-
Notifications
You must be signed in to change notification settings - Fork 1.6k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
improve and generalize
option_and_then_some lint
- rename it to bind_instead_of_map
- Loading branch information
Showing
16 changed files
with
503 additions
and
105 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 +1,309 @@ | ||
| use super::{contains_return, BIND_INSTEAD_OF_MAP}; | ||
| use crate::utils::{ | ||
| in_macro, match_qpath, match_type, method_calls, multispan_sugg_with_applicability, paths, remove_blocks, snippet, | ||
| snippet_with_macro_callsite, span_lint_and_sugg, span_lint_and_then, | ||
| }; | ||
| use if_chain::if_chain; | ||
| use rustc_errors::Applicability; | ||
| use rustc_hir as hir; | ||
| use rustc_hir::intravisit::{self, Visitor}; | ||
| use rustc_lint::LateContext; | ||
| use rustc_middle::hir::map::Map; | ||
| use rustc_span::Span; | ||
|
|
||
| pub(crate) struct OptionAndThenSome; | ||
| impl BindInsteadOfMap for OptionAndThenSome { | ||
| const TYPE_NAME: &'static str = "Option"; | ||
| const TYPE_QPATH: &'static [&'static str] = &paths::OPTION; | ||
|
|
||
| const BAD_METHOD_NAME: &'static str = "and_then"; | ||
| const BAD_VARIANT_NAME: &'static str = "Some"; | ||
| const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::OPTION_SOME; | ||
|
|
||
| const GOOD_METHOD_NAME: &'static str = "map"; | ||
| } | ||
|
|
||
| pub(crate) struct ResultAndThenOk; | ||
| impl BindInsteadOfMap for ResultAndThenOk { | ||
| const TYPE_NAME: &'static str = "Result"; | ||
| const TYPE_QPATH: &'static [&'static str] = &paths::RESULT; | ||
|
|
||
| const BAD_METHOD_NAME: &'static str = "and_then"; | ||
| const BAD_VARIANT_NAME: &'static str = "Ok"; | ||
| const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::RESULT_OK; | ||
|
|
||
| const GOOD_METHOD_NAME: &'static str = "map"; | ||
| } | ||
|
|
||
| pub(crate) struct ResultOrElseErrInfo; | ||
| impl BindInsteadOfMap for ResultOrElseErrInfo { | ||
| const TYPE_NAME: &'static str = "Result"; | ||
| const TYPE_QPATH: &'static [&'static str] = &paths::RESULT; | ||
|
|
||
| const BAD_METHOD_NAME: &'static str = "or_else"; | ||
| const BAD_VARIANT_NAME: &'static str = "Err"; | ||
| const BAD_VARIANT_QPATH: &'static [&'static str] = &paths::RESULT_ERR; | ||
|
|
||
| const GOOD_METHOD_NAME: &'static str = "map_err"; | ||
| } | ||
|
|
||
| pub(crate) trait BindInsteadOfMap { | ||
| const TYPE_NAME: &'static str; | ||
| const TYPE_QPATH: &'static [&'static str]; | ||
|
|
||
| const BAD_METHOD_NAME: &'static str; | ||
| const BAD_VARIANT_NAME: &'static str; | ||
| const BAD_VARIANT_QPATH: &'static [&'static str]; | ||
|
|
||
| const GOOD_METHOD_NAME: &'static str; | ||
|
|
||
| fn no_op_msg() -> String { | ||
| format!( | ||
| "using `{}.{}({})`, which is a no-op", | ||
| Self::TYPE_NAME, | ||
| Self::BAD_METHOD_NAME, | ||
| Self::BAD_VARIANT_NAME | ||
| ) | ||
| } | ||
|
|
||
| fn lint_msg() -> String { | ||
| format!( | ||
| "using `{}.{}(|x| {}(y))`, which is more succinctly expressed as `{}(|x| y)`", | ||
| Self::TYPE_NAME, | ||
| Self::BAD_METHOD_NAME, | ||
| Self::BAD_VARIANT_NAME, | ||
| Self::GOOD_METHOD_NAME | ||
| ) | ||
| } | ||
|
|
||
| fn lint_closure_autofixable( | ||
| cx: &LateContext<'_, '_>, | ||
| expr: &hir::Expr<'_>, | ||
| args: &[hir::Expr<'_>], | ||
| closure_expr: &hir::Expr<'_>, | ||
| closure_args_span: Span, | ||
| ) -> bool { | ||
| if_chain! { | ||
| if let hir::ExprKind::Call(ref some_expr, ref some_args) = closure_expr.kind; | ||
| if let hir::ExprKind::Path(ref qpath) = some_expr.kind; | ||
| if match_qpath(qpath, Self::BAD_VARIANT_QPATH); | ||
| if some_args.len() == 1; | ||
| then { | ||
| let inner_expr = &some_args[0]; | ||
|
|
||
| if contains_return(inner_expr) { | ||
| return false; | ||
| } | ||
|
|
||
| let some_inner_snip = if inner_expr.span.from_expansion() { | ||
| snippet_with_macro_callsite(cx, inner_expr.span, "_") | ||
| } else { | ||
| snippet(cx, inner_expr.span, "_") | ||
| }; | ||
|
|
||
| let closure_args_snip = snippet(cx, closure_args_span, ".."); | ||
| let option_snip = snippet(cx, args[0].span, ".."); | ||
| let note = format!("{}.{}({} {})", option_snip, Self::GOOD_METHOD_NAME, closure_args_snip, some_inner_snip); | ||
| span_lint_and_sugg( | ||
| cx, | ||
| BIND_INSTEAD_OF_MAP, | ||
| expr.span, | ||
| Self::lint_msg().as_ref(), | ||
| "try this", | ||
| note, | ||
| Applicability::MachineApplicable, | ||
| ); | ||
| true | ||
| } else { | ||
| false | ||
| } | ||
| } | ||
| } | ||
|
|
||
| fn lint_closure(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, closure_expr: &hir::Expr<'_>) { | ||
| let mut suggs = Vec::new(); | ||
| let can_sugg = find_all_ret_expressions(cx, closure_expr, |ret_expr| { | ||
| if_chain! { | ||
| if !in_macro(ret_expr.span); | ||
| if let hir::ExprKind::Call(ref func_path, ref args) = ret_expr.kind; | ||
| if let hir::ExprKind::Path(ref qpath) = func_path.kind; | ||
| if match_qpath(qpath, Self::BAD_VARIANT_QPATH); | ||
| if args.len() == 1; | ||
| if !contains_return(&args[0]); | ||
| then { | ||
| suggs.push((ret_expr.span, args[0].span.source_callsite())); | ||
| true | ||
| } else { | ||
| false | ||
| } | ||
| } | ||
| }); | ||
|
|
||
| if can_sugg { | ||
| span_lint_and_then(cx, BIND_INSTEAD_OF_MAP, expr.span, Self::lint_msg().as_ref(), |diag| { | ||
| multispan_sugg_with_applicability( | ||
| diag, | ||
| "try this", | ||
| Applicability::MachineApplicable, | ||
| std::iter::once((*method_calls(expr, 1).2.get(0).unwrap(), Self::GOOD_METHOD_NAME.into())).chain( | ||
| suggs | ||
| .into_iter() | ||
| .map(|(span1, span2)| (span1, snippet(cx, span2, "_").into())), | ||
| ), | ||
| ) | ||
| }); | ||
| } | ||
| } | ||
|
|
||
| /// Lint use of `_.and_then(|x| Some(y))` for `Option`s | ||
| fn lint(cx: &LateContext<'_, '_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { | ||
| if !match_type(cx, cx.tables.expr_ty(&args[0]), Self::TYPE_QPATH) { | ||
| return; | ||
| } | ||
|
|
||
| match args[1].kind { | ||
| hir::ExprKind::Closure(_, _, body_id, closure_args_span, _) => { | ||
| let closure_body = cx.tcx.hir().body(body_id); | ||
| let closure_expr = remove_blocks(&closure_body.value); | ||
|
|
||
| if !Self::lint_closure_autofixable(cx, expr, args, closure_expr, closure_args_span) { | ||
| Self::lint_closure(cx, expr, closure_expr); | ||
| } | ||
| }, | ||
| // `_.and_then(Some)` case, which is no-op. | ||
| hir::ExprKind::Path(ref qpath) if match_qpath(qpath, Self::BAD_VARIANT_QPATH) => { | ||
| span_lint_and_sugg( | ||
| cx, | ||
| BIND_INSTEAD_OF_MAP, | ||
| expr.span, | ||
| Self::no_op_msg().as_ref(), | ||
| "use the expression directly", | ||
| snippet(cx, args[0].span, "..").into(), | ||
| Applicability::MachineApplicable, | ||
| ); | ||
| }, | ||
| _ => {}, | ||
| } | ||
| } | ||
| } | ||
|
|
||
| /// returns `true` if expr contains match expr desugared from try | ||
| fn contains_try(expr: &hir::Expr<'_>) -> bool { | ||
| struct TryFinder { | ||
| found: bool, | ||
| } | ||
|
|
||
| impl<'hir> intravisit::Visitor<'hir> for TryFinder { | ||
| type Map = Map<'hir>; | ||
|
|
||
| fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> { | ||
| intravisit::NestedVisitorMap::None | ||
| } | ||
|
|
||
| fn visit_expr(&mut self, expr: &'hir hir::Expr<'hir>) { | ||
| if self.found { | ||
| return; | ||
| } | ||
| match expr.kind { | ||
| hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar) => self.found = true, | ||
| _ => intravisit::walk_expr(self, expr), | ||
| } | ||
| } | ||
| } | ||
|
|
||
| let mut visitor = TryFinder { found: false }; | ||
| visitor.visit_expr(expr); | ||
| visitor.found | ||
| } | ||
|
|
||
| fn find_all_ret_expressions<'hir, F>(_cx: &LateContext<'_, '_>, expr: &'hir hir::Expr<'hir>, callback: F) -> bool | ||
| where | ||
| F: FnMut(&'hir hir::Expr<'hir>) -> bool, | ||
| { | ||
| struct RetFinder<F> { | ||
| in_stmt: bool, | ||
| failed: bool, | ||
| cb: F, | ||
| } | ||
|
|
||
| struct WithStmtGuarg<'a, F> { | ||
| val: &'a mut RetFinder<F>, | ||
| prev_in_stmt: bool, | ||
| } | ||
|
|
||
| impl<F> RetFinder<F> { | ||
| fn inside_stmt(&mut self, in_stmt: bool) -> WithStmtGuarg<'_, F> { | ||
| let prev_in_stmt = std::mem::replace(&mut self.in_stmt, in_stmt); | ||
| WithStmtGuarg { | ||
| val: self, | ||
| prev_in_stmt, | ||
| } | ||
| } | ||
| } | ||
|
|
||
| impl<F> std::ops::Deref for WithStmtGuarg<'_, F> { | ||
| type Target = RetFinder<F>; | ||
|
|
||
| fn deref(&self) -> &Self::Target { | ||
| self.val | ||
| } | ||
| } | ||
|
|
||
| impl<F> std::ops::DerefMut for WithStmtGuarg<'_, F> { | ||
| fn deref_mut(&mut self) -> &mut Self::Target { | ||
| self.val | ||
| } | ||
| } | ||
|
|
||
| impl<F> Drop for WithStmtGuarg<'_, F> { | ||
| fn drop(&mut self) { | ||
| self.val.in_stmt = self.prev_in_stmt; | ||
| } | ||
| } | ||
|
|
||
| impl<'hir, F: FnMut(&'hir hir::Expr<'hir>) -> bool> intravisit::Visitor<'hir> for RetFinder<F> { | ||
| type Map = Map<'hir>; | ||
|
|
||
| fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> { | ||
| intravisit::NestedVisitorMap::None | ||
| } | ||
|
|
||
| fn visit_stmt(&mut self, stmt: &'hir hir::Stmt<'_>) { | ||
| intravisit::walk_stmt(&mut *self.inside_stmt(true), stmt) | ||
| } | ||
|
|
||
| fn visit_expr(&mut self, expr: &'hir hir::Expr<'_>) { | ||
| if self.failed { | ||
| return; | ||
| } | ||
| if self.in_stmt { | ||
| match expr.kind { | ||
| hir::ExprKind::Ret(Some(expr)) => self.inside_stmt(false).visit_expr(expr), | ||
| _ => intravisit::walk_expr(self, expr), | ||
| } | ||
| } else { | ||
| match expr.kind { | ||
| hir::ExprKind::Match(cond, arms, _) => { | ||
| self.inside_stmt(true).visit_expr(cond); | ||
| for arm in arms { | ||
| self.visit_expr(arm.body); | ||
| } | ||
| }, | ||
| hir::ExprKind::Block(..) => intravisit::walk_expr(self, expr), | ||
| hir::ExprKind::Ret(Some(expr)) => self.visit_expr(expr), | ||
| _ => self.failed |= !(self.cb)(expr), | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| !contains_try(expr) && { | ||
| let mut ret_finder = RetFinder { | ||
| in_stmt: false, | ||
| failed: false, | ||
| cb: callback, | ||
| }; | ||
| ret_finder.visit_expr(expr); | ||
| !ret_finder.failed | ||
| } | ||
| } |
Oops, something went wrong.