provides on top of what the system offers and it's unclear whether we should
be doing so. This is now behind a new `file_path` feature.
* `Metadata::{accessed, modified}` - we do not currently have a good
abstraction for a moment in time which is what these APIs should likely be
returning, so these remain `#[unstable]` for now. These are now behind a new
`fs_time` feature
* `set_file_times` - like with `Metadata::accessed`, we do not currently have
the appropriate abstraction for the arguments here so this API remains
unstable behind the `fs_time` feature gate.
* `PathExt` - the precise set of methods on this trait may change over time and
some methods may be removed. This API remains unstable behind the `path_ext`
feature gate.
* `set_permissions` - we may wish to expose a more granular ability to set the
permissions on a file instead of just a blanket \"set all permissions\" method.
This function remains behind the `fs` feature.
The following apis are now `#[deprecated]`
* The `TempDir` type is now entirely deprecated and is [located on
crates.io][tempdir] as the `tempdir` crate with [its source][github] at
rust-lang/tempdir.
[tempdir]: https://crates.io/crates/tempdir
[github]: https://github.com/rust-lang/tempdir
The stability of some of these APIs has been questioned over the past few weeks
in using these APIs, and it is intentional that the majority of APIs here are
marked `#[stable]`. The `std::fs` module has a lot of room to grow and the
material is [being tracked in a RFC issue][rfc-issue].
[rfc-issue]: rust-lang/rfcs#939
Closes#22879
[breaking-change]
This module is now superseded by the `std::process` module. This module still
has some room to expand to get quite back up to parity with the `old_io`
version, and there is a [tracking issue][issue] for feature requests as well as
known room for expansion.
[issue]: https://github.com/rust-lang/rfcs/issues/941
[breaking-change]
The new `io` module has had some time to bake and this commit stabilizes some of
the utilities associated with it. This commit also deprecates a number of
`std::old_io::util` functions and structures.
These items are now `#[stable]`
* `Cursor`
* `Cursor::{new, into_inner, get_ref, get_mut, position, set_position}`
* Implementations of I/O traits for `Cursor<T>`
* Delegating implementations of I/O traits for references and `Box` pointers
* Implementations of I/O traits for primitives like slices and `Vec<T>`
* `ReadExt::bytes`
* `Bytes` (and impls)
* `ReadExt::chain`
* `Chain` (and impls)
* `ReadExt::take` (and impls)
* `BufReadExt::lines`
* `Lines` (and impls)
* `io::copy`
* `io::{empty, Empty}` (and impls)
* `io::{sink, Sink}` (and impls)
* `io::{repeat, Repeat}` (and impls)
These items remain `#[unstable]`
* Core I/O traits. These may want a little bit more time to bake along with the
commonly used methods like `read_to_end`.
* `BufReadExt::split` - this function may be renamed to not conflict with
`SliceExt::split`.
* `Error` - there are a number of questions about its representation,
`ErrorKind`, and usability.
These items are now `#[deprecated]` in `old_io`
* `LimitReader` - use `take` instead
* `NullWriter` - use `io::sink` instead
* `ZeroReader` - use `io::repeat` instead
* `NullReader` - use `io::empty` instead
* `MultiWriter` - use `broadcast` instead
* `ChainedReader` - use `chain` instead
* `TeeReader` - use `tee` instead
* `copy` - use `io::copy` instead
[breaking-change]
Unstable items used in a macro expansion will now always trigger
stability warnings, *unless* the unstable items are directly inside a
macro marked with `#[allow_internal_unstable]`. IOW, the compiler warns
unless the span of the unstable item is a subspan of the definition of a
macro marked with that attribute.
E.g.
#[allow_internal_unstable]
macro_rules! foo {
($e: expr) => {{
$e;
unstable(); // no warning
only_called_by_foo!();
}}
}
macro_rules! only_called_by_foo {
() => { unstable() } // warning
}
foo!(unstable()) // warning
The unstable inside `foo` is fine, due to the attribute. But the
`unstable` inside `only_called_by_foo` is not, since that macro doesn't
have the attribute, and the `unstable` passed into `foo` is also not
fine since it isn't contained in the macro itself (that is, even though
it is only used directly in the macro).
In the process this makes the stability tracking much more precise,
e.g. previously `println!(\"{}\", unstable())` got no warning, but now it
does. As such, this is a bug fix that may cause [breaking-change]s.
The attribute is definitely feature gated, since it explicitly allows
side-stepping the feature gating system.
---
This updates `thread_local!` macro to use the attribute, since it uses
unstable features internally (initialising a struct with unstable
fields).
This commit performs a stabilization pass over the `std::fs` module now that
it's had some time to bake. The change was largely just adding `#[stable]` tags,
but there are a few APIs that remain `#[unstable]`.
The following apis are now marked `#[stable]`:
* `std::fs` (the name)
* `File`
* `Metadata`
* `ReadDir`
* `DirEntry`
* `OpenOptions`
* `Permissions`
* `File::{open, create}`
* `File::{sync_all, sync_data}`
* `File::set_len`
* `File::metadata`
* Trait implementations for `File` and `&File`
* `OpenOptions::new`
* `OpenOptions::{read, write, append, truncate, create}`
* `OpenOptions::open` - this function was modified, however, to not attempt to
reject cross-platform openings of directories. This means that some platforms
will succeed in opening a directory and others will fail.
* `Metadata::{is_dir, is_file, len, permissions}`
* `Permissions::{readonly, set_readonly}`
* `Iterator for ReadDir`
* `DirEntry::path`
* `remove_file` - like with `OpenOptions::open`, the extra windows code to
remove a readonly file has been removed. This means that removing a readonly
file will succeed on some platforms but fail on others.
* `metadata`
* `rename`
* `copy`
* `hard_link`
* `soft_link`
* `read_link`
* `create_dir`
* `create_dir_all`
* `remove_dir`
* `remove_dir_all`
* `read_dir`
The following apis remain `#[unstable]`.
* `WalkDir` and `walk` - there are many methods by which a directory walk can be
constructed, and it's unclear whether the current semantics are the right
ones. For example symlinks are not handled super well currently. This is now
behind a new `fs_walk` feature.
* `File::path` - this is an extra abstraction which the standard library
provides on top of what the system offers and it's unclear whether we should
be doing so. This is now behind a new `file_path` feature.
* `Metadata::{accessed, modified}` - we do not currently have a good
abstraction for a moment in time which is what these APIs should likely be
returning, so these remain `#[unstable]` for now. These are now behind a new
`fs_time` feature
* `set_file_times` - like with `Metadata::accessed`, we do not currently have
the appropriate abstraction for the arguments here so this API remains
unstable behind the `fs_time` feature gate.
* `PathExt` - the precise set of methods on this trait may change over time and
some methods may be removed. This API remains unstable behind the `path_ext`
feature gate.
* `set_permissions` - we may wish to expose a more granular ability to set the
permissions on a file instead of just a blanket "set all permissions" method.
This function remains behind the `fs` feature.
The following apis are now `#[deprecated]`
* The `TempDir` type is now entirely deprecated and is [located on
crates.io][tempdir] as the `tempdir` crate with [its source][github] at
rust-lang/tempdir.
[tempdir]: https://crates.io/crates/tempdir
[github]: https://github.com/rust-lang/tempdir
The stability of some of these APIs has been questioned over the past few weeks
in using these APIs, and it is intentional that the majority of APIs here are
marked `#[stable]`. The `std::fs` module has a lot of room to grow and the
material is [being tracked in a RFC issue][rfc-issue].
[rfc-issue]: https://github.com/rust-lang/rfcs/issues/939
[breaking-change]
The two main sub-modules, `c_str` and `os_str`, have now had some time to bake
in the standard library. This commits performs a sweep over the modules adding
various stability tags.
The following APIs are now marked `#[stable]`
* `OsString`
* `OsStr`
* `OsString::from_string`
* `OsString::from_str`
* `OsString::new`
* `OsString::into_string`
* `OsString::push` (renamed from `push_os_str`, added an `AsOsStr` bound)
* various trait implementations for `OsString`
* `OsStr::from_str`
* `OsStr::to_str`
* `OsStr::to_string_lossy`
* `OsStr::to_os_string`
* various trait implementations for `OsStr`
* `CString`
* `CStr`
* `NulError`
* `CString::new` - this API's implementation may change as a result of
rust-lang/rfcs#912 but the usage of `CString::new(thing)` looks like it is
unlikely to change. Additionally, the `IntoBytes` bound is also likely to
change but the set of implementors for the trait will not change (despite the
trait perhaps being renamed).
* `CString::from_vec_unchecked`
* `CString::as_bytes`
* `CString::as_bytes_with_nul`
* `NulError::nul_position`
* `NulError::into_vec`
* `CStr::from_ptr`
* `CStr::as_ptr`
* `CStr::to_bytes`
* `CStr::to_bytes_with_nul`
* various trait implementations for `CStr`
The following APIs remain `#[unstable]`
* `OsStr*Ext` traits remain unstable as the organization of `os::platform` is
uncertain still and the traits may change location.
* `AsOsStr` remains unstable as generic conversion traits are likely to be
rethought soon.
The following APIs were deprecated
* `OsString::push_os_str` is now called `push` and takes `T: AsOsStr` instead (a
superset of the previous functionality).
This module is now superseded by the `std::process` module. This module still
has some room to expand to get quite back up to parity with the `old_io`
version, and there is a [tracking issue][issue] for feature requests as well as
known room for expansion.
[issue]: https://github.com/rust-lang/rfcs/issues/941
[breaking-change]
The new `io` module has had some time to bake and this commit stabilizes some of
the utilities associated with it. This commit also deprecates a number of
`std::old_io::util` functions and structures.
These items are now `#[stable]`
* `Cursor`
* `Cursor::{new, into_inner, get_ref, get_mut, position, set_position}`
* Implementations of I/O traits for `Cursor<T>`
* Delegating implementations of I/O traits for references and `Box` pointers
* Implementations of I/O traits for primitives like slices and `Vec<T>`
* `ReadExt::bytes`
* `Bytes` (and impls)
* `ReadExt::chain`
* `Chain` (and impls)
* `ReadExt::take` (and impls)
* `BufReadExt::lines`
* `Lines` (and impls)
* `io::copy`
* `io::{empty, Empty}` (and impls)
* `io::{sink, Sink}` (and impls)
* `io::{repeat, Repeat}` (and impls)
These items remain `#[unstable]`
* Core I/O traits. These may want a little bit more time to bake along with the
commonly used methods like `read_to_end`.
* `BufReadExt::split` - this function may be renamed to not conflict with
`SliceExt::split`.
* `Error` - there are a number of questions about its representation,
`ErrorKind`, and usability.
These items are now `#[deprecated]` in `old_io`
* `LimitReader` - use `take` instead
* `NullWriter` - use `io::sink` instead
* `ZeroReader` - use `io::repeat` instead
* `NullReader` - use `io::empty` instead
* `MultiWriter` - use `broadcast` instead
* `ChainedReader` - use `chain` instead
* `TeeReader` - use `tee` instead
* `copy` - use `io::copy` instead
[breaking-change]
This commit deprecates the majority of std::old_io::fs in favor of std::fs and
its new functionality. Some functions remain non-deprecated but are now behind a
feature gate called `old_fs`. These functions will be deprecated once
suitable replacements have been implemented.
The compiler has been migrated to new `std::fs` and `std::path` APIs where
appropriate as part of this change.
Many of the modifications putting in `Box::new` calls also include a
pointer to Issue 22405, which tracks going back to `box <expr>` if
possible in the future.
(Still tried to use `Box<_>` where it sufficed; thus some tests still
have `box_syntax` enabled, as they use a mix of `box` and `Box::new`.)
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
This is the kind of change that one is expected to need to make to
accommodate overloaded-`box`.
----
Note that this is not *all* of the changes necessary to accommodate
Issue 22181. It is merely the subset of those cases where there was
already a let-binding in place that made it easy to add the necesasry
type ascription.
(For unnamed intermediate `Box` values, one must go down a different
route; `Box::new` is the option that maximizes portability, but has
potential inefficiency depending on whether the call is inlined.)
----
There is one place worth note, `run-pass/coerce-match.rs`, where I
used an ugly form of `Box<_>` type ascription where I would have
preferred to use `Box::new` to accommodate overloaded-`box`. I
deliberately did not use `Box::new` here, because that is already done
in coerce-match-calls.rs.
----
Precursor for overloaded-`box` and placement-`in`; see Issue 22181.
Rebase and follow-through on work done by @cmr and @aatch.
Implements most of rust-lang/rfcs#560. Errors encountered from the checks during building were fixed.
The checks for division, remainder and bit-shifting have not been implemented yet.
See also PR #20795
cc @Aatch ; cc @nikomatsakis
aarch64-linux-android build has been broken since #22839.
Aarch64 android has _Unwind_GetIPInfo, so re-define this only for arm32 android.
r? @alexcrichton
This changes the type of some public constants/statics in libunicode.
Notably some `&'static &'static [(char, char)]` have changed
to `&'static [(char, char)]`. The regexp crate seems to be the
sole user of these, yet this is technically a [breaking-change]
* The lint visitor's visit_ty method did not recurse, and had a
reference to the now closed#10894
* The newly enabled recursion has only affected the `deprectated` lint
which now detects uses of deprecated items in trait impls and
function return types
* Renamed some references to `CowString` and `CowVec` to `Cow<str>` and
`Cow<[T]>`, respectively, which appear outside of the crate which
defines them
* Replaced a few instances of `InvariantType<T>` with
`PhantomData<Cell<T>>`
* Disabled the `deprecated` lint in several places that
reference/implement traits on deprecated items which will get cleaned
up in the future
* Unfortunately, this means that if a library declares
`#![deny(deprecated)]` and marks anything as deprecated, it will have
to disable the lint for any uses of said item, e.g. any impl the now
deprecated item
For any library that denies deprecated items but has deprecated items
of its own, this is a [breaking-change]
I had originally intended for the lint to ignore uses of deprecated items that are declared in the same crate, but this goes against some previous test cases that expect the lint to capture *all* uses of deprecated items, so I maintained the previous approach to avoid changing the expected behavior of the lint.
Tested locally on OS X, so hopefully there aren't any deprecated item uses behind a `cfg` that I may have missed.
Regarding the `rand` changes: It is unfortunate that Wrapping(T) does
not support the `+=` operator. We may want to try to fix that before
1.0 to make porting code like this palatable.
Regarding `std::rand`, just arith-overflow in first example from
`std::rand::random()` doc.
* `core::num`: adjust `UnsignedInt::is_power_of_two`,
`UnsignedInt::next_power_of_two`, `Int::pow`.
In particular for `Int::pow`: (1.) do not panic when `base`
overflows if `acc` never observes the overflowed `base`, and (2.)
if `acc` does observe the overflowed `base`, make sure we only
panic if we would have otherwise (e.g. during a computation of
`base * base`).
* also in `core::num`: avoid underflow during computation of `uint::MAX`.
* `std::num`: adjust tests `uint::test_uint_from_str_overflow`,
`uint::test_uint_to_str_overflow`, `strconv`
* `coretest::num`: adjust `test::test_int_from_str_overflow`.
* `collections::btree::node`: accommodate (transient) underflow.
* `collections::btree::map`: avoid underflow during `fn next`
for `BTreeMap::range` methods.
* `collections::slice`: note that pnkfelix deliberately used
`new_pos_wrapping` only once; the other cases of arithmetic do not
over- nor underflow, which is a useful property to leave implicitly
checked/documented via the remaining calls to `fn new_pos(..)`.
* `collections::vec_deque` applied wrapping ops (somewhat blindly)
to two implementation methods, and many tests.
* `std::collections:#️⃣:table` : Use `OverflowingOps` trait to
track overflow during `calculate_offsets` and `calculate_allocation`
functions.
Many of the core rust libraries have places that rely on integer
wrapping behaviour. These places have been altered to use the wrapping_*
methods:
* core:#️⃣:sip - A number of macros
* core::str - The `maximal_suffix` method in `TwoWaySearcher`
* rustc::util::nodemap - Implementation of FnvHash
* rustc_back::sha2 - A number of macros and other places
* rand::isaac - Isaac64Rng, changed to use the Wrapping helper type
Some places had "benign" underflow. This is when underflow or overflow
occurs, but the unspecified value is not used due to other conditions.
* collections::bit::Bitv - underflow when `self.nbits` is zero.
* collections:#️⃣:{map,table} - Underflow when searching an empty
table. Did cause undefined behaviour in this case due to an
out-of-bounds ptr::offset based on the underflowed index. However the
resulting pointers would never be read from.
* syntax::ext::deriving::encodable - Underflow when calculating the
index of the last field in a variant with no fields.
These cases were altered to avoid the underflow, often by moving the
underflowing operation to a place where underflow could not happen.
There was one case that relied on the fact that unsigned arithmetic and
two's complement arithmetic are identical with wrapping semantics. This
was changed to use the wrapping_* methods.
Finally, the calculation of variant discriminants could overflow if the
preceeding discriminant was `U64_MAX`. The logic in `rustc::middle::ty`
for this was altered to avoid the overflow completely, while the
remaining places were changed to use wrapping methods. This is because
`rustc::middle::ty::enum_variants` now throws an error when the
calculated discriminant value overflows a `u64`.
This behaviour can be triggered by the following code:
```
enum Foo {
A = U64_MAX,
B
}
```
This commit also implements the remaining integer operators for
Wrapped<T>.
