diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs index 8f18e0312862f..25cbf8c88debb 100644 --- a/src/librustc/dep_graph/graph.rs +++ b/src/librustc/dep_graph/graph.rs @@ -30,7 +30,7 @@ rustc_index::newtype_index! { } impl DepNodeIndex { - const INVALID: DepNodeIndex = DepNodeIndex::MAX; + pub const INVALID: DepNodeIndex = DepNodeIndex::MAX; } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)] diff --git a/src/librustc/hir/map/def_collector.rs b/src/librustc/hir/map/def_collector.rs index 1997e2aab35e8..ca6b2d03001ce 100644 --- a/src/librustc/hir/map/def_collector.rs +++ b/src/librustc/hir/map/def_collector.rs @@ -90,7 +90,7 @@ impl<'a> DefCollector<'a> { } } - pub fn visit_macro_invoc(&mut self, id: NodeId) { + fn visit_macro_invoc(&mut self, id: NodeId) { self.definitions.set_invocation_parent(id.placeholder_to_expn_id(), self.parent_def); } } diff --git a/src/librustc_metadata/creader.rs b/src/librustc_metadata/creader.rs index 042252bc13e61..50a2187c93740 100644 --- a/src/librustc_metadata/creader.rs +++ b/src/librustc_metadata/creader.rs @@ -3,10 +3,11 @@ use crate::cstore::{self, CStore, CrateSource, MetadataBlob}; use crate::locator::{self, CratePaths}; use crate::schema::{CrateRoot, CrateDep}; -use rustc_data_structures::sync::{Lrc, RwLock, Lock}; +use rustc_data_structures::sync::{Lrc, RwLock, Lock, AtomicCell}; use rustc::hir::def_id::CrateNum; use rustc_data_structures::svh::Svh; +use rustc::dep_graph::DepNodeIndex; use rustc::middle::cstore::DepKind; use rustc::mir::interpret::AllocDecodingState; use rustc::session::{Session, CrateDisambiguator}; @@ -196,6 +197,9 @@ impl<'a> CrateLoader<'a> { dep_kind: DepKind, name: Symbol ) -> (CrateNum, Lrc) { + let _prof_timer = + self.sess.prof.generic_activity("metadata_register_crate"); + let crate_root = lib.metadata.get_root(); self.verify_no_symbol_conflicts(span, &crate_root); @@ -271,7 +275,8 @@ impl<'a> CrateLoader<'a> { }, private_dep, span, - raw_proc_macros + raw_proc_macros, + dep_node_index: AtomicCell::new(DepNodeIndex::INVALID), }; let cmeta = Lrc::new(cmeta); diff --git a/src/librustc_metadata/cstore.rs b/src/librustc_metadata/cstore.rs index 833c846573f63..98a08e501f14c 100644 --- a/src/librustc_metadata/cstore.rs +++ b/src/librustc_metadata/cstore.rs @@ -2,6 +2,7 @@ // crates and libraries use crate::schema; +use rustc::dep_graph::DepNodeIndex; use rustc::hir::def_id::{CrateNum, DefIndex}; use rustc::hir::map::definitions::DefPathTable; use rustc::middle::cstore::{DepKind, ExternCrate, MetadataLoader}; @@ -9,7 +10,7 @@ use rustc::mir::interpret::AllocDecodingState; use rustc_index::vec::IndexVec; use rustc::util::nodemap::{FxHashMap, NodeMap}; -use rustc_data_structures::sync::{Lrc, RwLock, Lock}; +use rustc_data_structures::sync::{Lrc, RwLock, Lock, AtomicCell}; use syntax::ast; use syntax::ext::base::SyntaxExtension; use syntax_pos; @@ -83,6 +84,13 @@ pub struct CrateMetadata { pub span: Span, pub raw_proc_macros: Option<&'static [ProcMacro]>, + + /// The `DepNodeIndex` of the `DepNode` representing this upstream crate. + /// It is initialized on the first access in `get_crate_dep_node_index()`. + /// Do not access the value directly, as it might not have been initialized + /// yet. + /// The field must always be initialized to `DepNodeIndex::INVALID`. + pub(super) dep_node_index: AtomicCell, } pub struct CStore { diff --git a/src/librustc_metadata/cstore_impl.rs b/src/librustc_metadata/cstore_impl.rs index 6dab9a404b74a..642a7632b3df8 100644 --- a/src/librustc_metadata/cstore_impl.rs +++ b/src/librustc_metadata/cstore_impl.rs @@ -48,23 +48,22 @@ macro_rules! provide { $tcx: TyCtxt<$lt>, def_id_arg: T, ) -> as QueryConfig<$lt>>::Value { + let _prof_timer = + $tcx.prof.generic_activity("metadata_decode_entry"); + #[allow(unused_variables)] let ($def_id, $other) = def_id_arg.into_args(); assert!(!$def_id.is_local()); - let def_path_hash = $tcx.def_path_hash(DefId { - krate: $def_id.krate, - index: CRATE_DEF_INDEX - }); - let dep_node = def_path_hash - .to_dep_node(rustc::dep_graph::DepKind::CrateMetadata); - // The DepNodeIndex of the DepNode::CrateMetadata should be - // cached somewhere, so that we can use read_index(). - $tcx.dep_graph.read(dep_node); - let $cdata = $tcx.crate_data_as_rc_any($def_id.krate); let $cdata = $cdata.downcast_ref::() .expect("CrateStore created data is not a CrateMetadata"); + + if $tcx.dep_graph.is_fully_enabled() { + let crate_dep_node_index = $cdata.get_crate_dep_node_index($tcx); + $tcx.dep_graph.read_index(crate_dep_node_index); + } + $compute })* @@ -449,6 +448,8 @@ impl cstore::CStore { } pub fn load_macro_untracked(&self, id: DefId, sess: &Session) -> LoadedMacro { + let _prof_timer = sess.prof.generic_activity("metadata_load_macro"); + let data = self.get_crate_data(id.krate); if data.is_proc_macro_crate() { return LoadedMacro::ProcMacro(data.load_proc_macro(id.index, sess)); @@ -526,20 +527,10 @@ impl CrateStore for cstore::CStore { /// parent `DefId` as well as some idea of what kind of data the /// `DefId` refers to. fn def_key(&self, def: DefId) -> DefKey { - // Note: loading the def-key (or def-path) for a def-id is not - // a *read* of its metadata. This is because the def-id is - // really just an interned shorthand for a def-path, which is the - // canonical name for an item. - // - // self.dep_graph.read(DepNode::MetaData(def)); self.get_crate_data(def.krate).def_key(def.index) } fn def_path(&self, def: DefId) -> DefPath { - // See `Note` above in `def_key()` for why this read is - // commented out: - // - // self.dep_graph.read(DepNode::MetaData(def)); self.get_crate_data(def.krate).def_path(def.index) } diff --git a/src/librustc_metadata/decoder.rs b/src/librustc_metadata/decoder.rs index 3b655023d28e4..132ef7d424131 100644 --- a/src/librustc_metadata/decoder.rs +++ b/src/librustc_metadata/decoder.rs @@ -13,6 +13,7 @@ use rustc::hir::def::{self, Res, DefKind, CtorOf, CtorKind}; use rustc::hir::def_id::{CrateNum, DefId, DefIndex, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE}; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::FxHashMap; +use rustc::dep_graph::{DepNodeIndex, DepKind}; use rustc::middle::lang_items; use rustc::mir::{self, interpret}; use rustc::mir::interpret::AllocDecodingSession; @@ -1365,6 +1366,30 @@ impl<'a, 'tcx> CrateMetadata { // This shouldn't borrow twice, but there is no way to downgrade RefMut to Ref. self.source_map_import_info.borrow() } + + /// Get the `DepNodeIndex` corresponding this crate. The result of this + /// method is cached in the `dep_node_index` field. + pub(super) fn get_crate_dep_node_index(&self, tcx: TyCtxt<'tcx>) -> DepNodeIndex { + let mut dep_node_index = self.dep_node_index.load(); + + if unlikely!(dep_node_index == DepNodeIndex::INVALID) { + // We have not cached the DepNodeIndex for this upstream crate yet, + // so use the dep-graph to find it out and cache it. + // Note that multiple threads can enter this block concurrently. + // That is fine because the DepNodeIndex remains constant + // throughout the whole compilation session, and multiple stores + // would always write the same value. + + let def_path_hash = self.def_path_hash(CRATE_DEF_INDEX); + let dep_node = def_path_hash.to_dep_node(DepKind::CrateMetadata); + + dep_node_index = tcx.dep_graph.dep_node_index_of(&dep_node); + assert!(dep_node_index != DepNodeIndex::INVALID); + self.dep_node_index.store(dep_node_index); + } + + dep_node_index + } } // Cannot be implemented on 'ProcMacro', as libproc_macro diff --git a/src/librustc_metadata/lib.rs b/src/librustc_metadata/lib.rs index 9273b064ba9ce..6aa684b1c3d01 100644 --- a/src/librustc_metadata/lib.rs +++ b/src/librustc_metadata/lib.rs @@ -1,6 +1,7 @@ #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")] #![feature(box_patterns)] +#![feature(core_intrinsics)] #![feature(crate_visibility_modifier)] #![feature(drain_filter)] #![feature(in_band_lifetimes)] @@ -11,6 +12,7 @@ #![feature(rustc_private)] #![feature(slice_patterns)] #![feature(specialization)] +#![feature(stmt_expr_attributes)] #![recursion_limit="256"] diff --git a/src/librustc_mir/error_codes.rs b/src/librustc_mir/error_codes.rs index 77853ff1fe80a..7d114f6f2ace1 100644 --- a/src/librustc_mir/error_codes.rs +++ b/src/librustc_mir/error_codes.rs @@ -64,7 +64,9 @@ E0004: r##" This error indicates that the compiler cannot guarantee a matching pattern for one or more possible inputs to a match expression. Guaranteed matches are required in order to assign values to match expressions, or alternatively, -determine the flow of execution. Erroneous code example: +determine the flow of execution. + +Erroneous code example: ```compile_fail,E0004 enum Terminator { @@ -109,7 +111,9 @@ match x { E0005: r##" Patterns used to bind names must be irrefutable, that is, they must guarantee -that a name will be extracted in all cases. Erroneous code example: +that a name will be extracted in all cases. + +Erroneous code example: ```compile_fail,E0005 let x = Some(1); @@ -145,6 +149,8 @@ like the following is invalid as it requires the entire `Option` to be moved into a variable called `op_string` while simultaneously requiring the inner `String` to be moved into a variable called `s`. +Erroneous code example: + ```compile_fail,E0007 let x = Some("s".to_string()); @@ -208,15 +214,128 @@ match x { ``` "##, +E0010: r##" +The value of statics and constants must be known at compile time, and they live +for the entire lifetime of a program. Creating a boxed value allocates memory on +the heap at runtime, and therefore cannot be done at compile time. + +Erroneous code example: + +```compile_fail,E0010 +const CON: Vec = vec![0]; // error! +``` +"##, + +E0013: r##" +Static and const variables can refer to other const variables. But a const +variable cannot refer to a static variable. + +Erroneous code example: + +```compile_fail,E0013 +static X: i32 = 42; +const Y: i32 = X; +``` + +In this example, `Y` cannot refer to `X` here. To fix this, the value can be +extracted as a const and then used: + +``` +const A: i32 = 42; +static X: i32 = A; +const Y: i32 = A; +``` +"##, + +// FIXME(#57563) Change the language here when const fn stabilizes +E0015: r##" +The only functions that can be called in static or constant expressions are +`const` functions, and struct/enum constructors. `const` functions are only +available on a nightly compiler. Rust currently does not support more general +compile-time function execution. + +``` +const FOO: Option = Some(1); // enum constructor +struct Bar {x: u8} +const BAR: Bar = Bar {x: 1}; // struct constructor +``` + +See [RFC 911] for more details on the design of `const fn`s. + +[RFC 911]: https://github.com/rust-lang/rfcs/blob/master/text/0911-const-fn.md +"##, + +E0017: r##" +References in statics and constants may only refer to immutable values. + +Erroneous code example: + +```compile_fail,E0017 +static X: i32 = 1; +const C: i32 = 2; + +// these three are not allowed: +const CR: &mut i32 = &mut C; +static STATIC_REF: &'static mut i32 = &mut X; +static CONST_REF: &'static mut i32 = &mut C; +``` + +Statics are shared everywhere, and if they refer to mutable data one might +violate memory safety since holding multiple mutable references to shared data +is not allowed. + +If you really want global mutable state, try using `static mut` or a global +`UnsafeCell`. +"##, + +E0019: r##" +A function call isn't allowed in the const's initialization expression +because the expression's value must be known at compile-time. + +Erroneous code example: + +```compile_fail,E0019 +#![feature(box_syntax)] + +fn main() { + struct MyOwned; + + static STATIC11: Box = box MyOwned; // error! +} +``` + +Remember: you can't use a function call inside a const's initialization +expression! However, you can totally use it anywhere else: + +``` +enum Test { + V1 +} + +impl Test { + fn func(&self) -> i32 { + 12 + } +} + +fn main() { + const FOO: Test = Test::V1; + + FOO.func(); // here is good + let x = FOO.func(); // or even here! +} +``` +"##, + E0030: r##" When matching against a range, the compiler verifies that the range is -non-empty. Range patterns include both end-points, so this is equivalent to +non-empty. Range patterns include both end-points, so this is equivalent to requiring the start of the range to be less than or equal to the end of the range. -For example: +Erroneous code example: -```compile_fail +```compile_fail,E0030 match 5u32 { // This range is ok, albeit pointless. 1 ..= 1 => {} @@ -226,7 +345,61 @@ match 5u32 { ``` "##, +E0133: r##" +Unsafe code was used outside of an unsafe function or block. + +Erroneous code example: + +```compile_fail,E0133 +unsafe fn f() { return; } // This is the unsafe code + +fn main() { + f(); // error: call to unsafe function requires unsafe function or block +} +``` + +Using unsafe functionality is potentially dangerous and disallowed by safety +checks. Examples: + +* Dereferencing raw pointers +* Calling functions via FFI +* Calling functions marked unsafe + +These safety checks can be relaxed for a section of the code by wrapping the +unsafe instructions with an `unsafe` block. For instance: + +``` +unsafe fn f() { return; } + +fn main() { + unsafe { f(); } // ok! +} +``` + +See also https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html +"##, + E0158: r##" +An associated const has been referenced in a pattern. + +Erroneous code example: + +```compile_fail,E0158 +enum EFoo { A, B, C, D } + +trait Foo { + const X: EFoo; +} + +fn test(arg: EFoo) { + match arg { + A::X => { // error! + println!("A::X"); + } + } +} +``` + `const` and `static` mean different things. A `const` is a compile-time constant, an alias for a literal value. This property means you can match it directly within a pattern. @@ -247,6 +420,39 @@ match Some(42) { ``` "##, +E0161: r##" +A value was moved. However, its size was not known at compile time, and only +values of a known size can be moved. + +Erroneous code example: + +```compile_fail,E0161 +#![feature(box_syntax)] + +fn main() { + let array: &[isize] = &[1, 2, 3]; + let _x: Box<[isize]> = box *array; + // error: cannot move a value of type [isize]: the size of [isize] cannot + // be statically determined +} +``` + +In Rust, you can only move a value when its size is known at compile time. + +To work around this restriction, consider "hiding" the value behind a reference: +either `&x` or `&mut x`. Since a reference has a fixed size, this lets you move +it around as usual. Example: + +``` +#![feature(box_syntax)] + +fn main() { + let array: &[isize] = &[1, 2, 3]; + let _x: Box<&[isize]> = box array; // ok! +} +``` +"##, + E0162: r##" #### Note: this error code is no longer emitted by the compiler. @@ -468,158 +674,6 @@ The `op_string_ref` binding has type `&Option<&String>` in both cases. See also https://github.com/rust-lang/rust/issues/14587 "##, -E0010: r##" -The value of statics and constants must be known at compile time, and they live -for the entire lifetime of a program. Creating a boxed value allocates memory on -the heap at runtime, and therefore cannot be done at compile time. Erroneous -code example: - -```compile_fail,E0010 -#![feature(box_syntax)] - -const CON : Box = box 0; -``` -"##, - -E0013: r##" -Static and const variables can refer to other const variables. But a const -variable cannot refer to a static variable. For example, `Y` cannot refer to -`X` here: - -```compile_fail,E0013 -static X: i32 = 42; -const Y: i32 = X; -``` - -To fix this, the value can be extracted as a const and then used: - -``` -const A: i32 = 42; -static X: i32 = A; -const Y: i32 = A; -``` -"##, - -// FIXME(#57563) Change the language here when const fn stabilizes -E0015: r##" -The only functions that can be called in static or constant expressions are -`const` functions, and struct/enum constructors. `const` functions are only -available on a nightly compiler. Rust currently does not support more general -compile-time function execution. - -``` -const FOO: Option = Some(1); // enum constructor -struct Bar {x: u8} -const BAR: Bar = Bar {x: 1}; // struct constructor -``` - -See [RFC 911] for more details on the design of `const fn`s. - -[RFC 911]: https://github.com/rust-lang/rfcs/blob/master/text/0911-const-fn.md -"##, - -E0017: r##" -References in statics and constants may only refer to immutable values. -Erroneous code example: - -```compile_fail,E0017 -static X: i32 = 1; -const C: i32 = 2; - -// these three are not allowed: -const CR: &mut i32 = &mut C; -static STATIC_REF: &'static mut i32 = &mut X; -static CONST_REF: &'static mut i32 = &mut C; -``` - -Statics are shared everywhere, and if they refer to mutable data one might -violate memory safety since holding multiple mutable references to shared data -is not allowed. - -If you really want global mutable state, try using `static mut` or a global -`UnsafeCell`. -"##, - -E0019: r##" -A function call isn't allowed in the const's initialization expression -because the expression's value must be known at compile-time. Erroneous code -example: - -```compile_fail -enum Test { - V1 -} - -impl Test { - fn test(&self) -> i32 { - 12 - } -} - -fn main() { - const FOO: Test = Test::V1; - - const A: i32 = FOO.test(); // You can't call Test::func() here! -} -``` - -Remember: you can't use a function call inside a const's initialization -expression! However, you can totally use it anywhere else: - -``` -enum Test { - V1 -} - -impl Test { - fn func(&self) -> i32 { - 12 - } -} - -fn main() { - const FOO: Test = Test::V1; - - FOO.func(); // here is good - let x = FOO.func(); // or even here! -} -``` -"##, - -E0133: r##" -Unsafe code was used outside of an unsafe function or block. - -Erroneous code example: - -```compile_fail,E0133 -unsafe fn f() { return; } // This is the unsafe code - -fn main() { - f(); // error: call to unsafe function requires unsafe function or block -} -``` - -Using unsafe functionality is potentially dangerous and disallowed by safety -checks. Examples: - -* Dereferencing raw pointers -* Calling functions via FFI -* Calling functions marked unsafe - -These safety checks can be relaxed for a section of the code by wrapping the -unsafe instructions with an `unsafe` block. For instance: - -``` -unsafe fn f() { return; } - -fn main() { - unsafe { f(); } // ok! -} -``` - -See also https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html -"##, - E0373: r##" This error occurs when an attempt is made to use data captured by a closure, when that data may no longer exist. It's most commonly seen when attempting to @@ -672,7 +726,9 @@ about safety. "##, E0381: r##" -It is not allowed to use or capture an uninitialized variable. For example: +It is not allowed to use or capture an uninitialized variable. + +Erroneous code example: ```compile_fail,E0381 fn main() { @@ -694,7 +750,9 @@ fn main() { E0382: r##" This error occurs when an attempt is made to use a variable after its contents -have been moved elsewhere. For example: +have been moved elsewhere. + +Erroneous code example: ```compile_fail,E0382 struct MyStruct { s: u32 } @@ -842,7 +900,8 @@ x = Foo { a: 2 }; E0384: r##" This error occurs when an attempt is made to reassign an immutable variable. -For example: + +Erroneous code example: ```compile_fail,E0384 fn main() { @@ -862,13 +921,15 @@ fn main() { ``` "##, -/*E0386: r##" +E0386: r##" +#### Note: this error code is no longer emitted by the compiler. + This error occurs when an attempt is made to mutate the target of a mutable reference stored inside an immutable container. For example, this can happen when storing a `&mut` inside an immutable `Box`: -```compile_fail,E0386 +``` let mut x: i64 = 1; let y: Box<_> = Box::new(&mut x); **y = 2; // error, cannot assign to data in an immutable container @@ -892,13 +953,15 @@ let x: i64 = 1; let y: Box> = Box::new(Cell::new(x)); y.set(2); ``` -"##,*/ +"##, E0387: r##" #### Note: this error code is no longer emitted by the compiler. This error occurs when an attempt is made to mutate or mutably reference data -that a closure has captured immutably. Examples of this error are shown below: +that a closure has captured immutably. + +Erroneous code example: ```compile_fail // Accepts a function or a closure that captures its environment immutably. @@ -963,7 +1026,7 @@ An attempt was made to mutate data using a non-mutable reference. This commonly occurs when attempting to assign to a non-mutable reference of a mutable reference (`&(&mut T)`). -Example of erroneous code: +Erroneous code example: ```compile_fail struct FancyNum { @@ -1022,43 +1085,11 @@ fn main() { ``` "##, -E0161: r##" -A value was moved. However, its size was not known at compile time, and only -values of a known size can be moved. +E0492: r##" +A borrow of a constant containing interior mutability was attempted. Erroneous code example: -```compile_fail -#![feature(box_syntax)] - -fn main() { - let array: &[isize] = &[1, 2, 3]; - let _x: Box<[isize]> = box *array; - // error: cannot move a value of type [isize]: the size of [isize] cannot - // be statically determined -} -``` - -In Rust, you can only move a value when its size is known at compile time. - -To work around this restriction, consider "hiding" the value behind a reference: -either `&x` or `&mut x`. Since a reference has a fixed size, this lets you move -it around as usual. Example: - -``` -#![feature(box_syntax)] - -fn main() { - let array: &[isize] = &[1, 2, 3]; - let _x: Box<&[isize]> = box array; // ok! -} -``` -"##, - -E0492: r##" -A borrow of a constant containing interior mutability was attempted. Erroneous -code example: - ```compile_fail,E0492 use std::sync::atomic::AtomicUsize; @@ -1174,7 +1205,9 @@ static FOO: Foo = Foo { field1: DropType::A }; // We initialize all fields "##, E0499: r##" -A variable was borrowed as mutable more than once. Erroneous code example: +A variable was borrowed as mutable more than once. + +Erroneous code example: ```compile_fail,E0499 let mut i = 0; @@ -1205,7 +1238,9 @@ a; "##, E0500: r##" -A borrowed variable was used by a closure. Example of erroneous code: +A borrowed variable was used by a closure. + +Erroneous code example: ```compile_fail,E0500 fn you_know_nothing(jon_snow: &mut i32) { @@ -1256,7 +1291,7 @@ situation, the closure is borrowing the variable. Take a look at http://rustbyexample.com/fn/closures/capture.html for more information about capturing. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0501 fn inside_closure(x: &mut i32) { @@ -1329,7 +1364,7 @@ E0502: r##" This error indicates that you are trying to borrow a variable as mutable when it has already been borrowed as immutable. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0502 fn bar(x: &mut i32) {} @@ -1360,7 +1395,7 @@ https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html. E0503: r##" A value was used after it was mutably borrowed. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0503 fn main() { @@ -1418,7 +1453,7 @@ E0504: r##" This error occurs when an attempt is made to move a borrowed variable into a closure. -Example of erroneous code: +Erroneous code example: ```compile_fail struct FancyNum { @@ -1609,7 +1644,7 @@ http://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html E0506: r##" This error occurs when an attempt is made to assign to a borrowed value. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0506 struct FancyNum { @@ -1827,7 +1862,7 @@ http://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html E0508: r##" A value was moved out of a non-copy fixed-size array. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0508 struct NonCopy; @@ -1872,7 +1907,7 @@ E0509: r##" This error occurs when an attempt is made to move out of a value whose type implements the `Drop` trait. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0509 struct FancyNum { @@ -1982,30 +2017,14 @@ Here executing `x = None` would modify the value being matched and require us to go "back in time" to the `None` arm. "##, -E0579: r##" -When matching against an exclusive range, the compiler verifies that the range -is non-empty. Exclusive range patterns include the start point but not the end -point, so this is equivalent to requiring the start of the range to be less -than the end of the range. - -For example: - -```compile_fail -match 5u32 { - // This range is ok, albeit pointless. - 1 .. 2 => {} - // This range is empty, and the compiler can tell. - 5 .. 5 => {} -} -``` -"##, - E0515: r##" Cannot return value that references local variable Local variables, function parameters and temporaries are all dropped before the end of the function body. So a reference to them cannot be returned. +Erroneous code example: + ```compile_fail,E0515 fn get_dangling_reference() -> &'static i32 { let x = 0; @@ -2101,6 +2120,28 @@ fn dragoooon(x: &mut isize) { ``` "##, +E0579: r##" +When matching against an exclusive range, the compiler verifies that the range +is non-empty. Exclusive range patterns include the start point but not the end +point, so this is equivalent to requiring the start of the range to be less +than the end of the range. + +Erroneous code example: + +```compile_fail,E0579 +#![feature(exclusive_range_pattern)] + +fn main() { + match 5u32 { + // This range is ok, albeit pointless. + 1 .. 2 => {} + // This range is empty, and the compiler can tell. + 5 .. 5 => {} // error! + } +} +``` +"##, + E0595: r##" #### Note: this error code is no longer emitted by the compiler. @@ -2124,7 +2165,7 @@ let mut c = || { x += 1 }; E0596: r##" This error occurs because you tried to mutably borrow a non-mutable variable. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0596 let x = 1; @@ -2143,7 +2184,7 @@ let y = &mut x; // ok! E0597: r##" This error occurs because a value was dropped while it was still borrowed -Example of erroneous code: +Erroneous code example: ```compile_fail,E0597 struct Foo<'a> { @@ -2180,6 +2221,8 @@ E0626: r##" This error occurs because a borrow in a generator persists across a yield point. +Erroneous code example: + ```compile_fail,E0626 # #![feature(generators, generator_trait, pin)] # use std::ops::Generator; @@ -2271,7 +2314,7 @@ E0712: r##" This error occurs because a borrow of a thread-local variable was made inside a function which outlived the lifetime of the function. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0712 #![feature(thread_local)] @@ -2293,7 +2336,7 @@ E0713: r##" This error occurs when an attempt is made to borrow state past the end of the lifetime of a type that implements the `Drop` trait. -Example of erroneous code: +Erroneous code example: ```compile_fail,E0713 #![feature(nll)] diff --git a/src/librustc_mir/hair/pattern/check_match.rs b/src/librustc_mir/hair/pattern/check_match.rs index c521b7352214b..9bed4fb66ea9d 100644 --- a/src/librustc_mir/hair/pattern/check_match.rs +++ b/src/librustc_mir/hair/pattern/check_match.rs @@ -62,12 +62,13 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, 'tcx> { fn visit_local(&mut self, loc: &'tcx hir::Local) { intravisit::walk_local(self, loc); - self.check_irrefutable(&loc.pat, match loc.source { - hir::LocalSource::Normal => "local binding", - hir::LocalSource::ForLoopDesugar => "`for` loop binding", - hir::LocalSource::AsyncFn => "async fn binding", - hir::LocalSource::AwaitDesugar => "`await` future binding", - }); + let (msg, sp) = match loc.source { + hir::LocalSource::Normal => ("local binding", Some(loc.span)), + hir::LocalSource::ForLoopDesugar => ("`for` loop binding", None), + hir::LocalSource::AsyncFn => ("async fn binding", None), + hir::LocalSource::AwaitDesugar => ("`await` future binding", None), + }; + self.check_irrefutable(&loc.pat, msg, sp); // Check legality of move bindings and `@` patterns. self.check_patterns(false, &loc.pat); @@ -77,7 +78,7 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, 'tcx> { intravisit::walk_body(self, body); for param in &body.params { - self.check_irrefutable(¶m.pat, "function argument"); + self.check_irrefutable(¶m.pat, "function argument", None); self.check_patterns(false, ¶m.pat); } } @@ -242,7 +243,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> { }) } - fn check_irrefutable(&self, pat: &'tcx Pat, origin: &str) { + fn check_irrefutable(&self, pat: &'tcx Pat, origin: &str, sp: Option) { let module = self.tcx.hir().get_module_parent(pat.hir_id); MatchCheckCtxt::create_and_enter(self.tcx, self.param_env, module, |ref mut cx| { let mut patcx = PatCtxt::new(self.tcx, @@ -266,18 +267,35 @@ impl<'tcx> MatchVisitor<'_, 'tcx> { "refutable pattern in {}: {} not covered", origin, joined_patterns ); - match &pat.kind { + let suggest_if_let = match &pat.kind { hir::PatKind::Path(hir::QPath::Resolved(None, path)) if path.segments.len() == 1 && path.segments[0].args.is_none() => { const_not_var(&mut err, cx.tcx, pat, path); + false } _ => { err.span_label( pat.span, pattern_not_covered_label(&witnesses, &joined_patterns), ); + true + } + }; + + if let (Some(span), true) = (sp, suggest_if_let) { + err.note("`let` bindings require an \"irrefutable pattern\", like a `struct` or \ + an `enum` with only one variant"); + if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) { + err.span_suggestion( + span, + "you might want to use `if let` to ignore the variant that isn't matched", + format!("if {} {{ /* */ }}", &snippet[..snippet.len() - 1]), + Applicability::HasPlaceholders, + ); } + err.note("for more information, visit \ + https://doc.rust-lang.org/book/ch18-02-refutability.html"); } adt_defined_here(cx, &mut err, pattern_ty, &witnesses); diff --git a/src/librustc_resolve/build_reduced_graph.rs b/src/librustc_resolve/build_reduced_graph.rs index 030f9b97eb8b9..f23174b1146b9 100644 --- a/src/librustc_resolve/build_reduced_graph.rs +++ b/src/librustc_resolve/build_reduced_graph.rs @@ -162,25 +162,15 @@ impl<'a> Resolver<'a> { Some(ext) } - // FIXME: `extra_placeholders` should be included into the `fragment` as regular placeholders. crate fn build_reduced_graph( &mut self, fragment: &AstFragment, - extra_placeholders: &[NodeId], parent_scope: ParentScope<'a>, ) -> LegacyScope<'a> { let mut def_collector = DefCollector::new(&mut self.definitions, parent_scope.expansion); fragment.visit_with(&mut def_collector); - for placeholder in extra_placeholders { - def_collector.visit_macro_invoc(*placeholder); - } - let mut visitor = BuildReducedGraphVisitor { r: self, parent_scope }; fragment.visit_with(&mut visitor); - for placeholder in extra_placeholders { - visitor.parent_scope.legacy = visitor.visit_invoc(*placeholder); - } - visitor.parent_scope.legacy } @@ -1063,8 +1053,17 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { None } + // Mark the given macro as unused unless its name starts with `_`. + // Macro uses will remove items from this set, and the remaining + // items will be reported as `unused_macros`. + fn insert_unused_macro(&mut self, ident: Ident, node_id: NodeId, span: Span) { + if !ident.as_str().starts_with("_") { + self.r.unused_macros.insert(node_id, span); + } + } + fn define_macro(&mut self, item: &ast::Item) -> LegacyScope<'a> { - let parent_scope = &self.parent_scope; + let parent_scope = self.parent_scope; let expansion = parent_scope.expansion; let (ext, ident, span, is_legacy) = match &item.kind { ItemKind::MacroDef(def) => { @@ -1104,7 +1103,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { (res, vis, span, expansion, IsMacroExport)); } else { self.r.check_reserved_macro_name(ident, res); - self.r.unused_macros.insert(item.id, span); + self.insert_unused_macro(ident, item.id, span); } LegacyScope::Binding(self.r.arenas.alloc_legacy_binding(LegacyBinding { parent_legacy_scope: parent_scope.legacy, binding, ident @@ -1113,7 +1112,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> { let module = parent_scope.module; let vis = self.resolve_visibility(&item.vis); if vis != ty::Visibility::Public { - self.r.unused_macros.insert(item.id, span); + self.insert_unused_macro(ident, item.id, span); } self.r.define(module, ident, MacroNS, (res, vis, span, expansion)); self.parent_scope.legacy diff --git a/src/librustc_resolve/macros.rs b/src/librustc_resolve/macros.rs index 2b87bba83861c..2cac28d4f4329 100644 --- a/src/librustc_resolve/macros.rs +++ b/src/librustc_resolve/macros.rs @@ -107,15 +107,11 @@ impl<'a> base::Resolver for Resolver<'a> { }); } - // FIXME: `extra_placeholders` should be included into the `fragment` as regular placeholders. - fn visit_ast_fragment_with_placeholders( - &mut self, expansion: ExpnId, fragment: &AstFragment, extra_placeholders: &[NodeId] - ) { + fn visit_ast_fragment_with_placeholders(&mut self, expansion: ExpnId, fragment: &AstFragment) { // Integrate the new AST fragment into all the definition and module structures. // We are inside the `expansion` now, but other parent scope components are still the same. let parent_scope = ParentScope { expansion, ..self.invocation_parent_scopes[&expansion] }; - let output_legacy_scope = - self.build_reduced_graph(fragment, extra_placeholders, parent_scope); + let output_legacy_scope = self.build_reduced_graph(fragment, parent_scope); self.output_legacy_scopes.insert(expansion, output_legacy_scope); parent_scope.module.unexpanded_invocations.borrow_mut().remove(&expansion); diff --git a/src/librustc_typeck/check/method/suggest.rs b/src/librustc_typeck/check/method/suggest.rs index ebeb9ba25c6cb..96cc5aa1dc24b 100644 --- a/src/librustc_typeck/check/method/suggest.rs +++ b/src/librustc_typeck/check/method/suggest.rs @@ -809,31 +809,25 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Get the `hir::Param` to verify whether it already has any bounds. // We do this to avoid suggesting code that ends up as `T: FooBar`, // instead we suggest `T: Foo + Bar` in that case. - let mut has_bounds = false; + let mut has_bounds = None; let mut impl_trait = false; if let Node::GenericParam(ref param) = hir.get(id) { - match param.kind { - hir::GenericParamKind::Type { synthetic: Some(_), .. } => { - // We've found `fn foo(x: impl Trait)` instead of - // `fn foo(x: T)`. We want to suggest the correct - // `fn foo(x: impl Trait + TraitBound)` instead of - // `fn foo(x: T)`. (#63706) - impl_trait = true; - has_bounds = param.bounds.len() > 1; - } - _ => { - has_bounds = !param.bounds.is_empty(); - } + let kind = ¶m.kind; + if let hir::GenericParamKind::Type { synthetic: Some(_), .. } = kind { + // We've found `fn foo(x: impl Trait)` instead of + // `fn foo(x: T)`. We want to suggest the correct + // `fn foo(x: impl Trait + TraitBound)` instead of + // `fn foo(x: T)`. (See #63706.) + impl_trait = true; + has_bounds = param.bounds.get(1); + } else { + has_bounds = param.bounds.get(0); } } let sp = hir.span(id); - // `sp` only covers `T`, change it so that it covers - // `T:` when appropriate - let sp = if has_bounds { - sp.to(self.tcx - .sess - .source_map() - .next_point(self.tcx.sess.source_map().next_point(sp))) + // `sp` only covers `T`, change it so that it covers `T:` when appropriate. + let sp = if let Some(first_bound) = has_bounds { + sp.until(first_bound.span()) } else { sp }; @@ -849,7 +843,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { param, if impl_trait { " +" } else { ":" }, self.tcx.def_path_str(t.def_id), - if has_bounds { " +"} else { "" }, + if has_bounds.is_some() { " + " } else { "" }, )), Applicability::MaybeIncorrect, ); diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs index 583fb3f770183..0bf21c45a347c 100644 --- a/src/libsyntax/ext/base.rs +++ b/src/libsyntax/ext/base.rs @@ -849,8 +849,7 @@ pub trait Resolver { fn next_node_id(&mut self) -> NodeId; fn resolve_dollar_crates(&mut self); - fn visit_ast_fragment_with_placeholders(&mut self, expn_id: ExpnId, fragment: &AstFragment, - extra_placeholders: &[NodeId]); + fn visit_ast_fragment_with_placeholders(&mut self, expn_id: ExpnId, fragment: &AstFragment); fn register_builtin_macro(&mut self, ident: ast::Ident, ext: SyntaxExtension); fn expansion_for_ast_pass( diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs index bbd8da2acef05..328311041bfc8 100644 --- a/src/libsyntax/ext/expand.rs +++ b/src/libsyntax/ext/expand.rs @@ -23,7 +23,6 @@ use errors::{Applicability, FatalError}; use smallvec::{smallvec, SmallVec}; use syntax_pos::{Span, DUMMY_SP, FileName}; -use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sync::Lrc; use std::io::ErrorKind; use std::{iter, mem, slice}; @@ -72,6 +71,22 @@ macro_rules! ast_fragments { } impl AstFragment { + pub fn add_placeholders(&mut self, placeholders: &[NodeId]) { + if placeholders.is_empty() { + return; + } + match self { + $($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| { + // We are repeating through arguments with `many`, to do that we have to + // mention some macro variable from those arguments even if it's not used. + #[cfg_attr(bootstrap, allow(unused_macros))] + macro _repeating($flat_map_ast_elt) {} + placeholder(AstFragmentKind::$Kind, *id).$make_ast() + })),)?)* + _ => panic!("unexpected AST fragment kind") + } + } + pub fn make_opt_expr(self) -> Option> { match self { AstFragment::OptExpr(expr) => expr, @@ -339,7 +354,6 @@ impl<'a, 'b> MacroExpander<'a, 'b> { // Unresolved macros produce dummy outputs as a recovery measure. invocations.reverse(); let mut expanded_fragments = Vec::new(); - let mut all_derive_placeholders: FxHashMap> = FxHashMap::default(); let mut undetermined_invocations = Vec::new(); let (mut progress, mut force) = (false, !self.monotonic); loop { @@ -416,9 +430,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { self.cx.resolver.add_derives(invoc.expansion_data.id, SpecialDerives::COPY); } - let derive_placeholders = - all_derive_placeholders.entry(invoc.expansion_data.id).or_default(); - derive_placeholders.reserve(derives.len()); + let mut derive_placeholders = Vec::with_capacity(derives.len()); invocations.reserve(derives.len()); for path in derives { let expn_id = ExpnId::fresh(None); @@ -434,7 +446,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> { } let fragment = invoc.fragment_kind .expect_from_annotatables(::std::iter::once(item)); - self.collect_invocations(fragment, derive_placeholders) + self.collect_invocations(fragment, &derive_placeholders) } }; @@ -453,10 +465,8 @@ impl<'a, 'b> MacroExpander<'a, 'b> { let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic); while let Some(expanded_fragments) = expanded_fragments.pop() { for (expn_id, expanded_fragment) in expanded_fragments.into_iter().rev() { - let derive_placeholders = - all_derive_placeholders.remove(&expn_id).unwrap_or_else(Vec::new); placeholder_expander.add(NodeId::placeholder_from_expn_id(expn_id), - expanded_fragment, derive_placeholders); + expanded_fragment); } } fragment_with_placeholders.mut_visit_with(&mut placeholder_expander); @@ -489,13 +499,14 @@ impl<'a, 'b> MacroExpander<'a, 'b> { monotonic: self.monotonic, }; fragment.mut_visit_with(&mut collector); + fragment.add_placeholders(extra_placeholders); collector.invocations }; - // FIXME: Merge `extra_placeholders` into the `fragment` as regular placeholders. if self.monotonic { self.cx.resolver.visit_ast_fragment_with_placeholders( - self.cx.current_expansion.id, &fragment, extra_placeholders); + self.cx.current_expansion.id, &fragment + ); } (fragment, invocations) diff --git a/src/libsyntax/ext/placeholders.rs b/src/libsyntax/ext/placeholders.rs index 8eecef1020d0a..6efd5397129dc 100644 --- a/src/libsyntax/ext/placeholders.rs +++ b/src/libsyntax/ext/placeholders.rs @@ -1,4 +1,4 @@ -use crate::ast::{self, NodeId}; +use crate::ast; use crate::source_map::{DUMMY_SP, dummy_spanned}; use crate::ext::base::ExtCtxt; use crate::ext::expand::{AstFragment, AstFragmentKind}; @@ -170,17 +170,8 @@ impl<'a, 'b> PlaceholderExpander<'a, 'b> { } } - pub fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment, placeholders: Vec) { + pub fn add(&mut self, id: ast::NodeId, mut fragment: AstFragment) { fragment.mut_visit_with(self); - if let AstFragment::Items(mut items) = fragment { - for placeholder in placeholders { - match self.remove(placeholder) { - AstFragment::Items(derived_items) => items.extend(derived_items), - _ => unreachable!(), - } - } - fragment = AstFragment::Items(items); - } self.expanded_fragments.insert(id, fragment); } diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs index d2c76b669dd5f..65611ae97285d 100644 --- a/src/libsyntax/lib.rs +++ b/src/libsyntax/lib.rs @@ -11,6 +11,7 @@ #![feature(const_fn)] #![feature(const_transmute)] #![feature(crate_visibility_modifier)] +#![feature(decl_macro)] #![feature(label_break_value)] #![feature(mem_take)] #![feature(nll)] diff --git a/src/test/ui/consts/const-match-check.eval1.stderr b/src/test/ui/consts/const-match-check.eval1.stderr index 24d2e3ce53937..087cc3c86a68d 100644 --- a/src/test/ui/consts/const-match-check.eval1.stderr +++ b/src/test/ui/consts/const-match-check.eval1.stderr @@ -3,6 +3,13 @@ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1 | LL | A = { let 0 = 0; 0 }, | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | A = { if let 0 = 0 { /* */ } 0 }, + | ^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error diff --git a/src/test/ui/consts/const-match-check.eval2.stderr b/src/test/ui/consts/const-match-check.eval2.stderr index 5d59d06f7982a..80d9f794bc1d5 100644 --- a/src/test/ui/consts/const-match-check.eval2.stderr +++ b/src/test/ui/consts/const-match-check.eval2.stderr @@ -3,6 +3,13 @@ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1 | LL | let x: [i32; { let 0 = 0; 0 }] = []; | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | let x: [i32; { if let 0 = 0 { /* */ } 0 }] = []; + | ^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error diff --git a/src/test/ui/consts/const-match-check.matchck.stderr b/src/test/ui/consts/const-match-check.matchck.stderr index 6d74c26f9f7a5..e6b2f212bb430 100644 --- a/src/test/ui/consts/const-match-check.matchck.stderr +++ b/src/test/ui/consts/const-match-check.matchck.stderr @@ -3,24 +3,52 @@ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1 | LL | const X: i32 = { let 0 = 0; 0 }; | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | const X: i32 = { if let 0 = 0 { /* */ } 0 }; + | ^^^^^^^^^^^^^^^^^^^^^^ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered --> $DIR/const-match-check.rs:8:23 | LL | static Y: i32 = { let 0 = 0; 0 }; | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | static Y: i32 = { if let 0 = 0 { /* */ } 0 }; + | ^^^^^^^^^^^^^^^^^^^^^^ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered --> $DIR/const-match-check.rs:13:26 | LL | const X: i32 = { let 0 = 0; 0 }; | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | const X: i32 = { if let 0 = 0 { /* */ } 0 }; + | ^^^^^^^^^^^^^^^^^^^^^^ error[E0005]: refutable pattern in local binding: `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered --> $DIR/const-match-check.rs:19:26 | LL | const X: i32 = { let 0 = 0; 0 }; | ^ patterns `std::i32::MIN..=-1i32` and `1i32..=std::i32::MAX` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | const X: i32 = { if let 0 = 0 { /* */ } 0 }; + | ^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 4 previous errors diff --git a/src/test/ui/empty/empty-never-array.stderr b/src/test/ui/empty/empty-never-array.stderr index 7d59d553d88fd..d865b59f0b945 100644 --- a/src/test/ui/empty/empty-never-array.stderr +++ b/src/test/ui/empty/empty-never-array.stderr @@ -11,6 +11,13 @@ LL | | } ... LL | let Helper::U(u) = Helper::T(t, []); | ^^^^^^^^^^^^ pattern `T(_, _)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Helper::U(u) = Helper::T(t, []) { /* */ } + | error[E0381]: use of possibly-uninitialized variable: `u` --> $DIR/empty-never-array.rs:12:5 diff --git a/src/test/ui/error-codes/E0005.stderr b/src/test/ui/error-codes/E0005.stderr index 56a4bcffc81a2..577c6e886d523 100644 --- a/src/test/ui/error-codes/E0005.stderr +++ b/src/test/ui/error-codes/E0005.stderr @@ -3,6 +3,13 @@ error[E0005]: refutable pattern in local binding: `None` not covered | LL | let Some(y) = x; | ^^^^^^^ pattern `None` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Some(y) = x { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.nll.stderr b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.nll.stderr new file mode 100644 index 0000000000000..d77fbc1e8239d --- /dev/null +++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.nll.stderr @@ -0,0 +1,16 @@ +error[E0005]: refutable pattern in local binding: `Err(_)` not covered + --> $DIR/feature-gate-exhaustive-patterns.rs:7:9 + | +LL | let Ok(_x) = foo(); + | ^^^^^^ pattern `Err(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Ok(_x) = foo() { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0005`. diff --git a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr index dd4ca1f67e330..d77fbc1e8239d 100644 --- a/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr +++ b/src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr @@ -3,6 +3,13 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered | LL | let Ok(_x) = foo(); | ^^^^^^ pattern `Err(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Ok(_x) = foo() { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error diff --git a/src/test/ui/issues/issue-31561.stderr b/src/test/ui/issues/issue-31561.stderr index 9ec26b024bce2..d3c8e876b8a88 100644 --- a/src/test/ui/issues/issue-31561.stderr +++ b/src/test/ui/issues/issue-31561.stderr @@ -12,6 +12,13 @@ LL | | } ... LL | let Thing::Foo(y) = Thing::Foo(1); | ^^^^^^^^^^^^^ patterns `Bar` and `Baz` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Thing::Foo(y) = Thing::Foo(1) { /* */ } + | error: aborting due to previous error diff --git a/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.rs b/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.rs new file mode 100644 index 0000000000000..e0eaafdfc2f22 --- /dev/null +++ b/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.rs @@ -0,0 +1,11 @@ +trait Foo { + fn foo(&self); +} + +trait Bar {} + +fn do_stuff(t : T) { + t.foo() //~ ERROR no method named `foo` found for type `T` in the current scope +} + +fn main() {} diff --git a/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.stderr b/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.stderr new file mode 100644 index 0000000000000..24bf60abf6a78 --- /dev/null +++ b/src/test/ui/issues/issue-65284-suggest-generic-trait-bound.stderr @@ -0,0 +1,15 @@ +error[E0599]: no method named `foo` found for type `T` in the current scope + --> $DIR/issue-65284-suggest-generic-trait-bound.rs:8:7 + | +LL | t.foo() + | ^^^ method not found in `T` + | + = help: items from traits can only be used if the type parameter is bounded by the trait +help: the following trait defines an item `foo`, perhaps you need to restrict type parameter `T` with it: + | +LL | fn do_stuff(t : T) { + | ^^^^^^^^ + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0599`. diff --git a/src/test/ui/match/non-exhaustive-defined-here.stderr b/src/test/ui/match/non-exhaustive-defined-here.stderr index 25b8bbdab2d8e..e5f01174ac1bf 100644 --- a/src/test/ui/match/non-exhaustive-defined-here.stderr +++ b/src/test/ui/match/non-exhaustive-defined-here.stderr @@ -41,6 +41,13 @@ LL | | } ... LL | let E::A = e; | ^^^^ patterns `B` and `C` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let E::A = e { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^ error[E0004]: non-exhaustive patterns: `&B` and `&C` not covered --> $DIR/non-exhaustive-defined-here.rs:40:11 @@ -85,6 +92,13 @@ LL | | } ... LL | let E::A = e; | ^^^^ patterns `&B` and `&C` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let E::A = e { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^ error[E0004]: non-exhaustive patterns: `&&mut &B` and `&&mut &C` not covered --> $DIR/non-exhaustive-defined-here.rs:48:11 @@ -129,6 +143,13 @@ LL | | } ... LL | let E::A = e; | ^^^^ patterns `&&mut &B` and `&&mut &C` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let E::A = e { /* */ } + | error[E0004]: non-exhaustive patterns: `None` not covered --> $DIR/non-exhaustive-defined-here.rs:65:11 @@ -163,6 +184,13 @@ LL | | } ... LL | let Opt::Some(ref _x) = e; | ^^^^^^^^^^^^^^^^^ pattern `None` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Opt::Some(ref _x) = e { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 8 previous errors diff --git a/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr b/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr index b9385952fafa3..f9ae75b18317d 100644 --- a/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr +++ b/src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr @@ -3,6 +3,13 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered | LL | let Ok(x) = res; | ^^^^^ pattern `Err(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Ok(x) = res { /* */ } + | error[E0381]: use of possibly-uninitialized variable: `x` --> $DIR/recursive-types-are-not-uninhabited.rs:8:5 diff --git a/src/test/ui/refutable-pattern-errors.stderr b/src/test/ui/refutable-pattern-errors.stderr index 3b13e25293d58..0cf5d9cd5f12a 100644 --- a/src/test/ui/refutable-pattern-errors.stderr +++ b/src/test/ui/refutable-pattern-errors.stderr @@ -9,6 +9,13 @@ error[E0005]: refutable pattern in local binding: `(std::i32::MIN..=0i32, _)` an | LL | let (1, (Some(1), 2..=3)) = (1, (None, 2)); | ^^^^^^^^^^^^^^^^^^^^^ patterns `(std::i32::MIN..=0i32, _)` and `(2i32..=std::i32::MAX, _)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let (1, (Some(1), 2..=3)) = (1, (None, 2)) { /* */ } + | error: aborting due to 2 previous errors diff --git a/src/test/ui/uninhabited/uninhabited-irrefutable.stderr b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr index 29ff1dc376089..26e1be34ea75d 100644 --- a/src/test/ui/uninhabited/uninhabited-irrefutable.stderr +++ b/src/test/ui/uninhabited/uninhabited-irrefutable.stderr @@ -12,6 +12,13 @@ LL | | } ... LL | let Foo::D(_y) = x; | ^^^^^^^^^^ pattern `A(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Foo::D(_y) = x { /* */ } + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error diff --git a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr index 25519ab2d6a7d..a49344e45cec6 100644 --- a/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr +++ b/src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr @@ -51,6 +51,13 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered | LL | let Ok(x) = x; | ^^^^^ pattern `Err(_)` not covered + | + = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant + = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html +help: you might want to use `if let` to ignore the variant that isn't matched + | +LL | if let Ok(x) = x { /* */ } + | error: aborting due to 7 previous errors