diff --git a/.github/workflows/clippy_bors.yml b/.github/workflows/clippy_bors.yml index 3958ba012..0c80394f0 100644 --- a/.github/workflows/clippy_bors.yml +++ b/.github/workflows/clippy_bors.yml @@ -232,7 +232,8 @@ jobs: matrix: integration: - 'rust-lang/cargo' - - 'rust-lang/rls' + # FIXME: re-enable once fmt_macros is renamed in RLS + # - 'rust-lang/rls' - 'rust-lang/chalk' - 'rust-lang/rustfmt' - 'Marwes/combine' diff --git a/CHANGELOG.md b/CHANGELOG.md index 2ac905719..adc945a69 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -6,11 +6,88 @@ document. ## Unreleased / In Rust Nightly -[891e1a8...master](https://github.com/rust-lang/rust-clippy/compare/891e1a8...master) +[7ea7cd1...master](https://github.com/rust-lang/rust-clippy/compare/7ea7cd1...master) + +## Rust 1.45 + +Current beta, release 2020-07-16 + +[891e1a8...7ea7cd1](https://github.com/rust-lang/rust-clippy/compare/891e1a8...7ea7cd1) + +### New lints + +* [`match_wildcard_for_single_variants`] [#5582](https://github.com/rust-lang/rust-clippy/pull/5582) +* [`unsafe_derive_deserialize`] [#5493](https://github.com/rust-lang/rust-clippy/pull/5493) +* [`if_let_mutex`] [#5332](https://github.com/rust-lang/rust-clippy/pull/5332) +* [`mismatched_target_os`] [#5506](https://github.com/rust-lang/rust-clippy/pull/5506) +* [`await_holding_lock`] [#5439](https://github.com/rust-lang/rust-clippy/pull/5439) +* [`match_on_vec_items`] [#5522](https://github.com/rust-lang/rust-clippy/pull/5522) +* [`manual_async_fn`] [#5576](https://github.com/rust-lang/rust-clippy/pull/5576) +* [`reversed_empty_ranges`] [#5583](https://github.com/rust-lang/rust-clippy/pull/5583) +* [`manual_non_exhaustive`] [#5550](https://github.com/rust-lang/rust-clippy/pull/5550) + +### Moves and Deprecations + +* Downgrade [`match_bool`] to pedantic [#5408](https://github.com/rust-lang/rust-clippy/pull/5408) +* Downgrade [`match_wild_err_arm`] to pedantic and update help messages. [#5622](https://github.com/rust-lang/rust-clippy/pull/5622) +* Downgrade [`useless_let_if_seq`] to nursery. [#5599](https://github.com/rust-lang/rust-clippy/pull/5599) +* Generalize `option_and_then_some` and rename to [`bind_instead_of_map`]. [#5529](https://github.com/rust-lang/rust-clippy/pull/5529) +* Rename `identity_conversion` to [`useless_conversion`]. [#5568](https://github.com/rust-lang/rust-clippy/pull/5568) +* Merge `block_in_if_condition_expr` and `block_in_if_condition_stmt` into [`blocks_in_if_conditions`]. +[#5563](https://github.com/rust-lang/rust-clippy/pull/5563) +* Merge `option_map_unwrap_or`, `option_map_unwrap_or_else` and `result_map_unwrap_or_else` into [`map_unwrap_or`]. +[#5563](https://github.com/rust-lang/rust-clippy/pull/5563) +* Merge `option_unwrap_used` and `result_unwrap_used` into [`unwrap_used`]. +[#5563](https://github.com/rust-lang/rust-clippy/pull/5563) +* Merge `option_expect_used` and `result_expect_used` into [`expect_used`]. +[#5563](https://github.com/rust-lang/rust-clippy/pull/5563) +* Merge `for_loop_over_option` and `for_loop_over_result` into [`for_loops_over_fallibles`]. +[#5563](https://github.com/rust-lang/rust-clippy/pull/5563) + +### Enhancements + +* Avoid running cargo lints when not enabled to improve performance. [#5505](https://github.com/rust-lang/rust-clippy/pull/5505) +* Extend [`useless_conversion`] with `TryFrom` and `TryInto`. [#5631](https://github.com/rust-lang/rust-clippy/pull/5631) +* Lint also in type parameters and where clauses in [`unused_unit`]. [#5592](https://github.com/rust-lang/rust-clippy/pull/5592) +* Do not suggest deriving `Default` in [`new_without_default`]. [#5616](https://github.com/rust-lang/rust-clippy/pull/5616) + +### False Positive Fixes + +* [`while_let_on_iterator`] [#5525](https://github.com/rust-lang/rust-clippy/pull/5525) +* [`empty_line_after_outer_attr`] [#5609](https://github.com/rust-lang/rust-clippy/pull/5609) +* [`unnecessary_unwrap`] [#5558](https://github.com/rust-lang/rust-clippy/pull/5558) +* [`comparison_chain`] [#5596](https://github.com/rust-lang/rust-clippy/pull/5596) +* Don't trigger [`used_underscore_binding`] in await desugaring. [#5535](https://github.com/rust-lang/rust-clippy/pull/5535) +* Don't trigger [`borrowed_box`] on mutable references. [#5491](https://github.com/rust-lang/rust-clippy/pull/5491) +* Allow `1 << 0` in [`identity_op`]. [#5602](https://github.com/rust-lang/rust-clippy/pull/5602) +* Allow `use super::*;` glob imports in [`wildcard_imports`]. [#5564](https://github.com/rust-lang/rust-clippy/pull/5564) +* Whitelist more words in [`doc_markdown`]. [#5611](https://github.com/rust-lang/rust-clippy/pull/5611) +* Skip dev and build deps in [`multiple_crate_versions`]. [#5636](https://github.com/rust-lang/rust-clippy/pull/5636) +* Honor `allow` attribute on arguments in [`ptr_arg`]. [#5647](https://github.com/rust-lang/rust-clippy/pull/5647) +* Honor lint level attributes for [`redundant_field_names`], [`just_underscores_and_digits`], [`many_single_char_names`] +and [`similar_names`]. [#5651](https://github.com/rust-lang/rust-clippy/pull/5651) +* Ignore calls to `len` in [`or_fun_call`]. [#4429](https://github.com/rust-lang/rust-clippy/pull/4429) + +### Suggestion Improvements + +* Simplify suggestions in [`manual_memcpy`]. [#5536](https://github.com/rust-lang/rust-clippy/pull/5536) +* Fix suggestion in [`redundant_pattern_matching`] for macros. [#5511](https://github.com/rust-lang/rust-clippy/pull/5511) +* Avoid suggesting `copied()` for mutable references in [`map_clone`]. [#5530](https://github.com/rust-lang/rust-clippy/pull/5530) +* Improve help message for [`clone_double_ref`]. [#5547](https://github.com/rust-lang/rust-clippy/pull/5547) + +### ICE Fixes + +* Fix ICE caused in unwrap module. [#5590](https://github.com/rust-lang/rust-clippy/pull/5590) +* Fix ICE on rustc test issue-69020-assoc-const-arith-overflow.rs [#5499](https://github.com/rust-lang/rust-clippy/pull/5499) + +### Documentation + +* Clarify the documentation of [`unnecessary_mut_passed`]. [#5639](https://github.com/rust-lang/rust-clippy/pull/5639) +* Extend example for [`unneeded_field_pattern`]. [#5541](https://github.com/rust-lang/rust-clippy/pull/5541) ## Rust 1.44 -Current beta, release 2020-06-04 +Current stable, released 2020-06-04 [204bb9b...891e1a8](https://github.com/rust-lang/rust-clippy/compare/204bb9b...891e1a8) @@ -93,7 +170,7 @@ Current beta, release 2020-06-04 ## Rust 1.43 -Current stable, released 2020-04-23 +Released 2020-04-23 [4ee1206...204bb9b](https://github.com/rust-lang/rust-clippy/compare/4ee1206...204bb9b) @@ -1401,6 +1478,7 @@ Released 2018-09-13 [`items_after_statements`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements [`iter_cloned_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_cloned_collect [`iter_next_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_loop +[`iter_next_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_next_slice [`iter_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth [`iter_nth_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_nth_zero [`iter_skip_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#iter_skip_next @@ -1601,9 +1679,11 @@ Released 2018-09-13 [`unnecessary_fold`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation +[`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by [`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap [`unneeded_field_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_field_pattern [`unneeded_wildcard_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#unneeded_wildcard_pattern +[`unnested_or_patterns`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnested_or_patterns [`unreachable`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreachable [`unreadable_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#unreadable_literal [`unsafe_derive_deserialize`]: https://rust-lang.github.io/rust-clippy/master/index.html#unsafe_derive_deserialize @@ -1630,6 +1710,7 @@ Released 2018-09-13 [`useless_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_transmute [`useless_vec`]: https://rust-lang.github.io/rust-clippy/master/index.html#useless_vec [`vec_box`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_box +[`vec_resize_to_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#vec_resize_to_zero [`verbose_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_bit_mask [`verbose_file_reads`]: https://rust-lang.github.io/rust-clippy/master/index.html#verbose_file_reads [`vtable_address_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#vtable_address_comparisons diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md index 0f47ac98f..9f7bdcb1b 100644 --- a/CONTRIBUTING.md +++ b/CONTRIBUTING.md @@ -12,14 +12,16 @@ anything, feel free to ask questions on issues or visit the `#clippy` on [Discor All contributors are expected to follow the [Rust Code of Conduct]. -* [Getting started](#getting-started) - * [Finding something to fix/improve](#finding-something-to-fiximprove) -* [Writing code](#writing-code) -* [How Clippy works](#how-clippy-works) -* [Fixing nightly build failures](#fixing-build-failures-caused-by-rust) -* [Issue and PR Triage](#issue-and-pr-triage) -* [Bors and Homu](#bors-and-homu) -* [Contributions](#contributions) +- [Contributing to Clippy](#contributing-to-clippy) + - [Getting started](#getting-started) + - [Finding something to fix/improve](#finding-something-to-fiximprove) + - [Writing code](#writing-code) + - [Getting code-completion for rustc internals to work](#getting-code-completion-for-rustc-internals-to-work) + - [How Clippy works](#how-clippy-works) + - [Fixing build failures caused by Rust](#fixing-build-failures-caused-by-rust) + - [Issue and PR triage](#issue-and-pr-triage) + - [Bors and Homu](#bors-and-homu) + - [Contributions](#contributions) [Discord]: https://discord.gg/rust-lang [Rust Code of Conduct]: https://www.rust-lang.org/policies/code-of-conduct @@ -91,6 +93,24 @@ quick read. [rfc_stability]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#stability-guarantees [rfc_lint_cats]: https://github.com/rust-lang/rfcs/blob/master/text/2476-clippy-uno.md#lint-audit-and-categories +## Getting code-completion for rustc internals to work + +Unfortunately, [`rust-analyzer`][ra_homepage] does not (yet?) understand how Clippy uses compiler-internals +using `extern crate` and it also needs to be able to read the source files of the rustc-compiler which are not +available via a `rustup` component at the time of writing. +To work around this, you need to have a copy of the [rustc-repo][rustc_repo] available which can be obtained via +`git clone https://github.com/rust-lang/rust/`. +Then you can run a `cargo dev` command to automatically make Clippy use the rustc-repo via path-dependencies +which rust-analyzer will be able to understand. +Run `cargo dev ra-setup --repo-path ` where `` is an absolute path to the rustc repo +you just cloned. +The command will add path-dependencies pointing towards rustc-crates inside the rustc repo to +Clippys `Cargo.toml`s and should allow rust-analyzer to understand most of the types that Clippy uses. +Just make sure to remove the dependencies again before finally making a pull request! + +[ra_homepage]: https://rust-analyzer.github.io/ +[rustc_repo]: https://github.com/rust-lang/rust/ + ## How Clippy works [`clippy_lints/src/lib.rs`][lint_crate_entry] imports all the different lint modules and registers in the [`LintStore`]. diff --git a/Cargo.toml b/Cargo.toml index 6999b6bd7..836897927 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -37,7 +37,7 @@ tempfile = { version = "3.1.0", optional = true } lazy_static = "1.0" [dev-dependencies] -cargo_metadata = "0.9.0" +cargo_metadata = "0.9.1" compiletest_rs = { version = "0.5.0", features = ["tmp"] } tester = "0.7" lazy_static = "1.0" diff --git a/clippy_dev/src/lib.rs b/clippy_dev/src/lib.rs index 6fdd282c6..5baa31d5c 100644 --- a/clippy_dev/src/lib.rs +++ b/clippy_dev/src/lib.rs @@ -11,6 +11,7 @@ use walkdir::WalkDir; pub mod fmt; pub mod new_lint; +pub mod ra_setup; pub mod stderr_length_check; pub mod update_lints; @@ -400,7 +401,7 @@ fn test_replace_region_no_changes() { changed: false, new_lines: "123\n456\n789".to_string(), }; - let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, || vec![]); + let result = replace_region_in_text(text, r#"^\s*123$"#, r#"^\s*456"#, false, Vec::new); assert_eq!(expected, result); } diff --git a/clippy_dev/src/main.rs b/clippy_dev/src/main.rs index d99235f7c..281037ae3 100644 --- a/clippy_dev/src/main.rs +++ b/clippy_dev/src/main.rs @@ -1,7 +1,7 @@ #![cfg_attr(feature = "deny-warnings", deny(warnings))] use clap::{App, Arg, SubCommand}; -use clippy_dev::{fmt, new_lint, stderr_length_check, update_lints}; +use clippy_dev::{fmt, new_lint, ra_setup, stderr_length_check, update_lints}; fn main() { let matches = App::new("Clippy developer tooling") @@ -87,6 +87,19 @@ fn main() { SubCommand::with_name("limit_stderr_length") .about("Ensures that stderr files do not grow longer than a certain amount of lines."), ) + .subcommand( + SubCommand::with_name("ra-setup") + .about("Alter dependencies so rust-analyzer can find rustc internals") + .arg( + Arg::with_name("rustc-repo-path") + .long("repo-path") + .short("r") + .help("The path to a rustc repo that will be used for setting the dependencies") + .takes_value(true) + .value_name("path") + .required(true), + ), + ) .get_matches(); match matches.subcommand() { @@ -115,6 +128,7 @@ fn main() { ("limit_stderr_length", _) => { stderr_length_check::check(); }, + ("ra-setup", Some(matches)) => ra_setup::run(matches.value_of("rustc-repo-path")), _ => {}, } } diff --git a/clippy_dev/src/new_lint.rs b/clippy_dev/src/new_lint.rs index c0b2dac2f..1e032a7bc 100644 --- a/clippy_dev/src/new_lint.rs +++ b/clippy_dev/src/new_lint.rs @@ -147,6 +147,8 @@ fn get_manifest_contents(lint_name: &str, hint: &str) -> String { name = "{}" version = "0.1.0" publish = false + +[workspace] "#, hint, lint_name ) diff --git a/clippy_dev/src/ra_setup.rs b/clippy_dev/src/ra_setup.rs new file mode 100644 index 000000000..8617445c8 --- /dev/null +++ b/clippy_dev/src/ra_setup.rs @@ -0,0 +1,90 @@ +#![allow(clippy::filter_map)] + +use std::fs; +use std::fs::File; +use std::io::prelude::*; +use std::path::PathBuf; + +// This module takes an absolute path to a rustc repo and alters the dependencies to point towards +// the respective rustc subcrates instead of using extern crate xyz. +// This allows rust analyzer to analyze rustc internals and show proper information inside clippy +// code. See https://github.com/rust-analyzer/rust-analyzer/issues/3517 and https://github.com/rust-lang/rust-clippy/issues/5514 for details + +pub fn run(rustc_path: Option<&str>) { + // we can unwrap here because the arg is required here + let rustc_path = PathBuf::from(rustc_path.unwrap()); + assert!(rustc_path.is_dir(), "path is not a directory"); + let rustc_source_basedir = rustc_path.join("src"); + assert!( + rustc_source_basedir.is_dir(), + "are you sure the path leads to a rustc repo?" + ); + + let clippy_root_manifest = fs::read_to_string("Cargo.toml").expect("failed to read ./Cargo.toml"); + let clippy_root_lib_rs = fs::read_to_string("src/driver.rs").expect("failed to read ./src/driver.rs"); + inject_deps_into_manifest( + &rustc_source_basedir, + "Cargo.toml", + &clippy_root_manifest, + &clippy_root_lib_rs, + ) + .expect("Failed to inject deps into ./Cargo.toml"); + + let clippy_lints_manifest = + fs::read_to_string("clippy_lints/Cargo.toml").expect("failed to read ./clippy_lints/Cargo.toml"); + let clippy_lints_lib_rs = + fs::read_to_string("clippy_lints/src/lib.rs").expect("failed to read ./clippy_lints/src/lib.rs"); + inject_deps_into_manifest( + &rustc_source_basedir, + "clippy_lints/Cargo.toml", + &clippy_lints_manifest, + &clippy_lints_lib_rs, + ) + .expect("Failed to inject deps into ./clippy_lints/Cargo.toml"); +} + +fn inject_deps_into_manifest( + rustc_source_dir: &PathBuf, + manifest_path: &str, + cargo_toml: &str, + lib_rs: &str, +) -> std::io::Result<()> { + let extern_crates = lib_rs + .lines() + // get the deps + .filter(|line| line.starts_with("extern crate")) + // we have something like "extern crate foo;", we only care about the "foo" + // ↓ ↓ + // extern crate rustc_middle; + .map(|s| &s[13..(s.len() - 1)]); + + let new_deps = extern_crates.map(|dep| { + // format the dependencies that are going to be put inside the Cargo.toml + format!( + "{dep} = {{ path = \"{source_path}/lib{dep}\" }}\n", + dep = dep, + source_path = rustc_source_dir.display() + ) + }); + + // format a new [dependencies]-block with the new deps we need to inject + let mut all_deps = String::from("[dependencies]\n"); + new_deps.for_each(|dep_line| { + all_deps.push_str(&dep_line); + }); + + // replace "[dependencies]" with + // [dependencies] + // dep1 = { path = ... } + // dep2 = { path = ... } + // etc + let new_manifest = cargo_toml.replacen("[dependencies]\n", &all_deps, 1); + + // println!("{}", new_manifest); + let mut file = File::create(manifest_path)?; + file.write_all(new_manifest.as_bytes())?; + + println!("Dependency paths injected: {}", manifest_path); + + Ok(()) +} diff --git a/clippy_lints/Cargo.toml b/clippy_lints/Cargo.toml index 76baf27fb..e959c1a65 100644 --- a/clippy_lints/Cargo.toml +++ b/clippy_lints/Cargo.toml @@ -17,11 +17,11 @@ keywords = ["clippy", "lint", "plugin"] edition = "2018" [dependencies] -cargo_metadata = "0.9.0" +cargo_metadata = "0.9.1" if_chain = "1.0.0" itertools = "0.9" lazy_static = "1.0.2" -pulldown-cmark = { version = "0.7", default-features = false } +pulldown-cmark = { version = "0.7.1", default-features = false } quine-mc_cluskey = "0.2.2" regex-syntax = "0.6" serde = { version = "1.0", features = ["derive"] } diff --git a/clippy_lints/src/assign_ops.rs b/clippy_lints/src/assign_ops.rs index 05e2650d0..13e61fe98 100644 --- a/clippy_lints/src/assign_ops.rs +++ b/clippy_lints/src/assign_ops.rs @@ -24,7 +24,11 @@ declare_clippy_lint! { /// let mut a = 5; /// let b = 0; /// // ... + /// // Bad /// a = a + b; + /// + /// // Good + /// a += b; /// ``` pub ASSIGN_OP_PATTERN, style, diff --git a/clippy_lints/src/await_holding_lock.rs b/clippy_lints/src/await_holding_lock.rs index 832910763..a88f922d8 100644 --- a/clippy_lints/src/await_holding_lock.rs +++ b/clippy_lints/src/await_holding_lock.rs @@ -54,18 +54,13 @@ declare_lint_pass!(AwaitHoldingLock => [AWAIT_HOLDING_LOCK]); impl LateLintPass<'_, '_> for AwaitHoldingLock { fn check_body(&mut self, cx: &LateContext<'_, '_>, body: &'_ Body<'_>) { use AsyncGeneratorKind::{Block, Closure, Fn}; - match body.generator_kind { - Some(GeneratorKind::Async(Block)) - | Some(GeneratorKind::Async(Closure)) - | Some(GeneratorKind::Async(Fn)) => { - let body_id = BodyId { - hir_id: body.value.hir_id, - }; - let def_id = cx.tcx.hir().body_owner_def_id(body_id); - let tables = cx.tcx.typeck_tables_of(def_id); - check_interior_types(cx, &tables.generator_interior_types, body.value.span); - }, - _ => {}, + if let Some(GeneratorKind::Async(Block | Closure | Fn)) = body.generator_kind { + let body_id = BodyId { + hir_id: body.value.hir_id, + }; + let def_id = cx.tcx.hir().body_owner_def_id(body_id); + let tables = cx.tcx.typeck_tables_of(def_id); + check_interior_types(cx, &tables.generator_interior_types, body.value.span); } } } diff --git a/clippy_lints/src/cargo_common_metadata.rs b/clippy_lints/src/cargo_common_metadata.rs index 16b46423c..c40a387d2 100644 --- a/clippy_lints/src/cargo_common_metadata.rs +++ b/clippy_lints/src/cargo_common_metadata.rs @@ -36,13 +36,9 @@ declare_clippy_lint! { "common metadata is defined in `Cargo.toml`" } -fn warning(cx: &LateContext<'_, '_>, message: &str) { - span_lint(cx, CARGO_COMMON_METADATA, DUMMY_SP, message); -} - fn missing_warning(cx: &LateContext<'_, '_>, package: &cargo_metadata::Package, field: &str) { let message = format!("package `{}` is missing `{}` metadata", package.name, field); - warning(cx, &message); + span_lint(cx, CARGO_COMMON_METADATA, DUMMY_SP, &message); } fn is_empty_str(value: &Option) -> bool { @@ -66,12 +62,7 @@ impl LateLintPass<'_, '_> for CargoCommonMetadata { return; } - let metadata = if let Ok(metadata) = cargo_metadata::MetadataCommand::new().no_deps().exec() { - metadata - } else { - warning(cx, "could not read cargo metadata"); - return; - }; + let metadata = unwrap_cargo_metadata!(cx, CARGO_COMMON_METADATA, false); for package in metadata.packages { if is_empty_vec(&package.authors) { diff --git a/clippy_lints/src/checked_conversions.rs b/clippy_lints/src/checked_conversions.rs index d9776dd50..e845ef99c 100644 --- a/clippy_lints/src/checked_conversions.rs +++ b/clippy_lints/src/checked_conversions.rs @@ -58,24 +58,18 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CheckedConversions { } }; - if_chain! { - if let Some(cv) = result; - if let Some(to_type) = cv.to_type; - - then { + if let Some(cv) = result { + if let Some(to_type) = cv.to_type { let mut applicability = Applicability::MachineApplicable; - let snippet = snippet_with_applicability(cx, cv.expr_to_cast.span, "_", &mut - applicability); + let snippet = snippet_with_applicability(cx, cv.expr_to_cast.span, "_", &mut applicability); span_lint_and_sugg( cx, CHECKED_CONVERSIONS, item.span, "Checked cast can be simplified.", "try", - format!("{}::try_from({}).is_ok()", - to_type, - snippet), - applicability + format!("{}::try_from({}).is_ok()", to_type, snippet), + applicability, ); } } @@ -184,7 +178,7 @@ fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option> { if_chain! { if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind; if let Some((candidate, check)) = normalize_le_ge(op, left, right); - if let Some((from, to)) = get_types_from_cast(check, MAX_VALUE, INTS); + if let Some((from, to)) = get_types_from_cast(check, INTS, "max_value", "MAX"); then { Conversion::try_new(candidate, from, to) @@ -224,7 +218,7 @@ fn check_lower_bound_zero<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> O /// Check for `expr >= (to_type::MIN as from_type)` fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option> { - if let Some((from, to)) = get_types_from_cast(check, MIN_VALUE, SINTS) { + if let Some((from, to)) = get_types_from_cast(check, SINTS, "min_value", "MIN") { Conversion::try_new(candidate, from, to) } else { None @@ -232,10 +226,16 @@ fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Op } /// Tries to extract the from- and to-type from a cast expression -fn get_types_from_cast<'a>(expr: &'a Expr<'_>, func: &'a str, types: &'a [&str]) -> Option<(&'a str, &'a str)> { - // `to_type::maxmin_value() as from_type` +fn get_types_from_cast<'a>( + expr: &'a Expr<'_>, + types: &'a [&str], + func: &'a str, + assoc_const: &'a str, +) -> Option<(&'a str, &'a str)> { + // `to_type::max_value() as from_type` + // or `to_type::MAX as from_type` let call_from_cast: Option<(&Expr<'_>, &str)> = if_chain! { - // to_type::maxmin_value(), from_type + // to_type::max_value(), from_type if let ExprKind::Cast(ref limit, ref from_type) = &expr.kind; if let TyKind::Path(ref from_type_path) = &from_type.kind; if let Some(from_sym) = int_ty_to_sym(from_type_path); @@ -247,17 +247,17 @@ fn get_types_from_cast<'a>(expr: &'a Expr<'_>, func: &'a str, types: &'a [&str]) } }; - // `from_type::from(to_type::maxmin_value())` + // `from_type::from(to_type::max_value())` let limit_from: Option<(&Expr<'_>, &str)> = call_from_cast.or_else(|| { if_chain! { - // `from_type::from, to_type::maxmin_value()` + // `from_type::from, to_type::max_value()` if let ExprKind::Call(ref from_func, ref args) = &expr.kind; - // `to_type::maxmin_value()` + // `to_type::max_value()` if args.len() == 1; if let limit = &args[0]; // `from_type::from` if let ExprKind::Path(ref path) = &from_func.kind; - if let Some(from_sym) = get_implementing_type(path, INTS, FROM); + if let Some(from_sym) = get_implementing_type(path, INTS, "from"); then { Some((limit, from_sym)) @@ -268,22 +268,26 @@ fn get_types_from_cast<'a>(expr: &'a Expr<'_>, func: &'a str, types: &'a [&str]) }); if let Some((limit, from_type)) = limit_from { - if_chain! { - if let ExprKind::Call(ref fun_name, _) = &limit.kind; - // `to_type, maxmin_value` - if let ExprKind::Path(ref path) = &fun_name.kind; - // `to_type` - if let Some(to_type) = get_implementing_type(path, types, func); - - then { - Some((from_type, to_type)) - } else { - None - } + match limit.kind { + // `from_type::from(_)` + ExprKind::Call(path, _) => { + if let ExprKind::Path(ref path) = path.kind { + // `to_type` + if let Some(to_type) = get_implementing_type(path, types, func) { + return Some((from_type, to_type)); + } + } + }, + // `to_type::MAX` + ExprKind::Path(ref path) => { + if let Some(to_type) = get_implementing_type(path, types, assoc_const) { + return Some((from_type, to_type)); + } + }, + _ => {}, } - } else { - None - } + }; + None } /// Gets the type which implements the called function @@ -336,10 +340,6 @@ fn normalize_le_ge<'a>(op: &BinOp, left: &'a Expr<'a>, right: &'a Expr<'a>) -> O } // Constants -const FROM: &str = "from"; -const MAX_VALUE: &str = "max_value"; -const MIN_VALUE: &str = "min_value"; - const UINTS: &[&str] = &["u8", "u16", "u32", "u64", "usize"]; const SINTS: &[&str] = &["i8", "i16", "i32", "i64", "isize"]; const INTS: &[&str] = &["u8", "u16", "u32", "u64", "usize", "i8", "i16", "i32", "i64", "isize"]; diff --git a/clippy_lints/src/copies.rs b/clippy_lints/src/copies.rs index 66722786e..b6d50bdfa 100644 --- a/clippy_lints/src/copies.rs +++ b/clippy_lints/src/copies.rs @@ -1,9 +1,9 @@ -use crate::utils::{get_parent_expr, higher, if_sequence, same_tys, snippet, span_lint_and_note, span_lint_and_then}; +use crate::utils::{get_parent_expr, higher, if_sequence, snippet, span_lint_and_note, span_lint_and_then}; use crate::utils::{SpanlessEq, SpanlessHash}; use rustc_data_structures::fx::FxHashMap; use rustc_hir::{Arm, Block, Expr, ExprKind, MatchSource, Pat, PatKind}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty::Ty; +use rustc_middle::ty::{Ty, TyS}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::symbol::Symbol; use std::collections::hash_map::Entry; @@ -242,15 +242,11 @@ fn lint_same_fns_in_if_cond(cx: &LateContext<'_, '_>, conds: &[&Expr<'_>]) { /// Implementation of `MATCH_SAME_ARMS`. fn lint_match_arms<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &Expr<'_>) { - fn same_bindings<'tcx>( - cx: &LateContext<'_, 'tcx>, - lhs: &FxHashMap>, - rhs: &FxHashMap>, - ) -> bool { + fn same_bindings<'tcx>(lhs: &FxHashMap>, rhs: &FxHashMap>) -> bool { lhs.len() == rhs.len() && lhs .iter() - .all(|(name, l_ty)| rhs.get(name).map_or(false, |r_ty| same_tys(cx, l_ty, r_ty))) + .all(|(name, l_ty)| rhs.get(name).map_or(false, |r_ty| TyS::same_type(l_ty, r_ty))) } if let ExprKind::Match(_, ref arms, MatchSource::Normal) = expr.kind { @@ -269,7 +265,7 @@ fn lint_match_arms<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &Expr<'_>) { (min_index..=max_index).all(|index| arms[index].guard.is_none()) && SpanlessEq::new(cx).eq_expr(&lhs.body, &rhs.body) && // all patterns should have the same bindings - same_bindings(cx, &bindings(cx, &lhs.pat), &bindings(cx, &rhs.pat)) + same_bindings(&bindings(cx, &lhs.pat), &bindings(cx, &rhs.pat)) }; let indexed_arms: Vec<(usize, &Arm<'_>)> = arms.iter().enumerate().collect(); diff --git a/clippy_lints/src/double_parens.rs b/clippy_lints/src/double_parens.rs index 7f2ff8b9b..05517f6f9 100644 --- a/clippy_lints/src/double_parens.rs +++ b/clippy_lints/src/double_parens.rs @@ -13,10 +13,24 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad + /// fn simple_double_parens() -> i32 { + /// ((0)) + /// } + /// + /// // Good + /// fn simple_no_parens() -> i32 { + /// 0 + /// } + /// + /// // or + /// /// # fn foo(bar: usize) {} - /// ((0)); + /// // Bad /// foo((0)); - /// ((1, 2)); + /// + /// // Good + /// foo(0); /// ``` pub DOUBLE_PARENS, complexity, diff --git a/clippy_lints/src/drop_bounds.rs b/clippy_lints/src/drop_bounds.rs index f49668082..5a7f75948 100644 --- a/clippy_lints/src/drop_bounds.rs +++ b/clippy_lints/src/drop_bounds.rs @@ -27,6 +27,10 @@ declare_clippy_lint! { /// ```rust /// fn foo() {} /// ``` + /// Could be written as: + /// ```rust + /// fn foo() {} + /// ``` pub DROP_BOUNDS, correctness, "Bounds of the form `T: Drop` are useless" diff --git a/clippy_lints/src/duration_subsec.rs b/clippy_lints/src/duration_subsec.rs index b35a8facf..afefa2506 100644 --- a/clippy_lints/src/duration_subsec.rs +++ b/clippy_lints/src/duration_subsec.rs @@ -22,8 +22,14 @@ declare_clippy_lint! { /// ```rust /// # use std::time::Duration; /// let dur = Duration::new(5, 0); + /// + /// // Bad /// let _micros = dur.subsec_nanos() / 1_000; /// let _millis = dur.subsec_nanos() / 1_000_000; + /// + /// // Good + /// let _micros = dur.subsec_micros(); + /// let _millis = dur.subsec_millis(); /// ``` pub DURATION_SUBSEC, complexity, diff --git a/clippy_lints/src/enum_variants.rs b/clippy_lints/src/enum_variants.rs index a5871cf0c..cb0fd59a2 100644 --- a/clippy_lints/src/enum_variants.rs +++ b/clippy_lints/src/enum_variants.rs @@ -25,31 +25,47 @@ declare_clippy_lint! { /// BattenbergCake, /// } /// ``` + /// Could be written as: + /// ```rust + /// enum Cake { + /// BlackForest, + /// Hummingbird, + /// Battenberg, + /// } + /// ``` pub ENUM_VARIANT_NAMES, style, "enums where all variants share a prefix/postfix" } declare_clippy_lint! { - /// **What it does:** Detects enumeration variants that are prefixed or suffixed - /// by the same characters. + /// **What it does:** Detects public enumeration variants that are + /// prefixed or suffixed by the same characters. /// - /// **Why is this bad?** Enumeration variant names should specify their variant, + /// **Why is this bad?** Public enumeration variant names should specify their variant, /// not repeat the enumeration name. /// /// **Known problems:** None. /// /// **Example:** /// ```rust - /// enum Cake { + /// pub enum Cake { /// BlackForestCake, /// HummingbirdCake, /// BattenbergCake, /// } /// ``` + /// Could be written as: + /// ```rust + /// pub enum Cake { + /// BlackForest, + /// Hummingbird, + /// Battenberg, + /// } + /// ``` pub PUB_ENUM_VARIANT_NAMES, pedantic, - "enums where all variants share a prefix/postfix" + "public enums where all variants share a prefix/postfix" } declare_clippy_lint! { @@ -66,6 +82,12 @@ declare_clippy_lint! { /// struct BlackForestCake; /// } /// ``` + /// Could be written as: + /// ```rust + /// mod cake { + /// struct BlackForest; + /// } + /// ``` pub MODULE_NAME_REPETITIONS, pedantic, "type names prefixed/postfixed with their containing module's name" diff --git a/clippy_lints/src/eq_op.rs b/clippy_lints/src/eq_op.rs index 4e1c1f131..d7819d737 100644 --- a/clippy_lints/src/eq_op.rs +++ b/clippy_lints/src/eq_op.rs @@ -39,7 +39,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```ignore + /// // Bad /// &x == y + /// + /// // Good + /// x == *y /// ``` pub OP_REF, style, diff --git a/clippy_lints/src/escape.rs b/clippy_lints/src/escape.rs index 1ec60a0e6..7227683aa 100644 --- a/clippy_lints/src/escape.rs +++ b/clippy_lints/src/escape.rs @@ -28,9 +28,16 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// # fn foo(bar: usize) {} + /// + /// // Bad /// let x = Box::new(1); /// foo(*x); /// println!("{}", *x); + /// + /// // Good + /// let x = 1; + /// foo(x); + /// println!("{}", x); /// ``` pub BOXED_LOCAL, perf, diff --git a/clippy_lints/src/eta_reduction.rs b/clippy_lints/src/eta_reduction.rs index e3e1136b6..d093025fd 100644 --- a/clippy_lints/src/eta_reduction.rs +++ b/clippy_lints/src/eta_reduction.rs @@ -26,7 +26,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust,ignore + /// // Bad /// xs.map(|x| foo(x)) + /// + /// // Good + /// xs.map(foo) /// ``` /// where `foo(_)` is a plain function that takes the exact argument type of /// `x`. diff --git a/clippy_lints/src/eval_order_dependence.rs b/clippy_lints/src/eval_order_dependence.rs index 5206266cc..74144fb29 100644 --- a/clippy_lints/src/eval_order_dependence.rs +++ b/clippy_lints/src/eval_order_dependence.rs @@ -21,11 +21,20 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// let mut x = 0; + /// + /// // Bad /// let a = { /// x = 1; /// 1 /// } + x; /// // Unclear whether a is 1 or 2. + /// + /// // Good + /// let tmp = { + /// x = 1; + /// 1 + /// }; + /// let a = tmp + x; /// ``` pub EVAL_ORDER_DEPENDENCE, complexity, diff --git a/clippy_lints/src/fallible_impl_from.rs b/clippy_lints/src/fallible_impl_from.rs index 17639cc2a..928128164 100644 --- a/clippy_lints/src/fallible_impl_from.rs +++ b/clippy_lints/src/fallible_impl_from.rs @@ -20,12 +20,31 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// struct Foo(i32); + /// + /// // Bad /// impl From for Foo { /// fn from(s: String) -> Self { /// Foo(s.parse().unwrap()) /// } /// } /// ``` + /// + /// ```rust + /// // Good + /// struct Foo(i32); + /// + /// use std::convert::TryFrom; + /// impl TryFrom for Foo { + /// type Error = (); + /// fn try_from(s: String) -> Result { + /// if let Ok(parsed) = s.parse() { + /// Ok(Foo(parsed)) + /// } else { + /// Err(()) + /// } + /// } + /// } + /// ``` pub FALLIBLE_IMPL_FROM, nursery, "Warn on impls of `From<..>` that contain `panic!()` or `unwrap()`" @@ -120,7 +139,7 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it move |diag| { diag.help( "`From` is intended for infallible conversions only. \ - Use `TryFrom` if there's a possibility for the conversion to fail."); + Use `TryFrom` if there's a possibility for the conversion to fail."); diag.span_note(fpu.result, "potential failure(s)"); }); } diff --git a/clippy_lints/src/floating_point_arithmetic.rs b/clippy_lints/src/floating_point_arithmetic.rs index 86317fb8b..3a912d928 100644 --- a/clippy_lints/src/floating_point_arithmetic.rs +++ b/clippy_lints/src/floating_point_arithmetic.rs @@ -28,7 +28,6 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust - /// /// let a = 3f32; /// let _ = a.powf(1.0 / 3.0); /// let _ = (1.0 + a).ln(); @@ -38,7 +37,6 @@ declare_clippy_lint! { /// is better expressed as /// /// ```rust - /// /// let a = 3f32; /// let _ = a.cbrt(); /// let _ = a.ln_1p(); diff --git a/clippy_lints/src/format.rs b/clippy_lints/src/format.rs index 5b092526c..1530538aa 100644 --- a/clippy_lints/src/format.rs +++ b/clippy_lints/src/format.rs @@ -25,9 +25,13 @@ declare_clippy_lint! { /// /// **Examples:** /// ```rust + /// + /// // Bad /// # let foo = "foo"; - /// format!("foo"); /// format!("{}", foo); + /// + /// // Good + /// format!("foo"); /// ``` pub USELESS_FORMAT, complexity, diff --git a/clippy_lints/src/formatting.rs b/clippy_lints/src/formatting.rs index eb4b7a826..156246fb8 100644 --- a/clippy_lints/src/formatting.rs +++ b/clippy_lints/src/formatting.rs @@ -112,12 +112,8 @@ declare_lint_pass!(Formatting => [ impl EarlyLintPass for Formatting { fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) { for w in block.stmts.windows(2) { - match (&w[0].kind, &w[1].kind) { - (&StmtKind::Expr(ref first), &StmtKind::Expr(ref second)) - | (&StmtKind::Expr(ref first), &StmtKind::Semi(ref second)) => { - check_missing_else(cx, first, second); - }, - _ => (), + if let (StmtKind::Expr(first), StmtKind::Expr(second) | StmtKind::Semi(second)) = (&w[0].kind, &w[1].kind) { + check_missing_else(cx, first, second); } } } diff --git a/clippy_lints/src/functions.rs b/clippy_lints/src/functions.rs index c24a24733..325b6cf32 100644 --- a/clippy_lints/src/functions.rs +++ b/clippy_lints/src/functions.rs @@ -49,11 +49,11 @@ declare_clippy_lint! { /// **Known problems:** None. /// /// **Example:** - /// ``` rust + /// ```rust /// fn im_too_long() { - /// println!(""); - /// // ... 100 more LoC - /// println!(""); + /// println!(""); + /// // ... 100 more LoC + /// println!(""); /// } /// ``` pub TOO_MANY_LINES, @@ -79,10 +79,16 @@ declare_clippy_lint! { /// `some_argument.get_raw_ptr()`). /// /// **Example:** - /// ```rust + /// ```rust,ignore + /// // Bad /// pub fn foo(x: *const u8) { /// println!("{}", unsafe { *x }); /// } + /// + /// // Good + /// pub unsafe fn foo(x: *const u8) { + /// println!("{}", unsafe { *x }); + /// } /// ``` pub NOT_UNSAFE_PTR_ARG_DEREF, correctness, diff --git a/clippy_lints/src/implicit_saturating_sub.rs b/clippy_lints/src/implicit_saturating_sub.rs index 155a93de4..fdaf37e5e 100644 --- a/clippy_lints/src/implicit_saturating_sub.rs +++ b/clippy_lints/src/implicit_saturating_sub.rs @@ -25,13 +25,6 @@ declare_clippy_lint! { /// if i != 0 { /// i -= 1; /// } - /// ``` - /// Use instead: - /// ```rust - /// let end: u32 = 10; - /// let start: u32 = 5; - /// - /// let mut i: u32 = end - start; /// /// // Good /// i = i.saturating_sub(1); diff --git a/clippy_lints/src/int_plus_one.rs b/clippy_lints/src/int_plus_one.rs index d5dbd4956..e91fb0c2f 100644 --- a/clippy_lints/src/int_plus_one.rs +++ b/clippy_lints/src/int_plus_one.rs @@ -10,7 +10,6 @@ use crate::utils::{snippet_opt, span_lint_and_sugg}; declare_clippy_lint! { /// **What it does:** Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block /// - /// /// **Why is this bad?** Readability -- better to use `> y` instead of `>= y + 1`. /// /// **Known problems:** None. diff --git a/clippy_lints/src/integer_division.rs b/clippy_lints/src/integer_division.rs index fe34d33fe..d537ef3f3 100644 --- a/clippy_lints/src/integer_division.rs +++ b/clippy_lints/src/integer_division.rs @@ -15,10 +15,13 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust - /// fn main() { - /// let x = 3 / 2; - /// println!("{}", x); - /// } + /// // Bad + /// let x = 3 / 2; + /// println!("{}", x); + /// + /// // Good + /// let x = 3f32 / 2f32; + /// println!("{}", x); /// ``` pub INTEGER_DIVISION, restriction, diff --git a/clippy_lints/src/items_after_statements.rs b/clippy_lints/src/items_after_statements.rs index e7062b7c1..c8576bcfc 100644 --- a/clippy_lints/src/items_after_statements.rs +++ b/clippy_lints/src/items_after_statements.rs @@ -16,6 +16,7 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// fn foo() { /// println!("cake"); /// } @@ -28,6 +29,21 @@ declare_clippy_lint! { /// foo(); // prints "foo" /// } /// ``` + /// + /// ```rust + /// // Good + /// fn foo() { + /// println!("cake"); + /// } + /// + /// fn main() { + /// fn foo() { + /// println!("foo"); + /// } + /// foo(); // prints "foo" + /// foo(); // prints "foo" + /// } + /// ``` pub ITEMS_AFTER_STATEMENTS, pedantic, "blocks where an item comes after a statement" diff --git a/clippy_lints/src/len_zero.rs b/clippy_lints/src/len_zero.rs index 2ec0b5a8d..f5bfede75 100644 --- a/clippy_lints/src/len_zero.rs +++ b/clippy_lints/src/len_zero.rs @@ -1,4 +1,4 @@ -use crate::utils::{get_item_name, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty}; +use crate::utils::{get_item_name, higher, snippet_with_applicability, span_lint, span_lint_and_sugg, walk_ptrs_ty}; use rustc_ast::ast::LitKind; use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; @@ -259,6 +259,17 @@ fn check_len( /// Checks if this type has an `is_empty` method. fn has_is_empty(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + /// Special case ranges until `range_is_empty` is stabilized. See issue 3807. + fn should_skip_range(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + higher::range(cx, expr).map_or(false, |_| { + !cx.tcx + .features() + .declared_lib_features + .iter() + .any(|(name, _)| name.as_str() == "range_is_empty") + }) + } + /// Gets an `AssocItem` and return true if it matches `is_empty(self)`. fn is_is_empty(cx: &LateContext<'_, '_>, item: &ty::AssocItem) -> bool { if let ty::AssocKind::Fn = item.kind { @@ -284,6 +295,10 @@ fn has_is_empty(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { }) } + if should_skip_range(cx, expr) { + return false; + } + let ty = &walk_ptrs_ty(cx.tables.expr_ty(expr)); match ty.kind { ty::Dynamic(ref tt, ..) => { diff --git a/clippy_lints/src/let_and_return.rs b/clippy_lints/src/let_and_return.rs new file mode 100644 index 000000000..6d3fb317b --- /dev/null +++ b/clippy_lints/src/let_and_return.rs @@ -0,0 +1,141 @@ +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::def_id::DefId; +use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor}; +use rustc_hir::{Block, Expr, ExprKind, PatKind, StmtKind}; +use rustc_lint::{LateContext, LateLintPass, LintContext}; +use rustc_middle::hir::map::Map; +use rustc_middle::lint::in_external_macro; +use rustc_middle::ty::subst::GenericArgKind; +use rustc_session::{declare_lint_pass, declare_tool_lint}; + +use crate::utils::{in_macro, match_qpath, snippet_opt, span_lint_and_then}; + +declare_clippy_lint! { + /// **What it does:** Checks for `let`-bindings, which are subsequently + /// returned. + /// + /// **Why is this bad?** It is just extraneous code. Remove it to make your code + /// more rusty. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// ```rust + /// fn foo() -> String { + /// let x = String::new(); + /// x + /// } + /// ``` + /// instead, use + /// ``` + /// fn foo() -> String { + /// String::new() + /// } + /// ``` + pub LET_AND_RETURN, + style, + "creating a let-binding and then immediately returning it like `let x = expr; x` at the end of a block" +} + +declare_lint_pass!(LetReturn => [LET_AND_RETURN]); + +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetReturn { + fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx Block<'_>) { + // we need both a let-binding stmt and an expr + if_chain! { + if let Some(retexpr) = block.expr; + if let Some(stmt) = block.stmts.iter().last(); + if let StmtKind::Local(local) = &stmt.kind; + if local.ty.is_none(); + if local.attrs.is_empty(); + if let Some(initexpr) = &local.init; + if let PatKind::Binding(.., ident, _) = local.pat.kind; + if let ExprKind::Path(qpath) = &retexpr.kind; + if match_qpath(qpath, &[&*ident.name.as_str()]); + if !last_statement_borrows(cx, initexpr); + if !in_external_macro(cx.sess(), initexpr.span); + if !in_external_macro(cx.sess(), retexpr.span); + if !in_external_macro(cx.sess(), local.span); + if !in_macro(local.span); + then { + span_lint_and_then( + cx, + LET_AND_RETURN, + retexpr.span, + "returning the result of a `let` binding from a block", + |err| { + err.span_label(local.span, "unnecessary `let` binding"); + + if let Some(snippet) = snippet_opt(cx, initexpr.span) { + err.multipart_suggestion( + "return the expression directly", + vec![ + (local.span, String::new()), + (retexpr.span, snippet), + ], + Applicability::MachineApplicable, + ); + } else { + err.span_help(initexpr.span, "this expression can be directly returned"); + } + }, + ); + } + } + } +} + +fn last_statement_borrows<'tcx>(cx: &LateContext<'_, 'tcx>, expr: &'tcx Expr<'tcx>) -> bool { + let mut visitor = BorrowVisitor { cx, borrows: false }; + walk_expr(&mut visitor, expr); + visitor.borrows +} + +struct BorrowVisitor<'a, 'tcx> { + cx: &'a LateContext<'a, 'tcx>, + borrows: bool, +} + +impl BorrowVisitor<'_, '_> { + fn fn_def_id(&self, expr: &Expr<'_>) -> Option { + match &expr.kind { + ExprKind::MethodCall(..) => self.cx.tables.type_dependent_def_id(expr.hir_id), + ExprKind::Call( + Expr { + kind: ExprKind::Path(qpath), + .. + }, + .., + ) => self.cx.tables.qpath_res(qpath, expr.hir_id).opt_def_id(), + _ => None, + } + } +} + +impl<'tcx> Visitor<'tcx> for BorrowVisitor<'_, 'tcx> { + type Map = Map<'tcx>; + + fn visit_expr(&mut self, expr: &'tcx Expr<'_>) { + if self.borrows { + return; + } + + if let Some(def_id) = self.fn_def_id(expr) { + self.borrows = self + .cx + .tcx + .fn_sig(def_id) + .output() + .skip_binder() + .walk() + .any(|arg| matches!(arg.unpack(), GenericArgKind::Lifetime(_))); + } + + walk_expr(self, expr); + } + + fn nested_visit_map(&mut self) -> NestedVisitorMap { + NestedVisitorMap::None + } +} diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index b7d928d24..cd258c7b5 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -1,5 +1,6 @@ // error-pattern:cargo-clippy +#![feature(bindings_after_at)] #![feature(box_syntax)] #![feature(box_patterns)] #![feature(or_patterns)] @@ -12,6 +13,7 @@ #![cfg_attr(feature = "deny-warnings", deny(warnings))] #![feature(crate_visibility_modifier)] #![feature(concat_idents)] +#![feature(drain_filter)] // FIXME: switch to something more ergonomic here, once available. // (Currently there is no way to opt into sysroot crates without `extern crate`.) @@ -239,6 +241,7 @@ mod large_const_arrays; mod large_enum_variant; mod large_stack_arrays; mod len_zero; +mod let_and_return; mod let_if_seq; mod let_underscore; mod lifetimes; @@ -318,6 +321,8 @@ mod try_err; mod types; mod unicode; mod unnamed_address; +mod unnecessary_sort_by; +mod unnested_or_patterns; mod unsafe_removed_from_name; mod unused_io_amount; mod unused_self; @@ -325,6 +330,7 @@ mod unwrap; mod use_self; mod useless_conversion; mod vec; +mod vec_resize_to_zero; mod verbose_file_reads; mod wildcard_dependencies; mod wildcard_imports; @@ -594,6 +600,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &large_stack_arrays::LARGE_STACK_ARRAYS, &len_zero::LEN_WITHOUT_IS_EMPTY, &len_zero::LEN_ZERO, + &let_and_return::LET_AND_RETURN, &let_if_seq::USELESS_LET_IF_SEQ, &let_underscore::LET_UNDERSCORE_LOCK, &let_underscore::LET_UNDERSCORE_MUST_USE, @@ -664,6 +671,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &methods::INTO_ITER_ON_REF, &methods::ITERATOR_STEP_BY_ZERO, &methods::ITER_CLONED_COLLECT, + &methods::ITER_NEXT_SLICE, &methods::ITER_NTH, &methods::ITER_NTH_ZERO, &methods::ITER_SKIP_NEXT, @@ -769,7 +777,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: ®ex::INVALID_REGEX, ®ex::REGEX_MACRO, ®ex::TRIVIAL_REGEX, - &returns::LET_AND_RETURN, &returns::NEEDLESS_RETURN, &returns::UNUSED_UNIT, &serde_api::SERDE_API_MISUSE, @@ -832,6 +839,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &unicode::ZERO_WIDTH_SPACE, &unnamed_address::FN_ADDRESS_COMPARISONS, &unnamed_address::VTABLE_ADDRESS_COMPARISONS, + &unnecessary_sort_by::UNNECESSARY_SORT_BY, + &unnested_or_patterns::UNNESTED_OR_PATTERNS, &unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME, &unused_io_amount::UNUSED_IO_AMOUNT, &unused_self::UNUSED_SELF, @@ -847,6 +856,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &utils::internal_lints::OUTER_EXPN_EXPN_DATA, &utils::internal_lints::PRODUCE_ICE, &vec::USELESS_VEC, + &vec_resize_to_zero::VEC_RESIZE_TO_ZERO, &verbose_file_reads::VERBOSE_FILE_READS, &wildcard_dependencies::WILDCARD_DEPENDENCIES, &wildcard_imports::ENUM_GLOB_USE, @@ -994,6 +1004,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|| box ptr_offset_with_cast::PtrOffsetWithCast); store.register_late_pass(|| box redundant_clone::RedundantClone); store.register_late_pass(|| box slow_vector_initialization::SlowVectorInit); + store.register_late_pass(|| box unnecessary_sort_by::UnnecessarySortBy); store.register_late_pass(|| box types::RefToMut); store.register_late_pass(|| box assertions_on_constants::AssertionsOnConstants); store.register_late_pass(|| box missing_const_for_fn::MissingConstForFn); @@ -1016,6 +1027,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_early_pass(|| box formatting::Formatting); store.register_early_pass(|| box misc_early::MiscEarlyLints); store.register_early_pass(|| box returns::Return); + store.register_late_pass(|| box let_and_return::LetReturn); store.register_early_pass(|| box collapsible_if::CollapsibleIf); store.register_early_pass(|| box items_after_statements::ItemsAfterStatements); store.register_early_pass(|| box precedence::Precedence); @@ -1062,10 +1074,12 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_early_pass(|| box manual_non_exhaustive::ManualNonExhaustive); store.register_late_pass(|| box manual_async_fn::ManualAsyncFn); store.register_early_pass(|| box redundant_field_names::RedundantFieldNames); + store.register_late_pass(|| box vec_resize_to_zero::VecResizeToZero); let single_char_binding_names_threshold = conf.single_char_binding_names_threshold; store.register_early_pass(move || box non_expressive_names::NonExpressiveNames { single_char_binding_names_threshold, }); + store.register_early_pass(|| box unnested_or_patterns::UnnestedOrPatterns); store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![ LintId::of(&arithmetic::FLOAT_ARITHMETIC), @@ -1164,6 +1178,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&types::CAST_POSSIBLE_TRUNCATION), LintId::of(&types::CAST_POSSIBLE_WRAP), LintId::of(&types::CAST_PRECISION_LOSS), + LintId::of(&types::CAST_PTR_ALIGNMENT), LintId::of(&types::CAST_SIGN_LOSS), LintId::of(&types::IMPLICIT_HASHER), LintId::of(&types::INVALID_UPCAST_COMPARISONS), @@ -1257,6 +1272,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&large_enum_variant::LARGE_ENUM_VARIANT), LintId::of(&len_zero::LEN_WITHOUT_IS_EMPTY), LintId::of(&len_zero::LEN_ZERO), + LintId::of(&let_and_return::LET_AND_RETURN), LintId::of(&let_underscore::LET_UNDERSCORE_LOCK), LintId::of(&lifetimes::EXTRA_UNUSED_LIFETIMES), LintId::of(&lifetimes::NEEDLESS_LIFETIMES), @@ -1303,6 +1319,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&methods::INTO_ITER_ON_REF), LintId::of(&methods::ITERATOR_STEP_BY_ZERO), LintId::of(&methods::ITER_CLONED_COLLECT), + LintId::of(&methods::ITER_NEXT_SLICE), LintId::of(&methods::ITER_NTH), LintId::of(&methods::ITER_NTH_ZERO), LintId::of(&methods::ITER_SKIP_NEXT), @@ -1381,7 +1398,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(®ex::INVALID_REGEX), LintId::of(®ex::REGEX_MACRO), LintId::of(®ex::TRIVIAL_REGEX), - LintId::of(&returns::LET_AND_RETURN), LintId::of(&returns::NEEDLESS_RETURN), LintId::of(&returns::UNUSED_UNIT), LintId::of(&serde_api::SERDE_API_MISUSE), @@ -1410,7 +1426,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&types::ABSURD_EXTREME_COMPARISONS), LintId::of(&types::BORROWED_BOX), LintId::of(&types::BOX_VEC), - LintId::of(&types::CAST_PTR_ALIGNMENT), LintId::of(&types::CAST_REF_TO_MUT), LintId::of(&types::CHAR_LIT_AS_U8), LintId::of(&types::FN_TO_NUMERIC_CAST), @@ -1424,12 +1439,15 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&unicode::ZERO_WIDTH_SPACE), LintId::of(&unnamed_address::FN_ADDRESS_COMPARISONS), LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS), + LintId::of(&unnecessary_sort_by::UNNECESSARY_SORT_BY), + LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS), LintId::of(&unsafe_removed_from_name::UNSAFE_REMOVED_FROM_NAME), LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT), LintId::of(&unwrap::PANICKING_UNWRAP), LintId::of(&unwrap::UNNECESSARY_UNWRAP), LintId::of(&useless_conversion::USELESS_CONVERSION), LintId::of(&vec::USELESS_VEC), + LintId::of(&vec_resize_to_zero::VEC_RESIZE_TO_ZERO), LintId::of(&write::PRINTLN_EMPTY_STRING), LintId::of(&write::PRINT_LITERAL), LintId::of(&write::PRINT_WITH_NEWLINE), @@ -1464,6 +1482,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&inherent_to_string::INHERENT_TO_STRING), LintId::of(&len_zero::LEN_WITHOUT_IS_EMPTY), LintId::of(&len_zero::LEN_ZERO), + LintId::of(&let_and_return::LET_AND_RETURN), LintId::of(&literal_representation::INCONSISTENT_DIGIT_GROUPING), LintId::of(&loops::EMPTY_LOOP), LintId::of(&loops::FOR_KV_MAP), @@ -1483,6 +1502,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&methods::CHARS_NEXT_CMP), LintId::of(&methods::INTO_ITER_ON_REF), LintId::of(&methods::ITER_CLONED_COLLECT), + LintId::of(&methods::ITER_NEXT_SLICE), LintId::of(&methods::ITER_NTH_ZERO), LintId::of(&methods::ITER_SKIP_NEXT), LintId::of(&methods::MANUAL_SATURATING_ARITHMETIC), @@ -1515,7 +1535,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&redundant_static_lifetimes::REDUNDANT_STATIC_LIFETIMES), LintId::of(®ex::REGEX_MACRO), LintId::of(®ex::TRIVIAL_REGEX), - LintId::of(&returns::LET_AND_RETURN), LintId::of(&returns::NEEDLESS_RETURN), LintId::of(&returns::UNUSED_UNIT), LintId::of(&single_component_path_imports::SINGLE_COMPONENT_PATH_IMPORTS), @@ -1604,6 +1623,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&types::UNIT_ARG), LintId::of(&types::UNNECESSARY_CAST), LintId::of(&types::VEC_BOX), + LintId::of(&unnecessary_sort_by::UNNECESSARY_SORT_BY), + LintId::of(&unnested_or_patterns::UNNESTED_OR_PATTERNS), LintId::of(&unwrap::UNNECESSARY_UNWRAP), LintId::of(&useless_conversion::USELESS_CONVERSION), LintId::of(&zero_div_zero::ZERO_DIVIDED_BY_ZERO), @@ -1669,7 +1690,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&transmute::WRONG_TRANSMUTE), LintId::of(&transmuting_null::TRANSMUTING_NULL), LintId::of(&types::ABSURD_EXTREME_COMPARISONS), - LintId::of(&types::CAST_PTR_ALIGNMENT), LintId::of(&types::CAST_REF_TO_MUT), LintId::of(&types::UNIT_CMP), LintId::of(&unicode::ZERO_WIDTH_SPACE), @@ -1677,6 +1697,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&unnamed_address::VTABLE_ADDRESS_COMPARISONS), LintId::of(&unused_io_amount::UNUSED_IO_AMOUNT), LintId::of(&unwrap::PANICKING_UNWRAP), + LintId::of(&vec_resize_to_zero::VEC_RESIZE_TO_ZERO), ]); store.register_group(true, "clippy::perf", Some("clippy_perf"), vec![ diff --git a/clippy_lints/src/literal_representation.rs b/clippy_lints/src/literal_representation.rs index ec7c4531e..7ba43562d 100644 --- a/clippy_lints/src/literal_representation.rs +++ b/clippy_lints/src/literal_representation.rs @@ -24,7 +24,11 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust + /// // Bad /// let x: u64 = 61864918973511; + /// + /// // Good + /// let x: u64 = 61_864_918_973_511; /// ``` pub UNREADABLE_LITERAL, pedantic, @@ -44,7 +48,11 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust + /// // Probably mistyped /// 2_32; + /// + /// // Good + /// 2_i32; /// ``` pub MISTYPED_LITERAL_SUFFIXES, correctness, @@ -63,7 +71,11 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust + /// // Bad /// let x: u64 = 618_64_9189_73_511; + /// + /// // Good + /// let x: u64 = 61_864_918_973_511; /// ``` pub INCONSISTENT_DIGIT_GROUPING, style, diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs index 38a5829b3..57c62d739 100644 --- a/clippy_lints/src/loops.rs +++ b/clippy_lints/src/loops.rs @@ -8,7 +8,7 @@ use crate::utils::{ multispan_sugg, snippet, snippet_opt, snippet_with_applicability, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, SpanlessEq, }; -use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sugg}; +use crate::utils::{is_type_diagnostic_item, qpath_res, sugg}; use if_chain::if_chain; use rustc_ast::ast; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; @@ -24,10 +24,10 @@ use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::map::Map; use rustc_middle::lint::in_external_macro; use rustc_middle::middle::region; -use rustc_middle::ty::{self, Ty}; +use rustc_middle::ty::{self, Ty, TyS}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::Span; -use rustc_span::BytePos; +use rustc_span::symbol::Symbol; use rustc_typeck::expr_use_visitor::{ConsumeMode, Delegate, ExprUseVisitor, Place, PlaceBase}; use std::iter::{once, Iterator}; use std::mem; @@ -1256,7 +1256,7 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e } else if method_name == "into_iter" && match_trait_method(cx, arg, &paths::INTO_ITERATOR) { let receiver_ty = cx.tables.expr_ty(&args[0]); let receiver_ty_adjusted = cx.tables.expr_ty_adjusted(&args[0]); - if same_tys(cx, receiver_ty, receiver_ty_adjusted) { + if TyS::same_type(receiver_ty, receiver_ty_adjusted) { let mut applicability = Applicability::MachineApplicable; let object = snippet_with_applicability(cx, args[0].span, "_", &mut applicability); span_lint_and_sugg( @@ -1277,7 +1277,7 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e mutbl: Mutability::Not, }, ); - if same_tys(cx, receiver_ty_adjusted, ref_receiver_ty) { + if TyS::same_type(receiver_ty_adjusted, ref_receiver_ty) { lint_iter_method(cx, args, arg, method_name) } } @@ -2381,32 +2381,32 @@ fn check_needless_collect<'a, 'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'a, ' match_type(cx, ty, &paths::BTREEMAP) || is_type_diagnostic_item(cx, ty, sym!(hashmap_type)) { if method.ident.name == sym!(len) { - let span = shorten_needless_collect_span(expr); + let span = shorten_span(expr, sym!(collect)); span_lint_and_sugg( cx, NEEDLESS_COLLECT, span, NEEDLESS_COLLECT_MSG, "replace with", - ".count()".to_string(), + "count()".to_string(), Applicability::MachineApplicable, ); } if method.ident.name == sym!(is_empty) { - let span = shorten_needless_collect_span(expr); + let span = shorten_span(expr, sym!(iter)); span_lint_and_sugg( cx, NEEDLESS_COLLECT, span, NEEDLESS_COLLECT_MSG, "replace with", - ".next().is_none()".to_string(), + "get(0).is_none()".to_string(), Applicability::MachineApplicable, ); } if method.ident.name == sym!(contains) { let contains_arg = snippet(cx, args[1].span, "??"); - let span = shorten_needless_collect_span(expr); + let span = shorten_span(expr, sym!(collect)); span_lint_and_then( cx, NEEDLESS_COLLECT, @@ -2422,7 +2422,7 @@ fn check_needless_collect<'a, 'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'a, ' span, "replace with", format!( - ".any(|{}| x == {})", + "any(|{}| x == {})", arg, pred ), Applicability::MachineApplicable, @@ -2435,13 +2435,13 @@ fn check_needless_collect<'a, 'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'a, ' } } -fn shorten_needless_collect_span(expr: &Expr<'_>) -> Span { - if_chain! { - if let ExprKind::MethodCall(_, _, ref args) = expr.kind; - if let ExprKind::MethodCall(_, ref span, _) = args[0].kind; - then { - return expr.span.with_lo(span.lo() - BytePos(1)); +fn shorten_span(expr: &Expr<'_>, target_fn_name: Symbol) -> Span { + let mut current_expr = expr; + while let ExprKind::MethodCall(ref path, ref span, ref args) = current_expr.kind { + if path.ident.name == target_fn_name { + return expr.span.with_lo(span.lo()); } + current_expr = &args[0]; } unreachable!() } diff --git a/clippy_lints/src/matches.rs b/clippy_lints/src/matches.rs index 94380acfc..6d7af45a4 100644 --- a/clippy_lints/src/matches.rs +++ b/clippy_lints/src/matches.rs @@ -36,10 +36,17 @@ declare_clippy_lint! { /// ```rust /// # fn bar(stool: &str) {} /// # let x = Some("abc"); + /// + /// // Bad /// match x { /// Some(ref foo) => bar(foo), /// _ => (), /// } + /// + /// // Good + /// if let Some(ref foo) = x { + /// bar(foo); + /// } /// ``` pub SINGLE_MATCH, style, @@ -97,11 +104,19 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust,ignore + /// // Bad /// match x { /// &A(ref y) => foo(y), /// &B => bar(), /// _ => frob(&x), /// } + /// + /// // Good + /// match *x { + /// A(ref y) => foo(y), + /// B => bar(), + /// _ => frob(x), + /// } /// ``` pub MATCH_REF_PATS, style, @@ -197,10 +212,15 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// let x: Option<()> = None; + /// + /// // Bad /// let r: Option<&()> = match x { /// None => None, /// Some(ref v) => Some(v), /// }; + /// + /// // Good + /// let r: Option<&()> = x.as_ref(); /// ``` pub MATCH_AS_REF, complexity, @@ -219,10 +239,18 @@ declare_clippy_lint! { /// ```rust /// # enum Foo { A(usize), B(usize) } /// # let x = Foo::B(1); + /// + /// // Bad /// match x { /// Foo::A(_) => {}, /// _ => {}, /// } + /// + /// // Good + /// match x { + /// Foo::A(_) => {}, + /// Foo::B(_) => {}, + /// } /// ``` pub WILDCARD_ENUM_MATCH_ARM, restriction, @@ -242,16 +270,14 @@ declare_clippy_lint! { /// ```rust /// # enum Foo { A, B, C } /// # let x = Foo::B; + /// // Bad /// match x { /// Foo::A => {}, /// Foo::B => {}, /// _ => {}, /// } - /// ``` - /// Use instead: - /// ```rust - /// # enum Foo { A, B, C } - /// # let x = Foo::B; + /// + /// // Good /// match x { /// Foo::A => {}, /// Foo::B => {}, @@ -273,10 +299,17 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// match "foo" { /// "a" => {}, /// "bar" | _ => {}, /// } + /// + /// // Good + /// match "foo" { + /// "a" => {}, + /// _ => {}, + /// } /// ``` pub WILDCARD_IN_OR_PATTERNS, complexity, diff --git a/clippy_lints/src/methods/manual_saturating_arithmetic.rs b/clippy_lints/src/methods/manual_saturating_arithmetic.rs index aaed6d750..4f5c06e78 100644 --- a/clippy_lints/src/methods/manual_saturating_arithmetic.rs +++ b/clippy_lints/src/methods/manual_saturating_arithmetic.rs @@ -57,7 +57,7 @@ pub fn lint(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, args: &[&[hir::Expr< ); } else { match (mm, arith) { - (MinMax::Max, "add") | (MinMax::Max, "mul") | (MinMax::Min, "sub") => (), + (MinMax::Max, "add" | "mul") | (MinMax::Min, "sub") => (), _ => return, } diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 52ca962e7..214cf0c13 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -18,7 +18,7 @@ use rustc_lint::{LateContext, LateLintPass, Lint, LintContext}; use rustc_middle::hir::map::Map; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::subst::GenericArgKind; -use rustc_middle::ty::{self, Ty}; +use rustc_middle::ty::{self, Ty, TyS}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::Span; use rustc_span::symbol::{sym, SymbolStr}; @@ -26,12 +26,12 @@ use rustc_span::symbol::{sym, SymbolStr}; use crate::consts::{constant, Constant}; use crate::utils::usage::mutated_variables; use crate::utils::{ - get_arg_name, get_parent_expr, get_trait_def_id, has_iter_method, implements_trait, in_macro, is_copy, + get_arg_name, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait, in_macro, is_copy, is_ctor_or_promotable_const_function, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_trait_method, match_type, match_var, method_calls, method_chain_args, paths, - remove_blocks, return_ty, same_tys, single_segment_path, snippet, snippet_with_applicability, - snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, - span_lint_and_then, sugg, walk_ptrs_ty, walk_ptrs_ty_depth, SpanlessEq, + remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, + span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then, sugg, walk_ptrs_ty, + walk_ptrs_ty_depth, SpanlessEq, }; declare_clippy_lint! { @@ -218,7 +218,12 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// # let x = Ok::<_, ()>(()); - /// x.ok().expect("why did I do this again?") + /// + /// // Bad + /// x.ok().expect("why did I do this again?"); + /// + /// // Good + /// x.expect("why did I do this again?"); /// ``` pub OK_EXPECT, style, @@ -273,8 +278,12 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// # let opt = Some(1); - /// opt.map_or(None, |a| Some(a + 1)) - /// # ; + /// + /// // Bad + /// opt.map_or(None, |a| Some(a + 1)); + /// + /// // Good + /// opt.and_then(|a| Some(a + 1)); /// ``` pub OPTION_MAP_OR_NONE, style, @@ -390,14 +399,19 @@ declare_clippy_lint! { /// **What it does:** Checks for usage of `_.map(_).flatten(_)`, /// /// **Why is this bad?** Readability, this can be written more concisely as a - /// single method call. + /// single method call using `_.flat_map(_)` /// /// **Known problems:** /// /// **Example:** /// ```rust /// let vec = vec![vec![1]]; + /// + /// // Bad /// vec.iter().map(|x| x.iter()).flatten(); + /// + /// // Good + /// vec.iter().flat_map(|x| x.iter()); /// ``` pub MAP_FLATTEN, pedantic, @@ -417,7 +431,16 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// let vec = vec![1]; + /// + /// // Bad /// vec.iter().filter(|x| **x == 0).map(|x| *x * 2); + /// + /// // Good + /// vec.iter().filter_map(|x| if *x == 0 { + /// Some(*x * 2) + /// } else { + /// None + /// }); /// ``` pub FILTER_MAP, pedantic, @@ -634,7 +657,12 @@ declare_clippy_lint! { /// ```rust /// # use std::rc::Rc; /// let x = Rc::new(1); + /// + /// // Bad /// x.clone(); + /// + /// // Good + /// Rc::clone(&x); /// ``` pub CLONE_ON_REF_PTR, restriction, @@ -741,7 +769,12 @@ declare_clippy_lint! { /// **Known problems:** Does not catch multi-byte unicode characters. /// /// **Example:** - /// `_.split("x")` could be `_.split('x')` + /// ```rust,ignore + /// // Bad + /// _.split("x"); + /// + /// // Good + /// _.split('x'); pub SINGLE_CHAR_PATTERN, perf, "using a single-character str where a char could be used, e.g., `_.split(\"x\")`" @@ -964,8 +997,8 @@ declare_clippy_lint! { } declare_clippy_lint! { - /// **What it does:** Checks for usage of `.chars().last()` or - /// `.chars().next_back()` on a `str` to check if it ends with a given char. + /// **What it does:** Checks for usage of `_.chars().last()` or + /// `_.chars().next_back()` on a `str` to check if it ends with a given char. /// /// **Why is this bad?** Readability, this can be written more concisely as /// `_.ends_with(_)`. @@ -975,8 +1008,12 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// # let name = "_"; - /// name.chars().last() == Some('_') || name.chars().next_back() == Some('-') - /// # ; + /// + /// // Bad + /// name.chars().last() == Some('_') || name.chars().next_back() == Some('-'); + /// + /// // Good + /// name.ends_with('_') || name.ends_with('-'); /// ``` pub CHARS_LAST_CMP, style, @@ -1044,17 +1081,15 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// let _ = (0..3).filter_map(|x| if x > 2 { Some(x) } else { None }); - /// ``` - /// As there is no transformation of the argument this could be written as: - /// ```rust + /// + /// // As there is no transformation of the argument this could be written as: /// let _ = (0..3).filter(|&x| x > 2); /// ``` /// /// ```rust /// let _ = (0..4).filter_map(|x| Some(x + 1)); - /// ``` - /// As there is no conditional check on the argument this could be written as: - /// ```rust + /// + /// // As there is no conditional check on the argument this could be written as: /// let _ = (0..4).map(|x| x + 1); /// ``` pub UNNECESSARY_FILTER_MAP, @@ -1075,7 +1110,11 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust + /// // Bad /// let _ = (&vec![3, 4, 5]).into_iter(); + /// + /// // Good + /// let _ = (&vec![3, 4, 5]).iter(); /// ``` pub INTO_ITER_ON_REF, style, @@ -1242,6 +1281,32 @@ declare_clippy_lint! { "using `as_ref().map(Deref::deref)`, which is more succinctly expressed as `as_deref()`" } +declare_clippy_lint! { + /// **What it does:** Checks for usage of `iter().next()` on a Slice or an Array + /// + /// **Why is this bad?** These can be shortened into `.get()` + /// + /// **Known problems:** None. + /// + /// **Example:** + /// ```rust + /// # let a = [1, 2, 3]; + /// # let b = vec![1, 2, 3]; + /// a[2..].iter().next(); + /// b.iter().next(); + /// ``` + /// should be written as: + /// ```rust + /// # let a = [1, 2, 3]; + /// # let b = vec![1, 2, 3]; + /// a.get(2); + /// b.get(0); + /// ``` + pub ITER_NEXT_SLICE, + style, + "using `.iter().next()` on a sliced array, which can be shortened to just `.get()`" +} + declare_lint_pass!(Methods => [ UNWRAP_USED, EXPECT_USED, @@ -1273,6 +1338,7 @@ declare_lint_pass!(Methods => [ FIND_MAP, MAP_FLATTEN, ITERATOR_STEP_BY_ZERO, + ITER_NEXT_SLICE, ITER_NTH, ITER_NTH_ZERO, ITER_SKIP_NEXT, @@ -1320,6 +1386,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods { }, ["next", "filter"] => lint_filter_next(cx, expr, arg_lists[1]), ["next", "skip_while"] => lint_skip_while_next(cx, expr, arg_lists[1]), + ["next", "iter"] => lint_iter_next(cx, expr, arg_lists[1]), ["map", "filter"] => lint_filter_map(cx, expr, arg_lists[1], arg_lists[0]), ["map", "filter_map"] => lint_filter_map_map(cx, expr, arg_lists[1], arg_lists[0]), ["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1]), @@ -1336,9 +1403,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods { lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1]) }, ["extend", ..] => lint_extend(cx, expr, arg_lists[0]), - ["as_ptr", "unwrap"] | ["as_ptr", "expect"] => { - lint_cstring_as_ptr(cx, expr, &arg_lists[1][0], &arg_lists[0][0]) - }, + ["as_ptr", "unwrap" | "expect"] => lint_cstring_as_ptr(cx, expr, &arg_lists[1][0], &arg_lists[0][0]), ["nth", "iter"] => lint_iter_nth(cx, expr, &arg_lists, false), ["nth", "iter_mut"] => lint_iter_nth(cx, expr, &arg_lists, true), ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]), @@ -1351,12 +1416,10 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods { ["filter_map", ..] => unnecessary_filter_map::lint(cx, expr, arg_lists[0]), ["count", "map"] => lint_suspicious_map(cx, expr), ["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr), - ["unwrap_or", arith @ "checked_add"] - | ["unwrap_or", arith @ "checked_sub"] - | ["unwrap_or", arith @ "checked_mul"] => { + ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { manual_saturating_arithmetic::lint(cx, expr, &arg_lists, &arith["checked_".len()..]) }, - ["add"] | ["offset"] | ["sub"] | ["wrapping_offset"] | ["wrapping_add"] | ["wrapping_sub"] => { + ["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => { check_pointer_offset(cx, expr, arg_lists[0]) }, ["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]), @@ -1481,7 +1544,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods { let contains_self_ty = |ty: Ty<'tcx>| { ty.walk().any(|inner| match inner.unpack() { - GenericArgKind::Type(inner_ty) => same_tys(cx, self_ty, inner_ty), + GenericArgKind::Type(inner_ty) => TyS::same_type(self_ty, inner_ty), GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false, }) @@ -1508,7 +1571,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods { } } - if name == "new" && !same_tys(cx, ret_ty, self_ty) { + if name == "new" && !TyS::same_type(ret_ty, self_ty) { span_lint( cx, NEW_RET_NO_SELF, @@ -1762,8 +1825,7 @@ fn lint_expect_fun_call( hir::ExprKind::Call(fun, _) => { if let hir::ExprKind::Path(ref p) = fun.kind { match cx.tables.qpath_res(p, fun.hir_id) { - hir::def::Res::Def(hir::def::DefKind::Fn, def_id) - | hir::def::Res::Def(hir::def::DefKind::AssocFn, def_id) => matches!( + hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!( cx.tcx.fn_sig(def_id).output().skip_binder().kind, ty::Ref(ty::ReStatic, ..) ), @@ -2199,6 +2261,60 @@ fn lint_step_by<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &hir::Expr<'_>, args } } +fn lint_iter_next<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) { + let caller_expr = &iter_args[0]; + + // Skip lint if the `iter().next()` expression is a for loop argument, + // since it is already covered by `&loops::ITER_NEXT_LOOP` + let mut parent_expr_opt = get_parent_expr(cx, expr); + while let Some(parent_expr) = parent_expr_opt { + if higher::for_loop(parent_expr).is_some() { + return; + } + parent_expr_opt = get_parent_expr(cx, parent_expr); + } + + if derefs_to_slice(cx, caller_expr, cx.tables.expr_ty(caller_expr)).is_some() { + // caller is a Slice + if_chain! { + if let hir::ExprKind::Index(ref caller_var, ref index_expr) = &caller_expr.kind; + if let Some(higher::Range { start: Some(start_expr), end: None, limits: ast::RangeLimits::HalfOpen }) + = higher::range(cx, index_expr); + if let hir::ExprKind::Lit(ref start_lit) = &start_expr.kind; + if let ast::LitKind::Int(start_idx, _) = start_lit.node; + then { + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + ITER_NEXT_SLICE, + expr.span, + "Using `.iter().next()` on a Slice without end index.", + "try calling", + format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx), + applicability, + ); + } + } + } else if is_type_diagnostic_item(cx, cx.tables.expr_ty(caller_expr), sym!(vec_type)) + || matches!(&walk_ptrs_ty(cx.tables.expr_ty(caller_expr)).kind, ty::Array(_, _)) + { + // caller is a Vec or an Array + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + ITER_NEXT_SLICE, + expr.span, + "Using `.iter().next()` on an array", + "try calling", + format!( + "{}.get(0)", + snippet_with_applicability(cx, caller_expr.span, "..", &mut applicability) + ), + applicability, + ); + } +} + fn lint_iter_nth<'a, 'tcx>( cx: &LateContext<'a, 'tcx>, expr: &hir::Expr<'_>, diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index e1d524c22..f513161bb 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -38,10 +38,16 @@ declare_clippy_lint! { /// dereferences, e.g., changing `*x` to `x` within the function. /// /// **Example:** - /// ```rust + /// ```rust,ignore + /// // Bad /// fn foo(ref x: u8) -> bool { /// true /// } + /// + /// // Good + /// fn foo(x: &u8) -> bool { + /// true + /// } /// ``` pub TOPLEVEL_REF_ARG, style, @@ -60,7 +66,11 @@ declare_clippy_lint! { /// ```rust /// # let x = 1.0; /// + /// // Bad /// if x == f32::NAN { } + /// + /// // Good + /// if x.is_nan() { } /// ``` pub CMP_NAN, correctness, @@ -83,8 +93,15 @@ declare_clippy_lint! { /// ```rust /// let x = 1.2331f64; /// let y = 1.2332f64; + /// + /// // Bad /// if y == 1.23f64 { } /// if y != x {} // where both are floats + /// + /// // Good + /// let error = 0.01f64; // Use an epsilon for comparison + /// if (y - 1.23f64).abs() < error { } + /// if (y - x).abs() > error { } /// ``` pub FLOAT_CMP, correctness, @@ -191,7 +208,11 @@ declare_clippy_lint! { /// **Example:** /// /// ```rust + /// // Bad /// let a = 0 as *const u32; + /// + /// // Good + /// let a = std::ptr::null::(); /// ``` pub ZERO_PTR, style, @@ -214,7 +235,13 @@ declare_clippy_lint! { /// ```rust /// let x: f64 = 1.0; /// const ONE: f64 = 1.00; - /// x == ONE; // where both are floats + /// + /// // Bad + /// if x == ONE { } // where both are floats + /// + /// // Good + /// let error = 0.1f64; // Use an epsilon for comparison + /// if (x - ONE).abs() < error { } /// ``` pub FLOAT_CMP_CONST, restriction, @@ -248,17 +275,14 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MiscLints { return; } for arg in iter_input_pats(decl, body) { - match arg.pat.kind { - PatKind::Binding(BindingAnnotation::Ref, ..) | PatKind::Binding(BindingAnnotation::RefMut, ..) => { - span_lint( - cx, - TOPLEVEL_REF_ARG, - arg.pat.span, - "`ref` directly on a function argument is ignored. Consider using a reference type \ - instead.", - ); - }, - _ => {}, + if let PatKind::Binding(BindingAnnotation::Ref | BindingAnnotation::RefMut, ..) = arg.pat.kind { + span_lint( + cx, + TOPLEVEL_REF_ARG, + arg.pat.span, + "`ref` directly on a function argument is ignored. \ + Consider using a reference type instead.", + ); } } } diff --git a/clippy_lints/src/misc_early.rs b/clippy_lints/src/misc_early.rs index 552222eba..ad39e59d0 100644 --- a/clippy_lints/src/misc_early.rs +++ b/clippy_lints/src/misc_early.rs @@ -59,7 +59,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// fn foo(a: i32, _a: i32) {} + /// + /// // Good + /// fn bar(a: i32, _b: i32) {} /// ``` pub DUPLICATE_UNDERSCORE_ARGUMENT, style, @@ -77,7 +81,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust,ignore - /// (|| 42)() + /// // Bad + /// let a = (|| 42)() + /// + /// // Good + /// let a = 42 /// ``` pub REDUNDANT_CLOSURE_CALL, complexity, @@ -112,7 +120,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// let y = 0x1a9BAcD; + /// + /// // Good + /// let y = 0x1A9BACD; /// ``` pub MIXED_CASE_HEX_LITERALS, style, @@ -129,7 +141,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// let y = 123832i32; + /// + /// // Good + /// let y = 123832_i32; /// ``` pub UNSEPARATED_LITERAL_SUFFIX, pedantic, @@ -207,9 +223,16 @@ declare_clippy_lint! { /// ```rust /// # let v = Some("abc"); /// + /// // Bad /// match v { /// Some(x) => (), - /// y @ _ => (), // easier written as `y`, + /// y @ _ => (), + /// } + /// + /// // Good + /// match v { + /// Some(x) => (), + /// y => (), /// } /// ``` pub REDUNDANT_PATTERN, @@ -235,16 +258,13 @@ declare_clippy_lint! { /// # struct TupleStruct(u32, u32, u32); /// # let t = TupleStruct(1, 2, 3); /// + /// // Bad /// match t { /// TupleStruct(0, .., _) => (), /// _ => (), /// } - /// ``` - /// can be written as - /// ```rust - /// # struct TupleStruct(u32, u32, u32); - /// # let t = TupleStruct(1, 2, 3); /// + /// // Good /// match t { /// TupleStruct(0, ..) => (), /// _ => (), diff --git a/clippy_lints/src/multiple_crate_versions.rs b/clippy_lints/src/multiple_crate_versions.rs index b6770804e..6c42014b4 100644 --- a/clippy_lints/src/multiple_crate_versions.rs +++ b/clippy_lints/src/multiple_crate_versions.rs @@ -7,7 +7,7 @@ use rustc_lint::{LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::DUMMY_SP; -use cargo_metadata::{DependencyKind, MetadataCommand, Node, Package, PackageId}; +use cargo_metadata::{DependencyKind, Node, Package, PackageId}; use if_chain::if_chain; use itertools::Itertools; @@ -42,13 +42,7 @@ impl LateLintPass<'_, '_> for MultipleCrateVersions { return; } - let metadata = if let Ok(metadata) = MetadataCommand::new().exec() { - metadata - } else { - span_lint(cx, MULTIPLE_CRATE_VERSIONS, DUMMY_SP, "could not read cargo metadata"); - return; - }; - + let metadata = unwrap_cargo_metadata!(cx, MULTIPLE_CRATE_VERSIONS, true); let local_name = cx.tcx.crate_name(LOCAL_CRATE).as_str(); let mut packages = metadata.packages; packages.sort_by(|a, b| a.name.cmp(&b.name)); diff --git a/clippy_lints/src/mut_reference.rs b/clippy_lints/src/mut_reference.rs index 67a1ac78a..58a8e1a10 100644 --- a/clippy_lints/src/mut_reference.rs +++ b/clippy_lints/src/mut_reference.rs @@ -16,7 +16,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```ignore + /// // Bad /// my_vec.push(&mut value) + /// + /// // Good + /// my_vec.push(&value) /// ``` pub UNNECESSARY_MUT_PASSED, style, diff --git a/clippy_lints/src/mutex_atomic.rs b/clippy_lints/src/mutex_atomic.rs index 4e1a8be48..78b15afc5 100644 --- a/clippy_lints/src/mutex_atomic.rs +++ b/clippy_lints/src/mutex_atomic.rs @@ -22,9 +22,15 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// # let y = true; + /// + /// // Bad /// # use std::sync::Mutex; - /// # let y = 1; /// let x = Mutex::new(&y); + /// + /// // Good + /// # use std::sync::atomic::AtomicBool; + /// let x = AtomicBool::new(y); /// ``` pub MUTEX_ATOMIC, perf, @@ -46,6 +52,10 @@ declare_clippy_lint! { /// ```rust /// # use std::sync::Mutex; /// let x = Mutex::new(0usize); + /// + /// // Good + /// # use std::sync::atomic::AtomicUsize; + /// let x = AtomicUsize::new(0usize); /// ``` pub MUTEX_INTEGER, nursery, diff --git a/clippy_lints/src/needless_bool.rs b/clippy_lints/src/needless_bool.rs index efa77db82..15b129fa0 100644 --- a/clippy_lints/src/needless_bool.rs +++ b/clippy_lints/src/needless_bool.rs @@ -15,8 +15,7 @@ use rustc_span::Span; declare_clippy_lint! { /// **What it does:** Checks for expressions of the form `if c { true } else { - /// false }` - /// (or vice versa) and suggest using the condition directly. + /// false }` (or vice versa) and suggests using the condition directly. /// /// **Why is this bad?** Redundant code. /// diff --git a/clippy_lints/src/needless_borrow.rs b/clippy_lints/src/needless_borrow.rs index 9ee875d75..5880d1d61 100644 --- a/clippy_lints/src/needless_borrow.rs +++ b/clippy_lints/src/needless_borrow.rs @@ -18,12 +18,16 @@ declare_clippy_lint! { /// **Why is this bad?** Suggests that the receiver of the expression borrows /// the expression. /// + /// **Known problems:** None. + /// /// **Example:** /// ```rust + /// // Bad /// let x: &i32 = &&&&&&5; - /// ``` /// - /// **Known problems:** None. + /// // Good + /// let x: &i32 = &5; + /// ``` pub NEEDLESS_BORROW, nursery, "taking a reference that is going to be automatically dereferenced" diff --git a/clippy_lints/src/needless_continue.rs b/clippy_lints/src/needless_continue.rs index 28183810d..a971d041c 100644 --- a/clippy_lints/src/needless_continue.rs +++ b/clippy_lints/src/needless_continue.rs @@ -424,7 +424,7 @@ fn erode_from_back(s: &str) -> String { } fn span_of_first_expr_in_block(block: &ast::Block) -> Option { - block.stmts.iter().next().map(|stmt| stmt.span) + block.stmts.get(0).map(|stmt| stmt.span) } #[cfg(test)] diff --git a/clippy_lints/src/needless_update.rs b/clippy_lints/src/needless_update.rs index 4b2586877..d866bab2f 100644 --- a/clippy_lints/src/needless_update.rs +++ b/clippy_lints/src/needless_update.rs @@ -21,6 +21,16 @@ declare_clippy_lint! { /// # z: i32, /// # } /// # let zero_point = Point { x: 0, y: 0, z: 0 }; + /// + /// // Bad + /// Point { + /// x: 1, + /// y: 1, + /// z: 1, + /// ..zero_point + /// }; + /// + /// // Ok /// Point { /// x: 1, /// y: 1, diff --git a/clippy_lints/src/new_without_default.rs b/clippy_lints/src/new_without_default.rs index e556e5d59..dd236535c 100644 --- a/clippy_lints/src/new_without_default.rs +++ b/clippy_lints/src/new_without_default.rs @@ -1,13 +1,13 @@ use crate::utils::paths; use crate::utils::sugg::DiagnosticBuilderExt; -use crate::utils::{get_trait_def_id, return_ty, same_tys, span_lint_hir_and_then}; +use crate::utils::{get_trait_def_id, return_ty, span_lint_hir_and_then}; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::HirIdSet; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; -use rustc_middle::ty::Ty; +use rustc_middle::ty::{Ty, TyS}; use rustc_session::{declare_tool_lint, impl_lint_pass}; declare_clippy_lint! { @@ -93,7 +93,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NewWithoutDefault { let self_def_id = cx.tcx.hir().local_def_id(cx.tcx.hir().get_parent_item(id)); let self_ty = cx.tcx.type_of(self_def_id); if_chain! { - if same_tys(cx, self_ty, return_ty(cx, id)); + if TyS::same_type(self_ty, return_ty(cx, id)); if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT); then { if self.impling_types.is_none() { diff --git a/clippy_lints/src/no_effect.rs b/clippy_lints/src/no_effect.rs index b8bfa676a..2eacd3c80 100644 --- a/clippy_lints/src/no_effect.rs +++ b/clippy_lints/src/no_effect.rs @@ -147,7 +147,7 @@ fn reduce_expression<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'a>) -> Option if let ExprKind::Path(ref qpath) = callee.kind { let res = qpath_res(cx, qpath, callee.hir_id); match res { - Res::Def(DefKind::Struct, ..) | Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(..), _) + Res::Def(DefKind::Struct | DefKind::Variant | DefKind::Ctor(..), ..) if !has_drop(cx, cx.tables.expr_ty(expr)) => { Some(args.iter().collect()) diff --git a/clippy_lints/src/ptr.rs b/clippy_lints/src/ptr.rs index 4eac571f9..c77b44e0c 100644 --- a/clippy_lints/src/ptr.rs +++ b/clippy_lints/src/ptr.rs @@ -47,7 +47,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```ignore + /// // Bad /// fn foo(&Vec) { .. } + /// + /// // Good + /// fn foo(&[u32]) { .. } /// ``` pub PTR_ARG, style, @@ -65,9 +69,15 @@ declare_clippy_lint! { /// /// **Example:** /// ```ignore + /// // Bad /// if x == ptr::null { /// .. /// } + /// + /// // Good + /// if x.is_null() { + /// .. + /// } /// ``` pub CMP_NULL, style, @@ -76,19 +86,16 @@ declare_clippy_lint! { declare_clippy_lint! { /// **What it does:** This lint checks for functions that take immutable - /// references and return - /// mutable ones. + /// references and return mutable ones. /// /// **Why is this bad?** This is trivially unsound, as one can create two - /// mutable references - /// from the same (immutable!) source. This - /// [error](https://github.com/rust-lang/rust/issues/39465) + /// mutable references from the same (immutable!) source. + /// This [error](https://github.com/rust-lang/rust/issues/39465) /// actually lead to an interim Rust release 1.15.1. /// /// **Known problems:** To be on the conservative side, if there's at least one - /// mutable reference - /// with the output lifetime, this lint will not trigger. In practice, this - /// case is unlikely anyway. + /// mutable reference with the output lifetime, this lint will not trigger. + /// In practice, this case is unlikely anyway. /// /// **Example:** /// ```ignore diff --git a/clippy_lints/src/question_mark.rs b/clippy_lints/src/question_mark.rs index ea654467b..e4361b00f 100644 --- a/clippy_lints/src/question_mark.rs +++ b/clippy_lints/src/question_mark.rs @@ -88,7 +88,7 @@ impl QuestionMark { replacement_str, applicability, ) - } + } } } } diff --git a/clippy_lints/src/ranges.rs b/clippy_lints/src/ranges.rs index 1eb26d97e..52e540d4e 100644 --- a/clippy_lints/src/ranges.rs +++ b/clippy_lints/src/ranges.rs @@ -241,14 +241,26 @@ fn check_inclusive_range_minus_one(cx: &LateContext<'_, '_>, expr: &Expr<'_>) { } fn check_reversed_empty_range(cx: &LateContext<'_, '_>, expr: &Expr<'_>) { - fn inside_indexing_expr<'a>(cx: &'a LateContext<'_, '_>, expr: &Expr<'_>) -> Option<&'a Expr<'a>> { - match get_parent_expr(cx, expr) { - parent_expr @ Some(Expr { + fn inside_indexing_expr(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + matches!( + get_parent_expr(cx, expr), + Some(Expr { kind: ExprKind::Index(..), .. - }) => parent_expr, - _ => None, + }) + ) + } + + fn is_for_loop_arg(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool { + let mut cur_expr = expr; + while let Some(parent_expr) = get_parent_expr(cx, cur_expr) { + match higher::for_loop(parent_expr) { + Some((_, args, _)) if args.hir_id == expr.hir_id => return true, + _ => cur_expr = parent_expr, + } } + + false } fn is_empty_range(limits: RangeLimits, ordering: Ordering) -> bool { @@ -267,34 +279,18 @@ fn check_reversed_empty_range(cx: &LateContext<'_, '_>, expr: &Expr<'_>) { if let Some(ordering) = Constant::partial_cmp(cx.tcx, ty, &start_idx, &end_idx); if is_empty_range(limits, ordering); then { - if let Some(parent_expr) = inside_indexing_expr(cx, expr) { - let (reason, outcome) = if ordering == Ordering::Equal { - ("empty", "always yield an empty slice") - } else { - ("reversed", "panic at run-time") - }; - - span_lint_and_then( - cx, - REVERSED_EMPTY_RANGES, - expr.span, - &format!("this range is {} and using it to index a slice will {}", reason, outcome), - |diag| { - if_chain! { - if ordering == Ordering::Equal; - if let ty::Slice(slice_ty) = cx.tables.expr_ty(parent_expr).kind; - then { - diag.span_suggestion( - parent_expr.span, - "if you want an empty slice, use", - format!("[] as &[{}]", slice_ty), - Applicability::MaybeIncorrect - ); - } - } - } - ); - } else { + if inside_indexing_expr(cx, expr) { + // Avoid linting `N..N` as it has proven to be useful, see #5689 and #5628 ... + if ordering != Ordering::Equal { + span_lint( + cx, + REVERSED_EMPTY_RANGES, + expr.span, + "this range is reversed and using it to index a slice will panic at run-time", + ); + } + // ... except in for loop arguments for backwards compatibility with `reverse_range_loop` + } else if ordering != Ordering::Equal || is_for_loop_arg(cx, expr) { span_lint_and_then( cx, REVERSED_EMPTY_RANGES, diff --git a/clippy_lints/src/reference.rs b/clippy_lints/src/reference.rs index d5797468e..fe457aad5 100644 --- a/clippy_lints/src/reference.rs +++ b/clippy_lints/src/reference.rs @@ -16,8 +16,13 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust,ignore + /// // Bad /// let a = f(*&mut b); /// let c = *&d; + /// + /// // Good + /// let a = f(b); + /// let c = d; /// ``` pub DEREF_ADDROF, complexity, diff --git a/clippy_lints/src/regex.rs b/clippy_lints/src/regex.rs index 30084e3e1..a2c35c426 100644 --- a/clippy_lints/src/regex.rs +++ b/clippy_lints/src/regex.rs @@ -86,11 +86,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Regex { if let Some(span) = is_expn_of(expr.span, "regex"); then { if !self.spans.contains(&span) { - span_lint(cx, - REGEX_MACRO, - span, - "`regex!(_)` found. \ - Please use `Regex::new(_)`, which is faster for now."); + span_lint( + cx, + REGEX_MACRO, + span, + "`regex!(_)` found. \ + Please use `Regex::new(_)`, which is faster for now." + ); self.spans.insert(span); } self.last = Some(block.hir_id); diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs index 35464f629..3c9397441 100644 --- a/clippy_lints/src/returns.rs +++ b/clippy_lints/src/returns.rs @@ -8,7 +8,7 @@ use rustc_session::{declare_lint_pass, declare_tool_lint}; use rustc_span::source_map::Span; use rustc_span::BytePos; -use crate::utils::{in_macro, match_path_ast, snippet_opt, span_lint_and_sugg, span_lint_and_then}; +use crate::utils::{snippet_opt, span_lint_and_sugg, span_lint_and_then}; declare_clippy_lint! { /// **What it does:** Checks for return statements at the end of a block. @@ -36,33 +36,6 @@ declare_clippy_lint! { "using a return statement like `return expr;` where an expression would suffice" } -declare_clippy_lint! { - /// **What it does:** Checks for `let`-bindings, which are subsequently - /// returned. - /// - /// **Why is this bad?** It is just extraneous code. Remove it to make your code - /// more rusty. - /// - /// **Known problems:** None. - /// - /// **Example:** - /// ```rust - /// fn foo() -> String { - /// let x = String::new(); - /// x - /// } - /// ``` - /// instead, use - /// ``` - /// fn foo() -> String { - /// String::new() - /// } - /// ``` - pub LET_AND_RETURN, - style, - "creating a let-binding and then immediately returning it like `let x = expr; x` at the end of a block" -} - declare_clippy_lint! { /// **What it does:** Checks for unit (`()`) expressions that can be removed. /// @@ -90,7 +63,7 @@ enum RetReplacement { Block, } -declare_lint_pass!(Return => [NEEDLESS_RETURN, LET_AND_RETURN, UNUSED_UNIT]); +declare_lint_pass!(Return => [NEEDLESS_RETURN, UNUSED_UNIT]); impl Return { // Check the final stmt or expr in a block for unnecessary return. @@ -105,7 +78,7 @@ impl Return { } } - // Check a the final expression in a block if it's a return. + // Check the final expression in a block if it's a return. fn check_final_expr( &mut self, cx: &EarlyContext<'_>, @@ -186,54 +159,6 @@ impl Return { }, } } - - // Check for "let x = EXPR; x" - fn check_let_return(cx: &EarlyContext<'_>, block: &ast::Block) { - let mut it = block.stmts.iter(); - - // we need both a let-binding stmt and an expr - if_chain! { - if let Some(retexpr) = it.next_back(); - if let ast::StmtKind::Expr(ref retexpr) = retexpr.kind; - if let Some(stmt) = it.next_back(); - if let ast::StmtKind::Local(ref local) = stmt.kind; - // don't lint in the presence of type inference - if local.ty.is_none(); - if local.attrs.is_empty(); - if let Some(ref initexpr) = local.init; - if let ast::PatKind::Ident(_, ident, _) = local.pat.kind; - if let ast::ExprKind::Path(_, ref path) = retexpr.kind; - if match_path_ast(path, &[&*ident.name.as_str()]); - if !in_external_macro(cx.sess(), initexpr.span); - if !in_external_macro(cx.sess(), retexpr.span); - if !in_external_macro(cx.sess(), local.span); - if !in_macro(local.span); - then { - span_lint_and_then( - cx, - LET_AND_RETURN, - retexpr.span, - "returning the result of a `let` binding from a block", - |err| { - err.span_label(local.span, "unnecessary `let` binding"); - - if let Some(snippet) = snippet_opt(cx, initexpr.span) { - err.multipart_suggestion( - "return the expression directly", - vec![ - (local.span, String::new()), - (retexpr.span, snippet), - ], - Applicability::MachineApplicable, - ); - } else { - err.span_help(initexpr.span, "this expression can be directly returned"); - } - }, - ); - } - } - } } impl EarlyLintPass for Return { @@ -254,7 +179,6 @@ impl EarlyLintPass for Return { } fn check_block(&mut self, cx: &EarlyContext<'_>, block: &ast::Block) { - Self::check_let_return(cx, block); if_chain! { if let Some(ref stmt) = block.stmts.last(); if let ast::StmtKind::Expr(ref expr) = stmt.kind; diff --git a/clippy_lints/src/shadow.rs b/clippy_lints/src/shadow.rs index 11360b0ef..68c36f918 100644 --- a/clippy_lints/src/shadow.rs +++ b/clippy_lints/src/shadow.rs @@ -25,7 +25,12 @@ declare_clippy_lint! { /// **Example:** /// ```rust /// # let x = 1; + /// + /// // Bad /// let x = &x; + /// + /// // Good + /// let y = &x; // use different variable name /// ``` pub SHADOW_SAME, restriction, @@ -77,7 +82,12 @@ declare_clippy_lint! { /// # let y = 1; /// # let z = 2; /// let x = y; + /// + /// // Bad /// let x = z; // shadows the earlier binding + /// + /// // Good + /// let w = z; // use different variable name /// ``` pub SHADOW_UNRELATED, pedantic, diff --git a/clippy_lints/src/single_component_path_imports.rs b/clippy_lints/src/single_component_path_imports.rs index 8d767a7fe..2e853e830 100644 --- a/clippy_lints/src/single_component_path_imports.rs +++ b/clippy_lints/src/single_component_path_imports.rs @@ -16,7 +16,7 @@ declare_clippy_lint! { /// /// **Example:** /// - /// ```rust, ignore + /// ```rust,ignore /// use regex; /// /// fn main() { @@ -24,7 +24,7 @@ declare_clippy_lint! { /// } /// ``` /// Better as - /// ```rust, ignore + /// ```rust,ignore /// fn main() { /// regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap(); /// } diff --git a/clippy_lints/src/slow_vector_initialization.rs b/clippy_lints/src/slow_vector_initialization.rs index fb3706be1..a7c4f2c22 100644 --- a/clippy_lints/src/slow_vector_initialization.rs +++ b/clippy_lints/src/slow_vector_initialization.rs @@ -22,11 +22,17 @@ declare_clippy_lint! { /// ```rust /// # use core::iter::repeat; /// # let len = 4; + /// + /// // Bad /// let mut vec1 = Vec::with_capacity(len); /// vec1.resize(len, 0); /// /// let mut vec2 = Vec::with_capacity(len); - /// vec2.extend(repeat(0).take(len)) + /// vec2.extend(repeat(0).take(len)); + /// + /// // Good + /// let mut vec1 = vec![0; len]; + /// let mut vec2 = vec![0; len]; /// ``` pub SLOW_VECTOR_INITIALIZATION, perf, diff --git a/clippy_lints/src/strings.rs b/clippy_lints/src/strings.rs index 2c51271e3..f84566ef7 100644 --- a/clippy_lints/src/strings.rs +++ b/clippy_lints/src/strings.rs @@ -24,6 +24,10 @@ declare_clippy_lint! { /// ```rust /// let mut x = "Hello".to_owned(); /// x = x + ", World"; + /// + /// // More readable + /// x += ", World"; + /// x.push_str(", World"); /// ``` pub STRING_ADD_ASSIGN, pedantic, @@ -69,7 +73,11 @@ declare_clippy_lint! { /// /// **Example:** /// ```rust + /// // Bad /// let bs = "a byte string".as_bytes(); + /// + /// // Good + /// let bs = b"a byte string"; /// ``` pub STRING_LIT_AS_BYTES, style, diff --git a/clippy_lints/src/suspicious_trait_impl.rs b/clippy_lints/src/suspicious_trait_impl.rs index f1e223d9a..a9e6fa329 100644 --- a/clippy_lints/src/suspicious_trait_impl.rs +++ b/clippy_lints/src/suspicious_trait_impl.rs @@ -71,8 +71,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl { if let hir::Node::Expr(e) = cx.tcx.hir().get(parent_expr) { match e.kind { hir::ExprKind::Binary(..) - | hir::ExprKind::Unary(hir::UnOp::UnNot, _) - | hir::ExprKind::Unary(hir::UnOp::UnNeg, _) + | hir::ExprKind::Unary(hir::UnOp::UnNot | hir::UnOp::UnNeg, _) | hir::ExprKind::AssignOp(..) => return, _ => {}, } @@ -191,8 +190,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BinaryExprVisitor { fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) { match expr.kind { hir::ExprKind::Binary(..) - | hir::ExprKind::Unary(hir::UnOp::UnNot, _) - | hir::ExprKind::Unary(hir::UnOp::UnNeg, _) + | hir::ExprKind::Unary(hir::UnOp::UnNot | hir::UnOp::UnNeg, _) | hir::ExprKind::AssignOp(..) => self.in_binary_expr = true, _ => {}, } diff --git a/clippy_lints/src/transmute.rs b/clippy_lints/src/transmute.rs index e24d2c4f4..1869638f6 100644 --- a/clippy_lints/src/transmute.rs +++ b/clippy_lints/src/transmute.rs @@ -312,7 +312,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { e.span, &format!("transmute from a type (`{}`) to itself", from_ty), ), - (&ty::Ref(_, rty, rty_mutbl), &ty::RawPtr(ptr_ty)) => span_lint_and_then( + (ty::Ref(_, rty, rty_mutbl), ty::RawPtr(ptr_ty)) => span_lint_and_then( cx, USELESS_TRANSMUTE, e.span, @@ -321,10 +321,10 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) { let rty_and_mut = ty::TypeAndMut { ty: rty, - mutbl: rty_mutbl, + mutbl: *rty_mutbl, }; - let sugg = if ptr_ty == rty_and_mut { + let sugg = if *ptr_ty == rty_and_mut { arg.as_ty(to_ty) } else { arg.as_ty(cx.tcx.mk_ptr(rty_and_mut)).as_ty(to_ty) @@ -334,7 +334,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { } }, ), - (&ty::Int(_), &ty::RawPtr(_)) | (&ty::Uint(_), &ty::RawPtr(_)) => span_lint_and_then( + (ty::Int(_) | ty::Uint(_), ty::RawPtr(_)) => span_lint_and_then( cx, USELESS_TRANSMUTE, e.span, @@ -350,16 +350,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { } }, ), - (&ty::Float(_), &ty::Ref(..)) - | (&ty::Float(_), &ty::RawPtr(_)) - | (&ty::Char, &ty::Ref(..)) - | (&ty::Char, &ty::RawPtr(_)) => span_lint( + (ty::Float(_) | ty::Char, ty::Ref(..) | ty::RawPtr(_)) => span_lint( cx, WRONG_TRANSMUTE, e.span, &format!("transmute from a `{}` to a pointer", from_ty), ), - (&ty::RawPtr(from_ptr), _) if from_ptr.ty == to_ty => span_lint( + (ty::RawPtr(from_ptr), _) if from_ptr.ty == to_ty => span_lint( cx, CROSSPOINTER_TRANSMUTE, e.span, @@ -368,7 +365,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { from_ty, to_ty ), ), - (_, &ty::RawPtr(to_ptr)) if to_ptr.ty == from_ty => span_lint( + (_, ty::RawPtr(to_ptr)) if to_ptr.ty == from_ty => span_lint( cx, CROSSPOINTER_TRANSMUTE, e.span, @@ -377,7 +374,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { from_ty, to_ty ), ), - (&ty::RawPtr(from_pty), &ty::Ref(_, to_ref_ty, mutbl)) => span_lint_and_then( + (ty::RawPtr(from_pty), ty::Ref(_, to_ref_ty, mutbl)) => span_lint_and_then( cx, TRANSMUTE_PTR_TO_REF, e.span, @@ -388,13 +385,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { ), |diag| { let arg = sugg::Sugg::hir(cx, &args[0], ".."); - let (deref, cast) = if mutbl == Mutability::Mut { + let (deref, cast) = if *mutbl == Mutability::Mut { ("&mut *", "*mut") } else { ("&*", "*const") }; - let arg = if from_pty.ty == to_ref_ty { + let arg = if from_pty.ty == *to_ref_ty { arg } else { arg.as_ty(&format!("{} {}", cast, get_type_snippet(cx, qpath, to_ref_ty))) @@ -408,7 +405,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { ); }, ), - (&ty::Int(ast::IntTy::I32), &ty::Char) | (&ty::Uint(ast::UintTy::U32), &ty::Char) => { + (ty::Int(ast::IntTy::I32) | ty::Uint(ast::UintTy::U32), &ty::Char) => { span_lint_and_then( cx, TRANSMUTE_INT_TO_CHAR, @@ -430,13 +427,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { }, ) }, - (&ty::Ref(_, ty_from, from_mutbl), &ty::Ref(_, ty_to, to_mutbl)) => { + (ty::Ref(_, ty_from, from_mutbl), ty::Ref(_, ty_to, to_mutbl)) => { if_chain! { if let (&ty::Slice(slice_ty), &ty::Str) = (&ty_from.kind, &ty_to.kind); if let ty::Uint(ast::UintTy::U8) = slice_ty.kind; if from_mutbl == to_mutbl; then { - let postfix = if from_mutbl == Mutability::Mut { + let postfix = if *from_mutbl == Mutability::Mut { "_mut" } else { "" @@ -465,13 +462,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { |diag| if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) { let ty_from_and_mut = ty::TypeAndMut { ty: ty_from, - mutbl: from_mutbl + mutbl: *from_mutbl }; - let ty_to_and_mut = ty::TypeAndMut { ty: ty_to, mutbl: to_mutbl }; + let ty_to_and_mut = ty::TypeAndMut { ty: ty_to, mutbl: *to_mutbl }; let sugg_paren = arg .as_ty(cx.tcx.mk_ptr(ty_from_and_mut)) .as_ty(cx.tcx.mk_ptr(ty_to_and_mut)); - let sugg = if to_mutbl == Mutability::Mut { + let sugg = if *to_mutbl == Mutability::Mut { sugg_paren.mut_addr_deref() } else { sugg_paren.addr_deref() @@ -488,19 +485,19 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { } } }, - (&ty::RawPtr(_), &ty::RawPtr(to_ty)) => span_lint_and_then( + (ty::RawPtr(_), ty::RawPtr(to_ty)) => span_lint_and_then( cx, TRANSMUTE_PTR_TO_PTR, e.span, "transmute from a pointer to a pointer", |diag| { if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) { - let sugg = arg.as_ty(cx.tcx.mk_ptr(to_ty)); + let sugg = arg.as_ty(cx.tcx.mk_ptr(*to_ty)); diag.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified); } }, ), - (&ty::Int(ast::IntTy::I8), &ty::Bool) | (&ty::Uint(ast::UintTy::U8), &ty::Bool) => { + (ty::Int(ast::IntTy::I8) | ty::Uint(ast::UintTy::U8), ty::Bool) => { span_lint_and_then( cx, TRANSMUTE_INT_TO_BOOL, @@ -518,7 +515,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { }, ) }, - (&ty::Int(_), &ty::Float(_)) | (&ty::Uint(_), &ty::Float(_)) => span_lint_and_then( + (ty::Int(_) | ty::Uint(_), ty::Float(_)) => span_lint_and_then( cx, TRANSMUTE_INT_TO_FLOAT, e.span, @@ -541,7 +538,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { ); }, ), - (&ty::Float(float_ty), &ty::Int(_)) | (&ty::Float(float_ty), &ty::Uint(_)) => span_lint_and_then( + (ty::Float(float_ty), ty::Int(_) | ty::Uint(_)) => span_lint_and_then( cx, TRANSMUTE_FLOAT_TO_INT, e.span, @@ -585,7 +582,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute { ); }, ), - (&ty::Adt(ref from_adt, ref from_substs), &ty::Adt(ref to_adt, ref to_substs)) => { + (ty::Adt(from_adt, from_substs), ty::Adt(to_adt, to_substs)) => { if from_adt.did != to_adt.did || !COLLECTIONS.iter().any(|path| match_def_path(cx, to_adt.did, path)) { return; diff --git a/clippy_lints/src/types.rs b/clippy_lints/src/types.rs index 6ed9ff22e..bc5fe44b3 100644 --- a/clippy_lints/src/types.rs +++ b/clippy_lints/src/types.rs @@ -10,14 +10,14 @@ use rustc_errors::{Applicability, DiagnosticBuilder}; use rustc_hir as hir; use rustc_hir::intravisit::{walk_body, walk_expr, walk_ty, FnKind, NestedVisitorMap, Visitor}; use rustc_hir::{ - BinOpKind, Body, Expr, ExprKind, FnDecl, FnRetTy, FnSig, GenericArg, GenericParamKind, HirId, ImplItem, + BinOpKind, Block, Body, Expr, ExprKind, FnDecl, FnRetTy, FnSig, GenericArg, GenericParamKind, HirId, ImplItem, ImplItemKind, Item, ItemKind, Lifetime, Local, MatchSource, MutTy, Mutability, QPath, Stmt, StmtKind, TraitFn, TraitItem, TraitItemKind, TyKind, UnOp, }; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::map::Map; use rustc_middle::lint::in_external_macro; -use rustc_middle::ty::{self, InferTy, Ty, TyCtxt, TypeckTables}; +use rustc_middle::ty::{self, InferTy, Ty, TyCtxt, TyS, TypeckTables}; use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass}; use rustc_span::hygiene::{ExpnKind, MacroKind}; use rustc_span::source_map::Span; @@ -29,10 +29,10 @@ use rustc_typeck::hir_ty_to_ty; use crate::consts::{constant, Constant}; use crate::utils::paths; use crate::utils::{ - clip, comparisons, differing_macro_contexts, higher, in_constant, int_bits, is_type_diagnostic_item, + clip, comparisons, differing_macro_contexts, higher, in_constant, indent_of, int_bits, is_type_diagnostic_item, last_path_segment, match_def_path, match_path, method_chain_args, multispan_sugg, numeric_literal::NumericLiteral, - qpath_res, same_tys, sext, snippet, snippet_opt, snippet_with_applicability, snippet_with_macro_callsite, - span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, unsext, + qpath_res, sext, snippet, snippet_block_with_applicability, snippet_opt, snippet_with_applicability, + snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, unsext, }; declare_clippy_lint! { @@ -779,24 +779,22 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnitArg { match expr.kind { ExprKind::Call(_, args) | ExprKind::MethodCall(_, _, args) => { - for arg in args { - if is_unit(cx.tables.expr_ty(arg)) && !is_unit_literal(arg) { - if let ExprKind::Match(.., match_source) = &arg.kind { - if *match_source == MatchSource::TryDesugar { - continue; + let args_to_recover = args + .iter() + .filter(|arg| { + if is_unit(cx.tables.expr_ty(arg)) && !is_unit_literal(arg) { + if let ExprKind::Match(.., MatchSource::TryDesugar) = &arg.kind { + false + } else { + true } + } else { + false } - - span_lint_and_sugg( - cx, - UNIT_ARG, - arg.span, - "passing a unit value to a function", - "if you intended to pass a unit value, use a unit literal instead", - "()".to_string(), - Applicability::MaybeIncorrect, - ); - } + }) + .collect::>(); + if !args_to_recover.is_empty() { + lint_unit_args(cx, expr, &args_to_recover); } }, _ => (), @@ -804,6 +802,101 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnitArg { } } +fn lint_unit_args(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args_to_recover: &[&Expr<'_>]) { + let mut applicability = Applicability::MachineApplicable; + let (singular, plural) = if args_to_recover.len() > 1 { + ("", "s") + } else { + ("a ", "") + }; + span_lint_and_then( + cx, + UNIT_ARG, + expr.span, + &format!("passing {}unit value{} to a function", singular, plural), + |db| { + let mut or = ""; + args_to_recover + .iter() + .filter_map(|arg| { + if_chain! { + if let ExprKind::Block(block, _) = arg.kind; + if block.expr.is_none(); + if let Some(last_stmt) = block.stmts.iter().last(); + if let StmtKind::Semi(last_expr) = last_stmt.kind; + if let Some(snip) = snippet_opt(cx, last_expr.span); + then { + Some(( + last_stmt.span, + snip, + )) + } + else { + None + } + } + }) + .for_each(|(span, sugg)| { + db.span_suggestion( + span, + "remove the semicolon from the last statement in the block", + sugg, + Applicability::MaybeIncorrect, + ); + or = "or "; + }); + let sugg = args_to_recover + .iter() + .filter(|arg| !is_empty_block(arg)) + .enumerate() + .map(|(i, arg)| { + let indent = if i == 0 { + 0 + } else { + indent_of(cx, expr.span).unwrap_or(0) + }; + format!( + "{}{};", + " ".repeat(indent), + snippet_block_with_applicability(cx, arg.span, "..", Some(expr.span), &mut applicability) + ) + }) + .collect::>(); + let mut and = ""; + if !sugg.is_empty() { + let plural = if sugg.len() > 1 { "s" } else { "" }; + db.span_suggestion( + expr.span.with_hi(expr.span.lo()), + &format!("{}move the expression{} in front of the call...", or, plural), + format!("{}\n", sugg.join("\n")), + applicability, + ); + and = "...and " + } + db.multipart_suggestion( + &format!("{}use {}unit literal{} instead", and, singular, plural), + args_to_recover + .iter() + .map(|arg| (arg.span, "()".to_string())) + .collect::>(), + applicability, + ); + }, + ); +} + +fn is_empty_block(expr: &Expr<'_>) -> bool { + matches!( + expr.kind, + ExprKind::Block( + Block { + stmts: &[], expr: None, .. + }, + _, + ) + ) +} + fn is_questionmark_desugar_marked_call(expr: &Expr<'_>) -> bool { use rustc_span::hygiene::DesugaringKind; if let ExprKind::Call(ref callee, _) = expr.kind { @@ -974,7 +1067,8 @@ declare_clippy_lint! { /// behavior. /// /// **Known problems:** Using `std::ptr::read_unaligned` and `std::ptr::write_unaligned` or similar - /// on the resulting pointer is fine. + /// on the resulting pointer is fine. Is over-zealous: Casts with manual alignment checks or casts like + /// u64-> u8 -> u16 can be fine. Miri is able to do a more in-depth analysis. /// /// **Example:** /// ```rust @@ -982,7 +1076,7 @@ declare_clippy_lint! { /// let _ = (&mut 1u8 as *mut u8) as *mut u16; /// ``` pub CAST_PTR_ALIGNMENT, - correctness, + pedantic, "cast from a pointer to a more-strictly-aligned pointer" } @@ -2462,7 +2556,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for ImplicitHasherConstructorVisitor<'a, 'b, 't if let ExprKind::Path(QPath::TypeRelative(ref ty, ref method)) = fun.kind; if let TyKind::Path(QPath::Resolved(None, ty_path)) = ty.kind; then { - if !same_tys(self.cx, self.target.ty(), self.body.expr_ty(e)) { + if !TyS::same_type(self.target.ty(), self.body.expr_ty(e)) { return; } diff --git a/clippy_lints/src/unnecessary_sort_by.rs b/clippy_lints/src/unnecessary_sort_by.rs new file mode 100644 index 000000000..33d8331c2 --- /dev/null +++ b/clippy_lints/src/unnecessary_sort_by.rs @@ -0,0 +1,267 @@ +use crate::utils; +use crate::utils::paths; +use crate::utils::sugg::Sugg; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir::{Expr, ExprKind, Mutability, Param, Pat, PatKind, Path, PathSegment, QPath}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::symbol::Ident; + +declare_clippy_lint! { + /// **What it does:** + /// Detects when people use `Vec::sort_by` and pass in a function + /// which compares the two arguments, either directly or indirectly. + /// + /// **Why is this bad?** + /// It is more clear to use `Vec::sort_by_key` (or `Vec::sort` if + /// possible) than to use `Vec::sort_by` and and a more complicated + /// closure. + /// + /// **Known problems:** + /// If the suggested `Vec::sort_by_key` uses Reverse and it isn't + /// imported by a use statement in the current frame, then a `use` + /// statement that imports it will need to be added (which this lint + /// can't do). + /// + /// **Example:** + /// + /// ```rust + /// # struct A; + /// # impl A { fn foo(&self) {} } + /// # let mut vec: Vec = Vec::new(); + /// vec.sort_by(|a, b| a.foo().cmp(&b.foo())); + /// ``` + /// Use instead: + /// ```rust + /// # struct A; + /// # impl A { fn foo(&self) {} } + /// # let mut vec: Vec = Vec::new(); + /// vec.sort_by_key(|a| a.foo()); + /// ``` + pub UNNECESSARY_SORT_BY, + complexity, + "Use of `Vec::sort_by` when `Vec::sort_by_key` or `Vec::sort` would be clearer" +} + +declare_lint_pass!(UnnecessarySortBy => [UNNECESSARY_SORT_BY]); + +enum LintTrigger { + Sort(SortDetection), + SortByKey(SortByKeyDetection), +} + +struct SortDetection { + vec_name: String, + unstable: bool, +} + +struct SortByKeyDetection { + vec_name: String, + closure_arg: String, + closure_body: String, + reverse: bool, + unstable: bool, +} + +/// Detect if the two expressions are mirrored (identical, except one +/// contains a and the other replaces it with b) +fn mirrored_exprs( + cx: &LateContext<'_, '_>, + a_expr: &Expr<'_>, + a_ident: &Ident, + b_expr: &Expr<'_>, + b_ident: &Ident, +) -> bool { + match (&a_expr.kind, &b_expr.kind) { + // Two boxes with mirrored contents + (ExprKind::Box(left_expr), ExprKind::Box(right_expr)) => { + mirrored_exprs(cx, left_expr, a_ident, right_expr, b_ident) + }, + // Two arrays with mirrored contents + (ExprKind::Array(left_exprs), ExprKind::Array(right_exprs)) => left_exprs + .iter() + .zip(right_exprs.iter()) + .all(|(left, right)| mirrored_exprs(cx, left, a_ident, right, b_ident)), + // The two exprs are function calls. + // Check to see that the function itself and its arguments are mirrored + (ExprKind::Call(left_expr, left_args), ExprKind::Call(right_expr, right_args)) => { + mirrored_exprs(cx, left_expr, a_ident, right_expr, b_ident) + && left_args + .iter() + .zip(right_args.iter()) + .all(|(left, right)| mirrored_exprs(cx, left, a_ident, right, b_ident)) + }, + // The two exprs are method calls. + // Check to see that the function is the same and the arguments are mirrored + // This is enough because the receiver of the method is listed in the arguments + (ExprKind::MethodCall(left_segment, _, left_args), ExprKind::MethodCall(right_segment, _, right_args)) => { + left_segment.ident == right_segment.ident + && left_args + .iter() + .zip(right_args.iter()) + .all(|(left, right)| mirrored_exprs(cx, left, a_ident, right, b_ident)) + }, + // Two tuples with mirrored contents + (ExprKind::Tup(left_exprs), ExprKind::Tup(right_exprs)) => left_exprs + .iter() + .zip(right_exprs.iter()) + .all(|(left, right)| mirrored_exprs(cx, left, a_ident, right, b_ident)), + // Two binary ops, which are the same operation and which have mirrored arguments + (ExprKind::Binary(left_op, left_left, left_right), ExprKind::Binary(right_op, right_left, right_right)) => { + left_op.node == right_op.node + && mirrored_exprs(cx, left_left, a_ident, right_left, b_ident) + && mirrored_exprs(cx, left_right, a_ident, right_right, b_ident) + }, + // Two unary ops, which are the same operation and which have the same argument + (ExprKind::Unary(left_op, left_expr), ExprKind::Unary(right_op, right_expr)) => { + left_op == right_op && mirrored_exprs(cx, left_expr, a_ident, right_expr, b_ident) + }, + // The two exprs are literals of some kind + (ExprKind::Lit(left_lit), ExprKind::Lit(right_lit)) => left_lit.node == right_lit.node, + (ExprKind::Cast(left, _), ExprKind::Cast(right, _)) => mirrored_exprs(cx, left, a_ident, right, b_ident), + (ExprKind::DropTemps(left_block), ExprKind::DropTemps(right_block)) => { + mirrored_exprs(cx, left_block, a_ident, right_block, b_ident) + }, + (ExprKind::Field(left_expr, left_ident), ExprKind::Field(right_expr, right_ident)) => { + left_ident.name == right_ident.name && mirrored_exprs(cx, left_expr, a_ident, right_expr, right_ident) + }, + // Two paths: either one is a and the other is b, or they're identical to each other + ( + ExprKind::Path(QPath::Resolved( + _, + Path { + segments: left_segments, + .. + }, + )), + ExprKind::Path(QPath::Resolved( + _, + Path { + segments: right_segments, + .. + }, + )), + ) => { + (left_segments + .iter() + .zip(right_segments.iter()) + .all(|(left, right)| left.ident == right.ident) + && left_segments + .iter() + .all(|seg| &seg.ident != a_ident && &seg.ident != b_ident)) + || (left_segments.len() == 1 + && &left_segments[0].ident == a_ident + && right_segments.len() == 1 + && &right_segments[0].ident == b_ident) + }, + // Matching expressions, but one or both is borrowed + ( + ExprKind::AddrOf(left_kind, Mutability::Not, left_expr), + ExprKind::AddrOf(right_kind, Mutability::Not, right_expr), + ) => left_kind == right_kind && mirrored_exprs(cx, left_expr, a_ident, right_expr, b_ident), + (_, ExprKind::AddrOf(_, Mutability::Not, right_expr)) => { + mirrored_exprs(cx, a_expr, a_ident, right_expr, b_ident) + }, + (ExprKind::AddrOf(_, Mutability::Not, left_expr), _) => mirrored_exprs(cx, left_expr, a_ident, b_expr, b_ident), + _ => false, + } +} + +fn detect_lint(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option { + if_chain! { + if let ExprKind::MethodCall(name_ident, _, args) = &expr.kind; + if let name = name_ident.ident.name.to_ident_string(); + if name == "sort_by" || name == "sort_unstable_by"; + if let [vec, Expr { kind: ExprKind::Closure(_, _, closure_body_id, _, _), .. }] = args; + if utils::match_type(cx, &cx.tables.expr_ty(vec), &paths::VEC); + if let closure_body = cx.tcx.hir().body(*closure_body_id); + if let &[ + Param { pat: Pat { kind: PatKind::Binding(_, _, left_ident, _), .. }, ..}, + Param { pat: Pat { kind: PatKind::Binding(_, _, right_ident, _), .. }, .. } + ] = &closure_body.params; + if let ExprKind::MethodCall(method_path, _, [ref left_expr, ref right_expr]) = &closure_body.value.kind; + if method_path.ident.name.to_ident_string() == "cmp"; + then { + let (closure_body, closure_arg, reverse) = if mirrored_exprs( + &cx, + &left_expr, + &left_ident, + &right_expr, + &right_ident + ) { + (Sugg::hir(cx, &left_expr, "..").to_string(), left_ident.name.to_string(), false) + } else if mirrored_exprs(&cx, &left_expr, &right_ident, &right_expr, &left_ident) { + (Sugg::hir(cx, &left_expr, "..").to_string(), right_ident.name.to_string(), true) + } else { + return None; + }; + let vec_name = Sugg::hir(cx, &args[0], "..").to_string(); + let unstable = name == "sort_unstable_by"; + if_chain! { + if let ExprKind::Path(QPath::Resolved(_, Path { + segments: [PathSegment { ident: left_name, .. }], .. + })) = &left_expr.kind; + if left_name == left_ident; + then { + Some(LintTrigger::Sort(SortDetection { vec_name, unstable })) + } + else { + Some(LintTrigger::SortByKey(SortByKeyDetection { + vec_name, + unstable, + closure_arg, + closure_body, + reverse + })) + } + } + } else { + None + } + } +} + +impl LateLintPass<'_, '_> for UnnecessarySortBy { + fn check_expr(&mut self, cx: &LateContext<'_, '_>, expr: &Expr<'_>) { + match detect_lint(cx, expr) { + Some(LintTrigger::SortByKey(trigger)) => utils::span_lint_and_sugg( + cx, + UNNECESSARY_SORT_BY, + expr.span, + "use Vec::sort_by_key here instead", + "try", + format!( + "{}.sort{}_by_key(|&{}| {})", + trigger.vec_name, + if trigger.unstable { "_unstable" } else { "" }, + trigger.closure_arg, + if trigger.reverse { + format!("Reverse({})", trigger.closure_body) + } else { + trigger.closure_body.to_string() + }, + ), + if trigger.reverse { + Applicability::MaybeIncorrect + } else { + Applicability::MachineApplicable + }, + ), + Some(LintTrigger::Sort(trigger)) => utils::span_lint_and_sugg( + cx, + UNNECESSARY_SORT_BY, + expr.span, + "use Vec::sort here instead", + "try", + format!( + "{}.sort{}()", + trigger.vec_name, + if trigger.unstable { "_unstable" } else { "" }, + ), + Applicability::MachineApplicable, + ), + None => {}, + } + } +} diff --git a/clippy_lints/src/unnested_or_patterns.rs b/clippy_lints/src/unnested_or_patterns.rs new file mode 100644 index 000000000..8c281126c --- /dev/null +++ b/clippy_lints/src/unnested_or_patterns.rs @@ -0,0 +1,407 @@ +#![allow(clippy::wildcard_imports, clippy::enum_glob_use)] + +use crate::utils::ast_utils::{eq_field_pat, eq_id, eq_pat, eq_path}; +use crate::utils::{over, span_lint_and_then}; +use rustc_ast::ast::{self, Pat, PatKind, PatKind::*, DUMMY_NODE_ID}; +use rustc_ast::mut_visit::*; +use rustc_ast::ptr::P; +use rustc_ast_pretty::pprust; +use rustc_errors::Applicability; +use rustc_lint::{EarlyContext, EarlyLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::DUMMY_SP; + +use std::cell::Cell; +use std::mem; + +declare_clippy_lint! { + /// **What it does:** + /// + /// Checks for unnested or-patterns, e.g., `Some(0) | Some(2)` and + /// suggests replacing the pattern with a nested one, `Some(0 | 2)`. + /// + /// Another way to think of this is that it rewrites patterns in + /// *disjunctive normal form (DNF)* into *conjunctive normal form (CNF)*. + /// + /// **Why is this bad?** + /// + /// In the example above, `Some` is repeated, which unncessarily complicates the pattern. + /// + /// **Known problems:** None. + /// + /// **Example:** + /// + /// ```rust + /// fn main() { + /// if let Some(0) | Some(2) = Some(0) {} + /// } + /// ``` + /// Use instead: + /// ```rust + /// #![feature(or_patterns)] + /// + /// fn main() { + /// if let Some(0 | 2) = Some(0) {} + /// } + /// ``` + pub UNNESTED_OR_PATTERNS, + complexity, + "unnested or-patterns, e.g., `Foo(Bar) | Foo(Baz) instead of `Foo(Bar | Baz)`" +} + +declare_lint_pass!(UnnestedOrPatterns => [UNNESTED_OR_PATTERNS]); + +impl EarlyLintPass for UnnestedOrPatterns { + fn check_arm(&mut self, cx: &EarlyContext<'_>, a: &ast::Arm) { + lint_unnested_or_patterns(cx, &a.pat); + } + + fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) { + if let ast::ExprKind::Let(pat, _) = &e.kind { + lint_unnested_or_patterns(cx, pat); + } + } + + fn check_param(&mut self, cx: &EarlyContext<'_>, p: &ast::Param) { + lint_unnested_or_patterns(cx, &p.pat); + } + + fn check_local(&mut self, cx: &EarlyContext<'_>, l: &ast::Local) { + lint_unnested_or_patterns(cx, &l.pat); + } +} + +fn lint_unnested_or_patterns(cx: &EarlyContext<'_>, pat: &Pat) { + if !cx.sess.opts.unstable_features.is_nightly_build() { + // User cannot do `#![feature(or_patterns)]`, so bail. + return; + } + + if let Ident(.., None) | Lit(_) | Wild | Path(..) | Range(..) | Rest | MacCall(_) = pat.kind { + // This is a leaf pattern, so cloning is unprofitable. + return; + } + + let mut pat = P(pat.clone()); + + // Nix all the paren patterns everywhere so that they aren't in our way. + remove_all_parens(&mut pat); + + // Transform all unnested or-patterns into nested ones, and if there were none, quit. + if !unnest_or_patterns(&mut pat) { + return; + } + + span_lint_and_then(cx, UNNESTED_OR_PATTERNS, pat.span, "unnested or-patterns", |db| { + insert_necessary_parens(&mut pat); + db.span_suggestion_verbose( + pat.span, + "nest the patterns", + pprust::pat_to_string(&pat), + Applicability::MachineApplicable, + ); + }); +} + +/// Remove all `(p)` patterns in `pat`. +fn remove_all_parens(pat: &mut P) { + struct Visitor; + impl MutVisitor for Visitor { + fn visit_pat(&mut self, pat: &mut P) { + noop_visit_pat(pat, self); + let inner = match &mut pat.kind { + Paren(i) => mem::replace(&mut i.kind, Wild), + _ => return, + }; + pat.kind = inner; + } + } + Visitor.visit_pat(pat); +} + +/// Insert parens where necessary according to Rust's precedence rules for patterns. +fn insert_necessary_parens(pat: &mut P) { + struct Visitor; + impl MutVisitor for Visitor { + fn visit_pat(&mut self, pat: &mut P) { + use ast::{BindingMode::*, Mutability::*}; + noop_visit_pat(pat, self); + let target = match &mut pat.kind { + // `i @ a | b`, `box a | b`, and `& mut? a | b`. + Ident(.., Some(p)) | Box(p) | Ref(p, _) if matches!(&p.kind, Or(ps) if ps.len() > 1) => p, + Ref(p, Not) if matches!(p.kind, Ident(ByValue(Mut), ..)) => p, // `&(mut x)` + _ => return, + }; + target.kind = Paren(P(take_pat(target))); + } + } + Visitor.visit_pat(pat); +} + +/// Unnest or-patterns `p0 | ... | p1` in the pattern `pat`. +/// For example, this would transform `Some(0) | FOO | Some(2)` into `Some(0 | 2) | FOO`. +fn unnest_or_patterns(pat: &mut P) -> bool { + struct Visitor { + changed: bool, + } + impl MutVisitor for Visitor { + fn visit_pat(&mut self, p: &mut P) { + // This is a bottom up transformation, so recurse first. + noop_visit_pat(p, self); + + // Don't have an or-pattern? Just quit early on. + let alternatives = match &mut p.kind { + Or(ps) => ps, + _ => return, + }; + + // Collapse or-patterns directly nested in or-patterns. + let mut idx = 0; + let mut this_level_changed = false; + while idx < alternatives.len() { + let inner = if let Or(ps) = &mut alternatives[idx].kind { + mem::take(ps) + } else { + idx += 1; + continue; + }; + this_level_changed = true; + alternatives.splice(idx..=idx, inner); + } + + // Focus on `p_n` and then try to transform all `p_i` where `i > n`. + let mut focus_idx = 0; + while focus_idx < alternatives.len() { + this_level_changed |= transform_with_focus_on_idx(alternatives, focus_idx); + focus_idx += 1; + } + self.changed |= this_level_changed; + + // Deal with `Some(Some(0)) | Some(Some(1))`. + if this_level_changed { + noop_visit_pat(p, self); + } + } + } + + let mut visitor = Visitor { changed: false }; + visitor.visit_pat(pat); + visitor.changed +} + +/// Match `$scrutinee` against `$pat` and extract `$then` from it. +/// Panics if there is no match. +macro_rules! always_pat { + ($scrutinee:expr, $pat:pat => $then:expr) => { + match $scrutinee { + $pat => $then, + _ => unreachable!(), + } + }; +} + +/// Focus on `focus_idx` in `alternatives`, +/// attempting to extend it with elements of the same constructor `C` +/// in `alternatives[focus_idx + 1..]`. +fn transform_with_focus_on_idx(alternatives: &mut Vec>, focus_idx: usize) -> bool { + // Extract the kind; we'll need to make some changes in it. + let mut focus_kind = mem::replace(&mut alternatives[focus_idx].kind, PatKind::Wild); + // We'll focus on `alternatives[focus_idx]`, + // so we're draining from `alternatives[focus_idx + 1..]`. + let start = focus_idx + 1; + + // We're trying to find whatever kind (~"constructor") we found in `alternatives[start..]`. + let changed = match &mut focus_kind { + // These pattern forms are "leafs" and do not have sub-patterns. + // Therefore they are not some form of constructor `C`, + // with which a pattern `C(p_0)` may be formed, + // which we would want to join with other `C(p_j)`s. + Ident(.., None) | Lit(_) | Wild | Path(..) | Range(..) | Rest | MacCall(_) + // Dealt with elsewhere. + | Or(_) | Paren(_) => false, + // Transform `box x | ... | box y` into `box (x | y)`. + // + // The cases below until `Slice(...)` deal with *singleton* products. + // These patterns have the shape `C(p)`, and not e.g., `C(p0, ..., pn)`. + Box(target) => extend_with_matching( + target, start, alternatives, + |k| matches!(k, Box(_)), + |k| always_pat!(k, Box(p) => p), + ), + // Transform `&m x | ... | &m y` into `&m (x | y)`. + Ref(target, m1) => extend_with_matching( + target, start, alternatives, + |k| matches!(k, Ref(_, m2) if m1 == m2), // Mutabilities must match. + |k| always_pat!(k, Ref(p, _) => p), + ), + // Transform `b @ p0 | ... b @ p1` into `b @ (p0 | p1)`. + Ident(b1, i1, Some(target)) => extend_with_matching( + target, start, alternatives, + // Binding names must match. + |k| matches!(k, Ident(b2, i2, Some(_)) if b1 == b2 && eq_id(*i1, *i2)), + |k| always_pat!(k, Ident(_, _, Some(p)) => p), + ), + // Transform `[pre, x, post] | ... | [pre, y, post]` into `[pre, x | y, post]`. + Slice(ps1) => extend_with_matching_product( + ps1, start, alternatives, + |k, ps1, idx| matches!(k, Slice(ps2) if eq_pre_post(ps1, ps2, idx)), + |k| always_pat!(k, Slice(ps) => ps), + ), + // Transform `(pre, x, post) | ... | (pre, y, post)` into `(pre, x | y, post)`. + Tuple(ps1) => extend_with_matching_product( + ps1, start, alternatives, + |k, ps1, idx| matches!(k, Tuple(ps2) if eq_pre_post(ps1, ps2, idx)), + |k| always_pat!(k, Tuple(ps) => ps), + ), + // Transform `S(pre, x, post) | ... | S(pre, y, post)` into `S(pre, x | y, post)`. + TupleStruct(path1, ps1) => extend_with_matching_product( + ps1, start, alternatives, + |k, ps1, idx| matches!( + k, + TupleStruct(path2, ps2) if eq_path(path1, path2) && eq_pre_post(ps1, ps2, idx) + ), + |k| always_pat!(k, TupleStruct(_, ps) => ps), + ), + // Transform a record pattern `S { fp_0, ..., fp_n }`. + Struct(path1, fps1, rest1) => extend_with_struct_pat(path1, fps1, *rest1, start, alternatives), + }; + + alternatives[focus_idx].kind = focus_kind; + changed +} + +/// Here we focusing on a record pattern `S { fp_0, ..., fp_n }`. +/// In particular, for a record pattern, the order in which the field patterns is irrelevant. +/// So when we fixate on some `ident_k: pat_k`, we try to find `ident_k` in the other pattern +/// and check that all `fp_i` where `i ∈ ((0...n) \ k)` between two patterns are equal. +fn extend_with_struct_pat( + path1: &ast::Path, + fps1: &mut Vec, + rest1: bool, + start: usize, + alternatives: &mut Vec>, +) -> bool { + (0..fps1.len()).any(|idx| { + let pos_in_2 = Cell::new(None); // The element `k`. + let tail_or = drain_matching( + start, + alternatives, + |k| { + matches!(k, Struct(path2, fps2, rest2) + if rest1 == *rest2 // If one struct pattern has `..` so must the other. + && eq_path(path1, path2) + && fps1.len() == fps2.len() + && fps1.iter().enumerate().all(|(idx_1, fp1)| { + if idx_1 == idx { + // In the case of `k`, we merely require identical field names + // so that we will transform into `ident_k: p1_k | p2_k`. + let pos = fps2.iter().position(|fp2| eq_id(fp1.ident, fp2.ident)); + pos_in_2.set(pos); + pos.is_some() + } else { + fps2.iter().any(|fp2| eq_field_pat(fp1, fp2)) + } + })) + }, + // Extract `p2_k`. + |k| always_pat!(k, Struct(_, mut fps, _) => fps.swap_remove(pos_in_2.take().unwrap()).pat), + ); + extend_with_tail_or(&mut fps1[idx].pat, tail_or) + }) +} + +/// Like `extend_with_matching` but for products with > 1 factor, e.g., `C(p_0, ..., p_n)`. +/// Here, the idea is that we fixate on some `p_k` in `C`, +/// allowing it to vary between two `targets` and `ps2` (returned by `extract`), +/// while also requiring `ps1[..n] ~ ps2[..n]` (pre) and `ps1[n + 1..] ~ ps2[n + 1..]` (post), +/// where `~` denotes semantic equality. +fn extend_with_matching_product( + targets: &mut Vec>, + start: usize, + alternatives: &mut Vec>, + predicate: impl Fn(&PatKind, &[P], usize) -> bool, + extract: impl Fn(PatKind) -> Vec>, +) -> bool { + (0..targets.len()).any(|idx| { + let tail_or = drain_matching( + start, + alternatives, + |k| predicate(k, targets, idx), + |k| extract(k).swap_remove(idx), + ); + extend_with_tail_or(&mut targets[idx], tail_or) + }) +} + +/// Extract the pattern from the given one and replace it with `Wild`. +/// This is meant for temporarily swapping out the pattern for manipulation. +fn take_pat(from: &mut Pat) -> Pat { + let dummy = Pat { + id: DUMMY_NODE_ID, + kind: Wild, + span: DUMMY_SP, + }; + mem::replace(from, dummy) +} + +/// Extend `target` as an or-pattern with the alternatives +/// in `tail_or` if there are any and return if there were. +fn extend_with_tail_or(target: &mut Pat, tail_or: Vec>) -> bool { + fn extend(target: &mut Pat, mut tail_or: Vec>) { + match target { + // On an existing or-pattern in the target, append to it. + Pat { kind: Or(ps), .. } => ps.append(&mut tail_or), + // Otherwise convert the target to an or-pattern. + target => { + let mut init_or = vec![P(take_pat(target))]; + init_or.append(&mut tail_or); + target.kind = Or(init_or); + }, + } + } + + let changed = !tail_or.is_empty(); + if changed { + // Extend the target. + extend(target, tail_or); + } + changed +} + +// Extract all inner patterns in `alternatives` matching our `predicate`. +// Only elements beginning with `start` are considered for extraction. +fn drain_matching( + start: usize, + alternatives: &mut Vec>, + predicate: impl Fn(&PatKind) -> bool, + extract: impl Fn(PatKind) -> P, +) -> Vec> { + let mut tail_or = vec![]; + let mut idx = 0; + for pat in alternatives.drain_filter(|p| { + // Check if we should extract, but only if `idx >= start`. + idx += 1; + idx > start && predicate(&p.kind) + }) { + tail_or.push(extract(pat.into_inner().kind)); + } + tail_or +} + +fn extend_with_matching( + target: &mut Pat, + start: usize, + alternatives: &mut Vec>, + predicate: impl Fn(&PatKind) -> bool, + extract: impl Fn(PatKind) -> P, +) -> bool { + extend_with_tail_or(target, drain_matching(start, alternatives, predicate, extract)) +} + +/// Are the patterns in `ps1` and `ps2` equal save for `ps1[idx]` compared to `ps2[idx]`? +fn eq_pre_post(ps1: &[P], ps2: &[P], idx: usize) -> bool { + ps1[idx].is_rest() == ps2[idx].is_rest() // Avoid `[x, ..] | [x, 0]` => `[x, .. | 0]`. + && ps1.len() == ps2.len() + && over(&ps1[..idx], &ps2[..idx], |l, r| eq_pat(l, r)) + && over(&ps1[idx + 1..], &ps2[idx + 1..], |l, r| eq_pat(l, r)) +} diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index 8b971e706..036dd16a2 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -101,7 +101,7 @@ fn collect_unwrap_info<'a, 'tcx>( if let ExprKind::Binary(op, left, right) = &expr.kind { match (invert, op.node) { - (false, BinOpKind::And) | (false, BinOpKind::BitAnd) | (true, BinOpKind::Or) | (true, BinOpKind::BitOr) => { + (false, BinOpKind::And | BinOpKind::BitAnd) | (true, BinOpKind::Or | BinOpKind::BitOr) => { let mut unwrap_info = collect_unwrap_info(cx, left, branch, invert); unwrap_info.append(&mut collect_unwrap_info(cx, right, branch, invert)); return unwrap_info; diff --git a/clippy_lints/src/useless_conversion.rs b/clippy_lints/src/useless_conversion.rs index 7fa97b246..141035a98 100644 --- a/clippy_lints/src/useless_conversion.rs +++ b/clippy_lints/src/useless_conversion.rs @@ -1,12 +1,12 @@ use crate::utils::{ - is_type_diagnostic_item, match_def_path, match_trait_method, paths, same_tys, snippet, snippet_with_macro_callsite, + is_type_diagnostic_item, match_def_path, match_trait_method, paths, snippet, snippet_with_macro_callsite, span_lint_and_help, span_lint_and_sugg, }; use if_chain::if_chain; use rustc_errors::Applicability; use rustc_hir::{Expr, ExprKind, HirId, MatchSource}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty; +use rustc_middle::ty::{self, TyS}; use rustc_session::{declare_tool_lint, impl_lint_pass}; declare_clippy_lint! { @@ -65,7 +65,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessConversion { if match_trait_method(cx, e, &paths::INTO) && &*name.ident.as_str() == "into" { let a = cx.tables.expr_ty(e); let b = cx.tables.expr_ty(&args[0]); - if same_tys(cx, a, b) { + if TyS::same_type(a, b) { let sugg = snippet_with_macro_callsite(cx, args[0].span, "").to_string(); span_lint_and_sugg( cx, @@ -81,7 +81,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessConversion { if match_trait_method(cx, e, &paths::INTO_ITERATOR) && &*name.ident.as_str() == "into_iter" { let a = cx.tables.expr_ty(e); let b = cx.tables.expr_ty(&args[0]); - if same_tys(cx, a, b) { + if TyS::same_type(a, b) { let sugg = snippet(cx, args[0].span, "").into_owned(); span_lint_and_sugg( cx, @@ -101,7 +101,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessConversion { if is_type_diagnostic_item(cx, a, sym!(result_type)); if let ty::Adt(_, substs) = a.kind; if let Some(a_type) = substs.types().next(); - if same_tys(cx, a_type, b); + if TyS::same_type(a_type, b); then { span_lint_and_help( @@ -131,7 +131,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessConversion { if is_type_diagnostic_item(cx, a, sym!(result_type)); if let ty::Adt(_, substs) = a.kind; if let Some(a_type) = substs.types().next(); - if same_tys(cx, a_type, b); + if TyS::same_type(a_type, b); then { let hint = format!("consider removing `{}()`", snippet(cx, path.span, "TryFrom::try_from")); @@ -148,7 +148,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UselessConversion { if_chain! { if match_def_path(cx, def_id, &paths::FROM_FROM); - if same_tys(cx, a, b); + if TyS::same_type(a, b); then { let sugg = snippet(cx, args[0].span.source_callsite(), "").into_owned(); diff --git a/clippy_lints/src/utils/ast_utils.rs b/clippy_lints/src/utils/ast_utils.rs new file mode 100755 index 000000000..dcf09da19 --- /dev/null +++ b/clippy_lints/src/utils/ast_utils.rs @@ -0,0 +1,526 @@ +//! Utilities for manipulating and extracting information from `rustc_ast::ast`. +//! +//! - The `eq_foobar` functions test for semantic equality but ignores `NodeId`s and `Span`s. + +#![allow(clippy::similar_names, clippy::wildcard_imports, clippy::enum_glob_use)] + +use crate::utils::{both, over}; +use rustc_ast::ast::{self, *}; +use rustc_ast::ptr::P; +use rustc_span::symbol::Ident; +use std::mem; + +/// Checks if each element in the first slice is contained within the latter as per `eq_fn`. +pub fn unordered_over(left: &[X], right: &[X], mut eq_fn: impl FnMut(&X, &X) -> bool) -> bool { + left.len() == right.len() && left.iter().all(|l| right.iter().any(|r| eq_fn(l, r))) +} + +pub fn eq_id(l: Ident, r: Ident) -> bool { + l.name == r.name +} + +pub fn eq_pat(l: &Pat, r: &Pat) -> bool { + use PatKind::*; + match (&l.kind, &r.kind) { + (Paren(l), _) => eq_pat(l, r), + (_, Paren(r)) => eq_pat(l, r), + (Wild, Wild) | (Rest, Rest) => true, + (Lit(l), Lit(r)) => eq_expr(l, r), + (Ident(b1, i1, s1), Ident(b2, i2, s2)) => b1 == b2 && eq_id(*i1, *i2) && both(s1, s2, |l, r| eq_pat(l, r)), + (Range(lf, lt, le), Range(rf, rt, re)) => { + eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt) && eq_range_end(&le.node, &re.node) + }, + (Box(l), Box(r)) + | (Ref(l, Mutability::Not), Ref(r, Mutability::Not)) + | (Ref(l, Mutability::Mut), Ref(r, Mutability::Mut)) => eq_pat(l, r), + (Tuple(l), Tuple(r)) | (Slice(l), Slice(r)) => over(l, r, |l, r| eq_pat(l, r)), + (Path(lq, lp), Path(rq, rp)) => both(lq, rq, |l, r| eq_qself(l, r)) && eq_path(lp, rp), + (TupleStruct(lp, lfs), TupleStruct(rp, rfs)) => eq_path(lp, rp) && over(lfs, rfs, |l, r| eq_pat(l, r)), + (Struct(lp, lfs, lr), Struct(rp, rfs, rr)) => { + lr == rr && eq_path(lp, rp) && unordered_over(lfs, rfs, |lf, rf| eq_field_pat(lf, rf)) + }, + (Or(ls), Or(rs)) => unordered_over(ls, rs, |l, r| eq_pat(l, r)), + (MacCall(l), MacCall(r)) => eq_mac_call(l, r), + _ => false, + } +} + +pub fn eq_range_end(l: &RangeEnd, r: &RangeEnd) -> bool { + match (l, r) { + (RangeEnd::Excluded, RangeEnd::Excluded) => true, + (RangeEnd::Included(l), RangeEnd::Included(r)) => { + matches!(l, RangeSyntax::DotDotEq) == matches!(r, RangeSyntax::DotDotEq) + }, + _ => false, + } +} + +pub fn eq_field_pat(l: &FieldPat, r: &FieldPat) -> bool { + l.is_placeholder == r.is_placeholder + && eq_id(l.ident, r.ident) + && eq_pat(&l.pat, &r.pat) + && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r)) +} + +pub fn eq_qself(l: &QSelf, r: &QSelf) -> bool { + l.position == r.position && eq_ty(&l.ty, &r.ty) +} + +pub fn eq_path(l: &Path, r: &Path) -> bool { + over(&l.segments, &r.segments, |l, r| eq_path_seg(l, r)) +} + +pub fn eq_path_seg(l: &PathSegment, r: &PathSegment) -> bool { + eq_id(l.ident, r.ident) && both(&l.args, &r.args, |l, r| eq_generic_args(l, r)) +} + +pub fn eq_generic_args(l: &GenericArgs, r: &GenericArgs) -> bool { + match (l, r) { + (GenericArgs::AngleBracketed(l), GenericArgs::AngleBracketed(r)) => { + over(&l.args, &r.args, |l, r| eq_angle_arg(l, r)) + }, + (GenericArgs::Parenthesized(l), GenericArgs::Parenthesized(r)) => { + over(&l.inputs, &r.inputs, |l, r| eq_ty(l, r)) && eq_fn_ret_ty(&l.output, &r.output) + }, + _ => false, + } +} + +pub fn eq_angle_arg(l: &AngleBracketedArg, r: &AngleBracketedArg) -> bool { + match (l, r) { + (AngleBracketedArg::Arg(l), AngleBracketedArg::Arg(r)) => eq_generic_arg(l, r), + (AngleBracketedArg::Constraint(l), AngleBracketedArg::Constraint(r)) => eq_assoc_constraint(l, r), + _ => false, + } +} + +pub fn eq_generic_arg(l: &GenericArg, r: &GenericArg) -> bool { + match (l, r) { + (GenericArg::Lifetime(l), GenericArg::Lifetime(r)) => eq_id(l.ident, r.ident), + (GenericArg::Type(l), GenericArg::Type(r)) => eq_ty(l, r), + (GenericArg::Const(l), GenericArg::Const(r)) => eq_expr(&l.value, &r.value), + _ => false, + } +} + +pub fn eq_expr_opt(l: &Option>, r: &Option>) -> bool { + both(l, r, |l, r| eq_expr(l, r)) +} + +pub fn eq_expr(l: &Expr, r: &Expr) -> bool { + use ExprKind::*; + if !over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r)) { + return false; + } + match (&l.kind, &r.kind) { + (Paren(l), _) => eq_expr(l, r), + (_, Paren(r)) => eq_expr(l, r), + (Err, Err) => true, + (Box(l), Box(r)) | (Try(l), Try(r)) | (Await(l), Await(r)) => eq_expr(l, r), + (Array(l), Array(r)) | (Tup(l), Tup(r)) => over(l, r, |l, r| eq_expr(l, r)), + (Repeat(le, ls), Repeat(re, rs)) => eq_expr(le, re) && eq_expr(&ls.value, &rs.value), + (Call(lc, la), Call(rc, ra)) => eq_expr(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)), + (MethodCall(lc, la), MethodCall(rc, ra)) => eq_path_seg(lc, rc) && over(la, ra, |l, r| eq_expr(l, r)), + (Binary(lo, ll, lr), Binary(ro, rl, rr)) => lo.node == ro.node && eq_expr(ll, rl) && eq_expr(lr, rr), + (Unary(lo, l), Unary(ro, r)) => mem::discriminant(lo) == mem::discriminant(ro) && eq_expr(l, r), + (Lit(l), Lit(r)) => l.kind == r.kind, + (Cast(l, lt), Cast(r, rt)) | (Type(l, lt), Type(r, rt)) => eq_expr(l, r) && eq_ty(lt, rt), + (Let(lp, le), Let(rp, re)) => eq_pat(lp, rp) && eq_expr(le, re), + (If(lc, lt, le), If(rc, rt, re)) => eq_expr(lc, rc) && eq_block(lt, rt) && eq_expr_opt(le, re), + (While(lc, lt, ll), While(rc, rt, rl)) => eq_label(ll, rl) && eq_expr(lc, rc) && eq_block(lt, rt), + (ForLoop(lp, li, lt, ll), ForLoop(rp, ri, rt, rl)) => { + eq_label(ll, rl) && eq_pat(lp, rp) && eq_expr(li, ri) && eq_block(lt, rt) + }, + (Loop(lt, ll), Loop(rt, rl)) => eq_label(ll, rl) && eq_block(lt, rt), + (Block(lb, ll), Block(rb, rl)) => eq_label(ll, rl) && eq_block(lb, rb), + (TryBlock(l), TryBlock(r)) => eq_block(l, r), + (Yield(l), Yield(r)) | (Ret(l), Ret(r)) => eq_expr_opt(l, r), + (Break(ll, le), Break(rl, re)) => eq_label(ll, rl) && eq_expr_opt(le, re), + (Continue(ll), Continue(rl)) => eq_label(ll, rl), + (Assign(l1, l2, _), Assign(r1, r2, _)) | (Index(l1, l2), Index(r1, r2)) => eq_expr(l1, r1) && eq_expr(l2, r2), + (AssignOp(lo, lp, lv), AssignOp(ro, rp, rv)) => lo.node == ro.node && eq_expr(lp, rp) && eq_expr(lv, rv), + (Field(lp, lf), Field(rp, rf)) => eq_id(*lf, *rf) && eq_expr(lp, rp), + (Match(ls, la), Match(rs, ra)) => eq_expr(ls, rs) && over(la, ra, |l, r| eq_arm(l, r)), + (Closure(lc, la, lm, lf, lb, _), Closure(rc, ra, rm, rf, rb, _)) => { + lc == rc && la.is_async() == ra.is_async() && lm == rm && eq_fn_decl(lf, rf) && eq_expr(lb, rb) + }, + (Async(lc, _, lb), Async(rc, _, rb)) => lc == rc && eq_block(lb, rb), + (Range(lf, lt, ll), Range(rf, rt, rl)) => ll == rl && eq_expr_opt(lf, rf) && eq_expr_opt(lt, rt), + (AddrOf(lbk, lm, le), AddrOf(rbk, rm, re)) => lbk == rbk && lm == rm && eq_expr(le, re), + (Path(lq, lp), Path(rq, rp)) => both(lq, rq, |l, r| eq_qself(l, r)) && eq_path(lp, rp), + (MacCall(l), MacCall(r)) => eq_mac_call(l, r), + (Struct(lp, lfs, lb), Struct(rp, rfs, rb)) => { + eq_path(lp, rp) && eq_expr_opt(lb, rb) && unordered_over(lfs, rfs, |l, r| eq_field(l, r)) + }, + _ => false, + } +} + +pub fn eq_field(l: &Field, r: &Field) -> bool { + l.is_placeholder == r.is_placeholder + && eq_id(l.ident, r.ident) + && eq_expr(&l.expr, &r.expr) + && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r)) +} + +pub fn eq_arm(l: &Arm, r: &Arm) -> bool { + l.is_placeholder == r.is_placeholder + && eq_pat(&l.pat, &r.pat) + && eq_expr(&l.body, &r.body) + && eq_expr_opt(&l.guard, &r.guard) + && over(&l.attrs, &r.attrs, |l, r| eq_attr(l, r)) +} + +pub fn eq_label(l: &Option: Sized, +{ + let x: Dst = *(Box::new(Dst { x: 1 }) as Box>); +} + +fn return_str() -> str +where + str: Sized, +{ + *"Sized".to_string().into_boxed_str() +} + +fn use_op(s: String) -> String +where + String: ::std::ops::Neg, +{ + -s +} + +fn use_for() +where + i32: Iterator, +{ + for _ in 2i32 {} +} + +fn main() {} diff --git a/tests/ui/crashes/ice-3969.stderr b/tests/ui/crashes/ice-3969.stderr new file mode 100644 index 000000000..923db0664 --- /dev/null +++ b/tests/ui/crashes/ice-3969.stderr @@ -0,0 +1,22 @@ +error: trait objects without an explicit `dyn` are deprecated + --> $DIR/ice-3969.rs:25:17 + | +LL | for<'a> Dst: Sized, + | ^^^^^^ help: use `dyn`: `dyn A + 'a` + | + = note: `-D bare-trait-objects` implied by `-D warnings` + +error: trait objects without an explicit `dyn` are deprecated + --> $DIR/ice-3969.rs:27:16 + | +LL | let x: Dst = *(Box::new(Dst { x: 1 }) as Box>); + | ^ help: use `dyn`: `dyn A` + +error: trait objects without an explicit `dyn` are deprecated + --> $DIR/ice-3969.rs:27:57 + | +LL | let x: Dst = *(Box::new(Dst { x: 1 }) as Box>); + | ^ help: use `dyn`: `dyn A` + +error: aborting due to 3 previous errors + diff --git a/tests/ui/crashes/regressions.rs b/tests/ui/crashes/regressions.rs index 623ae51f9..3d5063d1a 100644 --- a/tests/ui/crashes/regressions.rs +++ b/tests/ui/crashes/regressions.rs @@ -6,4 +6,8 @@ pub fn foo(bar: *const u8) { println!("{:#p}", bar); } +// Regression test for https://github.com/rust-lang/rust-clippy/issues/4917 +/// ::new()).iter(); //~ WARN equivalent to .iter() let _ = std::path::Path::new("12/34").iter(); //~ WARN equivalent to .iter() let _ = std::path::PathBuf::from("12/34").iter(); //~ ERROR equivalent to .iter() + + let _ = (&[1, 2, 3]).iter().next(); //~ WARN equivalent to .iter() } diff --git a/tests/ui/into_iter_on_ref.rs b/tests/ui/into_iter_on_ref.rs index 94bc16896..416056d3f 100644 --- a/tests/ui/into_iter_on_ref.rs +++ b/tests/ui/into_iter_on_ref.rs @@ -40,4 +40,6 @@ fn main() { let _ = (&HashSet::::new()).into_iter(); //~ WARN equivalent to .iter() let _ = std::path::Path::new("12/34").into_iter(); //~ WARN equivalent to .iter() let _ = std::path::PathBuf::from("12/34").into_iter(); //~ ERROR equivalent to .iter() + + let _ = (&[1, 2, 3]).into_iter().next(); //~ WARN equivalent to .iter() } diff --git a/tests/ui/into_iter_on_ref.stderr b/tests/ui/into_iter_on_ref.stderr index 80e2d104f..1cd6400b0 100644 --- a/tests/ui/into_iter_on_ref.stderr +++ b/tests/ui/into_iter_on_ref.stderr @@ -156,5 +156,11 @@ error: this `.into_iter()` call is equivalent to `.iter()` and will not move the LL | let _ = std::path::PathBuf::from("12/34").into_iter(); //~ ERROR equivalent to .iter() | ^^^^^^^^^ help: call directly: `iter` -error: aborting due to 26 previous errors +error: this `.into_iter()` call is equivalent to `.iter()` and will not move the `array` + --> $DIR/into_iter_on_ref.rs:44:26 + | +LL | let _ = (&[1, 2, 3]).into_iter().next(); //~ WARN equivalent to .iter() + | ^^^^^^^^^ help: call directly: `iter` + +error: aborting due to 27 previous errors diff --git a/tests/ui/iter_next_slice.fixed b/tests/ui/iter_next_slice.fixed new file mode 100644 index 000000000..79c1db87a --- /dev/null +++ b/tests/ui/iter_next_slice.fixed @@ -0,0 +1,24 @@ +// run-rustfix +#![warn(clippy::iter_next_slice)] + +fn main() { + // test code goes here + let s = [1, 2, 3]; + let v = vec![1, 2, 3]; + + s.get(0); + // Should be replaced by s.get(0) + + s.get(2); + // Should be replaced by s.get(2) + + v.get(5); + // Should be replaced by v.get(5) + + v.get(0); + // Should be replaced by v.get(0) + + let o = Some(5); + o.iter().next(); + // Shouldn't be linted since this is not a Slice or an Array +} diff --git a/tests/ui/iter_next_slice.rs b/tests/ui/iter_next_slice.rs new file mode 100644 index 000000000..ef9a55f3d --- /dev/null +++ b/tests/ui/iter_next_slice.rs @@ -0,0 +1,24 @@ +// run-rustfix +#![warn(clippy::iter_next_slice)] + +fn main() { + // test code goes here + let s = [1, 2, 3]; + let v = vec![1, 2, 3]; + + s.iter().next(); + // Should be replaced by s.get(0) + + s[2..].iter().next(); + // Should be replaced by s.get(2) + + v[5..].iter().next(); + // Should be replaced by v.get(5) + + v.iter().next(); + // Should be replaced by v.get(0) + + let o = Some(5); + o.iter().next(); + // Shouldn't be linted since this is not a Slice or an Array +} diff --git a/tests/ui/iter_next_slice.stderr b/tests/ui/iter_next_slice.stderr new file mode 100644 index 000000000..bbf61df0c --- /dev/null +++ b/tests/ui/iter_next_slice.stderr @@ -0,0 +1,28 @@ +error: Using `.iter().next()` on an array + --> $DIR/iter_next_slice.rs:9:5 + | +LL | s.iter().next(); + | ^^^^^^^^^^^^^^^ help: try calling: `s.get(0)` + | + = note: `-D clippy::iter-next-slice` implied by `-D warnings` + +error: Using `.iter().next()` on a Slice without end index. + --> $DIR/iter_next_slice.rs:12:5 + | +LL | s[2..].iter().next(); + | ^^^^^^^^^^^^^^^^^^^^ help: try calling: `s.get(2)` + +error: Using `.iter().next()` on a Slice without end index. + --> $DIR/iter_next_slice.rs:15:5 + | +LL | v[5..].iter().next(); + | ^^^^^^^^^^^^^^^^^^^^ help: try calling: `v.get(5)` + +error: Using `.iter().next()` on an array + --> $DIR/iter_next_slice.rs:18:5 + | +LL | v.iter().next(); + | ^^^^^^^^^^^^^^^ help: try calling: `v.get(0)` + +error: aborting due to 4 previous errors + diff --git a/tests/ui/len_zero.fixed b/tests/ui/len_zero.fixed index 624e5ef8f..a29b832eb 100644 --- a/tests/ui/len_zero.fixed +++ b/tests/ui/len_zero.fixed @@ -141,3 +141,11 @@ fn main() { fn test_slice(b: &[u8]) { if !b.is_empty() {} } + +mod issue_3807 { + // Avoid suggesting changes to ranges if the user did not enable `range_is_empty`. + // See https://github.com/rust-lang/rust/issues/48111#issuecomment-445132965 + fn no_suggestion() { + let _ = (0..42).len() == 0; + } +} diff --git a/tests/ui/len_zero.rs b/tests/ui/len_zero.rs index 7fba971cf..8fd0093f4 100644 --- a/tests/ui/len_zero.rs +++ b/tests/ui/len_zero.rs @@ -141,3 +141,11 @@ fn main() { fn test_slice(b: &[u8]) { if b.len() != 0 {} } + +mod issue_3807 { + // Avoid suggesting changes to ranges if the user did not enable `range_is_empty`. + // See https://github.com/rust-lang/rust/issues/48111#issuecomment-445132965 + fn no_suggestion() { + let _ = (0..42).len() == 0; + } +} diff --git a/tests/ui/len_zero_ranges.fixed b/tests/ui/len_zero_ranges.fixed new file mode 100644 index 000000000..7da26f8ff --- /dev/null +++ b/tests/ui/len_zero_ranges.fixed @@ -0,0 +1,14 @@ +// run-rustfix + +#![feature(range_is_empty)] +#![warn(clippy::len_zero)] +#![allow(unused)] + +mod issue_3807 { + // With the feature enabled, `is_empty` should be suggested + fn suggestion_is_fine() { + let _ = (0..42).is_empty(); + } +} + +fn main() {} diff --git a/tests/ui/len_zero_ranges.rs b/tests/ui/len_zero_ranges.rs new file mode 100644 index 000000000..be7b4244b --- /dev/null +++ b/tests/ui/len_zero_ranges.rs @@ -0,0 +1,14 @@ +// run-rustfix + +#![feature(range_is_empty)] +#![warn(clippy::len_zero)] +#![allow(unused)] + +mod issue_3807 { + // With the feature enabled, `is_empty` should be suggested + fn suggestion_is_fine() { + let _ = (0..42).len() == 0; + } +} + +fn main() {} diff --git a/tests/ui/len_zero_ranges.stderr b/tests/ui/len_zero_ranges.stderr new file mode 100644 index 000000000..6e5fa41fb --- /dev/null +++ b/tests/ui/len_zero_ranges.stderr @@ -0,0 +1,10 @@ +error: length comparison to zero + --> $DIR/len_zero_ranges.rs:10:17 + | +LL | let _ = (0..42).len() == 0; + | ^^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `(0..42).is_empty()` + | + = note: `-D clippy::len-zero` implied by `-D warnings` + +error: aborting due to previous error + diff --git a/tests/ui/let_and_return.rs b/tests/ui/let_and_return.rs new file mode 100644 index 000000000..09614b8c1 --- /dev/null +++ b/tests/ui/let_and_return.rs @@ -0,0 +1,138 @@ +#![allow(unused)] +#![warn(clippy::let_and_return)] + +fn test() -> i32 { + let _y = 0; // no warning + let x = 5; + x +} + +fn test_inner() -> i32 { + if true { + let x = 5; + x + } else { + 0 + } +} + +fn test_nowarn_1() -> i32 { + let mut x = 5; + x += 1; + x +} + +fn test_nowarn_2() -> i32 { + let x = 5; + x + 1 +} + +fn test_nowarn_3() -> (i32, i32) { + // this should technically warn, but we do not compare complex patterns + let (x, y) = (5, 9); + (x, y) +} + +fn test_nowarn_4() -> i32 { + // this should technically warn, but not b/c of clippy::let_and_return, but b/c of useless type + let x: i32 = 5; + x +} + +fn test_nowarn_5(x: i16) -> u16 { + #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)] + let x = x as u16; + x +} + +// False positive example +trait Decode { + fn decode(d: D) -> Result + where + Self: Sized; +} + +macro_rules! tuple_encode { + ($($x:ident),*) => ( + impl<$($x: Decode),*> Decode for ($($x),*) { + #[inline] + #[allow(non_snake_case)] + fn decode(mut d: D) -> Result { + // Shouldn't trigger lint + Ok(($({let $x = Decode::decode(&mut d)?; $x }),*)) + } + } + ); +} + +tuple_encode!(T0, T1, T2, T3, T4, T5, T6, T7); + +mod no_lint_if_stmt_borrows { + mod issue_3792 { + use std::io::{self, BufRead, Stdin}; + + fn read_line() -> String { + let stdin = io::stdin(); + let line = stdin.lock().lines().next().unwrap().unwrap(); + line + } + } + + mod issue_3324 { + use std::cell::RefCell; + use std::rc::{Rc, Weak}; + + fn test(value: Weak>) -> u32 { + let value = value.upgrade().unwrap(); + let ret = value.borrow().baz(); + ret + } + + struct Bar {} + + impl Bar { + fn new() -> Self { + Bar {} + } + fn baz(&self) -> u32 { + 0 + } + } + + fn main() { + let a = Rc::new(RefCell::new(Bar::new())); + let b = Rc::downgrade(&a); + test(b); + } + } + + mod free_function { + struct Inner; + + struct Foo<'a> { + inner: &'a Inner, + } + + impl Drop for Foo<'_> { + fn drop(&mut self) {} + } + + impl Foo<'_> { + fn value(&self) -> i32 { + 42 + } + } + + fn some_foo(inner: &Inner) -> Foo<'_> { + Foo { inner } + } + + fn test() -> i32 { + let x = Inner {}; + let value = some_foo(&x).value(); + value + } + } +} + +fn main() {} diff --git a/tests/ui/let_return.stderr b/tests/ui/let_and_return.stderr similarity index 89% rename from tests/ui/let_return.stderr rename to tests/ui/let_and_return.stderr index 128a22c86..eacf948b3 100644 --- a/tests/ui/let_return.stderr +++ b/tests/ui/let_and_return.stderr @@ -1,5 +1,5 @@ error: returning the result of a `let` binding from a block - --> $DIR/let_return.rs:7:5 + --> $DIR/let_and_return.rs:7:5 | LL | let x = 5; | ---------- unnecessary `let` binding @@ -14,7 +14,7 @@ LL | 5 | error: returning the result of a `let` binding from a block - --> $DIR/let_return.rs:13:9 + --> $DIR/let_and_return.rs:13:9 | LL | let x = 5; | ---------- unnecessary `let` binding diff --git a/tests/ui/let_return.rs b/tests/ui/let_return.rs deleted file mode 100644 index 23645d48f..000000000 --- a/tests/ui/let_return.rs +++ /dev/null @@ -1,70 +0,0 @@ -#![allow(unused)] -#![warn(clippy::let_and_return)] - -fn test() -> i32 { - let _y = 0; // no warning - let x = 5; - x -} - -fn test_inner() -> i32 { - if true { - let x = 5; - x - } else { - 0 - } -} - -fn test_nowarn_1() -> i32 { - let mut x = 5; - x += 1; - x -} - -fn test_nowarn_2() -> i32 { - let x = 5; - x + 1 -} - -fn test_nowarn_3() -> (i32, i32) { - // this should technically warn, but we do not compare complex patterns - let (x, y) = (5, 9); - (x, y) -} - -fn test_nowarn_4() -> i32 { - // this should technically warn, but not b/c of clippy::let_and_return, but b/c of useless type - let x: i32 = 5; - x -} - -fn test_nowarn_5(x: i16) -> u16 { - #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)] - let x = x as u16; - x -} - -// False positive example -trait Decode { - fn decode(d: D) -> Result - where - Self: Sized; -} - -macro_rules! tuple_encode { - ($($x:ident),*) => ( - impl<$($x: Decode),*> Decode for ($($x),*) { - #[inline] - #[allow(non_snake_case)] - fn decode(mut d: D) -> Result { - // Shouldn't trigger lint - Ok(($({let $x = Decode::decode(&mut d)?; $x }),*)) - } - } - ); -} - -tuple_encode!(T0, T1, T2, T3, T4, T5, T6, T7); - -fn main() {} diff --git a/tests/ui/needless_collect.fixed b/tests/ui/needless_collect.fixed index b4227eaf2..be37dc16b 100644 --- a/tests/ui/needless_collect.fixed +++ b/tests/ui/needless_collect.fixed @@ -9,7 +9,7 @@ use std::collections::{BTreeSet, HashMap, HashSet}; fn main() { let sample = [1; 5]; let len = sample.iter().count(); - if sample.iter().next().is_none() { + if sample.get(0).is_none() { // Empty } sample.iter().cloned().any(|x| x == 1); diff --git a/tests/ui/needless_collect.stderr b/tests/ui/needless_collect.stderr index 8884c8e16..9113aad90 100644 --- a/tests/ui/needless_collect.stderr +++ b/tests/ui/needless_collect.stderr @@ -1,28 +1,28 @@ error: avoid using `collect()` when not needed - --> $DIR/needless_collect.rs:11:28 + --> $DIR/needless_collect.rs:11:29 | LL | let len = sample.iter().collect::>().len(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `.count()` + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()` | = note: `-D clippy::needless-collect` implied by `-D warnings` error: avoid using `collect()` when not needed - --> $DIR/needless_collect.rs:12:21 + --> $DIR/needless_collect.rs:12:15 | LL | if sample.iter().collect::>().is_empty() { - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `.next().is_none()` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `get(0).is_none()` error: avoid using `collect()` when not needed - --> $DIR/needless_collect.rs:15:27 + --> $DIR/needless_collect.rs:15:28 | LL | sample.iter().cloned().collect::>().contains(&1); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `.any(|x| x == 1)` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `any(|x| x == 1)` error: avoid using `collect()` when not needed - --> $DIR/needless_collect.rs:16:34 + --> $DIR/needless_collect.rs:16:35 | LL | sample.iter().map(|x| (x, x)).collect::>().len(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `.count()` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `count()` error: aborting due to 4 previous errors diff --git a/tests/ui/neg_cmp_op_on_partial_ord.rs b/tests/ui/neg_cmp_op_on_partial_ord.rs index 856a430ba..ca70e3b71 100644 --- a/tests/ui/neg_cmp_op_on_partial_ord.rs +++ b/tests/ui/neg_cmp_op_on_partial_ord.rs @@ -4,6 +4,7 @@ use std::cmp::Ordering; +#[allow(clippy::unnested_or_patterns)] #[warn(clippy::neg_cmp_op_on_partial_ord)] fn main() { let a_value = 1.0; diff --git a/tests/ui/neg_cmp_op_on_partial_ord.stderr b/tests/ui/neg_cmp_op_on_partial_ord.stderr index d05fd34ce..8c5d54822 100644 --- a/tests/ui/neg_cmp_op_on_partial_ord.stderr +++ b/tests/ui/neg_cmp_op_on_partial_ord.stderr @@ -1,5 +1,5 @@ error: The use of negated comparison operators on partially ordered types produces code that is hard to read and refactor. Please consider using the `partial_cmp` method instead, to make it clear that the two values could be incomparable. - --> $DIR/neg_cmp_op_on_partial_ord.rs:15:21 + --> $DIR/neg_cmp_op_on_partial_ord.rs:16:21 | LL | let _not_less = !(a_value < another_value); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -7,19 +7,19 @@ LL | let _not_less = !(a_value < another_value); = note: `-D clippy::neg-cmp-op-on-partial-ord` implied by `-D warnings` error: The use of negated comparison operators on partially ordered types produces code that is hard to read and refactor. Please consider using the `partial_cmp` method instead, to make it clear that the two values could be incomparable. - --> $DIR/neg_cmp_op_on_partial_ord.rs:18:30 + --> $DIR/neg_cmp_op_on_partial_ord.rs:19:30 | LL | let _not_less_or_equal = !(a_value <= another_value); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: The use of negated comparison operators on partially ordered types produces code that is hard to read and refactor. Please consider using the `partial_cmp` method instead, to make it clear that the two values could be incomparable. - --> $DIR/neg_cmp_op_on_partial_ord.rs:21:24 + --> $DIR/neg_cmp_op_on_partial_ord.rs:22:24 | LL | let _not_greater = !(a_value > another_value); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ error: The use of negated comparison operators on partially ordered types produces code that is hard to read and refactor. Please consider using the `partial_cmp` method instead, to make it clear that the two values could be incomparable. - --> $DIR/neg_cmp_op_on_partial_ord.rs:24:33 + --> $DIR/neg_cmp_op_on_partial_ord.rs:25:33 | LL | let _not_greater_or_equal = !(a_value >= another_value); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/tests/ui/or_fun_call.fixed b/tests/ui/or_fun_call.fixed index 7bb08797e..2045ffdb5 100644 --- a/tests/ui/or_fun_call.fixed +++ b/tests/ui/or_fun_call.fixed @@ -29,7 +29,7 @@ fn or_fun_call() { with_enum.unwrap_or(Enum::A(5)); let with_const_fn = Some(Duration::from_secs(1)); - with_const_fn.unwrap_or(Duration::from_secs(5)); + with_const_fn.unwrap_or_else(|| Duration::from_secs(5)); let with_constructor = Some(vec![1]); with_constructor.unwrap_or_else(make); @@ -94,7 +94,7 @@ fn test_or_with_ctors() { let b = "b".to_string(); let _ = Some(Bar("a".to_string(), Duration::from_secs(1))) - .or(Some(Bar(b, Duration::from_secs(2)))); + .or_else(|| Some(Bar(b, Duration::from_secs(2)))); let vec = vec!["foo"]; let _ = opt.ok_or(vec.len()); diff --git a/tests/ui/or_fun_call.stderr b/tests/ui/or_fun_call.stderr index 96d55771e..bc5978b53 100644 --- a/tests/ui/or_fun_call.stderr +++ b/tests/ui/or_fun_call.stderr @@ -1,10 +1,16 @@ +error: use of `unwrap_or` followed by a function call + --> $DIR/or_fun_call.rs:32:19 + | +LL | with_const_fn.unwrap_or(Duration::from_secs(5)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| Duration::from_secs(5))` + | + = note: `-D clippy::or-fun-call` implied by `-D warnings` + error: use of `unwrap_or` followed by a function call --> $DIR/or_fun_call.rs:35:22 | LL | with_constructor.unwrap_or(make()); | ^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(make)` - | - = note: `-D clippy::or-fun-call` implied by `-D warnings` error: use of `unwrap_or` followed by a call to `new` --> $DIR/or_fun_call.rs:38:5 @@ -78,5 +84,11 @@ error: use of `or` followed by a function call LL | let _ = Some("a".to_string()).or(Some("b".to_string())); | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `or_else(|| Some("b".to_string()))` -error: aborting due to 13 previous errors +error: use of `or` followed by a function call + --> $DIR/or_fun_call.rs:97:10 + | +LL | .or(Some(Bar(b, Duration::from_secs(2)))); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `or_else(|| Some(Bar(b, Duration::from_secs(2))))` + +error: aborting due to 15 previous errors diff --git a/tests/ui/reversed_empty_ranges_fixable.fixed b/tests/ui/reversed_empty_ranges_fixable.fixed index 332c0427e..79e482eec 100644 --- a/tests/ui/reversed_empty_ranges_fixable.fixed +++ b/tests/ui/reversed_empty_ranges_fixable.fixed @@ -4,8 +4,6 @@ const ANSWER: i32 = 42; fn main() { - let arr = [1, 2, 3, 4, 5]; - // These should be linted: (21..=42).rev().for_each(|x| println!("{}", x)); @@ -14,16 +12,18 @@ fn main() { for _ in (-42..=-21).rev() {} for _ in (21u32..42u32).rev() {} - let _ = &[] as &[i32]; - // These should be ignored as they are not empty ranges: (21..=42).for_each(|x| println!("{}", x)); (21..42).for_each(|x| println!("{}", x)); + let arr = [1, 2, 3, 4, 5]; let _ = &arr[1..=3]; let _ = &arr[1..3]; for _ in 21..=42 {} for _ in 21..42 {} + + // This range is empty but should be ignored, see issue #5689 + let _ = &arr[0..0]; } diff --git a/tests/ui/reversed_empty_ranges_fixable.rs b/tests/ui/reversed_empty_ranges_fixable.rs index 901ec8bcc..b2e8bf337 100644 --- a/tests/ui/reversed_empty_ranges_fixable.rs +++ b/tests/ui/reversed_empty_ranges_fixable.rs @@ -4,8 +4,6 @@ const ANSWER: i32 = 42; fn main() { - let arr = [1, 2, 3, 4, 5]; - // These should be linted: (42..=21).for_each(|x| println!("{}", x)); @@ -14,16 +12,18 @@ fn main() { for _ in -21..=-42 {} for _ in 42u32..21u32 {} - let _ = &arr[3..3]; - // These should be ignored as they are not empty ranges: (21..=42).for_each(|x| println!("{}", x)); (21..42).for_each(|x| println!("{}", x)); + let arr = [1, 2, 3, 4, 5]; let _ = &arr[1..=3]; let _ = &arr[1..3]; for _ in 21..=42 {} for _ in 21..42 {} + + // This range is empty but should be ignored, see issue #5689 + let _ = &arr[0..0]; } diff --git a/tests/ui/reversed_empty_ranges_fixable.stderr b/tests/ui/reversed_empty_ranges_fixable.stderr index 9a646fd99..de83c4f3d 100644 --- a/tests/ui/reversed_empty_ranges_fixable.stderr +++ b/tests/ui/reversed_empty_ranges_fixable.stderr @@ -1,5 +1,5 @@ error: this range is empty so it will yield no values - --> $DIR/reversed_empty_ranges_fixable.rs:11:5 + --> $DIR/reversed_empty_ranges_fixable.rs:9:5 | LL | (42..=21).for_each(|x| println!("{}", x)); | ^^^^^^^^^ @@ -11,7 +11,7 @@ LL | (21..=42).rev().for_each(|x| println!("{}", x)); | ^^^^^^^^^^^^^^^ error: this range is empty so it will yield no values - --> $DIR/reversed_empty_ranges_fixable.rs:12:13 + --> $DIR/reversed_empty_ranges_fixable.rs:10:13 | LL | let _ = (ANSWER..21).filter(|x| x % 2 == 0).take(10).collect::>(); | ^^^^^^^^^^^^ @@ -22,7 +22,7 @@ LL | let _ = (21..ANSWER).rev().filter(|x| x % 2 == 0).take(10).collect:: $DIR/reversed_empty_ranges_fixable.rs:14:14 + --> $DIR/reversed_empty_ranges_fixable.rs:12:14 | LL | for _ in -21..=-42 {} | ^^^^^^^^^ @@ -33,7 +33,7 @@ LL | for _ in (-42..=-21).rev() {} | ^^^^^^^^^^^^^^^^^ error: this range is empty so it will yield no values - --> $DIR/reversed_empty_ranges_fixable.rs:15:14 + --> $DIR/reversed_empty_ranges_fixable.rs:13:14 | LL | for _ in 42u32..21u32 {} | ^^^^^^^^^^^^ @@ -43,11 +43,5 @@ help: consider using the following if you are attempting to iterate over this ra LL | for _ in (21u32..42u32).rev() {} | ^^^^^^^^^^^^^^^^^^^^ -error: this range is empty and using it to index a slice will always yield an empty slice - --> $DIR/reversed_empty_ranges_fixable.rs:17:18 - | -LL | let _ = &arr[3..3]; - | ----^^^^- help: if you want an empty slice, use: `[] as &[i32]` - -error: aborting due to 5 previous errors +error: aborting due to 4 previous errors diff --git a/tests/ui/reversed_empty_ranges_unfixable.rs b/tests/ui/reversed_empty_ranges_unfixable.rs index 561a35625..264d3d1e9 100644 --- a/tests/ui/reversed_empty_ranges_unfixable.rs +++ b/tests/ui/reversed_empty_ranges_unfixable.rs @@ -4,11 +4,12 @@ const ANSWER: i32 = 42; const SOME_NUM: usize = 3; fn main() { - let _ = (42 + 10..42 + 10).map(|x| x / 2).find(|&x| x == 21); - let arr = [1, 2, 3, 4, 5]; let _ = &arr[3usize..=1usize]; let _ = &arr[SOME_NUM..1]; for _ in ANSWER..ANSWER {} + + // Should not be linted, see issue #5689 + let _ = (42 + 10..42 + 10).map(|x| x / 2).find(|&x| x == 21); } diff --git a/tests/ui/reversed_empty_ranges_unfixable.stderr b/tests/ui/reversed_empty_ranges_unfixable.stderr index 240188cbb..f23d4eb0f 100644 --- a/tests/ui/reversed_empty_ranges_unfixable.stderr +++ b/tests/ui/reversed_empty_ranges_unfixable.stderr @@ -1,28 +1,22 @@ -error: this range is empty so it will yield no values - --> $DIR/reversed_empty_ranges_unfixable.rs:7:13 +error: this range is reversed and using it to index a slice will panic at run-time + --> $DIR/reversed_empty_ranges_unfixable.rs:8:18 | -LL | let _ = (42 + 10..42 + 10).map(|x| x / 2).find(|&x| x == 21); - | ^^^^^^^^^^^^^^^^^^ +LL | let _ = &arr[3usize..=1usize]; + | ^^^^^^^^^^^^^^^ | = note: `-D clippy::reversed-empty-ranges` implied by `-D warnings` error: this range is reversed and using it to index a slice will panic at run-time - --> $DIR/reversed_empty_ranges_unfixable.rs:10:18 - | -LL | let _ = &arr[3usize..=1usize]; - | ^^^^^^^^^^^^^^^ - -error: this range is reversed and using it to index a slice will panic at run-time - --> $DIR/reversed_empty_ranges_unfixable.rs:11:18 + --> $DIR/reversed_empty_ranges_unfixable.rs:9:18 | LL | let _ = &arr[SOME_NUM..1]; | ^^^^^^^^^^^ error: this range is empty so it will yield no values - --> $DIR/reversed_empty_ranges_unfixable.rs:13:14 + --> $DIR/reversed_empty_ranges_unfixable.rs:11:14 | LL | for _ in ANSWER..ANSWER {} | ^^^^^^^^^^^^^^ -error: aborting due to 4 previous errors +error: aborting due to 3 previous errors diff --git a/tests/ui/string_lit_as_bytes.fixed b/tests/ui/string_lit_as_bytes.fixed index 7ad272ade..ccf8f61c4 100644 --- a/tests/ui/string_lit_as_bytes.fixed +++ b/tests/ui/string_lit_as_bytes.fixed @@ -14,6 +14,8 @@ fn str_lit_as_bytes() { let strify = stringify!(foobar).as_bytes(); + let current_version = env!("CARGO_PKG_VERSION").as_bytes(); + let includestr = include_bytes!("entry_unfixable.rs"); let _ = b"string with newline\t\n"; diff --git a/tests/ui/string_lit_as_bytes.rs b/tests/ui/string_lit_as_bytes.rs index 1bf4538b7..178df08e2 100644 --- a/tests/ui/string_lit_as_bytes.rs +++ b/tests/ui/string_lit_as_bytes.rs @@ -14,6 +14,8 @@ fn str_lit_as_bytes() { let strify = stringify!(foobar).as_bytes(); + let current_version = env!("CARGO_PKG_VERSION").as_bytes(); + let includestr = include_str!("entry_unfixable.rs").as_bytes(); let _ = "string with newline\t\n".as_bytes(); diff --git a/tests/ui/string_lit_as_bytes.stderr b/tests/ui/string_lit_as_bytes.stderr index ff6e3346d..99c512354 100644 --- a/tests/ui/string_lit_as_bytes.stderr +++ b/tests/ui/string_lit_as_bytes.stderr @@ -13,13 +13,13 @@ LL | let bs = r###"raw string with 3# plus " ""###.as_bytes(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a byte string literal instead: `br###"raw string with 3# plus " ""###` error: calling `as_bytes()` on `include_str!(..)` - --> $DIR/string_lit_as_bytes.rs:17:22 + --> $DIR/string_lit_as_bytes.rs:19:22 | LL | let includestr = include_str!("entry_unfixable.rs").as_bytes(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using `include_bytes!(..)` instead: `include_bytes!("entry_unfixable.rs")` error: calling `as_bytes()` on a string literal - --> $DIR/string_lit_as_bytes.rs:19:13 + --> $DIR/string_lit_as_bytes.rs:21:13 | LL | let _ = "string with newline/t/n".as_bytes(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using a byte string literal instead: `b"string with newline/t/n"` diff --git a/tests/ui/unit_arg.fixed b/tests/ui/unit_arg.fixed deleted file mode 100644 index a739cf7ad..000000000 --- a/tests/ui/unit_arg.fixed +++ /dev/null @@ -1,64 +0,0 @@ -// run-rustfix -#![warn(clippy::unit_arg)] -#![allow(unused_braces, clippy::no_effect, unused_must_use)] - -use std::fmt::Debug; - -fn foo(t: T) { - println!("{:?}", t); -} - -fn foo3(t1: T1, t2: T2, t3: T3) { - println!("{:?}, {:?}, {:?}", t1, t2, t3); -} - -struct Bar; - -impl Bar { - fn bar(&self, t: T) { - println!("{:?}", t); - } -} - -fn bad() { - foo(()); - foo(()); - foo(()); - foo(()); - foo3((), 2, 2); - let b = Bar; - b.bar(()); -} - -fn ok() { - foo(()); - foo(1); - foo({ 1 }); - foo3("a", 3, vec![3]); - let b = Bar; - b.bar({ 1 }); - b.bar(()); - question_mark(); -} - -fn question_mark() -> Result<(), ()> { - Ok(Ok(())?)?; - Ok(Ok(()))??; - Ok(()) -} - -#[allow(dead_code)] -mod issue_2945 { - fn unit_fn() -> Result<(), i32> { - Ok(()) - } - - fn fallible() -> Result<(), i32> { - Ok(unit_fn()?) - } -} - -fn main() { - bad(); - ok(); -} diff --git a/tests/ui/unit_arg.rs b/tests/ui/unit_arg.rs index d90c49f79..2992abae7 100644 --- a/tests/ui/unit_arg.rs +++ b/tests/ui/unit_arg.rs @@ -1,6 +1,5 @@ -// run-rustfix #![warn(clippy::unit_arg)] -#![allow(unused_braces, clippy::no_effect, unused_must_use)] +#![allow(clippy::no_effect, unused_must_use, unused_variables)] use std::fmt::Debug; @@ -21,7 +20,6 @@ impl Bar { } fn bad() { - foo({}); foo({ 1; }); @@ -30,11 +28,25 @@ fn bad() { foo(1); foo(2); }); - foo3({}, 2, 2); let b = Bar; b.bar({ 1; }); + taking_multiple_units(foo(0), foo(1)); + taking_multiple_units(foo(0), { + foo(1); + foo(2); + }); + taking_multiple_units( + { + foo(0); + foo(1); + }, + { + foo(2); + foo(3); + }, + ); } fn ok() { @@ -65,6 +77,13 @@ mod issue_2945 { } } +#[allow(dead_code)] +fn returning_expr() -> Option<()> { + Some(foo(1)) +} + +fn taking_multiple_units(a: (), b: ()) {} + fn main() { bad(); ok(); diff --git a/tests/ui/unit_arg.stderr b/tests/ui/unit_arg.stderr index 21ccc684e..56f6a855d 100644 --- a/tests/ui/unit_arg.stderr +++ b/tests/ui/unit_arg.stderr @@ -1,79 +1,181 @@ error: passing a unit value to a function - --> $DIR/unit_arg.rs:24:9 + --> $DIR/unit_arg.rs:23:5 | -LL | foo({}); - | ^^ - | - = note: `-D clippy::unit-arg` implied by `-D warnings` -help: if you intended to pass a unit value, use a unit literal instead - | -LL | foo(()); - | ^^ - -error: passing a unit value to a function - --> $DIR/unit_arg.rs:25:9 - | -LL | foo({ - | _________^ +LL | / foo({ LL | | 1; LL | | }); - | |_____^ + | |______^ | -help: if you intended to pass a unit value, use a unit literal instead + = note: `-D clippy::unit-arg` implied by `-D warnings` +help: remove the semicolon from the last statement in the block + | +LL | 1 + | +help: or move the expression in front of the call... + | +LL | { +LL | 1; +LL | }; + | +help: ...and use a unit literal instead | LL | foo(()); | ^^ error: passing a unit value to a function - --> $DIR/unit_arg.rs:28:9 + --> $DIR/unit_arg.rs:26:5 | LL | foo(foo(1)); - | ^^^^^^ + | ^^^^^^^^^^^ | -help: if you intended to pass a unit value, use a unit literal instead +help: move the expression in front of the call... + | +LL | foo(1); + | +help: ...and use a unit literal instead | LL | foo(()); | ^^ error: passing a unit value to a function - --> $DIR/unit_arg.rs:29:9 + --> $DIR/unit_arg.rs:27:5 | -LL | foo({ - | _________^ +LL | / foo({ LL | | foo(1); LL | | foo(2); LL | | }); - | |_____^ + | |______^ | -help: if you intended to pass a unit value, use a unit literal instead +help: remove the semicolon from the last statement in the block + | +LL | foo(2) + | +help: or move the expression in front of the call... + | +LL | { +LL | foo(1); +LL | foo(2); +LL | }; + | +help: ...and use a unit literal instead | LL | foo(()); | ^^ error: passing a unit value to a function - --> $DIR/unit_arg.rs:33:10 + --> $DIR/unit_arg.rs:32:5 | -LL | foo3({}, 2, 2); - | ^^ - | -help: if you intended to pass a unit value, use a unit literal instead - | -LL | foo3((), 2, 2); - | ^^ - -error: passing a unit value to a function - --> $DIR/unit_arg.rs:35:11 - | -LL | b.bar({ - | ___________^ +LL | / b.bar({ LL | | 1; LL | | }); - | |_____^ + | |______^ | -help: if you intended to pass a unit value, use a unit literal instead +help: remove the semicolon from the last statement in the block + | +LL | 1 + | +help: or move the expression in front of the call... + | +LL | { +LL | 1; +LL | }; + | +help: ...and use a unit literal instead | LL | b.bar(()); | ^^ -error: aborting due to 6 previous errors +error: passing unit values to a function + --> $DIR/unit_arg.rs:35:5 + | +LL | taking_multiple_units(foo(0), foo(1)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: move the expressions in front of the call... + | +LL | foo(0); +LL | foo(1); + | +help: ...and use unit literals instead + | +LL | taking_multiple_units((), ()); + | ^^ ^^ + +error: passing unit values to a function + --> $DIR/unit_arg.rs:36:5 + | +LL | / taking_multiple_units(foo(0), { +LL | | foo(1); +LL | | foo(2); +LL | | }); + | |______^ + | +help: remove the semicolon from the last statement in the block + | +LL | foo(2) + | +help: or move the expressions in front of the call... + | +LL | foo(0); +LL | { +LL | foo(1); +LL | foo(2); +LL | }; + | +help: ...and use unit literals instead + | +LL | taking_multiple_units((), ()); + | ^^ ^^ + +error: passing unit values to a function + --> $DIR/unit_arg.rs:40:5 + | +LL | / taking_multiple_units( +LL | | { +LL | | foo(0); +LL | | foo(1); +... | +LL | | }, +LL | | ); + | |_____^ + | +help: remove the semicolon from the last statement in the block + | +LL | foo(1) + | +help: remove the semicolon from the last statement in the block + | +LL | foo(3) + | +help: or move the expressions in front of the call... + | +LL | { +LL | foo(0); +LL | foo(1); +LL | }; +LL | { +LL | foo(2); + ... +help: ...and use unit literals instead + | +LL | (), +LL | (), + | + +error: passing a unit value to a function + --> $DIR/unit_arg.rs:82:5 + | +LL | Some(foo(1)) + | ^^^^^^^^^^^^ + | +help: move the expression in front of the call... + | +LL | foo(1); + | +help: ...and use a unit literal instead + | +LL | Some(()) + | ^^ + +error: aborting due to 8 previous errors diff --git a/tests/ui/unit_arg_empty_blocks.rs b/tests/ui/unit_arg_empty_blocks.rs new file mode 100644 index 000000000..18a31eb3d --- /dev/null +++ b/tests/ui/unit_arg_empty_blocks.rs @@ -0,0 +1,26 @@ +#![warn(clippy::unit_arg)] +#![allow(clippy::no_effect, unused_must_use, unused_variables)] + +use std::fmt::Debug; + +fn foo(t: T) { + println!("{:?}", t); +} + +fn foo3(t1: T1, t2: T2, t3: T3) { + println!("{:?}, {:?}, {:?}", t1, t2, t3); +} + +fn bad() { + foo({}); + foo3({}, 2, 2); + taking_two_units({}, foo(0)); + taking_three_units({}, foo(0), foo(1)); +} + +fn taking_two_units(a: (), b: ()) {} +fn taking_three_units(a: (), b: (), c: ()) {} + +fn main() { + bad(); +} diff --git a/tests/ui/unit_arg_empty_blocks.stderr b/tests/ui/unit_arg_empty_blocks.stderr new file mode 100644 index 000000000..bb5848358 --- /dev/null +++ b/tests/ui/unit_arg_empty_blocks.stderr @@ -0,0 +1,51 @@ +error: passing a unit value to a function + --> $DIR/unit_arg_empty_blocks.rs:15:5 + | +LL | foo({}); + | ^^^^--^ + | | + | help: use a unit literal instead: `()` + | + = note: `-D clippy::unit-arg` implied by `-D warnings` + +error: passing a unit value to a function + --> $DIR/unit_arg_empty_blocks.rs:16:5 + | +LL | foo3({}, 2, 2); + | ^^^^^--^^^^^^^ + | | + | help: use a unit literal instead: `()` + +error: passing unit values to a function + --> $DIR/unit_arg_empty_blocks.rs:17:5 + | +LL | taking_two_units({}, foo(0)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: move the expression in front of the call... + | +LL | foo(0); + | +help: ...and use unit literals instead + | +LL | taking_two_units((), ()); + | ^^ ^^ + +error: passing unit values to a function + --> $DIR/unit_arg_empty_blocks.rs:18:5 + | +LL | taking_three_units({}, foo(0), foo(1)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: move the expressions in front of the call... + | +LL | foo(0); +LL | foo(1); + | +help: ...and use unit literals instead + | +LL | taking_three_units((), (), ()); + | ^^ ^^ ^^ + +error: aborting due to 4 previous errors + diff --git a/tests/ui/unnecessary_sort_by.fixed b/tests/ui/unnecessary_sort_by.fixed new file mode 100644 index 000000000..779fd5770 --- /dev/null +++ b/tests/ui/unnecessary_sort_by.fixed @@ -0,0 +1,26 @@ +// run-rustfix + +use std::cmp::Reverse; + +fn id(x: isize) -> isize { + x +} + +fn main() { + let mut vec: Vec = vec![3, 6, 1, 2, 5]; + // Forward examples + vec.sort(); + vec.sort_unstable(); + vec.sort_by_key(|&a| (a + 5).abs()); + vec.sort_unstable_by_key(|&a| id(-a)); + // Reverse examples + vec.sort_by_key(|&b| Reverse(b)); + vec.sort_by_key(|&b| Reverse((b + 5).abs())); + vec.sort_unstable_by_key(|&b| Reverse(id(-b))); + // Negative examples (shouldn't be changed) + let c = &7; + vec.sort_by(|a, b| (b - a).cmp(&(a - b))); + vec.sort_by(|_, b| b.cmp(&5)); + vec.sort_by(|_, b| b.cmp(c)); + vec.sort_unstable_by(|a, _| a.cmp(c)); +} diff --git a/tests/ui/unnecessary_sort_by.rs b/tests/ui/unnecessary_sort_by.rs new file mode 100644 index 000000000..0485a5630 --- /dev/null +++ b/tests/ui/unnecessary_sort_by.rs @@ -0,0 +1,26 @@ +// run-rustfix + +use std::cmp::Reverse; + +fn id(x: isize) -> isize { + x +} + +fn main() { + let mut vec: Vec = vec![3, 6, 1, 2, 5]; + // Forward examples + vec.sort_by(|a, b| a.cmp(b)); + vec.sort_unstable_by(|a, b| a.cmp(b)); + vec.sort_by(|a, b| (a + 5).abs().cmp(&(b + 5).abs())); + vec.sort_unstable_by(|a, b| id(-a).cmp(&id(-b))); + // Reverse examples + vec.sort_by(|a, b| b.cmp(a)); + vec.sort_by(|a, b| (b + 5).abs().cmp(&(a + 5).abs())); + vec.sort_unstable_by(|a, b| id(-b).cmp(&id(-a))); + // Negative examples (shouldn't be changed) + let c = &7; + vec.sort_by(|a, b| (b - a).cmp(&(a - b))); + vec.sort_by(|_, b| b.cmp(&5)); + vec.sort_by(|_, b| b.cmp(c)); + vec.sort_unstable_by(|a, _| a.cmp(c)); +} diff --git a/tests/ui/unnecessary_sort_by.stderr b/tests/ui/unnecessary_sort_by.stderr new file mode 100644 index 000000000..903b6e509 --- /dev/null +++ b/tests/ui/unnecessary_sort_by.stderr @@ -0,0 +1,46 @@ +error: use Vec::sort here instead + --> $DIR/unnecessary_sort_by.rs:12:5 + | +LL | vec.sort_by(|a, b| a.cmp(b)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort()` + | + = note: `-D clippy::unnecessary-sort-by` implied by `-D warnings` + +error: use Vec::sort here instead + --> $DIR/unnecessary_sort_by.rs:13:5 + | +LL | vec.sort_unstable_by(|a, b| a.cmp(b)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_unstable()` + +error: use Vec::sort_by_key here instead + --> $DIR/unnecessary_sort_by.rs:14:5 + | +LL | vec.sort_by(|a, b| (a + 5).abs().cmp(&(b + 5).abs())); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_by_key(|&a| (a + 5).abs())` + +error: use Vec::sort_by_key here instead + --> $DIR/unnecessary_sort_by.rs:15:5 + | +LL | vec.sort_unstable_by(|a, b| id(-a).cmp(&id(-b))); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_unstable_by_key(|&a| id(-a))` + +error: use Vec::sort_by_key here instead + --> $DIR/unnecessary_sort_by.rs:17:5 + | +LL | vec.sort_by(|a, b| b.cmp(a)); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_by_key(|&b| Reverse(b))` + +error: use Vec::sort_by_key here instead + --> $DIR/unnecessary_sort_by.rs:18:5 + | +LL | vec.sort_by(|a, b| (b + 5).abs().cmp(&(a + 5).abs())); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_by_key(|&b| Reverse((b + 5).abs()))` + +error: use Vec::sort_by_key here instead + --> $DIR/unnecessary_sort_by.rs:19:5 + | +LL | vec.sort_unstable_by(|a, b| id(-b).cmp(&id(-a))); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `vec.sort_unstable_by_key(|&b| Reverse(id(-b)))` + +error: aborting due to 7 previous errors + diff --git a/tests/ui/unnested_or_patterns.fixed b/tests/ui/unnested_or_patterns.fixed new file mode 100644 index 000000000..b39e89109 --- /dev/null +++ b/tests/ui/unnested_or_patterns.fixed @@ -0,0 +1,33 @@ +// run-rustfix + +#![feature(or_patterns)] +#![feature(box_patterns)] +#![warn(clippy::unnested_or_patterns)] +#![allow(clippy::cognitive_complexity, clippy::match_ref_pats)] +#![allow(unreachable_patterns, irrefutable_let_patterns, unused_variables)] + +fn main() { + if let box (0 | 2) = Box::new(0) {} + if let box (0 | 1 | 2 | 3 | 4) = Box::new(0) {} + const C0: &u8 = &1; + if let &(0 | 2) | C0 = &0 {} + if let &mut (0 | 2) = &mut 0 {} + if let x @ (0 | 2) = 0 {} + if let (0, 1 | 2 | 3) = (0, 0) {} + if let (1 | 2 | 3, 0) = (0, 0) {} + if let (x, ..) | (x, 1 | 2) = (0, 1) {} + if let [0 | 1] = [0] {} + if let [x, 0 | 1] = [0, 1] {} + if let [x, 0 | 1 | 2] = [0, 1] {} + if let [x, ..] | [x, 1 | 2] = [0, 1] {} + struct TS(u8, u8); + if let TS(0 | 1, x) = TS(0, 0) {} + if let TS(1 | 2 | 3, 0) = TS(0, 0) {} + if let TS(x, ..) | TS(x, 1 | 2) = TS(0, 0) {} + struct S { + x: u8, + y: u8, + } + if let S { x: 0 | 1, y } = (S { x: 0, y: 1 }) {} + if let S { x: 0, y, .. } | S { y, x: 1 } = (S { x: 0, y: 1 }) {} +} diff --git a/tests/ui/unnested_or_patterns.rs b/tests/ui/unnested_or_patterns.rs new file mode 100644 index 000000000..096f5a711 --- /dev/null +++ b/tests/ui/unnested_or_patterns.rs @@ -0,0 +1,33 @@ +// run-rustfix + +#![feature(or_patterns)] +#![feature(box_patterns)] +#![warn(clippy::unnested_or_patterns)] +#![allow(clippy::cognitive_complexity, clippy::match_ref_pats)] +#![allow(unreachable_patterns, irrefutable_let_patterns, unused_variables)] + +fn main() { + if let box 0 | box 2 = Box::new(0) {} + if let box ((0 | 1)) | box (2 | 3) | box 4 = Box::new(0) {} + const C0: &u8 = &1; + if let &0 | C0 | &2 = &0 {} + if let &mut 0 | &mut 2 = &mut 0 {} + if let x @ 0 | x @ 2 = 0 {} + if let (0, 1) | (0, 2) | (0, 3) = (0, 0) {} + if let (1, 0) | (2, 0) | (3, 0) = (0, 0) {} + if let (x, ..) | (x, 1) | (x, 2) = (0, 1) {} + if let [0] | [1] = [0] {} + if let [x, 0] | [x, 1] = [0, 1] {} + if let [x, 0] | [x, 1] | [x, 2] = [0, 1] {} + if let [x, ..] | [x, 1] | [x, 2] = [0, 1] {} + struct TS(u8, u8); + if let TS(0, x) | TS(1, x) = TS(0, 0) {} + if let TS(1, 0) | TS(2, 0) | TS(3, 0) = TS(0, 0) {} + if let TS(x, ..) | TS(x, 1) | TS(x, 2) = TS(0, 0) {} + struct S { + x: u8, + y: u8, + } + if let S { x: 0, y } | S { y, x: 1 } = (S { x: 0, y: 1 }) {} + if let S { x: 0, y, .. } | S { y, x: 1 } = (S { x: 0, y: 1 }) {} +} diff --git a/tests/ui/unnested_or_patterns.stderr b/tests/ui/unnested_or_patterns.stderr new file mode 100644 index 000000000..1899dc657 --- /dev/null +++ b/tests/ui/unnested_or_patterns.stderr @@ -0,0 +1,179 @@ +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:10:12 + | +LL | if let box 0 | box 2 = Box::new(0) {} + | ^^^^^^^^^^^^^ + | + = note: `-D clippy::unnested-or-patterns` implied by `-D warnings` +help: nest the patterns + | +LL | if let box (0 | 2) = Box::new(0) {} + | ^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:11:12 + | +LL | if let box ((0 | 1)) | box (2 | 3) | box 4 = Box::new(0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let box (0 | 1 | 2 | 3 | 4) = Box::new(0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:13:12 + | +LL | if let &0 | C0 | &2 = &0 {} + | ^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let &(0 | 2) | C0 = &0 {} + | ^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:14:12 + | +LL | if let &mut 0 | &mut 2 = &mut 0 {} + | ^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let &mut (0 | 2) = &mut 0 {} + | ^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:15:12 + | +LL | if let x @ 0 | x @ 2 = 0 {} + | ^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let x @ (0 | 2) = 0 {} + | ^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:16:12 + | +LL | if let (0, 1) | (0, 2) | (0, 3) = (0, 0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let (0, 1 | 2 | 3) = (0, 0) {} + | ^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:17:12 + | +LL | if let (1, 0) | (2, 0) | (3, 0) = (0, 0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let (1 | 2 | 3, 0) = (0, 0) {} + | ^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:18:12 + | +LL | if let (x, ..) | (x, 1) | (x, 2) = (0, 1) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let (x, ..) | (x, 1 | 2) = (0, 1) {} + | ^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:19:12 + | +LL | if let [0] | [1] = [0] {} + | ^^^^^^^^^ + | +help: nest the patterns + | +LL | if let [0 | 1] = [0] {} + | ^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:20:12 + | +LL | if let [x, 0] | [x, 1] = [0, 1] {} + | ^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let [x, 0 | 1] = [0, 1] {} + | ^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:21:12 + | +LL | if let [x, 0] | [x, 1] | [x, 2] = [0, 1] {} + | ^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let [x, 0 | 1 | 2] = [0, 1] {} + | ^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:22:12 + | +LL | if let [x, ..] | [x, 1] | [x, 2] = [0, 1] {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let [x, ..] | [x, 1 | 2] = [0, 1] {} + | ^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:24:12 + | +LL | if let TS(0, x) | TS(1, x) = TS(0, 0) {} + | ^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let TS(0 | 1, x) = TS(0, 0) {} + | ^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:25:12 + | +LL | if let TS(1, 0) | TS(2, 0) | TS(3, 0) = TS(0, 0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let TS(1 | 2 | 3, 0) = TS(0, 0) {} + | ^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:26:12 + | +LL | if let TS(x, ..) | TS(x, 1) | TS(x, 2) = TS(0, 0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let TS(x, ..) | TS(x, 1 | 2) = TS(0, 0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns.rs:31:12 + | +LL | if let S { x: 0, y } | S { y, x: 1 } = (S { x: 0, y: 1 }) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let S { x: 0 | 1, y } = (S { x: 0, y: 1 }) {} + | ^^^^^^^^^^^^^^^^^ + +error: aborting due to 16 previous errors + diff --git a/tests/ui/unnested_or_patterns2.fixed b/tests/ui/unnested_or_patterns2.fixed new file mode 100644 index 000000000..02a129c55 --- /dev/null +++ b/tests/ui/unnested_or_patterns2.fixed @@ -0,0 +1,18 @@ +// run-rustfix + +#![feature(or_patterns)] +#![feature(box_patterns)] +#![warn(clippy::unnested_or_patterns)] +#![allow(clippy::cognitive_complexity, clippy::match_ref_pats)] +#![allow(unreachable_patterns, irrefutable_let_patterns, unused_variables)] + +fn main() { + if let Some(Some(0 | 1)) = None {} + if let Some(Some(0 | 1 | 2)) = None {} + if let Some(Some(0 | 1 | 2 | 3 | 4)) = None {} + if let Some(Some(0 | 1 | 2)) = None {} + if let ((0 | 1 | 2,),) = ((0,),) {} + if let 0 | 1 | 2 = 0 {} + if let box (0 | 1 | 2 | 3 | 4) = Box::new(0) {} + if let box box (0 | 2 | 4) = Box::new(Box::new(0)) {} +} diff --git a/tests/ui/unnested_or_patterns2.rs b/tests/ui/unnested_or_patterns2.rs new file mode 100644 index 000000000..acf315898 --- /dev/null +++ b/tests/ui/unnested_or_patterns2.rs @@ -0,0 +1,18 @@ +// run-rustfix + +#![feature(or_patterns)] +#![feature(box_patterns)] +#![warn(clippy::unnested_or_patterns)] +#![allow(clippy::cognitive_complexity, clippy::match_ref_pats)] +#![allow(unreachable_patterns, irrefutable_let_patterns, unused_variables)] + +fn main() { + if let Some(Some(0)) | Some(Some(1)) = None {} + if let Some(Some(0)) | Some(Some(1) | Some(2)) = None {} + if let Some(Some(0 | 1) | Some(2)) | Some(Some(3) | Some(4)) = None {} + if let Some(Some(0) | Some(1 | 2)) = None {} + if let ((0,),) | ((1,) | (2,),) = ((0,),) {} + if let 0 | (1 | 2) = 0 {} + if let box (0 | 1) | (box 2 | box (3 | 4)) = Box::new(0) {} + if let box box 0 | box (box 2 | box 4) = Box::new(Box::new(0)) {} +} diff --git a/tests/ui/unnested_or_patterns2.stderr b/tests/ui/unnested_or_patterns2.stderr new file mode 100644 index 000000000..1847fd8e0 --- /dev/null +++ b/tests/ui/unnested_or_patterns2.stderr @@ -0,0 +1,91 @@ +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:10:12 + | +LL | if let Some(Some(0)) | Some(Some(1)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: `-D clippy::unnested-or-patterns` implied by `-D warnings` +help: nest the patterns + | +LL | if let Some(Some(0 | 1)) = None {} + | ^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:11:12 + | +LL | if let Some(Some(0)) | Some(Some(1) | Some(2)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let Some(Some(0 | 1 | 2)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:12:12 + | +LL | if let Some(Some(0 | 1) | Some(2)) | Some(Some(3) | Some(4)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let Some(Some(0 | 1 | 2 | 3 | 4)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:13:12 + | +LL | if let Some(Some(0) | Some(1 | 2)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let Some(Some(0 | 1 | 2)) = None {} + | ^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:14:12 + | +LL | if let ((0,),) | ((1,) | (2,),) = ((0,),) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let ((0 | 1 | 2,),) = ((0,),) {} + | ^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:15:12 + | +LL | if let 0 | (1 | 2) = 0 {} + | ^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let 0 | 1 | 2 = 0 {} + | ^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:16:12 + | +LL | if let box (0 | 1) | (box 2 | box (3 | 4)) = Box::new(0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let box (0 | 1 | 2 | 3 | 4) = Box::new(0) {} + | ^^^^^^^^^^^^^^^^^^^^^^^ + +error: unnested or-patterns + --> $DIR/unnested_or_patterns2.rs:17:12 + | +LL | if let box box 0 | box (box 2 | box 4) = Box::new(Box::new(0)) {} + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | +help: nest the patterns + | +LL | if let box box (0 | 2 | 4) = Box::new(Box::new(0)) {} + | ^^^^^^^^^^^^^^^^^^^ + +error: aborting due to 8 previous errors + diff --git a/tests/ui/vec_resize_to_zero.rs b/tests/ui/vec_resize_to_zero.rs new file mode 100644 index 000000000..0263e2f5f --- /dev/null +++ b/tests/ui/vec_resize_to_zero.rs @@ -0,0 +1,15 @@ +#![warn(clippy::vec_resize_to_zero)] + +fn main() { + // applicable here + vec![1, 2, 3, 4, 5].resize(0, 5); + + // not applicable + vec![1, 2, 3, 4, 5].resize(2, 5); + + // applicable here, but only implemented for integer litterals for now + vec!["foo", "bar", "baz"].resize(0, "bar"); + + // not applicable + vec!["foo", "bar", "baz"].resize(2, "bar") +} diff --git a/tests/ui/vec_resize_to_zero.stderr b/tests/ui/vec_resize_to_zero.stderr new file mode 100644 index 000000000..feb846298 --- /dev/null +++ b/tests/ui/vec_resize_to_zero.stderr @@ -0,0 +1,13 @@ +error: emptying a vector with `resize` + --> $DIR/vec_resize_to_zero.rs:5:5 + | +LL | vec![1, 2, 3, 4, 5].resize(0, 5); + | ^^^^^^^^^^^^^^^^^^^^------------ + | | + | help: ...or you can empty the vector with: `clear()` + | + = note: `-D clippy::vec-resize-to-zero` implied by `-D warnings` + = help: the arguments may be inverted... + +error: aborting due to previous error + diff --git a/tests/ui/wildcard_enum_match_arm.fixed b/tests/ui/wildcard_enum_match_arm.fixed index 2aa24ea11..4f8754a93 100644 --- a/tests/ui/wildcard_enum_match_arm.fixed +++ b/tests/ui/wildcard_enum_match_arm.fixed @@ -6,7 +6,8 @@ unused_variables, dead_code, clippy::single_match, - clippy::wildcard_in_or_patterns + clippy::wildcard_in_or_patterns, + clippy::unnested_or_patterns )] use std::io::ErrorKind; diff --git a/tests/ui/wildcard_enum_match_arm.rs b/tests/ui/wildcard_enum_match_arm.rs index 07c93feaf..5e66644ce 100644 --- a/tests/ui/wildcard_enum_match_arm.rs +++ b/tests/ui/wildcard_enum_match_arm.rs @@ -6,7 +6,8 @@ unused_variables, dead_code, clippy::single_match, - clippy::wildcard_in_or_patterns + clippy::wildcard_in_or_patterns, + clippy::unnested_or_patterns )] use std::io::ErrorKind; diff --git a/tests/ui/wildcard_enum_match_arm.stderr b/tests/ui/wildcard_enum_match_arm.stderr index 7151a5c57..e03b3be43 100644 --- a/tests/ui/wildcard_enum_match_arm.stderr +++ b/tests/ui/wildcard_enum_match_arm.stderr @@ -1,5 +1,5 @@ error: wildcard match will miss any future added variants - --> $DIR/wildcard_enum_match_arm.rs:37:9 + --> $DIR/wildcard_enum_match_arm.rs:38:9 | LL | _ => eprintln!("Not red"), | ^ help: try this: `Color::Green | Color::Blue | Color::Rgb(..) | Color::Cyan` @@ -11,25 +11,25 @@ LL | #![deny(clippy::wildcard_enum_match_arm)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: wildcard match will miss any future added variants - --> $DIR/wildcard_enum_match_arm.rs:41:9 + --> $DIR/wildcard_enum_match_arm.rs:42:9 | LL | _not_red => eprintln!("Not red"), | ^^^^^^^^ help: try this: `_not_red @ Color::Green | _not_red @ Color::Blue | _not_red @ Color::Rgb(..) | _not_red @ Color::Cyan` error: wildcard match will miss any future added variants - --> $DIR/wildcard_enum_match_arm.rs:45:9 + --> $DIR/wildcard_enum_match_arm.rs:46:9 | LL | not_red => format!("{:?}", not_red), | ^^^^^^^ help: try this: `not_red @ Color::Green | not_red @ Color::Blue | not_red @ Color::Rgb(..) | not_red @ Color::Cyan` error: wildcard match will miss any future added variants - --> $DIR/wildcard_enum_match_arm.rs:61:9 + --> $DIR/wildcard_enum_match_arm.rs:62:9 | LL | _ => "No red", | ^ help: try this: `Color::Red | Color::Green | Color::Blue | Color::Rgb(..) | Color::Cyan` error: match on non-exhaustive enum doesn't explicitly match all known variants - --> $DIR/wildcard_enum_match_arm.rs:78:9 + --> $DIR/wildcard_enum_match_arm.rs:79:9 | LL | _ => {}, | ^ help: try this: `std::io::ErrorKind::PermissionDenied | std::io::ErrorKind::ConnectionRefused | std::io::ErrorKind::ConnectionReset | std::io::ErrorKind::ConnectionAborted | std::io::ErrorKind::NotConnected | std::io::ErrorKind::AddrInUse | std::io::ErrorKind::AddrNotAvailable | std::io::ErrorKind::BrokenPipe | std::io::ErrorKind::AlreadyExists | std::io::ErrorKind::WouldBlock | std::io::ErrorKind::InvalidInput | std::io::ErrorKind::InvalidData | std::io::ErrorKind::TimedOut | std::io::ErrorKind::WriteZero | std::io::ErrorKind::Interrupted | std::io::ErrorKind::Other | std::io::ErrorKind::UnexpectedEof | _`