about summary refs log tree commit diff
path: root/src/librustc_feature
AgeCommit message (Collapse)AuthorLines
2020-08-30mv compiler to compiler/mark-1765/+0
2020-08-22Auto merge of #74566 - lzutao:guard, r=petrochenkovbors-0/+4
Gate if-let guard feature Enhanced on #74315. That PR is in crater queue so I don't want to push to it. Close #74232 cc #51114
2020-08-08fix `min_const_generics` versionBastian Kauschke-1/+1
2020-08-08Gate to if-let guard featureLzu Tao-0/+4
2020-08-08Auto merge of #74877 - lcnr:min_const_generics, r=oli-obkbors-0/+3
Implement the `min_const_generics` feature gate Implements both https://github.com/rust-lang/lang-team/issues/37 and https://github.com/rust-lang/compiler-team/issues/332. Adds the new feature gate `#![feature(min_const_generics)]`. This feature gate adds the following limitations to using const generics: - generic parameters must only be used in types if they are trivial. (either `N` or `{ N }`) - generic parameters must be either integers, `bool` or `char`. We do allow arbitrary expressions in associated consts though, meaning that the following is allowed, even if `<[u8; 0] as Foo>::ASSOC` is not const evaluatable. ```rust trait Foo { const ASSOC: usize; } impl<const N: usize> Foo for [u8; N] { const ASSOC: usize = 64 / N; } ``` r? @varkor cc @eddyb @withoutboats
2020-08-05add tracking issueBastian Kauschke-1/+1
2020-08-05add min_const_generics feature gateBastian Kauschke-0/+3
2020-08-05Fix typo in `librustc_feature/active.rs`Waffle Lapkin-1/+1
2020-07-22Rollup merge of #73868 - ecstatic-morse:fix-stable-version, r=jonas-schievinkManish Goregaokar-2/+2
Advertise correct stable version for const control flow #72437 was opened before the 1.45 release but merged afterwards. These will be stable in 1.46.
2020-07-20mir: use attribute over `-Z polymorphize-errors`David Wood-0/+1
This commit replaces the `-Z polymorphize-errors` debugging flag with a `#[rustc_polymorphize_error]` attribute for use on functions. Signed-off-by: David Wood <david@davidtw.co>
2020-07-19Advertise correct stable version for const control flowDylan MacKenzie-2/+2
2020-07-16Revert "Remove "important traits" feature"Manish Goregaokar-0/+3
This reverts commit 1244ced9580b942926afc06815e0691cf3f4a846.
2020-07-11Rollup merge of #72920 - oli-obk:const_transmute, r=RalfJungManish Goregaokar-0/+3
Stabilize `transmute` in constants and statics but not const fn cc #53605 (leaving issue open so we can add `transmute` to `const fn` later) Previous attempt: #64011 r? @RalfJung cc @rust-lang/wg-const-eval
2020-07-11Stabilize `transmute` in constants and statics but not const fnOliver Scherer-0/+3
2020-07-10Avoid "whitelist"Tamir Duberstein-72/+72
Other terms are more inclusive and precise.
2020-07-04add `lazy_normalization_consts` feature gateBastian Kauschke-0/+4
2020-07-03Rollup merge of #73670 - davidhewitt:format-args-capture, r=varkorManish Goregaokar-0/+3
Add `format_args_capture` feature This is the initial implementation PR for [RFC 2795](https://github.com/rust-lang/rfcs/pull/2795). Note that, as dicussed in the tracking issue (#67984), the feature gate has been called `format_args_capture`. Next up I guess I need to add documentation for this feature. I've not written any docs before for rustc / std so I would appreciate suggestions on where I should add docs.
2020-06-30Stabilize `#[track_caller]`.Adam Perry-5/+4
Does not yet make its constness stable, though. Use of `Location::caller` in const contexts is still gated by `#![feature(const_caller_location)]`.
2020-06-28Mark `const_loop` feature gate as acceptedDylan MacKenzie-3/+2
2020-06-28Mark feature gate as acceptedDylan MacKenzie-3/+2
2020-06-24Add `format_args_capture` featureDavid Hewitt-0/+3
2020-06-23Rollup merge of #73398 - oli-obk:const_raw_ptr_cmp, r=varkor,RalfJung,nagisaManish Goregaokar-3/+5
A way forward for pointer equality in const eval r? @varkor on the first commit and @RalfJung on the second commit cc #53020
2020-06-19Remove the const_raw_ptr_comparison feature gate.Oliver Scherer-3/+5
We can never supply a meaningful implementation of this. Instead, the follow up commits will create two intrinsics that approximate comparisons: * `ptr_maybe_eq` * `ptr_maybe_ne` The fact that `ptr_maybe_eq(a, b)` is not necessarily the same value as `!ptr_maybe_ne(a, b)` is a symptom of this entire problem.
2020-06-16warn against 'specialization' featureRalf Jung-0/+1
2020-06-13Add feature gate for precise live drop checkingDylan MacKenzie-0/+3
2020-06-09[AVR] Raise and link to a tracking issue for the `avr-interrupt` calling ↵Dylan McKay-3/+3
convention Also fix the order of the feature gate to fix the tidy errors.
2020-06-09[AVR] Add AVR platform supportJake Goulding-0/+3
2020-05-29Rollup merge of #71862 - LeSeulArtichaut:unsafe-block-in-unsafe-fn, ↵Ralf Jung-0/+3
r=nikomatsakis Implement RFC 2585: unsafe blocks in unsafe fn Tracking issue: #71668 r? @RalfJung cc @nikomatsakis
2020-05-29Whitelist #[allow_internal_unstable]Jonas Schievink-1/+1
This should hopefully work around https://github.com/rust-lang/rust/issues/65023, which currently makes almost every bootstrap fail for me.
2020-05-27Implement RFC 2585LeSeulArtichaut-0/+3
2020-05-20Implement `#[ffi_const]` and `#[ffi_pure]` function attributesMatthias Schiffer-0/+8
Introduce function attribute corresponding to the `const`/`pure` attributes supported by GCC, clang and other compilers. Based on the work of gnzlbg <gonzalobg88@gmail.com>.
2020-05-19Auto merge of #69171 - Amanieu:new-asm, r=nagisa,nikomatsakisbors-0/+1
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`.
2020-05-18Minor fixesAmanieu d'Antras-1/+1
2020-05-18Add RISC-V target featuresAmanieu d'Antras-0/+1
2020-05-03Stabilize fn-like proc macros in expression, pattern and statement positionsVadim Petrochenkov-2/+1
2020-05-03Implement RFC 2523, `#[cfg(version(..))]`mibac138-0/+4
2020-05-01Allow `#[target_feature]` on safe functionsLeSeulArtichaut-0/+3
2020-03-29#[link]: mention wasm_import_module instead of cfgJonas Schievink-1/+1
2020-03-29Auto merge of #70370 - petrochenkov:nosmatch, r=Centrilbors-5/+2
Remove attribute `#[structural_match]` and any references to it A small remaining part of https://github.com/rust-lang/rust/issues/63438.
2020-03-26bump negative impls version to 1.44.0Niko Matsakis-1/+1
2020-03-26create a tracking issue and link to itNiko Matsakis-3/+3
2020-03-26introduce `negative_impls` feature gate and documentNiko Matsakis-0/+3
They used to be covered by `optin_builtin_traits` but negative impls are now applicable to all traits, not just auto traits. This also adds docs in the unstable book for the current state of auto traits.
2020-03-24Remove attribute `#[structural_match]` and any references to itVadim Petrochenkov-5/+2
2020-03-22remove redundant closures (clippy::redundant_closure)Matthias Krüger-1/+1
2020-03-17Rollup merge of #69870 - petrochenkov:cfgacc, r=matthewjasperMazdak Farrokhzad-7/+1
expand: Implement something similar to `#[cfg(accessible(path))]` cc https://github.com/rust-lang/rust/issues/64797 The feature is implemented as a `#[cfg_accessible(path)]` attribute macro rather than as `#[cfg(accessible(path))]` because it needs to wait until `path` becomes resolvable, and `cfg` cannot wait, but macros can wait. Later we can think about desugaring or not desugaring `#[cfg(accessible(path))]` into `#[cfg_accessible(path)]`. This implementation is also incomplete in the sense that it never returns "false" from `cfg_accessible(path)`, it requires some tweaks to resolve, which is not quite ready to answer queries like this during early resolution. However, the most important part of this PR is not `cfg_accessible` itself, but expansion infrastructure for retrying expansions. Before this PR we could say "we cannot resolve this macro path, let's try it later", with this PR we can say "we cannot expand this macro, let's try it later" as well. This is a pre-requisite for - turning `#[derive(...)]` into a regular attribute macro, - properly supporting eager expansion for macros that cannot yet be resolved like ``` fn main() { println!(not_available_yet!()); } macro_rules! make_available { () => { #[macro_export] macro_rules! not_available_yet { () => { "Hello world!" } }} } make_available!(); ```
2020-03-15Add attributes to allow specializing on traitsMatthew Jasper-0/+8
2020-03-15Add `min_specialization` featureMatthew Jasper-0/+5
Currently the only difference between it and `specialization` is that it only allows specializing functions.
2020-03-10Rollup merge of #69514 - GuillaumeGomez:remove-spotlight, r=kinnisonMazdak Farrokhzad-3/+0
Remove spotlight I had a few comments saying that this feature was at best misunderstood or not even used so I decided to organize a poll about on [twitter](https://twitter.com/imperioworld_/status/1232769353503956994). After 87 votes, the result is very clear: it's not useful. Considering the amount of code we have just to run it, I think it's definitely worth it to remove it. r? @kinnison cc @ollie27
2020-03-09expand/builtin_macros: Minor cleanupVadim Petrochenkov-7/+1
2020-03-08Rollup merge of #69561 - JohnTitor:clean-up-unstable-book, r=Mark-SimulacrumMazdak Farrokhzad-3/+3
Clean up unstable book - #58402's feature was renamed to `tidy_test_never_used_anywhere_else` and it is now used for tidy only - `read_initializer` link is wrong and the doc should be auto-generated so removed - Add dummy doc for `link_cfg` - Stop generating `compiler_builtins_lib` doc in favor of b8ccc0f8a60ac16fdc00f4b2e36e1a5db8b78295 - Make `rustc_attrs` tracking issue "None"
generated by cgit-pink 1.4.1-3-g733a5 (git 2.37.1) at 2026-02-24 03:16:27 +0000