From 597e02dcdf28e9cfbb7854bca38c28f2e4d15425 Mon Sep 17 00:00:00 2001 From: Devin R Date: Wed, 26 Feb 2020 07:40:31 -0500 Subject: [PATCH] warn on macro_use attr --- CHANGELOG.md | 1 + README.md | 2 +- clippy_lints/src/lib.rs | 4 +++ clippy_lints/src/macro_use.rs | 53 ++++++++++++++++++++++++++++++++ src/lintlist/mod.rs | 9 +++++- tests/ui/macro_use_import.rs | 11 +++++++ tests/ui/macro_use_import.stderr | 10 ++++++ 7 files changed, 88 insertions(+), 2 deletions(-) create mode 100644 clippy_lints/src/macro_use.rs create mode 100644 tests/ui/macro_use_import.rs create mode 100644 tests/ui/macro_use_import.stderr diff --git a/CHANGELOG.md b/CHANGELOG.md index 4d8e24943897..9ba9fdd4b8a0 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1209,6 +1209,7 @@ Released 2018-09-13 [`linkedlist`]: https://rust-lang.github.io/rust-clippy/master/index.html#linkedlist [`logic_bug`]: https://rust-lang.github.io/rust-clippy/master/index.html#logic_bug [`lossy_float_literal`]: https://rust-lang.github.io/rust-clippy/master/index.html#lossy_float_literal +[`macro_use_import`]: https://rust-lang.github.io/rust-clippy/master/index.html#macro_use_import [`main_recursion`]: https://rust-lang.github.io/rust-clippy/master/index.html#main_recursion [`manual_memcpy`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_memcpy [`manual_saturating_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_saturating_arithmetic diff --git a/README.md b/README.md index 6915b1bde025..8635b2b6d5a5 100644 --- a/README.md +++ b/README.md @@ -5,7 +5,7 @@ A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code. -[There are 359 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html) +[There are 360 lints included in this crate!](https://rust-lang.github.io/rust-clippy/master/index.html) We have a bunch of lint categories to allow you to choose how much Clippy is supposed to ~~annoy~~ help you: diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 327cc56cafa5..86ab7d839054 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -234,6 +234,7 @@ pub mod let_underscore; pub mod lifetimes; pub mod literal_representation; pub mod loops; +pub mod macro_use; pub mod main_recursion; pub mod map_clone; pub mod map_unit_fn; @@ -599,6 +600,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &loops::WHILE_IMMUTABLE_CONDITION, &loops::WHILE_LET_LOOP, &loops::WHILE_LET_ON_ITERATOR, + ¯o_use::MACRO_USE_IMPORT, &main_recursion::MAIN_RECURSION, &map_clone::MAP_CLONE, &map_unit_fn::OPTION_MAP_UNIT_FN, @@ -1012,6 +1014,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_early_pass(move || box excessive_bools::ExcessiveBools::new(max_struct_bools, max_fn_params_bools)); store.register_early_pass(|| box option_env_unwrap::OptionEnvUnwrap); store.register_late_pass(|| box wildcard_imports::WildcardImports); + store.register_early_pass(|| box macro_use::MacroUseImport); store.register_group(true, "clippy::restriction", Some("clippy_restriction"), vec![ LintId::of(&arithmetic::FLOAT_ARITHMETIC), @@ -1079,6 +1082,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&literal_representation::LARGE_DIGIT_GROUPS), LintId::of(&loops::EXPLICIT_INTO_ITER_LOOP), LintId::of(&loops::EXPLICIT_ITER_LOOP), + LintId::of(¯o_use::MACRO_USE_IMPORT), LintId::of(&matches::SINGLE_MATCH_ELSE), LintId::of(&methods::FILTER_MAP), LintId::of(&methods::FILTER_MAP_NEXT), diff --git a/clippy_lints/src/macro_use.rs b/clippy_lints/src/macro_use.rs new file mode 100644 index 000000000000..43671d694131 --- /dev/null +++ b/clippy_lints/src/macro_use.rs @@ -0,0 +1,53 @@ +use crate::utils::{snippet, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_ast::ast; +use rustc_errors::Applicability; +use rustc_lint::{EarlyContext, EarlyLintPass}; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::edition::Edition; + +declare_clippy_lint! { + /// **What it does:** Checks for `#[macro_use] use...`. + /// + /// **Why is this bad?** Since the Rust 2018 edition you can import + /// macro's directly, this is considered idiomatic. + /// + /// **Known problems:** This lint does not generate an auto-applicable suggestion. + /// + /// **Example:** + /// ```rust + /// #[macro_use] + /// use lazy_static; + /// ``` + pub MACRO_USE_IMPORT, + pedantic, + "#[macro_use] is no longer needed" +} + +declare_lint_pass!(MacroUseImport => [MACRO_USE_IMPORT]); + +impl EarlyLintPass for MacroUseImport { + fn check_item(&mut self, ecx: &EarlyContext<'_>, item: &ast::Item) { + if_chain! { + if ecx.sess.opts.edition == Edition::Edition2018; + if let ast::ItemKind::Use(use_tree) = &item.kind; + if let Some(mac_attr) = item + .attrs + .iter() + .find(|attr| attr.ident().map(|s| s.to_string()) == Some("macro_use".to_string())); + then { + let msg = "`macro_use` attributes are no longer needed in the Rust 2018 edition"; + let help = format!("use {}::", snippet(ecx, use_tree.span, "_")); + span_lint_and_sugg( + ecx, + MACRO_USE_IMPORT, + mac_attr.span, + msg, + "remove the attribute and import the macro directly, try", + help, + Applicability::HasPlaceholders, + ); + } + } + } +} diff --git a/src/lintlist/mod.rs b/src/lintlist/mod.rs index 2b93e4279f0d..1635ff7babd7 100644 --- a/src/lintlist/mod.rs +++ b/src/lintlist/mod.rs @@ -6,7 +6,7 @@ pub use lint::Lint; pub use lint::LINT_LEVELS; // begin lint list, do not remove this comment, it’s used in `update_lints` -pub const ALL_LINTS: [Lint; 359] = [ +pub const ALL_LINTS: [Lint; 360] = [ Lint { name: "absurd_extreme_comparisons", group: "correctness", @@ -1015,6 +1015,13 @@ pub const ALL_LINTS: [Lint; 359] = [ deprecation: None, module: "float_literal", }, + Lint { + name: "macro_use_import", + group: "pedantic", + desc: "#[macro_use] is no longer needed", + deprecation: None, + module: "macro_use", + }, Lint { name: "main_recursion", group: "style", diff --git a/tests/ui/macro_use_import.rs b/tests/ui/macro_use_import.rs new file mode 100644 index 000000000000..33ce2b524ef7 --- /dev/null +++ b/tests/ui/macro_use_import.rs @@ -0,0 +1,11 @@ +// compile-flags: --edition 2018 +#![warn(clippy::macro_use_import)] + +use std::collections::HashMap; +#[macro_use] +use std::prelude; + +fn main() { + let _ = HashMap::::new(); + println!(); +} diff --git a/tests/ui/macro_use_import.stderr b/tests/ui/macro_use_import.stderr new file mode 100644 index 000000000000..1d86ba584411 --- /dev/null +++ b/tests/ui/macro_use_import.stderr @@ -0,0 +1,10 @@ +error: `macro_use` attributes are no longer needed in the Rust 2018 edition + --> $DIR/macro_use_import.rs:5:1 + | +LL | #[macro_use] + | ^^^^^^^^^^^^ help: remove the attribute and import the macro directly, try: `use std::prelude::` + | + = note: `-D clippy::macro-use-import` implied by `-D warnings` + +error: aborting due to previous error +