2020-05-17 15:36:26 +00:00
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mod bind_instead_of_map;
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2019-10-16 19:54:20 +00:00
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mod inefficient_to_string;
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2019-09-04 12:06:28 +00:00
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mod manual_saturating_arithmetic;
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2019-01-31 01:15:29 +00:00
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mod option_map_unwrap_or;
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mod unnecessary_filter_map;
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2020-08-16 18:47:50 +00:00
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mod unnecessary_lazy_eval;
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2019-01-31 01:15:29 +00:00
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use std::borrow::Cow;
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use std::fmt;
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use std::iter;
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2020-05-17 15:36:26 +00:00
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use bind_instead_of_map::BindInsteadOfMap;
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2018-07-19 08:00:54 +00:00
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use if_chain::if_chain;
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2020-03-01 03:23:33 +00:00
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use rustc_ast::ast;
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2018-12-29 15:04:45 +00:00
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use rustc_errors::Applicability;
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2020-01-06 16:39:50 +00:00
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use rustc_hir as hir;
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2020-01-09 07:13:22 +00:00
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use rustc_hir::intravisit::{self, Visitor};
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2020-01-12 06:08:41 +00:00
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use rustc_lint::{LateContext, LateLintPass, Lint, LintContext};
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2020-03-30 09:02:14 +00:00
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use rustc_middle::hir::map::Map;
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use rustc_middle::lint::in_external_macro;
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2020-04-07 19:53:56 +00:00
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use rustc_middle::ty::subst::GenericArgKind;
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2020-06-09 14:36:01 +00:00
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use rustc_middle::ty::{self, Ty, TyS};
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2020-01-11 11:37:08 +00:00
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use rustc_session::{declare_lint_pass, declare_tool_lint};
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2020-01-04 10:00:00 +00:00
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use rustc_span::source_map::Span;
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2020-04-13 06:57:34 +00:00
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use rustc_span::symbol::{sym, SymbolStr};
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2015-08-11 18:53:50 +00:00
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2019-12-28 22:37:23 +00:00
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use crate::consts::{constant, Constant};
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2019-06-02 06:47:06 +00:00
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use crate::utils::usage::mutated_variables;
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2019-01-31 01:15:29 +00:00
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use crate::utils::{
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2020-06-09 14:36:01 +00:00
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get_arg_name, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait, in_macro, is_copy,
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2019-10-05 10:42:09 +00:00
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is_ctor_or_promotable_const_function, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment,
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match_def_path, match_qpath, match_trait_method, match_type, match_var, method_calls, method_chain_args, paths,
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2020-06-09 14:36:01 +00:00
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remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite,
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span_lint, span_lint_and_help, span_lint_and_note, span_lint_and_sugg, span_lint_and_then, sugg, walk_ptrs_ty,
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walk_ptrs_ty_depth, SpanlessEq,
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2019-01-31 01:15:29 +00:00
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};
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2018-09-29 12:12:40 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2020-05-17 15:36:26 +00:00
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/// **What it does:** Checks for `.unwrap()` calls on `Option`s and on `Result`s.
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2019-03-05 16:50:33 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// **Why is this bad?** It is better to handle the `None` or `Err` case,
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/// or at least call `.expect(_)` with a more helpful message. Still, for a lot of
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2019-03-05 16:50:33 +00:00
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/// quick-and-dirty code, `unwrap` is a good choice, which is why this lint is
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/// `Allow` by default.
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///
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2020-05-17 15:36:26 +00:00
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/// `result.unwrap()` will let the thread panic on `Err` values.
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/// Normally, you want to implement more sophisticated error handling,
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2020-01-04 04:47:01 +00:00
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/// and propagate errors upwards with `?` operator.
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2019-03-05 16:50:33 +00:00
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///
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/// Even if you want to panic on errors, not all `Error`s implement good
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2019-01-31 01:15:29 +00:00
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/// messages on display. Therefore, it may be beneficial to look at the places
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2019-03-05 16:50:33 +00:00
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/// where they may get displayed. Activate this lint to do just that.
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///
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/// **Known problems:** None.
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///
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2020-05-17 15:36:26 +00:00
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/// **Examples:**
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2019-03-05 16:50:33 +00:00
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/// ```rust
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2020-05-17 15:36:26 +00:00
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/// # let opt = Some(1);
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///
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/// // Bad
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/// opt.unwrap();
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///
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/// // Good
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/// opt.expect("more helpful message");
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2019-08-03 19:24:50 +00:00
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/// ```
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///
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2020-05-17 15:36:26 +00:00
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/// // or
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2019-08-03 19:24:50 +00:00
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///
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2019-03-05 16:50:33 +00:00
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/// ```rust
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2020-05-17 15:36:26 +00:00
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/// # let res: Result<usize, ()> = Ok(1);
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///
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/// // Bad
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/// res.unwrap();
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///
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/// // Good
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2019-08-03 19:24:50 +00:00
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/// res.expect("more helpful message");
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2019-03-05 16:50:33 +00:00
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/// ```
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2020-05-17 15:36:26 +00:00
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pub UNWRAP_USED,
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2018-03-28 13:24:26 +00:00
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restriction,
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2020-05-17 15:36:26 +00:00
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"using `.unwrap()` on `Result` or `Option`, which should at least get a better message using `expect()`"
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2016-02-05 23:13:29 +00:00
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}
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2015-12-14 21:16:56 +00:00
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2019-10-15 19:33:07 +00:00
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declare_clippy_lint! {
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2020-05-17 15:36:26 +00:00
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/// **What it does:** Checks for `.expect()` calls on `Option`s and `Result`s.
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2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// **Why is this bad?** Usually it is better to handle the `None` or `Err` case.
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/// Still, for a lot of quick-and-dirty code, `expect` is a good choice, which is why
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/// this lint is `Allow` by default.
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2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// `result.expect()` will let the thread panic on `Err`
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/// values. Normally, you want to implement more sophisticated error handling,
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/// and propagate errors upwards with `?` operator.
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2019-10-15 19:33:07 +00:00
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///
|
2020-05-17 15:36:26 +00:00
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/// **Known problems:** None.
|
2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// **Examples:**
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/// ```rust,ignore
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/// # let opt = Some(1);
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2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// // Bad
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2019-10-15 19:33:07 +00:00
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/// opt.expect("one");
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///
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2020-05-17 15:36:26 +00:00
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/// // Good
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2019-10-15 19:33:07 +00:00
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/// let opt = Some(1);
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/// opt?;
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/// ```
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///
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2020-05-17 15:36:26 +00:00
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/// // or
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2019-10-15 19:33:07 +00:00
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///
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/// ```rust
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2020-05-17 15:36:26 +00:00
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/// # let res: Result<usize, ()> = Ok(1);
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2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// // Bad
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/// res.expect("one");
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2019-10-15 19:33:07 +00:00
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///
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2020-05-17 15:36:26 +00:00
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/// // Good
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2019-10-15 19:33:07 +00:00
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/// res?;
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2019-10-16 17:43:26 +00:00
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/// # Ok::<(), ()>(())
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2019-10-15 19:33:07 +00:00
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/// ```
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2020-05-17 15:36:26 +00:00
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pub EXPECT_USED,
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2019-10-15 19:33:07 +00:00
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restriction,
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2020-05-17 15:36:26 +00:00
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"using `.expect()` on `Result` or `Option`, which might be better handled"
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2019-10-15 19:33:07 +00:00
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for methods that should live in a trait
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/// implementation of a `std` trait (see [llogiq's blog
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/// post](http://llogiq.github.io/2015/07/30/traits.html) for further
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/// information) instead of an inherent implementation.
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///
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/// **Why is this bad?** Implementing the traits improve ergonomics for users of
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/// the code, often with very little cost. Also people seeing a `mul(...)`
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/// method
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/// may expect `*` to work equally, so you should have good reason to disappoint
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/// them.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
|
2020-01-30 22:44:37 +00:00
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/// ```rust
|
2019-03-05 16:50:33 +00:00
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/// struct X;
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/// impl X {
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/// fn add(&self, other: &X) -> X {
|
2020-01-30 22:44:37 +00:00
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/// // ..
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/// # X
|
2019-03-05 16:50:33 +00:00
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/// }
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/// }
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/// ```
|
2016-08-06 08:18:36 +00:00
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pub SHOULD_IMPLEMENT_TRAIT,
|
2018-03-28 13:24:26 +00:00
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style,
|
2016-02-05 23:13:29 +00:00
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"defining a method that should be implementing a std trait"
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}
|
2015-12-14 21:16:56 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for methods with certain name prefixes and which
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/// doesn't match how self is taken. The actual rules are:
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///
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/// |Prefix |`self` taken |
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/// |-------|----------------------|
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/// |`as_` |`&self` or `&mut self`|
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/// |`from_`| none |
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/// |`into_`|`self` |
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/// |`is_` |`&self` or none |
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/// |`to_` |`&self` |
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///
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/// **Why is this bad?** Consistency breeds readability. If you follow the
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/// conventions, your users won't be surprised that they, e.g., need to supply a
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/// mutable reference to a `as_..` function.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
|
2020-01-30 22:44:37 +00:00
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/// ```rust
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/// # struct X;
|
2019-03-05 16:50:33 +00:00
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/// impl X {
|
2020-01-30 22:44:37 +00:00
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/// fn as_str(self) -> &'static str {
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/// // ..
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/// # ""
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2019-03-05 16:50:33 +00:00
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/// }
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/// }
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/// ```
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2018-11-27 20:49:09 +00:00
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pub WRONG_SELF_CONVENTION,
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style,
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"defining a method named with an established prefix (like \"into_\") that takes `self` with the wrong convention"
|
2016-02-05 23:13:29 +00:00
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}
|
2015-12-14 21:16:56 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
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/// **What it does:** This is the same as
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/// [`wrong_self_convention`](#wrong_self_convention), but for public items.
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///
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/// **Why is this bad?** See [`wrong_self_convention`](#wrong_self_convention).
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///
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/// **Known problems:** Actually *renaming* the function may break clients if
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/// the function is part of the public interface. In that case, be mindful of
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/// the stability guarantees you've given your users.
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///
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/// **Example:**
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/// ```rust
|
2019-08-03 19:24:50 +00:00
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/// # struct X;
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/// impl<'a> X {
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/// pub fn as_str(self) -> &'a str {
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/// "foo"
|
2019-03-05 16:50:33 +00:00
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/// }
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/// }
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/// ```
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2018-11-27 20:49:09 +00:00
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pub WRONG_PUB_SELF_CONVENTION,
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restriction,
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"defining a public method named with an established prefix (like \"into_\") that takes `self` with the wrong convention"
|
2016-02-05 23:13:29 +00:00
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}
|
2015-12-14 21:16:56 +00:00
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|
2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for usage of `ok().expect(..)`.
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///
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/// **Why is this bad?** Because you usually call `expect()` on the `Result`
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/// directly to get a better error message.
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///
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/// **Known problems:** The error type needs to implement `Debug`
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///
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|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
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|
|
/// # let x = Ok::<_, ()>(());
|
2020-06-09 14:36:01 +00:00
|
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///
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/// // Bad
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|
/// x.ok().expect("why did I do this again?");
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///
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/// // Good
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|
/// x.expect("why did I do this again?");
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-11-27 20:49:09 +00:00
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pub OK_EXPECT,
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|
|
|
style,
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|
"using `ok().expect()`, which gives worse error messages than calling `expect` directly on the Result"
|
2016-02-05 23:13:29 +00:00
|
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|
}
|
2015-12-14 21:16:56 +00:00
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2020-05-17 15:36:26 +00:00
|
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|
/// **What it does:** Checks for usage of `option.map(_).unwrap_or(_)` or `option.map(_).unwrap_or_else(_)` or
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/// `result.map(_).unwrap_or_else(_)`.
|
2019-03-05 16:50:33 +00:00
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///
|
2020-05-17 15:36:26 +00:00
|
|
|
/// **Why is this bad?** Readability, these can be written more concisely (resp.) as
|
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|
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/// `option.map_or(_, _)`, `option.map_or_else(_, _)` and `result.map_or_else(_, _)`.
|
2019-03-05 16:50:33 +00:00
|
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///
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/// **Known problems:** The order of the arguments is not in execution order
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///
|
2020-05-17 15:36:26 +00:00
|
|
|
/// **Examples:**
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```rust
|
2019-08-03 16:42:05 +00:00
|
|
|
/// # let x = Some(1);
|
2019-03-05 16:50:33 +00:00
|
|
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///
|
2020-05-17 15:36:26 +00:00
|
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/// // Bad
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|
/// x.map(|a| a + 1).unwrap_or(0);
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
2020-05-17 15:36:26 +00:00
|
|
|
/// // Good
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|
|
/// x.map_or(0, |a| a + 1);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
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///
|
2020-05-17 15:36:26 +00:00
|
|
|
/// // or
|
2019-03-05 16:50:33 +00:00
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|
|
///
|
|
|
|
/// ```rust
|
2019-08-03 16:42:05 +00:00
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|
|
/// # let x: Result<usize, ()> = Ok(1);
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|
|
|
/// # fn some_function(foo: ()) -> usize { 1 }
|
2020-05-17 15:36:26 +00:00
|
|
|
///
|
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|
|
/// // Bad
|
2019-08-03 16:42:05 +00:00
|
|
|
/// x.map(|a| a + 1).unwrap_or_else(some_function);
|
2020-05-17 15:36:26 +00:00
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// x.map_or_else(some_function, |a| a + 1);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2020-05-17 15:36:26 +00:00
|
|
|
pub MAP_UNWRAP_OR,
|
2018-11-27 20:49:09 +00:00
|
|
|
pedantic,
|
2020-05-17 15:36:26 +00:00
|
|
|
"using `.map(f).unwrap_or(a)` or `.map(f).unwrap_or_else(func)`, which are more succinctly expressed as `map_or(a, f)` or `map_or_else(a, f)`"
|
2017-10-30 12:04:26 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `_.map_or(None, _)`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.and_then(_)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** The order of the arguments is not in execution order.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # let opt = Some(1);
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Bad
|
|
|
|
/// opt.map_or(None, |a| Some(a + 1));
|
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// opt.and_then(|a| Some(a + 1));
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-11-27 20:49:09 +00:00
|
|
|
pub OPTION_MAP_OR_NONE,
|
|
|
|
style,
|
|
|
|
"using `Option.map_or(None, f)`, which is more succinctly expressed as `and_then(f)`"
|
2017-10-10 10:06:01 +00:00
|
|
|
}
|
|
|
|
|
2020-04-04 06:59:52 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `_.map_or(None, Some)`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.ok()`.
|
|
|
|
///
|
2020-04-04 20:42:24 +00:00
|
|
|
/// **Known problems:** None.
|
2020-04-04 06:59:52 +00:00
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-04-05 00:20:23 +00:00
|
|
|
///
|
|
|
|
/// Bad:
|
2020-04-04 06:59:52 +00:00
|
|
|
/// ```rust
|
2020-04-05 00:20:23 +00:00
|
|
|
/// # let r: Result<u32, &str> = Ok(1);
|
2020-04-04 20:44:11 +00:00
|
|
|
/// assert_eq!(Some(1), r.map_or(None, Some));
|
2020-04-05 00:20:23 +00:00
|
|
|
/// ```
|
2020-04-04 20:44:11 +00:00
|
|
|
///
|
2020-04-05 00:20:23 +00:00
|
|
|
/// Good:
|
|
|
|
/// ```rust
|
|
|
|
/// # let r: Result<u32, &str> = Ok(1);
|
2020-04-04 20:44:11 +00:00
|
|
|
/// assert_eq!(Some(1), r.ok());
|
2020-04-04 06:59:52 +00:00
|
|
|
/// ```
|
|
|
|
pub RESULT_MAP_OR_INTO_OPTION,
|
|
|
|
style,
|
|
|
|
"using `Result.map_or(None, Some)`, which is more succinctly expressed as `ok()`"
|
|
|
|
}
|
|
|
|
|
2019-08-15 03:53:11 +00:00
|
|
|
declare_clippy_lint! {
|
2020-05-17 15:36:26 +00:00
|
|
|
/// **What it does:** Checks for usage of `_.and_then(|x| Some(y))`, `_.and_then(|x| Ok(y))` or
|
|
|
|
/// `_.or_else(|x| Err(y))`.
|
2019-08-15 03:53:11 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
2020-05-17 15:36:26 +00:00
|
|
|
/// `_.map(|x| y)` or `_.map_err(|x| y)`.
|
2019-08-15 03:53:11 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
2020-05-17 15:36:26 +00:00
|
|
|
/// # fn opt() -> Option<&'static str> { Some("42") }
|
|
|
|
/// # fn res() -> Result<&'static str, &'static str> { Ok("42") }
|
|
|
|
/// let _ = opt().and_then(|s| Some(s.len()));
|
|
|
|
/// let _ = res().and_then(|s| if s.len() == 42 { Ok(10) } else { Ok(20) });
|
|
|
|
/// let _ = res().or_else(|s| if s.len() == 42 { Err(10) } else { Err(20) });
|
2019-08-15 03:53:11 +00:00
|
|
|
/// ```
|
|
|
|
///
|
|
|
|
/// The correct use would be:
|
|
|
|
///
|
|
|
|
/// ```rust
|
2020-05-17 15:36:26 +00:00
|
|
|
/// # fn opt() -> Option<&'static str> { Some("42") }
|
|
|
|
/// # fn res() -> Result<&'static str, &'static str> { Ok("42") }
|
|
|
|
/// let _ = opt().map(|s| s.len());
|
|
|
|
/// let _ = res().map(|s| if s.len() == 42 { 10 } else { 20 });
|
|
|
|
/// let _ = res().map_err(|s| if s.len() == 42 { 10 } else { 20 });
|
2019-08-15 03:53:11 +00:00
|
|
|
/// ```
|
2020-05-17 15:36:26 +00:00
|
|
|
pub BIND_INSTEAD_OF_MAP,
|
2019-08-15 03:53:11 +00:00
|
|
|
complexity,
|
|
|
|
"using `Option.and_then(|x| Some(y))`, which is more succinctly expressed as `map(|x| y)`"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `_.filter(_).next()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.find(_)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// # let vec = vec![1];
|
|
|
|
/// vec.iter().filter(|x| **x == 0).next();
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2019-08-20 14:55:17 +00:00
|
|
|
/// Could be written as
|
|
|
|
/// ```rust
|
|
|
|
/// # let vec = vec![1];
|
|
|
|
/// vec.iter().find(|x| **x == 0);
|
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub FILTER_NEXT,
|
2018-03-29 11:41:53 +00:00
|
|
|
complexity,
|
2016-02-05 23:13:29 +00:00
|
|
|
"using `filter(p).next()`, which is more succinctly expressed as `.find(p)`"
|
|
|
|
}
|
2015-08-11 18:53:50 +00:00
|
|
|
|
2020-01-20 01:54:54 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `_.skip_while(condition).next()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.find(!condition)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// # let vec = vec![1];
|
|
|
|
/// vec.iter().skip_while(|x| **x == 0).next();
|
|
|
|
/// ```
|
|
|
|
/// Could be written as
|
|
|
|
/// ```rust
|
|
|
|
/// # let vec = vec![1];
|
|
|
|
/// vec.iter().find(|x| **x != 0);
|
|
|
|
/// ```
|
|
|
|
pub SKIP_WHILE_NEXT,
|
|
|
|
complexity,
|
|
|
|
"using `skip_while(p).next()`, which is more succinctly expressed as `.find(!p)`"
|
|
|
|
}
|
|
|
|
|
2018-09-21 07:26:38 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `_.map(_).flatten(_)`,
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as a
|
2020-06-09 14:36:01 +00:00
|
|
|
/// single method call using `_.flat_map(_)`
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:**
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 16:42:05 +00:00
|
|
|
/// let vec = vec![vec![1]];
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Bad
|
2019-08-03 16:42:05 +00:00
|
|
|
/// vec.iter().map(|x| x.iter()).flatten();
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// vec.iter().flat_map(|x| x.iter());
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-11-27 20:49:09 +00:00
|
|
|
pub MAP_FLATTEN,
|
|
|
|
pedantic,
|
|
|
|
"using combinations of `flatten` and `map` which can usually be written as a single method call"
|
2018-09-21 07:26:38 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `_.filter(_).map(_)`,
|
|
|
|
/// `_.filter(_).flat_map(_)`, `_.filter_map(_).flat_map(_)` and similar.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as a
|
|
|
|
/// single method call.
|
|
|
|
///
|
|
|
|
/// **Known problems:** Often requires a condition + Option/Iterator creation
|
|
|
|
/// inside the closure.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 16:42:05 +00:00
|
|
|
/// let vec = vec![1];
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Bad
|
2019-08-03 16:42:05 +00:00
|
|
|
/// vec.iter().filter(|x| **x == 0).map(|x| *x * 2);
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// vec.iter().filter_map(|x| if *x == 0 {
|
|
|
|
/// Some(*x * 2)
|
|
|
|
/// } else {
|
|
|
|
/// None
|
|
|
|
/// });
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-11-27 20:49:09 +00:00
|
|
|
pub FILTER_MAP,
|
|
|
|
pedantic,
|
|
|
|
"using combinations of `filter`, `map`, `filter_map` and `flat_map` which can usually be written as a single method call"
|
2016-06-21 11:04:50 +00:00
|
|
|
}
|
|
|
|
|
2019-04-27 22:06:35 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `_.filter_map(_).next()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as a
|
|
|
|
/// single method call.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// (0..3).filter_map(|x| if x == 2 { Some(x) } else { None }).next();
|
|
|
|
/// ```
|
|
|
|
/// Can be written as
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// (0..3).find_map(|x| if x == 2 { Some(x) } else { None });
|
|
|
|
/// ```
|
|
|
|
pub FILTER_MAP_NEXT,
|
|
|
|
pedantic,
|
|
|
|
"using combination of `filter_map` and `next` which can usually be written as a single method call"
|
|
|
|
}
|
|
|
|
|
2019-06-24 13:08:26 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `flat_map(|x| x)`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely by using `flatten`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-11 20:18:58 +00:00
|
|
|
/// # let iter = vec![vec![0]].into_iter();
|
|
|
|
/// iter.flat_map(|x| x);
|
2019-06-24 13:08:26 +00:00
|
|
|
/// ```
|
|
|
|
/// Can be written as
|
|
|
|
/// ```rust
|
2019-08-11 20:18:58 +00:00
|
|
|
/// # let iter = vec![vec![0]].into_iter();
|
|
|
|
/// iter.flatten();
|
2019-06-24 13:08:26 +00:00
|
|
|
/// ```
|
2019-08-11 18:34:25 +00:00
|
|
|
pub FLAT_MAP_IDENTITY,
|
2019-08-12 08:52:09 +00:00
|
|
|
complexity,
|
2019-06-24 13:08:26 +00:00
|
|
|
"call to `flat_map` where `flatten` is sufficient"
|
|
|
|
}
|
|
|
|
|
2019-04-27 22:06:35 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `_.find(_).map(_)`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as a
|
|
|
|
/// single method call.
|
|
|
|
///
|
|
|
|
/// **Known problems:** Often requires a condition + Option/Iterator creation
|
|
|
|
/// inside the closure.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 16:42:05 +00:00
|
|
|
/// (0..3).find(|x| *x == 2).map(|x| x * 2);
|
2019-04-27 22:06:35 +00:00
|
|
|
/// ```
|
|
|
|
/// Can be written as
|
|
|
|
/// ```rust
|
|
|
|
/// (0..3).find_map(|x| if x == 2 { Some(x * 2) } else { None });
|
|
|
|
/// ```
|
|
|
|
pub FIND_MAP,
|
|
|
|
pedantic,
|
|
|
|
"using a combination of `find` and `map` can usually be written as a single method call"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for an iterator search (such as `find()`,
|
|
|
|
/// `position()`, or `rposition()`) followed by a call to `is_some()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.any(_)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// # let vec = vec![1];
|
|
|
|
/// vec.iter().find(|x| **x == 0).is_some();
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2019-08-20 14:55:17 +00:00
|
|
|
/// Could be written as
|
|
|
|
/// ```rust
|
|
|
|
/// # let vec = vec![1];
|
2019-08-24 09:34:40 +00:00
|
|
|
/// vec.iter().any(|x| *x == 0);
|
2019-08-20 14:55:17 +00:00
|
|
|
/// ```
|
2018-11-27 20:49:09 +00:00
|
|
|
pub SEARCH_IS_SOME,
|
|
|
|
complexity,
|
|
|
|
"using an iterator search followed by `is_some()`, which is more succinctly expressed as a call to `any()`"
|
2016-02-05 23:13:29 +00:00
|
|
|
}
|
2015-12-30 08:38:03 +00:00
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `.chars().next()` on a `str` to check
|
|
|
|
/// if it starts with a given char.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.starts_with(_)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// let name = "foo";
|
2019-08-20 14:55:17 +00:00
|
|
|
/// if name.chars().next() == Some('_') {};
|
|
|
|
/// ```
|
|
|
|
/// Could be written as
|
|
|
|
/// ```rust
|
|
|
|
/// let name = "foo";
|
|
|
|
/// if name.starts_with('_') {};
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub CHARS_NEXT_CMP,
|
2020-02-13 01:03:49 +00:00
|
|
|
style,
|
2016-02-05 23:13:29 +00:00
|
|
|
"using `.chars().next()` to check if a string starts with a char"
|
|
|
|
}
|
2016-01-20 01:23:39 +00:00
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for calls to `.or(foo(..))`, `.unwrap_or(foo(..))`,
|
|
|
|
/// etc., and suggests to use `or_else`, `unwrap_or_else`, etc., or
|
|
|
|
/// `unwrap_or_default` instead.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** The function will always be called and potentially
|
|
|
|
/// allocate an object acting as the default.
|
|
|
|
///
|
|
|
|
/// **Known problems:** If the function has side-effects, not calling it will
|
|
|
|
/// change the semantic of the program, but you shouldn't rely on that anyway.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// foo.unwrap_or(String::new());
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
|
|
|
/// this can instead be written:
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// foo.unwrap_or_else(String::new);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
|
|
|
/// or
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// foo.unwrap_or_default();
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub OR_FUN_CALL,
|
2018-03-29 11:41:53 +00:00
|
|
|
perf,
|
2016-08-06 08:18:36 +00:00
|
|
|
"using any `*or` method with a function call, which suggests `*or_else`"
|
2016-02-05 23:13:29 +00:00
|
|
|
}
|
2016-01-16 17:47:45 +00:00
|
|
|
|
2018-05-28 19:00:45 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for calls to `.expect(&format!(...))`, `.expect(foo(..))`,
|
|
|
|
/// etc., and suggests to use `unwrap_or_else` instead
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** The function will always be called.
|
|
|
|
///
|
|
|
|
/// **Known problems:** If the function has side-effects, not calling it will
|
2019-04-18 13:08:14 +00:00
|
|
|
/// change the semantics of the program, but you shouldn't rely on that anyway.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// # let err_code = "418";
|
|
|
|
/// # let err_msg = "I'm a teapot";
|
|
|
|
/// foo.expect(&format!("Err {}: {}", err_code, err_msg));
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
|
|
|
/// or
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// # let err_code = "418";
|
|
|
|
/// # let err_msg = "I'm a teapot";
|
|
|
|
/// foo.expect(format!("Err {}: {}", err_code, err_msg).as_str());
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
|
|
|
/// this can instead be written:
|
|
|
|
/// ```rust
|
2019-08-03 06:01:27 +00:00
|
|
|
/// # let foo = Some(String::new());
|
|
|
|
/// # let err_code = "418";
|
|
|
|
/// # let err_msg = "I'm a teapot";
|
|
|
|
/// foo.unwrap_or_else(|| panic!("Err {}: {}", err_code, err_msg));
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-05-28 19:00:45 +00:00
|
|
|
pub EXPECT_FUN_CALL,
|
|
|
|
perf,
|
|
|
|
"using any `expect` method with a function call"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `.clone()` on a `Copy` type.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** The only reason `Copy` types implement `Clone` is for
|
|
|
|
/// generics, not for using the `clone` method on a concrete type.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// 42u64.clone();
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub CLONE_ON_COPY,
|
2018-03-28 13:24:26 +00:00
|
|
|
complexity,
|
2016-08-06 08:18:36 +00:00
|
|
|
"using `clone` on a `Copy` type"
|
2016-02-05 23:13:29 +00:00
|
|
|
}
|
2016-02-02 21:35:01 +00:00
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `.clone()` on a ref-counted pointer,
|
|
|
|
/// (`Rc`, `Arc`, `rc::Weak`, or `sync::Weak`), and suggests calling Clone via unified
|
2019-01-31 01:15:29 +00:00
|
|
|
/// function syntax instead (e.g., `Rc::clone(foo)`).
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Calling '.clone()' on an Rc, Arc, or Weak
|
|
|
|
/// can obscure the fact that only the pointer is being cloned, not the underlying
|
|
|
|
/// data.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-03 19:24:50 +00:00
|
|
|
/// # use std::rc::Rc;
|
|
|
|
/// let x = Rc::new(1);
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Bad
|
2019-08-03 19:24:50 +00:00
|
|
|
/// x.clone();
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// Rc::clone(&x);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2017-09-10 01:51:54 +00:00
|
|
|
pub CLONE_ON_REF_PTR,
|
2018-03-28 13:24:26 +00:00
|
|
|
restriction,
|
2017-09-10 01:51:54 +00:00
|
|
|
"using 'clone' on a ref-counted pointer"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `.clone()` on an `&&T`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Cloning an `&&T` copies the inner `&T`, instead of
|
|
|
|
/// cloning the underlying `T`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// fn main() {
|
|
|
|
/// let x = vec![1];
|
|
|
|
/// let y = &&x;
|
|
|
|
/// let z = y.clone();
|
|
|
|
/// println!("{:p} {:p}", *y, z); // prints out the same pointer
|
|
|
|
/// }
|
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub CLONE_DOUBLE_REF,
|
2018-03-28 13:24:26 +00:00
|
|
|
correctness,
|
2016-08-06 08:18:36 +00:00
|
|
|
"using `clone` on `&&T`"
|
2016-02-05 23:13:29 +00:00
|
|
|
}
|
2016-02-05 10:34:15 +00:00
|
|
|
|
2019-10-16 19:54:20 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `.to_string()` on an `&&T` where
|
|
|
|
/// `T` implements `ToString` directly (like `&&str` or `&&String`).
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** This bypasses the specialized implementation of
|
|
|
|
/// `ToString` and instead goes through the more expensive string formatting
|
|
|
|
/// facilities.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// // Generic implementation for `T: Display` is used (slow)
|
|
|
|
/// ["foo", "bar"].iter().map(|s| s.to_string());
|
|
|
|
///
|
|
|
|
/// // OK, the specialized impl is used
|
|
|
|
/// ["foo", "bar"].iter().map(|&s| s.to_string());
|
|
|
|
/// ```
|
|
|
|
pub INEFFICIENT_TO_STRING,
|
2020-04-03 03:00:12 +00:00
|
|
|
pedantic,
|
2019-10-16 19:54:20 +00:00
|
|
|
"using `to_string` on `&&T` where `T: ToString`"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2020-04-10 17:08:31 +00:00
|
|
|
/// **What it does:** Checks for `new` not returning a type that contains `Self`.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** As a convention, `new` methods are used to make a new
|
|
|
|
/// instance of a type.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # struct Foo;
|
|
|
|
/// # struct NotAFoo;
|
2019-03-05 16:50:33 +00:00
|
|
|
/// impl Foo {
|
2020-01-30 22:44:37 +00:00
|
|
|
/// fn new() -> NotAFoo {
|
|
|
|
/// # NotAFoo
|
2019-03-05 16:50:33 +00:00
|
|
|
/// }
|
|
|
|
/// }
|
|
|
|
/// ```
|
2020-04-10 17:08:31 +00:00
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// # struct Foo;
|
|
|
|
/// # struct FooError;
|
|
|
|
/// impl Foo {
|
|
|
|
/// // Good. Return type contains `Self`
|
|
|
|
/// fn new() -> Result<Foo, FooError> {
|
|
|
|
/// # Ok(Foo)
|
|
|
|
/// }
|
|
|
|
/// }
|
|
|
|
/// ```
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// # struct Foo;
|
|
|
|
/// struct Bar(Foo);
|
|
|
|
/// impl Foo {
|
|
|
|
/// // Bad. The type name must contain `Self`.
|
|
|
|
/// fn new() -> Bar {
|
|
|
|
/// # Bar(Foo)
|
|
|
|
/// }
|
|
|
|
/// }
|
|
|
|
/// ```
|
2016-08-06 08:18:36 +00:00
|
|
|
pub NEW_RET_NO_SELF,
|
2020-04-09 17:38:20 +00:00
|
|
|
style,
|
2020-04-10 17:08:31 +00:00
|
|
|
"not returning type containing `Self` in a `new` method"
|
2016-02-13 01:20:22 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for string methods that receive a single-character
|
2019-01-31 01:15:29 +00:00
|
|
|
/// `str` as an argument, e.g., `_.split("x")`.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Performing these methods using a `char` is faster than
|
|
|
|
/// using a `str`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** Does not catch multi-byte unicode characters.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-06-09 14:36:01 +00:00
|
|
|
/// ```rust,ignore
|
|
|
|
/// // Bad
|
|
|
|
/// _.split("x");
|
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// _.split('x');
|
2018-11-27 20:49:09 +00:00
|
|
|
pub SINGLE_CHAR_PATTERN,
|
|
|
|
perf,
|
2019-01-31 01:15:29 +00:00
|
|
|
"using a single-character str where a char could be used, e.g., `_.split(\"x\")`"
|
2016-02-15 03:40:43 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for getting the inner pointer of a temporary
|
|
|
|
/// `CString`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** The inner pointer of a `CString` is only valid as long
|
|
|
|
/// as the `CString` is alive.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # use std::ffi::CString;
|
|
|
|
/// # fn call_some_ffi_func(_: *const i8) {}
|
|
|
|
/// #
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let c_str = CString::new("foo").unwrap().as_ptr();
|
|
|
|
/// unsafe {
|
|
|
|
/// call_some_ffi_func(c_str);
|
|
|
|
/// }
|
|
|
|
/// ```
|
2020-08-13 19:52:21 +00:00
|
|
|
/// Here `c_str` points to a freed address. The correct use would be:
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # use std::ffi::CString;
|
|
|
|
/// # fn call_some_ffi_func(_: *const i8) {}
|
|
|
|
/// #
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let c_str = CString::new("foo").unwrap();
|
|
|
|
/// unsafe {
|
|
|
|
/// call_some_ffi_func(c_str.as_ptr());
|
|
|
|
/// }
|
|
|
|
/// ```
|
2016-04-14 15:25:31 +00:00
|
|
|
pub TEMPORARY_CSTRING_AS_PTR,
|
2018-03-28 13:24:26 +00:00
|
|
|
correctness,
|
2016-04-14 15:25:31 +00:00
|
|
|
"getting the inner pointer of a temporary `CString`"
|
|
|
|
}
|
|
|
|
|
2019-12-18 16:59:43 +00:00
|
|
|
declare_clippy_lint! {
|
2019-12-18 16:59:59 +00:00
|
|
|
/// **What it does:** Checks for calling `.step_by(0)` on iterators which panics.
|
2019-12-18 16:59:43 +00:00
|
|
|
///
|
2019-12-18 16:59:59 +00:00
|
|
|
/// **Why is this bad?** This very much looks like an oversight. Use `panic!()` instead if you
|
|
|
|
/// actually intend to panic.
|
2019-12-18 16:59:43 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 21:12:00 +00:00
|
|
|
/// ```rust,should_panic
|
2019-12-18 16:59:59 +00:00
|
|
|
/// for x in (0..100).step_by(0) {
|
|
|
|
/// //..
|
2019-12-18 16:59:43 +00:00
|
|
|
/// }
|
|
|
|
/// ```
|
|
|
|
pub ITERATOR_STEP_BY_ZERO,
|
|
|
|
correctness,
|
2019-12-19 04:51:26 +00:00
|
|
|
"using `Iterator::step_by(0)`, which will panic at runtime"
|
2019-12-18 16:59:43 +00:00
|
|
|
}
|
|
|
|
|
2019-12-28 22:37:23 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for the use of `iter.nth(0)`.
|
|
|
|
///
|
2020-02-02 22:19:16 +00:00
|
|
|
/// **Why is this bad?** `iter.next()` is equivalent to
|
|
|
|
/// `iter.nth(0)`, as they both consume the next element,
|
|
|
|
/// but is more readable.
|
2019-12-28 22:37:23 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// # use std::collections::HashSet;
|
|
|
|
/// // Bad
|
|
|
|
/// # let mut s = HashSet::new();
|
|
|
|
/// # s.insert(1);
|
|
|
|
/// let x = s.iter().nth(0);
|
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// # let mut s = HashSet::new();
|
|
|
|
/// # s.insert(1);
|
|
|
|
/// let x = s.iter().next();
|
|
|
|
/// ```
|
|
|
|
pub ITER_NTH_ZERO,
|
|
|
|
style,
|
|
|
|
"replace `iter.nth(0)` with `iter.next()`"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for use of `.iter().nth()` (and the related
|
|
|
|
/// `.iter_mut().nth()`) on standard library types with O(1) element access.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** `.get()` and `.get_mut()` are more efficient and more
|
|
|
|
/// readable.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let some_vec = vec![0, 1, 2, 3];
|
|
|
|
/// let bad_vec = some_vec.iter().nth(3);
|
|
|
|
/// let bad_slice = &some_vec[..].iter().nth(3);
|
|
|
|
/// ```
|
|
|
|
/// The correct use would be:
|
|
|
|
/// ```rust
|
|
|
|
/// let some_vec = vec![0, 1, 2, 3];
|
|
|
|
/// let bad_vec = some_vec.get(3);
|
|
|
|
/// let bad_slice = &some_vec[..].get(3);
|
|
|
|
/// ```
|
2016-06-16 09:02:00 +00:00
|
|
|
pub ITER_NTH,
|
2018-03-28 13:24:26 +00:00
|
|
|
perf,
|
2016-06-16 21:46:29 +00:00
|
|
|
"using `.iter().nth()` on a standard library type with O(1) element access"
|
2016-06-16 08:36:11 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for use of `.skip(x).next()` on iterators.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** `.nth(x)` is cleaner
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let some_vec = vec![0, 1, 2, 3];
|
|
|
|
/// let bad_vec = some_vec.iter().skip(3).next();
|
|
|
|
/// let bad_slice = &some_vec[..].iter().skip(3).next();
|
|
|
|
/// ```
|
|
|
|
/// The correct use would be:
|
|
|
|
/// ```rust
|
|
|
|
/// let some_vec = vec![0, 1, 2, 3];
|
|
|
|
/// let bad_vec = some_vec.iter().nth(3);
|
|
|
|
/// let bad_slice = &some_vec[..].iter().nth(3);
|
|
|
|
/// ```
|
2016-10-14 11:35:25 +00:00
|
|
|
pub ITER_SKIP_NEXT,
|
2018-03-28 13:24:26 +00:00
|
|
|
style,
|
2016-10-14 11:35:25 +00:00
|
|
|
"using `.skip(x).next()` on an iterator"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for use of `.get().unwrap()` (or
|
|
|
|
/// `.get_mut().unwrap`) on a standard library type which implements `Index`
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Using the Index trait (`[]`) is more clear and more
|
|
|
|
/// concise.
|
|
|
|
///
|
|
|
|
/// **Known problems:** Not a replacement for error handling: Using either
|
|
|
|
/// `.unwrap()` or the Index trait (`[]`) carries the risk of causing a `panic`
|
|
|
|
/// if the value being accessed is `None`. If the use of `.get().unwrap()` is a
|
|
|
|
/// temporary placeholder for dealing with the `Option` type, then this does
|
|
|
|
/// not mitigate the need for error handling. If there is a chance that `.get()`
|
|
|
|
/// will be `None` in your program, then it is advisable that the `None` case
|
|
|
|
/// is handled in a future refactor instead of using `.unwrap()` or the Index
|
|
|
|
/// trait.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-03-05 22:23:50 +00:00
|
|
|
/// let mut some_vec = vec![0, 1, 2, 3];
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let last = some_vec.get(3).unwrap();
|
|
|
|
/// *some_vec.get_mut(0).unwrap() = 1;
|
|
|
|
/// ```
|
|
|
|
/// The correct use would be:
|
|
|
|
/// ```rust
|
2019-03-05 22:23:50 +00:00
|
|
|
/// let mut some_vec = vec![0, 1, 2, 3];
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let last = some_vec[3];
|
|
|
|
/// some_vec[0] = 1;
|
|
|
|
/// ```
|
2016-11-01 06:30:13 +00:00
|
|
|
pub GET_UNWRAP,
|
2019-03-09 18:12:22 +00:00
|
|
|
restriction,
|
2016-11-01 06:30:13 +00:00
|
|
|
"using `.get().unwrap()` or `.get_mut().unwrap()` when using `[]` would work instead"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for the use of `.extend(s.chars())` where s is a
|
|
|
|
/// `&str` or `String`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** `.push_str(s)` is clearer
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let abc = "abc";
|
|
|
|
/// let def = String::from("def");
|
|
|
|
/// let mut s = String::new();
|
|
|
|
/// s.extend(abc.chars());
|
|
|
|
/// s.extend(def.chars());
|
|
|
|
/// ```
|
|
|
|
/// The correct use would be:
|
|
|
|
/// ```rust
|
|
|
|
/// let abc = "abc";
|
|
|
|
/// let def = String::from("def");
|
|
|
|
/// let mut s = String::new();
|
|
|
|
/// s.push_str(abc);
|
2019-03-05 22:23:50 +00:00
|
|
|
/// s.push_str(&def);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2016-11-19 15:21:40 +00:00
|
|
|
pub STRING_EXTEND_CHARS,
|
2018-03-28 13:24:26 +00:00
|
|
|
style,
|
2016-11-19 15:36:23 +00:00
|
|
|
"using `x.extend(s.chars())` where s is a `&str` or `String`"
|
2016-11-19 15:21:40 +00:00
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for the use of `.cloned().collect()` on slice to
|
|
|
|
/// create a `Vec`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** `.to_vec()` is clearer
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let s = [1, 2, 3, 4, 5];
|
|
|
|
/// let s2: Vec<isize> = s[..].iter().cloned().collect();
|
|
|
|
/// ```
|
|
|
|
/// The better use would be:
|
|
|
|
/// ```rust
|
|
|
|
/// let s = [1, 2, 3, 4, 5];
|
|
|
|
/// let s2: Vec<isize> = s.to_vec();
|
|
|
|
/// ```
|
2017-02-12 09:03:09 +00:00
|
|
|
pub ITER_CLONED_COLLECT,
|
2018-03-28 13:24:26 +00:00
|
|
|
style,
|
2017-02-12 09:03:09 +00:00
|
|
|
"using `.cloned().collect()` on slice to create a `Vec`"
|
|
|
|
}
|
2016-10-14 11:35:25 +00:00
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2020-06-09 14:36:01 +00:00
|
|
|
/// **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.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as
|
|
|
|
/// `_.ends_with(_)`.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # let name = "_";
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Bad
|
|
|
|
/// name.chars().last() == Some('_') || name.chars().next_back() == Some('-');
|
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// name.ends_with('_') || name.ends_with('-');
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2017-09-16 05:50:07 +00:00
|
|
|
pub CHARS_LAST_CMP,
|
2018-03-28 13:24:26 +00:00
|
|
|
style,
|
2017-09-16 05:50:07 +00:00
|
|
|
"using `.chars().last()` or `.chars().next_back()` to check if a string ends with a char"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for usage of `.as_ref()` or `.as_mut()` where the
|
|
|
|
/// types before and after the call are the same.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** The call is unnecessary.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// # fn do_stuff(x: &[i32]) {}
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let x: &[i32] = &[1, 2, 3, 4, 5];
|
|
|
|
/// do_stuff(x.as_ref());
|
|
|
|
/// ```
|
|
|
|
/// The correct use would be:
|
|
|
|
/// ```rust
|
2019-08-02 06:13:54 +00:00
|
|
|
/// # fn do_stuff(x: &[i32]) {}
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let x: &[i32] = &[1, 2, 3, 4, 5];
|
|
|
|
/// do_stuff(x);
|
|
|
|
/// ```
|
2017-10-20 15:39:20 +00:00
|
|
|
pub USELESS_ASREF,
|
2018-03-28 13:24:26 +00:00
|
|
|
complexity,
|
2017-10-20 15:39:20 +00:00
|
|
|
"using `as_ref` where the types before and after the call are the same"
|
|
|
|
}
|
|
|
|
|
2018-03-28 13:24:26 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for using `fold` when a more succinct alternative exists.
|
|
|
|
/// Specifically, this checks for `fold`s which could be replaced by `any`, `all`,
|
|
|
|
/// `sum` or `product`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability.
|
|
|
|
///
|
2020-08-11 13:43:21 +00:00
|
|
|
/// **Known problems:** None.
|
2019-03-05 16:50:33 +00:00
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let _ = (0..3).fold(false, |acc, x| acc || x > 2);
|
|
|
|
/// ```
|
|
|
|
/// This could be written as:
|
|
|
|
/// ```rust
|
|
|
|
/// let _ = (0..3).any(|x| x > 2);
|
|
|
|
/// ```
|
2018-01-17 20:21:29 +00:00
|
|
|
pub UNNECESSARY_FOLD,
|
2018-03-28 13:24:26 +00:00
|
|
|
style,
|
2018-01-17 21:54:09 +00:00
|
|
|
"using `fold` when a more succinct alternative exists"
|
2018-01-14 08:27:53 +00:00
|
|
|
}
|
|
|
|
|
2018-09-26 04:52:36 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for `filter_map` calls which could be replaced by `filter` or `map`.
|
|
|
|
/// More specifically it checks if the closure provided is only performing one of the
|
|
|
|
/// filter or map operations and suggests the appropriate option.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Complexity. The intent is also clearer if only a single
|
|
|
|
/// operation is being performed.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```rust
|
|
|
|
/// let _ = (0..3).filter_map(|x| if x > 2 { Some(x) } else { None });
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // As there is no transformation of the argument this could be written as:
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let _ = (0..3).filter(|&x| x > 2);
|
|
|
|
/// ```
|
|
|
|
///
|
|
|
|
/// ```rust
|
2019-12-19 23:48:17 +00:00
|
|
|
/// let _ = (0..4).filter_map(|x| Some(x + 1));
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // As there is no conditional check on the argument this could be written as:
|
2019-12-19 23:48:17 +00:00
|
|
|
/// let _ = (0..4).map(|x| x + 1);
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-09-26 04:52:36 +00:00
|
|
|
pub UNNECESSARY_FILTER_MAP,
|
|
|
|
complexity,
|
|
|
|
"using `filter_map` when a more succinct alternative exists"
|
|
|
|
}
|
|
|
|
|
2018-10-20 20:03:38 +00:00
|
|
|
declare_clippy_lint! {
|
2019-03-05 16:50:33 +00:00
|
|
|
/// **What it does:** Checks for `into_iter` calls on references which should be replaced by `iter`
|
|
|
|
/// or `iter_mut`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability. Calling `into_iter` on a reference will not move out its
|
|
|
|
/// content into the resulting iterator, which is confusing. It is better just call `iter` or
|
|
|
|
/// `iter_mut` directly.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
2020-06-09 14:36:01 +00:00
|
|
|
/// // Bad
|
2019-03-05 16:50:33 +00:00
|
|
|
/// let _ = (&vec![3, 4, 5]).into_iter();
|
2020-06-09 14:36:01 +00:00
|
|
|
///
|
|
|
|
/// // Good
|
|
|
|
/// let _ = (&vec![3, 4, 5]).iter();
|
2019-03-05 16:50:33 +00:00
|
|
|
/// ```
|
2018-10-20 20:03:38 +00:00
|
|
|
pub INTO_ITER_ON_REF,
|
|
|
|
style,
|
|
|
|
"using `.into_iter()` on a reference"
|
|
|
|
}
|
|
|
|
|
2019-08-15 20:56:16 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for calls to `map` followed by a `count`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** It looks suspicious. Maybe `map` was confused with `filter`.
|
2020-01-20 06:05:40 +00:00
|
|
|
/// If the `map` call is intentional, this should be rewritten. Or, if you intend to
|
|
|
|
/// drive the iterator to completion, you can just use `for_each` instead.
|
2019-08-15 20:56:16 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// let _ = (0..3).map(|x| x + 2).count();
|
|
|
|
/// ```
|
|
|
|
pub SUSPICIOUS_MAP,
|
2019-08-18 14:49:11 +00:00
|
|
|
complexity,
|
2019-08-15 20:56:16 +00:00
|
|
|
"suspicious usage of map"
|
|
|
|
}
|
|
|
|
|
2019-08-31 18:25:28 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for `MaybeUninit::uninit().assume_init()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** For most types, this is undefined behavior.
|
|
|
|
///
|
|
|
|
/// **Known problems:** For now, we accept empty tuples and tuples / arrays
|
|
|
|
/// of `MaybeUninit`. There may be other types that allow uninitialized
|
|
|
|
/// data, but those are not yet rigorously defined.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// // Beware the UB
|
|
|
|
/// use std::mem::MaybeUninit;
|
|
|
|
///
|
|
|
|
/// let _: usize = unsafe { MaybeUninit::uninit().assume_init() };
|
|
|
|
/// ```
|
|
|
|
///
|
|
|
|
/// Note that the following is OK:
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// use std::mem::MaybeUninit;
|
|
|
|
///
|
|
|
|
/// let _: [MaybeUninit<bool>; 5] = unsafe {
|
|
|
|
/// MaybeUninit::uninit().assume_init()
|
|
|
|
/// };
|
|
|
|
/// ```
|
|
|
|
pub UNINIT_ASSUMED_INIT,
|
|
|
|
correctness,
|
|
|
|
"`MaybeUninit::uninit().assume_init()`"
|
|
|
|
}
|
|
|
|
|
2019-09-04 07:08:48 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for `.checked_add/sub(x).unwrap_or(MAX/MIN)`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** These can be written simply with `saturating_add/sub` methods.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
2019-09-04 12:10:08 +00:00
|
|
|
/// # let y: u32 = 0;
|
|
|
|
/// # let x: u32 = 100;
|
2020-04-07 22:24:18 +00:00
|
|
|
/// let add = x.checked_add(y).unwrap_or(u32::MAX);
|
|
|
|
/// let sub = x.checked_sub(y).unwrap_or(u32::MIN);
|
2019-09-04 07:08:48 +00:00
|
|
|
/// ```
|
|
|
|
///
|
|
|
|
/// can be written using dedicated methods for saturating addition/subtraction as:
|
|
|
|
///
|
|
|
|
/// ```rust
|
2019-09-04 12:10:08 +00:00
|
|
|
/// # let y: u32 = 0;
|
|
|
|
/// # let x: u32 = 100;
|
|
|
|
/// let add = x.saturating_add(y);
|
|
|
|
/// let sub = x.saturating_sub(y);
|
2019-09-04 07:08:48 +00:00
|
|
|
/// ```
|
|
|
|
pub MANUAL_SATURATING_ARITHMETIC,
|
|
|
|
style,
|
|
|
|
"`.chcked_add/sub(x).unwrap_or(MAX/MIN)`"
|
|
|
|
}
|
|
|
|
|
2019-11-14 19:18:24 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for `offset(_)`, `wrapping_`{`add`, `sub`}, etc. on raw pointers to
|
|
|
|
/// zero-sized types
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** This is a no-op, and likely unintended
|
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
2019-11-25 13:06:34 +00:00
|
|
|
/// unsafe { (&() as *const ()).offset(1) };
|
2019-11-14 19:18:24 +00:00
|
|
|
/// ```
|
|
|
|
pub ZST_OFFSET,
|
|
|
|
correctness,
|
|
|
|
"Check for offset calculations on raw pointers to zero-sized types"
|
|
|
|
}
|
|
|
|
|
2020-01-02 05:12:23 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for `FileType::is_file()`.
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** When people testing a file type with `FileType::is_file`
|
|
|
|
/// they are testing whether a path is something they can get bytes from. But
|
2020-01-05 12:25:07 +00:00
|
|
|
/// `is_file` doesn't cover special file types in unix-like systems, and doesn't cover
|
2020-01-02 05:12:23 +00:00
|
|
|
/// symlink in windows. Using `!FileType::is_dir()` is a better way to that intention.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # || {
|
2020-01-02 05:12:23 +00:00
|
|
|
/// let metadata = std::fs::metadata("foo.txt")?;
|
|
|
|
/// let filetype = metadata.file_type();
|
|
|
|
///
|
|
|
|
/// if filetype.is_file() {
|
|
|
|
/// // read file
|
|
|
|
/// }
|
2020-01-30 22:44:37 +00:00
|
|
|
/// # Ok::<_, std::io::Error>(())
|
|
|
|
/// # };
|
2020-01-02 05:12:23 +00:00
|
|
|
/// ```
|
|
|
|
///
|
2020-01-05 12:25:07 +00:00
|
|
|
/// should be written as:
|
2020-01-02 05:12:23 +00:00
|
|
|
///
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # || {
|
2020-01-02 05:12:23 +00:00
|
|
|
/// let metadata = std::fs::metadata("foo.txt")?;
|
|
|
|
/// let filetype = metadata.file_type();
|
|
|
|
///
|
|
|
|
/// if !filetype.is_dir() {
|
|
|
|
/// // read file
|
|
|
|
/// }
|
2020-01-30 22:44:37 +00:00
|
|
|
/// # Ok::<_, std::io::Error>(())
|
|
|
|
/// # };
|
2020-01-02 05:12:23 +00:00
|
|
|
/// ```
|
|
|
|
pub FILETYPE_IS_FILE,
|
2020-01-05 12:25:07 +00:00
|
|
|
restriction,
|
|
|
|
"`FileType::is_file` is not recommended to test for readable file type"
|
2020-01-02 05:12:23 +00:00
|
|
|
}
|
|
|
|
|
2019-12-23 04:48:15 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Checks for usage of `_.as_ref().map(Deref::deref)` or it's aliases (such as String::as_str).
|
|
|
|
///
|
|
|
|
/// **Why is this bad?** Readability, this can be written more concisely as a
|
|
|
|
/// single method call.
|
|
|
|
///
|
|
|
|
/// **Known problems:** None.
|
|
|
|
///
|
|
|
|
/// **Example:**
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # let opt = Some("".to_string());
|
|
|
|
/// opt.as_ref().map(String::as_str)
|
|
|
|
/// # ;
|
2019-12-23 04:48:15 +00:00
|
|
|
/// ```
|
|
|
|
/// Can be written as
|
2020-01-30 22:44:37 +00:00
|
|
|
/// ```rust
|
|
|
|
/// # let opt = Some("".to_string());
|
|
|
|
/// opt.as_deref()
|
|
|
|
/// # ;
|
2019-12-23 04:48:15 +00:00
|
|
|
/// ```
|
|
|
|
pub OPTION_AS_REF_DEREF,
|
|
|
|
complexity,
|
|
|
|
"using `as_ref().map(Deref::deref)`, which is more succinctly expressed as `as_deref()`"
|
|
|
|
}
|
|
|
|
|
2020-06-09 14:36:01 +00:00
|
|
|
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()`"
|
|
|
|
}
|
|
|
|
|
2020-08-14 10:52:19 +00:00
|
|
|
declare_clippy_lint! {
|
|
|
|
/// **What it does:** Warns when using push_str with a single-character string literal,
|
|
|
|
/// and push with a char would work fine.
|
|
|
|
///
|
2020-08-14 23:40:47 +00:00
|
|
|
/// **Why is this bad?** It's less clear that we are pushing a single character
|
2020-08-14 10:52:19 +00:00
|
|
|
///
|
|
|
|
/// **Known problems:** None
|
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
/// ```
|
|
|
|
/// let mut string = String::new();
|
|
|
|
/// string.push_str("R");
|
|
|
|
/// ```
|
|
|
|
/// Could be written as
|
|
|
|
/// ```
|
|
|
|
/// let mut string = String::new();
|
|
|
|
/// string.push('R');
|
|
|
|
/// ```
|
|
|
|
pub SINGLE_CHAR_PUSH_STR,
|
|
|
|
style,
|
|
|
|
"`push_str()` used with a single-character string literal as parameter"
|
|
|
|
}
|
|
|
|
|
2020-06-15 09:21:56 +00:00
|
|
|
declare_clippy_lint! {
|
2020-06-15 12:55:23 +00:00
|
|
|
/// **What it does:** As the counterpart to `or_fun_call`, this lint looks for unnecessary
|
|
|
|
/// lazily evaluated closures on `Option` and `Result`.
|
|
|
|
///
|
|
|
|
/// This lint suggests changing the following functions, when eager evaluation results in
|
|
|
|
/// simpler code:
|
|
|
|
/// - `unwrap_or_else` to `unwrap_or`
|
|
|
|
/// - `and_then` to `and`
|
|
|
|
/// - `or_else` to `or`
|
|
|
|
/// - `get_or_insert_with` to `get_or_insert`
|
|
|
|
/// - `ok_or_else` to `ok_or`
|
2020-06-15 09:21:56 +00:00
|
|
|
///
|
|
|
|
/// **Why is this bad?** Using eager evaluation is shorter and simpler in some cases.
|
|
|
|
///
|
2020-06-15 12:55:23 +00:00
|
|
|
/// **Known problems:** It is possible, but not recommended for `Deref` and `Index` to have
|
|
|
|
/// side effects. Eagerly evaluating them can change the semantics of the program.
|
2020-06-15 09:21:56 +00:00
|
|
|
///
|
|
|
|
/// **Example:**
|
|
|
|
///
|
|
|
|
/// ```rust
|
|
|
|
/// // example code where clippy issues a warning
|
|
|
|
/// let opt: Option<u32> = None;
|
|
|
|
///
|
|
|
|
/// opt.unwrap_or_else(|| 42);
|
|
|
|
/// ```
|
|
|
|
/// Use instead:
|
|
|
|
/// ```rust
|
|
|
|
/// let opt: Option<u32> = None;
|
|
|
|
///
|
|
|
|
/// opt.unwrap_or(42);
|
|
|
|
/// ```
|
2020-08-16 20:16:39 +00:00
|
|
|
pub UNNECESSARY_LAZY_EVALUATIONS,
|
2020-06-15 09:21:56 +00:00
|
|
|
style,
|
|
|
|
"using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation"
|
|
|
|
}
|
|
|
|
|
2019-04-08 20:43:55 +00:00
|
|
|
declare_lint_pass!(Methods => [
|
2020-05-17 15:36:26 +00:00
|
|
|
UNWRAP_USED,
|
|
|
|
EXPECT_USED,
|
2019-04-08 20:43:55 +00:00
|
|
|
SHOULD_IMPLEMENT_TRAIT,
|
|
|
|
WRONG_SELF_CONVENTION,
|
|
|
|
WRONG_PUB_SELF_CONVENTION,
|
|
|
|
OK_EXPECT,
|
2020-05-17 15:36:26 +00:00
|
|
|
MAP_UNWRAP_OR,
|
2020-04-04 06:59:52 +00:00
|
|
|
RESULT_MAP_OR_INTO_OPTION,
|
2019-04-08 20:43:55 +00:00
|
|
|
OPTION_MAP_OR_NONE,
|
2020-05-17 15:36:26 +00:00
|
|
|
BIND_INSTEAD_OF_MAP,
|
2019-04-08 20:43:55 +00:00
|
|
|
OR_FUN_CALL,
|
|
|
|
EXPECT_FUN_CALL,
|
|
|
|
CHARS_NEXT_CMP,
|
|
|
|
CHARS_LAST_CMP,
|
|
|
|
CLONE_ON_COPY,
|
|
|
|
CLONE_ON_REF_PTR,
|
|
|
|
CLONE_DOUBLE_REF,
|
2019-10-16 19:54:20 +00:00
|
|
|
INEFFICIENT_TO_STRING,
|
2019-04-08 20:43:55 +00:00
|
|
|
NEW_RET_NO_SELF,
|
|
|
|
SINGLE_CHAR_PATTERN,
|
2020-08-14 10:52:19 +00:00
|
|
|
SINGLE_CHAR_PUSH_STR,
|
2019-04-08 20:43:55 +00:00
|
|
|
SEARCH_IS_SOME,
|
|
|
|
TEMPORARY_CSTRING_AS_PTR,
|
|
|
|
FILTER_NEXT,
|
2020-01-20 01:54:54 +00:00
|
|
|
SKIP_WHILE_NEXT,
|
2019-04-08 20:43:55 +00:00
|
|
|
FILTER_MAP,
|
2019-04-27 22:06:35 +00:00
|
|
|
FILTER_MAP_NEXT,
|
2019-08-11 18:34:25 +00:00
|
|
|
FLAT_MAP_IDENTITY,
|
2019-04-27 22:06:35 +00:00
|
|
|
FIND_MAP,
|
2019-04-08 20:43:55 +00:00
|
|
|
MAP_FLATTEN,
|
2019-12-18 16:59:43 +00:00
|
|
|
ITERATOR_STEP_BY_ZERO,
|
2020-06-09 14:36:01 +00:00
|
|
|
ITER_NEXT_SLICE,
|
2019-04-08 20:43:55 +00:00
|
|
|
ITER_NTH,
|
2019-12-28 22:37:23 +00:00
|
|
|
ITER_NTH_ZERO,
|
2019-04-08 20:43:55 +00:00
|
|
|
ITER_SKIP_NEXT,
|
|
|
|
GET_UNWRAP,
|
|
|
|
STRING_EXTEND_CHARS,
|
|
|
|
ITER_CLONED_COLLECT,
|
|
|
|
USELESS_ASREF,
|
|
|
|
UNNECESSARY_FOLD,
|
|
|
|
UNNECESSARY_FILTER_MAP,
|
|
|
|
INTO_ITER_ON_REF,
|
2019-08-15 20:56:16 +00:00
|
|
|
SUSPICIOUS_MAP,
|
2019-08-31 18:25:28 +00:00
|
|
|
UNINIT_ASSUMED_INIT,
|
2019-09-04 07:08:48 +00:00
|
|
|
MANUAL_SATURATING_ARITHMETIC,
|
2019-11-14 19:18:24 +00:00
|
|
|
ZST_OFFSET,
|
2020-01-02 05:12:23 +00:00
|
|
|
FILETYPE_IS_FILE,
|
2019-12-23 04:48:15 +00:00
|
|
|
OPTION_AS_REF_DEREF,
|
2020-08-16 20:16:39 +00:00
|
|
|
UNNECESSARY_LAZY_EVALUATIONS,
|
2019-04-08 20:43:55 +00:00
|
|
|
]);
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
impl<'tcx> LateLintPass<'tcx> for Methods {
|
2020-04-06 22:46:40 +00:00
|
|
|
#[allow(clippy::too_many_lines)]
|
2020-06-25 20:41:36 +00:00
|
|
|
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) {
|
2017-03-31 22:14:04 +00:00
|
|
|
if in_macro(expr.span) {
|
2016-01-20 17:32:17 +00:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2019-08-28 08:41:32 +00:00
|
|
|
let (method_names, arg_lists, method_spans) = method_calls(expr, 2);
|
2019-11-06 09:50:24 +00:00
|
|
|
let method_names: Vec<SymbolStr> = method_names.iter().map(|s| s.as_str()).collect();
|
|
|
|
let method_names: Vec<&str> = method_names.iter().map(|s| &**s).collect();
|
2018-10-31 04:26:29 +00:00
|
|
|
|
2018-11-01 05:06:47 +00:00
|
|
|
match method_names.as_slice() {
|
2018-10-31 04:26:29 +00:00
|
|
|
["unwrap", "get"] => lint_get_unwrap(cx, expr, arg_lists[1], false),
|
|
|
|
["unwrap", "get_mut"] => lint_get_unwrap(cx, expr, arg_lists[1], true),
|
2018-11-01 05:06:47 +00:00
|
|
|
["unwrap", ..] => lint_unwrap(cx, expr, arg_lists[0]),
|
2018-10-31 04:26:29 +00:00
|
|
|
["expect", "ok"] => lint_ok_expect(cx, expr, arg_lists[1]),
|
2019-10-15 19:33:07 +00:00
|
|
|
["expect", ..] => lint_expect(cx, expr, arg_lists[0]),
|
2019-10-05 12:23:52 +00:00
|
|
|
["unwrap_or", "map"] => option_map_unwrap_or::lint(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]),
|
2020-06-15 09:21:56 +00:00
|
|
|
["unwrap_or_else", "map"] => {
|
2020-08-16 18:47:50 +00:00
|
|
|
if !lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0]) {
|
|
|
|
unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "unwrap_or");
|
|
|
|
}
|
2020-06-15 09:21:56 +00:00
|
|
|
},
|
2018-11-01 05:06:47 +00:00
|
|
|
["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]),
|
2020-05-17 15:36:26 +00:00
|
|
|
["and_then", ..] => {
|
2020-08-16 18:47:50 +00:00
|
|
|
unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], false, "and");
|
2020-05-17 15:36:26 +00:00
|
|
|
bind_instead_of_map::OptionAndThenSome::lint(cx, expr, arg_lists[0]);
|
|
|
|
bind_instead_of_map::ResultAndThenOk::lint(cx, expr, arg_lists[0]);
|
|
|
|
},
|
|
|
|
["or_else", ..] => {
|
2020-08-16 18:47:50 +00:00
|
|
|
unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], false, "or");
|
2020-05-17 15:36:26 +00:00
|
|
|
bind_instead_of_map::ResultOrElseErrInfo::lint(cx, expr, arg_lists[0]);
|
|
|
|
},
|
2018-10-31 04:26:29 +00:00
|
|
|
["next", "filter"] => lint_filter_next(cx, expr, arg_lists[1]),
|
2020-01-20 01:54:54 +00:00
|
|
|
["next", "skip_while"] => lint_skip_while_next(cx, expr, arg_lists[1]),
|
2020-06-09 14:36:01 +00:00
|
|
|
["next", "iter"] => lint_iter_next(cx, expr, arg_lists[1]),
|
2018-10-31 04:26:29 +00:00
|
|
|
["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]),
|
2019-04-27 22:06:35 +00:00
|
|
|
["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1]),
|
|
|
|
["map", "find"] => lint_find_map(cx, expr, arg_lists[1], arg_lists[0]),
|
2018-10-31 04:26:29 +00:00
|
|
|
["flat_map", "filter"] => lint_filter_flat_map(cx, expr, arg_lists[1], arg_lists[0]),
|
|
|
|
["flat_map", "filter_map"] => lint_filter_map_flat_map(cx, expr, arg_lists[1], arg_lists[0]),
|
2019-08-28 08:41:32 +00:00
|
|
|
["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]),
|
2018-10-31 04:26:29 +00:00
|
|
|
["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]),
|
2019-08-29 08:06:56 +00:00
|
|
|
["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]),
|
|
|
|
["is_some", "position"] => {
|
|
|
|
lint_search_is_some(cx, expr, "position", arg_lists[1], arg_lists[0], method_spans[1])
|
|
|
|
},
|
|
|
|
["is_some", "rposition"] => {
|
|
|
|
lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1])
|
|
|
|
},
|
2018-11-01 05:06:47 +00:00
|
|
|
["extend", ..] => lint_extend(cx, expr, arg_lists[0]),
|
2020-06-09 14:36:01 +00:00
|
|
|
["as_ptr", "unwrap" | "expect"] => lint_cstring_as_ptr(cx, expr, &arg_lists[1][0], &arg_lists[0][0]),
|
2019-12-28 22:37:23 +00:00
|
|
|
["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]),
|
2019-12-18 16:59:43 +00:00
|
|
|
["step_by", ..] => lint_step_by(cx, expr, arg_lists[0]),
|
2020-08-11 13:43:21 +00:00
|
|
|
["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]),
|
2018-10-31 04:26:29 +00:00
|
|
|
["collect", "cloned"] => lint_iter_cloned_collect(cx, expr, arg_lists[1]),
|
2018-12-17 20:33:50 +00:00
|
|
|
["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]),
|
|
|
|
["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]),
|
2019-08-28 08:41:32 +00:00
|
|
|
["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]),
|
2018-11-01 05:06:47 +00:00
|
|
|
["filter_map", ..] => unnecessary_filter_map::lint(cx, expr, arg_lists[0]),
|
2019-08-15 20:56:16 +00:00
|
|
|
["count", "map"] => lint_suspicious_map(cx, expr),
|
2019-08-31 18:25:28 +00:00
|
|
|
["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr),
|
2020-06-09 14:36:01 +00:00
|
|
|
["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => {
|
2019-09-04 12:06:28 +00:00
|
|
|
manual_saturating_arithmetic::lint(cx, expr, &arg_lists, &arith["checked_".len()..])
|
2019-09-04 07:08:48 +00:00
|
|
|
},
|
2020-06-09 14:36:01 +00:00
|
|
|
["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => {
|
2019-11-14 19:18:24 +00:00
|
|
|
check_pointer_offset(cx, expr, arg_lists[0])
|
|
|
|
},
|
2020-01-03 06:59:14 +00:00
|
|
|
["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]),
|
2019-12-23 04:48:15 +00:00
|
|
|
["map", "as_ref"] => lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], false),
|
|
|
|
["map", "as_mut"] => lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], true),
|
2020-08-16 18:47:50 +00:00
|
|
|
["unwrap_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "unwrap_or"),
|
|
|
|
["get_or_insert_with", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "get_or_insert"),
|
|
|
|
["ok_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "ok_or"),
|
2018-11-27 20:14:15 +00:00
|
|
|
_ => {},
|
2018-10-31 04:26:29 +00:00
|
|
|
}
|
|
|
|
|
2019-09-27 15:16:06 +00:00
|
|
|
match expr.kind {
|
2020-06-09 21:44:04 +00:00
|
|
|
hir::ExprKind::MethodCall(ref method_call, ref method_span, ref args, _) => {
|
2018-06-28 13:46:58 +00:00
|
|
|
lint_or_fun_call(cx, expr, *method_span, &method_call.ident.as_str(), args);
|
|
|
|
lint_expect_fun_call(cx, expr, *method_span, &method_call.ident.as_str(), args);
|
2016-04-20 19:09:38 +00:00
|
|
|
|
2020-07-17 08:47:04 +00:00
|
|
|
let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]);
|
2019-05-17 21:53:54 +00:00
|
|
|
if args.len() == 1 && method_call.ident.name == sym!(clone) {
|
2016-08-08 14:43:45 +00:00
|
|
|
lint_clone_on_copy(cx, expr, &args[0], self_ty);
|
2017-09-10 01:51:54 +00:00
|
|
|
lint_clone_on_ref_ptr(cx, expr, &args[0]);
|
2016-02-05 10:34:15 +00:00
|
|
|
}
|
2019-10-16 19:54:20 +00:00
|
|
|
if args.len() == 1 && method_call.ident.name == sym!(to_string) {
|
|
|
|
inefficient_to_string::lint(cx, expr, &args[0], self_ty);
|
|
|
|
}
|
2016-04-20 19:09:38 +00:00
|
|
|
|
2020-08-14 10:52:19 +00:00
|
|
|
if let Some(fn_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) {
|
|
|
|
if match_def_path(cx, fn_def_id, &paths::PUSH_STR) {
|
|
|
|
lint_single_char_push_string(cx, expr, args);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-09-26 09:03:36 +00:00
|
|
|
match self_ty.kind {
|
|
|
|
ty::Ref(_, ty, _) if ty.kind == ty::Str => {
|
2019-05-17 23:34:52 +00:00
|
|
|
for &(method, pos) in &PATTERN_METHODS {
|
|
|
|
if method_call.ident.name.as_str() == method && args.len() > pos {
|
2018-11-27 20:14:15 +00:00
|
|
|
lint_single_char_pattern(cx, expr, &args[pos]);
|
|
|
|
}
|
2016-04-20 19:09:38 +00:00
|
|
|
}
|
2016-12-20 17:21:30 +00:00
|
|
|
},
|
2019-05-17 21:53:54 +00:00
|
|
|
ty::Ref(..) if method_call.ident.name == sym!(into_iter) => {
|
2018-10-20 20:03:38 +00:00
|
|
|
lint_into_iter(cx, expr, self_ty, *method_span);
|
|
|
|
},
|
2016-04-20 19:09:38 +00:00
|
|
|
_ => (),
|
2016-02-15 03:40:43 +00:00
|
|
|
}
|
2016-12-20 17:21:30 +00:00
|
|
|
},
|
2018-11-27 20:14:15 +00:00
|
|
|
hir::ExprKind::Binary(op, ref lhs, ref rhs)
|
|
|
|
if op.node == hir::BinOpKind::Eq || op.node == hir::BinOpKind::Ne =>
|
|
|
|
{
|
2017-09-16 05:50:07 +00:00
|
|
|
let mut info = BinaryExprInfo {
|
2018-03-15 15:07:15 +00:00
|
|
|
expr,
|
2017-09-16 05:50:07 +00:00
|
|
|
chain: lhs,
|
|
|
|
other: rhs,
|
2018-07-12 07:50:09 +00:00
|
|
|
eq: op.node == hir::BinOpKind::Eq,
|
2017-09-16 05:50:07 +00:00
|
|
|
};
|
|
|
|
lint_binary_expr_with_method_call(cx, &mut info);
|
2018-11-27 20:14:15 +00:00
|
|
|
}
|
2016-01-20 01:23:39 +00:00
|
|
|
_ => (),
|
2015-08-11 18:53:50 +00:00
|
|
|
}
|
|
|
|
}
|
2015-08-24 16:13:02 +00:00
|
|
|
|
2020-08-09 13:35:41 +00:00
|
|
|
#[allow(clippy::too_many_lines)]
|
2020-06-25 20:41:36 +00:00
|
|
|
fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
|
2019-08-10 03:58:52 +00:00
|
|
|
if in_external_macro(cx.sess(), impl_item.span) {
|
2016-01-20 17:32:17 +00:00
|
|
|
return;
|
|
|
|
}
|
2019-08-10 03:58:52 +00:00
|
|
|
let name = impl_item.ident.name.as_str();
|
|
|
|
let parent = cx.tcx.hir().get_parent_item(impl_item.hir_id);
|
2019-06-18 09:15:47 +00:00
|
|
|
let item = cx.tcx.hir().expect_item(parent);
|
2019-07-06 03:52:51 +00:00
|
|
|
let def_id = cx.tcx.hir().local_def_id(item.hir_id);
|
2020-04-07 19:53:56 +00:00
|
|
|
let self_ty = cx.tcx.type_of(def_id);
|
2017-10-28 18:23:05 +00:00
|
|
|
if_chain! {
|
2020-03-16 15:00:16 +00:00
|
|
|
if let hir::ImplItemKind::Fn(ref sig, id) = impl_item.kind;
|
2018-12-08 00:56:03 +00:00
|
|
|
if let Some(first_arg) = iter_input_pats(&sig.decl, cx.tcx.hir().body(id)).next();
|
2020-01-18 05:14:36 +00:00
|
|
|
if let hir::ItemKind::Impl{ of_trait: None, .. } = item.kind;
|
2019-08-10 04:00:27 +00:00
|
|
|
|
2019-08-23 12:20:55 +00:00
|
|
|
let method_def_id = cx.tcx.hir().local_def_id(impl_item.hir_id);
|
|
|
|
let method_sig = cx.tcx.fn_sig(method_def_id);
|
|
|
|
let method_sig = cx.tcx.erase_late_bound_regions(&method_sig);
|
2017-11-04 19:55:56 +00:00
|
|
|
|
2019-08-23 12:20:55 +00:00
|
|
|
let first_arg_ty = &method_sig.inputs().iter().next();
|
2019-08-10 04:00:27 +00:00
|
|
|
|
2019-08-23 12:20:55 +00:00
|
|
|
// check conventions w.r.t. conversion method names and predicates
|
|
|
|
if let Some(first_arg_ty) = first_arg_ty;
|
|
|
|
|
|
|
|
then {
|
|
|
|
if cx.access_levels.is_exported(impl_item.hir_id) {
|
2020-07-29 23:41:12 +00:00
|
|
|
// check missing trait implementations
|
|
|
|
for method_config in &TRAIT_METHODS {
|
|
|
|
if name == method_config.method_name &&
|
|
|
|
sig.decl.inputs.len() == method_config.param_count &&
|
|
|
|
method_config.output_type.matches(cx, &sig.decl.output) &&
|
|
|
|
method_config.self_kind.matches(cx, self_ty, first_arg_ty) &&
|
2020-08-09 13:35:41 +00:00
|
|
|
fn_header_equals(method_config.fn_header, sig.header) &&
|
2020-07-29 23:41:12 +00:00
|
|
|
method_config.lifetime_param_cond(&impl_item)
|
2020-06-20 22:12:09 +00:00
|
|
|
{
|
2020-07-29 23:41:12 +00:00
|
|
|
span_lint_and_help(
|
|
|
|
cx,
|
|
|
|
SHOULD_IMPLEMENT_TRAIT,
|
|
|
|
impl_item.span,
|
|
|
|
&format!(
|
|
|
|
"method `{}` can be confused for the standard trait method `{}::{}`",
|
|
|
|
method_config.method_name,
|
|
|
|
method_config.trait_name,
|
|
|
|
method_config.method_name
|
|
|
|
),
|
|
|
|
None,
|
|
|
|
&format!(
|
|
|
|
"consider implementing the trait `{}` or choosing a less ambiguous method name",
|
|
|
|
method_config.trait_name
|
|
|
|
)
|
|
|
|
);
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
2019-08-10 04:00:27 +00:00
|
|
|
}
|
2019-08-23 12:20:55 +00:00
|
|
|
}
|
2018-10-01 11:47:06 +00:00
|
|
|
|
2019-08-23 12:20:55 +00:00
|
|
|
if let Some((ref conv, self_kinds)) = &CONVENTIONS
|
|
|
|
.iter()
|
|
|
|
.find(|(ref conv, _)| conv.check(&name))
|
|
|
|
{
|
2020-04-07 19:53:56 +00:00
|
|
|
if !self_kinds.iter().any(|k| k.matches(cx, self_ty, first_arg_ty)) {
|
2019-08-23 12:20:55 +00:00
|
|
|
let lint = if item.vis.node.is_pub() {
|
|
|
|
WRONG_PUB_SELF_CONVENTION
|
|
|
|
} else {
|
|
|
|
WRONG_SELF_CONVENTION
|
|
|
|
};
|
2019-08-10 04:00:27 +00:00
|
|
|
|
2019-08-23 12:20:55 +00:00
|
|
|
span_lint(
|
|
|
|
cx,
|
|
|
|
lint,
|
|
|
|
first_arg.pat.span,
|
2020-05-17 15:36:26 +00:00
|
|
|
&format!("methods called `{}` usually take {}; consider choosing a less ambiguous name",
|
2019-08-23 12:20:55 +00:00
|
|
|
conv,
|
|
|
|
&self_kinds
|
|
|
|
.iter()
|
|
|
|
.map(|k| k.description())
|
|
|
|
.collect::<Vec<_>>()
|
|
|
|
.join(" or ")
|
|
|
|
),
|
|
|
|
);
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
|
|
|
}
|
2016-08-08 15:09:36 +00:00
|
|
|
}
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
2018-10-03 03:11:56 +00:00
|
|
|
|
2020-03-16 15:00:16 +00:00
|
|
|
if let hir::ImplItemKind::Fn(_, _) = impl_item.kind {
|
2019-08-10 03:58:52 +00:00
|
|
|
let ret_ty = return_ty(cx, impl_item.hir_id);
|
2018-10-05 02:01:04 +00:00
|
|
|
|
2020-04-07 19:53:56 +00:00
|
|
|
let contains_self_ty = |ty: Ty<'tcx>| {
|
|
|
|
ty.walk().any(|inner| match inner.unpack() {
|
2020-06-09 14:36:01 +00:00
|
|
|
GenericArgKind::Type(inner_ty) => TyS::same_type(self_ty, inner_ty),
|
2020-04-07 19:53:56 +00:00
|
|
|
|
|
|
|
GenericArgKind::Lifetime(_) | GenericArgKind::Const(_) => false,
|
|
|
|
})
|
|
|
|
};
|
|
|
|
|
2018-10-20 00:54:25 +00:00
|
|
|
// walk the return type and check for Self (this does not check associated types)
|
2020-04-07 19:53:56 +00:00
|
|
|
if contains_self_ty(ret_ty) {
|
2019-08-23 12:20:55 +00:00
|
|
|
return;
|
2018-10-20 00:54:25 +00:00
|
|
|
}
|
2018-10-19 11:55:06 +00:00
|
|
|
|
2018-10-20 00:54:25 +00:00
|
|
|
// if return type is impl trait, check the associated types
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Opaque(def_id, _) = ret_ty.kind {
|
2018-10-20 00:54:25 +00:00
|
|
|
// one of the associated types must be Self
|
2020-06-19 08:22:25 +00:00
|
|
|
for &(predicate, _span) in cx.tcx.predicates_of(def_id).predicates {
|
2020-07-08 22:35:55 +00:00
|
|
|
if let ty::PredicateAtom::Projection(projection_predicate) = predicate.skip_binders() {
|
2020-05-28 13:45:24 +00:00
|
|
|
// walk the associated type and check for Self
|
2020-06-19 08:22:25 +00:00
|
|
|
if contains_self_ty(projection_predicate.ty) {
|
2020-05-28 13:45:24 +00:00
|
|
|
return;
|
|
|
|
}
|
2018-10-05 02:01:04 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-09 14:36:01 +00:00
|
|
|
if name == "new" && !TyS::same_type(ret_ty, self_ty) {
|
2018-11-27 20:14:15 +00:00
|
|
|
span_lint(
|
|
|
|
cx,
|
|
|
|
NEW_RET_NO_SELF,
|
2019-08-10 03:58:52 +00:00
|
|
|
impl_item.span,
|
2018-11-27 20:14:15 +00:00
|
|
|
"methods called `new` usually return `Self`",
|
|
|
|
);
|
2018-10-03 10:55:31 +00:00
|
|
|
}
|
2018-10-03 03:11:56 +00:00
|
|
|
}
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-01-16 17:47:45 +00:00
|
|
|
/// Checks for the `OR_FUN_CALL` lint.
|
2019-01-13 15:19:02 +00:00
|
|
|
#[allow(clippy::too_many_lines)]
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_or_fun_call<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &hir::Expr<'_>,
|
2019-05-12 08:18:38 +00:00
|
|
|
method_span: Span,
|
|
|
|
name: &str,
|
2019-12-27 07:12:26 +00:00
|
|
|
args: &'tcx [hir::Expr<'_>],
|
2019-05-12 08:18:38 +00:00
|
|
|
) {
|
|
|
|
// Searches an expression for method calls or function calls that aren't ctors
|
2019-06-19 18:36:23 +00:00
|
|
|
struct FunCallFinder<'a, 'tcx> {
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &'a LateContext<'tcx>,
|
2019-05-12 08:18:38 +00:00
|
|
|
found: bool,
|
|
|
|
}
|
|
|
|
|
|
|
|
impl<'a, 'tcx> intravisit::Visitor<'tcx> for FunCallFinder<'a, 'tcx> {
|
2020-01-09 07:13:22 +00:00
|
|
|
type Map = Map<'tcx>;
|
|
|
|
|
2019-12-27 07:12:26 +00:00
|
|
|
fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
|
2019-09-27 15:16:06 +00:00
|
|
|
let call_found = match &expr.kind {
|
2019-05-12 08:32:19 +00:00
|
|
|
// ignore enum and struct constructors
|
2019-10-05 10:38:38 +00:00
|
|
|
hir::ExprKind::Call(..) => !is_ctor_or_promotable_const_function(self.cx, expr),
|
2019-05-12 08:18:38 +00:00
|
|
|
hir::ExprKind::MethodCall(..) => true,
|
|
|
|
_ => false,
|
|
|
|
};
|
|
|
|
|
2019-05-12 08:32:19 +00:00
|
|
|
if call_found {
|
2019-10-05 10:38:38 +00:00
|
|
|
self.found |= true;
|
2019-05-12 08:18:38 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
if !self.found {
|
|
|
|
intravisit::walk_expr(self, expr);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-03-15 22:41:20 +00:00
|
|
|
fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
|
2019-05-12 08:18:38 +00:00
|
|
|
intravisit::NestedVisitorMap::None
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-01-31 01:15:29 +00:00
|
|
|
/// Checks for `unwrap_or(T::new())` or `unwrap_or(T::default())`.
|
2016-12-21 09:25:14 +00:00
|
|
|
fn check_unwrap_or_default(
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &LateContext<'_>,
|
2016-12-21 11:14:54 +00:00
|
|
|
name: &str,
|
2019-12-27 07:12:26 +00:00
|
|
|
fun: &hir::Expr<'_>,
|
|
|
|
self_expr: &hir::Expr<'_>,
|
|
|
|
arg: &hir::Expr<'_>,
|
2016-12-21 11:14:54 +00:00
|
|
|
or_has_args: bool,
|
2017-08-09 07:30:56 +00:00
|
|
|
span: Span,
|
2016-12-21 09:25:14 +00:00
|
|
|
) -> bool {
|
2019-08-23 12:36:00 +00:00
|
|
|
if_chain! {
|
|
|
|
if !or_has_args;
|
|
|
|
if name == "unwrap_or";
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Path(ref qpath) = fun.kind;
|
2019-08-23 12:36:00 +00:00
|
|
|
let path = &*last_path_segment(qpath).ident.as_str();
|
|
|
|
if ["default", "new"].contains(&path);
|
2020-07-17 08:47:04 +00:00
|
|
|
let arg_ty = cx.typeck_results().expr_ty(arg);
|
2019-08-23 12:36:00 +00:00
|
|
|
if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT);
|
|
|
|
if implements_trait(cx, arg_ty, default_trait_id, &[]);
|
2016-01-18 12:11:07 +00:00
|
|
|
|
2019-08-23 12:36:00 +00:00
|
|
|
then {
|
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
OR_FUN_CALL,
|
|
|
|
span,
|
|
|
|
&format!("use of `{}` followed by a call to `{}`", name, path),
|
|
|
|
"try this",
|
|
|
|
format!(
|
|
|
|
"{}.unwrap_or_default()",
|
|
|
|
snippet_with_applicability(cx, self_expr.span, "_", &mut applicability)
|
|
|
|
),
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
|
|
|
|
true
|
|
|
|
} else {
|
|
|
|
false
|
2016-01-18 12:11:07 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-01-31 01:15:29 +00:00
|
|
|
/// Checks for `*or(foo())`.
|
2018-08-01 20:48:41 +00:00
|
|
|
#[allow(clippy::too_many_arguments)]
|
2020-06-25 20:41:36 +00:00
|
|
|
fn check_general_case<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2016-12-21 11:14:54 +00:00
|
|
|
name: &str,
|
2018-02-22 15:11:20 +00:00
|
|
|
method_span: Span,
|
2017-01-14 23:31:20 +00:00
|
|
|
fun_span: Span,
|
2019-12-27 07:12:26 +00:00
|
|
|
self_expr: &hir::Expr<'_>,
|
|
|
|
arg: &'tcx hir::Expr<'_>,
|
2016-12-21 11:14:54 +00:00
|
|
|
or_has_args: bool,
|
2017-08-09 07:30:56 +00:00
|
|
|
span: Span,
|
2016-12-21 09:25:14 +00:00
|
|
|
) {
|
2020-06-09 21:44:04 +00:00
|
|
|
if let hir::ExprKind::MethodCall(ref path, _, ref args, _) = &arg.kind {
|
2020-05-28 13:45:24 +00:00
|
|
|
if path.ident.as_str() == "len" {
|
2020-07-17 08:47:04 +00:00
|
|
|
let ty = walk_ptrs_ty(cx.typeck_results().expr_ty(&args[0]));
|
2020-05-28 13:45:24 +00:00
|
|
|
|
|
|
|
match ty.kind {
|
|
|
|
ty::Slice(_) | ty::Array(_, _) => return,
|
|
|
|
_ => (),
|
|
|
|
}
|
|
|
|
|
|
|
|
if match_type(cx, ty, &paths::VEC) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-05-20 17:18:32 +00:00
|
|
|
// (path, fn_has_argument, methods, suffix)
|
2017-09-05 09:33:04 +00:00
|
|
|
let know_types: &[(&[_], _, &[_], _)] = &[
|
2019-05-17 21:53:54 +00:00
|
|
|
(&paths::BTREEMAP_ENTRY, false, &["or_insert"], "with"),
|
|
|
|
(&paths::HASHMAP_ENTRY, false, &["or_insert"], "with"),
|
|
|
|
(&paths::OPTION, false, &["map_or", "ok_or", "or", "unwrap_or"], "else"),
|
|
|
|
(&paths::RESULT, true, &["or", "unwrap_or"], "else"),
|
2017-09-05 09:33:04 +00:00
|
|
|
];
|
2016-01-19 23:53:26 +00:00
|
|
|
|
2019-08-23 20:31:22 +00:00
|
|
|
if_chain! {
|
|
|
|
if know_types.iter().any(|k| k.2.contains(&name));
|
2017-10-19 17:16:03 +00:00
|
|
|
|
2019-08-23 20:31:22 +00:00
|
|
|
let mut finder = FunCallFinder { cx: &cx, found: false };
|
|
|
|
if { finder.visit_expr(&arg); finder.found };
|
2019-09-08 09:03:45 +00:00
|
|
|
if !contains_return(&arg);
|
2017-10-19 17:16:03 +00:00
|
|
|
|
2020-07-17 08:47:04 +00:00
|
|
|
let self_ty = cx.typeck_results().expr_ty(self_expr);
|
2016-01-16 17:47:45 +00:00
|
|
|
|
2019-08-23 20:31:22 +00:00
|
|
|
if let Some(&(_, fn_has_arguments, poss, suffix)) =
|
2020-05-17 15:36:26 +00:00
|
|
|
know_types.iter().find(|&&i| match_type(cx, self_ty, i.0));
|
2016-01-19 23:53:26 +00:00
|
|
|
|
2019-08-23 20:31:22 +00:00
|
|
|
if poss.contains(&name);
|
2016-01-16 17:47:45 +00:00
|
|
|
|
2019-08-23 20:31:22 +00:00
|
|
|
then {
|
|
|
|
let sugg: Cow<'_, _> = match (fn_has_arguments, !or_has_args) {
|
|
|
|
(true, _) => format!("|_| {}", snippet_with_macro_callsite(cx, arg.span, "..")).into(),
|
|
|
|
(false, false) => format!("|| {}", snippet_with_macro_callsite(cx, arg.span, "..")).into(),
|
|
|
|
(false, true) => snippet_with_macro_callsite(cx, fun_span, ".."),
|
|
|
|
};
|
|
|
|
let span_replace_word = method_span.with_hi(span.hi());
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
OR_FUN_CALL,
|
|
|
|
span_replace_word,
|
|
|
|
&format!("use of `{}` followed by a function call", name),
|
|
|
|
"try this",
|
|
|
|
format!("{}_{}({})", name, suffix, sugg),
|
|
|
|
Applicability::HasPlaceholders,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
2016-01-18 12:11:07 +00:00
|
|
|
}
|
|
|
|
|
2016-01-19 23:53:26 +00:00
|
|
|
if args.len() == 2 {
|
2019-09-27 15:16:06 +00:00
|
|
|
match args[1].kind {
|
2018-07-12 07:30:57 +00:00
|
|
|
hir::ExprKind::Call(ref fun, ref or_args) => {
|
2017-01-14 23:31:20 +00:00
|
|
|
let or_has_args = !or_args.is_empty();
|
|
|
|
if !check_unwrap_or_default(cx, name, fun, &args[0], &args[1], or_has_args, expr.span) {
|
2018-11-27 20:14:15 +00:00
|
|
|
check_general_case(
|
|
|
|
cx,
|
|
|
|
name,
|
|
|
|
method_span,
|
|
|
|
fun.span,
|
|
|
|
&args[0],
|
|
|
|
&args[1],
|
|
|
|
or_has_args,
|
|
|
|
expr.span,
|
|
|
|
);
|
2017-01-14 23:31:20 +00:00
|
|
|
}
|
2017-01-15 00:03:46 +00:00
|
|
|
},
|
2020-06-09 21:44:04 +00:00
|
|
|
hir::ExprKind::MethodCall(_, span, ref or_args, _) => check_general_case(
|
2018-11-27 20:14:15 +00:00
|
|
|
cx,
|
|
|
|
name,
|
|
|
|
method_span,
|
|
|
|
span,
|
|
|
|
&args[0],
|
|
|
|
&args[1],
|
|
|
|
!or_args.is_empty(),
|
|
|
|
expr.span,
|
|
|
|
),
|
2017-01-15 00:03:46 +00:00
|
|
|
_ => {},
|
2016-01-16 17:47:45 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-05-28 19:00:45 +00:00
|
|
|
/// Checks for the `EXPECT_FUN_CALL` lint.
|
2019-01-13 15:19:02 +00:00
|
|
|
#[allow(clippy::too_many_lines)]
|
2019-12-27 07:12:26 +00:00
|
|
|
fn lint_expect_fun_call(
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &LateContext<'_>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &hir::Expr<'_>,
|
|
|
|
method_span: Span,
|
|
|
|
name: &str,
|
|
|
|
args: &[hir::Expr<'_>],
|
|
|
|
) {
|
2019-01-26 09:55:54 +00:00
|
|
|
// Strip `&`, `as_ref()` and `as_str()` off `arg` until we're left with either a `String` or
|
|
|
|
// `&str`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn get_arg_root<'a>(cx: &LateContext<'_>, arg: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> {
|
2019-01-26 09:55:54 +00:00
|
|
|
let mut arg_root = arg;
|
|
|
|
loop {
|
2019-09-27 15:16:06 +00:00
|
|
|
arg_root = match &arg_root.kind {
|
2019-11-27 22:30:10 +00:00
|
|
|
hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => expr,
|
2020-06-09 21:44:04 +00:00
|
|
|
hir::ExprKind::MethodCall(method_name, _, call_args, _) => {
|
2019-01-26 09:55:54 +00:00
|
|
|
if call_args.len() == 1
|
2019-05-17 21:53:54 +00:00
|
|
|
&& (method_name.ident.name == sym!(as_str) || method_name.ident.name == sym!(as_ref))
|
2019-01-26 09:55:54 +00:00
|
|
|
&& {
|
2020-07-17 08:47:04 +00:00
|
|
|
let arg_type = cx.typeck_results().expr_ty(&call_args[0]);
|
2019-01-26 09:55:54 +00:00
|
|
|
let base_type = walk_ptrs_ty(arg_type);
|
2020-04-23 06:09:42 +00:00
|
|
|
base_type.kind == ty::Str || is_type_diagnostic_item(cx, base_type, sym!(string_type))
|
2019-01-26 09:55:54 +00:00
|
|
|
}
|
|
|
|
{
|
|
|
|
&call_args[0]
|
|
|
|
} else {
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
},
|
|
|
|
_ => break,
|
|
|
|
};
|
|
|
|
}
|
|
|
|
arg_root
|
|
|
|
}
|
|
|
|
|
|
|
|
// Only `&'static str` or `String` can be used directly in the `panic!`. Other types should be
|
|
|
|
// converted to string.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn requires_to_string(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool {
|
2020-07-17 08:47:04 +00:00
|
|
|
let arg_ty = cx.typeck_results().expr_ty(arg);
|
2020-04-23 06:09:42 +00:00
|
|
|
if is_type_diagnostic_item(cx, arg_ty, sym!(string_type)) {
|
2019-01-26 09:55:54 +00:00
|
|
|
return false;
|
|
|
|
}
|
2020-02-15 16:24:49 +00:00
|
|
|
if let ty::Ref(_, ty, ..) = arg_ty.kind {
|
|
|
|
if ty.kind == ty::Str && can_be_static_str(cx, arg) {
|
2019-01-26 09:55:54 +00:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
};
|
|
|
|
true
|
|
|
|
}
|
|
|
|
|
2020-02-15 16:24:49 +00:00
|
|
|
// Check if an expression could have type `&'static str`, knowing that it
|
|
|
|
// has type `&str` for some lifetime.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn can_be_static_str(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool {
|
2020-02-15 16:24:49 +00:00
|
|
|
match arg.kind {
|
|
|
|
hir::ExprKind::Lit(_) => true,
|
|
|
|
hir::ExprKind::Call(fun, _) => {
|
|
|
|
if let hir::ExprKind::Path(ref p) = fun.kind {
|
2020-06-26 02:55:23 +00:00
|
|
|
match cx.qpath_res(p, fun.hir_id) {
|
2020-06-09 14:36:01 +00:00
|
|
|
hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!(
|
2020-02-15 16:24:49 +00:00
|
|
|
cx.tcx.fn_sig(def_id).output().skip_binder().kind,
|
|
|
|
ty::Ref(ty::ReStatic, ..)
|
|
|
|
),
|
|
|
|
_ => false,
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
false
|
|
|
|
}
|
|
|
|
},
|
2020-07-17 08:47:04 +00:00
|
|
|
hir::ExprKind::MethodCall(..) => {
|
|
|
|
cx.typeck_results()
|
|
|
|
.type_dependent_def_id(arg.hir_id)
|
|
|
|
.map_or(false, |method_id| {
|
|
|
|
matches!(
|
|
|
|
cx.tcx.fn_sig(method_id).output().skip_binder().kind,
|
|
|
|
ty::Ref(ty::ReStatic, ..)
|
|
|
|
)
|
|
|
|
})
|
|
|
|
},
|
2020-07-14 12:59:59 +00:00
|
|
|
hir::ExprKind::Path(ref p) => matches!(
|
|
|
|
cx.qpath_res(p, arg.hir_id),
|
|
|
|
hir::def::Res::Def(hir::def::DefKind::Const | hir::def::DefKind::Static, _)
|
|
|
|
),
|
2020-02-15 16:24:49 +00:00
|
|
|
_ => false,
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-11-27 14:13:57 +00:00
|
|
|
fn generate_format_arg_snippet(
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &LateContext<'_>,
|
2019-12-27 07:12:26 +00:00
|
|
|
a: &hir::Expr<'_>,
|
2018-11-27 14:13:57 +00:00
|
|
|
applicability: &mut Applicability,
|
2019-01-19 12:13:06 +00:00
|
|
|
) -> Vec<String> {
|
2019-08-23 20:51:44 +00:00
|
|
|
if_chain! {
|
2019-11-27 22:30:10 +00:00
|
|
|
if let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref format_arg) = a.kind;
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Match(ref format_arg_expr, _, _) = format_arg.kind;
|
|
|
|
if let hir::ExprKind::Tup(ref format_arg_expr_tup) = format_arg_expr.kind;
|
2018-06-24 13:32:40 +00:00
|
|
|
|
2019-08-23 20:51:44 +00:00
|
|
|
then {
|
|
|
|
format_arg_expr_tup
|
|
|
|
.iter()
|
|
|
|
.map(|a| snippet_with_applicability(cx, a.span, "..", applicability).into_owned())
|
|
|
|
.collect()
|
|
|
|
} else {
|
|
|
|
unreachable!()
|
|
|
|
}
|
|
|
|
}
|
2018-06-06 15:53:11 +00:00
|
|
|
}
|
|
|
|
|
2019-12-27 07:12:26 +00:00
|
|
|
fn is_call(node: &hir::ExprKind<'_>) -> bool {
|
2019-01-24 04:58:53 +00:00
|
|
|
match node {
|
2019-11-27 22:30:10 +00:00
|
|
|
hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => {
|
2019-09-27 15:16:06 +00:00
|
|
|
is_call(&expr.kind)
|
2019-01-24 04:58:53 +00:00
|
|
|
},
|
|
|
|
hir::ExprKind::Call(..)
|
|
|
|
| hir::ExprKind::MethodCall(..)
|
|
|
|
// These variants are debatable or require further examination
|
|
|
|
| hir::ExprKind::Match(..)
|
|
|
|
| hir::ExprKind::Block{ .. } => true,
|
|
|
|
_ => false,
|
2018-08-02 06:56:53 +00:00
|
|
|
}
|
2019-01-24 04:58:53 +00:00
|
|
|
}
|
2018-08-02 06:56:53 +00:00
|
|
|
|
2019-09-27 15:16:06 +00:00
|
|
|
if args.len() != 2 || name != "expect" || !is_call(&args[1].kind) {
|
2019-01-24 04:58:53 +00:00
|
|
|
return;
|
|
|
|
}
|
2018-10-08 00:07:10 +00:00
|
|
|
|
2020-07-17 08:47:04 +00:00
|
|
|
let receiver_type = cx.typeck_results().expr_ty_adjusted(&args[0]);
|
2020-04-12 13:23:07 +00:00
|
|
|
let closure_args = if is_type_diagnostic_item(cx, receiver_type, sym!(option_type)) {
|
2019-01-24 04:58:53 +00:00
|
|
|
"||"
|
2020-04-12 13:23:07 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, receiver_type, sym!(result_type)) {
|
2019-01-24 04:58:53 +00:00
|
|
|
"|_|"
|
|
|
|
} else {
|
|
|
|
return;
|
|
|
|
};
|
|
|
|
|
2019-01-26 09:55:54 +00:00
|
|
|
let arg_root = get_arg_root(cx, &args[1]);
|
2018-10-08 00:07:10 +00:00
|
|
|
|
2019-01-24 04:58:53 +00:00
|
|
|
let span_replace_word = method_span.with_hi(expr.span.hi());
|
2018-10-08 00:07:10 +00:00
|
|
|
|
2019-01-24 04:58:53 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2018-05-28 19:00:45 +00:00
|
|
|
|
2019-01-24 04:58:53 +00:00
|
|
|
//Special handling for `format!` as arg_root
|
2019-11-25 12:56:24 +00:00
|
|
|
if_chain! {
|
|
|
|
if let hir::ExprKind::Block(block, None) = &arg_root.kind;
|
|
|
|
if block.stmts.len() == 1;
|
|
|
|
if let hir::StmtKind::Local(local) = &block.stmts[0].kind;
|
|
|
|
if let Some(arg_root) = &local.init;
|
|
|
|
if let hir::ExprKind::Call(ref inner_fun, ref inner_args) = arg_root.kind;
|
|
|
|
if is_expn_of(inner_fun.span, "format").is_some() && inner_args.len() == 1;
|
|
|
|
if let hir::ExprKind::Call(_, format_args) = &inner_args[0].kind;
|
|
|
|
then {
|
|
|
|
let fmt_spec = &format_args[0];
|
|
|
|
let fmt_args = &format_args[1];
|
2018-06-05 20:15:08 +00:00
|
|
|
|
2019-11-25 12:56:24 +00:00
|
|
|
let mut args = vec![snippet(cx, fmt_spec.span, "..").into_owned()];
|
2019-01-19 12:13:06 +00:00
|
|
|
|
2019-11-25 12:56:24 +00:00
|
|
|
args.extend(generate_format_arg_snippet(cx, fmt_args, &mut applicability));
|
2018-06-06 15:53:11 +00:00
|
|
|
|
2019-11-25 12:56:24 +00:00
|
|
|
let sugg = args.join(", ");
|
2018-06-06 15:53:11 +00:00
|
|
|
|
2019-11-25 12:56:24 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
EXPECT_FUN_CALL,
|
|
|
|
span_replace_word,
|
|
|
|
&format!("use of `{}` followed by a function call", name),
|
|
|
|
"try this",
|
|
|
|
format!("unwrap_or_else({} panic!({}))", closure_args, sugg),
|
|
|
|
applicability,
|
|
|
|
);
|
2018-06-05 20:15:08 +00:00
|
|
|
|
2019-11-25 12:56:24 +00:00
|
|
|
return;
|
2018-06-05 20:15:08 +00:00
|
|
|
}
|
2018-05-28 19:00:45 +00:00
|
|
|
}
|
|
|
|
|
2019-01-24 04:58:53 +00:00
|
|
|
let mut arg_root_snippet: Cow<'_, _> = snippet_with_applicability(cx, arg_root.span, "..", &mut applicability);
|
2019-01-26 09:55:54 +00:00
|
|
|
if requires_to_string(cx, arg_root) {
|
2019-01-24 04:58:53 +00:00
|
|
|
arg_root_snippet.to_mut().push_str(".to_string()");
|
2018-05-28 19:00:45 +00:00
|
|
|
}
|
2019-01-24 04:58:53 +00:00
|
|
|
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
EXPECT_FUN_CALL,
|
|
|
|
span_replace_word,
|
|
|
|
&format!("use of `{}` followed by a function call", name),
|
|
|
|
"try this",
|
|
|
|
format!("unwrap_or_else({} {{ panic!({}) }})", closure_args, arg_root_snippet),
|
|
|
|
applicability,
|
|
|
|
);
|
2018-05-28 19:00:45 +00:00
|
|
|
}
|
|
|
|
|
2016-02-02 21:35:01 +00:00
|
|
|
/// Checks for the `CLONE_ON_COPY` lint.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_clone_on_copy(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'_>) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let ty = cx.typeck_results().expr_ty(expr);
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Ref(_, inner, _) = arg_ty.kind {
|
|
|
|
if let ty::Ref(_, innermost, _) = inner.kind {
|
2017-08-09 07:30:56 +00:00
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
CLONE_DOUBLE_REF,
|
|
|
|
expr.span,
|
|
|
|
"using `clone` on a double-reference; \
|
2020-05-17 15:36:26 +00:00
|
|
|
this will copy the reference instead of cloning the inner type",
|
2020-04-17 06:08:00 +00:00
|
|
|
|diag| {
|
2018-11-27 20:14:15 +00:00
|
|
|
if let Some(snip) = sugg::Sugg::hir_opt(cx, arg) {
|
|
|
|
let mut ty = innermost;
|
|
|
|
let mut n = 0;
|
2019-09-26 09:03:36 +00:00
|
|
|
while let ty::Ref(_, inner, _) = ty.kind {
|
2018-11-27 20:14:15 +00:00
|
|
|
ty = inner;
|
|
|
|
n += 1;
|
|
|
|
}
|
|
|
|
let refs: String = iter::repeat('&').take(n + 1).collect();
|
|
|
|
let derefs: String = iter::repeat('*').take(n).collect();
|
2020-04-29 19:40:57 +00:00
|
|
|
let explicit = format!("<{}{}>::clone({})", refs, ty, snip);
|
2020-04-17 06:08:00 +00:00
|
|
|
diag.span_suggestion(
|
2018-11-27 20:14:15 +00:00
|
|
|
expr.span,
|
|
|
|
"try dereferencing it",
|
|
|
|
format!("{}({}{}).clone()", refs, derefs, snip.deref()),
|
|
|
|
Applicability::MaybeIncorrect,
|
|
|
|
);
|
2020-04-17 06:08:00 +00:00
|
|
|
diag.span_suggestion(
|
2018-11-27 20:14:15 +00:00
|
|
|
expr.span,
|
2020-04-29 19:40:57 +00:00
|
|
|
"or try being explicit if you are sure, that you want to clone a reference",
|
2018-11-27 20:14:15 +00:00
|
|
|
explicit,
|
|
|
|
Applicability::MaybeIncorrect,
|
|
|
|
);
|
2017-11-30 09:54:55 +00:00
|
|
|
}
|
2017-08-09 07:30:56 +00:00
|
|
|
},
|
|
|
|
);
|
2016-08-08 14:43:45 +00:00
|
|
|
return; // don't report clone_on_copy
|
2016-02-02 21:35:01 +00:00
|
|
|
}
|
|
|
|
}
|
2016-08-08 14:43:45 +00:00
|
|
|
|
2017-06-11 02:34:47 +00:00
|
|
|
if is_copy(cx, ty) {
|
2017-11-30 09:54:55 +00:00
|
|
|
let snip;
|
|
|
|
if let Some(snippet) = sugg::Sugg::hir_opt(cx, arg) {
|
2019-08-19 06:17:53 +00:00
|
|
|
let parent = cx.tcx.hir().get_parent_node(expr.hir_id);
|
|
|
|
match &cx.tcx.hir().get(parent) {
|
2019-09-27 15:16:06 +00:00
|
|
|
hir::Node::Expr(parent) => match parent.kind {
|
2019-08-19 06:17:53 +00:00
|
|
|
// &*x is a nop, &x.clone() is not
|
2020-04-09 13:50:09 +00:00
|
|
|
hir::ExprKind::AddrOf(..) => return,
|
2019-08-19 06:17:53 +00:00
|
|
|
// (*x).func() is useless, x.clone().func() can work in case func borrows mutably
|
2020-07-17 08:47:04 +00:00
|
|
|
hir::ExprKind::MethodCall(_, _, parent_args, _) if expr.hir_id == parent_args[0].hir_id => {
|
|
|
|
return;
|
|
|
|
},
|
2020-04-09 13:50:09 +00:00
|
|
|
|
2019-08-19 06:17:53 +00:00
|
|
|
_ => {},
|
|
|
|
},
|
|
|
|
hir::Node::Stmt(stmt) => {
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::StmtKind::Local(ref loc) = stmt.kind {
|
|
|
|
if let hir::PatKind::Ref(..) = loc.pat.kind {
|
2019-08-19 06:17:53 +00:00
|
|
|
// let ref y = *x borrows x, let ref y = x.clone() does not
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
},
|
|
|
|
_ => {},
|
|
|
|
}
|
|
|
|
|
2018-10-19 18:51:25 +00:00
|
|
|
// x.clone() might have dereferenced x, possibly through Deref impls
|
2020-07-17 08:47:04 +00:00
|
|
|
if cx.typeck_results().expr_ty(arg) == ty {
|
2018-12-08 11:09:32 +00:00
|
|
|
snip = Some(("try removing the `clone` call", format!("{}", snippet)));
|
|
|
|
} else {
|
2018-12-09 11:03:10 +00:00
|
|
|
let deref_count = cx
|
2020-07-17 08:47:04 +00:00
|
|
|
.typeck_results()
|
2018-12-09 11:03:10 +00:00
|
|
|
.expr_adjustments(arg)
|
|
|
|
.iter()
|
2020-07-14 12:59:59 +00:00
|
|
|
.filter(|adj| matches!(adj.kind, ty::adjustment::Adjust::Deref(_)))
|
2018-10-19 18:51:25 +00:00
|
|
|
.count();
|
|
|
|
let derefs: String = iter::repeat('*').take(deref_count).collect();
|
|
|
|
snip = Some(("try dereferencing it", format!("{}{}", derefs, snippet)));
|
2017-11-30 09:54:55 +00:00
|
|
|
}
|
|
|
|
} else {
|
|
|
|
snip = None;
|
|
|
|
}
|
2020-04-17 06:08:00 +00:00
|
|
|
span_lint_and_then(cx, CLONE_ON_COPY, expr.span, "using `clone` on a `Copy` type", |diag| {
|
2017-11-30 09:54:55 +00:00
|
|
|
if let Some((text, snip)) = snip {
|
2020-07-14 12:59:59 +00:00
|
|
|
diag.span_suggestion(expr.span, text, snip, Applicability::MachineApplicable);
|
2017-08-09 07:30:56 +00:00
|
|
|
}
|
|
|
|
});
|
2016-08-08 14:43:45 +00:00
|
|
|
}
|
2016-02-02 21:35:01 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_clone_on_ref_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let obj_ty = walk_ptrs_ty(cx.typeck_results().expr_ty(arg));
|
2017-09-10 01:51:54 +00:00
|
|
|
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Adt(_, subst) = obj_ty.kind {
|
2020-04-10 21:18:03 +00:00
|
|
|
let caller_type = if is_type_diagnostic_item(cx, obj_ty, sym::Rc) {
|
2018-01-15 03:58:09 +00:00
|
|
|
"Rc"
|
2020-04-10 21:18:03 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, obj_ty, sym::Arc) {
|
2018-01-15 03:58:09 +00:00
|
|
|
"Arc"
|
2019-05-17 21:53:54 +00:00
|
|
|
} else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) {
|
2018-01-15 03:58:09 +00:00
|
|
|
"Weak"
|
|
|
|
} else {
|
|
|
|
return;
|
|
|
|
};
|
2017-09-10 01:51:54 +00:00
|
|
|
|
2020-08-25 20:20:35 +00:00
|
|
|
let snippet = snippet_with_macro_callsite(cx, arg.span, "_");
|
2020-08-24 12:01:27 +00:00
|
|
|
|
2018-01-15 03:58:09 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
CLONE_ON_REF_PTR,
|
|
|
|
expr.span,
|
2020-01-06 06:30:43 +00:00
|
|
|
"using `.clone()` on a ref-counted pointer",
|
2018-01-15 03:58:09 +00:00
|
|
|
"try this",
|
2020-08-24 12:01:27 +00:00
|
|
|
format!("{}::<{}>::clone(&{})", caller_type, subst.type_at(0), snippet),
|
2018-11-27 14:13:57 +00:00
|
|
|
Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak
|
2018-01-15 03:58:09 +00:00
|
|
|
);
|
|
|
|
}
|
2017-09-10 01:51:54 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_string_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
|
2016-11-19 15:21:40 +00:00
|
|
|
let arg = &args[1];
|
2019-05-17 21:53:54 +00:00
|
|
|
if let Some(arglists) = method_chain_args(arg, &["chars"]) {
|
2016-11-19 15:21:40 +00:00
|
|
|
let target = &arglists[0][0];
|
2020-07-17 08:47:04 +00:00
|
|
|
let self_ty = walk_ptrs_ty(cx.typeck_results().expr_ty(target));
|
2019-09-26 09:03:36 +00:00
|
|
|
let ref_str = if self_ty.kind == ty::Str {
|
2016-11-19 15:36:23 +00:00
|
|
|
""
|
2020-04-23 06:09:42 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, self_ty, sym!(string_type)) {
|
2016-11-20 16:19:36 +00:00
|
|
|
"&"
|
2016-11-19 15:36:23 +00:00
|
|
|
} else {
|
|
|
|
return;
|
|
|
|
};
|
|
|
|
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2017-08-09 07:30:56 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
STRING_EXTEND_CHARS,
|
|
|
|
expr.span,
|
|
|
|
"calling `.extend(_.chars())`",
|
|
|
|
"try this",
|
|
|
|
format!(
|
|
|
|
"{}.push_str({}{})",
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, args[0].span, "_", &mut applicability),
|
2017-08-09 07:30:56 +00:00
|
|
|
ref_str,
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, target.span, "_", &mut applicability)
|
2017-08-09 07:30:56 +00:00
|
|
|
),
|
2018-11-27 14:13:57 +00:00
|
|
|
applicability,
|
2017-08-09 07:30:56 +00:00
|
|
|
);
|
2016-11-19 15:21:40 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let obj_ty = walk_ptrs_ty(cx.typeck_results().expr_ty(&args[0]));
|
2020-04-23 06:09:42 +00:00
|
|
|
if is_type_diagnostic_item(cx, obj_ty, sym!(string_type)) {
|
2016-11-19 15:21:40 +00:00
|
|
|
lint_string_extend(cx, expr, args);
|
2016-10-16 19:13:09 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_cstring_as_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, source: &hir::Expr<'_>, unwrap: &hir::Expr<'_>) {
|
2017-10-23 19:18:02 +00:00
|
|
|
if_chain! {
|
2020-07-17 08:47:04 +00:00
|
|
|
let source_type = cx.typeck_results().expr_ty(source);
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Adt(def, substs) = source_type.kind;
|
2020-04-12 13:23:07 +00:00
|
|
|
if cx.tcx.is_diagnostic_item(sym!(result_type), def.did);
|
2019-08-21 05:35:04 +00:00
|
|
|
if match_type(cx, substs.type_at(0), &paths::CSTRING);
|
2017-10-23 19:18:02 +00:00
|
|
|
then {
|
2017-11-04 19:56:05 +00:00
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TEMPORARY_CSTRING_AS_PTR,
|
|
|
|
expr.span,
|
|
|
|
"you are getting the inner pointer of a temporary `CString`",
|
2020-04-17 06:08:00 +00:00
|
|
|
|diag| {
|
|
|
|
diag.note("that pointer will be invalid outside this expression");
|
|
|
|
diag.span_help(unwrap.span, "assign the `CString` to a variable to extend its lifetime");
|
2017-11-04 19:56:05 +00:00
|
|
|
});
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
|
|
|
}
|
2016-04-14 15:25:31 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_iter_cloned_collect<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) {
|
2019-08-23 20:51:44 +00:00
|
|
|
if_chain! {
|
2020-07-17 08:47:04 +00:00
|
|
|
if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym!(vec_type));
|
|
|
|
if let Some(slice) = derefs_to_slice(cx, &iter_args[0], cx.typeck_results().expr_ty(&iter_args[0]));
|
2019-08-23 20:51:44 +00:00
|
|
|
if let Some(to_replace) = expr.span.trim_start(slice.span.source_callsite());
|
|
|
|
|
|
|
|
then {
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
ITER_CLONED_COLLECT,
|
|
|
|
to_replace,
|
|
|
|
"called `iter().cloned().collect()` on a slice to create a `Vec`. Calling `to_vec()` is both faster and \
|
2020-05-17 15:36:26 +00:00
|
|
|
more readable",
|
2019-08-23 20:51:44 +00:00
|
|
|
"try",
|
|
|
|
".to_vec()".to_string(),
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
2019-02-18 05:30:50 +00:00
|
|
|
}
|
2017-02-12 09:03:09 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) {
|
2018-01-17 19:12:44 +00:00
|
|
|
fn check_fold_with_op(
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &LateContext<'_>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &hir::Expr<'_>,
|
|
|
|
fold_args: &[hir::Expr<'_>],
|
2019-08-28 08:41:32 +00:00
|
|
|
fold_span: Span,
|
2018-07-12 07:50:09 +00:00
|
|
|
op: hir::BinOpKind,
|
2018-01-17 20:21:29 +00:00
|
|
|
replacement_method_name: &str,
|
2018-11-27 20:14:15 +00:00
|
|
|
replacement_has_args: bool,
|
|
|
|
) {
|
2018-01-17 19:12:44 +00:00
|
|
|
if_chain! {
|
|
|
|
// Extract the body of the closure passed to fold
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Closure(_, _, body_id, _, _) = fold_args[2].kind;
|
2018-12-08 00:56:03 +00:00
|
|
|
let closure_body = cx.tcx.hir().body(body_id);
|
2018-01-17 19:12:44 +00:00
|
|
|
let closure_expr = remove_blocks(&closure_body.value);
|
2018-01-14 08:27:53 +00:00
|
|
|
|
2018-01-17 19:12:44 +00:00
|
|
|
// Check if the closure body is of the form `acc <op> some_expr(x)`
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Binary(ref bin_op, ref left_expr, ref right_expr) = closure_expr.kind;
|
2018-01-17 19:12:44 +00:00
|
|
|
if bin_op.node == op;
|
2018-01-14 08:27:53 +00:00
|
|
|
|
2018-01-17 19:12:44 +00:00
|
|
|
// Extract the names of the two arguments to the closure
|
2019-08-28 09:27:06 +00:00
|
|
|
if let Some(first_arg_ident) = get_arg_name(&closure_body.params[0].pat);
|
|
|
|
if let Some(second_arg_ident) = get_arg_name(&closure_body.params[1].pat);
|
2018-01-14 08:27:53 +00:00
|
|
|
|
2018-01-22 05:46:32 +00:00
|
|
|
if match_var(&*left_expr, first_arg_ident);
|
|
|
|
if replacement_has_args || match_var(&*right_expr, second_arg_ident);
|
2018-01-14 09:30:08 +00:00
|
|
|
|
2019-08-14 17:35:06 +00:00
|
|
|
then {
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2018-01-17 20:21:29 +00:00
|
|
|
let sugg = if replacement_has_args {
|
|
|
|
format!(
|
2019-08-14 17:35:06 +00:00
|
|
|
"{replacement}(|{s}| {r})",
|
2018-01-17 20:21:29 +00:00
|
|
|
replacement = replacement_method_name,
|
|
|
|
s = second_arg_ident,
|
2018-11-27 14:13:57 +00:00
|
|
|
r = snippet_with_applicability(cx, right_expr.span, "EXPR", &mut applicability),
|
2018-01-17 20:21:29 +00:00
|
|
|
)
|
|
|
|
} else {
|
|
|
|
format!(
|
2019-08-14 17:35:06 +00:00
|
|
|
"{replacement}()",
|
2018-01-17 20:21:29 +00:00
|
|
|
replacement = replacement_method_name,
|
|
|
|
)
|
|
|
|
};
|
|
|
|
|
2018-01-17 19:12:44 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
2018-01-17 20:21:29 +00:00
|
|
|
UNNECESSARY_FOLD,
|
2019-08-28 08:41:32 +00:00
|
|
|
fold_span.with_hi(expr.span.hi()),
|
2019-01-31 01:15:29 +00:00
|
|
|
// TODO #2371 don't suggest e.g., .any(|x| f(x)) if we can suggest .any(f)
|
2018-01-17 19:12:44 +00:00
|
|
|
"this `.fold` can be written more succinctly using another method",
|
|
|
|
"try",
|
2018-01-17 21:06:16 +00:00
|
|
|
sugg,
|
2018-11-27 14:13:57 +00:00
|
|
|
applicability,
|
2018-01-17 19:12:44 +00:00
|
|
|
);
|
|
|
|
}
|
2018-01-14 08:27:53 +00:00
|
|
|
}
|
|
|
|
}
|
2018-01-17 19:12:44 +00:00
|
|
|
|
2018-10-08 00:07:10 +00:00
|
|
|
// Check that this is a call to Iterator::fold rather than just some function called fold
|
2019-05-17 21:53:54 +00:00
|
|
|
if !match_trait_method(cx, expr, &paths::ITERATOR) {
|
2018-10-08 00:07:10 +00:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2018-11-27 20:14:15 +00:00
|
|
|
assert!(
|
|
|
|
fold_args.len() == 3,
|
|
|
|
"Expected fold_args to have three entries - the receiver, the initial value and the closure"
|
|
|
|
);
|
2018-10-08 00:07:10 +00:00
|
|
|
|
2018-01-17 19:12:44 +00:00
|
|
|
// Check if the first argument to .fold is a suitable literal
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Lit(ref lit) = fold_args[1].kind {
|
2019-06-20 11:44:00 +00:00
|
|
|
match lit.node {
|
2019-08-28 08:41:32 +00:00
|
|
|
ast::LitKind::Bool(false) => {
|
|
|
|
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Or, "any", true)
|
|
|
|
},
|
|
|
|
ast::LitKind::Bool(true) => {
|
|
|
|
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::And, "all", true)
|
|
|
|
},
|
|
|
|
ast::LitKind::Int(0, _) => {
|
|
|
|
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Add, "sum", false)
|
|
|
|
},
|
|
|
|
ast::LitKind::Int(1, _) => {
|
|
|
|
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Mul, "product", false)
|
|
|
|
},
|
2019-06-20 11:44:00 +00:00
|
|
|
_ => (),
|
|
|
|
}
|
|
|
|
}
|
2018-01-14 08:27:53 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_step_by<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, args: &'tcx [hir::Expr<'_>]) {
|
2019-12-18 16:59:43 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-07-17 08:47:04 +00:00
|
|
|
if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &args[1]) {
|
2019-12-18 16:59:43 +00:00
|
|
|
span_lint(
|
|
|
|
cx,
|
|
|
|
ITERATOR_STEP_BY_ZERO,
|
|
|
|
expr.span,
|
|
|
|
"Iterator::step_by(0) will panic at runtime",
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_iter_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) {
|
2020-06-09 14:36:01 +00:00
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
2020-07-17 08:47:04 +00:00
|
|
|
if derefs_to_slice(cx, caller_expr, cx.typeck_results().expr_ty(caller_expr)).is_some() {
|
2020-06-09 14:36:01 +00:00
|
|
|
// 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 })
|
2020-08-04 13:24:13 +00:00
|
|
|
= higher::range(index_expr);
|
2020-06-09 14:36:01 +00:00
|
|
|
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,
|
2020-08-11 10:42:50 +00:00
|
|
|
"using `.iter().next()` on a Slice without end index",
|
2020-06-09 14:36:01 +00:00
|
|
|
"try calling",
|
|
|
|
format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx),
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
2020-07-17 08:47:04 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(caller_expr), sym!(vec_type))
|
|
|
|
|| matches!(
|
|
|
|
&walk_ptrs_ty(cx.typeck_results().expr_ty(caller_expr)).kind,
|
|
|
|
ty::Array(_, _)
|
|
|
|
)
|
2020-06-09 14:36:01 +00:00
|
|
|
{
|
|
|
|
// caller is a Vec or an Array
|
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
ITER_NEXT_SLICE,
|
|
|
|
expr.span,
|
2020-08-11 10:42:50 +00:00
|
|
|
"using `.iter().next()` on an array",
|
2020-06-09 14:36:01 +00:00
|
|
|
"try calling",
|
|
|
|
format!(
|
|
|
|
"{}.get(0)",
|
|
|
|
snippet_with_applicability(cx, caller_expr.span, "..", &mut applicability)
|
|
|
|
),
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_iter_nth<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &hir::Expr<'_>,
|
2019-12-28 22:37:23 +00:00
|
|
|
nth_and_iter_args: &[&'tcx [hir::Expr<'tcx>]],
|
2019-12-27 07:12:26 +00:00
|
|
|
is_mut: bool,
|
|
|
|
) {
|
2019-12-28 22:37:23 +00:00
|
|
|
let iter_args = nth_and_iter_args[1];
|
2016-12-20 17:21:30 +00:00
|
|
|
let mut_str = if is_mut { "_mut" } else { "" };
|
2020-07-17 08:47:04 +00:00
|
|
|
let caller_type = if derefs_to_slice(cx, &iter_args[0], cx.typeck_results().expr_ty(&iter_args[0])).is_some() {
|
2016-06-29 20:35:58 +00:00
|
|
|
"slice"
|
2020-07-17 08:47:04 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym!(vec_type)) {
|
2016-06-29 20:35:58 +00:00
|
|
|
"Vec"
|
2020-07-17 08:47:04 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym!(vecdeque_type)) {
|
2016-06-29 20:35:58 +00:00
|
|
|
"VecDeque"
|
2016-12-20 17:21:30 +00:00
|
|
|
} else {
|
2019-12-28 22:37:23 +00:00
|
|
|
let nth_args = nth_and_iter_args[0];
|
|
|
|
lint_iter_nth_zero(cx, expr, &nth_args);
|
2016-06-16 21:46:29 +00:00
|
|
|
return; // caller is not a type that we want to lint
|
2016-06-29 20:35:58 +00:00
|
|
|
};
|
|
|
|
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2017-08-09 07:30:56 +00:00
|
|
|
cx,
|
|
|
|
ITER_NTH,
|
|
|
|
expr.span,
|
2020-01-24 08:04:37 +00:00
|
|
|
&format!("called `.iter{0}().nth()` on a {1}", mut_str, caller_type),
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2020-01-25 22:01:16 +00:00
|
|
|
&format!("calling `.get{}()` is both faster and more readable", mut_str),
|
2017-08-09 07:30:56 +00:00
|
|
|
);
|
2016-06-16 08:36:11 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_iter_nth_zero<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_args: &'tcx [hir::Expr<'_>]) {
|
2019-12-28 22:37:23 +00:00
|
|
|
if_chain! {
|
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR);
|
2020-07-17 08:47:04 +00:00
|
|
|
if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &nth_args[1]);
|
2019-12-28 22:37:23 +00:00
|
|
|
then {
|
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
ITER_NTH_ZERO,
|
|
|
|
expr.span,
|
2020-07-26 19:07:07 +00:00
|
|
|
"called `.nth(0)` on a `std::iter::Iterator`, when `.next()` is equivalent",
|
|
|
|
"try calling `.next()` instead of `.nth(0)`",
|
2019-12-28 22:37:23 +00:00
|
|
|
format!("{}.next()", snippet_with_applicability(cx, nth_args[0].span, "..", &mut applicability)),
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_get_unwrap<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args: &'tcx [hir::Expr<'_>], is_mut: bool) {
|
2019-10-02 15:19:30 +00:00
|
|
|
// Note: we don't want to lint `get_mut().unwrap` for `HashMap` or `BTreeMap`,
|
2016-11-02 00:48:32 +00:00
|
|
|
// because they do not implement `IndexMut`
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2020-07-17 08:47:04 +00:00
|
|
|
let expr_ty = cx.typeck_results().expr_ty(&get_args[0]);
|
2018-09-13 08:36:13 +00:00
|
|
|
let get_args_str = if get_args.len() > 1 {
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, get_args[1].span, "_", &mut applicability)
|
2018-09-13 08:36:13 +00:00
|
|
|
} else {
|
|
|
|
return; // not linting on a .get().unwrap() chain or variant
|
|
|
|
};
|
2019-01-06 09:46:03 +00:00
|
|
|
let mut needs_ref;
|
2016-11-02 00:33:43 +00:00
|
|
|
let caller_type = if derefs_to_slice(cx, &get_args[0], expr_ty).is_some() {
|
2018-09-13 08:36:13 +00:00
|
|
|
needs_ref = get_args_str.parse::<usize>().is_ok();
|
2016-11-01 06:30:13 +00:00
|
|
|
"slice"
|
2020-04-13 06:57:34 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, expr_ty, sym!(vec_type)) {
|
2018-09-13 08:36:13 +00:00
|
|
|
needs_ref = get_args_str.parse::<usize>().is_ok();
|
2016-11-01 06:30:13 +00:00
|
|
|
"Vec"
|
2020-04-23 06:09:42 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, expr_ty, sym!(vecdeque_type)) {
|
2018-09-13 08:36:13 +00:00
|
|
|
needs_ref = get_args_str.parse::<usize>().is_ok();
|
2016-11-01 06:30:13 +00:00
|
|
|
"VecDeque"
|
2020-04-23 06:09:42 +00:00
|
|
|
} else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym!(hashmap_type)) {
|
2018-09-13 08:36:13 +00:00
|
|
|
needs_ref = true;
|
2016-11-01 06:30:13 +00:00
|
|
|
"HashMap"
|
2019-05-17 21:53:54 +00:00
|
|
|
} else if !is_mut && match_type(cx, expr_ty, &paths::BTREEMAP) {
|
2018-09-13 08:36:13 +00:00
|
|
|
needs_ref = true;
|
2016-11-01 06:30:13 +00:00
|
|
|
"BTreeMap"
|
|
|
|
} else {
|
|
|
|
return; // caller is not a type that we want to lint
|
|
|
|
};
|
|
|
|
|
2019-01-06 09:46:03 +00:00
|
|
|
let mut span = expr.span;
|
|
|
|
|
2019-04-04 09:15:30 +00:00
|
|
|
// Handle the case where the result is immediately dereferenced
|
2019-01-06 09:46:03 +00:00
|
|
|
// by not requiring ref and pulling the dereference into the
|
|
|
|
// suggestion.
|
2019-01-07 04:22:39 +00:00
|
|
|
if_chain! {
|
|
|
|
if needs_ref;
|
|
|
|
if let Some(parent) = get_parent_expr(cx, expr);
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Unary(hir::UnOp::UnDeref, _) = parent.kind;
|
2019-01-07 04:22:39 +00:00
|
|
|
then {
|
|
|
|
needs_ref = false;
|
|
|
|
span = parent.span;
|
2019-01-06 09:46:03 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-11-02 18:48:16 +00:00
|
|
|
let mut_str = if is_mut { "_mut" } else { "" };
|
2018-11-27 20:14:15 +00:00
|
|
|
let borrow_str = if !needs_ref {
|
|
|
|
""
|
|
|
|
} else if is_mut {
|
|
|
|
"&mut "
|
|
|
|
} else {
|
|
|
|
"&"
|
|
|
|
};
|
2019-01-06 09:46:03 +00:00
|
|
|
|
2017-08-09 07:30:56 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
GET_UNWRAP,
|
2019-01-06 09:46:03 +00:00
|
|
|
span,
|
2017-08-09 07:30:56 +00:00
|
|
|
&format!(
|
|
|
|
"called `.get{0}().unwrap()` on a {1}. Using `[]` is more clear and more concise",
|
2018-11-27 20:14:15 +00:00
|
|
|
mut_str, caller_type
|
2017-08-09 07:30:56 +00:00
|
|
|
),
|
|
|
|
"try this",
|
|
|
|
format!(
|
|
|
|
"{}{}[{}]",
|
|
|
|
borrow_str,
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, get_args[0].span, "_", &mut applicability),
|
2018-09-13 08:36:13 +00:00
|
|
|
get_args_str
|
2017-08-09 07:30:56 +00:00
|
|
|
),
|
2018-11-27 14:13:57 +00:00
|
|
|
applicability,
|
2017-08-09 07:30:56 +00:00
|
|
|
);
|
2016-11-01 06:30:13 +00:00
|
|
|
}
|
|
|
|
|
2020-08-11 13:43:21 +00:00
|
|
|
fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) {
|
2016-10-14 11:35:25 +00:00
|
|
|
// lint if caller of skip is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-08-11 13:43:21 +00:00
|
|
|
if let [caller, n] = skip_args {
|
|
|
|
let hint = format!(".nth({})", snippet(cx, n.span, ".."));
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
ITER_SKIP_NEXT,
|
|
|
|
expr.span.trim_start(caller.span).unwrap(),
|
|
|
|
"called `skip(x).next()` on an iterator",
|
|
|
|
"use `nth` instead",
|
|
|
|
hint,
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
|
|
|
}
|
2016-10-14 11:35:25 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn derefs_to_slice<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'tcx>,
|
2019-02-18 06:32:53 +00:00
|
|
|
ty: Ty<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
) -> Option<&'tcx hir::Expr<'tcx>> {
|
2020-06-25 20:41:36 +00:00
|
|
|
fn may_slice<'a>(cx: &LateContext<'a>, ty: Ty<'a>) -> bool {
|
2019-09-26 09:03:36 +00:00
|
|
|
match ty.kind {
|
2018-08-22 21:34:52 +00:00
|
|
|
ty::Slice(_) => true,
|
|
|
|
ty::Adt(def, _) if def.is_box() => may_slice(cx, ty.boxed_ty()),
|
2020-04-13 06:57:34 +00:00
|
|
|
ty::Adt(..) => is_type_diagnostic_item(cx, ty, sym!(vec_type)),
|
2020-07-14 12:59:59 +00:00
|
|
|
ty::Array(_, size) => size
|
|
|
|
.try_eval_usize(cx.tcx, cx.param_env)
|
|
|
|
.map_or(false, |size| size < 32),
|
2018-08-22 21:34:52 +00:00
|
|
|
ty::Ref(_, inner, _) => may_slice(cx, inner),
|
2016-01-30 12:48:39 +00:00
|
|
|
_ => false,
|
2016-01-26 22:51:06 +00:00
|
|
|
}
|
|
|
|
}
|
2016-07-05 21:26:47 +00:00
|
|
|
|
2020-06-09 21:44:04 +00:00
|
|
|
if let hir::ExprKind::MethodCall(ref path, _, ref args, _) = expr.kind {
|
2020-07-17 08:47:04 +00:00
|
|
|
if path.ident.name == sym!(iter) && may_slice(cx, cx.typeck_results().expr_ty(&args[0])) {
|
2019-02-18 05:30:50 +00:00
|
|
|
Some(&args[0])
|
2016-01-27 13:51:30 +00:00
|
|
|
} else {
|
|
|
|
None
|
|
|
|
}
|
|
|
|
} else {
|
2019-09-26 09:03:36 +00:00
|
|
|
match ty.kind {
|
2019-02-18 05:30:50 +00:00
|
|
|
ty::Slice(_) => Some(expr),
|
|
|
|
ty::Adt(def, _) if def.is_box() && may_slice(cx, ty.boxed_ty()) => Some(expr),
|
2018-11-27 20:14:15 +00:00
|
|
|
ty::Ref(_, inner, _) => {
|
|
|
|
if may_slice(cx, inner) {
|
2019-02-18 05:30:50 +00:00
|
|
|
Some(expr)
|
2018-11-27 20:14:15 +00:00
|
|
|
} else {
|
|
|
|
None
|
|
|
|
}
|
2016-12-20 17:21:30 +00:00
|
|
|
},
|
2016-01-30 12:48:39 +00:00
|
|
|
_ => None,
|
2016-01-27 13:51:30 +00:00
|
|
|
}
|
2016-01-25 13:02:47 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-12-27 09:22:53 +00:00
|
|
|
/// lint use of `unwrap()` for `Option`s and `Result`s
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_unwrap(cx: &LateContext<'_>, expr: &hir::Expr<'_>, unwrap_args: &[hir::Expr<'_>]) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let obj_ty = walk_ptrs_ty(cx.typeck_results().expr_ty(&unwrap_args[0]));
|
2015-12-27 09:22:53 +00:00
|
|
|
|
2020-04-12 13:23:07 +00:00
|
|
|
let mess = if is_type_diagnostic_item(cx, obj_ty, sym!(option_type)) {
|
2020-05-17 15:36:26 +00:00
|
|
|
Some((UNWRAP_USED, "an Option", "None"))
|
2020-04-12 13:23:07 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, obj_ty, sym!(result_type)) {
|
2020-05-17 15:36:26 +00:00
|
|
|
Some((UNWRAP_USED, "a Result", "Err"))
|
2016-01-04 04:26:12 +00:00
|
|
|
} else {
|
2016-01-03 13:36:24 +00:00
|
|
|
None
|
|
|
|
};
|
|
|
|
|
|
|
|
if let Some((lint, kind, none_value)) = mess {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2017-08-09 07:30:56 +00:00
|
|
|
cx,
|
|
|
|
lint,
|
|
|
|
expr.span,
|
2020-01-24 08:04:37 +00:00
|
|
|
&format!("used `unwrap()` on `{}` value", kind,),
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2017-08-09 07:30:56 +00:00
|
|
|
&format!(
|
2020-01-25 22:01:16 +00:00
|
|
|
"if you don't want to handle the `{}` case gracefully, consider \
|
2020-05-17 15:36:26 +00:00
|
|
|
using `expect()` to provide a better panic message",
|
2020-01-24 08:04:37 +00:00
|
|
|
none_value,
|
2017-08-09 07:30:56 +00:00
|
|
|
),
|
|
|
|
);
|
2015-12-27 09:22:53 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-10-15 19:33:07 +00:00
|
|
|
/// lint use of `expect()` for `Option`s and `Result`s
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_expect(cx: &LateContext<'_>, expr: &hir::Expr<'_>, expect_args: &[hir::Expr<'_>]) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let obj_ty = walk_ptrs_ty(cx.typeck_results().expr_ty(&expect_args[0]));
|
2019-10-15 19:33:07 +00:00
|
|
|
|
2020-04-12 13:23:07 +00:00
|
|
|
let mess = if is_type_diagnostic_item(cx, obj_ty, sym!(option_type)) {
|
2020-05-17 15:36:26 +00:00
|
|
|
Some((EXPECT_USED, "an Option", "None"))
|
2020-04-12 13:23:07 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, obj_ty, sym!(result_type)) {
|
2020-05-17 15:36:26 +00:00
|
|
|
Some((EXPECT_USED, "a Result", "Err"))
|
2019-10-15 19:33:07 +00:00
|
|
|
} else {
|
|
|
|
None
|
|
|
|
};
|
|
|
|
|
|
|
|
if let Some((lint, kind, none_value)) = mess {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-10-15 19:33:07 +00:00
|
|
|
cx,
|
|
|
|
lint,
|
|
|
|
expr.span,
|
2020-01-24 08:04:37 +00:00
|
|
|
&format!("used `expect()` on `{}` value", kind,),
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2020-01-25 22:01:16 +00:00
|
|
|
&format!("if this value is an `{}`, it will panic", none_value,),
|
2019-10-15 19:33:07 +00:00
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-12-27 09:22:53 +00:00
|
|
|
/// lint use of `ok().expect()` for `Result`s
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_ok_expect(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ok_args: &[hir::Expr<'_>]) {
|
2019-08-23 20:51:44 +00:00
|
|
|
if_chain! {
|
|
|
|
// lint if the caller of `ok()` is a `Result`
|
2020-07-17 08:47:04 +00:00
|
|
|
if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&ok_args[0]), sym!(result_type));
|
|
|
|
let result_type = cx.typeck_results().expr_ty(&ok_args[0]);
|
2019-08-23 20:51:44 +00:00
|
|
|
if let Some(error_type) = get_error_type(cx, result_type);
|
|
|
|
if has_debug_impl(error_type, cx);
|
|
|
|
|
|
|
|
then {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-08-23 20:51:44 +00:00
|
|
|
cx,
|
|
|
|
OK_EXPECT,
|
|
|
|
expr.span,
|
2020-01-24 08:04:37 +00:00
|
|
|
"called `ok().expect()` on a `Result` value",
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2020-01-25 22:01:16 +00:00
|
|
|
"you can call `expect()` directly on the `Result`",
|
2019-08-23 20:51:44 +00:00
|
|
|
);
|
2015-12-27 09:22:53 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-04-15 16:37:37 +00:00
|
|
|
/// lint use of `map().flatten()` for `Iterators` and 'Options'
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_map_flatten<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_args: &'tcx [hir::Expr<'_>]) {
|
2018-09-21 07:26:38 +00:00
|
|
|
// lint if caller of `.map().flatten()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-08-11 13:43:21 +00:00
|
|
|
let map_closure_ty = cx.typeck_results().expr_ty(&map_args[1]);
|
|
|
|
let is_map_to_option = match map_closure_ty.kind {
|
|
|
|
ty::Closure(_, _) | ty::FnDef(_, _) | ty::FnPtr(_) => {
|
|
|
|
let map_closure_sig = match map_closure_ty.kind {
|
|
|
|
ty::Closure(_, substs) => substs.as_closure().sig(),
|
|
|
|
_ => map_closure_ty.fn_sig(cx.tcx),
|
|
|
|
};
|
|
|
|
let map_closure_return_ty = cx.tcx.erase_late_bound_regions(&map_closure_sig.output());
|
|
|
|
is_type_diagnostic_item(cx, map_closure_return_ty, sym!(option_type))
|
|
|
|
},
|
|
|
|
_ => false,
|
|
|
|
};
|
|
|
|
|
|
|
|
let method_to_use = if is_map_to_option {
|
|
|
|
// `(...).map(...)` has type `impl Iterator<Item=Option<...>>
|
|
|
|
"filter_map"
|
|
|
|
} else {
|
|
|
|
// `(...).map(...)` has type `impl Iterator<Item=impl Iterator<...>>
|
|
|
|
"flat_map"
|
|
|
|
};
|
2018-09-21 07:26:38 +00:00
|
|
|
let func_snippet = snippet(cx, map_args[1].span, "..");
|
2020-08-11 13:43:21 +00:00
|
|
|
let hint = format!(".{0}({1})", method_to_use, func_snippet);
|
2020-01-24 08:04:37 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
MAP_FLATTEN,
|
2020-08-11 13:43:21 +00:00
|
|
|
expr.span.with_lo(map_args[0].span.hi()),
|
|
|
|
"called `map(..).flatten()` on an `Iterator`",
|
|
|
|
&format!("try using `{}` instead", method_to_use),
|
2020-01-24 08:04:37 +00:00
|
|
|
hint,
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
2018-09-21 07:26:38 +00:00
|
|
|
}
|
2020-04-15 16:37:37 +00:00
|
|
|
|
|
|
|
// lint if caller of `.map().flatten()` is an Option
|
2020-07-17 08:47:04 +00:00
|
|
|
if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym!(option_type)) {
|
2020-04-15 16:37:37 +00:00
|
|
|
let func_snippet = snippet(cx, map_args[1].span, "..");
|
2020-08-11 13:43:21 +00:00
|
|
|
let hint = format!(".and_then({})", func_snippet);
|
2020-04-15 16:37:37 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
MAP_FLATTEN,
|
2020-08-11 13:43:21 +00:00
|
|
|
expr.span.with_lo(map_args[0].span.hi()),
|
|
|
|
"called `map(..).flatten()` on an `Option`",
|
2020-04-15 16:37:37 +00:00
|
|
|
"try using `and_then` instead",
|
|
|
|
hint,
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
|
|
|
}
|
2018-09-21 07:26:38 +00:00
|
|
|
}
|
|
|
|
|
2017-10-30 12:04:26 +00:00
|
|
|
/// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s
|
2020-08-16 18:50:30 +00:00
|
|
|
/// Return true if lint triggered
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_map_unwrap_or_else<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
map_args: &'tcx [hir::Expr<'_>],
|
|
|
|
unwrap_args: &'tcx [hir::Expr<'_>],
|
2020-08-16 18:47:50 +00:00
|
|
|
) -> bool {
|
2015-12-27 22:15:09 +00:00
|
|
|
// lint if the caller of `map()` is an `Option`
|
2020-07-17 08:47:04 +00:00
|
|
|
let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym!(option_type));
|
|
|
|
let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym!(result_type));
|
2019-06-02 06:47:06 +00:00
|
|
|
|
2017-10-30 12:04:26 +00:00
|
|
|
if is_option || is_result {
|
2019-06-02 06:47:06 +00:00
|
|
|
// Don't make a suggestion that may fail to compile due to mutably borrowing
|
2019-06-04 06:27:31 +00:00
|
|
|
// the same variable twice.
|
2019-06-02 06:47:06 +00:00
|
|
|
let map_mutated_vars = mutated_variables(&map_args[0], cx);
|
|
|
|
let unwrap_mutated_vars = mutated_variables(&unwrap_args[1], cx);
|
|
|
|
if let (Some(map_mutated_vars), Some(unwrap_mutated_vars)) = (map_mutated_vars, unwrap_mutated_vars) {
|
|
|
|
if map_mutated_vars.intersection(&unwrap_mutated_vars).next().is_some() {
|
2020-08-16 18:47:50 +00:00
|
|
|
return false;
|
2019-06-02 06:47:06 +00:00
|
|
|
}
|
|
|
|
} else {
|
2020-08-16 18:47:50 +00:00
|
|
|
return false;
|
2019-06-02 06:47:06 +00:00
|
|
|
}
|
|
|
|
|
2015-12-27 09:22:53 +00:00
|
|
|
// lint message
|
2017-10-30 12:04:26 +00:00
|
|
|
let msg = if is_option {
|
2020-01-06 06:30:43 +00:00
|
|
|
"called `map(f).unwrap_or_else(g)` on an `Option` value. This can be done more directly by calling \
|
2020-05-17 15:36:26 +00:00
|
|
|
`map_or_else(g, f)` instead"
|
2017-10-30 12:04:26 +00:00
|
|
|
} else {
|
2020-01-06 06:30:43 +00:00
|
|
|
"called `map(f).unwrap_or_else(g)` on a `Result` value. This can be done more directly by calling \
|
2020-05-17 15:36:26 +00:00
|
|
|
`.map_or_else(g, f)` instead"
|
2017-10-30 12:04:26 +00:00
|
|
|
};
|
2015-12-27 09:22:53 +00:00
|
|
|
// get snippets for args to map() and unwrap_or_else()
|
|
|
|
let map_snippet = snippet(cx, map_args[1].span, "..");
|
|
|
|
let unwrap_snippet = snippet(cx, unwrap_args[1].span, "..");
|
|
|
|
// lint, with note if neither arg is > 1 line and both map() and
|
|
|
|
// unwrap_or_else() have the same span
|
2016-01-04 04:26:12 +00:00
|
|
|
let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1;
|
2017-08-31 12:47:45 +00:00
|
|
|
let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt();
|
2015-12-27 09:22:53 +00:00
|
|
|
if same_span && !multiline {
|
2020-01-27 02:26:42 +00:00
|
|
|
span_lint_and_note(
|
2017-08-09 07:30:56 +00:00
|
|
|
cx,
|
2020-05-17 15:36:26 +00:00
|
|
|
MAP_UNWRAP_OR,
|
2017-08-09 07:30:56 +00:00
|
|
|
expr.span,
|
|
|
|
msg,
|
2020-04-18 10:29:36 +00:00
|
|
|
None,
|
2017-08-09 07:30:56 +00:00
|
|
|
&format!(
|
2019-11-26 14:14:28 +00:00
|
|
|
"replace `map({0}).unwrap_or_else({1})` with `map_or_else({1}, {0})`",
|
|
|
|
map_snippet, unwrap_snippet,
|
2017-08-09 07:30:56 +00:00
|
|
|
),
|
|
|
|
);
|
2020-08-16 18:50:30 +00:00
|
|
|
return true;
|
2016-01-04 04:26:12 +00:00
|
|
|
} else if same_span && multiline {
|
2020-05-17 15:36:26 +00:00
|
|
|
span_lint(cx, MAP_UNWRAP_OR, expr.span, msg);
|
2020-08-16 18:50:30 +00:00
|
|
|
return true;
|
2020-08-16 18:47:50 +00:00
|
|
|
}
|
2015-12-27 09:22:53 +00:00
|
|
|
}
|
2020-08-16 18:50:30 +00:00
|
|
|
|
|
|
|
false
|
2015-12-27 09:22:53 +00:00
|
|
|
}
|
|
|
|
|
2020-04-04 06:59:52 +00:00
|
|
|
/// lint use of `_.map_or(None, _)` for `Option`s and `Result`s
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_or_args: &'tcx [hir::Expr<'_>]) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_or_args[0]), sym!(option_type));
|
|
|
|
let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_or_args[0]), sym!(result_type));
|
2020-04-04 06:59:52 +00:00
|
|
|
|
|
|
|
// There are two variants of this `map_or` lint:
|
|
|
|
// (1) using `map_or` as an adapter from `Result<T,E>` to `Option<T>`
|
|
|
|
// (2) using `map_or` as a combinator instead of `and_then`
|
|
|
|
//
|
|
|
|
// (For this lint) we don't care if any other type calls `map_or`
|
|
|
|
if !is_option && !is_result {
|
|
|
|
return;
|
|
|
|
}
|
2017-10-10 13:35:24 +00:00
|
|
|
|
2020-04-04 22:02:38 +00:00
|
|
|
let (lint_name, msg, instead, hint) = {
|
2020-04-04 21:24:22 +00:00
|
|
|
let default_arg_is_none = if let hir::ExprKind::Path(ref qpath) = map_or_args[1].kind {
|
2019-05-17 21:53:54 +00:00
|
|
|
match_qpath(qpath, &paths::OPTION_NONE)
|
2020-04-04 21:24:22 +00:00
|
|
|
} else {
|
|
|
|
return;
|
|
|
|
};
|
|
|
|
|
2020-04-04 20:53:08 +00:00
|
|
|
if !default_arg_is_none {
|
|
|
|
// nothing to lint!
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2020-04-04 21:24:22 +00:00
|
|
|
let f_arg_is_some = if let hir::ExprKind::Path(ref qpath) = map_or_args[2].kind {
|
|
|
|
match_qpath(qpath, &paths::OPTION_SOME)
|
2017-10-10 10:06:01 +00:00
|
|
|
} else {
|
2017-10-10 13:35:24 +00:00
|
|
|
false
|
|
|
|
};
|
|
|
|
|
2020-04-04 20:53:08 +00:00
|
|
|
if is_option {
|
|
|
|
let self_snippet = snippet(cx, map_or_args[0].span, "..");
|
|
|
|
let func_snippet = snippet(cx, map_or_args[2].span, "..");
|
2020-01-06 06:30:43 +00:00
|
|
|
let msg = "called `map_or(None, f)` on an `Option` value. This can be done more directly by calling \
|
2017-10-10 13:35:24 +00:00
|
|
|
`and_then(f)` instead";
|
2020-04-04 20:53:08 +00:00
|
|
|
(
|
2020-01-24 08:04:37 +00:00
|
|
|
OPTION_MAP_OR_NONE,
|
|
|
|
msg,
|
|
|
|
"try using `and_then` instead",
|
2020-04-04 20:53:08 +00:00
|
|
|
format!("{0}.and_then({1})", self_snippet, func_snippet),
|
|
|
|
)
|
|
|
|
} else if f_arg_is_some {
|
|
|
|
let msg = "called `map_or(None, Some)` on a `Result` value. This can be done more directly by calling \
|
|
|
|
`ok()` instead";
|
|
|
|
let self_snippet = snippet(cx, map_or_args[0].span, "..");
|
|
|
|
(
|
|
|
|
RESULT_MAP_OR_INTO_OPTION,
|
|
|
|
msg,
|
|
|
|
"try using `ok` instead",
|
|
|
|
format!("{0}.ok()", self_snippet),
|
|
|
|
)
|
|
|
|
} else {
|
|
|
|
// nothing to lint!
|
|
|
|
return;
|
2017-10-10 10:06:01 +00:00
|
|
|
}
|
2020-04-04 06:59:52 +00:00
|
|
|
};
|
|
|
|
|
2020-04-04 20:53:08 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
2020-04-04 22:02:38 +00:00
|
|
|
lint_name,
|
2020-04-04 20:53:08 +00:00
|
|
|
expr.span,
|
|
|
|
msg,
|
|
|
|
instead,
|
|
|
|
hint,
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
2017-10-10 10:06:01 +00:00
|
|
|
}
|
|
|
|
|
2016-06-21 12:39:56 +00:00
|
|
|
/// lint use of `filter().next()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) {
|
2015-12-29 00:56:58 +00:00
|
|
|
// lint if caller of `.filter().next()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2016-12-20 17:21:30 +00:00
|
|
|
let msg = "called `filter(p).next()` on an `Iterator`. This is more succinctly expressed by calling \
|
|
|
|
`.find(p)` instead.";
|
2015-12-29 00:56:58 +00:00
|
|
|
let filter_snippet = snippet(cx, filter_args[1].span, "..");
|
2016-01-04 04:26:12 +00:00
|
|
|
if filter_snippet.lines().count() <= 1 {
|
|
|
|
// add note if not multi-line
|
2020-01-27 02:26:42 +00:00
|
|
|
span_lint_and_note(
|
2017-08-09 07:30:56 +00:00
|
|
|
cx,
|
|
|
|
FILTER_NEXT,
|
|
|
|
expr.span,
|
|
|
|
msg,
|
2020-04-18 10:29:36 +00:00
|
|
|
None,
|
2017-08-09 07:30:56 +00:00
|
|
|
&format!("replace `filter({0}).next()` with `find({0})`", filter_snippet),
|
|
|
|
);
|
2016-01-04 04:26:12 +00:00
|
|
|
} else {
|
2015-12-29 00:56:58 +00:00
|
|
|
span_lint(cx, FILTER_NEXT, expr.span, msg);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-01-20 01:54:54 +00:00
|
|
|
/// lint use of `skip_while().next()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_skip_while_next<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2020-01-20 01:54:54 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_skip_while_args: &'tcx [hir::Expr<'_>],
|
|
|
|
) {
|
|
|
|
// lint if caller of `.skip_while().next()` is an Iterator
|
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2020-01-20 12:07:31 +00:00
|
|
|
cx,
|
|
|
|
SKIP_WHILE_NEXT,
|
|
|
|
expr.span,
|
|
|
|
"called `skip_while(p).next()` on an `Iterator`",
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2020-01-20 12:07:31 +00:00
|
|
|
"this is more succinctly expressed by calling `.find(!p)` instead",
|
|
|
|
);
|
2020-01-20 01:54:54 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-06-21 12:39:56 +00:00
|
|
|
/// lint use of `filter().map()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_map<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_filter_args: &'tcx [hir::Expr<'_>],
|
|
|
|
_map_args: &'tcx [hir::Expr<'_>],
|
2017-11-04 19:55:56 +00:00
|
|
|
) {
|
2016-06-08 17:54:22 +00:00
|
|
|
// lint if caller of `.filter().map()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-01-24 08:04:37 +00:00
|
|
|
let msg = "called `filter(p).map(q)` on an `Iterator`";
|
2020-01-25 22:01:16 +00:00
|
|
|
let hint = "this is more succinctly expressed by calling `.filter_map(..)` instead";
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
|
2016-06-22 08:44:46 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-04-27 22:06:35 +00:00
|
|
|
/// lint use of `filter_map().next()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_map_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) {
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2019-04-27 22:06:35 +00:00
|
|
|
let msg = "called `filter_map(p).next()` on an `Iterator`. This is more succinctly expressed by calling \
|
|
|
|
`.find_map(p)` instead.";
|
|
|
|
let filter_snippet = snippet(cx, filter_args[1].span, "..");
|
|
|
|
if filter_snippet.lines().count() <= 1 {
|
2020-01-27 02:26:42 +00:00
|
|
|
span_lint_and_note(
|
2019-04-27 22:06:35 +00:00
|
|
|
cx,
|
|
|
|
FILTER_MAP_NEXT,
|
|
|
|
expr.span,
|
|
|
|
msg,
|
2020-04-18 10:29:36 +00:00
|
|
|
None,
|
2019-04-27 22:06:35 +00:00
|
|
|
&format!("replace `filter_map({0}).next()` with `find_map({0})`", filter_snippet),
|
|
|
|
);
|
|
|
|
} else {
|
|
|
|
span_lint(cx, FILTER_MAP_NEXT, expr.span, msg);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/// lint use of `find().map()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_find_map<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_find_args: &'tcx [hir::Expr<'_>],
|
|
|
|
map_args: &'tcx [hir::Expr<'_>],
|
2019-04-27 22:06:35 +00:00
|
|
|
) {
|
|
|
|
// lint if caller of `.filter().map()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, &map_args[0], &paths::ITERATOR) {
|
2020-01-24 08:04:37 +00:00
|
|
|
let msg = "called `find(p).map(q)` on an `Iterator`";
|
2020-01-25 22:01:16 +00:00
|
|
|
let hint = "this is more succinctly expressed by calling `.find_map(..)` instead";
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FIND_MAP, expr.span, msg, None, hint);
|
2019-04-27 22:06:35 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-11-15 17:06:57 +00:00
|
|
|
/// lint use of `filter_map().map()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_map_map<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_filter_args: &'tcx [hir::Expr<'_>],
|
|
|
|
_map_args: &'tcx [hir::Expr<'_>],
|
2017-11-04 19:55:56 +00:00
|
|
|
) {
|
2016-06-22 08:44:46 +00:00
|
|
|
// lint if caller of `.filter().map()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-01-24 08:04:37 +00:00
|
|
|
let msg = "called `filter_map(p).map(q)` on an `Iterator`";
|
2020-01-25 22:01:16 +00:00
|
|
|
let hint = "this is more succinctly expressed by only calling `.filter_map(..)` instead";
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
|
2016-06-08 17:54:22 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-06-21 12:39:56 +00:00
|
|
|
/// lint use of `filter().flat_map()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_flat_map<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_filter_args: &'tcx [hir::Expr<'_>],
|
|
|
|
_map_args: &'tcx [hir::Expr<'_>],
|
2017-11-04 19:55:56 +00:00
|
|
|
) {
|
2016-06-08 17:54:22 +00:00
|
|
|
// lint if caller of `.filter().flat_map()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-01-24 08:04:37 +00:00
|
|
|
let msg = "called `filter(p).flat_map(q)` on an `Iterator`";
|
2020-01-25 22:01:16 +00:00
|
|
|
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
|
2020-01-29 16:23:47 +00:00
|
|
|
and filtering by returning `iter::empty()`";
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
|
2016-06-08 17:54:22 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-06-21 12:39:56 +00:00
|
|
|
/// lint use of `filter_map().flat_map()` for `Iterators`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filter_map_flat_map<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
_filter_args: &'tcx [hir::Expr<'_>],
|
|
|
|
_map_args: &'tcx [hir::Expr<'_>],
|
2017-11-04 19:55:56 +00:00
|
|
|
) {
|
2016-06-08 17:54:22 +00:00
|
|
|
// lint if caller of `.filter_map().flat_map()` is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2020-01-24 08:04:37 +00:00
|
|
|
let msg = "called `filter_map(p).flat_map(q)` on an `Iterator`";
|
2020-01-25 22:01:16 +00:00
|
|
|
let hint = "this is more succinctly expressed by calling `.flat_map(..)` \
|
2020-01-29 16:23:47 +00:00
|
|
|
and filtering by returning `iter::empty()`";
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint);
|
2016-06-08 17:54:22 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-06-24 13:08:26 +00:00
|
|
|
/// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_flat_map_identity<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
|
|
|
flat_map_args: &'tcx [hir::Expr<'_>],
|
2019-08-28 08:41:32 +00:00
|
|
|
flat_map_span: Span,
|
2019-08-11 18:34:25 +00:00
|
|
|
) {
|
2019-08-12 18:35:50 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ITERATOR) {
|
2019-09-27 15:16:06 +00:00
|
|
|
let arg_node = &flat_map_args[1].kind;
|
2019-06-24 13:08:26 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
let apply_lint = |message: &str| {
|
2019-08-28 08:41:32 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
FLAT_MAP_IDENTITY,
|
|
|
|
flat_map_span.with_hi(expr.span.hi()),
|
|
|
|
message,
|
|
|
|
"try",
|
|
|
|
"flatten()".to_string(),
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
2019-08-12 18:35:50 +00:00
|
|
|
};
|
2019-06-24 13:08:26 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
if_chain! {
|
|
|
|
if let hir::ExprKind::Closure(_, _, body_id, _, _) = arg_node;
|
|
|
|
let body = cx.tcx.hir().body(*body_id);
|
2019-08-11 17:51:43 +00:00
|
|
|
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::PatKind::Binding(_, _, binding_ident, _) = body.params[0].pat.kind;
|
|
|
|
if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = body.value.kind;
|
2019-08-11 17:51:43 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
if path.segments.len() == 1;
|
|
|
|
if path.segments[0].ident.as_str() == binding_ident.as_str();
|
2019-08-11 17:51:43 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
then {
|
2019-08-12 19:42:57 +00:00
|
|
|
apply_lint("called `flat_map(|x| x)` on an `Iterator`");
|
2019-08-11 19:02:01 +00:00
|
|
|
}
|
2019-08-12 18:35:50 +00:00
|
|
|
}
|
2019-08-11 17:51:43 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
if_chain! {
|
|
|
|
if let hir::ExprKind::Path(ref qpath) = arg_node;
|
2019-08-11 17:51:43 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY);
|
2019-08-11 19:02:01 +00:00
|
|
|
|
2019-08-12 18:35:50 +00:00
|
|
|
then {
|
2019-08-12 19:42:57 +00:00
|
|
|
apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`");
|
2019-08-11 19:02:01 +00:00
|
|
|
}
|
2019-08-11 17:51:43 +00:00
|
|
|
}
|
|
|
|
}
|
2019-06-24 13:08:26 +00:00
|
|
|
}
|
|
|
|
|
2015-12-30 08:38:03 +00:00
|
|
|
/// lint searching an Iterator followed by `is_some()`
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_search_is_some<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'tcx hir::Expr<'_>,
|
2016-12-21 11:14:54 +00:00
|
|
|
search_method: &str,
|
2019-12-27 07:12:26 +00:00
|
|
|
search_args: &'tcx [hir::Expr<'_>],
|
|
|
|
is_some_args: &'tcx [hir::Expr<'_>],
|
2019-08-29 08:06:56 +00:00
|
|
|
method_span: Span,
|
2016-12-21 11:14:54 +00:00
|
|
|
) {
|
2015-12-30 08:38:03 +00:00
|
|
|
// lint if caller of search is an Iterator
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, &is_some_args[0], &paths::ITERATOR) {
|
2017-08-09 07:30:56 +00:00
|
|
|
let msg = format!(
|
|
|
|
"called `is_some()` after searching an `Iterator` with {}. This is more succinctly \
|
2017-09-05 09:33:04 +00:00
|
|
|
expressed by calling `any()`.",
|
2017-08-09 07:30:56 +00:00
|
|
|
search_method
|
|
|
|
);
|
2015-12-30 08:38:03 +00:00
|
|
|
let search_snippet = snippet(cx, search_args[1].span, "..");
|
2016-01-04 04:26:12 +00:00
|
|
|
if search_snippet.lines().count() <= 1 {
|
2019-04-30 17:08:16 +00:00
|
|
|
// suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()`
|
2019-08-26 10:50:15 +00:00
|
|
|
// suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()`
|
2019-04-30 20:03:51 +00:00
|
|
|
let any_search_snippet = if_chain! {
|
|
|
|
if search_method == "find";
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].kind;
|
2019-04-30 20:03:51 +00:00
|
|
|
let closure_body = cx.tcx.hir().body(body_id);
|
2019-08-28 09:27:06 +00:00
|
|
|
if let Some(closure_arg) = closure_body.params.get(0);
|
2019-04-30 20:03:51 +00:00
|
|
|
then {
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::PatKind::Ref(..) = closure_arg.pat.kind {
|
2019-08-29 08:06:56 +00:00
|
|
|
Some(search_snippet.replacen('&', "", 1))
|
|
|
|
} else if let Some(name) = get_arg_name(&closure_arg.pat) {
|
|
|
|
Some(search_snippet.replace(&format!("*{}", name), &name.as_str()))
|
|
|
|
} else {
|
|
|
|
None
|
2019-08-26 10:50:15 +00:00
|
|
|
}
|
2019-04-30 20:03:51 +00:00
|
|
|
} else {
|
|
|
|
None
|
|
|
|
}
|
|
|
|
};
|
2016-01-04 04:26:12 +00:00
|
|
|
// add note if not multi-line
|
2019-08-26 10:50:15 +00:00
|
|
|
span_lint_and_sugg(
|
2017-08-09 07:30:56 +00:00
|
|
|
cx,
|
|
|
|
SEARCH_IS_SOME,
|
2019-08-29 08:06:56 +00:00
|
|
|
method_span.with_hi(expr.span.hi()),
|
2017-08-09 07:30:56 +00:00
|
|
|
&msg,
|
2019-08-26 10:50:15 +00:00
|
|
|
"try this",
|
|
|
|
format!(
|
|
|
|
"any({})",
|
2019-04-30 17:08:16 +00:00
|
|
|
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
|
2018-11-27 20:14:15 +00:00
|
|
|
),
|
2019-08-26 10:50:15 +00:00
|
|
|
Applicability::MachineApplicable,
|
2017-08-09 07:30:56 +00:00
|
|
|
);
|
2016-01-04 04:26:12 +00:00
|
|
|
} else {
|
2015-12-30 08:38:03 +00:00
|
|
|
span_lint(cx, SEARCH_IS_SOME, expr.span, &msg);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2017-09-16 05:50:07 +00:00
|
|
|
/// Used for `lint_binary_expr_with_method_call`.
|
|
|
|
#[derive(Copy, Clone)]
|
|
|
|
struct BinaryExprInfo<'a> {
|
2019-12-27 07:12:26 +00:00
|
|
|
expr: &'a hir::Expr<'a>,
|
|
|
|
chain: &'a hir::Expr<'a>,
|
|
|
|
other: &'a hir::Expr<'a>,
|
2017-09-16 05:50:07 +00:00
|
|
|
eq: bool,
|
|
|
|
}
|
|
|
|
|
|
|
|
/// Checks for the `CHARS_NEXT_CMP` and `CHARS_LAST_CMP` lints.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_binary_expr_with_method_call(cx: &LateContext<'_>, info: &mut BinaryExprInfo<'_>) {
|
2017-09-16 05:50:07 +00:00
|
|
|
macro_rules! lint_with_both_lhs_and_rhs {
|
|
|
|
($func:ident, $cx:expr, $info:ident) => {
|
|
|
|
if !$func($cx, $info) {
|
|
|
|
::std::mem::swap(&mut $info.chain, &mut $info.other);
|
|
|
|
if $func($cx, $info) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
2018-11-27 20:14:15 +00:00
|
|
|
};
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
lint_with_both_lhs_and_rhs!(lint_chars_next_cmp, cx, info);
|
|
|
|
lint_with_both_lhs_and_rhs!(lint_chars_last_cmp, cx, info);
|
|
|
|
lint_with_both_lhs_and_rhs!(lint_chars_next_cmp_with_unwrap, cx, info);
|
|
|
|
lint_with_both_lhs_and_rhs!(lint_chars_last_cmp_with_unwrap, cx, info);
|
|
|
|
}
|
|
|
|
|
2019-05-27 03:32:04 +00:00
|
|
|
/// Wrapper fn for `CHARS_NEXT_CMP` and `CHARS_LAST_CMP` lints.
|
2018-07-23 11:01:12 +00:00
|
|
|
fn lint_chars_cmp(
|
2020-06-25 20:41:36 +00:00
|
|
|
cx: &LateContext<'_>,
|
2018-07-23 11:01:12 +00:00
|
|
|
info: &BinaryExprInfo<'_>,
|
2019-05-17 21:53:54 +00:00
|
|
|
chain_methods: &[&str],
|
2017-11-04 19:55:56 +00:00
|
|
|
lint: &'static Lint,
|
|
|
|
suggest: &str,
|
|
|
|
) -> bool {
|
2017-10-23 19:18:02 +00:00
|
|
|
if_chain! {
|
|
|
|
if let Some(args) = method_chain_args(info.chain, chain_methods);
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Call(ref fun, ref arg_char) = info.other.kind;
|
2017-10-23 19:18:02 +00:00
|
|
|
if arg_char.len() == 1;
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Path(ref qpath) = fun.kind;
|
2017-10-23 19:18:02 +00:00
|
|
|
if let Some(segment) = single_segment_path(qpath);
|
2019-05-17 21:53:54 +00:00
|
|
|
if segment.ident.name == sym!(Some);
|
2017-10-23 19:18:02 +00:00
|
|
|
then {
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2020-07-17 08:47:04 +00:00
|
|
|
let self_ty = walk_ptrs_ty(cx.typeck_results().expr_ty_adjusted(&args[0][0]));
|
2017-11-04 19:55:56 +00:00
|
|
|
|
2019-09-26 09:03:36 +00:00
|
|
|
if self_ty.kind != ty::Str {
|
2017-10-23 19:18:02 +00:00
|
|
|
return false;
|
|
|
|
}
|
2017-11-04 19:55:56 +00:00
|
|
|
|
2018-11-20 13:06:29 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
lint,
|
|
|
|
info.expr.span,
|
|
|
|
&format!("you should use the `{}` method", suggest),
|
|
|
|
"like this",
|
|
|
|
format!("{}{}.{}({})",
|
|
|
|
if info.eq { "" } else { "!" },
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, args[0][0].span, "_", &mut applicability),
|
2018-11-20 13:06:29 +00:00
|
|
|
suggest,
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, arg_char[0].span, "_", &mut applicability)),
|
|
|
|
applicability,
|
2018-11-20 13:06:29 +00:00
|
|
|
);
|
2017-11-04 19:55:56 +00:00
|
|
|
|
2017-10-23 19:18:02 +00:00
|
|
|
return true;
|
2016-01-20 01:23:39 +00:00
|
|
|
}
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
2016-01-20 01:23:39 +00:00
|
|
|
|
|
|
|
false
|
|
|
|
}
|
|
|
|
|
2017-09-16 05:50:07 +00:00
|
|
|
/// Checks for the `CHARS_NEXT_CMP` lint.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_chars_next_cmp<'tcx>(cx: &LateContext<'tcx>, info: &BinaryExprInfo<'_>) -> bool {
|
2019-05-17 21:53:54 +00:00
|
|
|
lint_chars_cmp(cx, info, &["chars", "next"], CHARS_NEXT_CMP, "starts_with")
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/// Checks for the `CHARS_LAST_CMP` lint.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_chars_last_cmp<'tcx>(cx: &LateContext<'tcx>, info: &BinaryExprInfo<'_>) -> bool {
|
2019-05-17 21:53:54 +00:00
|
|
|
if lint_chars_cmp(cx, info, &["chars", "last"], CHARS_LAST_CMP, "ends_with") {
|
2017-09-16 05:50:07 +00:00
|
|
|
true
|
|
|
|
} else {
|
2019-05-17 21:53:54 +00:00
|
|
|
lint_chars_cmp(cx, info, &["chars", "next_back"], CHARS_LAST_CMP, "ends_with")
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/// Wrapper fn for `CHARS_NEXT_CMP` and `CHARS_LAST_CMP` lints with `unwrap()`.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_chars_cmp_with_unwrap<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2018-07-23 11:01:12 +00:00
|
|
|
info: &BinaryExprInfo<'_>,
|
2019-05-17 21:53:54 +00:00
|
|
|
chain_methods: &[&str],
|
2017-11-04 19:55:56 +00:00
|
|
|
lint: &'static Lint,
|
|
|
|
suggest: &str,
|
|
|
|
) -> bool {
|
2017-10-23 19:18:02 +00:00
|
|
|
if_chain! {
|
|
|
|
if let Some(args) = method_chain_args(info.chain, chain_methods);
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Lit(ref lit) = info.other.kind;
|
2017-10-23 19:18:02 +00:00
|
|
|
if let ast::LitKind::Char(c) = lit.node;
|
|
|
|
then {
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2017-10-23 19:18:02 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
lint,
|
|
|
|
info.expr.span,
|
|
|
|
&format!("you should use the `{}` method", suggest),
|
|
|
|
"like this",
|
|
|
|
format!("{}{}.{}('{}')",
|
|
|
|
if info.eq { "" } else { "!" },
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, args[0][0].span, "_", &mut applicability),
|
2017-10-23 19:18:02 +00:00
|
|
|
suggest,
|
2018-11-20 13:06:29 +00:00
|
|
|
c),
|
2018-11-27 14:13:57 +00:00
|
|
|
applicability,
|
2017-10-23 19:18:02 +00:00
|
|
|
);
|
2017-11-04 19:55:56 +00:00
|
|
|
|
2019-08-23 20:52:04 +00:00
|
|
|
true
|
|
|
|
} else {
|
|
|
|
false
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
|
|
|
}
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/// Checks for the `CHARS_NEXT_CMP` lint with `unwrap()`.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_chars_next_cmp_with_unwrap<'tcx>(cx: &LateContext<'tcx>, info: &BinaryExprInfo<'_>) -> bool {
|
2019-05-17 22:58:25 +00:00
|
|
|
lint_chars_cmp_with_unwrap(cx, info, &["chars", "next", "unwrap"], CHARS_NEXT_CMP, "starts_with")
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/// Checks for the `CHARS_LAST_CMP` lint with `unwrap()`.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_chars_last_cmp_with_unwrap<'tcx>(cx: &LateContext<'tcx>, info: &BinaryExprInfo<'_>) -> bool {
|
2019-05-17 22:58:25 +00:00
|
|
|
if lint_chars_cmp_with_unwrap(cx, info, &["chars", "last", "unwrap"], CHARS_LAST_CMP, "ends_with") {
|
2017-09-16 05:50:07 +00:00
|
|
|
true
|
|
|
|
} else {
|
2019-05-17 22:58:25 +00:00
|
|
|
lint_chars_cmp_with_unwrap(cx, info, &["chars", "next_back", "unwrap"], CHARS_LAST_CMP, "ends_with")
|
2017-09-16 05:50:07 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-08-14 23:40:47 +00:00
|
|
|
fn get_hint_if_single_char_arg(
|
|
|
|
cx: &LateContext<'_>,
|
|
|
|
arg: &hir::Expr<'_>,
|
2020-08-14 10:52:19 +00:00
|
|
|
applicability: &mut Applicability,
|
|
|
|
) -> Option<String> {
|
2018-09-23 13:25:10 +00:00
|
|
|
if_chain! {
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Lit(lit) = &arg.kind;
|
2019-08-09 03:45:49 +00:00
|
|
|
if let ast::LitKind::Str(r, style) = lit.node;
|
2020-08-14 10:52:19 +00:00
|
|
|
let string = r.as_str();
|
|
|
|
if string.len() == 1;
|
2018-09-23 13:25:10 +00:00
|
|
|
then {
|
2020-08-14 10:52:19 +00:00
|
|
|
let snip = snippet_with_applicability(cx, arg.span, &string, applicability);
|
2019-08-09 03:45:49 +00:00
|
|
|
let ch = if let ast::StrStyle::Raw(nhash) = style {
|
|
|
|
let nhash = nhash as usize;
|
|
|
|
// for raw string: r##"a"##
|
|
|
|
&snip[(nhash + 2)..(snip.len() - 1 - nhash)]
|
|
|
|
} else {
|
|
|
|
// for regular string: "a"
|
|
|
|
&snip[1..(snip.len() - 1)]
|
|
|
|
};
|
|
|
|
let hint = format!("'{}'", if ch == "'" { "\\'" } else { ch });
|
2020-08-14 10:52:19 +00:00
|
|
|
Some(hint)
|
|
|
|
} else {
|
|
|
|
None
|
2016-02-15 03:40:43 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-08-14 10:52:19 +00:00
|
|
|
/// lint for length-1 `str`s for methods in `PATTERN_METHODS`
|
2020-08-14 23:40:47 +00:00
|
|
|
fn lint_single_char_pattern(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) {
|
2020-08-14 10:52:19 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
|
|
if let Some(hint) = get_hint_if_single_char_arg(cx, arg, &mut applicability) {
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
SINGLE_CHAR_PATTERN,
|
|
|
|
arg.span,
|
|
|
|
"single-character string constant used as pattern",
|
|
|
|
"try using a `char` instead",
|
|
|
|
hint,
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/// lint for length-1 `str`s as argument for `push_str`
|
2020-08-14 23:40:47 +00:00
|
|
|
fn lint_single_char_push_string(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
|
2020-08-14 10:52:19 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
|
|
|
if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[1], &mut applicability) {
|
|
|
|
let base_string_snippet = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
|
|
|
|
let sugg = format!("{}.push({})", base_string_snippet, extension_string);
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
SINGLE_CHAR_PUSH_STR,
|
|
|
|
expr.span,
|
|
|
|
"calling `push_str()` using a single-character string literal",
|
|
|
|
"consider using `push` with a character literal",
|
|
|
|
sugg,
|
|
|
|
applicability,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2017-10-20 15:39:20 +00:00
|
|
|
/// Checks for the `USELESS_ASREF` lint.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) {
|
2017-10-20 15:39:20 +00:00
|
|
|
// when we get here, we've already checked that the call name is "as_ref" or "as_mut"
|
|
|
|
// check if the call is to the actual `AsRef` or `AsMut` trait
|
2019-05-17 21:53:54 +00:00
|
|
|
if match_trait_method(cx, expr, &paths::ASREF_TRAIT) || match_trait_method(cx, expr, &paths::ASMUT_TRAIT) {
|
2017-10-20 15:39:20 +00:00
|
|
|
// check if the type after `as_ref` or `as_mut` is the same as before
|
|
|
|
let recvr = &as_ref_args[0];
|
2020-07-17 08:47:04 +00:00
|
|
|
let rcv_ty = cx.typeck_results().expr_ty(recvr);
|
|
|
|
let res_ty = cx.typeck_results().expr_ty(expr);
|
2017-10-20 15:39:20 +00:00
|
|
|
let (base_res_ty, res_depth) = walk_ptrs_ty_depth(res_ty);
|
|
|
|
let (base_rcv_ty, rcv_depth) = walk_ptrs_ty_depth(rcv_ty);
|
|
|
|
if base_rcv_ty == base_res_ty && rcv_depth >= res_depth {
|
2018-12-17 20:33:50 +00:00
|
|
|
// allow the `as_ref` or `as_mut` if it is followed by another method call
|
|
|
|
if_chain! {
|
|
|
|
if let Some(parent) = get_parent_expr(cx, expr);
|
2020-06-09 21:44:04 +00:00
|
|
|
if let hir::ExprKind::MethodCall(_, ref span, _, _) = parent.kind;
|
2018-12-17 20:33:50 +00:00
|
|
|
if span != &expr.span;
|
|
|
|
then {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-11-27 14:13:57 +00:00
|
|
|
let mut applicability = Applicability::MachineApplicable;
|
2017-10-20 15:39:20 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
USELESS_ASREF,
|
|
|
|
expr.span,
|
|
|
|
&format!("this call to `{}` does nothing", call_name),
|
|
|
|
"try this",
|
2018-11-27 14:13:57 +00:00
|
|
|
snippet_with_applicability(cx, recvr.span, "_", &mut applicability).to_string(),
|
|
|
|
applicability,
|
2017-10-20 15:39:20 +00:00
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(&'static str, &'static str)> {
|
2019-08-23 20:52:04 +00:00
|
|
|
has_iter_method(cx, self_ref_ty).map(|ty_name| {
|
2019-09-26 09:03:36 +00:00
|
|
|
let mutbl = match self_ref_ty.kind {
|
2019-02-20 08:10:25 +00:00
|
|
|
ty::Ref(_, _, mutbl) => mutbl,
|
|
|
|
_ => unreachable!(),
|
|
|
|
};
|
|
|
|
let method_name = match mutbl {
|
2019-12-21 18:38:45 +00:00
|
|
|
hir::Mutability::Not => "iter",
|
|
|
|
hir::Mutability::Mut => "iter_mut",
|
2019-02-20 08:10:25 +00:00
|
|
|
};
|
2019-11-07 12:44:57 +00:00
|
|
|
(ty_name, method_name)
|
2019-08-23 20:52:04 +00:00
|
|
|
})
|
2018-10-20 20:03:38 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_into_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_>, method_span: Span) {
|
2019-05-17 21:53:54 +00:00
|
|
|
if !match_trait_method(cx, expr, &paths::INTO_ITERATOR) {
|
2018-10-20 20:03:38 +00:00
|
|
|
return;
|
|
|
|
}
|
2019-11-07 12:44:57 +00:00
|
|
|
if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ref_ty) {
|
2018-10-20 20:03:38 +00:00
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
2019-11-07 12:44:57 +00:00
|
|
|
INTO_ITER_ON_REF,
|
2018-10-20 20:03:38 +00:00
|
|
|
method_span,
|
|
|
|
&format!(
|
2020-01-06 06:30:43 +00:00
|
|
|
"this `.into_iter()` call is equivalent to `.{}()` and will not move the `{}`",
|
2018-11-27 20:14:15 +00:00
|
|
|
method_name, kind,
|
2018-10-20 20:03:38 +00:00
|
|
|
),
|
|
|
|
"call directly",
|
2018-11-27 14:13:57 +00:00
|
|
|
method_name.to_string(),
|
|
|
|
Applicability::MachineApplicable,
|
2018-10-20 20:03:38 +00:00
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-08-31 18:25:28 +00:00
|
|
|
/// lint for `MaybeUninit::uninit().assume_init()` (we already have the latter)
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_maybe_uninit(cx: &LateContext<'_>, expr: &hir::Expr<'_>, outer: &hir::Expr<'_>) {
|
2019-08-31 18:25:28 +00:00
|
|
|
if_chain! {
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Call(ref callee, ref args) = expr.kind;
|
2019-08-31 18:25:28 +00:00
|
|
|
if args.is_empty();
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Path(ref path) = callee.kind;
|
2019-08-31 18:25:28 +00:00
|
|
|
if match_qpath(path, &paths::MEM_MAYBEUNINIT_UNINIT);
|
2020-07-17 08:47:04 +00:00
|
|
|
if !is_maybe_uninit_ty_valid(cx, cx.typeck_results().expr_ty_adjusted(outer));
|
2019-08-31 18:25:28 +00:00
|
|
|
then {
|
|
|
|
span_lint(
|
|
|
|
cx,
|
|
|
|
UNINIT_ASSUMED_INIT,
|
|
|
|
outer.span,
|
|
|
|
"this call for this type may be undefined behavior"
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn is_maybe_uninit_ty_valid(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
|
2019-09-26 09:03:36 +00:00
|
|
|
match ty.kind {
|
2019-08-31 18:25:28 +00:00
|
|
|
ty::Array(ref component, _) => is_maybe_uninit_ty_valid(cx, component),
|
|
|
|
ty::Tuple(ref types) => types.types().all(|ty| is_maybe_uninit_ty_valid(cx, ty)),
|
2020-04-12 13:23:54 +00:00
|
|
|
ty::Adt(ref adt, _) => match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT),
|
2019-08-31 18:25:28 +00:00
|
|
|
_ => false,
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_suspicious_map(cx: &LateContext<'_>, expr: &hir::Expr<'_>) {
|
2020-01-27 01:56:22 +00:00
|
|
|
span_lint_and_help(
|
2019-08-15 20:56:16 +00:00
|
|
|
cx,
|
|
|
|
SUSPICIOUS_MAP,
|
|
|
|
expr.span,
|
2019-08-18 14:49:11 +00:00
|
|
|
"this call to `map()` won't have an effect on the call to `count()`",
|
2020-04-18 10:28:29 +00:00
|
|
|
None,
|
2020-01-20 06:05:40 +00:00
|
|
|
"make sure you did not confuse `map` with `filter` or `for_each`",
|
2019-08-15 20:56:16 +00:00
|
|
|
);
|
|
|
|
}
|
|
|
|
|
2019-12-23 04:48:15 +00:00
|
|
|
/// lint use of `_.as_ref().map(Deref::deref)` for `Option`s
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_option_as_ref_deref<'tcx>(
|
|
|
|
cx: &LateContext<'tcx>,
|
2019-12-23 04:48:15 +00:00
|
|
|
expr: &hir::Expr<'_>,
|
|
|
|
as_ref_args: &[hir::Expr<'_>],
|
|
|
|
map_args: &[hir::Expr<'_>],
|
|
|
|
is_mut: bool,
|
|
|
|
) {
|
2020-04-06 13:48:38 +00:00
|
|
|
let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not);
|
|
|
|
|
2020-07-17 08:47:04 +00:00
|
|
|
let option_ty = cx.typeck_results().expr_ty(&as_ref_args[0]);
|
2020-04-23 06:09:42 +00:00
|
|
|
if !is_type_diagnostic_item(cx, option_ty, sym!(option_type)) {
|
2019-12-23 04:48:15 +00:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
let deref_aliases: [&[&str]; 9] = [
|
|
|
|
&paths::DEREF_TRAIT_METHOD,
|
|
|
|
&paths::DEREF_MUT_TRAIT_METHOD,
|
|
|
|
&paths::CSTRING_AS_C_STR,
|
|
|
|
&paths::OS_STRING_AS_OS_STR,
|
|
|
|
&paths::PATH_BUF_AS_PATH,
|
|
|
|
&paths::STRING_AS_STR,
|
|
|
|
&paths::STRING_AS_MUT_STR,
|
|
|
|
&paths::VEC_AS_SLICE,
|
|
|
|
&paths::VEC_AS_MUT_SLICE,
|
|
|
|
];
|
|
|
|
|
|
|
|
let is_deref = match map_args[1].kind {
|
2020-08-21 05:23:04 +00:00
|
|
|
hir::ExprKind::Path(ref expr_qpath) => cx
|
|
|
|
.qpath_res(expr_qpath, map_args[1].hir_id)
|
|
|
|
.opt_def_id()
|
|
|
|
.map_or(false, |fun_def_id| {
|
|
|
|
deref_aliases.iter().any(|path| match_def_path(cx, fun_def_id, path))
|
|
|
|
}),
|
2019-12-23 04:48:15 +00:00
|
|
|
hir::ExprKind::Closure(_, _, body_id, _, _) => {
|
|
|
|
let closure_body = cx.tcx.hir().body(body_id);
|
|
|
|
let closure_expr = remove_blocks(&closure_body.value);
|
2020-04-06 13:48:38 +00:00
|
|
|
|
|
|
|
match &closure_expr.kind {
|
2020-06-09 21:44:04 +00:00
|
|
|
hir::ExprKind::MethodCall(_, _, args, _) => {
|
2020-04-06 13:48:38 +00:00
|
|
|
if_chain! {
|
|
|
|
if args.len() == 1;
|
|
|
|
if let hir::ExprKind::Path(qpath) = &args[0].kind;
|
2020-06-26 02:55:23 +00:00
|
|
|
if let hir::def::Res::Local(local_id) = cx.qpath_res(qpath, args[0].hir_id);
|
2020-04-06 13:48:38 +00:00
|
|
|
if closure_body.params[0].pat.hir_id == local_id;
|
2020-07-26 19:07:07 +00:00
|
|
|
let adj = cx
|
|
|
|
.typeck_results()
|
|
|
|
.expr_adjustments(&args[0])
|
|
|
|
.iter()
|
|
|
|
.map(|x| &x.kind)
|
|
|
|
.collect::<Box<[_]>>();
|
2020-04-06 13:48:38 +00:00
|
|
|
if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj;
|
|
|
|
then {
|
2020-07-17 08:47:04 +00:00
|
|
|
let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap();
|
2020-04-06 13:48:38 +00:00
|
|
|
deref_aliases.iter().any(|path| match_def_path(cx, method_did, path))
|
|
|
|
} else {
|
|
|
|
false
|
|
|
|
}
|
|
|
|
}
|
|
|
|
},
|
|
|
|
hir::ExprKind::AddrOf(hir::BorrowKind::Ref, m, ref inner) if same_mutability(m) => {
|
|
|
|
if_chain! {
|
|
|
|
if let hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner1) = inner.kind;
|
|
|
|
if let hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner2) = inner1.kind;
|
|
|
|
if let hir::ExprKind::Path(ref qpath) = inner2.kind;
|
2020-06-26 02:55:23 +00:00
|
|
|
if let hir::def::Res::Local(local_id) = cx.qpath_res(qpath, inner2.hir_id);
|
2020-04-06 13:48:38 +00:00
|
|
|
then {
|
|
|
|
closure_body.params[0].pat.hir_id == local_id
|
|
|
|
} else {
|
|
|
|
false
|
|
|
|
}
|
|
|
|
}
|
|
|
|
},
|
|
|
|
_ => false,
|
2019-12-23 04:48:15 +00:00
|
|
|
}
|
|
|
|
},
|
|
|
|
_ => false,
|
|
|
|
};
|
|
|
|
|
|
|
|
if is_deref {
|
|
|
|
let current_method = if is_mut {
|
2020-04-07 13:25:07 +00:00
|
|
|
format!(".as_mut().map({})", snippet(cx, map_args[1].span, ".."))
|
2019-12-23 04:48:15 +00:00
|
|
|
} else {
|
2020-04-07 13:25:07 +00:00
|
|
|
format!(".as_ref().map({})", snippet(cx, map_args[1].span, ".."))
|
2019-12-23 04:48:15 +00:00
|
|
|
};
|
|
|
|
let method_hint = if is_mut { "as_deref_mut" } else { "as_deref" };
|
|
|
|
let hint = format!("{}.{}()", snippet(cx, as_ref_args[0].span, ".."), method_hint);
|
|
|
|
let suggestion = format!("try using {} instead", method_hint);
|
|
|
|
|
|
|
|
let msg = format!(
|
2020-04-07 13:25:07 +00:00
|
|
|
"called `{0}` on an Option value. This can be done more directly \
|
|
|
|
by calling `{1}` instead",
|
2019-12-23 04:48:15 +00:00
|
|
|
current_method, hint
|
|
|
|
);
|
|
|
|
span_lint_and_sugg(
|
|
|
|
cx,
|
|
|
|
OPTION_AS_REF_DEREF,
|
|
|
|
expr.span,
|
|
|
|
&msg,
|
|
|
|
&suggestion,
|
|
|
|
hint,
|
|
|
|
Applicability::MachineApplicable,
|
|
|
|
);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-02-02 21:35:01 +00:00
|
|
|
/// Given a `Result<T, E>` type, return its error type (`E`).
|
2020-06-25 20:41:36 +00:00
|
|
|
fn get_error_type<'a>(cx: &LateContext<'_>, ty: Ty<'a>) -> Option<Ty<'a>> {
|
2019-09-26 09:03:36 +00:00
|
|
|
match ty.kind {
|
2020-04-12 13:23:07 +00:00
|
|
|
ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym!(result_type)) => substs.types().nth(1),
|
2019-08-23 20:52:04 +00:00
|
|
|
_ => None,
|
2015-11-19 13:39:27 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2016-04-14 16:13:15 +00:00
|
|
|
/// This checks whether a given type is known to implement Debug.
|
2020-06-25 20:41:36 +00:00
|
|
|
fn has_debug_impl<'tcx>(ty: Ty<'tcx>, cx: &LateContext<'tcx>) -> bool {
|
2019-09-04 14:19:59 +00:00
|
|
|
cx.tcx
|
|
|
|
.get_diagnostic_item(sym::debug_trait)
|
|
|
|
.map_or(false, |debug| implements_trait(cx, ty, debug, &[]))
|
2015-11-19 19:13:36 +00:00
|
|
|
}
|
2015-11-19 13:39:27 +00:00
|
|
|
|
2016-02-13 00:42:46 +00:00
|
|
|
enum Convention {
|
|
|
|
Eq(&'static str),
|
|
|
|
StartsWith(&'static str),
|
|
|
|
}
|
|
|
|
|
2018-05-30 16:24:44 +00:00
|
|
|
#[rustfmt::skip]
|
2018-10-01 11:47:06 +00:00
|
|
|
const CONVENTIONS: [(Convention, &[SelfKind]); 7] = [
|
2016-02-13 00:42:46 +00:00
|
|
|
(Convention::Eq("new"), &[SelfKind::No]),
|
|
|
|
(Convention::StartsWith("as_"), &[SelfKind::Ref, SelfKind::RefMut]),
|
|
|
|
(Convention::StartsWith("from_"), &[SelfKind::No]),
|
|
|
|
(Convention::StartsWith("into_"), &[SelfKind::Value]),
|
|
|
|
(Convention::StartsWith("is_"), &[SelfKind::Ref, SelfKind::No]),
|
2018-10-01 11:47:06 +00:00
|
|
|
(Convention::Eq("to_mut"), &[SelfKind::RefMut]),
|
2016-02-13 00:42:46 +00:00
|
|
|
(Convention::StartsWith("to_"), &[SelfKind::Ref]),
|
2016-01-30 12:39:16 +00:00
|
|
|
];
|
|
|
|
|
2020-04-08 10:57:58 +00:00
|
|
|
const FN_HEADER: hir::FnHeader = hir::FnHeader {
|
|
|
|
unsafety: hir::Unsafety::Normal,
|
|
|
|
constness: hir::Constness::NotConst,
|
|
|
|
asyncness: hir::IsAsync::NotAsync,
|
|
|
|
abi: rustc_target::spec::abi::Abi::Rust,
|
|
|
|
};
|
|
|
|
|
2020-07-29 23:41:12 +00:00
|
|
|
struct ShouldImplTraitCase {
|
|
|
|
trait_name: &'static str,
|
|
|
|
method_name: &'static str,
|
|
|
|
param_count: usize,
|
2020-08-09 13:35:41 +00:00
|
|
|
fn_header: hir::FnHeader,
|
2020-07-29 23:41:12 +00:00
|
|
|
// implicit self kind expected (none, self, &self, ...)
|
|
|
|
self_kind: SelfKind,
|
|
|
|
// checks against the output type
|
|
|
|
output_type: OutType,
|
|
|
|
// certain methods with explicit lifetimes can't implement the equivalent trait method
|
|
|
|
lint_explicit_lifetime: bool,
|
|
|
|
}
|
|
|
|
impl ShouldImplTraitCase {
|
|
|
|
const fn new(
|
|
|
|
trait_name: &'static str,
|
|
|
|
method_name: &'static str,
|
|
|
|
param_count: usize,
|
2020-08-09 13:35:41 +00:00
|
|
|
fn_header: hir::FnHeader,
|
2020-07-29 23:41:12 +00:00
|
|
|
self_kind: SelfKind,
|
|
|
|
output_type: OutType,
|
|
|
|
lint_explicit_lifetime: bool,
|
|
|
|
) -> ShouldImplTraitCase {
|
|
|
|
ShouldImplTraitCase {
|
|
|
|
trait_name,
|
|
|
|
method_name,
|
|
|
|
param_count,
|
|
|
|
fn_header,
|
|
|
|
self_kind,
|
|
|
|
output_type,
|
|
|
|
lint_explicit_lifetime,
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
fn lifetime_param_cond(&self, impl_item: &hir::ImplItem<'_>) -> bool {
|
|
|
|
self.lint_explicit_lifetime
|
|
|
|
|| !impl_item.generics.params.iter().any(|p| {
|
|
|
|
matches!(
|
|
|
|
p.kind,
|
|
|
|
hir::GenericParamKind::Lifetime {
|
|
|
|
kind: hir::LifetimeParamKind::Explicit
|
|
|
|
}
|
|
|
|
)
|
|
|
|
})
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-05-30 16:24:44 +00:00
|
|
|
#[rustfmt::skip]
|
2020-07-29 23:41:12 +00:00
|
|
|
const TRAIT_METHODS: [ShouldImplTraitCase; 30] = [
|
2020-08-09 13:35:41 +00:00
|
|
|
ShouldImplTraitCase::new("std::ops::Add", "add", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::convert::AsMut", "as_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::convert::AsRef", "as_ref", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::BitAnd", "bitand", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::BitOr", "bitor", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::BitXor", "bitxor", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::borrow::Borrow", "borrow", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::borrow::BorrowMut", "borrow_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::clone::Clone", "clone", 1, FN_HEADER, SelfKind::Ref, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::cmp::Ord", "cmp", 2, FN_HEADER, SelfKind::Ref, OutType::Any, true),
|
2020-06-19 20:12:51 +00:00
|
|
|
// FIXME: default doesn't work
|
2020-08-09 13:35:41 +00:00
|
|
|
ShouldImplTraitCase::new("std::default::Default", "default", 0, FN_HEADER, SelfKind::No, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Deref", "deref", 1, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::DerefMut", "deref_mut", 1, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Div", "div", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Drop", "drop", 1, FN_HEADER, SelfKind::RefMut, OutType::Unit, true),
|
|
|
|
ShouldImplTraitCase::new("std::cmp::PartialEq", "eq", 2, FN_HEADER, SelfKind::Ref, OutType::Bool, true),
|
|
|
|
ShouldImplTraitCase::new("std::iter::FromIterator", "from_iter", 1, FN_HEADER, SelfKind::No, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::str::FromStr", "from_str", 1, FN_HEADER, SelfKind::No, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::hash::Hash", "hash", 2, FN_HEADER, SelfKind::Ref, OutType::Unit, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Index", "index", 2, FN_HEADER, SelfKind::Ref, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::IndexMut", "index_mut", 2, FN_HEADER, SelfKind::RefMut, OutType::Ref, true),
|
|
|
|
ShouldImplTraitCase::new("std::iter::IntoIterator", "into_iter", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Mul", "mul", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Neg", "neg", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::iter::Iterator", "next", 1, FN_HEADER, SelfKind::RefMut, OutType::Any, false),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Not", "not", 1, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Rem", "rem", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Shl", "shl", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Shr", "shr", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
|
|
|
ShouldImplTraitCase::new("std::ops::Sub", "sub", 2, FN_HEADER, SelfKind::Value, OutType::Any, true),
|
2016-01-30 12:39:16 +00:00
|
|
|
];
|
2015-08-24 16:13:02 +00:00
|
|
|
|
2018-05-30 16:24:44 +00:00
|
|
|
#[rustfmt::skip]
|
2019-05-17 23:34:52 +00:00
|
|
|
const PATTERN_METHODS: [(&str, usize); 17] = [
|
|
|
|
("contains", 1),
|
|
|
|
("starts_with", 1),
|
|
|
|
("ends_with", 1),
|
|
|
|
("find", 1),
|
|
|
|
("rfind", 1),
|
|
|
|
("split", 1),
|
|
|
|
("rsplit", 1),
|
|
|
|
("split_terminator", 1),
|
|
|
|
("rsplit_terminator", 1),
|
|
|
|
("splitn", 2),
|
|
|
|
("rsplitn", 2),
|
|
|
|
("matches", 1),
|
|
|
|
("rmatches", 1),
|
|
|
|
("match_indices", 1),
|
|
|
|
("rmatch_indices", 1),
|
|
|
|
("trim_start_matches", 1),
|
|
|
|
("trim_end_matches", 1),
|
2016-02-15 03:40:43 +00:00
|
|
|
];
|
|
|
|
|
2017-01-05 02:01:53 +00:00
|
|
|
#[derive(Clone, Copy, PartialEq, Debug)]
|
2015-08-24 16:13:02 +00:00
|
|
|
enum SelfKind {
|
2016-02-01 11:51:33 +00:00
|
|
|
Value,
|
|
|
|
Ref,
|
|
|
|
RefMut,
|
|
|
|
No,
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
impl SelfKind {
|
2020-06-25 20:41:36 +00:00
|
|
|
fn matches<'a>(self, cx: &LateContext<'a>, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
|
|
|
|
fn matches_value<'a>(cx: &LateContext<'a>, parent_ty: Ty<'_>, ty: Ty<'_>) -> bool {
|
2019-08-10 04:01:15 +00:00
|
|
|
if ty == parent_ty {
|
|
|
|
true
|
|
|
|
} else if ty.is_box() {
|
|
|
|
ty.boxed_ty() == parent_ty
|
2020-04-10 17:03:34 +00:00
|
|
|
} else if is_type_diagnostic_item(cx, ty, sym::Rc) || is_type_diagnostic_item(cx, ty, sym::Arc) {
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Adt(_, substs) = ty.kind {
|
2019-08-10 04:01:15 +00:00
|
|
|
substs.types().next().map_or(false, |t| t == parent_ty)
|
|
|
|
} else {
|
|
|
|
false
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
false
|
2017-01-04 04:40:42 +00:00
|
|
|
}
|
2019-08-10 04:01:15 +00:00
|
|
|
}
|
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn matches_ref<'a>(cx: &LateContext<'a>, mutability: hir::Mutability, parent_ty: Ty<'a>, ty: Ty<'a>) -> bool {
|
2019-09-26 09:03:36 +00:00
|
|
|
if let ty::Ref(_, t, m) = ty.kind {
|
2019-08-10 04:00:27 +00:00
|
|
|
return m == mutability && t == parent_ty;
|
2017-06-06 17:26:50 +00:00
|
|
|
}
|
2019-08-10 04:00:27 +00:00
|
|
|
|
|
|
|
let trait_path = match mutability {
|
2019-12-21 18:38:45 +00:00
|
|
|
hir::Mutability::Not => &paths::ASREF_TRAIT,
|
|
|
|
hir::Mutability::Mut => &paths::ASMUT_TRAIT,
|
2019-08-10 04:00:27 +00:00
|
|
|
};
|
|
|
|
|
2019-08-22 03:03:26 +00:00
|
|
|
let trait_def_id = match get_trait_def_id(cx, trait_path) {
|
|
|
|
Some(did) => did,
|
|
|
|
None => return false,
|
|
|
|
};
|
2019-08-10 04:00:27 +00:00
|
|
|
implements_trait(cx, ty, trait_def_id, &[parent_ty.into()])
|
|
|
|
}
|
|
|
|
|
|
|
|
match self {
|
2020-04-10 17:03:34 +00:00
|
|
|
Self::Value => matches_value(cx, parent_ty, ty),
|
2019-12-21 18:38:45 +00:00
|
|
|
Self::Ref => matches_ref(cx, hir::Mutability::Not, parent_ty, ty) || ty == parent_ty && is_copy(cx, ty),
|
|
|
|
Self::RefMut => matches_ref(cx, hir::Mutability::Mut, parent_ty, ty),
|
2019-08-10 04:00:27 +00:00
|
|
|
Self::No => ty != parent_ty,
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
}
|
2015-09-01 16:52:48 +00:00
|
|
|
|
2019-09-18 06:37:41 +00:00
|
|
|
#[must_use]
|
2018-05-31 18:15:48 +00:00
|
|
|
fn description(self) -> &'static str {
|
|
|
|
match self {
|
2019-07-31 00:25:35 +00:00
|
|
|
Self::Value => "self by value",
|
|
|
|
Self::Ref => "self by reference",
|
|
|
|
Self::RefMut => "self by mutable reference",
|
|
|
|
Self::No => "no self",
|
2015-09-01 16:52:48 +00:00
|
|
|
}
|
|
|
|
}
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
|
2016-02-13 00:42:46 +00:00
|
|
|
impl Convention {
|
2019-09-18 06:37:41 +00:00
|
|
|
#[must_use]
|
2016-02-13 00:42:46 +00:00
|
|
|
fn check(&self, other: &str) -> bool {
|
|
|
|
match *self {
|
2019-07-31 00:25:35 +00:00
|
|
|
Self::Eq(this) => this == other,
|
|
|
|
Self::StartsWith(this) => other.starts_with(this) && this != other,
|
2016-02-13 00:42:46 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
impl fmt::Display for Convention {
|
2018-07-23 11:01:12 +00:00
|
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
|
2016-02-13 00:42:46 +00:00
|
|
|
match *self {
|
2019-07-31 00:25:35 +00:00
|
|
|
Self::Eq(this) => this.fmt(f),
|
|
|
|
Self::StartsWith(this) => this.fmt(f).and_then(|_| '*'.fmt(f)),
|
2016-02-13 00:42:46 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2015-08-24 16:13:02 +00:00
|
|
|
#[derive(Clone, Copy)]
|
|
|
|
enum OutType {
|
2016-02-01 11:51:33 +00:00
|
|
|
Unit,
|
|
|
|
Bool,
|
|
|
|
Any,
|
|
|
|
Ref,
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
impl OutType {
|
2020-06-25 20:41:36 +00:00
|
|
|
fn matches(self, cx: &LateContext<'_>, ty: &hir::FnRetTy<'_>) -> bool {
|
2019-12-30 04:02:10 +00:00
|
|
|
let is_unit = |ty: &hir::Ty<'_>| SpanlessEq::new(cx).eq_ty_kind(&ty.kind, &hir::TyKind::Tup(&[]));
|
2015-08-24 16:13:02 +00:00
|
|
|
match (self, ty) {
|
2020-02-17 09:36:17 +00:00
|
|
|
(Self::Unit, &hir::FnRetTy::DefaultReturn(_)) => true,
|
|
|
|
(Self::Unit, &hir::FnRetTy::Return(ref ty)) if is_unit(ty) => true,
|
|
|
|
(Self::Bool, &hir::FnRetTy::Return(ref ty)) if is_bool(ty) => true,
|
|
|
|
(Self::Any, &hir::FnRetTy::Return(ref ty)) if !is_unit(ty) => true,
|
|
|
|
(Self::Ref, &hir::FnRetTy::Return(ref ty)) => matches!(ty.kind, hir::TyKind::Rptr(_, _)),
|
2016-01-04 04:26:12 +00:00
|
|
|
_ => false,
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-12-30 04:02:10 +00:00
|
|
|
fn is_bool(ty: &hir::Ty<'_>) -> bool {
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::TyKind::Path(ref p) = ty.kind {
|
2019-05-17 21:53:54 +00:00
|
|
|
match_qpath(p, &["bool"])
|
2016-06-05 18:46:42 +00:00
|
|
|
} else {
|
|
|
|
false
|
2015-08-24 16:13:02 +00:00
|
|
|
}
|
2015-08-11 18:53:50 +00:00
|
|
|
}
|
2019-09-08 09:03:45 +00:00
|
|
|
|
|
|
|
// Returns `true` if `expr` contains a return expression
|
2019-12-27 07:12:26 +00:00
|
|
|
fn contains_return(expr: &hir::Expr<'_>) -> bool {
|
2019-09-08 09:03:45 +00:00
|
|
|
struct RetCallFinder {
|
|
|
|
found: bool,
|
|
|
|
}
|
|
|
|
|
|
|
|
impl<'tcx> intravisit::Visitor<'tcx> for RetCallFinder {
|
2020-01-09 07:13:22 +00:00
|
|
|
type Map = Map<'tcx>;
|
|
|
|
|
2019-12-27 07:12:26 +00:00
|
|
|
fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
|
2019-09-08 09:03:45 +00:00
|
|
|
if self.found {
|
|
|
|
return;
|
|
|
|
}
|
2019-09-27 15:16:06 +00:00
|
|
|
if let hir::ExprKind::Ret(..) = &expr.kind {
|
2019-09-08 09:03:45 +00:00
|
|
|
self.found = true;
|
|
|
|
} else {
|
|
|
|
intravisit::walk_expr(self, expr);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2020-03-15 22:41:20 +00:00
|
|
|
fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
|
2019-09-08 09:03:45 +00:00
|
|
|
intravisit::NestedVisitorMap::None
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2019-09-11 06:26:57 +00:00
|
|
|
let mut visitor = RetCallFinder { found: false };
|
2019-09-08 09:03:45 +00:00
|
|
|
visitor.visit_expr(expr);
|
|
|
|
visitor.found
|
|
|
|
}
|
2019-11-14 19:18:24 +00:00
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn check_pointer_offset(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
|
2019-11-14 19:18:24 +00:00
|
|
|
if_chain! {
|
|
|
|
if args.len() == 2;
|
2020-07-17 08:47:04 +00:00
|
|
|
if let ty::RawPtr(ty::TypeAndMut { ref ty, .. }) = cx.typeck_results().expr_ty(&args[0]).kind;
|
2019-11-14 19:18:24 +00:00
|
|
|
if let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(ty));
|
|
|
|
if layout.is_zst();
|
|
|
|
then {
|
|
|
|
span_lint(cx, ZST_OFFSET, expr.span, "offset calculation on zero-sized value");
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2020-01-03 06:59:14 +00:00
|
|
|
|
2020-06-25 20:41:36 +00:00
|
|
|
fn lint_filetype_is_file(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) {
|
2020-07-17 08:47:04 +00:00
|
|
|
let ty = cx.typeck_results().expr_ty(&args[0]);
|
2020-01-03 06:59:14 +00:00
|
|
|
|
|
|
|
if !match_type(cx, ty, &paths::FILE_TYPE) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2020-01-08 08:50:37 +00:00
|
|
|
let span: Span;
|
2020-01-07 08:33:33 +00:00
|
|
|
let verb: &str;
|
|
|
|
let lint_unary: &str;
|
|
|
|
let help_unary: &str;
|
2020-01-03 06:59:14 +00:00
|
|
|
if_chain! {
|
|
|
|
if let Some(parent) = get_parent_expr(cx, expr);
|
|
|
|
if let hir::ExprKind::Unary(op, _) = parent.kind;
|
2020-01-08 08:56:28 +00:00
|
|
|
if op == hir::UnOp::UnNot;
|
2020-01-03 06:59:14 +00:00
|
|
|
then {
|
2020-01-07 08:33:33 +00:00
|
|
|
lint_unary = "!";
|
2020-01-08 08:40:34 +00:00
|
|
|
verb = "denies";
|
2020-01-07 08:33:33 +00:00
|
|
|
help_unary = "";
|
2020-01-08 08:50:37 +00:00
|
|
|
span = parent.span;
|
2020-01-03 06:59:14 +00:00
|
|
|
} else {
|
2020-01-07 08:33:33 +00:00
|
|
|
lint_unary = "";
|
|
|
|
verb = "covers";
|
|
|
|
help_unary = "!";
|
2020-01-08 08:50:37 +00:00
|
|
|
span = expr.span;
|
2020-01-03 06:59:14 +00:00
|
|
|
}
|
|
|
|
}
|
2020-01-07 08:33:33 +00:00
|
|
|
let lint_msg = format!("`{}FileType::is_file()` only {} regular files", lint_unary, verb);
|
|
|
|
let help_msg = format!("use `{}FileType::is_dir()` instead", help_unary);
|
2020-04-18 10:28:29 +00:00
|
|
|
span_lint_and_help(cx, FILETYPE_IS_FILE, span, &lint_msg, None, &help_msg);
|
2020-01-03 06:59:14 +00:00
|
|
|
}
|
2020-04-08 10:57:58 +00:00
|
|
|
|
|
|
|
fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool {
|
|
|
|
expected.constness == actual.constness
|
|
|
|
&& expected.unsafety == actual.unsafety
|
|
|
|
&& expected.asyncness == actual.asyncness
|
|
|
|
}
|