forked from rust-lang/rust-clippy
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Auto merge of rust-lang#11413 - jonboh:master, r=Alexendoo
new unnecessary_map_on_constructor lint changelog: [`unnecessary_map_on_constructor`]: adds lint for cases in which map is not necessary. `Some(4).map(myfunction)` => `Some(myfunction(4))` Closes rust-lang#6472 Note that the case mentioned in the issue `Some(..).and_then(|..| Some(..))` is fixed by a chain of lint changes. This PR completes the last part of that chain. By `bind_instead_of_map`[lint](https://rust-lang.github.io/rust-clippy/master/index.html#/bind_instead_of_map): `Some(4).and_then(|x| Some(foo(4)))` => `Some(4).map(|x| foo)` By `redundant_closure` [lint](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure): `Some(4).map(|x| foo)` => `Some(4).map(fun)` Finally by this PR `unnecessary_map_on_constructor`: `Some(4).map(fun)` => `Some(fun(4))` I'm not sure this is the desired behavior for clippy and if it should be addressed in another issue/PR. I'd be up to give it a try if that's the case.
- Loading branch information
Showing
16 changed files
with
319 additions
and
53 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,93 @@ | ||
| use clippy_utils::diagnostics::span_lint_and_sugg; | ||
| use clippy_utils::source::snippet_with_applicability; | ||
| use clippy_utils::ty::get_type_diagnostic_name; | ||
| use rustc_errors::Applicability; | ||
| use rustc_hir as hir; | ||
| use rustc_lint::{LateContext, LateLintPass}; | ||
| use rustc_session::{declare_lint_pass, declare_tool_lint}; | ||
| use rustc_span::sym; | ||
|
|
||
| declare_clippy_lint! { | ||
| /// ### What it does | ||
| /// Suggest removing the use of a may (or map_err) method when an Option or Result is being construted. | ||
| /// | ||
| /// ### Why is this bad? | ||
| /// It introduces unnecessary complexity. In this case the function can be used directly and | ||
| /// construct the Option or Result from the output. | ||
| /// | ||
| /// ### Example | ||
| /// ```rust | ||
| /// Some(4).map(i32::swap_bytes); | ||
| /// ``` | ||
| /// Use instead: | ||
| /// ```rust | ||
| /// Some(i32::swap_bytes(4)); | ||
| /// ``` | ||
| #[clippy::version = "1.73.0"] | ||
| pub UNNECESSARY_MAP_ON_CONSTRUCTOR, | ||
| complexity, | ||
| "using `map`/`map_err` on `Option` or `Result` constructors" | ||
| } | ||
| declare_lint_pass!(UnnecessaryMapOnConstructor => [UNNECESSARY_MAP_ON_CONSTRUCTOR]); | ||
|
|
||
| impl<'tcx> LateLintPass<'tcx> for UnnecessaryMapOnConstructor { | ||
| fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx rustc_hir::Expr<'tcx>) { | ||
| if expr.span.from_expansion() { | ||
| return; | ||
| } | ||
| if let hir::ExprKind::MethodCall(path, recv, args, ..) = expr.kind | ||
| && let Some(sym::Option | sym::Result) = get_type_diagnostic_name(cx, cx.typeck_results().expr_ty(recv)){ | ||
| let (constructor_path, constructor_item) = | ||
| if let hir::ExprKind::Call(constructor, constructor_args) = recv.kind | ||
| && let hir::ExprKind::Path(constructor_path) = constructor.kind | ||
| && let Some(arg) = constructor_args.get(0) | ||
| { | ||
| if constructor.span.from_expansion() || arg.span.from_expansion() { | ||
| return; | ||
| } | ||
| (constructor_path, arg) | ||
| } else { | ||
| return; | ||
| }; | ||
| let constructor_symbol = match constructor_path { | ||
| hir::QPath::Resolved(_, path) => { | ||
| if let Some(path_segment) = path.segments.last() { | ||
| path_segment.ident.name | ||
| } else { | ||
| return; | ||
| } | ||
| }, | ||
| hir::QPath::TypeRelative(_, path) => path.ident.name, | ||
| hir::QPath::LangItem(_, _, _) => return, | ||
| }; | ||
| match constructor_symbol { | ||
| sym::Some | sym::Ok if path.ident.name == rustc_span::sym::map => (), | ||
| sym::Err if path.ident.name == sym!(map_err) => (), | ||
| _ => return, | ||
| } | ||
|
|
||
| if let Some(map_arg) = args.get(0) | ||
| && let hir::ExprKind::Path(fun) = map_arg.kind | ||
| { | ||
| if map_arg.span.from_expansion() { | ||
| return; | ||
| } | ||
| let mut applicability = Applicability::MachineApplicable; | ||
| let fun_snippet = snippet_with_applicability(cx, fun.span(), "_", &mut applicability); | ||
| let constructor_snippet = | ||
| snippet_with_applicability(cx, constructor_path.span(), "_", &mut applicability); | ||
| let constructor_arg_snippet = | ||
| snippet_with_applicability(cx, constructor_item.span, "_", &mut applicability); | ||
| span_lint_and_sugg( | ||
| cx, | ||
| UNNECESSARY_MAP_ON_CONSTRUCTOR, | ||
| expr.span, | ||
| &format!("unnecessary {} on constructor {constructor_snippet}(_)", path.ident.name), | ||
| "try", | ||
| format!("{constructor_snippet}({fun_snippet}({constructor_arg_snippet}))"), | ||
| applicability, | ||
| ); | ||
| } | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.