Update Clippy, RLS, and rustfmt
r? @Dylan-DPC
This makes Clippy test-pass again: 3089c3b
Otherwise this includes bugfixes and a few new lints.
Fixes#72231Fixes#72232
Stabilize str_strip feature
This PR stabilizes these APIs:
```rust
impl str {
/// Returns a string slice with the prefix removed.
///
/// If the string starts with the pattern `prefix`, `Some` is returned with the substring where
/// the prefix is removed. Unlike `trim_start_matches`, this method removes the prefix exactly
/// once.
pub fn strip_prefix<'a, P: Pattern<'a>>(&'a self, prefix: P) -> Option<&'a str>;
/// Returns a string slice with the suffix removed.
///
/// If the string ends with the pattern `suffix`, `Some` is returned with the substring where
/// the suffix is removed. Unlike `trim_end_matches`, this method removes the suffix exactly
/// once.
pub fn strip_suffix<'a, P>(&'a self, suffix: P) -> Option<&'a str>
where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>;
}
```
Closes #67302
Pass more `Copy` types by value.
There are a lot of locations where we pass `&T where T: Copy` by reference,
which should both be slightly less performant and less readable IMO.
This PR currently consists of three fairly self contained commits:
- passes `ty::Predicate` by value and stops depending on `AsRef<ty::Predicate>`.
- changes `<&List<_>>::into_iter` to iterate over the elements by value. This would break `List`s
of non copy types. But as the only list constructor requires `T` to be copy anyways, I think
the improved readability is worth this potential future restriction.
- passes `mir::PlaceElem` by value. Mir currently has quite a few copy types which are passed by reference, e.g. `Local`. As I don't have a lot of experience working with MIR, I mostly did this to get some feedback from people who use MIR more frequently
- tries to reuse `ty::Predicate` in case it did not change in some places, which should hopefully
fix the regression caused by #72055
r? @nikomatsakis for the first commit, which continues the work of #72055 and makes adding `PredicateKind::ForAll` slightly more pleasant. Feel free to reassign though
Shebang handling was too agressive in stripping out the first line in cases where it is actually _not_ a shebang, but instead, valid rust (#70528). This is a second attempt at resolving this issue (the first attempt was flawed, for, among other reasons, causing an ICE in certain cases (#71372, #71471).
The behavior is now codified by a number of UI tests, but simply:
For the first line to be a shebang, the following must all be true:
1. The line must start with `#!`
2. The line must contain a non whitespace character after `#!`
3. The next character in the file, ignoring comments & whitespace must not be `[`
I believe this is a strict superset of what we used to allow, so perhaps a crater run is unnecessary, but probably not a terrible idea.
Rollup of 7 pull requests
Successful merges:
- #71289 (Allow using `Self::` in doc)
- #72375 (Improve E0599 explanation)
- #72385 (Add some teams to prioritization exclude_labels)
- #72395 (Allow rust-highfive to label issues it creates.)
- #72453 (Add flag to open docs: x.py doc --open)
- #72459 (Add core::future::IntoFuture)
- #72461 (Clean up E0600 explanation)
Failed merges:
r? @ghost
Allow rust-highfive to label issues it creates.
This is my first meaningful PR, I am unsure how to test this code so any pointers would be welcome!
I am about 50% sure it works.
Update cargo
9 commits in cb06cb2696df2567ce06d1a39b1b40612a29f853..500b2bd01c958f5a33b6aa3f080bea015877b83c
2020-05-08 21:57:44 +0000 to 2020-05-18 17:12:54 +0000
- Handle LTO with an rlib/cdylib crate type (rust-lang/cargo#8254)
- Gracefully handle errors during a build. (rust-lang/cargo#8247)
- Update `im-rc` to 15.0.0 (rust-lang/cargo#8255)
- Fix `cargo update` with unused patch. (rust-lang/cargo#8243)
- Rephrased error message for disallowed sections in virtual workspace (rust-lang/cargo#8200)
- Ignore broken console output in some situations. (rust-lang/cargo#8236)
- Expand error message to explain that a string was found (rust-lang/cargo#8235)
- Add context to some fs errors. (rust-lang/cargo#8232)
- Move SipHasher to an isolated module. (rust-lang/cargo#8233)
Implement new asm! syntax from RFC 2850
This PR implements the new `asm!` syntax proposed in https://github.com/rust-lang/rfcs/pull/2850.
# Design
A large part of this PR revolves around taking an `asm!` macro invocation and plumbing it through all of the compiler layers down to LLVM codegen. Throughout the various stages, an `InlineAsm` generally consists of 3 components:
- The template string, which is stored as an array of `InlineAsmTemplatePiece`. Each piece represents either a literal or a placeholder for an operand (just like format strings).
```rust
pub enum InlineAsmTemplatePiece {
String(String),
Placeholder { operand_idx: usize, modifier: Option<char>, span: Span },
}
```
- The list of operands to the `asm!` (`in`, `[late]out`, `in[late]out`, `sym`, `const`). These are represented differently at each stage of lowering, but follow a common pattern:
- `in`, `out` and `inout` all have an associated register class (`reg`) or explicit register (`"eax"`).
- `inout` has 2 forms: one with a single expression that is both read from and written to, and one with two separate expressions for the input and output parts.
- `out` and `inout` have a `late` flag (`lateout` / `inlateout`) to indicate that the register allocator is allowed to reuse an input register for this output.
- `out` and the split variant of `inout` allow `_` to be specified for an output, which means that the output is discarded. This is used to allocate scratch registers for assembly code.
- `sym` is a bit special since it only accepts a path expression, which must point to a `static` or a `fn`.
- The options set at the end of the `asm!` macro. The only one that is particularly of interest to rustc is `NORETURN` which makes `asm!` return `!` instead of `()`.
```rust
bitflags::bitflags! {
pub struct InlineAsmOptions: u8 {
const PURE = 1 << 0;
const NOMEM = 1 << 1;
const READONLY = 1 << 2;
const PRESERVES_FLAGS = 1 << 3;
const NORETURN = 1 << 4;
const NOSTACK = 1 << 5;
}
}
```
## AST
`InlineAsm` is represented as an expression in the AST:
```rust
pub struct InlineAsm {
pub template: Vec<InlineAsmTemplatePiece>,
pub operands: Vec<(InlineAsmOperand, Span)>,
pub options: InlineAsmOptions,
}
pub enum InlineAsmRegOrRegClass {
Reg(Symbol),
RegClass(Symbol),
}
pub enum InlineAsmOperand {
In {
reg: InlineAsmRegOrRegClass,
expr: P<Expr>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: Option<P<Expr>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: P<Expr>,
},
SplitInOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_expr: P<Expr>,
out_expr: Option<P<Expr>>,
},
Const {
expr: P<Expr>,
},
Sym {
expr: P<Expr>,
},
}
```
The `asm!` macro is implemented in librustc_builtin_macros and outputs an `InlineAsm` AST node. The template string is parsed using libfmt_macros, positional and named operands are resolved to explicit operand indicies. Since target information is not available to macro invocations, validation of the registers and register classes is deferred to AST lowering.
## HIR
`InlineAsm` is represented as an expression in the HIR:
```rust
pub struct InlineAsm<'hir> {
pub template: &'hir [InlineAsmTemplatePiece],
pub operands: &'hir [InlineAsmOperand<'hir>],
pub options: InlineAsmOptions,
}
pub enum InlineAsmRegOrRegClass {
Reg(InlineAsmReg),
RegClass(InlineAsmRegClass),
}
pub enum InlineAsmOperand<'hir> {
In {
reg: InlineAsmRegOrRegClass,
expr: Expr<'hir>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: Option<Expr<'hir>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: Expr<'hir>,
},
SplitInOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_expr: Expr<'hir>,
out_expr: Option<Expr<'hir>>,
},
Const {
expr: Expr<'hir>,
},
Sym {
expr: Expr<'hir>,
},
}
```
AST lowering is where `InlineAsmRegOrRegClass` is converted from `Symbol`s to an actual register or register class. If any modifiers are specified for a template string placeholder, these are validated against the set allowed for that operand type. Finally, explicit registers for inputs and outputs are checked for conflicts (same register used for different operands).
## Type checking
Each register class has a whitelist of types that it may be used with. After the types of all operands have been determined, the `intrinsicck` pass will check that these types are in the whitelist. It also checks that split `inout` operands have compatible types and that `const` operands are integers or floats. Suggestions are emitted where needed if a template modifier should be used for an operand based on the type that was passed into it.
## HAIR
`InlineAsm` is represented as an expression in the HAIR:
```rust
crate enum ExprKind<'tcx> {
// [..]
InlineAsm {
template: &'tcx [InlineAsmTemplatePiece],
operands: Vec<InlineAsmOperand<'tcx>>,
options: InlineAsmOptions,
},
}
crate enum InlineAsmOperand<'tcx> {
In {
reg: InlineAsmRegOrRegClass,
expr: ExprRef<'tcx>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: Option<ExprRef<'tcx>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: ExprRef<'tcx>,
},
SplitInOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_expr: ExprRef<'tcx>,
out_expr: Option<ExprRef<'tcx>>,
},
Const {
expr: ExprRef<'tcx>,
},
SymFn {
expr: ExprRef<'tcx>,
},
SymStatic {
expr: ExprRef<'tcx>,
},
}
```
The only significant change compared to HIR is that `Sym` has been lowered to either a `SymFn` whose `expr` is a `Literal` ZST of the `fn`, or a `SymStatic` whose `expr` is a `StaticRef`.
## MIR
`InlineAsm` is represented as a `Terminator` in the MIR:
```rust
pub enum TerminatorKind<'tcx> {
// [..]
/// Block ends with an inline assembly block. This is a terminator since
/// inline assembly is allowed to diverge.
InlineAsm {
/// The template for the inline assembly, with placeholders.
template: &'tcx [InlineAsmTemplatePiece],
/// The operands for the inline assembly, as `Operand`s or `Place`s.
operands: Vec<InlineAsmOperand<'tcx>>,
/// Miscellaneous options for the inline assembly.
options: InlineAsmOptions,
/// Destination block after the inline assembly returns, unless it is
/// diverging (InlineAsmOptions::NORETURN).
destination: Option<BasicBlock>,
},
}
pub enum InlineAsmOperand<'tcx> {
In {
reg: InlineAsmRegOrRegClass,
value: Operand<'tcx>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
place: Option<Place<'tcx>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_value: Operand<'tcx>,
out_place: Option<Place<'tcx>>,
},
Const {
value: Operand<'tcx>,
},
SymFn {
value: Box<Constant<'tcx>>,
},
SymStatic {
value: Box<Constant<'tcx>>,
},
}
```
As part of HAIR lowering, `InOut` and `SplitInOut` operands are lowered to a split form with a separate `in_value` and `out_place`.
Semantically, the `InlineAsm` terminator is similar to the `Call` terminator except that it has multiple output places where a `Call` only has a single return place output.
The constant promotion pass is used to ensure that `const` operands are actually constants (using the same logic as `#[rustc_args_required_const]`).
## Codegen
Operands are lowered one more time before being passed to LLVM codegen:
```rust
pub enum InlineAsmOperandRef<'tcx, B: BackendTypes + ?Sized> {
In {
reg: InlineAsmRegOrRegClass,
value: OperandRef<'tcx, B::Value>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
place: Option<PlaceRef<'tcx, B::Value>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_value: OperandRef<'tcx, B::Value>,
out_place: Option<PlaceRef<'tcx, B::Value>>,
},
Const {
string: String,
},
SymFn {
instance: Instance<'tcx>,
},
SymStatic {
def_id: DefId,
},
}
```
The operands are lowered to LLVM operands and constraint codes as follow:
- `out` and the output part of `inout` operands are added first, as required by LLVM. Late output operands have a `=` prefix added to their constraint code, non-late output operands have a `=&` prefix added to their constraint code.
- `in` operands are added normally.
- `inout` operands are tied to the matching output operand.
- `sym` operands are passed as function pointers or pointers, using the `"s"` constraint.
- `const` operands are formatted to a string and directly inserted in the template string.
The template string is converted to LLVM form:
- `$` characters are escaped as `$$`.
- `const` operands are converted to strings and inserted directly.
- Placeholders are formatted as `${X:M}` where `X` is the operand index and `M` is the modifier character. Modifiers are converted from the Rust form to the LLVM form.
The various options are converted to clobber constraints or LLVM attributes, refer to the [RFC](https://github.com/Amanieu/rfcs/blob/inline-asm/text/0000-inline-asm.md#mapping-to-llvm-ir) for more details.
Note that LLVM is sometimes rather picky about what types it accepts for certain constraint codes so we sometimes need to insert conversions to/from a supported type. See the target-specific ISelLowering.cpp files in LLVM for details.
# Adding support for new architectures
Adding inline assembly support to an architecture is mostly a matter of defining the registers and register classes for that architecture. All the definitions for register classes are located in `src/librustc_target/asm/`.
Additionally you will need to implement lowering of these register classes to LLVM constraint codes in `src/librustc_codegen_llvm/asm.rs`.
Literal error reporting cleanup
While doing some performance work, I noticed some code duplication in `librustc_parser/lexer/mod.rs`, so I cleaned it up.
This PR is probably best reviewed commit by commit.
I'm not sure what the API stability practices for `librustc_lexer` are. Four public methods in `unescape.rs` can be removed, but two are used by clippy, so I left them in for now.
I could open a PR for Rust-Analyzer when this one lands.
But how do I open a PR for clippy? (Git submodules are frustrating to work with)
rustc_driver: factor out computing the exit code
In a recent Miri PR I [added a convenience wrapper](https://github.com/rust-lang/miri/pull/1405/files#diff-c3d602c5c8035a16699ce9c015bfeceaR125) around `catch_fatal_errors` and `run_compiler` that @oli-obk suggested I could upstream. However, after seeing what could be shared between `rustc_driver::main`, clippy and Miri, really the only thing I found is computing the exit code -- so that's what this PR does.
What prevents using the Miri convenience function in `rustc_driver::main` and clippy is that they do extra work inside `catch_fatal_errors`, and while I could abstract that away, clippy actually *computes the callbacks* inside there, and I fond no good way to abstract that and thus gave up. Maybe the clippy thing could be moved out, I am not sure if it ever can actually raise a `FatalErrorMarker` -- someone more knowledgeable in clippy would have to do that.
Doc alias improvements
After [this message](https://github.com/rust-lang/rust/issues/50146#issuecomment-496601755), I realized that the **doc alias**. So this PR does the followings:
* Align the alias discovery on items added into the search-index. It brings a few nice advantages:
* Instead of cloning the data between the two (in rustdoc source code), we now have the search-index one and aliases which reference to the first one. So we go from one big map containing a lot of duplicated data to just integers...
* In the front-end (main.js), I improved the code around aliases to allow them to go through the same transformation as other items when we show the search results.
* Improve the search tester in order to perform multiple requests into one file (I think it's better in this case than having a file for each case considering how many there are...)
* I also had to add the new function inside the tester (`handleAliases`)
Once this PR is merged, I intend to finally stabilize this feature.
r? @ollie27
cc @rust-lang/rustdoc
bootstrap: remove lldb dist packaging
The lldb-preview rustup package is missing on every single target, and has never been shipped beyond x86_64-apple-darwin. It was removed in #62592 which landed around a year ago, and there's not been demand that we re-enable it since, so we're now removing support entirely to cleanup the code a bit.
The hope is that this will also kill the useless "lldb-preview" row on https://rust-lang.github.io/rustup-components-history/.
Update Clippy to 43a1777
Updates Clippy to 43a1777b89
We should establish a process on how often and when to update Clippy. (After X feature PRs? Once per week? Only on bug fixes and in the release week? ...?)
r? @oli-obk
