This is a spiritual succesor to #34268/8531d581, in which we replaced a
number of matches of None to the unit value with `if let` conditionals
where it was judged that this made for clearer/simpler code (as would be
recommended by Manishearth/rust-clippy's `single_match` lint). The same
rationale applies to matches of None to the empty block.
To allow these braced macro invocation, this PR removes the optional expression from `ast::Block` and instead uses a `StmtKind::Expr` at the end of the statement list.
Currently, braced macro invocations in blocks can expand into statements (and items) except when they are last in a block, in which case they can only expand into expressions.
For example,
```rust
macro_rules! make_stmt {
() => { let x = 0; }
}
fn f() {
make_stmt! {} //< This is OK...
let x = 0; //< ... unless this line is commented out.
}
```
Fixes#34418.
syntax-[breaking-change] cc #31645
(Only breaking because ast::TokenTree is now tokenstream::TokenTree.)
This pull request refactors TokenTrees into their own file as src/libsyntax/tokenstream.rs, moving them out of src/libsyntax/ast.rs, in order to prepare for an accompanying TokenStream implementation (per RFC 1566).
This PR refactors the 'errors' part of libsyntax into its own crate (librustc_errors). This is the first part of a few refactorings to simplify error reporting and potentially support more output formats (like a standardized JSON output and possibly an --explain mode that can work with the user's code), though this PR stands on its own and doesn't assume further changes.
As part of separating out the errors crate, I have also refactored the code position portion of codemap into its own crate (libsyntax_pos). While it's helpful to have the common code positions in a separate crate for the new errors crate, this may also enable further simplifications in the future.
**syntax-[breaking-change]** cc #31645
New `TraitItemKind::Macro` variant
This change adds support for macro expansion inside trait items by adding the new `TraitItemKind::Macro` and associated parsing code.
Pretty-print attributes on tuple structs and add tests
This adds support to the pretty printer to print attributes added to tuple struct elements. Furthermore, it adds a test that makes sure we will print attributes on all variant data types.
This adds support to the pretty printer to print attributes
added to tuple struct elements. Furthermore, it adds a test
that makes sure we will print attributes on all variant data
types.
The use of ...?instead of try!(...) in libsyntax makes
extracting libsyntax into syntex quite painful since it's
not stable yet. This makes backports take a much longer time
and causes a lot of problems for the syntex dependencies. Even
if it was, it'd take a few release cycles until syntex would
be able to use it. Since it's not stable and that this feature
is just syntax sugar, it would be most helpful if we could remove
it.
cc #34311
Casual grepping revealed some places in the codebase (some of which
antedated `if let`'s December 2014 stabilization in c200ae5a) where we
were using a match with a `None => ()` arm where (in the present
author's opinion) an `if let` conditional would be more readable. (Other
places where matching to the unit value did seem to better express the
intent were left alone.)
It's likely that we don't care about making such trivial,
non-functional, sheerly æsthetic changes.
But if we do, this is a patch.
This makes the "shadowing labels" warning *not* print the entire loop
as a span, but only the lifetime.
Also makes #31719 go away, but does not fix its root cause (the span
of the expanded loop is still wonky, but not used anymore).
Fix spans and expected token lists, fix#33413 + other cosmetic improvements
Add test for #33413
Convert between `Arg` and `ExplicitSelf` precisely
Simplify pretty-printing for methods
Paths are mostly parsed without taking whitespaces into account, e.g. `std :: vec :: Vec :: new ()` parses successfully, however, there are some special cases involving keywords `super`, `self` and `Self`. For example, `self::` is considered a path start only if there are no spaces between `self` and `::`. These restrictions probably made sense when `self` and friends weren't keywords, but now they are unnecessary.
The first two commits remove this special treatment of whitespaces by removing `token::IdentStyle` entirely and therefore fix https://github.com/rust-lang/rust/issues/14109.
This change also affects naked `self` and `super` (which are not tightly followed by `::`, obviously) they can now be parsed as paths, however they are still not resolved correctly in imports (cc @jseyfried, see `compile-fail/use-keyword.rs`), so https://github.com/rust-lang/rust/issues/29036 is not completely fixed.
The third commit also makes `super`, `self`, `Self` and `static` keywords nominally (before this they acted as keywords for all purposes) and removes most of remaining \"special idents\".
The last commit (before tests) contains some small improvements - some qualified paths with type parameters are parsed correctly, `parse_path` is not used for parsing single identifiers, imports are sanity checked for absence of type parameters - such type parameters can be generated by syntax extensions or by macros when https://github.com/rust-lang/rust/issues/10415 is fixed (~~soon!~~already!).
This patch changes some pretty basic things in `libsyntax`, like `token::Token` and the keyword list, so it's a plugin-[breaking-change].
r? @eddyb
This commit applies all stabilizations, renamings, and deprecations that the
library team has decided on for the upcoming 1.9 release. All tracking issues
have gone through a cycle-long "final comment period" and the specific APIs
stabilized/deprecated are:
Stable
* `std::panic`
* `std::panic::catch_unwind` (renamed from `recover`)
* `std::panic::resume_unwind` (renamed from `propagate`)
* `std::panic::AssertUnwindSafe` (renamed from `AssertRecoverSafe`)
* `std::panic::UnwindSafe` (renamed from `RecoverSafe`)
* `str::is_char_boundary`
* `<*const T>::as_ref`
* `<*mut T>::as_ref`
* `<*mut T>::as_mut`
* `AsciiExt::make_ascii_uppercase`
* `AsciiExt::make_ascii_lowercase`
* `char::decode_utf16`
* `char::DecodeUtf16`
* `char::DecodeUtf16Error`
* `char::DecodeUtf16Error::unpaired_surrogate`
* `BTreeSet::take`
* `BTreeSet::replace`
* `BTreeSet::get`
* `HashSet::take`
* `HashSet::replace`
* `HashSet::get`
* `OsString::with_capacity`
* `OsString::clear`
* `OsString::capacity`
* `OsString::reserve`
* `OsString::reserve_exact`
* `OsStr::is_empty`
* `OsStr::len`
* `std::os::unix::thread`
* `RawPthread`
* `JoinHandleExt`
* `JoinHandleExt::as_pthread_t`
* `JoinHandleExt::into_pthread_t`
* `HashSet::hasher`
* `HashMap::hasher`
* `CommandExt::exec`
* `File::try_clone`
* `SocketAddr::set_ip`
* `SocketAddr::set_port`
* `SocketAddrV4::set_ip`
* `SocketAddrV4::set_port`
* `SocketAddrV6::set_ip`
* `SocketAddrV6::set_port`
* `SocketAddrV6::set_flowinfo`
* `SocketAddrV6::set_scope_id`
* `<[T]>::copy_from_slice`
* `ptr::read_volatile`
* `ptr::write_volatile`
* The `#[deprecated]` attribute
* `OpenOptions::create_new`
Deprecated
* `std::raw::Slice` - use raw parts of `slice` module instead
* `std::raw::Repr` - use raw parts of `slice` module instead
* `str::char_range_at` - use slicing plus `chars()` plus `len_utf8`
* `str::char_range_at_reverse` - use slicing plus `chars().rev()` plus `len_utf8`
* `str::char_at` - use slicing plus `chars()`
* `str::char_at_reverse` - use slicing plus `chars().rev()`
* `str::slice_shift_char` - use `chars()` plus `Chars::as_str`
* `CommandExt::session_leader` - use `before_exec` instead.
Closes#27719
cc #27751 (deprecating the `Slice` bits)
Closes#27754Closes#27780Closes#27809Closes#27811Closes#27830Closes#28050Closes#29453Closes#29791Closes#29935Closes#30014Closes#30752Closes#31262
cc #31398 (still need to deal with `before_exec`)
Closes#31405Closes#31572Closes#31755Closes#31756
Automated conversion using the untry tool [1] and the following command:
```
$ find -name '*.rs' -type f | xargs untry
```
at the root of the Rust repo.
[1]: https://github.com/japaric/untry
syntax: Always pretty print a newline after doc comments
Before this patch, code that had a doc comment as the first
line, as in:
```rust
/// Foo
struct Foo;
```
Was pretty printed into:
```rust
///Foostruct Foo;
```
This makes sure that that there is always a trailing newline
after a doc comment.
Closes#31722
The `?` postfix operator is sugar equivalent to the try! macro, but is more amenable to chaining:
`File::open("foo")?.metadata()?.is_dir()`.
`?` is accepted on any *expression* that can return a `Result`, e.g. `x()?`, `y!()?`, `{z}?`,
`(w)?`, etc. And binds more tightly than unary operators, e.g. `!x?` is parsed as `!(x?)`.
cc #31436
Before this patch, code that had a doc comment as the first
line, as in:
```rust
/// Foo
struct Foo;
```
Was pretty printed into:
```rust
///Foostruct Foo;
```
This makes sure that that there is always a trailing newline
after a doc comment.
Closes#31722
Pretty printing of macro with braces but without terminated semicolon
removed more boxes from stack than it put there, resulting in panic.
This fixes the issue #30731.
This commit removes the `-D warnings` flag being passed through the makefiles to
all crates to instead be a crate attribute. We want these attributes always
applied for all our standard builds, and this is more amenable to Cargo-based
builds as well.
Note that all `deny(warnings)` attributes are gated with a `cfg(stage0)`
attribute currently to match the same semantics we have today
This PR is a rebase of the original PR by @eddyb https://github.com/rust-lang/rust/pull/21836 with some unrebasable parts manually reapplied, feature gate added + type equality restriction added as described below.
This implementation is partial because the type equality restriction is applied to all type ascription expressions and not only those in lvalue contexts. Thus, all difficulties with detection of these contexts and translation of coercions having effect in runtime are avoided.
So, you can't write things with coercions like `let slice = &[1, 2, 3]: &[u8];`. It obviously makes type ascription less useful than it should be, but it's still much more useful than not having type ascription at all.
In particular, things like `let v = something.iter().collect(): Vec<_>;` and `let u = t.into(): U;` work as expected and I'm pretty happy with these improvements alone.
Part of https://github.com/rust-lang/rust/issues/23416
This PR reverts #29543 and instead implements proper support for "=*m" and "+*m" indirect output operands. This provides a framework on top of which support for plain memory operands ("m", "=m" and "+m") can be implemented.
This also fixes the liveness analysis pass not handling read/write operands correctly.
This commit is the standard API stabilization commit for the 1.6 release cycle.
The list of issues and APIs below have all been through their cycle-long FCP and
the libs team decisions are listed below
Stabilized APIs
* `Read::read_exact`
* `ErrorKind::UnexpectedEof` (renamed from `UnexpectedEOF`)
* libcore -- this was a bit of a nuanced stabilization, the crate itself is now
marked as `#[stable]` and the methods appearing via traits for primitives like
`char` and `str` are now also marked as stable. Note that the extension traits
themeselves are marked as unstable as they're imported via the prelude. The
`try!` macro was also moved from the standard library into libcore to have the
same interface. Otherwise the functions all have copied stability from the
standard library now.
* The `#![no_std]` attribute
* `fs::DirBuilder`
* `fs::DirBuilder::new`
* `fs::DirBuilder::recursive`
* `fs::DirBuilder::create`
* `os::unix::fs::DirBuilderExt`
* `os::unix::fs::DirBuilderExt::mode`
* `vec::Drain`
* `vec::Vec::drain`
* `string::Drain`
* `string::String::drain`
* `vec_deque::Drain`
* `vec_deque::VecDeque::drain`
* `collections::hash_map::Drain`
* `collections::hash_map::HashMap::drain`
* `collections::hash_set::Drain`
* `collections::hash_set::HashSet::drain`
* `collections::binary_heap::Drain`
* `collections::binary_heap::BinaryHeap::drain`
* `Vec::extend_from_slice` (renamed from `push_all`)
* `Mutex::get_mut`
* `Mutex::into_inner`
* `RwLock::get_mut`
* `RwLock::into_inner`
* `Iterator::min_by_key` (renamed from `min_by`)
* `Iterator::max_by_key` (renamed from `max_by`)
Deprecated APIs
* `ErrorKind::UnexpectedEOF` (renamed to `UnexpectedEof`)
* `OsString::from_bytes`
* `OsStr::to_cstring`
* `OsStr::to_bytes`
* `fs::walk_dir` and `fs::WalkDir`
* `path::Components::peek`
* `slice::bytes::MutableByteVector`
* `slice::bytes::copy_memory`
* `Vec::push_all` (renamed to `extend_from_slice`)
* `Duration::span`
* `IpAddr`
* `SocketAddr::ip`
* `Read::tee`
* `io::Tee`
* `Write::broadcast`
* `io::Broadcast`
* `Iterator::min_by` (renamed to `min_by_key`)
* `Iterator::max_by` (renamed to `max_by_key`)
* `net::lookup_addr`
New APIs (still unstable)
* `<[T]>::sort_by_key` (added to mirror `min_by_key`)
Closes#27585Closes#27704Closes#27707Closes#27710Closes#27711Closes#27727Closes#27740Closes#27744Closes#27799Closes#27801
cc #27801 (doesn't close as `Chars` is still unstable)
Closes#28968
nodes in statement position.
Extended #[cfg] folder to allow removal of statements, and
of expressions in optional positions like expression lists and trailing
block expressions.
Extended lint checker to recognize lint levels on expressions and
locals.
This commit generalises parsing of associative operators from left-associative
only (with some ugly hacks to support right-associative assignment) to properly
left/right-associative operators.
Parsing still is not general enough to handle non-associative,
non-highest-precedence prefix or non-highest-precedence postfix operators (e.g.
`..` range syntax), though. That should be fixed in the future.
Lastly, this commit adds support for parsing right-associative `<-` (left arrow)
operator with precedence higher than assignment as the operator for placement-in
feature.
This PR switches the implemented ordering from `unsafe const fn` (as was in the original RFC) to `const unsafe fn` (which is what the lang team decided on)
This PR removes random remaining `Ident`s outside of libsyntax and performs general cleanup
In particular, interfaces of `Name` and `Ident` are tidied up, `Name`s and `Ident`s being small `Copy` aggregates are always passed to functions by value, and `Ident`s are never used as keys in maps, because `Ident` comparisons are tricky.
Although this PR closes https://github.com/rust-lang/rust/issues/6993 there's still work related to it:
- `Name` can be made `NonZero` to compress numerous `Option<Name>`s and `Option<Ident>`s but it requires const unsafe functions.
- Implementation of `PartialEq` on `Ident` should be eliminated and replaced with explicit hygienic, non-hygienic or member-wise comparisons.
- Finally, large parts of AST can potentially be converted to `Name`s in the same way as HIR to clearly separate identifiers used in hygienic and non-hygienic contexts.
r? @nrc
Make sure Name, SyntaxContext and Ident are passed by value
Make sure Idents don't serve as keys (or parts of keys) in maps, Ident comparison is not well defined
In the case where there are no paren in the AST, the pretty printer doesn't correctly print binary operations where precedence is concerned. Parenthesis may be missing due to some kind of expansion or manipulation of the AST.
Example:
Pretty printer prints Expr(*, Expr(+, 1, 1), 2) as 1 + 1 * 2, as opposed to (1 + 1) * 2
r? @nrc
