From 063f8aa094a740b98b0dab49d8361441c8f1d0c4 Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Thu, 25 Nov 2021 11:50:57 +0300
Subject: [PATCH 1/3] Ignore associated types in traits when considering type
complexity
---
clippy_lints/src/types/mod.rs | 8 +++++---
tests/ui/type_complexity_issue_1013.rs | 23 +++++++++++++++++++++++
2 files changed, 28 insertions(+), 3 deletions(-)
create mode 100644 tests/ui/type_complexity_issue_1013.rs
diff --git a/clippy_lints/src/types/mod.rs b/clippy_lints/src/types/mod.rs
index 5a7ef760a30..69cd49d884c 100644
--- a/clippy_lints/src/types/mod.rs
+++ b/clippy_lints/src/types/mod.rs
@@ -350,7 +350,7 @@ impl<'tcx> LateLintPass<'tcx> for Types {
fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
match item.kind {
- ImplItemKind::Const(ty, _) | ImplItemKind::TyAlias(ty) => self.check_ty(
+ ImplItemKind::Const(ty, _) => self.check_ty(
cx,
ty,
CheckTyContext {
@@ -358,8 +358,10 @@ impl<'tcx> LateLintPass<'tcx> for Types {
..CheckTyContext::default()
},
),
- // methods are covered by check_fn
- ImplItemKind::Fn(..) => (),
+ // Methods are covered by check_fn.
+ // Type aliases are ignored because oftentimes it's impossible to
+ // make type alias declaration in trait simpler, see #1013
+ ImplItemKind::Fn(..) | ImplItemKind::TyAlias(..) => (),
}
}
diff --git a/tests/ui/type_complexity_issue_1013.rs b/tests/ui/type_complexity_issue_1013.rs
new file mode 100644
index 00000000000..c68ab3aaf94
--- /dev/null
+++ b/tests/ui/type_complexity_issue_1013.rs
@@ -0,0 +1,23 @@
+#![warn(clippy::type_complexity)]
+use std::iter::{Filter, Map};
+use std::vec::IntoIter;
+
+struct S;
+
+impl IntoIterator for S {
+ type Item = i32;
+ // Should not warn since there is no way to simplify this
+ type IntoIter = Filter<Map<IntoIter<i32>, fn(i32) -> i32>, fn(&i32) -> bool>;
+
+ fn into_iter(self) -> Self::IntoIter {
+ fn m(a: i32) -> i32 {
+ a
+ }
+ fn p(_: &i32) -> bool {
+ true
+ }
+ vec![1i32, 2, 3].into_iter().map(m as fn(_) -> _).filter(p)
+ }
+}
+
+fn main() {}
From 40a6c519b447a45c4ec1cdda4be067207d836306 Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Thu, 25 Nov 2021 12:47:29 +0300
Subject: [PATCH 2/3] Update tests for type_complexity lint
---
tests/ui/type_complexity.rs | 8 ++++++++
tests/ui/type_complexity.stderr | 20 ++++++++++++++++----
tests/ui/type_complexity_issue_1013.rs | 23 -----------------------
3 files changed, 24 insertions(+), 27 deletions(-)
delete mode 100644 tests/ui/type_complexity_issue_1013.rs
diff --git a/tests/ui/type_complexity.rs b/tests/ui/type_complexity.rs
index 383bbb49dbe..62d00e00729 100644
--- a/tests/ui/type_complexity.rs
+++ b/tests/ui/type_complexity.rs
@@ -30,6 +30,14 @@ trait T {
fn def_method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
}
+impl T for () {
+ const A: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
+
+ // Should not warn since there is likely no way to simplify this (#1013)
+ type B = Vec<Vec<Box<(u32, u32, u32, u32)>>>;
+ fn method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
+}
+
fn test1() -> Vec<Vec<Box<(u32, u32, u32, u32)>>> {
vec![]
}
diff --git a/tests/ui/type_complexity.stderr b/tests/ui/type_complexity.stderr
index 7879233fdf2..693f2adcfc8 100644
--- a/tests/ui/type_complexity.stderr
+++ b/tests/ui/type_complexity.stderr
@@ -73,22 +73,34 @@ LL | fn def_method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:33:15
+ --> $DIR/type_complexity.rs:34:14
+ |
+LL | const A: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: very complex type used. Consider factoring parts into `type` definitions
+ --> $DIR/type_complexity.rs:38:25
+ |
+LL | fn method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: very complex type used. Consider factoring parts into `type` definitions
+ --> $DIR/type_complexity.rs:41:15
|
LL | fn test1() -> Vec<Vec<Box<(u32, u32, u32, u32)>>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:37:14
+ --> $DIR/type_complexity.rs:45:14
|
LL | fn test2(_x: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:40:13
+ --> $DIR/type_complexity.rs:48:13
|
LL | let _y: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-error: aborting due to 15 previous errors
+error: aborting due to 17 previous errors
diff --git a/tests/ui/type_complexity_issue_1013.rs b/tests/ui/type_complexity_issue_1013.rs
deleted file mode 100644
index c68ab3aaf94..00000000000
--- a/tests/ui/type_complexity_issue_1013.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-#![warn(clippy::type_complexity)]
-use std::iter::{Filter, Map};
-use std::vec::IntoIter;
-
-struct S;
-
-impl IntoIterator for S {
- type Item = i32;
- // Should not warn since there is no way to simplify this
- type IntoIter = Filter<Map<IntoIter<i32>, fn(i32) -> i32>, fn(&i32) -> bool>;
-
- fn into_iter(self) -> Self::IntoIter {
- fn m(a: i32) -> i32 {
- a
- }
- fn p(_: &i32) -> bool {
- true
- }
- vec![1i32, 2, 3].into_iter().map(m as fn(_) -> _).filter(p)
- }
-}
-
-fn main() {}
From c176568abd9290088ec604be644c021caa81f508 Mon Sep 17 00:00:00 2001
From: Maybe Waffle <waffle.lapkin@gmail.com>
Date: Wed, 8 Dec 2021 14:27:49 +0300
Subject: [PATCH 3/3] Ignore associated items in trait *implementations* when
considering type complexity
---
clippy_lints/src/types/mod.rs | 40 ++++++++++++++++++++++++---------
tests/ui/type_complexity.rs | 3 ++-
tests/ui/type_complexity.stderr | 20 ++++-------------
3 files changed, 35 insertions(+), 28 deletions(-)
diff --git a/clippy_lints/src/types/mod.rs b/clippy_lints/src/types/mod.rs
index 69cd49d884c..481e5957435 100644
--- a/clippy_lints/src/types/mod.rs
+++ b/clippy_lints/src/types/mod.rs
@@ -350,14 +350,24 @@ impl<'tcx> LateLintPass<'tcx> for Types {
fn check_impl_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx ImplItem<'_>) {
match item.kind {
- ImplItemKind::Const(ty, _) => self.check_ty(
- cx,
- ty,
- CheckTyContext {
- is_in_trait_impl: true,
- ..CheckTyContext::default()
- },
- ),
+ ImplItemKind::Const(ty, _) => {
+ let is_in_trait_impl = if let Some(hir::Node::Item(item)) =
+ cx.tcx.hir().find(cx.tcx.hir().get_parent_item(item.hir_id()))
+ {
+ matches!(item.kind, ItemKind::Impl(hir::Impl { of_trait: Some(_), .. }))
+ } else {
+ false
+ };
+
+ self.check_ty(
+ cx,
+ ty,
+ CheckTyContext {
+ is_in_trait_impl,
+ ..CheckTyContext::default()
+ },
+ );
+ },
// Methods are covered by check_fn.
// Type aliases are ignored because oftentimes it's impossible to
// make type alias declaration in trait simpler, see #1013
@@ -419,6 +429,14 @@ impl Types {
}
fn check_fn_decl(&mut self, cx: &LateContext<'_>, decl: &FnDecl<'_>, context: CheckTyContext) {
+ // Ignore functions in trait implementations as they are usually forced by the trait definition.
+ //
+ // FIXME: idially we would like to warn *if the compicated type can be simplified*, but it's hard to
+ // check.
+ if context.is_in_trait_impl {
+ return;
+ }
+
for input in decl.inputs {
self.check_ty(cx, input, context);
}
@@ -437,12 +455,12 @@ impl Types {
return;
}
- if !context.is_nested_call && type_complexity::check(cx, hir_ty, self.type_complexity_threshold) {
+ // Skip trait implementations; see issue #605.
+ if context.is_in_trait_impl {
return;
}
- // Skip trait implementations; see issue #605.
- if context.is_in_trait_impl {
+ if !context.is_nested_call && type_complexity::check(cx, hir_ty, self.type_complexity_threshold) {
return;
}
diff --git a/tests/ui/type_complexity.rs b/tests/ui/type_complexity.rs
index 62d00e00729..86a7bd7b627 100644
--- a/tests/ui/type_complexity.rs
+++ b/tests/ui/type_complexity.rs
@@ -30,11 +30,12 @@ trait T {
fn def_method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
}
+// Should not warn since there is likely no way to simplify this (#1013)
impl T for () {
const A: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
- // Should not warn since there is likely no way to simplify this (#1013)
type B = Vec<Vec<Box<(u32, u32, u32, u32)>>>;
+
fn method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
}
diff --git a/tests/ui/type_complexity.stderr b/tests/ui/type_complexity.stderr
index 693f2adcfc8..9da7edb1c3b 100644
--- a/tests/ui/type_complexity.stderr
+++ b/tests/ui/type_complexity.stderr
@@ -73,34 +73,22 @@ LL | fn def_method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:34:14
- |
-LL | const A: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:38:25
- |
-LL | fn method(&self, p: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:41:15
+ --> $DIR/type_complexity.rs:42:15
|
LL | fn test1() -> Vec<Vec<Box<(u32, u32, u32, u32)>>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:45:14
+ --> $DIR/type_complexity.rs:46:14
|
LL | fn test2(_x: Vec<Vec<Box<(u32, u32, u32, u32)>>>) {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: very complex type used. Consider factoring parts into `type` definitions
- --> $DIR/type_complexity.rs:48:13
+ --> $DIR/type_complexity.rs:49:13
|
LL | let _y: Vec<Vec<Box<(u32, u32, u32, u32)>>> = vec![];
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-error: aborting due to 17 previous errors
+error: aborting due to 15 previous errors