From f0f07accbce24adb5706eeb4e14e0e1c6b2b973b Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 00:14:38 +0900 Subject: [PATCH 01/35] move expect_used, filter_next, get_unwrap, ok_expect and unwrap_used to their own modules --- clippy_lints/src/methods/expect_used.rs | 30 +++ clippy_lints/src/methods/filter_next.rs | 31 +++ clippy_lints/src/methods/get_unwrap.rs | 84 +++++++ clippy_lints/src/methods/mod.rs | 218 ++---------------- clippy_lints/src/methods/ok_expect.rs | 45 ++++ .../src/methods/option_map_unwrap_or.rs | 2 +- .../src/methods/unnecessary_lazy_eval.rs | 2 +- clippy_lints/src/methods/unwrap_used.rs | 34 +++ 8 files changed, 244 insertions(+), 202 deletions(-) create mode 100644 clippy_lints/src/methods/expect_used.rs create mode 100644 clippy_lints/src/methods/filter_next.rs create mode 100644 clippy_lints/src/methods/get_unwrap.rs create mode 100644 clippy_lints/src/methods/ok_expect.rs create mode 100644 clippy_lints/src/methods/unwrap_used.rs diff --git a/clippy_lints/src/methods/expect_used.rs b/clippy_lints/src/methods/expect_used.rs new file mode 100644 index 0000000000000..90b781bd9d190 --- /dev/null +++ b/clippy_lints/src/methods/expect_used.rs @@ -0,0 +1,30 @@ +use crate::utils::{is_type_diagnostic_item, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::EXPECT_USED; + +/// lint use of `expect()` for `Option`s and `Result`s +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, expect_args: &[hir::Expr<'_>]) { + let obj_ty = cx.typeck_results().expr_ty(&expect_args[0]).peel_refs(); + + let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) { + Some((EXPECT_USED, "an Option", "None")) + } else if is_type_diagnostic_item(cx, obj_ty, sym::result_type) { + Some((EXPECT_USED, "a Result", "Err")) + } else { + None + }; + + if let Some((lint, kind, none_value)) = mess { + span_lint_and_help( + cx, + lint, + expr.span, + &format!("used `expect()` on `{}` value", kind,), + None, + &format!("if this value is an `{}`, it will panic", none_value,), + ); + } +} diff --git a/clippy_lints/src/methods/filter_next.rs b/clippy_lints/src/methods/filter_next.rs new file mode 100644 index 0000000000000..81619e73017f2 --- /dev/null +++ b/clippy_lints/src/methods/filter_next.rs @@ -0,0 +1,31 @@ +use crate::utils::{match_trait_method, paths, snippet, span_lint, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::FILTER_NEXT; + +/// lint use of `filter().next()` for `Iterators` +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) { + // lint if caller of `.filter().next()` is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + let msg = "called `filter(..).next()` on an `Iterator`. This is more succinctly expressed by calling \ + `.find(..)` instead"; + let filter_snippet = snippet(cx, filter_args[1].span, ".."); + if filter_snippet.lines().count() <= 1 { + let iter_snippet = snippet(cx, filter_args[0].span, ".."); + // add note if not multi-line + span_lint_and_sugg( + cx, + FILTER_NEXT, + expr.span, + msg, + "try this", + format!("{}.find({})", iter_snippet, filter_snippet), + Applicability::MachineApplicable, + ); + } else { + span_lint(cx, FILTER_NEXT, expr.span, msg); + } + } +} diff --git a/clippy_lints/src/methods/get_unwrap.rs b/clippy_lints/src/methods/get_unwrap.rs new file mode 100644 index 0000000000000..2684c50e01b7d --- /dev/null +++ b/clippy_lints/src/methods/get_unwrap.rs @@ -0,0 +1,84 @@ +use crate::methods::derefs_to_slice; +use crate::utils::{ + get_parent_expr, is_type_diagnostic_item, match_type, paths, snippet_with_applicability, span_lint_and_sugg, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::GET_UNWRAP; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args: &'tcx [hir::Expr<'_>], is_mut: bool) { + // Note: we don't want to lint `get_mut().unwrap` for `HashMap` or `BTreeMap`, + // because they do not implement `IndexMut` + let mut applicability = Applicability::MachineApplicable; + let expr_ty = cx.typeck_results().expr_ty(&get_args[0]); + let get_args_str = if get_args.len() > 1 { + snippet_with_applicability(cx, get_args[1].span, "..", &mut applicability) + } else { + return; // not linting on a .get().unwrap() chain or variant + }; + let mut needs_ref; + let caller_type = if derefs_to_slice(cx, &get_args[0], expr_ty).is_some() { + needs_ref = get_args_str.parse::().is_ok(); + "slice" + } else if is_type_diagnostic_item(cx, expr_ty, sym::vec_type) { + needs_ref = get_args_str.parse::().is_ok(); + "Vec" + } else if is_type_diagnostic_item(cx, expr_ty, sym!(vecdeque_type)) { + needs_ref = get_args_str.parse::().is_ok(); + "VecDeque" + } else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym!(hashmap_type)) { + needs_ref = true; + "HashMap" + } else if !is_mut && match_type(cx, expr_ty, &paths::BTREEMAP) { + needs_ref = true; + "BTreeMap" + } else { + return; // caller is not a type that we want to lint + }; + + let mut span = expr.span; + + // Handle the case where the result is immediately dereferenced + // by not requiring ref and pulling the dereference into the + // suggestion. + if_chain! { + if needs_ref; + if let Some(parent) = get_parent_expr(cx, expr); + if let hir::ExprKind::Unary(hir::UnOp::Deref, _) = parent.kind; + then { + needs_ref = false; + span = parent.span; + } + } + + let mut_str = if is_mut { "_mut" } else { "" }; + let borrow_str = if !needs_ref { + "" + } else if is_mut { + "&mut " + } else { + "&" + }; + + span_lint_and_sugg( + cx, + GET_UNWRAP, + span, + &format!( + "called `.get{0}().unwrap()` on a {1}. Using `[]` is more clear and more concise", + mut_str, caller_type + ), + "try this", + format!( + "{}{}[{}]", + borrow_str, + snippet_with_applicability(cx, get_args[0].span, "..", &mut applicability), + get_args_str + ), + applicability, + ); +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index e8af9b3d7d912..71080e9bef0c9 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -1,14 +1,19 @@ mod bind_instead_of_map; mod bytes_nth; +mod expect_used; mod filter_map_identity; +mod filter_next; +mod get_unwrap; mod implicit_clone; mod inefficient_to_string; mod inspect_for_each; mod iter_count; mod manual_saturating_arithmetic; +mod ok_expect; mod option_map_unwrap_or; mod unnecessary_filter_map; mod unnecessary_lazy_eval; +mod unwrap_used; use std::borrow::Cow; use std::fmt; @@ -1649,15 +1654,15 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let method_names: Vec<&str> = method_names.iter().map(|s| &**s).collect(); match method_names.as_slice() { - ["unwrap", "get"] => lint_get_unwrap(cx, expr, arg_lists[1], false), - ["unwrap", "get_mut"] => lint_get_unwrap(cx, expr, arg_lists[1], true), - ["unwrap", ..] => lint_unwrap(cx, expr, arg_lists[0]), - ["expect", "ok"] => lint_ok_expect(cx, expr, arg_lists[1]), - ["expect", ..] => lint_expect(cx, expr, arg_lists[0]), - ["unwrap_or", "map"] => option_map_unwrap_or::lint(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]), + ["unwrap", "get"] => get_unwrap::check(cx, expr, arg_lists[1], false), + ["unwrap", "get_mut"] => get_unwrap::check(cx, expr, arg_lists[1], true), + ["unwrap", ..] => unwrap_used::check(cx, expr, arg_lists[0]), + ["expect", "ok"] => ok_expect::check(cx, expr, arg_lists[1]), + ["expect", ..] => expect_used::check(cx, expr, arg_lists[0]), + ["unwrap_or", "map"] => option_map_unwrap_or::check(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]), ["unwrap_or_else", "map"] => { if !lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0], self.msrv.as_ref()) { - unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "unwrap_or"); + unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"); } }, ["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]), @@ -1665,15 +1670,15 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let biom_option_linted = bind_instead_of_map::OptionAndThenSome::lint(cx, expr, arg_lists[0]); let biom_result_linted = bind_instead_of_map::ResultAndThenOk::lint(cx, expr, arg_lists[0]); if !biom_option_linted && !biom_result_linted { - unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "and"); + unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "and"); } }, ["or_else", ..] => { if !bind_instead_of_map::ResultOrElseErrInfo::lint(cx, expr, arg_lists[0]) { - unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "or"); + unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "or"); } }, - ["next", "filter"] => lint_filter_next(cx, expr, arg_lists[1]), + ["next", "filter"] => filter_next::check(cx, expr, arg_lists[1]), ["next", "skip_while"] => lint_skip_while_next(cx, expr, arg_lists[1]), ["next", "iter"] => lint_iter_next(cx, expr, arg_lists[1]), ["map", "filter"] => lint_filter_map(cx, expr, false), @@ -1724,9 +1729,9 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["map", "as_mut"] => { lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) }, - ["unwrap_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "unwrap_or"), - ["get_or_insert_with", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "get_or_insert"), - ["ok_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], "ok_or"), + ["unwrap_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"), + ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), + ["ok_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "ok_or"), ["collect", "map"] => lint_map_collect(cx, expr, arg_lists[1], arg_lists[0]), ["for_each", "inspect"] => inspect_for_each::lint(cx, expr, method_spans[1]), ["to_owned", ..] => implicit_clone::check(cx, expr, sym::ToOwned), @@ -2712,79 +2717,6 @@ fn lint_iter_nth_zero<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_ar } } -fn lint_get_unwrap<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args: &'tcx [hir::Expr<'_>], is_mut: bool) { - // Note: we don't want to lint `get_mut().unwrap` for `HashMap` or `BTreeMap`, - // because they do not implement `IndexMut` - let mut applicability = Applicability::MachineApplicable; - let expr_ty = cx.typeck_results().expr_ty(&get_args[0]); - let get_args_str = if get_args.len() > 1 { - snippet_with_applicability(cx, get_args[1].span, "..", &mut applicability) - } else { - return; // not linting on a .get().unwrap() chain or variant - }; - let mut needs_ref; - let caller_type = if derefs_to_slice(cx, &get_args[0], expr_ty).is_some() { - needs_ref = get_args_str.parse::().is_ok(); - "slice" - } else if is_type_diagnostic_item(cx, expr_ty, sym::vec_type) { - needs_ref = get_args_str.parse::().is_ok(); - "Vec" - } else if is_type_diagnostic_item(cx, expr_ty, sym::vecdeque_type) { - needs_ref = get_args_str.parse::().is_ok(); - "VecDeque" - } else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym::hashmap_type) { - needs_ref = true; - "HashMap" - } else if !is_mut && match_type(cx, expr_ty, &paths::BTREEMAP) { - needs_ref = true; - "BTreeMap" - } else { - return; // caller is not a type that we want to lint - }; - - let mut span = expr.span; - - // Handle the case where the result is immediately dereferenced - // by not requiring ref and pulling the dereference into the - // suggestion. - if_chain! { - if needs_ref; - if let Some(parent) = get_parent_expr(cx, expr); - if let hir::ExprKind::Unary(hir::UnOp::Deref, _) = parent.kind; - then { - needs_ref = false; - span = parent.span; - } - } - - let mut_str = if is_mut { "_mut" } else { "" }; - let borrow_str = if !needs_ref { - "" - } else if is_mut { - "&mut " - } else { - "&" - }; - - span_lint_and_sugg( - cx, - GET_UNWRAP, - span, - &format!( - "called `.get{0}().unwrap()` on a {1}. Using `[]` is more clear and more concise", - mut_str, caller_type - ), - "try this", - format!( - "{}{}[{}]", - borrow_str, - snippet_with_applicability(cx, get_args[0].span, "..", &mut applicability), - get_args_str - ), - applicability, - ); -} - fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) { // lint if caller of skip is an Iterator if match_trait_method(cx, expr, &paths::ITERATOR) { @@ -2843,80 +2775,6 @@ fn derefs_to_slice<'tcx>( } } -/// lint use of `unwrap()` for `Option`s and `Result`s -fn lint_unwrap(cx: &LateContext<'_>, expr: &hir::Expr<'_>, unwrap_args: &[hir::Expr<'_>]) { - let obj_ty = cx.typeck_results().expr_ty(&unwrap_args[0]).peel_refs(); - - let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) { - Some((UNWRAP_USED, "an Option", "None")) - } else if is_type_diagnostic_item(cx, obj_ty, sym::result_type) { - Some((UNWRAP_USED, "a Result", "Err")) - } else { - None - }; - - if let Some((lint, kind, none_value)) = mess { - span_lint_and_help( - cx, - lint, - expr.span, - &format!("used `unwrap()` on `{}` value", kind,), - None, - &format!( - "if you don't want to handle the `{}` case gracefully, consider \ - using `expect()` to provide a better panic message", - none_value, - ), - ); - } -} - -/// lint use of `expect()` for `Option`s and `Result`s -fn lint_expect(cx: &LateContext<'_>, expr: &hir::Expr<'_>, expect_args: &[hir::Expr<'_>]) { - let obj_ty = cx.typeck_results().expr_ty(&expect_args[0]).peel_refs(); - - let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) { - Some((EXPECT_USED, "an Option", "None")) - } else if is_type_diagnostic_item(cx, obj_ty, sym::result_type) { - Some((EXPECT_USED, "a Result", "Err")) - } else { - None - }; - - if let Some((lint, kind, none_value)) = mess { - span_lint_and_help( - cx, - lint, - expr.span, - &format!("used `expect()` on `{}` value", kind,), - None, - &format!("if this value is an `{}`, it will panic", none_value,), - ); - } -} - -/// lint use of `ok().expect()` for `Result`s -fn lint_ok_expect(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ok_args: &[hir::Expr<'_>]) { - if_chain! { - // lint if the caller of `ok()` is a `Result` - 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]); - if let Some(error_type) = get_error_type(cx, result_type); - if has_debug_impl(error_type, cx); - - then { - span_lint_and_help( - cx, - OK_EXPECT, - expr.span, - "called `ok().expect()` on a `Result` value", - None, - "you can call `expect()` directly on the `Result`", - ); - } - } -} - /// lint use of `map().flatten()` for `Iterators` and 'Options' fn lint_map_flatten<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_args: &'tcx [hir::Expr<'_>]) { // lint if caller of `.map().flatten()` is an Iterator @@ -3107,31 +2965,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `filter().next()` for `Iterators` -fn lint_filter_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, filter_args: &'tcx [hir::Expr<'_>]) { - // lint if caller of `.filter().next()` is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - let msg = "called `filter(..).next()` on an `Iterator`. This is more succinctly expressed by calling \ - `.find(..)` instead"; - let filter_snippet = snippet(cx, filter_args[1].span, ".."); - if filter_snippet.lines().count() <= 1 { - let iter_snippet = snippet(cx, filter_args[0].span, ".."); - // add note if not multi-line - span_lint_and_sugg( - cx, - FILTER_NEXT, - expr.span, - msg, - "try this", - format!("{}.find({})", iter_snippet, filter_snippet), - Applicability::MachineApplicable, - ); - } else { - span_lint(cx, FILTER_NEXT, expr.span, msg); - } - } -} - /// lint use of `skip_while().next()` for `Iterators` fn lint_skip_while_next<'tcx>( cx: &LateContext<'tcx>, @@ -3914,21 +3747,6 @@ fn lint_map_collect( } } -/// Given a `Result` type, return its error type (`E`). -fn get_error_type<'a>(cx: &LateContext<'_>, ty: Ty<'a>) -> Option> { - match ty.kind() { - ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym::result_type) => substs.types().nth(1), - _ => None, - } -} - -/// This checks whether a given type is known to implement Debug. -fn has_debug_impl<'tcx>(ty: Ty<'tcx>, cx: &LateContext<'tcx>) -> bool { - cx.tcx - .get_diagnostic_item(sym::debug_trait) - .map_or(false, |debug| implements_trait(cx, ty, debug, &[])) -} - enum Convention { Eq(&'static str), StartsWith(&'static str), diff --git a/clippy_lints/src/methods/ok_expect.rs b/clippy_lints/src/methods/ok_expect.rs new file mode 100644 index 0000000000000..c1706cc7cc7d2 --- /dev/null +++ b/clippy_lints/src/methods/ok_expect.rs @@ -0,0 +1,45 @@ +use crate::utils::{implements_trait, is_type_diagnostic_item, span_lint_and_help}; +use if_chain::if_chain; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty}; +use rustc_span::sym; + +use super::OK_EXPECT; + +/// lint use of `ok().expect()` for `Result`s +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ok_args: &[hir::Expr<'_>]) { + if_chain! { + // lint if the caller of `ok()` is a `Result` + 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]); + if let Some(error_type) = get_error_type(cx, result_type); + if has_debug_impl(error_type, cx); + + then { + span_lint_and_help( + cx, + OK_EXPECT, + expr.span, + "called `ok().expect()` on a `Result` value", + None, + "you can call `expect()` directly on the `Result`", + ); + } + } +} + +/// Given a `Result` type, return its error type (`E`). +fn get_error_type<'a>(cx: &LateContext<'_>, ty: Ty<'a>) -> Option> { + match ty.kind() { + ty::Adt(_, substs) if is_type_diagnostic_item(cx, ty, sym::result_type) => substs.types().nth(1), + _ => None, + } +} + +/// This checks whether a given type is known to implement Debug. +fn has_debug_impl<'tcx>(ty: Ty<'tcx>, cx: &LateContext<'tcx>) -> bool { + cx.tcx + .get_diagnostic_item(sym::debug_trait) + .map_or(false, |debug| implements_trait(cx, ty, debug, &[])) +} diff --git a/clippy_lints/src/methods/option_map_unwrap_or.rs b/clippy_lints/src/methods/option_map_unwrap_or.rs index 7763fd5f113fa..7cdd49bbf0307 100644 --- a/clippy_lints/src/methods/option_map_unwrap_or.rs +++ b/clippy_lints/src/methods/option_map_unwrap_or.rs @@ -12,7 +12,7 @@ use rustc_span::{sym, Symbol}; use super::MAP_UNWRAP_OR; /// lint use of `map().unwrap_or()` for `Option`s -pub(super) fn lint<'tcx>( +pub(super) fn check<'tcx>( cx: &LateContext<'tcx>, expr: &rustc_hir::Expr<'_>, map_args: &'tcx [rustc_hir::Expr<'_>], diff --git a/clippy_lints/src/methods/unnecessary_lazy_eval.rs b/clippy_lints/src/methods/unnecessary_lazy_eval.rs index 40ccb8c80b342..a17259d697faa 100644 --- a/clippy_lints/src/methods/unnecessary_lazy_eval.rs +++ b/clippy_lints/src/methods/unnecessary_lazy_eval.rs @@ -9,7 +9,7 @@ use super::UNNECESSARY_LAZY_EVALUATIONS; /// lint use of `_else(simple closure)` for `Option`s and `Result`s that can be /// replaced with `(return value of simple closure)` -pub(super) fn lint<'tcx>( +pub(super) fn check<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, args: &'tcx [hir::Expr<'_>], diff --git a/clippy_lints/src/methods/unwrap_used.rs b/clippy_lints/src/methods/unwrap_used.rs new file mode 100644 index 0000000000000..094c3fc45c493 --- /dev/null +++ b/clippy_lints/src/methods/unwrap_used.rs @@ -0,0 +1,34 @@ +use crate::utils::{is_type_diagnostic_item, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::UNWRAP_USED; + +/// lint use of `unwrap()` for `Option`s and `Result`s +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, unwrap_args: &[hir::Expr<'_>]) { + let obj_ty = cx.typeck_results().expr_ty(&unwrap_args[0]).peel_refs(); + + let mess = if is_type_diagnostic_item(cx, obj_ty, sym::option_type) { + Some((UNWRAP_USED, "an Option", "None")) + } else if is_type_diagnostic_item(cx, obj_ty, sym::result_type) { + Some((UNWRAP_USED, "a Result", "Err")) + } else { + None + }; + + if let Some((lint, kind, none_value)) = mess { + span_lint_and_help( + cx, + lint, + expr.span, + &format!("used `unwrap()` on `{}` value", kind,), + None, + &format!( + "if you don't want to handle the `{}` case gracefully, consider \ + using `expect()` to provide a better panic message", + none_value, + ), + ); + } +} From 483bac2dc0a47df87141a98df1d470b25cd2eda3 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 00:31:15 +0900 Subject: [PATCH 02/35] move skip_while_next to its own module --- clippy_lints/src/methods/mod.rs | 22 ++------------------- clippy_lints/src/methods/skip_while_next.rs | 20 +++++++++++++++++++ 2 files changed, 22 insertions(+), 20 deletions(-) create mode 100644 clippy_lints/src/methods/skip_while_next.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 71080e9bef0c9..34def45a8dd83 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -11,6 +11,7 @@ mod iter_count; mod manual_saturating_arithmetic; mod ok_expect; mod option_map_unwrap_or; +mod skip_while_next; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; @@ -1679,7 +1680,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { } }, ["next", "filter"] => filter_next::check(cx, expr, arg_lists[1]), - ["next", "skip_while"] => lint_skip_while_next(cx, expr, arg_lists[1]), + ["next", "skip_while"] => skip_while_next::check(cx, expr, arg_lists[1]), ["next", "iter"] => lint_iter_next(cx, expr, arg_lists[1]), ["map", "filter"] => lint_filter_map(cx, expr, false), ["map", "filter_map"] => lint_filter_map_map(cx, expr, arg_lists[1], arg_lists[0]), @@ -2965,25 +2966,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `skip_while().next()` for `Iterators` -fn lint_skip_while_next<'tcx>( - cx: &LateContext<'tcx>, - 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) { - span_lint_and_help( - cx, - SKIP_WHILE_NEXT, - expr.span, - "called `skip_while(

).next()` on an `Iterator`", - None, - "this is more succinctly expressed by calling `.find(!

)` instead", - ); - } -} - /// lint use of `filter().map()` or `find().map()` for `Iterators` fn lint_filter_map<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_find: bool) { if_chain! { diff --git a/clippy_lints/src/methods/skip_while_next.rs b/clippy_lints/src/methods/skip_while_next.rs new file mode 100644 index 0000000000000..8ba6ae952003e --- /dev/null +++ b/clippy_lints/src/methods/skip_while_next.rs @@ -0,0 +1,20 @@ +use crate::utils::{match_trait_method, paths, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::SKIP_WHILE_NEXT; + +/// lint use of `skip_while().next()` for `Iterators` +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, 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) { + span_lint_and_help( + cx, + SKIP_WHILE_NEXT, + expr.span, + "called `skip_while(

).next()` on an `Iterator`", + None, + "this is more succinctly expressed by calling `.find(!

)` instead", + ); + } +} From 110dac7f58257a0186daf13688aa8b02fba67bdb Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 00:43:27 +0900 Subject: [PATCH 03/35] move option_as_ref_deref to its own module --- clippy_lints/src/methods/mod.rs | 114 +--------------- .../src/methods/option_as_ref_deref.rs | 122 ++++++++++++++++++ 2 files changed, 125 insertions(+), 111 deletions(-) create mode 100644 clippy_lints/src/methods/option_as_ref_deref.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 34def45a8dd83..c6b6ef34bc442 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -10,6 +10,7 @@ mod inspect_for_each; mod iter_count; mod manual_saturating_arithmetic; mod ok_expect; +mod option_as_ref_deref; mod option_map_unwrap_or; mod skip_while_next; mod unnecessary_filter_map; @@ -1725,10 +1726,10 @@ impl<'tcx> LateLintPass<'tcx> for Methods { }, ["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]), ["map", "as_ref"] => { - lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) + option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) }, ["map", "as_mut"] => { - lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) + option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) }, ["unwrap_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"), ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), @@ -3584,115 +3585,6 @@ fn lint_suspicious_map(cx: &LateContext<'_>, expr: &hir::Expr<'_>) { ); } -const OPTION_AS_REF_DEREF_MSRV: RustcVersion = RustcVersion::new(1, 40, 0); - -/// lint use of `_.as_ref().map(Deref::deref)` for `Option`s -fn lint_option_as_ref_deref<'tcx>( - cx: &LateContext<'tcx>, - expr: &hir::Expr<'_>, - as_ref_args: &[hir::Expr<'_>], - map_args: &[hir::Expr<'_>], - is_mut: bool, - msrv: Option<&RustcVersion>, -) { - if !meets_msrv(msrv, &OPTION_AS_REF_DEREF_MSRV) { - return; - } - - let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not); - - let option_ty = cx.typeck_results().expr_ty(&as_ref_args[0]); - if !is_type_diagnostic_item(cx, option_ty, sym::option_type) { - 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 { - 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)) - }), - hir::ExprKind::Closure(_, _, body_id, _, _) => { - let closure_body = cx.tcx.hir().body(body_id); - let closure_expr = remove_blocks(&closure_body.value); - - match &closure_expr.kind { - hir::ExprKind::MethodCall(_, _, args, _) => { - if_chain! { - if args.len() == 1; - if path_to_local_id(&args[0], closure_body.params[0].pat.hir_id); - let adj = cx - .typeck_results() - .expr_adjustments(&args[0]) - .iter() - .map(|x| &x.kind) - .collect::>(); - if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj; - then { - let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap(); - 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::Deref, ref inner1) = inner.kind; - if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner2) = inner1.kind; - then { - path_to_local_id(inner2, closure_body.params[0].pat.hir_id) - } else { - false - } - } - }, - _ => false, - } - }, - _ => false, - }; - - if is_deref { - let current_method = if is_mut { - format!(".as_mut().map({})", snippet(cx, map_args[1].span, "..")) - } else { - format!(".as_ref().map({})", snippet(cx, map_args[1].span, "..")) - }; - 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!( - "called `{0}` on an Option value. This can be done more directly \ - by calling `{1}` instead", - current_method, hint - ); - span_lint_and_sugg( - cx, - OPTION_AS_REF_DEREF, - expr.span, - &msg, - &suggestion, - hint, - Applicability::MachineApplicable, - ); - } -} - fn lint_map_collect( cx: &LateContext<'_>, expr: &hir::Expr<'_>, diff --git a/clippy_lints/src/methods/option_as_ref_deref.rs b/clippy_lints/src/methods/option_as_ref_deref.rs new file mode 100644 index 0000000000000..89067dbfe0e51 --- /dev/null +++ b/clippy_lints/src/methods/option_as_ref_deref.rs @@ -0,0 +1,122 @@ +use crate::utils::{ + is_type_diagnostic_item, match_def_path, meets_msrv, path_to_local_id, paths, remove_blocks, snippet, + span_lint_and_sugg, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_semver::RustcVersion; +use rustc_span::sym; + +use super::OPTION_AS_REF_DEREF; + +const OPTION_AS_REF_DEREF_MSRV: RustcVersion = RustcVersion::new(1, 40, 0); + +/// lint use of `_.as_ref().map(Deref::deref)` for `Option`s +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &hir::Expr<'_>, + as_ref_args: &[hir::Expr<'_>], + map_args: &[hir::Expr<'_>], + is_mut: bool, + msrv: Option<&RustcVersion>, +) { + if !meets_msrv(msrv, &OPTION_AS_REF_DEREF_MSRV) { + return; + } + + let same_mutability = |m| (is_mut && m == &hir::Mutability::Mut) || (!is_mut && m == &hir::Mutability::Not); + + let option_ty = cx.typeck_results().expr_ty(&as_ref_args[0]); + if !is_type_diagnostic_item(cx, option_ty, sym::option_type) { + 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 { + 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)) + }), + hir::ExprKind::Closure(_, _, body_id, _, _) => { + let closure_body = cx.tcx.hir().body(body_id); + let closure_expr = remove_blocks(&closure_body.value); + + match &closure_expr.kind { + hir::ExprKind::MethodCall(_, _, args, _) => { + if_chain! { + if args.len() == 1; + if path_to_local_id(&args[0], closure_body.params[0].pat.hir_id); + let adj = cx + .typeck_results() + .expr_adjustments(&args[0]) + .iter() + .map(|x| &x.kind) + .collect::>(); + if let [ty::adjustment::Adjust::Deref(None), ty::adjustment::Adjust::Borrow(_)] = *adj; + then { + let method_did = cx.typeck_results().type_dependent_def_id(closure_expr.hir_id).unwrap(); + 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::Deref, ref inner1) = inner.kind; + if let hir::ExprKind::Unary(hir::UnOp::Deref, ref inner2) = inner1.kind; + then { + path_to_local_id(inner2, closure_body.params[0].pat.hir_id) + } else { + false + } + } + }, + _ => false, + } + }, + _ => false, + }; + + if is_deref { + let current_method = if is_mut { + format!(".as_mut().map({})", snippet(cx, map_args[1].span, "..")) + } else { + format!(".as_ref().map({})", snippet(cx, map_args[1].span, "..")) + }; + 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!( + "called `{0}` on an Option value. This can be done more directly \ + by calling `{1}` instead", + current_method, hint + ); + span_lint_and_sugg( + cx, + OPTION_AS_REF_DEREF, + expr.span, + &msg, + &suggestion, + hint, + Applicability::MachineApplicable, + ); + } +} From 60a053725e5c5c3a78e3d0918ca00e9e98324a95 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 00:48:21 +0900 Subject: [PATCH 04/35] move suspicious_map to its own module --- clippy_lints/src/methods/mod.rs | 14 ++------------ clippy_lints/src/methods/suspicious_map.rs | 16 ++++++++++++++++ 2 files changed, 18 insertions(+), 12 deletions(-) create mode 100644 clippy_lints/src/methods/suspicious_map.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index c6b6ef34bc442..a807afb605119 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -13,6 +13,7 @@ mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; mod skip_while_next; +mod suspicious_map; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; @@ -1716,7 +1717,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { unnecessary_filter_map::lint(cx, expr, arg_lists[0]); filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); }, - ["count", "map"] => lint_suspicious_map(cx, expr), + ["count", "map"] => suspicious_map::check(cx, expr), ["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr), ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { manual_saturating_arithmetic::lint(cx, expr, &arg_lists, &arith["checked_".len()..]) @@ -3574,17 +3575,6 @@ fn is_maybe_uninit_ty_valid(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { } } -fn lint_suspicious_map(cx: &LateContext<'_>, expr: &hir::Expr<'_>) { - span_lint_and_help( - cx, - SUSPICIOUS_MAP, - expr.span, - "this call to `map()` won't have an effect on the call to `count()`", - None, - "make sure you did not confuse `map` with `filter` or `for_each`", - ); -} - fn lint_map_collect( cx: &LateContext<'_>, expr: &hir::Expr<'_>, diff --git a/clippy_lints/src/methods/suspicious_map.rs b/clippy_lints/src/methods/suspicious_map.rs new file mode 100644 index 0000000000000..e135a826dc4d0 --- /dev/null +++ b/clippy_lints/src/methods/suspicious_map.rs @@ -0,0 +1,16 @@ +use crate::utils::span_lint_and_help; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::SUSPICIOUS_MAP; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>) { + span_lint_and_help( + cx, + SUSPICIOUS_MAP, + expr.span, + "this call to `map()` won't have an effect on the call to `count()`", + None, + "make sure you did not confuse `map` with `filter` or `for_each`", + ); +} From 8623b331eebfa097bb33dff1df5efa324e6a780a Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 00:55:19 +0900 Subject: [PATCH 05/35] move filetype_is_file to its own module --- clippy_lints/src/methods/filetype_is_file.rs | 39 ++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 35 +----------------- 2 files changed, 41 insertions(+), 33 deletions(-) create mode 100644 clippy_lints/src/methods/filetype_is_file.rs diff --git a/clippy_lints/src/methods/filetype_is_file.rs b/clippy_lints/src/methods/filetype_is_file.rs new file mode 100644 index 0000000000000..b03835f97e634 --- /dev/null +++ b/clippy_lints/src/methods/filetype_is_file.rs @@ -0,0 +1,39 @@ +use crate::utils::{get_parent_expr, match_type, paths, span_lint_and_help}; +use if_chain::if_chain; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::source_map::Span; + +use super::FILETYPE_IS_FILE; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + let ty = cx.typeck_results().expr_ty(&args[0]); + + if !match_type(cx, ty, &paths::FILE_TYPE) { + return; + } + + let span: Span; + let verb: &str; + let lint_unary: &str; + let help_unary: &str; + if_chain! { + if let Some(parent) = get_parent_expr(cx, expr); + if let hir::ExprKind::Unary(op, _) = parent.kind; + if op == hir::UnOp::Not; + then { + lint_unary = "!"; + verb = "denies"; + help_unary = ""; + span = parent.span; + } else { + lint_unary = ""; + verb = "covers"; + help_unary = "!"; + span = expr.span; + } + } + let lint_msg = format!("`{}FileType::is_file()` only {} regular files", lint_unary, verb); + let help_msg = format!("use `{}FileType::is_dir()` instead", help_unary); + span_lint_and_help(cx, FILETYPE_IS_FILE, span, &lint_msg, None, &help_msg); +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index a807afb605119..54a6a4cf93417 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -1,6 +1,7 @@ mod bind_instead_of_map; mod bytes_nth; mod expect_used; +mod filetype_is_file; mod filter_map_identity; mod filter_next; mod get_unwrap; @@ -1725,7 +1726,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => { check_pointer_offset(cx, expr, arg_lists[0]) }, - ["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]), + ["is_file", ..] => filetype_is_file::check(cx, expr, arg_lists[0]), ["map", "as_ref"] => { option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) }, @@ -3859,38 +3860,6 @@ fn check_pointer_offset(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir: } } -fn lint_filetype_is_file(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - let ty = cx.typeck_results().expr_ty(&args[0]); - - if !match_type(cx, ty, &paths::FILE_TYPE) { - return; - } - - let span: Span; - let verb: &str; - let lint_unary: &str; - let help_unary: &str; - if_chain! { - if let Some(parent) = get_parent_expr(cx, expr); - if let hir::ExprKind::Unary(op, _) = parent.kind; - if op == hir::UnOp::Not; - then { - lint_unary = "!"; - verb = "denies"; - help_unary = ""; - span = parent.span; - } else { - lint_unary = ""; - verb = "covers"; - help_unary = "!"; - span = expr.span; - } - } - let lint_msg = format!("`{}FileType::is_file()` only {} regular files", lint_unary, verb); - let help_msg = format!("use `{}FileType::is_dir()` instead", help_unary); - span_lint_and_help(cx, FILETYPE_IS_FILE, span, &lint_msg, None, &help_msg); -} - fn lint_from_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { let ty = cx.typeck_results().expr_ty(expr); let arg_ty = cx.typeck_results().expr_ty(&args[0]); From 35147d4cf342ee479d50afcb70aceab4ea506c2d Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 01:03:47 +0900 Subject: [PATCH 06/35] move uninit_assumed_init to its own module --- clippy_lints/src/methods/mod.rs | 31 ++-------------- .../src/methods/uninit_assumed_init.rs | 35 +++++++++++++++++++ 2 files changed, 37 insertions(+), 29 deletions(-) create mode 100644 clippy_lints/src/methods/uninit_assumed_init.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 54a6a4cf93417..acb8318970ec5 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -15,6 +15,7 @@ mod option_as_ref_deref; mod option_map_unwrap_or; mod skip_while_next; mod suspicious_map; +mod uninit_assumed_init; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; @@ -1719,7 +1720,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); }, ["count", "map"] => suspicious_map::check(cx, expr), - ["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr), + ["assume_init"] => uninit_assumed_init::check(cx, &arg_lists[0][0], expr), ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { manual_saturating_arithmetic::lint(cx, expr, &arg_lists, &arith["checked_".len()..]) }, @@ -3548,34 +3549,6 @@ fn lint_into_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_ } } -/// lint for `MaybeUninit::uninit().assume_init()` (we already have the latter) -fn lint_maybe_uninit(cx: &LateContext<'_>, expr: &hir::Expr<'_>, outer: &hir::Expr<'_>) { - if_chain! { - if let hir::ExprKind::Call(ref callee, ref args) = expr.kind; - if args.is_empty(); - if let hir::ExprKind::Path(ref path) = callee.kind; - if match_qpath(path, &paths::MEM_MAYBEUNINIT_UNINIT); - if !is_maybe_uninit_ty_valid(cx, cx.typeck_results().expr_ty_adjusted(outer)); - then { - span_lint( - cx, - UNINIT_ASSUMED_INIT, - outer.span, - "this call for this type may be undefined behavior" - ); - } - } -} - -fn is_maybe_uninit_ty_valid(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { - match ty.kind() { - 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)), - ty::Adt(ref adt, _) => match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT), - _ => false, - } -} - fn lint_map_collect( cx: &LateContext<'_>, expr: &hir::Expr<'_>, diff --git a/clippy_lints/src/methods/uninit_assumed_init.rs b/clippy_lints/src/methods/uninit_assumed_init.rs new file mode 100644 index 0000000000000..798b66192c818 --- /dev/null +++ b/clippy_lints/src/methods/uninit_assumed_init.rs @@ -0,0 +1,35 @@ +use crate::utils::{match_def_path, match_qpath, paths, span_lint}; +use if_chain::if_chain; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty}; + +use super::UNINIT_ASSUMED_INIT; + +/// lint for `MaybeUninit::uninit().assume_init()` (we already have the latter) +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, outer: &hir::Expr<'_>) { + if_chain! { + if let hir::ExprKind::Call(ref callee, ref args) = expr.kind; + if args.is_empty(); + if let hir::ExprKind::Path(ref path) = callee.kind; + if match_qpath(path, &paths::MEM_MAYBEUNINIT_UNINIT); + if !is_maybe_uninit_ty_valid(cx, cx.typeck_results().expr_ty_adjusted(outer)); + then { + span_lint( + cx, + UNINIT_ASSUMED_INIT, + outer.span, + "this call for this type may be undefined behavior" + ); + } + } +} + +fn is_maybe_uninit_ty_valid(cx: &LateContext<'_>, ty: Ty<'_>) -> bool { + match ty.kind() { + 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)), + ty::Adt(ref adt, _) => match_def_path(cx, adt.did, &paths::MEM_MAYBEUNINIT), + _ => false, + } +} From 45ee914df0c1d1a6a15272bd6833023dd4185b9b Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 01:09:33 +0900 Subject: [PATCH 07/35] move iter_cloned_collect to its own module --- .../src/methods/iter_cloned_collect.rs | 30 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 24 ++------------- 2 files changed, 32 insertions(+), 22 deletions(-) create mode 100644 clippy_lints/src/methods/iter_cloned_collect.rs diff --git a/clippy_lints/src/methods/iter_cloned_collect.rs b/clippy_lints/src/methods/iter_cloned_collect.rs new file mode 100644 index 0000000000000..c3e48ffa5fae4 --- /dev/null +++ b/clippy_lints/src/methods/iter_cloned_collect.rs @@ -0,0 +1,30 @@ +use crate::methods::derefs_to_slice; +use crate::utils::{is_type_diagnostic_item, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::ITER_CLONED_COLLECT; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) { + if_chain! { + 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])); + 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 \ + more readable", + "try", + ".to_vec()".to_string(), + Applicability::MachineApplicable, + ); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index acb8318970ec5..92d8077c1ab2d 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -8,6 +8,7 @@ mod get_unwrap; mod implicit_clone; mod inefficient_to_string; mod inspect_for_each; +mod iter_cloned_collect; mod iter_count; mod manual_saturating_arithmetic; mod ok_expect; @@ -1711,7 +1712,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]), ["step_by", ..] => lint_step_by(cx, expr, arg_lists[0]), ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]), - ["collect", "cloned"] => lint_iter_cloned_collect(cx, expr, arg_lists[1]), + ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]), ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]), ["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]), @@ -2494,27 +2495,6 @@ fn lint_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_> } } -fn lint_iter_cloned_collect<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) { - if_chain! { - 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])); - 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 \ - more readable", - "try", - ".to_vec()".to_string(), - Applicability::MachineApplicable, - ); - } - } -} - fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) { fn check_fold_with_op( cx: &LateContext<'_>, From 6376da70be18d6cb9dbe22b5a661896cf916bc51 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Wed, 3 Mar 2021 01:16:16 +0900 Subject: [PATCH 08/35] replace `lints` and `lint` with `check` --- .../src/methods/bind_instead_of_map.rs | 2 +- clippy_lints/src/methods/bytes_nth.rs | 2 +- .../src/methods/inefficient_to_string.rs | 2 +- clippy_lints/src/methods/inspect_for_each.rs | 2 +- clippy_lints/src/methods/iter_count.rs | 2 +- .../methods/manual_saturating_arithmetic.rs | 2 +- clippy_lints/src/methods/mod.rs | 22 +++++++++---------- .../src/methods/unnecessary_filter_map.rs | 2 +- 8 files changed, 18 insertions(+), 18 deletions(-) diff --git a/clippy_lints/src/methods/bind_instead_of_map.rs b/clippy_lints/src/methods/bind_instead_of_map.rs index 540a1484a8558..5decb81d9f2e2 100644 --- a/clippy_lints/src/methods/bind_instead_of_map.rs +++ b/clippy_lints/src/methods/bind_instead_of_map.rs @@ -158,7 +158,7 @@ pub(crate) trait BindInsteadOfMap { } /// Lint use of `_.and_then(|x| Some(y))` for `Option`s - fn lint(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) -> bool { + fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) -> bool { if !match_type(cx, cx.typeck_results().expr_ty(&args[0]), Self::TYPE_QPATH) { return false; } diff --git a/clippy_lints/src/methods/bytes_nth.rs b/clippy_lints/src/methods/bytes_nth.rs index defc50ede2243..71a7e195e41ce 100644 --- a/clippy_lints/src/methods/bytes_nth.rs +++ b/clippy_lints/src/methods/bytes_nth.rs @@ -7,7 +7,7 @@ use rustc_span::sym; use super::BYTES_NTH; -pub(super) fn lints<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>]) { +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>]) { if_chain! { if let ExprKind::MethodCall(_, _, ref args, _) = expr.kind; let ty = cx.typeck_results().expr_ty(&iter_args[0]).peel_refs(); diff --git a/clippy_lints/src/methods/inefficient_to_string.rs b/clippy_lints/src/methods/inefficient_to_string.rs index c83b6f2c32963..3045b09c2389f 100644 --- a/clippy_lints/src/methods/inefficient_to_string.rs +++ b/clippy_lints/src/methods/inefficient_to_string.rs @@ -10,7 +10,7 @@ use rustc_middle::ty::{self, Ty}; use rustc_span::sym; /// Checks for the `INEFFICIENT_TO_STRING` lint -pub fn lint<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'tcx>) { +pub fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'tcx>) { if_chain! { if let Some(to_string_meth_did) = cx.typeck_results().type_dependent_def_id(expr.hir_id); if match_def_path(cx, to_string_meth_did, &paths::TO_STRING_METHOD); diff --git a/clippy_lints/src/methods/inspect_for_each.rs b/clippy_lints/src/methods/inspect_for_each.rs index 6d41ee38a2767..959457a5bfc96 100644 --- a/clippy_lints/src/methods/inspect_for_each.rs +++ b/clippy_lints/src/methods/inspect_for_each.rs @@ -7,7 +7,7 @@ use crate::utils::{match_trait_method, paths, span_lint_and_help}; use super::INSPECT_FOR_EACH; /// lint use of `inspect().for_each()` for `Iterators` -pub(super) fn lint<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, inspect_span: Span) { +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, inspect_span: Span) { if match_trait_method(cx, expr, &paths::ITERATOR) { let msg = "called `inspect(..).for_each(..)` on an `Iterator`"; let hint = "move the code from `inspect(..)` to `for_each(..)` and remove the `inspect(..)`"; diff --git a/clippy_lints/src/methods/iter_count.rs b/clippy_lints/src/methods/iter_count.rs index 71d65a01d3e85..869440e0165b2 100644 --- a/clippy_lints/src/methods/iter_count.rs +++ b/clippy_lints/src/methods/iter_count.rs @@ -8,7 +8,7 @@ use rustc_span::sym; use super::ITER_COUNT; -pub(crate) fn lints<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>], iter_method: &str) { +pub(crate) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>, iter_args: &'tcx [Expr<'tcx>], iter_method: &str) { let ty = cx.typeck_results().expr_ty(&iter_args[0]); let caller_type = if derefs_to_slice(cx, &iter_args[0], ty).is_some() { "slice" diff --git a/clippy_lints/src/methods/manual_saturating_arithmetic.rs b/clippy_lints/src/methods/manual_saturating_arithmetic.rs index eaa604c2ae63e..0b414e0eb9567 100644 --- a/clippy_lints/src/methods/manual_saturating_arithmetic.rs +++ b/clippy_lints/src/methods/manual_saturating_arithmetic.rs @@ -6,7 +6,7 @@ use rustc_hir as hir; use rustc_lint::LateContext; use rustc_target::abi::LayoutOf; -pub fn lint(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[&[hir::Expr<'_>]], arith: &str) { +pub fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[&[hir::Expr<'_>]], arith: &str) { let unwrap_arg = &args[0][1]; let arith_lhs = &args[1][0]; let arith_rhs = &args[1][1]; diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 92d8077c1ab2d..639d013f786cd 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -1673,14 +1673,14 @@ impl<'tcx> LateLintPass<'tcx> for Methods { }, ["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]), ["and_then", ..] => { - let biom_option_linted = bind_instead_of_map::OptionAndThenSome::lint(cx, expr, arg_lists[0]); - let biom_result_linted = bind_instead_of_map::ResultAndThenOk::lint(cx, expr, arg_lists[0]); + let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, arg_lists[0]); + let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, arg_lists[0]); if !biom_option_linted && !biom_result_linted { unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "and"); } }, ["or_else", ..] => { - if !bind_instead_of_map::ResultOrElseErrInfo::lint(cx, expr, arg_lists[0]) { + if !bind_instead_of_map::ResultOrElseErrInfo::check(cx, expr, arg_lists[0]) { unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "or"); } }, @@ -1703,12 +1703,12 @@ impl<'tcx> LateLintPass<'tcx> for Methods { lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1]) }, ["extend", ..] => lint_extend(cx, expr, arg_lists[0]), - ["count", "into_iter"] => iter_count::lints(cx, expr, &arg_lists[1], "into_iter"), - ["count", "iter"] => iter_count::lints(cx, expr, &arg_lists[1], "iter"), - ["count", "iter_mut"] => iter_count::lints(cx, expr, &arg_lists[1], "iter_mut"), + ["count", "into_iter"] => iter_count::check(cx, expr, &arg_lists[1], "into_iter"), + ["count", "iter"] => iter_count::check(cx, expr, &arg_lists[1], "iter"), + ["count", "iter_mut"] => iter_count::check(cx, expr, &arg_lists[1], "iter_mut"), ["nth", "iter"] => lint_iter_nth(cx, expr, &arg_lists, false), ["nth", "iter_mut"] => lint_iter_nth(cx, expr, &arg_lists, true), - ["nth", "bytes"] => bytes_nth::lints(cx, expr, &arg_lists[1]), + ["nth", "bytes"] => bytes_nth::check(cx, expr, &arg_lists[1]), ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]), ["step_by", ..] => lint_step_by(cx, expr, arg_lists[0]), ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]), @@ -1717,13 +1717,13 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]), ["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]), ["filter_map", ..] => { - unnecessary_filter_map::lint(cx, expr, arg_lists[0]); + unnecessary_filter_map::check(cx, expr, arg_lists[0]); filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); }, ["count", "map"] => suspicious_map::check(cx, expr), ["assume_init"] => uninit_assumed_init::check(cx, &arg_lists[0][0], expr), ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { - manual_saturating_arithmetic::lint(cx, expr, &arg_lists, &arith["checked_".len()..]) + manual_saturating_arithmetic::check(cx, expr, &arg_lists, &arith["checked_".len()..]) }, ["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => { check_pointer_offset(cx, expr, arg_lists[0]) @@ -1739,7 +1739,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), ["ok_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "ok_or"), ["collect", "map"] => lint_map_collect(cx, expr, arg_lists[1], arg_lists[0]), - ["for_each", "inspect"] => inspect_for_each::lint(cx, expr, method_spans[1]), + ["for_each", "inspect"] => inspect_for_each::check(cx, expr, method_spans[1]), ["to_owned", ..] => implicit_clone::check(cx, expr, sym::ToOwned), ["to_os_string", ..] => implicit_clone::check(cx, expr, sym::OsStr), ["to_path_buf", ..] => implicit_clone::check(cx, expr, sym::Path), @@ -1765,7 +1765,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { lint_clone_on_ref_ptr(cx, expr, &args[0]); } if args.len() == 1 && method_call.ident.name == sym!(to_string) { - inefficient_to_string::lint(cx, expr, &args[0], self_ty); + inefficient_to_string::check(cx, expr, &args[0], self_ty); } if let Some(fn_def_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) { diff --git a/clippy_lints/src/methods/unnecessary_filter_map.rs b/clippy_lints/src/methods/unnecessary_filter_map.rs index 5691fcb88e95c..12b2cf0a16582 100644 --- a/clippy_lints/src/methods/unnecessary_filter_map.rs +++ b/clippy_lints/src/methods/unnecessary_filter_map.rs @@ -9,7 +9,7 @@ use if_chain::if_chain; use super::UNNECESSARY_FILTER_MAP; -pub(super) fn lint(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { if !match_trait_method(cx, expr, &paths::ITERATOR) { return; } From 9b0a42b67d66cb79bdd09379d0b0e7959fc1505a Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 4 Mar 2021 19:46:44 +0900 Subject: [PATCH 09/35] move zst_offset to its own module --- clippy_lints/src/methods/mod.rs | 15 ++------------- clippy_lints/src/methods/zst_offset.rs | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+), 13 deletions(-) create mode 100644 clippy_lints/src/methods/zst_offset.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 639d013f786cd..c944568dc6194 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -20,6 +20,7 @@ mod uninit_assumed_init; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; +mod zst_offset; use std::borrow::Cow; use std::fmt; @@ -1726,7 +1727,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { manual_saturating_arithmetic::check(cx, expr, &arg_lists, &arith["checked_".len()..]) }, ["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => { - check_pointer_offset(cx, expr, arg_lists[0]) + zst_offset::check(cx, expr, arg_lists[0]) }, ["is_file", ..] => filetype_is_file::check(cx, expr, arg_lists[0]), ["map", "as_ref"] => { @@ -3801,18 +3802,6 @@ fn is_bool(ty: &hir::Ty<'_>) -> bool { } } -fn check_pointer_offset(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - if_chain! { - if args.len() == 2; - if let ty::RawPtr(ty::TypeAndMut { ref ty, .. }) = cx.typeck_results().expr_ty(&args[0]).kind(); - 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"); - } - } -} - fn lint_from_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { let ty = cx.typeck_results().expr_ty(expr); let arg_ty = cx.typeck_results().expr_ty(&args[0]); diff --git a/clippy_lints/src/methods/zst_offset.rs b/clippy_lints/src/methods/zst_offset.rs new file mode 100644 index 0000000000000..f1335726736ca --- /dev/null +++ b/clippy_lints/src/methods/zst_offset.rs @@ -0,0 +1,19 @@ +use crate::utils::span_lint; +use if_chain::if_chain; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; + +use super::ZST_OFFSET; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + if_chain! { + if args.len() == 2; + if let ty::RawPtr(ty::TypeAndMut { ref ty, .. }) = cx.typeck_results().expr_ty(&args[0]).kind(); + 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"); + } + } +} From db91d9cf9a620cc258ab84a152a9333351ac166e Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 4 Mar 2021 19:47:06 +0900 Subject: [PATCH 10/35] move map_collect_result_unit to its own module --- .../src/methods/map_collect_result_unit.rs | 45 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 39 +--------------- 2 files changed, 47 insertions(+), 37 deletions(-) create mode 100644 clippy_lints/src/methods/map_collect_result_unit.rs diff --git a/clippy_lints/src/methods/map_collect_result_unit.rs b/clippy_lints/src/methods/map_collect_result_unit.rs new file mode 100644 index 0000000000000..5b20e268d9f7e --- /dev/null +++ b/clippy_lints/src/methods/map_collect_result_unit.rs @@ -0,0 +1,45 @@ +use crate::utils::{is_type_diagnostic_item, match_trait_method, paths, snippet, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::symbol::sym; + +use super::MAP_COLLECT_RESULT_UNIT; + +pub(super) fn check( + cx: &LateContext<'_>, + expr: &hir::Expr<'_>, + map_args: &[hir::Expr<'_>], + collect_args: &[hir::Expr<'_>], +) { + if_chain! { + // called on Iterator + if let [map_expr] = collect_args; + if match_trait_method(cx, map_expr, &paths::ITERATOR); + // return of collect `Result<(),_>` + let collect_ret_ty = cx.typeck_results().expr_ty(expr); + if is_type_diagnostic_item(cx, collect_ret_ty, sym::result_type); + if let ty::Adt(_, substs) = collect_ret_ty.kind(); + if let Some(result_t) = substs.types().next(); + if result_t.is_unit(); + // get parts for snippet + if let [iter, map_fn] = map_args; + then { + span_lint_and_sugg( + cx, + MAP_COLLECT_RESULT_UNIT, + expr.span, + "`.map().collect()` can be replaced with `.try_for_each()`", + "try this", + format!( + "{}.try_for_each({})", + snippet(cx, iter.span, ".."), + snippet(cx, map_fn.span, "..") + ), + Applicability::MachineApplicable, + ); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index c944568dc6194..baa342ab3bb8c 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -11,6 +11,7 @@ mod inspect_for_each; mod iter_cloned_collect; mod iter_count; mod manual_saturating_arithmetic; +mod map_collect_result_unit; mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; @@ -1739,7 +1740,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["unwrap_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"), ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), ["ok_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "ok_or"), - ["collect", "map"] => lint_map_collect(cx, expr, arg_lists[1], arg_lists[0]), + ["collect", "map"] => map_collect_result_unit::check(cx, expr, arg_lists[1], arg_lists[0]), ["for_each", "inspect"] => inspect_for_each::check(cx, expr, method_spans[1]), ["to_owned", ..] => implicit_clone::check(cx, expr, sym::ToOwned), ["to_os_string", ..] => implicit_clone::check(cx, expr, sym::OsStr), @@ -3530,42 +3531,6 @@ fn lint_into_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_ } } -fn lint_map_collect( - cx: &LateContext<'_>, - expr: &hir::Expr<'_>, - map_args: &[hir::Expr<'_>], - collect_args: &[hir::Expr<'_>], -) { - if_chain! { - // called on Iterator - if let [map_expr] = collect_args; - if match_trait_method(cx, map_expr, &paths::ITERATOR); - // return of collect `Result<(),_>` - let collect_ret_ty = cx.typeck_results().expr_ty(expr); - if is_type_diagnostic_item(cx, collect_ret_ty, sym::result_type); - if let ty::Adt(_, substs) = collect_ret_ty.kind(); - if let Some(result_t) = substs.types().next(); - if result_t.is_unit(); - // get parts for snippet - if let [iter, map_fn] = map_args; - then { - span_lint_and_sugg( - cx, - MAP_COLLECT_RESULT_UNIT, - expr.span, - "`.map().collect()` can be replaced with `.try_for_each()`", - "try this", - format!( - "{}.try_for_each({})", - snippet(cx, iter.span, ".."), - snippet(cx, map_fn.span, "..") - ), - Applicability::MachineApplicable, - ); - } - } -} - enum Convention { Eq(&'static str), StartsWith(&'static str), From 3fe099ba8d2f6f4d085e7480f020f9f87e6b39e8 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 4 Mar 2021 22:50:53 +0900 Subject: [PATCH 11/35] move iter_next_slice to its own module --- clippy_lints/src/methods/iter_next_slice.rs | 68 +++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 66 ++------------------ 2 files changed, 73 insertions(+), 61 deletions(-) create mode 100644 clippy_lints/src/methods/iter_next_slice.rs diff --git a/clippy_lints/src/methods/iter_next_slice.rs b/clippy_lints/src/methods/iter_next_slice.rs new file mode 100644 index 0000000000000..3c03a949cfed0 --- /dev/null +++ b/clippy_lints/src/methods/iter_next_slice.rs @@ -0,0 +1,68 @@ +use crate::methods::derefs_to_slice; +use crate::utils::{get_parent_expr, higher, is_type_diagnostic_item, snippet_with_applicability, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_ast::ast; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::symbol::sym; + +use super::ITER_NEXT_SLICE; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) { + let caller_expr = &iter_args[0]; + + // Skip lint if the `iter().next()` expression is a for loop argument, + // since it is already covered by `&loops::ITER_NEXT_LOOP` + let mut parent_expr_opt = get_parent_expr(cx, expr); + while let Some(parent_expr) = parent_expr_opt { + if higher::for_loop(parent_expr).is_some() { + return; + } + parent_expr_opt = get_parent_expr(cx, parent_expr); + } + + if derefs_to_slice(cx, caller_expr, cx.typeck_results().expr_ty(caller_expr)).is_some() { + // caller is a Slice + if_chain! { + if let hir::ExprKind::Index(ref caller_var, ref index_expr) = &caller_expr.kind; + if let Some(higher::Range { start: Some(start_expr), end: None, limits: ast::RangeLimits::HalfOpen }) + = higher::range(index_expr); + if let hir::ExprKind::Lit(ref start_lit) = &start_expr.kind; + if let ast::LitKind::Int(start_idx, _) = start_lit.node; + then { + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + ITER_NEXT_SLICE, + expr.span, + "using `.iter().next()` on a Slice without end index", + "try calling", + format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx), + applicability, + ); + } + } + } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(caller_expr), sym::vec_type) + || matches!( + &cx.typeck_results().expr_ty(caller_expr).peel_refs().kind(), + ty::Array(_, _) + ) + { + // caller is a Vec or an Array + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + ITER_NEXT_SLICE, + expr.span, + "using `.iter().next()` on an array", + "try calling", + format!( + "{}.get(0)", + snippet_with_applicability(cx, caller_expr.span, "..", &mut applicability) + ), + applicability, + ); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index baa342ab3bb8c..46c9524af5536 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -10,6 +10,7 @@ mod inefficient_to_string; mod inspect_for_each; mod iter_cloned_collect; mod iter_count; +mod iter_next_slice; mod manual_saturating_arithmetic; mod map_collect_result_unit; mod ok_expect; @@ -46,9 +47,9 @@ use crate::consts::{constant, Constant}; use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ - contains_return, contains_ty, get_parent_expr, get_trait_def_id, has_iter_method, higher, implements_trait, - in_macro, is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, - match_qpath, match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, + contains_return, contains_ty, get_parent_expr, get_trait_def_id, has_iter_method, implements_trait, in_macro, + is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, + match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, strip_pat_refs, sugg, walk_ptrs_ty_depth, SpanlessEq, @@ -1688,7 +1689,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { }, ["next", "filter"] => filter_next::check(cx, expr, arg_lists[1]), ["next", "skip_while"] => skip_while_next::check(cx, expr, arg_lists[1]), - ["next", "iter"] => lint_iter_next(cx, expr, arg_lists[1]), + ["next", "iter"] => iter_next_slice::check(cx, expr, arg_lists[1]), ["map", "filter"] => lint_filter_map(cx, expr, false), ["map", "filter_map"] => lint_filter_map_map(cx, expr, arg_lists[1], arg_lists[0]), ["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1], self.msrv.as_ref()), @@ -2598,63 +2599,6 @@ fn lint_step_by<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, args: &'tcx } } -fn lint_iter_next<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, iter_args: &'tcx [hir::Expr<'_>]) { - let caller_expr = &iter_args[0]; - - // Skip lint if the `iter().next()` expression is a for loop argument, - // since it is already covered by `&loops::ITER_NEXT_LOOP` - let mut parent_expr_opt = get_parent_expr(cx, expr); - while let Some(parent_expr) = parent_expr_opt { - if higher::for_loop(parent_expr).is_some() { - return; - } - parent_expr_opt = get_parent_expr(cx, parent_expr); - } - - if derefs_to_slice(cx, caller_expr, cx.typeck_results().expr_ty(caller_expr)).is_some() { - // caller is a Slice - if_chain! { - if let hir::ExprKind::Index(ref caller_var, ref index_expr) = &caller_expr.kind; - if let Some(higher::Range { start: Some(start_expr), end: None, limits: ast::RangeLimits::HalfOpen }) - = higher::range(index_expr); - if let hir::ExprKind::Lit(ref start_lit) = &start_expr.kind; - if let ast::LitKind::Int(start_idx, _) = start_lit.node; - then { - let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - ITER_NEXT_SLICE, - expr.span, - "using `.iter().next()` on a Slice without end index", - "try calling", - format!("{}.get({})", snippet_with_applicability(cx, caller_var.span, "..", &mut applicability), start_idx), - applicability, - ); - } - } - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(caller_expr), sym::vec_type) - || matches!( - &cx.typeck_results().expr_ty(caller_expr).peel_refs().kind(), - ty::Array(_, _) - ) - { - // caller is a Vec or an Array - let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - ITER_NEXT_SLICE, - expr.span, - "using `.iter().next()` on an array", - "try calling", - format!( - "{}.get(0)", - snippet_with_applicability(cx, caller_expr.span, "..", &mut applicability) - ), - applicability, - ); - } -} - fn lint_iter_nth<'tcx>( cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, From 5912ca986c52041d01384393cbf2da10270738ee Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 4 Mar 2021 23:06:05 +0900 Subject: [PATCH 12/35] move iter_nth, iter_nth_zero and iterator_step_by_zero to their own module --- clippy_lints/src/methods/iter_nth.rs | 38 ++++++++++ clippy_lints/src/methods/iter_nth_zero.rs | 27 +++++++ .../src/methods/iterator_step_by_zero.rs | 19 +++++ clippy_lints/src/methods/mod.rs | 74 ++----------------- 4 files changed, 91 insertions(+), 67 deletions(-) create mode 100644 clippy_lints/src/methods/iter_nth.rs create mode 100644 clippy_lints/src/methods/iter_nth_zero.rs create mode 100644 clippy_lints/src/methods/iterator_step_by_zero.rs diff --git a/clippy_lints/src/methods/iter_nth.rs b/clippy_lints/src/methods/iter_nth.rs new file mode 100644 index 0000000000000..c8adea9536b2d --- /dev/null +++ b/clippy_lints/src/methods/iter_nth.rs @@ -0,0 +1,38 @@ +use crate::methods::derefs_to_slice; +use crate::methods::iter_nth_zero; +use crate::utils::{is_type_diagnostic_item, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::symbol::sym; + +use super::ITER_NTH; + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &hir::Expr<'_>, + nth_and_iter_args: &[&'tcx [hir::Expr<'tcx>]], + is_mut: bool, +) { + let iter_args = nth_and_iter_args[1]; + let mut_str = if is_mut { "_mut" } else { "" }; + let caller_type = if derefs_to_slice(cx, &iter_args[0], cx.typeck_results().expr_ty(&iter_args[0])).is_some() { + "slice" + } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym::vec_type) { + "Vec" + } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym!(vecdeque_type)) { + "VecDeque" + } else { + let nth_args = nth_and_iter_args[0]; + iter_nth_zero::check(cx, expr, &nth_args); + return; // caller is not a type that we want to lint + }; + + span_lint_and_help( + cx, + ITER_NTH, + expr.span, + &format!("called `.iter{0}().nth()` on a {1}", mut_str, caller_type), + None, + &format!("calling `.get{}()` is both faster and more readable", mut_str), + ); +} diff --git a/clippy_lints/src/methods/iter_nth_zero.rs b/clippy_lints/src/methods/iter_nth_zero.rs new file mode 100644 index 0000000000000..247192d81f3ec --- /dev/null +++ b/clippy_lints/src/methods/iter_nth_zero.rs @@ -0,0 +1,27 @@ +use crate::consts::{constant, Constant}; +use crate::utils::{match_trait_method, paths, snippet_with_applicability, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::ITER_NTH_ZERO; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_args: &'tcx [hir::Expr<'_>]) { + if_chain! { + if match_trait_method(cx, expr, &paths::ITERATOR); + if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &nth_args[1]); + then { + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + ITER_NTH_ZERO, + expr.span, + "called `.nth(0)` on a `std::iter::Iterator`, when `.next()` is equivalent", + "try calling `.next()` instead of `.nth(0)`", + format!("{}.next()", snippet_with_applicability(cx, nth_args[0].span, "..", &mut applicability)), + applicability, + ); + } + } +} diff --git a/clippy_lints/src/methods/iterator_step_by_zero.rs b/clippy_lints/src/methods/iterator_step_by_zero.rs new file mode 100644 index 0000000000000..3e05d7f76b75a --- /dev/null +++ b/clippy_lints/src/methods/iterator_step_by_zero.rs @@ -0,0 +1,19 @@ +use crate::consts::{constant, Constant}; +use crate::utils::{match_trait_method, paths, span_lint}; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::ITERATOR_STEP_BY_ZERO; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, args: &'tcx [hir::Expr<'_>]) { + if match_trait_method(cx, expr, &paths::ITERATOR) { + if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &args[1]) { + span_lint( + cx, + ITERATOR_STEP_BY_ZERO, + expr.span, + "`Iterator::step_by(0)` will panic at runtime", + ); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 46c9524af5536..259d370550c84 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -11,6 +11,9 @@ mod inspect_for_each; mod iter_cloned_collect; mod iter_count; mod iter_next_slice; +mod iter_nth; +mod iter_nth_zero; +mod iterator_step_by_zero; mod manual_saturating_arithmetic; mod map_collect_result_unit; mod ok_expect; @@ -43,7 +46,6 @@ use rustc_span::source_map::Span; use rustc_span::symbol::{sym, Symbol, SymbolStr}; use rustc_typeck::hir_ty_to_ty; -use crate::consts::{constant, Constant}; use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ @@ -1709,11 +1711,11 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["count", "into_iter"] => iter_count::check(cx, expr, &arg_lists[1], "into_iter"), ["count", "iter"] => iter_count::check(cx, expr, &arg_lists[1], "iter"), ["count", "iter_mut"] => iter_count::check(cx, expr, &arg_lists[1], "iter_mut"), - ["nth", "iter"] => lint_iter_nth(cx, expr, &arg_lists, false), - ["nth", "iter_mut"] => lint_iter_nth(cx, expr, &arg_lists, true), + ["nth", "iter"] => iter_nth::check(cx, expr, &arg_lists, false), + ["nth", "iter_mut"] => iter_nth::check(cx, expr, &arg_lists, true), ["nth", "bytes"] => bytes_nth::check(cx, expr, &arg_lists[1]), - ["nth", ..] => lint_iter_nth_zero(cx, expr, arg_lists[0]), - ["step_by", ..] => lint_step_by(cx, expr, arg_lists[0]), + ["nth", ..] => iter_nth_zero::check(cx, expr, arg_lists[0]), + ["step_by", ..] => iterator_step_by_zero::check(cx, expr, arg_lists[0]), ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]), ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]), @@ -2586,68 +2588,6 @@ fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: } } -fn lint_step_by<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, args: &'tcx [hir::Expr<'_>]) { - if match_trait_method(cx, expr, &paths::ITERATOR) { - if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &args[1]) { - span_lint( - cx, - ITERATOR_STEP_BY_ZERO, - expr.span, - "`Iterator::step_by(0)` will panic at runtime", - ); - } - } -} - -fn lint_iter_nth<'tcx>( - cx: &LateContext<'tcx>, - expr: &hir::Expr<'_>, - nth_and_iter_args: &[&'tcx [hir::Expr<'tcx>]], - is_mut: bool, -) { - let iter_args = nth_and_iter_args[1]; - let mut_str = if is_mut { "_mut" } else { "" }; - let caller_type = if derefs_to_slice(cx, &iter_args[0], cx.typeck_results().expr_ty(&iter_args[0])).is_some() { - "slice" - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym::vec_type) { - "Vec" - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym::vecdeque_type) { - "VecDeque" - } else { - let nth_args = nth_and_iter_args[0]; - lint_iter_nth_zero(cx, expr, &nth_args); - return; // caller is not a type that we want to lint - }; - - span_lint_and_help( - cx, - ITER_NTH, - expr.span, - &format!("called `.iter{0}().nth()` on a {1}", mut_str, caller_type), - None, - &format!("calling `.get{}()` is both faster and more readable", mut_str), - ); -} - -fn lint_iter_nth_zero<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, nth_args: &'tcx [hir::Expr<'_>]) { - if_chain! { - if match_trait_method(cx, expr, &paths::ITERATOR); - if let Some((Constant::Int(0), _)) = constant(cx, cx.typeck_results(), &nth_args[1]); - then { - let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - ITER_NTH_ZERO, - expr.span, - "called `.nth(0)` on a `std::iter::Iterator`, when `.next()` is equivalent", - "try calling `.next()` instead of `.nth(0)`", - format!("{}.next()", snippet_with_applicability(cx, nth_args[0].span, "..", &mut applicability)), - applicability, - ); - } - } -} - fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) { // lint if caller of skip is an Iterator if match_trait_method(cx, expr, &paths::ITERATOR) { From b5d809a660240d5c826989839bd5eaab63fbb312 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 4 Mar 2021 23:47:30 +0900 Subject: [PATCH 13/35] move wrong_self_convention to its own module --- clippy_lints/src/methods/mod.rs | 81 +++---------------- .../src/methods/wrong_self_convention.rs | 76 +++++++++++++++++ 2 files changed, 86 insertions(+), 71 deletions(-) create mode 100644 clippy_lints/src/methods/wrong_self_convention.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 259d370550c84..3cd720bc9ca70 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -25,10 +25,10 @@ mod uninit_assumed_init; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; +mod wrong_self_convention; mod zst_offset; use std::borrow::Cow; -use std::fmt; use std::iter; use bind_instead_of_map::BindInsteadOfMap; @@ -1868,7 +1868,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { } } - lint_wrong_self_convention( + wrong_self_convention::check( cx, &name, item.vis.node.is_pub(), @@ -1924,7 +1924,14 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let self_ty = TraitRef::identity(cx.tcx, item.def_id.to_def_id()).self_ty(); then { - lint_wrong_self_convention(cx, &item.ident.name.as_str(), false, self_ty, first_arg_ty, first_arg_span); + wrong_self_convention::check( + cx, + &item.ident.name.as_str(), + false, + self_ty, + first_arg_ty, + first_arg_span + ); } } @@ -1949,39 +1956,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods { extract_msrv_attr!(LateContext); } -fn lint_wrong_self_convention<'tcx>( - cx: &LateContext<'tcx>, - item_name: &str, - is_pub: bool, - self_ty: &'tcx TyS<'tcx>, - first_arg_ty: &'tcx TyS<'tcx>, - first_arg_span: Span, -) { - let lint = if is_pub { - WRONG_PUB_SELF_CONVENTION - } else { - WRONG_SELF_CONVENTION - }; - if let Some((ref conv, self_kinds)) = &CONVENTIONS.iter().find(|(ref conv, _)| conv.check(item_name)) { - if !self_kinds.iter().any(|k| k.matches(cx, self_ty, first_arg_ty)) { - span_lint( - cx, - lint, - first_arg_span, - &format!( - "methods called `{}` usually take {}; consider choosing a less ambiguous name", - conv, - &self_kinds - .iter() - .map(|k| k.description()) - .collect::>() - .join(" or ") - ), - ); - } - } -} - /// Checks for the `OR_FUN_CALL` lint. #[allow(clippy::too_many_lines)] fn lint_or_fun_call<'tcx>( @@ -3415,22 +3389,6 @@ fn lint_into_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_ } } -enum Convention { - Eq(&'static str), - StartsWith(&'static str), -} - -#[rustfmt::skip] -const CONVENTIONS: [(Convention, &[SelfKind]); 7] = [ - (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]), - (Convention::Eq("to_mut"), &[SelfKind::RefMut]), - (Convention::StartsWith("to_"), &[SelfKind::Ref]), -]; - const FN_HEADER: hir::FnHeader = hir::FnHeader { unsafety: hir::Unsafety::Normal, constness: hir::Constness::NotConst, @@ -3602,25 +3560,6 @@ impl SelfKind { } } -impl Convention { - #[must_use] - fn check(&self, other: &str) -> bool { - match *self { - Self::Eq(this) => this == other, - Self::StartsWith(this) => other.starts_with(this) && this != other, - } - } -} - -impl fmt::Display for Convention { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> { - match *self { - Self::Eq(this) => this.fmt(f), - Self::StartsWith(this) => this.fmt(f).and_then(|_| '*'.fmt(f)), - } - } -} - #[derive(Clone, Copy)] enum OutType { Unit, diff --git a/clippy_lints/src/methods/wrong_self_convention.rs b/clippy_lints/src/methods/wrong_self_convention.rs new file mode 100644 index 0000000000000..90fab57743661 --- /dev/null +++ b/clippy_lints/src/methods/wrong_self_convention.rs @@ -0,0 +1,76 @@ +use crate::methods::SelfKind; +use crate::utils::span_lint; +use rustc_lint::LateContext; +use rustc_middle::ty::TyS; +use rustc_span::source_map::Span; +use std::fmt; + +use super::WRONG_PUB_SELF_CONVENTION; +use super::WRONG_SELF_CONVENTION; + +#[rustfmt::skip] +const CONVENTIONS: [(Convention, &[SelfKind]); 7] = [ + (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]), + (Convention::Eq("to_mut"), &[SelfKind::RefMut]), + (Convention::StartsWith("to_"), &[SelfKind::Ref]), +]; +enum Convention { + Eq(&'static str), + StartsWith(&'static str), +} + +impl Convention { + #[must_use] + fn check(&self, other: &str) -> bool { + match *self { + Self::Eq(this) => this == other, + Self::StartsWith(this) => other.starts_with(this) && this != other, + } + } +} + +impl fmt::Display for Convention { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> { + match *self { + Self::Eq(this) => this.fmt(f), + Self::StartsWith(this) => this.fmt(f).and_then(|_| '*'.fmt(f)), + } + } +} + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + item_name: &str, + is_pub: bool, + self_ty: &'tcx TyS<'tcx>, + first_arg_ty: &'tcx TyS<'tcx>, + first_arg_span: Span, +) { + let lint = if is_pub { + WRONG_PUB_SELF_CONVENTION + } else { + WRONG_SELF_CONVENTION + }; + if let Some((ref conv, self_kinds)) = &CONVENTIONS.iter().find(|(ref conv, _)| conv.check(item_name)) { + if !self_kinds.iter().any(|k| k.matches(cx, self_ty, first_arg_ty)) { + span_lint( + cx, + lint, + first_arg_span, + &format!( + "methods called `{}` usually take {}; consider choosing a less ambiguous name", + conv, + &self_kinds + .iter() + .map(|k| k.description()) + .collect::>() + .join(" or ") + ), + ); + } + } +} From 2ade32ddf2ec13a6ec2e03c14e7393ce784d4d18 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Fri, 5 Mar 2021 00:16:43 +0900 Subject: [PATCH 14/35] move string_extend_chars and clone_on_ref_ptr to their own module --- clippy_lints/src/methods/clone_on_ref_ptr.rs | 36 ++++++++++ clippy_lints/src/methods/mod.rs | 72 ++----------------- .../src/methods/string_extend_chars.rs | 42 +++++++++++ 3 files changed, 82 insertions(+), 68 deletions(-) create mode 100644 clippy_lints/src/methods/clone_on_ref_ptr.rs create mode 100644 clippy_lints/src/methods/string_extend_chars.rs diff --git a/clippy_lints/src/methods/clone_on_ref_ptr.rs b/clippy_lints/src/methods/clone_on_ref_ptr.rs new file mode 100644 index 0000000000000..3d5a68d69d7d2 --- /dev/null +++ b/clippy_lints/src/methods/clone_on_ref_ptr.rs @@ -0,0 +1,36 @@ +use crate::utils::{is_type_diagnostic_item, match_type, paths, snippet_with_macro_callsite, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::symbol::sym; + +use super::CLONE_ON_REF_PTR; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) { + let obj_ty = cx.typeck_results().expr_ty(arg).peel_refs(); + + if let ty::Adt(_, subst) = obj_ty.kind() { + let caller_type = if is_type_diagnostic_item(cx, obj_ty, sym::Rc) { + "Rc" + } else if is_type_diagnostic_item(cx, obj_ty, sym::Arc) { + "Arc" + } else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) { + "Weak" + } else { + return; + }; + + let snippet = snippet_with_macro_callsite(cx, arg.span, ".."); + + span_lint_and_sugg( + cx, + CLONE_ON_REF_PTR, + expr.span, + "using `.clone()` on a ref-counted pointer", + "try this", + format!("{}::<{}>::clone(&{})", caller_type, subst.type_at(0), snippet), + Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak + ); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 3cd720bc9ca70..480f32a434084 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -1,5 +1,6 @@ mod bind_instead_of_map; mod bytes_nth; +mod clone_on_ref_ptr; mod expect_used; mod filetype_is_file; mod filter_map_identity; @@ -20,6 +21,7 @@ mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; mod skip_while_next; +mod string_extend_chars; mod suspicious_map; mod uninit_assumed_init; mod unnecessary_filter_map; @@ -1707,7 +1709,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["is_some", "rposition"] => { lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1]) }, - ["extend", ..] => lint_extend(cx, expr, arg_lists[0]), + ["extend", ..] => string_extend_chars::check(cx, expr, arg_lists[0]), ["count", "into_iter"] => iter_count::check(cx, expr, &arg_lists[1], "into_iter"), ["count", "iter"] => iter_count::check(cx, expr, &arg_lists[1], "iter"), ["count", "iter_mut"] => iter_count::check(cx, expr, &arg_lists[1], "iter_mut"), @@ -1767,7 +1769,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]); if args.len() == 1 && method_call.ident.name == sym::clone { lint_clone_on_copy(cx, expr, &args[0], self_ty); - lint_clone_on_ref_ptr(cx, expr, &args[0]); + clone_on_ref_ptr::check(cx, expr, &args[0]); } if args.len() == 1 && method_call.ident.name == sym!(to_string) { inefficient_to_string::check(cx, expr, &args[0], self_ty); @@ -2408,72 +2410,6 @@ fn lint_clone_on_copy(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Exp } } -fn lint_clone_on_ref_ptr(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) { - let obj_ty = cx.typeck_results().expr_ty(arg).peel_refs(); - - if let ty::Adt(_, subst) = obj_ty.kind() { - let caller_type = if is_type_diagnostic_item(cx, obj_ty, sym::Rc) { - "Rc" - } else if is_type_diagnostic_item(cx, obj_ty, sym::Arc) { - "Arc" - } else if match_type(cx, obj_ty, &paths::WEAK_RC) || match_type(cx, obj_ty, &paths::WEAK_ARC) { - "Weak" - } else { - return; - }; - - let snippet = snippet_with_macro_callsite(cx, arg.span, ".."); - - span_lint_and_sugg( - cx, - CLONE_ON_REF_PTR, - expr.span, - "using `.clone()` on a ref-counted pointer", - "try this", - format!("{}::<{}>::clone(&{})", caller_type, subst.type_at(0), snippet), - Applicability::Unspecified, // Sometimes unnecessary ::<_> after Rc/Arc/Weak - ); - } -} - -fn lint_string_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - let arg = &args[1]; - if let Some(arglists) = method_chain_args(arg, &["chars"]) { - let target = &arglists[0][0]; - let self_ty = cx.typeck_results().expr_ty(target).peel_refs(); - let ref_str = if *self_ty.kind() == ty::Str { - "" - } else if is_type_diagnostic_item(cx, self_ty, sym::string_type) { - "&" - } else { - return; - }; - - let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - STRING_EXTEND_CHARS, - expr.span, - "calling `.extend(_.chars())`", - "try this", - format!( - "{}.push_str({}{})", - snippet_with_applicability(cx, args[0].span, "..", &mut applicability), - ref_str, - snippet_with_applicability(cx, target.span, "..", &mut applicability) - ), - applicability, - ); - } -} - -fn lint_extend(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - let obj_ty = cx.typeck_results().expr_ty(&args[0]).peel_refs(); - if is_type_diagnostic_item(cx, obj_ty, sym::string_type) { - lint_string_extend(cx, expr, args); - } -} - fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) { fn check_fold_with_op( cx: &LateContext<'_>, diff --git a/clippy_lints/src/methods/string_extend_chars.rs b/clippy_lints/src/methods/string_extend_chars.rs new file mode 100644 index 0000000000000..0a08ea26175fe --- /dev/null +++ b/clippy_lints/src/methods/string_extend_chars.rs @@ -0,0 +1,42 @@ +use crate::utils::{is_type_diagnostic_item, method_chain_args, snippet_with_applicability, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::symbol::sym; + +use super::STRING_EXTEND_CHARS; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + let obj_ty = cx.typeck_results().expr_ty(&args[0]).peel_refs(); + if is_type_diagnostic_item(cx, obj_ty, sym::string_type) { + let arg = &args[1]; + if let Some(arglists) = method_chain_args(arg, &["chars"]) { + let target = &arglists[0][0]; + let self_ty = cx.typeck_results().expr_ty(target).peel_refs(); + let ref_str = if *self_ty.kind() == ty::Str { + "" + } else if is_type_diagnostic_item(cx, self_ty, sym::string_type) { + "&" + } else { + return; + }; + + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + STRING_EXTEND_CHARS, + expr.span, + "calling `.extend(_.chars())`", + "try this", + format!( + "{}.push_str({}{})", + snippet_with_applicability(cx, args[0].span, "..", &mut applicability), + ref_str, + snippet_with_applicability(cx, target.span, "..", &mut applicability) + ), + applicability, + ); + } + } +} From 8006dab817e6bfa0a71a593d46c5569e8a98a6b7 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 15:29:02 +0900 Subject: [PATCH 15/35] move single_char_insert_string to its own module --- clippy_lints/src/methods/mod.rs | 23 ++-------------- .../src/methods/single_char_insert_string.rs | 27 +++++++++++++++++++ 2 files changed, 29 insertions(+), 21 deletions(-) create mode 100644 clippy_lints/src/methods/single_char_insert_string.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 480f32a434084..ef671e41cb59b 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -20,6 +20,7 @@ mod map_collect_result_unit; mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; +mod single_char_insert_string; mod skip_while_next; mod string_extend_chars; mod suspicious_map; @@ -1779,7 +1780,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { if match_def_path(cx, fn_def_id, &paths::PUSH_STR) { lint_single_char_push_string(cx, expr, args); } else if match_def_path(cx, fn_def_id, &paths::INSERT_STR) { - lint_single_char_insert_string(cx, expr, args); + single_char_insert_string::check(cx, expr, args); } } @@ -3235,26 +3236,6 @@ fn lint_single_char_push_string(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args } } -/// lint for length-1 `str`s as argument for `insert_str` -fn lint_single_char_insert_string(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - let mut applicability = Applicability::MachineApplicable; - if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[2], &mut applicability) { - let base_string_snippet = - snippet_with_applicability(cx, args[0].span.source_callsite(), "_", &mut applicability); - let pos_arg = snippet_with_applicability(cx, args[1].span, "..", &mut applicability); - let sugg = format!("{}.insert({}, {})", base_string_snippet, pos_arg, extension_string); - span_lint_and_sugg( - cx, - SINGLE_CHAR_ADD_STR, - expr.span, - "calling `insert_str()` using a single-character string literal", - "consider using `insert` with a character literal", - sugg, - applicability, - ); - } -} - /// Checks for the `USELESS_ASREF` lint. fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) { // when we get here, we've already checked that the call name is "as_ref" or "as_mut" diff --git a/clippy_lints/src/methods/single_char_insert_string.rs b/clippy_lints/src/methods/single_char_insert_string.rs new file mode 100644 index 0000000000000..0ce8b66978dc1 --- /dev/null +++ b/clippy_lints/src/methods/single_char_insert_string.rs @@ -0,0 +1,27 @@ +use crate::methods::get_hint_if_single_char_arg; +use crate::utils::{snippet_with_applicability, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::SINGLE_CHAR_ADD_STR; + +/// lint for length-1 `str`s as argument for `insert_str` +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + let mut applicability = Applicability::MachineApplicable; + if let Some(extension_string) = get_hint_if_single_char_arg(cx, &args[2], &mut applicability) { + let base_string_snippet = + snippet_with_applicability(cx, args[0].span.source_callsite(), "_", &mut applicability); + let pos_arg = snippet_with_applicability(cx, args[1].span, "..", &mut applicability); + let sugg = format!("{}.insert({}, {})", base_string_snippet, pos_arg, extension_string); + span_lint_and_sugg( + cx, + SINGLE_CHAR_ADD_STR, + expr.span, + "calling `insert_str()` using a single-character string literal", + "consider using `insert` with a character literal", + sugg, + applicability, + ); + } +} From 805aa47f43ab9b61a69f63682176604cdcda8fae Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 15:39:28 +0900 Subject: [PATCH 16/35] move single_char_push_string to its own module --- clippy_lints/src/methods/mod.rs | 22 ++-------------- .../src/methods/single_char_push_string.rs | 26 +++++++++++++++++++ 2 files changed, 28 insertions(+), 20 deletions(-) create mode 100644 clippy_lints/src/methods/single_char_push_string.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index ef671e41cb59b..24d610cf5f8f7 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -21,6 +21,7 @@ mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; mod single_char_insert_string; +mod single_char_push_string; mod skip_while_next; mod string_extend_chars; mod suspicious_map; @@ -1778,7 +1779,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { 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); + single_char_push_string::check(cx, expr, args); } else if match_def_path(cx, fn_def_id, &paths::INSERT_STR) { single_char_insert_string::check(cx, expr, args); } @@ -3217,25 +3218,6 @@ fn lint_single_char_pattern(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &h } } -/// lint for length-1 `str`s as argument for `push_str` -fn lint_single_char_push_string(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - 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.source_callsite(), "..", &mut applicability); - let sugg = format!("{}.push({})", base_string_snippet, extension_string); - span_lint_and_sugg( - cx, - SINGLE_CHAR_ADD_STR, - expr.span, - "calling `push_str()` using a single-character string literal", - "consider using `push` with a character literal", - sugg, - applicability, - ); - } -} - /// Checks for the `USELESS_ASREF` lint. fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) { // when we get here, we've already checked that the call name is "as_ref" or "as_mut" diff --git a/clippy_lints/src/methods/single_char_push_string.rs b/clippy_lints/src/methods/single_char_push_string.rs new file mode 100644 index 0000000000000..deacc70b713e5 --- /dev/null +++ b/clippy_lints/src/methods/single_char_push_string.rs @@ -0,0 +1,26 @@ +use crate::methods::get_hint_if_single_char_arg; +use crate::utils::{snippet_with_applicability, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::SINGLE_CHAR_ADD_STR; + +/// lint for length-1 `str`s as argument for `push_str` +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + 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.source_callsite(), "..", &mut applicability); + let sugg = format!("{}.push({})", base_string_snippet, extension_string); + span_lint_and_sugg( + cx, + SINGLE_CHAR_ADD_STR, + expr.span, + "calling `push_str()` using a single-character string literal", + "consider using `push` with a character literal", + sugg, + applicability, + ); + } +} From 0c8d143515a19b04a404765ecb8145a183dc2186 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 17:28:14 +0900 Subject: [PATCH 17/35] move into_iter_on_ref and single_char_pattern to their own modules --- clippy_lints/src/methods/into_iter_on_ref.rs | 42 ++++++++++++ clippy_lints/src/methods/mod.rs | 67 +++---------------- .../src/methods/single_char_pattern.rs | 23 +++++++ 3 files changed, 74 insertions(+), 58 deletions(-) create mode 100644 clippy_lints/src/methods/into_iter_on_ref.rs create mode 100644 clippy_lints/src/methods/single_char_pattern.rs diff --git a/clippy_lints/src/methods/into_iter_on_ref.rs b/clippy_lints/src/methods/into_iter_on_ref.rs new file mode 100644 index 0000000000000..d94b243404c36 --- /dev/null +++ b/clippy_lints/src/methods/into_iter_on_ref.rs @@ -0,0 +1,42 @@ +use crate::utils::{has_iter_method, match_trait_method, paths, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty}; +use rustc_span::source_map::Span; + +use super::INTO_ITER_ON_REF; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_>, method_span: Span) { + if !match_trait_method(cx, expr, &paths::INTO_ITERATOR) { + return; + } + if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ref_ty) { + span_lint_and_sugg( + cx, + INTO_ITER_ON_REF, + method_span, + &format!( + "this `.into_iter()` call is equivalent to `.{}()` and will not consume the `{}`", + method_name, kind, + ), + "call directly", + method_name.to_string(), + Applicability::MachineApplicable, + ); + } +} + +fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(&'static str, &'static str)> { + has_iter_method(cx, self_ref_ty).map(|ty_name| { + let mutbl = match self_ref_ty.kind() { + ty::Ref(_, _, mutbl) => mutbl, + _ => unreachable!(), + }; + let method_name = match mutbl { + hir::Mutability::Not => "iter", + hir::Mutability::Mut => "iter_mut", + }; + (ty_name, method_name) + }) +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 24d610cf5f8f7..28e2d896e6cdb 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -9,6 +9,7 @@ mod get_unwrap; mod implicit_clone; mod inefficient_to_string; mod inspect_for_each; +mod into_iter_on_ref; mod iter_cloned_collect; mod iter_count; mod iter_next_slice; @@ -21,6 +22,7 @@ mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; mod single_char_insert_string; +mod single_char_pattern; mod single_char_push_string; mod skip_while_next; mod string_extend_chars; @@ -53,12 +55,11 @@ use rustc_typeck::hir_ty_to_ty; use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ - contains_return, contains_ty, get_parent_expr, get_trait_def_id, has_iter_method, implements_trait, in_macro, - is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, - match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, - remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, - span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, strip_pat_refs, sugg, walk_ptrs_ty_depth, - SpanlessEq, + contains_return, contains_ty, get_parent_expr, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, + is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_trait_method, + match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, remove_blocks, return_ty, + single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, + span_lint_and_help, span_lint_and_sugg, span_lint_and_then, strip_pat_refs, sugg, walk_ptrs_ty_depth, SpanlessEq, }; declare_clippy_lint! { @@ -1789,12 +1790,12 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ty::Ref(_, ty, _) if *ty.kind() == ty::Str => { for &(method, pos) in &PATTERN_METHODS { if method_call.ident.name.as_str() == method && args.len() > pos { - lint_single_char_pattern(cx, expr, &args[pos]); + single_char_pattern::check(cx, expr, &args[pos]); } } }, ty::Ref(..) if method_call.ident.name == sym::into_iter => { - lint_into_iter(cx, expr, self_ty, *method_span); + into_iter_on_ref::check(cx, expr, self_ty, *method_span); }, _ => (), } @@ -3202,22 +3203,6 @@ fn get_hint_if_single_char_arg( } } -/// lint for length-1 `str`s for methods in `PATTERN_METHODS` -fn lint_single_char_pattern(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) { - 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, - ); - } -} - /// Checks for the `USELESS_ASREF` lint. fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) { // when we get here, we've already checked that the call name is "as_ref" or "as_mut" @@ -3254,40 +3239,6 @@ fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_re } } -fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(Symbol, &'static str)> { - has_iter_method(cx, self_ref_ty).map(|ty_name| { - let mutbl = match self_ref_ty.kind() { - ty::Ref(_, _, mutbl) => mutbl, - _ => unreachable!(), - }; - let method_name = match mutbl { - hir::Mutability::Not => "iter", - hir::Mutability::Mut => "iter_mut", - }; - (ty_name, method_name) - }) -} - -fn lint_into_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty<'_>, method_span: Span) { - if !match_trait_method(cx, expr, &paths::INTO_ITERATOR) { - return; - } - if let Some((kind, method_name)) = ty_has_iter_method(cx, self_ref_ty) { - span_lint_and_sugg( - cx, - INTO_ITER_ON_REF, - method_span, - &format!( - "this `.into_iter()` call is equivalent to `.{}()` and will not consume the `{}`", - method_name, kind, - ), - "call directly", - method_name.to_string(), - Applicability::MachineApplicable, - ); - } -} - const FN_HEADER: hir::FnHeader = hir::FnHeader { unsafety: hir::Unsafety::Normal, constness: hir::Constness::NotConst, diff --git a/clippy_lints/src/methods/single_char_pattern.rs b/clippy_lints/src/methods/single_char_pattern.rs new file mode 100644 index 0000000000000..61cbc9d2f0a62 --- /dev/null +++ b/clippy_lints/src/methods/single_char_pattern.rs @@ -0,0 +1,23 @@ +use crate::methods::get_hint_if_single_char_arg; +use crate::utils::span_lint_and_sugg; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::SINGLE_CHAR_PATTERN; + +/// lint for length-1 `str`s for methods in `PATTERN_METHODS` +pub(super) fn check(cx: &LateContext<'_>, _expr: &hir::Expr<'_>, arg: &hir::Expr<'_>) { + 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, + ); + } +} From 2561b7ea062f0c07f27d9ebdf0c355ab29a4edf9 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 17:46:50 +0900 Subject: [PATCH 18/35] move from_iter_insteam_of_collect to its own module --- .../methods/from_iter_instead_of_collect.rs | 67 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 62 +---------------- 2 files changed, 69 insertions(+), 60 deletions(-) create mode 100644 clippy_lints/src/methods/from_iter_instead_of_collect.rs diff --git a/clippy_lints/src/methods/from_iter_instead_of_collect.rs b/clippy_lints/src/methods/from_iter_instead_of_collect.rs new file mode 100644 index 0000000000000..e50d0a3340026 --- /dev/null +++ b/clippy_lints/src/methods/from_iter_instead_of_collect.rs @@ -0,0 +1,67 @@ +use crate::utils::{get_trait_def_id, implements_trait, paths, span_lint_and_sugg, sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::{LateContext, LintContext}; +use rustc_middle::ty::Ty; + +use super::FROM_ITER_INSTEAD_OF_COLLECT; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { + let ty = cx.typeck_results().expr_ty(expr); + let arg_ty = cx.typeck_results().expr_ty(&args[0]); + + if_chain! { + if let Some(from_iter_id) = get_trait_def_id(cx, &paths::FROM_ITERATOR); + if let Some(iter_id) = get_trait_def_id(cx, &paths::ITERATOR); + + if implements_trait(cx, ty, from_iter_id, &[]) && implements_trait(cx, arg_ty, iter_id, &[]); + then { + // `expr` implements `FromIterator` trait + let iter_expr = sugg::Sugg::hir(cx, &args[0], "..").maybe_par(); + let turbofish = extract_turbofish(cx, expr, ty); + let sugg = format!("{}.collect::<{}>()", iter_expr, turbofish); + span_lint_and_sugg( + cx, + FROM_ITER_INSTEAD_OF_COLLECT, + expr.span, + "usage of `FromIterator::from_iter`", + "use `.collect()` instead of `::from_iter()`", + sugg, + Applicability::MaybeIncorrect, + ); + } + } +} + +fn extract_turbofish(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ty: Ty<'tcx>) -> String { + if_chain! { + let call_site = expr.span.source_callsite(); + if let Ok(snippet) = cx.sess().source_map().span_to_snippet(call_site); + let snippet_split = snippet.split("::").collect::>(); + if let Some((_, elements)) = snippet_split.split_last(); + + then { + // is there a type specifier? (i.e.: like `` in `collections::BTreeSet::::`) + if let Some(type_specifier) = snippet_split.iter().find(|e| e.starts_with('<') && e.ends_with('>')) { + // remove the type specifier from the path elements + let without_ts = elements.iter().filter_map(|e| { + if e == type_specifier { None } else { Some((*e).to_string()) } + }).collect::>(); + // join and add the type specifier at the end (i.e.: `collections::BTreeSet`) + format!("{}{}", without_ts.join("::"), type_specifier) + } else { + // type is not explicitly specified so wildcards are needed + // i.e.: 2 wildcards in `std::collections::BTreeMap<&i32, &char>` + let ty_str = ty.to_string(); + let start = ty_str.find('<').unwrap_or(0); + let end = ty_str.find('>').unwrap_or_else(|| ty_str.len()); + let nb_wildcard = ty_str[start..end].split(',').count(); + let wildcards = format!("_{}", ", _".repeat(nb_wildcard - 1)); + format!("{}<{}>", elements.join("::"), wildcards) + } + } else { + ty.to_string() + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 28e2d896e6cdb..9a0ef6c01c1a2 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -5,6 +5,7 @@ mod expect_used; mod filetype_is_file; mod filter_map_identity; mod filter_next; +mod from_iter_instead_of_collect; mod get_unwrap; mod implicit_clone; mod inefficient_to_string; @@ -1761,7 +1762,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { hir::ExprKind::Call(ref func, ref args) => { if let hir::ExprKind::Path(path) = &func.kind { if match_qpath(path, &["from_iter"]) { - lint_from_iter(cx, expr, args); + from_iter_instead_of_collect::check(cx, expr, args); } } }, @@ -3440,65 +3441,6 @@ fn is_bool(ty: &hir::Ty<'_>) -> bool { } } -fn lint_from_iter(cx: &LateContext<'_>, expr: &hir::Expr<'_>, args: &[hir::Expr<'_>]) { - let ty = cx.typeck_results().expr_ty(expr); - let arg_ty = cx.typeck_results().expr_ty(&args[0]); - - if_chain! { - if let Some(from_iter_id) = get_trait_def_id(cx, &paths::FROM_ITERATOR); - if let Some(iter_id) = get_trait_def_id(cx, &paths::ITERATOR); - - if implements_trait(cx, ty, from_iter_id, &[]) && implements_trait(cx, arg_ty, iter_id, &[]); - then { - // `expr` implements `FromIterator` trait - let iter_expr = sugg::Sugg::hir(cx, &args[0], "..").maybe_par(); - let turbofish = extract_turbofish(cx, expr, ty); - let sugg = format!("{}.collect::<{}>()", iter_expr, turbofish); - span_lint_and_sugg( - cx, - FROM_ITER_INSTEAD_OF_COLLECT, - expr.span, - "usage of `FromIterator::from_iter`", - "use `.collect()` instead of `::from_iter()`", - sugg, - Applicability::MaybeIncorrect, - ); - } - } -} - -fn extract_turbofish(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ty: Ty<'tcx>) -> String { - if_chain! { - let call_site = expr.span.source_callsite(); - if let Ok(snippet) = cx.sess().source_map().span_to_snippet(call_site); - let snippet_split = snippet.split("::").collect::>(); - if let Some((_, elements)) = snippet_split.split_last(); - - then { - // is there a type specifier? (i.e.: like `` in `collections::BTreeSet::::`) - if let Some(type_specifier) = snippet_split.iter().find(|e| e.starts_with('<') && e.ends_with('>')) { - // remove the type specifier from the path elements - let without_ts = elements.iter().filter_map(|e| { - if e == type_specifier { None } else { Some((*e).to_string()) } - }).collect::>(); - // join and add the type specifier at the end (i.e.: `collections::BTreeSet`) - format!("{}{}", without_ts.join("::"), type_specifier) - } else { - // type is not explicitly specified so wildcards are needed - // i.e.: 2 wildcards in `std::collections::BTreeMap<&i32, &char>` - let ty_str = ty.to_string(); - let start = ty_str.find('<').unwrap_or(0); - let end = ty_str.find('>').unwrap_or_else(|| ty_str.len()); - let nb_wildcard = ty_str[start..end].split(',').count(); - let wildcards = format!("_{}", ", _".repeat(nb_wildcard - 1)); - format!("{}<{}>", elements.join("::"), wildcards) - } - } else { - ty.to_string() - } - } -} - fn fn_header_equals(expected: hir::FnHeader, actual: hir::FnHeader) -> bool { expected.constness == actual.constness && expected.unsafety == actual.unsafety From 183daeb961c83d5be108cfa5ee463bba412dedc4 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 17:55:29 +0900 Subject: [PATCH 19/35] move filter_map to its own module --- clippy_lints/src/methods/filter_map.rs | 85 ++++++++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 81 ++---------------------- 2 files changed, 89 insertions(+), 77 deletions(-) create mode 100644 clippy_lints/src/methods/filter_map.rs diff --git a/clippy_lints/src/methods/filter_map.rs b/clippy_lints/src/methods/filter_map.rs new file mode 100644 index 0000000000000..f559160004cb1 --- /dev/null +++ b/clippy_lints/src/methods/filter_map.rs @@ -0,0 +1,85 @@ +use crate::utils::{match_trait_method, path_to_local_id, paths, snippet, span_lint_and_sugg, SpanlessEq}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_hir::{Expr, ExprKind, PatKind, UnOp}; +use rustc_lint::LateContext; +use rustc_middle::ty::TyS; +use rustc_span::symbol::sym; + +use super::MANUAL_FILTER_MAP; +use super::MANUAL_FIND_MAP; + +/// lint use of `filter().map()` or `find().map()` for `Iterators` +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_find: bool) { + if_chain! { + if let ExprKind::MethodCall(_, _, [map_recv, map_arg], map_span) = expr.kind; + if let ExprKind::MethodCall(_, _, [_, filter_arg], filter_span) = map_recv.kind; + if match_trait_method(cx, map_recv, &paths::ITERATOR); + + // filter(|x| ...is_some())... + if let ExprKind::Closure(_, _, filter_body_id, ..) = filter_arg.kind; + let filter_body = cx.tcx.hir().body(filter_body_id); + if let [filter_param] = filter_body.params; + // optional ref pattern: `filter(|&x| ..)` + let (filter_pat, is_filter_param_ref) = if let PatKind::Ref(ref_pat, _) = filter_param.pat.kind { + (ref_pat, true) + } else { + (filter_param.pat, false) + }; + // closure ends with is_some() or is_ok() + if let PatKind::Binding(_, filter_param_id, _, None) = filter_pat.kind; + if let ExprKind::MethodCall(path, _, [filter_arg], _) = filter_body.value.kind; + if let Some(opt_ty) = cx.typeck_results().expr_ty(filter_arg).ty_adt_def(); + if let Some(is_result) = if cx.tcx.is_diagnostic_item(sym::option_type, opt_ty.did) { + Some(false) + } else if cx.tcx.is_diagnostic_item(sym::result_type, opt_ty.did) { + Some(true) + } else { + None + }; + if path.ident.name.as_str() == if is_result { "is_ok" } else { "is_some" }; + + // ...map(|x| ...unwrap()) + if let ExprKind::Closure(_, _, map_body_id, ..) = map_arg.kind; + let map_body = cx.tcx.hir().body(map_body_id); + if let [map_param] = map_body.params; + if let PatKind::Binding(_, map_param_id, map_param_ident, None) = map_param.pat.kind; + // closure ends with expect() or unwrap() + if let ExprKind::MethodCall(seg, _, [map_arg, ..], _) = map_body.value.kind; + if matches!(seg.ident.name, sym::expect | sym::unwrap | sym::unwrap_or); + + let eq_fallback = |a: &Expr<'_>, b: &Expr<'_>| { + // in `filter(|x| ..)`, replace `*x` with `x` + let a_path = if_chain! { + if !is_filter_param_ref; + if let ExprKind::Unary(UnOp::Deref, expr_path) = a.kind; + then { expr_path } else { a } + }; + // let the filter closure arg and the map closure arg be equal + if_chain! { + if path_to_local_id(a_path, filter_param_id); + if path_to_local_id(b, map_param_id); + if TyS::same_type(cx.typeck_results().expr_ty_adjusted(a), cx.typeck_results().expr_ty_adjusted(b)); + then { + return true; + } + } + false + }; + if SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, map_arg); + then { + let span = filter_span.to(map_span); + let (filter_name, lint) = if is_find { + ("find", MANUAL_FIND_MAP) + } else { + ("filter", MANUAL_FILTER_MAP) + }; + let msg = format!("`{}(..).map(..)` can be simplified as `{0}_map(..)`", filter_name); + let to_opt = if is_result { ".ok()" } else { "" }; + let sugg = format!("{}_map(|{}| {}{})", filter_name, map_param_ident, + snippet(cx, map_arg.span, ".."), to_opt); + span_lint_and_sugg(cx, lint, span, &msg, "try", sugg, Applicability::MachineApplicable); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 9a0ef6c01c1a2..61d562cbc2844 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -3,6 +3,7 @@ mod bytes_nth; mod clone_on_ref_ptr; mod expect_used; mod filetype_is_file; +mod filter_map; mod filter_map_identity; mod filter_next; mod from_iter_instead_of_collect; @@ -43,7 +44,7 @@ use if_chain::if_chain; use rustc_ast::ast; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::{Expr, ExprKind, PatKind, TraitItem, TraitItemKind, UnOp}; +use rustc_hir::{PatKind, TraitItem, TraitItemKind}; use rustc_lint::{LateContext, LateLintPass, Lint, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, TraitRef, Ty, TyS}; @@ -1698,10 +1699,10 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["next", "filter"] => filter_next::check(cx, expr, arg_lists[1]), ["next", "skip_while"] => skip_while_next::check(cx, expr, arg_lists[1]), ["next", "iter"] => iter_next_slice::check(cx, expr, arg_lists[1]), - ["map", "filter"] => lint_filter_map(cx, expr, false), + ["map", "filter"] => filter_map::check(cx, expr, false), ["map", "filter_map"] => lint_filter_map_map(cx, expr, arg_lists[1], arg_lists[0]), ["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1], self.msrv.as_ref()), - ["map", "find"] => lint_filter_map(cx, expr, true), + ["map", "find"] => filter_map::check(cx, expr, true), ["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]), ["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]), @@ -2750,80 +2751,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `filter().map()` or `find().map()` for `Iterators` -fn lint_filter_map<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, is_find: bool) { - if_chain! { - if let ExprKind::MethodCall(_, _, [map_recv, map_arg], map_span) = expr.kind; - if let ExprKind::MethodCall(_, _, [_, filter_arg], filter_span) = map_recv.kind; - if match_trait_method(cx, map_recv, &paths::ITERATOR); - - // filter(|x| ...is_some())... - if let ExprKind::Closure(_, _, filter_body_id, ..) = filter_arg.kind; - let filter_body = cx.tcx.hir().body(filter_body_id); - if let [filter_param] = filter_body.params; - // optional ref pattern: `filter(|&x| ..)` - let (filter_pat, is_filter_param_ref) = if let PatKind::Ref(ref_pat, _) = filter_param.pat.kind { - (ref_pat, true) - } else { - (filter_param.pat, false) - }; - // closure ends with is_some() or is_ok() - if let PatKind::Binding(_, filter_param_id, _, None) = filter_pat.kind; - if let ExprKind::MethodCall(path, _, [filter_arg], _) = filter_body.value.kind; - if let Some(opt_ty) = cx.typeck_results().expr_ty(filter_arg).ty_adt_def(); - if let Some(is_result) = if cx.tcx.is_diagnostic_item(sym::option_type, opt_ty.did) { - Some(false) - } else if cx.tcx.is_diagnostic_item(sym::result_type, opt_ty.did) { - Some(true) - } else { - None - }; - if path.ident.name.as_str() == if is_result { "is_ok" } else { "is_some" }; - - // ...map(|x| ...unwrap()) - if let ExprKind::Closure(_, _, map_body_id, ..) = map_arg.kind; - let map_body = cx.tcx.hir().body(map_body_id); - if let [map_param] = map_body.params; - if let PatKind::Binding(_, map_param_id, map_param_ident, None) = map_param.pat.kind; - // closure ends with expect() or unwrap() - if let ExprKind::MethodCall(seg, _, [map_arg, ..], _) = map_body.value.kind; - if matches!(seg.ident.name, sym::expect | sym::unwrap | sym::unwrap_or); - - let eq_fallback = |a: &Expr<'_>, b: &Expr<'_>| { - // in `filter(|x| ..)`, replace `*x` with `x` - let a_path = if_chain! { - if !is_filter_param_ref; - if let ExprKind::Unary(UnOp::Deref, expr_path) = a.kind; - then { expr_path } else { a } - }; - // let the filter closure arg and the map closure arg be equal - if_chain! { - if path_to_local_id(a_path, filter_param_id); - if path_to_local_id(b, map_param_id); - if TyS::same_type(cx.typeck_results().expr_ty_adjusted(a), cx.typeck_results().expr_ty_adjusted(b)); - then { - return true; - } - } - false - }; - if SpanlessEq::new(cx).expr_fallback(eq_fallback).eq_expr(filter_arg, map_arg); - then { - let span = filter_span.to(map_span); - let (filter_name, lint) = if is_find { - ("find", MANUAL_FIND_MAP) - } else { - ("filter", MANUAL_FILTER_MAP) - }; - let msg = format!("`{}(..).map(..)` can be simplified as `{0}_map(..)`", filter_name); - let to_opt = if is_result { ".ok()" } else { "" }; - let sugg = format!("{}_map(|{}| {}{})", filter_name, map_param_ident, - snippet(cx, map_arg.span, ".."), to_opt); - span_lint_and_sugg(cx, lint, span, &msg, "try", sugg, Applicability::MachineApplicable); - } - } -} - const FILTER_MAP_NEXT_MSRV: RustcVersion = RustcVersion::new(1, 30, 0); /// lint use of `filter_map().next()` for `Iterators` From 805dcd12d41e72c16bbca83496f4b89ba49eed64 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:05:15 +0900 Subject: [PATCH 20/35] move filter_map_map to its own module --- clippy_lints/src/methods/filter_map_map.rs | 20 ++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 18 ++---------------- 2 files changed, 22 insertions(+), 16 deletions(-) create mode 100644 clippy_lints/src/methods/filter_map_map.rs diff --git a/clippy_lints/src/methods/filter_map_map.rs b/clippy_lints/src/methods/filter_map_map.rs new file mode 100644 index 0000000000000..d015b4c7b385e --- /dev/null +++ b/clippy_lints/src/methods/filter_map_map.rs @@ -0,0 +1,20 @@ +use crate::utils::{match_trait_method, paths, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::FILTER_MAP; + +/// lint use of `filter_map().map()` for `Iterators` +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + _filter_args: &'tcx [hir::Expr<'_>], + _map_args: &'tcx [hir::Expr<'_>], +) { + // lint if caller of `.filter_map().map()` is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + let msg = "called `filter_map(..).map(..)` on an `Iterator`"; + let hint = "this is more succinctly expressed by only calling `.filter_map(..)` instead"; + span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 61d562cbc2844..2e5dc857b4419 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -5,6 +5,7 @@ mod expect_used; mod filetype_is_file; mod filter_map; mod filter_map_identity; +mod filter_map_map; mod filter_next; mod from_iter_instead_of_collect; mod get_unwrap; @@ -1700,7 +1701,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["next", "skip_while"] => skip_while_next::check(cx, expr, arg_lists[1]), ["next", "iter"] => iter_next_slice::check(cx, expr, arg_lists[1]), ["map", "filter"] => filter_map::check(cx, expr, false), - ["map", "filter_map"] => lint_filter_map_map(cx, expr, arg_lists[1], arg_lists[0]), + ["map", "filter_map"] => filter_map_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1], self.msrv.as_ref()), ["map", "find"] => filter_map::check(cx, expr, true), ["flat_map", "filter"] => lint_filter_flat_map(cx, expr, arg_lists[1], arg_lists[0]), @@ -2785,21 +2786,6 @@ fn lint_filter_map_next<'tcx>( } } -/// lint use of `filter_map().map()` for `Iterators` -fn lint_filter_map_map<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - _filter_args: &'tcx [hir::Expr<'_>], - _map_args: &'tcx [hir::Expr<'_>], -) { - // lint if caller of `.filter_map().map()` is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - let msg = "called `filter_map(..).map(..)` on an `Iterator`"; - let hint = "this is more succinctly expressed by only calling `.filter_map(..)` instead"; - span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); - } -} - /// lint use of `filter().flat_map()` for `Iterators` fn lint_filter_flat_map<'tcx>( cx: &LateContext<'tcx>, From 2baf043c374396dea3354eb8bc56af7539bf30b4 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:11:42 +0900 Subject: [PATCH 21/35] move filter_map_next to its own module --- clippy_lints/src/methods/filter_map_next.rs | 40 +++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 37 ++----------------- 2 files changed, 42 insertions(+), 35 deletions(-) create mode 100644 clippy_lints/src/methods/filter_map_next.rs diff --git a/clippy_lints/src/methods/filter_map_next.rs b/clippy_lints/src/methods/filter_map_next.rs new file mode 100644 index 0000000000000..a789df922ffdb --- /dev/null +++ b/clippy_lints/src/methods/filter_map_next.rs @@ -0,0 +1,40 @@ +use crate::utils::{match_trait_method, meets_msrv, paths, snippet, span_lint, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_semver::RustcVersion; + +use super::FILTER_MAP_NEXT; + +const FILTER_MAP_NEXT_MSRV: RustcVersion = RustcVersion::new(1, 30, 0); + +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + filter_args: &'tcx [hir::Expr<'_>], + msrv: Option<&RustcVersion>, +) { + if match_trait_method(cx, expr, &paths::ITERATOR) { + if !meets_msrv(msrv, &FILTER_MAP_NEXT_MSRV) { + return; + } + + let msg = "called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling \ + `.find_map(..)` instead"; + let filter_snippet = snippet(cx, filter_args[1].span, ".."); + if filter_snippet.lines().count() <= 1 { + let iter_snippet = snippet(cx, filter_args[0].span, ".."); + span_lint_and_sugg( + cx, + FILTER_MAP_NEXT, + expr.span, + msg, + "try this", + format!("{}.find_map({})", iter_snippet, filter_snippet), + Applicability::MachineApplicable, + ); + } else { + span_lint(cx, FILTER_MAP_NEXT, expr.span, msg); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 2e5dc857b4419..fe1327564b20c 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -6,6 +6,7 @@ mod filetype_is_file; mod filter_map; mod filter_map_identity; mod filter_map_map; +mod filter_map_next; mod filter_next; mod from_iter_instead_of_collect; mod get_unwrap; @@ -1702,7 +1703,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["next", "iter"] => iter_next_slice::check(cx, expr, arg_lists[1]), ["map", "filter"] => filter_map::check(cx, expr, false), ["map", "filter_map"] => filter_map_map::check(cx, expr, arg_lists[1], arg_lists[0]), - ["next", "filter_map"] => lint_filter_map_next(cx, expr, arg_lists[1], self.msrv.as_ref()), + ["next", "filter_map"] => filter_map_next::check(cx, expr, arg_lists[1], self.msrv.as_ref()), ["map", "find"] => filter_map::check(cx, expr, true), ["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]), @@ -2752,40 +2753,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -const FILTER_MAP_NEXT_MSRV: RustcVersion = RustcVersion::new(1, 30, 0); - -/// lint use of `filter_map().next()` for `Iterators` -fn lint_filter_map_next<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - filter_args: &'tcx [hir::Expr<'_>], - msrv: Option<&RustcVersion>, -) { - if match_trait_method(cx, expr, &paths::ITERATOR) { - if !meets_msrv(msrv, &FILTER_MAP_NEXT_MSRV) { - return; - } - - let msg = "called `filter_map(..).next()` on an `Iterator`. This is more succinctly expressed by calling \ - `.find_map(..)` instead"; - let filter_snippet = snippet(cx, filter_args[1].span, ".."); - if filter_snippet.lines().count() <= 1 { - let iter_snippet = snippet(cx, filter_args[0].span, ".."); - span_lint_and_sugg( - cx, - FILTER_MAP_NEXT, - expr.span, - msg, - "try this", - format!("{}.find_map({})", iter_snippet, filter_snippet), - Applicability::MachineApplicable, - ); - } else { - span_lint(cx, FILTER_MAP_NEXT, expr.span, msg); - } - } -} - /// lint use of `filter().flat_map()` for `Iterators` fn lint_filter_flat_map<'tcx>( cx: &LateContext<'tcx>, From 6d941616f925298124eabe3ca10e48ec10bb33a9 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:19:18 +0900 Subject: [PATCH 22/35] move filter_flat_map to its own module --- clippy_lints/src/methods/filter_flat_map.rs | 21 +++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 19 ++----------------- 2 files changed, 23 insertions(+), 17 deletions(-) create mode 100644 clippy_lints/src/methods/filter_flat_map.rs diff --git a/clippy_lints/src/methods/filter_flat_map.rs b/clippy_lints/src/methods/filter_flat_map.rs new file mode 100644 index 0000000000000..8da867fce515c --- /dev/null +++ b/clippy_lints/src/methods/filter_flat_map.rs @@ -0,0 +1,21 @@ +use crate::utils::{match_trait_method, paths, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::FILTER_MAP; + +/// lint use of `filter().flat_map()` for `Iterators` +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + _filter_args: &'tcx [hir::Expr<'_>], + _map_args: &'tcx [hir::Expr<'_>], +) { + // lint if caller of `.filter().flat_map()` is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + let msg = "called `filter(..).flat_map(..)` on an `Iterator`"; + let hint = "this is more succinctly expressed by calling `.flat_map(..)` \ + and filtering by returning `iter::empty()`"; + span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index fe1327564b20c..3251a49da099b 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -3,6 +3,7 @@ mod bytes_nth; mod clone_on_ref_ptr; mod expect_used; mod filetype_is_file; +mod filter_flat_map; mod filter_map; mod filter_map_identity; mod filter_map_map; @@ -1705,7 +1706,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["map", "filter_map"] => filter_map_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["next", "filter_map"] => filter_map_next::check(cx, expr, arg_lists[1], self.msrv.as_ref()), ["map", "find"] => filter_map::check(cx, expr, true), - ["flat_map", "filter"] => lint_filter_flat_map(cx, expr, arg_lists[1], arg_lists[0]), + ["flat_map", "filter"] => filter_flat_map::check(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]), ["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]), ["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]), @@ -2753,22 +2754,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `filter().flat_map()` for `Iterators` -fn lint_filter_flat_map<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - _filter_args: &'tcx [hir::Expr<'_>], - _map_args: &'tcx [hir::Expr<'_>], -) { - // lint if caller of `.filter().flat_map()` is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - let msg = "called `filter(..).flat_map(..)` on an `Iterator`"; - let hint = "this is more succinctly expressed by calling `.flat_map(..)` \ - and filtering by returning `iter::empty()`"; - span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); - } -} - /// lint use of `filter_map().flat_map()` for `Iterators` fn lint_filter_map_flat_map<'tcx>( cx: &LateContext<'tcx>, From f430384f04ee3ee62156a9e3060ba4d9054278b5 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:22:15 +0900 Subject: [PATCH 23/35] move filter_map_flat_map to its own module --- .../src/methods/filter_map_flat_map.rs | 21 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 19 ++--------------- 2 files changed, 23 insertions(+), 17 deletions(-) create mode 100644 clippy_lints/src/methods/filter_map_flat_map.rs diff --git a/clippy_lints/src/methods/filter_map_flat_map.rs b/clippy_lints/src/methods/filter_map_flat_map.rs new file mode 100644 index 0000000000000..a6db138623a8c --- /dev/null +++ b/clippy_lints/src/methods/filter_map_flat_map.rs @@ -0,0 +1,21 @@ +use crate::utils::{match_trait_method, paths, span_lint_and_help}; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::FILTER_MAP; + +/// lint use of `filter_map().flat_map()` for `Iterators` +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + _filter_args: &'tcx [hir::Expr<'_>], + _map_args: &'tcx [hir::Expr<'_>], +) { + // lint if caller of `.filter_map().flat_map()` is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + let msg = "called `filter_map(..).flat_map(..)` on an `Iterator`"; + let hint = "this is more succinctly expressed by calling `.flat_map(..)` \ + and filtering by returning `iter::empty()`"; + span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 3251a49da099b..34e1463f6305f 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -5,6 +5,7 @@ mod expect_used; mod filetype_is_file; mod filter_flat_map; mod filter_map; +mod filter_map_flat_map; mod filter_map_identity; mod filter_map_map; mod filter_map_next; @@ -1707,7 +1708,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["next", "filter_map"] => filter_map_next::check(cx, expr, arg_lists[1], self.msrv.as_ref()), ["map", "find"] => filter_map::check(cx, expr, true), ["flat_map", "filter"] => filter_flat_map::check(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]), + ["flat_map", "filter_map"] => filter_map_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]), ["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]), ["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]), @@ -2754,22 +2755,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `filter_map().flat_map()` for `Iterators` -fn lint_filter_map_flat_map<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - _filter_args: &'tcx [hir::Expr<'_>], - _map_args: &'tcx [hir::Expr<'_>], -) { - // lint if caller of `.filter_map().flat_map()` is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - let msg = "called `filter_map(..).flat_map(..)` on an `Iterator`"; - let hint = "this is more succinctly expressed by calling `.flat_map(..)` \ - and filtering by returning `iter::empty()`"; - span_lint_and_help(cx, FILTER_MAP, expr.span, msg, None, hint); - } -} - /// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient fn lint_flat_map_identity<'tcx>( cx: &LateContext<'tcx>, From 37ba779a532cd229a18e8a99342f351ba035aa30 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:30:40 +0900 Subject: [PATCH 24/35] move flat_map_identity to its own module --- clippy_lints/src/methods/flat_map_identity.rs | 57 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 52 +---------------- 2 files changed, 59 insertions(+), 50 deletions(-) create mode 100644 clippy_lints/src/methods/flat_map_identity.rs diff --git a/clippy_lints/src/methods/flat_map_identity.rs b/clippy_lints/src/methods/flat_map_identity.rs new file mode 100644 index 0000000000000..ce3194f8a2373 --- /dev/null +++ b/clippy_lints/src/methods/flat_map_identity.rs @@ -0,0 +1,57 @@ +use crate::utils::{match_qpath, match_trait_method, paths, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::source_map::Span; + +use super::FLAT_MAP_IDENTITY; + +/// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + flat_map_args: &'tcx [hir::Expr<'_>], + flat_map_span: Span, +) { + if match_trait_method(cx, expr, &paths::ITERATOR) { + let arg_node = &flat_map_args[1].kind; + + let apply_lint = |message: &str| { + span_lint_and_sugg( + cx, + FLAT_MAP_IDENTITY, + flat_map_span.with_hi(expr.span.hi()), + message, + "try", + "flatten()".to_string(), + Applicability::MachineApplicable, + ); + }; + + if_chain! { + if let hir::ExprKind::Closure(_, _, body_id, _, _) = arg_node; + let body = cx.tcx.hir().body(*body_id); + + 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; + + if path.segments.len() == 1; + if path.segments[0].ident.name == binding_ident.name; + + then { + apply_lint("called `flat_map(|x| x)` on an `Iterator`"); + } + } + + if_chain! { + if let hir::ExprKind::Path(ref qpath) = arg_node; + + if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY); + + then { + apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`"); + } + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 34e1463f6305f..6a425e6e3ed0b 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -10,6 +10,7 @@ mod filter_map_identity; mod filter_map_map; mod filter_map_next; mod filter_next; +mod flat_map_identity; mod from_iter_instead_of_collect; mod get_unwrap; mod implicit_clone; @@ -1709,7 +1710,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["map", "find"] => filter_map::check(cx, expr, true), ["flat_map", "filter"] => filter_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["flat_map", "filter_map"] => filter_map_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]), - ["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]), + ["flat_map", ..] => flat_map_identity::check(cx, expr, arg_lists[0], method_spans[0]), ["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]), ["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]), ["is_some", "position"] => { @@ -2755,55 +2756,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint use of `flat_map` for `Iterators` where `flatten` would be sufficient -fn lint_flat_map_identity<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - flat_map_args: &'tcx [hir::Expr<'_>], - flat_map_span: Span, -) { - if match_trait_method(cx, expr, &paths::ITERATOR) { - let arg_node = &flat_map_args[1].kind; - - let apply_lint = |message: &str| { - span_lint_and_sugg( - cx, - FLAT_MAP_IDENTITY, - flat_map_span.with_hi(expr.span.hi()), - message, - "try", - "flatten()".to_string(), - Applicability::MachineApplicable, - ); - }; - - if_chain! { - if let hir::ExprKind::Closure(_, _, body_id, _, _) = arg_node; - let body = cx.tcx.hir().body(*body_id); - - 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; - - if path.segments.len() == 1; - if path.segments[0].ident.name == binding_ident.name; - - then { - apply_lint("called `flat_map(|x| x)` on an `Iterator`"); - } - } - - if_chain! { - if let hir::ExprKind::Path(ref qpath) = arg_node; - - if match_qpath(qpath, &paths::STD_CONVERT_IDENTITY); - - then { - apply_lint("called `flat_map(std::convert::identity)` on an `Iterator`"); - } - } - } -} - /// lint searching an Iterator followed by `is_some()` /// or calling `find()` on a string followed by `is_some()` fn lint_search_is_some<'tcx>( From 24909fabd27091a7b363dcbc549636e98ba4a898 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:41:43 +0900 Subject: [PATCH 25/35] move map_flatten and search_is_some to their own modules --- clippy_lints/src/methods/map_flatten.rs | 61 +++++++++ clippy_lints/src/methods/mod.rs | 150 +-------------------- clippy_lints/src/methods/search_is_some.rs | 101 ++++++++++++++ 3 files changed, 168 insertions(+), 144 deletions(-) create mode 100644 clippy_lints/src/methods/map_flatten.rs create mode 100644 clippy_lints/src/methods/search_is_some.rs diff --git a/clippy_lints/src/methods/map_flatten.rs b/clippy_lints/src/methods/map_flatten.rs new file mode 100644 index 0000000000000..14a14e4f9ecd1 --- /dev/null +++ b/clippy_lints/src/methods/map_flatten.rs @@ -0,0 +1,61 @@ +use crate::utils::{is_type_diagnostic_item, match_trait_method, paths, snippet, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::symbol::sym; + +use super::MAP_FLATTEN; + +/// lint use of `map().flatten()` for `Iterators` and 'Options' +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_args: &'tcx [hir::Expr<'_>]) { + // lint if caller of `.map().flatten()` is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + 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> + "filter_map" + } else { + // `(...).map(...)` has type `impl Iterator> + "flat_map" + }; + let func_snippet = snippet(cx, map_args[1].span, ".."); + let hint = format!(".{0}({1})", method_to_use, func_snippet); + span_lint_and_sugg( + cx, + MAP_FLATTEN, + expr.span.with_lo(map_args[0].span.hi()), + "called `map(..).flatten()` on an `Iterator`", + &format!("try using `{}` instead", method_to_use), + hint, + Applicability::MachineApplicable, + ); + } + + // lint if caller of `.map().flatten()` is an Option + if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::option_type) { + let func_snippet = snippet(cx, map_args[1].span, ".."); + let hint = format!(".and_then({})", func_snippet); + span_lint_and_sugg( + cx, + MAP_FLATTEN, + expr.span.with_lo(map_args[0].span.hi()), + "called `map(..).flatten()` on an `Option`", + "try using `and_then` instead", + hint, + Applicability::MachineApplicable, + ); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 6a425e6e3ed0b..2b8bb0b4216c7 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -25,9 +25,11 @@ mod iter_nth_zero; mod iterator_step_by_zero; mod manual_saturating_arithmetic; mod map_collect_result_unit; +mod map_flatten; mod ok_expect; mod option_as_ref_deref; mod option_map_unwrap_or; +mod search_is_some; mod single_char_insert_string; mod single_char_pattern; mod single_char_push_string; @@ -1711,13 +1713,13 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["flat_map", "filter"] => filter_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["flat_map", "filter_map"] => filter_map_flat_map::check(cx, expr, arg_lists[1], arg_lists[0]), ["flat_map", ..] => flat_map_identity::check(cx, expr, arg_lists[0], method_spans[0]), - ["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]), - ["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]), + ["flatten", "map"] => map_flatten::check(cx, expr, arg_lists[1]), + ["is_some", "find"] => search_is_some::check(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]) + search_is_some::check(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]) + search_is_some::check(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1]) }, ["extend", ..] => string_extend_chars::check(cx, expr, arg_lists[0]), ["count", "into_iter"] => iter_count::check(cx, expr, &arg_lists[1], "into_iter"), @@ -2566,59 +2568,6 @@ fn derefs_to_slice<'tcx>( } } -/// lint use of `map().flatten()` for `Iterators` and 'Options' -fn lint_map_flatten<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_args: &'tcx [hir::Expr<'_>]) { - // lint if caller of `.map().flatten()` is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - 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> - "filter_map" - } else { - // `(...).map(...)` has type `impl Iterator> - "flat_map" - }; - let func_snippet = snippet(cx, map_args[1].span, ".."); - let hint = format!(".{0}({1})", method_to_use, func_snippet); - span_lint_and_sugg( - cx, - MAP_FLATTEN, - expr.span.with_lo(map_args[0].span.hi()), - "called `map(..).flatten()` on an `Iterator`", - &format!("try using `{}` instead", method_to_use), - hint, - Applicability::MachineApplicable, - ); - } - - // lint if caller of `.map().flatten()` is an Option - if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::option_type) { - let func_snippet = snippet(cx, map_args[1].span, ".."); - let hint = format!(".and_then({})", func_snippet); - span_lint_and_sugg( - cx, - MAP_FLATTEN, - expr.span.with_lo(map_args[0].span.hi()), - "called `map(..).flatten()` on an `Option`", - "try using `and_then` instead", - hint, - Applicability::MachineApplicable, - ); - } -} - const MAP_UNWRAP_OR_MSRV: RustcVersion = RustcVersion::new(1, 41, 0); /// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s @@ -2756,93 +2705,6 @@ fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map ); } -/// lint searching an Iterator followed by `is_some()` -/// or calling `find()` on a string followed by `is_some()` -fn lint_search_is_some<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - search_method: &str, - search_args: &'tcx [hir::Expr<'_>], - is_some_args: &'tcx [hir::Expr<'_>], - method_span: Span, -) { - // lint if caller of search is an Iterator - if match_trait_method(cx, &is_some_args[0], &paths::ITERATOR) { - let msg = format!( - "called `is_some()` after searching an `Iterator` with `{}`", - search_method - ); - let hint = "this is more succinctly expressed by calling `any()`"; - let search_snippet = snippet(cx, search_args[1].span, ".."); - if search_snippet.lines().count() <= 1 { - // suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()` - // suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()` - let any_search_snippet = if_chain! { - if search_method == "find"; - if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].kind; - let closure_body = cx.tcx.hir().body(body_id); - if let Some(closure_arg) = closure_body.params.get(0); - then { - if let hir::PatKind::Ref(..) = closure_arg.pat.kind { - Some(search_snippet.replacen('&', "", 1)) - } else if let PatKind::Binding(_, _, ident, _) = strip_pat_refs(&closure_arg.pat).kind { - let name = &*ident.name.as_str(); - Some(search_snippet.replace(&format!("*{}", name), name)) - } else { - None - } - } else { - None - } - }; - // add note if not multi-line - span_lint_and_sugg( - cx, - SEARCH_IS_SOME, - method_span.with_hi(expr.span.hi()), - &msg, - "use `any()` instead", - format!( - "any({})", - any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str) - ), - Applicability::MachineApplicable, - ); - } else { - span_lint_and_help(cx, SEARCH_IS_SOME, expr.span, &msg, None, hint); - } - } - // lint if `find()` is called by `String` or `&str` - else if search_method == "find" { - let is_string_or_str_slice = |e| { - let self_ty = cx.typeck_results().expr_ty(e).peel_refs(); - if is_type_diagnostic_item(cx, self_ty, sym::string_type) { - true - } else { - *self_ty.kind() == ty::Str - } - }; - if_chain! { - if is_string_or_str_slice(&search_args[0]); - if is_string_or_str_slice(&search_args[1]); - then { - let msg = "called `is_some()` after calling `find()` on a string"; - let mut applicability = Applicability::MachineApplicable; - let find_arg = snippet_with_applicability(cx, search_args[1].span, "..", &mut applicability); - span_lint_and_sugg( - cx, - SEARCH_IS_SOME, - method_span.with_hi(expr.span.hi()), - msg, - "use `contains()` instead", - format!("contains({})", find_arg), - applicability, - ); - } - } - } -} - /// Used for `lint_binary_expr_with_method_call`. #[derive(Copy, Clone)] struct BinaryExprInfo<'a> { diff --git a/clippy_lints/src/methods/search_is_some.rs b/clippy_lints/src/methods/search_is_some.rs new file mode 100644 index 0000000000000..e9e654432208d --- /dev/null +++ b/clippy_lints/src/methods/search_is_some.rs @@ -0,0 +1,101 @@ +use crate::utils::{ + is_type_diagnostic_item, match_trait_method, paths, snippet, snippet_with_applicability, span_lint_and_help, + span_lint_and_sugg, strip_pat_refs, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_hir::PatKind; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::source_map::Span; +use rustc_span::symbol::sym; + +use super::SEARCH_IS_SOME; + +/// lint searching an Iterator followed by `is_some()` +/// or calling `find()` on a string followed by `is_some()` +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + search_method: &str, + search_args: &'tcx [hir::Expr<'_>], + is_some_args: &'tcx [hir::Expr<'_>], + method_span: Span, +) { + // lint if caller of search is an Iterator + if match_trait_method(cx, &is_some_args[0], &paths::ITERATOR) { + let msg = format!( + "called `is_some()` after searching an `Iterator` with `{}`", + search_method + ); + let hint = "this is more succinctly expressed by calling `any()`"; + let search_snippet = snippet(cx, search_args[1].span, ".."); + if search_snippet.lines().count() <= 1 { + // suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()` + // suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()` + let any_search_snippet = if_chain! { + if search_method == "find"; + if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].kind; + let closure_body = cx.tcx.hir().body(body_id); + if let Some(closure_arg) = closure_body.params.get(0); + then { + if let hir::PatKind::Ref(..) = closure_arg.pat.kind { + Some(search_snippet.replacen('&', "", 1)) + } else if let PatKind::Binding(_, _, ident, _) = strip_pat_refs(&closure_arg.pat).kind { + let name = &*ident.name.as_str(); + Some(search_snippet.replace(&format!("*{}", name), name)) + } else { + None + } + } else { + None + } + }; + // add note if not multi-line + span_lint_and_sugg( + cx, + SEARCH_IS_SOME, + method_span.with_hi(expr.span.hi()), + &msg, + "use `any()` instead", + format!( + "any({})", + any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str) + ), + Applicability::MachineApplicable, + ); + } else { + span_lint_and_help(cx, SEARCH_IS_SOME, expr.span, &msg, None, hint); + } + } + // lint if `find()` is called by `String` or `&str` + else if search_method == "find" { + let is_string_or_str_slice = |e| { + let self_ty = cx.typeck_results().expr_ty(e).peel_refs(); + if is_type_diagnostic_item(cx, self_ty, sym::string_type) { + true + } else { + *self_ty.kind() == ty::Str + } + }; + if_chain! { + if is_string_or_str_slice(&search_args[0]); + if is_string_or_str_slice(&search_args[1]); + then { + let msg = "called `is_some()` after calling `find()` on a string"; + let mut applicability = Applicability::MachineApplicable; + let find_arg = snippet_with_applicability(cx, search_args[1].span, "..", &mut applicability); + span_lint_and_sugg( + cx, + SEARCH_IS_SOME, + method_span.with_hi(expr.span.hi()), + msg, + "use `contains()` instead", + format!("contains({})", find_arg), + applicability, + ); + } + } + } +} From 171c4c148540846c8aab4e1f0f491e8bfb892fcf Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:45:25 +0900 Subject: [PATCH 26/35] move iter_skip_next to its own module --- clippy_lints/src/methods/iter_skip_next.rs | 24 ++++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 21 ++----------------- 2 files changed, 26 insertions(+), 19 deletions(-) create mode 100644 clippy_lints/src/methods/iter_skip_next.rs diff --git a/clippy_lints/src/methods/iter_skip_next.rs b/clippy_lints/src/methods/iter_skip_next.rs new file mode 100644 index 0000000000000..5f5969134e490 --- /dev/null +++ b/clippy_lints/src/methods/iter_skip_next.rs @@ -0,0 +1,24 @@ +use crate::utils::{match_trait_method, paths, snippet, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::ITER_SKIP_NEXT; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) { + // lint if caller of skip is an Iterator + if match_trait_method(cx, expr, &paths::ITERATOR) { + 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(..).next()` on an iterator", + "use `nth` instead", + hint, + Applicability::MachineApplicable, + ); + } + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 2b8bb0b4216c7..927375f9e0b17 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -22,6 +22,7 @@ mod iter_count; mod iter_next_slice; mod iter_nth; mod iter_nth_zero; +mod iter_skip_next; mod iterator_step_by_zero; mod manual_saturating_arithmetic; mod map_collect_result_unit; @@ -1730,7 +1731,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["nth", "bytes"] => bytes_nth::check(cx, expr, &arg_lists[1]), ["nth", ..] => iter_nth_zero::check(cx, expr, arg_lists[0]), ["step_by", ..] => iterator_step_by_zero::check(cx, expr, arg_lists[0]), - ["next", "skip"] => lint_iter_skip_next(cx, expr, arg_lists[1]), + ["next", "skip"] => iter_skip_next::check(cx, expr, arg_lists[1]), ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]), ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]), @@ -2510,24 +2511,6 @@ fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: } } -fn lint_iter_skip_next(cx: &LateContext<'_>, expr: &hir::Expr<'_>, skip_args: &[hir::Expr<'_>]) { - // lint if caller of skip is an Iterator - if match_trait_method(cx, expr, &paths::ITERATOR) { - 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(..).next()` on an iterator", - "use `nth` instead", - hint, - Applicability::MachineApplicable, - ); - } - } -} - fn derefs_to_slice<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>, From caaba8270c7de1bf3446f3345e7e794295db59fd Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:53:31 +0900 Subject: [PATCH 27/35] move clone_on_copy to its own module --- clippy_lints/src/methods/clone_on_copy.rs | 109 ++++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 106 +-------------------- 2 files changed, 112 insertions(+), 103 deletions(-) create mode 100644 clippy_lints/src/methods/clone_on_copy.rs diff --git a/clippy_lints/src/methods/clone_on_copy.rs b/clippy_lints/src/methods/clone_on_copy.rs new file mode 100644 index 0000000000000..4a130ed47db15 --- /dev/null +++ b/clippy_lints/src/methods/clone_on_copy.rs @@ -0,0 +1,109 @@ +use crate::utils::{is_copy, span_lint_and_then, sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty::{self, Ty}; +use std::iter; + +use super::CLONE_DOUBLE_REF; +use super::CLONE_ON_COPY; + +/// Checks for the `CLONE_ON_COPY` lint. +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'_>) { + let ty = cx.typeck_results().expr_ty(expr); + if let ty::Ref(_, inner, _) = arg_ty.kind() { + if let ty::Ref(_, innermost, _) = inner.kind() { + span_lint_and_then( + cx, + CLONE_DOUBLE_REF, + expr.span, + &format!( + "using `clone` on a double-reference; \ + this will copy the reference of type `{}` instead of cloning the inner type", + ty + ), + |diag| { + if let Some(snip) = sugg::Sugg::hir_opt(cx, arg) { + let mut ty = innermost; + let mut n = 0; + while let ty::Ref(_, inner, _) = ty.kind() { + ty = inner; + n += 1; + } + let refs: String = iter::repeat('&').take(n + 1).collect(); + let derefs: String = iter::repeat('*').take(n).collect(); + let explicit = format!("<{}{}>::clone({})", refs, ty, snip); + diag.span_suggestion( + expr.span, + "try dereferencing it", + format!("{}({}{}).clone()", refs, derefs, snip.deref()), + Applicability::MaybeIncorrect, + ); + diag.span_suggestion( + expr.span, + "or try being explicit if you are sure, that you want to clone a reference", + explicit, + Applicability::MaybeIncorrect, + ); + } + }, + ); + return; // don't report clone_on_copy + } + } + + if is_copy(cx, ty) { + let snip; + if let Some(snippet) = sugg::Sugg::hir_opt(cx, arg) { + let parent = cx.tcx.hir().get_parent_node(expr.hir_id); + match &cx.tcx.hir().get(parent) { + hir::Node::Expr(parent) => match parent.kind { + // &*x is a nop, &x.clone() is not + hir::ExprKind::AddrOf(..) => return, + // (*x).func() is useless, x.clone().func() can work in case func borrows mutably + hir::ExprKind::MethodCall(_, _, parent_args, _) if expr.hir_id == parent_args[0].hir_id => { + return; + }, + + _ => {}, + }, + hir::Node::Stmt(stmt) => { + if let hir::StmtKind::Local(ref loc) = stmt.kind { + if let hir::PatKind::Ref(..) = loc.pat.kind { + // let ref y = *x borrows x, let ref y = x.clone() does not + return; + } + } + }, + _ => {}, + } + + // x.clone() might have dereferenced x, possibly through Deref impls + if cx.typeck_results().expr_ty(arg) == ty { + snip = Some(("try removing the `clone` call", format!("{}", snippet))); + } else { + let deref_count = cx + .typeck_results() + .expr_adjustments(arg) + .iter() + .filter(|adj| matches!(adj.kind, ty::adjustment::Adjust::Deref(_))) + .count(); + let derefs: String = iter::repeat('*').take(deref_count).collect(); + snip = Some(("try dereferencing it", format!("{}{}", derefs, snippet))); + } + } else { + snip = None; + } + span_lint_and_then( + cx, + CLONE_ON_COPY, + expr.span, + &format!("using `clone` on type `{}` which implements the `Copy` trait", ty), + |diag| { + if let Some((text, snip)) = snip { + diag.span_suggestion(expr.span, text, snip, Applicability::MachineApplicable); + } + }, + ); + } +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 927375f9e0b17..f248a09e18ef3 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -1,5 +1,6 @@ mod bind_instead_of_map; mod bytes_nth; +mod clone_on_copy; mod clone_on_ref_ptr; mod expect_used; mod filetype_is_file; @@ -45,7 +46,6 @@ mod wrong_self_convention; mod zst_offset; use std::borrow::Cow; -use std::iter; use bind_instead_of_map::BindInsteadOfMap; use if_chain::if_chain; @@ -69,7 +69,7 @@ use crate::utils::{ is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, - span_lint_and_help, span_lint_and_sugg, span_lint_and_then, strip_pat_refs, sugg, walk_ptrs_ty_depth, SpanlessEq, + span_lint_and_help, span_lint_and_sugg, strip_pat_refs, walk_ptrs_ty_depth, SpanlessEq, }; declare_clippy_lint! { @@ -1781,7 +1781,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]); if args.len() == 1 && method_call.ident.name == sym::clone { - lint_clone_on_copy(cx, expr, &args[0], self_ty); + clone_on_copy::check(cx, expr, &args[0], self_ty); clone_on_ref_ptr::check(cx, expr, &args[0]); } if args.len() == 1 && method_call.ident.name == sym!(to_string) { @@ -2323,106 +2323,6 @@ fn lint_expect_fun_call( ); } -/// Checks for the `CLONE_ON_COPY` lint. -fn lint_clone_on_copy(cx: &LateContext<'_>, expr: &hir::Expr<'_>, arg: &hir::Expr<'_>, arg_ty: Ty<'_>) { - let ty = cx.typeck_results().expr_ty(expr); - if let ty::Ref(_, inner, _) = arg_ty.kind() { - if let ty::Ref(_, innermost, _) = inner.kind() { - span_lint_and_then( - cx, - CLONE_DOUBLE_REF, - expr.span, - &format!( - "using `clone` on a double-reference; \ - this will copy the reference of type `{}` instead of cloning the inner type", - ty - ), - |diag| { - if let Some(snip) = sugg::Sugg::hir_opt(cx, arg) { - let mut ty = innermost; - let mut n = 0; - while let ty::Ref(_, inner, _) = ty.kind() { - ty = inner; - n += 1; - } - let refs: String = iter::repeat('&').take(n + 1).collect(); - let derefs: String = iter::repeat('*').take(n).collect(); - let explicit = format!("<{}{}>::clone({})", refs, ty, snip); - diag.span_suggestion( - expr.span, - "try dereferencing it", - format!("{}({}{}).clone()", refs, derefs, snip.deref()), - Applicability::MaybeIncorrect, - ); - diag.span_suggestion( - expr.span, - "or try being explicit if you are sure, that you want to clone a reference", - explicit, - Applicability::MaybeIncorrect, - ); - } - }, - ); - return; // don't report clone_on_copy - } - } - - if is_copy(cx, ty) { - let snip; - if let Some(snippet) = sugg::Sugg::hir_opt(cx, arg) { - let parent = cx.tcx.hir().get_parent_node(expr.hir_id); - match &cx.tcx.hir().get(parent) { - hir::Node::Expr(parent) => match parent.kind { - // &*x is a nop, &x.clone() is not - hir::ExprKind::AddrOf(..) => return, - // (*x).func() is useless, x.clone().func() can work in case func borrows mutably - hir::ExprKind::MethodCall(_, _, parent_args, _) if expr.hir_id == parent_args[0].hir_id => { - return; - }, - - _ => {}, - }, - hir::Node::Stmt(stmt) => { - if let hir::StmtKind::Local(ref loc) = stmt.kind { - if let hir::PatKind::Ref(..) = loc.pat.kind { - // let ref y = *x borrows x, let ref y = x.clone() does not - return; - } - } - }, - _ => {}, - } - - // x.clone() might have dereferenced x, possibly through Deref impls - if cx.typeck_results().expr_ty(arg) == ty { - snip = Some(("try removing the `clone` call", format!("{}", snippet))); - } else { - let deref_count = cx - .typeck_results() - .expr_adjustments(arg) - .iter() - .filter(|adj| matches!(adj.kind, ty::adjustment::Adjust::Deref(_))) - .count(); - let derefs: String = iter::repeat('*').take(deref_count).collect(); - snip = Some(("try dereferencing it", format!("{}{}", derefs, snippet))); - } - } else { - snip = None; - } - span_lint_and_then( - cx, - CLONE_ON_COPY, - expr.span, - &format!("using `clone` on type `{}` which implements the `Copy` trait", ty), - |diag| { - if let Some((text, snip)) = snip { - diag.span_suggestion(expr.span, text, snip, Applicability::MachineApplicable); - } - }, - ); - } -} - fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) { fn check_fold_with_op( cx: &LateContext<'_>, From 78e572c62782b4bd027c23b9d56a14b0b42ba93a Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 18:59:35 +0900 Subject: [PATCH 28/35] move useless_asref to its own module --- clippy_lints/src/methods/mod.rs | 45 +++-------------------- clippy_lints/src/methods/useless_asref.rs | 45 +++++++++++++++++++++++ 2 files changed, 50 insertions(+), 40 deletions(-) create mode 100644 clippy_lints/src/methods/useless_asref.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index f248a09e18ef3..eaf247536b6e3 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -42,6 +42,7 @@ mod uninit_assumed_init; mod unnecessary_filter_map; mod unnecessary_lazy_eval; mod unwrap_used; +mod useless_asref; mod wrong_self_convention; mod zst_offset; @@ -65,11 +66,11 @@ use rustc_typeck::hir_ty_to_ty; use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ - contains_return, contains_ty, get_parent_expr, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, + contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_trait_method, match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, remove_blocks, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, - span_lint_and_help, span_lint_and_sugg, strip_pat_refs, walk_ptrs_ty_depth, SpanlessEq, + span_lint_and_help, span_lint_and_sugg, strip_pat_refs, SpanlessEq, }; declare_clippy_lint! { @@ -1733,8 +1734,8 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["step_by", ..] => iterator_step_by_zero::check(cx, expr, arg_lists[0]), ["next", "skip"] => iter_skip_next::check(cx, expr, arg_lists[1]), ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), - ["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]), - ["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]), + ["as_ref"] => useless_asref::check(cx, expr, "as_ref", arg_lists[0]), + ["as_mut"] => useless_asref::check(cx, expr, "as_mut", arg_lists[0]), ["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]), ["filter_map", ..] => { unnecessary_filter_map::check(cx, expr, arg_lists[0]); @@ -2751,42 +2752,6 @@ fn get_hint_if_single_char_arg( } } -/// Checks for the `USELESS_ASREF` lint. -fn lint_asref(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) { - // 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 - if match_trait_method(cx, expr, &paths::ASREF_TRAIT) || match_trait_method(cx, expr, &paths::ASMUT_TRAIT) { - // check if the type after `as_ref` or `as_mut` is the same as before - let recvr = &as_ref_args[0]; - let rcv_ty = cx.typeck_results().expr_ty(recvr); - let res_ty = cx.typeck_results().expr_ty(expr); - 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 { - // 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); - if let hir::ExprKind::MethodCall(_, ref span, _, _) = parent.kind; - if span != &expr.span; - then { - return; - } - } - - let mut applicability = Applicability::MachineApplicable; - span_lint_and_sugg( - cx, - USELESS_ASREF, - expr.span, - &format!("this call to `{}` does nothing", call_name), - "try this", - snippet_with_applicability(cx, recvr.span, "..", &mut applicability).to_string(), - applicability, - ); - } - } -} - const FN_HEADER: hir::FnHeader = hir::FnHeader { unsafety: hir::Unsafety::Normal, constness: hir::Constness::NotConst, diff --git a/clippy_lints/src/methods/useless_asref.rs b/clippy_lints/src/methods/useless_asref.rs new file mode 100644 index 0000000000000..e4554f8d4897e --- /dev/null +++ b/clippy_lints/src/methods/useless_asref.rs @@ -0,0 +1,45 @@ +use crate::utils::{ + get_parent_expr, match_trait_method, paths, snippet_with_applicability, span_lint_and_sugg, walk_ptrs_ty_depth, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::USELESS_ASREF; + +/// Checks for the `USELESS_ASREF` lint. +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, call_name: &str, as_ref_args: &[hir::Expr<'_>]) { + // 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 + if match_trait_method(cx, expr, &paths::ASREF_TRAIT) || match_trait_method(cx, expr, &paths::ASMUT_TRAIT) { + // check if the type after `as_ref` or `as_mut` is the same as before + let recvr = &as_ref_args[0]; + let rcv_ty = cx.typeck_results().expr_ty(recvr); + let res_ty = cx.typeck_results().expr_ty(expr); + 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 { + // 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); + if let hir::ExprKind::MethodCall(_, ref span, _, _) = parent.kind; + if span != &expr.span; + then { + return; + } + } + + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + USELESS_ASREF, + expr.span, + &format!("this call to `{}` does nothing", call_name), + "try this", + snippet_with_applicability(cx, recvr.span, "..", &mut applicability).to_string(), + applicability, + ); + } + } +} From bbed852f6fb82aa85f72fc8b2aeffdb90f409495 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 19:05:51 +0900 Subject: [PATCH 29/35] unnecessary_fold to its own module --- clippy_lints/src/methods/mod.rs | 100 ++---------------- clippy_lints/src/methods/unnecessary_fold.rs | 101 +++++++++++++++++++ 2 files changed, 107 insertions(+), 94 deletions(-) create mode 100644 clippy_lints/src/methods/unnecessary_fold.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index eaf247536b6e3..702c8e76f4992 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -40,6 +40,7 @@ mod string_extend_chars; mod suspicious_map; mod uninit_assumed_init; mod unnecessary_filter_map; +mod unnecessary_fold; mod unnecessary_lazy_eval; mod unwrap_used; mod useless_asref; @@ -53,7 +54,7 @@ use if_chain::if_chain; use rustc_ast::ast; use rustc_errors::Applicability; use rustc_hir as hir; -use rustc_hir::{PatKind, TraitItem, TraitItemKind}; +use rustc_hir::{TraitItem, TraitItemKind}; use rustc_lint::{LateContext, LateLintPass, Lint, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, TraitRef, Ty, TyS}; @@ -67,10 +68,9 @@ use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::usage::mutated_variables; use crate::utils::{ contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, - is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_trait_method, - match_type, meets_msrv, method_calls, method_chain_args, path_to_local_id, paths, remove_blocks, return_ty, - single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, - span_lint_and_help, span_lint_and_sugg, strip_pat_refs, SpanlessEq, + is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, meets_msrv, + method_calls, method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, + snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, SpanlessEq, }; declare_clippy_lint! { @@ -1736,7 +1736,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), ["as_ref"] => useless_asref::check(cx, expr, "as_ref", arg_lists[0]), ["as_mut"] => useless_asref::check(cx, expr, "as_mut", arg_lists[0]), - ["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]), + ["fold", ..] => unnecessary_fold::check(cx, expr, arg_lists[0], method_spans[0]), ["filter_map", ..] => { unnecessary_filter_map::check(cx, expr, arg_lists[0]); filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); @@ -2324,94 +2324,6 @@ fn lint_expect_fun_call( ); } -fn lint_unnecessary_fold(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) { - fn check_fold_with_op( - cx: &LateContext<'_>, - expr: &hir::Expr<'_>, - fold_args: &[hir::Expr<'_>], - fold_span: Span, - op: hir::BinOpKind, - replacement_method_name: &str, - replacement_has_args: bool, - ) { - if_chain! { - // Extract the body of the closure passed to fold - if let hir::ExprKind::Closure(_, _, body_id, _, _) = fold_args[2].kind; - let closure_body = cx.tcx.hir().body(body_id); - let closure_expr = remove_blocks(&closure_body.value); - - // Check if the closure body is of the form `acc some_expr(x)` - if let hir::ExprKind::Binary(ref bin_op, ref left_expr, ref right_expr) = closure_expr.kind; - if bin_op.node == op; - - // Extract the names of the two arguments to the closure - if let [param_a, param_b] = closure_body.params; - if let PatKind::Binding(_, first_arg_id, ..) = strip_pat_refs(¶m_a.pat).kind; - if let PatKind::Binding(_, second_arg_id, second_arg_ident, _) = strip_pat_refs(¶m_b.pat).kind; - - if path_to_local_id(left_expr, first_arg_id); - if replacement_has_args || path_to_local_id(right_expr, second_arg_id); - - then { - let mut applicability = Applicability::MachineApplicable; - let sugg = if replacement_has_args { - format!( - "{replacement}(|{s}| {r})", - replacement = replacement_method_name, - s = second_arg_ident, - r = snippet_with_applicability(cx, right_expr.span, "EXPR", &mut applicability), - ) - } else { - format!( - "{replacement}()", - replacement = replacement_method_name, - ) - }; - - span_lint_and_sugg( - cx, - UNNECESSARY_FOLD, - fold_span.with_hi(expr.span.hi()), - // TODO #2371 don't suggest e.g., .any(|x| f(x)) if we can suggest .any(f) - "this `.fold` can be written more succinctly using another method", - "try", - sugg, - applicability, - ); - } - } - } - - // Check that this is a call to Iterator::fold rather than just some function called fold - if !match_trait_method(cx, expr, &paths::ITERATOR) { - return; - } - - assert!( - fold_args.len() == 3, - "Expected fold_args to have three entries - the receiver, the initial value and the closure" - ); - - // Check if the first argument to .fold is a suitable literal - if let hir::ExprKind::Lit(ref lit) = fold_args[1].kind { - match lit.node { - 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) - }, - _ => (), - } - } -} - fn derefs_to_slice<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>, diff --git a/clippy_lints/src/methods/unnecessary_fold.rs b/clippy_lints/src/methods/unnecessary_fold.rs new file mode 100644 index 0000000000000..a26443f4ee944 --- /dev/null +++ b/clippy_lints/src/methods/unnecessary_fold.rs @@ -0,0 +1,101 @@ +use crate::utils::{ + match_trait_method, path_to_local_id, paths, remove_blocks, snippet_with_applicability, span_lint_and_sugg, + strip_pat_refs, +}; +use if_chain::if_chain; +use rustc_ast::ast; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_hir::PatKind; +use rustc_lint::LateContext; +use rustc_span::source_map::Span; + +use super::UNNECESSARY_FOLD; + +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, fold_args: &[hir::Expr<'_>], fold_span: Span) { + fn check_fold_with_op( + cx: &LateContext<'_>, + expr: &hir::Expr<'_>, + fold_args: &[hir::Expr<'_>], + fold_span: Span, + op: hir::BinOpKind, + replacement_method_name: &str, + replacement_has_args: bool, + ) { + if_chain! { + // Extract the body of the closure passed to fold + if let hir::ExprKind::Closure(_, _, body_id, _, _) = fold_args[2].kind; + let closure_body = cx.tcx.hir().body(body_id); + let closure_expr = remove_blocks(&closure_body.value); + + // Check if the closure body is of the form `acc some_expr(x)` + if let hir::ExprKind::Binary(ref bin_op, ref left_expr, ref right_expr) = closure_expr.kind; + if bin_op.node == op; + + // Extract the names of the two arguments to the closure + if let [param_a, param_b] = closure_body.params; + if let PatKind::Binding(_, first_arg_id, ..) = strip_pat_refs(¶m_a.pat).kind; + if let PatKind::Binding(_, second_arg_id, second_arg_ident, _) = strip_pat_refs(¶m_b.pat).kind; + + if path_to_local_id(left_expr, first_arg_id); + if replacement_has_args || path_to_local_id(right_expr, second_arg_id); + + then { + let mut applicability = Applicability::MachineApplicable; + let sugg = if replacement_has_args { + format!( + "{replacement}(|{s}| {r})", + replacement = replacement_method_name, + s = second_arg_ident, + r = snippet_with_applicability(cx, right_expr.span, "EXPR", &mut applicability), + ) + } else { + format!( + "{replacement}()", + replacement = replacement_method_name, + ) + }; + + span_lint_and_sugg( + cx, + UNNECESSARY_FOLD, + fold_span.with_hi(expr.span.hi()), + // TODO #2371 don't suggest e.g., .any(|x| f(x)) if we can suggest .any(f) + "this `.fold` can be written more succinctly using another method", + "try", + sugg, + applicability, + ); + } + } + } + + // Check that this is a call to Iterator::fold rather than just some function called fold + if !match_trait_method(cx, expr, &paths::ITERATOR) { + return; + } + + assert!( + fold_args.len() == 3, + "Expected fold_args to have three entries - the receiver, the initial value and the closure" + ); + + // Check if the first argument to .fold is a suitable literal + if let hir::ExprKind::Lit(ref lit) = fold_args[1].kind { + match lit.node { + 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) + }, + _ => (), + } + } +} From 5557596926b493f1fdb85aef6bd78941f231f962 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 19:11:52 +0900 Subject: [PATCH 30/35] move option_map_or_none to its own module --- clippy_lints/src/methods/mod.rs | 73 +---------------- .../src/methods/option_map_or_none.rs | 78 +++++++++++++++++++ 2 files changed, 80 insertions(+), 71 deletions(-) create mode 100644 clippy_lints/src/methods/option_map_or_none.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 702c8e76f4992..0c67c3b892b24 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -30,6 +30,7 @@ mod map_collect_result_unit; mod map_flatten; mod ok_expect; mod option_as_ref_deref; +mod option_map_or_none; mod option_map_unwrap_or; mod search_is_some; mod single_char_insert_string; @@ -1692,7 +1693,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"); } }, - ["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]), + ["map_or", ..] => option_map_or_none::check(cx, expr, arg_lists[0]), ["and_then", ..] => { let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, arg_lists[0]); let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, arg_lists[0]); @@ -2431,76 +2432,6 @@ fn lint_map_unwrap_or_else<'tcx>( false } -/// lint use of `_.map_or(None, _)` for `Option`s and `Result`s -fn lint_map_or_none<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_or_args: &'tcx [hir::Expr<'_>]) { - 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); - - // There are two variants of this `map_or` lint: - // (1) using `map_or` as an adapter from `Result` to `Option` - // (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; - } - - let (lint_name, msg, instead, hint) = { - let default_arg_is_none = if let hir::ExprKind::Path(ref qpath) = map_or_args[1].kind { - match_qpath(qpath, &paths::OPTION_NONE) - } else { - return; - }; - - if !default_arg_is_none { - // nothing to lint! - return; - } - - let f_arg_is_some = if let hir::ExprKind::Path(ref qpath) = map_or_args[2].kind { - match_qpath(qpath, &paths::OPTION_SOME) - } else { - false - }; - - if is_option { - let self_snippet = snippet(cx, map_or_args[0].span, ".."); - let func_snippet = snippet(cx, map_or_args[2].span, ".."); - let msg = "called `map_or(None, ..)` on an `Option` value. This can be done more directly by calling \ - `and_then(..)` instead"; - ( - OPTION_MAP_OR_NONE, - msg, - "try using `and_then` instead", - 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; - } - }; - - span_lint_and_sugg( - cx, - lint_name, - expr.span, - msg, - instead, - hint, - Applicability::MachineApplicable, - ); -} - /// Used for `lint_binary_expr_with_method_call`. #[derive(Copy, Clone)] struct BinaryExprInfo<'a> { diff --git a/clippy_lints/src/methods/option_map_or_none.rs b/clippy_lints/src/methods/option_map_or_none.rs new file mode 100644 index 0000000000000..64f6ebc5062ef --- /dev/null +++ b/clippy_lints/src/methods/option_map_or_none.rs @@ -0,0 +1,78 @@ +use crate::utils::{is_type_diagnostic_item, match_qpath, paths, snippet, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_span::symbol::sym; + +use super::OPTION_MAP_OR_NONE; +use super::RESULT_MAP_OR_INTO_OPTION; + +/// lint use of `_.map_or(None, _)` for `Option`s and `Result`s +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_or_args: &'tcx [hir::Expr<'_>]) { + 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); + + // There are two variants of this `map_or` lint: + // (1) using `map_or` as an adapter from `Result` to `Option` + // (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; + } + + let (lint_name, msg, instead, hint) = { + let default_arg_is_none = if let hir::ExprKind::Path(ref qpath) = map_or_args[1].kind { + match_qpath(qpath, &paths::OPTION_NONE) + } else { + return; + }; + + if !default_arg_is_none { + // nothing to lint! + return; + } + + let f_arg_is_some = if let hir::ExprKind::Path(ref qpath) = map_or_args[2].kind { + match_qpath(qpath, &paths::OPTION_SOME) + } else { + false + }; + + if is_option { + let self_snippet = snippet(cx, map_or_args[0].span, ".."); + let func_snippet = snippet(cx, map_or_args[2].span, ".."); + let msg = "called `map_or(None, ..)` on an `Option` value. This can be done more directly by calling \ + `and_then(..)` instead"; + ( + OPTION_MAP_OR_NONE, + msg, + "try using `and_then` instead", + 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; + } + }; + + span_lint_and_sugg( + cx, + lint_name, + expr.span, + msg, + instead, + hint, + Applicability::MachineApplicable, + ); +} From b0824bf75fba159f40e498dd88386174feea5cf5 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 19:31:46 +0900 Subject: [PATCH 31/35] move map_unwrap_or to its own module --- clippy_lints/src/methods/map_unwrap_or.rs | 76 +++++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 75 ++-------------------- 2 files changed, 80 insertions(+), 71 deletions(-) create mode 100644 clippy_lints/src/methods/map_unwrap_or.rs diff --git a/clippy_lints/src/methods/map_unwrap_or.rs b/clippy_lints/src/methods/map_unwrap_or.rs new file mode 100644 index 0000000000000..63b2cf87f32ad --- /dev/null +++ b/clippy_lints/src/methods/map_unwrap_or.rs @@ -0,0 +1,76 @@ +use crate::utils::usage::mutated_variables; +use crate::utils::{is_type_diagnostic_item, meets_msrv, snippet, span_lint, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_semver::RustcVersion; +use rustc_span::symbol::sym; + +use super::MAP_UNWRAP_OR; + +const MAP_UNWRAP_OR_MSRV: RustcVersion = RustcVersion::new(1, 41, 0); + +/// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s +/// Return true if lint triggered +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + map_args: &'tcx [hir::Expr<'_>], + unwrap_args: &'tcx [hir::Expr<'_>], + msrv: Option<&RustcVersion>, +) -> bool { + if !meets_msrv(msrv, &MAP_UNWRAP_OR_MSRV) { + return false; + } + // lint if the caller of `map()` is an `Option` + 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); + + if is_option || is_result { + // Don't make a suggestion that may fail to compile due to mutably borrowing + // the same variable twice. + 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() { + return false; + } + } else { + return false; + } + + // lint message + let msg = if is_option { + "called `map().unwrap_or_else()` on an `Option` value. This can be done more directly by calling \ + `map_or_else(, )` instead" + } else { + "called `map().unwrap_or_else()` on a `Result` value. This can be done more directly by calling \ + `.map_or_else(, )` instead" + }; + // 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 + let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1; + let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt(); + if same_span && !multiline { + let var_snippet = snippet(cx, map_args[0].span, ".."); + span_lint_and_sugg( + cx, + MAP_UNWRAP_OR, + expr.span, + msg, + "try this", + format!("{}.map_or_else({}, {})", var_snippet, unwrap_snippet, map_snippet), + Applicability::MachineApplicable, + ); + return true; + } else if same_span && multiline { + span_lint(cx, MAP_UNWRAP_OR, expr.span, msg); + return true; + } + } + + false +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 0c67c3b892b24..5f62942530c40 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -28,6 +28,7 @@ mod iterator_step_by_zero; mod manual_saturating_arithmetic; mod map_collect_result_unit; mod map_flatten; +mod map_unwrap_or; mod ok_expect; mod option_as_ref_deref; mod option_map_or_none; @@ -66,11 +67,10 @@ use rustc_span::symbol::{sym, Symbol, SymbolStr}; use rustc_typeck::hir_ty_to_ty; use crate::utils::eager_or_lazy::is_lazyness_candidate; -use crate::utils::usage::mutated_variables; use crate::utils::{ contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, - is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, meets_msrv, - method_calls, method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, + is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, method_calls, + method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, SpanlessEq, }; @@ -1689,7 +1689,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["expect", ..] => expect_used::check(cx, expr, arg_lists[0]), ["unwrap_or", "map"] => option_map_unwrap_or::check(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]), ["unwrap_or_else", "map"] => { - if !lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0], self.msrv.as_ref()) { + if !map_unwrap_or::check(cx, expr, arg_lists[1], arg_lists[0], self.msrv.as_ref()) { unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"); } }, @@ -2365,73 +2365,6 @@ fn derefs_to_slice<'tcx>( } } -const MAP_UNWRAP_OR_MSRV: RustcVersion = RustcVersion::new(1, 41, 0); - -/// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s -/// Return true if lint triggered -fn lint_map_unwrap_or_else<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - map_args: &'tcx [hir::Expr<'_>], - unwrap_args: &'tcx [hir::Expr<'_>], - msrv: Option<&RustcVersion>, -) -> bool { - if !meets_msrv(msrv, &MAP_UNWRAP_OR_MSRV) { - return false; - } - // lint if the caller of `map()` is an `Option` - 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); - - if is_option || is_result { - // Don't make a suggestion that may fail to compile due to mutably borrowing - // the same variable twice. - 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() { - return false; - } - } else { - return false; - } - - // lint message - let msg = if is_option { - "called `map().unwrap_or_else()` on an `Option` value. This can be done more directly by calling \ - `map_or_else(, )` instead" - } else { - "called `map().unwrap_or_else()` on a `Result` value. This can be done more directly by calling \ - `.map_or_else(, )` instead" - }; - // 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 - let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1; - let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt(); - if same_span && !multiline { - let var_snippet = snippet(cx, map_args[0].span, ".."); - span_lint_and_sugg( - cx, - MAP_UNWRAP_OR, - expr.span, - msg, - "try this", - format!("{}.map_or_else({}, {})", var_snippet, unwrap_snippet, map_snippet), - Applicability::MachineApplicable, - ); - return true; - } else if same_span && multiline { - span_lint(cx, MAP_UNWRAP_OR, expr.span, msg); - return true; - } - } - - false -} - /// Used for `lint_binary_expr_with_method_call`. #[derive(Copy, Clone)] struct BinaryExprInfo<'a> { From f49349bf333001166e3a215b7b2eb5b5cb1c9989 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 19:40:34 +0900 Subject: [PATCH 32/35] move or_fun_call to its own module --- clippy_lints/src/methods/mod.rs | 168 +---------------------- clippy_lints/src/methods/or_fun_call.rs | 173 ++++++++++++++++++++++++ 2 files changed, 178 insertions(+), 163 deletions(-) create mode 100644 clippy_lints/src/methods/or_fun_call.rs diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 5f62942530c40..857c1bf0ec08a 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -33,6 +33,7 @@ mod ok_expect; mod option_as_ref_deref; mod option_map_or_none; mod option_map_unwrap_or; +mod or_fun_call; mod search_is_some; mod single_char_insert_string; mod single_char_pattern; @@ -66,12 +67,11 @@ use rustc_span::source_map::Span; use rustc_span::symbol::{sym, Symbol, SymbolStr}; use rustc_typeck::hir_ty_to_ty; -use crate::utils::eager_or_lazy::is_lazyness_candidate; use crate::utils::{ contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, - is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, method_calls, - method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, - snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, SpanlessEq, + is_type_diagnostic_item, iter_input_pats, match_def_path, match_qpath, method_calls, method_chain_args, paths, + return_ty, single_segment_path, snippet, snippet_with_applicability, span_lint, span_lint_and_help, + span_lint_and_sugg, SpanlessEq, }; declare_clippy_lint! { @@ -1778,7 +1778,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { } }, hir::ExprKind::MethodCall(ref method_call, ref method_span, ref args, _) => { - lint_or_fun_call(cx, expr, *method_span, &method_call.ident.as_str(), args); + or_fun_call::check(cx, expr, *method_span, &method_call.ident.as_str(), args); lint_expect_fun_call(cx, expr, *method_span, &method_call.ident.as_str(), args); let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]); @@ -1973,164 +1973,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods { extract_msrv_attr!(LateContext); } -/// Checks for the `OR_FUN_CALL` lint. -#[allow(clippy::too_many_lines)] -fn lint_or_fun_call<'tcx>( - cx: &LateContext<'tcx>, - expr: &hir::Expr<'_>, - method_span: Span, - name: &str, - args: &'tcx [hir::Expr<'_>], -) { - /// Checks for `unwrap_or(T::new())` or `unwrap_or(T::default())`. - fn check_unwrap_or_default( - cx: &LateContext<'_>, - name: &str, - fun: &hir::Expr<'_>, - self_expr: &hir::Expr<'_>, - arg: &hir::Expr<'_>, - or_has_args: bool, - span: Span, - ) -> bool { - if_chain! { - if !or_has_args; - if name == "unwrap_or"; - if let hir::ExprKind::Path(ref qpath) = fun.kind; - let path = &*last_path_segment(qpath).ident.as_str(); - if ["default", "new"].contains(&path); - let arg_ty = cx.typeck_results().expr_ty(arg); - if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT); - if implements_trait(cx, arg_ty, default_trait_id, &[]); - - 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 - } - } - } - - /// Checks for `*or(foo())`. - #[allow(clippy::too_many_arguments)] - fn check_general_case<'tcx>( - cx: &LateContext<'tcx>, - name: &str, - method_span: Span, - self_expr: &hir::Expr<'_>, - arg: &'tcx hir::Expr<'_>, - span: Span, - // None if lambda is required - fun_span: Option, - ) { - // (path, fn_has_argument, methods, suffix) - static KNOW_TYPES: [(&[&str], bool, &[&str], &str); 4] = [ - (&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"), - ]; - - if let hir::ExprKind::MethodCall(ref path, _, ref args, _) = &arg.kind { - if path.ident.as_str() == "len" { - let ty = cx.typeck_results().expr_ty(&args[0]).peel_refs(); - - match ty.kind() { - ty::Slice(_) | ty::Array(_, _) => return, - _ => (), - } - - if is_type_diagnostic_item(cx, ty, sym::vec_type) { - return; - } - } - } - - if_chain! { - if KNOW_TYPES.iter().any(|k| k.2.contains(&name)); - - if is_lazyness_candidate(cx, arg); - if !contains_return(&arg); - - let self_ty = cx.typeck_results().expr_ty(self_expr); - - if let Some(&(_, fn_has_arguments, poss, suffix)) = - KNOW_TYPES.iter().find(|&&i| match_type(cx, self_ty, i.0)); - - if poss.contains(&name); - - then { - let macro_expanded_snipped; - let sugg: Cow<'_, str> = { - let (snippet_span, use_lambda) = match (fn_has_arguments, fun_span) { - (false, Some(fun_span)) => (fun_span, false), - _ => (arg.span, true), - }; - let snippet = { - let not_macro_argument_snippet = snippet_with_macro_callsite(cx, snippet_span, ".."); - if not_macro_argument_snippet == "vec![]" { - macro_expanded_snipped = snippet(cx, snippet_span, ".."); - match macro_expanded_snipped.strip_prefix("$crate::vec::") { - Some(stripped) => Cow::from(stripped), - None => macro_expanded_snipped - } - } - else { - not_macro_argument_snippet - } - }; - - if use_lambda { - let l_arg = if fn_has_arguments { "_" } else { "" }; - format!("|{}| {}", l_arg, snippet).into() - } else { - snippet - } - }; - 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, - ); - } - } - } - - if args.len() == 2 { - match args[1].kind { - hir::ExprKind::Call(ref fun, ref or_args) => { - 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) { - let fun_span = if or_has_args { None } else { Some(fun.span) }; - check_general_case(cx, name, method_span, &args[0], &args[1], expr.span, fun_span); - } - }, - hir::ExprKind::Index(..) | hir::ExprKind::MethodCall(..) => { - check_general_case(cx, name, method_span, &args[0], &args[1], expr.span, None); - }, - _ => {}, - } - } -} - /// Checks for the `EXPECT_FUN_CALL` lint. #[allow(clippy::too_many_lines)] fn lint_expect_fun_call( diff --git a/clippy_lints/src/methods/or_fun_call.rs b/clippy_lints/src/methods/or_fun_call.rs new file mode 100644 index 0000000000000..5f7fc431d2248 --- /dev/null +++ b/clippy_lints/src/methods/or_fun_call.rs @@ -0,0 +1,173 @@ +use crate::utils::eager_or_lazy::is_lazyness_candidate; +use crate::utils::{ + contains_return, get_trait_def_id, implements_trait, is_type_diagnostic_item, last_path_segment, match_type, paths, + snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint_and_sugg, +}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::source_map::Span; +use rustc_span::symbol::sym; +use std::borrow::Cow; + +use super::OR_FUN_CALL; + +/// Checks for the `OR_FUN_CALL` lint. +#[allow(clippy::too_many_lines)] +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &hir::Expr<'_>, + method_span: Span, + name: &str, + args: &'tcx [hir::Expr<'_>], +) { + /// Checks for `unwrap_or(T::new())` or `unwrap_or(T::default())`. + fn check_unwrap_or_default( + cx: &LateContext<'_>, + name: &str, + fun: &hir::Expr<'_>, + self_expr: &hir::Expr<'_>, + arg: &hir::Expr<'_>, + or_has_args: bool, + span: Span, + ) -> bool { + if_chain! { + if !or_has_args; + if name == "unwrap_or"; + if let hir::ExprKind::Path(ref qpath) = fun.kind; + let path = &*last_path_segment(qpath).ident.as_str(); + if ["default", "new"].contains(&path); + let arg_ty = cx.typeck_results().expr_ty(arg); + if let Some(default_trait_id) = get_trait_def_id(cx, &paths::DEFAULT_TRAIT); + if implements_trait(cx, arg_ty, default_trait_id, &[]); + + 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 + } + } + } + + /// Checks for `*or(foo())`. + #[allow(clippy::too_many_arguments)] + fn check_general_case<'tcx>( + cx: &LateContext<'tcx>, + name: &str, + method_span: Span, + self_expr: &hir::Expr<'_>, + arg: &'tcx hir::Expr<'_>, + span: Span, + // None if lambda is required + fun_span: Option, + ) { + // (path, fn_has_argument, methods, suffix) + static KNOW_TYPES: [(&[&str], bool, &[&str], &str); 4] = [ + (&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"), + ]; + + if let hir::ExprKind::MethodCall(ref path, _, ref args, _) = &arg.kind { + if path.ident.as_str() == "len" { + let ty = cx.typeck_results().expr_ty(&args[0]).peel_refs(); + + match ty.kind() { + ty::Slice(_) | ty::Array(_, _) => return, + _ => (), + } + + if is_type_diagnostic_item(cx, ty, sym::vec_type) { + return; + } + } + } + + if_chain! { + if KNOW_TYPES.iter().any(|k| k.2.contains(&name)); + + if is_lazyness_candidate(cx, arg); + if !contains_return(&arg); + + let self_ty = cx.typeck_results().expr_ty(self_expr); + + if let Some(&(_, fn_has_arguments, poss, suffix)) = + KNOW_TYPES.iter().find(|&&i| match_type(cx, self_ty, i.0)); + + if poss.contains(&name); + + then { + let macro_expanded_snipped; + let sugg: Cow<'_, str> = { + let (snippet_span, use_lambda) = match (fn_has_arguments, fun_span) { + (false, Some(fun_span)) => (fun_span, false), + _ => (arg.span, true), + }; + let snippet = { + let not_macro_argument_snippet = snippet_with_macro_callsite(cx, snippet_span, ".."); + if not_macro_argument_snippet == "vec![]" { + macro_expanded_snipped = snippet(cx, snippet_span, ".."); + match macro_expanded_snipped.strip_prefix("$crate::vec::") { + Some(stripped) => Cow::from(stripped), + None => macro_expanded_snipped + } + } + else { + not_macro_argument_snippet + } + }; + + if use_lambda { + let l_arg = if fn_has_arguments { "_" } else { "" }; + format!("|{}| {}", l_arg, snippet).into() + } else { + snippet + } + }; + 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, + ); + } + } + } + + if args.len() == 2 { + match args[1].kind { + hir::ExprKind::Call(ref fun, ref or_args) => { + 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) { + let fun_span = if or_has_args { None } else { Some(fun.span) }; + check_general_case(cx, name, method_span, &args[0], &args[1], expr.span, fun_span); + } + }, + hir::ExprKind::Index(..) | hir::ExprKind::MethodCall(..) => { + check_general_case(cx, name, method_span, &args[0], &args[1], expr.span, None); + }, + _ => {}, + } + } +} From c711de28ee903c78ad465f6af99afdb977ab8dfe Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 22:26:29 +0900 Subject: [PATCH 33/35] move expect_fun_call to its own module --- clippy_lints/src/methods/expect_fun_call.rs | 199 +++++++++++++++++++ clippy_lints/src/methods/mod.rs | 206 +------------------- 2 files changed, 204 insertions(+), 201 deletions(-) create mode 100644 clippy_lints/src/methods/expect_fun_call.rs diff --git a/clippy_lints/src/methods/expect_fun_call.rs b/clippy_lints/src/methods/expect_fun_call.rs new file mode 100644 index 0000000000000..6866e9c652ab3 --- /dev/null +++ b/clippy_lints/src/methods/expect_fun_call.rs @@ -0,0 +1,199 @@ +use crate::utils::{is_expn_of, is_type_diagnostic_item, snippet, snippet_with_applicability, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_middle::ty; +use rustc_span::source_map::Span; +use rustc_span::symbol::sym; +use std::borrow::Cow; + +use super::EXPECT_FUN_CALL; + +/// Checks for the `EXPECT_FUN_CALL` lint. +#[allow(clippy::too_many_lines)] +pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, method_span: Span, name: &str, args: &[hir::Expr<'_>]) { + // Strip `&`, `as_ref()` and `as_str()` off `arg` until we're left with either a `String` or + // `&str` + fn get_arg_root<'a>(cx: &LateContext<'_>, arg: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> { + let mut arg_root = arg; + loop { + arg_root = match &arg_root.kind { + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => expr, + hir::ExprKind::MethodCall(method_name, _, call_args, _) => { + if call_args.len() == 1 + && (method_name.ident.name == sym::as_str || method_name.ident.name == sym!(as_ref)) + && { + let arg_type = cx.typeck_results().expr_ty(&call_args[0]); + let base_type = arg_type.peel_refs(); + *base_type.kind() == ty::Str || is_type_diagnostic_item(cx, base_type, sym::string_type) + } + { + &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. + fn requires_to_string(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool { + let arg_ty = cx.typeck_results().expr_ty(arg); + if is_type_diagnostic_item(cx, arg_ty, sym::string_type) { + return false; + } + if let ty::Ref(_, ty, ..) = arg_ty.kind() { + if *ty.kind() == ty::Str && can_be_static_str(cx, arg) { + return false; + } + }; + true + } + + // Check if an expression could have type `&'static str`, knowing that it + // has type `&str` for some lifetime. + fn can_be_static_str(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool { + match arg.kind { + hir::ExprKind::Lit(_) => true, + hir::ExprKind::Call(fun, _) => { + if let hir::ExprKind::Path(ref p) = fun.kind { + match cx.qpath_res(p, fun.hir_id) { + hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!( + cx.tcx.fn_sig(def_id).output().skip_binder().kind(), + ty::Ref(ty::ReStatic, ..) + ), + _ => false, + } + } else { + false + } + }, + 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, ..) + ) + }) + }, + 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, _) + ), + _ => false, + } + } + + fn generate_format_arg_snippet( + cx: &LateContext<'_>, + a: &hir::Expr<'_>, + applicability: &mut Applicability, + ) -> Vec { + if_chain! { + if let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref format_arg) = a.kind; + 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; + + then { + format_arg_expr_tup + .iter() + .map(|a| snippet_with_applicability(cx, a.span, "..", applicability).into_owned()) + .collect() + } else { + unreachable!() + } + } + } + + fn is_call(node: &hir::ExprKind<'_>) -> bool { + match node { + hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => { + is_call(&expr.kind) + }, + hir::ExprKind::Call(..) + | hir::ExprKind::MethodCall(..) + // These variants are debatable or require further examination + | hir::ExprKind::If(..) + | hir::ExprKind::Match(..) + | hir::ExprKind::Block{ .. } => true, + _ => false, + } + } + + if args.len() != 2 || name != "expect" || !is_call(&args[1].kind) { + return; + } + + let receiver_type = cx.typeck_results().expr_ty_adjusted(&args[0]); + let closure_args = if is_type_diagnostic_item(cx, receiver_type, sym::option_type) { + "||" + } else if is_type_diagnostic_item(cx, receiver_type, sym::result_type) { + "|_|" + } else { + return; + }; + + let arg_root = get_arg_root(cx, &args[1]); + + let span_replace_word = method_span.with_hi(expr.span.hi()); + + let mut applicability = Applicability::MachineApplicable; + + //Special handling for `format!` as arg_root + 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]; + + let mut args = vec![snippet(cx, fmt_spec.span, "..").into_owned()]; + + args.extend(generate_format_arg_snippet(cx, fmt_args, &mut applicability)); + + let sugg = args.join(", "); + + 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, + ); + + return; + } + } + + let mut arg_root_snippet: Cow<'_, _> = snippet_with_applicability(cx, arg_root.span, "..", &mut applicability); + if requires_to_string(cx, arg_root) { + arg_root_snippet.to_mut().push_str(".to_string()"); + } + + 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, + ); +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 857c1bf0ec08a..180620e860a5f 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -2,6 +2,7 @@ mod bind_instead_of_map; mod bytes_nth; mod clone_on_copy; mod clone_on_ref_ptr; +mod expect_fun_call; mod expect_used; mod filetype_is_file; mod filter_flat_map; @@ -50,8 +51,6 @@ mod useless_asref; mod wrong_self_convention; mod zst_offset; -use std::borrow::Cow; - use bind_instead_of_map::BindInsteadOfMap; use if_chain::if_chain; use rustc_ast::ast; @@ -68,10 +67,9 @@ use rustc_span::symbol::{sym, Symbol, SymbolStr}; use rustc_typeck::hir_ty_to_ty; use crate::utils::{ - contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, - is_type_diagnostic_item, iter_input_pats, match_def_path, match_qpath, method_calls, method_chain_args, paths, - return_ty, single_segment_path, snippet, snippet_with_applicability, span_lint, span_lint_and_help, - span_lint_and_sugg, SpanlessEq, + contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_type_diagnostic_item, + iter_input_pats, match_def_path, match_qpath, method_calls, method_chain_args, paths, return_ty, + single_segment_path, snippet_with_applicability, span_lint, span_lint_and_help, span_lint_and_sugg, SpanlessEq, }; declare_clippy_lint! { @@ -1779,7 +1777,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { }, hir::ExprKind::MethodCall(ref method_call, ref method_span, ref args, _) => { or_fun_call::check(cx, expr, *method_span, &method_call.ident.as_str(), args); - lint_expect_fun_call(cx, expr, *method_span, &method_call.ident.as_str(), args); + expect_fun_call::check(cx, expr, *method_span, &method_call.ident.as_str(), args); let self_ty = cx.typeck_results().expr_ty_adjusted(&args[0]); if args.len() == 1 && method_call.ident.name == sym::clone { @@ -1973,200 +1971,6 @@ impl<'tcx> LateLintPass<'tcx> for Methods { extract_msrv_attr!(LateContext); } -/// Checks for the `EXPECT_FUN_CALL` lint. -#[allow(clippy::too_many_lines)] -fn lint_expect_fun_call( - cx: &LateContext<'_>, - expr: &hir::Expr<'_>, - method_span: Span, - name: &str, - args: &[hir::Expr<'_>], -) { - // Strip `&`, `as_ref()` and `as_str()` off `arg` until we're left with either a `String` or - // `&str` - fn get_arg_root<'a>(cx: &LateContext<'_>, arg: &'a hir::Expr<'a>) -> &'a hir::Expr<'a> { - let mut arg_root = arg; - loop { - arg_root = match &arg_root.kind { - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => expr, - hir::ExprKind::MethodCall(method_name, _, call_args, _) => { - if call_args.len() == 1 - && (method_name.ident.name == sym::as_str || method_name.ident.name == sym!(as_ref)) - && { - let arg_type = cx.typeck_results().expr_ty(&call_args[0]); - let base_type = arg_type.peel_refs(); - *base_type.kind() == ty::Str || is_type_diagnostic_item(cx, base_type, sym::string_type) - } - { - &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. - fn requires_to_string(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool { - let arg_ty = cx.typeck_results().expr_ty(arg); - if is_type_diagnostic_item(cx, arg_ty, sym::string_type) { - return false; - } - if let ty::Ref(_, ty, ..) = arg_ty.kind() { - if *ty.kind() == ty::Str && can_be_static_str(cx, arg) { - return false; - } - }; - true - } - - // Check if an expression could have type `&'static str`, knowing that it - // has type `&str` for some lifetime. - fn can_be_static_str(cx: &LateContext<'_>, arg: &hir::Expr<'_>) -> bool { - match arg.kind { - hir::ExprKind::Lit(_) => true, - hir::ExprKind::Call(fun, _) => { - if let hir::ExprKind::Path(ref p) = fun.kind { - match cx.qpath_res(p, fun.hir_id) { - hir::def::Res::Def(hir::def::DefKind::Fn | hir::def::DefKind::AssocFn, def_id) => matches!( - cx.tcx.fn_sig(def_id).output().skip_binder().kind(), - ty::Ref(ty::ReStatic, ..) - ), - _ => false, - } - } else { - false - } - }, - 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, ..) - ) - }) - }, - 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, _) - ), - _ => false, - } - } - - fn generate_format_arg_snippet( - cx: &LateContext<'_>, - a: &hir::Expr<'_>, - applicability: &mut Applicability, - ) -> Vec { - if_chain! { - if let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, ref format_arg) = a.kind; - 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; - - then { - format_arg_expr_tup - .iter() - .map(|a| snippet_with_applicability(cx, a.span, "..", applicability).into_owned()) - .collect() - } else { - unreachable!() - } - } - } - - fn is_call(node: &hir::ExprKind<'_>) -> bool { - match node { - hir::ExprKind::AddrOf(hir::BorrowKind::Ref, _, expr) => { - is_call(&expr.kind) - }, - hir::ExprKind::Call(..) - | hir::ExprKind::MethodCall(..) - // These variants are debatable or require further examination - | hir::ExprKind::If(..) - | hir::ExprKind::Match(..) - | hir::ExprKind::Block{ .. } => true, - _ => false, - } - } - - if args.len() != 2 || name != "expect" || !is_call(&args[1].kind) { - return; - } - - let receiver_type = cx.typeck_results().expr_ty_adjusted(&args[0]); - let closure_args = if is_type_diagnostic_item(cx, receiver_type, sym::option_type) { - "||" - } else if is_type_diagnostic_item(cx, receiver_type, sym::result_type) { - "|_|" - } else { - return; - }; - - let arg_root = get_arg_root(cx, &args[1]); - - let span_replace_word = method_span.with_hi(expr.span.hi()); - - let mut applicability = Applicability::MachineApplicable; - - //Special handling for `format!` as arg_root - 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]; - - let mut args = vec![snippet(cx, fmt_spec.span, "..").into_owned()]; - - args.extend(generate_format_arg_snippet(cx, fmt_args, &mut applicability)); - - let sugg = args.join(", "); - - 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, - ); - - return; - } - } - - let mut arg_root_snippet: Cow<'_, _> = snippet_with_applicability(cx, arg_root.span, "..", &mut applicability); - if requires_to_string(cx, arg_root) { - arg_root_snippet.to_mut().push_str(".to_string()"); - } - - 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, - ); -} - fn derefs_to_slice<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>, From 99f860768cdd71c371cdaf7827c377dbaa4fe396 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 11 Mar 2021 20:02:29 +0900 Subject: [PATCH 34/35] remove unused imports --- clippy_lints/src/methods/into_iter_on_ref.rs | 3 ++- clippy_lints/src/methods/mod.rs | 3 +-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/clippy_lints/src/methods/into_iter_on_ref.rs b/clippy_lints/src/methods/into_iter_on_ref.rs index d94b243404c36..1e8315dbee25e 100644 --- a/clippy_lints/src/methods/into_iter_on_ref.rs +++ b/clippy_lints/src/methods/into_iter_on_ref.rs @@ -4,6 +4,7 @@ use rustc_hir as hir; use rustc_lint::LateContext; use rustc_middle::ty::{self, Ty}; use rustc_span::source_map::Span; +use rustc_span::symbol::Symbol; use super::INTO_ITER_ON_REF; @@ -27,7 +28,7 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, self_ref_ty: Ty< } } -fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(&'static str, &'static str)> { +fn ty_has_iter_method(cx: &LateContext<'_>, self_ref_ty: Ty<'_>) -> Option<(Symbol, &'static str)> { has_iter_method(cx, self_ref_ty).map(|ty_name| { let mutbl = match self_ref_ty.kind() { ty::Ref(_, _, mutbl) => mutbl, diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 180620e860a5f..7fd14c4f9b11c 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -62,8 +62,7 @@ use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, TraitRef, Ty, TyS}; use rustc_semver::RustcVersion; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::source_map::Span; -use rustc_span::symbol::{sym, Symbol, SymbolStr}; +use rustc_span::symbol::{sym, SymbolStr}; use rustc_typeck::hir_ty_to_ty; use crate::utils::{ From 83a955335f986c503ac114cf5009ff965bb21741 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Thu, 11 Mar 2021 20:18:33 +0900 Subject: [PATCH 35/35] fix interning-defined-symbol error --- clippy_lints/src/methods/get_unwrap.rs | 4 ++-- clippy_lints/src/methods/iter_nth.rs | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/clippy_lints/src/methods/get_unwrap.rs b/clippy_lints/src/methods/get_unwrap.rs index 2684c50e01b7d..e157db2712a9a 100644 --- a/clippy_lints/src/methods/get_unwrap.rs +++ b/clippy_lints/src/methods/get_unwrap.rs @@ -27,10 +27,10 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, get_args } else if is_type_diagnostic_item(cx, expr_ty, sym::vec_type) { needs_ref = get_args_str.parse::().is_ok(); "Vec" - } else if is_type_diagnostic_item(cx, expr_ty, sym!(vecdeque_type)) { + } else if is_type_diagnostic_item(cx, expr_ty, sym::vecdeque_type) { needs_ref = get_args_str.parse::().is_ok(); "VecDeque" - } else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym!(hashmap_type)) { + } else if !is_mut && is_type_diagnostic_item(cx, expr_ty, sym::hashmap_type) { needs_ref = true; "HashMap" } else if !is_mut && match_type(cx, expr_ty, &paths::BTREEMAP) { diff --git a/clippy_lints/src/methods/iter_nth.rs b/clippy_lints/src/methods/iter_nth.rs index c8adea9536b2d..cc3e56ea87277 100644 --- a/clippy_lints/src/methods/iter_nth.rs +++ b/clippy_lints/src/methods/iter_nth.rs @@ -19,7 +19,7 @@ pub(super) fn check<'tcx>( "slice" } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym::vec_type) { "Vec" - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym!(vecdeque_type)) { + } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&iter_args[0]), sym::vecdeque_type) { "VecDeque" } else { let nth_args = nth_and_iter_args[0];