This commit stabilizes the `ErrorKind` enumeration which is consumed by and
generated by the `io::Error` type. The purpose of this type is to serve as a
cross-platform namespace to categorize errors into. Two specific issues are
addressed as part of this stablization:
* The naming of each variant was scrutinized and some were tweaked. An example
is how `FileNotFound` was renamed to simply `NotFound`. These names should not
show either a Unix or Windows bias and the set of names is intended to grow
over time. For now the names will likely largely consist of those errors
generated by the I/O APIs in the standard library.
* The mapping of OS error codes onto kinds has been altered. Coalescing no
longer occurs (multiple error codes become one kind). It is intended that each
OS error code, if bound, corresponds to only one `ErrorKind`. The current set
of error kinds was expanded slightly to include some networking errors.
This commit also adds a `raw_os_error` function which returns an `Option<i32>`
to extract the underlying raw error code from the `Error`.
r? @alexcrichton or @aturon
This still needs to somehow figure out how to avoid unstable warnings arising from the use of unstable functions. I tried to use `#[allow_internal_unstable]` but it still spits out warnings as far as I can see. @huonw (I think you implemented it) does `#[allow_internal_unstable]` not work for some reason or am I using it incorrectly?
Previously it would fail on a trivial case like
/// Summary line
/// <trailing space>
/// Regular content
Compliant markdown preprocessor would render that as two separate paragraphs, but our summary line
extractor interprets both lines as the same paragraph and includes both into the short summary resulting in
This adds search by type (for functions/methods) support to Rustdoc. Target issue is at https://github.com/rust-lang/rfcs/issues/658.
I've described my approach here: https://github.com/rust-lang/rfcs/issues/658#issuecomment-76484200. I'll copy the text in here as well:
---
Hi, it took me longer than I wished, but I have implemented this in a not-too-complex way that I think can be extended to support more complex features (like the ones mentioned [here](https://github.com/rust-lang/rust/issues/12866#issuecomment-66945317)).
The idea is to generate a JSON representation of the types of methods/functions in the existing index, and then make the JS understand when it should look by type (and not by name).
I tried to come up with a JSON representation that can be extended to support generics, bounds, ref/mut annotations and so on. Here are a few samples:
Function:
```rust
fn to_uppercase(c: char) -> char
```
```json
{
"inputs": [
{"name": "char"}
],
"output": {
"name": "char",
}
}
```
Method (implemented or defined in trait):
```rust
// in struct Vec
// self is considered an argument as well
fn capacity(&self) -> usize
```
```json
{
"inputs": [
{"name": "vec"}
],
"output": {
"name": "usize"
}
}
```
This simple format can be extended by adding more fields, like `generic: bool`, a `bounds` mapping and so on.
I have a working implementation in https://github.com/rust-lang/rust/compare/master...mihneadb:rustdoc-search-by-type. You can check out a live demo [here](http://data.mihneadb.net/doc/std/index.html?search=charext%20-%3E%20char).
The feature list is not that long:
- search by types (you *can* use generics as well, as long as you use the exact name - e.g. [`vec,t -> `](http://data.mihneadb.net/doc/std/index.html?search=vec%2C%20t%20-%3E))
- order of arguments does not matter
- `self` is took into account as well (e.g. search for `vec -> usize`)
- does not use "complex" annotations (e.g. you don't search for `&char -> char` but for `char -> char`)
My goal is to get a working, minimal "base" merged so that others can build upon it. How should I proceed? Do I open a PR (badly in need of code review since this is my first non "hello world"-ish rust code)?
---
Previously it would fail on a trivial case like
/// Summary line
/// <trailing space>
/// Regular content
Compliant markdown preprocessor would render that as two separate paragraphs, but our summary line
extractor would interpret both lines as the same paragraph and include both into the short summary.
The new `std::io` module has had some time to bake now, and this commit
stabilizes its functionality. There are still portions of the module which
remain unstable, and below contains a summart of the actions taken.
This commit also deprecates the entire contents of the `old_io` module in a
blanket fashion. All APIs should now have a reasonable replacement in the
new I/O modules.
Stable APIs:
* `std::io` (the name)
* `std::io::prelude` (the name)
* `Read`
* `Read::read`
* `Read::{read_to_end, read_to_string}` after being modified to return a `usize`
for the number of bytes read.
* `ReadExt`
* `Write`
* `Write::write`
* `Write::{write_all, write_fmt}`
* `WriteExt`
* `BufRead`
* `BufRead::{fill_buf, consume}`
* `BufRead::{read_line, read_until}` after being modified to return a `usize`
for the number of bytes read.
* `BufReadExt`
* `BufReader`
* `BufReader::{new, with_capacity}`
* `BufReader::{get_ref, get_mut, into_inner}`
* `{Read,BufRead} for BufReader`
* `BufWriter`
* `BufWriter::{new, with_capacity}`
* `BufWriter::{get_ref, get_mut, into_inner}`
* `Write for BufWriter`
* `IntoInnerError`
* `IntoInnerError::{error, into_inner}`
* `{Error,Display} for IntoInnerError`
* `LineWriter`
* `LineWriter::{new, with_capacity}` - `with_capacity` was added
* `LineWriter::{get_ref, get_mut, into_inner}` - `get_mut` was added)
* `Write for LineWriter`
* `BufStream`
* `BufStream::{new, with_capacities}`
* `BufStream::{get_ref, get_mut, into_inner}`
* `{BufRead,Read,Write} for BufStream`
* `stdin`
* `Stdin`
* `Stdin::lock`
* `Stdin::read_line` - added method
* `StdinLock`
* `Read for Stdin`
* `{Read,BufRead} for StdinLock`
* `stdout`
* `Stdout`
* `Stdout::lock`
* `StdoutLock`
* `Write for Stdout`
* `Write for StdoutLock`
* `stderr`
* `Stderr`
* `Stderr::lock`
* `StderrLock`
* `Write for Stderr`
* `Write for StderrLock`
* `io::Result`
* `io::Error`
* `io::Error::last_os_error`
* `{Display, Error} for Error`
Unstable APIs:
(reasons can be found in the commit itself)
* `Write::flush`
* `Seek`
* `ErrorKind`
* `Error::new`
* `Error::from_os_error`
* `Error::kind`
Deprecated APIs
* `Error::description` - available via the `Error` trait
* `Error::detail` - available via the `Display` implementation
* `thread::Builder::{stdout, stderr}`
Changes in functionality:
* `old_io::stdio::set_stderr` is now a noop as the infrastructure for printing
backtraces has migrated to `std::io`.
[breaking-change]
This commit stabilizes essentially all of the new `std::path` API. The
API itself is changed in a couple of ways (which brings it in closer
alignment with the RFC):
* `.` components are now normalized away, unless they appear at the
start of a path. This in turn effects the semantics of e.g. asking for
the file name of `foo/` or `foo/.`, both of which yield `Some("foo")`
now. This semantics is what the original RFC specified, and is also
desirable given early experience rolling out the new API.
* The `parent` method is now `without_file` and succeeds if, and only
if, `file_name` is `Some(_)`. That means, in particular, that it fails
for a path like `foo/../`. This change affects `pop` as well.
In addition, the `old_path` module is now deprecated.
[breaking-change]
r? @alexcrichton
This commit stabilizes essentially all of the new `std::path` API. The
API itself is changed in a couple of ways (which brings it in closer
alignment with the RFC):
* `.` components are now normalized away, unless they appear at the
start of a path. This in turn effects the semantics of e.g. asking for
the file name of `foo/` or `foo/.`, both of which yield `Some("foo")`
now. This semantics is what the original RFC specified, and is also
desirable given early experience rolling out the new API.
* The `parent` function now succeeds if, and only if, the path has at
least one non-root/prefix component. This change affects `pop` as
well.
* The `Prefix` component now involves a separate `PrefixComponent`
struct, to better allow for keeping both parsed and unparsed prefix data.
In addition, the `old_path` module is now deprecated.
Closes#23264
[breaking-change]
The end result is that common fields (id, name, attributes, etc.) are stored in now-structures `ImplItem` and `TraitItem`.
The signature of a method is no longer duplicated between methods with a body (default/impl) and those without, they now share `MethodSig`.
This is also a [breaking-change] because of minor bugfixes and changes to syntax extensions:
* `pub fn` methods in a trait no longer parse - remove the `pub`, it has no meaning anymore
* `MacResult::make_methods` is now `make_impl_items` and the return type has changed accordingly
* `quote_method` is gone, because `P<ast::Method>` doesn't exist and it couldn't represent a full method anyways - could be replaced by `quote_impl_item`/`quote_trait_item` in the future, but I do hope we realize how silly that combinatorial macro expansion is and settle on a single `quote` macro + some type hints - or just no types at all (only token-trees)
r? @nikomatsakis This is necessary (hopefully also sufficient) for associated constants.
We require the *deferred* loading, not just an opportunistic
asynchronous loading. I think `<script defer>` is safe to use,
according to <http://caniuse.com/#feat=script-defer>.
This should fix#22615. Previously, the playpen links grabbed the content of all `.rusttest` containers on the same level to build the URL. Now they just select the one before the `pre` they are shown in.
I have only tested this by changing the file in my local build of the docs (not by running rustdoc itself).
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]
It had been a source of huge bloat in rustdoc outputs. Of course, we can simply disable compiler docs (as `rustc` generates over 90M of HTML) but this approach fares better even after such decision.
Each directory now has `sidebar-items.js`, which immediately calls `initSidebarItems` with a JSON sidebar data. This file is shared throughout every item in the sidebar. The current item is highlighted via a separate JS snippet (`window.sidebarCurrent`). The JS file is designed to be loaded asynchronously, as the sidebar is rendered before the content and slow sidebar loading blocks the entire rendering. For the minimal accessibility without JS, links to the parent items are left in HTML.
In the future, it might also be possible to integrate crates data with the same fashion: `sidebar-items.js` at the root path will do that. (Currently rustdoc skips writing JS in that case.)
This has a huge impact on the size of rustdoc outputs. Originally it was 326MB uncompressed (37.7MB gzipped, 6.1MB xz compressed); it is 169MB uncompressed (11.9MB gzipped, 5.9MB xz compressed) now. The sidebar JS only takes 10MB uncompressed & 0.3MB gzipped.
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 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).
The main gist of this PR is commit 1077efb which removes the list of supertraits from the `TraitDef` and pulls them into a separate table, which is accessed via `lookup_super_predicates`. This is analogous to `lookup_predicates`, which gets the complete where clause. This allows us to create the `TraitDef`, which contains the list generics and so forth, without fully knowing the list of supertraits. This in turn allows the *supertrait listing* to contain references to associated types like `<Self as Foo>::Item`, which were previously impossible because conversion required having the `TraitDef` for `Foo`.
We do not yet support `Self::Item` in a supertrait listing. This doesn't work because to convert that, it attempts to expand out the full set of supertraits, which are in the process of being created. This could potentially be worked out by having the expansion of supertraits proceed in a lazy fashion, but we'd have to define shadowing rules for associated types which we don't currently have.
Along the way (in 9de9ec5) I also removed the restriction against duplicate bounds and generalized the code so that it can handle having the same supertrait multiple times with different arguments, e.g. `Foo : Bar<i32> + Bar<u32>`. This restriction was serving no particular purpose, since the same trait could be extended multiple times indirectly, and in the era of multidispatch it is actively harmful.
This is technically a [breaking-change] because it affects the definition of a super-trait. Anything in a where clause that looks like `where Self : Foo` is now considered a supertrait. Because cycles are disallowed in supertraits, that could lead to some errors. This has not been observed in any existing code.
r? @nrc
It had been a source of huge bloat in rustdoc outputs. Of course,
we can simply disable compiler docs (as `rustc` generates over 90M
of HTML) but this approach fares better even after such decision.
Each directory now has `sidebar-items.js`, which immediately calls
`initSidebarItems` with a JSON sidebar data. This file is shared
throughout every item in the sidebar. The current item is
highlighted via a separate JS snippet (`window.sidebarCurrent`).
The JS file is designed to be loaded asynchronously, as the sidebar
is rendered before the content and slow sidebar loading blocks
the entire rendering. For the minimal accessibility without JS,
links to the parent items are left in HTML.
In the future, it might also be possible to integrate crates data
with the same fashion: `sidebar-items.js` at the root path will do
that. (Currently rustdoc skips writing JS in that case.)
This has a huge impact on the size of rustdoc outputs. Originally
it was 326MB uncompressed (37.7MB gzipped, 6.1MB xz compressed);
it is 169MB uncompressed (11.9MB gzipped, 5.9MB xz compressed) now.
The sidebar JS only takes 10MB uncompressed & 0.3MB gzipped.
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.
us to construct trait-references and do other things without forcing a
full evaluation of the supertraits. One downside of this scheme is that
we must invoke `ensure_super_predicates` before using any construct that
might require knowing about the super-predicates.
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]
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
This pulls out the implementations of most built-in lints into a
separate crate, to reduce edit-compile-test iteration times with
librustc_lint and increase parallelism. This should enable lints to be
refactored, added and deleted much more easily as it slashes the
edit-compile cycle to get a minimal working compiler to test with (`make
rustc-stage1`) from
librustc -> librustc_typeck -> ... -> librustc_driver ->
libcore -> ... -> libstd
to
librustc_lint -> librustc_driver -> libcore -> ... libstd
which is significantly faster, mainly due to avoiding the librustc build
itself.
The intention would be to move as much as possible of the infrastructure
into the crate too, but the plumbing is deeply intertwined with librustc
itself at the moment. Also, there are lints for which diagnostics are
registered directly in the compiler code, not in their own crate
traversal, and their definitions have to remain in librustc.
This is a [breaking-change] for direct users of the compiler APIs:
callers of `rustc::session::build_session` or
`rustc::session::build_session_` need to manually call
`rustc_lint::register_builtins` on their return value.
This should make #22206 easier.
Now that the `std::env` module has had some time to bake this commit marks most
of its APIs as `#[stable]`. Some notable APIs that are **not** stable (and still
use the same `env` feature gate) are:
* `{set,get}_exit_status` - there are still questions about whether this is the
right interface for setting/getting the exit status of a process.
* `page_size` - this may change location in the future or perhaps name as well.
This also effectively closes#22122 as the variants of `VarError` are
`#[stable]` now. (this is done intentionally)
